Apparent isotropic electrical property for electrical brain stimulation (EBS) using magnetic resonance diffusion weighted imaging (MR-DWI)

NASA Astrophysics Data System (ADS)

Lee, Mun Bae; Kwon, Oh-In

2018-04-01

Electrical brain stimulation (EBS) is an invasive electrotherapy and technique used in brain neurological disorders through direct or indirect stimulation using a small electric current. EBS has relied on computational modeling to achieve optimal stimulation effects and investigate the internal activations. Magnetic resonance diffusion weighted imaging (DWI) is commonly useful for diagnosis and investigation of tissue functions in various organs. The apparent diffusion coefficient (ADC) measures the intensity of water diffusion within biological tissues using DWI. By measuring trace ADC and magnetic flux density induced by the EBS, we propose a method to extract electrical properties including the effective extracellular ion-concentration (EEIC) and the apparent isotropic conductivity without any auxiliary additional current injection. First, the internal current density due to EBS is recovered using the measured one component of magnetic flux density. We update the EEIC by introducing a repetitive scheme called the diffusion weighting J-substitution algorithm using the recovered current density and the trace ADC. To verify the proposed method, we study an anesthetized canine brain to visualize electrical properties including electrical current density, effective extracellular ion-concentration, and effective isotropic conductivity by applying electrical stimulation of the brain.

Surface Electrical Stimulation for Treating Swallowing Disorders after Stroke: A Review of the Stimulation Intensity Levels and the Electrode Placements

PubMed Central

Poorjavad, Marziyeh; Talebian Moghadam, Saeed; Daemi, Mostafa

2014-01-01

Neuromuscular electrical stimulation (NMES) for treating dysphagia is a relatively new therapeutic method. There is a paucity of evidence about the use of NMES in patients with dysphagia caused by stroke. The present review aimed to introduce and discuss studies that have evaluated the efficacy of this method amongst dysphagic patients following stroke with emphasis on the intensity of stimulation (sensory or motor level) and the method of electrode placement on the neck. The majority of the reviewed studies describe some positive effects of the NMES on the neck musculature in the swallowing performance of poststroke dysphagic patients, especially when the intensity of the stimulus is adjusted at the sensory level or when the motor electrical stimulation is applied on the infrahyoid muscles during swallowing. PMID:24804147

Pulsed laser versus electrical energy for peripheral nerve stimulation

PubMed Central

Wells, Jonathon; Konrad, Peter; Kao, Chris; Jansen, E. Duco; Mahadevan-Jansen, Anita

2010-01-01

Transient optical neural stimulation has previously been shown to elicit highly controlled, artifact-free potentials within the nervous system in a non-contact fashion without resulting in damage to tissue. This paper presents the physiologic validity of elicited nerve and muscle potentials from pulsed laser induced stimulation of the peripheral nerve in a comparative study with the standard method of electrically evoked potentials. Herein, the fundamental physical properties underlying the two techniques are contrasted. Key laser parameters for efficient optical stimulation of the peripheral nerve are detailed. Strength response curves are shown to be linear for each stimulation modality, although fewer axons can be recruited with optically evoked potentials. Results compare the relative transient energy requirements for stimulation using each technique and demonstrate that optical methods can selectively excite functional nerve stimulation. Adjacent stimulation and recording of compound nerve potentials in their entirety from optical and electrical stimulation are presented, with optical responses shown to be free of any stimulation artifact. Thus, use of a pulsed laser exhibits some advantages when compared to standard electrical means for excitation of muscle potentials in the peripheral nerve in the research domain and possibly for clinical diagnostics in the future. PMID:17537515

Electrochemical activation and inhibition of neuromuscular systems through modulation of ion concentrations with ion-selective membranes

NASA Astrophysics Data System (ADS)

Song, Yong-Ak; Melik, Rohat; Rabie, Amr N.; Ibrahim, Ahmed M. S.; Moses, David; Tan, Ara; Han, Jongyoon; Lin, Samuel J.

2011-12-01

Conventional functional electrical stimulation aims to restore functional motor activity of patients with disabilities resulting from spinal cord injury or neurological disorders. However, intervention with functional electrical stimulation in neurological diseases lacks an effective implantable method that suppresses unwanted nerve signals. We have developed an electrochemical method to activate and inhibit a nerve by electrically modulating ion concentrations in situ along the nerve. Using ion-selective membranes to achieve different excitability states of the nerve, we observe either a reduction of the electrical threshold for stimulation by up to approximately 40%, or voluntary, reversible inhibition of nerve signal propagation. This low-threshold electrochemical stimulation method is applicable in current implantable neuroprosthetic devices, whereas the on-demand nerve-blocking mechanism could offer effective clinical intervention in disease states caused by uncontrolled nerve activation, such as epilepsy and chronic pain syndromes.

Contralaterally Controlled Functional Electrical Stimulation for Stroke Rehabilitation

PubMed Central

Knutson, Jayme S.; Harley, Mary Y.; Hisel, Terri Z.; Makowski, Nathaniel S.; Fu, Michael J.; Chae, John

2012-01-01

Contralaterally controlled functional electrical stimulation (CCFES) is an innovative method of delivering neuromuscular electrical stimulation for rehabilitation of paretic limbs after stroke. It is being studied to evaluate its efficacy in improving recovery of arm and hand function and ankle dorsiflexion in chronic and subacute stroke patients. The initial studies provide preliminary evidence supporting the efficacy of CCFES. PMID:23365893

Effect of the Masako maneuver and neuromuscular electrical stimulation on the improvement of swallowing function in patients with dysphagia caused by stroke

PubMed Central

Byeon, Haewon

2016-01-01

[Purpose] The aim of this study was to compare improvements in swallowing function by the intervention of the Masako maneuver and neuromuscular electrical stimulation in patients with dysphagia caused by stroke. [Subjects and Methods] The Masako maneuver (n=23) and neuromuscular electrical stimulation (n=24) were conducted in 47 patients with dysphagia caused by stroke over a period of 4 weeks. Swallowing recovery was recorded using the functional dysphagia scale based on videofluoroscopic studies. [Results] Mean functional dysphagia scale values for the Masako maneuver and neuromuscular electrical stimulation groups decreased after the treatments. However, the pre-post functional dysphagia scale values showed no statistically significant differences between the groups. [Conclusion] The Masako maneuver and neuromuscular electrical stimulation each showed significant effects on the improvement of swallowing function for the patients with dysphagia caused by stroke, but no significant difference was observed between the two treatment methods. PMID:27512266

Application of electrical stimulation for functional tissue engineering in vitro and in vivo

NASA Technical Reports Server (NTRS)

Park, Hyoungshin (Inventor); Freed, Lisa (Inventor); Vunjak-Novakovic, Gordana (Inventor); Langer, Robert (Inventor); Radisic, Milica (Inventor)

2013-01-01

The present invention provides new methods for the in vitro preparation of bioartificial tissue equivalents and their enhanced integration after implantation in vivo. These methods include submitting a tissue construct to a biomimetic electrical stimulation during cultivation in vitro to improve its structural and functional properties, and/or in vivo, after implantation of the construct, to enhance its integration with host tissue and increase cell survival and functionality. The inventive methods are particularly useful for the production of bioartificial equivalents and/or the repair and replacement of native tissues that contain electrically excitable cells and are subject to electrical stimulation in vivo, such as, for example, cardiac muscle tissue, striated skeletal muscle tissue, smooth muscle tissue, bone, vasculature, and nerve tissue.

Comparison between two methods of scorpion venom milking in Morocco

PubMed Central

2013-01-01

Background The present study compared two methods used successfully in a large-scale program for the collection of scorpion venoms, namely the milking of adult scorpions via manual and electrical stimulation. Results Our immunobiochemical characterizations clearly demonstrate that regularly applied electrical stimulation obtains scorpion venom more easily and, most importantly, in greater quantity. Qualitatively, the electrically collected venom showed lack of hemolymph contaminants such as hemocyanin. In contrast, manual obtainment of venom subjects scorpions to maximal trauma, leading to hemocyanin secretion. Our study highlighted the importance of reducing scorpion trauma during venom milking. Conclusions In conclusion, to produce high quality antivenom with specific antibodies, it is necessary to collect venom by the gentler electrical stimulation method. PMID:23849043

Concepts and methods in neuromodulation and functional electrical stimulation: an introduction.

PubMed

Holsheimer, J

1998-04-01

This article introduces two clinical fields in which stimulation is applied to the nervous system: neuromodulation and functional electrical stimulation. The concepts underlying these fields and their main clinical applications, as well as the methods and techniques used in each field, are described. Concepts and techniques common in one field that might be beneficial to the other are discussed. 1998 Blackwell Science, Inc.

A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty

PubMed Central

Beckwée, David; Bautmans, Ivan; Swinnen, Eva; Vermet, Yorick; Lefeber, Nina; Lievens, Pierre

2014-01-01

Objective: To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. Data Sources: PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Review Methods: Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. Results: A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. Conclusion: This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality. PMID:26770730

Posterior tibial nerve stimulation vs parasacral transcutaneous neuromodulation for overactive bladder in children.

PubMed

Barroso, Ubirajara; Viterbo, Walter; Bittencourt, Joana; Farias, Tiago; Lordêlo, Patrícia

2013-08-01

Parasacral transcutaneous electrical nerve stimulation and posterior tibial nerve stimulation have emerged as effective methods to treat overactive bladder in children. However, to our knowledge no study has compared the 2 methods. We evaluated the results of parasacral transcutaneous electrical nerve stimulation and posterior tibial nerve stimulation in children with overactive bladder. We prospectively studied children with overactive bladder without dysfunctional voiding. Success of treatment was evaluated by visual analogue scale and dysfunctional voiding symptom score, and by level of improvement of each specific symptom. Parasacral transcutaneous electrical nerve stimulation was performed 3 times weekly and posterior tibial nerve stimulation was performed once weekly. A total of 22 consecutive patients were treated with posterior tibial nerve stimulation and 37 with parasacral transcutaneous electrical nerve stimulation. There was no difference between the 2 groups regarding demographic characteristics or types of symptoms. Concerning the evaluation by visual analogue scale, complete resolution of symptoms was seen in 70% of the group undergoing parasacral transcutaneous electrical nerve stimulation and in 9% of the group undergoing posterior tibial nerve stimulation (p = 0.02). When the groups were compared, there was no statistically significant difference (p = 0.55). The frequency of persistence of urgency and diurnal urinary incontinence was nearly double in the group undergoing posterior tibial nerve stimulation. However, this difference was not statistically significant. We found that parasacral transcutaneous electrical nerve stimulation is more effective in resolving overactive bladder symptoms, which matches parental perception. However, there were no statistically significant differences in the evaluation by dysfunctional voiding symptom score, or in complete resolution of urgency or diurnal incontinence. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Effects of a multichannel dynamic functional electrical stimulation system on hemiplegic gait and muscle forces

PubMed Central

Qian, Jing-guang; Rong, Ke; Qian, Zhenyun; Wen, Chen; Zhang, Songning

2015-01-01

[Purpose] The purpose of the study was to design and implement a multichannel dynamic functional electrical stimulation system and investigate acute effects of functional electrical stimulation of the tibialis anterior and rectus femoris on ankle and knee sagittal-plane kinematics and related muscle forces of hemiplegic gait. [Subjects and Methods] A multichannel dynamic electrical stimulation system was developed with 8-channel low frequency current generators. Eight male hemiplegic patients were trained for 4 weeks with electric stimulation of the tibia anterior and rectus femoris muscles during walking, which was coupled with active contraction. Kinematic data were collected, and muscle forces of the tibialis anterior and rectus femoris of the affected limbs were analyzed using a musculoskelatal modeling approach before and after training. A paired sample t-test was used to detect the differences between before and after training. [Results] The step length of the affected limb significantly increased after the stimulation was applied. The maximum dorsiflexion angle and maximum knee flexion angle of the affected limb were both increased significantly during stimulation. The maximum muscle forces of both the tibia anterior and rectus femoris increased significantly during stimulation compared with before functional electrical stimulation was applied. [Conclusion] This study established a functional electrical stimulation strategy based on hemiplegic gait analysis and musculoskeletal modeling. The multichannel functional electrical stimulation system successfully corrected foot drop and altered circumduction hemiplegic gait pattern. PMID:26696734

[Intracellular free calcium changes of mouse oocytes during activation induced by ethanol or electrical stimulations and parthenogenetic development].

PubMed

Deng, M Q; Fan, B Q

1994-09-01

Oocytes collected 18-19 h after HCG injection were stimulated with 7-8% ethanol or electrical pulses (1.7 KV/cm field strength, 80-100 microseconds duration, 3-4 times, 5-6 min interval). The parthenogenetic embryos derived from the above-mentioned methods developed to blastocyst stage just like those developed from fertilized eggs. Mouse oocytes were rather sensitive to ethanol stimulation. More than 95% of the treated oocytes were activated after stimulation of 7-8% ethanol for 5 min. Multiple electrical stimulations induced higher activation percentages of oocytes than only single electrical stimulation (71.5% vs. 63.6%). Intact oocytes were loaded with fluorescent Ca2+ indicator fura-2 and intracellular free calcium changes during artificial activation were measured by fluorescence detector. The results showed that ethanol could induce repetitive transient Ca2+ concentration increase in activated oocytes. Single electrical stimulation only induced single free calcium concentration elevation in oocyte while multiple electrical pulses could induce repetitive Ca2+ increase (each electrical pulse elicited the corresponding Ca2+ concentration peak). The pronuclei were not observed in the oocytes which had not exhibited calcium concentration rise during activation. Apart from electrical stimulation parameter, sufficient amount of Ca2+ in electric medium was crucial to mouse oocyte activation when stimulated with electrical pulses. The oocytes were hardly activated by electrical stimulations in a medium without Ca2+ even with longer pulse duration and the intracellular free calcium concentration in the oocytes showed no elevation. This indicates that the inflow of extracellular Ca2+ from tiny pores across the oocyte membrane caused by electrical stimulation is the main source of intracellular free calcium increase.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrical Stimulation Promotes Cardiac Differentiation of Human Induced Pluripotent Stem Cells

PubMed Central

Hernández, Damián; Millard, Rodney; Sivakumaran, Priyadharshini; Wong, Raymond C. B.; Crombie, Duncan E.; Hewitt, Alex W.; Liang, Helena; Hung, Sandy S. C.; Pébay, Alice; Shepherd, Robert K.; Dusting, Gregory J.; Lim, Shiang Y.

2016-01-01

Background. Human induced pluripotent stem cells (iPSCs) are an attractive source of cardiomyocytes for cardiac repair and regeneration. In this study, we aim to determine whether acute electrical stimulation of human iPSCs can promote their differentiation to cardiomyocytes. Methods. Human iPSCs were differentiated to cardiac cells by forming embryoid bodies (EBs) for 5 days. EBs were then subjected to brief electrical stimulation and plated down for 14 days. Results. In iPS(Foreskin)-2 cell line, brief electrical stimulation at 65 mV/mm or 200 mV/mm for 5 min significantly increased the percentage of beating EBs present by day 14 after plating. Acute electrical stimulation also significantly increased the cardiac gene expression of ACTC1, TNNT2, MYH7, and MYL7. However, the cardiogenic effect of electrical stimulation was not reproducible in another iPS cell line, CERA007c6. Beating EBs from control and electrically stimulated groups expressed various cardiac-specific transcription factors and contractile muscle markers. Beating EBs were also shown to cycle calcium and were responsive to the chronotropic agents, isoproterenol and carbamylcholine, in a concentration-dependent manner. Conclusions. Our results demonstrate that brief electrical stimulation can promote cardiac differentiation of human iPS cells. The cardiogenic effect of brief electrical stimulation is dependent on the cell line used. PMID:26788064

Electrical Neural Stimulation and Simultaneous in Vivo Monitoring with Transparent Graphene Electrode Arrays Implanted in GCaMP6f Mice.

PubMed

Park, Dong-Wook; Ness, Jared P; Brodnick, Sarah K; Esquibel, Corinne; Novello, Joseph; Atry, Farid; Baek, Dong-Hyun; Kim, Hyungsoo; Bong, Jihye; Swanson, Kyle I; Suminski, Aaron J; Otto, Kevin J; Pashaie, Ramin; Williams, Justin C; Ma, Zhenqiang

2018-01-23

Electrical stimulation using implantable electrodes is widely used to treat various neuronal disorders such as Parkinson's disease and epilepsy and is a widely used research tool in neuroscience studies. However, to date, devices that help better understand the mechanisms of electrical stimulation in neural tissues have been limited to opaque neural electrodes. Imaging spatiotemporal neural responses to electrical stimulation with minimal artifact could allow for various studies that are impossible with existing opaque electrodes. Here, we demonstrate electrical brain stimulation and simultaneous optical monitoring of the underlying neural tissues using carbon-based, fully transparent graphene electrodes implanted in GCaMP6f mice. Fluorescence imaging of neural activity for varying electrical stimulation parameters was conducted with minimal image artifact through transparent graphene electrodes. In addition, full-field imaging of electrical stimulation verified more efficient neural activation with cathode leading stimulation compared to anode leading stimulation. We have characterized the charge density limitation of capacitive four-layer graphene electrodes as 116.07-174.10 μC/cm 2 based on electrochemical impedance spectroscopy, cyclic voltammetry, failure bench testing, and in vivo testing. This study demonstrates the transparent ability of graphene neural electrodes and provides a method to further increase understanding and potentially improve therapeutic electrical stimulation in the central and peripheral nervous systems.

Skeletal myotube formation enhanced by electrospun polyurethane carbon nanotube scaffolds

PubMed Central

Sirivisoot, Sirinrath; Harrison, Benjamin S

2011-01-01

Background This study examined the effects of electrically conductive materials made from electrospun single- or multiwalled carbon nanotubes with polyurethane to promote myoblast differentiation into myotubes in the presence and absence of electrical stimulation. Methods and results After electrical stimulation, the number of multinucleated myotubes on the electrospun polyurethane carbon nanotube scaffolds was significantly larger than that on nonconductive electrospun polyurethane scaffolds (5% and 10% w/v polyurethane). In the absence of electrical stimulation, myoblasts also differentiated on the electrospun polyurethane carbon nanotube scaffolds, as evidenced by expression of Myf-5 and myosin heavy chains. The myotube number and length were significantly greater on the electrospun carbon nanotubes with 10% w/v polyurethane than on those with 5% w/v polyurethane. The results suggest that, in the absence of electrical stimulation, skeletal myotube formation is dependent on the morphology of the electrospun scaffolds, while with electrical stimulation it is dependent on the electrical conductivity of the scaffolds. Conclusion This study indicates that electrospun polyurethane carbon nanotubes can be used to modulate skeletal myotube formation with or without application of electrical stimulation. PMID:22072883

A system for measuring thermal activation energy levels in silicon by thermally stimulated capacitance

NASA Technical Reports Server (NTRS)

Cockrum, R. H.

1982-01-01

One method being used to determine energy level(s) and electrical activity of impurities in silicon is described. The method is called capacitance transient spectroscopy (CTS). It can be classified into three basic categories: the thermally stimulated capacitance method, the voltage-stimulated capacitance method, and the light-stimulated capacitance method; the first two categories are discussed. From the total change in capacitance and the time constant of the capacitance response, emission rates, energy levels, and trap concentrations can be determined. A major advantage of using CTS is its ability to detect the presence of electrically active impurities that are invisible to other techniques, such as Zeeman effect atomic absorption, and the ability to detect more than one electrically active impurity in a sample. Examples of detection of majority and minority carrier traps from gold donor and acceptor centers in silicon using the capacitance transient spectrometer are given to illustrate the method and its sensitivity.

A pioneer work on electric brain stimulation in psychotic patients. Rudolph Gottfried Arndt and his 1870s studies.

PubMed

Steinberg, Holger

2013-07-01

Today's brain stimulation methods are commonly traced back historically to surgical brain operations. With this one-sided historical approach it is easy to overlook the fact that non-surgical electrical brain-stimulating applications preceded present-day therapies. The first study on transcranial electrical brain stimulation for the treatment of severe mental diseases in a larger group of patients was carried out in the 1870s. Between 1870 and 1878 German psychiatrist Rudolph Gottfried Arndt published the results of his studies in three reports. These are contextualized with contemporary developments of the time, focusing in particular on the (neuro-) sciences. As was common practice at the time, Arndt basically reported individual cases in which electricity was applied to treat severe psychoses with depressive symptoms or even catatonia, hypochondriac delusion and melancholia. Despite their lengthiness, there is frequently a lack of precise physical data on the application of psychological-psychopathological details. Only his 1878 report includes general rules for electrical brain stimulation. Despite their methodological shortcomings and lack of precise treatment data impeding exact understanding, Arndt's studies are pioneering works in the field of electric brain stimulation with psychoses and its positive impacts. Today's transcranial direct current stimulation, and partly vagus nerve stimulation, can be compared with Arndt's methods. Although Arndt's only tangible results were indications for the application of faradic electricity (for inactivity, stupor, weakness and manic depressions) and galvanic current (for affective disorders and psychoses), a historiography of present-day brain stimulation therapies should no longer neglect studies on electrotherapy published in German and international psychiatric and neurological journals and monographs in the 1870s and 1880s. Copyright © 2013 Elsevier Inc. All rights reserved.

Fast multigrid-based computation of the induced electric field for transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Laakso, Ilkka; Hirata, Akimasa

2012-12-01

In transcranial magnetic stimulation (TMS), the distribution of the induced electric field, and the affected brain areas, depends on the position of the stimulation coil and the individual geometry of the head and brain. The distribution of the induced electric field in realistic anatomies can be modelled using computational methods. However, existing computational methods for accurately determining the induced electric field in realistic anatomical models have suffered from long computation times, typically in the range of tens of minutes or longer. This paper presents a matrix-free implementation of the finite-element method with a geometric multigrid method that can potentially reduce the computation time to several seconds or less even when using an ordinary computer. The performance of the method is studied by computing the induced electric field in two anatomically realistic models. An idealized two-loop coil is used as the stimulating coil. Multiple computational grid resolutions ranging from 2 to 0.25 mm are used. The results show that, for macroscopic modelling of the electric field in an anatomically realistic model, computational grid resolutions of 1 mm or 2 mm appear to provide good numerical accuracy compared to higher resolutions. The multigrid iteration typically converges in less than ten iterations independent of the grid resolution. Even without parallelization, each iteration takes about 1.0 s or 0.1 s for the 1 and 2 mm resolutions, respectively. This suggests that calculating the electric field with sufficient accuracy in real time is feasible.

Electrical stimulation as a means for achieving recovery of function in stroke patients.

PubMed

Popović, Dejan B; Sinkaer, Thomas; Popović, Mirjana B

2009-01-01

This review presents technologies used in and assesses the main clinical outcomes of electrical therapies designed to speed up and increase functional recovery in stroke patients. The review describes methods which interface peripheral systems (e.g., cyclic neural stimulation, stimulation triggered by electrical activity of muscles, therapeutic functional electrical stimulation) and transcranial brain stimulation with surface and implantable electrodes. Our conclusion from reviewing these data is that integration of electrical therapy into exercise-active movement mediated by electrical activation of peripheral and central sensory-motor mechanisms enhances motor re-learning following damage to the central nervous system. Motor re-learning is considered here as a set of processes associated with practice or experience that leads to long-term changes in the capability for movement. An important suggestion is that therapeutic effects are likely to be much more effective when treatment is applied in the acute, rather than in the chronic, phase of stroke.

Classification of methods in transcranial electrical stimulation (tES) and evolving strategy from historical approaches to contemporary innovations.

PubMed

Guleyupoglu, Berkan; Schestatsky, Pedro; Edwards, Dylan; Fregni, Felipe; Bikson, Marom

2013-10-15

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES. Copyright © 2013 Elsevier B.V. All rights reserved.

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

PubMed Central

Guleyupoglu, Berkan; Schestatsky, Pedro; Edwards, Dylan; Fregni, Felipe; Bikson, Marom

2013-01-01

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of trans-cranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES. PMID:23954780

Kinematic MRI study of upper-airway biomechanics using electrical muscle stimulation

NASA Astrophysics Data System (ADS)

Brennick, Michael J.; Margulies, Susan S.; Ford, John C.; Gefter, Warren B.; Pack, Allan I.

1997-05-01

We have developed a new and powerful method to study the movement and function of upper airway muscles. Our method is to use direct electrical stimulation of individual upper airway muscles, while performing state of the art high resolution magnetic resonance imaging (MRI). We have adapted a paralyzed isolated UA cat model so that positive or negative static pressure in the UA can be controlled at specific levels while electrical muscle stimulation is applied during MRI. With these techniques we can assess the effect of muscle stimulation on airway cross-sectional area compliance and soft tissue motion. We are reporting the preliminary results and MRI techniques which have enabled us to examine changes in airway dimensions which result form electrical stimulation of specific upper airway dilator muscles. The results of this study will be relevant to the development of new clinical treatments for obstructive sleep apnea by providing new information as to exactly how upper airway muscles function to dilate the upper airway and the strength of stimulation required to prevent the airway obstruction when overall muscle tone may not be sufficient to maintain regular breathing.

Sulfonated polyaniline-based organic electrodes for controlled electrical stimulation of human osteosarcoma cells.

PubMed

Min, Yong; Yang, Yanyin; Poojari, Yadagiri; Liu, Yidong; Wu, Jen-Chieh; Hansford, Derek J; Epstein, Arthur J

2013-06-10

Electrically conducting polymers (CPs) were found to stimulate various cell types such as neurons, osteoblasts, and fibroblasts in both in vitro and in vivo studies. However, to our knowledge, no studies have been reported on the utility of CPs in stimulation of cancer or tumor cells in the literature. Here we report a facile fabrication method of self-doped sulfonated polyaniline (SPAN)-based interdigitated electrodes (IDEs) for controlled electrical stimulation of human osteosarcoma (HOS) cells. Increased degree of sulfonation was found to increase the SPAN conductivity, which in turn improved the cell attachment and cell growth without electrical stimulation. However, an enhanced cell growth was observed under controlled electrical (AC) stimulation at low applied voltage and frequency (≤800 mV and ≤1 kHz). The cell growth reached a maximum threshold at an applied voltage or frequency and beyond which pronounced cell death was observed. We believe that these organic electrodes may find utility in electrical stimulation of cancer or tumor cells for therapy and research and may also provide an alternative to the conventional metal-based electrodes.

[Effects of electric stimulation at the cerebellar fastigial nucleus on astrocytes in the hippocampus of neonatal rats with hypoxic-ischemic brain damage].

PubMed

Li, Xiao-Li; Jia, Tian-Ming; Luan, Bin; Liu, Tao; Yuan, Yan

2011-04-01

To study the effects of electric stimulation at the cerebellar fastigial nucleus on astrocytes in the hippocampus of neonatal rats with hypoxic-ischemic brain damage (HIBD) and the possible mechanism. One hundred and eighty 7-day-old neonatal Sprague-Dawley rats were randomly divided into three groups: sham-operation (control group) and HIBD with and without electric stimulation (n=60 each). The HIBD model of neonatal rats was prepared by the Rice-Vennucci method. Electric stimulation at the cerebellar fastigial nucleus was given 24 hrs after the operation in the electric stimulation group once daily and lasted for 30 minutes each time. The other two groups were not subjected to electric stimulation but captured to fix in corresponding periods. Rats were sacrificed 3, 7, 14 and 21 days after stimulations to observe the glial fibrillary acidic protein (GFAP) expression by immunohistochemisty and the ultrastructural changes of astrocytes in the hippocampus under an electron microscope. Immunohistochemical analysis showed the expression of GFAP in the HIBD groups with and without electric stimulation increased significantly compared with the control group on day 3, reached the peak on day 7, and the increased expression remained till to day 21. The GFAP expression in the electric stimulation group was significantly lower than that in the untreated HIBD group at all time points. Under the electron microscope, the astrocytes in the untreated HIBD group were swollen and the amount of organelles was reduced, while the swelling of astrocytes was alleviated and the organelles remained in integrity in the electric stimulation group. The electric stimulation at the cerebellar fastigial nucleus can inhibit the excessive proliferation of astrocytes and relieve the structural damage of astrocytes in neonatal rats following HIBD.

Transcranial magnetic stimulation--may be useful as a preoperative screen of motor tract function.

PubMed

Galloway, Gloria M; Dias, Brennan R; Brown, Judy L; Henry, Christina M; Brooks, David A; Buggie, Ed W

2013-08-01

Transcranial motor stimulation with noninvasive cortical surface stimulation, using a high-intensity magnetic field referred to as transcranial magnetic stimulation generally, is considered a nonpainful technique. In contrast, transcranial electric stimulation of the motor tracts typically cannot be done in unanesthesized patients. Intraoperative monitoring of motor tract function with transcranial electric stimulation is considered a standard practice in many institutions for patients during surgical procedures in which there is potential risk of motor tract impairment so that the risk of paraplegia or paraparesis can be reduced. Because transcranial electric stimulation cannot be typically done in the outpatient setting, transcranial magnetic stimulation may be able to provide a well-tolerated method for evaluation of the corticospinal motor tracts before surgery. One hundred fifty-five patients aged 5 to 20 years were evaluated preoperatively with single-stimulation nonrepetitive transcranial magnetic stimulation for preoperative assessment. The presence of responses to transcranial magnetic stimulation reliably predicted the presence of responses to transcranial electric stimulation intraoperatively. No complications occurred during the testing, and findings were correlated to the clinical history and used in the setup of the surgical monitoring.

Method to Reduce Muscle Fatigue During Transcutaneous Neuromuscular Electrical Stimulation in Major Knee and Ankle Muscle Groups.

PubMed

Sayenko, Dimitry G; Nguyen, Robert; Hirabayashi, Tomoyo; Popovic, Milos R; Masani, Kei

2015-09-01

A critical limitation with transcutaneous neuromuscular electrical stimulation as a rehabilitative approach is the rapid onset of muscle fatigue during repeated contractions. We have developed a method called spatially distributed sequential stimulation (SDSS) to reduce muscle fatigue by distributing the center of electrical field over a wide area within a single stimulation site, using an array of surface electrodes. To extend the previous findings and to prove feasibility of the method by exploring the fatigue-reducing ability of SDSS for lower limb muscle groups in the able-bodied population, as well as in individuals with spinal cord injury (SCI). SDSS was delivered through 4 active electrodes applied to the knee extensors and flexors, plantarflexors, and dorsiflexors, sending a stimulation pulse to each electrode one after another with 90° phase shift between successive electrodes. Isometric ankle torque was measured during fatiguing stimulations using SDSS and conventional single active electrode stimulation lasting 2 minutes. We demonstrated greater fatigue-reducing ability of SDSS compared with the conventional protocol, as revealed by larger values of fatigue index and/or torque peak mean in all muscles except knee flexors of able-bodied individuals, and in all muscles tested in individuals with SCI. Our study has revealed improvements in fatigue tolerance during transcutaneous neuromuscular electrical stimulation using SDSS, a stimulation strategy that alternates activation of subcompartments of muscles. The SDSS protocol can provide greater stimulation times with less decrement in mechanical output compared with the conventional protocol. © The Author(s) 2014.

Duplex communicable implanted antenna for magnetic direct feeding method: Functional electrical stimulation

NASA Astrophysics Data System (ADS)

Kato, Kentaro; Matsuki, Hidetoshi; Sato, Fumihiro; Satoh, Tadakuni; Handa, Nobuyasu

2009-04-01

Functional electrical stimulation (FES) is the therapy used for the rehabilitation of lost movement function by applying electrical stimulation (ES) to paralyzed extremities. To realize ES, we adapted the implanted direct feeding method (DFM). In this method, small implanted stimulators are placed under the skin at a depth of 10-20 mm and stimulus energy and signals for controlling devices are applied to them by a mounted system using magnetic coupling. This method has the merits of having no percutaneous points and high-precision stimulation. However, since the mounted system and implanted elements are separated, it is necessary to add feedback information from inside the body to confirm the system operation for safety therapy or to rehabilitate motor function smoothly. Satisfying both restrictions, we propose the magnetic connective dual resonance (MCDR) antenna, which has two resonance circuits. Adding the LC serial circuit to the LC parallel circuit gives the sending function. In this paper, we report the principle of the MCDR antenna and verify its duplex communication ability through communication experiment. This antenna enables DFM of FES to rehabilitate more complex movements.

Apparatuses and methods for detecting, identifying and quantitating radioactive nuclei and methods of distinguishing neutron stimulation of a radiation particle detector from gamma-ray stimulation of a detector

DOEpatents

Cole, Jerald D.; Drigert, Mark W.; Reber, Edward L.; Aryaeinejad, Rahmat

2001-01-01

In one aspect, the invention encompasses a method of detecting radioactive decay, comprising: a) providing a sample comprising a radioactive material, the radioactive material generating decay particles; b)providing a plurality of detectors proximate the sample, the detectors comprising a first set and a second set, the first set of the detectors comprising liquid state detectors utilizing liquid scintillation material coupled with photo tubes to generate a first electrical signal in response to decay particles stimulating the liquid scintillation material, the second set of the detectors comprising solid state detectors utilizing a crystalline solid to generate a second electrical signal in response to decay particles stimulating the crystalline solid; c) stimulating at least one of the detectors to generate at least one of the first and second electrical signals, the at least one of the first and second electrical signals being indicative of radioactive decay in the sample. In another aspect, the invention encompasses an apparatus for identifying and quantitating radioactive nuclei of a sample comprising radioactive material that decays to generate neutrons and high-energy .gamma.-rays.

The efficacy of electrical stimulation in lower extremity cutaneous wound healing: A systematic review.

PubMed

Ashrafi, Mohammed; Alonso-Rasgado, Teresa; Baguneid, Mohamed; Bayat, Ardeshir

2017-02-01

Current gold standard lower extremity cutaneous wound management is not always effective. Cutaneous wounds generate a "current of injury" which is directly involved in wound healing processes. Application of exogenous electrical stimulation has been hypothesised to imitate the natural electric current that occurs in cutaneous wounds. The aim of this extensive review was to provide a detailed update on the variety of electrical stimulation modalities used in the management of lower extremity wounds. Several different waveforms and delivery methods of electrical stimulation have been used. Pulsed current appears superior to other electrical modalities available. The majority of studies support the beneficial effects of pulsed current over conservative management of lower extremity cutaneous wounds. Although it appears to have no benefit over causal surgical intervention, it is a treatment option which could be utilised in those patients unsuitable for surgery. Other waveforms and modalities appear promising; however, they still lack large trial data to recommend a firm conclusion with regards to their use. Current studies also vary in quantity, quality and protocol across the different modalities. The ideal electrical stimulation device needs to be non-invasive, portable and cost-effective and provides minimal interference with patients' daily life. Further studies are necessary to establish the ideal electrical stimulation modality, parameters, method of delivery and duration of treatment. The development and implementation of newer devices in the management of acute and chronic wounds provides an exciting direction in the field of electrotherapy. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Semiparametric Identification of Human Arm Dynamics for Flexible Control of a Functional Electrical Stimulation Neuroprosthesis

PubMed Central

Schearer, Eric M.; Liao, Yu-Wei; Perreault, Eric J.; Tresch, Matthew C.; Memberg, William D.; Kirsch, Robert F.; Lynch, Kevin M.

2016-01-01

We present a method to identify the dynamics of a human arm controlled by an implanted functional electrical stimulation neuroprosthesis. The method uses Gaussian process regression to predict shoulder and elbow torques given the shoulder and elbow joint positions and velocities and the electrical stimulation inputs to muscles. We compare the accuracy of torque predictions of nonparametric, semiparametric, and parametric model types. The most accurate of the three model types is a semiparametric Gaussian process model that combines the flexibility of a black box function approximator with the generalization power of a parameterized model. The semiparametric model predicted torques during stimulation of multiple muscles with errors less than 20% of the total muscle torque and passive torque needed to drive the arm. The identified model allows us to define an arbitrary reaching trajectory and approximately determine the muscle stimulations required to drive the arm along that trajectory. PMID:26955041

Electrical foot stimulation and implications for the prevention of venous thromboembolic disease.

PubMed

Kaplan, Robert E; Czyrny, James J; Fung, Tat S; Unsworth, John D; Hirsh, Jack

2002-08-01

Venous stasis caused by immobility is an important risk factor for deep vein thrombosis following surgery and lower limb trauma, in bed-ridden medical patients, and in high-risk long distance air travelers. A safe and convenient method for reducing venous stasis would be useful in patients while in hospital and after discharge during their rehabilitation. 49 healthy subjects aged 51-76 were seated for 4 hours during which they received mild electrical stimulation of the calf, or sole of the foot (plantar muscles). Popliteal and femoral venous blood flow velocities were measured via doppler ultrasound. The non-stimulated lower extremity served as the simultaneous control. Subjects completed a questionnaire regarding their acceptance and tolerance of the electrical stimulation. There was a significant increase in venous femoral and popliteal blood flow for both calf (p < 0.035, p < 0.003), and plantar muscles (p < 0.0001, p < 0.009) on the stimulated side compared to the unstimulated side. The magnitude of the effect was similar for calf and plantar muscle stimulation. Subjects did not find the experience uncomfortable, and would use an electrical stimulator if told by their physician that they were at risk for developing blood clots. Mild electrical stimulation of the feet, as well as the calf, is a safe effective and convenient method for counteracting venous stasis and therefore has the potential to reduce the risk of deep vein thrombosis and pulmonary embolism for subjects who are immobilized.

Endogenous Cortical Oscillations Constrain Neuromodulation by Weak Electric Fields

PubMed Central

Schmidt, Stephen L.; Iyengar, Apoorva K.; Foulser, A. Alban; Boyle, Michael R.; Fröhlich, Flavio

2014-01-01

Background Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation modality that may modulate cognition by enhancing endogenous neocortical oscillations with the application of sine-wave electric fields. Yet, the role of endogenous network activity in enabling and shaping the effects of tACS has remained unclear. Objective We combined optogenetic stimulation and multichannel slice electrophysiology to elucidate how the effect of weak sine-wave electric field depends on the ongoing cortical oscillatory activity. We hypothesized that the structure of the response to stimulation depended on matching the stimulation frequency to the endogenous cortical oscillation. Methods We studied the effect of weak sine-wave electric fields on oscillatory activity in mouse neocortical slices. Optogenetic control of the network activity enabled the generation of in vivo like cortical oscillations for studying the temporal relationship between network activity and sine-wave electric field stimulation. Results Weak electric fields enhanced endogenous oscillations but failed to induce a frequency shift of the ongoing oscillation for stimulation frequencies that were not matched to the endogenous oscillation. This constraint on the effect of electric field stimulation imposed by endogenous network dynamics was limited to the case of weak electric fields targeting in vivo-like network dynamics. Together, these results suggest that the key mechanism of tACS may be enhancing but not overriding of intrinsic network dynamics. Conclusion Our results contribute to understanding the inconsistent tACS results from human studies and propose that stimulation precisely adjusted in frequency to the endogenous oscillations is key to rational design of non-invasive brain stimulation paradigms. PMID:25129402

The combined effects of transcutaneous electrical nerve stimulation (TENS) and stretching on muscle hardness and pressure pain threshold.

PubMed

Karasuno, Hiroshi; Ogihara, Hisayoshi; Morishita, Katsuyuki; Yokoi, Yuka; Fujiwara, Takayuki; Ogoma, Yoshiro; Abe, Koji

2016-04-01

[Purpose] This study aimed to clarify the immediate effects of a combined transcutaneous electrical nerve stimulation and stretching protocol. [Subjects] Fifteen healthy young males volunteered to participate in this study. The inclusion criterion was a straight leg raising range of motion of less than 70 degrees. [Methods] Subjects performed two protocols: 1) stretching (S group) of the medial hamstrings, and 2) tanscutaneous electrical nerve stimulation (100 Hz) with stretching (TS group). The TS group included a 20-minute electrical stimulation period followed by 10 minutes of stretching. The S group performed 10 minutes of stretching. Muscle hardness, pressure pain threshold, and straight leg raising range of motion were analyzed to evaluate the effects. The data were collected before transcutaneous electrical nerve stimulation (T1), before stretching (T2), immediately after stretching (T3), and 10 minutes after stretching (T4). [Results] Combined transcutaneous electrical nerve stimulation and stretching had significantly beneficial effects on muscle hardness, pressure pain threshold, and straight leg raising range of motion at T2, T3, and T4 compared with T1. [Conclusion] These results support the belief that transcutaneous electrical nerve stimulation combined with stretching is effective in reducing pain and decreasing muscle hardness, thus increasing range of motion.

Functional electrical stimulation to the abdominal wall muscles synchronized with the expiratory flow does not induce muscle fatigue.

PubMed

Okuno, Yukako; Takahashi, Ryoichi; Sewa, Yoko; Ohse, Hirotaka; Imura, Shigeyuki; Tomita, Kazuhide

2017-03-01

[Purpose] Continuous electrical stimulation of abdominal wall muscles is known to induce mild muscle fatigue. However, it is not clear whether this is also true for functional electrical stimulation delivered only during the expiratory phase of breathing. This study aimed to examine whether or not intermittent electrical stimulation delivered to abdominal wall muscles induces muscle fatigue. [Subjects and Methods] The subjects were nine healthy adults. Abdominal electrical stimulation was applied for 1.5 seconds from the start of expiration and then turned off during inspiration. The electrodes were attached to both sides of the abdomen at the lower margin of the 12th rib. Abdominal electrical stimulation was delivered for 15 minutes with the subject in a seated position. Expiratory flow was measured during stimulus. Trunk flexor torque and electromyography activity were measured to evaluate abdominal muscle fatigue. [Results] The mean stimulation on/off ratio was 1:2.3. The declining rate of abdominal muscle torque was 61.1 ± 19.1% before stimulus and 56.5 ± 20.9% after stimulus, not significantly different. The declining rate of mean power frequency was 47.8 ± 11.7% before stimulus and 47.9 ± 10.2% after stimulus, not significantly different. [Conclusion] It was found that intermittent electrical stimulation to abdominal muscles synchronized with the expiratory would not induce muscle fatigue.

A functional magnetic resonance imaging study of human brain in pain-related areas induced by electrical stimulation with different intensities.

PubMed

Yuan, Wang; Ming, Zhang; Rana, Netra; Hai, Liu; Chen-wang, Jin; Shao-hui, Ma

2010-01-01

Pain-related studies have mainly been performed through traditional methods, which lack the rigorous analysis of anatomical locations. Functional magnetic resonance imaging (fMRI) is a noninvasive method detecting neural activity, and has the ability to precisely locate related activations in vivo. Moreover, few studies have used painful stimulation of changed intensity to investigate relevant functioning nuclei in the human brain. This study mainly focused on the pain-related activations induced by electrical stimulation with different intensities using fMRI. Furthermore, the electrophysiological characteristics of different pain-susceptible-neurons were analyzed to construct the pain modulatory network, which was corresponding to painful stimulus of changed intensity. Twelve volunteers underwent functional scanning receiving different electrical stimulation. The data were collected and analyzed to generate the corresponding functional activation maps and response time curves related to pain. The common activations were mainly located in several specific regions, including the secondary somatosensory cortex (SII), insula, anterior cingulate cortex (ACC), thalamus, and other cerebral regions. Moreover, innocuous electrical stimulation primarily activated the lateral portions of SII and thalamus, as well as the posterior insula, anterior ACC, whereas noxious electrical stimulation primarily activated the medial portions of SII and thalamus, as well as the anterior insula, the posterior ACC, with larger extensions and greater intensities. Several specified cerebral regions displayed different response patterns during electrical stimulation by means of fMRI, which implied that the corresponding pain-susceptible-neurons might process specific aspects of pain. Elucidation of functions on pain-related regions will help to understand the delicate pain modulation of human brain.

A voltage-controlled capacitive discharge method for electrical activation of peripheral nerves.

PubMed

Rosellini, Will M; Yoo, Paul B; Engineer, Navzer; Armstrong, Scott; Weiner, Richard L; Burress, Chester; Cauller, Larry

2011-01-01

A voltage-controlled capacitive discharge (VCCD) method was investigated as an alternative to rectangular stimulus pulses currently used in peripheral nerve stimulation therapies.  In two anesthetized Gottingen mini pigs, the threshold (total charge per phase) for evoking a compound nerve action potential (CNAP) was compared between constant current (CC) and VCCD methods. Electrical pulses were applied to the tibial and posterior cutaneous femoralis nerves using standard and modified versions of the Medtronic 3778 Octad.  In contrast to CC stimulation, the combined application of VCCD pulses with a modified Octad resulted in a marked decrease (-73 ± 7.4%) in the stimulation threshold for evoking a CNAP. This was consistent for different myelinated fiber types and locations of stimulation.  The VCCD method provides a highly charge-efficient means of activating myelinated fibers that could potentially be used within a wireless peripheral nerve stimulator system. © 2011 International Neuromodulation Society.

Different Movement of Hyolaryngeal Structures by Various Application of Electrical Stimulation in Normal Individuals

PubMed Central

Kim, Sae Hyun; Oh, Byung-Mo; Han, Tae Ryun; Jeong, Ho Joong

2015-01-01

Objective To identify the differences in the movement of the hyoid bone and the vocal cord with and without electrical stimulation in normal subjects. Methods Two-dimensional motion analysis using a videofluoroscopic swallowing study with and without electrical stimulation was performed. Surface electrical stimulation was applied during swallowing using electrodes placed at three different locations on each subject. All subjects were analyzed three times using the following electrode placements: with one pair of electrodes on the suprahyoid muscles and a second pair on the infrahyoid muscles (SI); with placement of the electrode pairs on only the infrahyoid muscles (IO); and with the electrode pairs placed vertically on the suprahyoid and infrahyoid muscles (SIV). Results The main outcomes of this study demonstrated an initial downward displacement as well as different movements of the hyoid bone with the three electrode placements used for electrical stimulation. The initial positions of the hyoid bone with the SI and IO placements resulted in an inferior and anterior displaced position. During swallowing, the hyoid bone moved in a more superior and less anterior direction, resulting in almost the same peak position compared with no electrical stimulation. Conclusion These results demonstrate that electrical stimulation caused an initial depression of the hyoid bone, which had nearly the same peak position during swallowing. Electrical stimulation during swallowing was not dependent on the position of the electrode on the neck, such as on the infrahyoid or on both the suprahyoid and infrahyoid muscles. PMID:26361589

Electrical Stimulation for Pressure Injuries: A Health Technology Assessment

PubMed Central

Lambrinos, Anna; Falk, Lindsey; Ali, Arshia; Holubowich, Corinne; Walter, Melissa

2017-01-01

Background Pressure injuries (bedsores) are common and reduce quality of life. They are also costly and difficult to treat. This health technology assessment evaluates the effectiveness, cost-effectiveness, budget impact, and lived experience of adding electrical stimulation to standard wound care for pressure injuries. Methods We conducted a systematic search for studies published to December 7, 2016, limited to randomized and non–randomized controlled trials examining the effectiveness of electrical stimulation plus standard wound care versus standard wound care alone for patients with pressure injuries. We assessed the quality of evidence through Grading of Recommendations Assessment, Development, and Evaluation (GRADE). In addition, we conducted an economic literature review and a budget impact analysis to assess the cost-effectiveness and affordability of electrical stimulation for treatment of pressure ulcers in Ontario. Given uncertainties in clinical evidence and resource use, we did not conduct a primary economic evaluation. Finally, we conducted qualitative interviews with patients and caregivers about their experiences with pressure injuries, currently available treatments, and (if applicable) electrical stimulation. Results Nine randomized controlled trials and two non–randomized controlled trials were found from the systematic search. There was no significant difference in complete pressure injury healing between adjunct electrical stimulation and standard wound care. There was a significant difference in wound surface area reduction favouring electrical stimulation compared with standard wound care. The only study on cost-effectiveness of electrical stimulation was partially applicable to the patient population of interest. Therefore, the cost-effectiveness of electrical stimulation cannot be determined. We estimate that the cost of publicly funding electrical stimulation for pressure injuries would be $0.77 to $3.85 million yearly for the next 5 years. Patients and caregivers reported that pressure injuries were burdensome and reduced their quality of life. Patients and caregivers also noted that electrical stimulation seemed to reduce the time it took the wounds to heal. Conclusions While electrical stimulation is safe to use (GRADE quality of evidence: high) there is uncertainty about whether it improves wound healing (GRADE quality of evidence: low). In Ontario, publicly funding electrical stimulation for pressure injuries could result in extra costs of $0.77 to $3.85 million yearly for the next 5 years. PMID:29201261

Optical imaging of the retina in response to the electrical stimulation

NASA Astrophysics Data System (ADS)

Fujikado, Takashi; Okawa, Yoshitaka; Miyoshi, Tomomitsu; Hirohara, Yoko; Mihashi, Toshifumi; Tano, Yasuo

2008-02-01

Purposes: To determine if reflectance changes of the retina can be detected following electrical stimulation to the retina using a newly developed optical-imaging fundus camera. Methods: Eyes of cats were examined after pupil dilation. Retina was stimulated either focally by a ball-type electrode (BE) placed on the fenestrated sclera or diffusely using a ring-type electrode (RE) placed on the corneoscleral limbus. Electrical stimulation by biphasic pulse trains was applied for 4 seconds. Fundus images with near-infrared (800-880 nm) light were obtained between 2 seconds before and 20 seconds after the electrical stimulation (ES). A two-dimensional map of the reflectance changes (RCs) was constructed. The effect of Tetrodotoxin (TTX) was also investigated on RCs by ES using RE. Results: RCs were observed around the retinal locus where the stimulating electrodes were positioned (BE) or in the retina of the posterior pole (RE), in which the latency was about 0.5 to 1.0 sec and the peak time about 2 to 5 sec after the onset of ES. The intensity of the RCs increased with the increase of the stimulus current in both cases. RCs were completely suppressed after the injection of TTX. Conclusions: The functional changes of the retina either by focal or diffuse electrical stimulation were successfully detected by optical imaging of the retina. The contribution of retinal ganglion cells on RCs by ES was confirmed by TTX experiment. This method may be applied to the objective evaluation of the artificial retina.

ERAASR: an algorithm for removing electrical stimulation artifacts from multielectrode array recordings

NASA Astrophysics Data System (ADS)

O'Shea, Daniel J.; Shenoy, Krishna V.

2018-04-01

Objective. Electrical stimulation is a widely used and effective tool in systems neuroscience, neural prosthetics, and clinical neurostimulation. However, electrical artifacts evoked by stimulation prevent the detection of spiking activity on nearby recording electrodes, which obscures the neural population response evoked by stimulation. We sought to develop a method to clean artifact-corrupted electrode signals recorded on multielectrode arrays in order to recover the underlying neural spiking activity. Approach. We created an algorithm, which performs estimation and removal of array artifacts via sequential principal components regression (ERAASR). This approach leverages the similar structure of artifact transients, but not spiking activity, across simultaneously recorded channels on the array, across pulses within a train, and across trials. The ERAASR algorithm requires no special hardware, imposes no requirements on the shape of the artifact or the multielectrode array geometry, and comprises sequential application of straightforward linear methods with intuitive parameters. The approach should be readily applicable to most datasets where stimulation does not saturate the recording amplifier. Main results. The effectiveness of the algorithm is demonstrated in macaque dorsal premotor cortex using acute linear multielectrode array recordings and single electrode stimulation. Large electrical artifacts appeared on all channels during stimulation. After application of ERAASR, the cleaned signals were quiescent on channels with no spontaneous spiking activity, whereas spontaneously active channels exhibited evoked spikes which closely resembled spontaneously occurring spiking waveforms. Significance. We hope that enabling simultaneous electrical stimulation and multielectrode array recording will help elucidate the causal links between neural activity and cognition and facilitate naturalistic sensory protheses.

Coherent anti-Stokes Raman scattering under electric field stimulation

NASA Astrophysics Data System (ADS)

Capitaine, Erwan; Ould Moussa, Nawel; Louot, Christophe; Lefort, Claire; Pagnoux, Dominique; Duclère, Jean-René; Kaneyasu, Junya F.; Kano, Hideaki; Duponchel, Ludovic; Couderc, Vincent; Leproux, Philippe

2016-12-01

We introduce an experiment using electro-CARS, an electro-optical method based on the combination of ultrabroadband multiplex coherent anti-Stokes Raman scattering (M-CARS) spectroscopy and electric field stimulation. We demonstrate that this method can effectively discriminate the resonant CARS signal from the nonresonant background owing to a phenomenon of molecular orientation in the sample medium. Such molecular orientation is intrinsically related to the induction of an electric dipole moment by the applied static electric field. Evidence of the electro-CARS effect is obtained with a solution of n -alkanes (CnH2 n +2 , 15 ≤n ≤40 ), for which an enhancement of the CARS signal-to-noise ratio is achieved in the case of CH2 and CH3 symmetric/asymmetric stretching vibrations. Additionally, an electric-field-induced second-harmonic generation experiment is performed in order to corroborate the orientational organization of molecules due to the electric field excitation. Finally, we use a simple mathematical approach to compare the vibrational information extracted from electro-CARS measurements with spontaneous Raman data and to highlight the impact of electric stimulation on the vibrational signal.

Stimulation artifact correction method for estimation of early cortico-cortical evoked potentials.

PubMed

Trebaul, Lena; Rudrauf, David; Job, Anne-Sophie; Mălîia, Mihai Dragos; Popa, Irina; Barborica, Andrei; Minotti, Lorella; Mîndruţă, Ioana; Kahane, Philippe; David, Olivier

2016-05-01

Effective connectivity can be explored using direct electrical stimulations in patients suffering from drug-resistant focal epilepsies and investigated with intracranial electrodes. Responses to brief electrical pulses mimic the physiological propagation of signals and manifest as cortico-cortical evoked potentials (CCEP). The first CCEP component is believed to reflect direct connectivity with the stimulated region but the stimulation artifact, a sharp deflection occurring during a few milliseconds, frequently contaminates it. In order to recover the characteristics of early CCEP responses, we developed an artifact correction method based on electrical modeling of the electrode-tissue interface. The biophysically motivated artifact templates are then regressed out of the recorded data as in any classical template-matching removal artifact methods. Our approach is able to make the distinction between the physiological responses time-locked to the stimulation pulses and the non-physiological component. We tested the correction on simulated CCEP data in order to quantify its efficiency for different stimulation and recording parameters. We demonstrated the efficiency of the new correction method on simulations of single trial recordings for early responses contaminated with the stimulation artifact. The results highlight the importance of sampling frequency for an accurate analysis of CCEP. We then applied the approach to experimental data. The model-based template removal was compared to a correction based on the subtraction of the averaged artifact. This new correction method of stimulation artifact will enable investigators to better analyze early CCEP components and infer direct effective connectivity in future CCEP studies. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Transient finite element modeling of functional electrical stimulation.

PubMed

Filipovic, Nenad D; Peulic, Aleksandar S; Zdravkovic, Nebojsa D; Grbovic-Markovic, Vesna M; Jurisic-Skevin, Aleksandra J

2011-03-01

Transcutaneous functional electrical stimulation is commonly used for strengthening muscle. However, transient effects during stimulation are not yet well explored. The effect of an amplitude change of the stimulation can be described by static model, but there is no differency for different pulse duration. The aim of this study is to present the finite element (FE) model of a transient electrical stimulation on the forearm. Discrete FE equations were derived by using a standard Galerkin procedure. Different tissue conductive and dielectric properties are fitted using least square method and trial and error analysis from experimental measurement. This study showed that FE modeling of electrical stimulation can give the spatial-temporal distribution of applied current in the forearm. Three different cases were modeled with the same geometry but with different input of the current pulse, in order to fit the tissue properties by using transient FE analysis. All three cases were compared with experimental measurements of intramuscular voltage on one volunteer.

Neurite Outgrowth On Electrospun PLLA Fibers Is Enhanced By Exogenous Electrical Stimulation

PubMed Central

Koppes, A. N.; Zaccor, N. W.; Rivet, C. J.; Williams, L. A.; Piselli, J. M.; Gilbert, R. J.; Thompson, D. M.

2014-01-01

Objective Both electrical stimuli (endogenous and exogenous) and topographical cues are instructive to axonal extension. This report, for the first time, investigated the relative dominance of directional topographical guidance cues and directional electrical cues to enhance and/or direct primary neurite extension. We hypothesized the combination of electrical stimulation with electrospun fiber topography would induce longer neurite extension from DRG neurons than the presence of electrical stimulation or aligned topography alone. Approach To test the hypothesis, neurite outgrowth was examined on laminin-coated poly-L-lactide (PLLA) films or electrospun fibers (2 μm in diameter) in the presence or absence of electrical stimulation. Immunostained neurons were semi-automatically traced using Neurolucida software and morphology was evaluated. Results Neurite extension increased 74% on the aligned fibers compared to film controls. Stimulation alone increased outgrowth by 32% on films or fibers relative to unstimulated film controls. The co-presentation of topographical (fibers) with biophysical (electrical stimulation) cues resulted in a synergistic 126% increase in outgrowth relative to unstimulated film controls. Field polarity had no influence on the directionality of neurite, indicating topographical cues are responsible to guide neurite extension. Significance Both cues (electrical stimulation and fiber geometry) are modular in nature and can be synergistically applied in conjunction with other common methods in regenerative medicine such as controlled release of growth factors to further influence axonal growth in vivo. The combined application of electrical and aligned fiber topographical guidance cues described herein, if translated in vivo, could provide a more supportive environment for directed and robust axonal regeneration following peripheral nerve injury. PMID:24891494

Neurite outgrowth on electrospun PLLA fibers is enhanced by exogenous electrical stimulation.

PubMed

Koppes, A N; Zaccor, N W; Rivet, C J; Williams, L A; Piselli, J M; Gilbert, R J; Thompson, D M

2014-08-01

Both electrical stimuli (endogenous and exogenous) and topographical cues are instructive to axonal extension. This report, for the first time, investigated the relative dominance of directional topographical guidance cues and directional electrical cues to enhance and/or direct primary neurite extension. We hypothesized the combination of electrical stimulation with electrospun fiber topography would induce longer neurite extension from dorsal root ganglia neurons than the presence of electrical stimulation or aligned topography alone. To test the hypothesis, neurite outgrowth was examined on laminin-coated poly-L-lactide films or electrospun fibers (2 µm in diameter) in the presence or absence of electrical stimulation. Immunostained neurons were semi-automatically traced using Neurolucida software and morphology was evaluated. Neurite extension increased 74% on the aligned fibers compared to film controls. Stimulation alone increased outgrowth by 32% on films or fibers relative to unstimulated film controls. The co-presentation of topographical (fibers) with biophysical (electrical stimulation) cues resulted in a synergistic 126% increase in outgrowth relative to unstimulated film controls. Field polarity had no influence on the directionality of neurites, indicating topographical cues are responsible for guiding neurite extension. Both cues (electrical stimulation and fiber geometry) are modular in nature and can be synergistically applied in conjunction with other common methods in regenerative medicine such as controlled release of growth factors to further influence axonal growth in vivo. The combined application of electrical and aligned fiber topographical guidance cues described herein, if translated in vivo, could provide a more supportive environment for directed and robust axonal regeneration following peripheral nerve injury.

Playing the electric light orchestra—how electrical stimulation of visual cortex elucidates the neural basis of perception

PubMed Central

Cicmil, Nela; Krug, Kristine

2015-01-01

Vision research has the potential to reveal fundamental mechanisms underlying sensory experience. Causal experimental approaches, such as electrical microstimulation, provide a unique opportunity to test the direct contributions of visual cortical neurons to perception and behaviour. But in spite of their importance, causal methods constitute a minority of the experiments used to investigate the visual cortex to date. We reconsider the function and organization of visual cortex according to results obtained from stimulation techniques, with a special emphasis on electrical stimulation of small groups of cells in awake subjects who can report their visual experience. We compare findings from humans and monkeys, striate and extrastriate cortex, and superficial versus deep cortical layers, and identify a number of revealing gaps in the ‘causal map′ of visual cortex. Integrating results from different methods and species, we provide a critical overview of the ways in which causal approaches have been used to further our understanding of circuitry, plasticity and information integration in visual cortex. Electrical stimulation not only elucidates the contributions of different visual areas to perception, but also contributes to our understanding of neuronal mechanisms underlying memory, attention and decision-making. PMID:26240421

Determining which mechanisms lead to activation in the motor cortex: a modeling study of transcranial magnetic stimulation using realistic stimulus waveforms and sulcal geometry1

PubMed Central

Salvador, R.; Silva, S.; Basser, P. J.; Miranda, P. C.

2010-01-01

Objective To determine which mechanisms lead to activation of neurons in the motor cortex during transcranial magnetic stimulation (TMS) with different current directions and pulse waveforms. Methods The total electric field induced in a simplified model of a cortical sulcus by a figure-eight coil was calculated using the finite element method (FEM). This electric field was then used as the input to determine the response of compartmental models of several types of neurons. Results The modeled neurons were stimulated at different sites: fiber bends for pyramidal tract neurons, axonal terminations for cortical interneurons and axon collaterals, and a combination of both for pyramidal association fibers. All neurons were more easily stimulated by a PA directed electric field, except association fibers. Additionally, the second phase of a biphasic pulse was found to be more efficient than the first phase of either monophasic or biphasic pulses. Conclusion The stimulation threshold for different types of neurons depends on the pulse waveform and current direction. The reported results might account for the range of responses obtained in TMS of the motor cortex when using different stimulation parameters. Significance Modeling studies combining electric field calculations and neuronal models may lead to a deeper understanding of the effect of the TMS-induced electric field on cortical tissue, and may be used to evaluate improvements in TMS coil and waveform design. PMID:21035390

Language Mapping in Awake Surgery: Report of Two Cases with Review of Language Networks.

PubMed

Lim, Liang Hooi; Idris, Zamzuri; Reza, Faruque; Wan Hassan, Wan Mohd Nazaruddin; Mukmin, Laila Abd; Abdullah, Jafri Malin

2018-01-01

The role of language in communication plays a crucial role in human development and function. In patients who have a surgical lesion at the functional language areas, surgery should be intricately planned to avoid incurring further morbidity. This normally requires extensive functional and anatomical mappings of the brain to identify regions that are involved in language processing and production. In our case report, regions of the brain that are important for language functions were studied before surgery by employing (a) extraoperative methods such as functional magnetic resonance imaging, transmagnetic stimulation, and magnetoencephalography; (b) during the surgery by utilizing intraoperative awake surgical methods such as an intraoperative electrical stimulation; and (c) a two-stage surgery, in which electrical stimulation and first mapping are made thoroughly in the ward before second remapping during surgery. The extraoperative methods before surgery can guide the neurosurgeon to localize the functional language regions and tracts preoperatively. This will be confirmed using single-stage intraoperative electrical brain stimulation during surgery or a two-stage electrical brain stimulation before and during surgery. Here, we describe two cases in whom one has a superficial lesion and another a deep-seated lesion at language-related regions, in which language mapping was done to preserve its function. Additional review on the neuroanatomy of language regions, language network, and its impairment was also described.

Neural pathways from thalamus associated with regulation of aggressive behavior.

PubMed

Bandler, R J; Flynn, J P

1974-01-11

Small electrolytic lesions were made through electrodes in the thalamus of cats at sites where electrical stimulation elicited attack on a rat. Staining by modified Nauta reduced silver methods revealed that significant degeneration passed caudally from the lesions and entered the midbrain dorsal central gray region. Electrical stimulation of this dorsal midbrain region elicited attack on a rat, and destruction of this region suppressed the attack elicited by thalamic stimulation.

Evidence-Based Systematic Review: Effects of Neuromuscular Electrical Stimulation on Swallowing and Neural Activation

ERIC Educational Resources Information Center

Clark, Heather; Lazarus, Cathy; Arvedson, Joan; Schooling, Tracy; Frymark, Tobi

2009-01-01

Purpose: To systematically review the literature examining the effects of neuromuscular electrical stimulation (NMES) on swallowing and neural activation. The review was conducted as part of a series examining the effects of oral motor exercises (OMEs) on speech, swallowing, and neural activation. Method: A systematic search was conducted to…

Real-time and wearable functional electrical stimulation system for volitional hand motor function control using the electromyography bridge method

PubMed Central

Wang, Hai-peng; Bi, Zheng-yang; Zhou, Yang; Zhou, Yu-xuan; Wang, Zhi-gong; Lv, Xiao-ying

2017-01-01

Voluntary participation of hemiplegic patients is crucial for functional electrical stimulation therapy. A wearable functional electrical stimulation system has been proposed for real-time volitional hand motor function control using the electromyography bridge method. Through a series of novel design concepts, including the integration of a detecting circuit and an analog-to-digital converter, a miniaturized functional electrical stimulation circuit technique, a low-power super-regeneration chip for wireless receiving, and two wearable armbands, a prototype system has been established with reduced size, power, and overall cost. Based on wrist joint torque reproduction and classification experiments performed on six healthy subjects, the optimized surface electromyography thresholds and trained logistic regression classifier parameters were statistically chosen to establish wrist and hand motion control with high accuracy. Test results showed that wrist flexion/extension, hand grasp, and finger extension could be reproduced with high accuracy and low latency. This system can build a bridge of information transmission between healthy limbs and paralyzed limbs, effectively improve voluntary participation of hemiplegic patients, and elevate efficiency of rehabilitation training. PMID:28250759

[Methods of brain stimulation based on weak electric current--future tool for the clinician?].

PubMed

Kotilainen, Tuukka; Lehto, Soili M

2016-01-01

Methods of brain stimulation based on a weak electric current are non-invasive neuromodulation techniques. They include transcranial direct current, alternating current and random noise stimulation. These methods modify the membrane potential of neurons without triggering the action potential, and have been successfully utilized to influence cognition and regulation of emotions in healthy experimental subjects. In clinical studies, indications of the efficacy of these techniques have been obtained in the treatment of depression, schizophrenia, memory disorders and pain as well as in stroke rehabilitation. It is hoped that these techniques will become established as part of the care and rehabilitation of psychiatric and neurologic patients in the future.

The effects of electrical stimulation and exercise therapy in patients with limb girdle muscular dystrophy

PubMed Central

Kılınç, Muhammed; Yıldırım, Sibel A.; Tan, Ersin

2015-01-01

Objective: To evaluate and compare the effects of exercise therapy and electrical stimulation on muscle strength and functional activities in patients with limb-girdle muscular dystrophy (LGMD). Methods: This controlled clinical trial included 24 subjects who were diagnosed with LGMD by the Neurology Department of the Hacettepe University Hospital, Ankara, Turkey and were referred to the Physical Therapy Department between May 2013 and December 2014. Subjects were enrolled into an electrical stimulation (11 patients) group, or an exercise therapy (13 patients) group. Results: The mean age of patients was 31.62 years in the electrical stimulation group, and 30.14 years in the exercise therapy group. The most important results in this controlled clinical study were that the muscle strength in both groups was significantly decreased and post-treatment evaluation results indicated that muscle strength of the Deltoideus was higher in the electrical stimulation group, and the difference between the groups was maintained in the follow-up period (p<0.05). However, the muscle strength of quadriceps was similar in both groups, according to the post-treatment and follow-up evaluation results (p>0.05). Additionally, the electrical stimulation group presented more obvious overall improvements than the exercise therapy group according to muscle strength, endurance, and timed performance tests. Conclusions: Since no definitive treatments currently exist for patients with LGMD, these results provide important information on the role of exercise therapy and electrical stimulation for clinicians working in rehabilitation. PMID:26166595

Analyzing the tradeoff between electrical complexity and accuracy in patient-specific computational models of deep brain stimulation.

PubMed

Howell, Bryan; McIntyre, Cameron C

2016-06-01

Deep brain stimulation (DBS) is an adjunctive therapy that is effective in treating movement disorders and shows promise for treating psychiatric disorders. Computational models of DBS have begun to be utilized as tools to optimize the therapy. Despite advancements in the anatomical accuracy of these models, there is still uncertainty as to what level of electrical complexity is adequate for modeling the electric field in the brain and the subsequent neural response to the stimulation. We used magnetic resonance images to create an image-based computational model of subthalamic DBS. The complexity of the volume conductor model was increased by incrementally including heterogeneity, anisotropy, and dielectric dispersion in the electrical properties of the brain. We quantified changes in the load of the electrode, the electric potential distribution, and stimulation thresholds of descending corticofugal (DCF) axon models. Incorporation of heterogeneity altered the electric potentials and subsequent stimulation thresholds, but to a lesser degree than incorporation of anisotropy. Additionally, the results were sensitive to the choice of method for defining anisotropy, with stimulation thresholds of DCF axons changing by as much as 190%. Typical approaches for defining anisotropy underestimate the expected load of the stimulation electrode, which led to underestimation of the extent of stimulation. More accurate predictions of the electrode load were achieved with alternative approaches for defining anisotropy. The effects of dielectric dispersion were small compared to the effects of heterogeneity and anisotropy. The results of this study help delineate the level of detail that is required to accurately model electric fields generated by DBS electrodes.

Analyzing the tradeoff between electrical complexity and accuracy in patient-specific computational models of deep brain stimulation

NASA Astrophysics Data System (ADS)

Howell, Bryan; McIntyre, Cameron C.

2016-06-01

Objective. Deep brain stimulation (DBS) is an adjunctive therapy that is effective in treating movement disorders and shows promise for treating psychiatric disorders. Computational models of DBS have begun to be utilized as tools to optimize the therapy. Despite advancements in the anatomical accuracy of these models, there is still uncertainty as to what level of electrical complexity is adequate for modeling the electric field in the brain and the subsequent neural response to the stimulation. Approach. We used magnetic resonance images to create an image-based computational model of subthalamic DBS. The complexity of the volume conductor model was increased by incrementally including heterogeneity, anisotropy, and dielectric dispersion in the electrical properties of the brain. We quantified changes in the load of the electrode, the electric potential distribution, and stimulation thresholds of descending corticofugal (DCF) axon models. Main results. Incorporation of heterogeneity altered the electric potentials and subsequent stimulation thresholds, but to a lesser degree than incorporation of anisotropy. Additionally, the results were sensitive to the choice of method for defining anisotropy, with stimulation thresholds of DCF axons changing by as much as 190%. Typical approaches for defining anisotropy underestimate the expected load of the stimulation electrode, which led to underestimation of the extent of stimulation. More accurate predictions of the electrode load were achieved with alternative approaches for defining anisotropy. The effects of dielectric dispersion were small compared to the effects of heterogeneity and anisotropy. Significance. The results of this study help delineate the level of detail that is required to accurately model electric fields generated by DBS electrodes.

Effect of functional electrical stimulation on cardiovascular outcomes in patients with chronic heart failure.

PubMed

Kadoglou, Nikolaos Pe; Mandila, Christina; Karavidas, Apostolos; Farmakis, Dimitrios; Matzaraki, Vasiliki; Varounis, Christos; Arapi, Sofia; Perpinia, Anastasia; Parissis, John

2017-05-01

Background/design Functional electrical stimulation of lower limb muscles is an alternative method of training in patients with chronic heart failure (CHF). Although it improves exercise capacity in CHF, we performed a randomised, placebo-controlled study to investigate its effects on long-term clinical outcomes. Methods We randomly assigned 120 patients, aged 71 ± 8 years, with stable CHF (New York Heart Association (NYHA) class II/III (63%/37%), mean left ventricular ejection fraction 28 ± 5%), to either a 6-week functional electrical stimulation training programme or placebo. Patients were followed for up to 19 months for death and/or hospitalisation due to CHF decompensation. Results At baseline, there were no significant differences in demographic parameters, CHF severity and medications between groups. During a median follow-up of 383 days, 14 patients died (11 cardiac, three non-cardiac deaths), while 40 patients were hospitalised for CHF decompensation. Mortality did not differ between groups (log rank test P = 0.680), while the heart failure-related hospitalisation rate was significantly lower in the functional electrical stimulation group (hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.21-0.78, P = 0.007). The latter difference remained significant after adjustment for prognostic factors: age, gender, baseline NYHA class and left ventricular ejection fraction (HR 0.22, 95% CI 0.10-0.46, P < 0.001). Compared to placebo, functional electrical stimulation training was associated with a lower occurrence of the composite endpoint (death or heart failure-related hospitalisation) after adjustment for the above-mentioned prognostic factors (HR 0.21, 95% CI 0.103-0.435, P < 0.001). However, that effect was mostly driven by the favourable change in hospitalisation rates. Conclusions In CHF patients, 6 weeks functional electrical stimulation training reduced the risk of heart failure-related hospitalisations, without affecting the mortality rate. The beneficial long-term effects of this alternative method of training require further investigation.

Focused intracochlear electric stimulation with phased array channels.

PubMed

van den Honert, Chris; Kelsall, David C

2007-06-01

A method is described for producing focused intracochlear electric stimulation using an array of N electrodes. For each electrode site, N weights are computed that define the ratios of positive and negative electrode currents required to produce cancellation of the voltage within scala tympani at all of the N-1 other sites. Multiple sites can be stimulated simultaneously by superposition of their respective current vectors. The method allows N independent stimulus waveforms to be delivered to each of the N electrode sites without spatial overlap. Channel interaction from current spread associated with monopolar stimulation is substantially eliminated. The method operates by inverting the spread functions of individual monopoles as measured with the other electrodes. The method was implemented and validated with data from three human subjects implanted with 22-electrode perimodiolar arrays. Results indicate that (1) focusing is realizable with realistic precision; (2) focusing comes at the cost of increased total stimulation current; (3) uncanceled voltages that arise beyond the ends of the array are weak except when stimulating the two end channels; and (4) close perimodiolar positioning of the electrodes may be important for minimizing stimulation current and sensitivity to measurement errors.

Electrical stimulation in the treatment of pain.

PubMed

Rushton, David N

2002-05-20

To review the published literature concerning the treatment of painful conditions using devices that deliver electrical stimulation to nervous structures. The review briefly surveys the results obtained using surface electrodes ("TENS") as well as implanted devices. The method used is a critical review of the important published literature up to mid-1999. References were obtained using Medline and the keywords "pain", together with "electrical", "stimulation", "neurostimulation" or "TENS". Electrical stimulation has been found to be of potential benefit in the management of a range of painful conditions. Adequately controlled trials of electrical stimulation are often difficult to achieve. Implanted devices tend to be used in the more severe intractable pain conditions. It is likely that there is more than one mechanism of action. The mechanisms of action are however still often poorly understood, even though historically theoretical and experimental advances in the understanding of pain mechanisms prompted the development of clinical systems and the institution of clinical studies. TENS has proved to be remarkably safe, and provides significant analgesia in about half of patients experiencing moderate predictable pain. Implanted devices can be more effective, but they carry a risk of device failure, implant infection or surgical complication, and are reserved for the more severe intractable chronic pains. The main implanted devices used clinically are the spinal cord stimulator and the deep brain stimulator.

Gastric electrical stimulation with short pulses reduces vomiting but not dysrhythmias in dogs.

PubMed

Chen, Jiande D Z; Qian, Liwei; Ouyang, Hui; Yin, Jieyun

2003-02-01

The aim of this study was to investigate the acute effects of 3 different methods of electrical stimulation in the prevention of vasopressin-induced emetic response and gastric dysrhythmias. Seven female hound dogs chronically implanted with 4 pairs of electrodes on gastric serosa were used in a 5-session study. Saline and vasopressin were infused in sessions 1 and 2, respectively. In the other 3 sessions with vasopressin infusion, 3 different methods of electrical stimulation (short-pulse stimulation, long-pulse stimulation, and electroacupuncture) were applied. Gastric slow waves and vomiting and behaviors suggestive of nausea were recorded in each session. In a separate study, additional experiments were performed in 5 vagotomized dogs to investigate vagally mediated mechanisms. Vasopressin induced gastric dysrhythmias, uncoupling of slow waves, and vomiting and behaviors suggestive of nausea (P < 0.02, analysis of variance). Long-pulse stimulation, but not short-pulse stimulation or electroacupuncture, was capable of preventing vasopressin-induced gastric dysrhythmias and gastric slow wave uncoupling. Short-pulse stimulation and electroacupuncture, but not long-pulse stimulation, prevented vomiting and significantly reduced the symptom scores, which was not noted in the dogs with truncal vagotomy. Long-pulse stimulation normalizes vasopressin-induced slow wave abnormalities with no improvement in vomiting and behaviors suggestive of nausea. Short-pulse stimulation and electroacupuncture prevent vomiting and behaviors suggestive of nausea induced by vasopressin but have no effects on slow waves, and their effects are vagally mediated.

In vivo mapping of current density distribution in brain tissues during deep brain stimulation (DBS)

NASA Astrophysics Data System (ADS)

Sajib, Saurav Z. K.; Oh, Tong In; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

2017-01-01

New methods for in vivo mapping of brain responses during deep brain stimulation (DBS) are indispensable to secure clinical applications. Assessment of current density distribution, induced by internally injected currents, may provide an alternative method for understanding the therapeutic effects of electrical stimulation. The current flow and pathway are affected by internal conductivity, and can be imaged using magnetic resonance-based conductivity imaging methods. Magnetic resonance electrical impedance tomography (MREIT) is an imaging method that can enable highly resolved mapping of electromagnetic tissue properties such as current density and conductivity of living tissues. In the current study, we experimentally imaged current density distribution of in vivo canine brains by applying MREIT to electrical stimulation. The current density maps of three canine brains were calculated from the measured magnetic flux density data. The absolute current density values of brain tissues, including gray matter, white matter, and cerebrospinal fluid were compared to assess the active regions during DBS. The resulting current density in different tissue types may provide useful information about current pathways and volume activation for adjusting surgical planning and understanding the therapeutic effects of DBS.

In Vivo Demonstration of Addressable Microstimulators Powered by Rectification of Epidermically Applied Currents for Miniaturized Neuroprostheses

PubMed Central

2015-01-01

Electrical stimulation is used in order to restore nerve mediated functions in patients with neurological disorders, but its applicability is constrained by the invasiveness of the systems required to perform it. As an alternative to implantable systems consisting of central stimulation units wired to the stimulation electrodes, networks of wireless microstimulators have been devised for fine movement restoration. Miniaturization of these microstimulators is currently hampered by the available methods for powering them. Previously, we have proposed and demonstrated a heterodox electrical stimulation method based on electronic rectification of high frequency current bursts. These bursts can be delivered through textile electrodes on the skin. This approach has the potential to result in an unprecedented level of miniaturization as no bulky parts such as coils or batteries are included in the implant. We envision microstimulators designs based on application-specific integrated circuits (ASICs) that will be flexible, thread-like (diameters < 0.5 mm) and not only with controlled stimulation capabilities but also with sensing capabilities for artificial proprioception. We in vivo demonstrate that neuroprostheses composed of addressable microstimulators based on this electrical stimulation method are feasible and can perform controlled charge-balanced electrical stimulation of muscles. We developed miniature external circuit prototypes connected to two bipolar probes that were percutaneously implanted in agonist and antagonist muscles of the hindlimb of an anesthetized rabbit. The electronic implant architecture was able to decode commands that were amplitude modulated on the high frequency (1 MHz) auxiliary current bursts. The devices were capable of independently stimulating the target tissues, accomplishing controlled dorsiflexion and plantarflexion joint movements. In addition, we numerically show that the high frequency current bursts comply with safety standards both in terms of tissue heating and unwanted electro-stimulation. We demonstrate that addressable microstimulators powered by rectification of epidermically applied currents are feasible. PMID:26147771

In Vivo Demonstration of Addressable Microstimulators Powered by Rectification of Epidermically Applied Currents for Miniaturized Neuroprostheses.

PubMed

Becerra-Fajardo, Laura; Ivorra, Antoni

2015-01-01

Electrical stimulation is used in order to restore nerve mediated functions in patients with neurological disorders, but its applicability is constrained by the invasiveness of the systems required to perform it. As an alternative to implantable systems consisting of central stimulation units wired to the stimulation electrodes, networks of wireless microstimulators have been devised for fine movement restoration. Miniaturization of these microstimulators is currently hampered by the available methods for powering them. Previously, we have proposed and demonstrated a heterodox electrical stimulation method based on electronic rectification of high frequency current bursts. These bursts can be delivered through textile electrodes on the skin. This approach has the potential to result in an unprecedented level of miniaturization as no bulky parts such as coils or batteries are included in the implant. We envision microstimulators designs based on application-specific integrated circuits (ASICs) that will be flexible, thread-like (diameters < 0.5 mm) and not only with controlled stimulation capabilities but also with sensing capabilities for artificial proprioception. We in vivo demonstrate that neuroprostheses composed of addressable microstimulators based on this electrical stimulation method are feasible and can perform controlled charge-balanced electrical stimulation of muscles. We developed miniature external circuit prototypes connected to two bipolar probes that were percutaneously implanted in agonist and antagonist muscles of the hindlimb of an anesthetized rabbit. The electronic implant architecture was able to decode commands that were amplitude modulated on the high frequency (1 MHz) auxiliary current bursts. The devices were capable of independently stimulating the target tissues, accomplishing controlled dorsiflexion and plantarflexion joint movements. In addition, we numerically show that the high frequency current bursts comply with safety standards both in terms of tissue heating and unwanted electro-stimulation. We demonstrate that addressable microstimulators powered by rectification of epidermically applied currents are feasible.

Investigation of shape, position, and permeability of shielding material in quadruple butterfly coil for focused transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Rastogi, Priyam; Zhang, Bowen; Tang, Yalun; Lee, Erik G.; Hadimani, Ravi L.; Jiles, David C.

2018-05-01

Transcranial magnetic stimulation has been gaining popularity in the therapy for several neurological disorders. A time-varying magnetic field is used to generate electric field in the brain. As the development of TMS methods takes place, emphasis on the coil design increases in order to improve focal stimulation. Ideally reduction of stimulation of neighboring regions of the target area is desired. This study, focused on the improvement of the focality of the Quadruple Butterfly Coil (QBC) with supplemental use of different passive shields. Parameters such as shape, position and permeability of the shields have been explored to improve the focus of stimulation. Results have been obtained with the help of computer modelling of a MRI derived heterogeneous head model over the vertex position and the dorsolateral prefrontal cortex position using a finite element tool. Variables such as maximum electric field induced on the grey matter and scalp, volume and area of stimulation above half of the maximum value of electric field on the grey matter, and ratio of the maximum electric field in the brain versus the scalp have been investigated.

Validation of finite element model of transcranial electrical stimulation using scalp potentials: implications for clinical dose

NASA Astrophysics Data System (ADS)

Datta, Abhishek; Zhou, Xiang; Su, Yuzhou; Parra, Lucas C.; Bikson, Marom

2013-06-01

Objective. During transcranial electrical stimulation, current passage across the scalp generates voltage across the scalp surface. The goal was to characterize these scalp voltages for the purpose of validating subject-specific finite element method (FEM) models of current flow. Approach. Using a recording electrode array, we mapped skin voltages resulting from low-intensity transcranial electrical stimulation. These voltage recordings were used to compare the predictions obtained from the high-resolution model based on the subject undergoing transcranial stimulation. Main results. Each of the four stimulation electrode configurations tested resulted in a distinct distribution of scalp voltages; these spatial maps were linear with applied current amplitude (0.1 to 1 mA) over low frequencies (1 to 10 Hz). The FEM model accurately predicted the distinct voltage distributions and correlated the induced scalp voltages with current flow through cortex. Significance. Our results provide the first direct model validation for these subject-specific modeling approaches. In addition, the monitoring of scalp voltages may be used to verify electrode placement to increase transcranial electrical stimulation safety and reproducibility.

Functional Magnetic Resonance Imaging Networks Induced by Intracranial Stimulation May Help Defining the Epileptogenic Zone

PubMed Central

Zhang, Myron; Avitsian, Rafi; Bhattacharyya, Pallab; Bulacio, Juan; Cendes, Fernando; Enatsu, Rei; Lowe, Mark; Najm, Imad; Nair, Dileep; Phillips, Michael; Gonzalez-Martinez, Jorge

2014-01-01

Abstract Patients with medically intractable epilepsy often undergo invasive evaluation and surgery, with a 50% success rate. The low success rate is likely due to poor identification of the epileptogenic zone (EZ), the brain area causing seizures. This work introduces a new method using functional magnetic resonance imaging (fMRI) with simultaneous direct electrical stimulation of the brain that could help localize the EZ, performed in five patients with medically intractable epilepsy undergoing invasive evaluation with intracranial depth electrodes. Stimulation occurred in a location near the hypothesized EZ and a location away. Electrical recordings in response to stimulation were recorded and compared to fMRI. Multiple stimulation parameters were varied, like current and frequency. The brain areas showing fMRI response were compared with the areas resected and the success of surgery. Robust fMRI maps of activation networks were easily produced, which also showed a significant but weak positive correlation between quantitative measures of blood-oxygen-level-dependent (BOLD) activity and measures of electrical activity in response to direct electrical stimulation (mean correlation coefficient of 0.38 for all acquisitions that produced a strong BOLD response). For four patients with outcome data at 6 months, successful surgical outcome is consistent with the resection of brain areas containing high local fMRI activity. In conclusion, this method demonstrates the feasibility of simultaneous direct electrical stimulation and fMRI in humans, which allows the study of brain connectivity with high resolution and full spatial coverage. This innovative technique could be used to better define the localization and extension of the EZ in intractable epilepsies, as well as for other functional neurosurgical procedures. PMID:24735069

Differential contribution of electrically evoked dorsal root reflexes to peripheral vasodilatation and plasma extravasation

PubMed Central

2011-01-01

Background Dorsal root reflexes (DRRs) are antidromic activities traveling along the primary afferent fibers, which can be generated by peripheral stimulation or central stimulation. DRRs are thought to be involved in the generation of neurogenic inflammation, as indicated by plasma extravasation and vasodilatation. The hypothesis of this study was that electrical stimulation of the central stump of a cut dorsal root would lead to generation of DRRs, resulting in plasma extravasation and vasodilatation. Methods Sprague-Dawley rats were prepared to expose spinal cord and L4-L6 dorsal roots under pentobarbital general anesthesia. Electrical stimulation of either intact, proximal or distal, cut dorsal roots was applied while plasma extravasation or blood perfusion of the hindpaw was recorded. Results While stimulation of the peripheral stump of a dorsal root elicited plasma extravasation, electrical stimulation of the central stump of a cut dorsal root generated significant DRRs, but failed to induce plasma extravasation. However, stimulation of the central stump induced a significant increase in blood perfusion. Conclusions It is suggested that DRRs are involved in vasodilatation but not plasma extravasation in neurogenic inflammation in normal animals. PMID:21356101

The application of direct current electrical stimulation of the ear and cervical spine kinesitherapy in tinnitus treatment.

PubMed

Mielczarek, Marzena; Konopka, Wieslaw; Olszewski, Jurek

2013-02-01

The aim of the study was to evaluate the effectiveness of electrical stimulations of the hearing organ in tinnitus treatment adapting the frequency of stimulation according to tinnitus frequency, to assess the influence of cervical spine kinesitherapy on tinnitus, as well as to evaluate hearing after electrical stimulations alone and together with cervical spine kinesitherapy. The study comprised 80 tinnitus, sensorineural hearing loss patients (119 tinnitus ears) divided into two groups. In group I (n - 58 tinnitus ears) electrical stimulation of the hearing organ was performed, in group II (n - 61 tinnitus ears) electrical stimulation together with cervical spine kinesitherapy. Hydrotransmissive, selective electrical stimulations were conducted using direct, rectangular current. The passive electrode was placed on the forehead, the active--a silver probe--was immersed in the external ear canal in 0.9% saline solution. The treatment involved fifteen applications of electrical stimulations (each lasted for 4 min) administered three or four times a week (whole treatment lasted approximately 30 days). The evaluation of the results considered a case history (change from permanent to temporary tinnitus), questionnaires (the increase/decrease of the total points) and the audiometric evaluation of hearing level. Before the treatment, group I comprised 51 ears (87.93%) with permanent, and 7 ears (12.07%) with temporary tinnitus; group II - 55 ears (90.17%) with permanent and 6 ears (9.83%) with temporary tinnitus. After the treatment, in both groups the number of ears with permanent tinnitus decreased considerably obtaining the pauses or disappearing of tinnitus. Directly after the treatment, group I comprised 25 ears (43.11%) with permanent, and 10 ears (17.24%) with temporary tinnitus, in 23 ears (39.65%) tinnitus disappeared; group II - 33 ears (54.1%) with permanent and 11 ears (18.03%) with temporary tinnitus, in 17 ears (27.87%) tinnitus disappeared. Regarding questionnaires, improvement was observed in group I - in 43.11% of ears, in group II - 32.8%. In both groups audiometric improvement of hearing was recognized. (1) Electrical stimulation of the hearing organ, with the application of current frequencies according to tinnitus frequencies (selective electrical stimulation), was an efficient method in severe tinnitus treatment. (2) Cervical spine kinesitherapy in the treatment of tinnitus, using electrical stimulation, did not have any supporting influence. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Magnetic lumbosacral motor root stimulation with a flat, large round coil.

PubMed

Matsumoto, Hideyuki; Octaviana, Fitri; Hanajima, Ritsuko; Terao, Yasuo; Yugeta, Akihiro; Hamada, Masashi; Inomata-Terada, Satomi; Nakatani-Enomoto, Setsu; Tsuji, Shoji; Ugawa, Yoshikazu

2009-04-01

The aim of this paper is to develop a reliable method for supramaximal magnetic spinal motor root stimulation (MRS) for lower limb muscles using a specially devised coil. For this study, 42 healthy subjects were recruited. A 20-cm diameter coil designated as a Magnetic Augmented Translumbosacral Stimulation (MATS) coil was used. Compound muscle action potentials (CMAPs) were recorded from the abductor hallucis muscle. Their CMAPs were compared with those obtained by MRS using a conventional round or double coil and with those obtained using high-voltage electrical stimulation. The MATS coil evoked CMAPs to supramaximal stimulation in 80 of 84 muscles, although round and double coils elicited supramaximal CMAPs in only 15 and 18 of 84 muscles, respectively. The CMAP size to the MATS coil stimulation was the same as that to high-voltage electrical motor root stimulation. MATS coil achieved supramaximal stimulation of the lumbosacral spinal nerves. The CMAPs to supramaximal stimulation are necessary for measurement of the amplitude and area for the detection of conduction blocks. The MATS coil stimulation of lumbosacral motor roots is a reliable method for measuring the CMAP size from lower limb muscles in spinal motor root stimulation.

Strength, Pain, Function in OIF/OEF Amputees: A Nurse-Managed Program

DTIC Science & Technology

2014-03-25

resistance training and neuromuscular electrical stimulation in knee osteoarthritis : a randomized controlled trial. BMC Musculoskeletal Disorders, 13, 118... systematic review of the effects of different electromyostimulation methods on selected strength parameters in trained and elite athletes. Journal of...electrical stimulation on rehabilitation after ligament and meniscal injuries: a systematic review . Sao Paulo Medical Journal, 129(6), 414-423

A high-resolution computational localization method for transcranial magnetic stimulation mapping.

PubMed

Aonuma, Shinta; Gomez-Tames, Jose; Laakso, Ilkka; Hirata, Akimasa; Takakura, Tomokazu; Tamura, Manabu; Muragaki, Yoshihiro

2018-05-15

Transcranial magnetic stimulation (TMS) is used for the mapping of brain motor functions. The complexity of the brain deters determining the exact localization of the stimulation site using simplified methods (e.g., the region below the center of the TMS coil) or conventional computational approaches. This study aimed to present a high-precision localization method for a specific motor area by synthesizing computed non-uniform current distributions in the brain for multiple sessions of TMS. Peritumoral mapping by TMS was conducted on patients who had intra-axial brain neoplasms located within or close to the motor speech area. The electric field induced by TMS was computed using realistic head models constructed from magnetic resonance images of patients. A post-processing method was implemented to determine a TMS hotspot by combining the computed electric fields for the coil orientations and positions that delivered high motor-evoked potentials during peritumoral mapping. The method was compared to the stimulation site localized via intraoperative direct brain stimulation and navigated TMS. Four main results were obtained: 1) the dependence of the computed hotspot area on the number of peritumoral measurements was evaluated; 2) the estimated localization of the hand motor area in eight non-affected hemispheres was in good agreement with the position of a so-called "hand-knob"; 3) the estimated hotspot areas were not sensitive to variations in tissue conductivity; and 4) the hand motor areas estimated by this proposal and direct electric stimulation (DES) were in good agreement in the ipsilateral hemisphere of four glioma patients. The TMS localization method was validated by well-known positions of the "hand-knob" in brains for the non-affected hemisphere, and by a hotspot localized via DES during awake craniotomy for the tumor-containing hemisphere. Copyright © 2018 Elsevier Inc. All rights reserved.

MO-F-CAMPUS-I-01: EIT Imaging to Monitor Human Salivary Gland Functionality: A Feasibility Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohli, K; Karvat, A; Liu, J

Purpose: Clinically, there exists a need to develop a non-invasive technique for monitoring salivary activity. In this study, we investigate the feasibility of a using the electrical conductivity information from Electrical Impedance Tomography (EIT) to monitor salivary flow activity. Methods: To acquire EIT data, eight Ag/AgCl ECG electrodes were placed around the mandible of the subject. An EIT scan was obtained by injecting current at 50 KHz, 0.4 mA through each pair of electrodes and recording voltage across other electrode pairs. The functional conductivity image was obtained through reconstruction of the voltage data, using Electrical Impedance Tomography and Diffuse Opticalmore » Tomography Reconstruction Software (EIDORS) in Matlab. In using EIDORS, forward solution was obtained using a user-defined finite element model shape and inverse solution was obtained using one-step Gaussian solver. EIT scans of volunteer research team members were acquired for three different physiological states: pre-stimulation, stimulation and post-stimulation. For pre-stimulation phase, data were collected in intervals of 5 minutes for 15 minutes. The salivary glands were then stimulated in the subject using lemon and the data were collected immediately. Post-stimulation data were collected at 4 different timings after stimulation. Results: Variations were observed in the electrical conductivity patterns near parotid regions between the pre- and post-stimulation stages. The three images acquired during the 15 minute pre-stimulation phase showed no major changes in the conductivity. Immediately after stimulation, electrical conductivity increased near parotid regions and 15 minutes later slowly returned to pre-stimulation level. Conclusion: In the present study involving human subjects, the change in electrical conductivity pattern shown in the EIT images, acquired at different times with and without stimulation of salivary glands, appeared to be consistent with the change in salivary gland activity. The conductivity changes imaged through EIT are potentially useful for the purpose of salivary monitoring.« less

Effect of Dorsal and Ventral Hippocampal Lesions on Contextual Fear Conditioning and Unconditioned Defensive Behavior Induced by Electrical Stimulation of the Dorsal Periaqueductal Gray

PubMed Central

Ballesteros, Carolina Irurita; de Oliveira Galvão, Bruno; Maisonette, Silvia; Landeira-Fernandez, J.

2014-01-01

The dorsal (DH) and ventral (VH) subregions of the hippocampus are involved in contextual fear conditioning. However, it is still unknown whether these two brain areas also play a role in defensive behavior induced by electrical stimulation of the dorsal periaqueductal gray (dPAG). In the present study, rats were implanted with electrodes into the dPAG to determine freezing and escape response thresholds after sham or bilateral electrolytic lesions of the DH or VH. The duration of freezing behavior that outlasted electrical stimulation of the dPAG was also measured. The next day, these animals were subjected to contextual fear conditioning using footshock as an unconditioned stimulus. Electrolytic lesions of the DH and VH impaired contextual fear conditioning. Only VH lesions disrupted conditioned freezing immediately after footshock and increased the thresholds of aversive freezing and escape responses to dPAG electrical stimulation. Neither DH nor VH lesions disrupted post-dPAG stimulation freezing. These results indicate that the VH but not DH plays an important role in aversively defensive behavior induced by dPAG electrical stimulation. Interpretations of these findings should be made with caution because of the fact that a non-fiber-sparing lesion method was employed. PMID:24404134

Influence of different frequencies of transcutaneous electrical nerve stimulation on the threshold and pain intensity in young subjects

PubMed Central

Gomes, Adriana de Oliveira; Silvestre, Ana Caroline; da Silva, Cristina Ferreira; Gomes, Mariany Ribeiro; Bonfleur, Maria Lúcia; Bertolini, Gladson Ricardo Flor

2014-01-01

Objective To investigate the effects of different transcutaneous electrical nerve stimulation frequencies in nociception front of a pressure pain threshold and cold in healthy individuals. Methods Twenty healthy subjects were divided into four groups, all of which have gone through all forms of electrical stimulation at different weeks. Assessments were pre and post-therapy, 20 and 60 minutes after stimulation. To evaluate the pressure pain threshold, an algometer was used with one tapered tip, pressing the hypothenar region until voluntary report the word “pain”. Cold pain intensity was assessed by immersion in water at 5°C for 30 seconds; at the end, the subject was asked to quantify the pain intensity on a Visual Analog Scale for Pain. For electrical stimulation, two electrodes were used near the elbow, for 20 minutes, with an intensity strong, but not painful. The frequency was in accordance with the group: 0Hz (placebo); 7Hz; 100Hz; and 255Hz. Results Both for the assessment of pressure pain threshold as the cold pain intensity, there was no significant difference (p>0.05). Conclusion We conclude that the use of transcutaneous electrical nerve stimulation on dermatomes C6 to C8 produced no significant change in pressure pain threshold or cold discomfort. PMID:25295453

Physiological processes non-linearly affect electrophysiological recordings during transcranial electric stimulation.

PubMed

Noury, Nima; Hipp, Joerg F; Siegel, Markus

2016-10-15

Transcranial electric stimulation (tES) is a promising tool to non-invasively manipulate neuronal activity in the human brain. Several studies have shown behavioral effects of tES, but stimulation artifacts complicate the simultaneous investigation of neural activity with EEG or MEG. Here, we first show for EEG and MEG, that contrary to previous assumptions, artifacts do not simply reflect stimulation currents, but that heartbeat and respiration non-linearly modulate stimulation artifacts. These modulations occur irrespective of the stimulation frequency, i.e. during both transcranial alternating and direct current stimulations (tACS and tDCS). Second, we show that, although at first sight previously employed artifact rejection methods may seem to remove artifacts, data are still contaminated by non-linear stimulation artifacts. Because of their complex nature and dependence on the subjects' physiological state, these artifacts are prone to be mistaken as neural entrainment. In sum, our results uncover non-linear tES artifacts, show that current techniques fail to fully remove them, and pave the way for new artifact rejection methods. Copyright © 2016 Elsevier Inc. All rights reserved.

Transcranial electric stimulation for the investigation of speech perception and comprehension

PubMed Central

Zoefel, Benedikt; Davis, Matthew H.

2017-01-01

ABSTRACT Transcranial electric stimulation (tES), comprising transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), involves applying weak electrical current to the scalp, which can be used to modulate membrane potentials and thereby modify neural activity. Critically, behavioural or perceptual consequences of this modulation provide evidence for a causal role of neural activity in the stimulated brain region for the observed outcome. We present tES as a tool for the investigation of which neural responses are necessary for successful speech perception and comprehension. We summarise existing studies, along with challenges that need to be overcome, potential solutions, and future directions. We conclude that, although standardised stimulation parameters still need to be established, tES is a promising tool for revealing the neural basis of speech processing. Future research can use this method to explore the causal role of brain regions and neural processes for the perception and comprehension of speech. PMID:28670598

Innovative neurophysiological methods in itch research: long-latency evoked potentials after electrical and thermal stimulation in patients with atopic dermatitis.

PubMed

Yudina, Marina M; Toropina, Galina G; Lvov, Andrey; Gieler, Uwe

2011-10-01

The aim of this study was to examine the findings of innovative neurophysiological methods of itch research. Short-latency and pain-related somatosensory-evoked potentials after electrical stimulation, as well as long-latency evoked potentials after thermal stimulation were studied in 38 patients with atopic dermatitis (AD) and 26 healthy volunteers. Quantitative Sensory Testing of thermal perception was performed in 22 patients with AD from the main AD group and in 15 healthy volunteers. Brain hyperactivity to electrical stimuli, delayed thermal-evoked potentials and elevated thermal thresholds were revealed in patients with AD compared with healthy controls. The data indicate small nerve fibre dysfunction in patients with AD, which may contribute to the pathogenesis of AD and chronic itch. The study demonstrates objective approaches to assess the function of small nerve fibres in patients with chronic itch.

Evaluation method for in situ electric field in standardized human brain for different transcranial magnetic stimulation coils

NASA Astrophysics Data System (ADS)

Iwahashi, Masahiro; Gomez-Tames, Jose; Laakso, Ilkka; Hirata, Akimasa

2017-03-01

This study proposes a method to evaluate the electric field induced in the brain by transcranial magnetic stimulation (TMS) to realize focal stimulation in the target area considering the inter-subject difference of the brain anatomy. The TMS is a non-invasive technique used for treatment/diagnosis, and it works by inducing an electric field in a specific area of the brain via a coil-induced magnetic field. Recent studies that report on the electric field distribution in the brain induced by TMS coils have been limited to simplified human brain models or a small number of detailed human brain models. Until now, no method has been developed that appropriately evaluates the coil performance for a group of subjects. In this study, we first compare the magnetic field and the magnetic vector potential distributions to determine if they can be used as predictors of the TMS focality derived from the electric field distribution. Next, the hotspots of the electric field on the brain surface of ten subjects using six coils are compared. Further, decisive physical factors affecting the focality of the induced electric field by different coils are discussed by registering the computed electric field in a standard brain space for the first time, so as to evaluate coil characteristics for a large population of subjects. The computational results suggest that the induced electric field in the target area cannot be generalized without considering the morphological variability of the human brain. Moreover, there was no remarkable difference between the various coils, although focality could be improved to a certain extent by modifying the coil design (e.g., coil radius). Finally, the focality estimated by the electric field was more correlated with the magnetic vector potential than the magnetic field in a homogeneous sphere.

Evaluation method for in situ electric field in standardized human brain for different transcranial magnetic stimulation coils.

PubMed

Iwahashi, Masahiro; Gomez-Tames, Jose; Laakso, Ilkka; Hirata, Akimasa

2017-03-21

This study proposes a method to evaluate the electric field induced in the brain by transcranial magnetic stimulation (TMS) to realize focal stimulation in the target area considering the inter-subject difference of the brain anatomy. The TMS is a non-invasive technique used for treatment/diagnosis, and it works by inducing an electric field in a specific area of the brain via a coil-induced magnetic field. Recent studies that report on the electric field distribution in the brain induced by TMS coils have been limited to simplified human brain models or a small number of detailed human brain models. Until now, no method has been developed that appropriately evaluates the coil performance for a group of subjects. In this study, we first compare the magnetic field and the magnetic vector potential distributions to determine if they can be used as predictors of the TMS focality derived from the electric field distribution. Next, the hotspots of the electric field on the brain surface of ten subjects using six coils are compared. Further, decisive physical factors affecting the focality of the induced electric field by different coils are discussed by registering the computed electric field in a standard brain space for the first time, so as to evaluate coil characteristics for a large population of subjects. The computational results suggest that the induced electric field in the target area cannot be generalized without considering the morphological variability of the human brain. Moreover, there was no remarkable difference between the various coils, although focality could be improved to a certain extent by modifying the coil design (e.g., coil radius). Finally, the focality estimated by the electric field was more correlated with the magnetic vector potential than the magnetic field in a homogeneous sphere.

The impact of neuromuscular electrical stimulation on recovery after intensive, muscle damaging, maximal speed training in professional team sports players.

PubMed

Taylor, Tom; West, Daniel J; Howatson, Glyn; Jones, Chris; Bracken, Richard M; Love, Thomas D; Cook, Christian J; Swift, Eamon; Baker, Julien S; Kilduff, Liam P

2015-05-01

During congested fixture periods in team sports, limited recovery time and increased travel hinder the implementation of many recovery strategies; thus alternative methods are required. We examined the impact of a neuromuscular electrical stimulation device on 24-h recovery from an intensive training session in professional players. Twenty-eight professional rugby and football academy players completed this randomised and counter-balanced study, on 2 occasions, separated by 7 days. After baseline perceived soreness, blood (lactate and creatine kinase) and saliva (testosterone and cortisol) samples were collected, players completed a standardised warm-up and baseline countermovement jumps (jump height). Players then completed 60 m × 50 m maximal sprints, with 5 min recovery between efforts. After completing the sprint session, players wore a neuromuscular electrical stimulation device or remained in normal attire (CON) for 8 h. All measures were repeated immediately, 2 and 24-h post-sprint. Player jump height was reduced from baseline at all time points under both conditions; however, at 24-h neuromuscular electrical stimulation was significantly more recovered (mean±SD; neuromuscular electrical stimulation -3.2±3.2 vs. CON -7.2±3.7%; P<0.001). Creatine kinase concentrations increased at all time points under both conditions, but at 24-h was lower under neuromuscular electrical stimulation (P<0.001). At 24-h, perceived soreness was significantly lower under neuromuscular electrical stimulation, when compared to CON (P=0.02). There was no effect of condition on blood lactate, or saliva testosterone and cortisol responses (P>0.05). Neuromuscular electrical stimulation improves recovery from intensive training in professional team sports players. This strategy offers an easily applied recovery strategy which may have particular application during sleep and travel. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Emerging modalities in dysphagia rehabilitation: neuromuscular electrical stimulation.

PubMed

Huckabee, Maggie-Lee; Doeltgen, Sebastian

2007-10-12

The aim of this review article is to advise the New Zealand medical community about the application of neuromuscular electrical stimulation (NMES) as a treatment for pharyngeal swallowing impairment (dysphagia). NMES in this field of rehabilitation medicine has quickly emerged as a widely used method overseas but has been accompanied by significant controversy. Basic information is provided about the physiologic background of electrical stimulation. The literature reviewed in this manuscript was derived through a computer-assisted search using the biomedical database Medline to identify all relevant articles published until from the initiation of the databases up to January 2007. The reviewers used the following search strategy: [(deglutition disorders OR dysphagia) AND (neuromuscular electrical stimulation OR NMES)]. In addition, the technique of reference tracing was used and very recently published studies known to the authors but not yet included in the database systems were included. This review elucidates not only the substantive potential benefit of this treatment, but also potential key concerns for patient safety and long term outcome. The discussion within the clinical and research communities, especially around the commercially available VitalStim stimulator, is objectively explained.

Characteristics of bowl-shaped coils for transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Yamamoto, Keita; Suyama, Momoko; Takiyama, Yoshihiro; Kim, Dongmin; Saitoh, Youichi; Sekino, Masaki

2015-05-01

Transcranial magnetic stimulation (TMS) has recently been used as a method for the treatment of neurological and psychiatric diseases. Daily TMS sessions can provide continuous therapeutic effectiveness, and the installation of TMS systems at patients' homes has been proposed. A figure-eight coil, which is normally used for TMS therapy, induces a highly localized electric field; however, it is challenging to achieve accurate coil positioning above the targeted brain area using this coil. In this paper, a bowl-shaped coil for stimulating a localized but wider area of the brain is proposed. The coil's electromagnetic characteristics were analyzed using finite element methods, and the analysis showed that the bowl-shaped coil induced electric fields in a wider area of the brain model than a figure-eight coil. The expanded distribution of the electric field led to greater robustness of the coil to the coil-positioning error. To improve the efficiency of the coil, the relationship between individual coil design parameters and the resulting coil characteristics was numerically analyzed. It was concluded that lengthening the outer spherical radius and narrowing the width of the coil were effective methods for obtaining a more effective and more uniform distribution of the electric field.

Behavioral responses of deafened guinea pigs to intracochlear electrical stimulation: a new rapid psychophysical procedure.

PubMed

Agterberg, Martijn J H; Versnel, Huib

2014-07-01

In auditory research the guinea pig is often preferred above rats and mice because of the easily accessible cochlea and because the frequency range of its hearing is more comparable to that of humans. Studies of the guinea-pig auditory system primarily apply histological and electrophysiological measures. Behavioral animal paradigms, in particular in combination with these histological and electrophysiological methods, are necessary in the development of new therapeutic interventions. However, the guinea pig is not considered an attractive animal for behavioral experiments. Therefore, the purpose of this study was to develop a behavioral task suitable for guinea pigs, that can be utilized in cochlear-implant related research. Guinea pigs were trained in a modified shuttle-box in which a stream of air was used as unconditioned stimulus (UCS). A stream of air was preferred over conventionally used methods as electric foot-shocks since it produces less stress, which is a confounding factor in behavioral experiments. Hearing guinea pigs were trained to respond to acoustic stimuli. They responded correctly within only five sessions of ten minutes. The animals maintained their performance four weeks after the right cochlea was implanted with an electrode array. After systemic deafening, the animals responded in the first session immediately to intracochlear electrical stimulation. These responses were not affected by daily chronic electrical stimulation (CES). In conclusion, the present study demonstrates that guinea pigs can be trained relatively fast to respond to acoustic stimuli, and that the training has a lasting effect, which generalizes to intracochlear electrical stimulation after deafening. Furthermore, it demonstrates that bilaterally deafened guinea pigs with substantial (∼50%) loss of spiral ganglion cells (SGCs), detect intracochlear electrical stimulation. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of temperature on basal tension and thyroarytenoid muscle contraction in an isolated rat glottis model.

PubMed

Wang, Hsing-Won; Chu, Yueng-Hsiang; Chao, Pin-Zhir; Lee, Fei-Peng

2014-10-01

The pitch of voice is closely related to the vocal fold tension, which is the end result of coordinated movement of the intralaryngeal muscles, and especially the thyroarytenoid muscle. It is known that vocal quality may be affected by surrounding temperature; however, the effect of temperature on vocal fold tension is mostly unknown. Thus, the aim of this study was to evaluate the effect of temperature on isolated rat glottis and thyroarytenoid muscle contraction induced by electrical field stimulation. In vitro isometric tension of the glottis ring from 30 Sprague-Dawley rats was continuously recorded by the tissue bath method. Electrical field stimulation was applied to the glottis ring with two wire electrodes placed parallel to the glottis and connected to a direct-current stimulator. The tension changes of the rat glottis rings that were either untreated or treated with electrical field stimulation were recorded continuously at temperatures from 37 to 7 °C or from 7 to 37 °C. Warming from 7 to 37 °C increased the basal tension of the glottis rings and decreased the electrical field stimulation-induced glottis ring contraction, which was chiefly due to thyroarytenoid muscle contraction. In comparison, cooling from 37 to 7 °C decreased the basal tension and enhanced glottis ring contraction by electrical field stimulation. We concluded that warming increased the basal tension of the glottis in vitro and decreased the amplitude of electrical field stimulation-induced thyroarytenoid muscle contraction. Thus, vocal pitch and the fine tuning of vocal fold tension might be affected by temperature in vivo.

Spatially restricted electrical activation of retinal ganglion cells in the rabbit retina by hexapolar electrode return configuration

NASA Astrophysics Data System (ADS)

Habib, Amgad G.; Cameron, Morven A.; Suaning, Gregg J.; Lovell, Nigel H.; Morley, John W.

2013-06-01

Objective. Visual prostheses currently in development aim to restore some form of vision to patients suffering from diseases such as age-related macular degeneration and retinitis pigmentosa. Most rely on electrically stimulating inner retinal cells via electrodes implanted on or near the retina, resulting in percepts of light termed ‘phosphenes’. Activation of spatially distinct populations of cells in the retina is key for pattern vision to be produced. To achieve this, the electrical stimulation must be localized, activating cells only in the direct vicinity of the stimulating electrode(s). With this goal in mind, a hexagonal return (hexapolar) configuration has been proposed as an alternative to the traditional monopolar or bipolar return configurations for electrically stimulating the retina. This study investigated the efficacy of the hexapolar configuration in localizing the activation of retinal ganglion cells (RGCs), compared to a monopolar configuration. Approach. Patch-clamp electrophysiology was used to measure the activation thresholds of RGCs in whole-mount rabbit retina to monopolar and hexapolar electrical stimulation, applied subretinally. Main results. Hexapolar activation thresholds for RGCs located outside the hex guard were found to be significantly (>2 fold) higher than those located inside the area of tissue bounded by the hex guard. The hexapolar configuration localized the activation of RGCs more effectively than its monopolar counterpart. Furthermore, no difference in hexapolar thresholds or localization was observed when using cathodic-first versus anodic-first stimulation. Significance. The hexapolar configuration may provide an improved method for electrically stimulating spatially distinct populations of cells in retinal tissue.

Pulsatile desynchronizing delayed feedback for closed-loop deep brain stimulation

PubMed Central

Lysyansky, Borys; Rosenblum, Michael; Pikovsky, Arkady; Tass, Peter A.

2017-01-01

High-frequency (HF) deep brain stimulation (DBS) is the gold standard for the treatment of medically refractory movement disorders like Parkinson’s disease, essential tremor, and dystonia, with a significant potential for application to other neurological diseases. The standard setup of HF DBS utilizes an open-loop stimulation protocol, where a permanent HF electrical pulse train is administered to the brain target areas irrespectively of the ongoing neuronal dynamics. Recent experimental and clinical studies demonstrate that a closed-loop, adaptive DBS might be superior to the open-loop setup. We here combine the notion of the adaptive high-frequency stimulation approach, that aims at delivering stimulation adapted to the extent of appropriately detected biomarkers, with specifically desynchronizing stimulation protocols. To this end, we extend the delayed feedback stimulation methods, which are intrinsically closed-loop techniques and specifically designed to desynchronize abnormal neuronal synchronization, to pulsatile electrical brain stimulation. We show that permanent pulsatile high-frequency stimulation subjected to an amplitude modulation by linear or nonlinear delayed feedback methods can effectively and robustly desynchronize a STN-GPe network of model neurons and suggest this approach for desynchronizing closed-loop DBS. PMID:28273176

High-Frequency Transcutaneous Peripheral Nerve Stimulation Induces a Higher Increase of Heat Pain Threshold in the Cutaneous Area of the Stimulated Nerve When Confronted to the Neighbouring Areas

PubMed Central

Buonocore, M.; Camuzzini, N.; Cecini, M.; Dalla Toffola, E.

2013-01-01

Background. TENS (transcutaneous electrical nerve stimulation) is probably the most diffused physical therapy used for antalgic purposes. Although it continues to be used by trial and error, correct targeting of paresthesias evoked by the electrical stimulation on the painful area is diffusely considered very important for pain relief. Aim. To investigate if TENS antalgic effect is higher in the cutaneous area of the stimulated nerve when confronted to neighbouring areas. Methods. 10 volunteers (4 males, 6 females) underwent three different sessions: in two, heat pain thresholds (HPTs) were measured on the dorsal hand skin before, during and after electrical stimulation (100 Hz, 0.1 msec) of superficial radial nerve; in the third session HPTs, were measured without any stimulation. Results. Radial nerve stimulation induced an increase of HPT significantly higher in its cutaneous territory when confronted to the neighbouring ulnar nerve territory, and antalgic effect persisted beyond the stimulation time. Conclusions. The location of TENS electrodes is crucial for obtaining the strongest pain relief, and peripheral nerve trunk stimulation is advised whenever possible. Moreover, the present study indicates that continuous stimulation could be unnecessary, suggesting a strategy for avoiding the well-known tolerance-like effect of prolonged TENS application. PMID:24027756

The Effect of Transcutaneous Electrical Nerve Stimulation of Sympathetic Ganglions and Acupuncture Points on Distal Blood Flow.

PubMed

Kamali, Fahimeh; Mirkhani, Hossein; Nematollahi, Ahmadreza; Heidari, Saeed; Moosavi, Elahesadat; Mohamadi, Marzieh

2017-04-01

Transcutaneous electrical nerve stimulation (TENS) is a widely-practiced method to increase blood flow in clinical practice. The best location for stimulation to achieve optimal blood flow has not yet been determined. We compared the effect of TENS application at sympathetic ganglions and acupuncture points on blood flow in the foot of healthy individuals. Seventy-five healthy individuals were randomly assigned to three groups. The first group received cutaneous electrical stimulation at the thoracolumbar sympathetic ganglions. The second group received stimulation at acupuncture points. The third group received stimulation in the mid-calf area as a control group. Blood flow was recorded at time zero as baseline and every 3 minutes after baseline during stimulation, with a laser Doppler flow-meter. Individuals who received sympathetic ganglion stimulation showed significantly greater blood flow than those receiving acupuncture point stimulation or those in the control group (p<0.001). Data analysis revealed that blood flow at different times during stimulation increased significantly from time zero in each group. Therefore, the application of low-frequency TENS at the thoracolumbar sympathetic ganglions was more effective in increasing peripheral blood circulation than stimulation at acupuncture points. Copyright © 2017 Medical Association of Pharmacopuncture Institute. Published by Elsevier B.V. All rights reserved.

Stimulation of hair cells with ultraviolet light

NASA Astrophysics Data System (ADS)

Azimzadeh, Julien B.; Fabella, Brian A.; Hudspeth, A. J.

2018-05-01

Hair bundles are specialized organelles that transduce mechanical inputs into electrical outputs. To activate hair cells, physiologists have resorted to mechanical methods of hair-bundle stimulation. Here we describe a new method of hair-bundle stimulation, irradiation with ultraviolet light. A hair bundle illuminated by ultraviolet light rapidly moves towards its tall edge, a motion typically associated with excitatory stimulation. The motion disappears upon tip-link rupture and is associated with the opening of mechanotransduction channels. Hair bundles can be induced to move sinusoidally with oscillatory modulation of the stimulation power. We discuss the implications of ultraviolet stimulation as a novel hair-bundle stimulus.

When the Ostrich-Algorithm Fails: Blanking Method Affects Spike Train Statistics.

PubMed

Joseph, Kevin; Mottaghi, Soheil; Christ, Olaf; Feuerstein, Thomas J; Hofmann, Ulrich G

2018-01-01

Modern electroceuticals are bound to employ the usage of electrical high frequency (130-180 Hz) stimulation carried out under closed loop control, most prominent in the case of movement disorders. However, particular challenges are faced when electrical recordings of neuronal tissue are carried out during high frequency electrical stimulation, both in-vivo and in-vitro . This stimulation produces undesired artifacts and can render the recorded signal only partially useful. The extent of these artifacts is often reduced by temporarily grounding the recording input during stimulation pulses. In the following study, we quantify the effects of this method, "blanking," on the spike count and spike train statistics. Starting from a theoretical standpoint, we calculate a loss in the absolute number of action potentials, depending on: width of the blanking window, frequency of stimulation, and intrinsic neuronal activity. These calculations were then corroborated by actual high signal to noise ratio (SNR) single cell recordings. We state that, for clinically relevant frequencies of 130 Hz (used for movement disorders) and realistic blanking windows of 2 ms, up to 27% of actual existing spikes are lost. We strongly advice cautioned use of the blanking method when spike rate quantification is attempted. Blanking (artifact removal by temporarily grounding input), depending on recording parameters, can lead to significant spike loss. Very careful use of blanking circuits is advised.

When the Ostrich-Algorithm Fails: Blanking Method Affects Spike Train Statistics

PubMed Central

Joseph, Kevin; Mottaghi, Soheil; Christ, Olaf; Feuerstein, Thomas J.; Hofmann, Ulrich G.

2018-01-01

Modern electroceuticals are bound to employ the usage of electrical high frequency (130–180 Hz) stimulation carried out under closed loop control, most prominent in the case of movement disorders. However, particular challenges are faced when electrical recordings of neuronal tissue are carried out during high frequency electrical stimulation, both in-vivo and in-vitro. This stimulation produces undesired artifacts and can render the recorded signal only partially useful. The extent of these artifacts is often reduced by temporarily grounding the recording input during stimulation pulses. In the following study, we quantify the effects of this method, “blanking,” on the spike count and spike train statistics. Starting from a theoretical standpoint, we calculate a loss in the absolute number of action potentials, depending on: width of the blanking window, frequency of stimulation, and intrinsic neuronal activity. These calculations were then corroborated by actual high signal to noise ratio (SNR) single cell recordings. We state that, for clinically relevant frequencies of 130 Hz (used for movement disorders) and realistic blanking windows of 2 ms, up to 27% of actual existing spikes are lost. We strongly advice cautioned use of the blanking method when spike rate quantification is attempted. Impact statement Blanking (artifact removal by temporarily grounding input), depending on recording parameters, can lead to significant spike loss. Very careful use of blanking circuits is advised. PMID:29780301

Bio-robots automatic navigation with electrical reward stimulation.

PubMed

Sun, Chao; Zhang, Xinlu; Zheng, Nenggan; Chen, Weidong; Zheng, Xiaoxiang

2012-01-01

Bio-robots that controlled by outer stimulation through brain computer interface (BCI) suffer from the dependence on realtime guidance of human operators. Current automatic navigation methods for bio-robots focus on the controlling rules to force animals to obey man-made commands, with animals' intelligence ignored. This paper proposes a new method to realize the automatic navigation for bio-robots with electrical micro-stimulation as real-time rewards. Due to the reward-seeking instinct and trial-and-error capability, bio-robot can be steered to keep walking along the right route with rewards and correct its direction spontaneously when rewards are deprived. In navigation experiments, rat-robots learn the controlling methods in short time. The results show that our method simplifies the controlling logic and realizes the automatic navigation for rat-robots successfully. Our work might have significant implication for the further development of bio-robots with hybrid intelligence.

Literature Review and Meta-Analysis of Transcutaneous Electrical Nerve Stimulation in Treating Chronic Back Pain

PubMed Central

Wu, Lien-Chen; Weng, Pei-Wei; Chen, Chia-Hsien; Huang, Yi-You; Tsuang, Yang-Hwei; Chiang, Chang-Jung

2018-01-01

Background and Objectives This study is a meta-analysis of randomized controlled trials comparing the efficacy of transcutaneous electrical nerve stimulation (TENS) to a control and to other nerve stimulation therapies (NSTs) for the treatment of chronic back pain. Methods Citations were identified in MEDLINE, the Cochrane Library, Google Scholar, and ClinicalTrials.gov through June 2014 using the following keywords: nerve stimulation therapy, transcutaneous electrical nerve stimulation, back pain, chronic pain. Control treatments included sham, placebo, or medication only. Other NSTs included electroacupuncture, percutaneous electrical nerve stimulation, and percutaneous neuromodulation therapy. Results Twelve randomized controlled trials including 700 patients were included in the analysis. The efficacy of TENS was similar to that of control treatment for providing pain relief (standardized difference in means [SDM] = −0.20; 95% confidence interval [CI], −0.58 to 0.18; P = 0.293). Other types of NSTs were more effective than TENS in providing pain relief (SDM = 0.86; 95% CI, 0.15–1.57; P = 0.017). Transcutaneous electrical nerve stimulation was more effective than control treatment in improving functional disability only in patients with follow-up of less than 6 weeks (SDM = −1.24; 95% CI, −1.83 to −0.65; P < 0.001). There was no difference in functional disability outcomes between TENS and other NSTs. Conclusions These results suggest that TENS does not improve symptoms of lower back pain, but may offer short-term improvement of functional disability. PMID:29394211

Comparison of Three Non-Invasive Transcranial Electrical Stimulation Methods for Increasing Cortical Excitability.

PubMed

Inukai, Yasuto; Saito, Kei; Sasaki, Ryoki; Tsuiki, Shota; Miyaguchi, Shota; Kojima, Sho; Masaki, Mitsuhiro; Otsuru, Naofumi; Onishi, Hideaki

2016-01-01

Transcranial direct current stimulation (tDCS) is a representative non-invasive brain stimulation method (NIBS). tDCS increases cortical excitability not only in healthy individuals, but also in stroke patients where it contributes to motor function improvement. Recently, two additional types of transcranial electrical stimulation (tES) methods have been introduced that may also prove beneficial for stimulating cortical excitability; these are transcranial random noise stimulation (tRNS) and transcranial alternating current stimulation (tACS). However, comparison of tDCS with tRNS and tACS, in terms of efficacy in cortical excitability alteration, has not been reported thus far. We compared the efficacy of the three different tES methods for increasing cortical excitability using the same subject population and same current intensity. Fifteen healthy subjects participated in this study. Similar stimulation patterns (1.0 mA and 10 min) were used for the three conditions of stimulation (tDCS, tRNS, and tACS). Cortical excitability was explored via single-pulse TMS elicited motor evoked potentials (MEPs). Compared with pre-measurements, MEPs significantly increased with tDCS, tACS, and tRNS ( p < 0.05). Compared with sham measurements, significant increases in MEPs were also observed with tRNS and tACS ( p < 0.05), but not with tDCS. In addition, a significant correlation of the mean stimulation effect was observed between tRNS and tACS ( p = 0.019, r = 0.598). tRNS induced a significant increase in MEP compared with the Pre or Sham at all time points. tRNS resulted in the largest significant increase in MEPs. These findings suggest that tRNS is the most effective tES method and should be considered as part of a treatment plan for improving motor function in stroke patients.

Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields

PubMed Central

Ruffini, Giulio; Fox, Michael D.; Ripolles, Oscar; Miranda, Pedro Cavaleiro; Pascual-Leone, Alvaro

2014-01-01

Recently, multifocal transcranial current stimulation (tCS) devices using several relatively small electrodes have been used to achieve more focal stimulation of specific cortical targets. However, it is becoming increasingly recognized that many behavioral manifestations of neurological and psychiatric disease are not solely the result of abnormality in one isolated brain region but represent alterations in brain networks. In this paper we describe a method for optimizing the configuration of multifocal tCS for stimulation of brain networks, represented by spatially extended cortical targets. We show how, based on fMRI, PET, EEG or other data specifying a target map on the cortical surface for excitatory, inhibitory or neutral stimulation and a constraint of the maximal number of electrodes, a solution can be produced with the optimal currents and locations of the electrodes. The method described here relies on a fast calculation of multifocal tCS electric fields (including components normal and tangential to the cortical boundaries) using a five layer finite element model of a realistic head. Based on the hypothesis that the effects of current stimulation are to first order due to the interaction of electric fields with populations of elongated cortical neurons, it is argued that the optimization problem for tCS stimulation can be defined in terms of the component of the electric field normal to the cortical surface. Solutions are found using constrained least squares to optimize current intensities, while electrode number and their locations are selected using a genetic algorithm. For direct current tCS (tDCS) applications, we provide some examples of this technique using an available tCS system providing 8 small Ag/AgCl stimulation electrodes. We demonstrate the approach both for localized and spatially extended targets defined using rs-fcMRI and PET data, with clinical applications in stroke and depression. Finally, we extend these ideas to more general stimulation protocols, such as alternating current tCS (tACS). PMID:24345389

Electrical Stimulation of the Ventral Tegmental Area Induces Reanimation from General Anesthesia

PubMed Central

Solt, Ken; Van Dort, Christa J.; Chemali, Jessica J.; Taylor, Norman E.; Kenny, Jonathan D.; Brown, Emery N.

2014-01-01

BACKGROUND Methylphenidate or a D1 dopamine receptor agonist induce reanimation (active emergence) from general anesthesia. We tested whether electrical stimulation of dopaminergic nuclei also induces reanimation from general anesthesia. METHODS In adult rats, a bipolar insulated stainless steel electrode was placed in the ventral tegmental area (VTA, n = 5) or substantia nigra (SN, n = 5). After a minimum 7-day recovery period, the isoflurane dose sufficient to maintain loss of righting was established. Electrical stimulation was initiated and increased in intensity every 3 min to a maximum of 120μA. If stimulation restored the righting reflex, an additional experiment was performed at least 3 days later during continuous propofol anesthesia. Histological analysis was conducted to identify the location of the electrode tip. In separate experiments, stimulation was performed in the prone position during general anesthesia with isoflurane or propofol, and the electroencephalogram was recorded. RESULTS To maintain loss of righting, the dose of isoflurane was 0.9% ± 0.1 vol%, and the target plasma dose of propofol was 4.4 μg/ml ± 1.1 μg/ml (mean ± SD). In all rats with VTA electrodes, electrical stimulation induced a graded arousal response including righting that increased with current intensity. VTA stimulation induced a shift in electroencephalogram peak power from δ (<4 Hz) to θ (4–8 Hz). In all rats with SN electrodes, stimulation did not elicit an arousal response or significant electroencephalogram changes. CONCLUSIONS Electrical stimulation of the VTA, but not the SN, induces reanimation during general anesthesia with isoflurane or propofol. These results are consistent with the hypothesis that dopamine release by VTA, but not SN, neurons induces reanimation from general anesthesia. PMID:24398816

Development of less invasive neuromuscular electrical stimulation model for motor therapy in rodents

PubMed Central

Kanchiku, Tsukasa; Kato, Yoshihiko; Suzuki, Hidenori; Imajo, Yasuaki; Yoshida, Yuichiro; Moriya, Atsushi; Taguchi, Toshihiko; Jung, Ranu

2012-01-01

Background Combination therapy is essential for functional repairs of the spinal cord. Rehabilitative therapy can be considered as the key for reorganizing the nervous system after spinal cord regeneration therapy. Functional electrical stimulation has been used as a neuroprosthesis in quadriplegia and can be used for providing rehabilitative therapy to tap the capability for central nervous system reorganization after spinal cord regeneration therapy. Objective To develop a less invasive muscular electrical stimulation model capable of being combined with spinal cord regeneration therapy especially for motor therapy in the acute stage after spinal cord injury. Methods The tibialis anterior and gastrocnemius motor points were identified in intact anesthetized adult female Fischer rats, and stimulation needle electrodes were percutaneously inserted into these points. Threshold currents for visual twitches were obtained upon stimulation using pulses of 75 or 8 kHz for 200 ms. Biphasic pulse widths of 20, 40, 80, 100, 300, and 500 µs per phase were used to determine strength–duration curves. Using these parameters and previously obtained locomotor electromyogram data, stimulations were performed on bilateral joint muscle pairs to produce reciprocal flexion/extension movements of the ankle for 15 minutes while three-dimensional joint kinematics were assessed. Results Rhythmic muscular electrical stimulation with needle electrodes was successfully done, but decreased range of motion (ROM) over time. High-frequency and high-amplitude stimulation was also shown to be effective in alleviating decreases in ROM due to muscle fatigue. Conclusions This model will be useful for investigating the ability of rhythmic muscular electrical stimulation therapy to promote motor recovery, in addition to the efficacy of combining treatments with spinal cord regeneration therapy after spinal cord injuries. PMID:22507026

Cardiac cycle-synchronized electrical muscle stimulator for lower limb training with the potential to reduce the heart's pumping workload

PubMed Central

Matsuse, Hiroo; Akimoto, Ryuji; Kamiya, Shiro; Moritani, Toshio; Sasaki, Motoki; Ishizaki, Yuta; Ohtsuka, Masanori; Nakayoshi, Takaharu; Ueno, Takafumi; Shiba, Naoto; Fukumoto, Yoshihiro

2017-01-01

Background The lower limb muscle may play an important role in decreasing the heart’s pumping workload. Aging and inactivity cause atrophy and weakness of the muscle, leading to a loss of the heart-assisting role. An electrical lower limb muscle stimulator can prevent atrophy and weakness more effectively than conventional resistance training; however, it has been reported to increase the heart’s pumping workload in some situations. Therefore, more effective tools should be developed. Methods We newly developed a cardiac cycle-synchronized electrical lower limb muscle stimulator by combining a commercially available electrocardiogram monitor and belt electrode skeletal muscle electrical stimulator, making it possible to achieve strong and wide but not painful muscle contractions. Then, we tested the stimulator in 11 healthy volunteers to determine whether the special equipment enabled lower limb muscle training without harming the hemodynamics using plethysmography and a percutaneous cardiac output analyzer. Results In 9 of 11 subjects, the stimulator generated diastolic augmentation waves on the dicrotic notches and end-diastolic pressure reduction waves on the plethysmogram waveforms of the brachial artery, showing analogous waveforms in the intra-aortic balloon pumping heart-assisting therapy. The heart rate, stroke volume, and cardiac output significantly increased during the stimulation. There was no change in the systolic or diastolic blood pressure during the stimulation. Conclusion Cardiac cycle-synchronized electrical muscle stimulation for the lower limbs may enable muscle training without harmfully influencing the hemodynamics and with a potential to reduce the heart’s pumping workload, suggesting a promising tool for effectively treating both locomotor and cardiovascular disorders. PMID:29117189

Effects of combined application of progressive resistance training and Russian electrical stimulation on quadriceps femoris muscle strength in elderly women with knee osteoarthritis.

PubMed

Park, Seong Hoon; Hwangbo, Gak

2015-03-01

[Purpose] The aim of this study was to investigate the effects of combined application of progressive resistance training and Russian electrical stimulation on quadriceps femoris muscle strength in elderly women with osteoarthritis of the knee. [Subjects] Thirty women over 65 years of age diagnosed with knee osteoarthritis participated in the present study. The subjects were randomly assigned to a control group (n=10), a progressive resistance training group (n=10), or a Russian electrical stimulation group (n=10). [Methods] Each group was treated 3 times weekly for 8 weeks, and each session lasted 45 minutes. Muscle strength was assessed by measuring the peak torque of the quadriceps femoris muscle. Outcome measurements were performed at baseline and at the fourth and eighth weeks of the treatment period. [Results] All groups showed significant intragroup differences in the quadriceps femoris muscle peak torque after the treatment intervention. There were significant intergroup differences between the Russian electrical stimulation group and the other groups. [Conclusion] The results of this study suggest that combined application of progressive resistance training and Russian electrical stimulation can be effective in strengthening the quadriceps femoris muscle in elderly women with knee osteoarthritis.

A New Training for Older Adults Using Combined Neuromuscular Electrical Stimulation and Volitional Contraction: A Pilot Study.

PubMed

Takano, Yoshio; Matsuse, Hiroo; Tsukada, Yuuya; Omoto, Masayuki; Hashida, Ryuki; Shiba, Naoto

2016-01-01

The hybrid training system (HTS) resists the motion of a volitionally contracting agonist muscle using force generated by its electrically stimulated antagonist. We have developed a new training method using the principle of HTS. This study was designed to evaluate the effect of HTS with electrical stimulation on muscle strength and physical function by comparing it against training without electrical stimulation in older adults. 16 subjects were randomly divided into two groups: the squat and single leg lift training (control, CTR) group, and the CTR with HTS training group. Some electrical stimulation was applied to the quadriceps and hamstring muscles in the HTS group. The subjects performed training for 25 min per session 3 times a week for 12 weeks. At points before and after the research maximal isokinetic torque, knee-flexors (KFT) and knee-extensors (KET), a one-leg standing test (OLT), a functional reach test (FRT), a 10-meter maximal gait time (10MGT) and Timed up & go test (TUG) were conducted. None of the subjects had any injuries during the study period. TUG significantly improved after the training period in both the HTS group (7.15 sec to 6.01 sec P = 0.01) and in the CTR.

Direct Electrical Stimulation of the Human Entorhinal Region and Hippocampus Impairs Memory.

PubMed

Jacobs, Joshua; Miller, Jonathan; Lee, Sang Ah; Coffey, Tom; Watrous, Andrew J; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn; Gross, Robert E; Sheth, Sameer A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Kahana, Michael J; Rizzuto, Daniel S

2016-12-07

Deep brain stimulation (DBS) has shown promise for treating a range of brain disorders and neurological conditions. One recent study showed that DBS in the entorhinal region improved the accuracy of human spatial memory. Based on this line of work, we performed a series of experiments to more fully characterize the effects of DBS in the medial temporal lobe on human memory. Neurosurgical patients with implanted electrodes performed spatial and verbal-episodic memory tasks. During the encoding periods of both tasks, subjects received electrical stimulation at 50 Hz. In contrast to earlier work, electrical stimulation impaired memory performance significantly in both spatial and verbal tasks. Stimulation in both the entorhinal region and hippocampus caused decreased memory performance. These findings indicate that the entorhinal region and hippocampus are causally involved in human memory and suggest that refined methods are needed to use DBS in these regions to improve memory. Copyright © 2016 Elsevier Inc. All rights reserved.

The Effect of Electrical Stimulation in Improving Muscle Tone (Clinical)

NASA Astrophysics Data System (ADS)

Azman, M. F.; Azman, A. W.

2017-11-01

Electrical stimulation (ES) and also known as neuromuscular electrical stimulation (NMES) and transcutaneous electrical stimulation (TES) involves the use of electrical current to stimulate the nerves or nerve endings that innervate muscle beneath the skin. Electrical stimulation may be applied superficially on the skin (transcutaneously) or directly into a muscle or muscles (intramuscularly) for the primary purpose of enhancing muscle function. The basic theoretical premise is that if the peripheral nerve can be stimulated, the resulting excitation impulse will be transmitted along the nerve to the motor endplates in the muscle, producing a muscle contraction. In this work, the effect of mere electrical stimulation to the muscle bulk and strength are tested. This paper explains how electrical stimulation can affect the muscle bulk, muscle size, muscle tone, muscle atrophy and muscle strength. The experiment and data collection are performed on 5 subjects and the results obtained are analyzed. This research aims to understand the full potential of electrical stimulation and identifying its possible benefits or disadvantages to the muscle properties. The results indicated that electrical stimulation alone able to improve muscle properties but with certain limits and precautions which might be useful in rehabilitation programme.

A Mixed Integer Linear Programming Approach to Electrical Stimulation Optimization Problems.

PubMed

Abouelseoud, Gehan; Abouelseoud, Yasmine; Shoukry, Amin; Ismail, Nour; Mekky, Jaidaa

2018-02-01

Electrical stimulation optimization is a challenging problem. Even when a single region is targeted for excitation, the problem remains a constrained multi-objective optimization problem. The constrained nature of the problem results from safety concerns while its multi-objectives originate from the requirement that non-targeted regions should remain unaffected. In this paper, we propose a mixed integer linear programming formulation that can successfully address the challenges facing this problem. Moreover, the proposed framework can conclusively check the feasibility of the stimulation goals. This helps researchers to avoid wasting time trying to achieve goals that are impossible under a chosen stimulation setup. The superiority of the proposed framework over alternative methods is demonstrated through simulation examples.

Preparation of acellular myocardial scaffolds with well-preserved cardiomyocyte lacunae, and method for applying mechanical and electrical simulation to tissue construct.

PubMed

Wang, Bo; Williams, Lakiesha N; de Jongh Curry, Amy L; Liao, Jun

2014-01-01

Cardiac tissue engineering/regeneration using decellularized myocardium has attracted great research attention due to its potential benefit for myocardial infarction (MI) treatment. Here we describe an optimal decellularization protocol to generate 3D porcine myocardial scaffolds with well-preserved cardiomyocyte lacunae and a multi-stimulation bioreactor that is able to provide coordinated mechanical and electrical stimulation for facilitating cardiac construct development.

Calculating the electric field in real human head by transcranial magnetic stimulation with shield plate

NASA Astrophysics Data System (ADS)

Lu, Mai; Ueno, Shoogo

2009-04-01

In this paper, we present a transcranial magnetic stimulation (TMS) system by incorporating a conductive shield plate. The magnetic field, induced current density, and electric field in a real human head were calculated by impedance method and the results were compared with TMS without shielding. Our results show that the field localization can be improved by introducing a conductive shield plate; the stimulation magnitude (depth) in the brain is reduced comparing with the TMS without shielding. The strong magnetic field near the TMS coil is difficult to be efficiently shielded by a thinner conductive shield plate.

Magnetic field therapy: a review.

PubMed

Markov, Marko S

2007-01-01

There is increasing interest in using permanent magnets for therapeutic purposes encouraged by basic science publications and clinical reports. Magnetotherapy provides a non invasive, safe, and easy method to directly treat the site of injury, the source of pain and inflammation, and other types of disease. The physiological bases for the use of magnetic fields for tissue repair as well as physical principles of dosimetry and application of various magnetic fields are subjects of this review. Analysis of the magnetic and electromagnetic stimulation is followed by a discussion of the advantage of magnetic field stimulation compared with electric current and electric field stimulation.

Detection of a diabetic sural nerve from the magnetic field after electric stimulation

NASA Astrophysics Data System (ADS)

Hayami, Takehito; Iramina, Keiji; Hyodo, Akira; Chen, Xian; Sunagawa, Kenji

2009-04-01

In this study, we proposed a new diagnostic technique for diabetic neuropathy using biomagnetic measurement. Peripheral neuropathy is one of the most common complications of diabetes. To examine the injury, the skin potential around the nerve is often measured after electric stimulation. However, measuring the magnetic field may reveal precise condition of the injury. To evaluate the effect of measuring the magnetic field, a simulation study was performed. A diabetic sural nerve was simulated as a bundle of myelinated nerve fibers. Each fiber was modeled as an electric cable of Ranvier's nodes. Anatomical data were used to determine the number of nerve fibers and distribution of nerve fiber diameters. The electric potential and the magnetic field on the skin after electric stimulation were computed to the boundary element method. Biphasic time courses were obtained as the electric potential and the magnetic flux density at measurement points. In diabetic nerves, the longer interpeak latency of the electric potential wave and the shorter interpeak latency of the magnetic flux wave were obtained. Measuring both the electric potential and the magnetic flux density seemed to provide a noninvasive and objective marker for diabetic neuropathy.

Effects of Electrical and Optogenetic Deep Brain Stimulation on Synchronized Oscillatory Activity in Parkinsonian Basal Ganglia.

PubMed

Ratnadurai-Giridharan, Shivakeshavan; Cheung, Chung C; Rubchinsky, Leonid L

2017-11-01

Conventional deep brain stimulation of basal ganglia uses high-frequency regular electrical pulses to treat Parkinsonian motor symptoms but has a series of limitations. Relatively new and not yet clinically tested, optogenetic stimulation is an effective experimental stimulation technique to affect pathological network dynamics. We compared the effects of electrical and optogenetic stimulation of the basal gangliaon the pathologicalParkinsonian rhythmic neural activity. We studied the network response to electrical stimulation and excitatory and inhibitory optogenetic stimulations. Different stimulations exhibit different interactions with pathological activity in the network. We studied these interactions for different network and stimulation parameter values. Optogenetic stimulation was found to be more efficient than electrical stimulation in suppressing pathological rhythmicity. Our findings indicate that optogenetic control of neural synchrony may be more efficacious than electrical control because of the different ways of how stimulations interact with network dynamics.

One-shot percutaneous electrical nerve stimulation vs. transcutaneous electrical nerve stimulation for low back pain: comparison of therapeutic effects.

PubMed

Hsieh, Ru-Lan; Lee, Wen-Chung

2002-11-01

To investigate the therapeutic effects of one shot of low-frequency percutaneous electrical nerve stimulation one shot of transcutaneous electrical nerve stimulation in patients with low back pain. In total, 133 low back pain patients were recruited for this randomized, control study. Group 1 patients received medication only. Group 2 patients received medication plus one shot of percutaneous electrical nerve stimulation. Group 3 patients received medication plus one shot of transcutaneous electrical nerve stimulation. Therapeutic effects were measured using a visual analog scale, body surface score, pain pressure threshold, and the Quebec Back Pain Disability Scale. Immediately after one-shot treatment, the visual analog scale improved 1.53 units and the body surface score improved 3.06 units in the percutaneous electrical nerve stimulation group. In the transcutaneous electrical nerve stimulation group, the visual analog scale improved 1.50 units and the body surface score improved 3.98 units. The improvements did not differ between the two groups. There were no differences in improvement at 3 days or 1 wk after the treatment among the three groups. Simple one-shot treatment with percutaneous electrical nerve stimulation or transcutaneous electrical nerve stimulation provided immediate pain relief for low back pain patients. One-shot transcutaneous electrical nerve stimulation treatment is recommended due to the rarity of side effects and its convenient application.

21 CFR 882.1870 - Evoked response electrical stimulator.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring the...

21 CFR 882.1870 - Evoked response electrical stimulator.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring the...

21 CFR 882.1870 - Evoked response electrical stimulator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring the...

21 CFR 882.1870 - Evoked response electrical stimulator.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring the...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Transcutaneous electrical nerve stimulator for... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Transcutaneous electrical nerve stimulator for...

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Transcutaneous electrical nerve stimulator for...

Independent component analysis for cochlear implant artifacts attenuation from electrically evoked auditory steady-state response measurements

NASA Astrophysics Data System (ADS)

Deprez, Hanne; Gransier, Robin; Hofmann, Michael; van Wieringen, Astrid; Wouters, Jan; Moonen, Marc

2018-02-01

Objective. Electrically evoked auditory steady-state responses (EASSRs) are potentially useful for objective cochlear implant (CI) fitting and follow-up of the auditory maturation in infants and children with a CI. EASSRs are recorded in the electro-encephalogram (EEG) in response to electrical stimulation with continuous pulse trains, and are distorted by significant CI artifacts related to this electrical stimulation. The aim of this study is to evaluate a CI artifacts attenuation method based on independent component analysis (ICA) for three EASSR datasets. Approach. ICA has often been used to remove CI artifacts from the EEG to record transient auditory responses, such as cortical evoked auditory potentials. Independent components (ICs) corresponding to CI artifacts are then often manually identified. In this study, an ICA based CI artifacts attenuation method was developed and evaluated for EASSR measurements with varying CI artifacts and EASSR characteristics. Artifactual ICs were automatically identified based on their spectrum. Main results. For 40 Hz amplitude modulation (AM) stimulation at comfort level, in high SNR recordings, ICA succeeded in removing CI artifacts from all recording channels, without distorting the EASSR. For lower SNR recordings, with 40 Hz AM stimulation at lower levels, or 90 Hz AM stimulation, ICA either distorted the EASSR or could not remove all CI artifacts in most subjects, except for two of the seven subjects tested with low level 40 Hz AM stimulation. Noise levels were reduced after ICA was applied, and up to 29 ICs were rejected, suggesting poor ICA separation quality. Significance. We hypothesize that ICA is capable of separating CI artifacts and EASSR in case the contralateral hemisphere is EASSR dominated. For small EASSRs or large CI artifact amplitudes, ICA separation quality is insufficient to ensure complete CI artifacts attenuation without EASSR distortion.

Electromagnetic Field Modeling of Transcranial Electric and Magnetic Stimulation: Targeting, Individualization, and Safety of Convulsive and Subconvulsive Applications

NASA Astrophysics Data System (ADS)

Deng, Zhi-De

The proliferation of noninvasive transcranial electric and magnetic brain stimulation techniques and applications in recent years has led to important insights into brain function and pathophysiology of brain-based disorders. Transcranial electric and magnetic stimulation encompasses a wide spectrum of methods that have developed into therapeutic interventions for a variety of neurological and psychiatric disorders. Although these methods are at different stages of development, the physical principle underlying these techniques is the similar. Namely, an electromagnetic field is induced in the brain either via current injection through scalp electrodes or via electromagnetic induction. The induced electric field modulates the neuronal transmembrane potentials and, thereby, neuronal excitability or activity. Therefore, knowledge of the induced electric field distribution is key in the design and interpretation of basic research and clinical studies. This work aims to delineate the fundamental physical limitations, tradeoffs, and technological feasibility constraints associated with transcranial electric and magnetic stimulation, in order to inform the development of technologies that deliver safer, and more spatially, temporally, and patient specific stimulation. Part I of this dissertation expounds on the issue of spatial targeting of the electric field. Contrasting electroconvulsive therapy (ECT) and magnetic seizure therapy (MST) configurations that differ markedly in efficacy, side effects, and seizure induction efficiency could advance our understanding of the principles linking treatment parameters and therapeutic outcome and could provide a means of testing hypotheses of the mechanisms of therapeutic action. Using the finite element method, we systematically compare the electric field characteristics of existing forms of ECT and MST. We introduce a method of incorporating a modality-specific neural activation threshold in the electric field models that can inform dosage requirements in convulsive therapies. Our results indicate that the MST electric field is more focal and more confined to the superficial cortex compared to ECT. Further, the conventional ECT current amplitude is much higher than necessary for seizure induction. One of the factors important to clinical outcome is seizure expression. However, it is unknown how the induced electric field is related to seizure onset and propagation. In this work, we explore the effect of the electric field distribution on the quantitative ictal electroencephalography and current source density in ECT and MST. We further demonstrate how the ECT electrode shape, size, spacing, and current can be manipulated to yield more precise control of the induced electric field. If desirable, ECT can be made as focal as MST while using simpler stimulation equipment. Next, we demonstrate how the electric field induced by transcranial magnetic stimulation (TMS) can be controlled. We present the most comprehensive comparison of TMS coil electric field penetration and focality to date. The electric field distributions of more than 50 TMS coils were simulated. We show that TMS coils differ markedly in their electric field characteristics, but they all are subject to a consistent depth-focality tradeoff. Specifically, the ability to directly stimulate deeper brain structures is obtained at the expense of inducing wider electric field spread. Figure-8 type coils are fundamentally more focal compared to circular type coils. Understanding the depth-focality tradeoff can help researchers and clinicians to appropriately select coils and interpret TMS studies. This work also enables the development of novel TMS coils with electronically switchable active and sham modes as well as for deep TMS. Design considerations of these coils are extensively discussed. Part II of the dissertation aims to quantify the effect of individual, sex, and age differences in head geometry and conductivity on the induced neural stimulation strength and focality of ECT and MST. Across and within ECT studies, there is marked unexplained variability in seizure threshold and clinical outcomes. It is not known to what extent the age and sex effects on seizure threshold are mediated by interindividual variation in neural excitability and/or anatomy of the head. Addressing this question, we examine the effect on ECT and MST induced field characteristics of the variability in head diameter, scalp and skull thicknesses and conductivities, as well as brain volume, in a range of values that are representative of the patient population. Variations in the local tissue properties such as scalp and skull thickness and conductivity affect the existing ECT configurations more than MST. On the other hand, the existing MST coil configurations show greater sensitivity to head diameter variation compared to ECT. Due to the high focality of MST compared to ECT, the stimulated brain volume in MST is more sensitive to variation in tissue layer thicknesses. We further demonstrate how individualization of the stimulus pulse current amplitude, which is not presently done in ECT or MST, can be used as a means of compensating for interindividual anatomical variability, which could lead to better and more consistent clinical outcomes. Part III of the dissertation aims to systemically investigate, both computationally and experimentally, the safety of TMS and ECT in patients with a deep-brain stimulation system, and propose safety guidelines for the dual-device therapy. We showed that the induction of significant voltages in the subcutaneous leads in the scalp during TMS could result in unintended and potentially dangerous levels of electrical currents in the DBS electrode contacts. When applying ECT in patients with intracranial implants, we showed that there is an increase in the electric field strength in the brain due to conduction through the burr holes, especially when the burr holes are not fitted with nonconductive caps. Safety concerns presently limit the access of patients with intracranial electronic devices to therapies involving transcranial stimulation technology, which may preclude them from obtaining appropriate medical treatments. Gaining better understanding of the interactions between transcranial and implanted stimulation devices will demarcate significant safety risks from benign interactions, and will provide recommendations for reducing risk, thus enhancing the patient's therapeutic options.

Numerical dosimetry of transcranial magnetic stimulation coils

NASA Astrophysics Data System (ADS)

Crowther, Lawrence; Hadimani, Ravi; Jiles, David

2014-03-01

Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique capable of stimulating neurons by means of electromagnetic induction. TMS can be used to map brain function and shows promise for the diagnosis and treatment of neurological and psychiatric disorders. Calculation of fields induced in the brain are necessary to accurately identify stimulated neural tissue during TMS. This allows the development of novel TMS coil designs capable of stimulating deeper brain regions and increasing the localization of stimulation that can be achieved. We have performed numerical calculations of magnetic and electric field with high-resolution anatomically realistic human head models to find these stimulated brain regions for a variety of proposed TMS coil designs. The realistic head models contain heterogeneous tissue structures and electrical conductivities, yielding superior results to those obtained from the simplified homogeneous head models that are commonly employed. The attenuation of electric field as a function of depth in the brain and the localization of stimulating field have been methodically investigated. In addition to providing a quantitative comparison of different TMS coil designs the variation of induced field between subjects has been investigated. We also show the differences in induced fields between adult, adolescent and child head models to preemptively identify potential safety issues in the application of pediatric TMS.

A Systematic Review of Electric-Acoustic Stimulation

PubMed Central

Ching, Teresa Y. C.; Cowan, Robert

2013-01-01

Cochlear implant systems that combine electric and acoustic stimulation in the same ear are now commercially available and the number of patients using these devices is steadily increasing. In particular, electric-acoustic stimulation is an option for patients with severe, high frequency sensorineural hearing impairment. There have been a range of approaches to combining electric stimulation and acoustic hearing in the same ear. To develop a better understanding of fitting practices for devices that combine electric and acoustic stimulation, we conducted a systematic review addressing three clinical questions: what is the range of acoustic hearing in the implanted ear that can be effectively preserved for an electric-acoustic fitting?; what benefits are provided by combining acoustic stimulation with electric stimulation?; and what clinical fitting practices have been developed for devices that combine electric and acoustic stimulation? A search of the literature was conducted and 27 articles that met the strict evaluation criteria adopted for the review were identified for detailed analysis. The range of auditory thresholds in the implanted ear that can be successfully used for an electric-acoustic application is quite broad. The effectiveness of combined electric and acoustic stimulation as compared with electric stimulation alone was consistently demonstrated, highlighting the potential value of preservation and utilization of low frequency hearing in the implanted ear. However, clinical procedures for best fitting of electric-acoustic devices were varied. This clearly identified a need for further investigation of fitting procedures aimed at maximizing outcomes for recipients of electric-acoustic devices. PMID:23539259

Microprocessor controlled movement of solid colonic content using sequential neural electrical stimulation

PubMed Central

Amaris, M A; Rashev, P Z; Mintchev, M P; Bowes, K L

2002-01-01

Background and aims: Invoked peristaltic contractions and movement of solid content have not been attempted in normal canine colon. The purpose of this study was to determine if movement of solid content through the colon could be produced by microprocessor controlled sequential stimulation. Methods: The study was performed on six anaesthetised dogs. At laparotomy, a 15 cm segment of descending colon was selected, the proximal end closed with a purse string suture, and the distal end opened into a collecting container. Four sets of subserosal stimulating electrodes were implanted at 3 cm intervals. The segment of bowel was filled with a mixture of dog food and 50 plastic pellets before each of 2–5 random sessions of non-stimulated or stimulated emptying. Propagated contractions were generated using microprocessor controlled bipolar trains of 50 Hz rectangular voltage having 20 V (peak to peak) amplitude, 18 second stimulus duration, and a nine second phase lag between stimulation trains in sequential electrode sets. Results: Electrical stimulation using the above mentioned parameters resulted in powerful phasic contractions that closed the lumen. By phase locking the stimulation voltage between adjacent sets of electrodes, propagated contractions could be produced in an aboral or orad direction. The number of evacuated pellets during the stimulation sessions was significantly higher than during the non-stimulated sessions (p<0.01). Conclusions: Microprocessor controlled electrical stimulation accelerated movement of colonic content suggesting the possibility of future implantable colonic stimulators. PMID:11889065

Electric-acoustic interactions in the hearing cochlea: single fiber recordings.

PubMed

Tillein, J; Hartmann, R; Kral, A

2015-04-01

The present study investigates interactions of simultaneous electric and acoustic stimulation in single auditory nerve fibers in normal hearing cats. First, the auditory nerve was accessed with a microelectrode and response areas of single nerve fibers were determined for acoustic stimulation. Second, response thresholds to extracochlear sinusoidal electric stimulation using ball electrodes positioned at the round window were measured. Third, interactions that occurred with combined electric-acoustic stimulation were investigated in two areas: (1) the spectral domain (frequency response areas) and (2) the temporal domain (phase-locking to each stimulus) at moderate stimulus intensities (electric: 6 dB re threshold, acoustic: 20-40 dB re threshold at the characteristic frequency, CF). For fibers responding to both modalities responses to both electric and acoustic stimulation could be clearly identified. CFs, thresholds, and bandwidth (Q10dB) of acoustic responses were not significantly affected by simultaneous electric stimulation. Phase-locking of electric responses decreased in the presence of acoustic stimulation. Indication for electric stimulation of inner hair cells with 125 and 250 Hz were observed. However, these did not disturb the acoustic receptive fields of auditory nerve fibers. There was a trade-off between these responses when the intensities of the stimulation were varied: Relatively more intense stimulation dominated less intense stimulation. The scarcity of interaction between the different stimulus modalities demonstrates the ability of electric-acoustic stimulation to transfer useful information through both stimulation channels at the same time despite cochlear electrophonic effects. Application of 30 Hz electric stimulation resulted in a strong suppression of acoustic activity in the anodic phase of the stimulus. An electric stimulation like this might thus be used to control acoustic responses. This article is part of a Special Issue entitled . Copyright © 2014 Elsevier B.V. All rights reserved.

VAGUS NERVE STIMULATION REGULATES HEMOSTASIS IN SWINE

PubMed Central

Czura, Christopher J.; Schultz, Arthur; Kaipel, Martin; Khadem, Anna; Huston, Jared M.; Pavlov, Valentin A.; Redl, Heinz; Tracey, Kevin J.

2010-01-01

The central nervous system regulates peripheral immune responses via the vagus nerve, the primary neural component of the cholinergic anti-inflammatory pathway. Electrical stimulation of the vagus nerve suppresses pro-inflammatory cytokine release in response to endotoxin, I/R injury, and hypovolemic shock and protects against lethal hypotension. To determine the effect of vagus nerve stimulation on coagulation pathways, anesthetized pigs were subjected to partial ear resection before and after electrical vagus nerve stimulation. We observed that electrical vagus nerve stimulation significantly decreased bleeding time (pre–electrical vagus nerve stimulation = 1033 ± 210 s versus post–electrical vagus nerve stimulation = 585 ± 111 s; P < 0.05) and total blood loss (pre–electrical vagus nerve stimulation = 48.4 ± 6.8 mL versus post–electrical vagus nerve stimulation = 26.3 ± 6.7 mL; P < 0.05). Reduced bleeding time after vagus nerve stimulation was independent of changes in heart rate or blood pressure and correlated with increased thrombin/antithrombin III complex generation in shed blood. These data indicate that electrical stimulation of the vagus nerve attenuates peripheral hemorrhage in a porcine model of soft tissue injury and that this protective effect is associated with increased coagulation factor activity. PMID:19953009

21 CFR 868.2775 - Electrical peripheral nerve stimulator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator (neuromuscular blockade monitor) is...

21 CFR 868.2775 - Electrical peripheral nerve stimulator.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator (neuromuscular blockade monitor) is...

21 CFR 868.2775 - Electrical peripheral nerve stimulator.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator (neuromuscular blockade monitor) is...

Methodological dimensions of transcranial brain stimulation with the electrical current in human.

PubMed

Rostami, Maryam; Golesorkhi, Mehrshad; Ekhtiari, Hamed

2013-01-01

Transcranial current stimulation (TCS) is a neuromodulation method in which the patient is exposed to a mild electric current (direct or alternating) at 1-2 mA, resulting in an increase or a decrease in the brain excitability. This modification in neural activities can be used as a method for functional human brain mapping with causal inferences. This method might also facilitate the treatments of many neuropsychiatric disorders based on its inexpensive, simple, safe, noninvasive, painless, semi-focal excitatory and inhibitory effects. Given this, a comparison amongst different brain stimulation modalities has been made to determine the potential advantages of the TCS method. In addition, considerable methodological details on using TCS in basic and clinical neuroscience studies in human subjects have been introduced. Technical characteristics of TCS devices and their related accessories with regard to safety concerns have also been well articulated. Finally, some TCS application opportunities have been emphasized, including its potential use in the near future.

External trial deep brain stimulation device for the application of desynchronizing stimulation techniques.

PubMed

Hauptmann, C; Roulet, J-C; Niederhauser, J J; Döll, W; Kirlangic, M E; Lysyansky, B; Krachkovskyi, V; Bhatti, M A; Barnikol, U B; Sasse, L; Bührle, C P; Speckmann, E-J; Götz, M; Sturm, V; Freund, H-J; Schnell, U; Tass, P A

2009-12-01

In the past decade deep brain stimulation (DBS)-the application of electrical stimulation to specific target structures via implanted depth electrodes-has become the standard treatment for medically refractory Parkinson's disease and essential tremor. These diseases are characterized by pathological synchronized neuronal activity in particular brain areas. We present an external trial DBS device capable of administering effectively desynchronizing stimulation techniques developed with methods from nonlinear dynamics and statistical physics according to a model-based approach. These techniques exploit either stochastic phase resetting principles or complex delayed-feedback mechanisms. We explain how these methods are implemented into a safe and user-friendly device.

The effects of Transcutaneous Electrical Nerve Stimulation on postural control in patients with chronic low back pain.

PubMed

Rojhani-Shirazi, Z; Rezaeian, T

2015-01-01

Objective: The effects of transcutaneous electrical nerve stimulation (TENS) on postural control in patients with low back pain which is not well known. This study aimed to evaluate the effects of TENS on postural control in chronic low back pain. Methods: This study was an experimental research design. Twenty-eight patients with chronic LBP (25-45 Y/ O) participated and by using a random allocation, were divided to samples who participated in this study. The mean center of pressure (COP) velocity and displacement were measured before, immediately and 30 min after the intervention. The tests were done with eyes open and closed on a force platform. Sensory electrical stimulation was applied through the TENS device. The descriptive statistics, independent sample T-test and ANOVA with repeated measurement on time were used for data analysis. Results: The results of the present study demonstrated that the application of the sensory electrical stimulation in chronic LBP patients showed a statistically significant improvement in postural control in Medio-lateral direction with no corresponding effect on the anterior-posterior direction immediately following the TENS application and 30 minutes after it in closed eyes conditions as compared to baseline. The application of TENS decreased the displacement and velocity of COP (p≤0.05), 30 minutes after the application of sensory electrical stimulation. The results showed that the mean displacement and velocity of COP decreased in eyes open position (p≤0.05). Also, immediately and 30 minutes after the application of sensory electrical stimulation, COP displacement and velocity in ML direction with eyes closed significantly decreased in the intervention group in comparison with control group (p≤0.05). Conclusion: The application of TENS in patients with chronic low back pain could improve postural control in these patients.

The effects of Transcutaneous Electrical Nerve Stimulation on postural control in patients with chronic low back pain

PubMed Central

Rojhani-Shirazi, Z; Rezaeian, T

2015-01-01

Objective: The effects of transcutaneous electrical nerve stimulation (TENS) on postural control in patients with low back pain which is not well known. This study aimed to evaluate the effects of TENS on postural control in chronic low back pain. Methods: This study was an experimental research design. Twenty-eight patients with chronic LBP (25-45 Y/ O) participated and by using a random allocation, were divided to samples who participated in this study. The mean center of pressure (COP) velocity and displacement were measured before, immediately and 30 min after the intervention. The tests were done with eyes open and closed on a force platform. Sensory electrical stimulation was applied through the TENS device. The descriptive statistics, independent sample T-test and ANOVA with repeated measurement on time were used for data analysis. Results: The results of the present study demonstrated that the application of the sensory electrical stimulation in chronic LBP patients showed a statistically significant improvement in postural control in Medio-lateral direction with no corresponding effect on the anterior-posterior direction immediately following the TENS application and 30 minutes after it in closed eyes conditions as compared to baseline. The application of TENS decreased the displacement and velocity of COP (p≤0.05), 30 minutes after the application of sensory electrical stimulation. The results showed that the mean displacement and velocity of COP decreased in eyes open position (p≤0.05). Also, immediately and 30 minutes after the application of sensory electrical stimulation, COP displacement and velocity in ML direction with eyes closed significantly decreased in the intervention group in comparison with control group (p≤0.05). Conclusion: The application of TENS in patients with chronic low back pain could improve postural control in these patients. PMID:28255392

In Vivo Electrochemical Evidence for Simultaneous 5-HT and Histamine Release in the Rat Substantia Nigra pars Reticulata Following Medial Forebrain Bundle Stimulation

PubMed Central

Hashemi, Parastoo; Dankoski, Elyse C.; Wood, Kevin M.; Ambrose, R. Ellen; Wightman, R. Mark

2011-01-01

Exploring the mechanisms of serotonin (5-hydoxytryptophan (5-HT)) in the brain requires an in vivo method that combines fast temporal resolution with chemical selectivity. Fast-scan cyclic voltammetry (FSCV) is a technique with sufficient temporal and chemical resolution for probing dynamic 5-HT neurotransmission events; however, traditionally it has not been possible to probe in vivo 5-HT mechanisms. Recently, we optimized FSCV for measuring 5-HT release and uptake in vivo in the substantia nigra pars reticulata (SNR) with electrical stimulation of the dorsal raphe nucleus (DRN) in the rat brain. Here, we address technical challenges associated with rat DRN surgery by electrically stimulating 5-HT projections in the medial forebrain bundle (MFB), a more accessible anatomical location. MFB stimulation elicits 5-HT in the SNR; furthermore, we find simultaneous release of an additional species. We use electrochemical and pharmacological methods and describe physiological, anatomical and independent chemical analyses to identify this species as histamine. We also show pharmacologically that increasing the lifetime of extracellular histamine significantly decreases 5-HT release, most likely due to increased activation of histamine H-3 receptors that inhibit 5-HT release. Despite this, under physiological conditions, we find by kinetic comparisons of DRN and MFB stimulations that the simultaneous release of histamine does not interfere with the quantitative 5-HT concentration profile. We therefore present a novel and robust electrical stimulation of the MFB that is technically less challenging than DRN stimulation to study 5-HT and histamine release in the SNR. PMID:21682723

[A physiological investigation of chronic electrical stimulation with scala tympani electrodes in kittens].

PubMed

Ni, D

1992-12-01

A physiological investigation of cochlear electrical stimulation was undertaken in six two-month-old kittens. The scala tympani electrodes were implanted and electrically stimulated using biphasic balanced electrical pulses for periods of 1000-1500h in four ears. Four ears received implants for same period but without electrical stimulation. The other two ears served as normal control. The results indicated: 1) Chronic electrical stimulation of the cochlea within electrochemically safe limits did not influence the hearing of kittens and the normal delivery of impulses evoked by acoustic and electrical signals on the auditory brainstem pathway. 2) The wave shapes of EABRs were similar to those of ABRs. The amplitudes of EABRs showed a significant increase following chronic electrical stimulation, resulting in a leftward shift in the input/output function. The absolute latencies and interwave latencies of waves II-III, III-IV and II-IV were significantly shorter than those of ABRs. These results imply that there was no adverse effect of chronic electrical stimulation on the maturing auditory systems of kittens using these electrical parameters and the mechanism of electrical hearing should be further studied.

A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty.

PubMed

Beckwée, David; Bautmans, Ivan; Swinnen, Eva; Vermet, Yorick; Lefeber, Nina; Lievens, Pierre; Vaes, Peter

2014-01-01

To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality.

Late administration of high-frequency electrical stimulation increases nerve regeneration without aggravating neuropathic pain in a nerve crush injury.

PubMed

Su, Hong-Lin; Chiang, Chien-Yi; Lu, Zong-Han; Cheng, Fu-Chou; Chen, Chun-Jung; Sheu, Meei-Ling; Sheehan, Jason; Pan, Hung-Chuan

2018-06-25

High-frequency transcutaneous neuromuscular electrical nerve stimulation (TENS) is currently used for the administration of electrical current in denervated muscle to alleviate muscle atrophy and enhance motor function; however, the time window (i.e. either immediate or delayed) for achieving benefit is still undetermined. In this study, we conducted an intervention of sciatic nerve crush injury using high-frequency TENS at different time points to assess the effect of motor and sensory functional recovery. Animals with left sciatic nerve crush injury received TENS treatment starting immediately after injury or 1 week later at a high frequency(100 Hz) or at a low frequency (2 Hz) as a control. In SFI gait analysis, either immediate or late admission of high-frequency electrical stimulation exerted significant improvement compared to either immediate or late administration of low-frequency electrical stimulation. In an assessment of allodynia, immediate high frequency electrical stimulation caused a significantly decreased pain threshold compared to late high-frequency or low-frequency stimulation at immediate or late time points. Immunohistochemistry staining and western blot analysis of S-100 and NF-200 demonstrated that both immediate and late high frequency electrical stimulation showed a similar effect; however the effect was superior to that achieved with low frequency stimulation. Immediate high frequency electrical stimulation resulted in significant expression of TNF-α and synaptophysin in the dorsal root ganglion, somatosensory cortex, and hippocampus compared to late electrical stimulation, and this trend paralleled the observed effect on somatosensory evoked potential. The CatWalk gait analysis also showed that immediate electrical stimulation led to a significantly high regularity index. In primary dorsal root ganglion cells culture, high-frequency electrical stimulation also exerted a significant increase in expression of TNF-α, synaptophysin, and NGF in accordance with the in vivo results. Immediate or late transcutaneous high-frequency electrical stimulation exhibited the potential to stimulate the motor nerve regeneration. However, immediate electrical stimulation had a predilection to develop neuropathic pain. A delay in TENS initiation appears to be a reasonable approach for nerve repair and provides the appropriate time profile for its clinical application.

Electrical stimulus artifact cancellation and neural spike detection on large multi-electrode arrays

PubMed Central

Grosberg, Lauren E.; Madugula, Sasidhar; Litke, Alan; Cunningham, John; Chichilnisky, E. J.; Paninski, Liam

2017-01-01

Simultaneous electrical stimulation and recording using multi-electrode arrays can provide a valuable technique for studying circuit connectivity and engineering neural interfaces. However, interpreting these measurements is challenging because the spike sorting process (identifying and segregating action potentials arising from different neurons) is greatly complicated by electrical stimulation artifacts across the array, which can exhibit complex and nonlinear waveforms, and overlap temporarily with evoked spikes. Here we develop a scalable algorithm based on a structured Gaussian Process model to estimate the artifact and identify evoked spikes. The effectiveness of our methods is demonstrated in both real and simulated 512-electrode recordings in the peripheral primate retina with single-electrode and several types of multi-electrode stimulation. We establish small error rates in the identification of evoked spikes, with a computational complexity that is compatible with real-time data analysis. This technology may be helpful in the design of future high-resolution sensory prostheses based on tailored stimulation (e.g., retinal prostheses), and for closed-loop neural stimulation at a much larger scale than currently possible. PMID:29131818

Predicting non-isometric fatigue induced by electrical stimulation pulse trains as a function of pulse duration

PubMed Central

2013-01-01

Background Our previous model of the non-isometric muscle fatigue that occurs during repetitive functional electrical stimulation included models of force, motion, and fatigue and accounted for applied load but not stimulation pulse duration. Our objectives were to: 1) further develop, 2) validate, and 3) present outcome measures for a non-isometric fatigue model that can predict the effect of a range of pulse durations on muscle fatigue. Methods A computer-controlled stimulator sent electrical pulses to electrodes on the thighs of 25 able-bodied human subjects. Isometric and non-isometric non-fatiguing and fatiguing knee torques and/or angles were measured. Pulse duration (170–600 μs) was the independent variable. Measurements were divided into parameter identification and model validation subsets. Results The fatigue model was simplified by removing two of three non-isometric parameters. The third remained a function of other model parameters. Between 66% and 77% of the variability in the angle measurements was explained by the new model. Conclusion Muscle fatigue in response to different stimulation pulse durations can be predicted during non-isometric repetitive contractions. PMID:23374142

Electrical stimulus artifact cancellation and neural spike detection on large multi-electrode arrays.

PubMed

Mena, Gonzalo E; Grosberg, Lauren E; Madugula, Sasidhar; Hottowy, Paweł; Litke, Alan; Cunningham, John; Chichilnisky, E J; Paninski, Liam

2017-11-01

Simultaneous electrical stimulation and recording using multi-electrode arrays can provide a valuable technique for studying circuit connectivity and engineering neural interfaces. However, interpreting these measurements is challenging because the spike sorting process (identifying and segregating action potentials arising from different neurons) is greatly complicated by electrical stimulation artifacts across the array, which can exhibit complex and nonlinear waveforms, and overlap temporarily with evoked spikes. Here we develop a scalable algorithm based on a structured Gaussian Process model to estimate the artifact and identify evoked spikes. The effectiveness of our methods is demonstrated in both real and simulated 512-electrode recordings in the peripheral primate retina with single-electrode and several types of multi-electrode stimulation. We establish small error rates in the identification of evoked spikes, with a computational complexity that is compatible with real-time data analysis. This technology may be helpful in the design of future high-resolution sensory prostheses based on tailored stimulation (e.g., retinal prostheses), and for closed-loop neural stimulation at a much larger scale than currently possible.

The Effects of Transcutaneous Electrical Stimulation on the Orthodontic Movement of Teeth.

DTIC Science & Technology

1985-05-01

Transcutaneous electrical nerve stimulation is an alternating electrical current applied k., ’ to the skin or gingiva with surface electrodes. Many...AD-AI68 889 THE EFFECTS OF TRANSCUTANEOUS ELECTRICAL STIMULATION ON 1/i THE ORTHODONTIC MOVEMENT OF TEETH(U) AIR FORCE INST OF TECH WRIGHT-PATTERSON...SPECIAL FIELD OF THE THESIS: of Transcutaneous Electrical Stimiu- Transcutaneous Electrical Stimulation lation on the Orthodontic Movement

Repeated cycles of electrical stimulation decrease vasoconstriction and axon-reflex vasodilation to noradrenaline in the human forearm

PubMed Central

Drummond, Peter D

2007-01-01

What is already known about this subject Repeated cycles of electrical stimulation inhibit cutaneous vasoconstriction to noradrenaline, but the mechanism is unknown. Investigating this is important because peripheral electrical stimulation is useful for pain modulation and appears to assist cutaneous wound healing. What this study adds Intermittent, brief electrical stimulation of the forearm over a 10-day period inhibited vasoconstriction and axon-reflex vasodilation to noradrenaline, but did not affect vasoconstriction to vasopressin or axon-reflex vasodilation to histamine. Thus, electrical stimulation may evoke a specific reduction in responsiveness to noradrenaline. Aim To investigate whether desensitization to the vasomotor effects of noradrenaline is a specific effect of electrical stimulation. Methods Three sites on the forearm of 10 healthy volunteers were stimulated with 0.2 mA direct current for 2 min twice daily for 10 days. Noradrenaline and histamine were then displaced from ring-shaped iontophoresis chambers into two of the pretreated sites and two untreated sites on the contralateral forearm. Axon-reflex vasodilation was measured from the centre of the ring described by the iontophoresis chamber with a laser Doppler flowmeter. One or two days later, noradrenaline and vasopressin were introduced into pretreated and untreated sites by iontophoresis, and vasoconstriction at sites of administration was measured in the heated forearm. Results The pretreatment blocked vasoconstriction to noradrenaline [median increase in flow 1%, interquartile range (IR) −41 to 52%; median decrease at the untreated site 53%, IR. −70 to −10%; P < 0.05], but did not block vasoconstriction to vasopressin (median decrease 42% at the untreated site and 45% at the pretreated site). Axon-reflex vasodilation to noradrenaline was diminished at the pretreated site (median increase in flow 33%, IR 2–321%; untreated site 247%, IR 31–1087%; P < 0.05). However, axon-reflex vasodilation to histamine did not differ significantly between the pretreated site (median increase 1085%) and the untreated site (median increase 1345%). Conclusions The conditioning pretreatment appears to evoke a specific decrease in responsiveness to noradrenaline. Repeated cycles of electrical stimulation may downregulate neural and vascular responses to noradrenaline by repetitively activating cutaneous sympathetic nerve fibres. PMID:17441931

Cisplatin-induced gastric dysrhythmia and emesis in dogs and possible role of gastric electrical stimulation.

PubMed

Yu, Xiaoyun; Yang, Jie; Hou, Xiaohua; Zhang, Kan; Qian, Wei; Chen, J D Z

2009-05-01

The aim of this study was to investigate the effect of cisplatin on gastric myoelectrical activity and the role of gastric electrical stimulation in the treatment of cisplatin-induced emesis in dogs. Seven dogs implanted with electrodes on the gastric serosa were used in a two-session study. Cisplatin was infused in both the control session and the gastric electrical stimulation session, and gastric electrical stimulation was applied in the gastric electrical stimulation session. Gastric slow waves and emesis, as well as behaviors suggestive of nausea, were recorded during each session. The results were as follows: (1) cisplatin induced vomiting and other symptoms and induced gastric dysrhythmia. The percentage of normal slow waves decreased significantly during the 2.5 h before vomiting (P=0.01) and the period of vomiting (P<0.001). (2) Gastric electrical stimulation reduced emesis and the symptoms score. The total score in the control session was higher than that in the gastric electrical stimulation session (P=0.02). However, gastric electrical stimulation had no effects on gastric dysrhythmia. It is concluded that cisplatin induces emesis and gastric dysrhythmia. Gastric electrical stimulation may play a role in relieving chemotherapy-induced emetic responses and deserves further investigation.

Immediate effect of laryngeal surface electrical stimulation on swallowing performance.

PubMed

Takahashi, Keizo; Hori, Kazuhiro; Hayashi, Hirokazu; Fujiu-Kurachi, Masako; Ono, Takahiro; Tsujimura, Takanori; Magara, Jin; Inoue, Makoto

2018-01-01

Surface electrical stimulation of the laryngeal region is used to improve swallowing in dysphagic patients. However, little is known about how electrical stimulation affects tongue movements and related functions. We investigated the effect of electrical stimulation on tongue pressure and hyoid movement, as well as suprahyoid and infrahyoid muscle activity, in 18 healthy young participants. Electrical stimulation (0.2-ms duration, 80 Hz, 80% of each participant's maximal tolerance) of the laryngeal region was applied. Each subject swallowed 5 ml of barium sulfate liquid 36 times at 10-s intervals. During the middle 2 min, electrical stimulation was delivered. Tongue pressure, electromyographic activity of the suprahyoid and infrahyoid muscles, and videofluorographic images were simultaneously recorded. Tongue pressure during stimulation was significantly lower than before or after stimulation and was significantly greater after stimulation than at baseline. Suprahyoid activity after stimulation was larger than at baseline, while infrahyoid muscle activity did not change. During stimulation, the position of the hyoid at rest was descended, the highest hyoid position was significantly inferior, and the vertical movement was greater than before or after stimulation. After stimulation, the positions of the hyoid at rest and at the maximum elevation were more superior than before stimulation. The deviation of the highest positions of the hyoid before and after stimulation corresponded to the differences in tongue pressures at those times. These results suggest that surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. NEW & NOTEWORTHY Surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. Tongue muscles may contribute to overshot recovery more than hyoid muscles.

Common neural structures activated by epidural and transcutaneous lumbar spinal cord stimulation: Elicitation of posterior root-muscle reflexes

PubMed Central

Freundl, Brigitta; Binder, Heinrich; Minassian, Karen

2018-01-01

Epidural electrical stimulation of the lumbar spinal cord is currently regaining momentum as a neuromodulation intervention in spinal cord injury (SCI) to modify dysregulated sensorimotor functions and augment residual motor capacity. There is ample evidence that it engages spinal circuits through the electrical stimulation of large-to-medium diameter afferent fibers within lumbar and upper sacral posterior roots. Recent pilot studies suggested that the surface electrode-based method of transcutaneous spinal cord stimulation (SCS) may produce similar neuromodulatory effects as caused by epidural SCS. Neurophysiological and computer modeling studies proposed that this noninvasive technique stimulates posterior-root fibers as well, likely activating similar input structures to the spinal cord as epidural stimulation. Here, we add a yet missing piece of evidence substantiating this assumption. We conducted in-depth analyses and direct comparisons of the electromyographic (EMG) characteristics of short-latency responses in multiple leg muscles to both stimulation techniques derived from ten individuals with SCI each. Post-activation depression of responses evoked by paired pulses applied either epidurally or transcutaneously confirmed the reflex nature of the responses. The muscle responses to both techniques had the same latencies, EMG peak-to-peak amplitudes, and waveforms, except for smaller responses with shorter onset latencies in the triceps surae muscle group and shorter offsets of the responses in the biceps femoris muscle during epidural stimulation. Responses obtained in three subjects tested with both methods at different time points had near-identical waveforms per muscle group as well as same onset latencies. The present results strongly corroborate the activation of common neural input structures to the lumbar spinal cord—predominantly primary afferent fibers within multiple posterior roots—by both techniques and add to unraveling the basic mechanisms underlying electrical SCS. PMID:29381748

76 FR 48062 - Effective Date of Requirement for Premarket Approval for Cranial Electrotherapy Stimulator

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

... devices include headaches following treatment with electrical stimulation. Potential risk of seizure--electrical stimulation of the brain may result in seizures, particularly in patients with a history of... effects from electrical stimulation of the brain--The physiological effects associated with electrical...

Monitoring the bio-stimulation of hydrocarbon-contaminated soils by measurements of soil electrical properties, and CO2 content and its 13C/12C isotopic signature

NASA Astrophysics Data System (ADS)

Noel, C.; Gourry, J.; Ignatiadis, I.; Colombano, S.; Dictor, M.; Guimbaud, C.; Chartier, M.; Dumestre, A.; Dehez, S.; Naudet, V.

2013-12-01

Hydrocarbon contaminated soils represent an environmental issue as it impacts on ecosystems and aquifers. Where significant subsurface heterogeneity exists, conventional intrusive investigations and groundwater sampling can be insufficient to obtain a robust monitoring of hydrocarbon contaminants, as the information they provide is restricted to vertical profiles at discrete locations, with no information between sampling points. In order to obtain wider information in space volume on subsurface modifications, complementary methods can be used like geophysics. Among geophysical methods, geoelectrical techniques such as electrical resistivity (ER) and induced polarization (IP) seem the more promising, especially to study the effects of biodegradation processes. Laboratory and field geoelectrical experiments to characterize soils contaminated by oil products have shown that mature hydrocarbon-contaminated soils are characterized by enhanced electrical conductivity although hydrocarbons are electrically resistive. This high bulk conductivity is due to bacterial impacts on geological media, resulting in changes in the chemical and physical properties and thus, to the geophysical properties of the ground. Moreover, microbial activity induced CO2 production and isotopic deviation of carbon. Indeed, produced CO2 will reflect the pollutant isotopic signature. Thus, the ratio δ13C(CO2) will come closer to δ13C(hydrocarbon). BIOPHY, project supported by the French National Research Agency (ANR), proposes to use electrical methods and gas analyses to develop an operational and non-destructive method for monitoring in situ biodegradation of hydrocarbons in order to optimize soil treatment. Demonstration field is located in the South of Paris (France), where liquid fuels (gasoline and diesel) leaked from some tanks in 1997. In order to stimulate biodegradation, a trench has been dug to supply oxygen to the water table and thus stimulate aerobic metabolic bioprocesses. ER and IP surveys are performed regularly to monitor the stimulated biodegradation and progress of remediation until soil cleanup. Microbial activity is characterized by CO2 production increase and δ13C isotopic deviation, in the produced CO2 measured by infrared laser spectroscopy, and by an evolution of electrical conductivity and IP responses in correlation with microbiological and chemical analyses.

Utilising reinforcement learning to develop strategies for driving auditory neural implants.

PubMed

Lee, Geoffrey W; Zambetta, Fabio; Li, Xiaodong; Paolini, Antonio G

2016-08-01

In this paper we propose a novel application of reinforcement learning to the area of auditory neural stimulation. We aim to develop a simulation environment which is based off real neurological responses to auditory and electrical stimulation in the cochlear nucleus (CN) and inferior colliculus (IC) of an animal model. Using this simulator we implement closed loop reinforcement learning algorithms to determine which methods are most effective at learning effective acoustic neural stimulation strategies. By recording a comprehensive set of acoustic frequency presentations and neural responses from a set of animals we created a large database of neural responses to acoustic stimulation. Extensive electrical stimulation in the CN and the recording of neural responses in the IC provides a mapping of how the auditory system responds to electrical stimuli. The combined dataset is used as the foundation for the simulator, which is used to implement and test learning algorithms. Reinforcement learning, utilising a modified n-Armed Bandit solution, is implemented to demonstrate the model's function. We show the ability to effectively learn stimulation patterns which mimic the cochlea's ability to covert acoustic frequencies to neural activity. Time taken to learn effective replication using neural stimulation takes less than 20 min under continuous testing. These results show the utility of reinforcement learning in the field of neural stimulation. These results can be coupled with existing sound processing technologies to develop new auditory prosthetics that are adaptable to the recipients current auditory pathway. The same process can theoretically be abstracted to other sensory and motor systems to develop similar electrical replication of neural signals.

Neuromechanism Study of Insect–Machine Interface: Flight Control by Neural Electrical Stimulation

PubMed Central

Zhao, Huixia; Zheng, Nenggan; Ribi, Willi A.; Zheng, Huoqing; Xue, Lei; Gong, Fan; Zheng, Xiaoxiang; Hu, Fuliang

2014-01-01

The insect–machine interface (IMI) is a novel approach developed for man-made air vehicles, which directly controls insect flight by either neuromuscular or neural stimulation. In our previous study of IMI, we induced flight initiation and cessation reproducibly in restrained honeybees (Apis mellifera L.) via electrical stimulation of the bilateral optic lobes. To explore the neuromechanism underlying IMI, we applied electrical stimulation to seven subregions of the honeybee brain with the aid of a new method for localizing brain regions. Results showed that the success rate for initiating honeybee flight decreased in the order: α-lobe (or β-lobe), ellipsoid body, lobula, medulla and antennal lobe. Based on a comparison with other neurobiological studies in honeybees, we propose that there is a cluster of descending neurons in the honeybee brain that transmits neural excitation from stimulated brain areas to the thoracic ganglia, leading to flight behavior. This neural circuit may involve the higher-order integration center, the primary visual processing center and the suboesophageal ganglion, which is also associated with a possible learning and memory pathway. By pharmacologically manipulating the electrically stimulated honeybee brain, we have shown that octopamine, rather than dopamine, serotonin and acetylcholine, plays a part in the circuit underlying electrically elicited honeybee flight. Our study presents a new brain stimulation protocol for the honeybee–machine interface and has solved one of the questions with regard to understanding which functional divisions of the insect brain participate in flight control. It will support further studies to uncover the involved neurons inside specific brain areas and to test the hypothesized involvement of a visual learning and memory pathway in IMI flight control. PMID:25409523

Neuromechanism study of insect-machine interface: flight control by neural electrical stimulation.

PubMed

Zhao, Huixia; Zheng, Nenggan; Ribi, Willi A; Zheng, Huoqing; Xue, Lei; Gong, Fan; Zheng, Xiaoxiang; Hu, Fuliang

2014-01-01

The insect-machine interface (IMI) is a novel approach developed for man-made air vehicles, which directly controls insect flight by either neuromuscular or neural stimulation. In our previous study of IMI, we induced flight initiation and cessation reproducibly in restrained honeybees (Apis mellifera L.) via electrical stimulation of the bilateral optic lobes. To explore the neuromechanism underlying IMI, we applied electrical stimulation to seven subregions of the honeybee brain with the aid of a new method for localizing brain regions. Results showed that the success rate for initiating honeybee flight decreased in the order: α-lobe (or β-lobe), ellipsoid body, lobula, medulla and antennal lobe. Based on a comparison with other neurobiological studies in honeybees, we propose that there is a cluster of descending neurons in the honeybee brain that transmits neural excitation from stimulated brain areas to the thoracic ganglia, leading to flight behavior. This neural circuit may involve the higher-order integration center, the primary visual processing center and the suboesophageal ganglion, which is also associated with a possible learning and memory pathway. By pharmacologically manipulating the electrically stimulated honeybee brain, we have shown that octopamine, rather than dopamine, serotonin and acetylcholine, plays a part in the circuit underlying electrically elicited honeybee flight. Our study presents a new brain stimulation protocol for the honeybee-machine interface and has solved one of the questions with regard to understanding which functional divisions of the insect brain participate in flight control. It will support further studies to uncover the involved neurons inside specific brain areas and to test the hypothesized involvement of a visual learning and memory pathway in IMI flight control.

Neuromuscular electrostimulation techniques: historical aspects and current possibilities in treatment of pain and muscle waisting.

PubMed

Heidland, August; Fazeli, Gholamreza; Klassen, André; Sebekova, Katarina; Hennemann, Hans; Bahner, Udo; Di Iorio, Biagio

2013-01-01

Application of electricity for pain treatment dates back to thousands of years BC. The Ancient Egyptians and later the Greeks and Romans recognized that electrical fishes are capable of generating electric shocks for relief of pain. In the 18th and 19th centuries these natural producers of electricity were replaced by man-made electrical devices. This happened in following phases. The first was the application of static electrical currents (called Franklinism), which was produced by a friction generator. Christian Kratzenstein was the first to apply it medically, followed shortly by Benjamin Franklin. The second phase was Galvanism. This method applied a direct electrical current to the skin by chemical means, applied a direct and pulsed electrical current to the skin. In the third phase the electrical current was induced intermittently and in alternate directions (called Faradism). The fourth stage was the use of high frequency currents (called d'Arsonvalisation). The 19th century was the "golden age" of electrotherapy. It was used for countless dental, neurological, psychiatric and gynecological disturbances. However, at beginning of the 20th century electrotherapy fell from grace. It was dismissed as lacking a scientific basis and being used also by quacks and charlatans for unserious aims. Furthermore, the development of effective analgesic drugs decreased the interest in electricity. In the second half of the 20th century electrotherapy underwent a revival. Based on animal experiments and clinical investigations, its neurophysiological mechanisms were elucidated in more details. The pain relieving action of electricity was explained in particular by two main mechanisms: first, segmental inhibition of pain signals to the brain in the dorsal horn of the spinal cord and second, activation of the descending inhibitory pathway with enhanced release of endogenous opioids and other neurochemical compounds (serotonin, noradrenaline, gamma aminobutyric acid (GABA), acetylcholine and adenosine). The modern electrotherapy of neuromusculo- skeletal pain is based in particular on the following types: transcutaneous electrical nerve stimulation (TENS), percutaneous electrical nerve stimulation (PENS or electro-acupuncture) and spinal cord stimulation (SCS). In mild to moderate pain, TENS and PENS are effective methods, whereas SCS is very useful for therapy of refractory neuropathic or ischemic pain. In 2005, high tone external muscle stimulation (HTEMS) was introduced. In diabetic peripheral neuropathy, its analgesic action was more pronounced than TENS application. HTEMS appeared also to have value in the therapy of symptomatic peripheral neuropathy in end-stage renal disease (ESRD). Besides its pain-relieving effect, electrical stimulation is of major importance for prevention or treatment of muscle dysfunction and sarcopenia. In controlled clinical studies electrical myostimulation (EMS) has been shown to be effective against the sarcopenia of patients with chronic congestive heart disease, diabetes, chronic obstructive pulmonary disease and ESRD.

Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields.

PubMed

Ruffini, Giulio; Fox, Michael D; Ripolles, Oscar; Miranda, Pedro Cavaleiro; Pascual-Leone, Alvaro

2014-04-01

Recently, multifocal transcranial current stimulation (tCS) devices using several relatively small electrodes have been used to achieve more focal stimulation of specific cortical targets. However, it is becoming increasingly recognized that many behavioral manifestations of neurological and psychiatric disease are not solely the result of abnormality in one isolated brain region but represent alterations in brain networks. In this paper we describe a method for optimizing the configuration of multifocal tCS for stimulation of brain networks, represented by spatially extended cortical targets. We show how, based on fMRI, PET, EEG or other data specifying a target map on the cortical surface for excitatory, inhibitory or neutral stimulation and a constraint on the maximal number of electrodes, a solution can be produced with the optimal currents and locations of the electrodes. The method described here relies on a fast calculation of multifocal tCS electric fields (including components normal and tangential to the cortical boundaries) using a five layer finite element model of a realistic head. Based on the hypothesis that the effects of current stimulation are to first order due to the interaction of electric fields with populations of elongated cortical neurons, it is argued that the optimization problem for tCS stimulation can be defined in terms of the component of the electric field normal to the cortical surface. Solutions are found using constrained least squares to optimize current intensities, while electrode number and their locations are selected using a genetic algorithm. For direct current tCS (tDCS) applications, we provide some examples of this technique using an available tCS system providing 8 small Ag/AgCl stimulation electrodes. We demonstrate the approach both for localized and spatially extended targets defined using rs-fcMRI and PET data, with clinical applications in stroke and depression. Finally, we extend these ideas to more general stimulation protocols, such as alternating current tCS (tACS). Copyright © 2013 Elsevier Inc. All rights reserved.

Saturation in Phosphene Size with Increasing Current Levels Delivered to Human Visual Cortex.

PubMed

Bosking, William H; Sun, Ping; Ozker, Muge; Pei, Xiaomei; Foster, Brett L; Beauchamp, Michael S; Yoshor, Daniel

2017-07-26

Electrically stimulating early visual cortex results in a visual percept known as a phosphene. Although phosphenes can be evoked by a wide range of electrode sizes and current amplitudes, they are invariably described as small. To better understand this observation, we electrically stimulated 93 electrodes implanted in the visual cortex of 13 human subjects who reported phosphene size while stimulation current was varied. Phosphene size increased as the stimulation current was initially raised above threshold, but then rapidly reached saturation. Phosphene size also depended on the location of the stimulated site, with size increasing with distance from the foveal representation. We developed a model relating phosphene size to the amount of activated cortex and its location within the retinotopic map. First, a sigmoidal curve was used to predict the amount of activated cortex at a given current. Second, the amount of active cortex was converted to degrees of visual angle by multiplying by the inverse cortical magnification factor for that retinotopic location. This simple model accurately predicted phosphene size for a broad range of stimulation currents and cortical locations. The unexpected saturation in phosphene sizes suggests that the functional architecture of cerebral cortex may impose fundamental restrictions on the spread of artificially evoked activity and this may be an important consideration in the design of cortical prosthetic devices. SIGNIFICANCE STATEMENT Understanding the neural basis for phosphenes, the visual percepts created by electrical stimulation of visual cortex, is fundamental to the development of a visual cortical prosthetic. Our experiments in human subjects implanted with electrodes over visual cortex show that it is the activity of a large population of cells spread out across several millimeters of tissue that supports the perception of a phosphene. In addition, we describe an important feature of the production of phosphenes by electrical stimulation: phosphene size saturates at a relatively low current level. This finding implies that, with current methods, visual prosthetics will have a limited dynamic range available to control the production of spatial forms and that more advanced stimulation methods may be required. Copyright © 2017 the authors 0270-6474/17/377188-10$15.00/0.

9 CFR 307.7 - Safety requirements for electrical stimulating (EST) equipment.

Code of Federal Regulations, 2012 CFR

2012-01-01

... requirements for electrical stimulating (EST) equipment. (a) General. Electrical stimulating (EST) equipment is... of facilitating blood removal. These provisions do not apply to electrical equipment used to stun and... generate pulsed DC or AC voltage for stimulation and is separate from the equipment used to apply the...

9 CFR 307.7 - Safety requirements for electrical stimulating (EST) equipment.

Code of Federal Regulations, 2014 CFR

2014-01-01

... requirements for electrical stimulating (EST) equipment. (a) General. Electrical stimulating (EST) equipment is... of facilitating blood removal. These provisions do not apply to electrical equipment used to stun and... generate pulsed DC or AC voltage for stimulation and is separate from the equipment used to apply the...

[Selective training of the vastus medialis muscle using electrical stimulator for chondromalacia patella].

PubMed

Guo, K; Ye, Q; Lin, J; Shen, J; Yang, X

1996-04-01

Chondromalacia patella is closely related with subluxation and tilt of patella, as well as with muscular atrophy of quadriceps, especially in vastus medialis muscle. 364 cases of chondromalacia patella were treated with selective training of the vastus medialis muscle using electrical stimulator in our hospital. 211 cases were followed up after treatment from 6 months to 3 years. Among them excellent and good results were seen in 130 cases (62%), fair results were seen in 69 cases (33%) and no change was seen in 12 cases (5%). Significant reduction of CA (P < 0.01) and LPA (P < 0.001) were observed in all these patients in comparison with their primary angle. We believe that the selective training of the vastus medialis muscle using electrical stimulator is one of the effective methods for the treatment of chondromalacia patella.

Electric Field Comparison between Microelectrode Recording and Deep Brain Stimulation Systems—A Simulation Study

PubMed Central

Johansson, Johannes; Wårdell, Karin; Hemm, Simone

2018-01-01

The success of deep brain stimulation (DBS) relies primarily on the localization of the implanted electrode. Its final position can be chosen based on the results of intraoperative microelectrode recording (MER) and stimulation tests. The optimal position often differs from the final one selected for chronic stimulation with the DBS electrode. The aim of the study was to investigate, using finite element method (FEM) modeling and simulations, whether lead design, electrical setup, and operating modes induce differences in electric field (EF) distribution and in consequence, the clinical outcome. Finite element models of a MER system and a chronic DBS lead were developed. Simulations of the EF were performed for homogenous and patient-specific brain models to evaluate the influence of grounding (guide tube vs. stimulator case), parallel MER leads, and non-active DBS contacts. Results showed that the EF is deformed depending on the distance between the guide tube and stimulating contact. Several parallel MER leads and the presence of the non-active DBS contacts influence the EF distribution. The DBS EF volume can cover the intraoperatively produced EF, but can also extend to other anatomical areas. In conclusion, EF deformations between stimulation tests and DBS should be taken into consideration as they can alter the clinical outcome. PMID:29415442

Tinnitus treatment with precise and optimal electric stimulation: opportunities and challenges.

PubMed

Zeng, Fan-Gang; Djalilian, Hamid; Lin, Harrison

2015-10-01

Electric stimulation is a potent means of neuromodulation that has been used to restore hearing and minimize tremor, but its application on tinnitus symptoms has been limited. We examine recent evidence to identify the knowledge gaps in the use of electric stimulation for tinnitus treatment. Recent studies using electric stimulation to suppress tinnitus in humans are categorized according to their points of attacks. First, noninvasive, direct current stimulation uses an active electrode in the ear canal, tympanic membrane, or temporal scalp. Second, inner ear stimulation uses charge-balanced biphasic stimulation by placing an active electrode on the promontory or round window, or a cochlear implant array in the cochlea. Third, intraneural implants can provide targeted stimulation of specific sites along the auditory pathway. Although these studies demonstrated some success in tinnitus suppression, none established a link between tinnitus suppression efficacy and tinnitus-generating mechanisms. Electric stimulation provides a unique opportunity to suppress tinnitus. Challenges include matching electric stimulation sites and patterns to tinnitus locus and type, meeting the oftentimes-contradictory demands between tinnitus suppression and other indications, such as speech understanding, and justifying the costs and risks of electric stimulation for tinnitus symptoms.

Tinnitus Treatment with Precise and Optimal Electric Stimulation: Opportunities and Challenges

PubMed Central

Zeng, Fan-Gang; Djalilian, Hamid; Lin, Harrison

2015-01-01

Purpose of review Electric stimulation is a potent means of neuromodulation that has been used to restore hearing and minimize tremor, but its application on tinnitus symptoms has been limited. We examine recent evidence to identify the knowledge gaps in the use of electric stimulation for tinnitus treatment. Recent findings Recent studies using electric stimulation to suppress tinnitus in humans are categorized according to their points of attacks. First, non-invasive, direct-current stimulation uses an active electrode in the ear canal, tympanic membrane or temporal scalp. Second, inner ear stimulation uses charge-balanced biphasic stimulation by placing an active electrode on the promontory or round window, or a cochlear implant array in the cochlea. Third, intraneural implants can provide targeted stimulation of specific sites along the auditory pathway. Although these studies demonstrated some success in tinnitus suppression, none established a link between tinnitus suppression efficacy and tinnitus-generating mechanisms. Summary Electric stimulation provides a unique opportunity to suppress tinnitus. Challenges include matching electric stimulation sites and patterns to tinnitus locus and type, meeting the oftentimes-contradictory demands between tinnitus suppression and other indications, such as speech understanding, and justifying the costs and risks of electric stimulation for tinnitus symptoms. PMID:26208122

Comparison of electric field strength and spatial distribution of electroconvulsive therapy and magnetic seizure therapy in a realistic human head model

PubMed Central

Lee, Won Hee; Lisanby, Sarah H.; Laine, Andrew F.; Peterchev, Angel V.

2017-01-01

Background This study examines the strength and spatial distribution of the electric field induced in the brain by electroconvulsive therapy (ECT) and magnetic seizure therapy (MST). Methods The electric field induced by standard (bilateral, right unilateral, and bifrontal) and experimental (focal electrically administered seizure therapy and frontomedial) ECT electrode configurations as well as a circular MST coil configuration was simulated in an anatomically realistic finite element model of the human head. Maps of the electric field strength relative to an estimated neural activation threshold were used to evaluate the stimulation strength and focality in specific brain regions of interest for these ECT and MST paradigms and various stimulus current amplitudes. Results The standard ECT configurations and current amplitude of 800–900 mA produced the strongest overall stimulation with median of 1.8–2.9 times neural activation threshold and more than 94% of the brain volume stimulated at suprathreshold level. All standard ECT electrode placements exposed the hippocampi to suprathreshold electric field, although there were differences across modalities with bilateral and right unilateral producing respectively the strongest and weakest hippocampal stimulation. MST stimulation is up to 9 times weaker compared to conventional ECT, resulting in direct activation of only 21% of the brain. Reducing the stimulus current amplitude can make ECT as focal as MST. Conclusions The relative differences in electric field strength may be a contributing factor for the cognitive sparing observed with right unilateral compared to bilateral ECT, and MST compared to right unilateral ECT. These simulations could help understand the mechanisms of seizure therapies and develop interventions with superior risk/benefit ratio. PMID:27318858

ADVANCED ELECTROSTATIC ENHANCEMENT OF FABRIC FILTRATION

EPA Science Inventory

The paper discusses laboratory and pilot plant studies of a modification of the U.S. EPA's Electrically Stimulated Fabric Filtration (ESFF) method in which corona voltage on a center-wire electrode replaces the subcorona electrodes at the bag surface. The electric field which aff...

Chronic Electrical Stimulation with a Suprachoroidal Retinal Prosthesis: A Preclinical Safety and Efficacy Study

PubMed Central

Nayagam, David A. X.; Williams, Richard A.; Allen, Penelope J.; Shivdasani, Mohit N.; Luu, Chi D.; Salinas-LaRosa, Cesar M.; Finch, Sue; Ayton, Lauren N.; Saunders, Alexia L.; McPhedran, Michelle; McGowan, Ceara; Villalobos, Joel; Fallon, James B.; Wise, Andrew K.; Yeoh, Jonathan; Xu, Jin; Feng, Helen; Millard, Rodney; McWade, Melanie; Thien, Patrick C.; Williams, Chris E.; Shepherd, Robert K.

2014-01-01

Purpose To assess the safety and efficacy of chronic electrical stimulation of the retina with a suprachoroidal visual prosthesis. Methods Seven normally-sighted feline subjects were implanted for 96–143 days with a suprachoroidal electrode array and six were chronically stimulated for 70–105 days at levels that activated the visual cortex. Charge balanced, biphasic, current pulses were delivered to platinum electrodes in a monopolar stimulation mode. Retinal integrity/function and the mechanical stability of the implant were assessed monthly using electroretinography (ERG), optical coherence tomography (OCT) and fundus photography. Electrode impedances were measured weekly and electrically-evoked visual cortex potentials (eEVCPs) were measured monthly to verify that chronic stimuli were suprathreshold. At the end of the chronic stimulation period, thresholds were confirmed with multi-unit recordings from the visual cortex. Randomized, blinded histological assessments were performed by two pathologists to compare the stimulated and non-stimulated retina and adjacent tissue. Results All subjects tolerated the surgical and stimulation procedure with no evidence of discomfort or unexpected adverse outcomes. After an initial post-operative settling period, electrode arrays were mechanically stable. Mean electrode impedances were stable between 11–15 kΩ during the implantation period. Visually-evoked ERGs & OCT were normal, and mean eEVCP thresholds did not substantially differ over time. In 81 of 84 electrode-adjacent tissue samples examined, there were no discernible histopathological differences between stimulated and unstimulated tissue. In the remaining three tissue samples there were minor focal fibroblastic and acute inflammatory responses. Conclusions Chronic suprathreshold electrical stimulation of the retina using a suprachoroidal electrode array evoked a minimal tissue response and no adverse clinical or histological findings. Moreover, thresholds and electrode impedance remained stable for stimulation durations of up to 15 weeks. This study has demonstrated the safety and efficacy of suprachoroidal stimulation with charge balanced stimulus currents. PMID:24853376

Biomedical engineering meets acupuncture - development of a miniaturized 48-channel skin impedance measurement system for needle and laser acupuncture

PubMed Central

2010-01-01

Background Due to controversially discussed results in scientific literature concerning changes of electrical skin impedance before and during acupuncture a new measurement system has been developed. Methods The prototype measures and analyzes the electrical skin impedance computer-based and simultaneously in 48 channels within a 2.5×3.5 cm matrix. Preliminary measurements in one person were performed using metal needle and violet laser (405 nm) acupuncture at the acupoint Kongzui (LU6). The new system is an improvement on devices previously developed by other researchers for this purpose. Results Skin impedance in the immediate surroundings of the acupoint was lowered reproducibly following needle stimulation and also violet laser stimulation. Conclusions A new instrumentation for skin impedance measurements is presented. The following hypotheses suggested by our results will have to be tested in further studies: Needle acupuncture causes significant, specific local changes of electrical skin impedance parameters. Optical stimulation (violet laser) at an acupoint causes direct electrical biosignal changes. PMID:21092296

Non-invasive peripheral nerve stimulation via focused ultrasound in vivo

NASA Astrophysics Data System (ADS)

Downs, Matthew E.; Lee, Stephen A.; Yang, Georgiana; Kim, Seaok; Wang, Qi; Konofagou, Elisa E.

2018-02-01

Focused ultrasound (FUS) has been employed on a wide range of clinical applications to safely and non-invasively achieve desired effects that have previously required invasive and lengthy procedures with conventional methods. Conventional electrical neuromodulation therapies that are applied to the peripheral nervous system (PNS) are invasive and/or non-specific. Recently, focused ultrasound has demonstrated the ability to modulate the central nervous system and ex vivo peripheral neurons. Here, for the first time, noninvasive stimulation of the sciatic nerve eliciting a physiological response in vivo is demonstrated with FUS. FUS was applied on the sciatic nerve in mice with simultaneous electromyography (EMG) on the tibialis anterior muscle. EMG signals were detected during or directly after ultrasound stimulation along with observable muscle contraction of the hind limb. Transecting the sciatic nerve downstream of FUS stimulation eliminated EMG activity during FUS stimulation. Peak-to-peak EMG response amplitudes and latency were found to be comparable to conventional electrical stimulation methods. Histology along with behavioral and thermal testing did not indicate damage to the nerve or surrounding regions. The findings presented herein demonstrate that FUS can serve as a targeted, safe and non-invasive alternative to conventional peripheral nervous system stimulation to treat peripheral neuropathic diseases in the clinic.

Methods of automated absence seizure detection, interference by stimulation, and possibilities for prediction in genetic absence models.

PubMed

van Luijtelaar, Gilles; Lüttjohann, Annika; Makarov, Vladimir V; Maksimenko, Vladimir A; Koronovskii, Alexei A; Hramov, Alexander E

2016-02-15

Genetic rat models for childhood absence epilepsy have become instrumental in developing theories on the origin of absence epilepsy, the evaluation of new and experimental treatments, as well as in developing new methods for automatic seizure detection, prediction, and/or interference of seizures. Various methods for automated off and on-line analyses of ECoG in rodent models are reviewed, as well as data on how to interfere with the spike-wave discharges by different types of invasive and non-invasive electrical, magnetic, and optical brain stimulation. Also a new method for seizure prediction is proposed. Many selective and specific methods for off- and on-line spike-wave discharge detection seem excellent, with possibilities to overcome the issue of individual differences. Moreover, electrical deep brain stimulation is rather effective in interrupting ongoing spike-wave discharges with low stimulation intensity. A network based method is proposed for absence seizures prediction with a high sensitivity but a low selectivity. Solutions that prevent false alarms, integrated in a closed loop brain stimulation system open the ways for experimental seizure control. The presence of preictal cursor activity detected with state of the art time frequency and network analyses shows that spike-wave discharges are not caused by sudden and abrupt transitions but that there are detectable dynamic events. Their changes in time-space-frequency characteristics might yield new options for seizure prediction and seizure control. Copyright © 2015 Elsevier B.V. All rights reserved.

Functional Electrical Stimulation in Children and Adolescents with Cerebral Palsy

ERIC Educational Resources Information Center

van der Linden, Marietta

2012-01-01

In this article, the author talks about functional electrical stimulation in children and adolescents with cerebral palsy. Functional electrical stimulation (FES) is defined as the electrical stimulation of muscles that have impaired motor control, in order to produce a contraction to obtain functionally useful movement. It was first proposed in…

COMETS2: An advanced MATLAB toolbox for the numerical analysis of electric fields generated by transcranial direct current stimulation.

PubMed

Lee, Chany; Jung, Young-Jin; Lee, Sang Jun; Im, Chang-Hwan

2017-02-01

Since there is no way to measure electric current generated by transcranial direct current stimulation (tDCS) inside the human head through in vivo experiments, numerical analysis based on the finite element method has been widely used to estimate the electric field inside the head. In 2013, we released a MATLAB toolbox named COMETS, which has been used by a number of groups and has helped researchers to gain insight into the electric field distribution during stimulation. The aim of this study was to develop an advanced MATLAB toolbox, named COMETS2, for the numerical analysis of the electric field generated by tDCS. COMETS2 can generate any sizes of rectangular pad electrodes on any positions on the scalp surface. To reduce the large computational burden when repeatedly testing multiple electrode locations and sizes, a new technique to decompose the global stiffness matrix was proposed. As examples of potential applications, we observed the effects of sizes and displacements of electrodes on the results of electric field analysis. The proposed mesh decomposition method significantly enhanced the overall computational efficiency. We implemented an automatic electrode modeler for the first time, and proposed a new technique to enhance the computational efficiency. In this paper, an efficient toolbox for tDCS analysis is introduced (freely available at http://www.cometstool.com). It is expected that COMETS2 will be a useful toolbox for researchers who want to benefit from the numerical analysis of electric fields generated by tDCS. Copyright © 2016. Published by Elsevier B.V.

Efficacy of electroacupuncture compared with transcutaneous electric nerve stimulation for functional constipation

PubMed Central

Zeng, Yuxiao; Zhang, Xuecheng; Zhou, Jing; Wang, Xinwei; Jiao, Ruimin; Liu, Zhishun

2018-01-01

Abstract Background: To treat functional constipation, both electroacupuncture (EA) therapy and transcutaneous electric nerve stimulation (TENS) are safe and effective. However, no head-to-head comparison trial has been conducted. This trial compares the efficacy of electroacupuncture relative to transcutaneous electric nerve stimulation for functional constipation. Methods: Individuals with functional constipation will be randomly allocated to receive either EA or TENS (n = 51, each), 3 times per week for 8 weeks. The primary outcome is the percentage of participants with an average increase from baseline of 1 or more complete spontaneous bowel movements at week 8. The secondary outcome measures are the following: at the time of visits, changes in the number of complete spontaneous bowel movements, number of spontaneous bowel movements, stool character, difficulty in defecation, patients’ assessment of quality of life regarding constipation (self-report questionnaire), and use of auxiliary defecation methods. Discussion: The results of this trial should verify whether EA is more efficacious than TENS for relieving symptoms of functional constipation. The major limitation of the study is the lack of blinding of the participants and acupuncturist. PMID:29742718

Multi-Scale Computational Models for Electrical Brain Stimulation

PubMed Central

Seo, Hyeon; Jun, Sung C.

2017-01-01

Electrical brain stimulation (EBS) is an appealing method to treat neurological disorders. To achieve optimal stimulation effects and a better understanding of the underlying brain mechanisms, neuroscientists have proposed computational modeling studies for a decade. Recently, multi-scale models that combine a volume conductor head model and multi-compartmental models of cortical neurons have been developed to predict stimulation effects on the macroscopic and microscopic levels more precisely. As the need for better computational models continues to increase, we overview here recent multi-scale modeling studies; we focused on approaches that coupled a simplified or high-resolution volume conductor head model and multi-compartmental models of cortical neurons, and constructed realistic fiber models using diffusion tensor imaging (DTI). Further implications for achieving better precision in estimating cellular responses are discussed. PMID:29123476

Simulation of the Electrical Field in Equine Larynx to Optimize Functional Electrical Stimulation in Denervated Musculus Cricoarythenoideus Dorsalis

PubMed Central

Martinek, Johannes

2014-01-01

Distribution of the electrical field is very important to activate muscle and nerve cells properly. One therapeutic method to treat Recurrent Laryngeal Neuropathy (RLN) in horses can be performed by Functional Electrical Stimulation (FES). Current method to optimize the stimulation effect is to use implanted quadripolar electrodes to the musculus cricoarythenoideus dorsalis (CAD) and testing electrode configuration until best possible optimum is reached. For better understanding and finding of maximum possible activation of CAD a simulation model of the actual entire setting is currently in development. Therefore the geometric model is built from CT-data of a dissected larynx containing the quadripolar electrodes as well as fiducials for later data registration. The geometric model is the basis for a finite difference method containing of voxels with corresponding electrical conductivity of the different types of tissue due to threshold segmentation of the CT-data. Model validation can be done by the measurement of the 3D electrical potential distribution of a larynx positioned in an electrolytic tray. Finally, measured and calculated results have to be compared as well as further investigated. Preliminary results show, that changes of electrode as well as conductivity configuration leads to significant different voltage distributions and can be well presented by equipotential lines superimposed CT-slices – a Matlab graphical user interface visualizes the results in freely selectable slices of the 3D geometry. Voltage distribution along theoretically estimated fiber paths could be calculated as well as visualized. For further calculation of nerve or denervated muscle fiber activation and its optimization, real fiber paths have to be defined and referenced to the potential- and the CT-data. PMID:26913137

Charge-balanced biphasic electrical stimulation inhibits neurite extension of spiral ganglion neurons.

PubMed

Shen, Na; Liang, Qiong; Liu, Yuehong; Lai, Bin; Li, Wen; Wang, Zhengmin; Li, Shufeng

2016-06-15

Intracochlear application of exogenous or transgenic neurotrophins, such as neurotrophin-3 (NT-3) and brain derived neurotrophic factor (BDNF), could promote the resprouting of spiral ganglion neuron (SGN) neurites in deafened animals. These resprouting neurites might reduce the gap between cochlear implant electrodes and their targeting SGNs, allowing for an improvement of spatial resolution of electrical stimulation. This study is to investigate the impact of electrical stimulation employed in CI on the extension of resprouting SGN neurites. We established an in vitro model including the devices delivering charge-balanced biphasic electrical stimulation, and spiral ganglion (SG) dissociated culture treated with BDNF and NT-3. After electrical stimulation with varying durations and intensities, we quantified neurite lengths and Schwann cell densities in SG cultures. Stimulations that were greater than 50μA or longer than 8h significantly decreased SG neurite length. Schwann cell density under 100μA electrical stimulation for 48h was significantly lower compared to that in non-stimulated group. These electrical stimulation-induced decreases of neurite extension and Schwann cell density were attenuated by various types of voltage-dependent calcium channel (VDCC) blockers, or completely prevented by their combination, cadmium or calcium-free medium. Our study suggested that charge-balanced biphasic electrical stimulation inhibited the extension of resprouting SGN neurites and decreased Schwann cell density in vitro. Calcium influx through multiple types of VDCCs was involved in the electrical stimulation-induced inhibition. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Electrical Stimulation for Pressure Injuries: A Health Technology Assessment.

PubMed

2017-01-01

Pressure injuries (bedsores) are common and reduce quality of life. They are also costly and difficult to treat. This health technology assessment evaluates the effectiveness, cost-effectiveness, budget impact, and lived experience of adding electrical stimulation to standard wound care for pressure injuries. We conducted a systematic search for studies published to December 7, 2016, limited to randomized and non-randomized controlled trials examining the effectiveness of electrical stimulation plus standard wound care versus standard wound care alone for patients with pressure injuries. We assessed the quality of evidence through Grading of Recommendations Assessment, Development, and Evaluation (GRADE). In addition, we conducted an economic literature review and a budget impact analysis to assess the cost-effectiveness and affordability of electrical stimulation for treatment of pressure ulcers in Ontario. Given uncertainties in clinical evidence and resource use, we did not conduct a primary economic evaluation. Finally, we conducted qualitative interviews with patients and caregivers about their experiences with pressure injuries, currently available treatments, and (if applicable) electrical stimulation. Nine randomized controlled trials and two non-randomized controlled trials were found from the systematic search. There was no significant difference in complete pressure injury healing between adjunct electrical stimulation and standard wound care. There was a significant difference in wound surface area reduction favouring electrical stimulation compared with standard wound care.The only study on cost-effectiveness of electrical stimulation was partially applicable to the patient population of interest. Therefore, the cost-effectiveness of electrical stimulation cannot be determined. We estimate that the cost of publicly funding electrical stimulation for pressure injuries would be $0.77 to $3.85 million yearly for the next 5 years.Patients and caregivers reported that pressure injuries were burdensome and reduced their quality of life. Patients and caregivers also noted that electrical stimulation seemed to reduce the time it took the wounds to heal. While electrical stimulation is safe to use (GRADE quality of evidence: high) there is uncertainty about whether it improves wound healing (GRADE quality of evidence: low). In Ontario, publicly funding electrical stimulation for pressure injuries could result in extra costs of $0.77 to $3.85 million yearly for the next 5 years.

Electrical Stimulation of the Suprahyoid Muscles in Brain-injured Patients with Dysphagia: A Pilot Study

PubMed Central

Beom, Jaewon; Kim, Sang Jun

2011-01-01

Objective To investigate the therapeutic effects of repetitive electrical stimulation of the suprahyoid muscles in brain-injured patients with dysphagia. Method Twenty-eight brain-injured patients who showed reduced laryngeal elevation and supraglottic penetration or subglottic aspiration during a videofluoroscopic swallowing study (VFSS) were selected. The patients received either conventional dysphagia management (CDM) or CDM with repetitive electrical stimulation of the suprahyoid muscles (ESSM) for 4 weeks. The videofluoroscopic dysphagia scale (VDS) using the VFSS and American Speech-Language-Hearing Association National Outcome Measurement System (ASHA NOMS) swallowing scale (ASHA level) was used to determine swallowing function before and after treatment. Results VDS scores decreased from 29.8 to 17.9 in the ESSM group, and from 29.2 to 16.6 in the CDM group. However, there was no significant difference between the groups (p=0.796). Six patients (85.7%) in the ESSM group and 14 patients (66.7%) in the CDM group showed improvement according to the ASHA level with no significant difference between the ESSM and CDM groups (p=0.633). Conclusion Although repetitive neuromuscular electrical stimulation of the suprahyoid muscles did not further improve the swallowing function of dysphagia patients with reduced laryngeal elevation, more patients in the ESSM group showed improvement in the ASHA level than those in the CDM group. Further studies with concurrent controls and a larger sample group are required to fully establish the effects of repetitive neuromuscular electrical stimulation of the suprahyoid muscles in dysphagia patients. PMID:22506140

Dry cupping for plantar fasciitis: a randomized controlled trial.

PubMed

Ge, Weiqing; Leson, Chelsea; Vukovic, Corey

2017-05-01

[Purpose] The purpose of this study was to determine the effects of dry cupping on pain and function of patients with plantar fasciitis. [Subjects and Methods] Twenty-nine subjects (age 15 to 59 years old, 20 females and 9 males), randomly assigned into the two groups (dry cupping therapy and electrical stimulation therapy groups), participated in this study. The research design was a randomized controlled trial (RCT). Treatments were provided to the subjects twice a week for 4 weeks. Outcome measurements included the Visual Analogue Pain Scale (VAS) (at rest, first in the morning, and with activities), the Foot and Ankle Ability Measure (FAAM), the Lower Extremity Functional Scale (LEFS), as well as the pressure pain threshold. [Results]The data indicated that both dry cupping therapy and electrical stimulation therapy could reduce pain and increase function significantly in the population tested, as all the 95% Confidence Intervals (CIs) did not include 0 except for the pressure pain threshold. There was no significant difference between the dry cupping therapy and electrical stimulation groups in all the outcome measurements. [Conclusion] These results support that both dry cupping therapy and electrical stimulation therapy could reduce pain and increase function in the population tested.

Dry cupping for plantar fasciitis: a randomized controlled trial

PubMed Central

Ge, Weiqing; Leson, Chelsea; Vukovic, Corey

2017-01-01

[Purpose] The purpose of this study was to determine the effects of dry cupping on pain and function of patients with plantar fasciitis. [Subjects and Methods] Twenty-nine subjects (age 15 to 59 years old, 20 females and 9 males), randomly assigned into the two groups (dry cupping therapy and electrical stimulation therapy groups), participated in this study. The research design was a randomized controlled trial (RCT). Treatments were provided to the subjects twice a week for 4 weeks. Outcome measurements included the Visual Analogue Pain Scale (VAS) (at rest, first in the morning, and with activities), the Foot and Ankle Ability Measure (FAAM), the Lower Extremity Functional Scale (LEFS), as well as the pressure pain threshold. [Results]The data indicated that both dry cupping therapy and electrical stimulation therapy could reduce pain and increase function significantly in the population tested, as all the 95% Confidence Intervals (CIs) did not include 0 except for the pressure pain threshold. There was no significant difference between the dry cupping therapy and electrical stimulation groups in all the outcome measurements. [Conclusion] These results support that both dry cupping therapy and electrical stimulation therapy could reduce pain and increase function in the population tested. PMID:28603360

New directions in the rational design of electrical and magnetic seizure therapies: individualized Low Amplitude Seizure Therapy (iLAST) and Magnetic Seizure Therapy (MST).

PubMed

Radman, Thomas; Lisanby, Sarah H

2017-04-01

Electroconvulsive therapy remains a key treatment option for severe cases of depression, but undesirable side-effects continue to limit its use. Innovations in the design of novel seizure therapies seek to improve its risk benefit ratio through enhanced control of the focality of stimulation. The design of seizure therapies with increased spatial precision is motivated by avoiding stimulation of deep brain structures implicated in memory retention, including the hippocampus. The development of two innovations in seizure therapy-individualized low-amplitude seizure therapy (iLAST) and magnetic seizure therapy (MST), are detailed. iLAST is a method of seizure titration involving reducing current spread in the brain by titrating current amplitude from the traditional fixed amplitudes. MST, which can be used in conjunction with iLAST dosing methods, involves the use of magnetic stimulation to reduce shunting and spreading of current by the scalp occurring during electrical stimulation. Evidence is presented on the rationale for increasing the focality of ECT in hopes of preserving its effectiveness, while reducing cognitive side-effects. Finally, the value of electric field and neural modelling is illustrated to explain observed clinical effects of modifications to ECT technique, and their utility in the rational design of the next generation of seizure therapies.

Thermally-enhanced oil recovery method and apparatus

DOEpatents

Stahl, Charles R.; Gibson, Michael A.; Knudsen, Christian W.

1987-01-01

A thermally-enhanced oil recovery method and apparatus for exploiting deep well reservoirs utilizes electric downhole steam generators to provide supplemental heat to generate high quality steam from hot pressurized water which is heated at the surface. A downhole electric heater placed within a well bore for local heating of the pressurized liquid water into steam is powered by electricity from the above-ground gas turbine-driven electric generators fueled by any clean fuel such as natural gas, distillate or some crude oils, or may come from the field being stimulated. Heat recovered from the turbine exhaust is used to provide the hot pressurized water. Electrical power may be cogenerated and sold to an electric utility to provide immediate cash flow and improved economics. During the cogeneration period (no electrical power to some or all of the downhole units), the oil field can continue to be stimulated by injecting hot pressurized water, which will flash into lower quality steam at reservoir conditions. The heater includes electrical heating elements supplied with three-phase alternating current or direct current. The injection fluid flows through the heater elements to generate high quality steam to exit at the bottom of the heater assembly into the reservoir. The injection tube is closed at the bottom and has radial orifices for expanding the injection fluid to reservoir pressure.

Saccade Modulation by Optical and Electrical Stimulation in the Macaque Frontal Eye Field

PubMed Central

Grimaldi, Piercesare; Schweers, Nicole

2013-01-01

Recent studies have demonstrated that strong neural modulations can be evoked with optogenetic stimulation in macaque motor cortex without observing any evoked movements (Han et al., 2009, 2011; Diester et al., 2011). It remains unclear why such perturbations do not generate movements and if conditions exist under which they may evoke movements. In this study, we examine the effects of five optogenetic constructs in the macaque frontal eye field and use electrical microstimulation to assess whether optical perturbation of the local network leads to observable motor changes during optical, electrical, and combined stimulation. We report a significant increase in the probability of evoking saccadic eye movements when low current electrical stimulation is coupled to optical stimulation compared with when electrical stimulation is used alone. Experiments combining channelrhodopsin 2 (ChR2) and electrical stimulation with simultaneous fMRI revealed no discernible fMRI activity at the electrode tip with optical stimulation but strong activity with electrical stimulation. Our findings suggest that stimulation with current ChR2 optogenetic constructs generates subthreshold activity that contributes to the initiation of movements but, in most cases, is not sufficient to evoke a motor response. PMID:24133271

Detecting electroporation by assessing the time constants in the exponential response of human skin to voltage controlled impulse electrical stimulation.

PubMed

Bîrlea, Sinziana I; Corley, Gavin J; Bîrlea, Nicolae M; Breen, Paul P; Quondamatteo, Fabio; OLaighin, Gearóid

2009-01-01

We propose a new method for extracting the electrical properties of human skin based on the time constant analysis of its exponential response to impulse stimulation. As a result of this analysis an adjacent finding has arisen. We have found that stratum corneum electroporation can be detected using this analysis method. We have observed that a one time-constant model is appropriate for describing the electrical properties of human skin at low amplitude applied voltages (<30V), and a two time-constant model best describes skin electrical properties at higher amplitude applied voltages (>30V). Higher voltage amplitudes (>30V) have been proven to create pores in the skin's stratum corneum which offer a new, lower resistance, pathway for the passage of current through the skin. Our data shows that when pores are formed in the stratum corneum they can be detected, in-vivo, due to the fact that a second time constant describes current flow through them.

Efficacy of Selected Electrical Therapies on Chronic Low Back Pain: A Comparative Clinical Pilot Study.

PubMed

Rajfur, Joanna; Pasternok, Małgorzata; Rajfur, Katarzyna; Walewicz, Karolina; Fras, Beata; Bolach, Bartosz; Dymarek, Robert; Rosinczuk, Joanna; Halski, Tomasz; Taradaj, Jakub

2017-01-07

BACKGROUND In the currently available research publications on electrical therapy of low back pain, generally no control groups or detailed randomization were used, and such studies were often conducted with relatively small groups of patients, based solely on subjective questionnaires and pain assessment scales (lacking measurement methods to objectify the therapeutic progress). The available literature also lacks a comprehensive and large-scale clinical study. The purpose of this study was to assess the effects of treating low back pain using selected electrotherapy methods. The study assesses the influence of individual electrotherapeutic treatments on reduction of pain, improvement of the range of movement in lower section of the spine, and improvement of motor functions and mobility. MATERIAL AND METHODS The 127 patients qualified for the therapy (ultimately, 123 patients completed the study) and assigned to 6 comparison groups: A - conventional TENS, B - acupuncture-like TENS, C - high-voltage electrical stimulation, D - interferential current stimulation, E - diadynamic current, and F - control group. RESULTS The research showed that using electrical stimulation with interferential current penetrating deeper into the tissues results in a significant and more efficient elimination of pain, and an improvement of functional ability of patients suffering from low back pain on the basis of an analysis of both subjective and objective parameters. The TENS currents and high voltage were helpful, but not as effective. The use of diadynamic currents appears to be useless. CONCLUSIONS Selected electrical therapies (interferential current, TENS, and high voltage) appear to be effective in treating chronic low back pain.

Efficacy of Selected Electrical Therapies on Chronic Low Back Pain: A Comparative Clinical Pilot Study

PubMed Central

Rajfur, Joanna; Pasternok, Małgorzata; Rajfur, Katarzyna; Walewicz, Karolina; Fras, Beata; Bolach, Bartosz; Dymarek, Robert; Rosinczuk, Joanna; Halski, Tomasz; Taradaj, Jakub

2017-01-01

Background In the currently available research publications on electrical therapy of low back pain, generally no control groups or detailed randomization were used, and such studies were often conducted with relatively small groups of patients, based solely on subjective questionnaires and pain assessment scales (lacking measurement methods to objectify the therapeutic progress). The available literature also lacks a comprehensive and large-scale clinical study. The purpose of this study was to assess the effects of treating low back pain using selected electrotherapy methods. The study assesses the influence of individual electrotherapeutic treatments on reduction of pain, improvement of the range of movement in lower section of the spine, and improvement of motor functions and mobility. Material/Methods The 127 patients qualified for the therapy (ultimately, 123 patients completed the study) and assigned to 6 comparison groups: A – conventional TENS, B – acupuncture-like TENS, C – high-voltage electrical stimulation, D – interferential current stimulation, E – diadynamic current, and F – control group. Results The research showed that using electrical stimulation with interferential current penetrating deeper into the tissues results in a significant and more efficient elimination of pain, and an improvement of functional ability of patients suffering from low back pain on the basis of an analysis of both subjective and objective parameters. The TENS currents and high voltage were helpful, but not as effective. The use of diadynamic currents appears to be useless. Conclusions Selected electrical therapies (interferential current, TENS, and high voltage) appear to be effective in treating chronic low back pain. PMID:28062862

Deep Brain Stimulation of the Subthalamic Nucleus Parameter Optimization for Vowel Acoustics and Speech Intelligibility in Parkinson's Disease

ERIC Educational Resources Information Center

Knowles, Thea; Adams, Scott; Abeyesekera, Anita; Mancinelli, Cynthia; Gilmore, Greydon; Jog, Mandar

2018-01-01

Purpose: The settings of 3 electrical stimulation parameters were adjusted in 12 speakers with Parkinson's disease (PD) with deep brain stimulation of the subthalamic nucleus (STN-DBS) to examine their effects on vowel acoustics and speech intelligibility. Method: Participants were tested under permutations of low, mid, and high STN-DBS frequency,…

Rigor and reproducibility in research with transcranial electrical stimulation: An NIMH-sponsored workshop

PubMed Central

Bikson, Marom; Brunoni, Andre R.; Charvet, Leigh E.; Clark, Vincent P.; Cohen, Leonardo G.; Deng, Zhi-De; Dmochowski, Jacek; Edwards, Dylan J.; Frohlich, Flavio; Kappenman, Emily S.; Lim, Kelvin O.; Loo, Colleen; Mantovani, Antonio; McMullen, David P.; Parra, Lucas C.; Pearson, Michele; Richardson, Jessica D.; Rumsey, Judith M.; Sehatpour, Pejman; Sommers, David; Unal, Gozde; Wassermann, Eric M.; Woods, Adam J.; Lisanby, Sarah H.

2018-01-01

Background Neuropsychiatric disorders are a leading source of disability and require novel treatments that target mechanisms of disease. As such disorders are thought to result from aberrant neuronal circuit activity, neuromodulation approaches are of increasing interest given their potential for manipulating circuits directly. Low intensity transcranial electrical stimulation (tES) with direct currents (transcranial direct current stimulation, tDCS) or alternating currents (transcranial alternating current stimulation, tACS) represent novel, safe, well-tolerated, and relatively inexpensive putative treatment modalities. Objective This report seeks to promote the science, technology and effective clinical applications of these modalities, identify research challenges, and suggest approaches for addressing these needs in order to achieve rigorous, reproducible findings that can advance clinical treatment. Methods The National Institute of Mental Health (NIMH) convened a workshop in September 2016 that brought together experts in basic and human neuroscience, electrical stimulation biophysics and devices, and clinical trial methods to examine the physiological mechanisms underlying tDCS/tACS, technologies and technical strategies for optimizing stimulation protocols, and the state of the science with respect to therapeutic applications and trial designs. Results Advances in understanding mechanisms, methodological and technological improvements (e.g., electronics, computational models to facilitate proper dosing), and improved clinical trial designs are poised to advance rigorous, reproducible therapeutic applications of these techniques. A number of challenges were identified and meeting participants made recommendations made to address them. Conclusions These recommendations align with requirements in NIMH funding opportunity announcements to, among other needs, define dosimetry, demonstrate dose/response relationships, implement rigorous blinded trial designs, employ computational modeling, and demonstrate target engagement when testing stimulation-based interventions for the treatment of mental disorders. PMID:29398575

Modulation and detection of single neuron activity using spin transfer nano-oscillators

NASA Astrophysics Data System (ADS)

Algarin, Jose Miguel; Ramaswamy, Bharath; Venuti, Lucy; Swierzbinski, Matthew; Villar, Pablo; Chen, Yu-Jin; Krivorotov, Ilya; Weinberg, Irving N.; Herberholz, Jens; Araneda, Ricardo; Shapiro, Benjamin; Waks, Edo

2017-09-01

The brain is a complex network of interconnected circuits that exchange electrical signals with each other. These electrical signals provide insight on how neural circuits code information, and give rise to sensations, thoughts, emotions and actions. Currents methods to detect and modulate these electrical signals use implanted electrodes or optical fields with light sensitive dyes in the brain. These techniques require complex surgeries or suffer low resolution. In this talk we explore a new method to both image and stimulate single neurons using spintronics. We propose using a Spin Transfer Nano-Oscillators (STNOs) as a nanoscale sensor that converts neuronal action potentials to microwave field oscillations that can be detected wirelessly by magnetic induction. We will describe our recent proof-of-concept demonstration of both detection and wireless modulation of neuronal activity using STNOs. For detection we use electrodes to connect a STNO to a lateral giant crayfish neuron. When we stimulate the neuron, the STNO responds to the neuronal activity with a corresponding microwave signal. For modulation, we stimulate the STNOs wirelessly using an inductively coupled solenoid. The STNO rectifies the induced microwave signal to produce a direct voltage. This direct voltage from the STNO, when applied in the vicinity of a mammalian neuron, changes the frequency of electrical signals produced by the neuron.

Prediction of the Seizure Suppression Effect by Electrical Stimulation via a Computational Modeling Approach.

PubMed

Ahn, Sora; Jo, Sumin; Jun, Sang Beom; Lee, Hyang Woon; Lee, Seungjun

2017-01-01

In this paper, we identified factors that can affect seizure suppression via electrical stimulation by an integrative study based on experimental and computational approach. Preferentially, we analyzed the characteristics of seizure-like events (SLEs) using our previous in vitro experimental data. The results were analyzed in two groups classified according to the size of the effective region, in which the SLE was able to be completely suppressed by local stimulation. However, no significant differences were found between these two groups in terms of signal features or propagation characteristics (i.e., propagation delays, frequency spectrum, and phase synchrony). Thus, we further investigated important factors using a computational model that was capable of evaluating specific influences on effective region size. In the proposed model, signal transmission between neurons was based on two different mechanisms: synaptic transmission and the electrical field effect. We were able to induce SLEs having similar characteristics with differentially weighted adjustments for the two transmission methods in various noise environments. Although the SLEs had similar characteristics, their suppression effects differed. First of all, the suppression effect occurred only locally where directly received the stimulation effect in the high noise environment, but it occurred in the entire network in the low noise environment. Interestingly, in the same noise environment, the suppression effect was different depending on SLE propagation mechanism; only a local suppression effect was observed when the influence of the electrical field transmission was very weak, whereas a global effect was observed with a stronger electrical field effect. These results indicate that neuronal activities synchronized by a strong electrical field effect respond more sensitively to partial changes in the entire network. In addition, the proposed model was able to predict that stimulation of a seizure focus region is more effective for suppression. In conclusion, we confirmed the possibility of a computational model as a simulation tool to analyze the efficacy of deep brain stimulation (DBS) and investigated the key factors that determine the size of an effective region in seizure suppression via electrical stimulation.

Sequential segmental neuromuscular stimulation reduces fatigue and improves perfusion in dynamic graciloplasty.

PubMed

Zonnevijlle, E D; Somia, N N; Abadia, G P; Stremel, R W; Maldonado, C J; Werker, P M; Kon, M; Barker, J H

2000-09-01

Dynamic graciloplasty is used as a treatment modality for total urinary incontinence caused by a paralyzed sphincter. A problem with this application is undesirable fatigue of the muscle caused by continuous electrical stimulation. Therefore, the neosphincter must be trained via a rigorous regimen to transform it from a fatigue-prone state to a fatigue-resistant state. To avoid or shorten this training period, the application of sequential segmental neuromuscular stimulation (SSNS) was examined. This form of stimulation proved previously to be highly effective in acutely reducing fatigue caused by electrical stimulation. The contractile function and perfusion of gracilis muscles employed as neosphincters were compared between conventional, single-channel, continuous stimulation, and multichannel sequential stimulation in 8 dogs. The sequentially stimulated neosphincter proved to have an endurance 2.9 times longer (as measured by halftime to fatigue) than continuous stimulation and a better blood perfusion during stimulation (both of which were significant changes, p < 0.05). Clinically, this will not antiquate training of the muscle, but SSNS could reduce the need for long and rigorous training protocols, making dynamic graciloplasty more attractive as a method of treating urinary or fecal incontinence.

Biocompatible implants and methods of making and attaching the same

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rowley, Adrian P; Laude, Lucien D; Humayun, Mark S

2014-10-07

The invention provides a biocompatible silicone implant that can be securely affixed to living tissue through interaction with integral membrane proteins (integrins). A silicone article containing a laser-activated surface is utilized to make the implant. One example is an implantable prosthesis to treat blindness caused by outer retinal degenerative diseases. The device bypasses damaged photoreceptors and electrically stimulates the undamaged neurons of the retina. Electrical stimulation is achieved using a silicone microelectrode array (MEA). A safe, protein adhesive is used in attaching the MEA to the retinal surface and assist in alleviating focal pressure effects. Methods of making and attachingmore » such implants are also provided.« less

Intra-operative recording of motor tract potentials at the cervico-medullary junction following scalp electrical and magnetic stimulation of the motor cortex.

PubMed Central

Thompson, P D; Day, B L; Crockard, H A; Calder, I; Murray, N M; Rothwell, J C; Marsden, C D

1991-01-01

Activity in descending motor pathways after scalp electrical and magnetic brain stimulation of the motor cortex was recorded from the exposed cervico-medullary junction in six patients having trans-oral surgery of the upper cervical spine. Recordings during deep anaesthesia without muscle paralysis revealed an initial negative potential (D wave) at about 2 ms with electrical stimulation in five of the six patients. This was followed by a muscle potential which obscured any later waveforms. Magnetic stimulation produced clear potentials in only one patient. The earliest wave to magnetic stimulation during deep anaesthesia was 1-2 ms later than the earliest potential to electrical stimulation. Following lightening of the anaesthetic and the administration of muscle relaxants a series of later negative potentials (I waves) were more clearly seen to both electrical and magnetic stimulation. More I waves were recorded to magnetic stimulation during light anaesthesia than during deep anaesthesia. Increasing the intensity of electrical stimulation also produced an extra late I wave. At the highest intensity of magnetic stimulation the latency of the earliest potential was comparable to the D wave to electrical stimulation. The intervals between these various D and I waves corresponded to those previously described for the timing of single motor unit discharge after cortical stimulation. PMID:1654395

Synchronous electrical stimulation of laryngeal muscles: an alternative for enhancing recovery of unilateral recurrent laryngeal nerve paralysis.

PubMed

Garcia Perez, Alejandro; Hernández López, Xochiquetzal; Valadez Jiménez, Víctor Manuel; Minor Martínez, Arturo; Ysunza, Pablo Antonio

2014-07-01

Although electrical stimulation of the larynx has been widely studied for treating voice disorders, its effectiveness has not been assessed under safety and comfortable conditions. This article describes design, theoretical issues, and preliminary evaluation of an innovative system for transdermal electrical stimulation of the larynx. The proposed design includes synchronization of electrical stimuli with laryngeal neuromuscular activity. To study whether synchronous electrical stimulation of the larynx could be helpful for improving voice quality in patients with dysphonia due to unilateral recurrent laryngeal nerve paralysis (URLNP). A 3-year prospective study was carried out at the Instituto Nacional de Rehabilitacion in the Mexico City. Ten patients were subjected to transdermal current electrical stimulation synchronized with the fundamental frequency of the vibration of the vocal folds during phonation. The stimulation was triggered during the phase of maximum glottal occlusion. A complete acoustic voice analysis was performed before and after the period of electrical stimulation. Acoustic analysis revealed significant improvements in all parameters after the stimulation period. Transdermal synchronous electrical stimulation of vocal folds seems to be a safe and reliable procedure for enhancing voice quality in patients with (URLNP). Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Comparison electrical stimulation and passive stretching for blood glucose control type 2 diabetes mellitus patients

NASA Astrophysics Data System (ADS)

Arsianti, Rika Wahyuni; Parman, Dewy Haryanti; Lesmana, Hendy

2018-04-01

Physical exercise is one of the cornerstones for management and treatment type 2 diabetes mellitus. But not all people are able to perform physical exercise because of their physical limitation condition. The strategy for those people in this study is electrical stimulation and passive stretching. The aim of this study is to find out the effect of electrical stimulation and passive stretching to lowering blood glucose level. 20 subjects is divided into electrical stimulation and passive stretching group. The provision of electrical stimulation on lower extremities muscles for 30 minutes for electrical stimulation group (N=10). And other underwent passive stretching for 30 minutes (N=10). The result shows that blood glucose level is decrease from 192.9 ± 10.7087 mg/dL to 165.3 ± 10.527 mg/dL for electrical stimulation intervention group while for the passive stretching group the blood glucose decrease from 153 ± 12.468 mg/dL to 136.1 ± 12.346 mg/dL. Both electrical stimulation and passive stretching are effective to lowering blood glucose level and can be proposed for those people restricted to perform exercise.

Electrical and optical co-stimulation in the deaf white cat

NASA Astrophysics Data System (ADS)

Cao, Zhiping; Xu, Yingyue; Tan, Xiaodong; Suematsu, Naofumi; Robinson, Alan; Richter, Claus-Peter

2018-02-01

Spatial selectivity of neural stimulation with photons, such as infrared neural stimulation (INS) is higher than the selectivity obtained with electrical stimulation. To obtain more independent channels for stimulation in neural prostheses, INS may be implemented to better restore the fidelity of the damaged neural system. However, irradiation with infrared light also bares the risk of heat accumulation in the target tissue with subsequent neural damage. Lowering the threshold for stimulation could reduce the amount of heat delivered to the tissue and the risk for subsequent tissue damage. It has been shown in the rat sciatic nerve that simultaneous irradiation with infrared light and the delivery of biphasic sub-threshold electrical pulses can reduce the threshold for INS [1]. In this study, deaf white cats have been used to test whether opto-electrical co-stimulation can reduce the stimulation threshold for INS in the auditory system too. The cochleae of the deaf white cats have largely reduced spiral ganglion neuron counts and significant degeneration of the organ of Corti and do not respond to acoustic stimuli. Combined electrical and optical stimulation was used to demonstrate that simultaneous stimulation with infrared light and biphasic electrical pulses can reduce the threshold for stimulation.

Effects of combined electrical stimulation of the dorsal column and dorsal roots on wide-dynamic range neuronal activity in nerve-injured rats

PubMed Central

Yang, Fei; Zhang, Tong; Tiwari, Vinod; Shu, Bin; Zhang, Chen; Wang, Yun; Vera-Portocarrero, Louis P.; Raja, Srinivasa N.; Guan, Yun

2015-01-01

Objectives Electrical stimulation at the dorsal column (DC) and dorsal root (DR) may inhibit spinal wide-dynamic-range (WDR) neuronal activity in nerve-injured rats. The objective of this study was to determine if applying electrical conditioning stimulation (CS) at both sites provides additive or synergistic benefits. Materials and Methods By conducting in vivo extracellular recordings of WDR neurons in rats that had undergone L5 spinal nerve ligation, we tested whether combining 50 Hz CS at the two sites in either a concurrent (2.5 minutes) or alternate (5 minutes) pattern inhibits WDR neuronal activity better than CS at DC alone (5 minutes). The intensities of CS were determined by recording antidromic compound action potentials to graded stimulation at the DC and DR. We measured the current thresholds that resulted in the first detectable Aα/β waveform (Ab0) and the peak Aα/β waveform (Ab1) to select CS intensity at each site. The same number of electrical pulses and amount of current were delivered in different patterns to allow comparison. Results At a moderate intensity of 50%(Ab0+Ab1), different patterns of CS all attenuated the C-component of WDR neurons in response to graded intracutaneous electrical stimuli (0.1-10 mA, 2 ms), and inhibited windup in response to repetitive noxious stimuli (0.5 Hz). However, the inhibitory effects did not differ significantly between different patterns. At the lower intensity (Ab0), no CS inhibited WDR neurons. Conclusions These findings suggest that combined stimulation of DC and DR may not be superior to DC stimulation alone for inhibition of WDR neurons. PMID:26307526

Novel spinal instrumentation to enhance osteogenesis and fusion: a preliminary study.

PubMed

MacEwan, Matthew R; Talcott, Michael R; Moran, Daniel W; Leuthardt, Eric C

2016-09-01

OBJECTIVE Instrumented spinal fusion continues to exhibit high failure rates in patients undergoing multilevel lumbar fusion or pseudarthrosis revision; with Grade II or higher spondylolisthesis; or in those possessing risk factors such as obesity, tobacco use, or metabolic disorders. Direct current (DC) electrical stimulation of bone growth represents a unique surgical adjunct in vertebral fusion procedures, yet existing spinal fusion stimulators are not optimized to enhance interbody fusion. To develop an advanced method of applying DC electrical stimulation to promote interbody fusion, a novel osteogenic spinal system capable of routing DC through rigid instrumentation and into the vertebral bodies was fabricated. A pilot study was designed to assess the feasibility of osteogenic instrumentation and compare the ability of osteogenic instrumentation to promote successful interbody fusion in vivo to standard spinal instrumentation with autograft. METHODS Instrumented, single-level, posterior lumbar interbody fusion (PLIF) with autologous graft was performed at L4-5 in adult Toggenburg/Alpine goats, using both osteogenic spinal instrumentation (plus electrical stimulation) and standard spinal instrumentation (no electrical stimulation). At terminal time points (3 months, 6 months), animals were killed and lumbar spines were explanted for radiographic analysis using a SOMATOM Dual Source Definition CT Scanner and high-resolution Microcat II CT Scanner. Trabecular continuity, radiodensity within the fusion mass, and regional bone formation were examined to determine successful spinal fusion. RESULTS Quantitative analysis of average bone density in pedicle screw beds confirmed that electroactive pedicle screws used in the osteogenic spinal system focally enhanced bone density in instrumented vertebral bodies. Qualitative and quantitative analysis of high-resolution CT scans of explanted lumbar spines further demonstrated that the osteogenic spinal system induced solid bony fusion across the L4-5 disc space as early as 6 weeks postoperatively. In comparison, inactive spinal instrumentation with autograft was unable to promote successful interbody fusion by 6 months postoperatively. CONCLUSIONS Results of this study demonstrate that novel osteogenic spinal instrumentation supports interbody fusion through the focal delivery of DC electrical stimulation. With further technical development and scientific/clinical validation, osteogenic spinal instrumentation may offer a unique alternative to biological scaffolds and pharmaceutical adjuncts used in spinal fusion procedures.

Transcutaneous electrical nerve stimulation effect on postoperative complications.

PubMed

Sezen, Celal Bugra; Akboga, Suleyman Anil; Celik, Ali; Kalafat, Cem Emrah; Tastepe, Abdullah Irfan

2017-05-01

Objectives Transcutaneous electrical nerve stimulation has been used to control post-thoracotomy pain, with conflicting results. We aimed to assess its efficacy on post-thoracotomy pain and early complications. Methods Between January 2012 and December 2014, 87 patients underwent a standard posterolateral thoracotomy and were randomized in 2 groups: group T was 43 patients who had transcutaneous electrical nerve stimulation and group C was 44 patients who had placebo stimulation with an inoperative device. Pain score was measured using a visual analogue scale ranging from 0 to 10. The frequency of the device was set at 100 Hz and pulse width at 100 ms. Results There were no statistically significant differences in the demographic characteristics of the 2 groups, and there was no difference in the duration of hospitalization (4.74 ± 1.6 vs. 5.23 ± 1.5 days; p = 0.06). Postoperative pain scores of the two groups showed that on postoperative day 0, 1, and 2, the mean pain scores of group T were significantly lower ( p = 0.001, p < 0.001, and p = 0.003). There were no significant differences in early complications or surgical technique. Conclusion We concluded that electrical stimulation is a safe and effective adjunctive therapy for acute post-thoracotomy pain control. However, it does not affect the duration of hospitalization or early pulmonary complications.

Nanomaterial-Enabled Neural Stimulation

PubMed Central

Wang, Yongchen; Guo, Liang

2016-01-01

Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed. PMID:27013938

A microprocessor-based multichannel subsensory stochastic resonance electrical stimulator.

PubMed

Chang, Gwo-Ching

2013-01-01

Stochastic resonance electrical stimulation is a novel intervention which provides potential benefits for improving postural control ability in the elderly, those with diabetic neuropathy, and stroke patients. In this paper, a microprocessor-based subsensory white noise electrical stimulator for the applications of stochastic resonance stimulation is developed. The proposed stimulator provides four independent programmable stimulation channels with constant-current output, possesses linear voltage-to-current relationship, and has two types of stimulation modes, pulse amplitude and width modulation.

Corticospinal excitability is dependent on the parameters of peripheral electric stimulation: a preliminary study.

PubMed

Chipchase, Lucy S; Schabrun, Siobhan M; Hodges, Paul W

2011-09-01

To evaluate the effect of 6 electric stimulation paradigms on corticospinal excitability. Using a same subject pre-post test design, transcranial magnetic stimulation (TMS) was used to measure the responsiveness of corticomotor pathway to biceps and triceps brachii muscles before and after 30 minutes of electric stimulation over the biceps brachii. Six different electric stimulation paradigms were applied in random order, at least 3 days apart. Motor control research laboratory. Healthy subjects (N=10; 5 women, 5 men; mean age ± SD, 26 ± 3.6y). Six different electric stimulation paradigms with varied stimulus amplitude, frequency, and ramp settings. Amplitudes of TMS-induced motor evoked potentials at biceps and triceps brachii normalized to maximal M-wave amplitudes. Electric stimulation delivered at stimulus amplitude sufficient to evoke a sensory response at both 10 Hz and 100 Hz, and stimulus amplitude to create a noxious response at 10 Hz decreased corticomotor responsiveness (all P<0.01). Stimulation sufficient to induce a motor contraction (30 Hz) applied in a ramped pattern to mimic a voluntary activation increased corticomotor responsiveness (P=0.002), whereas constant low- and high-intensity motor stimulation at 10 Hz did not. Corticomotor excitability changes were similar for both the stimulated muscle and its antagonist. Stimulus amplitude (intensity) and the nature (muscle flicker vs contraction) of motor stimulation have a significant impact on changes in corticospinal excitability induced by electric stimulation. Here, we demonstrate that peripheral electric stimulation at stimulus amplitude to create a sensory response reduces corticomotor responsiveness. Conversely, stimulus amplitude to create a motor response increases corticomotor responsiveness, but only the parameters that create a motor response that mimics a voluntary muscle contraction. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

An improved genetic algorithm for designing optimal temporal patterns of neural stimulation

NASA Astrophysics Data System (ADS)

Cassar, Isaac R.; Titus, Nathan D.; Grill, Warren M.

2017-12-01

Objective. Electrical neuromodulation therapies typically apply constant frequency stimulation, but non-regular temporal patterns of stimulation may be more effective and more efficient. However, the design space for temporal patterns is exceedingly large, and model-based optimization is required for pattern design. We designed and implemented a modified genetic algorithm (GA) intended for design optimal temporal patterns of electrical neuromodulation. Approach. We tested and modified standard GA methods for application to designing temporal patterns of neural stimulation. We evaluated each modification individually and all modifications collectively by comparing performance to the standard GA across three test functions and two biophysically-based models of neural stimulation. Main results. The proposed modifications of the GA significantly improved performance across the test functions and performed best when all were used collectively. The standard GA found patterns that outperformed fixed-frequency, clinically-standard patterns in biophysically-based models of neural stimulation, but the modified GA, in many fewer iterations, consistently converged to higher-scoring, non-regular patterns of stimulation. Significance. The proposed improvements to standard GA methodology reduced the number of iterations required for convergence and identified superior solutions.

Infrared neural stimulation in the cochlea

PubMed Central

Richter, Claus-Peter; Rajguru, Suhrud; Bendett, Mark

2014-01-01

The application of photonics to manipulate and stimulate neurons and to study neural networks has gained momentum over the last decade. Two general methods have been used: the genetic expression of light or temperature sensitive ion channels in the plasma membrane of neurons (Optogenetics and Thermogenetics) and the direct stimulation of neurons using infrared radiation (Infrared Neural Stimulation, INS). Both approaches have their strengths and challenges, which are well understood with a profound understanding of the light tissue interaction(s). This paper compares the opportunities of the methods for the use in cochlear prostheses. Ample data are already available on the stimulation of the cochlea with INS. The data show that the stimulation is selective, feasible at rates that would be sufficient to encode acoustic information and may be beneficial over conventional pulsed electrical stimulation. A third approach, using lasers in stress confinement to generate pressure waves and to stimulate the functional cochlea mechanically will also be discussed. PMID:25075260

Infrared neural stimulation in the cochlea

NASA Astrophysics Data System (ADS)

Richter, Claus-Peter; Rajguru, Suhrud; Bendett, Mark

2013-03-01

The application of photonics to manipulate and stimulate neurons and to study neural networks has gained momentum over the last decade. Two general methods have been used: the genetic expression of light or temperature sensitive ion channels in the plasma membrane of neurons (Optogenetics and Thermogenetics) and the direct stimulation of neurons using infrared radiation (Infrared Neural Stimulation, INS). Both approaches have their strengths and challenges, which are well understood with a profound understanding of the light tissue interaction(s). This paper compares the opportunities of the methods for the use in cochlear prostheses. Ample data are already available on the stimulation of the cochlea with INS. The data show that the stimulation is selective, feasible at rates that would be sufficient to encode acoustic information and may be beneficial over conventional pulsed electrical stimulation. A third approach, using lasers in stress confinement to generate pressure waves and to stimulate the functional cochlea mechanically will also be discussed.

Electrically-evoked frequency-following response (EFFR) in the auditory brainstem of guinea pigs.

PubMed

He, Wenxin; Ding, Xiuyong; Zhang, Ruxiang; Chen, Jing; Zhang, Daoxing; Wu, Xihong

2014-01-01

It is still a difficult clinical issue to decide whether a patient is a suitable candidate for a cochlear implant and to plan postoperative rehabilitation, especially for some special cases, such as auditory neuropathy. A partial solution to these problems is to preoperatively evaluate the functional integrity of the auditory neural pathways. For evaluating the strength of phase-locking of auditory neurons, which was not reflected in previous methods using electrically evoked auditory brainstem response (EABR), a new method for recording phase-locking related auditory responses to electrical stimulation, called the electrically evoked frequency-following response (EFFR), was developed and evaluated using guinea pigs. The main objective was to assess feasibility of the method by testing whether the recorded signals reflected auditory neural responses or artifacts. The results showed the following: 1) the recorded signals were evoked by neuron responses rather than by artifact; 2) responses evoked by periodic signals were significantly higher than those evoked by the white noise; 3) the latency of the responses fell in the expected range; 4) the responses decreased significantly after death of the guinea pigs; and 5) the responses decreased significantly when the animal was replaced by an electrical resistance. All of these results suggest the method was valid. Recording obtained using complex tones with a missing fundamental component and using pure tones with various frequencies were consistent with those obtained using acoustic stimulation in previous studies.

Real-time 4D electrical resistivity imaging of tracer transport within an energically stimulated fracture zone

NASA Astrophysics Data System (ADS)

Johnson, T. C.

2016-12-01

Hydraulic fracture stimulation is used extensively in the subsurface energy sector to improve access between energy bearing formations and production boreholes. However, large uncertainties exist concerning the location and extent of stimulated fractures, and concerning the behavior of flow within those fractures. This uncertainty often results in significant risks, including induced seismicity and contamination of potable groundwater aquifers. Time-lapse electrical resistivity tomography (ERT) is a proven method of imaging fluid flow within fracture networks, by imaging the change in bulk conductivity induced by the presence of an electrically anomalous tracer within the fracture. In this work we demonstrate characterization and flow monitoring of a stimulated fracture using real-time four-dimensional ERT imaging within an unsaturated rhyolite formation. After stimulation, a conductive tracer was injected into the fracture zone. ERT survey data were continuously and autonomously collected, pre-processed on site, submitted to an off-site high performance computing system for inversion, and returned to the field for inspection. Surveys were collected at approximately 12 minute intervals. Data transmission and inversion required approximately 2 minutes per survey. The time-lapse imaging results show the dominant flow-paths within the stimulated fracture zone, thereby revealing the location and extent of the fracture, and the behavior of tracer flow within the fracture. Ultimately real-time imaging will enable site operators to better understand stimulation operations, and control post-stimulation reservoir operations for optimal performance and environmental protection.

Effects of brain-computer interface-based functional electrical stimulation on brain activation in stroke patients: a pilot randomized controlled trial.

PubMed

Chung, EunJung; Kim, Jung-Hee; Park, Dae-Sung; Lee, Byoung-Hee

2015-03-01

[Purpose] This study sought to determine the effects of brain-computer interface-based functional electrical stimulation (BCI-FES) on brain activation in patients with stroke. [Subjects] The subjects were randomized to in a BCI-FES group (n=5) and a functional electrical stimulation (FES) group (n=5). [Methods] Patients in the BCI-FES group received ankle dorsiflexion training with FES for 30 minutes per day, 5 times under the brain-computer interface-based program. The FES group received ankle dorsiflexion training with FES for the same amount of time. [Results] The BCI-FES group demonstrated significant differences in the frontopolar regions 1 and 2 attention indexes, and frontopolar 1 activation index. The FES group demonstrated no significant differences. There were significant differences in the frontopolar 1 region activation index between the two groups after the interventions. [Conclusion] The results of this study suggest that BCI-FES training may be more effective in stimulating brain activation than only FES training in patients recovering from stroke.

Effects of electrical stimulation on the histological properties of wounds in diabetic mice.

PubMed

Thawer, H A; Houghton, P E

2001-01-01

The purpose of this study was to identify mechanisms underlying electrically stimulated wound closure in diabetic mice. Adult male mice (n = 58) with full-thickness excisional wounds were treated five times using negative polarity over the wound site for 15 minutes each over a 16-day period with sham (0 Volts) or 5.0, 10.0, 12.5 Volts. In addition, animals (diabetic (n = 33) and nondiabetic (n = 22)) received treatments of electrical stimulation (12.5 V), or sham treatment (0 V) at wound sites which were then harvested and prepared for histological analysis at 2, 8, and 16 days postwounding. Using computerized image analysis of sections stained with a picro sirus red-fast green staining technique, we found that increasing doses of electrical stimulation reduced collagen/noncollagenous protein ratios measured in the superficial scar of nondiabetic animals, with no effect in diabetic animals. In the deep scar, lower doses of electrical stimulation (5.0 V) produced significantly (p < 0.01) increased collagen deposition in wounds of nondiabetic animals compared with sham controls. Higher doses of electrical stimulation (12.5 V) were required to produce changes in diabetic animals than were observed in nondiabetic animals. These results suggest that electrical stimulation altered collagen deposition in excisional wounds of diabetic and nondiabetic animals. Electrical stimulation had a differential effect on wound healing in diabetic compared with nondiabetic animals. These data speak to the need to study the effects of electrical stimulation on healing in disease-specific models.

Estimation of electrode location in a rat motor cortex by laminar analysis of electrophysiology and intracortical electrical stimulation

NASA Astrophysics Data System (ADS)

Yazdan-Shahmorad, A.; Lehmkuhle, M. J.; Gage, G. J.; Marzullo, T. C.; Parikh, H.; Miriani, R. M.; Kipke, D. R.

2011-08-01

While the development of microelectrode arrays has enabled access to disparate regions of a cortex for neurorehabilitation, neuroprosthetic and basic neuroscience research, accurate interpretation of the signals and manipulation of the cortical neurons depend upon the anatomical placement of the electrode arrays in a layered cortex. Toward this end, this report compares two in vivo methods for identifying the placement of electrodes in a linear array spaced 100 µm apart based on in situ laminar analysis of (1) ketamine-xylazine-induced field potential oscillations in a rat motor cortex and (2) an intracortical electrical stimulation-induced movement threshold. The first method is based on finding the polarity reversal in laminar oscillations which is reported to appear at the transition between layers IV and V in laminar 'high voltage spindles' of the rat cortical column. Analysis of histological images in our dataset indicates that polarity reversal is detected 150.1 ± 104.2 µm below the start of layer V. The second method compares the intracortical microstimulation currents that elicit a physical movement for anodic versus cathodic stimulation. It is based on the hypothesis that neural elements perpendicular to the electrode surface are preferentially excited by anodic stimulation while cathodic stimulation excites those with a direction component parallel to its surface. With this method, we expect to see a change in the stimulation currents that elicits a movement at the beginning of layer V when comparing anodic versus cathodic stimulation as the upper cortical layers contain neuronal structures that are primarily parallel to the cortical surface and lower layers contain structures that are primarily perpendicular. Using this method, there was a 78.7 ± 68 µm offset in the estimate of the depth of the start of layer V. The polarity reversal method estimates the beginning of layer V within ±90 µm with 95% confidence and the intracortical stimulation method estimates it within ±69.3 µm. We propose that these methods can be used to estimate the in situ location of laminar electrodes implanted in the rat motor cortex.

Effects of neuromuscular electrical stimulation, laser therapy and LED therapy on the masticatory system and the impact on sleep variables in cerebral palsy patients: a randomized, five arms clinical trial

PubMed Central

2012-01-01

Background Few studies demonstrate effectiveness of therapies for oral rehabilitation of patients with cerebral palsy (CP), given the difficulties in chewing, swallowing and speech, besides the intellectual, sensory and social limitations. Due to upper airway obstruction, they are also vulnerable to sleep disorders. This study aims to assess the sleep variables, through polysomnography, and masticatory dynamics, using electromiography, before and after neuromuscular electrical stimulation, associated or not with low power laser (Gallium Arsenide- Aluminun, =780 nm) and LED (= 660 nm) irradiation in CP patients. Methods/design 50 patients with CP, both gender, aged between 19 and 60 years will be enrolled in this study. The inclusion criteria are: voluntary participation, patient with hemiparesis, quadriparesis or diparetic CP, with ability to understand and respond to verbal commands. The exclusion criteria are: patients undergoing/underwent orthodontic, functional maxillary orthopedic or botulinum toxin treatment. Polysomnographic and surface electromyographic exams on masseter, temporalis and suprahyoid will be carry out in all sample. Questionnaire assessing oral characteristics will be applied. The sample will be divided into 5 treatment groups: Group 1: neuromuscular electrical stimulation; Group 2: laser therapy; Group 3: LED therapy; Group 4: neuromuscular electrical stimulation and laser therapy and Group 5: neuromuscular electrical stimulation and LED therapy. All patients will be treated during 8 consecutive weeks. After treatment, polysomnographic and electromiographic exams will be collected again. Discussion This paper describes a five arm clinical trial assessing the examination of sleep quality and masticatory function in patients with CP under non-invasive therapies. Trial registration The protocol for this study is registered with the Brazilian Registry of Clinical Trials - ReBEC RBR-994XFS Descriptors Cerebral Palsy. Stomatognathic System. Electromyography. Transcutaneous Electric Nerve Stimulation. Phototherapy. Sleep Disorders. Polysomnography. PMID:22587485

Effect of LKB1 deficiency on mitochondrial content, fiber type, and muscle performance in the mouse diaphragm

PubMed Central

Brown, Jacob D.; Hancock, Chad R.; Mongillo, Anthony D.; Barton, J. Benjamin; DiGiovanni, Ryan A.; Parcell, Allen C.; Winder, William W.; Thomson, David M.

2010-01-01

Aim The Liver Kinase B1 (LKB1)/AMP-Activated Protein Kinase (AMPK) signaling pathway is a major regulator of skeletal muscle metabolic processes. During exercise, LKB1-mediated phosphorylation of AMPK leads to its activation, promoting mitochondrial biogenesis and glucose transport, among other effects. The roles of LKB1 and AMPK have not been fully characterized in the diaphragm. Methods Two methods of AMPK activation were used to characterize LKB1/AMPK signaling in diaphragms from muscle-specific LKB1 knockout (KO) and littermate control mice: (1) acute injection of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) and (2) 5-min direct electrical stimulation of the diaphragm. Diaphragms were excised 60 minutes post-AICAR injection and immediately after electrical stimulation. Results AMPK phosphorylation increased with AICAR and electrical stimulation in control but not KO mice. Acetyl CoA carboxylase phosphorylation increased with AICAR in control but not KO mice, but increased in both genotypes with electrical stimulation. While the majority of mitochondrial protein levels were lower in KO diaphragms, uncoupling protein 3, complex I, and cytochrome oxidase IV protein levels were not different between genotypes. KO diaphragms have a lower percentage of IIx fibers and an elevated percentage of IIb fibers when compared to control diaphragms. While in vitro peak force generation was similar between genotypes, KO diaphragms fatigued more quickly and had an impaired ability to recover. Conclusion LKB1 regulates AMPK phosphorylation, mitochondrial protein expression, fiber type distribution, as well as recovery of the diaphragm from fatigue. PMID:21073663

Electrical stimulation of the hypothalamic nucleus paraventricularis mimics the effects of light on pineal melatonin synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olcese, J.; Reuss, S.; Steinlechner, S.

In an attempt to clarify further the role of the hypothalamic paraventricular nuclei (PVN) in the control of pineal function, the effects of 2 min electrical stimulation of these nuclei were investigated in acutely blinded, adult, male Sprague-Dawley rats. Pineal serotonin-N-acetyltransferase (NAT) activity, melatonin content and catecholamine levels were measured by means of radio-enzymatic, radioimmunoassay and high-performance liquid-chromatography methods, respectively. All three pineal parameters underwent significant declines following brief PVN stimulation during the night time. These observations lend credence to the view that the neural pathways transmitting light information to the sympathetic innervation controlling pineal melatonin synthesis. 22 references, 1more » figure.« less

Electrical stimulation accelerates motor functional recovery in autograft-repaired 10 mm femoral nerve gap in rats.

PubMed

Huang, Jinghui; Hu, Xueyu; Lu, Lei; Ye, Zhengxu; Wang, Yuqing; Luo, Zhuojing

2009-10-01

Electrical stimulation has been shown to enhance peripheral nerve regeneration after nerve injury. However, the impact of electrical stimulation on motor functional recovery after nerve injuries, especially over long nerve gap lesions, has not been investigated in a comprehensive manner. In the present study, we aimed to determine whether electrical stimulation (1 h, 20 Hz) is beneficial for motor functional recovery after a 10 mm femoral nerve gap lesion in rats. The proximal nerve stump was electrically stimulated for 1 h at 20 Hz frequency prior to nerve repair with an autologous graft. The rate of motor functional recovery was evaluated by single frame motion analysis and electrophysiological studies, and the nerve regeneration was investigated by double labeling and histological analysis. We found that brief electrical stimulation significantly accelerated motor functional recovery and nerve regeneration. Although the final outcome, both in functional terms and morphological terms, was not improved by electrical stimulation, the observed acceleration of functional recovery and axon regeneration may be of therapeutic importance in clinical setting.

Microprocessor controlled movement of liquid gastric content using sequential neural electrical stimulation

PubMed Central

Mintchev, M; Sanmiguel, C; Otto, S; Bowes, K

1998-01-01

Background—Gastric electrical stimulation has been attempted for several years with little success. 
Aims—To determine whether movement of liquid gastric content could be achieved using microprocessor controlled sequential electrical stimulation. 
Methods—Eight anaesthetised dogs underwent laparotomy and implantation of four sets of bipolar stainless steel wire electrodes. Each set consisted of two to six electrodes (10×0.25 mm, 3 cm apart) implanted circumferentially. The stomach was filled with water and the process of gastric emptying was monitored. Artificial contractions were produced using microprocessor controlled phase locked bipolar four second trains of 50 Hz, 14 V (peak to peak) rectangular voltage. In four of the dogs four force transducers were implanted close to each circumferential electrode set. In one gastroparetic patient the effect of direct electrical stimulation was determined at laparotomy. 
Results—Using the above stimulating parameters circumferential gastric contractions were produced which were artificially propagated distally by phase locking the stimulating voltage. Averaged stimulated gastric emptying times were significantly shorter than spontaneus emptying times (t1/2 6.7 (3.0) versus 25.3 (12.9) minutes, p<0.01). Gastric electrical stimulation of the gastroparetic patient at operation produced circumferential contractions. 
Conclusions—Microprocessor controlled electrical stimulation produced artificial peristalsis and notably accelerated the movement of liquid gastric content. 

 Keywords: gastric electrical stimulation; gastric motility PMID:9824339

Electrical stimulation of the midbrain excites the auditory cortex asymmetrically.

PubMed

Quass, Gunnar Lennart; Kurt, Simone; Hildebrandt, Jannis; Kral, Andrej

2018-05-17

Auditory midbrain implant users cannot achieve open speech perception and have limited frequency resolution. It remains unclear whether the spread of excitation contributes to this issue and how much it can be compensated by current-focusing, which is an effective approach in cochlear implants. The present study examined the spread of excitation in the cortex elicited by electric midbrain stimulation. We further tested whether current-focusing via bipolar and tripolar stimulation is effective with electric midbrain stimulation and whether these modes hold any advantage over monopolar stimulation also in conditions when the stimulation electrodes are in direct contact with the target tissue. Using penetrating multielectrode arrays, we recorded cortical population responses to single pulse electric midbrain stimulation in 10 ketamine/xylazine anesthetized mice. We compared monopolar, bipolar, and tripolar stimulation configurations with regard to the spread of excitation and the characteristic frequency difference between the stimulation/recording electrodes. The cortical responses were distributed asymmetrically around the characteristic frequency of the stimulated midbrain region with a strong activation in regions tuned up to one octave higher. We found no significant differences between monopolar, bipolar, and tripolar stimulation in threshold, evoked firing rate, or dynamic range. The cortical responses to electric midbrain stimulation are biased towards higher tonotopic frequencies. Current-focusing is not effective in direct contact electrical stimulation. Electrode maps should account for the asymmetrical spread of excitation when fitting auditory midbrain implants by shifting the frequency-bands downward and stimulating as dorsally as possible. Copyright © 2018 Elsevier Inc. All rights reserved.

Theoretical analysis of transcranial Hall-effect stimulation based on passive cable model

NASA Astrophysics Data System (ADS)

Yuan, Yi; Li, Xiao-Li

2015-12-01

Transcranial Hall-effect stimulation (THS) is a new stimulation method in which an ultrasonic wave in a static magnetic field generates an electric field in an area of interest such as in the brain to modulate neuronal activities. However, the biophysical basis of simulating the neurons remains unknown. To address this problem, we perform a theoretical analysis based on a passive cable model to investigate the THS mechanism of neurons. Nerve tissues are conductive; an ultrasonic wave can move ions embedded in the tissue in a static magnetic field to generate an electric field (due to Lorentz force). In this study, a simulation model for an ultrasonically induced electric field in a static magnetic field is derived. Then, based on the passive cable model, the analytical solution for the voltage distribution in a nerve tissue is determined. The simulation results showthat THS can generate a voltage to stimulate neurons. Because the THS method possesses a higher spatial resolution and a deeper penetration depth, it shows promise as a tool for treating or rehabilitating neuropsychiatric disorders. Project supported by the National Natural Science Foundation of China (Grant Nos. 61273063 and 61503321), the China Postdoctoral Science Foundation (Grant No. 2013M540215), the Natural Science Foundation of Hebei Province, China (Grant No. F2014203161), and the Youth Research Program of Yanshan University, China (Grant No. 02000134).

Muscle electrical stimulation improves neurovascular control and exercise tolerance in hospitalised advanced heart failure patients.

PubMed

Groehs, Raphaela V; Antunes-Correa, Ligia M; Nobre, Thais S; Alves, Maria-Janieire Nn; Rondon, Maria Urbana Pb; Barreto, Antônio Carlos Pereira; Negrão, Carlos E

2016-10-01

We investigated the effects of muscle functional electrical stimulation on muscle sympathetic nerve activity and muscle blood flow, and, in addition, exercise tolerance in hospitalised patients for stabilisation of heart failure. Thirty patients hospitalised for treatment of decompensated heart failure, class IV New York Heart Association and ejection fraction ≤ 30% were consecutively randomly assigned into two groups: functional electrical stimulation (n = 15; 54 ± 2 years) and control (n = 15; 49 ± 2 years). Muscle sympathetic nerve activity was directly recorded via microneurography and blood flow by venous occlusion plethysmography. Heart rate and blood pressure were evaluated on a beat-to-beat basis (Finometer), exercise tolerance by 6-minute walk test, quadriceps muscle strength by a dynamometer and quality of life by Minnesota questionnaire. Functional electrical stimulation consisted of stimulating the lower limbs at 10 Hz frequency, 150 ms pulse width and 70 mA intensity for 60 minutes/day for 8-10 consecutive days. The control group underwent electrical stimulation at an intensity of < 20 mA. Baseline characteristics were similar between groups, except age that was higher and C-reactive protein and forearm blood flow that were smaller in the functional electrical stimulation group. Functional electrical stimulation significantly decreased muscle sympathetic nerve activity and increased muscle blood flow and muscle strength. No changes were found in the control group. Walking distance and quality of life increased in both groups. However, these changes were greater in the functional electrical stimulation group. Functional electrical stimulation improves muscle sympathetic nerve activity and vasoconstriction and increases exercise tolerance, muscle strength and quality of life in hospitalised heart failure patients. These findings suggest that functional electrical stimulation may be useful to hospitalised patients with decompensated chronic heart failure. © The European Society of Cardiology 2016.

PI3K Phosphorylation Is Linked to Improved Electrical Excitability in an In Vitro Engineered Heart Tissue Disease Model System.

PubMed

Kana, Kujaany; Song, Hannah; Laschinger, Carol; Zandstra, Peter W; Radisic, Milica

2015-09-01

Myocardial infarction, a prevalent cardiovascular disease, is associated with cardiomyocyte cell death, and eventually heart failure. Cardiac tissue engineering has provided hopes for alternative treatment options, and high-fidelity tissue models for drug discovery. The signal transduction mechanisms relayed in response to mechanoelectrical (physical) stimulation or biochemical stimulation (hormones, cytokines, or drugs) in engineered heart tissues (EHTs) are poorly understood. In this study, an EHT model was used to elucidate the signaling mechanisms involved when insulin was applied in the presence of electrical stimulation, a stimulus that mimics functional heart tissue environment in vitro. EHTs were insulin treated, electrically stimulated, or applied in combination (insulin and electrical stimulation). Electrical excitability parameters (excitation threshold and maximum capture rate) were measured. Protein kinase B (AKT) and phosphatidylinositol-3-kinase (PI3K) phosphorylation revealed that insulin and electrical stimulation relayed electrical excitability through two separate signaling cascades, while there was a negative crosstalk between sustained activation of AKT and PI3K.

Joint inversion of hydraulic head and self-potential data associated with harmonic pumping tests

NASA Astrophysics Data System (ADS)

Soueid Ahmed, A.; Jardani, A.; Revil, A.; Dupont, J. P.

2016-09-01

Harmonic pumping tests consist in stimulating an aquifer by the means of hydraulic stimulations at some discrete frequencies. The inverse problem consisting in retrieving the hydraulic properties is inherently ill posed and is usually underdetermined when considering the number of well head data available in field conditions. To better constrain this inverse problem, we add self-potential data recorded at the ground surface to the head data. The self-potential method is a passive geophysical method. Its signals are generated by the groundwater flow through an electrokinetic coupling. We showed using a 3-D saturated unconfined synthetic aquifer that the self-potential method significantly improves the results of the harmonic hydraulic tomography. The hydroelectric forward problem is obtained by solving first the Richards equation, describing the groundwater flow, and then using the result in an electrical Poisson equation describing the self-potential problem. The joint inversion problem is solved using a reduction model based on the principal component geostatistical approach. In this method, the large prior covariance matrix is truncated and replaced by its low-rank approximation, allowing thus for notable computational time and storage savings. Three test cases are studied, to assess the validity of our approach. In the first test, we show that when the number of harmonic stimulations is low, combining the harmonic hydraulic and self-potential data does not improve the inversion results. In the second test where enough harmonic stimulations are performed, a significant improvement of the hydraulic parameters is observed. In the last synthetic test, we show that the electrical conductivity field required to invert the self-potential data can be determined with enough accuracy using an electrical resistivity tomography survey using the same electrodes configuration as used for the self-potential investigation.

Hybrid assistive systems for rehabilitation: lessons learned from functional electrical therapy in hemiplegics.

PubMed

Popović, Dejan B; Popović, Mirjana B

2006-01-01

This paper suggests that the optimal method for promoting of the recovery of upper extremity function in hemiplegic individuals is the use of hybrid assistive systems (HAS). The suggested HAS is a combination of stimulation of paralyzed distal segments (hand) in synchrony with robot controlled movements of proximal segments (upper arm and forearm). The use of HAS is envisioned as part of voluntary activation of preserved sensory-motor systems during task related exercise. This HAS design follows our results from functional electrical therapy, constraint induced movement therapy, intensive exercise therapy, and use of robots for rehabilitation. The suggestion is also based on strong evidences that cortical plasticity is best promoted by task related exercise and patterned electrical stimulation.

The relief of microtherm inhibition for p-fluoronitrobenzene mineralization using electrical stimulation at low temperatures.

PubMed

Zhang, Xueqin; Feng, Huajun; Liang, Yuxiang; Zhao, Zhiqing; Long, Yuyang; Fang, Yuan; Wang, Meizhen; Yin, Jun; Shen, Dongsheng

2015-05-01

Low temperature aggravates biological treatment of refractory p-fluoronitrobenzene (p-FNB) because of microtherm inhibition of microbial activity. Considering the potential characterization of energy supply for microbial metabolism and spurring microbial activity by electrical stimulation, a bioelectrochemical system (BES) was established to provide sustaining electrical stimulation for p-FNB mineralization at a low temperature. Electrical stimulation facilitated p-FNB treatment and bioelectrochemical reaction rate constants for the removal and defluorination of p-FNB at 10 °C were 0.0931 and 0.0054 h(-1), which were higher than the sums of the rates found using a biological system and an electrocatalytic system by 62.8 and 64.8%, respectively. At a low temperature, microbial activity in terms of dehydrogenase and ATPase was found to be higher with electrical stimulation, being 121.1 and 100.1% more active than that in the biological system. Moreover, stronger antioxidant ability was observed in the BES, which implied a better cold-resistance and relief of microtherm inhibition by electrical stimulation. Bacterial diversity analysis revealed a significant evolution of microbial community by electrical stimulation, and Clostridia was uniquely enriched. One bacterial sequence close to Pseudomonas became uniquely predominant, which appeared to be crucial for excellent p-FNB treatment performance in the BES at a low temperature. Economic evaluation revealed that the energy required to mineralize an extra mole of p-FNB was found to be 247 times higher by heating the system than by application of electrical stimulation. These results indicated that application of electrical stimulation is extremely promising for treating refractory waste at low temperatures.

Technique of electrical stimulation of the vestibular analyzer under clinical conditions

NASA Technical Reports Server (NTRS)

Khechinashvili, S. N.; Zargaryan, B. M.; Karakozov, K. G.

1980-01-01

Vestibular reactions appear under the action of direct current (dc) on the labyrinth of man and animals. A decrease of the stimulation effect of dc on the extralabyrinthine nervous formations in the suggested method is achieved by the use of electric pulses with steep front and back parts, as well as by previous anesthetization of the skin in the electrode application area by means of novocain solution electrophoresis. For this purpose a pulse producer giving trapezoid pulses with smoothly changing fronts and duration was constructed. With the help of an interrupter it is possible to stop the current increase instantly, and stimulation is performed at the level of the pulse 'plateau'. To induce vestibular reactions under monopolar stimulation, it is necessary to apply the current twice as high as that with bipolar electrode position. The use of short pulses with steep front and back parts for electrode stimulation of the vestibular analyzer is considered to be inexpedient.

Linking physics with physiology in TMS: a sphere field model to determine the cortical stimulation site in TMS.

PubMed

Thielscher, Axel; Kammer, Thomas

2002-11-01

A fundamental problem of transcranial magnetic stimulation (TMS) is determining the site and size of the stimulated cortical area. In the motor system, the most common procedure for this is motor mapping. The obtained two-dimensional distribution of coil positions with associated muscle responses is used to calculate a center of gravity on the skull. However, even in motor mapping the exact stimulation site on the cortex is not known and only rough estimates of its size are possible. We report a new method which combines physiological measurements with a physical model used to predict the electric field induced by the TMS coil. In four subjects motor responses in a small hand muscle were mapped with 9-13 stimulation sites at the head perpendicular to the central sulcus in order to keep the induced current direction constant in a given cortical region of interest. Input-output functions from these head locations were used to determine stimulator intensities that elicit half-maximal muscle responses. Based on these stimulator intensities the field distribution on the individual cortical surface was calculated as rendered from anatomical MR data. The region on the cortical surface in which the different stimulation sites produced the same electric field strength (minimal variance, 4.2 +/- 0.8%.) was determined as the most likely stimulation site on the cortex. In all subjects, it was located at the lateral part of the hand knob in the motor cortex. Comparisons of model calculations with the solutions obtained in this manner reveal that the stimulated cortex area innervating the target muscle is substantially smaller than the size of the electric field induced by the coil. Our results help to resolve fundamental questions raised by motor mapping studies as well as motor threshold measurements.

Restoration of Bladder and Bowel Function Using Electrical Stimulation and Block after Spinal Cord Injury

DTIC Science & Technology

2015-10-01

AWARD NUMBER: W81XWH-14-2-0132 TITLE: Restoration of Bladder and Bowel Function Using Electrical Stimulation and Block after Spinal Cord Injury...Sept 2015 4. TITLE AND SUBTITLE Restoration of Bladder and Bowel Function Using Electrical Stimulation and Block after Spinal Cord Injury 5a...evaluate the restoration of bladder and bowel function using electrical stimulation and block after spinal cord injury in human subjects. All staff

Effect of Fixed Versus Adjusted Transcutaneous Electrical Nerve Stimulation Amplitude on Chronic Mechanical Low Back Pain.

PubMed

Elserty, Noha; Kattabei, Omaima; Elhafez, Hytham

2016-07-01

This study aimed to investigate the effect of adjusting pulse amplitude of transcutaneous electrical nerve stimulation versus fixed pulse amplitude in treatment of chronic mechanical low back pain. Randomized clinical trial. El-sahel Teaching Hospital, Egypt. Forty-five patients with chronic low back pain assigned to three equal groups. Their ages ranged from 20 to 50 years. The three groups received the same exercise program. Group A received transcutaneous electrical nerve stimulation with fixed pulse amplitude for 40 minutes. Group B received transcutaneous electrical nerve stimulation with adjusted pulse amplitude for 40 minutes, with the pulse amplitude adjusted every 5 minutes. Group C received exercises only. Treatment sessions were applied three times per week for 4 weeks for the three groups. A visual analogue scale was used to assess pain severity, the Oswestry Disability Index was used to assess functional level, and a dual inclinometer was used to measure lumbar range of motion. Evaluations were performed before and after treatment. Visual analogue scale, Oswestry Disability Index, and back range of motion significantly differed between the two groups that received transcutaneous electrical nerve stimulation and the control group and did not significantly differ between fixed and adjusted pulse amplitude of transcutaneous electrical nerve stimulation. Adjusting pulse amplitude of transcutaneous electrical nerve stimulation does not produce a difference in the effect of transcutaneous electrical nerve stimulation used to treat chronic low back pain.

Intracochlear electrical stimulation suppresses apoptotic signaling in rat spiral ganglion neurons after deafening in vivo.

PubMed

Kopelovich, Jonathan C; Cagaanan, Alain P; Miller, Charles A; Abbas, Paul J; Green, Steven H

2013-11-01

To establish the intracellular consequences of electrical stimulation to spiral ganglion neurons after deafferentation. Here we use a rat model to determine the effect of both low and high pulse rate acute electrical stimulation on activation of the proapoptotic transcription factor Jun in deafferented spiral ganglion neurons in vivo. Experimental animal study. Hearing research laboratories of the University of Iowa Departments of Biology and Otolaryngology. A single electrode was implanted through the round window of kanamycin-deafened rats at either postnatal day 32 (P32, n = 24) or P60 (n = 22) for 4 hours of stimulation (monopolar, biphasic pulses, amplitude twice electrically evoked auditory brainstem response [eABR] threshold) at either 100 or 5000 Hz. Jun phosphorylation was assayed by immunofluorescence to quantitatively assess the effect of electrical stimulation on proapoptotic signaling. Jun phosphorylation was reliably suppressed by 100 Hz stimuli in deafened cochleae of P32 but not P60 rats. This effect was not significant in the basal cochlear turns. Stimulation frequency may be consequential: 100 Hz was significantly more effective than was 5 kHz stimulation in suppressing phospho-Jun. Suppression of Jun phosphorylation occurs in deafferented spiral ganglion neurons after only 4 hours of electrical stimulation. This finding is consistent with the hypothesis that electrical stimulation can decrease spiral ganglion neuron death after deafferentation.

Electrical stimulation in exercise training

NASA Technical Reports Server (NTRS)

Kroll, Walter

1994-01-01

Electrical stimulation has a long history of use in medicine dating back to 46 A.D. when the Roman physician Largus found the electrical discharge of torpedo fishes useful in the treatment of pain produced by headache and gout. A rival Greek physician, Dioscorides, discounted the value of the torpedo fish for headache relief but did recommend its use in the treatment of hemorrhoids. In 1745, the Leyden jar and various sized electrostatic generators were used to treat angina pectoris, epilepsy, hemiplegia, kidney stones, and sciatica. Benjamin Franklin used an electrical device to treat successfully a young woman suffering from convulsive fits. In the late 1800's battery powered hydroelectric baths were used to treat chronic inflammation of the uterus while electrified athletic supporters were advertised for the treatment of male problems. Fortunately, such an amusing early history of the simple beginnings of electrical stimulation did not prevent eventual development of a variety of useful therapeutic and rehabilitative applications of electrical stimulation. Over the centuries electrical stimulation has survived as a modality in the treatment of various medical disorders with its primary application being in the rehabilitation area. Recently, a surge of new interest in electrical stimulation has been kindled by the work of a Russian sport scientist who reported remarkable muscle strength and endurance improvements in elite athletes. Yakov Kots reported his research on electric stimulation and strength improvements in 1977 at a Canadian-Soviet Exchange Symposium held at Concordia University in Montreal. Since then an explosion of new studies has been seen in both sport science and in medicine. Based upon the reported works of Kots and the present surge of new investigations, one could be misled as to the origin of electrical stimulation as a technique to increase muscle strength. As a matter of fact, electric stimulation has been used as a technique to improve muscle strength for over a century. Bigelow reported in 1894, for example, the use of electrical stimulation on a young man for the purpose of increasing muscle strength. Employing a rapidly alternating sinusoidal induced current and a dynamometer for strength testing, Bigelow reported that the total lifting capacity of a patient increased from 4328 pounds to 4639 pounds after only 25 minutes of stimulation. In 1965, Massey et al. reported on the use of an Isotron electrical stimulator that emitted a high frequency current. Interestingly enough, the frequencies used by Massey et al. and the frequencies used by Bigelow in 1894 were in the same range of frequencies reported by Kots as being the most effective in strength development. It would seem the Russian secret of high frequency electrical stimulation for strength development, then, is not a modern development at all.

The Effect of Surface Electrical Stimulation on Vocal Fold Position

PubMed Central

Humbert, Ianessa A.; Poletto, Christopher J.; Saxon, Keith G.; Kearney, Pamela R.; Ludlow, Christy L.

2008-01-01

Objectives/Hypothesis Closure of the true and false vocal folds is a normal part of airway protection during swallowing. Individuals with reduced or delayed true vocal fold closure can be at risk for aspiration and benefit from intervention to ameliorate the problem. Surface electrical stimulation is currently used during therapy for dysphagia, despite limited knowledge of its physiological effects. Design Prospective single effects study. Methods The immediate physiological effect of surface stimulation on true vocal fold angle was examined at rest in 27 healthy adults using ten different electrode placements on the submental and neck regions. Fiberoptic nasolaryngoscopic recordings during passive inspiration were used to measure change in true vocal fold angle with stimulation. Results Vocal fold angles changed only to a small extent during two electrode placements (p ≤ 0.05). When two sets of electrodes were placed vertically on the neck the mean true vocal fold abduction was 2.4 degrees; while horizontal placements of electrodes in the submental region produced a mean adduction of 2.8 degrees (p=0.03). Conclusions Surface electrical stimulation to the submental and neck regions does not produce immediate true vocal fold adduction adequate for airway protection during swallowing and one position may produce a slight increase in true vocal fold opening. PMID:18043496

The effect of subthreshold continuous electrical stimulation on the facial function of patients with Bell's palsy.

PubMed

Kim, Jin; Choi, Jae Young

2016-01-01

The drug regimen plus electrical stimulation was more effective in treating Bell's palsy than the conventional drug treatment alone. The effectiveness of such a sub-threshold, continuous, low frequency electrical stimulation suggests a new therapeutic approach to accelerate nerve regeneration and improve functional recovery after injury. The purpose of this study was to determine whether sub-threshold, continuous electrical stimulation at 20 Hz facilitates functional recovery of patients with Bell's palsy. The authors performed a prospective randomized study that included 60 patients with mild-to-moderate grade Bell's palsy (HB grade ≤4, SB grade ≥40), to evaluate the effect of developed electrical stimulation on the resolution of symptoms. Thirty patients were treated with prednisolone or/and acyclovir plus electrical stimulation within 7 days of the onset of symptoms. The other 30 patients were treated with only prednisolone or/and acyclovir as a control group. The overall rate of patient recovery among those treated with prednisolone or/and acyclovir plus electrical stimulation (96%) was significantly better (p < 0.05) than the rate among those treated with only prednisolone or/and acyclovir (88%).

Why intra-epidermal electrical stimulation achieves stimulation of small fibres selectively: a simulation study

NASA Astrophysics Data System (ADS)

Motogi, Jun; Sugiyama, Yukiya; Laakso, Ilkka; Hirata, Akimasa; Inui, Koji; Tamura, Manabu; Muragaki, Yoshihiro

2016-06-01

The in situ electric field in the peripheral nerve of the skin is investigated to discuss the selective stimulation of nerve fibres. Coaxial planar electrodes with and without intra-epidermal needle tip were considered as electrodes of a stimulator. From electromagnetic analysis, the tip depth of the intra-epidermal electrode should be larger than the thickness of the stratum corneum, the electrical conductivity of which is much lower than the remaining tissue. The effect of different radii of the outer ring electrode on the in situ electric field is marginal. The minimum threshold in situ electric field (rheobase) for free nerve endings is estimated to be 6.3 kV m-1. The possible volume for electrostimulation, which can be obtained from the in situ electric field distribution, becomes deeper and narrower with increasing needle depth, suggesting that possible stimulation sites may be controlled by changing the needle depth. The injection current amplitude should be adjusted when changing the needle depth because the peak field strength also changes. This study shows that intra-epidermal electrical stimulation can achieve stimulation of small fibres selectively, because Aβ-, Aδ-, and C-fibre terminals are located at different depths in the skin.

[EFFECTS OF ELECTRICAL STIMULATION OF NUCLEUS RETICULARIS PONTIS ORALIS ON THE SLEEP-WAKING STATES IN KRUSHINSKII-MOLODKINA STRAIN RATS].

PubMed

Vataev, S I; Malgina, N A; Oganesyan, G A

2015-07-01

The effects of electrical stimulation of nucleus reticularis pontis oralis on the behavior and brain electrical activity during all phases of the sleep-waking cycle was studied in Krushinskii-Molodkina strain rats, which have an inherited predisposition to audiogenic seizures. Electrical stimulation with 7 Hz frequency in the deep stage of slow-wave sleep cause appearance the fast-wave sleep. Similar stimulation during fast-wave sleep periods did not effects on the electrographic patterns and EEG spectral characteristics of hippocampus, visual, auditory and somatocnen nrnrenc nf the cnrtey ThPe sfimul1stinns did nnt break a fast-wave sleenhut increased almost twice due the duration of these sleep episodes. After electrical stimulation by same frequency during the wakeftlness and superficial slow-wave sleep states, the patterns and spectral characteristics of brain electrical activity in rats showed no significant changes as compared with controls. The results of this study indicate that the state of the animals sleep-waking cycle at the time of stimulation is a critical variable that influences the responses which are induced by electrical stimulation of the nucleus reticularis pontis oralis.

Transcranial electric stimulation (tES) and NeuroImaging: the state-of-the-art, new insights and prospects in basic and clinical neuroscience.

PubMed

Soekadar, Surjo R; Herring, Jim Don; McGonigle, David

2016-10-15

Transcranial electric stimulation (tES) of the brain has attracted an increased interest in recent years. Yet, despite remarkable research efforts to date, the underlying neurobiological mechanisms of tES' effects are still incompletely understood. This Special Issue aims to provide a comprehensive and up-to-date overview of the state-of-the-art in studies combining tES and neuroimaging, while introducing most recent insights and outlining future prospects related to this new and rapidly growing field. The findings reported here combine methodological advancements with insights into the underlying mechanisms of tES itself. At the same time, they also point to the many caveats and specific challenges associated with such studies, which can arise from both technical and biological sources. Besides promising to advance basic neuroscience, combined tES and neuroimaging studies may also substantially change previous conceptions about the methods of action of electric or magnetic stimulation on the brain. Copyright © 2016. Published by Elsevier Inc.

All-Optical Electrophysiology for Disease Modeling and Pharmacological Characterization of Neurons.

PubMed

Werley, Christopher A; Brookings, Ted; Upadhyay, Hansini; Williams, Luis A; McManus, Owen B; Dempsey, Graham T

2017-09-11

A key challenge for establishing a phenotypic screen for neuronal excitability is measurement of membrane potential changes with high throughput and accuracy. Most approaches for probing excitability rely on low-throughput, invasive methods or lack cell-specific information. These limitations stimulated the development of novel strategies for characterizing the electrical properties of cultured neurons. Among these was the development of optogenetic technologies (Optopatch) that allow for stimulation and recording of membrane voltage signals from cultured neurons with single-cell sensitivity and millisecond temporal resolution. Neuronal activity is elicited using blue light activation of the channelrhodopsin variant 'CheRiff'. Action potentials and synaptic signals are measured with 'QuasAr', a rapid and sensitive voltage-indicating protein with near-infrared fluorescence that scales proportionately with transmembrane potential. This integrated technology of optical stimulation and recording of electrical signals enables investigation of neuronal electrical function with unprecedented scale and precision. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Characterization of Optically and Electrically Evoked Dopamine Release in Striatal Slices from Digenic Knock-in Mice with DAT-Driven Expression of Channelrhodopsin

PubMed Central

2017-01-01

Fast-scan cyclic voltammetry (FCV) is an established method to monitor increases in extracellular dopamine (DA) concentration ([DA]o) in the striatum, which is densely innervated by DA axons. Ex vivo brain slice preparations provide an opportunity to identify endogenous modulators of DA release. For these experiments, local electrical stimulation is often used to elicit release of DA, as well as other transmitters, in the striatal microcircuitry; changes in evoked increases in [DA]o after application of a pharmacological agent (e.g., a receptor antagonist) indicate a regulatory role for the transmitter system interrogated. Optogenetic methods that allow specific stimulation of DA axons provide a complementary, bottom-up approach for elucidating factors that regulate DA release. To this end, we have characterized DA release evoked by local electrical and optical stimulation in striatal slices from mice that genetically express a variant of channelrhodopsin-2 (ChR2). Evoked increases in [DA]o in the dorsal and ventral striatum (dStr and vStr) were examined in a cross of a Cre-dependent ChR2 line (“Ai32” mice) with a DAT::Cre mouse line. In dStr, repeated optical pulse-train stimulation at the same recording site resulted in rundown of evoked [DA]o using heterozygous mice, which contrasted with the stability seen with electrical stimulation. Similar rundown was seen in the presence of a nicotinic acetylcholine receptor (nAChR) antagonist, implicating the absence of concurrent nAChR activation in DA release instability in slices. Rundown with optical stimulation in dStr could be circumvented by recording from a population of sites, each stimulated only once. Same-site rundown was less pronounced with single-pulse stimulation, and a stable baseline could be attained. In vStr, stable optically evoked increases in [DA]o at single sites could be achieved using heterozygous mice, although with relatively low peak [DA]o. Low release could be overcome by using mice with a second copy of the Ai32 allele, which doubled ChR2 expression. The characteristics reported here should help future practitioners decide which Ai32;DAT::Cre genotype and recording protocol is optimal for the striatal subregion to be examined. PMID:28177213

Electrical stimulation of schwann cells promotes sustained increases in neurite outgrowth.

PubMed

Koppes, Abigail N; Nordberg, Andrea L; Paolillo, Gina M; Goodsell, Nicole M; Darwish, Haley A; Zhang, Linxia; Thompson, Deanna M

2014-02-01

Endogenous electric fields are instructive during embryogenesis by acting to direct cell migration, and postnatally, they can promote axonal growth after injury (McCaig 1991, Al-Majed 2000). However, the mechanisms for these changes are not well understood. Application of an appropriate electrical stimulus may increase the rate and success of nerve repair by directly promoting axonal growth. Previously, DC electrical stimulation at 50 mV/mm (1 mA, 8 h duration) was shown to promote neurite outgrowth and a more pronounced effect was observed if both peripheral glia (Schwann cells) and neurons were co-stimulated. If electrical stimulation is delivered to an injury site, both the neurons and all resident non-neuronal cells [e.g., Schwann cells, endothelial cells, fibroblasts] will be treated and this biophysical stimuli can influence axonal growth directly or indirectly via changes to the resident, non-neuronal cells. In this work, non-neuronal cells were electrically stimulated, and changes in morphology and neuro-supportive cells were evaluated. Schwann cell response (morphology and orientation) was examined after an 8 h stimulation over a range of DC fields (0-200 mV/mm, DC 1 mA), and changes in orientation were observed. Electrically prestimulating Schwann cells (50 mV/mm) promoted 30% more neurite outgrowth relative to co-stimulating both Schwann cells with neurons, suggesting that electrical stimulation modifies Schwann cell phenotype. Conditioned medium from the electrically prestimulated Schwann cells promoted a 20% increase in total neurite outgrowth and was sustained for 72 h poststimulation. An 11-fold increase in nerve growth factor but not brain-derived neurotrophic factor or glial-derived growth factor was found in the electrically prestimulated Schwann cell-conditioned medium. No significant changes in fibroblast or endothelial morphology and neuro-supportive behavior were observed poststimulation. Electrical stimulation is widely used in clinical settings; however, the rational application of this cue may directly impact and enhance neuro-supportive behavior, improving nerve repair.

Improved proprioceptive function by application of subsensory electrical noise: Effects of aging and task-demand.

PubMed

Toledo, Diana R; Barela, José A; Kohn, André F

2017-09-01

The application of subsensory noise stimulation over the lower limbs has been shown to improve proprioception and postural control under certain conditions. Whereas the effect specificity seems to depend on several factors, studies are still needed to determine the appropriate method for training and rehabilitation purposes. In the current study, we investigated whether the application of subsensory electrical noise over the legs improves proprioceptive function in young and older adults. We aimed to provide evidence that stronger and age-related differential effects occur in more demanding tasks. Proprioceptive function was initially assessed by testing the detection of passive ankle movement (kinesthetic perception) in twenty-eight subjects (14 young and 14 older adults). Thereafter, postural control was assessed during tasks with different sensory challenges: i) by removing visual information (eyes closed) and; ii) by moving the visual scene (moving room paradigm). Tests performed with the application of electrical noise stimulation were compared to those performed without noise. The results showed that electrical noise applied over the legs led to a reduction in the response time to kinesthetic perception in both young and older adults. On the other hand, the magnitude of postural sway was reduced by noise stimulation only during a more challenging task, namely, when the optical flow was changing in an unpredictable (nonperiodic) manner. No differential effects of stimulation between groups were observed. These findings suggest that the relevance of proprioceptive inputs in tasks with different challenges, but not the subjects' age, is a determining factor for sensorimotor improvements due to electrical noise stimulation. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

SPECT-imaging of activity-dependent changes in regional cerebral blood flow induced by electrical and optogenetic self-stimulation in mice.

PubMed

Kolodziej, Angela; Lippert, Michael; Angenstein, Frank; Neubert, Jenni; Pethe, Annette; Grosser, Oliver S; Amthauer, Holger; Schroeder, Ulrich H; Reymann, Klaus G; Scheich, Henning; Ohl, Frank W; Goldschmidt, Jürgen

2014-12-01

Electrical and optogenetic methods for brain stimulation are widely used in rodents for manipulating behavior and analyzing functional connectivities in neuronal circuits. High-resolution in vivo imaging of the global, brain-wide, activation patterns induced by these stimulations has remained challenging, in particular in awake behaving mice. We here mapped brain activation patterns in awake, intracranially self-stimulating mice using a novel protocol for single-photon emission computed tomography (SPECT) imaging of regional cerebral blood flow (rCBF). Mice were implanted with either electrodes for electrical stimulation of the medial forebrain bundle (mfb-microstim) or with optical fibers for blue-light stimulation of channelrhodopsin-2 expressing neurons in the ventral tegmental area (vta-optostim). After training for self-stimulation by current or light application, respectively, mice were implanted with jugular vein catheters and intravenously injected with the flow tracer 99m-technetium hexamethylpropyleneamine oxime (99mTc-HMPAO) during seven to ten minutes of intracranial self-stimulation or ongoing behavior without stimulation. The 99mTc-brain distributions were mapped in anesthetized animals after stimulation using multipinhole SPECT. Upon self-stimulation rCBF strongly increased at the electrode tip in mfb-microstim mice. In vta-optostim mice peak activations were found outside the stimulation site. Partly overlapping brain-wide networks of activations and deactivations were found in both groups. When testing all self-stimulating mice against all controls highly significant activations were found in the rostromedial nucleus accumbens shell. SPECT-imaging of rCBF using intravenous tracer-injection during ongoing behavior is a new tool for imaging regional brain activation patterns in awake behaving rodents providing higher spatial and temporal resolutions than 18F-2-fluoro-2-dexoyglucose positron emission tomography. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Cortical changes after mental imagery training combined with electromyography-triggered electrical stimulation in patients with chronic stroke.

PubMed

Hong, Il Ki; Choi, Jong Bae; Lee, Jong Ha

2012-09-01

Paresis of the upper extremity after stroke is not effectively solved by existing therapies. We investigated whether mental imagery training combined with electromyogram-triggered electric stimulation improved motor function of the paretic upper extremity in patients with chronic stroke and induced cortical changes. Fourteen subjects with chronic stroke (≥12 months) were randomly allocated to receive mental imagery training combined with electromyogram-triggered electric stimulation (n=7) or generalized functional electric stimulation (n=7) on the forearm extensor muscles of the paretic extremity in 2 20-minute daily sessions 5 days a week for 4 weeks. The upper extremity component of the Fugl-Meyer Motor Assessment, the Motor Activity Log, the modified Barthel Index, and (18)F-fluorodeoxyglucose brain positron emission tomography were measured before and after the intervention. The group receiving mental imagery training combined with electromyogram-triggered electric stimulation exhibited significant improvements in the upper extremity component of the Fugl-Meyer Motor Assessment after intervention (median, 7; interquartile range, 5-8; P<0.05), but the group receiving functional electric stimulation did not (median, 0; interquartile range, 0-3). Differences in score changes between the 2 groups were significant. The mental imagery training combined with electromyogram-triggered electric stimulation group showed significantly increased metabolism in the contralesional supplementary motor, precentral, and postcentral gyri (P(uncorrected)<0.001) after the intervention, but the functional electric stimulation group showed no significant differences. Mental imagery training combined with electromyogram-triggered electric stimulation improved motor function of the paretic extremity in patients with chronic stroke. The intervention increased metabolism in the contralesional motor-sensory cortex. Clinical Trial Registration- URL: https://e-irb.khmccri.or.kr/eirb/receipt/index.html?code=02&status=5. Unique identifier: KHUHMDIRB 1008-02.

CNS BOLD fMRI effects of sham-controlled transcutaneous electrical nerve stimulation in the left outer auditory canal - a pilot study.

PubMed

Kraus, Thomas; Kiess, Olga; Hösl, Katharina; Terekhin, Pavel; Kornhuber, Johannes; Forster, Clemens

2013-09-01

It has recently been shown that electrical stimulation of sensory afferents within the outer auditory canal may facilitate a transcutaneous form of central nervous system stimulation. Functional magnetic resonance imaging (fMRI) blood oxygenation level dependent (BOLD) effects in limbic and temporal structures have been detected in two independent studies. In the present study, we investigated BOLD fMRI effects in response to transcutaneous electrical stimulation of two different zones in the left outer auditory canal. It is hypothesized that different central nervous system (CNS) activation patterns might help to localize and specifically stimulate auricular cutaneous vagal afferents. 16 healthy subjects aged between 20 and 37 years were divided into two groups. 8 subjects were stimulated in the anterior wall, the other 8 persons received transcutaneous vagus nervous stimulation (tVNS) at the posterior side of their left outer auditory canal. For sham control, both groups were also stimulated in an alternating manner on their corresponding ear lobe, which is generally known to be free of cutaneous vagal innervation. Functional MR data from the cortex and brain stem level were collected and a group analysis was performed. In most cortical areas, BOLD changes were in the opposite direction when comparing anterior vs. posterior stimulation of the left auditory canal. The only exception was in the insular cortex, where both stimulation types evoked positive BOLD changes. Prominent decreases of the BOLD signals were detected in the parahippocampal gyrus, posterior cingulate cortex and right thalamus (pulvinar) following anterior stimulation. In subcortical areas at brain stem level, a stronger BOLD decrease as compared with sham stimulation was found in the locus coeruleus and the solitary tract only during stimulation of the anterior part of the auditory canal. The results of the study are in line with previous fMRI studies showing robust BOLD signal decreases in limbic structures and the brain stem during electrical stimulation of the left anterior auditory canal. BOLD signal decreases in the area of the nuclei of the vagus nerve may indicate an effective stimulation of vagal afferences. In contrast, stimulation at the posterior wall seems to lead to unspecific changes of the BOLD signal within the solitary tract, which is a key relay station of vagal neurotransmission. The results of the study show promise for a specific novel method of cranial nerve stimulation and provide a basis for further developments and applications of non-invasive transcutaneous vagus stimulation in psychiatric patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Differential effect of brief electrical stimulation on voltage-gated potassium channels

PubMed Central

Al Abed, Amr; Buskila, Yossi; Dokos, Socrates; Lovell, Nigel H.; Morley, John W.

2017-01-01

Electrical stimulation of neuronal tissue is a promising strategy to treat a variety of neurological disorders. The mechanism of neuronal activation by external electrical stimulation is governed by voltage-gated ion channels. This stimulus, typically brief in nature, leads to membrane potential depolarization, which increases ion flow across the membrane by increasing the open probability of these voltage-gated channels. In spiking neurons, it is activation of voltage-gated sodium channels (NaV channels) that leads to action potential generation. However, several other types of voltage-gated channels are expressed that also respond to electrical stimulation. In this study, we examine the response of voltage-gated potassium channels (KV channels) to brief electrical stimulation by whole cell patch-clamp electrophysiology and computational modeling. We show that nonspiking amacrine neurons of the retina exhibit a large variety of responses to stimulation, driven by different KV-channel subtypes. Computational modeling reveals substantial differences in the response of specific KV-channel subtypes that is dependent on channel kinetics. This suggests that the expression levels of different KV-channel subtypes in retinal neurons are a crucial predictor of the response that can be obtained. These data expand our knowledge of the mechanisms of neuronal activation and suggest that KV-channel expression is an important determinant of the sensitivity of neurons to electrical stimulation. NEW & NOTEWORTHY This paper describes the response of various voltage-gated potassium channels (KV channels) to brief electrical stimulation, such as is applied during prosthetic electrical stimulation. We show that the pattern of response greatly varies between KV channel subtypes depending on activation and inactivation kinetics of each channel. Our data suggest that problems encountered when artificially stimulating neurons such as cessation in firing at high frequencies, or “fading,” may be attributed to KV-channel activation. PMID:28202576

Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation

PubMed Central

Huang, Yu; Liu, Anli A; Lafon, Belen; Friedman, Daniel; Dayan, Michael; Wang, Xiuyuan; Bikson, Marom; Doyle, Werner K; Devinsky, Orrin; Parra, Lucas C

2017-01-01

Transcranial electric stimulation aims to stimulate the brain by applying weak electrical currents at the scalp. However, the magnitude and spatial distribution of electric fields in the human brain are unknown. We measured electric potentials intracranially in ten epilepsy patients and estimated electric fields across the entire brain by leveraging calibrated current-flow models. When stimulating at 2 mA, cortical electric fields reach 0.8 V/m, the lower limit of effectiveness in animal studies. When individual whole-head anatomy is considered, the predicted electric field magnitudes correlate with the recorded values in cortical (r = 0.86) and depth (r = 0.88) electrodes. Accurate models require adjustment of tissue conductivity values reported in the literature, but accuracy is not improved when incorporating white matter anisotropy or different skull compartments. This is the first study to validate and calibrate current-flow models with in vivo intracranial recordings in humans, providing a solid foundation to target stimulation and interpret clinical trials. DOI: http://dx.doi.org/10.7554/eLife.18834.001 PMID:28169833

Oral dosing of chemical indicators for in vivo monitoring of Ca2+ dynamics in insect muscle.

PubMed

Ferdinandus; Arai, Satoshi; Ishiwata, Shin'ichi; Suzuki, Madoka; Sato, Hirotaka

2015-01-01

This paper proposes a remarkably facile staining protocol to visually investigate dynamic physiological events in insect tissues. We attempted to monitor Ca2+ dynamics during contraction of electrically stimulated living muscle. Advances in circuit miniaturization and insect neuromuscular physiology have enabled the hybridization of living insects and man-made electronic components, such as microcomputers, the result of which has been often referred as a Living Machine, Biohybrid, or Cyborg Insect. In order for Cyborg Insects to be of practical use, electrical stimulation parameters need to be optimized to induce desired muscle response (motor action) and minimize the damage in the muscle due to the electrical stimuli. Staining tissues and organs as well as measuring the dynamics of chemicals of interest in muscle should be conducted to quantitatively and systematically evaluate the effect of various stimulation parameters on the muscle response. However, existing staining processes require invasive surgery and/or arduous procedures using genetically encoded sensors. In this study, we developed a non-invasive and remarkably facile method for staining, in which chemical indicators can be orally administered (oral dosing). A chemical Ca2+ indicator was orally introduced into an insect of interest via food containing the chemical indicator and the indicator diffused from the insect digestion system to the target muscle tissue. We found that there was a positive relationship between the fluorescence intensity of the indicator and the frequency of electrical stimulation which indicates the orally dosed indicator successfully monitored Ca2+ dynamics in the muscle tissue. This oral dosing method has a potential to globally stain tissues including neurons, and investigating various physiological events in insects.

Oral Dosing of Chemical Indicators for In Vivo Monitoring of Ca2+ Dynamics in Insect Muscle

PubMed Central

Ferdinandus; Arai, Satoshi; Ishiwata, Shin’ichi; Suzuki, Madoka; Sato, Hirotaka

2015-01-01

This paper proposes a remarkably facile staining protocol to visually investigate dynamic physiological events in insect tissues. We attempted to monitor Ca2+ dynamics during contraction of electrically stimulated living muscle. Advances in circuit miniaturization and insect neuromuscular physiology have enabled the hybridization of living insects and man-made electronic components, such as microcomputers, the result of which has been often referred as a Living Machine, Biohybrid, or Cyborg Insect. In order for Cyborg Insects to be of practical use, electrical stimulation parameters need to be optimized to induce desired muscle response (motor action) and minimize the damage in the muscle due to the electrical stimuli. Staining tissues and organs as well as measuring the dynamics of chemicals of interest in muscle should be conducted to quantitatively and systematically evaluate the effect of various stimulation parameters on the muscle response. However, existing staining processes require invasive surgery and/or arduous procedures using genetically encoded sensors. In this study, we developed a non-invasive and remarkably facile method for staining, in which chemical indicators can be orally administered (oral dosing). A chemical Ca2+ indicator was orally introduced into an insect of interest via food containing the chemical indicator and the indicator diffused from the insect digestion system to the target muscle tissue. We found that there was a positive relationship between the fluorescence intensity of the indicator and the frequency of electrical stimulation which indicates the orally dosed indicator successfully monitored Ca2+ dynamics in the muscle tissue. This oral dosing method has a potential to globally stain tissues including neurons, and investigating various physiological events in insects. PMID:25590329

Electrical stimulation of dorsal root entry zone attenuates wide-dynamic range neuronal activity in rats

PubMed Central

Yang, Fei; Zhang, Chen; Xu, Qian; Tiwari, Vinod; He, Shao-Qiu; Wang, Yun; Dong, Xinzhong; Vera-Portocarrero, Louis P.; Wacnik, Paul W.; Raja, Srinivasa N.; Guan, Yun

2014-01-01

Objectives Recent clinical studies suggest that neurostimulation at the dorsal root entry zone (DREZ) may alleviate neuropathic pain. However, the mechanisms of action for this therapeutic effect are unclear. Here, we examined whether DREZ stimulation inhibits spinal wide-dynamic-range (WDR) neuronal activity in nerve-injured rats. Materials and Methods We conducted in vivo extracellular single-unit recordings of WDR neurons in rats after an L5 spinal nerve ligation (SNL) or sham surgery. We set bipolar electrical stimulation (50 Hz, 0.2 ms, 5 min) of the DREZ at the intensity that activated only Aα/β-fibers by measuring the lowest current at which DREZ stimulation evoked a peak antidromic sciatic Aα/β-compound action potential without inducing an Aδ/C-compound action potential (i.e., Ab1). Results The elevated spontaneous activity rate of WDR neurons in SNL rats [n=25; data combined from day 14–16 (n = 15) and day 45–75 post-SNL groups (n=10)] was significantly decreased from the pre-stimulation level (p<0.01) at 0–15 min and 30–45 min post-stimulation. In both sham-operated (n=8) and nerve-injured rats, DREZ stimulation attenuated the C-component, but not A-component, of the WDR neuronal response to graded intracutaneous electrical stimuli (0.1–10 mA, 2 ms) applied to the skin receptive field. Further, DREZ stimulation blocked windup (a short form of neuronal sensitization) to repetitive noxious stimuli (0.5 Hz) at 0–15 min in all groups (p<0.05). Conclusions Attenuation of WDR neuronal activity may contribute to DREZ stimulation-induced analgesia. This finding supports the notion that DREZ may be a useful target for neuromodulatory control of pain. PMID:25308522

Development and Characterization of Organic Electronic Scaffolds for Bone Tissue Engineering.

PubMed

Iandolo, Donata; Ravichandran, Akhilandeshwari; Liu, Xianjie; Wen, Feng; Chan, Jerry K Y; Berggren, Magnus; Teoh, Swee-Hin; Simon, Daniel T

2016-06-01

Bones have been shown to exhibit piezoelectric properties, generating electrical potential upon mechanical deformation and responding to electrical stimulation with the generation of mechanical stress. Thus, the effects of electrical stimulation on bone tissue engineering have been extensively studied. However, in bone regeneration applications, only few studies have focused on the use of electroactive 3D biodegradable scaffolds at the interphase with stem cells. Here a method is described to combine the bone regeneration capabilities of 3D-printed macroporous medical grade polycaprolactone (PCL) scaffolds with the electrical and electrochemical capabilities of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). PCL scaffolds have been highly effective in vivo as bone regeneration grafts, and PEDOT is a leading material in the field of organic bioelectronics, due to its stability, conformability, and biocompatibility. A protocol is reported for scaffolds functionalization with PEDOT, using vapor-phase polymerization, resulting in a conformal conducting layer. Scaffolds' porosity and mechanical stability, important for in vivo bone regeneration applications, are retained. Human fetal mesenchymal stem cells proliferation is assessed on the functionalized scaffolds, showing the cytocompatibility of the polymeric coating. Altogether, these results show the feasibility of the proposed approach to obtain electroactive scaffolds for electrical stimulation of stem cells for regenerative medicine. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrical stimulation of anal sphincter or pudendal nerve improves anal sphincter pressure.

PubMed

Damaser, Margot S; Salcedo, Levilester; Wang, Guangjian; Zaszczurynski, Paul; Cruz, Michelle A; Butler, Robert S; Jiang, Hai-Hong; Zutshi, Massarat

2012-12-01

Stimulation of the pudendal nerve or the anal sphincter could provide therapeutic options for fecal incontinence with little involvement of other organs. The goal of this project was to assess the effects of pudendal nerve and anal sphincter stimulation on bladder and anal pressures. Ten virgin female Sprague Dawley rats were randomly allocated to control (n = 2), perianal stimulation (n = 4), and pudendal nerve stimulation (n = 4) groups. A monopolar electrode was hooked to the pudendal nerve or placed on the anal sphincter. Aballoon catheter was inserted into the anus to measure anal pressure, and a catheter was inserted into the bladder via the urethra to measure bladder pressure. Bladder and anal pressures were measured with different electrical stimulation parameters and different timing of electrical stimulation relative to spontaneous anal sphincter contractions. Increasing stimulation current had the most dramatic effect on both anal and bladder pressures. An immediate increase in anal pressure was observed when stimulating either the anal sphincter or the pudendal nerve at stimulation values of 1 mA or 2 mA. No increase in anal pressure was observed for lower current values. Bladder pressure increased at high current during anal sphincter stimulation, but not as much as during pudendal nerve stimulation. Increased bladder pressure during anal sphincter stimulation was due to contraction of the abdominal muscles. Electrical stimulation caused an increase in anal pressures with bladder involvement only at high current. These initial results suggest that electrical stimulation can increase anal sphincter pressure, enhancing continence control.

Electrical Programming of Soft Matter: Using Temporally Varying Electrical Inputs To Spatially Control Self Assembly.

PubMed

Yan, Kun; Liu, Yi; Zhang, Jitao; Correa, Santiago O; Shang, Wu; Tsai, Cheng-Chieh; Bentley, William E; Shen, Jana; Scarcelli, Giuliano; Raub, Christopher B; Shi, Xiao-Wen; Payne, Gregory F

2018-02-12

The growing importance of hydrogels in translational medicine has stimulated the development of top-down fabrication methods, yet often these methods lack the capabilities to generate the complex matrix architectures observed in biology. Here we show that temporally varying electrical signals can cue a self-assembling polysaccharide to controllably form a hydrogel with complex internal patterns. Evidence from theory and experiment indicate that internal structure emerges through a subtle interplay between the electrical current that triggers self-assembly and the electrical potential (or electric field) that recruits and appears to orient the polysaccharide chains at the growing gel front. These studies demonstrate that short sequences (minutes) of low-power (∼1 V) electrical inputs can provide the program to guide self-assembly that yields hydrogels with stable, complex, and spatially varying structure and properties.

Frequency dependence of behavioral modulation by hippocampal electrical stimulation

PubMed Central

La Corte, Giorgio; Wei, Yina; Chernyy, Nick; Gluckman, Bruce J.

2013-01-01

Electrical stimulation offers the potential to develop novel strategies for the treatment of refractory medial temporal lobe epilepsy. In particular, direct electrical stimulation of the hippocampus presents the opportunity to modulate pathological dynamics at the ictal focus, although the neuroanatomical substrate of this region renders it susceptible to altering cognition and affective processing as a side effect. We investigated the effects of three electrical stimulation paradigms on separate groups of freely moving rats (sham, 8-Hz and 40-Hz sine-wave stimulation of the ventral/intermediate hippocampus, where 8- and 40-Hz stimulation were chosen to mimic naturally occurring hippocampal oscillations). Animals exhibited attenuated locomotor and exploratory activity upon stimulation at 40 Hz, but not at sham or 8-Hz stimulation. Such behavioral modifications were characterized by a significant reduction in rearing frequency, together with increased freezing behavior. Logistic regression analysis linked the observed changes in animal locomotion to 40-Hz electrical stimulation independently of time-related variables occurring during testing. Spectral analysis, conducted to monitor the electrophysiological profile in the CA1 area of the dorsal hippocampus, showed a significant reduction in peak theta frequency, together with reduced theta power in the 40-Hz vs. the sham stimulation animal group, independent of locomotion speed (theta range: 4–12 Hz). These findings contribute to the development of novel and safe medical protocols by indicating a strategy to constrain or optimize parameters in direct hippocampal electrical stimulation. PMID:24198322

Alternative right ventricular pacing sites.

PubMed

Łuciuk, Dariusz; Łuciuk, Marek; Gajek, Jacek

2015-01-01

The main adverse effect of chronic stimulation is stimulation-induced heart failure in case of ventricular contraction dyssynchrony. Because of this fact, new techniques of stimulation should be considered to optimize electrotherapy. One of these methods is pacing from alternative right ventricular sites. The purpose of this article is to review currently accumulated data about alternative sites of cardiac pacing. Medline and PubMed bases were used to search English and Polish reports published recently. Recent studies report a deleterious effect of long term apical pacing. It is suggested that permanent apical stimulation, by omitting physiological conduction pattern with His-Purkinie network, may lead to electrical and mechanical dyssynchrony of heart muscle contraction. In the long term this pathological situation can lead to severe heart failure and death. Because of this, scientists began to search for some alternative sites of cardiac pacing to reduce the deleterious effect of stimulation. Based on current accumulated data, it is suggested that the right ventricular outflow tract, right ventricular septum, direct His-bundle or biventricular pacing are better alternatives due to more physiological electrical impulse propagation within the heart and the reduction of the dyssynchrony effect. These methods should preserve a better left ventricular function and prevent the development of heart failure in permanent paced patients. As there is still not enough, long-term, randomized, prospective, cross-over and multicenter studies, further research is required to validate the benefits of using this kind of therapy. The article should pay attention to new sites of cardiac stimulation as a better and safer method of treatment.

Suppression of stimulus artifact contaminating electrically evoked electromyography.

PubMed

Liu, Jie; Li, Sheng; Li, Xiaoyan; Klein, Cliff; Rymer, William Z; Zhou, Ping

2014-01-01

Electrical stimulation of muscle or nerve is a very useful technique for understanding of muscle activity and its pathological changes for both diagnostic and therapeutic purposes. During electrical stimulation of a muscle, the recorded M wave is often contaminated by a stimulus artifact. The stimulus artifact must be removed for appropriate analysis and interpretation of M waves. The objective of this study was to develop a novel software based method to remove stimulus artifacts contaminating or superimposing with electrically evoked surface electromyography (EMG) or M wave signals. The multiple stage method uses a series of signal processing techniques, including highlighting and detection of stimulus artifacts using Savitzky-Golay filtering, estimation of the artifact contaminated region with Otsu thresholding, and reconstruction of such region using signal interpolation and smoothing. The developed method was tested using M wave signals recorded from biceps brachii muscles by a linear surface electrode array. To evaluate the performance, a series of semi-synthetic signals were constructed from clean M wave and stimulus artifact recordings with different degrees of overlap between them. The effectiveness of the developed method was quantified by a significant increase in correlation coefficient and a significant decrease in root mean square error between the clean M wave and the reconstructed M wave, compared with those between the clean M wave and the originally contaminated signal. The validity of the developed method was also demonstrated when tested on each channel's M wave recording using a linear electrode array. The developed method can suppress stimulus artifacts contaminating M wave recordings.

A General Method for Evaluating Deep Brain Stimulation Effects on Intravenous Methamphetamine Self-Administration

PubMed Central

Batra, Vinita; Guerin, Glenn F.; Goeders, Nicholas E.; Wilden, Jessica A.

2016-01-01

Substance use disorders, particularly to methamphetamine, are devastating, relapsing diseases that disproportionally affect young people. There is a need for novel, effective and practical treatment strategies that are validated in animal models. Neuromodulation, including deep brain stimulation (DBS) therapy, refers to the use of electricity to influence pathological neuronal activity and has shown promise for psychiatric disorders, including drug dependence. DBS in clinical practice involves the continuous delivery of stimulation into brain structures using an implantable pacemaker-like system that is programmed externally by a physician to alleviate symptoms. This treatment will be limited in methamphetamine users due to challenging psychosocial situations. Electrical treatments that can be delivered intermittently, non-invasively and remotely from the drug-use setting will be more realistic. This article describes the delivery of intracranial electrical stimulation that is temporally and spatially separate from the drug-use environment for the treatment of IV methamphetamine dependence. Methamphetamine dependence is rapidly developed in rodents using an operant paradigm of intravenous (IV) self-administration that incorporates a period of extended access to drug and demonstrates both escalation of use and high motivation to obtain drug. PMID:26863392

Modeling Fast-scan Cyclic Voltammetry Data from Electrically Stimulated Dopamine Neurotransmission Data Using QNsim1.0.

PubMed

Harun, Rashed; Grassi, Christine M; Munoz, Miranda J; Wagner, Amy K

2017-06-05

Central dopaminergic (DAergic) pathways have an important role in a wide range of functions, such as attention, motivation, and movement. Dopamine (DA) is implicated in diseases and disorders including attention deficit hyperactivity disorder, Parkinson's disease, and traumatic brain injury. Thus, DA neurotransmission and the methods to study it are of intense scientific interest. In vivo fast-scan cyclic voltammetry (FSCV) is a method that allows for selectively monitoring DA concentration changes with fine temporal and spatial resolution. This technique is commonly used in conjunction with electrical stimulations of ascending DAergic pathways to control the impulse flow of dopamine neurotransmission. Although the stimulated DA neurotransmission paradigm can produce robust DA responses with clear morphologies, making them amenable for kinetic analysis, there is still much debate on how to interpret the responses in terms of their DA release and clearance components. To address this concern, a quantitative neurobiological (QN) framework of stimulated DA neurotransmission was recently developed to realistically model the dynamics of DA release and reuptake over the course of a stimulated DA response. The foundations of this model are based on experimental data from stimulated DA neurotransmission and on principles of neurotransmission adopted from various lines of research. The QN model implements 12 parameters related to stimulated DA release and reuptake dynamics to model DA responses. This work describes how to simulate DA responses using QNsim1.0 and also details principles that have been implemented to systematically discern alterations in the stimulated dopamine release and reuptake dynamics.

Comparison of effectiveness between cork-screw and peg-screw electrodes for transcranial motor evoked potential monitoring using the finite element method.

PubMed

Tomio, Ryosuke; Akiyama, Takenori; Ohira, Takayuki; Yoshida, Kazunari

2016-01-01

Intraoperative monitoring of motor evoked potentials by transcranial electric stimulation is popular in neurosurgery for monitoring motor function preservation. Some authors have reported that the peg-screw electrodes screwed into the skull can more effectively conduct current to the brain compared to subdermal cork-screw electrodes screwed into the skin. The aim of this study was to investigate the influence of electrode design on transcranial motor evoked potential monitoring. We estimated differences in effectiveness between the cork-screw electrode, peg-screw electrode, and cortical electrode to produce electric fields in the brain. We used the finite element method to visualize electric fields in the brain generated by transcranial electric stimulation using realistic three-dimensional head models developed from T1-weighted images. Surfaces from five layers of the head were separated as accurately as possible. We created the "cork-screws model," "1 peg-screw model," "peg-screws model," and "cortical electrode model". Electric fields in the brain radially diffused from the brain surface at a maximum just below the electrodes in coronal sections. The coronal sections and surface views of the brain showed higher electric field distributions under the peg-screw compared to the cork-screw. An extremely high electric field was observed under cortical electrodes. Our main finding was that the intensity of electric fields in the brain are higher in the peg-screw model than the cork-screw model.

Modelling the cost-utility of bio-electric stimulation therapy compared to standard care in the treatment of elderly patients with chronic non-healing wounds in the UK.

PubMed

Clegg, John P; Guest, Julian F

2007-04-01

To estimate the cost-utility of bio-electric stimulation therapy (Posifect) compared to standard care in elderly patients with chronic, non-healing wounds of > 6 months duration, from the perspective of the National Health Service (NHS) in the UK. Clinical and resource use data from a 16 week clinical evaluation of bio-electric stimulation therapy among patients who had recalcitrant wounds were combined with utility data obtained from a standard gamble analysis to construct a 16 week Markov model. The model considers the decision by a clinician to continue with a patient's previous care plan or treat with bio-electric stimulation therapy. Unit resource costs at 2005/2006 prices were applied to the resource utilisation estimates within the model, enabling the cost-utility of bio-electric stimulation therapy compared to standard care to be estimated. The acquisition cost of Posifect had not been decided at the time of performing this study. Hence, the base case analysis used a cost of 50 pounds per dressing. 33% of all wounds are expected to heal within 16 weeks after the start of bio-electric stimulation therapy. Consequently, using bio-electric stimulation therapy is expected to lead to a 51% decrease in the number of domiciliary clinician visits, from 4.7 to 2.3 per week. The model also showed that using bio-electric stimulation therapy instead of patients' standard care is expected to reduce the NHS cost of managing them by 16% from 2287 pounds (95% CI: 1838 pounds; 2735 pounds) to 1921 pounds (95% CI: 1609 pounds; 2233 pounds) and result in a health gain of 0.023 QALYs over 16 weeks. Hence, bio-electric stimulation therapy was found to be a dominant treatment. Sensitivity analyses demonstrated that the cost-utility of using bio-electric stimulation therapy relative to standard care is very sensitive to the acquisition cost of the therapy, the acquisition cost of patients' drugs and the number of clinician visits and less sensitive to utility values and the acquisition cost of other dressings. Within the limitations of the model, bio-electric stimulation therapy is expected to afford the NHS a cost-effective dressing compared to standard care in the management of chronic non-healing wounds of > 6 months duration. Bio-electric stimulation therapy's acquisition cost is expected to be offset by a reduction in the requirement for domiciliary clinician visits, leading to a release of NHS resources for use elsewhere in the system, thereby generating an increase in NHS efficiency.

Toward rational design of electrical stimulation strategies for epilepsy control

PubMed Central

Sunderam, Sridhar; Gluckman, Bruce; Reato, Davide; Bikson, Marom

2009-01-01

Electrical stimulation is emerging as a viable alternative for epilepsy patients whose seizures are not alleviated by drugs or surgery. Its attractions are temporal and spatial specificity of action, flexibility of waveform parameters and timing, and the perception that its effects are reversible unlike resective surgery. However, despite significant advances in our understanding of mechanisms of neural electrical stimulation, clinical electrotherapy for seizures relies heavily on empirical tuning of parameters and protocols. We highlight concurrent treatment goals with potentially conflicting design constraints that must be resolved when formulating rational strategies for epilepsy electrotherapy: namely seizure reduction versus cognitive impairment, stimulation efficacy versus tissue safety, and mechanistic insight versus clinical pragmatism. First, treatment markers, objectives, and metrics relevant to electrical stimulation for epilepsy are discussed from a clinical perspective. Then the experimental perspective is presented, with the biophysical mechanisms and modalities of open-loop electrical stimulation, and the potential benefits of closed-loop control for epilepsy. PMID:19926525

Research trend in thermally stimulated current method for development of materials and devices in Japan

NASA Astrophysics Data System (ADS)

Iwamoto, Mitsumasa; Taguchi, Dai

2018-03-01

Thermally stimulated current (TSC) measurement is widely used in a variety of research fields, i.e., physics, electronics, electrical engineering, chemistry, ceramics, and biology. TSC is short-circuit current that flows owing to the displacement of charges in samples during heating. TSC measurement is very simple, but TSC curves give very important information on charge behaviors. In the 1970s, TSC measurement contributed greatly to the development of electrical insulation engineering, semiconductor device technology, and so forth. Accordingly, the TSC experimental technique and its analytical method advanced. Over the past decades, many new molecules and advanced functional materials have been discovered and developed. Along with this, TSC measurement has attracted much attention in industries and academic laboratories as a way of characterizing newly discovered materials and devices. In this review, we report the latest research trend in the TSC method for the development of materials and devices in Japan.

Highly sensitive protein detection by biospecific AFM-based fishing with pulsed electrical stimulation.

PubMed

Pleshakova, Tatyana O; Malsagova, Kristina A; Kaysheva, Anna L; Kopylov, Arthur T; Tatur, Vadim Yu; Ziborov, Vadim S; Kanashenko, Sergey L; Galiullin, Rafael A; Ivanov, Yuri D

2017-08-01

We report here the highly sensitive detection of protein in solution at concentrations from 10 -15 to 10 -18 m using the combination of atomic force microscopy (AFM) and mass spectrometry. Biospecific detection of biotinylated bovine serum albumin was carried out by fishing out the protein onto the surface of AFM chips with immobilized avidin, which determined the specificity of the analysis. Electrical stimulation was applied to enhance the fishing efficiency. A high sensitivity of detection was achieved by application of nanosecond electric pulses to highly oriented pyrolytic graphite placed under the AFM chip. A peristaltic pump-based flow system, which is widely used in routine bioanalytical assays, was employed throughout the analysis. These results hold promise for the development of highly sensitive protein detection methods using nanosensor devices.

Directing lineage specification of human mesenchymal stem cells by decoupling electrical stimulation and physical patterning on unmodified graphene

NASA Astrophysics Data System (ADS)

Balikov, Daniel A.; Fang, Brian; Chun, Young Wook; Crowder, Spencer W.; Prasai, Dhiraj; Lee, Jung Bok; Bolotin, Kiril I.; Sung, Hak-Joon

2016-07-01

The organization and composition of the extracellular matrix (ECM) have been shown to impact the propagation of electrical signals in multiple tissue types. To date, many studies with electroactive biomaterial substrates have relied upon passive electrical stimulation of the ionic media to affect cell behavior. However, development of cell culture systems in which stimulation can be directly applied to the material - thereby isolating the signal to the cell-material interface and cell-cell contracts - would provide a more physiologically-relevant paradigm for investigating how electrical cues modulate lineage-specific stem cell differentiation. In the present study, we have employed unmodified, directly-stimulated, (un)patterned graphene as a cell culture substrate to investigate how extrinsic electrical cycling influences the differentiation of naïve human mesenchymal stem cells (hMSCs) without the bias of exogenous biochemicals. We first demonstrated that cyclic stimulation does not deteriorate the cell culture media or result in cytotoxic pH, which are critical experiments for correct interpretation of changes in cell behavior. We then measured how the expression of osteogenic and neurogenic lineage-specific markers were altered simply by exposure to electrical stimulation and/or physical patterns. Expression of the early osteogenic transcription factor RUNX2 was increased by electrical stimulation on all graphene substrates, but the mature marker osteopontin was only modulated when stimulation was combined with physical patterns. In contrast, the expression of the neurogenic markers MAP2 and β3-tubulin were enhanced in all electrical stimulation conditions, and were less responsive to the presence of patterns. These data indicate that specific combinations of non-biological inputs - material type, electrical stimulation, physical patterns - can regulate hMSC lineage specification. This study represents a substantial step in understanding how the interplay of electrophysical stimuli regulate stem cell behavior and helps to clarify the potential for graphene substrates in tissue engineering applications.

Electrical Stimulation Improves Microbial Salinity Resistance and Organofluorine Removal in Bioelectrochemical Systems

PubMed Central

Feng, Huajun; Zhang, Xueqin; Guo, Kun; Vaiopoulou, Eleni; Shen, Dongsheng; Long, Yuyang; Yin, Jun

2015-01-01

Fed batch bioelectrochemical systems (BESs) based on electrical stimulation were used to treat p-fluoronitrobenzene (p-FNB) wastewater at high salinities. At a NaCl concentration of 40 g/liter, p-FNB was removed 100% in 96 h in the BES, whereas in the biotic control (BC) (absence of current), p-FNB removal was only 10%. By increasing NaCl concentrations from 0 g/liter to 40 g/liter, defluorination efficiency decreased around 40% in the BES, and in the BC it was completely ceased. p-FNB was mineralized by 30% in the BES and hardly in the BC. Microorganisms were able to store 3.8 and 0.7 times more K+ and Na+ intracellularly in the BES than in the BC. Following the same trend, the ratio of protein to soluble polysaccharide increased from 3.1 to 7.8 as the NaCl increased from 0 to 40 g/liter. Both trends raise speculation that an electrical stimulation drives microbial preference toward K+ and protein accumulation to tolerate salinity. These findings are in accordance with an enrichment of halophilic organisms in the BES. Halobacterium dominated in the BES by 56.8% at a NaCl concentration of 40 g/liter, while its abundance was found as low as 17.5% in the BC. These findings propose a new method of electrical stimulation to improve microbial salinity resistance. PMID:25819966

A generic model of real-world non-ideal behaviour of FES-induced muscle contractions: simulation tool

NASA Astrophysics Data System (ADS)

Lynch, Cheryl L.; Graham, Geoff M.; Popovic, Milos R.

2011-08-01

Functional electrical stimulation (FES) applications are frequently evaluated in simulation prior to testing in human subjects. Such simulations are usually based on the typical muscle responses to electrical stimulation, which may result in an overly optimistic assessment of likely real-world performance. We propose a novel method for simulating FES applications that includes non-ideal muscle behaviour during electrical stimulation resulting from muscle fatigue, spasms and tremors. A 'non-idealities' block that can be incorporated into existing FES simulations and provides a realistic estimate of real-world performance is described. An implementation example is included, showing how the non-idealities block can be incorporated into a simulation of electrically stimulated knee extension against gravity for both a proportional-integral-derivative controller and a sliding mode controller. The results presented in this paper illustrate that the real-world performance of a FES system may be vastly different from the performance obtained in simulation using nominal muscle models. We believe that our non-idealities block should be included in future simulations that involve muscle response to FES, as this tool will provide neural engineers with a realistic simulation of the real-world performance of FES systems. This simulation strategy will help engineers and organizations save time and money by preventing premature human testing. The non-idealities block will become available free of charge at www.toronto-fes.ca in late 2011.

Mimicking muscle activity with electrical stimulation

NASA Astrophysics Data System (ADS)

Johnson, Lise A.; Fuglevand, Andrew J.

2011-02-01

Functional electrical stimulation is a rehabilitation technology that can restore some degree of motor function in individuals who have sustained a spinal cord injury or stroke. One way to identify the spatio-temporal patterns of muscle stimulation needed to elicit complex upper limb movements is to use electromyographic (EMG) activity recorded from able-bodied subjects as a template for electrical stimulation. However, this requires a transfer function to convert the recorded (or predicted) EMG signals into an appropriate pattern of electrical stimulation. Here we develop a generalized transfer function that maps EMG activity into a stimulation pattern that modulates muscle output by varying both the pulse frequency and the pulse amplitude. We show that the stimulation patterns produced by this transfer function mimic the active state measured by EMG insofar as they reproduce with good fidelity the complex patterns of joint torque and joint displacement.

An electrical bio-chip to transfer and detect electromagnetic stimulation on the cells based on vertically aligned carbon nanotubes.

PubMed

Rafizadeh-Tafti, Saeed; Haqiqatkhah, Mohammad Hossein; Saviz, Mehrdad; Janmaleki, Mohsen; Faraji Dana, Reza; Zanganeh, Somayeh; Abdolahad, Mohammad

2017-01-01

A highly sensitive impedimetric bio-chip based on vertically aligned multiwall carbon nanotubes (VAMWCNTs), was applied in direct interaction with lung cancer cells. Our tool provided both inducing and monitoring the bioelectrical changes in the cells initiated by electromagnetic (EM) wave stimulation. EM wave of 940MHz frequency with different intensities was used. Here, wave ablation might accumulate electrical charge on the tips of nanotubes penetrated into cell's membrane. The charge might induce ionic exchanges into the cell and cause alterations in electrical states of the membrane. Transmembrane electrostatic/dynamic states would be strongly affected due to such exchanges. Our novel modality was that, the cells' vitality changes caused by charge inductions were electrically detected with the same nanotubes in the architecture of electrodes for impedance measurement. The responses of the sensor were confirmed by electron and florescent microscopy images as well as biological assays. In summation, our method provided an effective biochip for enhancing and detecting external EM stimulation on the cells useful for future diagnostic and therapeutic applications, such as wave-guided drug-resistance breakage. Copyright © 2016 Elsevier B.V. All rights reserved.

Different effects of transcutaneous electric nerve stimulation and electroacupuncture at ST36–ST37 on the cerebral cortex

PubMed Central

Kang, Yu-Tien; Liao, Yi-Sheng; Hsieh, Ching-Liang

2015-01-01

Background The effects of transcutaneous electric nerve stimulation (TENS) and electroacupuncture (EA) on the cerebral cortex are largely unclear. The purpose of the present study was to investigate the effect of TENS and EA on the cerebral cortex by examining their effect on the median nerve-somatosensory evoked potentials (MN-SEPs). Methods Twenty volunteers were studied. The cortical and cervical spinal potentials were recorded by median nerve stimulation at the left wrist. Sham TENS, 2 Hz TENS and 2 Hz EA were applied to both ST36 and ST37. MN-SEPs were recorded during sham TENS, 2 Hz TENS and 2 Hz EA, with at least 1 week interval for each subject. One-way analysis of variance was used to determine the differences in latency and amplitude of the MN-SEPs observed in the stimulation and post-stimulation periods compared with baseline. Scheffe's post hoc correction was employed to identify pairwise differences. Results No differences in mean latency were found between the stimulation procedures during the stimulation and post-stimulation periods. 2 Hz EA but not sham TENS or 2 Hz TENS caused higher mean amplitudes in N20 and N30 during the stimulation and post-stimulation periods. Conclusions EA, but not TENS, induces changes in certain components of the signal. PMID:25432425

Electrical Stimulation Modulates High γ Activity and Human Memory Performance

PubMed Central

Berry, Brent M.; Miller, Laura R.; Khadjevand, Fatemeh; Ezzyat, Youssef; Wanda, Paul; Sperling, Michael R.; Lega, Bradley; Stead, S. Matt

2018-01-01

Direct electrical stimulation of the brain has emerged as a powerful treatment for multiple neurological diseases, and as a potential technique to enhance human cognition. Despite its application in a range of brain disorders, it remains unclear how stimulation of discrete brain areas affects memory performance and the underlying electrophysiological activities. Here, we investigated the effect of direct electrical stimulation in four brain regions known to support declarative memory: hippocampus (HP), parahippocampal region (PH) neocortex, prefrontal cortex (PF), and lateral temporal cortex (TC). Intracranial EEG recordings with stimulation were collected from 22 patients during performance of verbal memory tasks. We found that high γ (62–118 Hz) activity induced by word presentation was modulated by electrical stimulation. This modulatory effect was greatest for trials with “poor” memory encoding. The high γ modulation correlated with the behavioral effect of stimulation in a given brain region: it was negative, i.e., the induced high γ activity was decreased, in the regions where stimulation decreased memory performance, and positive in the lateral TC where memory enhancement was observed. Our results suggest that the effect of electrical stimulation on high γ activity induced by word presentation may be a useful biomarker for mapping memory networks and guiding therapeutic brain stimulation. PMID:29404403

Improving Balance Function Using Low Levels of Electrical Stimulation of the Balance Organs

NASA Technical Reports Server (NTRS)

Bloomberg, Jacob; Reschke, Millard; Mulavara, Ajitkumar; Wood, Scott; Serrador, Jorge; Fiedler, Matthew; Kofman, Igor; Peters, Brian T.; Cohen, Helen

2012-01-01

Crewmembers returning from long-duration space flight face significant challenges due to the microgravity-induced inappropriate adaptations in balance/ sensorimotor function. The Neuroscience Laboratory at JSC is developing a method based on stochastic resonance to enhance the brain s ability to detect signals from the balance organs of the inner ear and use them for rapid improvement in balance skill, especially when combined with balance training exercises. This method involves a stimulus delivery system that is wearable/portable providing imperceptible electrical stimulation to the balance organs of the human body. Stochastic resonance (SR) is a phenomenon whereby the response of a nonlinear system to a weak periodic input signal is optimized by the presence of a particular non-zero level of noise. This phenomenon of SR is based on the concept of maximizing the flow of information through a system by a non-zero level of noise. Application of imperceptible SR noise coupled with sensory input in humans has been shown to improve motor, cardiovascular, visual, hearing, and balance functions. SR increases contrast sensitivity and luminance detection; lowers the absolute threshold for tone detection in normal hearing individuals; improves homeostatic function in the human blood pressure regulatory system; improves noise-enhanced muscle spindle function; and improves detection of weak tactile stimuli using mechanical or electrical stimulation. SR noise has been shown to improve postural control when applied as mechanical noise to the soles of the feet, or when applied as electrical noise at the knee and to the back muscles.

Sound-by-sound thalamic stimulation modulates midbrain auditory excitability and relative binaural sensitivity in frogs

PubMed Central

Ponnath, Abhilash; Farris, Hamilton E.

2014-01-01

Descending circuitry can modulate auditory processing, biasing sensitivity to particular stimulus parameters and locations. Using awake in vivo single unit recordings, this study tested whether electrical stimulation of the thalamus modulates auditory excitability and relative binaural sensitivity in neurons of the amphibian midbrain. In addition, by using electrical stimuli that were either longer than the acoustic stimuli (i.e., seconds) or presented on a sound-by-sound basis (ms), experiments addressed whether the form of modulation depended on the temporal structure of the electrical stimulus. Following long duration electrical stimulation (3–10 s of 20 Hz square pulses), excitability (spikes/acoustic stimulus) to free-field noise stimuli decreased by 32%, but returned over 600 s. In contrast, sound-by-sound electrical stimulation using a single 2 ms duration electrical pulse 25 ms before each noise stimulus caused faster and varied forms of modulation: modulation lasted <2 s and, in different cells, excitability either decreased, increased or shifted in latency. Within cells, the modulatory effect of sound-by-sound electrical stimulation varied between different acoustic stimuli, including for different male calls, suggesting modulation is specific to certain stimulus attributes. For binaural units, modulation depended on the ear of input, as sound-by-sound electrical stimulation preceding dichotic acoustic stimulation caused asymmetric modulatory effects: sensitivity shifted for sounds at only one ear, or by different relative amounts for both ears. This caused a change in the relative difference in binaural sensitivity. Thus, sound-by-sound electrical stimulation revealed fast and ear-specific (i.e., lateralized) auditory modulation that is potentially suited to shifts in auditory attention during sound segregation in the auditory scene. PMID:25120437

Sound-by-sound thalamic stimulation modulates midbrain auditory excitability and relative binaural sensitivity in frogs.

PubMed

Ponnath, Abhilash; Farris, Hamilton E

2014-01-01

Descending circuitry can modulate auditory processing, biasing sensitivity to particular stimulus parameters and locations. Using awake in vivo single unit recordings, this study tested whether electrical stimulation of the thalamus modulates auditory excitability and relative binaural sensitivity in neurons of the amphibian midbrain. In addition, by using electrical stimuli that were either longer than the acoustic stimuli (i.e., seconds) or presented on a sound-by-sound basis (ms), experiments addressed whether the form of modulation depended on the temporal structure of the electrical stimulus. Following long duration electrical stimulation (3-10 s of 20 Hz square pulses), excitability (spikes/acoustic stimulus) to free-field noise stimuli decreased by 32%, but returned over 600 s. In contrast, sound-by-sound electrical stimulation using a single 2 ms duration electrical pulse 25 ms before each noise stimulus caused faster and varied forms of modulation: modulation lasted <2 s and, in different cells, excitability either decreased, increased or shifted in latency. Within cells, the modulatory effect of sound-by-sound electrical stimulation varied between different acoustic stimuli, including for different male calls, suggesting modulation is specific to certain stimulus attributes. For binaural units, modulation depended on the ear of input, as sound-by-sound electrical stimulation preceding dichotic acoustic stimulation caused asymmetric modulatory effects: sensitivity shifted for sounds at only one ear, or by different relative amounts for both ears. This caused a change in the relative difference in binaural sensitivity. Thus, sound-by-sound electrical stimulation revealed fast and ear-specific (i.e., lateralized) auditory modulation that is potentially suited to shifts in auditory attention during sound segregation in the auditory scene.

Transcutaneous Electrical Nerve Stimulation Combined with Oxybutynin is Superior to Monotherapy in Children with Urge Incontinence: A Randomized, Placebo Controlled Study.

PubMed

Borch, Luise; Hagstroem, Soeren; Kamperis, Konstantinos; Siggaard, C V; Rittig, Soeren

2017-08-01

We evaluated whether combination therapy with transcutaneous electrical nerve stimulation and oxybutynin results in a superior treatment response compared to either therapy alone in children with urge incontinence. In this placebo controlled study 66 children with a mean ± SD age of 7.3 ± 1.6 years who were diagnosed with urge incontinence were randomized to 3 treatment groups. Group 1 consisted of 22 children undergoing transcutaneous electrical nerve stimulation plus active oxybutynin administration. Group 2 included 21 children undergoing active transcutaneous electrical nerve stimulation plus placebo oxybutynin administration. Group 3 consisted of 23 children undergoing active oxybutynin administration plus placebo transcutaneous electrical nerve stimulation. The children received active or placebo transcutaneous electrical nerve stimulation over the sacral S2 to S3 outflow for 2 hours daily in combination with 5 mg active or placebo oxybutynin twice daily. The intervention period was 10 weeks. Primary outcome was number of wet days weekly. Secondary outcomes were severity of incontinence, frequency, maximum voided volume over expected bladder capacity for age, average voided volume over expected bladder capacity for age and visual analogue scale score. Combination therapy was superior to oxybutynin monotherapy, with an 83% greater chance of treatment response (p = 0.05). Combination therapy was also significantly more effective than transcutaneous electrical nerve stimulation monotherapy regarding reduced number of wet days weekly (mean difference -2.28, CI -4.06 to -0.49), severity of incontinence (-3.11, CI -5.98 to -0.23) and daily voiding frequency (-2.82, CI -4.48 to -1.17). Transcutaneous electrical nerve stimulation in combination with oxybutynin for childhood urge incontinence was superior to monotherapy consisting of transcutaneous electrical nerve stimulation or oxybutynin, although the latter only reached borderline statistical significance. Furthermore, transcutaneous electrical nerve stimulation was associated with a decreased risk of oxybutynin induced post-void residual urine greater than 20 ml. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Intraoperative muscle electrical stimulation for accurate positioning of the temporalis muscle tendon during dynamic, one-stage lengthening temporalis myoplasty for facial and lip reanimation.

PubMed

Har-Shai, Yaron; Gil, Tamir; Metanes, Issa; Labbé, Daniel

2010-07-01

Facial paralysis is a significant functional and aesthetic handicap. Facial reanimation is performed either by two-stage microsurgical methods or by regional one-stage muscle pedicle flaps. Labbé has modified and improved the regional muscle pedicle transfer flaps for facial reanimation (i.e., the lengthening temporalis myoplasty procedure). This true myoplasty technique is capable of producing a coordinated, spontaneous, and symmetrical smile. An intraoperative electrical stimulation of the temporal muscle is proposed to simulate the smile of the paralyzed side on the surgical table. The intraoperative electrical stimulation of the temporalis muscle, employing direct percutaneous electrode needles or transcutaneous electrical stimulation electrodes, was utilized in 11 primary and four secondary cases with complete facial palsy. The duration of the facial paralysis was up to 12 years. Postoperative follow-up ranged from 3 to 12 months. The insertion points of the temporalis muscle tendon to the nasolabial fold, upper lip, and oral commissure had been changed according to the intraoperative muscle stimulation in six patients of the 11 primary cases (55 percent) and in all four secondary (revisional) cases. A coordinated, spontaneous, and symmetrical smile was achieved in all patients by 3 months after surgery by employing speech therapy and biofeedback. This adjunct intraoperative refinement provides crucial feedback for the surgeon in both primary and secondary facial palsy cases regarding the vector of action of the temporalis muscle and the accuracy of the anchoring points of its tendon, thus enhancing a more coordinated and symmetrical smile.

Cerebral somatic pain modulation during autogenic training in fMRI.

PubMed

Naglatzki, R P; Schlamann, M; Gasser, T; Ladd, M E; Sure, U; Forsting, M; Gizewski, E R

2012-10-01

Functional magnetic resonance imaging (fMRI) studies are increasingly employed in different conscious states. Autogenic training (AT) is a common clinically used relaxation method. The purpose of this study was to investigate the cerebral modulation of pain activity patterns due to AT and to correlate the effects to the degree of experience with AT and strength of stimuli. Thirteen volunteers familiar with AT were studied with fMRI during painful electrical stimulation in a block design alternating between resting state and electrical stimulation, both without AT and while employing the same paradigm when utilizing their AT abilities. The subjective rating of painful stimulation and success in modulation during AT was assessed. During painful electrical stimulation without AT, fMRI revealed activation of midcingulate, right secondary sensory, right supplementary motor, and insular cortices, the right thalamus and left caudate nucleus. In contrast, utilizing AT only activation of left insular and supplementary motor cortices was revealed. The paired t-test revealed pain-related activation in the midcingulate, posterior cingulate and left anterior insular cortices for the condition without AT, and activation in the left ventrolateral prefrontal cortex under AT. Activation of the posterior cingulate cortex and thalamus correlated with the amplitude of electrical stimulation. This study revealed an effect on cerebral pain processing while performing AT. This might represent the cerebral correlate of different painful stimulus processing by subjects who are trained in performing relaxation techniques. However, due to the absence of a control group, further studies are needed to confirm this theory. © 2012 European Federation of International Association for the Study of Pain Chapters.

Chronic intravitreous infusion of ciliary neurotrophic factor modulates electrical retinal stimulation thresholds in the RCS rat.

PubMed

Kent, Tiffany L; Glybina, Inna V; Abrams, Gary W; Iezzi, Raymond

2008-01-01

To determine whether the sustained intravitreous delivery of CNTF modulates cortical response thresholds to electrical retinal stimulation in the RCS rat model of retinal degeneration. Animals were assigned to four groups: untreated, nonsurgical control and infusion groups of 10 ng/d CNTF, 1 ng/d CNTF, and PBS vehicle control. Thresholds for electrically evoked cortical potentials (EECPs) were recorded in response to transcorneal electrical stimulation of the retina at p30 and again at p60, after a three-week infusion. As the retina degenerated over time, EECP thresholds in response to electrical retinal stimulation increased. Eyes treated with 10 ng/d CNTF demonstrated significantly greater retinal sensitivity to electrical stimulation when compared with all other groups. In addition, eyes treated with 1 ng/d CNTF demonstrated significantly greater retinal sensitivity than both PBS-treated and untreated control groups. Retinal sensitivity to electrical stimulation was preserved in animals treated with chronic intravitreous infusion of CNTF. These data suggest that CNTF-mediated retinal neuroprotection may be a novel therapy that can lower stimulus thresholds in patients about to undergo retinal prosthesis implantation. Furthermore, it may maintain the long-term efficacy of these devices in patients.

Comparison of the induced fields using different coil configurations during deep transcranial magnetic stimulation.

PubMed

Lu, Mai; Ueno, Shoogo

2017-01-01

Stimulation of deeper brain structures by transcranial magnetic stimulation (TMS) plays a role in the study of reward and motivation mechanisms, which may be beneficial in the treatment of several neurological and psychiatric disorders. However, electric field distributions induced in the brain by deep transcranial magnetic stimulation (dTMS) are still unknown. In this paper, the double cone coil, H-coil and Halo-circular assembly (HCA) coil which have been proposed for dTMS have been numerically designed. The distributions of magnetic flux density, induced electric field in an anatomically based realistic head model by applying the dTMS coils were numerically calculated by the impedance method. Results were compared with that of standard figure-of-eight (Fo8) coil. Simulation results show that double cone, H- and HCA coils have significantly deep field penetration compared to the conventional Fo8 coil, at the expense of induced higher and wider spread electrical fields in superficial cortical regions. Double cone and HCA coils have better ability to stimulate deep brain subregions compared to that of the H-coil. In the mean time, both double cone and HCA coils increase risk for optical nerve excitation. Our results suggest although the dTMS coils offer new tool with potential for both research and clinical applications for psychiatric and neurological disorders associated with dysfunctions of deep brain regions, the selection of the most suitable coil settings for a specific clinical application should be based on a balanced evaluation between stimulation depth and focality.

A multi-pad electrode based functional electrical stimulation system for restoration of grasp

PubMed Central

2012-01-01

Background Functional electrical stimulation (FES) applied via transcutaneous electrodes is a common rehabilitation technique for assisting grasp in patients with central nervous system lesions. To improve the stimulation effectiveness of conventional FES, we introduce multi-pad electrodes and a new stimulation paradigm. Methods The new FES system comprises an electrode composed of small pads that can be activated individually. This electrode allows the targeting of motoneurons that activate synergistic muscles and produce a functional movement. The new stimulation paradigm allows asynchronous activation of motoneurons and provides controlled spatial distribution of the electrical charge that is delivered to the motoneurons. We developed an automated technique for the determination of the preferred electrode based on a cost function that considers the required movement of the fingers and the stabilization of the wrist joint. The data used within the cost function come from a sensorized garment that is easy to implement and does not require calibration. The design of the system also includes the possibility for fine-tuning and adaptation with a manually controllable interface. Results The device was tested on three stroke patients. The results show that the multi-pad electrodes provide the desired level of selectivity and can be used for generating a functional grasp. The results also show that the procedure, when performed on a specific user, results in the preferred electrode configuration characteristics for that patient. The findings from this study are of importance for the application of transcutaneous stimulation in the clinical and home environments. PMID:23009589

Toward an implantable functional electrical stimulation device to correct strabismus

PubMed Central

Velez, Federico G.; Isobe, Jun; Zealear, David; Judy, Jack W.; Edgerton, V. Reggie; Patnode, Stephanie; Lee, Hyowon; Hahn, Brian T.

2010-01-01

PURPOSE To investigate the feasibility of electrically stimulating the lateral rectus muscle to recover its physiologic abduction ability in cases of complete sixth cranial (abducens) nerve palsy. METHODS In the feline lateral rectus muscle model, the effects of a charge-balanced, biphasic, current-controlled stimulus on the movement of the eye were investigated while stimulation frequency, amplitude, and pulse duration was varied. Eye deflection was measured with a force transducer. Denervated conditions were simulated by injection of botulinum toxin A. RESULTS Three chemically denervated and 4 control lateral rectus muscles were analyzed. In control lateral rectus muscles, the minimum fusion frequency was approximately 170 Hz, and the maximum evoked abduction was 27°. The minimum fusion frequency was unchanged after 4 weeks of chemical denervation. Stimulation of chemically denervated lateral rectus muscle resulted in 17° of abduction. For both innervated and chemically denervated lateral rectus muscle, frequencies greater than 175 Hz yielded very little increase in abduction. Modulating amplitude produced noticeable movement throughout the tested range (0.2 to 9 mA). CONCLUSIONS Results from the feline lateral rectus muscle showed that electrical stimulation is a feasible approach to evoke a contraction from a denervated lateral rectus muscle. The degree of denervation of the feline lateral rectus muscle was indeterminate. Varying the stimulation amplitude allowed greater eye movement. It is very likely that both frequency and amplitude must be modulated for finer control of static eye position. PMID:19375369

Focal activation of primary visual cortex following supra-choroidal electrical stimulation of the retina: Intrinsic signal imaging and linear model analysis.

PubMed

Cloherty, Shaun L; Hietanen, Markus A; Suaning, Gregg J; Ibbotson, Michael R

2010-01-01

We performed optical intrinsic signal imaging of cat primary visual cortex (Area 17 and 18) while delivering bipolar electrical stimulation to the retina by way of a supra-choroidal electrode array. Using a general linear model (GLM) analysis we identified statistically significant (p < 0.01) activation in a localized region of cortex following supra-threshold electrical stimulation at a single retinal locus. (1) demonstrate that intrinsic signal imaging combined with linear model analysis provides a powerful tool for assessing cortical responses to prosthetic stimulation, and (2) confirm that supra-choroidal electrical stimulation can achieve localized activation of the cortex consistent with focal activation of the retina.

Electric stimulation and decimeter wave therapy improve the recovery of injured sciatic nerves

PubMed Central

Zhao, Feng; He, Wei; Zhang, Yingze; Tian, Dehu; Zhao, Hongfang; Yu, Kunlun; Bai, Jiangbo

2013-01-01

Drug treatment, electric stimulation and decimeter wave therapy have been shown to promote the repair and regeneration of the peripheral nerves at the injured site. This study prepared a Mackinnon's model of rat sciatic nerve compression. Electric stimulation was given immediately after neurolysis, and decimeter wave radiation was performed at 1 and 12 weeks post-operation. Histological observation revealed that intraoperative electric stimulation and decimeter wave therapy could improve the local blood circulation of repaired sites, alleviate hypoxia of compressed nerves, and lessen adhesion of compressed nerves, thereby decreasing the formation of new entrapments and enhancing compressed nerve regeneration through an improved microenvironment for regeneration. Immunohistochemical staining results revealed that intraoperative electric stimulation and decimeter wave could promote the expression of S-100 protein. Motor nerve conduction velocity and amplitude, the number and diameter of myelinated nerve fibers, and sciatic functional index were significantly increased in the treated rats. These results verified that intraoperative electric stimulation and decimeter wave therapy contributed to the regeneration and the recovery of the functions in the compressed nerves. PMID:25206506

Suppression of Stimulus Artifact Contaminating Electrically Evoked Electromyography

PubMed Central

Liu, Jie; Li, Sheng; Li, Xiaoyan; Klein, Cliff; Rymer, William Z.; Zhou, Ping

2013-01-01

Background Electrical stimulation of muscle or nerve is a very useful technique for understanding of muscle activity and its pathological changes for both diagnostic and therapeutic purposes. During electrical stimulation of a muscle, the recorded M wave is often contaminated by a stimulus artifact. The stimulus artifact must be removed for appropriate analysis and interpretation of M waves. Objectives The objective of this study was to develop a novel software based method to remove stimulus artifacts contaminating or superimposing with electrically evoked surface electromyography (EMG) or M wave signals. Methods The multiple stage method uses a series of signal processing techniques, including highlighting and detection of stimulus artifacts using the Savitzky-Golay filtering, estimation of the artifact contaminated region with the Otsu thresholding, and reconstruction of such region using signal interpolation and smoothing. The developed method was tested using M wave signals recorded from biceps brachii muscles by a linear surface electrode array. To evaluate the performance, a series of semi-synthetic signals were constructed from clean M wave and stimulus artifact recordings with different degrees of overlap between them. Results The effectiveness of the developed method was quantified by a significant increase in correlation coefficient and a significant decrease in root mean square error between the clean M wave and the reconstructed M wave, compared with those between the clean M wave and the originally contaminated signal. The validity of the developed method was also demonstrated when tested on each channel’s M wave recording using the linear electrode array. Conclusions The developed method can suppress stimulus artifacts contaminating M wave recordings. PMID:24419021

Phase-Locked Loop for Precisely Timed Acoustic Stimulation during Sleep

PubMed Central

Santostasi, Giovanni; Malkani, Roneil; Riedner, Brady; Bellesi, Michele; Tononi, Giulio; Paller, Ken A.; Zee, Phyllis C.

2016-01-01

Background A Brain-Computer Interface could potentially enhance the various benefits of sleep. New Method We describe a strategy for enhancing slow-wave sleep (SWS) by stimulating the sleeping brain with periodic acoustic stimuli that produce resonance in the form of enhanced slow-wave activity in the electroencephalogram (EEG). The system delivers each acoustic stimulus at a particular phase of an electrophysiological rhythm using a Phase-Locked Loop (PLL). Results The PLL is computationally economical and well suited to follow and predict the temporal behavior of the EEG during slow-wave sleep. Comparison with Existing Methods Acoustic stimulation methods may be able to enhance SWS without the risks inherent in electrical stimulation or pharmacological methods. The PLL method differs from other acoustic stimulation methods that are based on detecting a single slow wave rather than modeling slow-wave activity over an extended period of time. Conclusions By providing real-time estimates of the phase of ongoing EEG oscillations, the PLL can rapidly adjust to physiological changes, thus opening up new possibilities to study brain dynamics during sleep. Future application of these methods hold promise for enhancing sleep quality and associated daytime behavior and improving physiologic function. PMID:26617321

Postfatigue potentiation of the paralyzed soleus muscle: evidence for adaptation with long-term electrical stimulation training

PubMed Central

Shields, Richard K.; Dudley-Javoroski, Shauna; Littmann, Andrew E.

2012-01-01

Understanding the torque output behavior of paralyzed muscle has important implications for the use of functional neuromuscular electrical stimulation systems. Postfatigue potentiation is an augmentation of peak muscle torque during repetitive activation after a fatigue protocol. The purposes of this study were 1) to quantify postfatigue potentiation in the acutely and chronically paralyzed soleus and 2) to determine the effect of long-term soleus electrical stimulation training on the potentiation characteristics of recently paralyzed soleus muscle. Five subjects with chronic paralysis (>2 yr) demonstrated significant postfatigue potentiation during a repetitive soleus activation protocol that induced low-frequency fatigue. Ten subjects with acute paralysis (<6 mo) demonstrated no torque potentiation in response to repetitive stimulation. Seven of these acute subjects completed 2 yr of home-based isometric soleus electrical stimulation training of one limb (compliance = 83%; 8,300 contractions/wk). With the early implementation of electrically stimulated training, potentiation characteristics of trained soleus muscles were preserved as in the acute postinjury state. In contrast, untrained limbs showed marked postfatigue potentiation at 2 yr after spinal cord injury (SCI). A single acute SCI subject who was followed longitudinally developed potentiation characteristics very similar to the untrained limbs of the training subjects. The results of the present investigation support that postfatigue potentiation is a characteristic of fast-fatigable muscle and can be prevented by timely neuromuscular electrical stimulation training. Potentiation is an important consideration in the design of functional electrical stimulation control systems for people with SCI. PMID:16575026

Postfatigue potentiation of the paralyzed soleus muscle: evidence for adaptation with long-term electrical stimulation training.

PubMed

Shields, Richard K; Dudley-Javoroski, Shauna; Littmann, Andrew E

2006-08-01

Understanding the torque output behavior of paralyzed muscle has important implications for the use of functional neuromuscular electrical stimulation systems. Postfatigue potentiation is an augmentation of peak muscle torque during repetitive activation after a fatigue protocol. The purposes of this study were 1) to quantify postfatigue potentiation in the acutely and chronically paralyzed soleus and 2) to determine the effect of long-term soleus electrical stimulation training on the potentiation characteristics of recently paralyzed soleus muscle. Five subjects with chronic paralysis (>2 yr) demonstrated significant postfatigue potentiation during a repetitive soleus activation protocol that induced low-frequency fatigue. Ten subjects with acute paralysis (<6 mo) demonstrated no torque potentiation in response to repetitive stimulation. Seven of these acute subjects completed 2 yr of home-based isometric soleus electrical stimulation training of one limb (compliance = 83%; 8,300 contractions/wk). With the early implementation of electrically stimulated training, potentiation characteristics of trained soleus muscles were preserved as in the acute postinjury state. In contrast, untrained limbs showed marked postfatigue potentiation at 2 yr after spinal cord injury (SCI). A single acute SCI subject who was followed longitudinally developed potentiation characteristics very similar to the untrained limbs of the training subjects. The results of the present investigation support that postfatigue potentiation is a characteristic of fast-fatigable muscle and can be prevented by timely neuromuscular electrical stimulation training. Potentiation is an important consideration in the design of functional electrical stimulation control systems for people with SCI.

Electrical stimulation of rhesus monkey nucleus reticularis gigantocellularis. I. Characteristics of evoked head movements.

PubMed

Quessy, Stephan; Freedman, Edward G

2004-06-01

The nucleus reticularis gigantocellularis (NRG) receives monosynaptic input from the superior colliculus (SC) and projects directly to neck motor neuron pools. Neurons in NRG are well situated to play a critical role in transforming SC signals into head movement commands. A previous study of movements evoked by NRG stimulation in the primate reported a variety of ipsilateral and contralateral head movements with horizontal, vertical and torsional components. In addition to head movements, it was reported that NRG stimulation could evoke movements of the pinnae, face, upper torso, and co-contraction of neck muscles. In this report, the role of the rhesus monkey NRG in head movement control was investigated using electrical stimulation of the rostral portion of the NRG. The goal was to characterize head movements evoked by NRG stimulation, describe the effects of altering stimulation parameters, and assess the relative movements of the eyes and head. Results indicate that electrical stimulation in the rostral portion of the NRG of the primate can consistently evoke ipsilateral head rotations in the horizontal plane. Head movement amplitude and peak velocity depend upon stimulation parameters (primarily frequency and duration of stimulation trains). During stimulation-induced head movements the eyes counter-rotate (presumably a result of the vestibulo-ocular reflex: VOR). At 46 stimulation sites from two subjects the average gain of this counter-rotation was -0.38 (+/-0.18). After the end of the stimulation train the head generally continued to move. During this epoch, after electrical stimulation ceased, VOR gain remained at this reduced level. In addition, VOR gain was similarly low when electrical stimulation was carried out during active fixation of a visual target. These data extend existing descriptions of head movements evoked by electrical stimulation of the NRG, and add to the understanding of the role of this structure in producing head movements.

Monitoring hydraulic stimulation using telluric sounding

NASA Astrophysics Data System (ADS)

Rees, Nigel; Heinson, Graham; Conway, Dennis

2018-01-01

The telluric sounding (TS) method is introduced as a potential tool for monitoring hydraulic fracturing at depth. The advantage of this technique is that it requires only the measurement of electric fields, which are cheap and easy when compared with magnetotelluric measurements. Additionally, the transfer function between electric fields from two locations is essentially the identity matrix for a 1D Earth no matter what the vertical structure. Therefore, changes in the earth resulting from the introduction of conductive bodies underneath one of these sites can be associated with deviations away from the identity matrix, with static shift appearing as a galvanic multiplier at all periods. Singular value decomposition and eigenvalue analysis can reduce the complexity of the resulting telluric distortion matrix to simpler parameters that can be visualised in the form of Mohr circles. This technique would be useful in constraining the lateral extent of resistivity changes. We test the viability of utilising the TS method for monitoring on both a synthetic dataset and for a hydraulic stimulation of an enhanced geothermal system case study conducted in Paralana, South Australia. The synthetic data example shows small but consistent changes in the transfer functions associated with hydraulic stimulation, with grids of Mohr circles introduced as a useful diagnostic tool for visualising the extent of fluid movement. The Paralana electric field data were relatively noisy and affected by the dead band making the analysis of transfer functions difficult. However, changes in the order of 5% were observed from 5 s to longer periods. We conclude that deep monitoring using the TS method is marginal at depths in the order of 4 km and that in order to have meaningful interpretations, electric field data need to be of a high quality with low levels of site noise.[Figure not available: see fulltext.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahnood, Arman, E-mail: arman.ahnood@unimelb.edu.au; Ganesan, Kumaravelu; Stacey, Alastair

Beyond conventional electrically-driven neuronal stimulation methods, there is a growing interest in optically-driven approaches. In recent years, nitrogen-doped ultrananocrystalline diamond (N-UNCD) has emerged as a strong material candidate for use in electrically-driven stimulation electrodes. This work investigates the electrochemical activity of N-UNCD in response to pulsed illumination, to assess its potential for use as an optically-driven stimulation electrode. Whilst N-UNCD in the as-grown state exhibits a weak photoresponse, the oxygen plasma treated film exhibits two orders of magnitude enhancement in its sub-bandgap open circuit photovoltage response. The enhancement is attributed to the formation of a dense network of oxygen-terminated diamondmore » nanocrystals at the N-UNCD surface. Electrically connected to the N-UNCD bulk via sub-surface graphitic grain boundaries, these diamond nanocrystals introduce a semiconducting barrier between the sub-surface graphitic semimetal and the electrolyte solution, leading to a photovoltage under irradiation with wavelengths of λ = 450 nm and shorter. Within the safe optical exposure limit of 2 mW mm{sup −2}, charge injection capacity of 0.01 mC cm{sup −2} is achieved using a 15 × 15 μm electrode, meeting the requirements for extracellular and intercellular stimulation. The nanoscale nature of processes presented here along with the diamond's biocompatibility and biostability open an avenue for the use of oxygen treated N-UNCD as optically driven stimulating electrodes.« less

Transient photoresponse of nitrogen-doped ultrananocrystalline diamond electrodes in saline solution

NASA Astrophysics Data System (ADS)

Ahnood, Arman; Simonov, Alexandr N.; Laird, Jamie S.; Maturana, Matias I.; Ganesan, Kumaravelu; Stacey, Alastair; Ibbotson, Michael R.; Spiccia, Leone; Prawer, Steven

2016-03-01

Beyond conventional electrically-driven neuronal stimulation methods, there is a growing interest in optically-driven approaches. In recent years, nitrogen-doped ultrananocrystalline diamond (N-UNCD) has emerged as a strong material candidate for use in electrically-driven stimulation electrodes. This work investigates the electrochemical activity of N-UNCD in response to pulsed illumination, to assess its potential for use as an optically-driven stimulation electrode. Whilst N-UNCD in the as-grown state exhibits a weak photoresponse, the oxygen plasma treated film exhibits two orders of magnitude enhancement in its sub-bandgap open circuit photovoltage response. The enhancement is attributed to the formation of a dense network of oxygen-terminated diamond nanocrystals at the N-UNCD surface. Electrically connected to the N-UNCD bulk via sub-surface graphitic grain boundaries, these diamond nanocrystals introduce a semiconducting barrier between the sub-surface graphitic semimetal and the electrolyte solution, leading to a photovoltage under irradiation with wavelengths of λ = 450 nm and shorter. Within the safe optical exposure limit of 2 mW mm-2, charge injection capacity of 0.01 mC cm-2 is achieved using a 15 × 15 μm electrode, meeting the requirements for extracellular and intercellular stimulation. The nanoscale nature of processes presented here along with the diamond's biocompatibility and biostability open an avenue for the use of oxygen treated N-UNCD as optically driven stimulating electrodes.

Modeling extracellular electrical stimulation: I. Derivation and interpretation of neurite equations.

PubMed

Meffin, Hamish; Tahayori, Bahman; Grayden, David B; Burkitt, Anthony N

2012-12-01

Neuroprosthetic devices, such as cochlear and retinal implants, work by directly stimulating neurons with extracellular electrodes. This is commonly modeled using the cable equation with an applied extracellular voltage. In this paper a framework for modeling extracellular electrical stimulation is presented. To this end, a cylindrical neurite with confined extracellular space in the subthreshold regime is modeled in three-dimensional space. Through cylindrical harmonic expansion of Laplace's equation, we derive the spatio-temporal equations governing different modes of stimulation, referred to as longitudinal and transverse modes, under types of boundary conditions. The longitudinal mode is described by the well-known cable equation, however, the transverse modes are described by a novel ordinary differential equation. For the longitudinal mode, we find that different electrotonic length constants apply under the two different boundary conditions. Equations connecting current density to voltage boundary conditions are derived that are used to calculate the trans-impedance of the neurite-plus-thin-extracellular-sheath. A detailed explanation on depolarization mechanisms and the dominant current pathway under different modes of stimulation is provided. The analytic results derived here enable the estimation of a neurite's membrane potential under extracellular stimulation, hence bypassing the heavy computational cost of using numerical methods.

Muscle fiber type specific induction of slow myosin heavy chain 2 gene expression by electrical stimulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crew, Jennifer R.; Falzari, Kanakeshwari; DiMario, Joseph X., E-mail: joseph.dimario@rosalindfranklin.edu

Vertebrate skeletal muscle fiber types are defined by a broad array of differentially expressed contractile and metabolic protein genes. The mechanisms that establish and maintain these different fiber types vary throughout development and with changing functional demand. Chicken skeletal muscle fibers can be generally categorized as fast and fast/slow based on expression of the slow myosin heavy chain 2 (MyHC2) gene in fast/slow muscle fibers. To investigate the cellular and molecular mechanisms that control fiber type formation in secondary or fetal muscle fibers, myoblasts from the fast pectoralis major (PM) and fast/slow medial adductor (MA) muscles were isolated, allowed tomore » differentiate in vitro, and electrically stimulated. MA muscle fibers were induced to express the slow MyHC2 gene by electrical stimulation, whereas PM muscle fibers did not express the slow MyHC2 gene under identical stimulation conditions. However, PM muscle fibers did express the slow MyHC2 gene when electrical stimulation was combined with inhibition of inositol triphosphate receptor (IP3R) activity. Electrical stimulation was sufficient to increase nuclear localization of expressed nuclear-factor-of-activated-T-cells (NFAT), NFAT-mediated transcription, and slow MyHC2 promoter activity in MA muscle fibers. In contrast, both electrical stimulation and inhibitors of IP3R activity were required for these effects in PM muscle fibers. Electrical stimulation also increased levels of peroxisome-proliferator-activated receptor-{gamma} co-activator-1 (PGC-1{alpha}) protein in PM and MA muscle fibers. These results indicate that MA muscle fibers can be induced by electrical stimulation to express the slow MyHC2 gene and that fast PM muscle fibers are refractory to stimulation-induced slow MyHC2 gene expression due to fast PM muscle fiber specific cellular mechanisms involving IP3R activity.« less

Effects of transportation during the hot season, breed and electrical stimulation on histochemical and meat quality characteristics of goat longissimus muscle.

PubMed

Kadim, Isam T; Mahgoub, Osman; Al-Marzooqi, Waleed; Khalaf, Samera; Al-Sinawi, Shadia S H; Al-Amri, Issa

2010-06-01

The effects of transportation and electrical stimulation (90 V) on physiological, histochemical and meat quality characteristics of two breeds of Omani goats were assessed. Twenty 1-year-old male goats from each breed (Batina and Dhofari) were divided into two groups: 3 h transported during the hot season (42 degrees C day time temperature) and non-transported. Animals were blood-sampled before loading and prior to slaughter. Electrical stimulation was applied 20 min postmortem to 50% randomly selected carcasses of both breeds. Temperature and pH decline of the Longissimus was monitored. Ultimate pH, shear force, sarcomere length, myofibrillar fragmentation index, expressed juice, cooking loss and colour were measured from samples of Longissimus dorsi muscles. Electrical stimulation and transportation had a significant effect on most biochemical and meat quality characteristics of Longissimus dorsi. The transported goats had higher plasma cortisol (P < 0.01), adrenaline, nor-adrenaline and dopamine concentrations (P < 0.05) than non-transported goats. Electrical stimulation resulted in a significantly (P < 0.05) more rapid muscle pH fall during the first 12 h after slaughter. Muscles from electrically-stimulated carcasses had significantly (P < 0.05) longer sarcomeres, lower shear force value, a lighter colour (higher L* value), higher expressed juice and myofibrillar fragmentation index than those from non-stimulated ones. Meat from transported goats had significantly higher pH, expressed juice and shear force, but contained significantly lower sarcomere length and L* values than non-transported goats. The proportion of the myosin ATPase staining did not change as a function of stimulation, transportation or breed. These results indicated that subjecting goats to transportation for 3 h under high ambient temperatures can generate major physiological and muscle metabolism responses. Electrical stimulation improved quality characteristics of meat from both groups. This indicates that electrical stimulation may reduce detrimental effects of transportation on meat quality of Omani goats.

Differential effect of brief electrical stimulation on voltage-gated potassium channels.

PubMed

Cameron, Morven A; Al Abed, Amr; Buskila, Yossi; Dokos, Socrates; Lovell, Nigel H; Morley, John W

2017-05-01

Electrical stimulation of neuronal tissue is a promising strategy to treat a variety of neurological disorders. The mechanism of neuronal activation by external electrical stimulation is governed by voltage-gated ion channels. This stimulus, typically brief in nature, leads to membrane potential depolarization, which increases ion flow across the membrane by increasing the open probability of these voltage-gated channels. In spiking neurons, it is activation of voltage-gated sodium channels (Na V channels) that leads to action potential generation. However, several other types of voltage-gated channels are expressed that also respond to electrical stimulation. In this study, we examine the response of voltage-gated potassium channels (K V channels) to brief electrical stimulation by whole cell patch-clamp electrophysiology and computational modeling. We show that nonspiking amacrine neurons of the retina exhibit a large variety of responses to stimulation, driven by different K V -channel subtypes. Computational modeling reveals substantial differences in the response of specific K V -channel subtypes that is dependent on channel kinetics. This suggests that the expression levels of different K V -channel subtypes in retinal neurons are a crucial predictor of the response that can be obtained. These data expand our knowledge of the mechanisms of neuronal activation and suggest that K V -channel expression is an important determinant of the sensitivity of neurons to electrical stimulation. NEW & NOTEWORTHY This paper describes the response of various voltage-gated potassium channels (K V channels) to brief electrical stimulation, such as is applied during prosthetic electrical stimulation. We show that the pattern of response greatly varies between K V channel subtypes depending on activation and inactivation kinetics of each channel. Our data suggest that problems encountered when artificially stimulating neurons such as cessation in firing at high frequencies, or "fading," may be attributed to K V -channel activation. Copyright © 2017 the American Physiological Society.

Photovoltaic Retinal Prosthesis with High Pixel Density

PubMed Central

Mathieson, Keith; Loudin, James; Goetz, Georges; Huie, Philip; Wang, Lele; Kamins, Theodore I.; Galambos, Ludwig; Smith, Richard; Harris, James S.; Sher, Alexander; Palanker, Daniel

2012-01-01

Retinal degenerative diseases lead to blindness due to loss of the “image capturing” photoreceptors, while neurons in the “image processing” inner retinal layers are relatively well preserved. Electronic retinal prostheses seek to restore sight by electrically stimulating surviving neurons. Most implants are powered through inductive coils, requiring complex surgical methods to implant the coil-decoder-cable-array systems, which deliver energy to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which silicon photodiodes in each pixel receive power and data directly through pulsed near-infrared illumination and electrically stimulate neurons. Stimulation was produced in normal and degenerate rat retinas, with pulse durations from 0.5 to 4 ms, and threshold peak irradiances from 0.2 to 10 mW/mm2, two orders of magnitude below the ocular safety limit. Neural responses were elicited by illuminating a single 70 μm bipolar pixel, demonstrating the possibility of a fully-integrated photovoltaic retinal prosthesis with high pixel density. PMID:23049619

Charge and energy minimization in electrical/magnetic stimulation of nervous tissue

NASA Astrophysics Data System (ADS)

Jezernik, Sašo; Sinkjaer, Thomas; Morari, Manfred

2010-08-01

In this work we address the problem of stimulating nervous tissue with the minimal necessary energy at reduced/minimal charge. Charge minimization is related to a valid safety concern (avoidance and reduction of stimulation-induced tissue and electrode damage). Energy minimization plays a role in battery-driven electrical or magnetic stimulation systems (increased lifetime, repetition rates, reduction of power requirements, thermal management). Extensive new theoretical results are derived by employing an optimal control theory framework. These results include derivation of the optimal electrical stimulation waveform for a mixed energy/charge minimization problem, derivation of the charge-balanced energy-minimal electrical stimulation waveform, solutions of a pure charge minimization problem with and without a constraint on the stimulation amplitude, and derivation of the energy-minimal magnetic stimulation waveform. Depending on the set stimulus pulse duration, energy and charge reductions of up to 80% are deemed possible. Results are verified in simulations with an active, mammalian-like nerve fiber model.

Charge and energy minimization in electrical/magnetic stimulation of nervous tissue.

PubMed

Jezernik, Saso; Sinkjaer, Thomas; Morari, Manfred

2010-08-01

In this work we address the problem of stimulating nervous tissue with the minimal necessary energy at reduced/minimal charge. Charge minimization is related to a valid safety concern (avoidance and reduction of stimulation-induced tissue and electrode damage). Energy minimization plays a role in battery-driven electrical or magnetic stimulation systems (increased lifetime, repetition rates, reduction of power requirements, thermal management). Extensive new theoretical results are derived by employing an optimal control theory framework. These results include derivation of the optimal electrical stimulation waveform for a mixed energy/charge minimization problem, derivation of the charge-balanced energy-minimal electrical stimulation waveform, solutions of a pure charge minimization problem with and without a constraint on the stimulation amplitude, and derivation of the energy-minimal magnetic stimulation waveform. Depending on the set stimulus pulse duration, energy and charge reductions of up to 80% are deemed possible. Results are verified in simulations with an active, mammalian-like nerve fiber model.

The effect of transcutaneous electrical nerve stimulation in patients with acute exacerbation of chronic obstructive pulmonary disease: randomised controlled trial.

PubMed

Öncü, Emine; Zincir, Handan

2017-07-01

The aim of the present study was to assess the efficacy of transcutaneous electrical nerve stimulation in patients with acute exacerbation of chronic obstructive pulmonary disease. In patients with stable chronic obstructive pulmonary disease, transcutaneous electrical nerve stimulation has been known to attain improvement in forced expiratory volume in 1 seconds, physical activity, and quality of life. However, information about the effects of transcutaneous electrical nerve stimulation on acute exacerbation of chronic obstructive pulmonary disease is quite limited. A single-blind, randomised controlled trial. Data were collected between August 2013-May 2014. Eighty-two patients who were hospitalised with a diagnosis of acute exacerbation of chronic obstructive pulmonary disease were randomly assigned to a transcutaneous electrical nerve stimulation group receiving transcutaneous electrical nerve stimulation treatment for 20 seance over the acupuncture points with pharmacotherapy or placebo group receiving the same treatment without electrical current output from the transcutaneous electrical nerve stimulation device. Pulmonary functional test, six-minute walking distance, dyspnoea and fatigue scale, and St. George's Respiratory Questionnaire scores were assessed pre- and postprogram. The program started at the hospital by the researcher was sustained in the patient's home by the caregiver. All patients were able to complete the program, despite the exacerbation. The 20 seance transcutaneous electrical nerve stimulation program provided clinically significant improvement in forced expiratory volume in 1 seconds 21 ml, 19·51% but when compared with the placebo group, the difference was insignificant (p > 0·05). The six-minute walking distance increased by 48·10 m more in the placebo group (p < 0·05). There were no significant differences between the two groups' St. George's Respiratory Questionnaire, dyspnoea and fatigue score (p > 0·05). Adding transcutaneous electrical nerve stimulation therapy to pharmacotherapy in patients with acute exacerbation of chronic obstructive pulmonary disease provided clinical improvement in forced expiratory volume in 1 seconds and add benefit in exercise capacity, but no significant effect on the other outcomes measured. Transcutaneous electrical nerve stimulation can be used as a non-invasive complementary therapy due to its beneficial effects on forced expiratory volume in 1 seconds and exercise capacity in patients with acute exacerbation of chronic obstructive pulmonary disease. © 2016 John Wiley & Sons Ltd.

The Effect of Surface Electrical Stimulation on Hyo-Laryngeal Movement in Normal Individuals at Rest and During Swallowing

PubMed Central

Humbert, Ianessa A.; Poletto, Christopher J.; Saxon, Keith G.; Kearney, Pamela R.; Crujido, Lisa; Wright-Harp, Wilhelmina; Payne, Joan; Jeffries, Neal; Sonies, Barbara C.; Ludlow, Christy L.

2006-01-01

Surface electrical stimulation is currently used in therapy for swallowing problems, although little is known about its physiological effects on neck muscles or swallowing. Previously, when one surface electrode placement was used in dysphagic patients at rest, it lowered the hyo-laryngeal complex. Here we examined the effects of nine other placements in normal volunteers to determine: 1) if movements induced by surface stimulation using other placements differ, and 2) if lowering the hyo-laryngeal complex by surface electrical stimulation interfered with swallowing in healthy adults. Ten bipolar surface electrode placements overlying the submental and laryngeal regions were tested. Maximum tolerated stimulation levels were applied at rest while participants held their mouths closed. Videofluoroscopic recordings were used to measure hyoid bone and subglottic air column (laryngeal) movements from resting position and while swallowing 5ml of liquid barium with and without stimulation. Videofluoroscopic recordings of swallows were rated blind to condition using the NIH-Swallowing Safety Scale (NIH-SSS). Significant (p<0.0001) laryngeal and hyoid descent occurred with stimulation at rest. During swallowing, significant (p≤0.01) reductions in both the larynx and hyoid bone peak elevation occurred during stimulated swallows. The stimulated swallows were also judged less safe than non-stimulated swallows using the NIH-SSS (p=0.0275). Because surface electrical stimulation reduced hyo-laryngeal elevation during swallowing in normal volunteers, our findings suggest that surface electrical stimulation will reduce elevation during swallowing therapy for dysphagia. PMID:16873602

Auditory responses to electric and infrared neural stimulation of the rat cochlear nucleus.

PubMed

Verma, Rohit U; Guex, Amélie A; Hancock, Kenneth E; Durakovic, Nedim; McKay, Colette M; Slama, Michaël C C; Brown, M Christian; Lee, Daniel J

2014-04-01

In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported "optophonic" effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach. Copyright © 2014 Elsevier B.V. All rights reserved.

Auditory Responses to Electric and Infrared Neural Stimulation of the Rat Cochlear Nucleus

PubMed Central

Verma, Rohit; Guex, Amelie A.; Hancock, Kenneth E.; Durakovic, Nedim; McKay, Colette M.; Slama, Michaël C. C.; Brown, M. Christian; Lee, Daniel J.

2014-01-01

In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported “optophonic” effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach. PMID:24508368

A Suprachoroidal Electrical Retinal Stimulator Design for Long-Term Animal Experiments and In Vivo Assessment of Its Feasibility and Biocompatibility in Rabbits

PubMed Central

Zhou, J. A.; Woo, S. J.; Park, S. I.; Kim, E. T.; Seo, J. M.; Chung, H.; Kim, S. J.

2008-01-01

This article reports on a retinal stimulation system for long-term use in animal electrical stimulation experiments. The presented system consisted of an implantable stimulator which provided continuous electrical stimulation, and an external component which provided preset stimulation patterns and power to the implanted stimulator via a paired radio frequency (RF) coil. A rechargeable internal battery and a parameter memory component were introduced to the implanted retinal stimulator. As a result, the external component was not necessary during the stimulation mode. The inductive coil pair was used to pass the parameter data and to recharge the battery. A switch circuit was used to separate the stimulation mode from the battery recharging mode. The implantable stimulator was implemented with IC chips and the electronics, except for the stimulation electrodes, were hermetically packaged in a biocompatible metal case. A polyimide-based gold electrode array was used. Surgical implantation into rabbits was performed to verify the functionality and safety of this newly designed system. The electrodes were implanted in the suprachoroidal space. Evoked cortical potentials were recorded during electrical stimulation of the retina. Long-term follow-up using OCT showed no chorioretinal abnormality after implantation of the electrodes. PMID:18317521

“All talk no torque”- A novel set of metrics to quantify muscle fatigue through isometric dynamometry in Functional Electrical Stimulation (FES) muscle studies

NASA Astrophysics Data System (ADS)

Taylor, M. J.; Fornusek, C.; de Chazal, P.; Ruys, A. J.

2017-10-01

Functional Electrical Stimulation (FES) activates nerves and muscles that have been ravished and rendered paralysed by disease. As such, it is advantageous to study joint torques that arise due to electrical stimulation of muscle, to measure fatigue in an indirect, minimally-invasive way. Dynamometry is one way in which this can be achieved. In this paper, torque data is presented from an FES experiment on quadriceps, using isometric dynamometry to measure torque. A library of fatigue metrics to quantify these data are put forward. These metrics include; start and end torque peaks, percentage changes in torque over time, and maximum and minimum torque period algorithms (MTPA 1 and 2), and associated torque-time plots. It is illustrated, by example, how this novel library of metrics can model fatigue over time. Furthermore, these methods are critiqued by a qualitative assessment and compared against one another for their utility in modelling fatigue. Linear trendlines with coefficients of correlation (R 2) and qualitative descriptions of data are used to achieve this. We find that although arduous, individual peak plots yield the most relevant values upon which fatigue can be assessed. Methods to calculate peaks in data have less of a utility, offset by an order of magnitude of ˜101 in comparison with theoretically expected peak numbers. In light of this, we suggest that future methods would be well-inclined to investigate optimized form of peak analysis.

Effects of electrical stimulation of the hunger center in the lateral hypothalamus and food reinforcement on impulse activity of the stomach in rabbits under conditions of hunger and satiation.

PubMed

Zenina, O Yu; Kromin, A A

2012-10-01

Stimulation of the lateral hypothalamus in preliminary fed animals in the presence of the food is associated with successful food-procuring behavior, accompanied by regular generation of high-amplitude slow electrical waves by muscles of the lesser curvature, body, and antrum of the stomach, which was reflected in the structure of temporal organization of slow electrical activity in the form of unimodal distribution of slow wave periods typical of satiation state. Despite increased level of food motivation caused by stimulation of the lateral hypothalamus, the additional food intake completely abolished the inhibitory effects of hunger motivation excitement on slow electrical muscle activity in the lesser curvature, body, and antrum of the stomach of satiated rabbits. Changes in slow electrical activity of the stomach muscles in rabbits deprived of food over 24 h and offered food and associated food-procuring behavior during electrical stimulation of the lateral hypothalamus have a two-phase pattern. Despite food intake during phase I of electrical stimulation, the downstream inhibitory effect of hunger motivation excitement on myogenic pacemaker of the lesser curvature of stomach abolishes the stimulating effect of food reinforcement on slow electrical muscle activity in the lesser curvature, body, and antrum of the stomach. During phase II of electrical stimulation, the food reinforcement decreases inhibitory effect of hunger motivation excitement on myogenic pacemaker of the lesser curvature that paces maximal rhythm of slow electrical waves for muscles activity in the lesser curvature, body, and antrum of the stomach, which is reflected by unimodal distribution of slow electrical wave periods. Our results indicated that the structure of temporal organization of slow electrical activity of the stomach muscles reflects convergent interactions of food motivation and reinforcement excitations on the dorsal vagal complex neurons in medulla oblongata.

9 CFR 307.7 - Safety requirements for electrical stimulating (EST) equipment.

Code of Federal Regulations, 2013 CFR

2013-01-01

... manual stimulation or before the carcass chain is started in an automatic system. (c) Operation—(1... personnel, the electricity supplied to the stimulating surfaces shall be locked-off when cleaning...

Biophysical Stimuli: A Review of Electrical and Mechanical Stimulation in Hyaline Cartilage.

PubMed

Vaca-González, Juan J; Guevara, Johana M; Moncayo, Miguel A; Castro-Abril, Hector; Hata, Yoshie; Garzón-Alvarado, Diego A

2017-09-01

Objective Hyaline cartilage degenerative pathologies induce morphologic and biomechanical changes resulting in cartilage tissue damage. In pursuit of therapeutic options, electrical and mechanical stimulation have been proposed for improving tissue engineering approaches for cartilage repair. The purpose of this review was to highlight the effect of electrical stimulation and mechanical stimuli in chondrocyte behavior. Design Different information sources and the MEDLINE database were systematically revised to summarize the different contributions for the past 40 years. Results It has been shown that electric stimulation may increase cell proliferation and stimulate the synthesis of molecules associated with the extracellular matrix of the articular cartilage, such as collagen type II, aggrecan and glycosaminoglycans, while mechanical loads trigger anabolic and catabolic responses in chondrocytes. Conclusion The biophysical stimuli can increase cell proliferation and stimulate molecules associated with hyaline cartilage extracellular matrix maintenance.

Stimulation of the human medial temporal lobe between learning and recall selectively enhances forgetting

PubMed Central

Merkow, Maxwell B.; Burke, John F.; Ramayya, Ashwin G.; Sharan, Ashwini D.; Sperling, Michael R.; Kahana, Michael J.

2017-01-01

Background Direct electrical stimulation applied to the human medial temporal lobe (MTL) typically disrupts performance on memory tasks, however, the mechanism underlying this effect is not known. Objective To study the effects of MTL stimulation on memory performance Methods We studied the effects of MTL stimulation on memory in five patients undergoing invasive electrocorticographic monitoring during various phases of a memory task (encoding, distractor, recall). Results We found that MTL stimulation disrupted memory performance in a timing-dependent manner; we observed greater forgetting when applying stimulation during the delay between encoding and recall, compared to when it was applied during encoding or recall. Conclusions The results suggest that recall is most dependent on the MTL between learning and retrieval. PMID:28073638

Systematic study of the effects of stimulus parameters and stimulus location on afterdischarges elicited by electrical stimulation in the rat.

PubMed

Shigeto, Hiroshi; Boongird, Atthaporn; Baker, Kenneth; Kellinghaus, Christoph; Najm, Imad; Lüders, Hans

2013-03-01

Electrical brain stimulation is used in a variety of clinical situations, including cortical mapping for epilepsy surgery, cortical stimulation therapy to terminate seizure activity in the cortex, and in deep brain stimulation therapy. However, the effects of stimulus parameters are not fully understood. In this study, we systematically tested the impact of various stimulation parameters on the generation of motor symptoms and afterdischarges (ADs). Focal electrical stimulation was delivered at subdural cortical, intracortical, and hippocampal sites in a rat model. The effects of stimulus parameter on the generation of motor symptoms and on the occurrence of ADs were examined. The effect of stimulus irregularity was tested using random or regular 50Hz stimulation through subdural electrodes. Hippocampal stimulation produced ADs at lower thresholds than neocortical stimulation. Hippocampal stimulation also produced significantly longer ADs. Both in hippocampal and cortical stimulation, when the total current was kept constant with changing pulse width, the threshold for motor symptom or AD was lowest between 50 and 100Hz and higher at both low and high frequencies. However, if the pulse width was fixed, the threshold did not increase above 100Hz and it apparently continued to decrease through 800Hz even if the difference did not reach statistical significance. There was no significant difference between random and regular stimulation. Overall, these results indicate that electrode location and several stimulus parameters including frequency, pulse width, and total electricity are important in electrical stimulation to produce motor symptoms and ADs. Copyright © 2012 Elsevier B.V. All rights reserved.

A Micro-Electrode Array device coupled to a laser-based system for the local stimulation of neurons by optical release of glutamate.

PubMed

Ghezzi, Diego; Menegon, Andrea; Pedrocchi, Alessandra; Valtorta, Flavia; Ferrigno, Giancarlo

2008-10-30

Optical stimulation is a promising approach to investigate the local dynamic responses of cultured neurons. In particular, flash photolysis of caged compounds offers the advantage of allowing the rapid change of concentration of either extracellular or intracellular molecules, such as neurotransmitters or second messengers, for the stimulation or modulation of neuronal activity. We describe here the use of an ultra-violet (UV) laser diode coupled to an optical fibre for the local activation of caged compounds combined with a Micro-Electrode Array (MEA) device. Local uncaging was achieved by UV irradiation through the optical fibre previously positioned by using a red laser diode. The size of the stimulation was determined using caged fluorescein, whereas its efficacy was tested by studying the effect of uncaging the neurotransmitter glutamate. Uncaged glutamate evoked neuronal responses that were recorded using either fluorescence measurements or electrophysiological recordings with MEAs, thus showing the ability of our system to induce local neuronal excitation. This method allows overcoming the limitations of the MEA system related to unfocused electrical stimulation and induction of electrical artefacts. In addition, the coupling of a UV laser diode to an optical fibre allows a precise local stimulation and a quick change of the stimulation point.

Neurorehabilitation with new functional electrical stimulation for hemiparetic upper extremity in stroke patients.

PubMed

Hara, Yukihiro

2008-02-01

In recent years, our understanding of motor learning, neuroplasticity, and functional recovery after the occurrence of brain lesion has grown significantly. New findings in basic neuroscience have stimulated research in motor rehabilitation. Repeated motor practice and motor activity in a real-world environment have been identified in several prospective studies as favorable for motor recovery in stroke patients. Electrical stimulation can be applied in a variety of ways to the hemiparetic upper extremity following stroke. In this paper, an overview of current research into clinical and therapeutic applications of functional electrical stimulation (FES) is presented. In particular, electromyography (EMG)-initiated electrical muscle stimulation--but not electrical muscle stimulation alone--improves the motor function of the hemiparetic arm and hand. Triggered electrical stimulation is reported to be more effective than untriggered electrical stimulation in facilitating upper extremity motor recovery following stroke. Power-assisted FES induces greater muscle contraction by electrical stimulation in proportion to the voluntary integrated EMG signal picked up, which is regulated by a closed-loop control system. Power-assisted FES and motor point block for antagonist muscles have been applied with good results as a new hybrid FES therapy in an outpatient rehabilitation clinic for patients with stroke. Furthermore, a daily home program therapy with power-assisted FES using new equipment has been able to effectively improve wrist and finger extension and shoulder flexion. Proprioceptive sensory feedback might play an important role in power-assisted FES therapy. Although many physiotherapeutic modalities have been established, conclusive proof of their benefit and physiological models of their effects on neuronal structures and processes are still missing. A multichannel near-infrared spectroscopy study to noninvasively and dynamically measure hemoglobin levels in the brain during functional activity has shown that cerebral blood flow in the sensory-motor cortex on the injured side is higher during a power-assisted FES session than during simple active movement or simple electrical stimulation. Nevertheless, evidence-based strategies for motor rehabilitation are more easily available, particularly for patients with hemiparesis.

Efficacy of electroacupuncture compared with transcutaneous electric nerve stimulation for functional constipation: Study protocol for a randomized, controlled trial.

PubMed

Zeng, Yuxiao; Zhang, Xuecheng; Zhou, Jing; Wang, Xinwei; Jiao, Ruimin; Liu, Zhishun

2018-05-01

To treat functional constipation, both electroacupuncture (EA) therapy and transcutaneous electric nerve stimulation (TENS) are safe and effective. However, no head-to-head comparison trial has been conducted. This trial compares the efficacy of electroacupuncture relative to transcutaneous electric nerve stimulation for functional constipation. Individuals with functional constipation will be randomly allocated to receive either EA or TENS (n = 51, each), 3 times per week for 8 weeks. The primary outcome is the percentage of participants with an average increase from baseline of 1 or more complete spontaneous bowel movements at week 8. The secondary outcome measures are the following: at the time of visits, changes in the number of complete spontaneous bowel movements, number of spontaneous bowel movements, stool character, difficulty in defecation, patients' assessment of quality of life regarding constipation (self-report questionnaire), and use of auxiliary defecation methods. The results of this trial should verify whether EA is more efficacious than TENS for relieving symptoms of functional constipation. The major limitation of the study is the lack of blinding of the participants and acupuncturist.

Electromotile hearing: Acoustic tones mask psychophysical response to high-frequency electrical stimulation of intact guinea pig cochleaea)

PubMed Central

Le Prell, Colleen G.; Kawamoto, Kohei; Raphael, Yehoash; Dolan, David F.

2011-01-01

When sinusoidal electric stimulation is applied to the intact cochlea, a frequency-specific acoustic emission can be recorded in the ear canal. Acoustic emissions are produced by basilar membrane motion, and have been used to suggest a corresponding acoustic sensation termed “electromotile hearing.” Electromotile hearing has been specifically attributed to electric stimulation of outer hair cells in the intact organ of Corti. To determine the nature of the auditory perception produced by electric stimulation of a cochlea with intact outer hair cells, we tested guinea pigs in a psychophysical task. First, subjects were trained to report detection of sinusoidal acoustic stimuli and dynamic range was assessed using response latency. Subjects were then implanted with a ball electrode placed into scala tympani. Following the surgical implant procedure, subjects were transferred to a task in which acoustic signals were replaced by sinusoidal electric stimulation, and dynamic range was assessed again. Finally, the ability of acoustic pure-tone stimuli to mask the detection of the electric signals was assessed. Based on the masking effects, we conclude that sinusoidal electric stimulation of the intact cochlea results in perception of a tonal (rather than a broad-band or noisy) sound at a frequency of 8 kHz or above. PMID:17225416

Fundamentals of Transcranial Electric and Magnetic Stimulation Dose: Definition, Selection, and Reporting Practices

PubMed Central

Peterchev, Angel V.; Wagner, Timothy A.; Miranda, Pedro C.; Nitsche, Michael A.; Paulus, Walter; Lisanby, Sarah H.; Pascual-Leone, Alvaro; Bikson, Marom

2011-01-01

The growing use of transcranial electric and magnetic (EM) brain stimulation in basic research and in clinical applications necessitates a clear understanding of what constitutes the dose of EM stimulation and how it should be reported. The biological effects of EM stimulation are mediated through an electromagnetic field injected (via electric stimulation) or induced (via magnetic stimulation) in the body. Therefore, transcranial EM stimulation dose ought to be defined by all parameters of the stimulation device that affect the electromagnetic field generated in the body, including the stimulation electrode or coil configuration parameters: shape, size, position, and electrical properties, as well as the electrode or coil current (or voltage) waveform parameters: pulse shape, amplitude, width, polarity, and repetition frequency; duration of and interval between bursts or trains of pulses; total number of pulses; and interval between stimulation sessions and total number of sessions. Knowledge of the electromagnetic field generated in the body may not be sufficient but is necessary to understand the biological effects of EM stimulation. We believe that reporting of EM stimulation dose should be guided by the principle of reproducibility: sufficient information about the stimulation parameters should be provided so that the dose can be replicated. This paper provides fundamental definition and principles for reporting of dose that encompass any transcranial EM brain stimulation protocol. PMID:22305345

Fundamentals of transcranial electric and magnetic stimulation dose: definition, selection, and reporting practices.

PubMed

Peterchev, Angel V; Wagner, Timothy A; Miranda, Pedro C; Nitsche, Michael A; Paulus, Walter; Lisanby, Sarah H; Pascual-Leone, Alvaro; Bikson, Marom

2012-10-01

The growing use of transcranial electric and magnetic (EM) brain stimulation in basic research and in clinical applications necessitates a clear understanding of what constitutes the dose of EM stimulation and how it should be reported. This paper provides fundamental definitions and principles for reporting of dose that encompass any transcranial EM brain stimulation protocol. The biologic effects of EM stimulation are mediated through an electromagnetic field injected (via electric stimulation) or induced (via magnetic stimulation) in the body. Therefore, transcranial EM stimulation dose ought to be defined by all parameters of the stimulation device that affect the electromagnetic field generated in the body, including the stimulation electrode or coil configuration parameters: shape, size, position, and electrical properties, as well as the electrode or coil current (or voltage) waveform parameters: pulse shape, amplitude, width, polarity, and repetition frequency; duration of and interval between bursts or trains of pulses; total number of pulses; and interval between stimulation sessions and total number of sessions. Knowledge of the electromagnetic field generated in the body may not be sufficient but is necessary to understand the biologic effects of EM stimulation. We believe that reporting of EM stimulation dose should be guided by the principle of reproducibility: sufficient information about the stimulation parameters should be provided so that the dose can be replicated. Copyright © 2012 Elsevier Inc. All rights reserved.

Influence of the implanted pulse generator as reference electrode in finite element model of monopolar deep brain stimulation.

PubMed

Walckiers, Grégoire; Fuchs, Benjamin; Thiran, Jean-Philippe; Mosig, Juan R; Pollo, Claudio

2010-01-30

Electrical deep brain stimulation (DBS) is an efficient method to treat movement disorders. Many models of DBS, based mostly on finite elements, have recently been proposed to better understand the interaction between the electrical stimulation and the brain tissues. In monopolar DBS, clinically widely used, the implanted pulse generator (IPG) is used as reference electrode (RE). In this paper, the influence of the RE model of monopolar DBS is investigated. For that purpose, a finite element model of the full electric loop including the head, the neck and the superior chest is used. Head, neck and superior chest are made of simple structures such as parallelepipeds and cylinders. The tissues surrounding the electrode are accurately modelled from data provided by the diffusion tensor magnetic resonance imaging (DT-MRI). Three different configurations of RE are compared with a commonly used model of reduced size. The electrical impedance seen by the DBS system and the potential distribution are computed for each model. Moreover, axons are modelled to compute the area of tissue activated by stimulation. Results show that these indicators are influenced by the surface and position of the RE. The use of a RE model corresponding to the implanted device rather than the usually simplified model leads to an increase of the system impedance (+48%) and a reduction of the area of activated tissue (-15%). (c) 2009 Elsevier B.V. All rights reserved.

Effects of Robot-assisted Gait Training Combined with Functional Electrical Stimulation on Recovery of Locomotor Mobility in Chronic Stroke Patients: A Randomized Controlled Trial.

PubMed

Bae, Young-Hyeon; Ko, Young Jun; Chang, Won Hyuk; Lee, Ju Hyeok; Lee, Kyeong Bong; Park, Yoo Jung; Ha, Hyun Geun; Kim, Yun-Hee

2014-12-01

[Purpose] The purpose of the present study was to investigate the effects of robot-assisted gait training combined with functional electrical stimulation on locomotor recovery in patients with chronic stroke. [Subjects] The 20 subjects were randomly assigned into either an experimental group (n = 10) that received a combination of robot-assisted gait training and functional electrical stimulation on the ankle dorsiflexor of the affected side or a control group (n = 10) that received robot-assisted gait training only. [Methods] Both groups received the respective therapies for 30 min/day, 3 days/week for 5 weeks. The outcome was measured using the Modified Motor Assessment Scale (MMAS), Timed Up-and-Go Test (TUG), Berg Balance Scale (BBS), and gait parameters through gait analysis (Vicon 370 motion analysis system, Oxford Metrics Ltd., Oxford, UK). All the variables were measured before and after training. [Results] Step length and maximal knee extension were significantly greater than those before training in the experimental group only. Maximal Knee flexion showed a significant difference between the experimental and control groups. The MMAS, BBS, and TUG scores improved significantly after training compared with before training in both groups. [Conclusion] We suggest that the combination of robot-assisted gait training and functional electrical stimulation encourages patients to actively participate in training because it facilitates locomotor recovery without the risk of adverse effects.

Effectiveness of transcutaneous electrical nerve stimulation and interferential current in primary dysmenorrhea.

PubMed

Tugay, Nazan; Akbayrak, Türkan; Demirtürk, Funda; Karakaya, Ilkim Citak; Kocaacar, Ozge; Tugay, Umut; Karakaya, Mehmet Gürhan; Demirtürk, Fazli

2007-01-01

To compare the effectiveness of transcutaneous electrical nerve stimulation and interferential current in primary dysmenorrhea. A prospective, randomized, and controlled study. Hacettepe University School of Physical Therapy and Rehabilitation. Thirty-four volunteer subjects with primary dysmenorrhea (mean age: 21.35 +/- 1.70 years) were included. Statistical analyses were performed in 32 subjects who completed all measures. Fifteen subjects received interferential current application for 20 minutes and 17 subjects received transcutaneous electrical nerve stimulation for 20 minutes when they were experiencing dysmenorrhea. Physical characteristics, years since menarche, length of menstrual cycle (days), and duration of menstruation (days) were recorded. Visual analog scale ( VAS) intensities of menstrual pain, referred lower limb pain, and low back pain were recorded before treatment, and immediately, 8 hours, and 24 hours after treatment. Intensities of the evaluated parameters decreased beginning from just after the applications in both groups (P<0.05). Intensity of referring low back pain in first three measurement times was different between the groups (P<0.05), but this difference is thought to be due to the baseline values of the groups. So, it can be said that no superiority existed between the methods (P>0.05). Both transcutaneous electrical nerve stimulation and interferential current appear to be effective in primary dysmenorrhea. As they are free from the potentially adverse effects of analgesics, and no adverse effects are reported in the literature nor observed in this study, a clinical trial of their effectiveness in comparison with untreated and placebo-treated control groups is warranted.

The effect of surface electrical stimulation on swallowing in dysphagic Parkinson patients.

PubMed

Baijens, Laura W J; Speyer, Renée; Passos, Valeria Lima; Pilz, Walmari; Roodenburg, Nel; Clavé, Père

2012-12-01

Surface electrical stimulation has been applied on a large scale to treat oropharyngeal dysphagia. Patients suffering from oropharyngeal dysphagia in the presence of Parkinson's disease have been treated with surface electrical stimulation. Because of controversial reports on this treatment, a pilot study was set up. This study describes the effects of a single session of surface electrical stimulation using different electrode positions in ten patients with idiopathic Parkinson's disease (median Hoehn and Yahr score: II) and oropharyngeal dysphagia compared to ten age- and gender-matched healthy control subjects during videofluoroscopy of swallowing. Three different electrode positions were applied in random order per subject. For each electrode position, the electrical current was respectively turned "on" and "off" in random order. Temporal, spatial, and visuoperceptual variables were scored by experienced raters who were blinded to the group, electrode position, and status (on/off) of the electrical current. Interrater and interrater reliabilities were calculated. Only a few significant effects of a single session of surface electrical stimulation using different electrode positions in dysphagic Parkinson patients could be observed in this study. Furthermore, significant results for temporal and spatial variables were found regardless of the status of the electrical current in both groups suggesting placebo effects. Following adjustment for electrical current status as well as electrode positions (both not significant, P > 0.05) in the statistical model, significant group differences between Parkinson patients and healthy control subjects emerged. Further studies are necessary to evaluate the potential therapeutic effect and mechanism of electrical stimulation in dysphagic patients with Parkinson's disease.

Real time imaging of peripheral nerve vasculature using optical coherence angiography

NASA Astrophysics Data System (ADS)

Vasudevan, Srikanth; Kumsa, Doe; Takmakov, Pavel; Welle, Cristin G.; Hammer, Daniel X.

2016-03-01

The peripheral nervous system (PNS) carries bidirectional information between the central nervous system and distal organs. PNS stimulation has been widely used in medical devices for therapeutic indications, such as bladder control and seizure cessation. Investigational uses of PNS stimulation include providing sensory feedback for improved control of prosthetic limbs. While nerve safety has been well documented for stimulation parameters used in marketed devices, novel PNS stimulation devices may require alternative stimulation paradigms to achieve maximum therapeutic benefit. Improved testing paradigms to assess the safety of stimulation will expedite the development process for novel PNS stimulation devices. The objective of this research is to assess peripheral nerve vascular changes in real-time with optical coherence angiography (OCA). A 1300-nm OCA system was used to image vasculature changes in the rat sciatic nerve in the region around a surface contacting single electrode. Nerves and vasculature were imaged without stimulation for 180 minutes to quantify resting blood vessel diameter. Walking track analysis was used to assess motor function before and 6 days following experiments. There was no significant change in vessel diameter between baseline and other time points in all animals. Motor function tests indicated the experiments did not impair functionality. We also evaluated the capabilities to image the nerve during electrical stimulation in a pilot study. Combining OCA with established nerve assessment methods can be used to study the effects of electrical stimulation safety on neural and vascular tissue in the periphery.

Comparison of the shock artifacts induced by tripolar and bipolar electrical stimulation techniques.

PubMed

Wee, A S; Jiles, K; Brennan, R

2001-01-01

Tripolar and bipolar electrical stimulation procedures were performed on the upper limbs of eight subjects. The mid-forearm was stimulated electrically (tripolar or bipolar) by surface electrodes, and the induced stimulus shock artifacts were recorded simultaneously from the wrist and elbow. During tripolar stimulation, two types of stimulating configurations were utilized: with the center electrode designated as the cathode and the two outermost electrodes connected to a common anode, and vice versa. During bipolar stimulation, the center electrode served as one pole of the stimulator, and one of the two outermost electrodes of the tripolar stimulator was disconnected. The stimulus intensity was kept constant in all stimulating procedures. Artifacts were reduced significantly during tripolar compared to bipolar stimulation, if the outermost electrodes of the tripolar stimulator (which were facing the recording electrodes) were also oriented toward the recording sites during bipolar stimulation and had the same stimulus polarity. Artifacts were slightly reduced in amplitude from tripolar stimulation, if the center electrode were oriented toward the recording sites during bipolar stimulation and had the same stimulus polarity as previously used during tripolar stimulation.

Electrical stimulation: a novel tool for tissue engineering.

PubMed

Balint, Richard; Cassidy, Nigel J; Cartmell, Sarah H

2013-02-01

New advances in tissue engineering are being made through the application of different types of electrical stimuli to influence cell proliferation and differentiation. Developments made in the last decade have allowed us to improve the structure and functionality of tissue-engineered products through the use of growth factors, hormones, drugs, physical stimuli, bioreactor use, and two-dimensional (2-D) and three-dimensional (3-D) artificial extracellular matrices (with various material properties and topography). Another potential type of stimulus is electricity, which is important in the physiology and development of the majority of all human tissues. Despite its great potential, its role in tissue regeneration and its ability to influence cell migration, orientation, proliferation, and differentiation has rarely been considered in tissue engineering. This review highlights the importance of endogenous electrical stimulation, gathering the current knowledge on its natural occurrence and role in vivo, discussing the novel methods of delivering this stimulus and examining its cellular and tissue level effects, while evaluating how the technique could benefit the tissue engineering discipline in the future.

Triple electrical channels on a triple fluid swivel and its use to monitor intracranial temperature with a thermocouple.

PubMed

Parada, M A; Puig de Parada, M; Hernandez, L; Hoebel, B G

1995-08-01

A low-torque, bubble-free and multiple-channel fluid swivel of easy construction was recently described. This paper describes the design, construction and testing of 3 electrical channels added to the original fluid swivel. The new channels were tested monitoring intrahypothalamic temperature (T(hy)) by means of a copper-constantan thermocouple in freely moving rats, before and after a single intraperitoneal (i.p.) amphetamine injection (3 mg/kg). This test showed an increase in T(hy) after the injection and the maintenance of the electrical continuity along the whole testing period, even when the animals were hyperactive. With this improvement the original swivel was transformed in a more versatile device for experiments requiring fluid handlings and electrophysiological manipulations. Electrical stimulation as in kindling or brain self-stimulation, and electrophysiological recordings as in electroencephalography, electromiography, electrocardiography, in vivo voltammetry and even neuronal unit recording, are just examples of the electrophysiological methods that can be combined with drug self-administration and microdialysis using the present device.

The effect of intra-operative transcutaneous electrical nerve stimulation on posterior neck pain following thyroidectomy.

PubMed

Park, C; Choi, J B; Lee, Y-S; Chang, H-S; Shin, C S; Kim, S; Han, D W

2015-04-01

Posterior neck pain following thyroidectomy is common because full neck extension is required during the procedure. We evaluated the effect of intra-operative transcutaneous electrical nerve stimulation on postoperative neck pain in patients undergoing total thyroidectomy under general anaesthesia. One hundred patients were randomly assigned to one of two groups; 50 patients received transcutaneous electrical nerve stimulation applied to the trapezius muscle and 50 patients acted as controls. Postoperative posterior neck pain and anterior wound pain were evaluated using an 11-point numerical rating scale at 30 min, 6 h, 24 h and 48 h following surgery. The numerical rating scale for posterior neck pain was significantly lower in the transcutaneous electrical nerve stimulation group compared with the control group at all time points (p < 0.05). There were no significant differences in the numerical rating scale for anterior wound pain at any time point. No adverse effects related to transcutaneous electrical nerve stimulation were observed. We conclude that intra-operative transcutaneous electrical nerve stimulation applied to the trapezius muscle reduced posterior neck pain following thyroidectomy. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

Does preoperative electrical stimulation of the skin alter the healing process?

PubMed

Borba, Graziela C; Hochman, Bernardo; Liebano, Richard E; Enokihara, Milvia M S S; Ferreira, Lydia M

2011-04-01

In vitro studies have demonstrated that electrical current may affect fibroblast proliferation and synthesis of collagen fibers. In humans, the application of electrical current by positioning the positive electrode on skin wounds resulted in thinner hypertrophic scars. The aim of this study was to evaluate the effects of preoperative electrical stimulation on cutaneous wound healing in rats. Forty rats were divided into two groups of 20 animals each. In the control group, an incision was made on the back of the animals. In the stimulation group, a preoperative electrical stimulation was applied using a rectangular pulse current at a frequency of 7.7 Hz, and intensity of 8 mA, for 30 min, with the positive electrode placed on the back of the animal, and the negative electrode placed on the abdominal wall. Following, an incision was made on their back. Biopsy was carried out on postoperative day 7 and 14, and histologic analysis was performed. The number of newly formed vessels, fibroblasts, and type III collagen fibers in the stimulation group on postoperative day 7 were greater than those in the control group. Preoperative positive-polarity electrical stimulation positively affects angiogenesis and fibroblast proliferation. Copyright © 2011 Elsevier Inc. All rights reserved.

Electrical Stimulation Followed by Mesenchymal Stem Cells Improves Anal Sphincter Anatomy and Function in a Rat Model at a Time Remote From Injury.

PubMed

Sun, Li; Yeh, Judy; Xie, Zhuojun; Kuang, Mei; Damaser, Margot S; Zutshi, Massarat

2016-05-01

We have explored cell-based therapy to aid anal sphincter repair, but a conditioning injury is required to direct stem cells to the site of injury because symptoms usually manifest at a time remote from injury. We aimed to investigate the effect of local electrical stimulation followed by mesenchymal stem cell delivery on anal sphincter regeneration at a time remote from injury. With the use of a rat model, electrical stimulation parameters and cell delivery route were selected based on in vivo cytokine expression and luciferase-labeled cell imaging of the anal sphincter complex. Three weeks after a partial anal sphincter excision, rats were randomly allocated to 4 groups based on different local interventions: no treatment, daily electrical stimulation for 3 days, daily stimulation for 3 days followed by stem cell injection on the third day, and daily electrical stimulation followed by stem cell injection on the first and third days. Histology-assessed anatomy and anal manometry evaluated physiology 4 weeks after intervention. The electrical stimulation parameters that significantly upregulated gene expression of homing cytokines also achieved mesenchymal stem cell retention when injected directly in the anal sphincter complex in comparison with intravascular and intraperitoneal injections. Four weeks after intervention, there was significantly more new muscle in the area of injury and significantly improved anal resting pressure in the group that received daily electrical stimulation for 3 days followed by a single injection of 1 million stem cells on the third day at the site of injury. This was a pilot study and therefore was not powered for functional outcome. In this rat injury model with optimized parameters, electrical stimulation with a single local mesenchymal stem cell injection administered 3 weeks after injury significantly improved both new muscle formation in the area of injury and anal sphincter pressures.

Optimization of Electrical Stimulation Parameters for Cardiac Tissue Engineering

PubMed Central

Tandon, Nina; Marsano, Anna; Maidhof, Robert; Wan, Leo; Park, Hyoungshin; Vunjak-Novakovic, Gordana

2010-01-01

In vitro application of pulsatile electrical stimulation to neonatal rat cardiomyocytes cultured on polymer scaffolds has been shown to improve the functional assembly of cells into contractile cardiac tissue constrcuts. However, to date, the conditions of electrical stimulation have not been optimized. We have systematically varied the electrode material, amplitude and frequency of stimulation, to determine the conditions that are optimal for cardiac tissue engineering. Carbon electrodes, exhibiting the highest charge-injection capacity and producing cardiac tissues with the best structural and contractile properties, and were thus used in tissue engineering studies. Cardiac tissues stimulated at 3V/cm amplitude and 3Hz frequency had the highest tissue density, the highest concentrations of cardiac troponin-I and connexin-43, and the best developed contractile behavior. These findings contribute to defining bioreactor design specifications and electrical stimulation regime for cardiac tissue engineering. PMID:21604379

[Phrenic nerve stimulation protects against mechanical ventilation-induced diaphragmatic dysfunction through myogenic regulatory factors].

PubMed

An, G H; Chen, M; Zhan, W F; Hu, B; Zhang, H X

2018-02-12

Objective: To explore the protective effect of electrical stimulation of phrenic nerve on diaphragmatic function during mechanical ventilation. Methods: Forty healthy adult SD rats were randomly divided into 5 groups: blank control group (BC), spontaneous breathing group (SB), electrical stimulation group (ES), mechanical ventilation group (MV), and electrical stimulation and mechanical ventilation group (MS). The rats in each group were treated for 18 h except for the BC group. After treatment, the diaphragm muscle tissue was obtained and the diaphragm contractility including peak-to-peak value(Vpp) and maximum rate of contraction(+ dT/dt max) were measured. Expression of MyoD and myogenin were detected. Results: Except for the ES and the MS groups, there was a significant difference for peak-to-peak value (Vpp) between each 2 groups ( P <0.05). Expression levels of MyoD in treatment groups were also significantly different ( P <0.05). Expressions of MS(Q-PCR 2(-ΔΔCt) value: 11.66±2.80) and MV(Q-PCR 2(-ΔΔCt) value: 40.89±24.71) in the treatment group were significantly different ( P <0.05). The expression of myogenin in the MS and the MV groups were significantly different from those of the BC group( P <0.05), however there was no significant difference between the MS(Q-PCR 2(-ΔΔCt) value: 2.58±2.75) and the MV group(Q-PCR 2(-ΔΔCt) value: 1.63±0.71). Conclusions: Electrical stimulation of the phrenic nerve can change the expression level of MyoD and myogenin to offset mechanical ventilation induced diaphragmatic function damage, and therefore plays a protective effect on the diaphragm.

Pain-related somatosensory evoked potentials and functional brain magnetic resonance in the evaluation of neurologic recovery after cardiac arrest: a case study of three patients.

PubMed

Zanatta, Paolo; Messerotti Benvenuti, Simone; Baldanzi, Fabrizio; Bendini, Matteo; Saccavini, Marsilio; Tamari, Wadih; Palomba, Daniela; Bosco, Enrico

2012-03-31

This case series investigates whether painful electrical stimulation increases the early prognostic value of both somatosensory-evoked potentials and functional magnetic resonance imaging in comatose patients after cardiac arrest. Three single cases with hypoxic-ischemic encephalopathy were considered. A neurophysiological evaluation with an electroencephalogram and somatosensory-evoked potentials during increased electrical stimulation in both median nerves was performed within five days of cardiac arrest. Each patient also underwent a functional magnetic resonance imaging evaluation with the same neurophysiological protocol one month after cardiac arrest. One patient, who completely recovered, showed a middle latency component at a high intensity of stimulation and the activation of all brain areas involved in cerebral pain processing. One patient in a minimally conscious state only showed the cortical somatosensory response and the activation of the primary somatosensory cortex. The last patient, who was in a vegetative state, did not show primary somatosensory evoked potentials; only the activation of subcortical brain areas occurred. These preliminary findings suggest that the pain-related somatosensory evoked potentials performed to increase the prognosis of comatose patients after cardiac arrest are associated with regional brain activity showed by functional magnetic resonance imaging during median nerves electrical stimulation. More importantly, this cases report also suggests that somatosensory evoked potentials and functional magnetic resonance imaging during painful electrical stimulation may be sensitive and complementary methods to predict the neurological outcome in the acute phase of coma. Thus, pain-related somatosensory-evoked potentials may be a reliable and a cost-effective tool for planning the early diagnostic evaluation of comatose patients.

Effects of sodium metabisulphite on guinea pig contractile airway smooth muscle responses in vitro.

PubMed Central

Sun, J.; Sakamoto, T.; Chung, K. F.

1995-01-01

BACKGROUND--Sodium metabisulphite (MBS) is known to induce bronchoconstriction in asthmatic patients. The effects of MBS on guinea pig airway smooth muscle and on neurally mediated contraction in vitro have been examined. METHODS--Tracheal and bronchial airway segments were placed in oxygenated buffer solution and electrical field stimulation was performed in the presence of indomethacin (10(-5) M) and propranolol (10(-6) M) for the measurement of isometric tension. Atropine (10(-6) M) was added to bronchial tissues. RESULTS--Concentrations of MBS up to 10(-3) M had no direct effect on airway smooth muscle contraction and did not alter either tracheal smooth muscle contraction induced by electrical field stimulation at all frequencies or acetylcholine-induced tracheal smooth muscle contraction. There was a similar response in the absence of epithelium, except for potentiation of the response induced by electrical field stimulation at 0.5 Hz (24 (10)% increase). However, MBS (10(-5), 10(-6) and 10(-7) M) augmented neurally-mediated non-adrenergic non-cholinergic contractile responses in the bronchi (13.3 (3.2)%, 23.8 (9.6)%, and 6.4 (1.6)%, respectively). MBS had no effect on the contractile response induced by substance P, but at higher concentrations (10(-3) M and 10(-4) M) it caused a time-dependent attenuation of responses induced by either electrical field stimulation or exogenously applied acetylcholine or substance P. CONCLUSIONS--MBS had no direct contractile responses but enhanced bronchoconstriction induced by activation of non-cholinergic neural pathways in the bronchus, probably through increased release of neuropeptides. At high concentrations MBS inhibited contractile responses initiated by receptor or neural stimulation. Images PMID:7570440

Rigor and reproducibility in research with transcranial electrical stimulation: An NIMH-sponsored workshop.

PubMed

Bikson, Marom; Brunoni, Andre R; Charvet, Leigh E; Clark, Vincent P; Cohen, Leonardo G; Deng, Zhi-De; Dmochowski, Jacek; Edwards, Dylan J; Frohlich, Flavio; Kappenman, Emily S; Lim, Kelvin O; Loo, Colleen; Mantovani, Antonio; McMullen, David P; Parra, Lucas C; Pearson, Michele; Richardson, Jessica D; Rumsey, Judith M; Sehatpour, Pejman; Sommers, David; Unal, Gozde; Wassermann, Eric M; Woods, Adam J; Lisanby, Sarah H

Neuropsychiatric disorders are a leading source of disability and require novel treatments that target mechanisms of disease. As such disorders are thought to result from aberrant neuronal circuit activity, neuromodulation approaches are of increasing interest given their potential for manipulating circuits directly. Low intensity transcranial electrical stimulation (tES) with direct currents (transcranial direct current stimulation, tDCS) or alternating currents (transcranial alternating current stimulation, tACS) represent novel, safe, well-tolerated, and relatively inexpensive putative treatment modalities. This report seeks to promote the science, technology and effective clinical applications of these modalities, identify research challenges, and suggest approaches for addressing these needs in order to achieve rigorous, reproducible findings that can advance clinical treatment. The National Institute of Mental Health (NIMH) convened a workshop in September 2016 that brought together experts in basic and human neuroscience, electrical stimulation biophysics and devices, and clinical trial methods to examine the physiological mechanisms underlying tDCS/tACS, technologies and technical strategies for optimizing stimulation protocols, and the state of the science with respect to therapeutic applications and trial designs. Advances in understanding mechanisms, methodological and technological improvements (e.g., electronics, computational models to facilitate proper dosing), and improved clinical trial designs are poised to advance rigorous, reproducible therapeutic applications of these techniques. A number of challenges were identified and meeting participants made recommendations made to address them. These recommendations align with requirements in NIMH funding opportunity announcements to, among other needs, define dosimetry, demonstrate dose/response relationships, implement rigorous blinded trial designs, employ computational modeling, and demonstrate target engagement when testing stimulation-based interventions for the treatment of mental disorders. Published by Elsevier Inc.

Functional identification of an aggression locus in the mouse hypothalamus

PubMed Central

Lin, Dayu; Boyle, Maureen P.; Dollar, Piotr; Lee, Hyosang; Perona, Pietro; Lein, Ed S.; Anderson, David J.

2010-01-01

Electrical stimulation of certain hypothalamic regions in cats and rodents can elicit attack behavior, but the exact location of relevant cells within these regions, their requirement for naturally occurring aggression and their relationship to mating circuits have not been clear. Genetic methods for neural circuit manipulation in mice provide a potentially powerful approach to this problem, but brain stimulation-evoked aggression has never been demonstrated in this species. Here we show that optogenetic, but not electrical, stimulation of neurons in the ventromedial hypothalamus, ventrolateral subdivision (VMHvl) causes male mice to attack both females and inanimate objects, as well as males. Pharmacogenetic silencing of VMHvl reversibly inhibits inter-male aggression. Immediate early gene analysis and single unit recordings from VMHvl during social interactions reveal overlapping but distinct neuronal subpopulations involved in fighting and mating. Neurons activated during attack are inhibited during mating, suggesting a potential neural substrate for competition between these behaviors. PMID:21307935

Functional identification of an aggression locus in the mouse hypothalamus.

PubMed

Lin, Dayu; Boyle, Maureen P; Dollar, Piotr; Lee, Hyosang; Lein, E S; Perona, Pietro; Anderson, David J

2011-02-10

Electrical stimulation of certain hypothalamic regions in cats and rodents can elicit attack behaviour, but the exact location of relevant cells within these regions, their requirement for naturally occurring aggression and their relationship to mating circuits have not been clear. Genetic methods for neural circuit manipulation in mice provide a potentially powerful approach to this problem, but brain-stimulation-evoked aggression has never been demonstrated in this species. Here we show that optogenetic, but not electrical, stimulation of neurons in the ventromedial hypothalamus, ventrolateral subdivision (VMHvl) causes male mice to attack both females and inanimate objects, as well as males. Pharmacogenetic silencing of VMHvl reversibly inhibits inter-male aggression. Immediate early gene analysis and single unit recordings from VMHvl during social interactions reveal overlapping but distinct neuronal subpopulations involved in fighting and mating. Neurons activated during attack are inhibited during mating, suggesting a potential neural substrate for competition between these opponent social behaviours.

Evaluation of Motor Neuron Excitability by CMAP Scanning with Electric Modulated Current

PubMed Central

Araújo, Tiago; Candeias, Rui; Nunes, Neuza; Gamboa, Hugo

2015-01-01

Introduction. Compound Muscle Action Potential (CMAP) scan is a noninvasive promissory technique for neurodegenerative pathologies diagnosis. In this work new CMAP scan protocols were implemented to study the influence of electrical pulse waveform on peripheral nerve excitability. Methods. A total of 13 healthy subjects were tested. Stimulation was performed with an increasing intensities range from 4 to 30 mA. The procedure was repeated 4 times per subject, using a different single pulse stimulation waveform: monophasic square and triangular and quadratic and biphasic square. Results. Different waveforms elicit different intensity-response amplitude curves. The square pulse needs less current to generate the same response amplitude regarding the other waves and this effect is gradually decreasing for the triangular, quadratic, and biphasic pulse, respectively. Conclusion. The stimulation waveform has a direct influence on the stimulus-response slope and consequently on the motoneurons excitability. This can be a new prognostic parameter for neurodegenerative disorders. PMID:26413499

Transcutaneous Electrical Nerve Stimulation in Children with Monosymptomatic Nocturnal Enuresis: A Randomized, Double-Blind, Placebo Controlled Study.

PubMed

Jørgensen, Cecilie Siggaard; Kamperis, Konstantinos; Borch, Luise; Borg, Britt; Rittig, Søren

2017-09-01

In a third of all children with monosymptomatic nocturnal enuresis their condition is refractory to first line treatments. Transcutaneous electrical nerve stimulation has been documented to be efficacious in children with daytime incontinence. We investigated the effect of transcutaneous electrical nerve stimulation in children with monosymptomatic nocturnal enuresis without nocturnal polyuria. Children with monosymptomatic nocturnal enuresis (3 or more wet nights per week) and no nocturnal polyuria were randomized to treatment with active or sham transcutaneous electrical nerve stimulation involving 1-hour sessions twice daily for 10 weeks in a double-blind design. Of the 52 children with monosymptomatic nocturnal enuresis included in the study 47 completed treatment (mean age 9.5 ± 2.1 years, 38 males). None of the children experienced a full response with complete remission of enuresis. Treatment with transcutaneous electrical nerve stimulation did not lead to significant changes in number of wet nights, nocturnal urine production on wet or dry nights, maximum voided volume with and without first morning voided volume, or voiding frequency when comparing parameters before and after treatment. The present study demonstrates no anti-enuretic effect of transcutaneous electrical nerve stimulation in children with monosymptomatic nocturnal enuresis without nocturnal polyuria. Nocturnal urine production and bladder capacity remained unchanged during and after treatment with transcutaneous electrical nerve stimulation. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Electrical management of neurogenic lower urinary tract disorders.

PubMed

Joussain, C; Denys, P

2015-09-01

Management of lower urinary tract dysfunction (LUTD) in neurological diseases remains a priority because it leads to many complications such as incontinence, renal failure and decreased quality of life. A pharmacological approach remains the first-line treatment for patients with neurogenic LUTD, but electrical stimulation is a well-validated and recommended second-line treatment. However, clinicians must be aware of the indications, advantages and side effects of the therapy. This report provides an update on the 2 main electrical stimulation therapies for neurogenic LUTD - inducing direct bladder contraction with the Brindley procedure and modulating LUT physiology (sacral neuromodulation, tibial posterior nerve stimulation or pudendal nerve stimulation). We also describe the indications of these therapies for neurogenic LUTD, following international guidelines, as illustrated by their efficacy in patients with neurologic disorders. Electrical stimulation could be proposed for neurogenic LUTD as second-line treatment after failure of oral pharmacologic approaches. Nevertheless, further investigations are needed for a better understanding of the mechanisms of action of these techniques and to confirm their efficacy. Other electrical investigations, such as deep-brain stimulation and repetitive transcranial magnetic stimulation, or improved sacral anterior root stimulation, which could be associated with non-invasive and highly specific deafferentation of posterior roots, may open new fields in the management of neurogenic LUTD. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Improving Balance Function Using Low Levels of Electrical Stimulation of the Balance Organs

NASA Technical Reports Server (NTRS)

Bloomberg, Jacob; Reschke, Millard; Mulavara, Ajitkumar; Wood, Scott; Serrador, Jorge; Fiedler, Matthew; Kofman, Igor; Peters, Brian T.; Cohen, Helen

2012-01-01

Crewmembers returning from long-duration space flight face significant challenges due to the microgravity-induced inappropriate adaptations in balance/sensorimotor function. The Neuroscience Laboratory at JSC is developing a method based on stochastic resonance to enhance the brain's ability to detect signals from the balance organs of the inner ear and use them for rapid improvement in balance skill, especially when combined with balance training exercises. This method involves a stimulus delivery system that is wearable/portable and provides imperceptible electrical stimulation to the balance organs of the human body. Stochastic resonance (SR) is a phenomenon whereby the response of a nonlinear system to a weak periodic input signal is optimized by the presence of a particular non-zero level of noise. This phenomenon of SR is based on the concept of maximizing the flow of information through a system by a non-zero level of noise. Application of imperceptible SR noise coupled with sensory input in humans has been shown to improve motor, cardiovascular, visual, hearing, and balance functions. SR increases contrast sensitivity and luminance detection; lowers the absolute threshold for tone detection in normal hearing individuals; improves homeostatic function in the human blood pressure regulatory system; improves noise-enhanced muscle spindle function; and improves detection of weak tactile stimuli using mechanical or electrical stimulation. SR noise has been shown to improve postural control when applied as mechanical noise to the soles of the feet, or when applied as electrical noise at the knee and to the back muscles. SR using imperceptible stochastic electrical stimulation of the vestibular system (stochastic vestibular stimulation, SVS) applied to normal subjects has shown to improve the degree of association between the weak input periodic signals introduced via venous blood pressure receptors and the heart-rate responses. Also, application of SVS over 24 hours improves the long-term heart-rate dynamics and motor responsiveness as indicated by daytime trunk activity measurements in patients with multi-system atrophy, Parkinson s disease, or both, including patients who were unresponsive to standard therapy for Parkinson s disease. Recent studies conducted at the NASA JSC Neurosciences Laboratories showed that imperceptible SVS, when applied to normal young healthy subjects, leads to significantly improved balance performance during postural disturbances on unstable compliant surfaces. These studies have shown the benefit of SR noise characteristic optimization with imperceptible SVS in the frequency range of 0-30 Hz, and amplitudes of stimulation have ranged from 100 to 400 microamperes.

Potential of M-Wave Elicited by Double Pulse for Muscle Fatigue Evaluation in Intermittent Muscle Activation by Functional Electrical Stimulation for Motor Rehabilitation

PubMed Central

Miura, Naoto; Watanabe, Takashi

2016-01-01

Clinical studies on application of functional electrical stimulation (FES) to motor rehabilitation have been increasing. However, muscle fatigue appears early in the course of repetitive movement production training by FES. Although M-wave variables were suggested to be reliable indices of muscle fatigue in long lasting constant electrical stimulation under the isometric condition, the ability of M-wave needs more studies under intermittent stimulation condition, because the intervals between electrical stimulations help recovery of muscle activation level. In this paper, M-waves elicited by double pulses were examined in muscle fatigue evaluation during repetitive movements considering rehabilitation training with surface electrical stimulation. M-waves were measured under the two conditions of repetitive stimulation: knee extension force production under the isometric condition and the dynamic movement condition by knee joint angle control. Amplitude of M-wave elicited by the 2nd pulse of a double pulse decreased during muscle fatigue in both measurement conditions, while the change in M-waves elicited by single pulses in a stimulation burst was not relevant to muscle fatigue in repeated activation with stimulation interval of 1 s. Fatigue index obtained from M-waves elicited by 2nd pulses was suggested to provide good estimation of muscle fatigue during repetitive movements with FES. PMID:27110556

21 CFR 868.2775 - Electrical peripheral nerve stimulator.

Code of Federal Regulations, 2012 CFR

2012-04-01

... a device used to apply an electrical current to a patient to test the level of pharmacological... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral nerve...

21 CFR 868.2775 - Electrical peripheral nerve stimulator.

Code of Federal Regulations, 2013 CFR

2013-04-01

... a device used to apply an electrical current to a patient to test the level of pharmacological... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral nerve...

Comparison of the induced fields using different coil configurations during deep transcranial magnetic stimulation

PubMed Central

Ueno, Shoogo

2017-01-01

Stimulation of deeper brain structures by transcranial magnetic stimulation (TMS) plays a role in the study of reward and motivation mechanisms, which may be beneficial in the treatment of several neurological and psychiatric disorders. However, electric field distributions induced in the brain by deep transcranial magnetic stimulation (dTMS) are still unknown. In this paper, the double cone coil, H-coil and Halo-circular assembly (HCA) coil which have been proposed for dTMS have been numerically designed. The distributions of magnetic flux density, induced electric field in an anatomically based realistic head model by applying the dTMS coils were numerically calculated by the impedance method. Results were compared with that of standard figure-of-eight (Fo8) coil. Simulation results show that double cone, H- and HCA coils have significantly deep field penetration compared to the conventional Fo8 coil, at the expense of induced higher and wider spread electrical fields in superficial cortical regions. Double cone and HCA coils have better ability to stimulate deep brain subregions compared to that of the H-coil. In the mean time, both double cone and HCA coils increase risk for optical nerve excitation. Our results suggest although the dTMS coils offer new tool with potential for both research and clinical applications for psychiatric and neurological disorders associated with dysfunctions of deep brain regions, the selection of the most suitable coil settings for a specific clinical application should be based on a balanced evaluation between stimulation depth and focality. PMID:28586349

Study on Electricity Business Expansion and Electricity Sales Based on Seasonal Adjustment

NASA Astrophysics Data System (ADS)

Zhang, Yumin; Han, Xueshan; Wang, Yong; Zhang, Li; Yang, Guangsen; Sun, Donglei; Wang, Bolun

2017-05-01

[1] proposed a novel analysis and forecast method of electricity business expansion based on Seasonal Adjustment, we extend this work to include the effect the micro and macro aspects, respectively. From micro aspect, we introduce the concept of load factor to forecast the stable value of electricity consumption of single new consumer after the installation of new capacity of the high-voltage transformer. From macro aspects, considering the growth of business expanding is also stimulated by the growth of electricity sales, it is necessary to analyse the antecedent relationship between business expanding and electricity sales. First, forecast electricity consumption of customer group and release rules of expanding capacity, respectively. Second, contrast the degree of fitting and prediction accuracy to find out the antecedence relationship and analyse the reason. Also, it can be used as a contrast to observe the influence of customer group in different ranges on the prediction precision. Finally, Simulation results indicate that the proposed method is accurate to help determine the value of expanding capacity and electricity consumption.

Differences in two-point discrimination and sensory threshold in the blind between braille and text reading: a pilot study.

PubMed

Noh, Ji-Woong; Park, Byoung-Sun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kang, Ji-Hye; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

2015-06-01

[Purpose] This study investigated two-point discrimination (TPD) and the electrical sensory threshold of the blind to define the effect of using Braille on the tactile and electrical senses. [Subjects and Methods] Twenty-eight blind participants were divided equally into a text-reading and a Braille-reading group. We measured tactile sensory and electrical thresholds using the TPD method and a transcutaneous electrical nerve stimulator. [Results] The left palm TPD values were significantly different between the groups. The values of the electrical sensory threshold in the left hand, the electrical pain threshold in the left hand, and the electrical pain threshold in the right hand were significantly lower in the Braille group than in the text group. [Conclusion] These findings make it difficult to explain the difference in tactility between groups, excluding both palms. However, our data show that using Braille can enhance development of the sensory median nerve in the blind, particularly in terms of the electrical sensory and pain thresholds.

Differences in two-point discrimination and sensory threshold in the blind between braille and text reading: a pilot study

PubMed Central

Noh, Ji-Woong; Park, Byoung-Sun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kang, Ji-Hye; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

2015-01-01

[Purpose] This study investigated two-point discrimination (TPD) and the electrical sensory threshold of the blind to define the effect of using Braille on the tactile and electrical senses. [Subjects and Methods] Twenty-eight blind participants were divided equally into a text-reading and a Braille-reading group. We measured tactile sensory and electrical thresholds using the TPD method and a transcutaneous electrical nerve stimulator. [Results] The left palm TPD values were significantly different between the groups. The values of the electrical sensory threshold in the left hand, the electrical pain threshold in the left hand, and the electrical pain threshold in the right hand were significantly lower in the Braille group than in the text group. [Conclusion] These findings make it difficult to explain the difference in tactility between groups, excluding both palms. However, our data show that using Braille can enhance development of the sensory median nerve in the blind, particularly in terms of the electrical sensory and pain thresholds. PMID:26180348

Colour stability of bovine Longissimus and Psoas major muscle as affected by electrical stimulation and hot boning.

PubMed

van Laack, R L; Smulders, F J

1990-01-01

From eight electrically stimulated and eight non-stimulated cows the righthand-side longissimus and psoas major muscles were hot boned within 1 1 2 h post mortem, vacuum packaged and chilled and storred at 1±1°C. Immediately after slaughter, the lefthand carcass-sides were blast-chilled for 1 1 2 h and subsequently chilled at 1±1°C until the following day. After cold boning, the longissimus and psoas major muscle were packaged, chilled and stored as the hot boned muscles. After 12 days of storage, steaks, cut from the primals, were displayed at 1±1°C under continuous illumination (300-400 lx). Colour measurements after 0, 2 and 4 days of display revealed a significant (p<0·10) effect of time of boning on non-stimulated psoas major muscle (lower values for a (∗), b (∗) values, chroma and %R630-%R580). Significant effects of electrical stimulation were not observed. Changes in hue tended to be more pronounced when the meat had been stimulated. Changes in chroma were largest (p<0·10) is non-stimulated, hot boned psoas muscle. Analysis of variances showed that in the longissimus muscle significant effects (p<0·10) of time boning and electrical stimulation were present. The effect of time of boning was often influenced by the use of electrical stimulation. Changes in hue and chroma indicated that hot boned samples had a higher colour stability than cold boned controls, especially when the carcasses had not been stimulated electrically. The observed differences in colour stability were rather small in all treatment groups and are not expected to present any practical merchandising problem. Copyright © 1990. Published by Elsevier Ltd.

Vomiting Center reanalyzed: An electrical stimulation study

NASA Technical Reports Server (NTRS)

Miller, A. D.; Wilson, V. J.

1982-01-01

Electrical stimulation of the brainstem of 15 decerebrate cats produced stimulus-bound vomiting in only 4 animals. Vomiting was reproducible in only one cat. Effective stimulating sites were located in the solitary tract and reticular formation. Restricted localization of a vomiting center, stimulation of which evoked readily reproducible results, could not be obtained.

An interval-possibilistic basic-flexible programming method for air quality management of municipal energy system through introducing electric vehicles.

PubMed

Yu, L; Li, Y P; Huang, G H; Shan, B G

2017-09-01

Contradictions of sustainable transportation development and environmental issues have been aggravated significantly and been one of the major concerns for energy systems planning and management. A heavy emphasis is placed on stimulation of electric vehicles (EVs) to handle these problems associated with various complexities and uncertainties in municipal energy system (MES). In this study, an interval-possibilistic basic-flexible programming (IPBFP) method is proposed for planning MES of Qingdao, where uncertainties expressed as interval-flexible variables and interval-possibilistic parameters can be effectively reflected. Support vector regression (SVR) is used for predicting electricity demand of the city under various scenarios. Solutions of EVs stimulation levels and satisfaction levels in association with flexible constraints and predetermined necessity degrees are analyzed, which can help identify the optimized energy-supply patterns that could plunk for improvement of air quality and hedge against violation of soft constraints. Results disclose that largely developing EVs can help facilitate the city's energy system with an environment-effective way. However, compared to the rapid growth of transportation, the EVs' contribution of improving the city's air quality is limited. It is desired that, to achieve an environmentally sustainable MES, more concerns should be focused on the integration of increasing renewable energy resources, stimulating EVs as well as improving energy transmission, transport and storage. Copyright © 2017 Elsevier B.V. All rights reserved.

Prediction and control of neural responses to pulsatile electrical stimulation

NASA Astrophysics Data System (ADS)

Campbell, Luke J.; Sly, David James; O'Leary, Stephen John

2012-04-01

This paper aims to predict and control the probability of firing of a neuron in response to pulsatile electrical stimulation of the type delivered by neural prostheses such as the cochlear implant, bionic eye or in deep brain stimulation. Using the cochlear implant as a model, we developed an efficient computational model that predicts the responses of auditory nerve fibers to electrical stimulation and evaluated the model's accuracy by comparing the model output with pooled responses from a group of guinea pig auditory nerve fibers. It was found that the model accurately predicted the changes in neural firing probability over time to constant and variable amplitude electrical pulse trains, including speech-derived signals, delivered at rates up to 889 pulses s-1. A simplified version of the model that did not incorporate adaptation was used to adaptively predict, within its limitations, the pulsatile electrical stimulus required to cause a desired response from neurons up to 250 pulses s-1. Future stimulation strategies for cochlear implants and other neural prostheses may be enhanced using similar models that account for the way that neural responses are altered by previous stimulation.

Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage

DTIC Science & Technology

2015-10-01

AWARD NUMBER: W81XWH-14-1-0591 TITLE: Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage PRINCIPAL...DATES COVERED 30 Sep 2014 – 29 Sep 2015 4. TITLE AND SUBTITLE Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage...instability, among other traumatic affections of joints, and occupations or sports that subject joints to high levels of impact and torsional loading

Computational electromagnetic methods for transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Gomez, Luis J.

Transcranial magnetic stimulation (TMS) is a noninvasive technique used both as a research tool for cognitive neuroscience and as a FDA approved treatment for depression. During TMS, coils positioned near the scalp generate electric fields and activate targeted brain regions. In this thesis, several computational electromagnetics methods that improve the analysis, design, and uncertainty quantification of TMS systems were developed. Analysis: A new fast direct technique for solving the large and sparse linear system of equations (LSEs) arising from the finite difference (FD) discretization of Maxwell's quasi-static equations was developed. Following a factorization step, the solver permits computation of TMS fields inside realistic brain models in seconds, allowing for patient-specific real-time usage during TMS. The solver is an alternative to iterative methods for solving FD LSEs, often requiring run-times of minutes. A new integral equation (IE) method for analyzing TMS fields was developed. The human head is highly-heterogeneous and characterized by high-relative permittivities (107). IE techniques for analyzing electromagnetic interactions with such media suffer from high-contrast and low-frequency breakdowns. The novel high-permittivity and low-frequency stable internally combined volume-surface IE method developed. The method not only applies to the analysis of high-permittivity objects, but it is also the first IE tool that is stable when analyzing highly-inhomogeneous negative permittivity plasmas. Design: TMS applications call for electric fields to be sharply focused on regions that lie deep inside the brain. Unfortunately, fields generated by present-day Figure-8 coils stimulate relatively large regions near the brain surface. An optimization method for designing single feed TMS coil-arrays capable of producing more localized and deeper stimulation was developed. Results show that the coil-arrays stimulate 2.4 cm into the head while stimulating 3.0 times less volume than Figure-8 coils. Uncertainty quantification (UQ): The location/volume/depth of the stimulated region during TMS is often strongly affected by variability in the position and orientation of TMS coils, as well as anatomical differences between patients. A surrogate model-assisted UQ framework was developed and used to statistically characterize TMS depression therapy. The framework identifies key parameters that strongly affect TMS fields, and partially explains variations in TMS treatment responses.

Application of conductive polymers, scaffolds and electrical stimulation for nerve tissue engineering.

PubMed

Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Baharvand, Hossein; Kiani, Sahar; Al-Deyab, Salem S; Ramakrishna, Seeram

2011-04-01

Among the numerous attempts to integrate tissue engineering concepts into strategies to repair nearly all parts of the body, neuronal repair stands out. This is partially due to the complexity of the nervous anatomical system, its functioning and the inefficiency of conventional repair approaches, which are based on single components of either biomaterials or cells alone. Electrical stimulation has been shown to enhance the nerve regeneration process and this consequently makes the use of electrically conductive polymers very attractive for the construction of scaffolds for nerve tissue engineering. In this review, by taking into consideration the electrical properties of nerve cells and the effect of electrical stimulation on nerve cells, we discuss the most commonly utilized conductive polymers, polypyrrole (PPy) and polyaniline (PANI), along with their design and modifications, thus making them suitable scaffolds for nerve tissue engineering. Other electrospun, composite, conductive scaffolds, such as PANI/gelatin and PPy/poly(ε-caprolactone), with or without electrical stimulation, are also discussed. Different procedures of electrical stimulation which have been used in tissue engineering, with examples on their specific applications in tissue engineering, are also discussed. Copyright © 2011 John Wiley & Sons, Ltd.

Self-Powered Nanocomposites under an External Rotating Magnetic Field for Noninvasive External Power Supply Electrical Stimulation.

PubMed

Wu, Fengluan; Jin, Long; Zheng, Xiaotong; Yan, Bingyun; Tang, Pandeng; Yang, Huikai; Deng, Weili; Yang, Weiqing

2017-11-08

Electrical stimulation in biology and gene expression has attracted considerable attention in recent years. However, it is inconvenient that the electric stimulation needs to be supplied an implanted power-transported wire connecting the external power supply. Here, we fabricated a self-powered composite nanofiber (CNF) and developed an electric generating system to realize electrical stimulation based on the electromagnetic induction effect under an external rotating magnetic field. The self-powered CNFs generating an electric signal consist of modified MWNTs (m-MWNTs) coated Fe 3 O 4 /PCL fibers. Moreover, the output current of the nanocomposites can be increased due to the presence of the magnetic nanoparticles during an external magnetic field is applied. In this paper, these CNFs were employed to replace a bullfrog's sciatic nerve and to realize the effective functional electrical stimulation. The cytotoxicity assays and animal tests of the nanocomposites were also used to evaluate the biocompatibility and tissue integration. These results demonstrated that this self-powered CNF not only plays a role as power source but also can act as an external power supply under an external rotating magnetic field for noninvasive the replacement of injured nerve.

Implantable power generation system utilizing muscle contractions excited by electrical stimulation.

PubMed

Sahara, Genta; Hijikata, Wataru; Tomioka, Kota; Shinshi, Tadahiko

2016-06-01

An implantable power generation system driven by muscle contractions for supplying power to active implantable medical devices, such as pacemakers and neurostimulators, is proposed. In this system, a muscle is intentionally contracted by an electrical stimulation in accordance with the demands of the active implantable medical device for electrical power. The proposed system, which comprises a small electromagnetic induction generator, electrodes with an electrical circuit for stimulation and a transmission device to convert the linear motion of the muscle contractions into rotational motion for the magneto rotor, generates electrical energy. In an ex vivo demonstration using the gastrocnemius muscle of a toad, which was 28 mm in length and weighed 1.3 g, the electrical energy generated by the prototype exceeded the energy consumed for electrical stimulation, with the net power being 111 µW. It was demonstrated that the proposed implantable power generation system has the potential to replace implantable batteries for active implantable medical devices. © IMechE 2016.

Transcranial Magnetic Stimulation-coil design with improved focality

NASA Astrophysics Data System (ADS)

Rastogi, P.; Lee, E. G.; Hadimani, R. L.; Jiles, D. C.

2017-05-01

Transcranial Magnetic Stimulation (TMS) is a technique for neuromodulation that can be used as a non-invasive therapy for various neurological disorders. In TMS, a time varying magnetic field generated from an electromagnetic coil placed on the scalp is used to induce an electric field inside the brain. TMS coil geometry plays an important role in determining the focality and depth of penetration of the induced electric field responsible for stimulation. Clinicians and basic scientists are interested in stimulating a localized area of the brain, while minimizing the stimulation of surrounding neural networks. In this paper, a novel coil has been proposed, namely Quadruple Butterfly Coil (QBC) with an improved focality over the commercial Figure-8 coil. Finite element simulations were conducted with both the QBC and the conventional Figure-8 coil. The two coil's stimulation profiles were assessed with 50 anatomically realistic MRI derived head models. The coils were positioned on the vertex and the scalp over the dorsolateral prefrontal cortex to stimulate the brain. Computer modeling of the coils has been done to determine the parameters of interest-volume of stimulation, maximum electric field, location of maximum electric field and area of stimulation across all 50 head models for both coils.

An investigation into the induced electric fields from transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Hadimani, Ravi; Lee, Erik; Duffy, Walter; Waris, Mohammed; Siddiqui, Waquar; Islam, Faisal; Rajamani, Mahesh; Nathan, Ryan; Jiles, David; David C Jiles Team; Walter Duffy Collaboration

Transcranial magnetic stimulation (TMS) is a promising tool for noninvasive brain stimulation that has been approved by the FDA for the treatment of major depressive disorder. To stimulate the brain, TMS uses large, transient pulses of magnetic field to induce an electric field in the head. This transient magnetic field is large enough to cause the depolarization of cortical neurons and initiate a synaptic signal transmission. For this study, 50 unique head models were created from MRI images. Previous simulation studies have primarily used a single head model, and thus give a limited image of the induced electric field from TMS. This study uses finite element analysis simulations on 50 unique, heterogeneous head models to better investigate the relationship between TMS and the electric field induced in brain tissues. Results showed a significant variation in the strength of the induced electric field in the brain, which can be reasonably predicted by the distance from the TMS coil to the stimulated brain. Further, it was seen that some models had high electric field intensities in over five times as much brain volume as other models.

Effects of electric stimulation of the hunger center in the lateral hypothalamus on slow electric activity and spike activity of fundal and antral stomach muscles in rabbits under conditions of hunger and satiation.

PubMed

Kromin, A A; Zenina, O Yu

2013-09-01

In chronic experiments on rabbits, the effect of electric stimulation of the hunger center in the lateral hypothalamus on myoelectric activity of the fundal and antral parts of the stomach was studied under conditions of hunger and satiation in the absence of food. Stimulation of the lateral hypothalamus in rabbits subjected to 24-h food deprivation and in previously fed rabbits produced incessant seeking behavior, which was followed by reorganization of the structure of temporal organization of slow wave electric activity of muscles of the stomach body and antrum specific for hungry and satiated animals. Increased hunger motivation during electric stimulation of the lateral hypothalamus manifested in the structure of temporal organization of slow wave electric activity of the stomach body and antrum muscles in rabbits subjected to 24-h food deprivation in the replacement of bimodal distribution of slow wave periods to a trimodal type typical of 2-day deprivation, while transition from satiation to hunger caused by electric stimulation of the lateral hypothalamus was associated with a shift from monomodal distributions of slow wave periods to a bimodal type typical of 24-h deprivation. Reorganization of the structure of temporal organization of slow wave electric activity of the stomach body and antrum muscles during electric stimulation of the lateral hypothalamus was determined by descending inhibitory influences of food motivational excitation on activity of the myogenic pacemaker of the lesser curvature of the stomach.

An electric stimulation system for electrokinetic particle manipulation in microfluidic devices.

PubMed

Lopez-de la Fuente, M S; Moncada-Hernandez, H; Perez-Gonzalez, V H; Lapizco-Encinas, B H; Martinez-Chapa, S O

2013-03-01

Microfluidic devices have grown significantly in the number of applications. Microfabrication techniques have evolved considerably; however, electric stimulation systems for microdevices have not advanced at the same pace. Electric stimulation of micro-fluidic devices is an important element in particle manipulation research. A flexible stimulation instrument is desired to perform configurable, repeatable, automated, and reliable experiments by allowing users to select the stimulation parameters. The instrument presented here is a configurable and programmable stimulation system for electrokinetic-driven microfluidic devices; it consists of a processor, a memory system, and a user interface to deliver several types of waveforms and stimulation patterns. It has been designed to be a flexible, highly configurable, low power instrument capable of delivering sine, triangle, and sawtooth waveforms with one single frequency or two superimposed frequencies ranging from 0.01 Hz to 40 kHz, and an output voltage of up to 30 Vpp. A specific stimulation pattern can be delivered over a single time period or as a sequence of different signals for different time periods. This stimulation system can be applied as a research tool where manipulation of particles suspended in liquid media is involved, such as biology, medicine, environment, embryology, and genetics. This system has the potential to lead to new schemes for laboratory procedures by allowing application specific and user defined electric stimulation. The development of this device is a step towards portable and programmable instrumentation for electric stimulation on electrokinetic-based microfluidic devices, which are meant to be integrated with lab-on-a-chip devices.

An electric stimulation system for electrokinetic particle manipulation in microfluidic devices

NASA Astrophysics Data System (ADS)

Lopez-de la Fuente, M. S.; Moncada-Hernandez, H.; Perez-Gonzalez, V. H.; Lapizco-Encinas, B. H.; Martinez-Chapa, S. O.

2013-03-01

Microfluidic devices have grown significantly in the number of applications. Microfabrication techniques have evolved considerably; however, electric stimulation systems for microdevices have not advanced at the same pace. Electric stimulation of micro-fluidic devices is an important element in particle manipulation research. A flexible stimulation instrument is desired to perform configurable, repeatable, automated, and reliable experiments by allowing users to select the stimulation parameters. The instrument presented here is a configurable and programmable stimulation system for electrokinetic-driven microfluidic devices; it consists of a processor, a memory system, and a user interface to deliver several types of waveforms and stimulation patterns. It has been designed to be a flexible, highly configurable, low power instrument capable of delivering sine, triangle, and sawtooth waveforms with one single frequency or two superimposed frequencies ranging from 0.01 Hz to 40 kHz, and an output voltage of up to 30 Vpp. A specific stimulation pattern can be delivered over a single time period or as a sequence of different signals for different time periods. This stimulation system can be applied as a research tool where manipulation of particles suspended in liquid media is involved, such as biology, medicine, environment, embryology, and genetics. This system has the potential to lead to new schemes for laboratory procedures by allowing application specific and user defined electric stimulation. The development of this device is a step towards portable and programmable instrumentation for electric stimulation on electrokinetic-based microfluidic devices, which are meant to be integrated with lab-on-a-chip devices.

Transcutaneous electric nerve stimulation (TENS) in dentistry- A review.

PubMed

Kasat, Vikrant; Gupta, Aditi; Ladda, Ruchi; Kathariya, Mitesh; Saluja, Harish; Farooqui, Anjum-Ara

2014-12-01

Transcutaneous electric nerve stimulation (TENS) is a non-pharmacological method which is widely used by medical and paramedical professionals for the management of acute and chronic pain in a variety of conditions. Similarly, it can be utilized for the management of pain during various dental procedures as well as pain due to various conditions affecting maxillofacial region. This review aims to provide an insight into clinical research evidence available for the analgesic and non analgesic uses of TENS in pediatric as well as adult patients related to the field of dentistry. Also, an attempt is made to briefly discuss history of therapeutic electricity, mechanism of action of TENS, components of TENs equipment, types, techniques of administration, advantages and contradictions of TENS. With this we hope to raise awareness among dental fraternity regarding its dental applications thereby increasing its use in dentistry. Key words:Dentistry, pain, TENS.

Transcutaneous electric nerve stimulation (TENS) in dentistry- A review

PubMed Central

Gupta, Aditi; Ladda, Ruchi; Kathariya, Mitesh; Saluja, Harish; Farooqui, Anjum-Ara

2014-01-01

Transcutaneous electric nerve stimulation (TENS) is a non-pharmacological method which is widely used by medical and paramedical professionals for the management of acute and chronic pain in a variety of conditions. Similarly, it can be utilized for the management of pain during various dental procedures as well as pain due to various conditions affecting maxillofacial region. This review aims to provide an insight into clinical research evidence available for the analgesic and non analgesic uses of TENS in pediatric as well as adult patients related to the field of dentistry. Also, an attempt is made to briefly discuss history of therapeutic electricity, mechanism of action of TENS, components of TENs equipment, types, techniques of administration, advantages and contradictions of TENS. With this we hope to raise awareness among dental fraternity regarding its dental applications thereby increasing its use in dentistry. Key words:Dentistry, pain, TENS. PMID:25674327

Can Direct Current Electrotherapy Be Used for Patients With Orthopedic Implants?

PubMed Central

Thaler, Evangeline; Korte, Holger

2017-01-01

Introduction: Although electrotherapy appears to have particularly interesting applications in the field of postoperative orthopedic rehabilitation, relatively little scientifically based research has been conducted in the area of electrotherapy with regard to safety involving patients with orthopedic implants. Method: Three electrotherapy forms were tested, such as high-volt stimulation (HVS), transcutaneous electric nerve stimulation (TENS), and galvanic current (GAL), using a model system containing a metal implant plate to evaluate whether heating in excess of 3°C would occur. Results: All changes in temperature for HVS, GAL, and TENS therapeutic electrical currents observed in our model system fall below the predefined 3°C. Conclusion: To the best of our knowledge, this is the first experimental based observation that prolonged exposure to a direct electrical current at therapeutic strength does not result in heating of metal titanium plates. PMID:28255511

Frequency-Dependent Activation of Glucose Utilization in the Superior Cervical Ganglion by Electrical Stimulation of Cervical Sympathetic Trunk

NASA Astrophysics Data System (ADS)

Yarowsky, Paul; Kadekaro, Massako; Sokoloff, Louis

1983-07-01

Electrical stimulation of the distal stump of the transected cervical sympathetic trunk produces a frequency-dependent activation of glucose utilization, measured by the deoxy[14C]glucose method, in the superior cervical ganglion of the urethane-anesthetized rat. The frequency dependence falls between 0-15 Hz; at 20 Hz the activation of glucose utilization is no greater than at 15 Hz. Deafferentation of the superior cervical ganglion by transection of the cervical sympathetic trunk does not diminish the rate of glucose utilization in the ganglion in the urethane-anesthetized rat. These results indicate that the rate of energy metabolism in an innervated neural structure is, at least in part, regulated by the impulse frequency of the electrical input to the structure, and this regulation may be an essential component of the mechanism of the coupling of metabolic activity to functional activity in the nervous system.

Effects of Electrical Stimulation Rate on Speech Recognition in Cochlear Implant Users

PubMed Central

Park, Sung Hye; Kim, Eunoak; Lee, Hyo-Jeong

2012-01-01

Background and Objectives The stimulus signals delivered in cochlear implant (CI) systems are generally derived by sampling the temporal envelope of each channel at some constant rate and using its intensity to control the stimulation current level delivered to the corresponding electrode site. The objective of the study was to investigate speech recognition performance of cochlear implant users in quiet and noisy environments using either moderate or high rates of electrical stimulations. Materials and Methods Six post-lingually deafened adult users of the Nucleus CI24 cochlear implant (Contour® electrode array, Cochlear™, Macquarie Park, Australia) with the Freedom® speech processor participated in the study. Stimulation rates of 900 and 2400 pulses-per-second/channel (pps/ch) were used after both stimulation programs were balanced for loudness. Monosyllabic word and sentence recognition scores in quiet and noisy environments were evaluated for each stimulation program after two months of practice. Subjects were also asked to respond to a questionnaire to examine their preference to any stimulation rate in different hearing conditions. Results Word recognition scores for monosyllabic words in quiet conditions with the 900 stimulation rate was better than that of the 2400 stimulation rate, although no significant differences between them were found for sentence test in noise. A survey questionnaire indicated that most subjects preferred the 900 stimulation rate to the 2400 stimulation rate, especially in quiet conditions. Conclusions Most subjects indicated a preference for 900 pps/ch rate in quiet conditions. It is recommended to remap at 900 pps/ch for those CI users whose performance in quiet conditions is less than ideal. PMID:24653862

Design of electrical stimulation bioreactors for cardiac tissue engineering.

PubMed

Tandon, N; Marsano, A; Cannizzaro, C; Voldman, J; Vunjak-Novakovic, G

2008-01-01

Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance spectroscopy (EIS) and we identified a safety range of 0 to 8 V/cm by comparing excitation thresholds and maximum capture rates for neonatal rat cardiomyocytes cultured with electrical stimulation. We conclude with recommendations for studies involving carbon electrodes for cardiac tissue engineering.

History of Resuscitation :4. Development of Resuscitation in the Mid-18 Century-4 : External Stimulation to the Body.

PubMed

Asai, Takashi

2017-05-01

From the mid-18th century, several different stimulations were used to attempt to resuscitate apparently dead people. These include sound, smell, and light stimulation to the ear, nose and eyes, rubbing the body surface and spirit given to the oral cavity. The most notable stimulation was use of electricity, which was initiated by better understanding of its power by Benjamin Franklin and Luigi A. Galvani. Charles Kite developed the first electrical machine to stimulate the heart, and by 1800, it was found that the most effective site for applying electricity was over the heart.

An animal model of functional electrical stimulation: evidence that the central nervous system modulates the consequences of training

PubMed Central

Hook, MA; Grau, JW

2011-01-01

Study Design Review of how spinal neurons can modulate the consequences of functional electrical stimulation (FES) in an animal model. Methods Spinal effects of FES are examined in male Sprague–Dawley rats transected at the second thoracic vertebra. The rats are exposed to FES training 24–48 h after surgery. Experimental manipulations of stimulation parameters, combined with physiological and pharmacological procedures, are used to examine the potential role of spinal neurons. Results The isolated spinal cord is inherently capable of learning the response–outcome relations imposed in FES training contingencies. Adaptive behavioral modifications are observed when an outcome (electrical stimulation) is contingent on a behavioral response. In contrast, a lack of correlation between the response and outcome in training produces a learning deficit in the spinal cord, rendering it incapable of adaptive learning for up to 48 h. The N-methyl-D-aspartic acid receptor appears to mediate both the adaptive plasticity and loss of plasticity, seen in this spinal model. Conclusion The behavioral effects observed with FES therapies are not simply due to the direct (motor) consequences of stimulation elicited by the activation of efferent motor neurons and/or selected muscles. FES training has the capacity to shape inherent spinal circuits and to produce a long-lasting behavioral modification. Further understanding of the spinal mechanisms underlying adaptive behavioral modification will be integral for establishing functional neural connections in a regenerating spinal system. PMID:17700514

Electrical conditioning of adipose-derived stem cells in a multi-chamber culture platform.

PubMed

Pavesi, A; Soncini, M; Zamperone, A; Pietronave, S; Medico, E; Redaelli, A; Prat, M; Fiore, G B

2014-07-01

In tissue engineering, several factors play key roles in providing adequate stimuli for cells differentiation, in particular biochemical and physical stimuli, which try to mimic the physiological microenvironments. Since electrical stimuli are important in the developing heart, we have developed an easy-to-use, cost-effective cell culture platform, able to provide controlled electrical stimulation aimed at investigating the influence of the electric field in the stem cell differentiation process. This bioreactor consists of an electrical stimulator and 12 independent, petri-like culture chambers and a 3-D computational model was used to characterize the distribution and the intensity of the electric field generated in the cell culture volume. We explored the effects of monophasic and biphasic square wave pulse stimulation on a mouse adipose-derived stem cell line (m17.ASC) comparing cell viability, proliferation, protein, and gene expression. Both monophasic (8 V, 2 ms, 1 Hz) and biphasic (+4 V, 1 ms and -4 V, 1 ms; 1 Hz) stimulation were compatible with cell survival and proliferation. Biphasic stimulation induced the expression of Connexin 43, which was found to localize also at the cell membrane, which is its recognized functional mediating intercellular electrical coupling. Electrically stimulated cells showed an induced transcriptional profile more closely related to that of neonatal cadiomyocytes, particularly for biphasic stimulation. The developed platform thus allowed to set-up precise conditions to drive adult stem cells toward a myocardial phenotype solely by physical stimuli, in the absence of exogenously added expensive bioactive molecules, and can thus represent a valuable tool for translational applications for heart tissue engineering and regeneration. © 2014 Wiley Periodicals, Inc.

Targeted therapies using electrical and magnetic neural stimulation for the treatment of chronic pain in spinal cord injury.

PubMed

Moreno-Duarte, Ingrid; Morse, Leslie R; Alam, Mahtab; Bikson, Marom; Zafonte, Ross; Fregni, Felipe

2014-01-15

Chronic neuropathic pain is one of the most common and disabling symptoms in individuals with spinal cord injury (SCI). Over two-thirds of subjects with SCI suffer from chronic pain influencing quality of life, rehabilitation, and recovery. Given the refractoriness of chronic pain to most pharmacological treatments, the majority of individuals with SCI report worsening of this condition over time. Moreover, only 4-6% of patients in this cohort report improvement. Novel treatments targeting mechanisms associated with pain-maladaptive plasticity, such as electromagnetic neural stimulation, may be desirable to improve outcomes. To date, few, small clinical trials have assessed the effects of invasive and noninvasive nervous system stimulation on pain after SCI. We aimed to review initial efficacy, safety and potential predictors of response by assessing the effects of neural stimulation techniques to treat SCI pain. A literature search was performed using the PubMed database including studies using the following targeted stimulation strategies: transcranial Direct Current Stimulation (tDCS), High Definition tDCS (HD-tDCS), repetitive Transcranial Magnetical Stimulation (rTMS), Cranial Electrotherapy Stimulation (CES), Transcutaneous Electrical Nerve Stimulation (TENS), Spinal Cord Stimulation (SCS) and Motor Cortex Stimulation (MCS), published prior to June of 2012. We included studies from 1998 to 2012. Eight clinical trials and one naturalistic observational study (nine studies in total) met the inclusion criteria. Among the clinical trials, three studies assessed the effects of tDCS, two of CES, two of rTMS and one of TENS. The naturalistic study investigated the analgesic effects of SCS. No clinical trials for epidural motor cortex stimulation (MCS) or HD-tDCS were found. Parameters of stimulation and also clinical characteristics varied significantly across studies. Three out of eight studies showed larger effects sizes (0.73, 0.88 and 1.86 respectively) for pain reduction. Classical neuropathic pain symptoms such as dysesthesia (defined as an unpleasant burning sensation in response to touch), allodynia (pain due to a non-painful stimulus), pain in paroxysms, location of SCI in thoracic and lumbar segments and pain in the lower limbs seem to be associated with a positive response to neural stimulation. No significant adverse effects were reported in these studies. Chronic pain in SCI is disabling and resistant to common pharmacologic approaches. Electrical and magnetic neural stimulation techniques have been developed to offer a potential tool in the management of these patients. Although some of these techniques are associated with large standardized mean differences to reduce pain, we found an important variability in these results across studies. There is a clear need for the development of methods to decrease treatment variability and increase response to neural stimulation for pain treatment. We discuss potential methods such as neuroimaging or EEG-guided neural stimulation and the development of better surrogate markers of response such as TMS-indexed cortical plasticity. Copyright © 2013. Published by Elsevier Inc.

Emotions induced by intracerebral electrical stimulation of the temporal lobe.

PubMed

Meletti, Stefano; Tassi, Laura; Mai, Roberto; Fini, Nicola; Tassinari, Carlo Alberto; Russo, Giorgio Lo

2006-01-01

To assess the quality and frequency of emotions induced by intracerebral electrical stimulation of the temporal lobe. Behavioral responses were obtained by electrical stimulation in 74 patients undergoing presurgical video-stereo-EEG monitoring for drug-resistant epilepsy. Intracerebral electrical stimulation was performed by delivering trains of electrical stimuli of alternating polarity; the intensity could vary from 0.2 to 3 mA. Stimulation frequency was 1 Hz or 50 Hz. Nine hundred thirty-eight stimulation procedures were performed. Seventy-nine emotional responses (ERs) were obtained (8.4%). Of these, 67 were "fear responses." Sad feelings were evoked 3 times, happy-pleasant feelings 9 times. Anger and disgust were never observed. The following variables affected the incidence of ER: (a) Anatomical site of stimulation. ERs (always fear) were maximal at the amygdala (12%) and minimal for lateral neocortical stimulation (3%, p < 0.01). (b) Pathology. Stimulation of a temporal lobe with hippocampal sclerosis was associated with a lower frequency of ERs compared with stimulation of a temporal lobe with no evidence of atrophy in the medial temporal structures. (c) Stimulation frequency. ERs were 12% at 50 Hz versus 6.0% at 1 Hz (p < 0.01). (d) Gender. In women fear responses were 16% compared with 3% in men (p < 0.01). There were no gender differences when analyzing nonemotional responses. These data confirm the role of the medial temporal lobe region in the expression of emotions, especially fear-related behaviors. Fear was observed more frequently in the absence of medial temporal sclerosis, supporting the hypothesis that emotional behaviors induced by stimulation are positive phenomena, strictly related to the physiological function of these regions. Further investigations should address why women express fear behaviors more frequently than men.

Cooperative role of electrical stimulation on microbial metabolism and selection of thermophilic communities for p-fluoronitrobenzene treatment.

PubMed

Zhang, Xueqin; Shen, Dongsheng; Feng, Huajun; Wang, Yanfeng; Li, Na; Han, Jingyi; Long, Yuyang

2015-01-01

A novel thermophilic bioelectrochemical system (TBES) based on electrical stimulation was established for the enhanced treatment of p-fluoronitrobenzene (p-FNB) wastewater. p-FNB removal rate constant in the TBES was 78.6% higher than that of the mesophilic BES (MBES), the elevation of which owing to high-temperature overtook the rate improvement of 50.8% in the electrocatalytic system (ECS). Additionally, an overwhelming mineralization efficiency of 91.96% ± 5.70% was obtained in the TBES. The superiority of TBES was attributed to the integrated role of electrical stimulation and high-temperature. Electrical stimulation provided an alternative for the microbial growth independent energy requirements, compensating insufficient energy support from p-FNB metabolism under the high-temperature stress. Besides, electrical stimulation facilitated microbial community evolution to form specific thermophilic biocatalysis. The uniquely selected thermophilic microorganisms including Coprothermobacter sp. and other ones cooperated to enhance p-FNB mineralization. Copyright © 2015 Elsevier Ltd. All rights reserved.

FES in Europe and Beyond: Current Translational Research

PubMed Central

Coste, Christine Azevedo; Mayr, Winfried; Bijak, Manfred; Musarò, Antonio; Carraro, Ugo

2016-01-01

Capacity of adult neural and muscle tissues to respond to external Electrical Stimulation (ES) is the biological basis for the development and implementation of mobility impairment physiotherapy protocols and of related assistive technologies, e.g, Functional Electrical Stimulation (FES). All body tissues, however, respond to electrical stimulation and, indeed, the most successful application of FES is electrical stimulation of the heart to revert or limit effects of arrhythmias (Pace-makers and Defibrillators). Here, we list and discuss results of FES current research activities, in particular those presented at 2016 Meetings: the PaduaMuscleDays, the Italian Institute of Myology Meeting, the 20th International Functional Electrical Stimulation Society (IFESS) conference held in Montpellier and the Vienna Workshop on FES. Several papers were recently e-published in the European Journal of Translational Myology as reports of meeting presentations. All the events and publications clearly show that FES research in Europe and beyond is alive and promisses translation of results into clinical management of a very large population of persons with deficiencies. PMID:28078074

Coupling BCI and cortical stimulation for brain-state-dependent stimulation: methods for spectral estimation in the presence of stimulation after-effects

PubMed Central

Walter, Armin; Murguialday, Ander R.; Rosenstiel, Wolfgang; Birbaumer, Niels; Bogdan, Martin

2012-01-01

Brain-state-dependent stimulation (BSDS) combines brain-computer interfaces (BCIs) and cortical stimulation into one paradigm that allows the online decoding for example of movement intention from brain signals while simultaneously applying stimulation. If the BCI decoding is performed by spectral features, stimulation after-effects such as artefacts and evoked activity present a challenge for a successful implementation of BSDS because they can impair the detection of targeted brain states. Therefore, efficient and robust methods are needed to minimize the influence of the stimulation-induced effects on spectral estimation without violating the real-time constraints of the BCI. In this work, we compared four methods for spectral estimation with autoregressive (AR) models in the presence of pulsed cortical stimulation. Using combined EEG-TMS (electroencephalography-transcranial magnetic stimulation) as well as combined electrocorticography (ECoG) and epidural electrical stimulation, three patients performed a motor task using a sensorimotor-rhythm BCI. Three stimulation paradigms were varied between sessions: (1) no stimulation, (2) single stimulation pulses applied independently (open-loop), or (3) coupled to the BCI output (closed-loop) such that stimulation was given only while an intention to move was detected using neural data. We found that removing the stimulation after-effects by linear interpolation can introduce a bias in the estimation of the spectral power of the sensorimotor rhythm, leading to an overestimation of decoding performance in the closed-loop setting. We propose the use of the Burg algorithm for segmented data to deal with stimulation after-effects. This work shows that the combination of BCIs controlled with spectral features and cortical stimulation in a closed-loop fashion is possible when the influence of stimulation after-effects on spectral estimation is minimized. PMID:23162436

Direct electrical stimulation as an input gate into brain functional networks: principles, advantages and limitations.

PubMed

Mandonnet, Emmanuel; Winkler, Peter A; Duffau, Hugues

2010-02-01

While the fundamental and clinical contribution of direct electrical stimulation (DES) of the brain is now well acknowledged, its advantages and limitations have not been re-evaluated for a long time. Here, we critically review exactly what DES can tell us about cerebral function. First, we show that DES is highly sensitive for detecting the cortical and axonal eloquent structures. Moreover, DES also provides a unique opportunity to study brain connectivity, since each area responsive to stimulation is in fact an input gate into a large-scale network rather than an isolated discrete functional site. DES, however, also has a limitation: its specificity is suboptimal. Indeed, DES may lead to interpretations that a structure is crucial because of the induction of a transient functional response when stimulated, whereas (1) this effect is caused by the backward spreading of the electro-stimulation along the network to an essential area and/or (2) the stimulated region can be functionally compensated owing to long-term brain plasticity mechanisms. In brief, although DES is still the gold standard for brain mapping, its combination with new methods such as perioperative neurofunctional imaging and biomathematical modeling is now mandatory, in order to clearly differentiate those networks that are actually indispensable to function from those that can be compensated.

Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage

DTIC Science & Technology

2017-10-01

expected. Statistics: Comparisons were analyzed using ANOVA with Tukey’s post -hoc test (pɘ.05). RESULTS: In study 1, a proportion of synovial...AWARD NUMBER: W81XWH-14-1-0591 TITLE: Electric Field Stimulation Enhances Healing of Post -Traumatic Osteoarthritic Cartilage PRINCIPAL...2016 – 29 Sep 2017 4. TITLE AND SUBTITLE Cartilage 5a. CONTRACT NUMBER Electric Field Stimulation Enhances Healing of Post -Traumatic Osteoarthritic

Testosterone Combined with Electrical Stimulation and Standing: Effect on Muscle and Bone

DTIC Science & Technology

2016-10-01

AWARD NUMBER: W81XWH-14-2-0190 TITLE: Testosterone Combined with Electrical Stimulation and Standing: Effect on Muscle and Bone PRINCIPAL...including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and...2015 - 29 Sep 2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Testosterone Combined with Electrical Stimulation and Standing: Effect on Muscle and Bone

Effects of Functional Electrical Stimulation Lower Extremity Training in Myotonic Dystrophy Type I: A Pilot Controlled Study.

PubMed

Cudia, Paola; Weis, Luca; Baba, Alfonc; Kiper, Pawel; Marcante, Andrea; Rossi, Simonetta; Angelini, Corrado; Piccione, Francesco

2016-11-01

Functional electrical stimulation (FES) is a new rehabilitative approach that combines electrical stimulation with a functional task. This pilot study evaluated the safety and effectiveness of FES lower extremity training in myotonic dystrophy type 1. This is a controlled pilot study that enrolled 20 patients with myotonic dystrophy type 1 over 2 years. Eight patients (age, 39-67 years) fulfilled the inclusion criteria. Four participants performed FES cycling training for 15 days (one daily session of 30 minutes for 5 days a week). A control group, matched for clinical and genetic variables, who had contraindications to electrical stimulation, performed 6 weeks of conventional resistance and aerobic training. The modified Medical Research Council Scale and functional assessments were performed before and after treatment. Cohen d effect size was used for statistical analysis. Functional electrical stimulation induced lower extremity training was well tolerated and resulted in a greater improvement of tibialis anterior muscle strength (d = 1,583), overall muscle strength (d = 1,723), and endurance (d = 0,626) than conventional training. Functional electrical stimulation might be considered a safe and valid tool to improve muscle function, also in muscles severely compromised in which no other restorative options are available. Confirmation of FES efficacy through further clinical trials is strongly advised.

Effect of electrical stimulation on beta-adrenergic receptor population and cyclic amp production in chicken and rat skeletal muscle cell cultures

NASA Technical Reports Server (NTRS)

Young, R. B.; Bridge, K. Y.; Strietzel, C. J.

2000-01-01

Expression of the beta-adrenergic receptor (betaAR) and its coupling to cyclic AMP (cAMP) synthesis are important components of the signaling system that controls muscle atrophy and hypertrophy, and the goal of this study was to determine if electrical stimulation in a pattern simulating slow muscle contraction would alter the betaAR response in primary cultures of avian and mammalian skeletal muscle cells. Specifically, chicken skeletal muscle cells and rat skeletal muscle cells that had been grown for 7 d in culture were subjected to electrical stimulation for an additional 2 d at a pulse frequency of 0.5 pulses/sec and a pulse duration of 200 msec. In chicken skeletal muscle cells, the betaAR population was not significantly affected by electrical stimulation; however, the ability of these cells to synthesize cyclic AMP was reduced by approximately one-half. In contrast, the betaAR population in rat muscle cells was increased slightly but not significantly by electrical stimulation, and the ability of these cells to synthesize cyclic AMP was increased by almost twofold. The basal levels of intracellular cyclic AMP in neither rat muscle cells nor chicken muscle cells were affected by electrical stimulation.

Effect of Electrical Stimulation on Beta-Adrenergic Receptor Population and Cyclic AMP Production in Chicken and Rat Skeletal Muscle Cell Cultures

NASA Technical Reports Server (NTRS)

Young, Ronald B.; Bridge, Kristin Y.; Strietzel, Catherine J.

2000-01-01

Expression of the beta-adrenergic receptor (PAR) and its coupling to Adenosine 3'5' Cyclic Monophosphate (cAMP) synthesis are important components of the signaling system that controls muscle atrophy and hypertrophy and the goal of this study was to determine if electrical stimulation in a pattern simulating slow muscle contraction would alter the PAR response in primary cultures of avian and mammalian skeletal muscle cells. Specifically chicken skeletal muscle cells and rat skeletal muscle cells that had been grown for 7 d in culture, were subjected to electrical stimulation for an additional 2 d at a pulse frequency of 0.5 pulses/sec and a pulse duration of 200 msec. In chicken skeletal muscle cells, the PAR population was not significantly affected by electrical stimulation; however, the ability, of these cells to synthesize cyclic AMP was reduced by approximately one-half. In contrast, the PAR population in rat muscle cells was increased slightly but not significantly by electrical stimulation, and the ability of these cells to synthesize cyclic AMP was increased by almost twofold. The basal levels of intracellular cyclic AMP in neither rat muscle cells nor chicken muscle cells were affected by electrical stimulation.

Neuroelectronics and modeling of electrical signals for monitoring and control of Parkinson's disease

NASA Astrophysics Data System (ADS)

Chintakuntla, Ritesh R.; Abraham, Jose K.; Varadan, Vijay K.

2009-03-01

The brain and the human nervous system are perhaps the most researched but least understood components of the human body. This is so because of the complex nature of its working and the high density of functions. The monitoring of neural signals could help one better understand the working of the brain and newer recording and monitoring methods have been developed ever since it was discovered that the brain communicates internally by means of electrical pulses. Neuroelectronics is the field which deals with the interface between electronics or semiconductors to living neurons. This includes monitoring of electrical activity from the brain as well as the development of feedback devices for stimulation of parts of the brain for treatment of disorders. In this paper these electrical signals are modeled through a nano/microelectrode arrays based on the electronic equivalent model using Cadence PSD 15.0. The results were compared with those previously published models such as Kupfmuller and Jenik's model, McGrogan's Neuron Model which are based on the Hodgkin and Huxley model. We have developed and equivalent circuit model using discrete passive components to simulate the electrical activity of the neurons. The simulated circuit can be easily be modified by adding some more ionic channels and the results can be used to predict necessary external stimulus needed for stimulation of neurons affected by the Parkinson's disease (PD). Implementing such a model in PD patients could predict the necessary voltages required for the electrical stimulation of the sub-thalamus region for the control tremor motion.

Bone healing in 2016

PubMed Central

Buza, John A.; Einhorn, Thomas

2016-01-01

Summary Delayed fracture healing and nonunion occurs in up to 5–10% of all fractures, and can present a challenging clinical scenario for the treating physician. Methods for the enhancement of skeletal repair may benefit patients that are at risk of, or have experienced, delayed healing or nonunion. These methods can be categorized into either physical stimulation therapies or biological therapies. Physical stimulation therapies include electrical stimulation, low-intensity pulsed ultrasonography, or extracorporeal shock wave therapy. Biological therapies can be further classified into local or systemic therapy based on the method of delivery. Local methods include autologous bone marrow, autologous bone graft, fibroblast growth factor-2, platelet-rich plasma, platelet-derived growth factor, and bone morphogenetic proteins. Systemic therapies include parathyroid hormone and bisphosphonates. This article reviews the current applications and supporting evidence for the use of these therapies in the enhancement of fracture healing. PMID:27920804

Simultaneous masking between electric and acoustic stimulation in cochlear implant users with residual low-frequency hearing.

PubMed

Krüger, Benjamin; Büchner, Andreas; Nogueira, Waldo

2017-09-01

Ipsilateral electric-acoustic stimulation (EAS) is becoming increasingly important in cochlear implant (CI) treatment. Improvements in electrode designs and surgical techniques have contributed to improved hearing preservation during implantation. Consequently, CI implantation criteria have been expanded toward people with significant residual low-frequency hearing, who may benefit from the combined use of both the electric and acoustic stimulation in the same ear. However, only few studies have investigated the mutual interaction between electric and acoustic stimulation modalities. This work characterizes the interaction between both stimulation modalities using psychophysical masking experiments and cone beam computer tomography (CBCT). Two psychophysical experiments for electric and acoustic masking were performed to measure the hearing threshold elevation of a probe stimulus in the presence of a masker stimulus. For electric masking, the probe stimulus was an acoustic tone while the masker stimulus was an electric pulse train. For acoustic masking, the probe stimulus was an electric pulse train and the masker stimulus was an acoustic tone. Five EAS users, implanted with a CI and ipsilateral residual low-frequency hearing, participated in the study. Masking was determined at different electrodes and different acoustic frequencies. CBCT scans were used to determine the individual place-pitch frequencies of the intracochlear electrode contacts by using the Stakhovskaya place-to-frequency transformation. This allows the characterization of masking as a function of the difference between electric and acoustic stimulation sites, which we term the electric-acoustic frequency difference (EAFD). The results demonstrate a significant elevation of detection thresholds for both experiments. In electric masking, acoustic-tone thresholds increased exponentially with decreasing EAFD. In contrast, for the acoustic masking experiment, threshold elevations were present regardless of the tested EAFDs. Based on the present findings, we conclude that there is an asymmetry between the electric and the acoustic masker modalities. These observations have implications for the design and fitting of EAS sound-coding strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of transcutaneous electrical nerve stimulation on spasticity, balance, and walking speed in stroke patients: A systematic review and meta-analysis.

PubMed

Lin, Shuqin; Sun, Qi; Wang, Haifeng; Xie, Guomin

2018-01-10

To evaluate the influence of transcutaneous electrical nerve stimulation in patients with stroke through a systematic review and meta-analysis. PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases were searched systematically. Randomized controlled trials assessing the effect of transcutaneous electrical nerve stimulation vs placebo transcutaneous electrical nerve stimulation on stroke were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome was modified Ashworth scale (MAS). Meta-analysis was performed using the random-effect model. Seven randomized controlled trials were included in the meta-analysis. Compared with placebo transcutaneous electrical nerve stimulation, transcutaneous electrical nerve stimulation supplementation significantly reduced MAS (standard mean difference (SMD) = -0.71; 95% confidence interval (95% CI) = -1.11 to -0.30; p = 0.0006), improved static balance with open eyes (SMD = -1.26; 95% CI = -1.83 to -0.69; p<0.0001) and closed eyes (SMD = -1.74; 95% CI = -2.36 to -1.12; p < 0.00001), and increased walking speed (SMD = 0.44; 95% CI = 0.05 to 0.84; p = 0.03), but did not improve results on the Timed Up and Go Test (SMD = -0.60; 95% CI=-1.22 to 0.03; p = 0.06). Transcutaneous electrical nerve stimulation is associated with significantly reduced spasticity, increased static balance and walking speed, but has no influence on dynamic balance.

A phenomenological model that predicts forces generated when electrical stimulation is superimposed on submaximal volitional contractions

PubMed Central

Perumal, Ramu; Wexler, Anthony S.; Kesar, Trisha M.; Jancosko, Angela; Laufer, Yocheved

2010-01-01

Superimposition of electrical stimulation during voluntary contractions is used to produce functional movements in individuals with central nervous system impairment, to evaluate the ability to activate a muscle, to characterize the nature of fatigue, and to improve muscle strength during postsurgical rehabilitation. Currently, the manner in which voluntary contractions and electrically elicited forces summate is not well understood. The objective of the present study is to develop a model that predicts the forces obtained when electrical stimulation is superimposed on a volitional contraction. Quadriceps femoris muscles of 12 able-bodied subjects were tested. Our results showed that the total force produced when electrical stimulation was superimposed during a volitional contraction could be modeled by the equation T = V + S[(MaxForce − V)/MaxForce]N, where T is the total force produced, V is the force in response to volitional contraction alone, S is the force response to the electrical stimulation alone, MaxForce is the maximum force-generating ability of the muscle, and N is a parameter that we posit depends on the differences in the motor unit recruitment order and firing rates between volitional and electrically elicited contractions. In addition, our results showed that the model predicted accurately (intraclass correlation coefficient ≥0.97) the total force in response to a wide range of stimulation intensities and frequencies superimposed on a wide range of volitional contraction levels. Thus the model will be helpful to clinicians and scientists to predict the amount of stimulation needed to produce the targeted force levels in individuals with partial paralysis. PMID:20299613

Stimulating Music: The Pleasures and Dangers of “Electric Music,” 1750–1900

PubMed Central

Kennaway, James

2014-01-01

Far from being a purely modern idea, the notion of “electric music” was already common in the eighteenth and nineteenth centuries. The shift in thinking about music from cosmic harmony to nervous stimulation made metaphors and speculative theories relating music and electricity irresistible. This essay considers the development of the idea of electric music, looking at its associations with a sexual “body electric.” It will then examine how this conception of music went from being the subject of sympathy to becoming part of a medical critique of music as a dangerous stimulant, with echoes in music criticism and beyond. PMID:24587689

Electronic enhancement of tear secretion

NASA Astrophysics Data System (ADS)

Brinton, Mark; Lim Chung, Jae; Kossler, Andrea; Kook, Koung Hoon; Loudin, Jim; Franke, Manfred; Palanker, Daniel

2016-02-01

Objective. To study electrical stimulation of the lacrimal gland and afferent nerves for enhanced tear secretion, as a potential treatment for dry eye disease. We investigate the response pathways and electrical parameters to safely maximize tear secretion. Approach. We evaluated the tear response to electrical stimulation of the lacrimal gland and afferent nerves in isofluorane-anesthetized rabbits. In acute studies, electrical stimulation was performed using bipolar platinum foil electrodes, implanted beneath the inferior lacrimal gland, and a monopolar electrode placed near the afferent ethmoid nerve. Wireless microstimulators with bipolar electrodes were implanted beneath the lacrimal gland for chronic studies. To identify the response pathways, we applied various pharmacological inhibitors. To optimize the stimulus, we measured tear secretion rate (Schirmer test) as a function of pulse amplitude (1.5-12 mA), duration (0.1-1 ms) and repetition rate (10-100 Hz). Main results. Stimulation of the lacrimal gland increased tear secretion by engaging efferent parasympathetic nerves. Tearing increased with stimulation amplitude, pulse duration and repetition rate, up to 70 Hz. Stimulation with 3 mA, 500 μs pulses at 70 Hz provided a 4.5 mm (125%) increase in Schirmer score. Modulating duty cycle further increased tearing up to 57%, compared to continuous stimulation in chronically implanted animals (36%). Ethmoid (afferent) nerve stimulation increased tearing similar to gland stimulation (3.6 mm) via a reflex pathway. In animals with chronically implanted stimulators, a nearly 6 mm increase (57%) was achieved with 12-fold less charge density per pulse (0.06-0.3 μC mm-2 with 170-680 μs pulses) than the damage threshold (3.5 μC mm-2 with 1 ms pulses). Significance. Electrical stimulation of the lacrimal gland or afferent nerves may be used as a treatment for dry eye disease. Clinical trials should validate this approach in patients with aqueous tear deficiency, and further optimize electrical parameters for maximum clinical efficacy.

Differences in Salivary Alpha-Amylase and Cortisol Responsiveness following Exposure to Electrical Stimulation versus the Trier Social Stress Tests

PubMed Central

Maruyama, Yoshihiro; Kawano, Aimi; Okamoto, Shizuko; Ando, Tomoko; Ishitobi, Yoshinobu; Tanaka, Yoshihiro; Inoue, Ayako; Imanaga, Junko; Kanehisa, Masayuki; Higuma, Haruka; Ninomiya, Taiga; Tsuru, Jusen; Hanada, Hiroaki; Akiyoshi, Jotaro

2012-01-01

Background Cortisol is an essential hormone in the regulation of the stress response along the HPA axis, and salivary cortisol has been used as a measure of free circulating cortisol levels. Recently, salivary alpha-amylase (sAA) has also emerged as a novel biomarker for psychosocial stress responsiveness within the sympathetic adrenomedullary (SAM) system. Principal Findings We measured sAA and salivary cortisol in healthy volunteers after exposure to the Trier Social Stress Test (TSST) and electric stimulation stress. One hundred forty-nine healthy volunteers participated in this study. All subjects were exposed to both the TSST and electric stimulation stress on separate days. We measured sAA and salivary cortisol levels three times immediately before, immediately after, and 20 min after the stress challenge. The State (STAI-S) and Trait (STAI-T) versions of the Spielberger Anxiety Inventory test and the Profile of Mood State (POMS) tests were administered to participants before the electrical stimulation and TSST protocols. We also measured HF, LF and LF/HF Heart Rate Variability ratio immediately after electrical stimulation and TSST exposure. Following TSST exposure or electrical stimulation, sAA levels displayed a rapid increase and recovery, returning to baseline levels 20 min after the stress challenge. Salivary cortisol responses showed a delayed increase, which remained significantly elevated from baseline levels 20 min after the stress challenge. Analyses revealed no differences between men and women with regard to their sAA response to the challenges (TSST or electric stimulations), while we found significantly higher salivary cortisol responses to the TSST in females. We also found that younger subjects tended to display higher sAA activity. Salivary cortisol levels were significantly correlated with the strength of the applied electrical stimulation. Conclusions These preliminary results suggest that the HPA axis (but not the SAM system) may show differential response patterns to distinct kinds of stressors. PMID:22859941

Effectiveness of Functional Electrical Stimulation in Improving Clinical Outcomes in the Upper Arm following Stroke: A Systematic Review and Meta-Analysis

PubMed Central

Vafadar, Amir K.; Côté, Julie N.; Archambault, Philippe S.

2015-01-01

Background. Different therapeutic methods are being used to prevent or decrease long-term impairments of the upper arm in stroke patients. Functional electrical stimulation (FES) is one of these methods, which aims to stimulate the nerves of the weakened muscles so that the resulting muscle contractions resemble those of a functional task. Objectives. The objective of this study was to review the evidence for the effect of FES on (1) shoulder subluxation, (2) pain, and (3) upper arm motor function in stroke patients, when added to conventional therapy. Methods. From the 727 retrieved articles, 10 (9 RCTs, 1 quasi-RCT) were selected for final analysis and were rated based on the PEDro (Physiotherapy Evidence Database) scores and the Sackett's levels of evidence. A meta-analysis was performed for all three considered outcomes. Results. The results of the meta-analyses showed a significant difference in shoulder subluxation in experimental groups compared to control groups, only if FES was applied early after stroke. No effects were found on pain or motor function outcomes. Conclusion. FES can be used to prevent or reduce shoulder subluxation early after stroke. However, it should not be used to reduce pain or improve upper arm motor function after stroke. PMID:25685805

Diagnostic relevance of transcranial magnetic and electric stimulation of the facial nerve in the management of facial palsy.

PubMed

Nowak, Dennis A; Linder, Stefan; Topka, Helge

2005-09-01

Earlier investigations have suggested that isolated conduction block of the facial nerve to transcranial magnetic stimulation early in the disorder represents a very sensitive and potentially specific finding in Bell's palsy differentiating the disease from other etiologies. Stimulation of the facial nerve was performed electrically at the stylomastoid foramen and magnetically at the labyrinthine segment of the Fallopian channel within 3 days from symptom onset in 65 patients with Bell's palsy, five patients with Zoster oticus, one patient with neuroborreliosis and one patient with nuclear facial nerve palsy due to multiple sclerosis. Absence or decreased amplitudes of muscle responses to early transcranial magnetic stimulation was not specific for Bell's palsy, but also evident in all cases of Zoster oticus and in the case of neuroborreliosis. Amplitudes of electrically evoked muscle responses were more markedly reduced in Zoster oticus as compared to Bell's palsy, most likely due to a more severe degree of axonal degeneration. The degree of amplitude reduction of the muscle response to electrical stimulation reliably correlated with the severity of facial palsy. Transcranial magnetic stimulation in the early diagnosis of Bell's palsy is less specific than previously thought. While not specific with respect to the etiology of facial palsy, transcranial magnetic stimulation seems capable of localizing the site of lesion within the Fallopian channel. Combined with transcranial magnetic stimulation, early electrical stimulation of the facial nerve at the stylomastoid foramen may help to establish correct diagnosis and prognosis.

Efficacy of Transcutaneous Electric Nerve Stimulation on Parotid Saliva Flow Rate in Relation to Age and Gender

PubMed Central

Dhillon, Manu; M Raju, Srinivasa; S Mohan, Raviprakash; Tomar, Divya

2016-01-01

Statement of the Problem Treatment with salivary substitutes and stimulation of salivary flow by either mechanical or pharmacologic methods has side effects and only provides symptomatic relief but no long-lasting results. Purpose To assess the effectiveness of extraoral transcutaneous electric nerve stimulation (TENS) as a mean of stimulating salivary function in healthy adult subjects; as well as to determine the gender and age-dependent changes in salivary flow rates of unstimulated and stimulated parotid saliva. Materials and Method Hundred patients were divided into two groups; Group I aged 20-40 and Group II aged ≥ 60 years. The TENS electrode pads were externally placed on the skin overlying the parotid glands. Unstimulated and stimulated parotid saliva was collected for 5 minutes each by using standardized collection techniques. Results Eighty seven of 100 subjects demonstrated increased salivary flow when stimulated via the TENS unit. Ten experienced no increase and 3 experienced a decrease. The mean unstimulated salivary flow rate was 0.01872 ml/min in Group I and 0.0088 ml/min in Group II. The mean stimulated salivary flow rate was 0.03084 ml/min (SD= 0.01248) in Group I, and 0.01556 ml/min (SD 0.0101) in Group II. After stimulation, the amount of salivary flow increased significantly in both groups (p< 0.001). Statistical comparison of the two groups revealed them to be significantly different (p< 0.001), with Group I producing more saliva. Gender-wise, no statistically significant difference was seen among the subjects in Group I (p = 0.148), and those in Group II (p= 0.448). Out of 12 subjects with 0 baseline flows, 7 continued to have no flow. Five subjects observed side effects, although minimal and transient. Conclusion The TENS unit was effective in increasing parotid gland salivary flow in healthy subjects. There was age-related but no gender-related variability in parotid salivary flow rate. PMID:27602390

Electrical Polarization of Titanium Surfaces for the Enhancement of Osteoblast Differentiation

PubMed Central

Gittens, Rolando A.; Olivares-Navarrete, Rene; Rettew, Robert; Butera, Robert J.; Alamgir, Faisal M.; Boyan, Barbara D.; Schwartz, Zvi

2014-01-01

Electrical stimulation has been used clinically to promote bone regeneration in cases of fractures with delayed union or nonunion, with several in vitro and in vivo reports suggesting its beneficial effects on bone formation. However, the use of electrical stimulation of titanium (Ti) implants to enhance osseointegration is less understood, in part because of the few in vitro models that attempt to represent the in vivo environment. In this article, the design of a new in vitro system that allows direct electrical stimulation of osteoblasts through their Ti substrates without the flow of exogenous currents through the media is presented, and the effect of applied electrical polarization on osteoblast differentiation and local factor production was evaluated. A custom-made polycarbonate tissue culture plate was designed to allow electrical connections directly underneath Ti disks placed inside the wells, which were supplied with electrical polarization ranging from 100 to 500 mV to stimulate MG63 osteoblasts. Our results show that electrical polarization applied directly through Ti substrates on which the cells are growing in the absence of applied electrical currents may increase osteoblast differentiation and local factor production in a voltage-dependent manner. PMID:23996899

Analgesic efficacy of cerebral and peripheral electrical stimulation in chronic nonspecific low back pain: a randomized, double-blind, factorial clinical trial.

PubMed

Hazime, Fuad Ahmad; de Freitas, Diego Galace; Monteiro, Renan Lima; Maretto, Rafaela Lasso; Carvalho, Nilza Aparecida de Almeida; Hasue, Renata Hydee; João, Silvia Maria Amado

2015-01-31

Chronic non-specific low back pain is a major socioeconomic public health issue worldwide and, despite the volume of research in the area, it is still a difficult-to-treat condition. The conservative analgesic therapy usually comprises a variety of pharmacological and non-pharmacological strategies, such as transcutaneous electrical nerve stimulation. The neuromatrix pain model and the new findings on the process of chronicity of pain point to a higher effectiveness of treatments that address central rather than peripheral structures. The transcranial direct current stimulation is a noninvasive technique of neuromodulation that has made recent advances in the treatment of chronic pain. The simultaneous combination of these two electrostimulation techniques (cerebral and peripheral) can provide an analgesic effect superior to isolated interventions. However, all the evidence on the analgesic efficacy of these techniques, alone or combined, is still fragmented. This is a protocol for a randomized clinical trial to investigate whether cerebral electrical stimulation combined with peripheral electrical stimulation is more effective in relieving pain than the isolated application of electrical stimulations in patients with chronic nonspecific low back pain. Ninety-two patients will be randomized into four groups to receive transcranial direct current stimulation (real/sham) + transcutaneous electrical nerve stimulation (real/sham) for 12 sessions over a period of four weeks. The primary clinical outcome (pain intensity) and the secondary ones (sensory and affective aspects of pain, physical functioning and global perceived effect) will be recorded before treatment, after four weeks, in Month 3 and in Month 6 after randomization. Confounding factors such as anxiety and depression, the patient's satisfaction with treatment and adverse effects will also be listed. Data will be collected by an examiner unaware of (blind to) the treatment allocation. The results of this study may assist in clinical decision-making about the combined use of cerebral and peripheral electrical stimulation for pain relief in patients with chronic low back pain. NCT01896453.

A partial hearing animal model for chronic electro-acoustic stimulation

NASA Astrophysics Data System (ADS)

Irving, S.; Wise, A. K.; Millard, R. E.; Shepherd, R. K.; Fallon, J. B.

2014-08-01

Objective. Cochlear implants (CIs) have provided some auditory function to hundreds of thousands of people around the world. Although traditionally carried out only in profoundly deaf patients, the eligibility criteria for implantation have recently been relaxed to include many partially-deaf patients with useful levels of hearing. These patients receive both electrical stimulation from their implant and acoustic stimulation via their residual hearing (electro-acoustic stimulation; EAS) and perform very well. It is unclear how EAS improves speech perception over electrical stimulation alone, and little evidence exists about the nature of the interactions between electric and acoustic stimuli. Furthermore, clinical results suggest that some patients that undergo cochlear implantation lose some, if not all, of their residual hearing, reducing the advantages of EAS over electrical stimulation alone. A reliable animal model with clinically-relevant partial deafness combined with clinical CIs is important to enable these issues to be studied. This paper outlines such a model that has been successfully used in our laboratory. Approach. This paper outlines a battery of techniques used in our laboratory to generate, validate and examine an animal model of partial deafness and chronic CI use. Main results. Ototoxic deafening produced bilaterally symmetrical hearing thresholds in neonatal and adult animals. Electrical activation of the auditory system was confirmed, and all animals were chronically stimulated via adapted clinical CIs. Acoustic compound action potentials (CAPs) were obtained from partially-hearing cochleae, using the CI amplifier. Immunohistochemical analysis allows the effects of deafness and electrical stimulation on cell survival to be studied. Significance. This animal model has applications in EAS research, including investigating the functional interactions between electric and acoustic stimulation, and the development of techniques to maintain residual hearing following cochlear implantation. The ability to record CAPs via the CI has clinical direct relevance for obtaining objective measures of residual hearing.

The Neural Correlates of Long-Term Carryover following Functional Electrical Stimulation for Stroke.

PubMed

Gandolla, Marta; Ward, Nick S; Molteni, Franco; Guanziroli, Eleonora; Ferrigno, Giancarlo; Pedrocchi, Alessandra

2016-01-01

Neurorehabilitation effective delivery for stroke is likely to be improved by establishing a mechanistic understanding of how to enhance adaptive plasticity. Functional electrical stimulation is effective at reducing poststroke foot drop; in some patients, the effect persists after therapy has finished with an unknown mechanism. We used fMRI to examine neural correlates of functional electrical stimulation key elements, volitional intent to move and concurrent stimulation, in a group of chronic stroke patients receiving functional electrical stimulation for foot-drop correction. Patients exhibited task-related activation in a complex network, sharing bilateral sensorimotor and supplementary motor activation with age-matched controls. We observed consistent separation of patients with and without carryover effect on the basis of brain responses. Patients who experienced the carryover effect had responses in supplementary motor area that correspond to healthy controls; the interaction between experimental factors in contralateral angular gyrus was seen only in those without carryover. We suggest that the functional electrical stimulation carryover mechanism of action is based on movement prediction and sense of agency/body ownership-the ability of a patient to plan the movement and to perceive the stimulation as a part of his/her own control loop is important for carryover effect to take place.

Application of constant current, low voltage electrical stimulation systems to pig carcasses and its effects on pork quality.

PubMed

Channon, H A; Walker, P J; Kerr, M G; Baud, S R

2003-12-01

This study examined the effectiveness of a constant current, low voltage electrical stimulation system on improving pork quality when applied to pigs at 2 min post-exsanguination. A total of 48 female Duroc×Large White/Landrace pigs of 85-90 kg liveweight were randomly allocated immediately prior to slaughter to one of four constant current electrical stimulation treatments: control (no electrical stimulation), 50, 200 and 400 mA. Stimulation was applied to pig carcasses at 2 min post-exsanguination for 30 s. No differences (P>0.05) in WB shear force values, muscle lightness or PSE incidence of pork M. longissimus lumborum (LL) was found due to electrical stimulation treatment. Muscle pH of the LL muscle was lower (P<0.001) in carcasses in the 200 and 400 mA treatments compared to those from carcasses in both the 50 mA and control treatment groups, when measured at the various time points from 40 min to 8 h post-slaughter. Although carcasses stimulated with 200 and 400 mA had higher percentage drip loss (P<0.05) and purge (P<0.001), this was not found to impact WB shear force values, muscle lightness or PSE incidence.

Matching native electrical stimulation by graded chemical stimulation in isolated mouse adrenal chromaffin cells.

PubMed

Fulop, Tiberiu; Smith, Corey

2007-11-30

Adrenal chromaffin cells release multiple transmitters in response to sympathetic stimulation. Modest cell firing, matching sympathetic tone, releases small freely soluble catecholamines. Elevated electrical firing rates matching input under sympathetic stress results in release of catecholamines as well as semi-soluble vaso- and neuro-active peptides packaged within the dense core of the secretory granule. This activity-dependent differential transmitter release has been shown to rely on a mechanistic shift in the mode of exocytosis through the regulated dilation of the secretory fusion pore between granule and cell surface membranes. However, biochemical description of the mechanism regulating fusion pore dilation remains elusive. In the experimental setting, electrical stimulation designed to mimic sympathetic input, is achieved through single-cell voltage-clamp. While precise, this approach is incompatible with biochemical and proteomic analysis, both of which require large sample sizes. We address this limitation in the current study. We describe a bulk chemical stimulation paradigm calibrated to match defined electrical activity. We utilize calcium and single-cell amperometric measurements to match extracellular potassium concentrations to physiological electrical stimulation under sympathetic tone as well as acute stress conditions. This approach provides larger samples of uniformly stimulated cells for determining molecular players in activity-dependent differential transmitter release from adrenal chromaffin cells.

Propofol, more than halothane, depresses electroencephalographic activation resulting from electrical stimulation in reticular formation.

PubMed

Antognini, J F; Bravo, E; Atherley, R; Carstens, E

2006-09-01

Halothane and propofol depress the central nervous system, and this is partly manifested by a decrease in electroencephalographic (EEG) activity. Little work has been performed to determine the differences between these anesthetics with regard to their effects on evoked EEG activity. We examined the effects of halothane and propofol on EEG responses to electrical stimulation of the reticular formation. Rats (n= 12) were anesthetized with either halothane or propofol, and EEG responses were recorded before and after electrical stimulation of the reticular formation. Two anesthetic concentrations were used (0.8 and 1.2 times the amount needed to prevent gross, purposeful movement in response to supramaximal noxious stimulation), and both anesthetics were studied in each rat using a cross-over design. Electrical stimulation in the reticular formation increased the spectral edge (SEF) and median edge (MEF) frequencies by approximately 1-2 Hz during halothane anesthesia at low and high concentrations. During propofol anesthesia, MEF increased at the low propofol infusion rate, but SEF was unaffected. At the high propofol infusion rate, SEF and MEF decreased following electrical stimulation in the reticular formation. At immobilizing concentrations, propofol produces a larger decrease than halothane in EEG responses to reticular formation stimulation, consistent with propofol having a more profound depressant effect on cortical and subcortical structures.

A collection of homework problems about the application of electricity and magnetism to medicine and biology

NASA Astrophysics Data System (ADS)

Roth, Bradley J.; Hobbie, Russell K.

2014-05-01

This article contains a collection of homework problems to help students learn how concepts from electricity and magnetism can be applied to topics in medicine and biology. The problems are at a level typical of an undergraduate electricity and magnetism class, covering topics such as nerve electrophysiology, transcranial magnetic stimulation, and magnetic resonance imaging. The goal of these problems is to train biology and medical students to use quantitative methods, and also to introduce physics and engineering students to biological phenomena.

Induction of neural differentiation by electrically stimulated gene expression of NeuroD2.

PubMed

Mie, Masayasu; Endoh, Tamaki; Yanagida, Yasuko; Kobatake, Eiry; Aizawa, Masuo

2003-02-13

Regulation of cell differentiation is an important assignment for cellular engineering. One of the techniques for regulation is gene transfection into undifferentiated cells. Transient expression of NeuroD2, one of neural bHLH transcription factors, converted mouse N1E-115 neuroblastoma cells into differentiated neurons. The regulation of neural bHLH expression should be a novel strategy for cell differentiation. In this study, we tried to regulate neural differentiation by NeuroD2 gene inserted under the control of heat shock protein-70 (HSP) promoter, which can be activated by electrical stimulation. Mouse neuroblastoma cell line, N1E-115, was stably transfected with expression vector containing mouse NeuroD2 cDNA under HSP promoter. Transfected cells were cultured on the electrode surface and applied electrical stimulation. After stimulation, NeuroD2 expression was induced, and transfected cells adopt a neuronal morphology at 3 days after stimulation. These results suggest that neural differentiation can be induced by electrically stimulated gene expression of NeuroD2.

A spectral element method with adaptive segmentation for accurately simulating extracellular electrical stimulation of neurons.

PubMed

Eiber, Calvin D; Dokos, Socrates; Lovell, Nigel H; Suaning, Gregg J

2017-05-01

The capacity to quickly and accurately simulate extracellular stimulation of neurons is essential to the design of next-generation neural prostheses. Existing platforms for simulating neurons are largely based on finite-difference techniques; due to the complex geometries involved, the more powerful spectral or differential quadrature techniques cannot be applied directly. This paper presents a mathematical basis for the application of a spectral element method to the problem of simulating the extracellular stimulation of retinal neurons, which is readily extensible to neural fibers of any kind. The activating function formalism is extended to arbitrary neuron geometries, and a segmentation method to guarantee an appropriate choice of collocation points is presented. Differential quadrature may then be applied to efficiently solve the resulting cable equations. The capacity for this model to simulate action potentials propagating through branching structures and to predict minimum extracellular stimulation thresholds for individual neurons is demonstrated. The presented model is validated against published values for extracellular stimulation threshold and conduction velocity for realistic physiological parameter values. This model suggests that convoluted axon geometries are more readily activated by extracellular stimulation than linear axon geometries, which may have ramifications for the design of neural prostheses.

Removal of urothelium affects bladder contractility and release of ATP but not release of NO in rat urinary bladder.

PubMed

Munoz, Alvaro; Gangitano, David A; Smith, Christopher P; Boone, Timothy B; Somogyi, George T

2010-05-24

The objective of our work was to investigate both the contractile function and the release of ATP and NO from strips of bladder tissue after removal of the urothelium. The method of removal was a gentle swabbing motion rather than a sharp surgical cutting to separate the urothelium from the smooth muscle. The contractile response and ATP and NO release were measured in intact as well as on swabbed preparations. The removal of the urothelial layer was affirmed microscopically. After the swabbing, the smaller contractions were evoked by electrical as well as by chemical stimulation (50 microM carbachol or 50 microM alpha, beta meATP). Electrical stimulation, carbachol and substance P (5 microM) evoked lower release of ATP in the swabbed strips than in intact strips. Although release of NO evoked by electrical stimulation or substance P was not changed, release of NO evoked by carbachol was significantly less in the swabbed preparations. Since swabbing removes only the urothelium, the presence of the suburothelial layer may explain the difference between our findings and those of others who found an increase in contractility. Evoked release of ATP is reduced in swabbed strips, indicating that ATP derives solely from the urothelium. On the other hand, electrical stimulation and substance P evoke identical degrees of NO release in both intact and swabbed preparations, suggesting that NO can be released from the suburothelium. Conversely, carbachol-induced release of NO is lower in swabbed strips, implying that the cholinergic receptors (muscarinic or nicotinic) are located in the upper layer of the urothelium.

Pre-pyloric neural electrical stimulation produces cholinergically-mediated reverse peristalsis in the acute canine model of microprocessor-invoked gastric motility for the treatment of obesity.

PubMed

Neshev, Emil; Onen, Denis; Jalilian, Ehsan; Mintchev, Martin P

2006-04-01

Gastric Electrical Stimulation (GES) has been suggested as a new tool for the treatment of obesity. Among the known methods for GES, only Neural Gastric Electrical Stimulation (NGES) provides direct control of contractility without utilizing the spontaneously existing gastric electrical activity as an intermediary. However, only one of the established GES techniques, gastric pacing, has been described to produce retrograde peristalsis for delaying gastric emptying. The aim of this study was to explore the possibility of producing retrograde peristalsis using either single electrode set or dual electrode set NGES. 8 anesthetized dogs underwent laparotomy and implantation of 2 circumferential electrode sets approximately 3 cm and 7 cm proximal to the pylorus, respectively. Single-set and dual-set NGES sessions were repeatedly administered using a custom-designed implantable neurostimulator. Gastric motility patterns were captured using 3 force transducers implanted on the anterior gastric wall along the gastric axis. Motility indices and velocities were employed to quantify the produced contractile patterns. Both single-set and dual-set NGES produced circumferential lumen-occluding contractions in the vicinity of the electrode sets. The invoked contractions propagated proximally in a retrograde fashion. The propagation scope was different depending on the number of electrode sets used. Different velocities of the invoked retrograde contractions associated with single- and dual-set NGES were observed and quantified. Contractility patterns reflected by the normalized motility indices were very similar regardless of the electrode stimulation technique. Pre-pyloric NGES can produce controlled retrograde peristalsis and serve as another avenue for the treatment of obesity.

Sensor probes and phantoms for advanced transcranial magnetic stimulation system developments

NASA Astrophysics Data System (ADS)

Meng, Qinglei; Patel, Prashil; Trivedi, Sudhir; Du, Xiaoming; Hong, Elliot; Choa, Fow-Sen

2015-05-01

Transcranial magnetic stimulation (TMS) has become one of the most widely used noninvasive method for brain tissue stimulation and has been used as a treatment tool for various neurological and psychiatric disorders including migraine, stroke, Parkinson's disease, dystonia, tinnitus and depression. In the process of developing advanced TMS deep brain stimulation tools, we need first to develop field measurement devices like sensory probes and brain phantoms, which can be used to calibrate the TMS systems. Currently there are commercially available DC magnetic or electric filed measurement sensors, but there is no instrument to measure transient fields. In our study, we used a commercial figure-8 shaped TMS coil to generate transient magnetic field and followed induced field and current. The coil was driven by power amplified signal from a pulse generator with tunable pulse rate, amplitude, and duration. In order to obtain a 3D plot of induced vector electric field, many types of probes were designed to detect single component of electric-field vectors along x, y and z axis in the space around TMS coil. We found that resistor probes has an optimized signal-to-noise ratio (SNR) near 3k ohm but it signal output is too weak compared with other techniques. We also found that inductor probes can have very high output for Curl E measurement, but it is not the E-field distribution we are interested in. Probes with electrical wire wrapped around iron coil can directly measure induced E-field with high sensitivity, which matched computer simulation results.

The effect of electrical stimulation in combination with Bobath techniques in the prevention of shoulder subluxation in acute stroke patients.

PubMed

Fil, Ayla; Armutlu, Kadriye; Atay, Ahmet Ozgur; Kerimoglu, Ulku; Elibol, Bulent

2011-01-01

To examine the efficiency of electrical stimulation in combination with Bobath techniques in the prevention of inferior and anterior shoulder subluxation in acute stroke patients. A prospective randomized controlled trial. Intensive care unit and inpatient clinics of neurology in a university hospital. Forty-eight patients with acute stroke, divided equally into control and study groups. Subjects in both groups were treated in accordance with the Bobath concept during the early hospitalization period. In addition to Bobath techniques, electrical stimulation was also applied to the supraspinatus muscle, mid and posterior portions of the deltoid muscle of patients in the study group. Two radiological methods were used to measure the horizontal, vertical and total asymmetry and vertical distance values of the shoulder joint. Motor functions of the arm were evaluated with the Motor Assessment Scale. The hospitalization period was 12.62 ± 2.24 days for the control group and 11.66 ± 1.88 days for the study group. Shoulder subluxation occurred in 9 (37.5%) subjects in the control group, whereas it was not observed in the study group. All shoulder joint displacement values were higher in the control group than in the study group (horizontal asymmetry P = 0.0001, vertical asymmetry P = 0.0001, total asymmetry P = 0.0001, vertical range P = 0.002). Application of electrical stimulation combined with the Bobath approach proved to be efficient in preventing inferior and anterior shoulder subluxation in the acute stages of stroke.

A histopathologic investigation on the effects of electrical stimulation on periodontal tissue regeneration in experimental bony defects in dogs.

PubMed

Kaynak, Deniz; Meffert, Roland; Günhan, Meral; Günhan, Omer

2005-12-01

One endpoint of periodontal therapy is to regenerate the structure lost due to periodontal disease. In the periodontium, gingival epithelium is regenerated by oral epithelium. Underlying connective tissue, periodontal ligament, bone, and cementum are derived from connective tissue. Primitive connective tissue cells may develop into osteoblasts and cementoblasts, which form bone and cementum. Several procedural advances may support these regenerations; however, the regeneration of alveolar bone does not always occur. Therefore, bone stimulating factors are a main topic for periodontal reconstructive research. The present study was designed to examine histopathologically whether the application of an electrical field could demonstrate enhanced alveolar and cementum regeneration and modify tissue factors. Seven beagle dogs were used for this experiment. Mandibular left and right sides served as control and experimental sides, respectively, and 4-walled intrabony defects were created bilaterally between the third and fourth premolars. The experimental side was treated with a capacitively coupled electrical field (CCEF) (sinusoidal wave, 60 kHz, and 5 V peak-to-peak), applied for 14 hours per day. The following measurements were performed on the microphotographs: 1) the distance from the cemento-enamel junction to the apical notch (CEJ-AN) and from the crest of newly formed bone (alveolar ridge) to the apical notch (AR-AN); 2) the thickness of new cementum in the apical notch region; and 3) the length of junctional epithelium. The following histopathologic parameters were assessed by a semiquantitative subjective method: 1) inflammatory cell infiltration (ICI); 2) cellular activity of the periodontal ligament; 3) number and morphology of osteoclasts; 4) resorption lacunae; and 5) osteoblastic activity. The results showed that the quantity of new bone fill and the mean value of the thickness of the cementum were significantly higher for the experimental side (P < 0.01). The location of the base of the pocket was positioned more coronally with respect to the apical point of the coronal notch in the experimental side (statistically significant P < 0.01). The length of the junctional epithelium and the number of osteoclasts were higher in the stimulated side than the coronal side; these findings were also statistically significant (P < 0.01). The comparison of the electrically stimulated versus non-stimulated mandibles with the semiquantitative subjective method demonstrated statistically significant differences in defined histopathologic parameters, except for osteoclast morphologies (P > 0.05). This study demonstrated that the CCEF method has the potential to produce reconstructive effects and bone deposits. Further investigations with respect to the theoretical determination of local field parameters of the periodontal tissue complex, such as permittivity, conductivity, strength of the field electrical stimulation applied to the periodontal field current density, wavelength, and signal frequency appropriate for this field, should be undertaken. Using different electromotive forces alone or in combination with bone graft materials, guided tissue regeneration techniques, and dental implants may achieve a new dimension in periodontal therapy in the near future.

Applied electric field enhances DRG neurite growth: influence of stimulation media, surface coating and growth supplements

NASA Astrophysics Data System (ADS)

Wood, Matthew D.; Willits, Rebecca Kuntz

2009-08-01

Electrical therapies have been found to aid repair of nerve injuries and have been shown to increase and direct neurite outgrowth during stimulation. This enhanced neural growth existed even after the electric field (EF) or stimulation was removed, but the factors that may influence the enhanced growth, such as stimulation media or surface coating, have not been fully investigated. This study characterized neurite outgrowth and branching under various conditions: EF magnitude and application time, ECM surface coating, medium during EF application and growth supplements. A uniform, low-magnitude EF (24 or 44 V m-1) was applied to dissociated chick embryo dorsal root ganglia seeded on collagen or laminin-coated surfaces. During the growth period, cells were either exposed to NGF or N2, and during stimulation cells were exposed to either unsupplemented media (Ca2+) or PBS (no Ca2+). Parallel controls for each experiment included cells exposed to the chamber with no stimulation and cells remaining outside the chamber. After brief electrical stimulation (10 min), neurite length significantly increased 24 h after application for all conditions studied. Of particular interest, increased stimulation time (10-100 min) further enhanced neurite length on laminin but not on collagen surfaces. Neurite branching was not affected by stimulation on any surface, and no preferential growth of neurites was noted after stimulation. Overall, the results of this report suggest that short-duration electric stimulation is sufficient to enhance neurite length under a variety of conditions. While further data are needed to fully elucidate a mechanism for this increased growth, these data suggest that one focus of those investigations should be the interaction between the growth cone and the substrata.

Correspondence between visual and electrical input filters of ON and OFF mouse retinal ganglion cells

NASA Astrophysics Data System (ADS)

Sekhar, S.; Jalligampala, A.; Zrenner, E.; Rathbun, D. L.

2017-08-01

Objective. Over the past two decades retinal prostheses have made major strides in restoring functional vision to patients blinded by diseases such as retinitis pigmentosa. Presently, implants use single pulses to activate the retina. Though this stimulation paradigm has proved beneficial to patients, an unresolved problem is the inability to selectively stimulate the on and off visual pathways. To this end our goal was to test, using white noise, voltage-controlled, cathodic, monophasic pulse stimulation, whether different retinal ganglion cell (RGC) types in the wild type retina have different electrical input filters. This is an important precursor to addressing pathway-selective stimulation. Approach. Using full-field visual flash and electrical and visual Gaussian noise stimulation, combined with the technique of spike-triggered averaging (STA), we calculate the electrical and visual input filters for different types of RGCs (classified as on, off or on-off based on their response to the flash stimuli). Main results. Examining the STAs, we found that the spiking activity of on cells during electrical stimulation correlates with a decrease in the voltage magnitude preceding a spike, while the spiking activity of off cells correlates with an increase in the voltage preceding a spike. No electrical preference was found for on-off cells. Comparing STAs of wild type and rd10 mice revealed narrower electrical STA deflections with shorter latencies in rd10. Significance. This study is the first comparison of visual cell types and their corresponding temporal electrical input filters in the retina. The altered input filters in degenerated rd10 retinas are consistent with photoreceptor stimulation underlying visual type-specific electrical STA shapes in wild type retina. It is therefore conceivable that existing implants could target partially degenerated photoreceptors that have only lost their outer segments, but not somas, to selectively activate the on and off visual pathways.

Design of Electrical Stimulation Bioreactors for Cardiac Tissue Engineering

PubMed Central

Tandon, N.; Marsano, A.; Cannizzaro, C.; Voldman, J.; Vunjak-Novakovic, G.

2009-01-01

Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance spectroscopy (EIS) and we identified a safety range of 0 to 8 V/cm by comparing excitation thresholds and maximum capture rates for neonatal rat cardiomyocytes cultured with electrical stimulation. We conclude with recommendations for studies involving carbon electrodes for cardiac tissue engineering. PMID:19163486

The Effects of Electroacupuncture on Cyclophosphamide-Induced Emesis in Ferrets.

DTIC Science & Technology

1996-07-01

Other studies conducted by Dundee’s group showed that acupressure and transcutaneous electrical stimulation ( TENS ) of the same acupoints also benefited...typically left in place for 20-30 minutes. The effects of acupuncture may be augmented with electrical stimulation (EA) and/or heat (e.g. moxibustion). Side...electrodes (Grass) were attached to the end of the needles and electrical stimulation was applied (the EA parameters will be described in detail later

Restoration of Bladder and Bowel Function Using Electrical Stimulation and Block after Spinal Cord Injury

DTIC Science & Technology

2016-10-01

AWARD NUMBER: W81XWH-14-2-0132 TITLE: Restoration of Bladder and Bowel Function Using Electrical Stimulation and Block after Spinal Cord Injury...per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...COVERED 29 Sep 2015 - 28 Sep 2016 4. TITLE AND SUBTITLE Restoration of Bladder and Bowel Function Using Electrical Stimulation and Block after Spinal

Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage

DTIC Science & Technology

2016-10-01

analyzed using ANOVA with Tukey’s post -hoc test (pɘ.05). RESULTS: In study 1, a proportion of synovial fibroblasts migrated to a maximum depth of ~250...AWARD NUMBER: W81XWH-14-1-0591 TITLE: Electric Field Stimulation Enhances Healing of Post -Traumatic Osteoarthritic Cartilage PRINCIPAL...COVERED 30 Sep 2015 – 29 Sep 2016 4. TITLE AND SUBTITLE Cartilage 5a. CONTRACT NUMBER Electric Field Stimulation Enhances Healing of Post -Traumatic

[The effectiveness of comprehensive rehabilitation of the patients presenting with coronary heart disease with the application of underwater shower massage and electrical stimulation].

PubMed

Rykov, S V; Lebedeva, O D; L'vova, N V; Tupitsina, Iu Iu

2014-01-01

The underwater shower massage and electrical stimulation were applied to treat 120 patients presenting with coronary heart disease. The estimation of the effectiveness of this treatment with the use of functional diagnostic methods revealed its psychocorrective effect manifested in the form of reduced frequency and duration of painful and painless angina seizures, restricted sympathetic influences on the heart as well as normalized sympathovagal balance, lipid status, antioxidative system, central and peripheral hemodynamics, improved systolic and diastolic function of the myocardium, enhanced tolerability of mental, emotional, and physical workload. The study allowed the predictors of the effectiveness of therapeutic and health-promoting measures to be identified.

Functional electrical stimulation-facilitated proliferation and regeneration of neural precursor cells in the brains of rats with cerebral infarction

PubMed Central

Xiang, Yun; Liu, Huihua; Yan, Tiebin; Zhuang, Zhiqiang; Jin, Dongmei; Peng, Yuan

2014-01-01

Previous studies have shown that proliferation of endogenous neural precursor cells cannot alone compensate for the damage to neurons and axons. From the perspective of neural plasticity, we observed the effects of functional electrical stimulation treatment on endogenous neural precursor cell proliferation and expression of basic fibroblast growth factor and epidermal growth factor in the rat brain on the infarct side. Functional electrical stimulation was performed in rat models of acute middle cerebral artery occlusion. Simultaneously, we set up a placebo stimulation group and a sham-operated group. Immunohistochemical staining showed that, at 7 and 14 days, compared with the placebo group, the numbers of nestin (a neural precursor cell marker)-positive cells in the subgranular zone and subventricular zone were increased in the functional electrical stimulation treatment group. Western blot assays and reverse-transcription PCR showed that total protein levels and gene expression of epidermal growth factor and basic fibroblast growth factor were also upregulated on the infarct side. Prehensile traction test results showed that, at 14 days, prehension function of rats in the functional electrical stimulation group was significantly better than in the placebo group. These results suggest that functional electrical stimulation can promote endogenous neural precursor cell proliferation in the brains of acute cerebral infarction rats, enhance expression of basic fibroblast growth factor and epidermal growth factor, and improve the motor function of rats. PMID:25206808

The effect of tinnitus specific intracochlear stimulation on speech perception in patients with unilateral or asymmetric hearing loss accompanied with tinnitus and the effect of formal auditory training.

PubMed

Arts, Remo A G J; George, Erwin L J; Janssen, Miranda A M L; Griessner, Andreas; Zierhofer, Clemens; Stokroos, Robert J

2018-06-01

Previous studies show that intracochlear electrical stimulation independent of environmental sounds appears to suppress tinnitus, even long-term. In order to assess the viability of this potential treatment option it is essential to study the effects of this tinnitus specific electrical stimulation on speech perception. A randomised, prospective crossover design. Ten patients with unilateral or asymmetric hearing loss and severe tinnitus complaints. The audiological effects of standard clinical CI, formal auditory training and tinnitus specific electrical stimulation were investigated. Results show that standard clinical CI in unilateral or asymmetric hearing loss is shown to be beneficial for speech perception in quiet, speech perception in noise and subjective hearing ability. Formal auditory training does not appear to improve speech perception performance. However, CI-related discomfort reduces significantly more rapidly during CI rehabilitation in subjects receiving formal auditory training. Furthermore, tinnitus specific electrical stimulation has neither positive nor negative effects on speech perception. In combination with the findings from previous studies on tinnitus suppression using intracochlear electrical stimulation independent of environmental sounds, the results of this study contribute to the viability of cochlear implantation based on tinnitus complaints.

A pilot study of contralateral homonymous muscle activity simulated electrical stimulation in chronic hemiplegia.

PubMed

Osu, Rieko; Otaka, Yohei; Ushiba, Junichi; Sakata, Sachiko; Yamaguchi, Tomofumi; Fujiwara, Toshiyuki; Kondo, Kunitsugu; Liu, Meigen

2012-01-01

For the recovery of hemiparetic hand function, a therapy was developed called contralateral homonymous muscle activity stimulated electrical stimulation (CHASE), which combines electrical stimulation and bilateral movements, and its feasibility was studied in three chronic stroke patients with severe hand hemiparesis. Patients with a subcortical lesion were asked to extend their wrist and fingers bilaterally while an electromyogram (EMG) was recorded from the extensor carpi radialis (ECR) muscle in the unaffected hand. Electric stimulation was applied to the homonymous wrist and finger extensors of the affected side. The intensity of the electrical stimulation was computed based on the EMG and scaled so that the movements of the paretic hand looked similar to those of the unaffected side. The patients received 30-minutes of therapy per day for 2 weeks. Improvement in the active range of motion of wrist extension was observed for all patients. There was a decrease in the scores of modified Ashworth scale in the flexors. Fugl-Meyer assessment scores of motor function of the upper extremities improved in two of the patients. The results suggest a positive outcome can be obtained using the CHASE system for upper extremity rehabilitation of patients with severe hemiplegia.

Ipsilateral masking between acoustic and electric stimulations.

PubMed

Lin, Payton; Turner, Christopher W; Gantz, Bruce J; Djalilian, Hamid R; Zeng, Fan-Gang

2011-08-01

Residual acoustic hearing can be preserved in the same ear following cochlear implantation with minimally traumatic surgical techniques and short-electrode arrays. The combined electric-acoustic stimulation significantly improves cochlear implant performance, particularly speech recognition in noise. The present study measures simultaneous masking by electric pulses on acoustic pure tones, or vice versa, to investigate electric-acoustic interactions and their underlying psychophysical mechanisms. Six subjects, with acoustic hearing preserved at low frequencies in their implanted ear, participated in the study. One subject had a fully inserted 24 mm Nucleus Freedom array and five subjects had Iowa/Nucleus hybrid implants that were only 10 mm in length. Electric masking data of the long-electrode subject showed that stimulation from the most apical electrodes produced threshold elevations over 10 dB for 500, 625, and 750 Hz probe tones, but no elevation for 125 and 250 Hz tones. On the contrary, electric stimulation did not produce any electric masking in the short-electrode subjects. In the acoustic masking experiment, 125-750 Hz pure tones were used to acoustically mask electric stimulation. The acoustic masking results showed that, independent of pure tone frequency, both long- and short-electrode subjects showed threshold elevations at apical and basal electrodes. The present results can be interpreted in terms of underlying physiological mechanisms related to either place-dependent peripheral masking or place-independent central masking.

Bone stimulation for fracture healing: What's all the fuss?

PubMed Central

Victoria, Galkowski; Petrisor, Brad; Drew, Brian; Dick, David

2009-01-01

Approximately 10% of the 7.9 million annual fracture patients in the United States experience nonunion and/or delayed unions, which have a substantial economic and quality of life impact. A variety of devices are being marketed under the name of “bone growth stimulators.” This article provides an overview of electrical and electromagnetic stimulation, ultrasound, and extracorporeal shock waves. More research is needed for knowledge of appropriate device configurations, advancement in the field, and encouragement in the initiation of new trials, particularly large multicenter trials and randomized control trials that have standardized device and protocol methods. PMID:19838359

Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

NASA Astrophysics Data System (ADS)

Muller, Leah; Rolston, John D.; Fox, Neal P.; Knowlton, Robert; Rao, Vikram R.; Chang, Edward F.

2018-04-01

Objective. Direct electrical stimulation (DES) is a clinical gold standard for human brain mapping and readily evokes conscious percepts, yet the neurophysiological changes underlying these percepts are not well understood. Approach. To determine the neural correlates of DES, we stimulated the somatosensory cortex of ten human participants at frequency-amplitude combinations that both elicited and failed to elicit conscious percepts, meanwhile recording neural activity directly surrounding the stimulation site. We then compared the neural activity of perceived trials to that of non-perceived trials. Main results. We found that stimulation evokes distributed high gamma activity, which correlates with conscious perception better than stimulation parameters themselves. Significance. Our findings suggest that high gamma activity is a reliable biomarker for perception evoked by both natural and electrical stimuli.

Electrical stimulation reduces smokers' craving by modulating the coupling between dorsal lateral prefrontal cortex and parahippocampal gyrus.

PubMed

Yang, Li-Zhuang; Shi, Bin; Li, Hai; Zhang, Wei; Liu, Ying; Wang, Hongzhi; Zhou, Yanfei; Wang, Ying; Lv, Wanwan; Ji, Xuebing; Hudak, Justin; Zhou, Yifeng; Fallgatter, Andreas J; Zhang, Xiaochu

2017-08-01

Applying electrical stimulation over the prefrontal cortex can help nicotine dependents reduce cigarette craving. However, the underlying mechanism remains ambiguous. This study investigates this issue with functional magnetic resonance imaging. Thirty-two male chronic smokers received real and sham stimulation over dorsal lateral prefrontal cortex (DLPFC) separated by 1 week. The neuroimaging data of the resting state, the smoking cue-reactivity task and the emotion task after stimulation were collected. The craving across the cue-reactivity task was diminished during real stimulation as compared with sham stimulation. The whole-brain analysis on the cue-reactivity task revealed a significant interaction between the stimulation condition (real vs sham) and the cue type (smoking vs neutral) in the left superior frontal gyrus and the left middle frontal gyrus. The functional connectivity between the left DLPFC and the right parahippocampal gyrus, as revealed by both psychophysical interaction analysis and the resting state functional connectivity, is altered by electrical stimulation. Moreover, the craving change across the real and sham condition is predicted by alteration of functional connectivity revealed by psychophysical interaction analysis. The local and long-distance coupling, altered by the electrical stimulation, might be the underlying neural mechanism of craving regulation. © The Author (2017). Published by Oxford University Press.

Murine model of neuromuscular electrical stimulation on squamous cell carcinoma: Potential implications for dysphagia therapy

PubMed Central

Linkov, Gary; Branski, Ryan C.; Amin, Milan; Chernichenko, Natalya; Chen, Chun-Hao; Alon, Gad; Langmore, Susan; Wong, Richard J.; Kraus, Dennis H.

2013-01-01

Background Dysphagia is a potential consequence of treatment for head and neck cancer. Neuromuscular electrical stimulation (NMES) has evolved as a treatment option, with the goal of improved swallow function in patients with chronic dysphagia. However, the effects of NMES on tumorigenicity are unknown and often confound the initiation of this therapy, potentially limiting its efficacy in treating patients with head and neck cancer. Methods Squamous cell carcinoma was grown in the flank of athymic, nude mice. Mice were randomized into treatment and control groups; the experimental group received daily NMES directly to the flank for 8 days. Results Tumor volumes, recorded on days 0, 3, 7, and 10, demonstrated no significant differences between groups on each day of measurement. Immunohistochemical analysis of apoptosis, proliferation, and vascularization also failed to demonstrate statistically significant differences between treated and untreated groups. Conclusions NMES does not promote the growth of underlying tumor in our model. These data may provide preliminary evidence that applying electrical stimulation over the muscles of the anterior neck does not increase the risk of tumorigenicity. Early initiation of NMES in this challenging population may be feasible from an oncologic standpoint. PMID:22083666

Comparing the magnetic resonant coupling radiofrequency stimulation to the traditional approaches: Ex-vivo tissue voltage measurement and electromagnetic simulation analysis

NASA Astrophysics Data System (ADS)

Yeung, Sai Ho; Pradhan, Raunaq; Feng, Xiaohua; Zheng, Yuanjin

2015-09-01

Recently, the design concept of magnetic resonant coupling has been adapted to electromagnetic therapy applications such as non-invasive radiofrequency (RF) stimulation. This technique can significantly increase the electric field radiated from the magnetic coil at the stimulation target, and hence enhancing the current flowing through the nerve, thus enabling stimulation. In this paper, the developed magnetic resonant coupling (MRC) stimulation, magnetic stimulation (MS) and transcutaneous electrical nerve stimulation (TENS) are compared. The differences between the MRC RF stimulation and other techniques are presented in terms of the operating mechanism, ex-vivo tissue voltage measurement and electromagnetic simulation analysis. The ev-vivo tissue voltage measurement experiment is performed on the compared devices based on measuring the voltage induced by electromagnetic induction at the tissue. The focusing effect, E field and voltage induced across the tissue, and the attenuation due to the increase of separation between the coil and the target are analyzed. The electromagnetic stimulation will also be performed to obtain the electric field and magnetic field distribution around the biological medium. The electric field intensity is proportional to the induced current and the magnetic field is corresponding to the electromagnetic induction across the biological medium. The comparison between the MRC RF stimulator and the MS and TENS devices revealed that the MRC RF stimulator has several advantages over the others for the applications of inducing current in the biological medium for stimulation purposes.

Comparing the magnetic resonant coupling radiofrequency stimulation to the traditional approaches: Ex-vivo tissue voltage measurement and electromagnetic simulation analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeung, Sai Ho; Pradhan, Raunaq; Feng, Xiaohua

Recently, the design concept of magnetic resonant coupling has been adapted to electromagnetic therapy applications such as non-invasive radiofrequency (RF) stimulation. This technique can significantly increase the electric field radiated from the magnetic coil at the stimulation target, and hence enhancing the current flowing through the nerve, thus enabling stimulation. In this paper, the developed magnetic resonant coupling (MRC) stimulation, magnetic stimulation (MS) and transcutaneous electrical nerve stimulation (TENS) are compared. The differences between the MRC RF stimulation and other techniques are presented in terms of the operating mechanism, ex-vivo tissue voltage measurement and electromagnetic simulation analysis. The ev-vivo tissuemore » voltage measurement experiment is performed on the compared devices based on measuring the voltage induced by electromagnetic induction at the tissue. The focusing effect, E field and voltage induced across the tissue, and the attenuation due to the increase of separation between the coil and the target are analyzed. The electromagnetic stimulation will also be performed to obtain the electric field and magnetic field distribution around the biological medium. The electric field intensity is proportional to the induced current and the magnetic field is corresponding to the electromagnetic induction across the biological medium. The comparison between the MRC RF stimulator and the MS and TENS devices revealed that the MRC RF stimulator has several advantages over the others for the applications of inducing current in the biological medium for stimulation purposes.« less

Shoulder Functional Electrical Stimulation During Wheelchair Propulsion in Spinal Cord Injury Subjects.

PubMed

Freixes, Orestes; Fernandez, Sergio Anibal; Gatti, Marcelo Andres; Crespo, Marcos Jose; Olmos, Lisandro Emilio; Russo, Maria Julieta

2017-01-01

Background: Subjects with spinal cord injury (SCI) propel their wheelchairs by generating a different level of muscle activity given their multiple deficits in muscle strength. Exercise training programs seem to be effective in improving wheelchair propulsion capacity. Functional electrical stimulation (FES) therapy is a complementary tool for rehabilitation programs. Objectives : To determine the accuracy of the synchronization between the FES activation and the push phase of the propulsion cycle by using hand pressure sensors that allow anterior deltoids activation when the hand is in contact with the pushrim. Methods: We analyzed 2 subjects, with injuries at C6 American Spinal Injury Association Impairment Scale (AIS) A and T12 AIS A. The stimulation parameters were set for a 30 Hz frequency symmetrical biphasic wave, 300 μs pulse width. Data were collected as participants propelled the wheelchair over a 10-m section of smooth, level vinyl floor. Subjects were evaluated in a motion analysis laboratory (ELITE; BTS, Milan, Italy). Results: Subject 1 showed synchronization between the FES activation and the push phase of 87.5% in the left hand and of 80% in the right hand. Subject 2 showed synchronization of 95.1% in the left and of hand 94.9% in the right hand. Conclusion : Our study determined a high accuracy of a novel FES therapeutic option, showing the synchronization between the electrical stimulation and the push phase of the propulsion cycle.

Burst Stimulation Improves Hemodynamics During Resuscitation after Prolonged Ventricular Fibrillation

PubMed Central

Walcott, Gregory; Melnick, Sharon; Killingsworth, Cheryl; Ideker, Raymond

2009-01-01

Background Although return of spontaneous circulation (ROSC) is frequently achieved during resuscitation for sudden cardiac arrest, systolic blood pressure can then decrease, requiring additional myocardial support. Previous studies have shown that a series of 1-ms electrical pulses delivered through the defibrillation patches during ventricular fibrillation (VF) can stimulate the autonomic nervous system to increase myocardial function following defibrillation. We hypothesized that a similar series of electrical pulses could increase myocardial function and blood pressure during the early post-resuscitation period. Methods and Results Six swine were studied that underwent 6–7 min. Each animal received 5, 10, 15, or 20 pulse packets consisting of 6 10 A, 1-ms pulses every 3–4 s in random order whenever systolic blood pressure became less than 50 mmHg. All four sets of pulse packets were delivered to each animal. Systolic blood pressure and cardiac function (left ventricular +dP/dt) were increased to pre-stimulation levels or above by all four sets of pulse packets. The increases were significantly greater for the longer than the shorter number of pulse packets. The mean±SD duration of the time that the systolic pressure remained above 50 mmHg following pulse delivery was 4.2±2.5 min. Conclusions Electrical stimulation during regular rhythm following prolonged VF and resuscitation can increase blood pressure and cardiac function to above pre-arrest levels. PMID:19655042

Motor evoked potential monitoring of the vagus nerve with transcranial electrical stimulation during skull base surgeries.

PubMed

Ito, Eiji; Ichikawa, Masahiro; Itakura, Takeshi; Ando, Hitoshi; Matsumoto, Yuka; Oda, Keiko; Sato, Taku; Watanabe, Tadashi; Sakuma, Jun; Saito, Kiyoshi

2013-01-01

Dysphasia is one of the most serious complications of skull base surgeries and results from damage to the brainstem and/or cranial nerves involved in swallowing. Here, the authors propose a method to monitor the function of the vagus nerve using endotracheal tube surface electrodes and transcranial electrical stimulation during skull base surgeries. Fifteen patients with skull base or brainstem tumors were enrolled. The authors used surface electrodes of an endotracheal tube to record compound electromyographic responses from the vocalis muscle. Motor neurons were stimulated using corkscrew electrodes placed subdermally on the scalp at C3 and C4. During surgery, the operator received a warning when the amplitude of the vagal motor evoked potential (MEP) decreased to less than 50% of the control level. After surgery, swallowing function was assessed clinically using grading criteria. In 5 patients, vagal MEP amplitude permanently deteriorated to less than 50% of the control level on the right side when meningiomas were dissected from the pons or basilar artery, or when a schwannoma was dissected from the vagal rootlets. These 5 patients had postoperative dysphagia. At 4 weeks after surgery, 2 patients still had dysphagia. In 2 patients, vagal MEPs of one side transiently disappeared when the tumors were dissected from the brainstem or the vagal rootlets. After surgery, both patients had dysphagia, which recovered in 4 weeks. In 7 patients, MEP amplitude was consistent, maintaining more than 50% of the control level throughout the operative procedures. After surgery all 7 patients were neurologically intact with normal swallowing function. Vagal MEP monitoring with transcranial electrical stimulation and endotracheal tube electrode recording was a safe and effective method to provide continuous real-time information on the integrity of both the supranuclear and infranuclear vagal pathway. This method is useful to prevent intraoperative injury of the brainstem corticobulbar tract or the vagal rootlets and to avoid the postoperative dysphagia that is often associated with brainstem or skull base surgeries.

Contralaterally Controlled Functional Electrical Stimulation Improves Hand Dexterity in Chronic Hemiparesis: A Randomized Trial

PubMed Central

Knutson, Jayme S.; Gunzler, Douglas D.; Wilson, Richard D.; Chae, John

2016-01-01

Background and Purpose It is unknown whether one method of neuromuscular stimulation for post-stroke upper limb rehabilitation is more effective than another. Our aim was to compare the effects of contralaterally controlled functional electrical stimulation (CCFES) to cyclic neuromuscular electrical stimulation (cNMES). Methods Stroke patients with chronic (> 6 months) moderate to severe upper extremity hemiparesis (n=80) were randomized to receive 10 sessions/week of CCFES- or cNMES-assisted hand opening exercise at home plus 20 sessions of functional task practice in the lab over 12 weeks. The task practice for the CCFES group was stimulation-assisted. The primary outcome was change in Box and Blocks Test (BBT) score at 6-months post-treatment. Upper extremity Fugl-Meyer (UEFM) and Arm Motor Abilities Test (AMAT) were also measured. Results At 6-months post-treatment, the CCFES group had greater improvement on the BBT, 4.6 (95% CI: 2.2, 7.0), than the cNMES group, 1.8 (95% CI: 0.6, 3.0); between-group difference, 2.8 (95% CI: 0.1, 5.5), p=0.045. No significant between-group difference was found for the UEFM (p=.888) or AMAT (p=.096). Participants who had the largest improvements on BBT were less than two years post-stroke with moderate (i.e., not severe) hand impairment at baseline. Among these, the 6-month post-treatment BBT gains of the CCFES group, 9.6 (95% CI: 5.6, 13.6), were greater than those of the cNMES group, 4.1 (95% CI: 1.7, 6.5); between-group difference, 5.5 (95% CI: 0.8, 10.2), p=0.023. Conclusions CCFES improved hand dexterity more than cNMES in chronic stroke survivors. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00891319. PMID:27608819

Electrical Heart Defibrillation with Ion Channel Blockers

NASA Astrophysics Data System (ADS)

Feeney, Erin; Clark, Courtney; Puwal, Steffan

Heart disease is the leading cause of mortality in the United States. Rotary electrical waves within heart muscle underlie electrical disorders of the heart termed fibrillation; their propagation and breakup leads to a complex distribution of electrical activation of the tissue (and of the ensuing mechanical contraction that comes from electrical activation). Successful heart defibrillation has, thus far, been limited to delivering large electrical shocks to activate the entire heart and reset its electrical activity. In theory, defibrillation of a system this nonlinear should be possible with small electrical perturbations (stimulations). A successful algorithm for such a low-energy defibrillator continues to elude researchers. We propose to examine in silica whether low-energy electrical stimulations can be combined with antiarrhythmic, ion channel-blocking drugs to achieve a higher rate of defibrillation and whether the antiarrhythmic drugs should be delivered before or after electrical stimulation has commenced. Progress toward a more successful, low-energy defibrillator will greatly minimize the adverse effects noted in defibrillation and will assist in the development of pediatric defibrillators.

Neuron matters: electric activation of neuronal tissue is dependent on the interaction between the neuron and the electric field.

PubMed

Ye, Hui; Steiger, Amanda

2015-08-12

In laboratory research and clinical practice, externally-applied electric fields have been widely used to control neuronal activity. It is generally accepted that neuronal excitability is controlled by electric current that depolarizes or hyperpolarizes the excitable cell membrane. What determines the amount of polarization? Research on the mechanisms of electric stimulation focus on the optimal control of the field properties (frequency, amplitude, and direction of the electric currents) to improve stimulation outcomes. Emerging evidence from modeling and experimental studies support the existence of interactions between the targeted neurons and the externally-applied electric fields. With cell-field interaction, we suggest a two-way process. When a neuron is positioned inside an electric field, the electric field will induce a change in the resting membrane potential by superimposing an electrically-induced transmembrane potential (ITP). At the same time, the electric field can be perturbed and re-distributed by the cell. This cell-field interaction may play a significant role in the overall effects of stimulation. The redistributed field can cause secondary effects to neighboring cells by altering their geometrical pattern and amount of membrane polarization. Neurons excited by the externally-applied electric field can also affect neighboring cells by ephaptic interaction. Both aspects of the cell-field interaction depend on the biophysical properties of the neuronal tissue, including geometric (i.e., size, shape, orientation to the field) and electric (i.e., conductivity and dielectricity) attributes of the cells. The biophysical basis of the cell-field interaction can be explained by the electromagnetism theory. Further experimental and simulation studies on electric stimulation of neuronal tissue should consider the prospect of a cell-field interaction, and a better understanding of tissue inhomogeneity and anisotropy is needed to fully appreciate the neural basis of cell-field interaction as well as the biological effects of electric stimulation.

Electric fields in hippocampus due to transcranial focal electrical stimulation via concentric ring electrodes.

PubMed

Besio, Walter G; Hadidi, Ruba; Makeyev, Oleksandr; Luna-Munguía, Hiram; Rocha, Luisa

2011-01-01

As epilepsy affects approximately one percent of the world population, electrical stimulation of brain has recently shown potential as an additive seizure control therapy. In this study we applied focal transcranial electrical stimulation (TFS) on the surface of the skull of rats via concentric ring electrodes. We recorded electric potentials with a bipolar electrode consisting of two stainless steel wires implanted into the left ventral hippocampus. TFS current was gradually increased by 20% starting at 103 μA allowing us to assess the relationship between TFS current and both potentials recorded from the bipolar electrode and the resulting electric field. Generally, increases in TFS current resulted in increases in the electric field. This allows us to estimate what extra-cranial TFS current would be sufficient to cause the activation of neurons in the hippocampus.

Effects of coil characteristics for femoral nerve magnetic stimulation.

PubMed

Tomazin, Katja; Verges, Samuel; Decorte, Nicolas; Oulerich, Alain; Millet, Guillaume Y

2010-03-01

The aim of this study was to compare the efficiency of two coils used for femoral nerve magnetic stimulation and to compare them with electrical stimulation in inducing maximal response of the quadriceps. The mechanical and electromyographic (EMG) responses were dependent on the coil used. The 45-mm double coil showed greater efficiency to elicit a maximal quadriceps response, which was similar to electrical stimulation.

An Electrical Muscle Stimulation Suit for Increasing Blood Pressure

DTIC Science & Technology

2008-09-01

an exploratory way in about 100 trials. Maximal indi- vidual stimulation intensity was selected to give a solid, tetanic muscle contraction without...therapy and in muscle strength training in athletes. However, if the electrical stimulation is too intense, the result will be muscle contraction pain...Each subject was instructed to have the investigator lower the intensity or stop the stimulation if muscle contraction pain was experienced

9 CFR 307.7 - Safety requirements for electrical stimulating (EST) equipment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... beam sensors form the enclosure, the stimulating equipment shall be automatically shut off when the sensor signals are broken. (3) Mandatory Warning Devices and Signals. The following warning devices or.... (ii) An ANSI Z53.1-Color Code sign reading (a) “Danger Electrical Hazard” for stimulating voltage...

9 CFR 307.7 - Safety requirements for electrical stimulating (EST) equipment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... beam sensors form the enclosure, the stimulating equipment shall be automatically shut off when the sensor signals are broken. (3) Mandatory Warning Devices and Signals. The following warning devices or.... (ii) An ANSI Z53.1-Color Code sign reading (a) “Danger Electrical Hazard” for stimulating voltage...

Preliminary results of sacral transcutaneous electrical nerve stimulation for fecal incontinence.

PubMed

Leung, Edmund; Francombe, James

2013-03-01

Fecal incontinence is a common debilitating condition. The aim of this study is to investigate the feasibility of sacral transcutaneous electrical nerve stimulation as an alternative treatment modality for fecal incontinence. All consecutive patients who presented with fecal incontinence to the senior author's clinic were prospectively recruited between June 2009 and September 2010. The severity of their fecal incontinence was assessed by the Wexner and Vaizey scores and anal physiology. Any improvement following a period of sacral transcutaneous electrical nerve stimulation treatment was determined by repeating the scores. In addition, patient satisfaction with the procedure was assessed by using a patient impression score. Twenty female patients with a median age of 57.5 years (range, 30-86) were evaluated. The median follow-up was 10 months (range, 5-12 months). Two patients did not record a change in their Vaizey score. The overall mean Wexner score was 7.9 ± 4.2 before in comparison with 4.0 ± 3.1 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 2.2-5.7, SE = 0.832). The overall mean Vaizey score was 12.7 ± 5.7 before in comparison with 5.8 ± 5.6 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 4.5-9.4, SE = 1.162). The pretreatment patient impression score was set at a mean of 1 ± 0 in comparison with 2.8 ± 1.1 after sacral transcutaneous electrical nerve stimulation treatment (p < 0.0001, CI = 1.2-2.3, SE = 0.25). The preliminary results suggest sacral transcutaneous electrical nerve stimulation is a promising noninvasive alternative to existing modalities in the treatment of idiopathic fecal incontinence.

Randomized clinical trial of transcutaneous electrical posterior tibial nerve stimulation versus lateral internal sphincterotomy for treatment of chronic anal fissure.

PubMed

Youssef, Tamer; Youssef, Mohamed; Thabet, Waleed; Lotfy, Ahmed; Shaat, Reham; Abd-Elrazek, Eman; Farid, Mohamed

2015-10-01

The objective of this study was to evaluate the efficacy of transcutaneous electrical posterior tibial nerve stimulation in treatment of patients with chronic anal fissure and to compare it with the conventional lateral internal sphincterotomy. Consecutive patients with chronic anal fissure were randomly allocated into two treatment groups: transcutaneous electrical posterior tibial nerve stimulation group and lateral internal sphincterotomy group. The primary outcome measures were number of patients with clinical improvement and healed fissure. Secondary outcome measures were complications, VAS pain scores, Wexner's constipation and Peascatori anal incontinence scores, anorectal manometry, and quality of life index. Seventy-three patients were randomized into two groups of 36 patients who were subjected to transcutaneous electrical nerve stimulation and 37 patients who underwent lateral internal sphincterotomy. All (100%) patients in lateral internal sphincterotomy group had clinical improvement at one month following the procedure in contrast to 27 (75%) patients in transcutaneous electrical nerve stimulation group. Recurrence of anal fissure after one year was reported in one (2.7%) and 11 (40.7%) patients in lateral internal sphincterotomy and transcutaneous electrical nerve stimulation groups respectively. Resting anal pressure and functional anal canal length were significantly reduced after lateral internal sphincterotomy. Transcutaneous electrical posterior tibial nerve stimulation for treatment of chronic anal fissure is a novel, non-invasive procedure and has no complications. However, given the higher rate of clinical improvement and fissure healing and the lower rate of fissure recurrence, lateral internal sphincterotomy remains the gold standard for treating chronic anal fissure. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Full-movement neuromuscular electrical stimulation improves plantar flexor spasticity and ankle active dorsiflexion in stroke patients: a randomized controlled study.

PubMed

Wang, Yong-Hui; Meng, Fei; Zhang, Yang; Xu, Mao-Yu; Yue, Shou-Wei

2016-06-01

To investigate whether full-movement neuromuscular electrical stimulation, which can generate full range of movement, reduces spasticity and/or improves motor function more effectively than control, sensory threshold-neuromuscular electrical stimulation, and motor threshold-neuromuscular electrical stimulation in sub-acute stroke patients. A randomized, single-blind, controlled study. Physical therapy room and functional assessment room. A total of 72 adult patients with sub-acute post-stroke hemiplegia and plantar flexor spasticity. Patients received 30-minute sessions of neuromuscular electrical stimulation on the motor points of the extensor hallucis and digitorum longus twice a day, five days per week for four weeks. Composite Spasticity Scale, Ankle Active Dorsiflexion Score, and walking time in the Timed Up and Go Test were assessed at pretreatment, posttreatment, and at two-week follow-up. After four weeks of treatment, when comparing interclass pretreatment and posttreatment, only the full-movement neuromuscular electrical stimulation group had a significant reduction in the Composite Spasticity Scale (mean % reduction = 19.91(4.96)%, F = 3.878, p < 0.05) and improvement in the Ankle Active Dorsiflexion Score (mean scores = 3.29(0.91), F = 3.140, p < 0.05). Furthermore, these improvements were maintained two weeks after the treatment ended. However, there were no significant differences in the walking time after four weeks of treatment among the four groups (F = 1.861, p > 0.05). Full-movement neuromuscular electrical stimulation with a stimulus intensity capable of generating full movement can significantly reduce plantar flexor spasticity and improve ankle active dorsiflexion, but cannot decrease walking time in the Timed Up and Go Test in sub-acute stroke patients. © The Author(s) 2015.

Electrotonic and action potentials in the Venus flytrap.

PubMed

Volkov, Alexander G; Vilfranc, Chrystelle L; Murphy, Veronica A; Mitchell, Colee M; Volkova, Maia I; O'Neal, Lawrence; Markin, Vladislav S

2013-06-15

The electrical phenomena and morphing structures in the Venus flytrap have attracted researchers since the nineteenth century. We have observed that mechanical stimulation of trigger hairs on the lobes of the Venus flytrap induces electrotonic potentials in the lower leaf. Electrostimulation of electrical circuits in the Venus flytrap can induce electrotonic potentials propagating along the upper and lower leaves. The instantaneous increase or decrease in voltage of stimulating potential generates a nonlinear electrical response in plant tissues. Any electrostimulation that is not instantaneous, such as sinusoidal or triangular functions, results in linear responses in the form of small electrotonic potentials. The amplitude and sign of electrotonic potentials depend on the polarity and the amplitude of the applied voltage. Electrical stimulation of the lower leaf induces electrical signals, which resemble action potentials, in the trap between the lobes and the midrib. The trap closes if the stimulating voltage is above the threshold level of 4.4V. Electrical responses in the Venus flytrap were analyzed and reproduced in the discrete electrical circuit. The information gained from this study can be used to elucidate the coupling of intracellular and intercellular communications in the form of electrical signals within plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

Equilibrium-point control of human elbow-joint movement under isometric environment by using multichannel functional electrical stimulation

PubMed Central

Matsui, Kazuhiro; Hishii, Yasuo; Maegaki, Kazuya; Yamashita, Yuto; Uemura, Mitsunori; Hirai, Hiroaki; Miyazaki, Fumio

2014-01-01

Functional electrical stimulation (FES) is considered an effective technique for aiding quadriplegic persons. However, the human musculoskeletal system has highly non-linearity and redundancy. It is thus difficult to stably and accurately control limbs using FES. In this paper, we propose a simple FES method that is consistent with the motion-control mechanism observed in humans. We focus on joint motion by a pair of agonist-antagonist muscles of the musculoskeletal system, and define the “electrical agonist-antagonist muscle ratio (EAA ratio)” and “electrical agonist-antagonist muscle activity (EAA activity)” in light of the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, respectively, to extract the equilibrium point and joint stiffness from electromyography (EMG) signals. These notions, the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, are based on the hypothesis that the equilibrium point and stiffness of the agonist-antagonist motion system are controlled by the central nervous system. We derived the transfer function between the input EAA ratio and force output of the end-point. We performed some experiments in an isometric environment using six subjects. This transfer-function model is expressed as a cascade-coupled dead time element and a second-order system. High-speed, high-precision, smooth control of the hand force were achieved through the agonist-antagonist muscle stimulation pattern determined by this transfer function model. PMID:24987326

Equilibrium-point control of human elbow-joint movement under isometric environment by using multichannel functional electrical stimulation.

PubMed

Matsui, Kazuhiro; Hishii, Yasuo; Maegaki, Kazuya; Yamashita, Yuto; Uemura, Mitsunori; Hirai, Hiroaki; Miyazaki, Fumio

2014-01-01

Functional electrical stimulation (FES) is considered an effective technique for aiding quadriplegic persons. However, the human musculoskeletal system has highly non-linearity and redundancy. It is thus difficult to stably and accurately control limbs using FES. In this paper, we propose a simple FES method that is consistent with the motion-control mechanism observed in humans. We focus on joint motion by a pair of agonist-antagonist muscles of the musculoskeletal system, and define the "electrical agonist-antagonist muscle ratio (EAA ratio)" and "electrical agonist-antagonist muscle activity (EAA activity)" in light of the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, respectively, to extract the equilibrium point and joint stiffness from electromyography (EMG) signals. These notions, the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, are based on the hypothesis that the equilibrium point and stiffness of the agonist-antagonist motion system are controlled by the central nervous system. We derived the transfer function between the input EAA ratio and force output of the end-point. We performed some experiments in an isometric environment using six subjects. This transfer-function model is expressed as a cascade-coupled dead time element and a second-order system. High-speed, high-precision, smooth control of the hand force were achieved through the agonist-antagonist muscle stimulation pattern determined by this transfer function model.

3D modeling of the total electric field induced by transcranial magnetic stimulation using the boundary element method

NASA Astrophysics Data System (ADS)

Salinas, F. S.; Lancaster, J. L.; Fox, P. T.

2009-06-01

Transcranial magnetic stimulation (TMS) delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians with a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete analysis of the macroscopic electric fields produced by TMS has not yet been performed. In this paper, we addressed the importance of the secondary E-field created by surface charge accumulation during TMS using the boundary element method (BEM). 3D models were developed using simple head geometries in order to test the model and compare it with measured values. The effects of tissue geometry, size and conductivity were also investigated. Finally, a realistically shaped head model was used to assess the effect of multiple surfaces on the total E-field. Secondary E-fields have the greatest impact at areas in close proximity to each tissue layer. Throughout the head, the secondary E-field magnitudes typically range from 20% to 35% of the primary E-field's magnitude. The direction of the secondary E-field was generally in opposition to the primary E-field; however, for some locations, this was not the case (i.e. going from high to low conductivity tissues). These findings show that realistically shaped head geometries are important for accurate modeling of the total E-field.

Flight behavior of the rhinoceros beetle Trypoxylus dichotomus during electrical nerve stimulation.

PubMed

Van Truong, Tien; Byun, Doyoung; Lavine, Laura Corley; Emlen, Douglas J; Park, Hoon Cheol; Kim, Min Jun

2012-09-01

Neuronal stimulation is an intricate part of understanding insect flight behavior and control insect itself. In this study, we investigated the effects of electrical pulses applied to the brain and basalar muscle of the rhinoceros beetle (Trypoxylus dichotomus). To understand specific neuronal stimulation mechanisms, responses and flight behavior of the beetle, four electrodes were implanted into the two optic lobes, the brain's central complex and the ventral nerve cord in the posterior pronotum. We demonstrated flight initiation, turning and cessation by stimulating the brain. The change undergone by the wing flapping in response to the electrical signal was analyzed from a sequence of images captured by a high-speed camera. Here, we provide evidence to distinguish the important differences between neuronal and muscular flight stimulations in beetles. We found that in the neural potential stimulation, both the hind wing and the elytron were suppressed. Interestingly, the beetle stopped flying whenever a stimulus potential was applied between the pronotum and one side of the optic lobe, or between the ventral nerve cord in the posterior pronotum and the central complex. In-depth experimentation demonstrated the effective of neural stimulation over muscle stimulation for flight control. During electrical stimulation of the optic lobes, the beetle performed unstable flight, resulting in alternating left and right turns. By applying the electrical signal into both the optic lobes and the central complex of the brain, we could precisely control the direction of the beetle flight. This work provides an insight into insect flight behavior for future development of insect-micro air vehicle.

A functional electrical stimulation system for human walking inspired by reflexive control principles.

PubMed

Meng, Lin; Porr, Bernd; Macleod, Catherine A; Gollee, Henrik

2017-04-01

This study presents an innovative multichannel functional electrical stimulation gait-assist system which employs a well-established purely reflexive control algorithm, previously tested in a series of bipedal walking robots. In these robots, ground contact information was used to activate motors in the legs, generating a gait cycle similar to that of humans. Rather than developing a sophisticated closed-loop functional electrical stimulation control strategy for stepping, we have instead utilised our simple reflexive model where muscle activation is induced through transfer functions which translate sensory signals, predominantly ground contact information, into motor actions. The functionality of the functional electrical stimulation system was tested by analysis of the gait function of seven healthy volunteers during functional electrical stimulation-assisted treadmill walking compared to unassisted walking. The results demonstrated that the system was successful in synchronising muscle activation throughout the gait cycle and was able to promote functional hip and ankle movements. Overall, the study demonstrates the potential of human-inspired robotic systems in the design of assistive devices for bipedal walking.

Quadruple Cone Coil with improved focality than Figure-8 coil in Transcranial Magnetic Stimulation

NASA Astrophysics Data System (ADS)

Rastogi, Priyam; Lee, Erik G.; Hadimani, Ravi L.; Jiles, David C.

Transcranial Magnetic Stimulation (TMS) is a non-invasive therapy which uses a time varying magnetic field to induce an electric field in the brain and to cause neuron depolarization. Magnetic coils play an important role in the TMS therapy since their coil geometry determines the focality and penetration's depth of the induced electric field in the brain. Quadruple Cone Coil (QCC) is a novel coil with an improved focality when compared to commercial Figure-8 coil. The results of this newly designed QCC coil are compared with the Figure-8 coil at two different positions of the head - vertex and dorsolateral prefrontal cortex, over the 50 anatomically realistic MRI derived head models. Parameters such as volume of stimulation, maximum electric, area of stimulation and location of maximum electric field are determined with the help of computer modelling of both coils. There is a decrease in volume of brain stimulated by 11.6 % and a modest improvement of 8 % in the location of maximum electric field due to QCC in comparison to the Figure-8 coil. The Carver Charitable Trust and The Galloway Foundation.

Electrical stimulation of acupoint combinations against deep venous thrombosis in elderly bedridden patients after major surgery.

PubMed

Hou, Lili; Chen, Cuiping; Xu, Lei; Yin, Peihao; Peng, Wen

2013-04-01

To compare the effects of electrical stimulation of different acupoint combinations among postoperative bedridden elderly patients on hemorheology and deep venous blood flow velocity and investigate the.role of electrical stimulation against deep vein thrombosis (DVT). From November 2010 to October 2011, a total of 160 elderly bedridden patients after major surgery were divided into the conventional care group, invigorating and promoting Qi group, blood-activating and damp-eliminating group, and acupoint-combination stimulation group. Whole blood viscosity, plasma viscosity, D-dimer levels, lower limb skin temperature, lower limb circumference, and flow velocities of the external iliac vein, femoral vein, popliteal vein, and deep calf veins in all patients were documented and compared among the four groups. Whole blood viscosity, plasma viscosity, D-dimer levels, and lower limb circumference were significantly reduced in the blood-activating and damp-eliminating group compared with the conventional care group (P < 0.05) and were almost equal to those in the acupoint-combination stimulation group (P > 0.05). Lower limb venous flow velocities were accelerated in the invigorating and promoting Qi group compared with the other groups, excluding the acupoint-combination stimulation group (P < 0.05). Hemorheological indices in postoperative bedridden elderly patients were improved after combined electrical stimulation at Yinlingquan (SP 9) and Sanyinjiao (SP 6). Combined electrical stimulation at Zusanli (ST 36) and Taichong (LR 3), on the other hand, accelerated lower limb venous flow.

Communication calls produced by electrical stimulation of four structures in the guinea pig brain

PubMed Central

Green, David B.; Shackleton, Trevor M.; Grimsley, Jasmine M. S.; Zobay, Oliver; Palmer, Alan R.

2018-01-01

One of the main central processes affecting the cortical representation of conspecific vocalizations is the collateral output from the extended motor system for call generation. Before starting to study this interaction we sought to compare the characteristics of calls produced by stimulating four different parts of the brain in guinea pigs (Cavia porcellus). By using anaesthetised animals we were able to reposition electrodes without distressing the animals. Trains of 100 electrical pulses were used to stimulate the midbrain periaqueductal grey (PAG), hypothalamus, amygdala, and anterior cingulate cortex (ACC). Each structure produced a similar range of calls, but in significantly different proportions. Two of the spontaneous calls (chirrup and purr) were never produced by electrical stimulation and although we identified versions of chutter, durr and tooth chatter, they differed significantly from our natural call templates. However, we were routinely able to elicit seven other identifiable calls. All seven calls were produced both during the 1.6 s period of stimulation and subsequently in a period which could last for more than a minute. A single stimulation site could produce four or five different calls, but the amygdala was much less likely to produce a scream, whistle or rising whistle than any of the other structures. These three high-frequency calls were more likely to be produced by females than males. There were also differences in the timing of the call production with the amygdala primarily producing calls during the electrical stimulation and the hypothalamus mainly producing calls after the electrical stimulation. For all four structures a significantly higher stimulation current was required in males than females. We conclude that all four structures can be stimulated to produce fictive vocalizations that should be useful in studying the relationship between the vocal motor system and cortical sensory representation. PMID:29584746

Communication calls produced by electrical stimulation of four structures in the guinea pig brain.

PubMed

Green, David B; Shackleton, Trevor M; Grimsley, Jasmine M S; Zobay, Oliver; Palmer, Alan R; Wallace, Mark N

2018-01-01

One of the main central processes affecting the cortical representation of conspecific vocalizations is the collateral output from the extended motor system for call generation. Before starting to study this interaction we sought to compare the characteristics of calls produced by stimulating four different parts of the brain in guinea pigs (Cavia porcellus). By using anaesthetised animals we were able to reposition electrodes without distressing the animals. Trains of 100 electrical pulses were used to stimulate the midbrain periaqueductal grey (PAG), hypothalamus, amygdala, and anterior cingulate cortex (ACC). Each structure produced a similar range of calls, but in significantly different proportions. Two of the spontaneous calls (chirrup and purr) were never produced by electrical stimulation and although we identified versions of chutter, durr and tooth chatter, they differed significantly from our natural call templates. However, we were routinely able to elicit seven other identifiable calls. All seven calls were produced both during the 1.6 s period of stimulation and subsequently in a period which could last for more than a minute. A single stimulation site could produce four or five different calls, but the amygdala was much less likely to produce a scream, whistle or rising whistle than any of the other structures. These three high-frequency calls were more likely to be produced by females than males. There were also differences in the timing of the call production with the amygdala primarily producing calls during the electrical stimulation and the hypothalamus mainly producing calls after the electrical stimulation. For all four structures a significantly higher stimulation current was required in males than females. We conclude that all four structures can be stimulated to produce fictive vocalizations that should be useful in studying the relationship between the vocal motor system and cortical sensory representation.

A new brain stimulation method: Noninvasive transcranial magneto-acoustical stimulation

NASA Astrophysics Data System (ADS)

Yuan, Yi; Chen, Yu-Dong; Li, Xiao-Li

2016-08-01

We investigate transcranial magneto-acoustical stimulation (TMAS) for noninvasive brain neuromodulation in vivo. TMAS as a novel technique uses an ultrasound wave to induce an electric current in the brain tissue in the static magnetic field. It has the advantage of high spatial resolution and penetration depth. The mechanism of TMAS onto a neuron is analyzed by combining the TMAS principle and Hodgkin-Huxley neuron model. The anesthetized rats are stimulated by TMAS, resulting in the local field potentials which are recorded and analyzed. The simulation results show that TMAS can induce neuronal action potential. The experimental results indicate that TMAS can not only increase the amplitude of local field potentials but also enhance the effect of focused ultrasound stimulation on the neuromodulation. In summary, TMAS can accomplish brain neuromodulation, suggesting a potentially powerful noninvasive stimulation method to interfere with brain rhythms for diagnostic and therapeutic purposes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503321 and 61273063) and the Natural Science Foundation of Hebei Province, China (Grant No. F2014203161).

A wireless wearable surface functional electrical stimulator

NASA Astrophysics Data System (ADS)

Wang, Hai-Peng; Guo, Ai-Wen; Zhou, Yu-Xuan; Xia, Yang; Huang, Jia; Xu, Chong-Yao; Huang, Zong-Hao; Lü, Xiao-Ying; Wang, Zhi-Gong

2017-09-01

In this paper, a wireless wearable functional electrical stimulator controlled by Android phone with real-time-varying stimulation parameters for multichannel surface functional electrical stimulation application has been developed. It can help post-stroke patients using more conveniently. This study focuses on the prototype design, including the specific wristband concept, circuits and stimulation pulse-generation algorithm. A novel stimulator circuit with a driving stage using a complementary current source technique is proposed to achieve a high-voltage compliance, a large output impedance and an accurate linear voltage-to-current conversion. The size of the prototype has been significantly decreased to 17 × 7.5 × 1 cm3. The performance of the prototype has been tested with a loaded resistor and wrist extension/flexion movement of three hemiplegic patients. According to the experiments, the stimulator can generate four-channel charge-balanced biphasic stimulation with a voltage amplitude up to 60 V, and the pulse frequency and width can be adjusted in real time with a range of 100-600 μs and 20-80 Hz, respectively.

Modulation of bicarbonate secretion in rabbit duodenum: the role of calcium.

PubMed

Hogan, D L; Yao, B; Isenberg, J I

1998-01-01

Surface epithelial bicarbonate secretion protects the proximal duodenum from acid peptic injury. Cyclic adenosine monophosphate and calcium serve as intracellular mediators of intestinal transport. Experiments were performed to examine whether calcium participates in duodenal bicarbonate transport. Stripped duodenal mucosa from rabbits was studied in Ussing chambers. HCO3- transport was stimulated by the calcium ionophore A23187, carbachol, vasoactive intestinal peptide, prostaglandin E2, dibutyryl-cyclic adenosine monophosphate, and electrical field stimulation. A23187 stimulated HCO3- secretion and Isc; tetrodotoxin failed to inhibit this effect. The calcium-channel blocker verapamil abolished HCO3- secretion stimulated by carbachol, vasoactive intestinal peptide, and electrical field stimulation, but failed to alter basal, prostaglandin E2- or dibutyryl-cyclic adenosine monophosphate-stimulated HCO3- secretion. Therefore, calcium is likely required during stimulation of duodenal epithelial HCO3- transport by carbachol, vasoactive intestinal peptide, and electrical field stimulation. Prostaglandin E2 and dibutyryl-cyclic adenosine monophosphate appear to activate duodenal HCO3- secretion by a calcium-independent pathway(s).

Multi-channel orbicularis oculi stimulation to restore eye-blink function in facial paralysis.

PubMed

Somia, N N; Zonnevijlle, E D; Stremel, R W; Maldonado, C; Gossman, M D; Barker, J H

2001-01-01

Facial paralysis due to facial nerve injury results in the loss of function of the muscles of the hemiface. The most serious complication in extreme cases is the loss of vision. In this study, we compared the effectiveness of single- and multiple-channel electrical stimulation to restore a complete and cosmetically acceptable eye blink. We established bilateral orbicularis oculi muscle (OOM) paralysis in eight dogs; the OOM of one side was directly stimulated using single-channel electrical stimulation and the opposite side was stimulated using multi-channel electrical stimulation. The changes in the palpebral fissure and complete palpebral closure were measured. The difference in current intensities between the multi-channel and single-channel simulation groups was significant, while only multi-channel stimulation produced complete eyelid closure. The latest electronic stimulation circuitry with high-quality implantable electrodes will make it possible to regulate precisely OOM contractions and thus generate complete and cosmetically acceptable eye-blink motion in patients with facial paralysis. Copyright 2001 Wiley-Liss, Inc.

[Functional electric stimulation (FES) in cerebral palsy].

PubMed

Miyazaki, M H; Lourenção, M I; Ribeiro Sobrinho, J B; Battistella, L R

1992-01-01

Our study concerns a patient with cerebral palsy, submitted to conventional occupational therapy and functional electrical stimulation. The results as to manual ability, spasticity, sensibility and synkinesis were satisfactory.

Experimental evaluation of electrical conductivity imaging of anisotropic brain tissues using a combination of diffusion tensor imaging and magnetic resonance electrical impedance tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sajib, Saurav Z. K.; Jeong, Woo Chul; Oh, Tong In

Anisotropy of biological tissues is a low-frequency phenomenon that is associated with the function and structure of cell membranes. Imaging of anisotropic conductivity has potential for the analysis of interactions between electromagnetic fields and biological systems, such as the prediction of current pathways in electrical stimulation therapy. To improve application to the clinical environment, precise approaches are required to understand the exact responses inside the human body subjected to the stimulated currents. In this study, we experimentally evaluate the anisotropic conductivity tensor distribution of canine brain tissues, using a recently developed diffusion tensor-magnetic resonance electrical impedance tomography method. At lowmore » frequency, electrical conductivity of the biological tissues can be expressed as a product of the mobility and concentration of ions in the extracellular space. From diffusion tensor images of the brain, we can obtain directional information on diffusive movements of water molecules, which correspond to the mobility of ions. The position dependent scale factor, which provides information on ion concentration, was successfully calculated from the magnetic flux density, to obtain the equivalent conductivity tensor. By combining the information from both techniques, we can finally reconstruct the anisotropic conductivity tensor images of brain tissues. The reconstructed conductivity images better demonstrate the enhanced signal intensity in strongly anisotropic brain regions, compared with those resulting from previous methods using a global scale factor.« less

Transcranial magnetic stimulation in the semi-quantitative, pre-operative assessment of patients undergoing spinal deformity surgery.

PubMed

Glasby, Michael A; Tsirikos, Athanasios I; Henderson, Lindsay; Horsburgh, Gillian; Jordan, Brian; Michaelson, Ciara; Adams, Christopher I; Garrido, Enrique

2017-08-01

To compare measurements of motor evoked potential latency stimulated either magnetically (mMEP) or electrically (eMEP) and central motor conduction time (CMCT) made pre-operatively in conscious patients using transcranial and intra-operatively using electrical cortical stimulation before and after successful instrumentation for the treatment of adolescent idiopathic scoliosis. A group initially of 51 patients with adolescent idiopathic scoliosis aged 12-19 years was evaluated pre-operatively in the outpatients' department with transcranial magnetic stimulation. The neurophysiological data were then compared statistically with intra-operative responses elicited by transcranial electrical stimulation both before and after successful surgical intervention. MEPs were measured as the cortically evoked compound action potentials of Abductor hallucis. Minimum F-waves were measured using conventional nerve conduction methods and the lower motor neuron conduction time was calculated and this was subtracted from MEP latency to give CMCT. Pre-operative testing was well tolerated in our paediatric/adolescent patients. No neurological injury occurred in any patient in this series. There was no significant difference in the values of mMEP and eMEP latencies seen pre-operatively in conscious patients and intra-operatively in patients under anaesthetic. The calculated quantities mCMCT and eCMCT showed the same statistical correlations as the quantities mMEP and eMEP latency. The congruency of mMEP and eMEP and of mCMCT and eCMCT suggests that these measurements may be used comparatively and semi-quantitatively for the comparison of pre-, intra-, and post-operative spinal cord function in spinal deformity surgery.

Gender effect on discrimination of location and frequency in surface electrical stimulation.

PubMed

Geng, Bo; Paramanathan, Senthoopiya A; Pedersen, Karina F; Lauridsen, Mette V; Gade, Julie; Lontis, Romulus; Jensen, Winnie

2015-01-01

This work investigated the gender effect on discrimination of surface electrical stimulation applied on the human forearm. Three experiments were conducted to examine the abilty of discriminating stimulation frequency, location, or both parameters in 14 healthy subjects. The results indicated a statistically significant impact of gender on the discrimination performance in all the three experiments (p <; 0.01, p <; 0.01, and p <; 0.001, respectively). The female group performed noticeably better than the male group (i.e., mean difference 15.4%, 11.9%, and 16.7% in repective experiment). The findings may provide evidence of gender difference in perceiving and interpreting electrical stimulation. Considering the gender difference may improve the efficacy of electrically evoked sensory feedback in applications such as prosthetic use and pain relief.

The Electrical Response to Injury: Molecular Mechanisms and Wound Healing

PubMed Central

Reid, Brian; Zhao, Min

2014-01-01

Significance: Natural, endogenous electric fields (EFs) and currents arise spontaneously after wounding of many tissues, especially epithelia, and are necessary for normal healing. This wound electrical activity is a long-lasting and regulated response. Enhancing or inhibiting this electrical activity increases or decreases wound healing, respectively. Cells that are responsible for wound closure such as corneal epithelial cells or skin keratinocytes migrate directionally in EFs of physiological magnitude. However, the mechanisms of how the wound electrical response is initiated and regulated remain unclear. Recent Advances: Wound EFs and currents appear to arise by ion channel up-regulation and redistribution, which are perhaps triggered by an intracellular calcium wave or cell depolarization. We discuss the possibility of stimulation of wound healing via pharmacological enhancement of the wound electric signal by stimulation of ion pumping. Critical Issues: Chronic wounds are a major problem in the elderly and diabetic patient. Any strategy to stimulate wound healing in these patients is desirable. Applying electrical stimulation directly is problematic, but pharmacological enhancement of the wound signal may be a promising strategy. Future Directions: Understanding the molecular regulation of wound electric signals may reveal some fundamental mechanisms in wound healing. Manipulating fluxes of ions and electric currents at wounds might offer new approaches to achieve better wound healing and to heal chronic wounds. PMID:24761358

Analysis of induced electrical currents from magnetic field coupling inside implantable neurostimulator leads

PubMed Central

2011-01-01

Background Over the last decade, the number of neurostimulator systems implanted in patients has been rapidly growing. Nearly 50, 000 neurostimulators are implanted worldwide annually. The most common type of implantable neurostimulators is indicated for pain relief. At the same time, commercial use of other electromagnetic technologies is expanding, making electromagnetic interference (EMI) of neurostimulator function an issue of concern. Typically reported sources of neurostimulator EMI include security systems, metal detectors and wireless equipment. When near such sources, patients with implanted neurostimulators have reported adverse events such as shock, pain, and increased stimulation. In recent in vitro studies, radio frequency identification (RFID) technology has been shown to inhibit the stimulation pulse of an implantable neurostimulator system during low frequency exposure at close distances. This could potentially be due to induced electrical currents inside the implantable neurostimulator leads that are caused by magnetic field coupling from the low frequency identification system. Methods To systematically address the concerns posed by EMI, we developed a test platform to assess the interference from coupled magnetic fields on implantable neurostimulator systems. To measure interference, we recorded the output of one implantable neurostimulator, programmed for best therapy threshold settings, when in close proximity to an operating low frequency RFID emitter. The output contained electrical potentials from the neurostimulator system and those induced by EMI from the RFID emitter. We also recorded the output of the same neurostimulator system programmed for best therapy threshold settings without RFID interference. Using the Spatially Extended Nonlinear Node (SENN) model, we compared threshold factors of spinal cord fiber excitation for both recorded outputs. Results The electric current induced by low frequency RFID emitter was not significant to have a noticeable effect on electrical stimulation. Conclusions We demonstrated a method for analyzing effects of coupled magnetic field interference on implantable neurostimulator system and its electrodes which could be used by device manufacturers during the design and testing phases of the development process. PMID:22014169

Developing and Evaluating a Flexible Wireless Microcoil Array Based Integrated Interface for Epidural Cortical Stimulation.

PubMed

Wang, Xing; Chaudhry, Sharjeel A; Hou, Wensheng; Jia, Xiaofeng

2017-02-05

Stroke leads to serious long-term disability. Electrical epidural cortical stimulation has made significant improvements in stroke rehabilitation therapy. We developed a preliminary wireless implantable passive interface, which consists of a stimulating surface electrode, receiving coil, and single flexible passive demodulated circuit printed by flexible printed circuit (FPC) technique and output pulse voltage stimulus by inductively coupling an external circuit. The wireless implantable board was implanted in cats' unilateral epidural space for electrical stimulation of the primary visual cortex (V1) while the evoked responses were recorded on the contralateral V1 using a needle electrode. The wireless implantable board output stable monophasic voltage stimuli. The amplitude of the monophasic voltage output could be adjusted by controlling the voltage of the transmitter circuit within a range of 5-20 V. In acute experiment, cortico-cortical evoked potential (CCEP) response was recorded on the contralateral V1. The amplitude of N2 in CCEP was modulated by adjusting the stimulation intensity of the wireless interface. These results demonstrated that a wireless interface based on a microcoil array can offer a valuable tool for researchers to explore electrical stimulation in research and the dura mater-electrode interface can effectively transmit electrical stimulation.

Doping Effect of Graphene Nanoplatelets on Electrical Insulation Properties of Polyethylene: From Macroscopic to Molecular Scale

PubMed Central

Jing, Ziang; Li, Changming; Zhao, Hong; Zhang, Guiling; Han, Baozhong

2016-01-01

The doping effect of graphene nanoplatelets (GNPs) on electrical insulation properties of polyethylene (PE) was studied by combining experimental and theoretical methods. The electric conduction properties and trap characteristics were tested for pure PE and PE/GNPs composites by using a direct measurement method and a thermal stimulated current (TSC) method. It was found that doping smaller GNPs is more beneficial to decrease the conductivity of PE/GNPs. The PE/GNPs composite with smaller size GNPs mainly introduces deep energy traps, while with increasing GNPs size, besides deep energy traps, shallow energy traps are also introduced. These results were also confirmed by density functional theory (DFT) and the non-equilibrium Green’s function (NEGF) method calculations. Therefore, doping small size GNPs is favorable for trapping charge carriers and enhancing insulation ability, which is suggested as an effective strategy in exploring powerful insulation materials. PMID:28773802

Influence of transcutaneous electrical stimulation on heterotopic ossification: an experimental study in Wistar rats

PubMed Central

Zotz, T.G.G.; de Paula, J.B.

2015-01-01

Heterotopic ossification (HO) is a metaplastic biological process in which there is newly formed bone in soft tissues, resulting in joint mobility deficit and pain. Different treatment modalities have been tried to prevent HO development, but there is no consensus on a therapeutic approach. Since electrical stimulation is a widely used resource in physiotherapy practice to stimulate joint mobility, with analgesic and anti-inflammatory effects, its usefulness for HO treatment was investigated. We aimed to identify the influence of electrical stimulation on induced HO in Wistar rats. Thirty-six male rats (350-390 g) were used, and all animals were anesthetized for blood sampling before HO induction, to quantify the serum alkaline phosphatase. HO induction was performed by bone marrow implantation in both quadriceps of the animals, which were then divided into 3 groups: control (CG), transcutaneous electrical nerve stimulation (TENS) group (TG), and functional electrical stimulation (FES) group (FG) with 12 rats each. All animals were anesthetized and electrically stimulated twice per week, for 35 days from induction day. After this period, another blood sample was collected and quadriceps muscles were bilaterally removed for histological and calcium analysis and the rats were killed. Calcium levels in muscles showed significantly lower results when comparing TG and FG (P<0.001) and between TG and CG (P<0.001). Qualitative histological analyses confirmed 100% HO in FG and CG, while in TG the HO was detected in 54.5% of the animals. The effects of the muscle contractions caused by FES increased HO, while anti-inflammatory effects of TENS reduced HO. PMID:26292223

Conceptualization and validation of an open-source closed-loop deep brain stimulation system in rat.

PubMed

Wu, Hemmings; Ghekiere, Hartwin; Beeckmans, Dorien; Tambuyzer, Tim; van Kuyck, Kris; Aerts, Jean-Marie; Nuttin, Bart

2015-04-21

Conventional deep brain stimulation (DBS) applies constant electrical stimulation to specific brain regions to treat neurological disorders. Closed-loop DBS with real-time feedback is gaining attention in recent years, after proved more effective than conventional DBS in terms of pathological symptom control clinically. Here we demonstrate the conceptualization and validation of a closed-loop DBS system using open-source hardware. We used hippocampal theta oscillations as system input, and electrical stimulation in the mesencephalic reticular formation (mRt) as controller output. It is well documented that hippocampal theta oscillations are highly related to locomotion, while electrical stimulation in the mRt induces freezing. We used an Arduino open-source microcontroller between input and output sources. This allowed us to use hippocampal local field potentials (LFPs) to steer electrical stimulation in the mRt. Our results showed that closed-loop DBS significantly suppressed locomotion compared to no stimulation, and required on average only 56% of the stimulation used in open-loop DBS to reach similar effects. The main advantages of open-source hardware include wide selection and availability, high customizability, and affordability. Our open-source closed-loop DBS system is effective, and warrants further research using open-source hardware for closed-loop neuromodulation.

Conceptualization and validation of an open-source closed-loop deep brain stimulation system in rat

PubMed Central

Wu, Hemmings; Ghekiere, Hartwin; Beeckmans, Dorien; Tambuyzer, Tim; van Kuyck, Kris; Aerts, Jean-Marie; Nuttin, Bart

2015-01-01

Conventional deep brain stimulation (DBS) applies constant electrical stimulation to specific brain regions to treat neurological disorders. Closed-loop DBS with real-time feedback is gaining attention in recent years, after proved more effective than conventional DBS in terms of pathological symptom control clinically. Here we demonstrate the conceptualization and validation of a closed-loop DBS system using open-source hardware. We used hippocampal theta oscillations as system input, and electrical stimulation in the mesencephalic reticular formation (mRt) as controller output. It is well documented that hippocampal theta oscillations are highly related to locomotion, while electrical stimulation in the mRt induces freezing. We used an Arduino open-source microcontroller between input and output sources. This allowed us to use hippocampal local field potentials (LFPs) to steer electrical stimulation in the mRt. Our results showed that closed-loop DBS significantly suppressed locomotion compared to no stimulation, and required on average only 56% of the stimulation used in open-loop DBS to reach similar effects. The main advantages of open-source hardware include wide selection and availability, high customizability, and affordability. Our open-source closed-loop DBS system is effective, and warrants further research using open-source hardware for closed-loop neuromodulation. PMID:25897892

Chronic cuffing of cervical vagus nerve inhibits efferent fiber integrity in rat model

NASA Astrophysics Data System (ADS)

Somann, Jesse P.; Albors, Gabriel O.; Neihouser, Kaitlyn V.; Lu, Kun-Han; Liu, Zhongming; Ward, Matthew P.; Durkes, Abigail; Robinson, J. Paul; Powley, Terry L.; Irazoqui, Pedro P.

2018-06-01

Objective. Numerous studies of vagal nerve stimulation (VNS) have been published showing it to be a potential treatment for chronic inflammation and other related diseases and disorders. Studies in recent years have shown that electrical stimulation of the vagal efferent fibers can artificially modulate cytokine levels and reduce systematic inflammation. Most VNS research in the treatment of inflammation have been acute studies on rodent subjects. Our study tested VNS on freely moving animals by stimulating and recording from the cervical vagus with nerve cuff electrodes over an extended period of time. Approach. We used methods of electrical stimulation, retrograde tracing (using Fluorogold) and post necropsy histological analysis of nerve tissue, flow cytometry to measure plasma cytokine levels, and MRI scanning of gastric emptying. This novel combination of methods allowed examination of physiological aspects of VNS previously unexplored. Main results. Through our study of 53 rat subjects, we found that chronically cuffing the left cervical vagus nerve suppressed efferent Fluorogold transport in 43 of 44 animals (36 showed complete suppression). Measured cytokine levels and gastric emptying rates concurrently showed nominal differences between chronically cuffed rats and those tested with similar acute methods. Meanwhile, results of electrophysiological and histological tests of the cuffed nerves revealed them to be otherwise healthy, consistent with previous literature. Significance. We hypothesize that due to these unforeseen and unexplored physiological consequences of the chronically cuffed vagus nerve in a rat, that inflammatory modulation and other vagal effects by VNS may become unreliable in chronic studies. Given our findings, we submit that it would benefit the VNS community to re-examine methods used in previous literature to verify the efficacy of the rat model for chronic VNS studies.

Design of electrodes and current limits for low frequency electrical impedance tomography of the brain.

PubMed

Gilad, O; Horesh, L; Holder, D S

2007-07-01

For the novel application of recording of resistivity changes related to neuronal depolarization in the brain with electrical impedance tomography, optimal recording is with applied currents below 100 Hz, which might cause neural stimulation of skin or underlying brain. The purpose of this work was to develop a method for application of low frequency currents to the scalp, which delivered the maximum current without significant stimulation of skin or underlying brain. We propose a recessed electrode design which enabled current injection with an acceptable skin sensation to be increased from 100 muA using EEG electrodes, to 1 mA in 16 normal volunteers. The effect of current delivered to the brain was assessed with an anatomically realistic finite element model of the adult head. The modelled peak cerebral current density was 0.3 A/m(2), which was 5 to 25-fold less than the threshold for stimulation of the brain estimated from literature review.

Application of an object-oriented programming paradigm in three-dimensional computer modeling of mechanically active gastrointestinal tissues.

PubMed

Rashev, P Z; Mintchev, M P; Bowes, K L

2000-09-01

The aim of this study was to develop a novel three-dimensional (3-D) object-oriented modeling approach incorporating knowledge of the anatomy, electrophysiology, and mechanics of externally stimulated excitable gastrointestinal (GI) tissues and emphasizing the "stimulus-response" principle of extracting the modeling parameters. The modeling method used clusters of class hierarchies representing GI tissues from three perspectives: 1) anatomical; 2) electrophysiological; and 3) mechanical. We elaborated on the first four phases of the object-oriented system development life-cycle: 1) analysis; 2) design; 3) implementation; and 4) testing. Generalized cylinders were used for the implementation of 3-D tissue objects modeling the cecum, the descending colon, and the colonic circular smooth muscle tissue. The model was tested using external neural electrical tissue excitation of the descending colon with virtual implanted electrodes and the stimulating current density distributions over the modeled surfaces were calculated. Finally, the tissue deformations invoked by electrical stimulation were estimated and represented by a mesh-surface visualization technique.

Tongue muscle plasticity following hypoglossal nerve stimulation in aged rats

PubMed Central

Connor, Nadine P.; Russell, John A.; Jackson, Michelle A.; Kletzien, Heidi; Wang, Hao; Schaser, Allison J.; Leverson, Glen E.; Zealear, David L.

2012-01-01

Introduction Age-related decreases in tongue muscle mass and strength have been reported. It may be possible to prevent age-related tongue muscle changes using neuromuscular electrical stimulation (NMES). Our hypothesis was that alterations in muscle contractile properties and myosin heavy chain composition would be found following NMES. Methods Fifty-four young, middle-aged and old Fischer 344/Brown Norway rats were included. Twenty-four rats underwent bilateral electrical stimulation of the hypoglossal nerves for 8 weeks and were compared with control or sham rats. Muscle contractile properties and myosin heavy chain (MHC) in the genioglossus (GG), styloglossus (SG) and hyoglossus (HG) muscles were examined. Results In comparison with unstimulated control rats, we found reduced muscle fatigue, increased contraction and half decay times and increased twitch and tetanic tension. Increased Type I MHC was found, except for GG in old and middle-aged rats. Discussion Transitions in tongue muscle contractile properties and phenotype were found following NMES. PMID:23169566

42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

Code of Federal Regulations, 2010 CFR

2010-10-01

... nerve stimulators (TENS). 414.232 Section 414.232 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Special payment rules for transcutaneous electrical nerve stimulators (TENS). (a) General payment rule. Except as provided in paragraph (b) of this section, payment for TENS is made on a purchase basis with...

A Dual Mode Pulsed Electro-Magnetic Cell Stimulator Produces Acceleration of Myogenic Differentiation

PubMed Central

Leon-Salas, Walter D.; Rizk, Hatem; Mo, Chenglin; Weisleder, Noah; Brotto, Leticia; Abreu, Eduardo; Brotto, Marco

2013-01-01

This paper presents the design and test of a dual-mode electric and magnetic biological stimulator (EM-Stim). The stimulator generates pulsing electric and magnetic fields at programmable rates and intensities. While electric and magnetic stimulators have been reported before, this is the first device that combines both modalities. The ability of the dual stimulation to target bone and muscle tissue simultaneously has the potential to improve the therapeutic treatment of osteoporosis and sarcopenia. The device is fully programmable, portable and easy to use, and can run from a battery or a power supply. The device can generate magnetic fields of up to 1.6 mT and output voltages of +/−40 V. The EM-Stim accelerated myogenic differentiation of myoblasts into myotubes as evidenced by morphometric, gene expression, and protein content analyses. Currently, there are many patents concerned with the application of single electrical or magnetic stimulation, but none that combine both simultaneously. However, we applied for and obtained a provisional patent for new device to fully explore its therapeutic potential in pre-clinical models. PMID:23445453

A dual mode pulsed electro-magnetic cell stimulator produces acceleration of myogenic differentiation.

PubMed

Leon-Salas, Walter D; Rizk, Hatem; Mo, Chenglin; Weisleder, Noah; Brotto, Leticia; Abreu, Eduardo; Brotto, Marco

2013-04-01

This paper presents the design and test of a dual-mode electric and magnetic biological stimulator (EM-Stim). The stimulator generates pulsing electric and magnetic fields at programmable rates and intensities. While electric and magnetic stimulators have been reported before, this is the first device that combines both modalities. The ability of the dual stimulation to target bone and muscle tissue simultaneously has the potential to improve the therapeutic treatment of osteoporosis and sarcopenia. The device is fully programmable, portable and easy to use, and can run from a battery or a power supply. The device can generate magnetic fields of up to 1.6 mT and output voltages of +/- 40 V. The EM-Stim accelerated myogenic differentiation of myoblasts into myotubes as evidenced by morphometric, gene expression, and protein content analyses. Currently, there are many patents concerned with the application of single electrical or magnetic stimulation, but none that combine both simultaneously. However, we applied for and obtained a provisional patent for new device to fully explore its therapeutic potential in pre-clinical models.

Effects of coil orientation on the electric field induced by TMS over the hand motor area

NASA Astrophysics Data System (ADS)

Laakso, Ilkka; Hirata, Akimasa; Ugawa, Yoshikazu

2014-01-01

Responses elicited by transcranial magnetic stimulation (TMS) over the hand motor area depend on the position and orientation of the stimulating coil. In this work, we computationally investigate the induced electric field for multiple coil orientations and locations in order to determine which parts of the brain are affected and how the sensitivity of motor cortical activation depends on the direction of the electric field. The finite element method is used for calculating the electric field induced by TMS in two individual anatomical models of the head and brain. The orientation of the coil affects both the strength and depth of penetration of the electric field, and the field strongly depends on the direction of the sulcus, where the target neurons are located. The coil position that gives the strongest electric field in the target cortical region may deviate from the closest scalp location by a distance on the order of 1 cm. Together with previous experimental data, the results support the hypothesis that the cortex is most sensitive to fields oriented perpendicular to the cortical layers, while it is relatively insensitive to fields parallel to them. This has important implications for targeting of TMS. To determine the most effective coil position and orientation, it is essential to consider both biological (the direction of the targeted axons) and physical factors (the strength and direction of the electric field).

Electrical stimulation modulates injury potentials in rats after spinal cord injury

PubMed Central

Zhang, Guanghao; Huo, Xiaolin; Wang, Aihua; Wu, Changzhe; Zhang, Cheng; Bai, Jinzhu

2013-01-01

An injury potential is the direct current potential difference between the site of spinal cord injury and the healthy nerves. Its initial amplitude is a significant indicator of the severity of spinal cord injury, and many cations, such as sodium and calcium, account for the major portion of injury potentials. This injury potential, as well as injury current, can be modulated by direct current field stimulation; however, the appropriate parameters of the electrical field are hard to define. In this paper, injury potential is used as a parameter to adjust the intensity of electrical stimulation. Injury potential could be modulated to slightly above 0 mV (as the anode-centered group) by placing the anodes at the site of the injured spinal cord and the cathodes at the rostral and caudal sections, or around –70 mV, which is resting membrane potential (as the cathode-centered group) by reversing the polarity of electrodes in the anode-centered group. In addition, rats receiving no electrical stimulation were used as the control group. Results showed that the absolute value of the injury potentials acquired after 30 minutes of electrical stimulation was higher than the control group rats and much lower than the initial absolute value, whether the anodes or the cathodes were placed at the site of injury. This phenomenon illustrates that by changing the polarity of the electrical field, electrical stimulation can effectively modulate the injury potentials in rats after spinal cord injury. This is also beneficial for the spontaneous repair of the cell membrane and the reduction of cation influx. PMID:25206563

Benefits and Risks of Cochlear Implants

MedlinePlus

... The cochlear implant stimulates the nerves directly with electrical currents. Although this stimulation appears to be safe, the long term effect of these electrical currents on the nerves is unknown. May not ...

Spread of cochlear excitation during stimulation with pulsed infrared radiation: inferior colliculus measurements

NASA Astrophysics Data System (ADS)

Richter, C.-P.; Rajguru, S. M.; Matic, A. I.; Moreno, E. L.; Fishman, A. J.; Robinson, A. M.; Suh, E.; Walsh, J. T., Jr.

2011-10-01

Infrared neural stimulation (INS) has received considerable attention over the last few years. It provides an alternative method to artificially stimulate neurons without electrical current or the introduction of exogenous chromophores. One of the primary benefits of INS could be the improved spatial selectivity when compared with electrical stimulation. In the present study, we have evaluated the spatial selectivity of INS in the acutely damaged cochlea of guinea pigs and compared it to stimulation with acoustic tone pips in normal-hearing animals. The radiation was delivered via a 200 µm diameter optical fiber, which was inserted through a cochleostomy into the scala tympani of the basal cochlear turn. The stimulated section along the cochlear spiral ganglion was estimated from the neural responses recorded from the central nucleus of the inferior colliculus (ICC). ICC responses were recorded in response to cochlear INS using a multichannel penetrating electrode array. Spatial tuning curves (STCs) were constructed from the responses. For INS, approximately 55% of the activation profiles showed a single maximum, ~22% had two maxima and ~13% had multiple maxima. The remaining 10% of the profiles occurred at the limits of the electrode array and could not be classified. The majority of ICC STCs indicated that the spread of activation evoked by optical stimuli is comparable to that produced by acoustic tone pips.

Femoral artery blood flow and microcirculatory perfusion during acute, low-level functional electrical stimulation in spinal cord injury.

PubMed

Barton, Thomas J; Low, David A; Janssen, Thomas W J; Sloots, Maurits; Smit, Christof A J; Thijssen, Dick H J

2018-04-19

Functional electrical stimulation (FES) may help to reduce the risk of developing macro- and microvascular complications in people with SCI. Low-intensity FES has significant clinical potential since this can be applied continuously throughout the day. This study examines the acute effects of low intensity FES using wearable clothing garment on vascular blood flow and oxygen consumption in people with SCI. Cross-sectional observation study METHODS: Eight participants with a motor complete SCI received 4x3 minutes of unilateral FES to the gluteal and hamstring muscles. Skin and deep femoral artery blood flow and oxygen consumption were measured at baseline and during each bout of stimulation. Femoral artery blood flow increased by 18.1% with the application of FES (P=0.02). Moreover, femoral artery blood flow increased further during each subsequent block of FES (P=0.004). Skin perfusion did not change during an individual block of stimulation (P=0.66). Skin perfusion progressively increased with each subsequent bout (P<0.001). There was no change in femoral or skin perfusion across time in the non-stimulated leg (all P>0.05). Low-intensity FES acutely increased blood flow during stimulation, with a progressive increase across subsequent FES bouts. These observations suggest continuous, low-intensity FES may represent a practical and effective strategy to improve perfusion and reduce the risk of vascular complications.

The influence of postmortem electrical stimulation on rigor mortis development, calpastatin activity, and tenderness in broiler and duck pectoralis.

PubMed

Alvarado, C Z; Sams, A R

2000-09-01

This study was conducted to evaluate the effects of electrical stimulation (ES) on rigor mortis development, calpastatin activity, and tenderness in anatomically similar avian muscles composed primarily of either red or white muscle fibers. A total of 72 broilers and 72 White Pekin ducks were either treated with postmortem (PM) ES (450 mA) at the neck in a 1% NaCl solution for 2 s on and 1 s off for a total of 15 s or were used as nonstimulated controls. Both pectoralis muscles were harvested from the carcasses after 0.25, 1.25, and 24 h PM and analyzed for pH, inosine:adenosine ratio (R-value), sarcomere length, gravimetric fragmentation index, calpastatin activity, shear value, and cook loss. All data were analyzed within species for the effects of ES. Electrically stimulated ducks had a lower muscle pH at 0.25 and 1.25 h PM and higher R-values at 0.25 h PM compared with controls. Electrically stimulated broilers had a lower muscle pH at 1.25 h and higher R-values at 0.25 and 1.25 h PM compared with controls. Muscles of electrically stimulated broilers exhibited increased myofibrillar fragmentation at 0.25 and 1.25 h PM, whereas there was no such difference over PM time in the duck muscle. Electrical stimulation did not affect calpastatin activity in either broilers or ducks; however, the calpastatin activity of the broilers did decrease over the aging time period, whereas that of the ducks did not. Electrical stimulation decreased shear values in broilers at 1.25 h PM compared with controls; however, there was no difference in shear values of duck muscle due to ES at any sampling time. Cook loss was lower for electrically stimulated broilers at 0.25 and 1.25 h PM compared with the controls, but had no effect in the ducks. These results suggest that the red fibers of the duck pectoralis have less potential for rigor mortis acceleration and tenderization due to ES than do the white fibers of the broiler pectoralis.

Motor neuron activation in peripheral nerves using infrared neural stimulation

NASA Astrophysics Data System (ADS)

Peterson, E. J.; Tyler, D. J.

2014-02-01

Objective. Localized activation of peripheral axons may improve selectivity of peripheral nerve interfaces. Infrared neural stimulation (INS) employs localized delivery to activate neural tissue. This study investigated INS to determine whether localized delivery limited functionality in larger mammalian nerves. Approach. The rabbit sciatic nerve was stimulated extraneurally with 1875 nm wavelength infrared light, electrical stimulation, or a combination of both. Infrared-sensitive regions (ISR) of the nerve surface and electromyogram (EMG) recruitment of the Medial Gastrocnemius, Lateral Gastrocnemius, Soleus, and Tibialis Anterior were the primary output measures. Stimulation applied included infrared-only, electrical-only, and combined infrared and electrical. Main results. 81% of nerves tested were sensitive to INS, with 1.7 ± 0.5 ISR detected per nerve. INS was selective to a single muscle within 81% of identified ISR. Activation energy threshold did not change significantly with stimulus power, but motor activation decreased significantly when radiant power was decreased. Maximum INS levels typically recruited up to 2-9% of any muscle. Combined infrared and electrical stimulation differed significantly from electrical recruitment in 7% of cases. Significance. The observed selectivity of INS indicates that it may be useful in augmenting rehabilitation, but significant challenges remain in increasing sensitivity and response magnitude to improve the functionality of INS.

Motor Neuron Activation in Peripheral Nerves Using Infrared Neural Stimulation

PubMed Central

Peterson, EJ; Tyler, DJ

2014-01-01

Objective Localized activation of peripheral axons may improve selectivity of peripheral nerve interfaces. Infrared neural stimulation (INS) employs localized delivery to activate neural tissue. This study investigated INS to determine whether localized delivery limited functionality in larger mammalian nerves. Approach The rabbit sciatic nerve was stimulated extraneurally with 1875 nm-wavelength infrared light, electrical stimulation, or a combination of both. Infrared-sensitive regions (ISR) of the nerve surface and electromyogram (EMG) recruitment of the Medial Gastrocnemius, Lateral Gastrocnemius, Soleus, and Tibialis Anterior were the primary output measures. Stimulation applied included infrared-only, electrical-only, and combined infrared and electrical. Main results 81% of nerves tested were sensitive to INS, with 1.7± 0.5 ISR detected per nerve. INS was selective to a single muscle within 81% of identified ISR. Activation energy threshold did not change significantly with stimulus power, but motor activation decreased significantly when radiant power was decreased. Maximum INS levels typically recruited up to 2–9% of any muscle. Combined infrared and electrical stimulation differed significantly from electrical recruitment in 7% of cases. Significance The observed selectivity of INS indicates it may be useful in augmenting rehabilitation, but significant challenges remain in increasing sensitivity and response magnitude to improve the functionality of INS. PMID:24310923

Effects of Surface Electrical Stimulation Both at Rest and During Swallowing in Chronic Pharyngeal Dysphagia§

PubMed Central

Ludlow, Christy L.; Humbert, Ianessa; Saxon, Keith; Poletto, Christopher; Sonies, Barbara; Crujido, Lisa

2006-01-01

We tested two hypotheses using surface electrical stimulation in chronic pharyngeal dysphagia: that stimulation 1) lowered the hyoid bone and/or larynx when applied at rest, and 2) increased aspiration, penetration or pharyngeal pooling during swallowing. Bipolar surface electrodes were placed on the skin overlying the submandibular and laryngeal regions. Maximum tolerated levels of stimulation were applied while patients held their mouth closed at rest. Videofluoroscopic recordings were used to measure hyoid movements in the superior-inferior (s-i) and anterior-posterior (a-p) dimensions and the subglottic air column (s-i) position while stimulation was on and off. Patients swallowed 5 ml liquid when stimulation was off, at low sensory stimulation levels, and at maximum tolerated levels (motor). Speech pathologists blinded to condition, tallied the frequency of aspiration, penetration, pooling and esophageal entry from videofluorographic recordings of swallows. Only significant (p=0.0175) hyoid depression occurred during stimulation at rest. Aspiration and pooling were significantly reduced only with low sensory threshold levels of stimulation (p=0.025) and not during maximum levels of surface electrical stimulation. Those patients who had reduced aspiration and penetration during swallowing with stimulation had greater hyoid depression during stimulation at rest (p= 0.006). Stimulation may have acted to resist patients’ hyoid elevation during swallowing. PMID:16718620

Co-release of noradrenaline and dopamine in the cerebral cortex elicited by single train and repeated train stimulation of the locus coeruleus

PubMed Central

Devoto, Paola; Flore, Giovanna; Saba, Pierluigi; Fà, Mauro; Gessa, Gian Luigi

2005-01-01

Background Previous studies by our group suggest that extracellular dopamine (DA) and noradrenaline (NA) may be co-released from noradrenergic nerve terminals in the cerebral cortex. We recently demonstrated that the concomitant release of DA and NA could be elicited in the cerebral cortex by electrical stimulation of the locus coeruleus (LC). This study analyses the effect of both single train and repeated electrical stimulation of LC on NA and DA release in the medial prefrontal cortex (mPFC), occipital cortex (Occ), and caudate nucleus. To rule out possible stressful effects of electrical stimulation, experiments were performed on chloral hydrate anaesthetised rats. Results Twenty min electrical stimulation of the LC, with burst type pattern of pulses, increased NA and DA both in the mPFC and in the Occ. NA in both cortices and DA in the mPFC returned to baseline within 20 min after the end of the stimulation period, while DA in the Occ reached a maximum increase during 20 min post-stimulation and remained higher than baseline values at 220 min post-stimulation. Local perfusion with tetrodotoxin (TTX, 10 μM) markedly reduced baseline NA and DA in the mPFC and Occ and totally suppressed the effect of electrical stimulation in both areas. A sequence of five 20 min stimulations at 20 min intervals were delivered to the LC. Each stimulus increased NA to the same extent and duration as the first stimulus, whereas DA remained elevated at the time next stimulus was delivered, so that baseline DA progressively increased in the mPFC and Occ to reach about 130 and 200% the initial level, respectively. In the presence of the NA transport (NAT) blocker desipramine (DMI, 100 μM), multiple LC stimulation still increased extracellular NA and DA levels. Electrical stimulation of the LC increased NA levels in the homolateral caudate nucleus, but failed to modify DA level. Conclusion The results confirm and extend that LC stimulation induces a concomitant release of DA and NA in the mPFC and Occ. The different time-course of LC-induced elevation of DA and NA suggests that their co-release may be differentially controlled. PMID:15865626

Closed-Loop Efficient Searching of Optimal Electrical Stimulation Parameters for Preferential Excitation of Retinal Ganglion Cells

PubMed Central

Guo, Tianruo; Yang, Chih Yu; Tsai, David; Muralidharan, Madhuvanthi; Suaning, Gregg J.; Morley, John W.; Dokos, Socrates; Lovell, Nigel H.

2018-01-01

The ability for visual prostheses to preferentially activate functionally-distinct retinal ganglion cells (RGCs) is important for improving visual perception. This study investigates the use of high frequency stimulation (HFS) to elicit RGC activation, using a closed-loop algorithm to search for optimal stimulation parameters for preferential ON and OFF RGC activation, resembling natural physiological neural encoding in response to visual stimuli. We evaluated the performance of a wide range of electrical stimulation amplitudes and frequencies on RGC responses in vitro using murine retinal preparations. It was possible to preferentially excite either ON or OFF RGCs by adjusting amplitudes and frequencies in HFS. ON RGCs can be preferentially activated at relatively higher stimulation amplitudes (>150 μA) and frequencies (2–6.25 kHz) while OFF RGCs are activated by lower stimulation amplitudes (40–90 μA) across all tested frequencies (1–6.25 kHz). These stimuli also showed great promise in eliciting RGC responses that parallel natural RGC encoding: ON RGCs exhibited an increase in spiking activity during electrical stimulation while OFF RGCs exhibited decreased spiking activity, given the same stimulation amplitude. In conjunction with the in vitro studies, in silico simulations indicated that optimal HFS parameters could be rapidly identified in practice, whilst sampling spiking activity of relevant neuronal subtypes. This closed-loop approach represents a step forward in modulating stimulation parameters to achieve appropriate neural encoding in retinal prostheses, advancing control over RGC subtypes activated by electrical stimulation. PMID:29615857

Brain plasticity after implanted peroneal nerve electrical stimulation to improve gait in chronic stroke patients: Two case reports.

PubMed

Thibaut, Aurore; Moissenet, Florent; Di Perri, Carol; Schreiber, Céline; Remacle, Angélique; Kolanowski, Elisabeth; Chantraine, Frédéric; Bernard, Claire; Hustinx, Roland; Tshibanda, Jean-Flory; Filipetti, Paul; Laureys, Steven; Gosseries, Olivia

2017-01-01

Recent studies have shown that stimulation of the peroneal nerve using an implantable 4-channel peroneal nerve stimulator could improve gait in stroke patients. To assess structural cortical and regional cerebral metabolism changes associated with an implanted peroneal nerve electrical stimulator to correct foot drop related to a central nervous system lesion. Two stroke patients presenting a foot drop related to a central nervous system lesion were implanted with an implanted peroneal nerve electrical stimulator. Both patients underwent clinical evaluations before implantation and one year after the activation of the stimulator. Structural magnetic resonance imaging (MRI) and [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) were acquired before and one year after the activation of the stimulator. Foot drop was corrected for both patients after the implantation of the stimulator. After one year of treatment, patient 1 improved in three major clinical tests, while patient 2 only improved in one test. Prior to treatment, FDG-PET showed a significant hypometabolism in premotor, primary and supplementary motor areas in both patients as compared to controls, with patient 2 presenting more widespread hypometabolism. One year after the activation of the stimulator, both patients showed significantly less hypometabolism in the damaged motor cortex. No difference was observed on the structural MRI. Clinical improvement of gait under peroneal nerve electrical stimulation in chronic stroke patients presenting foot drop was paralleled to metabolic changes in the damaged motor cortex.

Restoration of vision in blind individuals using bionic devices: a review with a focus on cortical visual prostheses.

PubMed

Lewis, Philip M; Ackland, Helen M; Lowery, Arthur J; Rosenfeld, Jeffrey V

2015-01-21

The field of neurobionics offers hope to patients with sensory and motor impairment. Blindness is a common cause of major sensory loss, with an estimated 39 million people worldwide suffering from total blindness in 2010. Potential treatment options include bionic devices employing electrical stimulation of the visual pathways. Retinal stimulation can restore limited visual perception to patients with retinitis pigmentosa, however loss of retinal ganglion cells precludes this approach. The optic nerve, lateral geniculate nucleus and visual cortex provide alternative stimulation targets, with several research groups actively pursuing a cortically-based device capable of driving several hundred stimulating electrodes. While great progress has been made since the earliest works of Brindley and Dobelle in the 1960s and 1970s, significant clinical, surgical, psychophysical, neurophysiological, and engineering challenges remain to be overcome before a commercially-available cortical implant will be realized. Selection of candidate implant recipients will require assessment of their general, psychological and mental health, and likely responses to visual cortex stimulation. Implant functionality, longevity and safety may be enhanced by careful electrode insertion, optimization of electrical stimulation parameters and modification of immune responses to minimize or prevent the host response to the implanted electrodes. Psychophysical assessment will include mapping the positions of potentially several hundred phosphenes, which may require repetition if electrode performance deteriorates over time. Therefore, techniques for rapid psychophysical assessment are required, as are methods for objectively assessing the quality of life improvements obtained from the implant. These measures must take into account individual differences in image processing, phosphene distribution and rehabilitation programs that may be required to optimize implant functionality. In this review, we detail these and other challenges facing developers of cortical visual prostheses in addition to briefly outlining the epidemiology of blindness, and the history of cortical electrical stimulation in the context of visual prosthetics. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Contralaterally Controlled Functional Electrical Stimulation Improves Hand Dexterity in Chronic Hemiparesis: A Randomized Trial.

PubMed

Knutson, Jayme S; Gunzler, Douglas D; Wilson, Richard D; Chae, John

2016-10-01

It is unknown whether one method of neuromuscular electrical stimulation for poststroke upper limb rehabilitation is more effective than another. Our aim was to compare the effects of contralaterally controlled functional electrical stimulation (CCFES) with cyclic neuromuscular electrical stimulation (cNMES). Stroke patients with chronic (>6 months) moderate to severe upper extremity hemiparesis (n=80) were randomized to receive 10 sessions/wk of CCFES- or cNMES-assisted hand opening exercise at home plus 20 sessions of functional task practice in the laboratory for 12 weeks. The task practice for the CCFES group was stimulation assisted. The primary outcome was change in Box and Block Test (BBT) score at 6 months post treatment. Upper extremity Fugl-Meyer and Arm Motor Abilities Test were also measured. At 6 months post treatment, the CCFES group had greater improvement on the BBT, 4.6 (95% confidence interval [CI], 2.2-7.0), than the cNMES group, 1.8 (95% CI, 0.6-3.0), between-group difference of 2.8 (95% CI, 0.1-5.5), P=0.045. No significant between-group difference was found for the upper extremity Fugl-Meyer (P=0.888) or Arm Motor Abilities Test (P=0.096). Participants who had the largest improvements on BBT were <2 years post stroke with moderate (ie, not severe) hand impairment at baseline. Among these, the 6-month post-treatment BBT gains of the CCFES group, 9.6 (95% CI, 5.6-13.6), were greater than those of the cNMES group, 4.1 (95% CI, 1.7-6.5), between-group difference of 5.5 (95% CI, 0.8-10.2), P=0.023. CCFES improved hand dexterity more than cNMES in chronic stroke survivors. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00891319. © 2016 American Heart Association, Inc.

Comparing conventional physical therapy rehabilitation with neuromuscular electrical stimulation after TKA.

PubMed

Levine, Michael; McElroy, Karen; Stakich, Valerie; Cicco, Jodie

2013-03-01

Rehabilitation following total knee arthroplasty (TKA) is a costly, cumbersome, and often painful process. Physical therapy contributes to the successful outcome of TKA but can be expensive. Alternative methods of obtaining good functional results that help minimize costs are desirable. Neuromuscular electrical stimulation (NMES) is a potential option. Neuromuscular electrical stimulation has been shown to increase quadriceps muscle strength and activation following TKA. Functional scores also improve following TKA when NMES is added to conventional therapy protocols vs therapy alone. The authors hypothesized that rehabilitation managed by a physical therapist would not result in a functional advantage for patients undergoing TKA when compared with NMES and an unsupervised at-home range of motion exercise program and that patient satisfaction would not differ between the 2 groups. Seventy patients were randomized into a postoperative protocol of conventional physical therapy with a licensed therapist, including range of motion exercises and strengthening exercises, or into a program of NMES and range of motion exercises performed at home without therapist supervision. Noninferiority of the NMES program was obtained 6 weeks postoperatively (Knee Society pain/function scores, Western Ontario and McMaster Universities Osteoarthritis Index, flexion). Noninferiority was shown 6 months postoperatively for all parameters. The results suggest that rehabilitation managed by a physical therapist results in no functional advantage or difference in patient satisfaction when compared with NMES and an unsupervised at-home range of motion program. Neuromuscular electrical stimulation and unsupervised at-home range of motion exercises may provide an option for reducing the cost of the postoperative TKA recovery process without compromising quadriceps strength or patient satisfaction. Copyright 2013, SLACK Incorporated.

Higher-order power harmonics of pulsed electrical stimulation modulates corticospinal contribution of peripheral nerve stimulation.

PubMed

Chen, Chiun-Fan; Bikson, Marom; Chou, Li-Wei; Shan, Chunlei; Khadka, Niranjan; Chen, Wen-Shiang; Fregni, Felipe

2017-03-03

It is well established that electrical-stimulation frequency is crucial to determining the scale of induced neuromodulation, particularly when attempting to modulate corticospinal excitability. However, the modulatory effects of stimulation frequency are not only determined by its absolute value but also by other parameters such as power at harmonics. The stimulus pulse shape further influences parameters such as excitation threshold and fiber selectivity. The explicit role of the power in these harmonics in determining the outcome of stimulation has not previously been analyzed. In this study, we adopted an animal model of peripheral electrical stimulation that includes an amplitude-adapted pulse train which induces force enhancements with a corticospinal contribution. We report that the electrical-stimulation-induced force enhancements were correlated with the amplitude of stimulation power harmonics during the amplitude-adapted pulse train. In an exploratory analysis, different levels of correlation were observed between force enhancement and power harmonics of 20-80 Hz (r = 0.4247, p = 0.0243), 100-180 Hz (r = 0.5894, p = 0.0001), 200-280 Hz (r = 0.7002, p < 0.0001), 300-380 Hz (r = 0.7449, p < 0.0001), 400-480 Hz (r = 0.7906, p < 0.0001), 500-600 Hz (r = 0.7717, p < 0.0001), indicating a trend of increasing correlation, specifically at higher order frequency power harmonics. This is a pilot, but important first demonstration that power at high order harmonics in the frequency spectrum of electrical stimulation pulses may contribute to neuromodulation, thus warrant explicit attention in therapy design and analysis.

Economic substitutability of electrical brain stimulation, food, and water.

PubMed Central

Green, L; Rachlin, H

1991-01-01

Concurrent variable-ratio schedules of electrical brain stimulation, food, and water were paired in various combinations as reinforcement of rats' lever presses. Relative prices of the concurrent reinforcers were varied by changing the ratio of the response requirements on the two levers. Economic substitutability, measured by the sensitivity of response ratio to changes in relative price, was highest with brain stimulation reinforcement of presses on both levers and lowest with food reinforcement of presses on one lever and water reinforcement of presses on the other. Substitutability with brain stimulation reinforcement of presses on one lever and either food or water reinforcement for presses on the other was about as high as with brain stimulation for presses on both levers. Electrical brain stimulation for rats may thus serve as an economic substitute for two reinforcers, neither of which is substitutable for the other. PMID:2037823

Electrical stimulation treatment for facial palsy after revision pleomorphic adenoma surgery

PubMed Central

Goldie, Simon; Sandeman, Jack; Cole, Richard; Dennis, Simon; Swain, Ian

2016-01-01

Surgery for pleomorphic adenoma recurrence presents a significant risk of facial nerve damage that can result in facial weakness effecting patients’ ability to communicate, mental health and self-image. We report two case studies that had marked facial weakness after resection of recurrent pleomorphic adenoma and their progress with electrical stimulation. Subjects received electrical stimulation twice daily for 24 weeks during which photographs of expressions, facial measurements and Sunnybrook scores were recorded. Both subjects recovered good facial function demonstrating Sunnybrook scores of 54 and 64 that improved to 88 and 96, respectively. Neither subjects demonstrated adverse effects of treatment. We conclude that electrical stimulation is a safe treatment and may improve facial palsy in patients after resection of recurrent pleomorphic adenoma. Larger studies would be difficult to pursue due to the low incidence of cases. PMID:27106613

A novel functional electrical stimulation-control system for restoring motor function of post-stroke hemiplegic patients

PubMed Central

Huang, Zonghao; Wang, Zhigong; Lv, Xiaoying; Zhou, Yuxuan; Wang, Haipeng; Zong, Sihao

2014-01-01

Hemiparesis is one of the most common consequences of stroke. Advanced rehabilitation techniques are essential for restoring motor function in hemiplegic patients. Functional electrical stimulation applied to the affected limb based on myoelectric signal from the unaffected limb is a promising therapy for hemiplegia. In this study, we developed a prototype system for evaluating this novel functional electrical stimulation-control strategy. Based on surface electromyography and a vector machine model, a self-administered, multi-movement, force-modulation functional electrical stimulation-prototype system for hemiplegia was implemented. This paper discusses the hardware design, the algorithm of the system, and key points of the self-oscillation-prone system. The experimental results demonstrate the feasibility of the prototype system for further clinical trials, which is being conducted to evaluate the efficacy of the proposed rehabilitation technique. PMID:25657728

An artificial arm/hand system with a haptic sensory function using electric stimulation of peripheral sensory nerve fibers.

PubMed

Mabuchi, Kunihiko

2013-01-01

We are currently developing an artificial arm/hand system which is capable of sensing stimuli and then transferring these stimuli to users as somatic sensations. Presently, we are evoking the virtual somatic sensations by electrically stimulating a sensory nerve fiber which innervates a single mechanoreceptor unit at the target area; this is done using a tungsten microelectrode that was percutaneously inserted into the use's peripheral nerve (a microstimulation method). The artificial arm/hand system is composed of a robot hand equipped with a pressure sensor system on its fingers. The sensor system detects mechanical stimuli, which are transferred to the user by means of the microstimulation method so that the user experiences the stimuli as the corresponding somatic sensations. In trials, the system worked satisfactorily and there was a good correlation between the pressure applied to the pressure sensors on the robot fingers and the subjective intensities of the evoked pressure sensations.

Electrical stimulation of transplanted motoneurons improves motor unit formation

PubMed Central

Liu, Yang; Grumbles, Robert M.

2014-01-01

Motoneurons die following spinal cord trauma and with neurological disease. Intact axons reinnervate nearby muscle fibers to compensate for the death of motoneurons, but when an entire motoneuron pool dies, there is complete denervation. To reduce denervation atrophy, we have reinnervated muscles in Fisher rats from local transplants of embryonic motoneurons in peripheral nerve. Since growth of axons from embryonic neurons is activity dependent, our aim was to test whether brief electrical stimulation of the neurons immediately after transplantation altered motor unit numbers and muscle properties 10 wk later. All surgical procedures and recordings were done in anesthetized animals. The muscle consequences of motoneuron death were mimicked by unilateral sciatic nerve section. One week later, 200,000 embryonic day 14 and 15 ventral spinal cord cells, purified for motoneurons, were injected into the tibial nerve 10–15 mm from the gastrocnemii muscles as the only neuron source for muscle reinnervation. The cells were stimulated immediately after transplantation for up to 1 h using protocols designed to examine differential effects due to pulse number, stimulation frequency, pattern, and duration. Electrical stimulation that included short rests and lasted for 1 h resulted in higher motor unit counts. Muscles with higher motor unit counts had more reinnervated fibers and were stronger. Denervated muscles had to be stimulated directly to evoke contractions. These results show that brief electrical stimulation of embryonic neurons, in vivo, has long-term effects on motor unit formation and muscle force. This muscle reinnervation provides the opportunity to use patterned electrical stimulation to produce functional movements. PMID:24848463

Lateral geniculate body evoked potentials elicited by visual and electrical stimulation.

PubMed

Choi, Chang Wook; Kim, Pan Sang; Shin, Sun Ae; Yang, Ji Yeon; Yang, Yun Sik

2014-08-01

Blind individuals who have photoreceptor loss are known to perceive phosphenes with electrical stimulation of their remaining retinal ganglion cells. We proposed that implantable lateral geniculate body (LGB) stimulus electrode arrays could be used to generate phosphene vision. We attempted to refine the basic reference of the electrical evoked potentials (EEPs) elicited by microelectrical stimulations of the optic nerve, optic tract and LGB of a domestic pig, and then compared it to visual evoked potentials (VEPs) elicited by short-flash stimuli. For visual function measurement, VEPs in response to short-flash stimuli on the left eye of the domestic pig were assessed over the visual cortex at position Oz with the reference electrode at Fz. After anesthesia, linearly configured platinum wire electrodes were inserted into the optic nerve, optic track and LGB. To determine the optimal stimulus current, EEPs were recorded repeatedly with controlling the pulse and power. The threshold of current and charge density to elicit EEPs at 0.3 ms pulse duration was about ±10 µA. Our experimental results showed that visual cortex activity can be effectively evoked by stimulation of the optic nerve, optic tract and LGB using penetrating electrodes. The latency of P1 was more shortened as the electrical stimulation was closer to LGB. The EEPs of two-channel in the visual cortex demonstrated a similar pattern with stimulation of different spots of the stimulating electrodes. We found that the LGB-stimulated EEP pattern was very similar to the simultaneously generated VEP on the control side, although implicit time deferred. EEPs and VEPs derived from visual-system stimulation were compared. The LGB-stimulated EEP wave demonstrated a similar pattern to the VEP waveform except implicit time, indicating prosthetic-based electrical stimulation of the LGB could be utilized for the blind to perceive vision of phosphenes.

Compositos CNTs/bioceramico para a estimulacao eletrica ossea in situ

NASA Astrophysics Data System (ADS)

Mata, Diogo Miguel Rodrigues Marinho da

The present thesis aims to develop a biocompatible and electroconductor bone graft containing carbon nanotubes (CNTs) that allows the in situ regeneration of bone cells by applying pulsed external electrical stimuli. The CNTs were produced by chemical vapor deposition (CVD) by a semi-continuous method with a yield of 500 mg/day. The deposition parameters were optimised to obtain high pure CNTs 99.96% with controlled morphologies, fundamental requisites for the biomedical application under study. The chemical functionalisation of CNTs was also optimised to maximise their processability and biocompatibility. The CNTs were functionalised by the Diels-Alder cycloaddition of 1,3-butadiene. The biological behaviour of the functionalised CNTs was evaluated in vitro with the osteoblastic cells line MG63 and in vivo, by subcutaneous implantation in rats. The materials did not induce an expressed inflammatory response, but the functionalised CNTs showed a superior in vitro and in vivo biocompatibility than the non-functionalised ones. Composites of ceramic matrix, of bioglass (Glass) and hydroxyapatite (HA), reinforced with carbon nanotubes (CNT/Glass/HA) were processed by a wet approach. The incorporation of just 4.4 vol% of CNTs allowed the increase of 10 orders of magnitude of the electrical conductivity of the matrix. In vitro studies with MG63 cells show that the CNT/Glass/HA composites guarantee the adhesion and proliferation of bone cells, and stimulate their phenotype expression, namely the alkaline phosphate (ALP). The interactions between the composite materials and the culture medium (α-MEM), under an applied electrical external field, were studied by scanning vibrating electrode technique. An increase of the culture medium electrical conductivity and the electrical field confinement in the presence of the conductive samples submerged in the medium was demonstrated. The in vitro electrical stimulation of MG63 cells on the conductive composites promotes the increase of the cell metabolic activity and DNA content by 130% and 60%, relatively to the non-stimulated condition, after only 3 days of daily stimulation of 15 μA for 15 min. Moreover, the osteoblastic gene expression for Runx2, osteocalcin (OC) and ALP was enhanced by 80%, 50% and 25%, after 5 days of stimulation. Instead, for dielectric materials, the stimulus delivering was less efficient, giving an equal or lower cellular response than the non-stimulated condition. The proposed electroconductive bone grafts offer exciting possibilities in bone regeneration strategies by delivering in situ electrical stimulus to cells and consequent control of the new bone tissue formation rate. It is expected that conductive smart biomaterials might turn the selective bone electrotherapy of clinical relevance by decreasing the postoperative healing times.

Direct recordings from the auditory cortex in a cochlear implant user.

PubMed

Nourski, Kirill V; Etler, Christine P; Brugge, John F; Oya, Hiroyuki; Kawasaki, Hiroto; Reale, Richard A; Abbas, Paul J; Brown, Carolyn J; Howard, Matthew A

2013-06-01

Electrical stimulation of the auditory nerve with a cochlear implant (CI) is the method of choice for treatment of severe-to-profound hearing loss. Understanding how the human auditory cortex responds to CI stimulation is important for advances in stimulation paradigms and rehabilitation strategies. In this study, auditory cortical responses to CI stimulation were recorded intracranially in a neurosurgical patient to examine directly the functional organization of the auditory cortex and compare the findings with those obtained in normal-hearing subjects. The subject was a bilateral CI user with a 20-year history of deafness and refractory epilepsy. As part of the epilepsy treatment, a subdural grid electrode was implanted over the left temporal lobe. Pure tones, click trains, sinusoidal amplitude-modulated noise, and speech were presented via the auxiliary input of the right CI speech processor. Additional experiments were conducted with bilateral CI stimulation. Auditory event-related changes in cortical activity, characterized by the averaged evoked potential and event-related band power, were localized to posterolateral superior temporal gyrus. Responses were stable across recording sessions and were abolished under general anesthesia. Response latency decreased and magnitude increased with increasing stimulus level. More apical intracochlear stimulation yielded the largest responses. Cortical evoked potentials were phase-locked to the temporal modulations of periodic stimuli and speech utterances. Bilateral electrical stimulation resulted in minimal artifact contamination. This study demonstrates the feasibility of intracranial electrophysiological recordings of responses to CI stimulation in a human subject, shows that cortical response properties may be similar to those obtained in normal-hearing individuals, and provides a basis for future comparisons with extracranial recordings.

Induction of functional tissue-engineered skeletal muscle constructs by defined electrical stimulation.

PubMed

Ito, Akira; Yamamoto, Yasunori; Sato, Masanori; Ikeda, Kazushi; Yamamoto, Masahiro; Fujita, Hideaki; Nagamori, Eiji; Kawabe, Yoshinori; Kamihira, Masamichi

2014-04-24

Electrical impulses are necessary for proper in vivo skeletal muscle development. To fabricate functional skeletal muscle tissues in vitro, recapitulation of the in vivo niche, including physical stimuli, is crucial. Here, we report a technique to engineer skeletal muscle tissues in vitro by electrical pulse stimulation (EPS). Electrically excitable tissue-engineered skeletal muscle constructs were stimulated with continuous electrical pulses of 0.3 V/mm amplitude, 4 ms width, and 1 Hz frequency, resulting in a 4.5-fold increase in force at day 14. In myogenic differentiation culture, the percentage of peak twitch force (%Pt) was determined as the load on the tissue constructs during the artificial exercise induced by continuous EPS. We optimized the stimulation protocol, wherein the tissues were first subjected to 24.5%Pt, which was increased to 50-60%Pt as the tissues developed. This technique may be a useful approach to fabricate tissue-engineered functional skeletal muscle constructs.