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Sample records for catchlike-inducing electrical stimulation

  1. Electrical stimulation: a societal perspective.

    PubMed

    Gater, D R; McDowell, S M; Abbas, J J

    2000-01-01

    Societal perspective on functional electrical stimulation is colored by media influence, popular thought, and political climate as much as by the science that supports it. The purpose of this article is to examine how these influences facilitate or inhibit the application of electrical stimulation in today's world and to describe the challenges facing the use of electrical stimulation in the future. Emphasis will be placed on perceived need, cost, and available resources and how these factors must be addressed to utilize functional electrical stimulation successfully in society.

  2. 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

  3. Evoked Electromyographically Controlled Electrical Stimulation

    PubMed Central

    Hayashibe, Mitsuhiro

    2016-01-01

    Time-variant muscle responses under electrical stimulation (ES) are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications. Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES) are also well known source of time-varying characteristics coming from muscle response under ES. Therefore, it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favor of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG) signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm. PMID:27471448

  4. Electrical stimulation of mechanoreceptors

    NASA Astrophysics Data System (ADS)

    Echenique, A. M.; Graffigna, J. P.

    2011-12-01

    Within the field of Rehabilitation Engineering, this work is aimed at identifying the optimal parameters of electric current stimulus which activate the nervous axons of mecanoreceptors found in the fingertip, allowing, this way, to resemble tactile senses. These sensorial feelings can be used by aiding technological means, namely, the sensorial substitution technology, in an attempt to render information to blind people through the tactile sense. The physical pressure on sensorial areas (fingertips) used for reading activities through the Braille System is the main effect that is imitated and studied in this research work. An experimental aiding prototype for Braille reading research has been developed and tested with blinds and reduced vision people, with highly satisfactory results.

  5. The Electrical Stimulation Modifies the Cerebral Function

    NASA Astrophysics Data System (ADS)

    Rocha, Luisa Lilia; López-Meraz, María Leonor; Cuéllar-Herrera, Manola; Neri-Bazán., Leticia

    2002-08-01

    Electrical stimulation has been used for therapeuthic purposes. In this review, we present the clinical and scientific bases for using electrical stimulation as a treatment for pharmacological refractory epilepsy. We also describe results in receptors of inhibitory neurotransmitters obtained in rat brain with or without epilepsy, undergoing brain stimulation. Brain electrical stimulation may improve our understanding of brain function and neuroplasticity.

  6. Electrical stimulation and motor recovery.

    PubMed

    Young, Wise

    2015-01-01

    In recent years, several investigators have successfully regenerated axons in animal spinal cords without locomotor recovery. One explanation is that the animals were not trained to use the regenerated connections. Intensive locomotor training improves walking recovery after spinal cord injury (SCI) in people, and >90% of people with incomplete SCI recover walking with training. Although the optimal timing, duration, intensity, and type of locomotor training are still controversial, many investigators have reported beneficial effects of training on locomotor function. The mechanisms by which training improves recovery are not clear, but an attractive theory is available. In 1949, Donald Hebb proposed a famous rule that has been paraphrased as "neurons that fire together, wire together." This rule provided a theoretical basis for a widely accepted theory that homosynaptic and heterosynaptic activity facilitate synaptic formation and consolidation. In addition, the lumbar spinal cord has a locomotor center, called the central pattern generator (CPG), which can be activated nonspecifically with electrical stimulation or neurotransmitters to produce walking. The CPG is an obvious target to reconnect after SCI. Stimulating motor cortex, spinal cord, or peripheral nerves can modulate lumbar spinal cord excitability. Motor cortex stimulation causes long-term changes in spinal reflexes and synapses, increases sprouting of the corticospinal tract, and restores skilled forelimb function in rats. Long used to treat chronic pain, motor cortex stimuli modify lumbar spinal network excitability and improve lower extremity motor scores in humans. Similarly, epidural spinal cord stimulation has long been used to treat pain and spasticity. Subthreshold epidural stimulation reduces the threshold for locomotor activity. In 2011, Harkema et al. reported lumbosacral epidural stimulation restores motor control in chronic motor complete patients. Peripheral nerve or functional electrical

  7. Neuromuscular Electrical Stimulation for Skeletal Muscle Function

    PubMed Central

    Doucet, Barbara M.; Lam, Amy; Griffin, Lisa

    2012-01-01

    Lack of neural innervation due to neurological damage renders muscle unable to produce force. Use of electrical stimulation is a medium in which investigators have tried to find a way to restore movement and the ability to perform activities of daily living. Different methods of applying electrical current to modify neuromuscular activity are electrical stimulation (ES), neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and functional electrical stimulation (FES). This review covers the aspects of electrical stimulation used for rehabilitation and functional purposes. Discussed are the various parameters of electrical stimulation, including frequency, pulse width/duration, duty cycle, intensity/amplitude, ramp time, pulse pattern, program duration, program frequency, and muscle group activated, and how they affect fatigue in the stimulated muscle. PMID:22737049

  8. Braille line using electrical stimulation

    NASA Astrophysics Data System (ADS)

    Puertas, A.; Purés, P.; Echenique, A. M.; Ensinck, J. P. Graffigna y. G.

    2007-11-01

    Conceived within the field of Rehabilitation Technologies for visually impaired persons, the present work aims at enabling the blind user to read written material by means of a tactile display. Once he is familiarized to operate this system, the user will be able to achieve greater performance in study, academic and job activities, thus achieving a rapid and easier social inclusion. The devise accepts any kind of text that is computer-loadable (documents, books, Internet information, and the like) which, through digital means, can be read as Braille text on the pad. This tactile display is composed of an electrodes platform that simulate, through stimulation the writing/reading Braille characters. In order to perceive said characters in similar way to the tactile feeling from paper material, the skin receptor of fingers are stimulated electrically so as to simulate the same pressure and depressions as those of the paper-based counterpart information. Once designed and developed, the display was tested with blind subjects, with relatively satisfactory results. As a continuing project, this prototype is currently being improved as regards.

  9. 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.

  10. 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.

  11. Advances in functional electrical stimulation (FES).

    PubMed

    Popović, Dejan B

    2014-12-01

    This review discusses the advancements that are needed to enhance the effects of electrical stimulation for restoring or assisting movement in humans with an injury/disease of the central nervous system. A complex model of the effects of electrical stimulation of peripheral systems is presented. The model indicates that both the motor and sensory systems are activated by electrical stimulation. We propose that a hierarchical hybrid controller may be suitable for functional electrical stimulation (FES) because this type of controller acts as a structural mimetic of its biological counterpart. Specific attention is given to the neural systems at the periphery with respect to the required electrodes and stimulators. Furthermore, we note that FES with surface electrodes is preferred for the therapy, although there is a definite advantage associated with implantable technology for life-long use. The last section of the review discusses the potential need to combine FES and robotic systems to provide assistance in some cases. PMID:25287528

  12. Electrical stimulation to accelerate wound healing

    PubMed Central

    Thakral, Gaurav; LaFontaine, Javier; Najafi, Bijan; Talal, Talal K.; Kim, Paul; Lavery, Lawrence A.

    2013-01-01

    Background There are several applications of electrical stimulation described in medical literature to accelerate wound healing and improve cutaneous perfusion. This is a simple technique that could be incorporated as an adjunctive therapy in plastic surgery. The objective of this review was to evaluate the results of randomized clinical trials that use electrical stimulation for wound healing. Method We identified 21 randomized clinical trials that used electrical stimulation for wound healing. We did not include five studies with treatment groups with less than eight subjects. Results Electrical stimulation was associated with faster wound area reduction or a higher proportion of wounds that healed in 14 out of 16 wound randomized clinical trials. The type of electrical stimulation, waveform, and duration of therapy vary in the literature. Conclusion Electrical stimulation has been shown to accelerate wound healing and increase cutaneous perfusion in human studies. Electrical stimulation is an adjunctive therapy that is underutilized in plastic surgery and could improve flap and graft survival, accelerate postoperative recovery, and decrease necrosis following foot reconstruction. PMID:24049559

  13. Electrical Cerebral Stimulation Modifies Inhibitory Systems

    NASA Astrophysics Data System (ADS)

    Cuéllar-Herrera, M.; Rocha, L.

    2003-09-01

    Electrical stimulation of the nervous tissue has been proposed as a method to treat some neurological disorders, such as epilepsy. Epileptic seizures result from excessive, synchronous, abnormal firing patterns of neurons that are located predominantly in the cerebral cortex. Many people with epilepsy continue presenting seizures even though they are under regimens of antiepileptic medications. An alternative therapy for treatment resistant epilepsy is cerebral electrical stimulation. The present study is focused to review the effects of different types of electrical stimulation and specifically changes in amino acids.

  14. Implantable neurotechnologies: electrical stimulation and applications.

    PubMed

    Nag, Sudip; Thakor, Nitish V

    2016-01-01

    Neural stimulation using injected electrical charge is widely used both in functional therapies and as an experimental tool for neuroscience applications. Electrical pulses can induce excitation of targeted neural pathways that aid in the treatment of neural disorders or dysfunction of the central and peripheral nervous system. In this review, we summarize the recent trends in the field of electrical stimulation for therapeutic interventions of nervous system disorders, such as for the restoration of brain, eye, ear, spinal cord, nerve and muscle function. Neural prosthetic applications are discussed, and functional electrical stimulation parameters for treating such disorders are reviewed. Important considerations for implantable packaging and enhancing device reliability are also discussed. Neural stimulators are expected to play a profound role in implantable neural devices that treat disorders and help restore functions in injured or disabled nervous system. PMID:26753775

  15. Increased skin temperature during transcutaneous electrical stimulation.

    PubMed

    Abram, S E; Asiddao, C B; Reynolds, A C

    1980-01-01

    Conflicting reports have appeared in the literature concerning the effects of transcutaneous electrical nerve stimulation on skin temperature. This report studied 33 patients with chronic pain involving one extremity (13 upper, 20 lower) to determine whether changes in sympathetic tone, as reflected in skin temperature, occurred in response to electrical stimulation of painful areas. Stimulation was carried out for 20 to 45 minutes. Skin temperatures were measured from the thumbs or great toes of stimulated and contralateral extremities before and during stimulation. Skin temperature rose 2.5 +/- 0.7 (mean +/- SEM) in both the ipsilateral and contralateral extremity in patients who experienced relief of pain during stimulation. There was no significant change in skin temperature in patients who experienced no relief.

  16. Binaural hearing with electrical stimulation

    PubMed Central

    Kan, Alan; Litovsky, Ruth Y.

    2014-01-01

    Bilateral cochlear implantation is becoming a standard of care in many clinics. While much benefit has been shown through bilateral implantation, patients who have bilateral cochlear implants (CIs) still do not perform as well as normal hearing listeners in sound localization and understanding speech in noisy environments. This difference in performance can arise from a number of different factors, including the areas of hardware and engineering, surgical precision and pathology of the auditory system in deaf persons. While surgical precision and individual pathology are factors that are beyond careful control, improvements can be made in the areas of clinical practice and the engineering of binaural speech processors. These improvements should be grounded in a good understanding of the sensitivities of bilateral CI patients to the acoustic binaural cues that are important to normal hearing listeners for sound localization and speech in noise understanding. To this end, we review the current state-of-the-art in the understanding of the sensitivities of bilateral CI patients to binaural cues in electric hearing, and highlight the important issues and challenges as they relate to clinical practice and the development of new binaural processing strategies. PMID:25193553

  17. Binaural hearing with electrical stimulation.

    PubMed

    Kan, Alan; Litovsky, Ruth Y

    2015-04-01

    Bilateral cochlear implantation is becoming a standard of care in many clinics. While much benefit has been shown through bilateral implantation, patients who have bilateral cochlear implants (CIs) still do not perform as well as normal hearing listeners in sound localization and understanding speech in noisy environments. This difference in performance can arise from a number of different factors, including the areas of hardware and engineering, surgical precision and pathology of the auditory system in deaf persons. While surgical precision and individual pathology are factors that are beyond careful control, improvements can be made in the areas of clinical practice and the engineering of binaural speech processors. These improvements should be grounded in a good understanding of the sensitivities of bilateral CI patients to the acoustic binaural cues that are important to normal hearing listeners for sound localization and speech in noise understanding. To this end, we review the current state-of-the-art in the understanding of the sensitivities of bilateral CI patients to binaural cues in electric hearing, and highlight the important issues and challenges as they relate to clinical practice and the development of new binaural processing strategies. This article is part of a Special Issue entitled .

  18. Transcutaneous Electrical Nerve Stimulation: Research Update.

    ERIC Educational Resources Information Center

    Johns, Florene Carnicelli

    Currently, research is being performed in the area of nonsurgical and nonchemical means for influencing the body's threshold for pain. Today, transcutaneous electrical nerve stimulation (TENS) is being widely used for this purpose. Application of this treatment can be confusing, however, because determining such things as selection of the proper…

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. Metallic taste from electrical and chemical stimulation.

    PubMed

    Lawless, Harry T; Stevens, David A; Chapman, Kathryn W; Kurtz, Anne

    2005-03-01

    A series of three experiments investigated the nature of metallic taste reports after stimulation with solutions of metal salts and after stimulation with metals and electric currents. To stimulate with electricity, a device was fabricated consisting of a small battery affixed to a plastic handle with the anode side exposed for placement on the tongue or oral tissues. Intensity of taste from metals and batteries was dependent upon the voltage and was more robust in areas dense in fungiform papillae. Metallic taste was reported from stimulation with ferrous sulfate solutions, from metals and from electric stimuli. However, reports of metallic taste were more frequent when the word 'metallic' was presented embedded in a list of choices, as opposed to simple free-choice labeling. Intensity decreased for ferrous sulfate when the nose was occluded, consistent with a decrease in retronasal smell, as previously reported. Intensity of taste evoked by copper metal, bimetallic stimuli (zinc/copper) or small batteries (1.5-3 V) was not affected by nasal occlusion. This difference suggests two distinct mechanisms for evocation of metallic taste reports, one dependent upon retronasal smell and a second mediated by oral chemoreceptors. PMID:15741603

  4. Electrical stimulation for epilepsy: stimulation of hippocampal foci.

    PubMed

    Velasco, F; Velasco, M; Velasco, A L; Menez, D; Rocha, L

    2001-01-01

    Subacute and chronic continuous electrical stimulation at the epileptic focus in the hippocampus or parahippocampal cortex at 130 Hz, 0.21-1.0 ms, 2.5-3.5 V (about 200-300 microA) induces a decrease in focal EEG epileptic interictal activity and also in the occurrence of clinical seizures. This may represent an alternative for the treatment of temporal lobe seizures originated in bilateral independent temporal lobe foci or occurring in patients where one is uncertain whether memory deficit might result from ablative procedures.

  5. Tissue damage thresholds during therapeutic electrical stimulation

    NASA Astrophysics Data System (ADS)

    Cogan, Stuart F.; Ludwig, Kip A.; Welle, Cristin G.; Takmakov, Pavel

    2016-04-01

    Objective. Recent initiatives in bioelectronic modulation of the nervous system by the NIH (SPARC), DARPA (ElectRx, SUBNETS) and the GlaxoSmithKline Bioelectronic Medicines effort are ushering in a new era of therapeutic electrical stimulation. These novel therapies are prompting a re-evaluation of established electrical thresholds for stimulation-induced tissue damage. Approach. In this review, we explore what is known and unknown in published literature regarding tissue damage from electrical stimulation. Main results. For macroelectrodes, the potential for tissue damage is often assessed by comparing the intensity of stimulation, characterized by the charge density and charge per phase of a stimulus pulse, with a damage threshold identified through histological evidence from in vivo experiments as described by the Shannon equation. While the Shannon equation has proved useful in assessing the likely occurrence of tissue damage, the analysis is limited by the experimental parameters of the original studies. Tissue damage is influenced by factors not explicitly incorporated into the Shannon equation, including pulse frequency, duty cycle, current density, and electrode size. Microelectrodes in particular do not follow the charge per phase and charge density co-dependence reflected in the Shannon equation. The relevance of these factors to tissue damage is framed in the context of available reports from modeling and in vivo studies. Significance. It is apparent that emerging applications, especially with microelectrodes, will require clinical charge densities that exceed traditional damage thresholds. Experimental data show that stimulation at higher charge densities can be achieved without causing tissue damage, suggesting that safety parameters for microelectrodes might be distinct from those defined for macroelectrodes. However, these increased charge densities may need to be justified by bench, non-clinical or clinical testing to provide evidence of device

  6. Electrical stimulation for the relief of pain.

    PubMed

    Miles, J

    1984-03-01

    Electrical stimulation can relieve some severe and otherwise persisting pains. At its best it can be associated with either a gradual reduction in the pain or an increased ability by the patient to control his suffering. It seems particularly appropriate for use in the field of benign persistent pain. Equipment design and materials, particularly for implantable circuits, are not perfect. Movement towards percutaneous implantation, obviating the need for open operation, seems progressively more popular. Any unit or group using this form of treatment, must be prepared to provide major technical facilities, both in the form of people and equipment in order to cater for the many purely technical problems that occur. A great deal of knowledge both neurophysiological and neurochemical seems to be accruing from the clinical use of electrical stimulation. We would do well to take advantage of this opportunity, in the hope that it might lead us to a better understanding of the functioning of the nervous system. This consideration remarkably parallels an observation made by John Hunter in his presentation to the Royal Society in 1773 (13) which anticipated the realisation of the part played by electricity in the function of nerves. Following his description of the extraordinary innervation of the electric organs of the Torpedo fish, he wrote: 'How far this may be connected with the power of the nerves in general, or how far it may lead to an explanation of their operations, time and future discoveries alone can fully determine.' PMID:6608312

  7. 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.

  8. Electrical Stimulation Technologies for Wound Healing

    PubMed Central

    Kloth, Luther C.

    2014-01-01

    Objective: To discuss the physiological bases for using exogenously applied electric field (EF) energy to enhance wound healing with conductive electrical stimulation (ES) devices. Approach: To describe the types of electrical currents that have been reported to enhance chronic wound-healing rate and closure. Results: Commercial ES devices that generate direct current (DC), and mono and biphasic pulsed current waveforms represent the principal ES technologies which are reported to enhance wound healing. Innovation: Wafer-thin, disposable ES technologies (wound dressings) that utilize mini or micro-batteries to deliver low-level DC for wound healing and antibacterial wound-treatment purposes are commercially available. Microfluidic wound-healing chips are currently being used with greater accuracy to investigate the EF effects on cellular electrotaxis. Conclusion: Numerous clinical trials described in subsequent sections of this issue have demonstrated that ES used adjunctively with standard wound care (SWC), enhances wound healing rate faster than SWC alone. PMID:24761348

  9. Electrical stimulation systems for cardiac tissue engineering

    PubMed Central

    Tandon, Nina; Cannizzaro, Christopher; Chao, Pen-Hsiu Grace; Maidhof, Robert; Marsano, Anna; Au, Hoi Ting Heidi; Radisic, Milica; Vunjak-Novakovic, Gordana

    2009-01-01

    We describe a protocol for tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cells with the application of pulsatile electrical fields designed to mimic those present in the native heart. Tissue culture is conducted in a customized chamber built to allow for cultivation of (i) engineered three-dimensional (3D) cardiac tissue constructs, (ii) cell monolayers on flat substrates or (iii) cells on patterned substrates. This also allows for analysis of the individual and interactive effects of pulsatile electrical field stimulation and substrate topography on cell differentiation and assembly. The protocol is designed to allow for delivery of predictable electrical field stimuli to cells, monitoring environmental parameters, and assessment of cell and tissue responses. The duration of the protocol is 5 d for two-dimensional cultures and 10 d for 3D cultures. PMID:19180087

  10. Electrical stimulation systems for cardiac tissue engineering.

    PubMed

    Tandon, Nina; Cannizzaro, Christopher; Chao, Pen-Hsiu Grace; Maidhof, Robert; Marsano, Anna; Au, Hoi Ting Heidi; Radisic, Milica; Vunjak-Novakovic, Gordana

    2009-01-01

    We describe a protocol for tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cells with the application of pulsatile electrical fields designed to mimic those present in the native heart. Tissue culture is conducted in a customized chamber built to allow for cultivation of (i) engineered three-dimensional (3D) cardiac tissue constructs, (ii) cell monolayers on flat substrates or (iii) cells on patterned substrates. This also allows for analysis of the individual and interactive effects of pulsatile electrical field stimulation and substrate topography on cell differentiation and assembly. The protocol is designed to allow for delivery of predictable electrical field stimuli to cells, monitoring environmental parameters, and assessment of cell and tissue responses. The duration of the protocol is 5 d for two-dimensional cultures and 10 d for 3D cultures.

  11. 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…

  12. Auricular electrical stimulation and dental pain threshold.

    PubMed Central

    Simmons, M. S.; Oleson, T. D.

    1993-01-01

    A modified double-blind evaluation of naloxone reversibility of dental analgesia produced by auricular electrical stimulation (AES) was examined in 40 subjects assigned randomly to one of four groups: AES followed by saline (AS), AES followed by naloxone (AN), placebo AES followed by saline (PS), and placebo AES followed by naloxone (PN). Dental pain threshold was tested using a hand-held dental pulp tester. A second investigator administered the true or placebo AES using an electrical stimulator. A third investigator injected intravenously saline or naloxone. The subjects and investigators 1 and 3 were blind to all treatment conditions. A repeated measures analysis of variance revealed a significant difference among the four groups. The AES groups exhibited a statistically significant 18% elevation of pain threshold, whereas the two placebo stimulation groups (PS and PN) remained essentially unchanged. The mean pain threshold increased to more than 23% for group AS, but fell to less than 12% for the subjects in group AN, who were given naloxone. These findings indicate a small but significant elevation of pain threshold by AES, an effect partially blocked by naloxone, suggesting an endogenous opioid system as one mechanism for AES analgesia. Images Figure 1 Figure 2 PMID:8185085

  13. Electrical Stimulation for Drug-Resistant Epilepsy

    PubMed Central

    Chambers, A; Bowen, JM

    2013-01-01

    Objective The objective of this analysis was to evaluate the effectiveness of deep brain stimulation (DBS) and vagus nerve stimulation (VNS) for the treatment of drug-resistant epilepsy in adults and children. Data Sources A literature search was performed using MEDLINE, EMBASE, the Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published from January 2007 until December 2012. Review Methods Systematic reviews, meta-analyses, randomized controlled trials (RCTs), and observational studies (in the absence of RCTs) of adults or children were included. DBS studies were included if they specified that the anterior nucleus of thalamus was the area of the brain stimulated. Outcomes of interest were seizure frequency, health resource utilization, and safety. A cost analysis was also performed. Results The search identified 6 studies that assessed changes in seizure frequency after electrical stimulation: 1 RCT on DBS in adults, 4 RCTs on VNS in adults, and 1 RCT on VNS in children. The studies of DBS and VNS in adults found significantly improved rates of seizure frequency, but the study of VNS in children did not find a significant difference in seizure frequency between the high and low stimulation groups. Significant reductions in hospitalizations and emergency department visits were found for adults and children who received VNS. No studies addressed the use of health resources for patients undergoing DBS. Five studies reported on adverse events, which ranged from serious to transient for both procedures in adults and were mostly transient in the 1 study of VNS in children. Limitations We found no evidence on DBS in children or on health care use related to DBS. The measurement of seizure frequency is self-reported and is therefore subject to bias and issues of compliance. Conclusions Based on evidence of low to moderate quality, both DBS and VNS seemed to reduce seizure frequency in adults. In children, VNS did not appear to be as

  14. Functional electrical stimulation bicycle ergometry: patient perceptions.

    PubMed

    Sipski, M L; Delisa, J A; Schweer, S

    1989-06-01

    Forty-seven patients who had participated in a clinical electrical stimulation ergometry program were administered a questionnaire to determine their perceptions of the therapy. Improved endurance was reported by 62% of paraplegics and 65% of quadriplegics. Sixty-two percent of paraplegics and 56% of quadriplegics reported improved self-image, while 54% of paraplegics and 77% of quadriplegics perceived their appearance was better. Thirty-nine percent of paraplegics and 24% of quadriplegics noted decreased lower extremity edema with training. Six out of nine patients with a previous history of neurogenic pain noted an increase in pain, which caused them to leave the program.

  15. Functional electrical stimulation and spinal cord injury.

    PubMed

    Ho, Chester H; Triolo, Ronald J; Elias, Anastasia L; Kilgore, Kevin L; DiMarco, Anthony F; Bogie, Kath; Vette, Albert H; Audu, Musa L; Kobetic, Rudi; Chang, Sarah R; Chan, K Ming; Dukelow, Sean; Bourbeau, Dennis J; Brose, Steven W; Gustafson, Kenneth J; Kiss, Zelma H T; Mushahwar, Vivian K

    2014-08-01

    Spinal cord injuries (SCI) can disrupt communications between the brain and the body, resulting in loss of control over otherwise intact neuromuscular systems. Functional electrical stimulation (FES) of the central and peripheral nervous system can use these intact neuromuscular systems to provide therapeutic exercise options to allow functional restoration and to manage medical complications following SCI. The use of FES for the restoration of muscular and organ functions may significantly decrease the morbidity and mortality following SCI. Many FES devices are commercially available and should be considered as part of the lifelong rehabilitation care plan for all eligible persons with SCI.

  16. Functional electrical stimulation and spinal cord injury.

    PubMed

    Ho, Chester H; Triolo, Ronald J; Elias, Anastasia L; Kilgore, Kevin L; DiMarco, Anthony F; Bogie, Kath; Vette, Albert H; Audu, Musa L; Kobetic, Rudi; Chang, Sarah R; Chan, K Ming; Dukelow, Sean; Bourbeau, Dennis J; Brose, Steven W; Gustafson, Kenneth J; Kiss, Zelma H T; Mushahwar, Vivian K

    2014-08-01

    Spinal cord injuries (SCI) can disrupt communications between the brain and the body, resulting in loss of control over otherwise intact neuromuscular systems. Functional electrical stimulation (FES) of the central and peripheral nervous system can use these intact neuromuscular systems to provide therapeutic exercise options to allow functional restoration and to manage medical complications following SCI. The use of FES for the restoration of muscular and organ functions may significantly decrease the morbidity and mortality following SCI. Many FES devices are commercially available and should be considered as part of the lifelong rehabilitation care plan for all eligible persons with SCI. PMID:25064792

  17. Electrical stimulation for the relief of pain.

    PubMed Central

    Miles, J.

    1984-01-01

    Electrical stimulation can relieve some severe and otherwise persisting pains. At its best it can be associated with either a gradual reduction in the pain or an increased ability by the patient to control his suffering. It seems particularly appropriate for use in the field of benign persistent pain. Equipment design and materials, particularly for implantable circuits, are not perfect. Movement towards percutaneous implantation, obviating the need for open operation, seems progressively more popular. Any unit or group using this form of treatment, must be prepared to provide major technical facilities, both in the form of people and equipment in order to cater for the many purely technical problems that occur. A great deal of knowledge both neurophysiological and neurochemical seems to be accruing from the clinical use of electrical stimulation. We would do well to take advantage of this opportunity, in the hope that it might lead us to a better understanding of the functioning of the nervous system. This consideration remarkably parallels an observation made by John Hunter in his presentation to the Royal Society in 1773 (13) which anticipated the realisation of the part played by electricity in the function of nerves. Following his description of the extraordinary innervation of the electric organs of the Torpedo fish, he wrote: 'How far this may be connected with the power of the nerves in general, or how far it may lead to an explanation of their operations, time and future discoveries alone can fully determine.' Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:6608312

  18. Deep Brain Electrical Stimulation in Epilepsy

    NASA Astrophysics Data System (ADS)

    Rocha, Luisa L.

    2008-11-01

    The deep brain electrical stimulation has been used for the treatment of neurological disorders such as Parkinson's disease, chronic pain, depression and epilepsy. Studies carried out in human brain indicate that the application of high frequency electrical stimulation (HFS) at 130 Hz in limbic structures of patients with intractable temporal lobe epilepsy abolished clinical seizures and significantly decreased the number of interictal spikes at focus. The anticonvulsant effects of HFS seem to be more effective in patients with less severe epilepsy, an effect associated with a high GABA tissue content and a low rate of cell loss. In addition, experiments using models of epilepsy indicate that HFS (pulses of 60 μs width at 130 Hz at subthreshold current intensity) of specific brain areas avoids the acquisition of generalized seizures and enhances the postictal seizure suppression. HFS is also able to modify the status epilepticus. It is concluded that the effects of HFS may be a good strategy to reduce or avoid the epileptic activity.

  19. A continuum model of retinal electrical stimulation

    NASA Astrophysics Data System (ADS)

    Joarder, Saiful A.; Abramian, Miganoosh; Suaning, Gregg J.; Lovell, Nigel H.; Dokos, Socrates

    2011-10-01

    A continuum mathematical model of retinal electrical stimulation is described. The model is represented by a passive vitreous domain, a thin layer of active retinal ganglion cell (RGC) tissue adjacent to deeper passive neural layers of the retina, the retinal pigmented epithelium (RPE) and choroid thus ending at the sclera. To validate the model, in vitro epiretinal responses to stimuli from 50 µm disk electrodes, arranged in a hexagonal mosaic, were recorded from rabbit retinas. 100 µs/phase anodic-first biphasic current pulses were delivered to the retinal surface in both the mathematical model and experiments. RGC responses were simulated and recorded using extracellular microelectrodes. The model's epiretinal thresholds compared favorably with the in vitro data. In addition, simulations showed that single-return bipolar electrodes recruited a larger area of the retina than twin-return or six-return electrodes arranged in a hexagonal layout in which a central stimulating electrode is surrounded by six, eqi-spaced returns. Simulations were also undertaken to investigate the patterns of RGC activation in an anatomically-accurate model of the retina, as well as RGC activation patterns for subretinal and suprachoroidal bipolar stimulation. This paper was originally submitted for the special issue containing contributions from the Sixth Biennial Research Congress of The Eye and the Chip.

  20. Electrochemical corrosion of STS304 acupuncture needles by electrical stimulation.

    PubMed

    Hwang, Hye Suk; Yang, Eun Jin; Ryu, Yeon Hee; Lee, Myeong Soo; Choi, Sun-Mi

    2010-06-01

    We present the first investigation of electrical corrosion in acupuncture needles after electrical stimulation. Using scanning electron microscopy, we observed the occurrence of electrochemical corrosion on the surface of stainless steel 304 acupuncture needles after electrical stimulation in the tibial muscles of rats. Biphasic pulse electrical stimuli with 10-Hz frequency, 1-mA intensity and 1-ms pulse width were applied to the needles. The terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method labels fragmented DNA. Positive staining using this test indicates apoptotic cells in electrically stimulated tissues. The risk of electrical corrosion was found to be less in bipolar, short-duration, low-current or voltage and short-period stimulation than in monopolar, long-duration, high-current or voltage and long-period stimulation. Evaluation with a scanning electron microscope revealed that electrical stimulation can increase the electrical corrosion of stainless steel 304 acupuncture needles. In biocompatibility studies of stainless steel 304 acupuncture needles for electrical stimulation, TUNEL-positive cells were detected in the tibial muscle within 5 days after electrical stimulation. The results of this study demonstrate that the corrosion products of stainless steel 304 acupuncture needles might affect the post-electrical stimulation tissue response. PMID:20633521

  1. Functional Electrical Stimulation and Spinal Cord Injury

    PubMed Central

    Ho, Chester H.; Triolo, Ronald J.; Elias, Anastasia L.; Kilgore, Kevin L.; DiMarco, Anthony F.; Bogie, Kath; Vette, Albert H.; Audu, Musa; Kobetic, Rudi; Chang, Sarah R.; Chan, K. Ming; Dukelow, Sean; Bourbeau, Dennis J.; Brose, Steven W.; Gustafson, Kenneth J.; Kiss, Zelma; Mushahwar, Vivian K.

    2015-01-01

    Synopsis Spinal cord injuries (SCI) can disrupt communications between the brain and the body, leading to a loss of control over otherwise intact neuromuscular systems. The use of electrical stimulation (ES) of the central and peripheral nervous system can take advantage of these intact neuromuscular systems to provide therapeutic exercise options, to allow functional restoration, and even to manage or prevent many medical complications following SCI. The use of ES for the restoration of upper extremity, lower extremity and truncal functions can make many activities of daily living a potential reality for individuals with SCI. Restoring bladder and respiratory functions and preventing pressure ulcers may significantly decrease the morbidity and mortality following SCI. Many of the ES devices are already commercially available and should be considered by all SCI clinicians routinely as part of the lifelong rehabilitation care plan for all eligible individuals with SCI. PMID:25064792

  2. Imaging Electrical Stimulation of the Human Cortex

    NASA Astrophysics Data System (ADS)

    Bahar, Sonya; Suh, Minah; Mehta, Ashesh D.; Schwartz, Theodore H.

    2004-03-01

    The intrinsic optical signal (IOS) is a change in light reflectance from neural tissue that correlates spatially with electrophysiological activity. Depending on the wavelength of incident light, the IOS reveals different physiological changes in the tissue. In order for the IOS to be applicable to problems such as the intraoperative brain mapping, it is critical to determine which wavelengths of incident light provide optimal information about the time course and spatial localization of the underlying activity. We performed intraoperative imaging of the human cortex during direct electrical stimulation, with illumination at 546 nm (corresponding mainly to blood flow) and 605 nm (corresponding to the oxy/deoxy ratio of hemoglobin). Incident light at 546 nm showed a much larger reflectance change than orange light; at 605 nm an initial reflectance change was observed which may correspond to the ``initial dip'' observed in BOLD (blood oxygen level dependent) fMRI imaging, followed by a large inverse reflectance signal which may correlate closely with the BOLD fMRI signal itself.

  3. 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

  4. Muscle damage induced by electrical stimulation.

    PubMed

    Nosaka, Kazunori; Aldayel, Abdulaziz; Jubeau, Marc; Chen, Trevor C

    2011-10-01

    Electrical stimulation (ES) induces muscle damage that is characterised by histological alterations of muscle fibres and connective tissue, increases in circulating creatine kinase (CK) activity, decreases in muscle strength and development of delayed onset muscle soreness (DOMS). Muscle damage is induced not only by eccentric contractions with ES but also by isometric contractions evoked by ES. Muscle damage profile following 40 isometric contractions of the knee extensors is similar between pulsed current (75 Hz, 400 μs) and alternating current (2.5 kHz delivered at 75 Hz, 400 μs) ES for similar force output. When comparing maximal voluntary and ES-evoked (75 Hz, 200 μs) 50 isometric contractions of the elbow flexors, ES results in greater decreases in maximal voluntary contraction strength, increases in plasma CK activity and DOMS. It appears that the magnitude of muscle damage induced by ES-evoked isometric contractions is comparable to that induced by maximal voluntary eccentric contractions, although the volume of affected muscles in ES is not as large as that of eccentric exercise-induced muscle damage. It seems likely that the muscle damage in ES is associated with high mechanical stress on the activated muscle fibres due to the specificity of motor unit recruitment (i.e., non-selective, synchronous and spatially fixed manner). The magnitude of muscle damage induced by ES is significantly reduced when the second ES bout is performed 2-4 weeks later. It is possible to attenuate the magnitude of muscle damage by "pre-conditioning" muscles, so that muscle damage should not limit the use of ES in training and rehabilitation. PMID:21811767

  5. 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

  6. 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...

  7. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... a device used to apply an electrical current to a patient to test the level of pharmacological... 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...

  8. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... a device used to apply an electrical current to a patient to test the level of pharmacological... 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...

  9. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... a device used to apply an electrical current to a patient to test the level of pharmacological... 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...

  10. 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...

  11. 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.

  12. 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

  13. Vascular effects of free radicals generated by electrical stimulation

    SciTech Connect

    Lamb, F.S.; Webb, R.C.

    1984-11-01

    Electrical field stimulation (9 V, 1.0 ms, 4 Hz) of isolated segments of rat tail arteries and dog coronary arteries inhibits contractile response to exogenous norephinephrine and elevated potassium concentration. This inhibitory effect of electrical stimulation is blocked by various agents that alter oxygen metabolism: superoxide dismutase, catalase, glutathione, ascorbate, and dimethyl sulfoxide. The observations suggest that the inhibitory effect is due to an action of oxygen free radical metabolites that are generated by the electrical stimulation of the oxygen-rich buffer. These free radical metabolites have two actions: 1) they oxidize drugs in the experimental system, and 2) they exert a direct inhbitory action on vascular smooth muscle.

  14. Selective Activation of Neuronal Targets With Sinusoidal Electric Stimulation

    PubMed Central

    Freeman, Daniel K.; Eddington, Donald K.; Rizzo, Joseph F.

    2010-01-01

    Electric stimulation of the CNS is being evaluated as a treatment modality for a variety of neurological, psychiatric, and sensory disorders. Despite considerable success in some applications, existing stimulation techniques offer little control over which cell types or neuronal substructures are activated by stimulation. The ability to more precisely control neuronal activation would likely improve the clinical outcomes associated with these applications. Here, we show that specific frequencies of sinusoidal stimulation can be used to preferentially activate certain retinal cell types: photoreceptors are activated at 5 Hz, bipolar cells at 25 Hz, and ganglion cells at 100 Hz. In addition, low-frequency stimulation (≤25 Hz) did not activate passing axons but still elicited robust synaptically mediated responses in ganglion cells; therefore, elicited neural activity is confined to within a focal region around the stimulating electrode. Our results suggest that sinusoidal stimulation provides significantly improved control over elicited neural activity relative to conventional pulsatile stimulation. PMID:20810683

  15. 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

  16. Optimization of electrical stimulation parameters for cardiac tissue engineering.

    PubMed

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

    2011-06-01

    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 engineered cardiac tissues. 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, were thus used in tissue engineering studies. Engineered cardiac tissues stimulated at 3 V/cm amplitude and 3 Hz frequency had the highest tissue density, the highest concentrations of cardiac troponin-I and connexin-43 and the best-developed contractile behaviour. These findings contribute to defining bioreactor design specifications and electrical stimulation regime for cardiac tissue engineering.

  17. A CONTINUED INVESTIGATION OF ELECTRICALLY STIMULATED FABRIC FILTRATION

    EPA Science Inventory

    The report summarizes three experiments performed by Southern Research Institute under a cooperative agreement with EPA. First was a demonstration of electrostatically stimulated fabric filtration (ESFF) used to collect particulate matter (PM) from fossil fuel electrical power pl...

  18. Electrical stimulation therapies for spinal fusions: current concepts.

    PubMed

    Gan, Jean C; Glazer, Paul A

    2006-09-01

    Electrical stimulation therapies have been used for more than 30 years to enhance spinal fusions. Although their positive effects on spinal fusions have been widely reported, the mechanisms of action of the technologies were only recently identified. Three types of technologies are available clinically: direct current, capacitive coupling, and inductive coupling. The latter is the basis of pulsed electromagnetic fields and combined magnetic fields. This review summarizes the current concepts on the mechanisms of action, animal and clinical studies, and cost justification for the use of electrical stimulation for spinal fusions. Scientific studies support the validity of electrical stimulation treatments. The mechanisms of action of each of the three electrical stimulation therapies are different. New data demonstrates that the upregulation of several growth factors may be responsible for the clinical success seen with the use of such technologies.

  19. The effect of electrical stimulation on obstructive sleep apnea syndrome.

    PubMed

    Guilleminault, C; Powell, N; Bowman, B; Stoohs, R

    1995-01-01

    Patients with severe obstructive sleep apnea polygraphically documented underwent electrical stimulation treatment trials. Submental and intraoral stimulations were applied during waking and during nocturnal sleep. The stimulation was applied using a custom-designed neuromuscular electrical stimulator (EdenTec Corp) providing symmetric biphasic constant voltage pulses. Pulse duration of each phase was set to 80 microseconds based on a subjective evaluation of pulse durations from 80 to 300 microseconds to minimize sensation while generating equivalent motor responses. Pulse repetition rate was set to 50 pulses per second. Cephalometric radiographs and endoscopies were obtained with and without stimulations during waking. Most commonly, stimulations induced alpha EEG arousals. Submental subcutaneous stimulation induced good contractions of platysmal muscles but had no impact on the upper airway. Intraoral stimulation induced clear tongue muscle movements but with change of shape of the upper airway and posterior movements of the tongue. Each time a breakage of apnea was noted, it was associated with a time-linked alpha EEG arousal. The results obtained by us and others do not, at this time, give convincing support for the use of electrical stimulation using submental surface or intraoral electrodes as a viable approach for effective control of obstructive sleep apnea syndrome symptoms.

  20. 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

  1. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    PubMed Central

    Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

    2015-01-01

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes. PMID:26193273

  2. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation.

    PubMed

    Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

    2015-07-16

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes.

  3. Electrical stimulation of a small brain area reversibly disrupts consciousness.

    PubMed

    Koubeissi, Mohamad Z; Bartolomei, Fabrice; Beltagy, Abdelrahman; Picard, Fabienne

    2014-08-01

    The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks.

  4. Electrical stimulation of a small brain area reversibly disrupts consciousness.

    PubMed

    Koubeissi, Mohamad Z; Bartolomei, Fabrice; Beltagy, Abdelrahman; Picard, Fabienne

    2014-08-01

    The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks. PMID:24967698

  5. Electric field stimulated growth of Zn whiskers

    NASA Astrophysics Data System (ADS)

    Niraula, D.; McCulloch, J.; Warrell, G. R.; Irving, R.; Karpov, V. G.; Shvydka, Diana

    2016-07-01

    We have investigated the impact of strong (˜104 V/cm) electric fields on the development of Zn whiskers. The original samples, with considerable whisker infestation were cut from Zn-coated steel floors and then exposed to electric fields stresses for 10-20 hours at room temperature. We used various electric field sources, from charges accumulated in samples irradiated by: (1) the electron beam of a scanning electron microscope (SEM), (2) the electron beam of a medical linear accelerator, and (3) the ion beam of a linear accelerator; we also used (4) the electric field produced by a Van der Graaf generator. In all cases, the exposed samples exhibited a considerable (tens of percent) increase in whiskers concentration compared to the control sample. The acceleration factor defined as the ratio of the measured whisker growth rate over that in zero field, was estimated to approach several hundred. The statistics of lengths of e-beam induced whiskers was found to follow the log-normal distribution known previously for metal whiskers. The observed accelerated whisker growth is attributed to electrostatic effects. These results offer promise for establishing whisker-related accelerated life testing protocols.

  6. 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.

  7. Safe neuromuscular electrical stimulator designed for the elderly.

    PubMed

    Krenn, Matthias; Haller, Michael; Bijak, Manfred; Unger, Ewald; Hofer, Christian; Kern, Helmut; Mayr, Winfried

    2011-03-01

    A stimulator for neuromuscular electrical stimulation (NMES) was designed, especially suiting the requirements of elderly people with reduced cognitive abilities and diminished fine motor skills. The aging of skeletal muscle is characterized by a progressive decline in muscle mass, force, and condition. Muscle training with NMES reduces the degradation process. The discussed system is intended for evoked muscle training of the anterior and posterior thigh. The core of the stimulator is based on a microcontroller with two modular output stages. The system has two charge-balanced biphasic voltage-controlled stimulation channels. Additionally, the evoked myoelectric signal (M-wave) and the myokinematic signal (surface acceleration) are measured. A central controller unit allows using the stimulator as a stand-alone device. To set up the training sequences and to evaluate the compliance data, a personal computer is connected to the stimulator via a universal serial bus. To help elderly people handle the stimulator by themselves, the user interface is kept very simple. For safety reasons, the electrode impedance is monitored during stimulation. A comprehensive compliance management with included measurements of muscle activity and stimulation intensity enables a scientific use of the stimulator in clinical trials.

  8. Bladder emptying by intermittent electrical stimulation of the pudendal nerve

    NASA Astrophysics Data System (ADS)

    Boggs, Joseph W.; Wenzel, Brian J.; Gustafson, Kenneth J.; Grill, Warren M.

    2006-03-01

    Persons with a suprasacral spinal cord injury cannot empty their bladder voluntarily. Bladder emptying can be restored by intermittent electrical stimulation of the sacral nerve roots (SR) to cause bladder contraction. However, this therapy requires sensory nerve transection to prevent dyssynergic contraction of the external urethral sphincter (EUS). Stimulation of the compound pudendal nerve trunk (PN) activates spinal micturition circuitry, leading to a reflex bladder contraction without a reflex EUS contraction. The present study determined if PN stimulation could produce bladder emptying without nerve transection in cats anesthetized with α-chloralose. With all nerves intact, intermittent PN stimulation emptied the bladder (64 ± 14% of initial volume, n = 37 across six cats) more effectively than either distention-evoked micturition (40 ± 19%, p < 0.001, n = 27 across six cats) or bilateral intermittent SR stimulation (25 ± 23%, p < 0.005, n = 4 across two cats). After bilateral transection of the nerves innervating the urethral sphincter, intermittent SR stimulation voided 79 ± 17% (n = 12 across three cats), comparable to clinical results obtained with SR stimulation. Voiding via intermittent PN stimulation did not increase after neurotomy (p > 0.10), indicating that PN stimulation was not limited by bladder-sphincter dyssynergia. Intermittent PN stimulation holds promise for restoring bladder emptying following spinal injury without requiring nerve transection.

  9. Safe neuromuscular electrical stimulator designed for the elderly.

    PubMed

    Krenn, Matthias; Haller, Michael; Bijak, Manfred; Unger, Ewald; Hofer, Christian; Kern, Helmut; Mayr, Winfried

    2011-03-01

    A stimulator for neuromuscular electrical stimulation (NMES) was designed, especially suiting the requirements of elderly people with reduced cognitive abilities and diminished fine motor skills. The aging of skeletal muscle is characterized by a progressive decline in muscle mass, force, and condition. Muscle training with NMES reduces the degradation process. The discussed system is intended for evoked muscle training of the anterior and posterior thigh. The core of the stimulator is based on a microcontroller with two modular output stages. The system has two charge-balanced biphasic voltage-controlled stimulation channels. Additionally, the evoked myoelectric signal (M-wave) and the myokinematic signal (surface acceleration) are measured. A central controller unit allows using the stimulator as a stand-alone device. To set up the training sequences and to evaluate the compliance data, a personal computer is connected to the stimulator via a universal serial bus. To help elderly people handle the stimulator by themselves, the user interface is kept very simple. For safety reasons, the electrode impedance is monitored during stimulation. A comprehensive compliance management with included measurements of muscle activity and stimulation intensity enables a scientific use of the stimulator in clinical trials. PMID:21401669

  10. Mapping of electrical muscle stimulation using MRI

    NASA Technical Reports Server (NTRS)

    Adams, Gregory R.; Harris, Robert T.; Woodard, Daniel; Dudley, Gary A.

    1993-01-01

    The pattern of muscle contractile activity elicited by electromyostimulation (EMS) was mapped and compared to the contractile-activity pattern produced by voluntary effort. This was done by examining the patterns and the extent of contrast shift, as indicated by T2 values, im magnetic resonance (MR) images after isometric activity of the left m. quadriceps of human subjects was elicited by EMS (1-sec train of 500-microsec sine wave pulses at 50 Hz) or voluntary effort. The results suggest that, whereas EMS stimulates the same fibers repeatedly, thereby increasing the metabolic demand and T2 values, the voluntary efforts are performed by more diffuse asynchronous activation of skeletal muscle even at forces up to 75 percent of maximal to maintain performance.

  11. Cortical excitability changes following grasping exercise augmented with electrical stimulation.

    PubMed

    Barsi, Gergely I; Popovic, Dejan B; Tarkka, Ina M; Sinkjaer, Thomas; Grey, Michael J

    2008-10-01

    Rehabilitation with augmented electrical stimulation can enhance functional recovery after stroke, and cortical plasticity may play a role in this process. The purpose of this study was to compare the effects of three training paradigms on cortical excitability in healthy subjects. Cortical excitability was evaluated by analysing the input-output relationship between transcranial magnetic stimulation intensity and motor evoked potentials (MEPs) from the flexor muscles of the fingers. The study was performed with 25 healthy volunteers who underwent 20-min simulated therapy sessions of: (1) functional electrical stimulation (FES) of the finger flexors and extensors, (2) voluntary movement (VOL) with sensory stimulation, and (3) therapeutic FES (TFES) where the electrical stimulation augmented voluntary activation. TFES training produced a significant increase in MEP magnitude throughout the stimulation range, suggesting an increase in cortical excitability. In contrast, neither the FES nor voluntary movement alone had such an effect. These results suggest that the combination of voluntary effort and FES has greater potential to induce plasticity in the motor cortex and that TFES might be a more effective approach in rehabilitation after stroke than FES or repetitive voluntary training alone.

  12. Corticospinal potentials after electrical and magnetic stimulation in man.

    PubMed

    Berardelli, A; Inghilleri, M; Cruccu, G; Manfredi, M

    1991-01-01

    The present report deals with our study of the descending volley evoked by both electrical and magnetic transcranial stimulation in man. We discuss the differences of these two techniques specifically as regards the latency and amplitude of evoked potentials. In both cases, electrodes were placed either in the epidural space or directly on the spinal cord. Following electrical stimulation, the descending volley consisted of an early wave which appeared at low stimulation intensity and increased in amplitude and decreased in latency when the strength of the stimulus was increased. At high stimulation intensities the early wave was followed by later waves which travel at the same speed as the initial wave. By delivering paired cortical stimuli, the early wave evoked by the test stimuli is present at 1-msec interval and progressively recovered with longer intervals. The recovery cycle of the later waves is also extremely short. Following magnetic stimulation, the descending volley also consisted of an initial wave followed by later waves. The initial wave has a slightly longer latency, a higher threshold and a smaller amplitude than the early wave evoked by electrical stimulation. The results are discussed with reference to the D and I waves recorded from the pyramidal tract in animals.

  13. 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.

  14. Electrically stimulated contractions of Vorticella convallaria

    NASA Astrophysics Data System (ADS)

    Kantha, Deependra; van Winkle, David

    2009-03-01

    The contraction of Vorticella convallaria was triggered by applying a voltage pulse in its host culturing medium. The 50V, 1ms wide pulse was applied across platinum wires separated by 0.7 cm on a microscope slide. The contractions were recorded as cines (image sequences) by a Phantom V5 camera (Vision Research) on a bright field microscope with 20X objective, with the image size of 256 pixels x 128 pixels at 7352 pictures per second. The starting time of the cines was synchronized with the starting of the electrical pulse. We recorded five contractions of each of 12 organisms. The cines were analyzed to obtain the initiation time, defined as the difference in time between the leading edge of the electrical pulse and the first frame showing zooid movement. From multiple contractions of same organism, we found the initiation time is reproducible. In comparing different organisms, we found the average initiation time of 1.73 ms with a standard deviation of 0.63 ms. This research is supported by the state of Florida (MARTECH) and Research Corporation.

  15. An update on functional electrical stimulation after spinal cord injury.

    PubMed

    Gorman, P H

    2000-01-01

    Recent advances in biomedical engineering as applied to neurologic rehabilitation have finally borne clinically relevant fruit. Nowhere is this more evident than in the field of functional electrical stimulation (FES). This article highlights the remarkable clinical progress that has been made in the use of electrical stimulation for restoring movement and function in individuals with spinal cord injury. Specific attention is given to respiratory-assist devices, hand-grasp systems, standing and walking, and bladder control. This review article features discussion of eight devices that have gone through the United States Food and Drug Administration (FDA) regulatory approval process. PMID:11402876

  16. Exploring Selective Neural Electrical Stimulation for Upper Limb Function Restoration

    PubMed Central

    Tigra, Wafa; Guiraud, David; Andreu, David; Coulet, Bertrand; Gelis, Anthony; Fattal, Charles; Maciejasz, Pawel; Picq, Chloé; Rossel, Olivier; Teissier, Jacques; Coste, Christine Azevedo

    2016-01-01

    This article introduces a new approach of selective neural electrical stimulation of the upper limb nerves. Median and radial nerves of individuals with tetraplegia are stimulated via a multipolar cuff electrode to elicit movements of wrist and hand in acute conditions during a surgical intervention. Various configurations corresponding to various combinations of a 12-poles cuff electrode contacts are tested. Video recording and electromyographic (EMG) signals recorded via sterile surface electrodes are used to evaluate the selectivity of each stimulation configuration in terms of activated muscles. In this abstract we introduce the protocol and preliminary results will be presented during the conference. PMID:27478571

  17. Hearing suppression induced by electrical stimulation of human auditory cortex.

    PubMed

    Fenoy, Albert J; Severson, Meryl A; Volkov, Igor O; Brugge, John F; Howard, Matthew A

    2006-11-01

    In the course of performing electrical stimulation functional mapping (ESFM) in neurosurgery patients, we identified three subjects who experienced hearing suppression during stimulation of sites within the superior temporal gyrus (STG). One of these patients had long standing tinnitus that affected both ears. In all subjects, auditory event related potentials (ERPs) were recorded from chronically implanted intracranial electrodes and the results were used to localize auditory cortical fields within the STG. Hearing suppression sites were identified within anterior lateral Heschl's gyrus (HG) and posterior lateral STG, in what may be auditory belt and parabelt fields. Cortical stimulation suppressed hearing in both ears, which persisted beyond the period of electrical stimulation. Subjects experienced other stimulation-evoked perceptions at some of these same sites, including symptoms of vestibular activation and alteration of audio-visual speech processing. In contrast, stimulation of presumed core auditory cortex within posterior medial HG evoked sound perceptions, or in one case an increase in tinnitus intensity, that affected the contralateral ear and did not persist beyond the period of stimulation. The current results confirm a rarely reported experimental observation, and correlate the cortical sites associated with hearing suppression with physiologically identified auditory cortical fields. PMID:16979144

  18. Spatially Patterned Electrical Stimulation to Enhance Resolution of Retinal Prostheses

    PubMed Central

    Hottowy, Paweł; Mathieson, Keith; Gunning, Deborah E.; Dąbrowski, Władysław; Litke, Alan M.; Chichilnisky, E. J.

    2014-01-01

    Retinal prostheses electrically stimulate neurons to produce artificial vision in people blinded by photoreceptor degenerative diseases. The limited spatial resolution of current devices results in indiscriminate stimulation of interleaved cells of different types, precluding veridical reproduction of natural activity patterns in the retinal output. Here we investigate the use of spatial patterns of current injection to increase the spatial resolution of stimulation, using high-density multielectrode recording and stimulation of identified ganglion cells in isolated macaque retina. As previously shown, current passed through a single electrode typically induced a single retinal ganglion cell spike with submillisecond timing precision. Current passed simultaneously through pairs of neighboring electrodes modified the probability of activation relative to injection through a single electrode. This modification could be accurately summarized by a piecewise linear model of current summation, consistent with a simple biophysical model based on multiple sites of activation. The generalizability of the piecewise linear model was tested by using the measured responses to stimulation with two electrodes to predict responses to stimulation with three electrodes. Finally, the model provided an accurate prediction of which among a set of spatial stimulation patterns maximized selective activation of a cell while minimizing activation of a neighboring cell. The results demonstrate that tailored multielectrode stimulation patterns based on a piecewise linear model may be useful in increasing the spatial resolution of retinal prostheses. PMID:24695706

  19. Cortical responses to C-fiber stimulation by intra-epidermal electrical stimulation: an MEG study.

    PubMed

    Motogi, Jun; Kodaira, Minori; Muragaki, Yoshihiro; Inui, Koji; Kakigi, Ryusuke

    2014-06-01

    Intra-epidermal electric stimulation (IES) is an alternative to laser stimulation for selective activation of cutaneous Aδ-fibers. IES is based on the fact that nociceptive fiber terminals are located in the epidermis, whereas receptors of other fibers end deep in the dermis. IES can selectively stimulate C-fibers if the electrode structure and stimulation parameters are carefully selected. However, stable selective stimulation of C-fibers using IES has proven difficult and cannot currently be used in clinical settings. The purpose of the present study was to determine if IES performed using a modified electrode reliably stimulates C-fibers. Magnetoencephalographic responses to IES to the foot were measured in seven healthy subjects. IES elicited somatosensory evoked fields in all subjects. The mean peak latency was 1,327 ± 116 ms in the opercular region contralateral to the stimulated side, 1,318 ± 90 ms in the opercular region ipsilateral to the stimulated side, and 1350 ± 139 ms in the primary somatosensory cortex. These results indicate that IES performed using the modified electrode can selectively stimulate C-fibers and may be a useful tool for pain research as well as clinical evaluation of peripheral small fiber function.

  20. Electrical and mechanical stimulation of cardiac cells and tissue constructs.

    PubMed

    Stoppel, Whitney L; Kaplan, David L; Black, Lauren D

    2016-01-15

    The field of cardiac tissue engineering has made significant strides over the last few decades, highlighted by the development of human cell derived constructs that have shown increasing functional maturity over time, particularly using bioreactor systems to stimulate the constructs. However, the functionality of these tissues is still unable to match that of native cardiac tissue and many of the stem-cell derived cardiomyocytes display an immature, fetal like phenotype. In this review, we seek to elucidate the biological underpinnings of both mechanical and electrical signaling, as identified via studies related to cardiac development and those related to an evaluation of cardiac disease progression. Next, we review the different types of bioreactors developed to individually deliver electrical and mechanical stimulation to cardiomyocytes in vitro in both two and three-dimensional tissue platforms. Reactors and culture conditions that promote functional cardiomyogenesis in vitro are also highlighted. We then cover the more recent work in the development of bioreactors that combine electrical and mechanical stimulation in order to mimic the complex signaling environment present in vivo. We conclude by offering our impressions on the important next steps for physiologically relevant mechanical and electrical stimulation of cardiac cells and engineered tissue in vitro.

  1. Acetylation mediates Cx43 reduction caused by electrical stimulation

    PubMed Central

    Meraviglia, Viviana; Azzimato, Valerio; Colussi, Claudia; Florio, Maria Cristina; Binda, Anna; Panariti, Alice; Qanud, Khaled; Suffredini, Silvia; Gennaccaro, Laura; Miragoli, Michele; Barbuti, Andrea; Lampe, Paul D.; Gaetano, Carlo; Pramstaller, Peter P.; Capogrossi, Maurizio C.; Recchia, Fabio A.; Pompilio, Giulio; Rivolta, Ilaria; Rossini, Alessandra

    2015-01-01

    Communication between cardiomyocytes depends upon Gap Junctions (GJ). Previous studies have demonstrated that electrical stimulation induces GJ remodeling and modifies histone acetylases (HAT) and deacetylases (HDAC) activities, although these two results have not been linked. The aim of this work was to establish whether electrical stimulation modulates GJ-mediated cardiac cell-cell communication by acetylation-dependent mechanisms. Field stimulation of HL-1 cardiomyocytes at 0.5 Hz for 24 hours significantly reduced Connexin43 (Cx43) expression and cell-cell communication. HDAC activity was down-regulated whereas HAT activity was not modified resulting in increased acetylation of Cx43. Consistent with a post-translational mechanism, we did not observe a reduction in Cx43 mRNA in electrically stimulated cells, while the proteasomal inhibitor MG132 maintained Cx43 expression. Further, the treatment of paced cells with the HAT inhibitor Anacardic Acid maintained both the levels of Cx43 and cell-cell communication. Finally, we observed increased acetylation of Cx43 in the left ventricles of dogs subjected to chronic tachypacing as a model of abnormal ventricular activation. In conclusion, our findings suggest that altered electrical activity can regulate cardiomyocyte communication by influencing the acetylation status of Cx43. PMID:26264759

  2. Electrical stimulation mapping of nouns and verbs in Broca's area.

    PubMed

    Havas, Viktória; Gabarrós, Andreu; Juncadella, Montserrat; Rifa-Ros, Xavi; Plans, Gerard; Acebes, Juan José; de Diego Balaguer, Ruth; Rodríguez-Fornells, Antoni

    2015-01-01

    Electric stimulation mapping (ESM) is frequently used during brain surgery to localise higher cognitive functions to avoid post-chirurgical disabilities. Experiments with brain imaging techniques and neuropsychological studies showed differences in the cortical representation and processing of nouns and verbs. The goal of the present study was to investigate whether electric stimulation in specific sites in the frontal cortex disrupted noun and verb production selectively. We found that most of the stimulated areas showed disruption of both verbs and nouns at the inferior frontal gyrus. However, when selective effects were obtained, verbs were more prone to disruption than nouns with important individual differences. The overall results indicate that selective impairments can be observed at inferior and middle frontal regions and the action naming task seems to be more suitable to avoid post-chirurgical language disabilities, as it shows a greater sensitivity to disruption with ESM than the classical object naming task. PMID:25957505

  3. Electrical stimulation mapping of nouns and verbs in Broca's area.

    PubMed

    Havas, Viktória; Gabarrós, Andreu; Juncadella, Montserrat; Rifa-Ros, Xavi; Plans, Gerard; Acebes, Juan José; de Diego Balaguer, Ruth; Rodríguez-Fornells, Antoni

    2015-01-01

    Electric stimulation mapping (ESM) is frequently used during brain surgery to localise higher cognitive functions to avoid post-chirurgical disabilities. Experiments with brain imaging techniques and neuropsychological studies showed differences in the cortical representation and processing of nouns and verbs. The goal of the present study was to investigate whether electric stimulation in specific sites in the frontal cortex disrupted noun and verb production selectively. We found that most of the stimulated areas showed disruption of both verbs and nouns at the inferior frontal gyrus. However, when selective effects were obtained, verbs were more prone to disruption than nouns with important individual differences. The overall results indicate that selective impairments can be observed at inferior and middle frontal regions and the action naming task seems to be more suitable to avoid post-chirurgical language disabilities, as it shows a greater sensitivity to disruption with ESM than the classical object naming task.

  4. Closing of venus flytrap by electrical stimulation of motor cells.

    PubMed

    Volkov, Alexander G; Adesina, Tejumade; Jovanov, Emil

    2007-05-01

    Electrical signaling and rapid closure of the carnivorous plant Dionaea muscipula Ellis (Venus flytrap) have been attracting the attention of researchers since XIX century, but the exact mechanism of Venus flytrap closure is still unknown. We found that the electrical stimulus between a midrib and a lobe closes the Venus flytrap leaf by activating motor cells without mechanical stimulation of trigger hairs. The closing time of Venus flytrap by electrical stimulation of motor cells is 0.3 s, the same as mechanically induced closing. The mean electrical charge required for the closure of the Venus flytrap leaf is 13.6 microC. Ion channel blockers such as Ba(2+), TEACl as well as uncouplers such as FCCP, 2,4-dinitrophenol and pentachlorophenol dramatically decrease the speed of the trap closing. Using an ultra-fast data acquisition system with measurements in real time, we found that the action potential in the Venus flytrap has a duration time of about 1.5 ms. Our results demonstrate that electrical stimulation can be used to study mechanisms of fast activity in motor cells of the plant kingdom.

  5. Volume conductor model of transcutaneous electrical stimulation with kilohertz signals

    PubMed Central

    Medina, Leonel E.; Grill, Warren M.

    2014-01-01

    Objective Incorporating high-frequency components in transcutaneous electrical stimulation (TES) waveforms may make it possible to stimulate deeper nerve fibers since the impedance of tissue declines with increasing frequency. However, the mechanisms of high-frequency TES remain largely unexplored. We investigated the properties of TES with frequencies beyond those typically used in neural stimulation. Approach We implemented a multilayer volume conductor model including dispersion and capacitive effects, coupled to a cable model of a nerve fiber. We simulated voltage- and current-controlled transcutaneous stimulation, and quantified the effects of frequency on the distribution of potentials and fiber excitation. We also quantified the effects of a novel transdermal amplitude modulated signal (TAMS) consisting of a non-zero offset sinusoidal carrier modulated by a square-pulse train. Main results The model revealed that high-frequency signals generated larger potentials at depth than did low frequencies, but this did not translate into lower stimulation thresholds. Both TAMS and conventional rectangular pulses activated more superficial fibers in addition to the deeper, target fibers, and at no frequency did we observe an inversion of the strength-distance relationship. Current regulated stimulation was more strongly influenced by fiber depth, whereas voltage regulated stimulation was more strongly influenced by skin thickness. Finally, our model reproduced the threshold-frequency relationship of experimentally measured motor thresholds. Significance The model may be used for prediction of motor thresholds in TES, and contributes to the understanding of high-frequency TES. PMID:25380254

  6. Electrical stimulation of the dorsolateral prefrontal cortex improves memory monitoring.

    PubMed

    Chua, Elizabeth F; Ahmed, Rifat

    2016-05-01

    The ability to accurately monitor one's own memory is an important feature of normal memory function. Converging evidence from neuroimaging and lesion studies have implicated the dorsolateral prefrontal cortex (DLPFC) in memory monitoring. Here we used high definition transcranial direct stimulation (HD-tDCS), a non-invasive form of brain stimulation, to test whether the DLPFC has a causal role in memory monitoring, and the nature of that role. We used a metamemory monitoring task, in which participants first attempted to recall the answer to a general knowledge question, then gave a feeling-of-knowing (FOK) judgment, followed by a forced choice recognition task. When participants received DLPFC stimulation, their feeling-of-knowing judgments were better predictors of memory performance, i.e., they had better memory monitoring accuracy, compared to stimulation of a control site, the anterior temporal lobe (ATL). Effects of DLPFC stimulation were specific to monitoring accuracy, as there was no significant increase in memory performance, and if anything, there was poorer memory performance with DLPFC stimulation. Thus we have demonstrated a causal role for the DLPFC in memory monitoring, and showed that electrically stimulating the left DLPFC led people to more accurately monitor and judge their own memory. PMID:26970142

  7. Electrical Stimulation of Coleopteran Muscle for Initiating Flight.

    PubMed

    Choo, Hao Yu; Li, Yao; Cao, Feng; Sato, Hirotaka

    2016-01-01

    Some researchers have long been interested in reconstructing natural insects into steerable robots or vehicles. However, until recently, these so-called cyborg insects, biobots, or living machines existed only in science fiction. Owing to recent advances in nano/micro manufacturing, data processing, and anatomical and physiological biology, we can now stimulate living insects to induce user-desired motor actions and behaviors. To improve the practicality and applicability of airborne cyborg insects, a reliable and controllable flight initiation protocol is required. This study demonstrates an electrical stimulation protocol that initiates flight in a beetle (Mecynorrhina torquata, Coleoptera). A reliable stimulation protocol was determined by analyzing a pair of dorsal longitudinal muscles (DLMs), flight muscles that oscillate the wings. DLM stimulation has achieved with a high success rate (> 90%), rapid response time (< 1.0 s), and small variation (< 0.33 s; indicating little habituation). Notably, the stimulation of DLMs caused no crucial damage to the free flight ability. In contrast, stimulation of optic lobes, which was earlier demonstrated as a successful flight initiation protocol, destabilized the beetle in flight. Thus, DLM stimulation is a promising secure protocol for inducing flight in cyborg insects or biobots. PMID:27050093

  8. Electrical Stimulation of Coleopteran Muscle for Initiating Flight.

    PubMed

    Choo, Hao Yu; Li, Yao; Cao, Feng; Sato, Hirotaka

    2016-01-01

    Some researchers have long been interested in reconstructing natural insects into steerable robots or vehicles. However, until recently, these so-called cyborg insects, biobots, or living machines existed only in science fiction. Owing to recent advances in nano/micro manufacturing, data processing, and anatomical and physiological biology, we can now stimulate living insects to induce user-desired motor actions and behaviors. To improve the practicality and applicability of airborne cyborg insects, a reliable and controllable flight initiation protocol is required. This study demonstrates an electrical stimulation protocol that initiates flight in a beetle (Mecynorrhina torquata, Coleoptera). A reliable stimulation protocol was determined by analyzing a pair of dorsal longitudinal muscles (DLMs), flight muscles that oscillate the wings. DLM stimulation has achieved with a high success rate (> 90%), rapid response time (< 1.0 s), and small variation (< 0.33 s; indicating little habituation). Notably, the stimulation of DLMs caused no crucial damage to the free flight ability. In contrast, stimulation of optic lobes, which was earlier demonstrated as a successful flight initiation protocol, destabilized the beetle in flight. Thus, DLM stimulation is a promising secure protocol for inducing flight in cyborg insects or biobots.

  9. Electrical Stimulation of Coleopteran Muscle for Initiating Flight

    PubMed Central

    Choo, Hao Yu; Li, Yao; Cao, Feng; Sato, Hirotaka

    2016-01-01

    Some researchers have long been interested in reconstructing natural insects into steerable robots or vehicles. However, until recently, these so-called cyborg insects, biobots, or living machines existed only in science fiction. Owing to recent advances in nano/micro manufacturing, data processing, and anatomical and physiological biology, we can now stimulate living insects to induce user-desired motor actions and behaviors. To improve the practicality and applicability of airborne cyborg insects, a reliable and controllable flight initiation protocol is required. This study demonstrates an electrical stimulation protocol that initiates flight in a beetle (Mecynorrhina torquata, Coleoptera). A reliable stimulation protocol was determined by analyzing a pair of dorsal longitudinal muscles (DLMs), flight muscles that oscillate the wings. DLM stimulation has achieved with a high success rate (> 90%), rapid response time (< 1.0 s), and small variation (< 0.33 s; indicating little habituation). Notably, the stimulation of DLMs caused no crucial damage to the free flight ability. In contrast, stimulation of optic lobes, which was earlier demonstrated as a successful flight initiation protocol, destabilized the beetle in flight. Thus, DLM stimulation is a promising secure protocol for inducing flight in cyborg insects or biobots. PMID:27050093

  10. Investigation of electrical responses to acupuncture stimulation: the effect of electrical grounding and insulation conditions.

    PubMed

    Lee, Yong-Heum; Ryu, Yeon-Hang; Jung, Byungjo

    2009-03-01

    Acupuncture in Oriental medicine has been widely used as a core therapeutic method due to its minimal side-effects and therapeutic efficacy. However, the electrical response to acupuncture stimulation (ERAS) has not been clearly studied under acupuncture conditions that might affect the efficacy of acupuncture therapy. In this study, the ERAS was objectively investigated by measuring meridian electric potentials (MEPs) when the electrical grounding conditions of the operator and subject were varied, and when the insulation conditions of acupuncture needle were varied. MEPs between Sang-geoheo (ST37) and Ha-geoheo (ST39) of the Stomach Meridian (ST) were measured by stimulating Jok-samni (ST36) with an acupuncture needle. For non-insulated acupuncture stimulation (NIAS), the average MEP peak was 148.6 +/- 20.6 when neither the operator nor the subject were electrically grounded, 23.1 +/- 8.8 when the subject only was electrically grounded, 348 +/- 76.8 when the operator only was electrically grounded, and 19.9 +/- 4.7 when both the operator and the subject were electrically grounded. The MEPs presented various magnitudes and patterns depending on the electrical grounding conditions. The MEP pattern was very similar to that of the charge and discharge of a capacitor. For insulated acupuncture stimulation (IAS), the average MEP peak was 20 +/- 4 in all electrical grounding conditions, which is not a significant electric response for acupuncture stimulation. In terms of electricity, this study verified that acupuncture therapy might be affected by acupuncture conditions such as (1) the electrical grounding condition of the operator and the subject and (2) the insulation condition of the acupuncture needle.

  11. Amplifier design for EMG recording from stimulation electrodes during functional electrical stimulation leg cycling ergometry.

    PubMed

    Shalaby, Raafat; Schauer, Thomas; Liedecke, Wolfgang; Raisch, Jörg

    2011-02-01

    Functional electrical stimulation leg cycle ergometry (FES-LCE), which is often used as exercise for people with spinal cord injury (SCI), has recently been applied in the motor rehabilitation of stroke patients. Recently completed studies show controversial results, but with a tendency to positive training effects. Current technology is identical to that used in FES-LCE for SCI, whereas the pathology of stroke differs strongly. Most stroke patients with hemiparesis are able to drive an ergometer independently. Depending on the degree of spasticity, the paretic leg will partially support or hinder movements. Electrical stimulation increases muscle force and endurance and both are prerequisites for restoring gait. However, the effect of FES-LCE on improving impaired motor coordination is unclear. To measure motor coordination during FES-LCE, an EMG-amplifier design has been investigated which suppresses stimulation artifacts and allows detection of volitional or reflex induced muscle activity. Direct measurement of EMG from stimulation electrodes between stimulation pulses is an important asset of this amplifier. Photo-MOS switches in front of the preamplifier are utilized to achieve this. The technology presented here can be used to monitor the effects of FES-LCE to adapt the stimulation strategy or to realize EMG-biofeedback training. PMID:21162696

  12. Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation.

    PubMed

    Rozand, Vianney; Grosprêtre, Sidney; Stapley, Paul J; Lepers, Romuald

    2015-09-13

    Percutaneous electrical nerve stimulation is a non-invasive method commonly used to evaluate neuromuscular function from brain to muscle (supra-spinal, spinal and peripheral levels). The present protocol describes how this method can be used to stimulate the posterior tibial nerve that activates plantar flexor muscles. Percutaneous electrical nerve stimulation consists of inducing an electrical stimulus to a motor nerve to evoke a muscular response. Direct (M-wave) and/or indirect (H-reflex) electrophysiological responses can be recorded at rest using surface electromyography. Mechanical (twitch torque) responses can be quantified with a force/torque ergometer. M-wave and twitch torque reflect neuromuscular transmission and excitation-contraction coupling, whereas H-reflex provides an index of spinal excitability. EMG activity and mechanical (superimposed twitch) responses can also be recorded during maximal voluntary contractions to evaluate voluntary activation level. Percutaneous nerve stimulation provides an assessment of neuromuscular function in humans, and is highly beneficial especially for studies evaluating neuromuscular plasticity following acute (fatigue) or chronic (training/detraining) exercise.

  13. Direct-current electrical stimulation of tendon healing in vitro

    SciTech Connect

    Nessler, J.P.; Mass, D.P.

    1987-04-01

    The intrinsic capacity of tendons to heal in response to injury has recently been demonstrated by many investigators. Electrical stimulation is often assumed to augment regeneration of various tissues. Using newly developed methods of whole-tendon culture, the authors examined the effect of direct-current electricity on healing in vitro. Deep flexor tendons of rabbits were excised, transected, repaired, and grown in an acellular culture medium for seven, 14, 21, or 42 days. Tendons through which a continuous 7-microAmp current was passed at the repair site were compared with nonstimulated controls. The incorporation of (/sup 14/C)proline and its conversion to (/sup 14/C)hydroxyproline was measured at seven days. The mean (/sup 14/C)proline and (/sup 14/C)hydroxyproline activities were 91% and 255% greater, respectively, in the stimulated group. The activity was also higher in the stimulated group, by 42 days. Histologic sections showed that intrinsic tenoblastic repair may be enhanced with electrical stimulation in vitro.

  14. Neural Responses to Electrical Stimulation on Patterned Silk Films

    PubMed Central

    Hronik-Tupaj, Marie; Raja, Waseem Khan; Tang-Schomer, Min; Omenetto, Fiorenzo G.; Kaplan, David L.

    2013-01-01

    Peripheral nerve injury is a critical issue for trauma patients. Following injury, incomplete axon regeneration or misguided axon innervation into tissue will result in loss of sensory and motor functions. The objective of this study was to examine axon outgrowth and axon alignment in response to surface patterning and electrical stimulation. To accomplish our objective, metal electrodes with dimensions of 1.5 mm × 4 cm, were sputter coated onto micropatterned silk protein films, with surface grooves 3.5 μm wide × 500 nm deep. P19 neurons were seeded on the patterned electronic silk films and stimulated at 120 mV, 1 kHz, for 45 minutes each day for 7 days. Responses were compared to neurons on flat electronic silk films, patterned silk films without stimulation, and flat silk films without stimulation. Significant alignment was found on the patterned film groups compared to the flat film groups. Axon outgrowth was greater (p < 0.05) on electronic films on day 5 and day 7 compared to the unstimulated groups. In conclusion, electrical stimulation, at 120 mV, 1 kHz, for 45 minutes daily, in addition to surface patterning, of 3.5 μm wide × 500 nm deep grooves, offered control of nerve axon outgrowth and alignment. PMID:23401351

  15. Remote Electrical Stimulation by Means of Implanted Rectifiers

    PubMed Central

    Ivorra, Antoni

    2011-01-01

    Miniaturization of active implantable medical devices is currently compromised by the available means for electrically powering them. Most common energy supply techniques for implants – batteries and inductive couplers – comprise bulky parts which, in most cases, are significantly larger than the circuitry they feed. Here, for overcoming such miniaturization bottleneck in the case of implants for electrical stimulation, it is proposed to make those implants act as rectifiers of high frequency bursts supplied by remote electrodes. In this way, low frequency currents will be generated locally around the implant and these low frequency currents will perform stimulation of excitable tissues whereas the high frequency currents will cause only innocuous heating. The present study numerically demonstrates that low frequency currents capable of stimulation can be produced by a miniature device behaving as a diode when high frequency currents, neither capable of thermal damage nor of stimulation, flow through the tissue where the device is implanted. Moreover, experimental evidence is provided by an in vivo proof of concept model consisting of an anesthetized earthworm in which a commercial diode was implanted. With currently available microelectronic techniques, very thin stimulation capsules (diameter <500 µm) deliverable by injection are easily conceivable. PMID:21850274

  16. Remote electrical stimulation by means of implanted rectifiers.

    PubMed

    Ivorra, Antoni

    2011-01-01

    Miniaturization of active implantable medical devices is currently compromised by the available means for electrically powering them. Most common energy supply techniques for implants--batteries and inductive couplers--comprise bulky parts which, in most cases, are significantly larger than the circuitry they feed. Here, for overcoming such miniaturization bottleneck in the case of implants for electrical stimulation, it is proposed to make those implants act as rectifiers of high frequency bursts supplied by remote electrodes. In this way, low frequency currents will be generated locally around the implant and these low frequency currents will perform stimulation of excitable tissues whereas the high frequency currents will cause only innocuous heating. The present study numerically demonstrates that low frequency currents capable of stimulation can be produced by a miniature device behaving as a diode when high frequency currents, neither capable of thermal damage nor of stimulation, flow through the tissue where the device is implanted. Moreover, experimental evidence is provided by an in vivo proof of concept model consisting of an anesthetized earthworm in which a commercial diode was implanted. With currently available microelectronic techniques, very thin stimulation capsules (diameter <500 µm) deliverable by injection are easily conceivable. PMID:21850274

  17. [Electrical nerve stimulation for plexus and nerve blocks].

    PubMed

    Birnbaum, J; Klotz, E; Bogusch, G; Volk, T

    2007-11-01

    Despite the increasing use of ultrasound, electrical nerve stimulation is commonly used as the standard for both plexus and peripheral nerve blocks. Several recent randomized trials have contributed to a better understanding of physiological and clinical correlations. Traditionally used currents and impulse widths are better defined in relation to the distance between needle tip and nerves. Commercially available devices enable transcutaneous nerve stimulation and provide new opportunities for the detection of puncture sites and for training. The electrically ideal position of the needle usually is defined by motor responses which can not be interpreted without profound anatomical knowledge. For instance, interscalene blocks can be successful even after motor responses of deltoid or pectoral muscles. Infraclavicular blocks should be aimed at stimulation of the posterior fascicle (extension). In contrast to multiple single nerve blocks, axillary single-shot blocks more commonly result in incomplete anaesthesia. Blockade of the femoral nerve can be performed without any nerve stimulation if the fascia iliaca block is used. Independently of the various approaches to the sciatic nerve, inversion and plantar flexion are the best options for single-shot blocks. Further clinical trials are needed to define the advantages of stimulating catheters in continuous nerve blocks.

  18. Electrical stimulation of the nervous system for pain control.

    PubMed

    Long, D M

    1978-01-01

    Transcutaneous electrical stimulation appears to be a valid technique for the treatment of many pain states. Its use in chronic pain is limited and it appears to be much more likely to be effective in the relief of acute painful states. Nevertheless, since it provides a simple way to treat a significant number of patients whose pain would otherwise by intractable, it has been a valuable addition to the armamentarium of the physician dealing with chronic pain. Peripheral nerve stimulation is an excellent way to relieve pain of peripheral nerve injury origin and certain painful, poorly understood, vasopastic or reflex sympathetic states. Spinal cord stimulation has been revived by the advent of percutaneous stimulators. The technique is currently the best available for the treatment of the patient suffering from the chronic low back syndrome with severe arachnoiditis, for whom no definitive therapy is available. Brain stimulation has been relegated to therapy for pain of central nervous system origin. It is a most promising technique though its application appears to be limited at this point to a few specific problems. The seriousness of potential complications has kept it from being widely applicable to date. There is little information concerning the mechanism whereby these various techniques are effective. Transcutaneous and peripheral nerve stimulation might have their effect through peripheral mechanisms or through a gating mechanism in the posterior horn (Melzack and Wall 1965; Campbell and Taub 1973). Spinal cord stimulation could act through a retrograde effect upon a dorsal horn gate or have more central actions. Brain stimulation in the opiate receptor system may be effective through activation of this system. The mechanisms of action of stimulation in the sensory system centrally are certainly not well understood (Bloedel 1974).

  19. Determinants of the electric field during transcranial direct current stimulation.

    PubMed

    Opitz, Alexander; Paulus, Walter; Will, Susanne; Antunes, Andre; Thielscher, Axel

    2015-04-01

    Transcranial direct current stimulation (tDCS) causes a complex spatial distribution of the electric current flow in the head which hampers the accurate localization of the stimulated brain areas. In this study we show how various anatomical features systematically shape the electric field distribution in the brain during tDCS. We constructed anatomically realistic finite element (FEM) models of two individual heads including conductivity anisotropy and different skull layers. We simulated a widely employed electrode montage to induce motor cortex plasticity and moved the stimulating electrode over the motor cortex in small steps to examine the resulting changes of the electric field distribution in the underlying cortex. We examined the effect of skull thickness and composition on the passing currents showing that thinner skull regions lead to higher electric field strengths. This effect is counteracted by a larger proportion of higher conducting spongy bone in thicker regions leading to a more homogenous current over the skull. Using a multiple regression model we could identify key factors that determine the field distribution to a significant extent, namely the thicknesses of the cerebrospinal fluid and the skull, the gyral depth and the distance to the anode and cathode. These factors account for up to 50% of the spatial variation of the electric field strength. Further, we demonstrate that individual anatomical factors can lead to stimulation "hotspots" which are partly resistant to electrode positioning. Our results give valuable novel insights in the biophysical foundation of tDCS and highlight the importance to account for individual anatomical factors when choosing an electrode montage.

  20. Determinants of the electric field during transcranial direct current stimulation.

    PubMed

    Opitz, Alexander; Paulus, Walter; Will, Susanne; Antunes, Andre; Thielscher, Axel

    2015-04-01

    Transcranial direct current stimulation (tDCS) causes a complex spatial distribution of the electric current flow in the head which hampers the accurate localization of the stimulated brain areas. In this study we show how various anatomical features systematically shape the electric field distribution in the brain during tDCS. We constructed anatomically realistic finite element (FEM) models of two individual heads including conductivity anisotropy and different skull layers. We simulated a widely employed electrode montage to induce motor cortex plasticity and moved the stimulating electrode over the motor cortex in small steps to examine the resulting changes of the electric field distribution in the underlying cortex. We examined the effect of skull thickness and composition on the passing currents showing that thinner skull regions lead to higher electric field strengths. This effect is counteracted by a larger proportion of higher conducting spongy bone in thicker regions leading to a more homogenous current over the skull. Using a multiple regression model we could identify key factors that determine the field distribution to a significant extent, namely the thicknesses of the cerebrospinal fluid and the skull, the gyral depth and the distance to the anode and cathode. These factors account for up to 50% of the spatial variation of the electric field strength. Further, we demonstrate that individual anatomical factors can lead to stimulation "hotspots" which are partly resistant to electrode positioning. Our results give valuable novel insights in the biophysical foundation of tDCS and highlight the importance to account for individual anatomical factors when choosing an electrode montage. PMID:25613437

  1. Electrical stimulation for pressure sore prevention and wound healing.

    PubMed

    Bogie, K M; Reger, S I; Levine, S P; Sahgal, V

    2000-01-01

    This paper reviews applications of therapeutic electrical stimulation (ES) specific to wound healing and pressure sore prevention. The application of ES for wound healing has been found to increase the rate of healing by more than 50%. Furthermore, the total number of wounds healed is also increased. However, optimal delivery techniques for ES therapy have not been established to date. A study of stimulation current effects on wound healing in a pig model has shown that direct current (DC) stimulation is most effective in wound area reduction and alternating current (AC) stimulation for wound volume reduction at current densities of 127 microA/cm2 and 1,125 microA/cm2, respectively. Preliminary studies have been carried out at two research centers to assess the role of ES in pressure sore prevention. Surface stimulation studies have shown that ES can produce positive short-term changes in tissue health variables such as regional blood flow and pressure distribution. The use of an implanted stimulation system consisting of intramuscular electrodes with percutaneous leads has been found to produce additional long-term changes. Specifically, gluteal muscle thickness increased by 50% with regular long-term ES application concurrent with a 20% decrease in regional interface pressures and increased tissue oxygen levels. These findings indicate that an implantable ES system may have great potential for pressure sore prevention, particularly for individuals who lack sensation or who are physically unable to perform regular independent pressure relief.

  2. Neuromuscular Electrical Stimulation for Mobility Support of Elderly

    PubMed Central

    2015-01-01

    The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within “MOBIL” we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in “compliance data storage” as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC) and maximum stimulation induced contraction (MSC) were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period. Therefore the

  3. Neuromuscular Electrical Stimulation for Mobility Support of Elderly.

    PubMed

    Mayr, Winfried

    2015-08-24

    The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within "MOBIL" we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in "compliance data storage" as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC) and maximum stimulation induced contraction (MSC) were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period. Therefore the

  4. Characterization of electrical stimulation electrodes for cardiac tissue engineering.

    PubMed

    Tandon, Nina; Cannizzaro, Chris; Figallo, Elisa; Voldman, Joel; Vunjak-Novakovic, Gordana

    2006-01-01

    Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. The goal of this study was to assess the conditions of electrical stimulation with respect to the electrode geometry, material properties and charge-transfer characteristics at the electrode-electrolyte interface. We compared various biocompatible materials, including nanoporous carbon, stainless steel, titanium and titanium nitride, for use in cardiac tissue engineering bioreactors. The faradaic and non-faradaic charge transfer mechanisms were assessed by electrochemical impedance spectroscopy (EIS), studying current injection characteristics, and examining surface properties of electrodes with scanning electron microscopy. Carbon electrodes were found to have the best current injection characteristics. However, these electrodes require careful handling because of their limited mechanical strength. The efficacy of various electrodes for use in 2-D and 3-D cardiac tissue engineering systems with neonatal rat cardiomyocytes is being determined by assessing cell viability, amplitude of contractions, excitation thresholds, maximum capture rate, and tissue morphology.

  5. Clinical application of neuromuscular electrical stimulation induced cardiovascular exercise.

    PubMed

    Caulfield, Brian; Crowe, Louis; Coughlan, Garrett; Minogue, Conor

    2011-01-01

    We need to find novel ways of increasing exercise participation, particularly in those populations who find it difficult to participate in voluntary exercise. In recent years researchers have started to investigate the potential for using electrical stimulation to artificially stimulate a pattern of muscle activity that would induce a physiological response consistent with cardiovascular exercise. Work to date has indicated that this is best achieved by using a stimulation protocol that results in rapid rhythmical isometric contractions of the large leg muscle groups at sub tetanic frequencies. Studies completed by our group indicate that this technique can serve as a viable alternative to voluntary cardiovascular exercise. Apart from being able to induce a cardiovascular exercise effect in patient populations (e.g. heart failure, COPD, spinal cord injury, obesity), this approach may also have value in promotion of exercise activity in a microgravity environment. PMID:22255036

  6. Electrical stimulation of the hypoglossal nerve: a potential therapy.

    PubMed

    Schwartz, Alan R; Smith, Philip L; Oliven, Arie

    2014-02-01

    Obstructive sleep apnea is characterized by recurrent episodes of pharyngeal collapse, which result from a decrease in pharyngeal dilator muscle tone. The genioglossus is a major pharyngeal dilator that maintains airway patency during sleep. Early studies in animal and humans have demonstrated that electrical stimulation of this muscle reduces pharyngeal collapsibility, increases airflow, and mitigates obstructive sleep apnea. These findings impelled the development of fully implantable hypoglossal nerve stimulating systems (HGNS), for which feasibility trial results are now available. These pilot studies have confirmed that hypoglossal nerve stimulation can prevent pharyngeal collapse without arousing patients from sleep. Potentially, a substantial segment of the patient population with obstructive sleep apnea can be treated with this novel approach. Furthermore, the feasibility trial findings suggest that the therapeutic potential of HGNS can be optimized by selecting patients judiciously, titrating the stimulus intensity optimally, and characterizing the underlying function and anatomy of the pharynx. These strategies are currently being examined in ongoing pivotal trials of HGNS.

  7. New algorithm to control a cycle ergometer using electrical stimulation.

    PubMed

    Petrofsky, J S

    2003-01-01

    Data were collected from four male subjects to determine the relationships between load, speed and muscle use during cycle ergometry. These data were then used to construct equations to govern the stimulation of muscle in paralysed individuals, during cycle ergometry induced by functional electrical stimulation (FES) of the quadriceps, gluteus maximus and hamstring muscles. The algorithm was tested on four subjects who were paralysed owing to a complete spinal cord injury between T4 and T11. Using the multivariate equation, the control of movement was improved, and work was accomplished that was double (2940 Nm min(-1) compared with 5880 Nm min(-1)) that of traditional FES cycle ergometry, when muscle stimulation was also controlled by electrical stimulation. Stress on the body, assessed by cardiac output, was increased almost two-fold during maximum work with the new algorithm (81 min(-1) compared with 15 l min(-1) with the new algorithm). These data support the concept that the limitation to workload that a person can achieve on FES cycle ergometry is in the control equations and not in the paralysed muscle.

  8. A Computational Framework for Electrical Stimulation of Vestibular Nerve.

    PubMed

    Marianelli, Prisca; Capogrosso, Marco; Bassi Luciani, Lorenzo; Panarese, Alessandro; Micera, Silvestro

    2015-09-01

    The vestibular organs are very important to generate reflexes critical for stabilizing gaze and body posture. Vestibular diseases significantly reduce the quality of life of people who are affected by them. Some research groups have recently started developing vestibular neuroprostheses to mitigate these symptoms. However, many scientific and technological issues need to be addressed to optimise their use in clinical trials. We developed a computational model able to mimic the response of human vestibular nerves and which can be exploited for "in-silico" testing of new strategies to design implantable vestibular prostheses. First, a digital model of the vestibular system was reconstructed from anatomical data. Monopolar stimulation was delivered at different positions and distances from ampullary nerves. The electrical potential induced by the injected current was computed through finite-element methods and drove extra-cellular stimulation of fibers in the vestibular, facial, and cochlear nerves. The electrical activity of vestibular nerves and the resulting eye movements elicited by different stimulation protocols were investigated. A set of electrode configurations was analyzed in terms of selectivity at increasing injected current. Electrode position along the nerve plays a major role in producing undesired activity in other nontargeted nerves, whereas distance from the fiber does not significantly affect selectivity. Indications are provided to minimize misalignment in nonoptimal electrode locations. Eye movements elicited by the different stimulation protocols are calculated and compared to experimental values, for the purpose of model validation. PMID:25751868

  9. Neuromuscular electric stimulation in patellofemoral dysfunction: literature review

    PubMed Central

    dos Santos, Ricardo Lucas; Souza, Márcia Leal São Pedro; dos Santos, Fernanda Andrade

    2013-01-01

    Patellofemoral dysfunction is a fairly common deficiency among young individuals that primarily affects females and may be characterized by pain, swelling and retropatellar crepitation. The purpose of this review of literature from the period between 2005 and 2011 was to systematize knowledge in relation to the increase in quadriceps muscle strength and pain relief in patients with patellofemoral dysfunction, using neuromuscular electrical stimulation and resistance exercises. The inclusion criteria were intervention articles from the past six years, in English, Spanish and Portuguese, which used muscle strengthening and neuromuscular electrical stimulation for rehabilitation obtained through searches in the electronic databases Medline and Lilacs and in the Bireme library. The bibliographic search yielded 28 references, of which nine were excluded in accordance with the aims and inclusion criteria while 16 articles were selected for reading of the abstracts and subsequent analysis. Mediumfrequency Neuromuscular Electrical Stimulation (NMES) can be used in association with resistance exercises as an adjuvant in the treatment of patellofemoral dysfunction (PFD), both to achieve muscle rebalance and for pain relief. PMID:24453645

  10. Laparoscopic insertion of gastric electrodes for electrical stimulation.

    PubMed

    Brody, Fred; Nam, Arthur; Drenon, Elizabeth; Ali, Aamir; Soffer, Edy

    2007-02-01

    Gastric electrical stimulation can provide symptomatic relief for patients with refractory gastroparesis. Traditionally, these wires are placed through a midline laparotomy. This paper describes and illustrates, in detail, the laparoscopic technique for successful implantation. Thirty-one consecutive patients from October 2003 to March 2005 underwent laparoscopic insertion of gastric stimulating wires for gastroparesis. Twenty-six patients were female. Four laparoscopic ports were used to insert a pair of electrodes. Anterior, cephalad retraction of the gastric wall is critical for accurate seromuscular placement of gastric leads. Intraoperative endoscopy was used to verify the seromuscular placement of the leads. Both leads were secured to a subcutaneous generator and electrical parameters were immediately established in the operating room. Patient demographics, operative details, and postoperative morbidities were recorded. All procedures were completed laparoscopically. The mean operative time was 114.4 +/- 20.9 minutes (range, 95-140). No perioperative mortality occurred. Two patients developed cellulitis at the generator site postoperatively and oral antibiotics were prescribed for one week postoperatively. No hardware was removed. Two patients had their generators repositioned due to pain at the pocket site. Gastric electrical stimulation is a novel treatment modality for patients with refractory gastroparesis and can be accomplished safely via laparoscopy. Laparoscopic insertion is successful even in patients with prior surgery and intact gastrointestinal tubes. Long-term follow-up and the current prospective multicenter trial continue to assess the efficacy of this treatment modality. PMID:17362169

  11. Practical aspects of cardiac tissue engineering with electrical stimulation.

    PubMed

    Cannizzaro, Christopher; Tandon, Nina; Figallo, Elisa; Park, Hyoungshin; Gerecht, Sharon; Radisic, Milica; Elvassore, Nicola; Vunjak-Novakovic, Gordana

    2007-01-01

    Heart disease is a leading cause of death in western society. Despite the success of heart transplantation, a chronic shortage of donor organs, along with the associated immunological complications of this approach, demands that alternative treatments be found. One such option is to repair, rather than replace, the heart with engineered cardiac tissue. Multiple studies have shown that to attain functional tissue, assembly signaling cues must be recapitulated in vitro. In their native environment, cardiomyocytes are directed to beat in synchrony by propagation of pacing current through the tissue. Recently, we have shown that electrical stimulation directs neonatal cardiomyocytes to assemble into native-like tissue in vitro. This chapter provides detailed methods we have employed in taking this "biomimetic" approach. After an initial discussion on how electric field stimulation can influence cell behavior, we examine the practical aspects of cardiac tissue engineering with electrical stimulation, such as electrode selection and cell seeding protocols, and conclude with what we feel are the remaining challenges to be overcome.

  12. [Research progress in reanimation of peripheral facial paralysis by use of functional electrical stimulation].

    PubMed

    Deng, Simin; Shen, Guofang

    2010-08-01

    With the development of electronics and information technology, the application of functional electrical stimulation in the medical field has been expanding. However, the use of functional electrical stimulation to treat patients with peripheral facial paralysis is still in its infancy. The main problems include: (1) Finding in the signals which could fire the stimulator; (2) Exploring the parameters for the stimulator; (3) The effects on the muscle attributed to the electrical stimulation. A review on these problems is presented.

  13. The facilitation of motor actions by acoustic and electric stimulation.

    PubMed

    Marinovic, Welber; Milford, Magdalene; Carroll, Timothy; Riek, Stephan

    2015-12-01

    The presentation of a loud acoustic stimulus during the preparation of motor actions can both speed movement initiation and increase response vigor. Several recent studies have explored this phenomenon as a means to investigate the mechanisms and neural correlates of movement preparation. Here, we sought to determine the generality of this effect across sensory modalities, and in particular whether unexpected somatosensory stimulation can facilitate movements in a manner similar to loud sounds. We show that electric and acoustic stimuli can be similarly effective in inducing the early release of motor actions, in both reaction time and anticipatory timing tasks. Consistent with recent response activation models of motor preparation, we also demonstrate that increasing the intensity of electric stimuli induces both progressive decreases in reaction time and increases in response vigor. Additionally, we show that the early release of motor actions can be induced by electric stimuli targeting predominantly either muscle afferents or skin afferents. Finally, we show that simultaneous acoustic and electric stimulation leads to earlier releases of anticipatory actions than either unimodal stimulus. These findings may lead to new avenues for experimental and clinical exploitation of the effects of accessory sensory information on movement preparation and initiation. PMID:26338375

  14. Giovanni Aldini: from animal electricity to human brain stimulation.

    PubMed

    Parent, André

    2004-11-01

    Two hundred years ago, Giovanni Aldini published a highly influential book that reported experiments in which the principles of Luigi Galvani (animal electricity) and Alessandro Volta (bimetallic electricity) were used together for the first time. Aldini was born in Bologna in 1762 and graduated in physics at the University of his native town in 1782. As nephew and assistant of Galvani, he actively participated in a series of crucial experiments with frog's muscles that led to the idea that electricity was the long-sought vital force coursing from brain to muscles. Aldini became professor of experimental physics at the University of Bologna in 1798. He traveled extensively throughout Europe, spending much time defending the concept of his discreet uncle against the incessant attacks of Volta, who did not believe in animal electricity. Aldini used Volta's bimetallic pile to apply electric current to dismembered bodies of animals and humans; these spectacular galvanic reanimation experiments made a strong and enduring impression on his contemporaries. Aldini also treated patients with personality disorders and reported complete rehabilitation following transcranial administration of electric current. Aldini's work laid the ground for the development of various forms of electrotherapy that were heavily used later in the 19th century. Even today, deep brain stimulation, a procedure currently employed to relieve patients with motor or behavioral disorders, owes much to Aldini and galvanism. In recognition of his merits, Aldini was made a knight of the Iron Crown and a councillor of state at Milan, where he died in 1834.

  15. Giovanni Aldini: from animal electricity to human brain stimulation.

    PubMed

    Parent, André

    2004-11-01

    Two hundred years ago, Giovanni Aldini published a highly influential book that reported experiments in which the principles of Luigi Galvani (animal electricity) and Alessandro Volta (bimetallic electricity) were used together for the first time. Aldini was born in Bologna in 1762 and graduated in physics at the University of his native town in 1782. As nephew and assistant of Galvani, he actively participated in a series of crucial experiments with frog's muscles that led to the idea that electricity was the long-sought vital force coursing from brain to muscles. Aldini became professor of experimental physics at the University of Bologna in 1798. He traveled extensively throughout Europe, spending much time defending the concept of his discreet uncle against the incessant attacks of Volta, who did not believe in animal electricity. Aldini used Volta's bimetallic pile to apply electric current to dismembered bodies of animals and humans; these spectacular galvanic reanimation experiments made a strong and enduring impression on his contemporaries. Aldini also treated patients with personality disorders and reported complete rehabilitation following transcranial administration of electric current. Aldini's work laid the ground for the development of various forms of electrotherapy that were heavily used later in the 19th century. Even today, deep brain stimulation, a procedure currently employed to relieve patients with motor or behavioral disorders, owes much to Aldini and galvanism. In recognition of his merits, Aldini was made a knight of the Iron Crown and a councillor of state at Milan, where he died in 1834. PMID:15595271

  16. Tinnitus suppression by electric stimulation of the auditory nerve

    PubMed Central

    Chang, Janice E.; Zeng, Fan-Gang

    2012-01-01

    Electric stimulation of the auditory nerve via a cochlear implant (CI) has been observed to suppress tinnitus, but parameters of an effective electric stimulus remain unexplored. Here we used CI research processors to systematically vary pulse rate, electrode place, and current amplitude of electric stimuli, and measure their effects on tinnitus loudness and stimulus loudness as a function of stimulus duration. Thirteen tinnitus subjects who used CIs were tested, with nine (70%) being “Responders” who achieved greater than 30% tinnitus loudness reduction in response to at least one stimulation condition and the remaining four (30%) being “Non-Responders” who had less than 30% tinnitus loudness reduction in response to any stimulus condition tested. Despite large individual variability, several interesting observations were made between stimulation parameters, tinnitus characteristics, and tinnitus suppression. If a subject's tinnitus was suppressed by one stimulus, then it was more likely to be suppressed by another stimulus. If the tinnitus contained a “pulsating” component, then it would be more likely suppressed by a given combination of stimulus parameters than tinnitus without these components. There was also a disassociation between the subjects' clinical speech processor and our research processor in terms of their effectiveness in tinnitus suppression. Finally, an interesting dichotomy was observed between loudness adaptation to electric stimuli and their effects on tinnitus loudness, with the Responders exhibiting higher degrees of loudness adaptation than the Non-Responders. Although the mechanisms underlying these observations remain to be resolved, their clinical implications are clear. When using a CI to manage tinnitus, the clinical processor that is optimized for speech perception needs to be customized for optimal tinnitus suppression. PMID:22479238

  17. Electrical stimulation vs thermal effects in a complex electromagnetic environment.

    PubMed

    Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Sánchez, Miguel

    2009-08-01

    Studies linking exposure to low levels of radiofrequencies with adverse health effects, notwithstanding their present apparent inconsistency, have contributed to a steady improvement in the quality of evaluating that exposure. In complex electromagnetic environments, with a multitude of emissions of different frequencies acting simultaneously, knowledge of the spectral content is fundamental to evaluating human exposure to non-ionizing radiation. In the present work, we quantify the most significant spectral components in the frequency band 0.5-2200 MHz in an urban area. The measurements were made with a spectrum analyzer and monopole, biconical, and log-periodic antennas. Power density levels were calculated separately for the medium wave, short wave, and frequency modulation radio broadcasting bands, and for the television and GSM, DCS, and UMTS mobile telephony bands. The measured levels were compared with the ICNIRP reference levels for exposure to multiple frequency sources for thermal effects and electrical stimulation. The results showed the criterion limiting exposure on the basis of preventing electrical stimulation of peripheral nerves and muscles to be stricter (exposure quotient 24.7 10(-4)) than that based on thermal considerations (exposure quotient 0.16 10(-4)). The bands that contribute most to the latter are short wave, with 46.2%, and mobile telephony with 32.6% of the total exposure. In a complex electromagnetic environment, knowledge of the radiofrequency spectrum is essential in order to quantify the contribution of each type of emission to the public's exposure. It is also necessary to evaluate the electrical effects as well as the thermal effects because the criterion to limit exposure on the basis of the effect of the electrical stimulation of tissues is stricter than that based on thermal effects.

  18. Electrical stimulation vs thermal effects in a complex electromagnetic environment.

    PubMed

    Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Sánchez, Miguel

    2009-08-01

    Studies linking exposure to low levels of radiofrequencies with adverse health effects, notwithstanding their present apparent inconsistency, have contributed to a steady improvement in the quality of evaluating that exposure. In complex electromagnetic environments, with a multitude of emissions of different frequencies acting simultaneously, knowledge of the spectral content is fundamental to evaluating human exposure to non-ionizing radiation. In the present work, we quantify the most significant spectral components in the frequency band 0.5-2200 MHz in an urban area. The measurements were made with a spectrum analyzer and monopole, biconical, and log-periodic antennas. Power density levels were calculated separately for the medium wave, short wave, and frequency modulation radio broadcasting bands, and for the television and GSM, DCS, and UMTS mobile telephony bands. The measured levels were compared with the ICNIRP reference levels for exposure to multiple frequency sources for thermal effects and electrical stimulation. The results showed the criterion limiting exposure on the basis of preventing electrical stimulation of peripheral nerves and muscles to be stricter (exposure quotient 24.7 10(-4)) than that based on thermal considerations (exposure quotient 0.16 10(-4)). The bands that contribute most to the latter are short wave, with 46.2%, and mobile telephony with 32.6% of the total exposure. In a complex electromagnetic environment, knowledge of the radiofrequency spectrum is essential in order to quantify the contribution of each type of emission to the public's exposure. It is also necessary to evaluate the electrical effects as well as the thermal effects because the criterion to limit exposure on the basis of the effect of the electrical stimulation of tissues is stricter than that based on thermal effects. PMID:19481236

  19. Modeling and percept of transcorneal electrical stimulation in humans.

    PubMed

    Xie, John; Wang, Gene-Jack; Yow, Lindy; J Cela, Carlos; Humayun, Mark S; Weiland, James D; Lazzi, Gianluca; Jadvar, Hossein

    2011-07-01

    Retinal activation via transcorneal electrical stimulation (TcES) in normal humans was investigated by comparing subject perception, model predictions, and brain activation patterns. The preferential location of retinal stimulation was predicted from 3-D admittance modeling. Visual cortex activation was measured using positron emission tomography (PET) and (18)F-fluorodeoxyglucose (FDG). Two different corneal electrodes were investigated: DTL-Plus and ERG-Jet. Modeling results predicted preferential stimulation of the peripheral, inferior, nasal retina during right eye TcES using DTL-Plus, but more extensive activation of peripheral, nasal hemiretina using ERG-Jet. The results from human FDG PET study using both corneal electrodes showed areas of visual cortex activation that consistently corresponded with the reported phosphene percept and modeling predictions. ERG-Jet was able to generate brighter phosphene percept than DTL-Plus and elicited retinotopically mapped primary visual cortex activation. This study demonstrates that admittance modeling and PET imaging consistently predict the perceived location of electrically elicited phosphenes produced during TcES.

  20. Effect of electrical stimulation superimposed with isokinetic contractions.

    PubMed

    Poumarat, G; Squire, P; Lawani, M

    1992-09-01

    Previous studies have considered the effects of the superimposition of electrical stimulation (ES) upon maximal voluntary contraction (MVC) under isometric conditions. This investigation considered these effects using isokinetic muscle action. Eleven males, non athletes, volunteered for the experiment. Isokinetic torque for extension of the right knee was measured by means of a Cybex 340 using two speeds of movement, 12 degrees/s and 30 degrees/s. Torque was measured at 5 degrees increments (from 100 degrees flexion to full extension) under conditions of MVC alone and MVC+ES. Stimulation was provided by means of a bi-phasic, symmetrical, square wave with a pulse width of 600 mu. Frequency of stimulation was either 30 Hz or 80 Hz. It was found that the pattern of torque production was unaffected by the application of ES. Peak torque values at both speeds were significantly lower when ES was applied at both frequencies compared to MVC alone. This inhibitory effect was found to extend throughout the middle range of movement. This tended to be more pronounced with the 80 Hz frequency. In general these findings were in agreement with those reported previously for isometric conditions. Possible explanations for these results include the inability of ES to recruit more motor units than MVC alone; the limitations of the subjects to tolerate a current of a sufficiently high intensity to elicit a stronger contraction, possibly due to lack of familiarization with these forms of muscle action; and the characteristics, especially pulse width, of the stimulating current.

  1. Modulating Human Auditory Processing by Transcranial Electrical Stimulation

    PubMed Central

    Heimrath, Kai; Fiene, Marina; Rufener, Katharina S.; Zaehle, Tino

    2016-01-01

    Transcranial electrical stimulation (tES) has become a valuable research tool for the investigation of neurophysiological processes underlying human action and cognition. In recent years, striking evidence for the neuromodulatory effects of transcranial direct current stimulation, transcranial alternating current stimulation, and transcranial random noise stimulation has emerged. While the wealth of knowledge has been gained about tES in the motor domain and, to a lesser extent, about its ability to modulate human cognition, surprisingly little is known about its impact on perceptual processing, particularly in the auditory domain. Moreover, while only a few studies systematically investigated the impact of auditory tES, it has already been applied in a large number of clinical trials, leading to a remarkable imbalance between basic and clinical research on auditory tES. Here, we review the state of the art of tES application in the auditory domain focussing on the impact of neuromodulation on acoustic perception and its potential for clinical application in the treatment of auditory related disorders. PMID:27013969

  2. Generation of Electrical Power from Stimulated Muscle Contractions Evaluated

    NASA Technical Reports Server (NTRS)

    Lewandowski, Beth; Kilgore, Kevin; Ercegovic, David B.

    2004-01-01

    This project is a collaborative effort between NASA Glenn Research Center's Revolutionary Aeropropulsion Concepts (RAC) Project, part of the NASA Aerospace Propulsion and Power Program of the Aerospace Technology Enterprise, and Case Western Reserve University's Cleveland Functional Electrical Stimulation (FES) Center. The RAC Project foresees implantable power requirements for future applications such as organically based sensor platforms and robotics that can interface with the human senses. One of the goals of the FES Center is to develop a totally implantable neural prosthesis. This goal is based on feedback from patients who would prefer a system with an internal power source over the currently used system with an external power source. The conversion system under investigation would transform the energy produced from a stimulated muscle contraction into electrical energy. We hypothesize that the output power of the system will be greater than the input power necessary to initiate, sustain, and control the electrical conversion system because of the stored potential energy of the muscle. If the system can be made biocompatible, durable, and with the potential for sustained use, then the biological power source will be a viable solution.

  3. Photoacoustic microscopy of microvascular responses to cortical electrical stimulation

    NASA Astrophysics Data System (ADS)

    Tsytsarev, Vassiliy; Hu, Song; Yao, Junjie; Maslov, Konstantin; Barbour, Dennis L.; Wang, Lihong V.

    2011-07-01

    Advances in the functional imaging of cortical hemodynamics have greatly facilitated the understanding of neurovascular coupling. In this study, label-free optical-resolution photoacoustic microscopy (OR-PAM) was used to monitor microvascular responses to direct electrical stimulations of the mouse somatosensory cortex through a cranial opening. The responses appeared in two forms: vasoconstriction and vasodilatation. The transition between these two forms of response was observed in single vessels by varying the stimulation intensity. Marked correlation was found between the current-dependent responses of two daughter vessels bifurcating from the same parent vessel. Statistical analysis of twenty-seven vessels from three different animals further characterized the spatial-temporal features and the current dependence of the microvascular response. Our results demonstrate that OR-PAM is a valuable tool to study neurovascular coupling at the microscopic level.

  4. Technical Rebuilding of Movement Function Using Functional Electrical Stimulation

    NASA Astrophysics Data System (ADS)

    Gföhler, Margit

    To rebuild lost movement functions, neuroprostheses based on functional electrical stimulation (FES) artificially activate skeletal muscles in corresponding sequences, using both residual body functions and artificial signals for control. Besides the functional gain, FES training also brings physiological and psychological benefits for spinal cord-injured subjects. In this chapter, current stimulation technology and the main components of FES-based neuroprostheses including enhanced control systems are presented. Technology and application of FES cycling and rowing, both approaches that enable spinal cord-injured subjects to participate in mainstream activities and improve their health and fitness by exercising like able-bodied subjects, are discussed in detail, and an overview of neuroprostheses that aim at restoring movement functions for daily life as walking or grasping is given.

  5. Neuronal excitability level transition induced by electrical stimulation

    NASA Astrophysics Data System (ADS)

    Florence, G.; Kurths, J.; Machado, B. S.; Fonoff, E. T.; Cerdeira, H. A.; Teixeira, M. J.; Sameshima, K.

    2014-12-01

    In experimental studies, electrical stimulation (ES) has been applied to induce neuronal activity or to disrupt pathological patterns. Nevertheless, the underlying mechanisms of these activity pattern transitions are not clear. To study these phenomena, we simulated a model of the hippocampal region CA1. The computational simulations using different amplitude levels and duration of ES revealed three states of neuronal excitability: burst-firing mode, depolarization block and spreading depression wave. We used the bifurcation theory to analyse the interference of ES in the cellular excitability and the neuronal dynamics. Understanding this process would help to improve the ES techniques to control some neurological disorders.

  6. New Perspectives in Edema Control via Electrical Stimulation

    PubMed Central

    Mendel, Frank C.; Fish, Dale R.

    1993-01-01

    Clinicians commonly use electrical stimulation (ES) to control acute edema. But, except for anecdotal reports, there is little evidence to support that practice. We recently conducted a series of controlled, blinded studies on several nonhuman animal models to determine the efficacy of several forms of ES, but high-voltage pulsed current (HVPC) in particular, in controlling acute posttraumatic edema. We observed that acute posttraumatic edema is curbed by HVPC when certain protocols are used. Results of these studies suggest to us that wave form, polarity, treatment schedule, intensity and frequency of pulses all influence ES, and that clinical protocols need revision. PMID:16558209

  7. Safety measures implemented for modular functioning electrical stimulators.

    PubMed

    Chen, Chiun-Fan; Lai, Jin-Shin; Chen, Shih-Wei; Lin, Yin-Tsong; Kuo, Te-Son

    2009-01-01

    The modular architecture allows for greater flexibility in the building of neural prostheses with a variety of channels but may result in unpredictable accidents under circumstances such as sensor displacements, improper coordination of the connected modules and malfunction of any individual module. A novel fail-safe interface is offered as a solution that puts in place the necessary safety measures when building a module based functional electrical stimulator. By using a single reference line in the interconnecting bus of the modules, various commands would immediately be directed to each module so that proper actions may be taken.

  8. Electrical stimulation of the salivatory nucleus in the rat.

    PubMed Central

    Donaldson, J; Mitchell, J; Templeton, D

    1984-01-01

    Unilateral electrical stimulation of the salivatory nucleus evoked a secretion from the ipsilateral parotid gland which was well maintained. Flow rate was not affected by sympathetic decentralization or by adrenoceptor antagonists but was abolished by atropine. Protein secretion was reduced by beta-adrenoceptor antagonists but not by sympathetic decentralization or adrenalectomy. In support of previous histochemical findings it is concluded that the cells of the reticular formation are the origin of the preganglionic parasympathetic fibres to the salivary glands but that a beta-adrenoceptor mechanism as yet unidentified is also involved in the protein secretion. PMID:6520785

  9. 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

  10. Transcranial electric stimulation entrains cortical neuronal populations in rats

    PubMed Central

    Ozen, Simal; Sirota, Anton; Belluscio, Mariano A.; Anastassiou, Costas A.; Stark, Eran; Koch, Christof; Buzsáki, György

    2010-01-01

    Low intensity electric fields have been suggested to affect the ongoing neuronal activity in vitro and in human studies. However, the physiological mechanism of how weak electrical fields affect and interact with intact brain activity is not well understood. We performed in vivo extracellular and intracellular recordings from the neocortex and hippocampus of anaesthetized rats and extracellular recordings in behaving rats. Electric fields were generated by sinusoid patterns at slow frequency (0.8, 1.25 or 1.7 Hz) via electrodes placed on the surface of the skull or the dura. Transcranial electric stimulation (TES) reliably entrained neurons in widespread cortical areas, including the hippocampus. The percentage of TES phase-locked neurons increased with stimulus intensity and depended on the behavioral state of the animal. TES-induced voltage gradient, as low as 1 mV/mm at the recording sites, was sufficient to phase-bias neuronal spiking. Intracellular recordings showed that both spiking and subthreshold activity were under the combined influence of TES forced fields and network activity. We suggest that TES in chronic preparations may be used for experimental and therapeutic control of brain activity. PMID:20739569

  11. Visualizing Simulated Electrical Fields from Electroencephalography and Transcranial Electric Brain Stimulation: A Comparative Evaluation

    PubMed Central

    Eichelbaum, Sebastian; Dannhauer, Moritz; Hlawitschka, Mario; Brooks, Dana; Knösche, Thomas R.; Scheuermann, Gerik

    2014-01-01

    Electrical activity of neuronal populations is a crucial aspect of brain activity. This activity is not measured directly but recorded as electrical potential changes using head surface electrodes (electroencephalogram - EEG). Head surface electrodes can also be deployed to inject electrical currents in order to modulate brain activity (transcranial electric stimulation techniques) for therapeutic and neuroscientific purposes. In electroencephalography and noninvasive electric brain stimulation, electrical fields mediate between electrical signal sources and regions of interest (ROI). These fields can be very complicated in structure, and are influenced in a complex way by the conductivity profile of the human head. Visualization techniques play a central role to grasp the nature of those fields because such techniques allow for an effective conveyance of complex data and enable quick qualitative and quantitative assessments. The examination of volume conduction effects of particular head model parameterizations (e.g., skull thickness and layering), of brain anomalies (e.g., holes in the skull, tumors), location and extent of active brain areas (e.g., high concentrations of current densities) and around current injecting electrodes can be investigated using visualization. Here, we evaluate a number of widely used visualization techniques, based on either the potential distribution or on the current-flow. In particular, we focus on the extractability of quantitative and qualitative information from the obtained images, their effective integration of anatomical context information, and their interaction. We present illustrative examples from clinically and neuroscientifically relevant cases and discuss the pros and cons of the various visualization techniques. PMID:24821532

  12. Emerging technology: electrical stimulation in obstructive sleep apnoea

    PubMed Central

    Steier, Joerg

    2015-01-01

    Electrical stimulation (ES) of the upper airway (UAW) dilator muscles for patients with obstructive sleep apnoea (OSA) has been used for several decades, but in recent years research in this field has experienced a renaissance; the results of several studies have triggered a steady rise in the interest in this topic. Prospective trials, although still lacking a sham-controlled and randomised approach, have revealed the potential of ES. Hypoglossal nerve stimulation (HNS) leads to a significant reduction in the apnoea-hypopnoea index and the oxygen desaturation index (ODI). There are similar results published from feasibility studies for transcutaneous ES. A limitation of HNS remains the invasive procedure, the costs involved and severe adverse events, while for the non-invasive approach complications are rare and limited. The limiting step for transcutaneous ES is to deliver a sufficient current without causing arousal from sleep. Despite the progress up to date, numerous variables including optimal stimulation settings, different devices and procedures remain to be further defined for the invasive and the non-invasive method. Further studies are required to identify which patients respond to this treatment. ES of the UAW dilator muscles in OSA has the potential to develop into a clinical alternative to continuous positive airway pressure (CPAP) therapy. It could benefit selected patients who fail standard therapy due to poor long-term compliance. It is likely that international societies will need to review and update their existing guidance on the use of ES in OSA. PMID:26380757

  13. Electrical stimulation to optimize cardioprotective exosomes from cardiac stem cells.

    PubMed

    Campbell, C R; Berman, A E; Weintraub, N L; Tang, Y L

    2016-03-01

    Injured or ischemic cardiac tissue has limited intrinsic capacity for regeneration. While stem cell transplantation is a promising approach to stimulating cardiac repair, its success in humans has thus far been limited. Harnessing the therapeutic benefits of stem cells requires a better understanding of their mechanisms of action and methods to optimize their function. Cardiac stem cells (CSC) represent a particularly effective cellular source for cardiac repair, and pre-conditioning CSC with electrical stimulation (EleS) was demonstrated to further enhance their function, although the mechanisms are unknown. Recent studies suggest that transplanted stem cells primarily exert their effects through communicating with endogenous tissues via the release of exosomes containing cardioprotective molecules such as miRNAs, which upon uptake by recipient cells may stimulate survival, proliferation, and angiogenesis. Exosomes are also effective therapeutic agents in isolation and may provide a feasible alternative to stem cell transplantation. We hypothesize that EleS enhances CSC-mediated cardiac repair through its beneficial effects on production of cardioprotective exosomes. Moreover, we hypothesize that the beneficial effects of biventricular pacing in patients with heart failure may in part result from EleS-induced preconditioning of endogenous CSC to promote cardiac repair. With future research, our hypothesis may provide applications to optimize stem cell therapy and augment current pacing protocols, which may significantly advance the treatment of patients with heart disease. PMID:26880625

  14. Functional regeneration of severed peripheral nerve using an implantable electrical stimulator.

    PubMed

    Lee, Tae Hyung; Pan, Hui; Kim, In Sook; Hwang, Soon Jung; Kim, Sung June

    2010-01-01

    This paper presents functional regeneration of severed peripheral nerve using a polymer-based implantable electrical stimulator. A polyimide based conduit electrode was made by micro-fabrication and a stimulation chip was designed to generate biphasic current pulse for electrical stimulation. The stimulation chip was packaged with a battery using silicone elastomer, and integrated with the electrode. The implantable electrical stimulator was implanted in the rat sciatic nerve with 7 mm gap. The electrical stimulation was applied for periods of one, two and four weeks between the proximal and the distal nerve stumps. After four weeks of post-operations, the degree of regeneration was evaluated through walking track assessments and by measuring neural response of the regenerated nerve. Based on these results, electrical stimulation, especially for two weeks of stimulation, could accelerate functional regeneration of the severed nerve.

  15. A systematic review of electric-acoustic stimulation: device fitting ranges, outcomes, and clinical fitting practices.

    PubMed

    Incerti, Paola V; Ching, Teresa Y C; Cowan, Robert

    2013-03-01

    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

  16. Influence of electrical stimulation on hip joint adductor muscle activity during maximum effort

    PubMed Central

    Nakano, Sota; Wada, Chikamune

    2016-01-01

    [Purpose] This study investigated whether hip adductor activity was influenced by electrical stimulation of the tensor fascia lata muscle. [Subjects and Methods] The subjects were 16 nondisabled males. Each subject was asked to adduct the hip joint with maximum effort. The electromyogram of the adductor longus was recorded under two experimental conditions, with and without electrical stimulation of the tensor fascia lata. [Results] In the presence of electrical stimulation, muscle activity decreased to 72.9% (57.8–89.3%) of that without stimulation. [Conclusion] These results suggested that inactivation of the adductor group was promoted by electrical stimulation of the tensor fascia lata. PMID:27313387

  17. 9 CFR 307.7 - Safety requirements for electrical stimulating (EST) equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... stimulating (EST) equipment. 307.7 Section 307.7 Animals and Animal Products FOOD SAFETY AND INSPECTION... requirements for electrical stimulating (EST) equipment. (a) General. Electrical stimulating (EST) equipment is... separate pieces—the control system and the applicator. The EST control system contains the circuitry...

  18. High-Voltage Pulsed Current Electrical Stimulation in Wound Treatment

    PubMed Central

    Polak, Anna; Franek, Andrzej; Taradaj, Jakub

    2014-01-01

    Significance: A range of studies point to the efficacy of electrical stimulation (ES) in wound treatment, but the methodology of its application has not been determined to date. This article provides a critical review of the results of clinical trials published by researchers using high-voltage pulsed current (HVPC) to treat chronic wounds. In describing the methodology of the trials, the article gives special attention to electric stimulus parameters, the frequency of procedures and total treatment duration. Recent Advances: HVPC is a monophasic pulsed electric current that consists of double-peaked impulses (5–200 μs), at very high peak-current amplitude (2–2.5 A), and high voltage (up to 500 V), at a frequency of 1–125 pulses per second. HVPC can activate “skin battery” and cellular galvanotaxis, and improves blood flow and capillary density. Critical Issues: HVPC efficacy was evaluated in conservatively treated patients with diabetic foot, venous leg and pressure ulcers (PUs), and in some patients with surgically treated venous insufficiency. Future Directions: The efficacy of HVPC as one of several biophysical energies promoting venous leg ulcer (VLU) and PU healing has been confirmed. Additional studies are needed to investigate its effect on the healing of other types of soft tissue defects. Other areas that require more research include the identification of the therapeutic effect of HVPC on infected wounds, the determination of the efficacy of cathodal versus anodal stimulation, and the minimal daily/weekly duration of HVPC required to ensure optimal promotion of wound healing. PMID:24761351

  19. 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.

  20. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... pain relief. 882.5890 Section 882.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... 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...

  1. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... pain relief. 882.5890 Section 882.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... 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...

  2. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... pain relief. 882.5890 Section 882.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... 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...

  3. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... pain relief. 882.5890 Section 882.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... 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...

  4. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... pain relief. 882.5890 Section 882.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... 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...

  5. Electrical stimulation: Its role in growth, repair and remodeling of the musculoskeletal system

    SciTech Connect

    Black, J.

    1986-01-01

    This book examines the increasingly popular field of electrical stimulation of lesions of the musculoskeletal system, exploring its use in both research and treatment. The book describes clinical experience with electrical stimulation in orthopedic, neuro- and plastic surgery, biological sources of electrical signals, and electromechanical characterization of tissues. Contents include: growth; remodeling and repair; electricity and magnetism; electrical properties of tissues; natural electrical signals in the musculoskeletal system; methods for stimulating tissues; cell, tissue and organ culture; animal studies; clinical applications; overview and a glossary.

  6. A personal user's view of functional electrical stimulation cycling.

    PubMed

    Fitzwater, Roger

    2002-03-01

    Two years of functional electrical stimulation cycling (FESC) as a researcher and subject have given me an insight into the direction that future FESC should take as well as providing me with significant health benefits and an enjoyable and functional ability to cycle. If FESC is to benefit spinal cord injured persons (SCIPs), researchers must turn their attention to making the activity convenient and enjoyable. What follows is a personal view and will be less scientifically rigorous than other presentations but hopefully still of value. It calls upon my experience as a general medical practitioner with a special interest in the value of exercise, a human powered vehicle enthusiast, an amateur FES researcher, but most importantly, an SCIP and FES cyclist.

  7. Electrical nerve stimulation for overactive bladder in children.

    PubMed

    Barroso, Ubirajara; Lordêlo, Patrícia

    2011-07-01

    Overactive bladder (OAB) is a urological condition that is frequently observed in children and requires treatment. Standard urotherapy is usually the first line of treatment; however, children with severe OAB do not respond to this therapy. Antimuscarinic drugs may be used, but complete resolution of symptoms with this medication is low. Studies, including two randomized clinical trials, have demonstrated that electrical nerve stimulation (ENS) can be used successfully for OAB in children. Electrodes have been placed in the genitals, anus, and intravesical area, and on the tibial posterior nerve, as well as used transcutaneously or implanted during a surgical procedure. This Review will discuss the use of ENS in children with OAB, with particular focus on the putative mechanisms of action, the different ENS techniques available, and clinical results for this therapy.

  8. A personal user's view of functional electrical stimulation cycling.

    PubMed

    Fitzwater, Roger

    2002-03-01

    Two years of functional electrical stimulation cycling (FESC) as a researcher and subject have given me an insight into the direction that future FESC should take as well as providing me with significant health benefits and an enjoyable and functional ability to cycle. If FESC is to benefit spinal cord injured persons (SCIPs), researchers must turn their attention to making the activity convenient and enjoyable. What follows is a personal view and will be less scientifically rigorous than other presentations but hopefully still of value. It calls upon my experience as a general medical practitioner with a special interest in the value of exercise, a human powered vehicle enthusiast, an amateur FES researcher, but most importantly, an SCIP and FES cyclist. PMID:11940034

  9. Role of Functional Electrical Stimulation in Tetraplegia Hand Surgery.

    PubMed

    Bersch, Ines; Fridén, Jan

    2016-06-01

    The use of functional electrical stimulation (FES) to improve upper limb function is an established method in the rehabilitation of persons with tetraplegia after spinal cord injury. Surgical reconstruction is another well-established yet underused technique to improve the performance of the upper extremities. Hand surgery plays an essential role in restoring hand function, mobility, and quality of life in the tetraplegic population. The knowledge about the effects of FES on a structural and functional level is fundamental for understanding how and when FES can be used best to support the effect of hand surgery, both pre- and postoperatively. In this article we discuss principles of FES and how FES improves functional outcome after surgical reconstruction. The reported results are based on preliminary clinical observations. PMID:27233590

  10. Repair of nonunions by electrically pulsed current stimulation.

    PubMed

    Zichner, L

    1981-01-01

    Five congenital and 52 acquired nonunions of bone were stimulated using an invasive device. The unit delivered a constant but pulsed right-angled current of positive polarity measuring 20 to 25 muAmps (voltage of 750 mV) and a frequency of 20 Hz. The power pack encapsulated in epoxy resin was implanted at the time of operative fragment stabilization. THe cathode was inserted at the site of the nonunion gap. After two to 12 months, all but two of the acquired nonunions and one of the congenital pseudarthroses healed. In the unsuccessful cases, the bone ends were often totally necrotic. Four cases required reimplantation because of broken wires or expiration of the battery, and two cases failed owing to purulent infection. Electrostimulation is an adjuvant treatment to fragment stabilization in hyporeactive and hypovascular or congenital pseudarthroses. Electrical stimuli may be assumed to simulate conditions which are essential for bone healing.

  11. Spatiotemporal structure of intracranial electric fields induced by transcranial electric stimulation in humans and nonhuman primates

    PubMed Central

    Opitz, Alexander; Falchier, Arnaud; Yan, Chao-Gan; Yeagle, Erin M.; Linn, Gary S.; Megevand, Pierre; Thielscher, Axel; Deborah A., Ross; Milham, Michael P.; Mehta, Ashesh D.; Schroeder, Charles E.

    2016-01-01

    Transcranial electric stimulation (TES) is an emerging technique, developed to non-invasively modulate brain function. However, the spatiotemporal distribution of the intracranial electric fields induced by TES remains poorly understood. In particular, it is unclear how much current actually reaches the brain, and how it distributes across the brain. Lack of this basic information precludes a firm mechanistic understanding of TES effects. In this study we directly measure the spatial and temporal characteristics of the electric field generated by TES using stereotactic EEG (s-EEG) electrode arrays implanted in cebus monkeys and surgical epilepsy patients. We found a small frequency dependent decrease (10%) in magnitudes of TES induced potentials and negligible phase shifts over space. Electric field strengths were strongest in superficial brain regions with maximum values of about 0.5 mV/mm. Our results provide crucial information of the underlying biophysics in TES applications in humans and the optimization and design of TES stimulation protocols. In addition, our findings have broad implications concerning electric field propagation in non-invasive recording techniques such as EEG/MEG. PMID:27535462

  12. Spatiotemporal structure of intracranial electric fields induced by transcranial electric stimulation in humans and nonhuman primates.

    PubMed

    Opitz, Alexander; Falchier, Arnaud; Yan, Chao-Gan; Yeagle, Erin M; Linn, Gary S; Megevand, Pierre; Thielscher, Axel; Deborah A, Ross; Milham, Michael P; Mehta, Ashesh D; Schroeder, Charles E

    2016-01-01

    Transcranial electric stimulation (TES) is an emerging technique, developed to non-invasively modulate brain function. However, the spatiotemporal distribution of the intracranial electric fields induced by TES remains poorly understood. In particular, it is unclear how much current actually reaches the brain, and how it distributes across the brain. Lack of this basic information precludes a firm mechanistic understanding of TES effects. In this study we directly measure the spatial and temporal characteristics of the electric field generated by TES using stereotactic EEG (s-EEG) electrode arrays implanted in cebus monkeys and surgical epilepsy patients. We found a small frequency dependent decrease (10%) in magnitudes of TES induced potentials and negligible phase shifts over space. Electric field strengths were strongest in superficial brain regions with maximum values of about 0.5 mV/mm. Our results provide crucial information of the underlying biophysics in TES applications in humans and the optimization and design of TES stimulation protocols. In addition, our findings have broad implications concerning electric field propagation in non-invasive recording techniques such as EEG/MEG. PMID:27535462

  13. The influence of antagonist muscle electrical stimulation on maximal hip adduction force

    PubMed Central

    Nakano, Sota; Wada, Chikamune

    2016-01-01

    [Purpose] The aim of this study was to determine whether electrical stimulation of the tensor fascia lata muscle decreases voluntary maximum resistance to passive abduction motion in participants without disease of the central nervous system. [Subjects] The participants were 16 healthy men. [Methods] The hip joint was moved from 10° adduction to 0° adduction with an angular velocity of 7°/s. During the passive leg motion, the subject was asked to resist the motion with maximum force. Two experimental conditions were prepared: (1) electrical stimulation provided to the tensor fascia lata muscle during the passive motion; and (2) no electrical stimulation provided. [Results] The force was 10.2 ± 3.5 kgf with electrical stimulation and 12.2 ± 3.8 kgf without electrical stimulation. [Conclusion] The results suggested that the maximum hip adduction force decreased in participants because of electrical stimulation of the tensor fascia lata muscle. PMID:26957742

  14. Chronic Stress Decreases Cerebrovascular Responses During Rat Hindlimb Electrical Stimulation

    PubMed Central

    Lee, Sohee; Kang, Bok-Man; Shin, Min-Kyoo; Min, Jiwoong; Heo, Chaejeong; Lee, Yubu; Baeg, Eunha; Suh, Minah

    2015-01-01

    Repeated stress is one of the major risk factors for cerebrovascular disease, including stroke, and vascular dementia. However, the functional alterations in the cerebral hemodynamic response induced by chronic stress have not been clarified. Here, we investigated the in vivo cerebral hemodynamic changes and accompanying cellular and molecular changes in chronically stressed rats. After 3 weeks of restraint stress, the elicitation of stress was verified by behavioral despair in the forced swimming test and by physical indicators of stress. The evoked changes in the cerebral blood volume and pial artery responses following hindpaw electrical stimulation were measured using optical intrinsic signal imaging. We observed that, compared to the control group, animals under chronic restraint stress exhibited a decreased hemodynamic response, with a smaller pial arterial dilation in the somatosensory cortex during hindpaw electrical stimulation. The effect of chronic restraint stress on vasomodulator enzymes, including neuronal nitric oxide synthase (nNOS) and heme oxygenase-2 (HO-2), was assessed in the somatosensory cortex. Chronic restraint stress downregulated nNOS and HO-2 compared to the control group. In addition, we examined the subtypes of cells that can explain the environmental changes due to the decreased vasomodulators. The expression of parvalbumin in GABAergic interneurons and glutamate receptor-1 in neurons were decreased, whereas the microglial activation was increased. Our results suggest that the chronic stress-induced alterations in cerebral vascular function and the modulations of the cellular expression in the neuro-vasomodulatory system may be crucial contributing factors in the development of various vascular-induced conditions in the brain. PMID:26778944

  15. Transcutaneous electrical spinal-cord stimulation in humans

    PubMed Central

    Gerasimenko, Yury; Gorodnichev, Ruslan; Moshonkina, Tatiana; Sayenko, Dimitry; Gad, Parag; Edgerton, V. Reggie

    2016-01-01

    Locomotor behavior is controlled by specific neural circuits called central pattern generators primarily located at the lumbosacral spinal cord. These locomotor-related neuronal circuits have a high level of automaticity; that is, they can produce a “stepping” movement pattern also seen on electromyography (EMG) in the absence of supraspinal and/or peripheral afferent inputs. These circuits can be modulated by epidural spinal-cord stimulation and/or pharmacological intervention. Such interventions have been used to neuromodulate the neuronal circuits in patients with motor-complete spinal-cord injury (SCI) to facilitate postural and locomotor adjustments and to regain voluntary motor control. Here, we describe a novel non-invasive stimulation strategy of painless transcutaneous electrical enabling motor control (pcEmc) to neuromodulate the physiological state of the spinal cord. The technique can facilitate a stepping performance in non-injured subjects with legs placed in a gravity-neutral position. The stepping movements were induced more effectively with multi-site than single-site spinal-cord stimulation. From these results, a multielectrode surface array technology was developed. Our preliminary data indicate that use of the multielectrode surface array can fine-tune the control of the locomotor behavior. As well, the pcEmc strategy combined with exoskeleton technology is effective for improving motor function in paralyzed patients with SCI. The potential impact of using pcEmc to neuromodulate the spinal circuitry has significant implications for furthering our understanding of the mechanisms controlling locomotion and for rehabilitating sensorimotor function even after severe SCI. PMID:26205686

  16. The value of electrical stimulation as an exercise training modality

    NASA Technical Reports Server (NTRS)

    Currier, Dean P.; Ray, J. Michael; Nyland, John; Noteboom, Tim

    1994-01-01

    Voluntary exercise is the traditional way of improving performance of the human body in both the healthy and unhealthy states. Physiological responses to voluntary exercise are well documented. It benefits the functions of bone, joints, connective tissue, and muscle. In recent years, research has shown that neuromuscular electrical stimulation (NMES) simulates voluntary exercise in many ways. Generically, NMES can perform three major functions: suppression of pain, improve healing of soft tissues, and produce muscle contractions. Low frequency NMES may gate or disrupt the sensory input to the central nervous system which results in masking or control of pain. At the same time NMES may contribute to the activation of endorphins, serotonin, vasoactive intestinal polypeptides, and ACTH which control pain and may even cause improved athletic performances. Soft tissue conditions such as wounds and inflammations have responded very favorably to NMES. NMES of various amplitudes can induce muscle contractions ranging from weak to intense levels. NMES seems to have made its greatest gains in rehabilitation where directed muscle contractions may improve joint ranges of motion correct joint contractures that result from shortening muscles; control abnormal movements through facilitating recruitment or excitation into the alpha motoneuron in orthopedically, neurologically, or healthy subjects with intense sensory, kinesthetic, and proprioceptive information; provide a conservative approach to management of spasticity in neurological patients; by stimulation of the antagonist muscle to a spastic muscle stimulation of the agonist muscle, and sensory habituation; serve as an orthotic substitute to conventional bracing used with stroke patients in lieu of dorsiflexor muscles in preventing step page gait and for shoulder muscles to maintain glenohumeral alignment to prevent subluxation; and of course NMES is used in maintaining or improving the performance or torque producing

  17. Highly Flexible Silicone Coated Neural Array for Intracochlear Electrical Stimulation

    PubMed Central

    Bhatti, P.; Van Beek-King, J.; Sharpe, A.; Crawford, J.; Tridandapani, S.; McKinnon, B.; Blake, D.

    2015-01-01

    We present an effective method for tailoring the flexibility of a commercial thin-film polymer electrode array for intracochlear electrical stimulation. Using a pneumatically driven dispensing system, an average 232 ± 64 μm (mean ± SD) thickness layer of silicone adhesive coating was applied to stiffen the underside of polyimide multisite arrays. Additional silicone was applied to the tip to protect neural tissue during insertion and along the array to improve surgical handling. Each array supported 20 platinum sites (180 μm dia., 250 μm pitch), spanning nearly 28 mm in length and 400 μm in width. We report an average intracochlear stimulating current threshold of 170 ± 93 μA to evoke an auditory brainstem response in 7 acutely deafened felines. A total of 10 arrays were each inserted through a round window approach into the cochlea's basal turn of eight felines with one delamination occurring upon insertion (preliminary results of the in vivo data presented at the 48th Annual Meeting American Neurotology Society, Orlando, FL, April 2013, and reported in Van Beek-King 2014). Using microcomputed tomography imaging (50 μm resolution), distances ranging from 100 to 565 μm from the cochlea's central modiolus were measured. Our method combines the utility of readily available commercial devices with a straightforward postprocessing step on the order of 24 hours. PMID:26236714

  18. Individual differences in transcranial electrical stimulation current density

    PubMed Central

    Russell, Michael J; Goodman, Theodore; Pierson, Ronald; Shepherd, Shane; Wang, Qiang; Groshong, Bennett; Wiley, David F

    2013-01-01

    Transcranial electrical stimulation (TCES) is effective in treating many conditions, but it has not been possible to accurately forecast current density within the complex anatomy of a given subject's head. We sought to predict and verify TCES current densities and determine the variability of these current distributions in patient-specific models based on magnetic resonance imaging (MRI) data. Two experiments were performed. The first experiment estimated conductivity from MRIs and compared the current density results against actual measurements from the scalp surface of 3 subjects. In the second experiment, virtual electrodes were placed on the scalps of 18 subjects to model simulated current densities with 2 mA of virtually applied stimulation. This procedure was repeated for 4 electrode locations. Current densities were then calculated for 75 brain regions. Comparison of modeled and measured external current in experiment 1 yielded a correlation of r = .93. In experiment 2, modeled individual differences were greatest near the electrodes (ten-fold differences were common), but simulated current was found in all regions of the brain. Sites that were distant from the electrodes (e.g. hypothalamus) typically showed two-fold individual differences. MRI-based modeling can effectively predict current densities in individual brains. Significant variation occurs between subjects with the same applied electrode configuration. Individualized MRI-based modeling should be considered in place of the 10-20 system when accurate TCES is needed. PMID:24285948

  19. Interaction of poststroke voluntary effort and functional neuromuscular electrical stimulation.

    PubMed

    Makowski, Nathaniel; Knutson, Jayme; Chae, John; Crago, Patrick

    2013-01-01

    Functional electrical stimulation (FES) may be able to augment functional arm and hand movement after stroke. Poststroke neuroprostheses that incorporate voluntary effort and FES to produce the desired movement must consider how forces generated by voluntary effort and FES combine, even in the same muscle, in order to provide an appropriate level of stimulation to elicit the desired assistive force. The goal of this study was to determine whether the force produced by voluntary effort and FES add together independently of effort or whether the increment in force depends on the level of voluntary effort. Isometric force matching tasks were performed under different combinations of voluntary effort and FES. Participants reached a steady level of force, and while attempting to maintain a constant effort level, FES was applied to augment the force. Results indicate that the increment in force produced by FES decreases as the level of initial voluntary effort increases. Potential mechanisms causing the change in force output are proposed, but the relative contribution of each mechanism is unknown.

  20. Numerical simulation of electrically stimulated osteogenesis in dental implants.

    PubMed

    Vanegas-Acosta, J C; Garzón-Alvarado, D A; Lancellotti, V

    2014-04-01

    Cell behavior and tissue formation are influenced by a static electric field (EF). Several protocols for EF exposure are aimed at increasing the rate of tissue recovery and reducing the healing times in wounds. However, the underlying mechanisms of the EF action on cells and tissues are still a matter of research. In this work we introduce a mathematical model for electrically stimulated osteogenesis at the bone-dental implant interface. The model describes the influence of the EF in the most critical biological processes leading to bone formation at the bone-dental implant interface. The numerical solution is able to reproduce the distribution of spatial-temporal patterns describing the influence of EF during blood clotting, osteogenic cell migration, granulation tissue formation, displacements of the fibrillar matrix, and formation of new bone. In addition, the model describes the EF-mediated cell behavior and tissue formation which lead to an increased osteogenesis in both smooth and rough implant surfaces. Since numerical results compare favorably with experimental evidence, the model can be used to predict the outcome of using electrostimulation in other types of wounds and tissues.

  1. Validating computationally predicted TMS stimulation areas using direct electrical stimulation in patients with brain tumors near precentral regions.

    PubMed

    Opitz, Alexander; Zafar, Noman; Bockermann, Volker; Rohde, Veit; Paulus, Walter

    2014-01-01

    The spatial extent of transcranial magnetic stimulation (TMS) is of paramount interest for all studies employing this method. It is generally assumed that the induced electric field is the crucial parameter to determine which cortical regions are excited. While it is difficult to directly measure the electric field, one usually relies on computational models to estimate the electric field distribution. Direct electrical stimulation (DES) is a local brain stimulation method generally considered the gold standard to map structure-function relationships in the brain. Its application is typically limited to patients undergoing brain surgery. In this study we compare the computationally predicted stimulation area in TMS with the DES area in six patients with tumors near precentral regions. We combine a motor evoked potential (MEP) mapping experiment for both TMS and DES with realistic individual finite element method (FEM) simulations of the electric field distribution during TMS and DES. On average, stimulation areas in TMS and DES show an overlap of up to 80%, thus validating our computational physiology approach to estimate TMS excitation volumes. Our results can help in understanding the spatial spread of TMS effects and in optimizing stimulation protocols to more specifically target certain cortical regions based on computational modeling.

  2. Validating computationally predicted TMS stimulation areas using direct electrical stimulation in patients with brain tumors near precentral regions.

    PubMed

    Opitz, Alexander; Zafar, Noman; Bockermann, Volker; Rohde, Veit; Paulus, Walter

    2014-01-01

    The spatial extent of transcranial magnetic stimulation (TMS) is of paramount interest for all studies employing this method. It is generally assumed that the induced electric field is the crucial parameter to determine which cortical regions are excited. While it is difficult to directly measure the electric field, one usually relies on computational models to estimate the electric field distribution. Direct electrical stimulation (DES) is a local brain stimulation method generally considered the gold standard to map structure-function relationships in the brain. Its application is typically limited to patients undergoing brain surgery. In this study we compare the computationally predicted stimulation area in TMS with the DES area in six patients with tumors near precentral regions. We combine a motor evoked potential (MEP) mapping experiment for both TMS and DES with realistic individual finite element method (FEM) simulations of the electric field distribution during TMS and DES. On average, stimulation areas in TMS and DES show an overlap of up to 80%, thus validating our computational physiology approach to estimate TMS excitation volumes. Our results can help in understanding the spatial spread of TMS effects and in optimizing stimulation protocols to more specifically target certain cortical regions based on computational modeling. PMID:24818076

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

    PubMed

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

    2015-11-01

    [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.

  4. Electrical stimulation vs. pulsed and continuous-wave optical stimulation of the rat prostate cavernous nerves, in vivo

    NASA Astrophysics Data System (ADS)

    Perkins, William C.; Lagoda, Gwen A.; Burnett, Arthur; Fried, Nathaniel M.

    2015-07-01

    Identification and preservation of the cavernous nerves (CNs) during prostate cancer surgery is critical for post-operative sexual function. Electrical nerve stimulation (ENS) mapping has previously been tested as an intraoperative tool for CN identification, but was found to be unreliable. ENS is limited by the need for electrode-tissue contact, poor spatial precision from electrical current spreading, and stimulation artifacts interfering with detection. Alternatively, optical nerve stimulation (ONS) provides noncontact stimulation, improved spatial selectivity, and elimination of stimulation artifacts. This study compares ENS to pulsed/CW ONS to explore the ONS mechanism. A total of eighty stimulations were performed in 5 rats, in vivo. ENS (4 V, 5 ms, 10 Hz) was compared to ONS using a pulsed diode laser nerve stimulator (1873 nm, 5 ms, 10 Hz) or CW diode laser nerve stimulator (1455 nm). Intracavernous pressure (ICP) response and nerve compound action potentials (nCAPs) were measured. All three stimulation modes (ENS, ONS-CW, ONS-P) produced comparable ICP magnitudes. However, ENS demonstrated more rapid ICP response times and well defined nCAPs compared to unmeasurable nCAPs for ONS. Further experiments measuring single action potentials during ENS and ONS are warranted to further understand differences in the ENS and ONS mechanisms.

  5. Kinetics of neuromuscular changes during low-frequency electrical stimulation.

    PubMed

    Papaiordanidou, Maria; Guiraud, David; Varray, Alain

    2010-01-01

    The purpose of the study was to examine the time course of neuromuscular fatigue components during a low-frequency electrostimulation (ES) session. Three bouts of 17 trains of stimulation at 30 HZ (4 s on, 6 s off) were used to electrically induce fatigue in the plantar flexor muscles. Before and after every 17-train bout, torque, electromyographic activity [expressed as root mean square (RMS) and median frequency (MF) values], evoked potentials (M-wave and H-reflex), and the level of voluntary activation (LOA, using twitch interpolation technique) were assessed. Torque during maximal voluntary contraction decreased significantly from the very first stimulation bout (-6.6 +/- 1.11%, P < 0.001) and throughout the session (-10.32 +/- 1.68% and -11.53 +/- 1.27%, for the second and third bouts, respectively). The LOA and RMS/Mmax values were significantly decreased during the ES session (-2.9 +/- 1.07% and -17.5 +/- 6.14%, P < 0.01 and P< 0.001, respectively, at the end of the protocol), while MF showed no changes. The Hmax/Mmax ratio and Mmax were not significantly modified during the session. All twitch parameters were significantly potentiated after the first bout and throughout the session (P < 0.001). The maximal torque decrease was evident from the early phase of a low-frequency ES protocol, with no concomitant inhibition of motoneuron excitability or depression of muscle contractile properties. These results are consistent with an early failure of the central drive to the muscle. PMID:19882645

  6. Electrical Vestibular Stimulation after Vestibular Deafferentation and in Vestibular Schwannoma

    PubMed Central

    Aw, Swee Tin; Todd, Michael John; Lehnen, Nadine; Aw, Grace Elizabeth; Weber, Konrad Peter; Eggert, Thomas; Halmagyi, Gabor Michael

    2013-01-01

    Background Vestibular reflexes, evoked by human electrical (galvanic) vestibular stimulation (EVS), are utilized to assess vestibular function and investigate its pathways. Our study aimed to investigate the electrically-evoked vestibulo-ocular reflex (eVOR) output after bilateral and unilateral vestibular deafferentations to determine the characteristics for interpreting unilateral lesions such as vestibular schwannomas. Methods EVOR was recorded with dual-search coils as binocular three-dimensional eye movements evoked by bipolar 100 ms-step at EVS intensities of [0.9, 2.5, 5.0, 7.5, 10.0]mA and unipolar 100 ms-step at 5 mA EVS intensity. Five bilateral vestibular deafferented (BVD), 12 unilateral vestibular deafferented (UVD), four unilateral vestibular schwannoma (UVS) patients and 17 healthy subjects were tested with bipolar EVS, and five UVDs with unipolar EVS. Results After BVD, bipolar EVS elicited no eVOR. After UVD, bipolar EVS of one functioning ear elicited bidirectional, excitatory eVOR to cathodal EVS with 9 ms latency and inhibitory eVOR to anodal EVS, opposite in direction, at half the amplitude with 12 ms latency, exhibiting an excitatory-inhibitory asymmetry. The eVOR patterns from UVS were consistent with responses from UVD confirming the vestibular loss on the lesion side. Unexpectedly, unipolar EVS of the UVD ear, instead of absent response, evoked one-third the bipolar eVOR while unipolar EVS of the functioning ear evoked half the bipolar response. Conclusions The bidirectional eVOR evoked by bipolar EVS from UVD with an excitatory-inhibitory asymmetry and the 3 ms latency difference between normal and lesion side may be useful for detecting vestibular lesions such as UVS. We suggest that current spread could account for the small eVOR to 5 mA unipolar EVS of the UVD ear. PMID:24349188

  7. Electrical stimulation for the treatment of lower urinary tract dysfunction after spinal cord injury

    PubMed Central

    McGee, Meredith J.; Amundsen, Cindy L.; Grill, Warren M.

    2015-01-01

    Electrical stimulation for bladder control is an alternative to traditional methods of treating neurogenic lower urinary tract dysfunction (NLUTD) resulting from spinal cord injury (SCI). In this review, we systematically discuss the neurophysiology of bladder dysfunction following SCI and the applications of electrical stimulation for bladder control following SCI, spanning from historic clinical approaches to recent pre-clinical studies that offer promising new strategies that may improve the feasibility and success of electrical stimulation therapy in patients with SCI. Electrical stimulation provides a unique opportunity to control bladder function by exploiting neural control mechanisms. Our understanding of the applications and limitations of electrical stimulation for bladder control has improved due to many pre-clinical studies performed in animals and translational clinical studies. Techniques that have emerged as possible opportunities to control bladder function include pudendal nerve stimulation and novel methods of stimulation, such as high frequency nerve block. Further development of novel applications of electrical stimulation will drive progress towards effective therapy for SCI. The optimal solution for restoration of bladder control may encompass a combination of efficient, targeted electrical stimulation, possibly at multiple locations, and pharmacological treatment to enhance symptom control. PMID:25582564

  8. [Transesophageal electric stimulation of the left atrium in the diagnosis of ischemic heart disease].

    PubMed

    Liakishev, A A; Kozlov, S G; Grosu, A A; Kulikova, T V; Sidorenko, B A

    1984-10-01

    The clinical picture and the results of bicycle ergometry and selective coronarography were compared with the findings of electrical stimulation of the left atrium in 24 patients. It was demonstrated that transesophagus electric stimulation of the left atrium may serve as a diagnostic method in coronary heart disease.

  9. Functional Electrical Stimulation in Spinal Cord Injury Respiratory Care

    PubMed Central

    Jarosz, Renata; Littlepage, Meagan M.; Creasey, Graham; McKenna, Stephen L.

    2012-01-01

    The management of chronic respiratory insufficiency and/or long-term inability to breathe independently has traditionally been via positive-pressure ventilation through a mechanical ventilator. Although life-sustaining, it is associated with limitations of function, lack of independence, decreased quality of life, sleep disturbance, and increased risk for infections. In addition, its mechanical and electronic complexity requires full understanding of the possible malfunctions by patients and caregivers. Ventilator-associated pneumonia, tracheal injury, and equipment malfunction account for common complications of prolonged ventilation, and respiratory infections are the most common cause of death in spinal cord–injured patients. The development of functional electric stimulation (FES) as an alternative to mechanical ventilation has been motivated by a goal to improve the quality of life of affected individuals. In this article, we will review the physiology, types, characteristics, risks and benefits, surgical techniques, and complications of the 2 commercially available FES strategies – phrenic nerve pacing (PNP) and diaphragm motor point pacing (DMPP). PMID:23459661

  10. Transcutaneous electrical nerve stimulation (TENS) in angina pectoris.

    PubMed

    Mannheimer, C; Carlsson, C A; Vedin, A; Wilhelmsson, C

    1986-09-01

    The aim of this study was to determine the efficacy of transcutaneous electrical nerve stimulation (TENS) in the treatment of chronic stable severe angina pectoris. In a short-term study the effect of TENS was studied in 10 male patients with angina pectoris (functional class III and IV). All patients had previously been stabilized on long-term maximal oral treatment. The effects of the treatment were measured by means of repeated bicycle ergometer tests. All patients had an increased working capacity (16-85%), decreased ST segment depression and reduced recovery time during TENS. No adverse effects were observed. A long-term study of TENS on similarly selected patients showed beneficial effects in terms of pain reduction, reduced frequency of anginal attacks, increased physical activity and increased working capacity during bicycle ergometer tests. An invasive study was carried out with respect to systemic and coronary hemodynamics and myocardial metabolism during pacing provoked myocardial ischemia in 13 patients. The results showed that TENS led to an increased tolerance to pacing, improved lactate metabolism, less pronounced ST segment depression. A drop in systolic blood pressure during TENS treatment at identical pacing rates indicated a decreased afterload. An increased coronary flow to ischemic areas in the myocardium was supported by the fact that the rate pressure product during anginal pain increased during TENS.

  11. Revealing humans’ sensorimotor functions with electrical cortical stimulation

    PubMed Central

    Desmurget, Michel; Sirigu, Angela

    2015-01-01

    Direct electrical stimulation (DES) of the human brain has been used by neurosurgeons for almost a century. Although this procedure serves only clinical purposes, it generates data that have a great scientific interest. Had DES not been employed, our comprehension of the organization of the sensorimotor systems involved in movement execution, language production, the emergence of action intentionality or the subjective feeling of movement awareness would have been greatly undermined. This does not mean, of course, that DES is a gold standard devoid of limitations and that other approaches are not of primary importance, including electrophysiology, modelling, neuroimaging or psychophysics in patients and healthy subjects. Rather, this indicates that the contribution of DES cannot be restricted, in humans, to the ubiquitous concepts of homunculus and somatotopy. DES is a fundamental tool in our attempt to understand the human brain because it represents a unique method for mapping sensorimotor pathways and interfering with the functioning of localized neural populations during the performance of well-defined behavioural tasks. PMID:26240422

  12. Electrical stimulation for difficult wounds: only an alternative procedure?

    PubMed

    Fraccalvieri, Marco; Salomone, Marco; Zingarelli, Enrico M; Rivarossa, Filippo; Bruschi, Stefano

    2015-12-01

    In the wound healing research, the exact mechanism of action of different modalities of electrical stimulation (ES) remains controversial and unresolved. In this study we discuss a particular ES, with a different type of waveform, corresponding to the principle of stochastic resonance. Between July 2008 and May 2010, 32 patients were enrolled and ES was applied to wounds using the bioelectrical signal therapy (BST) device (LifeWave, Petach Tiqwa, Israel). The outcome evaluated in group 1 (n = 21) was wound healing, while group 2 (n = 11) was evaluated for wound-related pain [Visual Number Scale (VNS) pain scale] during treatment. In group 1, 87% of the wounds closed in an average time of 97 days (range 10-150 days); three patients were lost to follow-up. In group 2, 45% of the patients experienced a complete pain disappearance after 7 days of treatment; 36% reported a reduction in VNS from 9·3 to 3·2 in 7 days; 19% stopped morphine-like painkillers after 2 weeks. The clinical application of the stochastic resonance enables the usage of easy-to-use, non-invasive, painless and pain-relief treatment. Our experience with ES has demonstrated the BST device to be a very good alternative in cases of small size defects, compared with other therapies such as surgery, dressing and negative pressure devices. PMID:24443795

  13. Electrical stimulation and swallowing: how much do we know?

    PubMed

    Humbert, Ianessa A; Michou, Emilia; MacRae, Phoebe R; Crujido, Lisa

    2012-08-01

    Consequences of dysphagia substantially reduce quality of life, increase the risk of medical complications and mortality, and pose a substantial cost to healthcare systems. As a result, it is of no wonder that the clinical and scientific communities are showing interest in new avenues for dysphagia rehabilitation. Electrical stimulation (e-stim) for the treatment of swallowing impairments is among the most studied swallowing interventions in the published literature, yet many unanswered questions about its efficacy remain. In the meantime, many speech-language pathologists who treat dysphagia are attending educational and training sessions to obtain certifications to use this technique. Here, we review the values and limitations of the published literature on the topic of e-stim for swallowing to assist clinicians in decision making in their clinical practice. The discussion provides a review of swallowing anatomy and physiology, the fundamentals of e-stim, and information essential for the readers' independent critique of these studies--all of which are crucial for evaluating the possible effects of e-stim.

  14. Electric Field Model of Transcranial Electric Stimulation in Nonhuman Primates: Correspondence to Individual Motor Threshold

    PubMed Central

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

    2015-01-01

    Objective To develop a pipeline for realistic head models of nonhuman primates (NHPs) for simulations of noninvasive brain stimulation, and use these models together with empirical threshold measurements to demonstrate that the models capture individual anatomical variability. Methods Based on structural MRI data, we created models of the electric field (E-field) induced by right unilateral (RUL) electroconvulsive therapy (ECT) in four rhesus macaques. Individual motor threshold (MT) was measured with transcranial electric stimulation (TES) administered through the RUL electrodes in the same subjects. Results The interindividual anatomical differences resulted in 57% variation in median E-field strength in the brain at fixed stimulus current amplitude. Individualization of the stimulus current by MT reduced the E-field variation in the target motor area by 27%. There was significant correlation between the measured MT and the ratio of simulated electrode current and E-field strength (r2 = 0.95, p = 0.026). Exploratory analysis revealed significant correlations of this ratio with anatomical parameters including of the superior electrode-to-cortex distance, vertex-to-cortex distance, and brain volume (r2 > 0.96, p < 0.02). The neural activation threshold was estimated to be 0.45 ± 0.07 V/cm for 0.2 ms stimulus pulse width. Conclusion These results suggest that our individual-specific NHP E-field models appropriately capture individual anatomical variability relevant to the dosing of TES/ECT. These findings are exploratory due to the small number of subjects. Significance This work can contribute insight in NHP studies of ECT and other brain stimulation interventions, help link the results to clinical studies, and ultimately lead to more rational brain stimulation dosing paradigms. PMID:25910001

  15. Cortical electrical stimulation in humans. The negative motor areas.

    PubMed

    Lüders, H O; Dinner, D S; Morris, H H; Wyllie, E; Comair, Y G

    1995-01-01

    Summarizing, we have presented evidence in humans for two "negative motor areas" which we had speculated play a significant role in the planning of voluntary motor movements. A review of the more recent experimental literature shows that histological, physiological, and electrical stimulation studies in animals reveal the existence of two frontal regions that from the experimental data also seem to play an essential role in the preparation (as opposed to execution) of voluntary movements. Current available evidence suggests that these two areas (areas F5 and F6 of Rizzolatti et al.) correspond to the negative motor areas we have described in human studies. Also of interest is that Broca's area in the dominant hemisphere overlaps the corresponding negative motor area. This observation suggests that Broca's area has evolved from area F5 of monkeys specializing in the planning of fine movements necessary for speech production. We feel that current evidence suggests the existence of three mechanisms by which cortical stimulation (by electrical stimulation or by epileptic activation) can generate negative motor phenomena: 1. The "silent period," which is consistently contralateral, has a somatotopic distribution, and tends to affect predominantly muscles involved in fine movements. It is of relatively short duration and seems to be generated by the activation of cortical areas in the primary sensorimotor region. The H-reflex is not inhibited during the silent period, suggesting that the silent period is generated by a decrease in the excitatory input through direct corticospinal neurons on the spinal alpha motoneurons. It is possible that in normal individuals this system is used for fine tuning of fine distal movements. The negative myoclonus seen in some patients with focal cortical epilepsy is probably generated by this mechanism. The primary and supplementary "negative motor areas" described in this chapter. This effect also has a somatotopic distribution but can

  16. Electrical stimulation therapy improves sleep respiratory parameters in obstructive sleep apnea syndrome: a meta-analysis.

    PubMed

    Tan, Jie-wen; Qi, Wei-wei; Ye, Rui-xin; Wu, Yuan-yuan

    2013-10-01

    Recent clinical trials have shown that electrical stimulation has beneficial effects in obstructive sleep apnea syndrome (OSAS). The purpose of this study was to evaluate the efficacy of electrical stimulation therapy for OSAS with a meta-analysis. The meta-analysis of all relative studies was performed through searching international literature, including PUBMED, CNKI, and EMBASE databases. This literature analysis compared all patients undergoing electrical stimulation therapy with respect to the respiratory disturbance index (RDI) and changes in sleep structure. Six studies were selected involving a total of 91 patients. The meta-analysis indicated that electrical stimulation therapy reduced RDI, longest apnea time, and improved the minimum SaO2. Based on the evidence found, electrical stimulation may be a potential therapy for OSAS, warranting further clinical trials.

  17. Videoradiography at submental electrical stimulation during apnea in obstructive sleep apnea syndrome. A case report.

    PubMed

    Hillarp, B; Rosén, I; Wickström, O

    1991-05-01

    Percutaneous submental electrical stimulation during sleep may be a new therapeutic method for patients with obstructive sleep apnea syndrome (OSAS). Electrical stimulation to the submental region during obstructive apnea is reported to break the apnea without arousal and to diminish apneic index, time spent in apnea, and oxygen desaturation. The mode of breaking the apnea by electrical stimulation has not yet been shown. However, genioglossus is supposed to be the muscle responsible for breaking the apnea by forward movement of the tongue. To visualize the effect of submental electrical stimulation, one patient with severe OSAS has been examined with videoradiography. Submental electrical stimulation evoked an immediate complex muscle activity in the tongue, palate, and hyoid bone. This was followed by a forward movement of the tongue which consistently broke obstructive apnea without apparent arousal. Time spent in apnea was diminished but intervals between apnea were not affected.

  18. Principles of electrical stimulation and dorsal column mapping as it relates to spinal cord stimulation: an overview.

    PubMed

    Ramasubbu, Chitra; Flagg, Artemus; Williams, Kayode

    2013-02-01

    The last 30 years have witnessed the growth of spinal cord stimulation as a treatment modality for an increasing number of chronic pain conditions. In spite of this growth, one of the greatest criticisms is the lack of concrete evidence for the mechanism of action. With the ever increasing enlightenment with regards to the neurophysiology of pain, and the development of more dynamic neuroimaging techniques, the opportunity to better define the mechanism of action of the spinal cord stimulator will continue to expand. In the interim, clinicians will benefit from the consolidation of the available knowledge that will enhance the effective use of the device. This review serves to provide an overview of the key principles of electrical stimulation and dorsal column mapping as it relates to spinal cord stimulation. We aim at enhancing the understanding regarding the basis for successful placement of leads and manipulation of electrical parameters. PMID:23299905

  19. 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

  20. 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

  1. Audio-Visual Stimulation in Conjunction with Functional Electrical Stimulation to Address Upper Limb and Lower Limb Movement Disorder.

    PubMed

    Kumar, Deepesh; Verma, Sunny; Bhattacharya, Sutapa; Lahiri, Uttama

    2016-06-13

    Neurological disorders often manifest themselves in the form of movement deficit on the part of the patient. Conventional rehabilitation often used to address these deficits, though powerful are often monotonous in nature. Adequate audio-visual stimulation can prove to be motivational. In the research presented here we indicate the applicability of audio-visual stimulation to rehabilitation exercises to address at least some of the movement deficits for upper and lower limbs. Added to the audio-visual stimulation, we also use Functional Electrical Stimulation (FES). In our presented research we also show the applicability of FES in conjunction with audio-visual stimulation delivered through VR-based platform for grasping skills of patients with movement disorder. PMID:27478568

  2. Audio-Visual Stimulation in Conjunction with Functional Electrical Stimulation to Address Upper Limb and Lower Limb Movement Disorder

    PubMed Central

    Kumar, Deepesh; Verma, Sunny; Bhattacharya, Sutapa; Lahiri, Uttama

    2016-01-01

    Neurological disorders often manifest themselves in the form of movement deficit on the part of the patient. Conventional rehabilitation often used to address these deficits, though powerful are often monotonous in nature. Adequate audio-visual stimulation can prove to be motivational. In the research presented here we indicate the applicability of audio-visual stimulation to rehabilitation exercises to address at least some of the movement deficits for upper and lower limbs. Added to the audio-visual stimulation, we also use Functional Electrical Stimulation (FES). In our presented research we also show the applicability of FES in conjunction with audio-visual stimulation delivered through VR-based platform for grasping skills of patients with movement disorder. PMID:27478568

  3. Programmed electrical stimulation protocols: variations on a theme.

    PubMed

    Fisher, J D; Kim, S G; Ferrick, K J; Roth, J

    1992-11-01

    A series of prospective protocols were designed to determine the yield ratio (true positives vs. false positives = nonclinical) in various patient groups using a variety of programmed electrical stimulation (PES) variables. First, a PES protocol was used in 772 patients. Single, double, and triple extrastimuli were delivered in sequence (leaving each successive extrastimulus just beyond its refractory period before moving to the next extrastimulus) during sinus rhythm and two ventricular paced rates at the RV apex, before moving to the outflow tract and repeating the sequence and then moving on to isoproterenol infusion with the PES sequence repeated at the apex. This protocol met NASPE standards for induction of VT in patients with coronary artery disease and a history of VT, while failing to induce monomorphic VT in any control patient. The best yield ratios combined with the greatest likelihood of inducing clinical tachycardia were achieved with sinus rhythm and three extrastimuli, and pacing at the lower rate and three extrastimuli. Pacing at the faster rate and triple extrastimuli was highly inductive of clinical arrhythmias, but had a low yield ratio due to induction of more nonclinical arrhythmias than other steps. The next protocol was performed in 61 patients with inducible ventricular tachycardia. In each case, the protocol described above was completed at the RV apex, even if tachycardia was also induced at an earlier point in the protocol. This allowed for more accurate yield ratios to be established for each step in the protocol, since each patient was exposed to each of these steps.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1279622

  4. Probing the physiology of ASH neuron in Caenorhabditis elegans using electric current stimulation

    NASA Astrophysics Data System (ADS)

    Chokshi, Trushal Vijaykumar; Bazopoulou, Daphne; Chronis, Nikos

    2011-08-01

    Electrical stimulation has been widely used to modulate and study the in vitro and in vivo functionality of the nervous system. Here, we characterized the effect of electrical stimulation on ASH neuron in Caenorhabditis elegans and employed it to probe the neuron's age dependent properties. We utilized an automated microfluidic-based platform and characterized the ASH neuronal activity in response to an electric current applied to the worm's body. The electrically induced ASH neuronal response was observed to be dependent on the magnitude, polarity, and spatial location of the electrical stimulus as well as on the age of the worm.

  5. Vestibular implantation and longitudinal electrical stimulation of the semicircular canal afferents in human subjects.

    PubMed

    Phillips, James O; Ling, Leo; Nie, Kaibao; Jameyson, Elyse; Phillips, Christopher M; Nowack, Amy L; Golub, Justin S; Rubinstein, Jay T

    2015-06-01

    Animal experiments and limited data in humans suggest that electrical stimulation of the vestibular end organs could be used to treat loss of vestibular function. In this paper we demonstrate that canal-specific two-dimensionally (2D) measured eye velocities are elicited from intermittent brief 2 s biphasic pulse electrical stimulation in four human subjects implanted with a vestibular prosthesis. The 2D measured direction of the slow phase eye movements changed with the canal stimulated. Increasing pulse current over a 0-400 μA range typically produced a monotonic increase in slow phase eye velocity. The responses decremented or in some cases fluctuated over time in most implanted canals but could be partially restored by changing the return path of the stimulation current. Implantation of the device in Meniere's patients produced hearing and vestibular loss in the implanted ear. Electrical stimulation was well tolerated, producing no sensation of pain, nausea, or auditory percept with stimulation that elicited robust eye movements. There were changes in slow phase eye velocity with current and over time, and changes in electrically evoked compound action potentials produced by stimulation and recorded with the implanted device. Perceived rotation in subjects was consistent with the slow phase eye movements in direction and scaled with stimulation current in magnitude. These results suggest that electrical stimulation of the vestibular end organ in human subjects provided controlled vestibular inputs over time, but in Meniere's patients this apparently came at the cost of hearing and vestibular function in the implanted ear.

  6. Olfactory hallucinations elicited by electrical stimulation via subdural electrodes: effects of direct stimulation of olfactory bulb and tract.

    PubMed

    Kumar, Gogi; Juhász, Csaba; Sood, Sandeep; Asano, Eishi

    2012-06-01

    In 1954, Penfield and Jasper briefly described that percepts of unpleasant odor were elicited by intraoperative electrical stimulation of the olfactory bulb in patients with epilepsy. Since then, few peer-reviewed studies have reported such phenomena elicited by stimulation mapping via subdural electrodes implanted on the ventral surface of the frontal lobe. Here, we determined what types of olfactory hallucinations could be reproduced by such stimulation in children with focal epilepsy. This study included 16 children (age range: 5 to 17 years) who underwent implantation of subdural electrodes to localize the presumed epileptogenic zone and eloquent areas. Pairs of electrodes were electrically stimulated, and clinical responses were observed. In case a patient reported a perception, she/he was asked to describe its nature. We also described the stimulus parameters to elicit a given symptom. Eleven patients reported a perception of smell in response to electrical stimulation while the remaining five did not. Nine patients perceived an unpleasant smell (like bitterness, smoke, or garbage) while two perceived a pleasant smell (like strawberry or good food). Such olfactory hallucinations were induced by stimulation proximal to the olfactory bulb or tract on either hemisphere but not by that of orbitofrontal gyri lateral to the medial orbital sulci. The range of stimulus parameters employed to elicit olfactory hallucinations was comparable to those for other sensorimotor symptoms. Our systematic study of children with epilepsy replicated stimulation-induced olfactory hallucinations. We failed to provide evidence that a positive olfactory perception could be elicited by conventional stimulation of secondary olfactory cortex alone.

  7. Electrical Stimulation as an Adjunctive Treatment of Painful and Sensory Diabetic Neuropathy

    PubMed Central

    Thakral, Gaurav; Kim, Paul J.; LaFontaine, Javier; Menzies, Robert; Najafi, Bijan; Lavery, Lawrence A.

    2013-01-01

    Background The objective of this review is to evaluate the use of electrical stimulation to treat diabetic neuropathy. Application of electrical stimulation may provide a novel treatment option for large and small fiber neuropathy in persons with diabetes. Large and small nerve neuropathy alters pain, proprioception, touch perception, and motor function, which cause burning foot pain and serve as protective mechanisms from ulcerations. Methods A content search for clinical trials involving electrical stimulation, neuropathy, and diabetes was conducted through PubMed. Randomized clinical trials and prospective studies with outcome measures affecting the lower extremity function were selected for review. Results We identified eight studies in which electrical stimulation was used to treat diabetic neuropathy. Six studies evaluated small fiber neuropathy. Two studies evaluated patients with both small and large fiber neuropathy and reported significant improvement in vibration and monofilament testing and reduction in symptoms in the electrical stimulation treatment group. Six of the eight painful neuropathy studies identified significant improvement in symptoms. There were no studies that evaluated electrical stimulation to treated diabetic motor neuropathy, fall prevention or postural instability. Conclusions Electrical stimulation may be an effective alternative and adjunctive therapy to current interventions for diabetic peripheral neuropathy. PMID:24124947

  8. Semiochemicals released by electrically stimulated red imported fire ants, Solenopsis invicta.

    PubMed

    Vander Meer, R K; Slowik, T J; Thorvilson, H G

    2002-12-01

    The red imported fire ant Solenopsis invicta Buren, has evolved sophisticated chemical communication systems that regulate the activities of the colony. Among these are recruitment pheromones that effectively attract and stimulate workers to follow a trail to food or alternative nesting sites. Alarm pheromones alert, activate, and attract workers to intruders or other disturbances. The attraction and accumulation of fire ant workers in electrical equipment may be explained by their release of pheromones that draw additional worker ants into the electrical contacts. We used chemical analysis and behavioral bioassays to investigate if semiochemicals were released by electrically shocked fire ants. Workers were subjected to a 120 V, alternating-current power source. In all cases, electrically stimulated workers released venom alkaloids as revealed by gas chromatography. We also demonstrated the release of alarm pheromones and recruitment pheromones that elicited attraction and orientation. Arrestant behavior was observed with the workers not electrically stimulated but near those that were, indicating release of unkown behavior-modifying substances from the electrically stimulated ants. It appears that fire ants respond to electrical stimulus by generally releasing exocrine gland products. The behaviors associated with these products support the hypothesis that the accumulation of fire ants in electrical equipment is the result of a foraging worker finding and closing electrical contacts, then releasing exocrine gland products that attract other workers to the site, who in turn are electrically stimulated. PMID:12564802

  9. Enhancement of muscle activity by electrical stimulation in cerebral palsy: a case-control study.

    PubMed

    Katz, Amir; Tirosh, Emanuel; Marmur, Rachel; Mizrahi, Joseph

    2008-03-01

    The objectives of this study were to compare the effects of low-intensity electrical stimulation of the quadriceps muscle in children with cerebral palsy in the following 2 modes: reconditioning by long-term training of the muscle versus real-time assist to the muscle during motion. To evaluate the force enhancement in the assist mode, we developed a method to dissociate the volitional and the induced components from the total electromyographic signal. The study group, including 5 children with cerebral palsy (mean age, 3.3 years; 0.4 SD), underwent 2 testing sessions: 1 before and 1 after 3-month training by electrical stimulation. Each session included 2 series of trials: 1 with electrical stimulation, as an orthotic assist, and 1 without electrical stimulation. The tests included flexion-extension movements of the knee at a self-selected pace. The results showed that, compared to before training, there was a significant increase in the average motion velocity and a decrease in motion jerk and in knee torque after training in both the electrical stimulation- assisted and -unassisted modes. Of special interest was the significant decrease in quadriceps-hamstrings co-contraction following training by electrical stimulation but not during electrical stimulation-assisted motion. The results obtained for the group with cerebral palsy were statistically different from those of the control group, but this difference decreased after long-term training by electrical stimulation. It was concluded that, in children with cerebral palsy, electrical stimulation is more beneficial in long-term training than when used as a real-time motion assist. Although muscle strength is not affected, more centrally controlled attributes such as co-contraction are improved.

  10. Bioreactor for modulation of cardiac microtissue phenotype by combined static stretch and electrical stimulation

    PubMed Central

    Miklas, Jason W; Nunes, Sara S; Sofla, Aarash; Reis, Lewis A; Pahnke, Aric; Xiao, Yun; Laschinger, Carol; Radisic, Milica

    2014-01-01

    We describe here a bioreactor capable of simultaneously applying mechanical and electrical field stimulation in conjunction with static strain and on-line force of contraction measurements. It consisted of a polydimethylsiloxane (PDMS) tissue chamber and a pneumatically driven stretch platform. The chamber contained eight tissue microwells (8.05 mm in length and 2.5 mm in width) with a pair of posts (2.78 mm in height and 0.8 mm in diameter) in each well to serve as fixation points and for measurements of contraction force. Carbon rods, stimulating electrodes, were placed into the PDMS chamber such that one pair stimulated four microwells. For feasibility studies, neonatal rat cardiomyocytes were seeded in collagen gels into the microwells. Following three days of gel compaction, electrical field stimulation at 3–4 V/cm and 1Hz, mechanical stimulation of 5% static strain or electromechanical stimulation (field stimulation at 3–4 V/cm, 1Hz and 5% static strain) were applied for 3 days. Cardiac microtissues subjected to electromechanical stimulation exhibited elevated amplitude of contraction and improved sarcomere structure as evidenced by sarcomeric α-actinin, actin and troponin T staining compared to microtissues subjected to electrical or mechanical stimulation alone or non-stimulated controls. The expression of atrial natriuretic factor and brain natriuretic peptide was also elevated in the electromechanically stimulated group. PMID:24876342

  11. Observation of pressure stimulated voltages in rocks using an electric potential sensor

    SciTech Connect

    Aydin, A.; Prance, R. J.; Prance, H.; Harland, C. J.

    2009-09-21

    Recent interest in the electrical activity in rock and the use of electric field transients as candidates for earthquake precursors has led to studies of pressure stimulated currents in laboratory samples. In this paper, an electric field sensor is used to measure directly the voltages associated with these currents. Stress was applied as uniaxial compression to marble and granite at an approximately constant rate. In contrast with the small pressure stimulated currents previously measured, large voltage signals are reported. Polarity reversal of the signal was observed immediately before fracture for the marble, in agreement with previous pressure stimulated current studies.

  12. Effect of intravaginal electrical stimulation on pelvic floor muscle strength.

    PubMed

    Amaro, João Luiz; Gameiro, Mônica Orsi; Padovani, Carlos Roberto

    2005-01-01

    The aim of this study was to evaluate the effect of intravaginal electrical stimulation (IES) on pelvic floor muscle (PFM) strength in patients with mixed urinary incontinence (MUI). Between January 2001 and February 2002, 40 MUI women (mean age: 48 years) were studied. Urge incontinence was the predominant symptom; 92.5% also presented mild stress urinary incontinence (SUI). Selection criteria were clinical history and urodynamics. Pre-treatment urodynamic study showed no statistical differences between the groups. Ten percent of the women in each group had involuntary detrusor contractions. Patients were randomly distributed, in a double-blind study, into two groups. Group G1 (n=20), effective IES, and group G2 (n=20), sham IES, with follow-up at 1 month. The following parameters were studied: (1) clinical questionnaire, (2) examiner's evaluation of perineal muscle strength, (3) objective evaluation of perineal muscle by perineometry, (4) vaginal weight test, and (5) urodynamic study. The IES protocol consisted of three 20-min sessions per week over a 7-week period using a Dualpex Uro 996 at 4 Hz. There was no statistically significant difference in the demographic data of both groups. The number of micturitions per 24 h after treatment was reduced significantly in both groups. Urge incontinence, present in all patients before treatment, was reduced to 15% in G1 and 31.5% in G2 post-treatment. The subjective evaluation of PFM strength demonstrated a significant improvement in G1. Objective evaluation of PFM force by perineometer showed a significant improvement in maximum peak contraction post-treatment in both groups. In the vaginal weight test, there was a significant increase in average number of cone retentions post-treatment in both groups. With regard to satisfaction level, after treatment, 80% of the patients in G1 and 65% of the patients in G2 were satisfied. There was no statistically significant difference between the groups. There was a significant

  13. Distribution of electrical stimulation current in a planar multilayer anisotropic tissue.

    PubMed

    Mesin, Luca; Merletti, Roberto

    2008-02-01

    This study analytically addresses the problem of neuromuscular electrical stimulation for a planar, multilayer, anisotropic model of a physiological tissue (referred to as volume conductor). Both conductivity and permittivity of the volume conductor are considered, including dispersive properties. The analytical solution is obtained in the 2-D Fourier transform domain, transforming in the planes parallel to the volume conductor surface. The model is efficient in terms of computational cost, as the solution is analytical (only numerical Fourier inversion is needed). It provides the current distribution in a physiological tissue induced by an electrical current delivered at the skin surface. Three representative examples of application of the model are considered. 1) The simulation of stimulation artefact during transcutaneous electrical stimulation and EMG detection. Only the effect of the volume conductor is considered, neglecting the other sources of artefact (such as the capacitive coupling between the stimulating and recording electrodes). 2) The simulation of the electrical current distribution within the muscle and the low-pass filter effect of the volume conductor on sinusoidal stimulation currents with different stimulation frequencies. 3) The estimation of the amplitude modulated current distribution within the muscle for interferential stimulation. The model is devoted to the simulation of neuromuscular stimulation, but the same method could be applied in other fields in which the estimation of the electrical current distribution in a medium induced by the injection of a current from the boundary of the medium is of interest.

  14. Tissue heterogeneity as a mechanism for localized neural stimulation by applied electric fields

    NASA Astrophysics Data System (ADS)

    Miranda, P. C.; Correia, L.; Salvador, R.; Basser, P. J.

    2007-09-01

    We investigate the heterogeneity of electrical conductivity as a new mechanism to stimulate excitable tissues via applied electric fields. In particular, we show that stimulation of axons crossing internal boundaries can occur at boundaries where the electric conductivity of the volume conductor changes abruptly. The effectiveness of this and other stimulation mechanisms was compared by means of models and computer simulations in the context of transcranial magnetic stimulation. While, for a given stimulation intensity, the largest membrane depolarization occurred where an axon terminates or bends sharply in a high electric field region, a slightly smaller membrane depolarization, still sufficient to generate action potentials, also occurred at an internal boundary where the conductivity jumped from 0.143 S m-1 to 0.333 S m-1, simulating a white-matter-grey-matter interface. Tissue heterogeneity can also give rise to local electric field gradients that are considerably stronger and more focal than those impressed by the stimulation coil and that can affect the membrane potential, albeit to a lesser extent than the two mechanisms mentioned above. Tissue heterogeneity may play an important role in electric and magnetic 'far-field' stimulation.

  15. Long-Term Effects of Gastric Stimulation on Gastric Electrical Physiology

    PubMed Central

    Williams, Patrick A.; Nikitina, Yana; Kedar, Archana; Lahr, Christopher J.; Helling, Thomas S.

    2016-01-01

    Introduction This study evaluates the modeling of gastric electrophysiology tracings during long-term gastric electrical stimulation for gastroparesis. We hypothesized that serosal electrogastrogram may change over time representing gastric remodeling from gastric stimulation. Patients Sixty-five patients with gastroparesis underwent placement of gastric stimulator for refractory symptoms. Mean age at initial stimulator placement was 44 years (range, 8–76), current mean age was 49, and the majority of the subjects were female (n = 51, 78 %). Only a minority had diabetes-induced gastroparesis (n = 16, 25 %); the remainder were either idiopathic or postsurgical. Methods At the time of stimulator placement, electrogastrogram was performed after the gastric leads were placed but before stimulation was begun. Patients underwent continuous stimulation until pacer batteries depleted. At the time of replacement, before the new pacemaker was attached, electrogastrogram was again performed. Results After a mean of 3.9 years of stimulation therapy, the mean of baseline frequency before stimulation therapy was 5.06 cycles/min and declined to 3.66 after replacement (p = 0.0000002). The mean amplitude was 0.33 mV before stimulation therapy and decreased to 0.31 mV (p = 0.73). The frequency/amplitude ratio was 38.4 before stimulation therapy and decreased to 21.9 (p = 0.001). Conclusion Long-term gastric electrical stimulation causes improvement in basal unstimulated gastric frequency to near normal. PMID:22956404

  16. Selectivity and resolution of surface electrical stimulation for grasp and release.

    PubMed

    Westerveld, Ard J; Schouten, Alfred C; Veltink, Peter H; van der Kooij, Herman

    2012-01-01

    Electrical stimulation of arm and hand muscles can be a functional tool for patients with motor dysfunction. Sufficient stimulation of finger and thumb musculature can support natural grasping function. Yet it remains unclear how different grasping movements can be selectively supported by electrical stimulation. The goal of this study is to determine to what extent activation of individual fingers is possible with surface electrical stimulation for the purpose of rehabilitation following stroke. The extensor digitorum communis (EDC) muscle, flexor pollicis longus (FPL) muscle, and the thenar muscle group, all involved in grasp and release, were selected for stimulation. The evoked forces in individual fingers were measured. Stimulation thresholds and selective ranges were determined for each subject. Electrode locations where the highest selective range occurred were compared between subjects and influences of different isometric wrist positions were assessed. In all subjects selective stimulation of middle finger extension and thumb flexion was possible. In addition, selective stimulation of index and ring finger extension was possible in most cases. In nine out of the ten EDC subjects we were able to stimulate three or all four fingers selectively. However, large variability in electrode locations for high selectivity was observed between the subjects. Within the designs of grasping prostheses and grasping rehabilitation devices, the variability of electrode locations should be taken into account. The results of our study facilitate the optimization of such designs and favour a design which allows individualized stimulation locations. PMID:22180518

  17. Electrical carotid sinus stimulation: chances and challenges in the management of treatment resistant arterial hypertension.

    PubMed

    Chobanyan-Jürgens, Kristine; Jordan, Jens

    2015-09-01

    Treatment resistant arterial hypertension is associated with excess cardiovascular morbidity and mortality. Electrical carotid sinus stimulators engaging baroreflex afferent activity have been developed for such patients. Indeed, baroreflex mechanisms contribute to long-term blood pressure control by governing efferent sympathetic and parasympathetic activity. The first-generation carotid sinus stimulator applying bilateral bipolar stimulation reduced blood pressure in a controlled clinical trial but nevertheless failed to meet the primary efficacy endpoint. The second-generation device utilizes smaller unilateral unipolar electrodes, thus decreasing invasiveness of the implantation while saving battery. An uncontrolled clinical study suggested improvement in blood pressure with the second-generation device. We hope that these findings as well as preliminary observations suggesting cardiovascular and renal organ protection with electrical carotid sinus stimulation will be confirmed in properly controlled clinical trials. Meanwhile, we should find ways to better identify patients who are most likely to benefit from electrical carotid sinus stimulation.

  18. Electrical stimulation in the bed nucleus of the stria terminalis alleviates severe obsessive-compulsive disorder.

    PubMed

    Luyten, L; Hendrickx, S; Raymaekers, S; Gabriëls, L; Nuttin, B

    2016-09-01

    In 1998, we proposed deep brain stimulation as a last-resort treatment option for patients suffering from severe, treatment-resistant obsessive-compulsive disorder (OCD). Here, 24 OCD patients were included in a long-term follow-up study to evaluate the effects of electrical stimulation in the anterior limbs of the internal capsule (ALIC) and bed nucleus of the stria terminalis (BST). We find that electrical stimulation in the ALIC/BST area is safe and significantly decreases obsessions, compulsions, and associated anxiety and depressive symptoms, and improves global functioning in a blinded crossover trial (n=17), after 4 years (n=18), and at last follow-up (up to 171 months, n=24). Moreover, our data indicate that BST may be a better stimulation target compared with ALIC to alleviate OCD symptoms. We conclude that electrical stimulation in BST is a promising therapeutic option for otherwise treatment-resistant OCD patients. PMID:26303665

  19. Alternating stimulation of synergistic muscles during functional electrical stimulation cycling improves endurance in persons with spinal cord injury.

    PubMed

    Decker, M J; Griffin, L; Abraham, L D; Brandt, L

    2010-12-01

    Therapeutic effects of functional electrical stimulation (FES) cycling for persons with spinal cord injury (SCI) are limited by high rates of muscular fatigue. FES-cycling performance limits and surface mechanomyography (MMG) of 12 persons with SCI were compared under two different stimulation protocols of the quadriceps muscles. One strategy used the standard "co-activation" protocol from the manufacturer of the FES cycle which involved intermittent simultaneous activation of the entire quadriceps muscle group for 400 ms. The other strategy was an "alternation" stimulation protocol which involved alternately stimulating the rectus femoris (RF) muscle for 100 ms and the vastus medialis (VM) and vastus lateralis (VL) muscles for 100 ms, with two sets with a 400 ms burst. Thus, during the alternation protocol, each of the muscle groups rested for two 100 ms "off" periods in each 400 ms burst. There was no difference in average cycling cadence (28 RPM) between the two protocols. The alternation stimulation protocol produced longer ride times and longer virtual distances traveled and used lower stimulation intensity levels with no differences in average MMG amplitudes compared to the co-activation protocol. These results demonstrate that FES-cycling performance can be enhanced by a synergistic muscle alternation stimulation strategy. PMID:20708950

  20. Alternating stimulation of synergistic muscles during functional electrical stimulation cycling improves endurance in persons with spinal cord injury.

    PubMed

    Decker, M J; Griffin, L; Abraham, L D; Brandt, L

    2010-12-01

    Therapeutic effects of functional electrical stimulation (FES) cycling for persons with spinal cord injury (SCI) are limited by high rates of muscular fatigue. FES-cycling performance limits and surface mechanomyography (MMG) of 12 persons with SCI were compared under two different stimulation protocols of the quadriceps muscles. One strategy used the standard "co-activation" protocol from the manufacturer of the FES cycle which involved intermittent simultaneous activation of the entire quadriceps muscle group for 400 ms. The other strategy was an "alternation" stimulation protocol which involved alternately stimulating the rectus femoris (RF) muscle for 100 ms and the vastus medialis (VM) and vastus lateralis (VL) muscles for 100 ms, with two sets with a 400 ms burst. Thus, during the alternation protocol, each of the muscle groups rested for two 100 ms "off" periods in each 400 ms burst. There was no difference in average cycling cadence (28 RPM) between the two protocols. The alternation stimulation protocol produced longer ride times and longer virtual distances traveled and used lower stimulation intensity levels with no differences in average MMG amplitudes compared to the co-activation protocol. These results demonstrate that FES-cycling performance can be enhanced by a synergistic muscle alternation stimulation strategy.

  1. 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

  2. Luteinizing hormone releasing factor in rat hypophysial portal blood collected during electrical stimulation of the hypothalamus

    PubMed Central

    Harris, G. W.; Ruf, K. B.

    1970-01-01

    1. Ovulation was induced in Nembutal-blocked pro-oestrous rats by electrical stimulation of the hypothalamus. 2. The same type of electrical stimulation was applied during the collection of hypophysial portal blood. 3. Pooled hypophysial portal plasma from donors in pro-oestrus, oestrus and met-oestrus was assayed for ovarian ascorbic acid depleting (OAAD) activity. 4. Electrical stimulation of the hypothalamus increased the OAAD activity, believed to be due to luteinizing hormone releasing factor (LRF), in pro-oestrus and met-oestrus, but not in oestrus. 5. It is concluded that the hypothalamic nerve fibres responsible for releasing LRF into the hypophysial portal vessels are depleted of their store of this releasing factor, or are refractory to electrical stimulation, during oestrus. PMID:5499765

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

    SciTech Connect

    Crew, Jennifer R.; Falzari, Kanakeshwari; DiMario, Joseph X.

    2010-04-01

    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 to 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.

  4. Prevention of quadriceps wasting after immobilization: an evaluation of the effect of electrical stimulation.

    PubMed

    Arvidsson, I; Arvidsson, H; Eriksson, E; Jansson, E

    1986-11-01

    Eighteen male and 20 female patients who underwent reconstruction of their anterior cruciate ligament (ACL) with a flap from the patellar tendon were randomly assigned into either closed cast, isometric muscle training and electric stimulation (ES group), or closed cast and isometric training alone (control group). The degree of quadriceps wasting was determined from computerized tomographic scans (CT) before and 6 weeks after surgery. Electrical stimulation was given with a battery operated stimulator that produced a rectangular asymmetric balanced biphasic pulse shape. The pulse rate was 40 Hz and the pulse width 300 microseconds. Patients received 30 min of stimulation three times daily during 5.5 weeks. Female control patients showed a larger decrease in quadriceps area on CT than male control patients (P less than .001). No significant difference was found between male electrically stimulated patients and control patients. In female patients, there was on the contrary, a highly significant difference in favor of electrical stimulation (P less than .001) When the different parts of the quadriceps were studied, a significantly lower degree of atrophy of the vastus medialis was found after electrical stimulation. Vastus lateralis did not show any difference. Measurements of CT attenuation, pre- and post-operatively, showed a decrease in attenuation of 17% for the vastus medialis and lateralis of the operated leg after immobilization, indicating an increase in fat content. In the rectus femoris, however, there was an increase in attenuation of 14.6%. Percutaneous muscle biopsies from the vastus lateralis obtained before, one week after, and 6 weeks after surgery revealed that the cross-sectional area of the individual muscle fibers decreased less in the electrically stimulated than in controls, but the difference was not significant. There were no differences between the two groups in the activity of an oxidative enzyme, citrate synthase, or a glycolytic enzyme

  5. Vestibulo-ocular responses evoked via bilateral electrical stimulation of the lateral semicircular canals

    PubMed Central

    Gong, Wangsong; Haburcakova, Csilla; Merfeld, Daniel M.

    2008-01-01

    We investigated the vestibulo-ocular responses (VOR) evoked by bilateral electrical stimulation of the nerves innervating horizontal semicircular canals in squirrel monkeys and compared these responses to those evoked by unilateral stimulation. In response to sinusoidal modulation of the electrical pulse rate, the VOR for bilateral stimulation roughly equals the addition of the responses evoked by unilateral right ear and unilateral left ear stimulation; the VOR time constants were about the same for bilateral and unilateral stimulation and both were much shorter than for normal animals. In response to individual pulse stimulation, the VOR evoked by bilateral stimulation closely matches the point-by-point addition of responses evoked by unilateral right ear and unilateral left ear stimulation. We conclude that, to first order, the VOR responses evoked by bilateral stimulation are the summation of the responses evoked by unilateral stimulation. These findings suggest that – from a physiologic viewpoint – unilateral and bilateral vestibular prostheses are about equally viable. Given these findings, one possible advantage of a bilateral prosthesis is higher gain. However, at least for short-term stimulation like that studied herein, no inherent advantage in terms of the response time constant (“velocity storage”) was found. PMID:18990631

  6. 9 CFR 307.7 - Safety requirements for electrical stimulating (EST) equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... enter: (i) A red light that flashes distinctly during the operating cycle of the stimulating equipment..., mechanical inspection, maintenance or testing are performed. (3) Water. To prevent an electrical shock, personnel shall not spray streams of water on energized carcasses or on energized stimulating surfaces....

  7. 42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... nerve stimulators (TENS). 414.232 Section 414.232 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... § 414.232 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...

  8. 42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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...

  9. 42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... nerve stimulators (TENS). 414.232 Section 414.232 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Surgical Dressings § 414.232 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...

  10. Modeling binaural responses in the auditory brainstem to electric stimulation of the auditory nerve.

    PubMed

    Chung, Yoojin; Delgutte, Bertrand; Colburn, H Steven

    2015-02-01

    Bilateral cochlear implants (CIs) provide improvements in sound localization and speech perception in noise over unilateral CIs. However, the benefits arise mainly from the perception of interaural level differences, while bilateral CI listeners' sensitivity to interaural time difference (ITD) is poorer than normal. To help understand this limitation, a set of ITD-sensitive neural models was developed to study binaural responses to electric stimulation. Our working hypothesis was that central auditory processing is normal with bilateral CIs so that the abnormality in the response to electric stimulation at the level of the auditory nerve fibers (ANFs) is the source of the limited ITD sensitivity. A descriptive model of ANF response to both acoustic and electric stimulation was implemented and used to drive a simplified biophysical model of neurons in the medial superior olive (MSO). The model's ITD sensitivity was found to depend strongly on the specific configurations of membrane and synaptic parameters for different stimulation rates. Specifically, stronger excitatory synaptic inputs and faster membrane responses were required for the model neurons to be ITD-sensitive at high stimulation rates, whereas weaker excitatory synaptic input and slower membrane responses were necessary at low stimulation rates, for both electric and acoustic stimulation. This finding raises the possibility of frequency-dependent differences in neural mechanisms of binaural processing; limitations in ITD sensitivity with bilateral CIs may be due to a mismatch between stimulation rate and cell parameters in ITD-sensitive neurons. PMID:25348578

  11. A new treatment for obstructive sleep apnea syndrome by electrical stimulation of submental region.

    PubMed

    Miki, H; Hida, W; Inoue, H; Takishima, T

    1988-01-01

    Loss of upper airway muscle tone during sleep has been thought to be responsible for obstructive apnea episodes. To examine the effect of electrical stimulation of the submental region on sleep apnea episodes, patients with obstructive sleep apnea syndrome were polysomnographically studied during all-night session with and without stimulation.

  12. 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

  13. Manganese-enhanced MR imaging of brain activation evoked by noxious peripheral electrical stimulation.

    PubMed

    Cha, Myeounghoon; Lee, Kyuhong; Lee, Chulhyun; Cho, Jee-Hyun; Cheong, Chaejoon; Sohn, Jin-Hun; Lee, Bae Hwan

    2016-02-01

    As imaging technology develops, magnetic resonance imaging (MRI) has furthered our understanding of brain function by clarifying the anatomical structure and generating functional imaging data related to information processing in pain conditions. Recent studies have reported that manganese (Mn(2+))-enhanced MRI (MEMRI) provides valuable information about the functions of the central nervous system. The aim of this study was to identify specific brain regions activated during noxious electric stimulation using high-resolution MEMRI. Male Sprague Dawley rats were divided into three groups: naïve, sham electrical stimulation, and noxious electric stimulation. Under urethane with α-chloralose mixture anesthesia, a catheter was placed in the external carotid artery to administrate 20% mannitol and manganese chloride (25mM MnCl2). Noxious electric stimulation (2Hz, 10V) was applied to the hind paw with a needle electrode. Stimulation-induced neuronal activation was detected using 4.7-T MRI. In response to noxious electrical stimulation, remarkable Mn(2+)-enhanced signals were observed in the agranular insular cortex, auditory cortex, primary somatosensory cortex of the hind limb, and granular and dysgranular insular cortex, which correspond to sensory tactile electric stimulus to the hindpaws. These results indicate that the combination of MEMRI with activity-induced Mn(2+)-dependent contrast can delineate functional areas in the rat brain.

  14. Manganese-enhanced MR imaging of brain activation evoked by noxious peripheral electrical stimulation.

    PubMed

    Cha, Myeounghoon; Lee, Kyuhong; Lee, Chulhyun; Cho, Jee-Hyun; Cheong, Chaejoon; Sohn, Jin-Hun; Lee, Bae Hwan

    2016-02-01

    As imaging technology develops, magnetic resonance imaging (MRI) has furthered our understanding of brain function by clarifying the anatomical structure and generating functional imaging data related to information processing in pain conditions. Recent studies have reported that manganese (Mn(2+))-enhanced MRI (MEMRI) provides valuable information about the functions of the central nervous system. The aim of this study was to identify specific brain regions activated during noxious electric stimulation using high-resolution MEMRI. Male Sprague Dawley rats were divided into three groups: naïve, sham electrical stimulation, and noxious electric stimulation. Under urethane with α-chloralose mixture anesthesia, a catheter was placed in the external carotid artery to administrate 20% mannitol and manganese chloride (25mM MnCl2). Noxious electric stimulation (2Hz, 10V) was applied to the hind paw with a needle electrode. Stimulation-induced neuronal activation was detected using 4.7-T MRI. In response to noxious electrical stimulation, remarkable Mn(2+)-enhanced signals were observed in the agranular insular cortex, auditory cortex, primary somatosensory cortex of the hind limb, and granular and dysgranular insular cortex, which correspond to sensory tactile electric stimulus to the hindpaws. These results indicate that the combination of MEMRI with activity-induced Mn(2+)-dependent contrast can delineate functional areas in the rat brain. PMID:26733299

  15. Novel application of GI electrical stimulation in Roux stasis syndrome (with video)

    PubMed Central

    Daram, Sumanth R.; Tang, Shou-Jiang; Vick, Kenneth; Aru, Giorgio; Lahr, Christopher; Amin, Om; Taylor, Michelle; Sheehan, John J.; Abell, Thomas L.

    2016-01-01

    Background About one-third of patients undergoing a Roux-en-Y anastomosis develop Roux stasis syndrome, likely because of disordered electrical conduction. GI electrical stimulation has been previously used successfully in the management of postsurgical gastroparesis. Objective Endoscopic placement of temporary electrodes and GI electrical stimulation in the management of severe Roux stasis syndrome in a patient with esophagojejunostomy and to determine whether the patient would be a candidate for surgical permanent electrode placement. Design Case report. Setting Academic medical center. Patients This study involved a patient with Roux stasis syndrome. Intervention Upper endoscopy was performed, followed by endoscopic placement of two temporary electrodes, one each in the two jejunal limbs. Electrical stimulation was provided by an external stimulation device. The patient was re-evaluated 5 days later. Main Outcome Measurements Electrogastrogram (EGG) parameters including frequency, amplitude, and frequency-amplitude ratio and total symptom score and health-related quality of life score. Results There was a significant improvement in EGG parameters with electrical stimulation. Also, the patient had a marked improvement in total GI symptom score, from 11 to 4, with a dramatic improvement in the health-related quality of life score from −3 to +3. Limitations Single case report. Conclusion Endoscopic placement of temporary electrodes is feasible and safe. GI electrical stimulation of the jejunal limb is a potentially effective treatment for Roux stasis syndrome. PMID:21872718

  16. Optogenetic versus electrical stimulation of dopamine terminals in the nucleus accumbens reveals local modulation of presynaptic release.

    PubMed

    Melchior, James R; Ferris, Mark J; Stuber, Garret D; Riddle, David R; Jones, Sara R

    2015-09-01

    The nucleus accumbens is highly heterogeneous, integrating regionally distinct afferent projections and accumbal interneurons, resulting in diverse local microenvironments. Dopamine (DA) neuron terminals similarly express a heterogeneous collection of terminal receptors that modulate DA signaling. Cyclic voltammetry is often used to probe DA terminal dynamics in brain slice preparations; however, this method traditionally requires electrical stimulation to induce DA release. Electrical stimulation excites all of the neuronal processes in the stimulation field, potentially introducing simultaneous, multi-synaptic modulation of DA terminal release. We used optogenetics to selectively stimulate DA terminals and used voltammetry to compare DA responses from electrical and optical stimulation of the same area of tissue around a recording electrode. We found that with multiple pulse stimulation trains, optically stimulated DA release increasingly exceeded that of electrical stimulation. Furthermore, electrical stimulation produced inhibition of DA release across longer duration stimulations. The GABAB antagonist, CGP 55845, increased electrically stimulated DA release significantly more than light stimulated release. The nicotinic acetylcholine receptor antagonist, dihydro-β-erythroidine hydrobromide, inhibited single pulse electrically stimulated DA release while having no effect on optically stimulated DA release. Our results demonstrate that electrical stimulation introduces local multi-synaptic modulation of DA release that is absent with optogenetically targeted stimulation. The nucleus accumbens is highly heterogeneous, integrating regionally distinct afferent projections and accumbal interneurons, resulting in diverse microenvironments. Local electrical stimulation excites all of the neuronal processes in the stimulation field, potentially modulating the dopamine signal - measured using cyclic voltammetry. Optogenetically targeting light stimulation to dopamine

  17. Failure of naloxone to reverse analgesia from transcutaneous electrical stimulation in patients with chronic pain.

    PubMed

    Abram, S E; Reynolds, A C; Cusick, J F

    1981-02-01

    To investigate the possible role of endogenous opiates in the mediation of analgesia produced by low intensity, high frequency transcutaneous electrical stimulation in the presence of chronic pain, an attempt was made to reverse stimulation-induced analgesia with naloxone. Fifteen patients with chronic pain who were consistently relieved of pain by low intensity, high frequency transcutaneous stimulation were studied. During stimulation at 58 Hz, patients were given double-blind intravenous injections of either naloxone (0.4 or 1.2 mg) or saline. Subjective pain ratings were recorded before stimulation, after stimulation, and after naloxone and saline injections. No reversal of analgesia was seen after naloxone or saline. These results suggest that transcutaneous stimulation at low intensity and high frequency may provide analgesia that is not associated with release of endogenous opiates in patients with chronic pain.

  18. Magnetic Versus Electrical Stimulation in the Interpolation Twitch Technique of Elbow Flexors

    PubMed Central

    Lampropoulou, Sofia I.; Nowicky, Alexander V.; Marston, Louise

    2012-01-01

    The study compared peripheral magnetic with electrical stimulation of the biceps brachii m. (BB) in the single pulse Interpolation Twitch Technique (ITT). 14 healthy participants (31±7 years) participated in a within-subjects repeated-measures design study. Single, constant-current electrical and magnetic stimuli were delivered over the motor point of BB with supramaximal intensity (20% above maximum) at rest and at various levels of voluntary contraction. Force measurements from right elbow isometric flexion and muscle electromyograms (EMG) from the BB, the triceps brachii m. (TB) and the abductor pollicis brevis m. (APB) were obtained. The twitch forces at rest and maximal contractions, the twitch force-voluntary force relationship, the M-waves and the voluntary activation (VA) of BB between magnetic and electrical stimulation were compared. The mean amplitude of the twitches evoked at MVC was not significantly different between electrical (0.62 ± 0.49 N) and magnetic (0.81 ± 0.49 N) stimulation (p > 0.05), and the maximum VA of BB was comparable between electrical (95%) and magnetic (93%) stimulation (p > 0. 05). No differences (p >0.05) were revealed in the BB M-waves between electrical (13.47 ± 0.49 mV.ms) and magnetic (12.61 ± 0.58 mV.ms) stimulation. The TB M-waves were also similar (p > 0.05) but electrically evoked APB M-waves were significantly larger than those evoked by magnetic stimulation (p < 0.05). The twitch-voluntary force relationship over the range of MVCs was best described by non-linear functions for both electrical and magnetic stimulation. The electrically evoked resting twitches were consistently larger in amplitude than the magnetically evoked ones (mean difference 3.1 ± 3.34 N, p < 0.05). Reduction of the inter-electrodes distance reduced the twitch amplitude by 6.5 ± 6.2 N (p < 0.05). The fundamental similarities in voluntary activation assessment of BB with peripheral electrical and magnetic stimulation point towards a promising

  19. Intrusive Thoughts Elicited by Direct Electrical Stimulation during Stereo-Electroencephalography.

    PubMed

    Popa, Irina; Donos, Cristian; Barborica, Andrei; Opris, Ioan; Mălîia, Mihai Dragoş; Ene, Mirela; Ciurea, Jean; Mîndruţă, Ioana

    2016-01-01

    Cortical direct electrical stimulation (DES) is a method of brain mapping used during invasive presurgical evaluation of patients with intractable epilepsy. Intellectual auras like intrusive thoughts, also known as forced thinking (FT), have been reported during frontal seizures. However, there are few reports on FT obtained during DES in frontal cortex. We report three cases in which we obtained intrusive thoughts while stimulating the dorsolateral prefrontal cortex and the white matter in the prefrontal region. In order to highlight the effective connectivity that might explain this clinical response, we have analyzed cortico-cortical potentials evoked by single pulse electrical stimulation. PMID:27486431

  20. On the Cause and Control of Residual Voltage Generated by Electrical Stimulation of Neural Tissue

    PubMed Central

    Krishnan, Ashwati; Kelly, Shawn K.

    2016-01-01

    Functional electrical stimulation of neural tissue is traditionally performed with symmetric cathodic-first biphasic pulses of current through an electrode/electrolyte interface. When the interface is modeled by a series R-C circuit, as is sometimes done for stimulator circuit design, the appearance of a net residual voltage across the electrode cannot be explained. Residual voltage can cause polarization of the electrode and pose a problem for safe electrical stimulation. This paper aims to (1) theoretically explain one reason for the residual voltage, which is the inclusion of the Faradaic impedance (2) suggest a simple dynamic feedback mechanism to eliminate residual voltage. PMID:23366780

  1. Intrusive Thoughts Elicited by Direct Electrical Stimulation during Stereo-Electroencephalography

    PubMed Central

    Popa, Irina; Donos, Cristian; Barborica, Andrei; Opris, Ioan; Mălîia, Mihai Dragoş; Ene, Mirela; Ciurea, Jean; Mîndruţă, Ioana

    2016-01-01

    Cortical direct electrical stimulation (DES) is a method of brain mapping used during invasive presurgical evaluation of patients with intractable epilepsy. Intellectual auras like intrusive thoughts, also known as forced thinking (FT), have been reported during frontal seizures. However, there are few reports on FT obtained during DES in frontal cortex. We report three cases in which we obtained intrusive thoughts while stimulating the dorsolateral prefrontal cortex and the white matter in the prefrontal region. In order to highlight the effective connectivity that might explain this clinical response, we have analyzed cortico-cortical potentials evoked by single pulse electrical stimulation. PMID:27486431

  2. Effects of acute selective pudendal nerve electrical stimulation after simulated childbirth injury

    PubMed Central

    Gill, Bradley C.; Dissaranan, Charuspong; Zutshi, Massarat; Balog, Brian M.; Lin, Danli; Damaser, Margot S.

    2013-01-01

    During childbirth, a combinatorial injury occurs and can result in stress urinary incontinence (SUI). Simulated childbirth injury, consisting of vaginal distension (VD) and pudendal nerve crush (PNC), results in slowed recovery of continence, as well as decreased expression of brain-derived neurotrophic factor (BDNF), a regenerative cytokine. Electrical stimulation has been shown to upregulate BDNF in motor neurons and facilitate axon regrowth through the increase of βII-tubulin expression after injury. In this study, female rats underwent selective pudendal nerve motor branch (PNMB) stimulation after simulated childbirth injury or sham injury to determine whether such stimulation affects bladder and anal function after injury and whether the stimulation increases BDNF expression in Onuf's nucleus after injury. Rats received 4 h of VD followed by bilateral PNC and 1 h of subthreshold electrical stimulation of the left PNMB and sham stimulation of the right PNMB. Rats underwent filling cystometry and anal pressure recording before, during, and after the stimulation. Bladder and anal contractile function were partially disrupted after injury. PNMB stimulation temporarily inhibited bladder contraction after injury. Two days and 1 wk after injury, BDNF expression in Onuf's nucleus of the stimulated side was significantly increased compared with the sham-stimulated side, whereas βII-tubulin expression in Onuf's nucleus of the stimulated side was significantly increased only 1 wk after injury. Acute electrical stimulation of the pudendal nerve proximal to the crush site upregulates BDNF and βII-tubulin in Onuf's nucleus after simulated childbirth injury, which could be a potential preventive option for SUI after childbirth injury. PMID:23152293

  3. Chronic effects of low-frequency low-intensity electrical stimulation of stretched human muscle

    NASA Astrophysics Data System (ADS)

    Shenkman, Boris S.; Lyubaeva, Ekaterina V.; Popov, Daniil V.; Netreba, Aleksey I.; Bravy, Yan R.; Tarakin, Pavel P.; Lemesheva, Yulia S.; Vinogradova, Olga L.

    2007-02-01

    Effects of low-frequency electrical stimulation, which is currently considered to be a possible countermeasure for long-duration spaceflights, with and without stretch were evaluated. Twelve young male volunteers were randomly distributed into two groups. In one group anterior thigh muscles—knee extensors of both legs were stimulated with frequency of 15 Hz for 4.5 wks, six times a week; each session was 6-h long. In the other group, electrical stimulation with the same parameters was applied to stretched knee extensors. Following stimulation the subjects exhibited an increase in fatigue resistance, and in the succinate dehydrogenase activity and a 10% gain in the percentage of muscle fibers with slow myosin heavy chain isoforms. In a stimulated group the peak voluntary strength went down significantly, the CSA of fast muscle fibers in m. quadriceps femoris became slightly less in size (10%). Electrical stimulation of the stretched muscles induced an insignificant decline in their strength and an increase of cross-sectional area of muscle fibers of both types. Thus chronic low-frequency electrical stimulation may be proposed as a candidate countermeasure against muscle strength and mass loss if it is combined with stretch.

  4. Biphasic Electrical Field Stimulation Aids in Tissue Engineering of Multicell-Type Cardiac Organoids

    PubMed Central

    Chiu, Loraine L.Y.; Iyer, Rohin K.; King, John-Paul

    2011-01-01

    The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5 V/cm, 1 Hz, 1 ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5 V/cm, 1 Hz, 2 ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence. PMID:18783322

  5. Biphasic electrical field stimulation aids in tissue engineering of multicell-type cardiac organoids.

    PubMed

    Chiu, Loraine L Y; Iyer, Rohin K; King, John-Paul; Radisic, Milica

    2011-06-01

    The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5 V/cm, 1 Hz, 1 ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5 V/cm, 1 Hz, 2 ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence.

  6. High and low frequency transcutaneous electrical nerve stimulation inhibits nociceptive responses induced by CO2 laser stimulation in humans.

    PubMed

    de Tommaso, Marina; Fiore, Pietro; Camporeale, Alfonso; Guido, Marco; Libro, Giuseppe; Losito, Luciana; Megna, Marisa; Puca, Francomichele; Megna, Gianfranco

    2003-05-15

    The aim of the study was to evaluate the effects of transcutaneous electric nerve stimulation (TENS) on CO(2) laser evoked potentials (LEPs) in 16 normal subjects. The volar side of the forearm was stimulated by 10 Hz TENS in eight subjects and by 100 Hz TENS in the remainder; the skin of the forearm was stimulated by CO(2) laser and the LEPs were recorded in basal conditions and soon after and 15 min after TENS. Both low and high frequency TENS significantly reduced the subjective rating of heat stimuli and the LEPs amplitude, although high frequency TENS appeared more efficacious. TENS seemed to exert a mild inhibition of the perception and processing of pain induced by laser Adelta fibres activation; the implications of these effects in the clinical employment of TENS remain to be clarified. PMID:12727307

  7. High and low frequency transcutaneous electrical nerve stimulation inhibits nociceptive responses induced by CO2 laser stimulation in humans.

    PubMed

    de Tommaso, Marina; Fiore, Pietro; Camporeale, Alfonso; Guido, Marco; Libro, Giuseppe; Losito, Luciana; Megna, Marisa; Puca, Francomichele; Megna, Gianfranco

    2003-05-15

    The aim of the study was to evaluate the effects of transcutaneous electric nerve stimulation (TENS) on CO(2) laser evoked potentials (LEPs) in 16 normal subjects. The volar side of the forearm was stimulated by 10 Hz TENS in eight subjects and by 100 Hz TENS in the remainder; the skin of the forearm was stimulated by CO(2) laser and the LEPs were recorded in basal conditions and soon after and 15 min after TENS. Both low and high frequency TENS significantly reduced the subjective rating of heat stimuli and the LEPs amplitude, although high frequency TENS appeared more efficacious. TENS seemed to exert a mild inhibition of the perception and processing of pain induced by laser Adelta fibres activation; the implications of these effects in the clinical employment of TENS remain to be clarified.

  8. Continuous electrical stimulation decreases retinal excitability but does not alter retinal morphology.

    PubMed

    Ray, A; Lee, E-J; Humayun, M S; Weiland, J D

    2011-08-01

    Retinal prostheses aim to provide visual perception through electrical stimulation of the retina. Hence they have to operate between threshold charge density and maximum safe charge density. To date most studies in the retina have concentrated on understanding the threshold, while stimulation safety has predominantly been studied in structures other than the retina. Toward this end, the present study focuses on determining the effect of continuous electrical stimulation of the retina both on retinal morphology and on the electrically evoked responses in the superior colliculus in a rodent model. The results demonstrate that the retina is able to tolerate 1 h long stimulation with only minor changes evident in retinal histology when examined three to 14 days later, even at charge densities (0.68 mC cm(-2)) above the safe limit of platinum delivered at high stimulus frequency (300 Hz). However, this continuous electrical stimulation causes an elevation in the threshold of the electrically evoked response in the superior colliculus, indicating some form of adaptation to continuous stimulation. PMID:21775787

  9. Dynamic Impedance Model of the Skin-Electrode Interface for Transcutaneous Electrical Stimulation

    PubMed Central

    Vargas Luna, José Luis; Krenn, Matthias; Cortés Ramírez, Jorge Armando; Mayr, Winfried

    2015-01-01

    Transcutaneous electrical stimulation can depolarize nerve or muscle cells applying impulses through electrodes attached on the skin. For these applications, the electrode-skin impedance is an important factor which influences effectiveness. Various models describe the interface using constant or current-depending resistive-capacitive equivalent circuit. Here, we develop a dynamic impedance model valid for a wide range stimulation intensities. The model considers electroporation and charge-dependent effects to describe the impedance variation, which allows to describe high-charge pulses. The parameters were adjusted based on rectangular, biphasic stimulation pulses generated by a stimulator, providing optionally current or voltage-controlled impulses, and applied through electrodes of different sizes. Both control methods deliver a different electrical field to the tissue, which is constant throughout the impulse duration for current-controlled mode or have a very current peak for voltage-controlled. The results show a predominant dependence in the current intensity in the case of both stimulation techniques that allows to keep a simple model. A verification simulation using the proposed dynamic model shows coefficient of determination of around 0.99 in both stimulation types. The presented method for fitting electrode-skin impedance can be simple extended to other stimulation waveforms and electrode configuration. Therefore, it can be embedded in optimization algorithms for designing electrical stimulation applications even for pulses with high charges and high current spikes. PMID:25942010

  10. A unique electrical thermal stimulation system comparable to moxibustion of subcutaneous tissue.

    PubMed

    Myoung, Hyoun-Seok; Lee, Kyoung-Joung

    2014-01-01

    Moxibustion strengthens immunity and it is an effective treatment modality, but, depending on the material quantity, shape, and composition, the thermal strength and intensity can be difficult to control, which may cause pain or epidermal burns. To overcome these limitations, a heat stimulating system which is able to control the thermal intensity was developed. The temperature distributions on epidermis, at 5 mm and 10 mm of depth, in rabbit femoral tissue were compared between moxibustion and the electric thermal stimulation system. The stimulation system consists of a high radio frequency dielectric heating equipment (2 MHz frequency, maximum power 200 W), isolation probe, isolation plate, negative pressure generator, and a temperature assessment system. The temperature was modulated by controlling the stimulation pulse duty ratio, repetition number, and output. There were 95% and 91% temperature distribution correlations between moxibustion and the thermal stimulus at 5 mm and 10 mm of depth in tissue, respectively. Moreover, the epidermal temperature in thermal stimulation was lower than that in moxibustion. These results showed that heat loss by the electric thermal stimulation system is less than that by the traditional moxibustion method. Furthermore, the proposed electric thermal stimulation did not cause adverse effects, such as suppuration or blisters, and also provided subcutaneous stimulation comparable to moxibustion. PMID:25126101

  11. Dynamic impedance model of the skin-electrode interface for transcutaneous electrical stimulation.

    PubMed

    Vargas Luna, José Luis; Krenn, Matthias; Cortés Ramírez, Jorge Armando; Mayr, Winfried

    2015-01-01

    Transcutaneous electrical stimulation can depolarize nerve or muscle cells applying impulses through electrodes attached on the skin. For these applications, the electrode-skin impedance is an important factor which influences effectiveness. Various models describe the interface using constant or current-depending resistive-capacitive equivalent circuit. Here, we develop a dynamic impedance model valid for a wide range stimulation intensities. The model considers electroporation and charge-dependent effects to describe the impedance variation, which allows to describe high-charge pulses. The parameters were adjusted based on rectangular, biphasic stimulation pulses generated by a stimulator, providing optionally current or voltage-controlled impulses, and applied through electrodes of different sizes. Both control methods deliver a different electrical field to the tissue, which is constant throughout the impulse duration for current-controlled mode or have a very current peak for voltage-controlled. The results show a predominant dependence in the current intensity in the case of both stimulation techniques that allows to keep a simple model. A verification simulation using the proposed dynamic model shows coefficient of determination of around 0.99 in both stimulation types. The presented method for fitting electrode-skin impedance can be simple extended to other stimulation waveforms and electrode configuration. Therefore, it can be embedded in optimization algorithms for designing electrical stimulation applications even for pulses with high charges and high current spikes. PMID:25942010

  12. Tissue engineering bioreactor systems for applying physical and electrical stimulations to cells.

    PubMed

    Jin, GyuHyun; Yang, Gi-Hoon; Kim, GeunHyung

    2015-05-01

    Bioreactor systems in tissue engineering applications provide various types of stimulation to mimic the tissues in vitro and in vivo. Various bioreactors have been designed to induce high cellular activities, including initial cell attachment, cell growth, and differentiation. Although cell-stimulation processes exert mostly positive effects on cellular responses, in some cases such stimulation can also have a negative effect on cultured cells. In this review, we discuss various types of bioreactor and the positive and negative effects of stimulation (physical, chemical, and electrical) on various cultured cell types.

  13. Release of noradrenaline and ATP by electrical stimulation and nicotine in guinea-pig vas deferens.

    PubMed

    von Kügelgen, I; Starke, K

    1991-10-01

    Effects of electrical stimulation and nicotine on ATP and tritium outflow and smooth muscle tension were studied in the guinea-pig isolated vas deferens preincubated with [3H]-noradrenaline. ATP was measured using the luciferase technique. Electrical stimulation caused biphasic contractions and an acceleration of ATP and tritium outflow. The contraction amplitude and the overflow of ATP increased markedly, whereas the overflow of tritium increased only slightly with the frequency of stimulation (1-10 Hz; constant number of 60 pulses). The contraction amplitude did not increase with an increase in pulse number (20-540 pulses; constant frequency of 5 Hz), whereas the overflow of ATP increased slightly, and that of tritium markedly. Nicotine caused monophasic, transient contractions and, again, an acceleration of ATP and tritium outflow. Contractions, ATP and tritium overflow increased with the concentration of nicotine (56-320 mumol/l) in an approximately parallel manner. The influence of some drugs on responses to electrical stimulation (60 pulses, 5 Hz) and nicotine (180 mumol/l) was investigated. Tetrodotoxin blocked all effects of electrical stimulation but did not change those of nicotine. The reverse was true for hexamethonium. Neither electrical stimulation nor nicotine caused contraction or an increase in ATP outflow after pretreatment with 6-hydroxydopamine. The main effects of prazosin 0.3 mumol/l were to reduce electrically evoked contractions (above all second phase) as well as nicotine-evoked contractions and the nicotine-evoked overflow of ATP (the latter by about 81%). Prazosin also tended to diminish the electrically evoked overflow of ATP. alpha,beta-Methylene-ATP 10 mumol/l elicited a transient contraction and ATP overflow on its own. The main change in the subsequent state of desensitization was a decrease of the first phase of electrically evoked contractions. The main effects of prazosin combined with desensitization by alpha

  14. Electrical stimulation of nerve cells using conductive nanofibrous scaffolds for nerve tissue engineering.

    PubMed

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Ramakrishna, Seeram

    2009-11-01

    Fabrication of scaffolds with suitable chemical, mechanical, and electrical properties is critical for the success of nerve tissue engineering. Electrical stimulation was directly applied to electrospun conductive nanofibrous scaffolds to enhance the nerve regeneration process. In the present study, electrospun conductive nanofibers were prepared by mixing 10 and 15 wt% doped polyaniline (PANI) with poly (epsilon-caprolactone)/gelatin (PG) (70:30) solution (PANI/PG) by electrospinning. The fiber diameter, pore size, hydrophilicity, tensile properties, conductivity, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy spectra of nanofibers were determined, and the in vitro biodegradability of the different nanofibrous scaffolds was also evaluated. Nanofibrous scaffolds containing 15% PANI was found to exhibit the most balanced properties to meet all the required specifications for electrical stimulation for its enhanced conductivity and is used for in vitro culture and electrical stimulation of nerve stem cells. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and scanning electron microscopy results showed that conductive nanofibrous scaffolds are suitable substrates for the attachment and proliferation of nerve stem cells. Electrical stimulation through conductive nanofibrous PANI/PG scaffolds showed enhanced cell proliferation and neurite outgrowth compared to the PANI/PG scaffolds that were not subjected to electrical stimulation.

  15. Vestibular implantation and longitudinal electrical stimulation of the semicircular canal afferents in human subjects

    PubMed Central

    Ling, Leo; Nie, Kaibao; Jameyson, Elyse; Phillips, Christopher M.; Nowack, Amy L.; Golub, Justin S.; Rubinstein, Jay T.

    2015-01-01

    Animal experiments and limited data in humans suggest that electrical stimulation of the vestibular end organs could be used to treat loss of vestibular function. In this paper we demonstrate that canal-specific two-dimensionally (2D) measured eye velocities are elicited from intermittent brief 2 s biphasic pulse electrical stimulation in four human subjects implanted with a vestibular prosthesis. The 2D measured direction of the slow phase eye movements changed with the canal stimulated. Increasing pulse current over a 0–400 μA range typically produced a monotonic increase in slow phase eye velocity. The responses decremented or in some cases fluctuated over time in most implanted canals but could be partially restored by changing the return path of the stimulation current. Implantation of the device in Meniere's patients produced hearing and vestibular loss in the implanted ear. Electrical stimulation was well tolerated, producing no sensation of pain, nausea, or auditory percept with stimulation that elicited robust eye movements. There were changes in slow phase eye velocity with current and over time, and changes in electrically evoked compound action potentials produced by stimulation and recorded with the implanted device. Perceived rotation in subjects was consistent with the slow phase eye movements in direction and scaled with stimulation current in magnitude. These results suggest that electrical stimulation of the vestibular end organ in human subjects provided controlled vestibular inputs over time, but in Meniere's patients this apparently came at the cost of hearing and vestibular function in the implanted ear. PMID:25652917

  16. 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.

  17. Neuromuscular electrical stimulation in critically ill patients in the intensive care unit: a systematic review

    PubMed Central

    Ferreira, Lucas Lima; Vanderlei, Luiz Carlos Marques; Valenti, Vitor Engrácia

    2014-01-01

    Objective To analyze the outcomes enabled by the neuromuscular electric stimulation in critically ill patients in intensive care unit assisted. Methods A systematic review of the literature by means of clinical trials published between 2002 and 2012 in the databases LILACS, SciELO, MEDLINE and PEDro using the descriptors “intensive care unit”, “physical therapy”, “physiotherapy”, “electric stimulation” and “randomized controlled trials”. Results We included four trials. The sample size varied between 8 to 33 individuals of both genders, with ages ranging between 52 and 79 years, undergoing invasive mechanical ventilation. Of the articles analyzed, three showed significant benefits of neuromuscular electrical stimulation in critically ill patients, such as improvement in peripheral muscle strength, exercise capacity, functionality, or loss of thickness of the muscle layer. Conclusion The application of neuromuscular electrical stimulation promotes a beneficial response in critically patients in intensive care. PMID:25295458

  18. Chronic Spinal Cord Electrical Stimulation Protects Against 6-hydroxydopamine Lesions

    NASA Astrophysics Data System (ADS)

    Yadav, Amol P.; Fuentes, Romulo; Zhang, Hao; Vinholo, Thais; Wang, Chi-Han; Freire, Marco Aurelio M.; Nicolelis, Miguel A. L.

    2014-01-01

    Although L-dopa continues to be the gold standard for treating motor symptoms of Parkinson's disease (PD), it presents long-term complications. Deep brain stimulation is effective, but only a small percentage of idiopathic PD patients are eligible. Based on results in animal models and a handful of patients, dorsal column stimulation (DCS) has been proposed as a potential therapy for PD. To date, the long-term effects of DCS in animal models have not been quantified. Here, we report that DCS applied twice a week in rats treated with bilateral 6-OHDA striatal infusions led to a significant improvement in symptoms. DCS-treated rats exhibited a higher density of dopaminergic innervation in the striatum and higher neuronal cell count in the substantia nigra pars compacta compared to a control group. These results suggest that DCS has a chronic therapeutical and neuroprotective effect, increasing its potential as a new clinical option for treating PD patients.

  19. Epilepsia partialis continua responsive to neocortical electrical stimulation.

    PubMed

    Valentin, Antonio; Ughratdar, Ismail; Cheserem, Beverly; Morris, Robert; Selway, Richard; Alarcon, Gonzalo

    2015-08-01

    Epilepsia partialis continua (EPC), defined as a syndrome of continuous focal jerking, is a rare form of focal status epilepticus that usually affects a distal limb, and when prolonged, can produce long-lasting deficits in limb function. Substantial electrophysiologic evidence links the origin of EPC to the motor cortex; thus surgical resection carries the risk of significant handicap. We present two patients with focal, drug-resistant EPC, who were admitted for intracranial video-electroencephalography monitoring to elucidate the location of the epileptogenic focus and identification of eloquent motor cortex with functional mapping. In both cases, the focus resided at or near eloquent motor cortex and therefore precluded resective surgery. Chronic cortical stimulation delivered through subdural strips at the seizure focus (continuous stimulation at 60-130 Hz, 2-3 mA) resulted in >90% reduction in seizures and abolition of the EPC after a follow-up of 22 months in both patients. Following permanent implantation of cortical stimulators, no adverse effects were noted. EPC restarted when intensity was reduced or batteries depleted. Battery replacement restored previous improvement. This two-case report opens up avenues for the treatment of this debilitating condition. PMID:26174165

  20. Epilepsia partialis continua responsive to neocortical electrical stimulation.

    PubMed

    Valentin, Antonio; Ughratdar, Ismail; Cheserem, Beverly; Morris, Robert; Selway, Richard; Alarcon, Gonzalo

    2015-08-01

    Epilepsia partialis continua (EPC), defined as a syndrome of continuous focal jerking, is a rare form of focal status epilepticus that usually affects a distal limb, and when prolonged, can produce long-lasting deficits in limb function. Substantial electrophysiologic evidence links the origin of EPC to the motor cortex; thus surgical resection carries the risk of significant handicap. We present two patients with focal, drug-resistant EPC, who were admitted for intracranial video-electroencephalography monitoring to elucidate the location of the epileptogenic focus and identification of eloquent motor cortex with functional mapping. In both cases, the focus resided at or near eloquent motor cortex and therefore precluded resective surgery. Chronic cortical stimulation delivered through subdural strips at the seizure focus (continuous stimulation at 60-130 Hz, 2-3 mA) resulted in >90% reduction in seizures and abolition of the EPC after a follow-up of 22 months in both patients. Following permanent implantation of cortical stimulators, no adverse effects were noted. EPC restarted when intensity was reduced or batteries depleted. Battery replacement restored previous improvement. This two-case report opens up avenues for the treatment of this debilitating condition.

  1. [Exploration Research of Treatment Effect Improvement of Transcutaneous Electrical Nerve Stimulation Using Parameter-changing Chaotic Signal].

    PubMed

    Zheng, Jincun; Zhang, Hui; Qin, Binyi; Wang, Hai; Nie, Guochao; Chen, Tiejun

    2015-10-01

    This article presents a transcutaneous electric stimulator that is based on chaotic signal. Firstly, we in the study used the MATLAB platform in the PC to generate chaotic signal through the chaos equation, and then we transferred the signal out by data acquisition equipment of USB-6251 manufactured by NI Company. In order to obtain high-power signal for transcutaneous electric stimulator, we used the chip of LM3886 to amplify the signal. Finally, we used the power-amplified chaotic signal to stimulate the internal nerve of human through the electrodes fixed on the skin. We obtained different stimulation effects of transcutaneous electric stimulator by changing the parameters of chaotic model. The preliminary test showed that the randomness of chaotic signals improved the applicability of electrical stimulation and the rules of chaos ensured that the stimulation was comfort. The method reported in this paper provides a new way for the design of transcutaneous electric stimulator.

  2. Comparison of Twitch Responses During Current- or Voltage-Controlled Transcutaneous Neuromuscular Electrical Stimulation.

    PubMed

    Vargas Luna, José Luis; Krenn, Matthias; Löfler, Stefan; Kern, Helmut; Cortés R, Jorge A; Mayr, Winfried

    2015-10-01

    Neuromuscular electrical stimulation (NMES) is an established method for functional restoration of muscle function, rehabilitation, and diagnostics. In this work, NMES was applied with surface electrodes placed on the anterior thigh to identify the main differences between current-controlled (CC) and voltage-controlled (VC) modes. Measurements of the evoked knee extension force and the myoelectric signal of quadriceps and hamstrings were taken during stimulation with different amplitudes, pulse widths, and stimulation techniques. The stimulation pulses were rectangular and symmetric biphasic for both stimulation modes. The electrode-tissue impedance influences the differences between CC and VC stimulation. The main difference is that for CC stimulation, variation of pulse width and amplitude influences the amount of nerve depolarization, whereas VC stimulation is only dependent on amplitude variations for pulse widths longer than 150 μs. An important remark is that these findings are strongly dependent on the characteristics of the electrode-skin interface. In our case, we used large stimulation electrodes placed on the anterior thigh, which cause higher capacitive effects. The controllability, voltage compliance, and charge characteristics of each stimulation technique should be considered during the stimulators design. For applications that require the activation of a large amount of nerve fibers, VC is a more suitable option. In contrast, if the application requires a high controllability, then CC should be chosen prior to VC. PMID:26471138

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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 dorsal root ganglia 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 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. Main 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 neurites, indicating topographical cues are responsible for guiding 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.

  4. 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

  5. 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

  6. Effect of neuromuscular electrical stimulation on facial muscle strength and oral function in stroke patients with facial palsy

    PubMed Central

    Choi, Jong-Bae

    2016-01-01

    [Purpose] The aim of this study was to investigate the effect of neuromuscular electrical stimulation on facial muscle strength and oral function in stroke patients with facial palsy. [Subjects and Methods] Nine subjects received the electrical stimulation and traditional dysphagia therapy. Electrical stimulation was applied to stimulate each subject’s facial muscles 30 minutes a day, 5 days a week, for 4 weeks. [Results] Subjects showed significant improvement in cheek and lip strength and oral function after the intervention. [Conclusion] This study demonstrates that electrical stimulation improves facial muscle strength and oral function in stroke patients with dysphagia. PMID:27799689

  7. Influence of air ions on brain activity induced by electrical stimulation in the rat

    NASA Astrophysics Data System (ADS)

    Olivereau, J. M.; Lambert, J. F.; Truong-Ngoc, A.

    1981-03-01

    The brain induced activity was studied in 18 rats wearing chronically skull implanted electrodes. The stimulating factor was various electrical stimulations of the mesencephalic reticular activating formation, given during the slow wave state of sleep. The results of 300 stimulations were measured by amplitude and frequency changes in the EEG simultaneously recorded. Animals previously exposed to positive air ions (3 weeks 80,000 ions/ml) exhibited lowered excitability of the reticulocortical system. Significantly higher stimulations were necessary to induce arousal. Negative air ions induced more intricate effects: brain excitability was lowered when tested with weak stimulations, but normal when evaluated with medium high level stimilations. Sleep seems first more stable but as stimulation increases, arousal is soon as effective as in controls. These results are in agreement with others findings in behavioral fields and partly explains them.

  8. Electrically stimulated osteogenesis on Ti-PPy/PLGA constructs prepared by laser-assisted processes.

    PubMed

    Paun, Irina Alexandra; Stokker-Cheregi, Flavian; Luculescu, Catalin Romeo; Acasandrei, Adriana Maria; Ion, Valentin; Zamfirescu, Marian; Mustaciosu, Cosmin Catalin; Mihailescu, Mona; Dinescu, Maria

    2015-10-01

    This work describes a versatile laser-based protocol for fabricating micro-patterned, electrically conductive titanium-polypyrrole/poly(lactic-co-glycolic)acid (Ti-PPy/PLGA) constructs for electrically stimulated (ES) osteogenesis. Ti supports were patterned using fs laser ablation in order to create high spatial resolution microstructures meant to provide mechanical resistance and physical cues for cell growth. Matrix Assisted Pulsed Laser Evaporation (MAPLE) was used to coat the patterned Ti supports with PPy/PLGA layers acting as biocompatible surfaces having chemical and electrical properties suitable for cell differentiation and mineralization. In vitro biological assays on osteoblast-like MG63 cells showed that the constructs maintained cell viability without cytotoxicity. At 24 h after cell seeding, electrical stimulation with currents of 200 μA was applied for 4 h. This treatment was shown to promote earlier onset of osteogenesis. More specifically, the alkaline phosphatase activity of the stimulated cultures reached the maximum before that of the non-stimulated ones, i.e. controls, indicating faster cell differentiation. Moreover, mineralization was found to occur at an earlier stage in the stimulated cultures, as compared to the controls, starting with Day 6 of cell culture. At later stages, calcium levels in the stimulated cultures were higher than those in control samples by about 70%, with Ca/P ratios similar to those of natural bone. In all, the laser-based protocol emerges as an efficient alternative to existing fabrication technologies. PMID:26117739

  9. Effect of electrical stimulation on thermal shrinkage temperature of bovine muscle collagen.

    PubMed

    Judge, M D; Reeves, E S; Aberle, E D

    1981-03-01

    The effect of beef carcass electrical stimulation on the thermal stability of intramuscular collagen was determined. Differential scanning calorimetric determinations of thermal shrinkage temperature revealed that electrical stimulation lowered the shrinkage temperature of collagen by an average of .6 C in the population of cattle studied. No difference between Hereford x Angus crossbreds and Charolais crossbreds were found, but the extent of the reduction of collagen shrinkage temperature caused by electrical stimulation was greater in animals that did not receive high grain diets or received grain for only a short period than in those fed grain for up to 210 days. Furthermore, panel tenderness and Warner-Bratzler shear tests showed that stimulation-induced tenderization was also greater in animals fed no grain or fed grain for a short time. No evidence of stimulation effects on myofibrillar proteins was observed from data on sarcomere length or myofibrillar fragmentation index. The reduction of thermal stability of bovine intramuscular collagen by electrical stimulation may result from a decrease in the number or strength of the collagen cross-links.

  10. The Neural Correlates of Long-Term Carryover following Functional Electrical Stimulation for Stroke

    PubMed Central

    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. PMID:27073701

  11. Electrically stimulated osteogenesis on Ti-PPy/PLGA constructs prepared by laser-assisted processes.

    PubMed

    Paun, Irina Alexandra; Stokker-Cheregi, Flavian; Luculescu, Catalin Romeo; Acasandrei, Adriana Maria; Ion, Valentin; Zamfirescu, Marian; Mustaciosu, Cosmin Catalin; Mihailescu, Mona; Dinescu, Maria

    2015-10-01

    This work describes a versatile laser-based protocol for fabricating micro-patterned, electrically conductive titanium-polypyrrole/poly(lactic-co-glycolic)acid (Ti-PPy/PLGA) constructs for electrically stimulated (ES) osteogenesis. Ti supports were patterned using fs laser ablation in order to create high spatial resolution microstructures meant to provide mechanical resistance and physical cues for cell growth. Matrix Assisted Pulsed Laser Evaporation (MAPLE) was used to coat the patterned Ti supports with PPy/PLGA layers acting as biocompatible surfaces having chemical and electrical properties suitable for cell differentiation and mineralization. In vitro biological assays on osteoblast-like MG63 cells showed that the constructs maintained cell viability without cytotoxicity. At 24 h after cell seeding, electrical stimulation with currents of 200 μA was applied for 4 h. This treatment was shown to promote earlier onset of osteogenesis. More specifically, the alkaline phosphatase activity of the stimulated cultures reached the maximum before that of the non-stimulated ones, i.e. controls, indicating faster cell differentiation. Moreover, mineralization was found to occur at an earlier stage in the stimulated cultures, as compared to the controls, starting with Day 6 of cell culture. At later stages, calcium levels in the stimulated cultures were higher than those in control samples by about 70%, with Ca/P ratios similar to those of natural bone. In all, the laser-based protocol emerges as an efficient alternative to existing fabrication technologies.

  12. Stimulants

    MedlinePlus

    Stimulants are drugs that increase your heart rate, breathing rate, and brain function. Some stimulants affect only a specific organ, such as the heart, lungs, brain, or nervous system. Epinephrine is a stimulant. It ...

  13. Effects of electrical stimulation on rat limb regeneration, a new look at an old model

    PubMed Central

    Leppik, Liudmila P.; Froemel, Dara; Slavici, Andrei; Ovadia, Zachri N.; Hudak, Lukasz; Henrich, Dirk; Marzi, Ingo; Barker, John H.

    2015-01-01

    Limb loss is a devastating disability and while current treatments provide aesthetic and functional restoration, they are associated with complications and risks. The optimal solution would be to harness the body’s regenerative capabilities to regrow new limbs. Several methods have been tried to regrow limbs in mammals, but none have succeeded. One such attempt, in the early 1970s, used electrical stimulation and demonstrated partial limb regeneration. Several researchers reproduced these findings, applying low voltage DC electrical stimulation to the stumps of amputated rat forelimbs reporting “blastema, and new bone, bone marrow, cartilage, nerve, skin, muscle and epiphyseal plate formation”. In spite of these encouraging results this research was discontinued. Recently there has been renewed interest in studying electrical stimulation, primarily at a cellular and subcellular level, and studies have demonstrated changes in stem cell behavior with increased proliferation, differentiation, matrix formation and migration, all important in tissue regeneration. We applied electrical stimulation, in vivo, to the stumps of amputated rat limbs and observed significant new bone, cartilage and vessel formation and prevention of neuroma formation. These findings demonstrate that electricity stimulates tissue regeneration and form the basis for further research leading to possible new treatments for regenerating limbs. PMID:26678416

  14. The effects of aging and electrical stimulation exercise on bone after spinal cord injury.

    PubMed

    Dolbow, James D; Dolbow, David R; Gorgey, Ashraf S; Adler, Robert A; Gater, David R

    2013-06-01

    Age related bone loss predisposes adults to osteoporosis. This is especially true for individuals with spinal cord injury (SCI). The effects of decreased bone loading with older age and paralysis significantly contribute to decreased bone mass and increased risk for fragility fractures. Loading bone via volitional muscle contractions or by using electrical stimulation are common methods for helping to prevent and/or decrease bone loss. However the effectiveness and safety of electrical stimulation activities remain unclear. The purpose of this review is to investigate the factors associated with aging and osteoporosis after SCI, the accuracy of bone measurement, the effects of various forms of bone loading activities with a focus on electrical stimulation activities and the safety of physical exercise with a focus on electrical stimulation cycling. Osteoporosis remains a disabling and costly condition for older adults and for those with paralysis. Both dual energy x-ray absorptiometry and peripheral quantitative computed tomography are valuable techniques for measuring bone mineral density (BMD) with the latter having the ability to differentiate trabecular and cortical bone. Physical activities have shown to be beneficial for increasing BMD however, the extent of the benefits related to aging and paralysis remain undetermined. Electrical stimulation activities administered appropriately are assumed safe due to thousands of documented safe FES cycling sessions. However, specific documentation is needed to verify safety and to development formal guidelines for optimal use.

  15. The Effects of Aging and Electrical Stimulation Exercise on Bone after Spinal Cord Injury

    PubMed Central

    Dolbow, James D.; Dolbow, David R.; Gorgey, Ashraf S.; Adler, Robert A.; Gater, David R.

    2013-01-01

    Age related bone loss predisposes adults to osteoporosis. This is especially true for individuals with spinal cord injury (SCI). The effects of decreased bone loading with older age and paralysis significantly contribute to decreased bone mass and increased risk for fragility fractures. Loading bone via volitional muscle contractions or by using electrical stimulation are common methods for helping to prevent and/or decrease bone loss. However the effectiveness and safety of electrical stimulation activities remain unclear. The purpose of this review is to investigate the factors associated with aging and osteoporosis after SCI, the accuracy of bone measurement, the effects of various forms of bone loading activities with a focus on electrical stimulation activities and the safety of physical exercise with a focus on electrical stimulation cycling. Osteoporosis remains a disabling and costly condition for older adults and for those with paralysis. Both dual energy x-ray absorptiometry and peripheral quantitative computed tomography are valuable techniques for measuring bone mineral density (BMD) with the latter having the ability to differentiate trabecular and cortical bone. Physical activities have shown to be beneficial for increasing BMD however, the extent of the benefits related to aging and paralysis remain undetermined. Electrical stimulation activities administered appropriately are assumed safe due to thousands of documented safe FES cycling sessions. However, specific documentation is needed to verify safety and to development formal guidelines for optimal use. PMID:23730530

  16. Percutaneous biphasic electrical stimulation for treatment of obstructive sleep apnea syndrome.

    PubMed

    Hu, Lianggang; Xu, Xiaomei; Gong, Yongsheng; Fan, Xiaofang; Wang, Liangxing; Zhang, Jianhua; Zeng, Yanjun

    2008-01-01

    In this paper, we study the effect of stimulation of the genioglossus with percutaneous biphasic electrical pulses on patients with the obstructive sleep apnea syndrome (OSAS). The experiment was conducted in 22 patients clinically diagnosed with OSAS. The patients were monitored with polysomnography (PSG) in the trial. When the sleep apnea was detected, the genioglossus was stimulated with percutaneous biphasic electrical pulses that were automatically regulated by a microcontroller to achieve the optimal effect. The percutaneous biphasic electrical stimulation caused contraction of the genioglossus, forward movement of the tongue, and relieving of the glossopharyngeal airway obstruction. The SaO2, apnea time, hypoxemia time, and change of respiratory disturbance index (RDI) were compared in patients with treatment and without treatment. With percutaneous biphasic electrical stimulation of the genioglossus, the OSAS patients showed apnea time decreased (P < 0.01), RDI decreased (P < 0.01), and SaO2 increased (P < 0.01). No tissue injury or major discomfort was noticed during the trial. The stimulation of genioglossus with percutaneous biphasic electrical current pulse is an effective method for treating OSAS. PMID:18232360

  17. Role of electrical stimulation for rehabilitation and regeneration after spinal cord injury: an overview

    PubMed Central

    Hayek, Ray

    2008-01-01

    Structural discontinuity in the spinal cord after injury results in a disruption in the impulse conduction resulting in loss of various bodily functions depending upon the level of injury. This article presents a summary of the scientific research employing electrical stimulation as a means for anatomical or functional recovery for patients suffering from spinal cord injury. Electrical stimulation in the form of functional electrical stimulation (FES) can help facilitate and improve upper/lower limb mobility along with other body functions lost due to injury e.g. respiratory, sexual, bladder or bowel functions by applying a controlled electrical stimulus to generate contractions and functional movement in the paralysed muscles. The available rehabilitative techniques based on FES technology and various Food and Drug Administration, USA approved neuroprosthetic devices that are in use are discussed. The second part of the article summarises the experimental work done in the past 2 decades to study the effects of weakly applied direct current fields in promoting regeneration of neurites towards the cathode and the new emerging technique of oscillating field stimulation which has shown to promote bidirectional regeneration in the injured nerve fibres. The present article is not intended to be an exhaustive review but rather a summary aiming to highlight these two applications of electrical stimulation and the degree of anatomical/functional recovery associated with these in the field of spinal cord injury research. PMID:18677518

  18. Percutaneous biphasic electrical stimulation for treatment of obstructive sleep apnea syndrome.

    PubMed

    Hu, Lianggang; Xu, Xiaomei; Gong, Yongsheng; Fan, Xiaofang; Wang, Liangxing; Zhang, Jianhua; Zeng, Yanjun

    2008-01-01

    In this paper, we study the effect of stimulation of the genioglossus with percutaneous biphasic electrical pulses on patients with the obstructive sleep apnea syndrome (OSAS). The experiment was conducted in 22 patients clinically diagnosed with OSAS. The patients were monitored with polysomnography (PSG) in the trial. When the sleep apnea was detected, the genioglossus was stimulated with percutaneous biphasic electrical pulses that were automatically regulated by a microcontroller to achieve the optimal effect. The percutaneous biphasic electrical stimulation caused contraction of the genioglossus, forward movement of the tongue, and relieving of the glossopharyngeal airway obstruction. The SaO2, apnea time, hypoxemia time, and change of respiratory disturbance index (RDI) were compared in patients with treatment and without treatment. With percutaneous biphasic electrical stimulation of the genioglossus, the OSAS patients showed apnea time decreased (P < 0.01), RDI decreased (P < 0.01), and SaO2 increased (P < 0.01). No tissue injury or major discomfort was noticed during the trial. The stimulation of genioglossus with percutaneous biphasic electrical current pulse is an effective method for treating OSAS.

  19. Non-invasive electric current stimulation for restoration of vision after unilateral occipital stroke.

    PubMed

    Gall, Carolin; Silvennoinen, Katri; Granata, Giuseppe; de Rossi, Francesca; Vecchio, Fabrizio; Brösel, Doreen; Bola, Michał; Sailer, Michael; Waleszczyk, Wioletta J; Rossini, Paolo M; Tatlisumak, Turgut; Sabel, Bernhard A

    2015-07-01

    Occipital stroke often leads to visual field loss, for which no effective treatment exists. Little is known about the potential of non-invasive electric current stimulation to ameliorate visual functions in patients suffering from unilateral occipital stroke. One reason is the traditional thinking that visual field loss after brain lesions is permanent. Since evidence is available documenting vision restoration by means of vision training or non-invasive electric current stimulation future studies should also consider investigating recovery processes after visual cortical strokes. Here, protocols of repetitive transorbital alternating current stimulation (rtACS) and transcranial direct current stimulation (tDCS) are presented and the European consortium for restoration of vision (REVIS) is introduced. Within the consortium different stimulation approaches will be applied to patients with unilateral occipital strokes resulting in homonymous hemianopic visual field defects. The aim of the study is to evaluate effects of current stimulation of the brain on vision parameters, vision-related quality of life, and physiological parameters that allow concluding about the mechanisms of vision restoration. These include EEG-spectra and coherence measures, and visual evoked potentials. The design of stimulation protocols involves an appropriate sham-stimulation condition and sufficient follow-up periods to test whether the effects are stable. This is the first application of non-invasive current stimulation for vision rehabilitation in stroke-related visual field deficits. Positive results of the trials could have far-reaching implications for clinical practice. The ability of non-invasive electrical current brain stimulation to modulate the activity of neuronal networks may have implications for stroke rehabilitation also in the visual domain.

  20. Non-invasive electric current stimulation for restoration of vision after unilateral occipital stroke.

    PubMed

    Gall, Carolin; Silvennoinen, Katri; Granata, Giuseppe; de Rossi, Francesca; Vecchio, Fabrizio; Brösel, Doreen; Bola, Michał; Sailer, Michael; Waleszczyk, Wioletta J; Rossini, Paolo M; Tatlisumak, Turgut; Sabel, Bernhard A

    2015-07-01

    Occipital stroke often leads to visual field loss, for which no effective treatment exists. Little is known about the potential of non-invasive electric current stimulation to ameliorate visual functions in patients suffering from unilateral occipital stroke. One reason is the traditional thinking that visual field loss after brain lesions is permanent. Since evidence is available documenting vision restoration by means of vision training or non-invasive electric current stimulation future studies should also consider investigating recovery processes after visual cortical strokes. Here, protocols of repetitive transorbital alternating current stimulation (rtACS) and transcranial direct current stimulation (tDCS) are presented and the European consortium for restoration of vision (REVIS) is introduced. Within the consortium different stimulation approaches will be applied to patients with unilateral occipital strokes resulting in homonymous hemianopic visual field defects. The aim of the study is to evaluate effects of current stimulation of the brain on vision parameters, vision-related quality of life, and physiological parameters that allow concluding about the mechanisms of vision restoration. These include EEG-spectra and coherence measures, and visual evoked potentials. The design of stimulation protocols involves an appropriate sham-stimulation condition and sufficient follow-up periods to test whether the effects are stable. This is the first application of non-invasive current stimulation for vision rehabilitation in stroke-related visual field deficits. Positive results of the trials could have far-reaching implications for clinical practice. The ability of non-invasive electrical current brain stimulation to modulate the activity of neuronal networks may have implications for stroke rehabilitation also in the visual domain. PMID:26072125

  1. Sustained cortical and subcortical neuromodulation induced by electrical tongue stimulation

    PubMed Central

    Tyler, Mitchell E.; Danilov, Yuri P.; Kaczmarek, Kurt A.; Meyerand, Mary E.

    2010-01-01

    This pilot study aimed to show that information-free stimulation of the tongue can improve behavioral measures and induce sustained neuromodulation of the balance-processing network in individuals with balance dysfunction. Twelve balance-impaired subjects received one week of cranial nerve non-invasive neuromodulation (CN-NINM). Before and after the week of stimulation, postural sway and fMRI activation were measured to monitor susceptibility to optic flow. Nine normal controls also underwent the postural sway and fMRI tests but did not receive CN-NINM. Results showed that before CN-NINM balance-impaired subjects swayed more than normal controls as expected (p≤0.05), and that overall sway and susceptibility to optic flow decreased after CN-NINM (p≤0.005 & p≤0.05). fMRI showed upregulation of visual sensitivity to optic flow in balance-impaired subjects that decreased after CN-NINM. A region of interest analysis indicated that CN-NINM may induce neuromodulation by increasing activity within the dorsal pons (p≤0.01). PMID:20614202

  2. Electric field stimulation setup for photoemission electron microscopes.

    PubMed

    Buzzi, M; Vaz, C A F; Raabe, J; Nolting, F

    2015-08-01

    Manipulating magnetisation by the application of an electric field in magnetoelectric multiferroics represents a timely issue due to the potential applications in low power electronics and the novel physics involved. Thanks to its element sensitivity and high spatial resolution, X-ray photoemission electron microscopy is a uniquely suited technique for the investigation of magnetoelectric coupling in multiferroic materials. In this work, we present a setup that allows for the application of in situ electric and magnetic fields while the sample is analysed in the microscope. As an example of the performances of the setup, we present measurements on Ni/Pb(Mg(0.66)Nb(0.33))O3-PbTiO3 and La(0.7)Sr(0.3)MnO3/PMN-PT artificial multiferroic nanostructures.

  3. Electric field stimulation setup for photoemission electron microscopes

    SciTech Connect

    Buzzi, M.; Vaz, C. A. F.; Raabe, J.; Nolting, F.

    2015-08-15

    Manipulating magnetisation by the application of an electric field in magnetoelectric multiferroics represents a timely issue due to the potential applications in low power electronics and the novel physics involved. Thanks to its element sensitivity and high spatial resolution, X-ray photoemission electron microscopy is a uniquely suited technique for the investigation of magnetoelectric coupling in multiferroic materials. In this work, we present a setup that allows for the application of in situ electric and magnetic fields while the sample is analysed in the microscope. As an example of the performances of the setup, we present measurements on Ni/Pb(Mg{sub 0.66}Nb{sub 0.33})O{sub 3}-PbTiO{sub 3} and La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/PMN-PT artificial multiferroic nanostructures.

  4. Electric field stimulation setup for photoemission electron microscopes.

    PubMed

    Buzzi, M; Vaz, C A F; Raabe, J; Nolting, F

    2015-08-01

    Manipulating magnetisation by the application of an electric field in magnetoelectric multiferroics represents a timely issue due to the potential applications in low power electronics and the novel physics involved. Thanks to its element sensitivity and high spatial resolution, X-ray photoemission electron microscopy is a uniquely suited technique for the investigation of magnetoelectric coupling in multiferroic materials. In this work, we present a setup that allows for the application of in situ electric and magnetic fields while the sample is analysed in the microscope. As an example of the performances of the setup, we present measurements on Ni/Pb(Mg(0.66)Nb(0.33))O3-PbTiO3 and La(0.7)Sr(0.3)MnO3/PMN-PT artificial multiferroic nanostructures. PMID:26329198

  5. Electric field stimulation setup for photoemission electron microscopes

    NASA Astrophysics Data System (ADS)

    Buzzi, M.; Vaz, C. A. F.; Raabe, J.; Nolting, F.

    2015-08-01

    Manipulating magnetisation by the application of an electric field in magnetoelectric multiferroics represents a timely issue due to the potential applications in low power electronics and the novel physics involved. Thanks to its element sensitivity and high spatial resolution, X-ray photoemission electron microscopy is a uniquely suited technique for the investigation of magnetoelectric coupling in multiferroic materials. In this work, we present a setup that allows for the application of in situ electric and magnetic fields while the sample is analysed in the microscope. As an example of the performances of the setup, we present measurements on Ni/Pb(Mg0.66Nb0.33)O3-PbTiO3 and La0.7Sr0.3MnO3/PMN-PT artificial multiferroic nanostructures.

  6. Changes in the frequency of swallowing during electrical stimulation of superior laryngeal nerve in rats.

    PubMed

    Tsuji, Kojun; Tsujimura, Takanori; Magara, Jin; Sakai, Shogo; Nakamura, Yuki; Inoue, Makoto

    2015-02-01

    The aim of the present study was to investigate the adaptation of the swallowing reflex in terms of reduced swallowing reflex initiation following continuous superior laryngeal nerve stimulation. Forty-four male Sprague Dawley rats were anesthetized with urethane. To identify swallowing, electromyographic activity of the left mylohyoid and thyrohyoid muscles was recorded. To evoke the swallowing response, the superior laryngeal nerve (SLN), recurrent laryngeal nerve, or cortical swallowing area was electrically stimulated. Repetitive swallowing evoked by continuous SLN stimulation was gradually reduced, and this reduction was dependent on the resting time duration between stimulations. Prior SLN stimulation also suppressed subsequent swallowing initiation. The reduction in evoked swallows induced by recurrent laryngeal nerve or cortical swallowing area stimulation was less than that following superior laryngeal nerve stimulation. Decerebration had no effect on the reduction in evoked swallows. Prior subthreshold stimulation reduced subsequent initiation of swallowing, suggesting that there was no relationship between swallowing movement evoked by prior stimulation and the subsequent reduction in swallowing initiation. Overall, these data suggest that reduced sensory afferent nerve firing and/or trans-synaptic responses, as well as part of the brainstem central pattern generator, are involved in adaptation of the swallowing reflex following continuous stimulation of swallow-inducing peripheral nerves and cortical areas.

  7. Electrical stimulation causes rapid changes in electrode impedance of cell-covered electrodes

    NASA Astrophysics Data System (ADS)

    Newbold, Carrie; Richardson, Rachael; Millard, Rodney; Seligman, Peter; Cowan, Robert; Shepherd, Robert

    2011-06-01

    Animal and clinical observations of a reduction in electrode impedance following electrical stimulation encouraged the development of an in vitro model of the electrode-tissue interface. This model was used previously to show an increase in impedance with cell and protein cover over electrodes. In this paper, the model was used to assess the changes in electrode impedance and cell cover following application of a charge-balanced biphasic current pulse train. Following stimulation, a large and rapid drop in total impedance (Zt) and access resistance (Ra) occurred. The magnitude of this impedance change was dependent on the current amplitude used, with a linear relationship determined between Ra and the resulting cell cover over the electrodes. The changes in impedance due to stimulation were shown to be transitory, with impedance returning to pre-stimulation levels several hours after cessation of stimulation. A loss of cells over the electrode surface was observed immediately after stimulation, suggesting that the level of stimulation applied was creating localized changes to cell adhesion. Similar changes in electrode impedance were observed for in vivo and in vitro work, thus helping to verify the in vitro model, although the underlying mechanisms may differ. A change in the porosity of the cellular layer was proposed to explain the alterations in electrode impedance in vitro. These in vitro studies provide insight into the possible mechanisms occurring at the electrode-tissue interface in association with electrical stimulation.

  8. Electrical stimulation causes rapid changes in electrode impedance of cell-covered electrodes

    PubMed Central

    Newbold, Carrie; Richardson, Rachael; Millard, Rodney; Seligman, Peter; Cowan, Robert; Shepherd, Robert

    2011-01-01

    Animal and clinical observations of a reduction in electrode impedance following electrical stimulation encouraged the development of an in vitro model of the electrode-tissue interface. This model was used previously to show an increase in impedance with cell and protein cover over electrodes. In this paper, the model was used to assess the changes in electrode impedance and cell cover following application of a charge-balanced biphasic current pulse train. Following stimulation, a large and rapid drop in total impedance (Zt) and access resistance (Ra) occurred. The magnitude of this impedance change was dependent on the current amplitude used, with a linear relationship determined between Ra and the resulting cell cover over the electrodes. The changes in impedance due to stimulation were shown to be transitory, with impedance returning to pre-stimulation levels several hours after cessation of stimulation. A loss of cells over the electrode surface was observed immediately after stimulation suggesting that the level of stimulation applied was creating localised changes to cell adhesion. Similar changes in electrode impedance were observed for in vivo and in vitro work, thus helping to verify the in vitro model, although the underlying mechanisms may differ. A change in the porosity of the cellular layer was proposed to explain the alterations in electrode impedance in vitro. These in vitro studies provide insight into the possible mechanisms occurring at the electrode-tissue interface in association with electrical stimulation. PMID:21572219

  9. 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.

  10. A Closed Loop Brain-machine Interface for Epilepsy Control Using Dorsal Column Electrical Stimulation.

    PubMed

    Pais-Vieira, Miguel; Yadav, Amol P; Moreira, Derek; Guggenmos, David; Santos, Amílcar; Lebedev, Mikhail; Nicolelis, Miguel A L

    2016-01-01

    Although electrical neurostimulation has been proposed as an alternative treatment for drug-resistant cases of epilepsy, current procedures such as deep brain stimulation, vagus, and trigeminal nerve stimulation are effective only in a fraction of the patients. Here we demonstrate a closed loop brain-machine interface that delivers electrical stimulation to the dorsal column (DCS) of the spinal cord to suppress epileptic seizures. Rats were implanted with cortical recording microelectrodes and spinal cord stimulating electrodes, and then injected with pentylenetetrazole to induce seizures. Seizures were detected in real time from cortical local field potentials, after which DCS was applied. This method decreased seizure episode frequency by 44% and seizure duration by 38%. We argue that the therapeutic effect of DCS is related to modulation of cortical theta waves, and propose that this closed-loop interface has the potential to become an effective and semi-invasive treatment for refractory epilepsy and other neurological disorders. PMID:27605389

  11. A Closed Loop Brain-machine Interface for Epilepsy Control Using Dorsal Column Electrical Stimulation

    PubMed Central

    Pais-Vieira, Miguel; Yadav, Amol P.; Moreira, Derek; Guggenmos, David; Santos, Amílcar; Lebedev, Mikhail; Nicolelis, Miguel A. L.

    2016-01-01

    Although electrical neurostimulation has been proposed as an alternative treatment for drug-resistant cases of epilepsy, current procedures such as deep brain stimulation, vagus, and trigeminal nerve stimulation are effective only in a fraction of the patients. Here we demonstrate a closed loop brain-machine interface that delivers electrical stimulation to the dorsal column (DCS) of the spinal cord to suppress epileptic seizures. Rats were implanted with cortical recording microelectrodes and spinal cord stimulating electrodes, and then injected with pentylenetetrazole to induce seizures. Seizures were detected in real time from cortical local field potentials, after which DCS was applied. This method decreased seizure episode frequency by 44% and seizure duration by 38%. We argue that the therapeutic effect of DCS is related to modulation of cortical theta waves, and propose that this closed-loop interface has the potential to become an effective and semi-invasive treatment for refractory epilepsy and other neurological disorders. PMID:27605389

  12. Do electrically stimulated sensory inputs and movements lead to long-term plasticity and rehabilitation gains?

    PubMed

    Dobkin, Bruce H

    2003-12-01

    Peripheral and cortical magnetic and electrical stimulation may find a therapeutic niche as augmentative rehabilitation interventions for lessening impairments and disabilities after brain and spinal cord injury. The momentum for these approaches arose from recent physiological studies that examined the effects of paradigms of stimulation on synaptic and biological adaptations within the cortex and lumbar cord. A case report about improvements made by Christopher Reeve is driving requests by patients with profound spinal cord injury for interventions that include resistance pedaling facilitated by electrical neuromuscular stimulation. Although the evidence for this particular approach is less than convincing, reorganization-inducing cortical and peripheral afferent stimulation protocols offer insights into the steps needed for scientific designs of these potential rehabilitation interventions. PMID:14624077

  13. A Closed Loop Brain-machine Interface for Epilepsy Control Using Dorsal Column Electrical Stimulation.

    PubMed

    Pais-Vieira, Miguel; Yadav, Amol P; Moreira, Derek; Guggenmos, David; Santos, Amílcar; Lebedev, Mikhail; Nicolelis, Miguel A L

    2016-09-08

    Although electrical neurostimulation has been proposed as an alternative treatment for drug-resistant cases of epilepsy, current procedures such as deep brain stimulation, vagus, and trigeminal nerve stimulation are effective only in a fraction of the patients. Here we demonstrate a closed loop brain-machine interface that delivers electrical stimulation to the dorsal column (DCS) of the spinal cord to suppress epileptic seizures. Rats were implanted with cortical recording microelectrodes and spinal cord stimulating electrodes, and then injected with pentylenetetrazole to induce seizures. Seizures were detected in real time from cortical local field potentials, after which DCS was applied. This method decreased seizure episode frequency by 44% and seizure duration by 38%. We argue that the therapeutic effect of DCS is related to modulation of cortical theta waves, and propose that this closed-loop interface has the potential to become an effective and semi-invasive treatment for refractory epilepsy and other neurological disorders.

  14. High intensity electrical stimulation effect on thigh musculature during immobilization for knee sprain. A case report.

    PubMed

    Nitz, A J; Dobner, J J

    1987-02-01

    We conducted high intensity electrical stimulation of the quadriceps femoris and hamstring muscle groups daily during a three-week period of lower extremity cast immobilization for an athlete who sustained Grade II medial collateral and anterior cruciate ligament sprains. Thigh muscle hypertrophy of the injured (stimulated) leg was suggested by an increase in girth measurement on the day of cast removal. Three weeks after cast removal, single-leg, vertical-leap height was 92% of that accomplished by the dominant, uninjured leg, and the patient was able to return to athletic competition. This case report documents the usefulness of high intensity electrical stimulation for maintaining limb motor function during cast immobilization. Limb stabilization during stimulation and simultaneous excitation of agonist-antagonist muscle pairs also are discussed.

  15. [Changes in the brain spontaneous bioelectrical activity during transcranial electrical and electromagnetic stimulation].

    PubMed

    Sharova, E V; Mel'nikov, A V; Novikova, M R; Kulikov, M A; Grechenko, T N; Shekhter, E D; Zaslavskiĭ, A Iu

    2006-01-01

    In order to study systemic brain reactions on transcranial electrical or electromagnetic medical stimulation and specify the neurophysiological criteria of its efficiency, comparative clinical and experimental examination was performed with the analysis of spontaneous bioelectric activity and behavioral or clinical parameters. We examined 6 patients with prolonged posttraumatic unconsciousness states treated with electrical stimulation and 17 intact Wistar rats subjected to electromagnetic stimulation of the brain. The effect of the transcranial stimulation was shown to depend on the initial level of the intercentral interactions of brain bioelectrical activity, estimated by the EEG coherence. Hypersynchronization of biopotentials as the main element of the brain reactivity can be the most useful for the rehabilitation of patients with cerebral pathology in cases of initially lowered level of the intercentral interactions in the absence of pathologically strengthened functional connections.

  16. Electrical potentials from the eye and optic nerve of Strombus: effects of electrical stimulation of the optic nerve.

    PubMed

    Gillary, H L

    1977-02-01

    1. Photic stimulation of the mature eye of Strombus can evoke in the optic nerve 'on' activity in numerous small afferent fibres and repetitive 'off' bursts of afferent impulses in a smaller number of larger fibres. 2. Synchronous invasion of the eye by electrically evoked impulses in small optic nerve fibres (apparently the 'on' afferents, antidromically activated) can evoke a burst of impulses in the larger 'off' fibres which propagate away from the eye. Invasion of the eye via one branch of optic nerve can evoke an answering burst in another branch. 3. Such electrically evoked bursts are similar to light-evoked 'off' bursts with respect to their impulse composition, their ability to be inhibited by illumination of the eye, and their susceptibility to MgCl2 anaesthesia. 4. Invasion of the eye by a train of repetitive electrically evoked impulses in the absence of photic stimulation can give rise to repetitive 'off' bursts as well as concomitant oscillatory potentials in the eye which are similar to those normally evoked by cessation of a photic stimulus. 5. The electrically evoked 'off' bursts appear to be caused by an excitatory rebound following the cessation of inhibitory synaptic input from photoreceptors which can be antidromically activated by electrical stimulation of the optic nerve. 6. The experimental results suggest that the rhythmic discharge of the 'off' fibres evoked by the cessation of a photic stimulus is mediated by the abrupt decrease of inhibitory synaptic input from the receptors. PMID:192827

  17. 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

  18. Femoral quadriceps neuromuscular electrical stimulation after total knee arthroplasty: a systematic review

    PubMed Central

    Volpato, Helena Bruna Bettoni; Szego, Paulo; Lenza, Mario; Milan, Silvia Lefone; Talerman, Claudia; Ferretti, Mario

    2016-01-01

    ABSTRACT The purpose of this study was to evaluate the effects of neuromuscular electrical stimulation in patients submitted to total knee arthroplasty. This was a systematic review with no language or publication status restriction. Our search was made in Cochrane Library, MEDLINE, Embase and LILACS. Randomized or quasi-randomized clinical trials evaluating neuromuscular electrical stimulation after total knee arthroplasty were included. Four studies with moderate risk of bias and low statistical power were included, totalizing 376 participants. There was no statistically significant difference in knee function, pain and range of motion during 12 month follow-up. This review concluded that neuromuscular electrical stimulation was less effective than traditional rehabilitation in function, muscular strength and range of motion. However, this technique was useful for quadriceps activation during the first days after surgery. PMID:26537511

  19. Effortful swallowing training combined with electrical stimulation in post-stroke dysphagia: a randomized controlled study.

    PubMed

    Park, Jin-Woo; Kim, Youngsun; Oh, Jong-Chi; Lee, Ho-Jun

    2012-12-01

    We tested the effect of effortful swallow combined with surface electrical stimulation used as a form of resistance training in post-stroke patients with dysphagia. Twenty post-stroke dysphagic patients were randomly divided into two groups: those who underwent effortful swallow with infrahyoid motor electrical stimulation (experimental group, n = 10) and effortful swallow with infrahyoid sensory electrical stimulation (control group, n = 10). In the experimental group, electrical stimulation was applied to the skin above the infrahyoid muscle with the current was adjusted until muscle contraction occurred and the hyoid bone was depressed. In the control group, the stimulation intensity was applied just above the sensory threshold. The patients in both groups were then asked to swallow effortfully in order to elevate their hyolaryngeal complex when the stimulation began. A total of 12 sessions of 20 min of training for 4 weeks were performed. Blinded biomechanical measurements of the extent of hyolaryngeal excursion, the maximal width of the upper esophageal sphincter (UES) opening, and the penetration-aspiration scale before and after training were performed. In the experimental group, the maximal vertical displacement of the larynx was increased significantly after the intervention (p < 0.05). The maximal vertical displacement of the hyoid bone and the maximal width of the UES opening increased but the increase was not found to be significant (p = 0.066). There was no increase in the control group. Effortful swallow training combined with electrical stimulation increased the extent of laryngeal excursion. This intervention can be used as a new treatment method in post-stroke patients with dysphagia. PMID:22447240

  20. Stimulated oxidation of metals (laser, electric field, etc.): Comparative studies

    NASA Astrophysics Data System (ADS)

    Nánai, László; Füle, Miklós

    2014-11-01

    In this report we demonstrate the importance of metal oxides, e.g. thin films and nanostructures, in modern science and technology. The basic laws of oxide thickness on base of diffusion of specimens versus time in different circumstances (Cabrera-Mott and Wagner laws) under the influence of external fields, e.g. electromagnetic field, static electric and magnetic field, are demonstrated. We give experimental results for various metal oxide layers over a wide range of different metals. Theoretical explanations are provided as well for the most reliable circumstances.

  1. Differential changes in gingival somatosensory sensitivity after painful electrical tooth stimulation.

    PubMed

    Baad-Hansen, Lene; Lu, Shengyi; Kemppainen, Pentti; List, Thomas; Zhang, Zhenting; Svensson, Peter

    2015-04-01

    We aimed to evaluate the effect of painful tooth stimulation on gingival somatosensory sensitivity of healthy volunteers in a randomized, controlled design. Thirteen healthy volunteers (six women, seven men; 28.4 ± 5.0 years) were included for two experimental sessions of electrical tooth stimulation: painful tooth stimulation and tooth stimulation below the sensory threshold (control). Eight of the human subjects participated in a third session without tooth stimulation. In all sessions, the somatosensory sensitivity of the gingiva adjacent to the stimulated tooth was evaluated with a standardized battery of quantitative sensory tests (QST) before, immediately after and 30 min after tooth stimulation. Painful tooth stimulation evoked significant decreases in warmth and heat pain thresholds (P < 0.001) as well as pressure pain thresholds (increased sensitivity) (P = 0.024) and increases in mechanical detection thresholds (decreased sensitivity) (P < 0.050). Similar thermal threshold changes (P < 0.019) but no mechanical changes were found after tooth stimulation below the sensory threshold (P > 0.086). No QST changes were detected in the session without tooth stimulation (P > 0.060). In conclusion, modest increased gingival sensitivity to warmth, painful heat and pressure stimuli as well as desensitization to non-painful mechanical stimulation were demonstrated after tooth stimulation. This suggests involvement of competing heterotopic facilitatory and inhibitory mechanisms. Furthermore, stimulation below the sensory threshold induced similar thermal sensitization suggesting the possibility of activation of axon-reflex-like mechanisms even at intensities below the perception threshold. These findings may have implications for interpretation of somatosensory results in patients with chronic intraoral pain. PMID:25567087

  2. Differential changes in gingival somatosensory sensitivity after painful electrical tooth stimulation.

    PubMed

    Baad-Hansen, Lene; Lu, Shengyi; Kemppainen, Pentti; List, Thomas; Zhang, Zhenting; Svensson, Peter

    2015-04-01

    We aimed to evaluate the effect of painful tooth stimulation on gingival somatosensory sensitivity of healthy volunteers in a randomized, controlled design. Thirteen healthy volunteers (six women, seven men; 28.4 ± 5.0 years) were included for two experimental sessions of electrical tooth stimulation: painful tooth stimulation and tooth stimulation below the sensory threshold (control). Eight of the human subjects participated in a third session without tooth stimulation. In all sessions, the somatosensory sensitivity of the gingiva adjacent to the stimulated tooth was evaluated with a standardized battery of quantitative sensory tests (QST) before, immediately after and 30 min after tooth stimulation. Painful tooth stimulation evoked significant decreases in warmth and heat pain thresholds (P < 0.001) as well as pressure pain thresholds (increased sensitivity) (P = 0.024) and increases in mechanical detection thresholds (decreased sensitivity) (P < 0.050). Similar thermal threshold changes (P < 0.019) but no mechanical changes were found after tooth stimulation below the sensory threshold (P > 0.086). No QST changes were detected in the session without tooth stimulation (P > 0.060). In conclusion, modest increased gingival sensitivity to warmth, painful heat and pressure stimuli as well as desensitization to non-painful mechanical stimulation were demonstrated after tooth stimulation. This suggests involvement of competing heterotopic facilitatory and inhibitory mechanisms. Furthermore, stimulation below the sensory threshold induced similar thermal sensitization suggesting the possibility of activation of axon-reflex-like mechanisms even at intensities below the perception threshold. These findings may have implications for interpretation of somatosensory results in patients with chronic intraoral pain.

  3. Does therapeutic electrical stimulation improve function in children with disabilities? A comprehensive literature review.

    PubMed

    Bosques, Glendaliz; Martin, Rebecca; McGee, Leah; Sadowsky, Cristina

    2016-05-31

    The use of therapeutic electrical stimulation for medical purposes is not new; it has been described in medical textbooks since the 18th century, but its use has been limited due to concerns for tolerance and lack of research showing efficacy. The purpose of this review is to discuss the potential clinical applicability, while clarifying the differences in electrical stimulation (ES) treatments and the theory behind potential benefits to remediate functional impairments in youth.The literature review was performed as follows: A total of 37 articles were reviewed and the evidence for use in pediatric diagnoses is reported.The synthesis of the literature suggests that improvements in various impairments may be possible with the integration of ES. Most studies were completed on children with cerebral palsy (CP). Electrical stimulation may improve muscle mass and strength, spasticity, passive range of motion (PROM), upper extremity function, walking speed, and positioning of the foot and ankle kinematics during walking. Sitting posture and static/dynamic sitting balance may be improved with ES to trunk musculature. Bone mineral density may be positively affected with the use of Functional Electrical Stimulation (FES) ergometry. ES may also be useful in the management of urinary tract dysfunction and chronic constipation. Among all reviewed studies, reports of direct adverse reactions to electrical stimulation were rare.In conclusion, NMES and FES appear to be safe and well tolerated in children with various disabilities. It is suggested that physiatrists and other healthcare providers better understand the indications and parameters in order to utilize these tools effectively in the pediatric population. MeSH terms: Electrical stimulation; child; review. PMID:27285801

  4. Nanowires and Electrical Stimulation Synergistically Improve Functions of hiPSC Cardiac Spheroids.

    PubMed

    Richards, Dylan J; Tan, Yu; Coyle, Robert; Li, Yang; Xu, Ruoyu; Yeung, Nelson; Parker, Arran; Menick, Donald R; Tian, Bozhi; Mei, Ying

    2016-07-13

    The advancement of human induced pluripotent stem-cell-derived cardiomyocyte (hiPSC-CM) technology has shown promising potential to provide a patient-specific, regenerative cell therapy strategy to treat cardiovascular disease. Despite the progress, the unspecific, underdeveloped phenotype of hiPSC-CMs has shown arrhythmogenic risk and limited functional improvements after transplantation. To address this, tissue engineering strategies have utilized both exogenous and endogenous stimuli to accelerate the development of hiPSC-CMs. Exogenous electrical stimulation provides a biomimetic pacemaker-like stimuli that has been shown to advance the electrical properties of tissue engineered cardiac constructs. Recently, we demonstrated that the incorporation of electrically conductive silicon nanowires to hiPSC cardiac spheroids led to advanced structural and functional development of hiPSC-CMs by improving the endogenous electrical microenvironment. Here, we reasoned that the enhanced endogenous electrical microenvironment of nanowired hiPSC cardiac spheroids would synergize with exogenous electrical stimulation to further advance the functional development of nanowired hiPSC cardiac spheroids. For the first time, we report that the combination of nanowires and electrical stimulation enhanced cell-cell junction formation, improved development of contractile machinery, and led to a significant decrease in the spontaneous beat rate of hiPSC cardiac spheroids. The advancements made here address critical challenges for the use of hiPSC-CMs in cardiac developmental and translational research and provide an advanced cell delivery vehicle for the next generation of cardiac repair.

  5. Perception of electrical and mechanical stimulation of the skin: implications for electrotactile feedback

    NASA Astrophysics Data System (ADS)

    Marcus, Patrick L.; Fuglevand, Andrew J.

    2009-12-01

    Spinal cord injury is often accompanied by impaired tactile and proprioceptive sensations. Normally, somatosensensory information derived from such sensations is important in the formation of voluntary motor commands. Therefore, as a preliminary step toward the development of an electrotactile feedback system to restore somatosensation, psychophysical methods were used to characterize perceptual attributes associated with electrical stimulation of the skin on the back of the neck in human subjects. These data were compared to mechanical stimulation of the skin on the back of neck and on the distal pad of the index finger. Spatial acuity of the neck, evaluated using two-point thresholds, was not significantly different for electrical (37 ± 14 mm) or mechanical stimulation (39 ± 10 mm). The exponent (β) of the best fitting power function relating perceived intensity to applied stimulus strength was used to characterize perceptual sensitivity to mechanical and electrical stimuli. For electrical stimuli, both current amplitude-modulated and frequency-modulated trains of pulses were tested. Perceptual sensitivity was significantly greater for current amplitude modulation (β = 1.14 ± 0.37) compared to frequency modulation (β = 0.57 ± 0.24) and mechanical stimulation (0.51 ± 0.12). Finally, based on the data gathered here, we derive a transfer function that could be used in the future to convert mechanical stimuli detected with artificial sensors placed on the fingers into electrotactile signals that evoke perceptions similar to those arising from normal mechanical stimulation of the skin.

  6. 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

  7. Effect of oscillating electrical field stimulation on motor function recovery and myelin regeneration after spinal cord injury in rats.

    PubMed

    Tian, Da-Sheng; Jing, Jue-Hua; Qian, Jun; Chen, Lei; Zhu, Bin

    2016-05-01

    [Purpose] The aim of this study was to evaluate the effect of oscillating electrical field stimulation on motor function recovery and myelin regeneration in rats with spinal cord injury. [Subjects and Methods] A rat model of spinal cord injury was constructed by using the Allen weight-drop method. These rats were randomly divided into normal, spinal cord injury, and spinal cord injury + oscillating electrical field stimulation groups. The experimental group received the intervention with oscillating electrical field stimulation, and the control group received the intervention with an electrical field stimulator without oscillating electrical field stimulation. Each group was then randomly divided into seven subgroups according to observation time (1, 2, 4, 6, 8, 10, and 12 weeks). Basso-Beattie-Bresnahan score and inclined plate test score evaluation, motor evoked potential detection, and histological observation were performed. [Results] In the first 2 weeks of oscillating electrical field stimulation, the oscillating electrical field stimulation and inclined plate test scores of spinal cord injury group and spinal cord injury + oscillating electrical field stimulation group were not significantly different. In the fourth week, the scores of the spinal cord injury group were significantly lower than those of the spinal cord injury + oscillating electrical field stimulation group. The motor evoked potential incubation period in the spinal cord injury + oscillating electrical field stimulation group at the various time points was shorter than that in the spinal cord injury group. In the sixth week, the relative area of myelin in the spinal cord injury + oscillating electrical field stimulation group was evidently larger than that in the spinal cord injury group. [Conclusion] Oscillating electrical field stimulation could effectively improve spinal cord conduction function and promote motor function recovery in rats with spinal cord injury, as well as promote myelin

  8. Effect of oscillating electrical field stimulation on motor function recovery and myelin regeneration after spinal cord injury in rats.

    PubMed

    Tian, Da-Sheng; Jing, Jue-Hua; Qian, Jun; Chen, Lei; Zhu, Bin

    2016-05-01

    [Purpose] The aim of this study was to evaluate the effect of oscillating electrical field stimulation on motor function recovery and myelin regeneration in rats with spinal cord injury. [Subjects and Methods] A rat model of spinal cord injury was constructed by using the Allen weight-drop method. These rats were randomly divided into normal, spinal cord injury, and spinal cord injury + oscillating electrical field stimulation groups. The experimental group received the intervention with oscillating electrical field stimulation, and the control group received the intervention with an electrical field stimulator without oscillating electrical field stimulation. Each group was then randomly divided into seven subgroups according to observation time (1, 2, 4, 6, 8, 10, and 12 weeks). Basso-Beattie-Bresnahan score and inclined plate test score evaluation, motor evoked potential detection, and histological observation were performed. [Results] In the first 2 weeks of oscillating electrical field stimulation, the oscillating electrical field stimulation and inclined plate test scores of spinal cord injury group and spinal cord injury + oscillating electrical field stimulation group were not significantly different. In the fourth week, the scores of the spinal cord injury group were significantly lower than those of the spinal cord injury + oscillating electrical field stimulation group. The motor evoked potential incubation period in the spinal cord injury + oscillating electrical field stimulation group at the various time points was shorter than that in the spinal cord injury group. In the sixth week, the relative area of myelin in the spinal cord injury + oscillating electrical field stimulation group was evidently larger than that in the spinal cord injury group. [Conclusion] Oscillating electrical field stimulation could effectively improve spinal cord conduction function and promote motor function recovery in rats with spinal cord injury, as well as promote myelin

  9. Effect of oscillating electrical field stimulation on motor function recovery and myelin regeneration after spinal cord injury in rats

    PubMed Central

    Tian, Da-Sheng; Jing, Jue-Hua; Qian, Jun; Chen, Lei; Zhu, Bin

    2016-01-01

    [Purpose] The aim of this study was to evaluate the effect of oscillating electrical field stimulation on motor function recovery and myelin regeneration in rats with spinal cord injury. [Subjects and Methods] A rat model of spinal cord injury was constructed by using the Allen weight-drop method. These rats were randomly divided into normal, spinal cord injury, and spinal cord injury + oscillating electrical field stimulation groups. The experimental group received the intervention with oscillating electrical field stimulation, and the control group received the intervention with an electrical field stimulator without oscillating electrical field stimulation. Each group was then randomly divided into seven subgroups according to observation time (1, 2, 4, 6, 8, 10, and 12 weeks). Basso-Beattie-Bresnahan score and inclined plate test score evaluation, motor evoked potential detection, and histological observation were performed. [Results] In the first 2 weeks of oscillating electrical field stimulation, the oscillating electrical field stimulation and inclined plate test scores of spinal cord injury group and spinal cord injury + oscillating electrical field stimulation group were not significantly different. In the fourth week, the scores of the spinal cord injury group were significantly lower than those of the spinal cord injury + oscillating electrical field stimulation group. The motor evoked potential incubation period in the spinal cord injury + oscillating electrical field stimulation group at the various time points was shorter than that in the spinal cord injury group. In the sixth week, the relative area of myelin in the spinal cord injury + oscillating electrical field stimulation group was evidently larger than that in the spinal cord injury group. [Conclusion] Oscillating electrical field stimulation could effectively improve spinal cord conduction function and promote motor function recovery in rats with spinal cord injury, as well as promote myelin

  10. Invasive and transcranial photoacoustic imaging of the vascular response to brain electrical stimulation

    NASA Astrophysics Data System (ADS)

    Tsytsarev, Vassiliy; Yao, Junjie; Hu, Song; Li, Li; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

    2010-02-01

    Advances in the brain functional imaging greatly facilitated the understanding of neurovascular coupling. For monitoring of the microvascular response to the brain electrical stimulation in vivo we used optical-resolution photoacoustic microscopy (OR-PAM) through the cranial openings as well as transcranially. Both types of the vascular response, vasoconstriction and vasodilatation, were clearly observed with good spatial and temporal resolution. Obtained results confirm one of the primary points of the neurovascular coupling theory that blood vessels could present vasoconstriction or vasodilatation in response to electrical stimulation, depending on the balance between inhibition and excitation of the different parts of the elements of the neurovascular coupling system.

  11. Pupillary responses evoked by electrical stimulation of area pretectalis in cats.

    PubMed

    Shoumura, K; Imai, H

    1986-01-01

    Pupillary responses evoked by electrical stimulation of the area pretectalis and neighboring midbrain structures were studied in the cat. The pupillary responses evoked were recorded using an infrared pupilloanalyzing system. Bilateral pupillary constriction was evoked with a low threshold current intensity by stimulation of the nucleus pretectalis medialis, nucleus pretectalis olivaris, rostral part of the nucleus pretectalis posterior, the most rostral part of the periaqueductal grey and the nucleus of posterior commissure. Bilateral pupillary dilation was induced with a low threshold current intensity by stimulating the nucleus pretectalis anterior, caudal periaqueductal grey and the midbrain tegmentum. The effects of changing stimulus intensity and stimulus frequency were also studied.

  12. Technical aspects of neurostimulation: Focus on equipment, electric field modeling, and stimulation protocols.

    PubMed

    Klooster, D C W; de Louw, A J A; Aldenkamp, A P; Besseling, R M H; Mestrom, R M C; Carrette, S; Zinger, S; Bergmans, J W M; Mess, W H; Vonck, K; Carrette, E; Breuer, L E M; Bernas, A; Tijhuis, A G; Boon, P

    2016-06-01

    Neuromodulation is a field of science, medicine, and bioengineering that encompasses implantable and non-implantable technologies for the purpose of improving quality of life and functioning of humans. Brain neuromodulation involves different neurostimulation techniques: transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS), which are being used both to study their effects on cognitive brain functions and to treat neuropsychiatric disorders. The mechanisms of action of neurostimulation remain incompletely understood. Insight into the technical basis of neurostimulation might be a first step towards a more profound understanding of these mechanisms, which might lead to improved clinical outcome and therapeutic potential. This review provides an overview of the technical basis of neurostimulation focusing on the equipment, the present understanding of induced electric fields, and the stimulation protocols. The review is written from a technical perspective aimed at supporting the use of neurostimulation in clinical practice. PMID:27021215

  13. Electrical stimulation of the hypoglossal nerve in the treatment of obstructive sleep apnea.

    PubMed

    Kezirian, Eric J; Boudewyns, An; Eisele, David W; Schwartz, Alan R; Smith, Philip L; Van de Heyning, Paul H; De Backer, Wilfried A

    2010-10-01

    Upper airway occlusion in obstructive sleep apnea has been attributed to a decline in pharyngeal neuromuscular activity occurring in a structurally narrowed airway. Surgical treatment focuses on the correction of anatomic abnormalities, but there is a potential role for activation of the upper airway musculature, especially with stimulation of the hypoglossal nerve and genioglossus muscle. We present evidence from research on upper airway neuromuscular electrical stimulation in animals and humans. We also present results from eight obstructive sleep apnea patients with a fully implanted system for hypoglossal nerve stimulation, demonstrating an improvement in upper airway collapsibility and obstructive sleep apnea severity. Future research, including optimization of device features and stimulation parameters as well as patient selection, is necessary to make hypoglossal nerve stimulation a viable alternative to positive airway pressure therapy and upper airway surgical procedures.

  14. The effects of stimulating lower leg muscles on the mechanical work and metabolic response in functional electrically stimulated pedaling.

    PubMed

    Hakansson, Nils A; Hull, M L

    2010-10-01

    Functional electrical stimulation (FES) pedaling with the muscles of the upper leg has been shown to provide benefit to spinal cord injured (SCI) individuals. FES pedaling with electrical stimulation timing patterns that minimize the stress-time integral of activated muscles has been shown to increase the work individuals can perform during the exercise compared to existing FES stimulation timing patterns. Activation of the lower leg muscles could further enhance the benefit of FES pedaling by increasing the metabolic response to the exercise. For SCI individuals, the objectives of this study were to experimentally determine whether FES pedaling with the upper and lower leg muscles would affect the work generated and increase the physiological responses compared to pedaling with the upper leg muscles alone. Work, rate of oxygen consumption ·VO₂, and blood lactate data were measured from nine SCI subjects (injury level T4-T12) as they pedaled using upper leg and upper and lower leg muscle groups on repeated trials. The subjects performed 6% more work with the upper and lower legs than with the upper legs alone, but the difference was not significant (p = 0.2433). The average rate of oxygen consumption associated with the upper leg muscles (441 ±231 mL/min) was not significantly different from the corresponding average for the upper and lower legs (473 ±213 mL/min) (p = 0.1176). The blood lactate concentration associated with the upper leg muscles (5.9 ±2.3 mmoles/L) was significantly lower than the corresponding average for the upper and lower legs (6.8 ±2.3 mmoles/L) (p = 0.0049). The results indicate that electrical stimulation timing patterns that incorporate the lower leg muscles do increase the blood lactate concentrations. However, there was not enough evidence to reject the null hypothesis that stimulating the lower leg muscles affected the work accomplished or increased the rate of oxygen consumption. In conclusion, incorporating the lower leg muscles

  15. 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.

  16. Manual and Electrical Needle Stimulation in Acupuncture Research: Pitfalls and Challenges of Heterogeneity

    PubMed Central

    Schnyer, Rosa; MacPherson, Hugh; Davis, Robert; Harris, Richard E.; Napadow, Vitaly; Wayne, Peter M.; Milley, Ryan J.; Lao, Lixing; Stener-Victorin, Elisabet; Kong, Jiang-Ti; Hammerschlag, Richard

    2015-01-01

    Abstract In the field of acupuncture research there is an implicit yet unexplored assumption that the evidence on manual and electrical stimulation techniques, derived from basic science studies, clinical trials, systematic reviews, and meta-analyses, is generally interchangeable. Such interchangeability would justify a bidirectional approach to acupuncture research, where basic science studies and clinical trials each inform the other. This article examines the validity of this fundamental assumption by critically reviewing the literature and comparing manual to electrical acupuncture in basic science studies, clinical trials, and meta-analyses. The evidence from this study does not support the assumption that these techniques are interchangeable. This article also identifies endemic methodologic limitations that have impaired progress in the field. For example, basic science studies have not matched the frequency and duration of manual needle stimulation to the frequency and duration of electrical stimulation. Further, most clinical trials purporting to compare the two types of stimulation have instead tested electroacupuncture as an adjunct to manual acupuncture. The current findings reveal fundamental gaps in the understanding of the mechanisms and relative effectiveness of manual versus electrical acupuncture. Finally, future research directions are suggested to better differentiate electrical from manual simulation, and implications for clinical practice are discussed. PMID:25710206

  17. Poisson-process electrical stimulation: circuit and axonal responses.

    PubMed

    Moradmand, K; Goldfinger, M D

    1995-12-01

    This work describes a simple circuit which generated a highly Poisson-like sequence of pulses. Resistor noise was amplified in three series stages followed by rectification through a relatively large shunt resistance. This yielded a sequence of variable-amplitude transients, which were inverted, amplified with DC adjustment, and fed into a Schmitt trigger/multivibrator chip for pulse generation. The pulse generation frequency was modulated by the amplification of the rectified transients. The stochastic characteristics of the output pulse train were Poisson-like over a wide frequency range, as assessed using the intervent interval distribution and expectation density as steady-state and real-time estimators, respectively. In separate tests, the output pulse train was applied to forelimb cutaneous axons of the anesthetized cat; trains of elicited propagating action potentials were recorded extracellularly from individual G1 axons in the cuneate fasciculus. The stochastic properties of the action potential train differed from those of the stimulus, with longer deadtime, lower mean rate, and an early expectation density peak. These physiological responses to circuit output were similar to those elicited by other generators of Poisson-like stimulation. PMID:8788055

  18. Slow Calcium Signals after Tetanic Electrical Stimulation in Skeletal Myotubes

    PubMed Central

    Eltit, José M.; Hidalgo, Jorge; Liberona, José L.; Jaimovich, Enrique

    2004-01-01

    The fluorescent calcium signal from rat myotubes in culture was monitored after field-stimulation with tetanic protocols. After the calcium signal sensitive to ryanodine and associated to the excitation-contraction coupling, a second long-lasting calcium signal refractory to ryanodine was consistently found. The onset kinetics of this slow signal were slightly modified in nominally calcium-free medium, as were both the frequency and number of pulses during tetanus. No signal was detected in the presence of tetrodotoxin. The participation of the dihydropyridine receptor (DHPR) as the voltage sensor for this signal was assessed by treatment with agonist and antagonist dihydropyridines (Bay K 8644 and nifedipine), showing an enhanced and inhibitory response, respectively. In the dysgenic GLT cell line, which lacks the α1S subunit of the DHPR, the signal was absent. Transfection of these cells with the α1S subunit restored the slow signal. In myotubes, the inositol 1,4,5-trisphosphate (IP3) mass increase induced by a tetanus protocol preceded in time the slow calcium signal. Both an IP3 receptor blocker and a phospholipase C inhibitor (xestospongin C and U73122, respectively) dramatically inhibit this signal. Long-lasting, IP3-generated slow calcium signals appear to be a physiological response to activity-related fluctuations in membrane potential sensed by the DHPR. PMID:15111418

  19. Cell stimulation and calcium mobilization by picosecond electric pulses

    PubMed Central

    Semenov, Iurii; Xiao, Shu; Kang, Dongkoo; Schoenbach, Karl H.; Pakhomov, Andrei G.

    2015-01-01

    We tested if picosecond electric pulses (psEP; 190 kV/cm, 500 ps at 50% height), which are much shorter than channel activation time, can activate voltage-gated (VG) channels. Cytosolic Ca2+ was monitored by Fura-2 ratiometric imaging in GH3 and NG108 cells (which express multiple types of VG calcium channels, VGCC), and in CHO cells (which express no VGCC). Trains of up to 100 psEP at 1 kHz elicited no response in CHO cells. However, even a single psEP significantly increased Ca2+ in both GH3 (by 114+/−48 nM) and NG108 cells (by 6 +/−1.1 nM). Trains of 100 psEP amplified the response to 379+/−33 nM and 719+/−315 nM, respectively. Ca2+ responses peaked within 2–15 s and recovered for over 100 s; they were 80–100% inhibited by verapamil and ω-conotoxin, but not by the substitution of Na+ with N-methyl-D-glucamine. There was no response to psEP in Ca2+-free medium, but adding external Ca2+ even 10 s later evoked Ca2+ response. We conclude that electrical stimuli as short as 500 ps can cause long-lasting opening of VGCC by a mechanism which does not involve conventional electroporation, heating (which was under 0.06 °K per psEP), or membrane depolarization by opening of VG Na+ channels. PMID:26011130

  20. Cell stimulation and calcium mobilization by picosecond electric pulses.

    PubMed

    Semenov, Iurii; Xiao, Shu; Kang, Dongkoo; Schoenbach, Karl H; Pakhomov, Andrei G

    2015-10-01

    We tested if picosecond electric pulses (psEP; 190 kV/cm, 500 ps at 50% height), which are much shorter than channel activation time, can activate voltage-gated (VG) channels. Cytosolic Ca(2+) was monitored by Fura-2 ratiometric imaging in GH3 and NG108 cells (which express multiple types of VG calcium channels, VGCC), and in CHO cells (which express no VGCC). Trains of up to 100 psEP at 1 kHz elicited no response in CHO cells. However, even a single psEP significantly increased Ca(2+) in both GH3 (by 114 ± 48 nM) and NG108 cells (by 6 ± 1.1 nM). Trains of 100 psEP amplified the response to 379 ± 33 nM and 719 ± 315 nM, respectively. Ca(2+) responses peaked within 2-15s and recovered for over 100 s; they were 80-100% inhibited by verapamil and ω-conotoxin, but not by the substitution of Na(+) with N-methyl-D-glucamine. There was no response to psEP in Ca(2+)-free medium, but adding external Ca(2+) even 10s later evoked Ca(2+) response. We conclude that electrical stimuli as short as 500 ps can cause long-lasting opening of VGCC by a mechanism which does not involve conventional electroporation, heating (which was under 0.06 K per psEP), or membrane depolarization by opening of VG Na(+) channels.

  1. Mandarin Speech Perception in Combined Electric and Acoustic Stimulation

    PubMed Central

    Li, Yongxin; Zhang, Guoping; Galvin, John J.; Fu, Qian-Jie

    2014-01-01

    For deaf individuals with residual low-frequency acoustic hearing, combined use of a cochlear implant (CI) and hearing aid (HA) typically provides better speech understanding than with either device alone. Because of coarse spectral resolution, CIs do not provide fundamental frequency (F0) information that contributes to understanding of tonal languages such as Mandarin Chinese. The HA can provide good representation of F0 and, depending on the range of aided acoustic hearing, first and second formant (F1 and F2) information. In this study, Mandarin tone, vowel, and consonant recognition in quiet and noise was measured in 12 adult Mandarin-speaking bimodal listeners with the CI-only and with the CI+HA. Tone recognition was significantly better with the CI+HA in noise, but not in quiet. Vowel recognition was significantly better with the CI+HA in quiet, but not in noise. There was no significant difference in consonant recognition between the CI-only and the CI+HA in quiet or in noise. There was a wide range in bimodal benefit, with improvements often greater than 20 percentage points in some tests and conditions. The bimodal benefit was compared to CI subjects’ HA-aided pure-tone average (PTA) thresholds between 250 and 2000 Hz; subjects were divided into two groups: “better” PTA (<50 dB HL) or “poorer” PTA (>50 dB HL). The bimodal benefit differed significantly between groups only for consonant recognition. The bimodal benefit for tone recognition in quiet was significantly correlated with CI experience, suggesting that bimodal CI users learn to better combine low-frequency spectro-temporal information from acoustic hearing with temporal envelope information from electric hearing. Given the small number of subjects in this study (n = 12), further research with Chinese bimodal listeners may provide more information regarding the contribution of acoustic and electric hearing to tonal language perception. PMID:25386962

  2. EFFECTS OF NEONATAL PARTIAL DEAFNESS AND CHRONIC INTRACOCHLEAR ELECTRICAL STIMULATION ON AUDITORY AND ELECTRICAL RESPONSE CHARACTERISTICS IN PRIMARY AUDITORY CORTEX

    PubMed Central

    Fallon, James B; Shepherd, Robert K.; Brown, Mel; Irvine, Dexter, R. F.

    2009-01-01

    The use of cochlear implants in patients with severe hearing losses but residual low-frequency hearing raises questions concerning the effects of chronic intracochlear electrical stimulation(ICES) on cortical responses to auditory and electrical stimuli. We investigated these questions by studying responses to tonal and electrical stimuli in primary auditory cortex (AI) of two groups of neonatally-deafened cats with residual high-threshold, low-frequency hearing. One group were implanted with a multi-channel intracochlear electrode at eight weeks of age, and received chronic ICES for up to nine months before cortical recording. Cats in the other group were implanted immediately prior to cortical recording as adults. In all cats in both groups, multi-neuron responses throughout the rostro-caudal extent of AI had low characteristic frequencies (CFs), in the frequency range of the residual hearing, and high-thresholds. Threshold and minimum latency at CF did not differ between the groups, but in the chronic ICES animals there was a higher proportion of electrically but not acoustically excited recording sites. Electrical response thresholds were higher and latencies shorter in the chronically stimulated animals. Thus, chronic implantation and ICES affected the extent of AI that could be activated by acoustic stimuli and resulted in changes in electrical response characteristics. PMID:19703532

  3. Using evoked EMG as a synthetic force sensor of isometric electrically stimulated muscle.

    PubMed

    Erfanian, A; Chizeck, H J; Hashemi, R M

    1998-02-01

    A method for the estimation of the force generated by electrically stimulated muscle during isometric contraction is developed here. It is based upon measurements of the evoked electromyogram (EMG) [EEMG] signal. Muscle stimulation is provided to the quadriceps muscle of a paralyzed human subject using percutaneous intramuscular electrodes, and EEMG signals are collected using surface electrodes. Through the use of novel signal acquisition and processing techniques, as well as a mathematical model that reflects both the excitation and activation phenomena involved in isometric muscle force generation, accurate prediction of stimulated muscle forces is obtained for large time horizons. This approach yields synthetic muscle force estimates for both unfatigued and fatigued states of the stimulated muscle. In addition, a method is developed that accomplishes automatic recalibration of the model to account for day-to-day changes in pickup electrode mounting as well as other factors contributing to EEMG gain variations. It is demonstrated that the use of the measured EEMG as the input to a predictive model of muscle torque generation is superior to the use of the electrical stimulation signal as the model input. This is because the measured EEMG signal captures all of the neural excitation, whereas stimulation-to-torque models only reflect that portion of the neural excitation that results directly from stimulation. The time-varying properties of the excitation process cannot be captured by existing stimulation-to-torque models, but they are tracked by the EEMG-to-torque models that are developed here. This work represents a promising approach to the real-time estimation of stimulated muscle force in functional neuromuscular stimulation applications.

  4. Short latency vestibular potentials evoked by electrical round window stimulation in the guinea pig.

    PubMed

    Bordure, P; Desmadryl, G; Uziel, A; Sans, A

    1989-11-01

    Short-latency potentials evoked by round window electrical stimulation were recorded in guinea pig by means of vertex-pinna skin electrodes using averaging techniques. Constant current shocks of 20 microseconds or 50 microseconds (25-300 microA) were used to evoke both auditory and vestibular brain-stem potentials. Pure auditory potentials, comparable to those evoked by acoustic clicks, were obtained by 20 microseconds electrical stimuli and disappeared during an auditory masking procedure made with a continuous white noise (110 dB SPL). Short latency potentials labeled V1, V2 and V3 were obtained by 50 microseconds electrical stimuli during an auditory masking procedure. This response disappeared after specific vestibular neurectomy, whereas the auditory response evoked by acoustic clicks or by electrical stimulation remained unchanged, suggesting that these latter potentials had a vestibular origin.

  5. Enhancement of bacterial denitrification for nitrate removal in groundwater with electrical stimulation from microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Zhang, Baogang; Liu, Ye; Tong, Shuang; Zheng, Maosheng; Zhao, Yinxin; Tian, Caixing; Liu, Hengyuan; Feng, Chuanping

    2014-12-01

    Electricity generated from the microbial fuel cell (MFC) is applied to the bioelectrical reactor (BER) directly as electrical stimulation means for enhancement of bacterial denitrification to remove nitrate effectively from groundwater. With maximum power density of 502.5 mW m-2 and voltage outputs ranging from 500 mV to 700 mV, the nitrate removal is accelerated, with less intermediates accumulation, compared with control sets without electrical stimulation. Denitrification bacteria proliferations and activities are promoted as its number and Adenosine-5'-triphosphate (ATP) concentration increased one order of magnitude (3.5 × 107 in per milliliter biofilm solution) and about 1.5 folds, respectively. Effects of electricity from MFCs on enhancement of bacterial behaviors are demonstrated for the first time. These results indicate that MFCs can be applied in the in-situ bioremediation of nitrate polluted groundwater for efficiency improvement.

  6. Short latency vestibular potentials evoked by electrical round window stimulation in the guinea pig.

    PubMed

    Bordure, P; Desmadryl, G; Uziel, A; Sans, A

    1989-11-01

    Short-latency potentials evoked by round window electrical stimulation were recorded in guinea pig by means of vertex-pinna skin electrodes using averaging techniques. Constant current shocks of 20 microseconds or 50 microseconds (25-300 microA) were used to evoke both auditory and vestibular brain-stem potentials. Pure auditory potentials, comparable to those evoked by acoustic clicks, were obtained by 20 microseconds electrical stimuli and disappeared during an auditory masking procedure made with a continuous white noise (110 dB SPL). Short latency potentials labeled V1, V2 and V3 were obtained by 50 microseconds electrical stimuli during an auditory masking procedure. This response disappeared after specific vestibular neurectomy, whereas the auditory response evoked by acoustic clicks or by electrical stimulation remained unchanged, suggesting that these latter potentials had a vestibular origin. PMID:2479525

  7. Differential fiber-specific block of nerve conduction in mammalian peripheral nerves using kilohertz electrical stimulation

    PubMed Central

    Patel, Yogi A.

    2015-01-01

    Kilohertz electrical stimulation (KES) has been shown to induce repeatable and reversible nerve conduction block in animal models. In this study, we characterized the ability of KES stimuli to selectively block specific components of stimulated nerve activity using in vivo preparations of the rat sciatic and vagus nerves. KES stimuli in the frequency range of 5–70 kHz and amplitudes of 0.1–3.0 mA were applied. Compound action potentials were evoked using either electrical or sensory stimulation, and block of components was assessed through direct nerve recordings and muscle force measurements. Distinct observable components of the compound action potential had unique conduction block thresholds as a function of frequency of KES. The fast component, which includes motor activity, had a monotonically increasing block threshold as a function of the KES frequency. The slow component, which includes sensory activity, showed a nonmonotonic block threshold relationship with increasing KES frequency. The distinct trends with frequency of the two components enabled selective block of one component with an appropriate choice of frequency and amplitude. These trends in threshold of the two components were similar when studying electrical stimulation and responses of the sciatic nerve, electrical stimulation and responses of the vagus nerve, and sensorimotor stimulation and responses of the sciatic nerve. This differential blocking effect of KES on specific fibers can extend the applications of KES conduction block to selective block and stimulation of neural signals for neuromodulation as well as selective control of neural circuits underlying sensorimotor function. PMID:25878155

  8. Electrical Stimulation via a Biocompatible Conductive Polymer Directs Retinal Progenitor Cell Differentiation

    PubMed Central

    Saigal, Rajiv; Cimetta, Elisa; Tandon, Nina; Zhou, Jing; Langer, Robert; Young, Michael

    2015-01-01

    The goal of this study was to simulate in vitro the spontaneous electrical wave activity associated with retinal development and investigate if such biometrically designed signals can enhance differentiation of mouse retinal progenitor cells (mRPC). To this end, we cultured cells on an electroconductive transplantable polymer, polypyrrole (PPy) and measured gene expression and morphology of the cells. Custom-made 8-well cell culture chambers were designed to accommodate PPy deposited onto indium tin oxide-coated (ITO) glass slides, with precise control of the PPy film thickness. mRPCs were isolated from post-natal day 1 (P1) green fluorescent protein positive (GFP+) mice, expanded, seeded onto PPY films, allowed to adhere for 24 hours, and then subjected to electrical stimulation (100 μA pulse trains, 5 s in duration, once per minute) for 4 days. Cultured cells and non-stimulated controls were processed for immunostaining and confocal analysis, and for RNA extraction and quantitative PCR. Stimulated cells expressed significantly higher levels of the early photoreceptor marker cone-rod homebox (CRX, the earliest known marker of photoreceptor identity), and protein kinase-C (PKC), and significantly lower levels of the glial fibrillary acidic protein (GFAP). Consistently, stimulated cells developed pronounced neuronal morphologies with significantly longer dendritic processes and larger cell bodies than non-stimulated controls. Taken together, the experimental evidence shows that the application of an electrical stimulation designed based on retinal development can be implemented to direct and enhance retinal differentiation of mRPCs, suggesting a role for biomimetic electrical stimulation in directing progenitor cells toward neural fates. PMID:24110015

  9. 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

  10. Influence of transcutaneous electrical stimulation on heterotopic ossification: an experimental study in Wistar rats.

    PubMed

    Zotz, T G G; Paula, J B de

    2015-11-01

    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.

  11. Electrical stimulation accelerates and enhances expression of regeneration-associated genes in regenerating rat femoral motoneurons.

    PubMed

    Al-Majed, Abdulhakeem A; Tam, Siu Lin; Gordon, Tessa

    2004-06-01

    1. In this study we investigated whether electrical stimulation accelerates the upregulation of Talpha1-tubulin and GAP-43 (regeneration-associated genes; RAGs) and the downregulation of the medium-molecular-weight neurofilament (NFM), in concert with stimulation-induced acceleration of BDNF and trkB gene expression and axonal regeneration. 2. Two weeks prior to unilateral femoral nerve transection and suture, fluorogold (Fluorochrome Inc., Denver) or fluororuby (Dextran tetramethylrhodamine, Mol. Probes, D-1817, Eugene, OR) was injected into quadriceps muscles of the left and right hindlimbs to label the femoral motoneuron pools as previously described. Over a period of 7 days, fresh spinal cords were processed for semiquantitation of mRNA by using in situ hybridization. 3. There was an increase in Talpha1-tubulin and GAP-43 mRNA and a decline in the NFM mRNA at 7 days after nerve suture and sham stimulation but not in intact nerves. In contrast, 1-h stimulation of sutured but not intact nerves dramatically accelerated the changes in gene expression: mRNA levels of Talpha1-tubulin and GAP-43 were significantly elevated above control levels by 2 days while NFM mRNA was significantly reduced by 2 days in the sutured nerves. Thereby, the neurofilament/tubulin expression ratio was reduced at 2 days after suture and stimulation, possibly allowing more tubulin to be transported faster into the growing axons to accelerate the elongation rate following stimulation. Importantly, the changes in RAGs and NFM gene expression were delayed relative to the accelerated upregulation of BDNF and trkB mRNA by electrical stimulation. 4. The temporal sequence of upregulation of BDNF and trkB, altered gene expression of RAGs and NFM, and accelerated axonal outgrowth from the proximal nerve stump are consistent with a key role of BDNF and trkB in mediating the altered expression of RAGs and, in turn, the promotion of axonal outgrowth after electrical stimulation.

  12. 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.

  13. 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.

  14. 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. PMID:27006422

  15. Successful Treatment of Dercum's Disease by Transcutaneous Electrical Stimulation

    PubMed Central

    Martinenghi, Sabina; Caretto, Amelia; Losio, Claudio; Scavini, Marina; Bosi, Emanuele

    2015-01-01

    Abstract Dercum's disease is a rare condition of painful subcutaneous growth of adipose tissue. Etiology is unknown and pain is difficult to control. We report the case of a 57-year-old man with generalized diffuse Dercum's disease, who improved after the treatment with transcutaneous frequency rhythmic electrical modulation system (FREMS). Treatment consisted in 4 cycles of 30 minutes FREMS sessions over a 6-month period. Measures of efficacy included pain assessment (visual analogue scale, VAS), adipose tissue thickness by magnetic resonance imaging, total body composition and regional fat mass by dual-energy X-ray absorptiometry, physical disability (Barthel index), and health status (Short Form-36 questionnaire). After FREMS treatment the patient's clinical conditions significantly improved, with reduction of pain on the VAS scale from 64 to 17 points, improvement of daily life abilities (the Barthel index increased from 12 to 18) and amelioration of health status (higher scores than baseline in all Short Form-36 domains). Furthermore, we documented a 12 mm reduction in subcutaneous adipose tissue thickness at the abdominal wall and a 7040 g decrease in total body fat mass. FREMS therapy proved to be effective and safe in the treatment of this rare and disabling condition.

  16. Successful Treatment of Dercum's Disease by Transcutaneous Electrical Stimulation

    PubMed Central

    Martinenghi, Sabina; Caretto, Amelia; Losio, Claudio; Scavini, Marina; Bosi, Emanuele

    2015-01-01

    Abstract Dercum's disease is a rare condition of painful subcutaneous growth of adipose tissue. Etiology is unknown and pain is difficult to control. We report the case of a 57-year-old man with generalized diffuse Dercum's disease, who improved after the treatment with transcutaneous frequency rhythmic electrical modulation system (FREMS). Treatment consisted in 4 cycles of 30 minutes FREMS sessions over a 6-month period. Measures of efficacy included pain assessment (visual analogue scale, VAS), adipose tissue thickness by magnetic resonance imaging, total body composition and regional fat mass by dual-energy X-ray absorptiometry, physical disability (Barthel index), and health status (Short Form-36 questionnaire). After FREMS treatment the patient's clinical conditions significantly improved, with reduction of pain on the VAS scale from 64 to 17 points, improvement of daily life abilities (the Barthel index increased from 12 to 18) and amelioration of health status (higher scores than baseline in all Short Form-36 domains). Furthermore, we documented a 12 mm reduction in subcutaneous adipose tissue thickness at the abdominal wall and a 7040 g decrease in total body fat mass. FREMS therapy proved to be effective and safe in the treatment of this rare and disabling condition. PMID:26091459

  17. Effect of stimulation parameters on electrically evoked auditory brainstem responses.

    PubMed

    Tavartkiladze, G A; Potalova, L A; Kruglov, A V; Belov, A

    2000-03-01

    It is evident that the conventional technique for cochlear implant adjustment is not suitable for children in their first years of life. In order to find a solution to this problem, the possibility of electrically evoked auditory brainstem response (EABR) recording was investigated. EABRs were recorded in 9 patients with the Nucleus multichannel cochlear implant. The main problems that have to be solved during EABR recording in cochlear implantees are: i) EABR distortion due to the stimulus artefact: and ii) difference in the stimulus presentation rate during EABR registration (low pulse rate) and conventional psychophysical threshold estimation (high pulse rate) in cochlear implant patients. The influence of stimulus artefact on the recording results was minimized by setting the implant to the widest amplifier frequency band and by zeroing the initial segment containing the stimulus artefact with subsequent zero-phase digital filtering. The dependence of the EABR amplitude and latency on the stimulus intensity, width, electrode location and interstimulus interval was investigated. It was concluded that despite the difference revealed between absolute values of EABR thresholds and psychophysical threshold levels, it is possible to calculate implant adjustment parameters based on the EABR data with the proper correction applied. PMID:11603775

  18. Electrical stimulation of cardiac adipose tissue-derived progenitor cells modulates cell phenotype and genetic machinery.

    PubMed

    Llucià-Valldeperas, A; Sanchez, B; Soler-Botija, C; Gálvez-Montón, C; Prat-Vidal, C; Roura, S; Rosell-Ferrer, J; Bragos, R; Bayes-Genis, A

    2015-11-01

    A major challenge of cardiac tissue engineering is directing cells to establish the physiological structure and function of the myocardium being replaced. Our aim was to examine the effect of electrical stimulation on the cardiodifferentiation potential of cardiac adipose tissue-derived progenitor cells (cardiac ATDPCs). Three different electrical stimulation protocols were tested; the selected protocol consisted of 2 ms monophasic square-wave pulses of 50 mV/cm at 1 Hz over 14 days. Cardiac and subcutaneous ATDPCs were grown on biocompatible patterned surfaces. Cardiomyogenic differentiation was examined by real-time PCR and immunocytofluorescence. In cardiac ATDPCs, MEF2A and GATA-4 were significantly upregulated at day 14 after stimulation, while subcutaneous ATDPCs only exhibited increased Cx43 expression. In response to electrical stimulation, cardiac ATDPCs elongated, and both cardiac and subcutaneous ATDPCs became aligned following the linear surface pattern of the construct. Cardiac ATDPC length increased by 11.3%, while subcutaneous ATDPC length diminished by 11.2% (p = 0.013 and p = 0.030 vs unstimulated controls, respectively). Compared to controls, electrostimulated cells became aligned better to the patterned surfaces when the pattern was perpendicular to the electric field (89.71 ± 28.47º for cardiac ATDPCs and 92.15 ± 15.21º for subcutaneous ATDPCs). Electrical stimulation of cardiac ATDPCs caused changes in cell phenotype and genetic machinery, making them more suitable for cardiac regeneration approaches. Thus, it seems advisable to use electrical cell training before delivery as a cell suspension or within engineered tissue.

  19. Electrical stimulation of the insular region attenuates nicotine-taking and nicotine-seeking behaviors.

    PubMed

    Pushparaj, Abhiram; Hamani, Clement; Yu, Wilson; Shin, Damian S; Kang, Bin; Nobrega, José N; Le Foll, Bernard

    2013-03-01

    Pharmacological inactivation of the granular insular cortex is able to block nicotine-taking and -seeking behaviors in rats. In this study, we explored the potential of modulating activity in the insular region using electrical stimulation. Animals were trained to self-administer nicotine (0.03 mg/kg per infusion) under a fixed ratio-5 (FR-5) schedule of reinforcement followed by a progressive ratio (PR) schedule. Evaluation of the effect of stimulation in the insular region was performed on nicotine self-administration under FR-5 and PR schedules, as well on reinstatement of nicotine-seeking behavior induced by nicotine-associated cues or nicotine-priming injections. The effect of stimulation was also examined in brain slices containing insular neurons. Stimulation significantly attenuated nicotine-taking, under both schedules of reinforcement, as well as nicotine-seeking behavior induced by cues and priming. These effects appear to be specific to nicotine-associated behaviors, as stimulation did not have any effect on food-taking behavior. They appear to be anatomically specific, as stimulation surrounding the insular region had no effect on behavior. Stimulation of brain slices containing the insular region was found to inactivate insular neurons. Our results suggest that deep brain stimulation to modulate insular activity should be further explored. PMID:23249816

  20. Automatic electrical stimulation of abdominal wall muscles increases tidal volume and cough peak flow in tetraplegia.

    PubMed

    Gollee, H; Hunt, K J; Allan, D B; Fraser, M H; McLean, A N

    2008-01-01

    Paralysis of the respiratory muscles in people with tetraplegia affects their ability to breathe and contributes to respiratory complications. Surface functional electrical stimulation (FES) of abdominal wall muscles can be used to increase tidal volume (V_{T}) and improve cough peak flow (CPF) in tetraplegic subjects who are able to breathe spontaneously. This study aims to evaluate the feasibility and effectiveness of a novel abdominal FES system which generates stimulation automatically, synchronised with the subjects' voluntary breathing activity. Four subjects with complete tetraplegia (C4-C6), breathing spontaneously, were recruited. The automatic stimulation system ensured that consistent stimulation was achieved. We compared spirometry during unassisted and FES-assisted quiet breathing and coughing, and measured the effect of stimulation on end-tidal CO_2 (EtCO_2) during quiet breathing. The system dependably recognised spontaneous respiratory effort, stimulating appropriately, and was well tolerated by patients. Significant increases in V_T during quiet breathing (range 0.05-0.23 L) and in CPF (range 0.04-0.49 L/s) were observed. Respiratory rate during quiet breathing decreased in all subjects when stimulated, whereas minute ventilation increased by 1.05-2.07 L/min. The changes in EtCO_2 were inconclusive. The automatic stimulation system augmented spontaneous breathing and coughing in tetraplegic patients and may provide a potential means of respiratory support for tetraplegic patients with reduced respiratory capacity.

  1. Aligned Nanofibers from Polypyrrole/Graphene as Electrodes for Regeneration of Optic Nerve via Electrical Stimulation.

    PubMed

    Yan, Lu; Zhao, Bingxin; Liu, Xiaohong; Li, Xuan; Zeng, Chao; Shi, Haiyan; Xu, Xiaoxue; Lin, Tong; Dai, Liming; Liu, Yong

    2016-03-23

    The damage of optic nerve will cause permanent visual field loss and irreversible ocular diseases, such as glaucoma. The damage of optic nerve is mainly derived from the atrophy, apoptosis or death of retinal ganglion cells (RGCs). Though some progress has been achieved on electronic retinal implants that can electrically stimulate undamaged parts of RGCs or retina to transfer signals, stimulated self-repair/regeneration of RGCs has not been realized yet. The key challenge for development of electrically stimulated regeneration of RGCs is the selection of stimulation electrodes with a sufficient safe charge injection limit (Q(inj), i.e., electrochemical capacitance). Most traditional electrodes tend to have low Q(inj) values. Herein, we synthesized polypyrrole functionalized graphene (PPy-G) via a facile but efficient polymerization-enhanced ball milling method for the first time. This technique could not only efficiently introduce electron-acceptor nitrogen to enhance capacitance, but also remain a conductive platform-the π-π conjugated carbon plane for charge transportation. PPy-G based aligned nanofibers were subsequently fabricated for guided growth and electrical stimulation (ES) of RGCs. Significantly enhanced viability, neurite outgrowth and antiaging ability of RGCs were observed after ES, suggesting possibilities for regeneration of optic nerve via ES on the suitable nanoelectrodes. PMID:26926578

  2. [Morphologic basis for electric stimulation therapy of the vastus medialis and vastus lateralis muscles].

    PubMed

    Chomiak, J

    1993-01-01

    Based on knowledge of the pattern of motorend plates in the m. vastus medialis (VM) and lateralis (VL), the author investigated the electrically most excitable sites which can be used in standard procedures of transcutaneous electric stimulation in muscular hypotrophy. The investigation was made in 21 patients, most of them after a reconstruction of the anterior cruciate ligament and one healthy adult. For stimulation and recording of potentials the EMG device Neuromatic 2000 C (Dantec, Scovlunde, Denmark) was used. First by means of a needle electrode the zone of motorend plates was verified. Then the minimal intensities causing muscular contraction and equal amplitude were compared during stimulation of the zone of motorend plates and 2.5 proximal and distal from the zone. The potentials were recorded by means of surface electrodes from distal portions of the muscle bellies. In five patients automatic RTI 50 analysis according to Brismar was used as well as monopolar stimulation where the cathode was placed at different sites above the muscle belly and the anode above the proximal margin of the muscle. The results of evaluation of minimal stimulation intensities of both muscles revealed significantly lowest values during stimulation of the zone of motorend plates (mean VM 8.5 mA, VL 9.9 mA) followed by intensities on stimulation proximally from the zone (VM 18.2 mA, VL 17.5 mA) and the highest intensities were recorded on stimulation of the distal part of the muscle (VM 21.2 mA, VL 25.8 mA). Similarly the results of RTI 50 analysis and monopolar stimulation provide evidence of maximal excitability in the area of the motorend plate zone.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Self directed home based electrical muscle stimulation training improves exercise tolerance and strength in healthy elderly.

    PubMed

    Caulfield, Brian; Prendergast, Ann; Rainsford, Gary; Minogue, Conor

    2013-01-01

    Advancing age is associated with a gradual decline in muscle strength, exercise tolerance and subsequent capacity for activities of daily living. It is important that we develop effective strategies to halt this process of gradual decline in order to enhance functional ability and capacity for independent living. To achieve this, we must overcome the challenge of sustaining ongoing engagement in physical exercise programmes in the sedentary elderly population, particularly those who experience barriers to exercise participation. Recent developments in electrical muscle stimulation technology could provide a potential solution. In this pilot case-control study we investigated the effects of a self-directed home based programme of electrical muscle stimulation training on muscle strength and exercise tolerance in a group of 16 healthy elderly volunteers (10f, 6m). Study participants completed 30 separate 1-hour electrical muscle stimulation sessions at home over a 6-week period. We observed significant improvements in quadriceps muscle strength and 6-minute walk distance, suggesting that this form of electrical muscle stimulation training has promise as an exercise modality in the elderly population.

  4. 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…

  5. 42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Special payment rules for transcutaneous electrical nerve stimulators (TENS). 414.232 Section 414.232 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM PAYMENT FOR PART B MEDICAL AND OTHER HEALTH SERVICES Payment for...

  6. Intensity discrimination as a function of stimulus level with electric stimulation.

    PubMed

    Nelson, D A; Schmitz, J L; Donaldson, G S; Viemeister, N F; Javel, E

    1996-10-01

    Difference limens (DLs) for changes in electric current were measured from multiple electrodes in each of eight cochlear-implanted subjects. Stimuli were 200-microseconds/phase biphasic pulse trains delivered at 125 Hz in 300-ms bursts. DLs were measured with an adaptive three-alternative forced-choice procedure. Fixed-level psychometric functions were also obtained in four subjects to validate the adaptive DLs. Relative intensity DLs, specified as Weber fractions in decibels [10 log (delta I/I)] for standards above absolute threshold, decreased as a power function of stimulus intensity relative to absolute threshold [delta I/I = beta (I/I0) alpha] in the same manner as Weber fractions for normal acoustic stimulation reported in previous studies. Exponents (alpha) of the power function for electric stimulation ranged from -0.4 to -3.2, on average, an order of magnitude larger than exponents for acoustic stimulation, which range from -0.07 to -0.11. Normalization of stimulus intensity to the dynamic range of hearing resulted in Weber functions with similar negative slopes for electric and acoustic stimulation, corresponding to an 8-dB average improvement in Weber fractions across the dynamic range. Sensitivity to intensity change ¿10 log beta¿ varied from -0.42 to -13.5 dB compared to +0.60 to -3.34 dB for acoustic stimulation, but on average was better with electric stimulation than with acoustic stimulation. Psychometric functions for intensity discrimination yielded Weber fractions consistent with adaptive procedures and d' was a linear function of delta I. Variability among repeated Weber-fraction estimates was constant across dynamic range. Relatively constant Weber fractions across all or part of the dynamic range, observed in some subjects, were traced to the intensity resolution limits of individual implanted receiver/stimulators. DLs could not be accurately described by constant amplitude changes, expressed as a percentage of dynamic range ¿delta A(% DR

  7. A preparation for studying electrical stimulation of the retina in vivo in rat.

    PubMed

    Baig-Silva, M S; Hathcock, C D; Hetling, J R

    2005-03-01

    A remaining challenge to the development of electronic prostheses for vision is improving the effectiveness of retinal stimulation. Electrode design and stimulus parameters need to be optimized such that the neural output from the retina conveys information to the mind's eye that aids the patient in interpreting his or her environment. This optimization will require a detailed understanding of the response of the retina to electrical stimulation. The identity and response characteristics of the cellular targets of stimulation need to be defined and evaluated. Described here is an in vivo preparation for studying electrical stimulation of the retina in rat at the cellular level. The use of rat makes available a number of well-described models of retinal disease that motivate prosthesis development. Artificial stimulation can be investigated by adapting techniques traditionally employed to study the response of the retina to photic stimuli, such as recording at the cornea, single-cell recording, and pharmacological dissection of the response. Pilot studies include amplitude-intensity response data for subretinal and transretinal stimulation paradigms recorded in wild-type rats and a transgenic rat model of autosomal dominant retinitis pigmentosa. The ability to record single-unit ganglion cell activity in vivo is also demonstrated.

  8. Repeated electrical stimulation of reward-related brain regions affects cocaine but not "natural" reinforcement.

    PubMed

    Levy, Dino; Shabat-Simon, Maytal; Shalev, Uri; Barnea-Ygael, Noam; Cooper, Ayelet; Zangen, Abraham

    2007-12-19

    Drug addiction is associated with long-lasting neuronal adaptations including alterations in dopamine and glutamate receptors in the brain reward system. Treatment strategies for cocaine addiction and especially the prevention of craving and relapse are limited, and their effectiveness is still questionable. We hypothesized that repeated stimulation of the brain reward system can induce localized neuronal adaptations that may either potentiate or reduce addictive behaviors. The present study was designed to test how repeated interference with the brain reward system using localized electrical stimulation of the medial forebrain bundle at the lateral hypothalamus (LH) or the prefrontal cortex (PFC) affects cocaine addiction-associated behaviors and some of the neuronal adaptations induced by repeated exposure to cocaine. Repeated high-frequency stimulation in either site influenced cocaine, but not sucrose reward-related behaviors. Stimulation of the LH reduced cue-induced seeking behavior, whereas stimulation of the PFC reduced both cocaine-seeking behavior and the motivation for its consumption. The behavioral findings were accompanied by glutamate receptor subtype alterations in the nucleus accumbens and the ventral tegmental area, both key structures of the reward system. It is therefore suggested that repeated electrical stimulation of the PFC can become a novel strategy for treating addiction. PMID:18094257

  9. Cell-stimulation therapy of lateral epicondylitis with frequency-modulated low-intensity electric current.

    PubMed

    Aliyev, R M; Geiger, G

    2012-03-01

    In addition to the routine therapy, the patients with lateral epicondylitis included into experimental group were subjected to a 12-week cell-stimulation therapy with low-intensity frequency-modulated electric current. The control group received the same routine therapy and sham stimulation (the therapeutic apparatus was not energized). The efficiency of this microcurrent therapy was estimated by comparing medical indices before therapy and at the end of a 12-week therapeutic course using a 10-point pain severity numeric rating scale (NRS) and Roles-Maudsley pain score. The study revealed high therapeutic efficiency of cell-stimulation with low-intensity electric current resulting probably from up-regulation of intracellular transmitters, interleukins, and prostaglandins playing the key role in the regulation of inflammation.

  10. Seizures induced by direct electrical cortical stimulation--Mechanisms and clinical considerations.

    PubMed

    Kovac, Stjepana; Kahane, Philippe; Diehl, Beate

    2016-01-01

    Direct electrical cortical stimulation (CS) is widely used to map eloquent cortex. It can be applied extraoperatively in patients undergoing intracranial EEG recordings using chronically implanted electrodes (subdural, depth or a combination), or it can be used intraoperatively. Seizures can be induced by CS but there is controversy regarding the utility of CS induced seizures in defining the epileptogenic zone and hence practice varies considerably between centres. Some centres use seizures induced by direct CS routinely to aid in defining the epileptogenic zone. In contrast, others do not rely on such information and explicitly avoid stimulating seizures during cortical mapping. Intra- and extraoperative techniques have been used to stimulate seizures with varying results, which may in part reflect these methodological differences. We here aim to review current views, definitions and studies on seizures induced by direct electrical CS. In addition we discuss mechanisms and methodological considerations of this procedure. PMID:25613034

  11. [Real-time Gait Training System with Embedded Functional Electrical Stimulation].

    PubMed

    Gu, Linyan; Ruan, Zhaomin; Jia, Guifeng; Xla, Jing; Qiu, Lijian; Wu, Changwang; Jin, Xiaoqing; Ning, Gangmin

    2015-07-01

    To solve the problem that mostly gait analysis is independent from the treatment, this work proposes a system that integrates the functions of gait training and assessment for foot drop treatment. The system uses a set of sensors to collect gait parameters and designes multi-mode functional electrical stimulators as actuator. Body area network technology is introduced to coordinate the data communication and execution of the sensors and stimulators, synchronize the gait analysis and foot drop treatment. Bluetooth 4.0 is applied to low the power consumption of the system. The system realizes the synchronization of treatment and gait analysis. It is able to acquire and analyze the dynamic parameters of ankle, knee and hip in real-time, and treat patients by guiding functional electrical stimulation delivery to the specific body locations of patients. PMID:26665943

  12. The effects of bilateral electric and bimodal electric--acoustic stimulation on language development.

    PubMed

    Nittrouer, Susan; Chapman, Christopher

    2009-09-01

    There is no doubt that cochlear implants have improved the spoken language abilities of children with hearing loss, but delays persist. Consequently, it is imperative that new treatment options be explored. This study evaluated one aspect of treatment that might be modified, that having to do with bilateral implants and bimodal stimulation. A total of 58 children with at least one implant were tested at 42 months of age on four language measures spanning a continuum from basic to generative in nature. When children were grouped by the kind of stimulation they had at 42 months (one implant, bilateral implants, or bimodal stimulation), no differences across groups were observed. This was true even when groups were constrained to only children who had at least 12 months to acclimatize to their stimulation configuration. However, when children were grouped according to whether or not they had spent any time with bimodal stimulation (either consistently since their first implant or as an interlude to receiving a second) advantages were found for children who had some bimodal experience, but those advantages were restricted to language abilities that are generative in nature. Thus, previously reported benefits of simultaneous bilateral implantation early in a child's life may not extend to generative language. In fact, children may benefit from a period of bimodal stimulation early in childhood because low-frequency speech signals provide prosody and serve as an aid in learning how to perceptually organize the signal that is received through a cochlear implant. PMID:19713210

  13. The effects of bilateral electric and bimodal electric--acoustic stimulation on language development.

    PubMed

    Nittrouer, Susan; Chapman, Christopher

    2009-09-01

    There is no doubt that cochlear implants have improved the spoken language abilities of children with hearing loss, but delays persist. Consequently, it is imperative that new treatment options be explored. This study evaluated one aspect of treatment that might be modified, that having to do with bilateral implants and bimodal stimulation. A total of 58 children with at least one implant were tested at 42 months of age on four language measures spanning a continuum from basic to generative in nature. When children were grouped by the kind of stimulation they had at 42 months (one implant, bilateral implants, or bimodal stimulation), no differences across groups were observed. This was true even when groups were constrained to only children who had at least 12 months to acclimatize to their stimulation configuration. However, when children were grouped according to whether or not they had spent any time with bimodal stimulation (either consistently since their first implant or as an interlude to receiving a second) advantages were found for children who had some bimodal experience, but those advantages were restricted to language abilities that are generative in nature. Thus, previously reported benefits of simultaneous bilateral implantation early in a child's life may not extend to generative language. In fact, children may benefit from a period of bimodal stimulation early in childhood because low-frequency speech signals provide prosody and serve as an aid in learning how to perceptually organize the signal that is received through a cochlear implant.

  14. 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

  15. Cerebellar and Spinal Direct Current Stimulation in Children: Computational Modeling of the Induced Electric Field

    PubMed Central

    Fiocchi, Serena; Ravazzani, Paolo; Priori, Alberto; Parazzini, Marta

    2016-01-01

    Recent studies have shown that the specific application of transcranial direct current stimulation (tDCS) over the cerebellum can modulate cerebellar activity. In parallel, transcutaneous spinal DC stimulation (tsDCS) was found to be able to modulate conduction along the spinal cord and spinal cord functions. Of particular interest is the possible use of these techniques in pediatric age, since many pathologies and injuries, which affect the cerebellar cortex as well as spinal cord circuits, are diffuse in adults as well as in children. Up to now, experimental studies of cerebellar and spinal DC stimulation on children are completely missing and therefore there is a lack of information about the safety of this technique as well as the appropriate dose to be used during the treatment. Therefore, the knowledge of electric quantities induced into the cerebellum and over the spinal cord during cerebellar tDCS and tsDCS, respectively, is required. This work attempts to address this issue by estimating through computational techniques, the electric field distributions induced in the target tissues during the two stimulation techniques applied to different models of children of various ages and gender. In detail, we used four voxel child models, aged between 5- and 8-years. Results revealed that, despite inter-individual differences, the cerebellum is the structure mainly involved by cerebellar tDCS, whereas the electric field generated by tsDCS can reach the spinal cord also in children. Moreover, it was found that there is a considerable spread toward the anterior area of the cerebellum and the brainstem region for cerebellar tDCS and in the spinal nerve for spinal direct current stimulation. Our study therefore predicts that the electric field spreads in complex patterns that strongly depend on individual anatomy, thus giving further insight into safety issues and informing data for pediatric investigations of these stimulation techniques. PMID:27799905

  16. 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. PMID:25409523

  17. Electrical stimulation of the midbrain increases heart rate and arterial blood pressure in awake humans

    PubMed Central

    Thornton, Judith M; Aziz, Tipu; Schlugman, David; Paterson, David J

    2002-01-01

    Electrical stimulation of the hypothalamus, basal ganglia or pedunculopontine nucleus in decorticate animals results in locomotion and a cardiorespiratory response resembling that seen during exercise. This has led to the hypothesis that parallel activation of cardiorespiratory and locomotor systems from the midbrain could form part of the ‘central command’ mechanism of exercise. However, the degree to which subcortical structures play a role in cardiovascular activation in awake humans has not been established. We studied the effects on heart rate (HR) and mean arterial blood pressure (MAP) of electrically stimulating the thalamus and basal ganglia in awake humans undergoing neurosurgery for movement disorders (n = 13 Parkinson's disease, n = 1 myoclonic dystonia, n = 1 spasmodic torticollis). HR and MAP increased during high frequency (> 90 Hz) electrical stimulation of the thalamus (HR 5 ± 3 beats min−1, P = 0.002, MAP 4 ± 3 mmHg, P = 0.05, n = 9), subthalamic nucleus (HR 5 ± 3 beats min−1, P = 0.002, MAP 5 ± 3 mmHg, P = 0.006, n = 8) or substantia nigra (HR 6 ± 3 beats min−1, P = 0.001, MAP 5 ± 2 mmHg, P = 0.005, n = 8). This was accompanied by the facilitation of movement, but without the movement itself. Stimulation of the internal globus pallidus did not increase cardiovascular variables but did facilitate movement. Low frequency (< 20 Hz) stimulation of any site did not affect cardiovascular variables or movement. Electrical stimulation of the midbrain in awake humans can cause a modest increase in cardiovascular variables that is not dependent on movement feedback from exercising muscles. The relationship between this type of response and that occurring during actual exercise is unclear, but it indicates that subcortical command could be involved in ‘parallel activation’ of the locomotor and cardiovascular systems and thus contribute to the neurocircuitry of ‘central command’. PMID:11882692

  18. Low frequency chronic electrical stimulation of normal and dystrophic chicken muscle.

    PubMed Central

    Barnard, E A; Barnard, P J; Jarvis, J C; Lai, J

    1986-01-01

    The fast-twitch posterior latissimus dorsi muscle of normal and genetically dystrophic chickens was subjected to continuous indirect electrical stimulation at 10 Hz for periods of 4-8 weeks. To sustain this in vivo nerve stimulation an internally implantable miniature stimulator device was designed. This regime of stimulation caused complete fatigue of the normal muscle within 5 min of its initiation. The dystrophic muscles maintained a very small degree of contractile activity during this initial phase. Tangible twitching of the muscle returned in 5 week birds between 3 and 5 days and in 10 week birds between 11 and 16 days after implantation. After 4 weeks of stimulation, no significant change was measured in the time-to-peak of the isometric twitch response, nor in the half-relaxation time. The resistance to fatigue was significantly increased in the stimulated muscles when tested with a series of tetani at 40 Hz. The mean fibre area was decreased, in all muscles stimulated for longer than 3 weeks, in comparison to their contralateral controls, except where fibre splitting in dystrophic birds abnormally reduced the control value. The majority fibre type of the muscle was changed from type IIB to IIA. The histochemical reactions for both NADH-linked oxidation and phosphorylase were distinctly increased in the stimulated muscles. In normal muscle, stimulation increased somewhat the number of nuclei per unit area and changed their intracellular distribution, so that a greater proportion was found adjacent to the sarcolemma. The normal posterior latissimus dorsi muscle responded to chronic stimulation with increases of 3-6-fold in its acetylcholinesterase (AChE) activity. The maximum change in AChE occurred after 2 weeks stimulation; a steady level, 3 times that of the control unstimulated muscle, persisted at later times. Chronic stimulation suppressed the over-production of AChE that is characteristic of dystrophic chicken fast-twitch muscle, to attain a level

  19. 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

  20. Playing the electric light orchestra--how electrical stimulation of visual cortex elucidates the neural basis of perception.

    PubMed

    Cicmil, Nela; Krug, Kristine

    2015-09-19

    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.

  1. Myoneural necrosis following high-frequency electrical stimulation of the cast-immobilized rabbit hindlimb

    NASA Technical Reports Server (NTRS)

    Friden, J.; Lieber, R. L.; Myers, R. R.; Powell, H. C.; Hargens, A. R.

    1989-01-01

    The morphological and physiological effects of 4 weeks of high-frequency electrical stimulation (1 h/day, 5 days/week) on cast-immobilized rabbit hindlimbs were investigated in the tibialis anterior muscle and peroneal nerve. In 2 out of 6 animals, high-frequency stimulation with immobilization caused muscle fiber death, internalization of muscle fiber nuclei, connective tissue proliferation, inflammatory response, altered fiber size distribution and variable staining intensities. The fast-twitch fibers were predominantly affected. Two of six peripheral nerves subjected to immobilization and stimulation showed severe damage. Tetanic forces were significantly reduced in the affected muscles. Therefore, the immobilization and high-frequency stimulation may be detrimental to myoneural structure and function and, thus, this combination of therapies should be applied conservatively.

  2. 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.

  3. Electrical stimulation of dog pudendal nerve regulates the excitatory pudendal-to-bladder reflex

    PubMed Central

    Ju, Yan-he; Liao, Li-min

    2016-01-01

    Pudendal nerve plays an important role in urine storage and voiding. Our hypothesis is that a neuroprosthetic device placed in the pudendal nerve trunk can modulate bladder function after suprasacral spinal cord injury. We had confirmed the inhibitory pudendal-to-bladder reflex by stimulating either the branch or the trunk of the pudendal nerve. This study explored the excitatory pudendal-to-bladder reflex in beagle dogs, with intact or injured spinal cord, by electrical stimulation of the pudendal nerve trunk. The optimal stimulation frequency was approximately 15–25 Hz. This excitatory effect was dependent to some extent on the bladder volume. We conclude that stimulation of the pudendal nerve trunk is a promising method to modulate bladder function. PMID:27212934

  4. Effects of Sensitive Electrical Stimulation Based Cueing in Parkinson’s Disease: A Preliminary Study

    PubMed Central

    Sijobert, Benoît; Azevedo-Coste, Christine; Andreu, David; Verna, Claudia; Geny, Christian

    2016-01-01

    This study aims to investigate the effect of a sensitive cueing on Freezing of Gait (FOG) and gait disorders in subjects suffering from Parkinson’s disease (PD). 13 participants with Parkinson’s disease were equipped with an electrical stimulator and a foot mounted inertial measurement unit (IMU). An IMU based algorithm triggered in real time an electrical stimulus applied on the arch of foot at heel off detection. Starting from standing, subjects were asked to walk at their preferred speed on a path comprising 5m straight, u-turn and walk around tasks. Cueing globally decreased the time to achieve the different tasks in all the subjects. In “freezer” subjects, the time to complete the entire path was reduced by 19%. FOG events occurrence was lowered by 12% compared to baseline before and after cueing. This preliminary work showed a positive global effect of an electrical stimulation based cueing on gait and FOG in PD. PMID:27478565

  5. Effects of Sensitive Electrical Stimulation Based Cueing in Parkinson's Disease: A Preliminary Study.

    PubMed

    Sijobert, Benoît; Azevedo-Coste, Christine; Andreu, David; Verna, Claudia; Geny, Christian

    2016-06-13

    This study aims to investigate the effect of a sensitive cueing on Freezing of Gait (FOG) and gait disorders in subjects suffering from Parkinson's disease (PD). 13 participants with Parkinson's disease were equipped with an electrical stimulator and a foot mounted inertial measurement unit (IMU). An IMU based algorithm triggered in real time an electrical stimulus applied on the arch of foot at heel off detection. Starting from standing, subjects were asked to walk at their preferred speed on a path comprising 5m straight, u-turn and walk around tasks. Cueing globally decreased the time to achieve the different tasks in all the subjects. In "freezer" subjects, the time to complete the entire path was reduced by 19%. FOG events occurrence was lowered by 12% compared to baseline before and after cueing. This preliminary work showed a positive global effect of an electrical stimulation based cueing on gait and FOG in PD. PMID:27478565

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

    NASA Technical Reports Server (NTRS)

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

  7. 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

  8. Development of network-based multichannel neuromuscular electrical stimulation system for stroke rehabilitation.

    PubMed

    Qu, Hongen; Xie, Yongji; Liu, Xiaoxuan; He, Xin; Hao, Manzhao; Bao, Yong; Xie, Qing; Lan, Ning

    2016-01-01

    Neuromuscular electrical stimulation (NMES) is a promising assistive technology for stroke rehabilitation. Here we present the design and development of a multimuscle stimulation system as an emerging therapy for people with paretic stroke. A network-based multichannel NMES system was integrated based on dual bus architecture of communication and an H-bridge current regulator with a power booster. The structure of the system was a body area network embedded with multiple stimulators and a communication protocol of controlled area network to transmit muscle stimulation parameter information to individual stimulators. A graphical user interface was designed to allow clinicians to specify temporal patterns and muscle stimulation parameters. We completed and tested a prototype of the hardware and communication software modules of the multichannel NMES system. The prototype system was first verified in nondisabled subjects for safety, and then tested in subjects with stroke for feasibility with assisting multijoint movements. Results showed that synergistic stimulation of multiple muscles in subjects with stroke improved performance of multijoint movements with more natural velocity profiles at elbow and shoulder and reduced acromion excursion due to compensatory trunk rotation. The network-based NMES system may provide an innovative solution that allows more physiological activation of multiple muscles in multijoint task training for patients with stroke. PMID:27149687

  9. 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.

  10. Sensory electrical stimulation improves foot placement during targeted stepping post-stroke

    PubMed Central

    Walker, Eric R.; Hyngstrom, Allison S.

    2015-01-01

    Proper foot placement is vital for maintaining balance during walking, requiring the integration of multiple sensory signals with motor commands. Disruption of brain structures post-stroke likely alters the processing of sensory information by motor centers, interfering with precision control of foot placement and walking function for stroke survivors. In this study, we examined whether somatosensory stimulation, which improves functional movements of the paretic hand, could be used to improve foot placement of the paretic limb. Foot placement was evaluated before, during, and after application of somatosensory electrical stimulation to the paretic foot during a targeted stepping task. Starting from standing, twelve chronic stroke participants initiated movement with the non-paretic limb and stepped to one of five target locations projected onto the floor with distances normalized to the paretic stride length. Targeting error and lower extremity kinematics were used to assess changes in foot placement and limb control due to somatosensory stimulation. Significant reductions in placement error in the medial–lateral direction (p = 0.008) were observed during the stimulation and post-stimulation blocks. Seven participants, presenting with a hip circumduction walking pattern, had reductions (p = 0.008) in the magnitude and duration of hip abduction during swing with somatosensory stimulation. Reductions in circumduction correlated with both functional and clinical measures, with larger improvements observed in participants with greater impairment. The results of this study suggest that somatosensory stimulation of the paretic foot applied during movement can improve the precision control of foot placement. PMID:24449007

  11. Development of network-based multichannel neuromuscular electrical stimulation system for stroke rehabilitation.

    PubMed

    Qu, Hongen; Xie, Yongji; Liu, Xiaoxuan; He, Xin; Hao, Manzhao; Bao, Yong; Xie, Qing; Lan, Ning

    2016-01-01

    Neuromuscular electrical stimulation (NMES) is a promising assistive technology for stroke rehabilitation. Here we present the design and development of a multimuscle stimulation system as an emerging therapy for people with paretic stroke. A network-based multichannel NMES system was integrated based on dual bus architecture of communication and an H-bridge current regulator with a power booster. The structure of the system was a body area network embedded with multiple stimulators and a communication protocol of controlled area network to transmit muscle stimulation parameter information to individual stimulators. A graphical user interface was designed to allow clinicians to specify temporal patterns and muscle stimulation parameters. We completed and tested a prototype of the hardware and communication software modules of the multichannel NMES system. The prototype system was first verified in nondisabled subjects for safety, and then tested in subjects with stroke for feasibility with assisting multijoint movements. Results showed that synergistic stimulation of multiple muscles in subjects with stroke improved performance of multijoint movements with more natural velocity profiles at elbow and shoulder and reduced acromion excursion due to compensatory trunk rotation. The network-based NMES system may provide an innovative solution that allows more physiological activation of multiple muscles in multijoint task training for patients with stroke.

  12. Comparison of skin sensory thresholds using pre-programmed or single-frequency transcutaneous electrical nerve stimulation

    PubMed Central

    Kang, Jong Ho

    2015-01-01

    [Purpose] The purpose of the present study was to compare the sensory thresholds of healthy subjects using pre-programmed or single-frequency transcutaneous electrical nerve stimulation. [Subjects] Ninety healthy adult subjects were randomly assigned to pre-programmed or single-frequency stimulation groups, each consisting of 45 participants. [Methods] Sensory thresholds were measured in the participants’ forearms using von Frey filaments before and after pre-programmed or single-frequency transcutaneous electrical nerve stimulation, and the result in values were analyzed. [Results] Significant increases in sensory threshold after stimulation were observed in both groups. However, there were no significant differences between the two groups in sensory thresholds after stimulation or in the magnitude of threshold increases following stimulation. [Conclusion] Our results show that there are no differences between sensory threshold increases induced by pre-programmed and single-frequency transcutaneous electrical nerve stimulation. PMID:26834358

  13. The influence of functional electrical stimulation on hand motor recovery in stroke patients: a review

    PubMed Central

    2014-01-01

    Neuromuscular stimulation has been used as one potential rehabilitative treatment option to restore motor function and improve recovery in patients with paresis. Especially stroke patients who often regain only limited hand function would greatly benefit from a therapy that enhances recovery and restores movement. Multiple studies investigated the effect of functional electrical stimulation on hand paresis, the results however are inconsistent. Here we review the current literature on functional electrical stimulation on hand motor recovery in stroke patients. We discuss the impact of different parameters such as stage after stoke, degree of impairment, spasticity and treatment protocols on the functional outcome. Importantly, we outline the results from recent studies investigating the cortical effects elicited by functional electrical stimulation giving insights into the underlying mechanisms responsible for long-term treatment effects. Bringing together the findings from present research it becomes clear that both, treatment outcomes as well as the neurophysiologic mechanisms causing functional recovery, vary depending on patient characteristics. In order to develop unified treatment guidelines it is essential to conduct homogenous studies assessing the impact of different parameters on rehabilitative success. PMID:25276333

  14. Seeing scenes: topographic visual hallucinations evoked by direct electrical stimulation of the parahippocampal place area.

    PubMed

    Mégevand, Pierre; Groppe, David M; Goldfinger, Matthew S; Hwang, Sean T; Kingsley, Peter B; Davidesco, Ido; Mehta, Ashesh D

    2014-04-16

    In recent years, functional neuroimaging has disclosed a network of cortical areas in the basal temporal lobe that selectively respond to visual scenes, including the parahippocampal place area (PPA). Beyond the observation that lesions involving the PPA cause topographic disorientation, there is little causal evidence linking neural activity in that area to the perception of places. Here, we combined functional magnetic resonance imaging (fMRI) and intracranial EEG (iEEG) recordings to delineate place-selective cortex in a patient implanted with stereo-EEG electrodes for presurgical evaluation of drug-resistant epilepsy. Bipolar direct electrical stimulation of a cortical area in the collateral sulcus and medial fusiform gyrus, which was place-selective according to both fMRI and iEEG, induced a topographic visual hallucination: the patient described seeing indoor and outdoor scenes that included views of the neighborhood he lives in. By contrast, stimulating the more lateral aspect of the basal temporal lobe caused distortion of the patient's perception of faces, as recently reported (Parvizi et al., 2012). Our results support the causal role of the PPA in the perception of visual scenes, demonstrate that electrical stimulation of higher order visual areas can induce complex hallucinations, and also reaffirm direct electrical brain stimulation as a tool to assess the function of the human cerebral cortex.

  15. Efficacy of Carcass Electrical Stimulation in Meat Quality Enhancement: A Review

    PubMed Central

    Adeyemi, Kazeem Dauda; Sazili, Awis Qurni

    2014-01-01

    The use of electrical stimulation (ES) as a management tool to improve meat quality and efficiency of meat processing is reviewed. The basis of the efficacy of ES is its ability to fast track postmortem glycolysis, which in turn stimulates myriad histological, physical, biochemical, biophysical and physiological changes in the postmortem muscle. Electrical stimulation hastens the onset and resolution of rigor mortis thereby reducing processing time and labor and plays a vital role in improving meat tenderness and other meat quality traits. However, ES may have negative impacts on some meat quality traits such as color stability and water holding capacity in some animals. Electrical stimulation is not an end in itself. In order to achieve the desired benefits from its application, the technique must be properly used in conjunction with various intricate antemortem, perimortem and postmortem management practices. Despite extensive research on ES, the fundamental mechanisms and the appropriate commercial applications remained obscured. In addition, muscles differ in their response to ES. Thus, elementary knowledge of the various alterations with respect to muscle type is needed in order to optimize the effectiveness of ES in the improvement of meat quality. PMID:25049973

  16. Functional Electrical Stimulation of Intrinsic Laryngeal Muscles under Varying Loads in Exercising Horses

    PubMed Central

    Cheetham, Jon; Regner, Abby; Jarvis, Jonathan C.; Priest, David; Sanders, Ira; Soderholm, Leo V.; Mitchell, Lisa M.; Ducharme, Norm G.

    2011-01-01

    Bilateral vocal fold paralysis (BVCP) is a life threatening condition and appears to be a good candidate for therapy using functional electrical stimulation (FES). Developing a working FES system has been technically difficult due to the inaccessible location and small size of the sole arytenoid abductor, the posterior cricoarytenoid (PCA) muscle. A naturally-occurring disease in horses shares many functional and etiological features with BVCP. In this study, the feasibility of FES for equine vocal fold paralysis was explored by testing arytenoid abduction evoked by electrical stimulation of the PCA muscle. Rheobase and chronaxie were determined for innervated PCA muscle. We then tested the hypothesis that direct muscle stimulation can maintain airway patency during strenuous exercise in horses with induced transient conduction block of the laryngeal motor nerve. Six adult horses were instrumented with a single bipolar intra-muscular electrode in the left PCA muscle. Rheobase and chronaxie were within the normal range for innervated muscle at 0.55±0.38 v and 0.38±0.19 ms respectively. Intramuscular stimulation of the PCA muscle significantly improved arytenoid abduction at all levels of exercise intensity and there was no significant difference between the level of abduction achieved with stimulation and control values under moderate loads. The equine larynx may provide a useful model for the study of bilateral fold paralysis. PMID:21904620

  17. Imaging artifacts induced by electrical stimulation during conventional fMRI of the brain

    PubMed Central

    Antal, Andrea; Bikson, Marom; Datta, Abhishek; Lafon, Belen; Dechent, Peter; Parra, Lucas C.; Paulus, Walter

    2013-01-01

    Functional magnetic resonance imaging (fMRI) of brain activation during transcranial electrical stimulation is used to provide insight into the mechanisms of neuromodulation and targeting of particular brain structures. However, the passage of current through the body may interfere with the concurrent detection of blood oxygen level dependent (BOLD) signal, which is sensitive to local magnetic fields. To test whether these currents can affect concurrent fMRI recordings we performed conventional gradient echo-planar imaging (EPI) during transcranial direct current (tDCS) and alternating current stimulation (tACS) on two post-mortem subjects. TDCS induced signals in both superficial and deep structures. The signal was specific to the electrode montage, with the strongest signal near cerebrospinal fluid (CSF) and scalp. The direction of change relative to non-stimulation reversed with tDCS stimulation polarity. For tACS there was no net effect of the MRI signal. High-resolution individualized modeling of current flow and induced static magnetic fields suggested a strong coincidence of the change EPI signal with regions of large current density and magnetic fields. These initial results indicate that: 1) fMRI studies of tDCS must consider this potentially confounding interference from current flow and 2) conventional MRI imaging protocols can be potentially used to measure current flow during transcranial electrical stimulation. The optimization of current measurement and artifact correction techniques, including consideration of the underlying physics, remains to be addressed. PMID:23099102

  18. Interphase gap as a means to reduce electrical stimulation thresholds for epiretinal prostheses

    NASA Astrophysics Data System (ADS)

    Weitz, Andrew C.; Behrend, Matthew R.; Ahuja, Ashish K.; Christopher, Punita; Wei, Jianing; Wuyyuru, Varalakshmi; Patel, Uday; Greenberg, Robert J.; Humayun, Mark S.; Chow, Robert H.; Weiland, James D.

    2014-02-01

    Objective. Epiretinal prostheses are designed to restore functional vision to the blind by electrically stimulating surviving retinal neurons. These devices have classically employed symmetric biphasic current pulses in order to maintain a balance of charge. Prior electrophysiological and psychophysical studies in peripheral nerve show that adding an interphase gap (IPG) between the two phases makes stimulation more efficient than pulses with no gap. This led us to investigate the effect of IPG duration on retinal stimulation thresholds. Approach. We measured retinal ganglion cell (RGC) electrical thresholds in salamander retina and phosphene perceptual thresholds in epiretinal prosthesis patients during stimulation with different IPG lengths. We also built Hodgkin-Huxley-type models of RGCs to further study how IPG affects thresholds. Main results. In general, there was a negative exponential correlation between threshold and IPG duration. Durations greater than or equal to ˜0.5 ms reduced salamander RGC thresholds by 20-25%. Psychophysical testing in five retinal prosthesis patients indicated that stimulating with IPGs can decrease perceptual thresholds by 10-15%. Results from computational models of RGCs corroborated the observed behavior. Significance. Incorporating interphase gaps can reduce the power consumption of epiretinal prostheses and increase the available dynamic range of phosphene size and brightness.

  19. Electrical stimulation of the parabrachial nucleus induces reanimation from isoflurane general anesthesia.

    PubMed

    Muindi, Fanuel; Kenny, Jonathan D; Taylor, Norman E; Solt, Ken; Wilson, Matthew A; Brown, Emery N; Van Dort, Christa J

    2016-06-01

    Clinically, emergence from general anesthesia is viewed as a passive process where anesthetics are discontinued at the end of surgery and anesthesiologists wait for the drugs to wear off. The mechanisms involved in emergence are not well understood and there are currently no drugs that can actively reverse the state of general anesthesia. An emerging hypothesis states that brain regions that control arousal become active during emergence and are a key part of the return to wakefulness. In this study, we tested the hypothesis that electrical activation of the glutamatergic parabrachial nucleus (PBN) in the brainstem is sufficient to induce reanimation (active emergence) during continuous isoflurane general anesthesia. Using c-Fos immunohistochemistry as a marker of neural activity, we first show a selective increase in active neurons in the PBN during passive emergence from isoflurane anesthesia. We then electrically stimulated the PBN to assess whether it is sufficient to induce reanimation from isoflurane general anesthesia. Stimulation induced behavioral arousal and restoration of the righting reflex during continuous isoflurane general anesthesia. In contrast, stimulation of the nearby central inferior colliculus (CIC) did not restore the righting reflex. Spectral analysis of the electroencephalogram (EEG) revealed that stimulation produced a significant decrease in EEG delta power during PBN stimulation. The results are consistent with the hypothesis that the PBN provides critical arousal input during emergence from isoflurane anesthesia.

  20. 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

  1. Functional electrical stimulation of intrinsic laryngeal muscles under varying loads in exercising horses.

    PubMed

    Cheetham, Jon; Regner, Abby; Jarvis, Jonathan C; Priest, David; Sanders, Ira; Soderholm, Leo V; Mitchell, Lisa M; Ducharme, Norm G

    2011-01-01

    Bilateral vocal fold paralysis (BVCP) is a life threatening condition and appears to be a good candidate for therapy using functional electrical stimulation (FES). Developing a working FES system has been technically difficult due to the inaccessible location and small size of the sole arytenoid abductor, the posterior cricoarytenoid (PCA) muscle. A naturally-occurring disease in horses shares many functional and etiological features with BVCP. In this study, the feasibility of FES for equine vocal fold paralysis was explored by testing arytenoid abduction evoked by electrical stimulation of the PCA muscle. Rheobase and chronaxie were determined for innervated PCA muscle. We then tested the hypothesis that direct muscle stimulation can maintain airway patency during strenuous exercise in horses with induced transient conduction block of the laryngeal motor nerve. Six adult horses were instrumented with a single bipolar intra-muscular electrode in the left PCA muscle. Rheobase and chronaxie were within the normal range for innervated muscle at 0.55±0.38 v and 0.38±0.19 ms respectively. Intramuscular stimulation of the PCA muscle significantly improved arytenoid abduction at all levels of exercise intensity and there was no significant difference between the level of abduction achieved with stimulation and control values under moderate loads. The equine larynx may provide a useful model for the study of bilateral fold paralysis. PMID:21904620

  2. Transtympanic electrical stimulation for immediate and long-term tinnitus suppression.

    PubMed

    Di Nardo, Walter; Cianfrone, Francesca; Scorpecci, Alessandro; Cantore, Italo; Giannantonio, Sara; Paludetti, Gaetano

    2009-01-01

    Tinnitus is a common symptom which often becomes disabling, affecting the emotional and psychosocial dimensions of life. There are many reports describing tinnitus suppression or attenuation through electrical stimulation of the ear, provided either by cochlear implants or by transtympanic stimulation. Our study project aims to assess the effects of electrical promontory stimulation (EPS) on persistent disabling tinnitus. We enrolled 11 patients affected by postlingual monoaural or binaural profound hearing loss and disabling tinnitus in the worse ear. EPS was performed with direct continuous positive current delivered by an active platinum-iridium needle electrode connected to a promontory stimulator device. The short-term effect on tinnitus was assessed during and immediately after the stimulation. Long-term effects were estimated after one month by comparing pre- and post-EPS Tinnitus Handicap Inventory (THI) scores. Immediately after EPS, five patients (45.4%) reported complete suppression and four (36.4%) reported attenuation of tinnitus. Two patients (18.2%) said it was unchanged. After one month, the THI score was reduced in five patients (45.4%) and remained unchanged in the other six patients (54.6%). The beneficial effects of EPS on tinnitus might be explained by interference with tinnitus generating circuits such as the dorsal cochlear nucleus and the inferior colliculus and by modification of cortical activity. EPS is to be considered a worthwhile attempt at tinnitus suppression, and could help select candidates for the positioning of an implantable electrical stimulator that might provide longer-term beneficial effect on tinnitus. PMID:19842353

  3. Influence of AC and DC electrical stimulation on wound healing in pigs: a biomechanical analysis.

    PubMed

    Kambic, H E; Reyes, E; Manning, T; Waters, K C; Reger, S I

    1993-01-01

    To evaluate the effects of electrical stimulation on the mechanical properties of healing skin, 20 Hanford mini-pigs weighing 10-15 kg with trochanteric pressure ulcers were subjected to electrical stimulation. Examination of the biomechanical properties of the skin and changes in wound area and volume was done on previously wounded and healing pigskin subject to AC or DC electrical stimulation. The behavior of normal pigskin was compared to (1) denervated controls, (2) denervated AC-stimulated skin, and (3) denervated DC-stimulated skin. A denervated limb trochanteric pressure sore model developed in house permitted the use of a 6.5-mm percutaneous cancellous screw for wound formation and a 3-cm-diameter spring compression indentor to create reproducible and uniformly controlled grade 3 or higher tissue ulcers in the monoplegic hind limbs. Denervation was accomplished by right unilateral extradural rhizotomies from L2 to S1 nerve roots. Electrodes were placed 1 cm distal and proximal to the wound periphery, and wounds were stimulated 2 h/day, 5 days/week for 30 days. Dumbbell-shaped skin specimens with a length to width ratio of 3:1 were uniaxially loaded in tension until failure at an extension rate of 150 mm/min. The stiffness values for skin samples oriented parallel to the current flow were reduced by nearly half the values obtained for normal controls. Statistical differences (P < .05) were found for stress, Young modulus, and stiffness when compared to normal skin. Samples oriented in the perpendicular direction were comparable to normal skin (P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Spectral distribution of local field potential responses to electrical stimulation of the retina

    NASA Astrophysics Data System (ADS)

    Wong, Yan T.; Halupka, Kerry; Kameneva, Tatiana; Cloherty, Shaun L.; Grayden, David B.; Burkitt, Anthony N.; Meffin, Hamish; Shivdasani, Mohit N.

    2016-06-01

    Objective. Different frequency bands of the local field potential (LFP) have been shown to reflect neuronal activity occurring at varying cortical scales. As such, recordings of the LFP may offer a novel way to test the efficacy of neural prostheses and allow improvement of stimulation strategies via neural feedback. Here we use LFP measurements from visual cortex to characterize neural responses to electrical stimulation of the retina. We aim to show that the LFP is a viable signal that contains sufficient information to optimize the performance of sensory neural prostheses. Approach. Clinically relevant electrode arrays were implanted in the suprachoroidal space of one eye in four felines. LFPs were simultaneously recorded in response to stimulation of individual electrodes using penetrating microelectrode arrays from the visual cortex. The frequency response of each electrode was extracted using multi-taper spectral analysis and the uniqueness of the responses was determined via a linear decoder. Main results. We found that cortical LFPs are reliably modulated by electrical stimulation of the retina and that the responses are spatially localized. We further characterized the spectral distribution of responses, with maximum information being contained in the low and high gamma bands. Finally, we found that LFP responses are unique to a large range of stimulus parameters (∼40) with a maximum conveyable information rate of 6.1 bits. Significance. These results show that the LFP can be used to validate responses to electrical stimulation of the retina and we provide the first steps towards using these responses to provide more efficacious stimulation strategies.

  5. Interdigitated array of Pt electrodes for electrical stimulation and engineering of aligned muscle tissue.

    PubMed

    Ahadian, Samad; Ramón-Azcón, Javier; Ostrovidov, Serge; Camci-Unal, Gulden; Hosseini, Vahid; Kaji, Hirokazu; Ino, Kosuke; Shiku, Hitoshi; Khademhosseini, Ali; Matsue, Tomokazu

    2012-09-21

    Engineered skeletal muscle tissues could be useful for applications in tissue engineering, drug screening, and bio-robotics. It is well-known that skeletal muscle cells are able to differentiate under electrical stimulation (ES), with an increase in myosin production, along with the formation of myofibers and contractile proteins. In this study, we describe the use of an interdigitated array of electrodes as a novel platform to electrically stimulate engineered muscle tissues. The resulting muscle myofibers were analyzed and quantified in terms of their myotube characteristics and gene expression. The engineered muscle tissues stimulated through the interdigitated array of electrodes demonstrated superior performance and maturation compared to the corresponding tissues stimulated through a conventional setup (i.e., through Pt wires in close proximity to the muscle tissue). In particular, the ES of muscle tissue (voltage 6 V, frequency 1 Hz and duration 10 ms for 1 day) through the interdigitated array of electrodes resulted in a higher degree of C2C12 myotube alignment (∼80%) as compared to ES using Pt wires (∼65%). In addition, higher amounts of C2C12 myotube coverage area, myotube length, muscle transcription factors and protein biomarkers were found for myotubes stimulated through the interdigitated array of electrodes compared to those stimulated using the Pt wires. Due to the wide array of potential applications of ES for two- and three-dimensional (2D and 3D) engineered tissues, the suggested platform could be employed for a variety of cell and tissue structures to more efficiently investigate their response to electrical fields.

  6. Improved bladder emptying in urinary retention by electrical stimulation of pudendal afferents

    NASA Astrophysics Data System (ADS)

    Peng, Chih-Wei; Chen, Jia-Jin Jason; Cheng, Chen-Li; Grill, Warren M.

    2008-06-01

    Urinary retention is the inability to empty the bladder completely, and may result from bladder hypocontractility, increases in outlet resistance or both. Chronic urinary retention can lead to several urological complications and is often refractory to pharmacologic, behavioral and surgical treatments. We sought to determine whether electrical stimulation of sensory fibers in the pudendal nerve could engage an augmenting reflex and thereby improve bladder emptying in an animal model of urinary retention. We measured the efficiency of bladder emptying with and without concomitant electrical stimulation of pudendal nerve afferents in urethane-anesthetized rats. Voiding efficiency (VE = voided volume/initial volume) was reduced from 72 ± 7% to 29 ± 7% following unilateral transection of the sensory branch of the pudendal nerve (UST) and from 70 ± 5% to 18 ± 4% following bilateral transection (BST). Unilateral electrical stimulation of the proximal transected sensory pudendal nerve during distention-evoked voiding contractions significantly improved VE. Low-intensity stimulation at frequencies of 1-50 Hz increased VE to 40-51% following UST and to 39-49% following BST, while high-intensity stimulation was ineffective at increasing VE. The increase in VE was mediated by increases in the duration of distention-evoked voiding bladder contractions, rather than increases in contraction amplitude. These results are consistent with an essential role for pudendal sensory feedback in efficient bladder emptying, and raise the possibility that electrical activation of pudendal nerve afferents may provide a new approach to restore efficient bladder emptying in persons with urinary retention.

  7. Differential responses to high-frequency electrical stimulation in ON and OFF retinal ganglion cells

    NASA Astrophysics Data System (ADS)

    Twyford, Perry; Cai, Changsi; Fried, Shelley

    2014-04-01

    Objective. The field of retinal prosthetics for artificial vision has advanced considerably in recent years, however clinical outcomes remain inconsistent. The performance of retinal prostheses is likely limited by the inability of electrical stimuli to preferentially activate different types of retinal ganglion cell (RGC). Approach. Here we examine the response of rabbit RGCs to high-frequency stimulation, using biphasic pulses applied at 2000 pulses per second. Responses were recorded using cell-attached patch clamp methods, and stimulation was applied epiretinally via a small cone electrode. Main results. When prolonged stimulus trains were applied to OFF-brisk transient (BT) RGCs, the cells exhibited a non-monotonic relationship between response strength and stimulus amplitude; this response pattern was different from those elicited previously by other electrical stimuli. When the amplitude of the stimulus was modulated transiently from a non-zero baseline amplitude, ON-BT and OFF-BT cells exhibited different activity patterns: ON cells showed an increase in activity while OFF cells exhibited a decrease in activity. Using a different envelope to modulate the amplitude of the stimulus, we observed the opposite effect: ON cells exhibited a decrease in activity while OFF cells show an increase in activity. Significance. As ON and OFF RGCs often exhibit opposing activity patterns in response to light stimulation, this work suggests that high-frequency electrical stimulation of RGCs may be able to elicit responses that are more physiological than traditional pulsatile stimuli. Additionally, the prospect of an electrical stimulus capable of cell-type specific selective activation has broad applications throughout the fields of neural stimulation and neuroprostheses.

  8. Interaction of electrical stimulation and voluntary hand movement in SII and the cerebellum during simulated therapeutic functional electrical stimulation in healthy adults.

    PubMed

    Iftime-Nielsen, Simona Denisia; Christensen, Mark Schram; Vingborg, Rune Jersin; Sinkjaer, Thomas; Roepstorff, Andreas; Grey, Michael James

    2012-01-01

    The therapeutic application of functional electrical stimulation (FES) has shown promising clinical results in the rehabilitation of post-stroke hemiplegia. It appears that the effect is optimal when the patterned electrical stimulation is used in close synchrony with voluntary movement, although the neural mechanisms that underlie the clinical successes reported with therapeutic FES are unknown. One possibility is that therapeutic FES takes advantage of the sensory consequences of an internal model. Here, we investigate fMRI cortical activity when FES is combined with voluntary effort (FESVOL) and we compare this activity to that produced when FES and voluntary activity (VOL) are performed alone. FESVOL revealed greater cerebellar activity compared with FES alone and reduced activity bilaterally in secondary somatosensory areas (SII) compared with VOL alone. Reduced activity was also observed for FESVOL compared with FES alone in the angular gyrus, middle frontal gyrus and inferior frontal gyrus. These findings indicate that during the VOL condition the cerebellum predicts the sensory consequences of the movement and this reduces the subsequent activation in SII. The decreased SII activity may reflect a better match between the internal model and the actual sensory feedback. The greater cerebellar activity coupled with reduced angular gyrus activity in FESVOL compared with FES suggests that the cortex may interpret sensory information during the FES condition as an error-like signal due to the lack of a voluntary component in the movement.

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

    SciTech Connect

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

    1987-02-02

    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, 1 figure.

  10. 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.

  11. [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.

  12. Infrared neural stimulation (INS) inhibits electrically evoked neural responses in the deaf white cat

    NASA Astrophysics Data System (ADS)

    Richter, Claus-Peter; Rajguru, Suhrud M.; Robinson, Alan; Young, Hunter K.

    2014-03-01

    Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.

  13. 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.

  14. Motor cortex electrical stimulation augments sprouting of the corticospinal tract and promotes recovery of motor function

    PubMed Central

    Carmel, Jason B.; Martin, John H.

    2014-01-01

    The corticospinal system—with its direct spinal pathway, the corticospinal tract (CST) – is the primary system for controlling voluntary movement. Our approach to CST repair after injury in mature animals was informed by our finding that activity drives establishment of connections with spinal cord circuits during postnatal development. After incomplete injury in maturity, spared CST circuits sprout, and partially restore lost function. Our approach harnesses activity to augment this injury-dependent CST sprouting and to promote function. Lesion of the medullary pyramid unilaterally eliminates all CST axons from one hemisphere and allows examination of CST sprouting from the unaffected hemisphere. We discovered that 10 days of electrical stimulation of either the spared CST or motor cortex induces CST axon sprouting that partially reconstructs the lost CST. Stimulation also leads to sprouting of the cortical projection to the magnocellular red nucleus, where the rubrospinal tract originates. Coordinated outgrowth of the CST and cortical projections to the red nucleus could support partial re-establishment of motor systems connections to the denervated spinal motor circuits. Stimulation restores skilled motor function in our animal model. Lesioned animals have a persistent forelimb deficit contralateral to pyramidotomy in the horizontal ladder task. Rats that received motor cortex stimulation either after acute or chronic injury showed a significant functional improvement that brought error rate to pre-lesion control levels. Reversible inactivation of the stimulated motor cortex reinstated the impairment demonstrating the importance of the stimulated system to recovery. Motor cortex electrical stimulation is an effective approach to promote spouting of spared CST axons. By optimizing activity-dependent sprouting in animals, we could have an approach that can be translated to the human for evaluation with minimal delay. PMID:24994971

  15. Differential responsiveness of the right parahippocampal region to electrical stimulation in fixed human brains: Implications for historical surgical stimulation studies?

    PubMed

    Rouleau, Nicolas; Persinger, Michael A

    2016-07-01

    If structure dictates function within the living human brain, then the persistence of specific responses to weak electric currents in fixed, deceased brains could reflect "hardwired" properties. Different key structures from the left and right hemispheres of brains that had been fixed for over 20years with ethanol-formalin-acetic acid were stimulated with either 1-Hz, 7-Hz, 10-Hz, 20-Hz, or 30-Hz, sine-wave, square-wave, or pulsed currents while needle-recorded quantitative electroencephalographic responses were obtained. Differential responses occurred only within the right hippocampus and parahippocampal gyrus. The right hippocampus displayed frequency-independent increases in gamma power relative to the left hemispheric homologue. The parahippocampal region responded exclusively to 7-Hz pulsed currents with wideband (8-30Hz) power. These profiles are consistent with dynamic connections associated with memory and consciousness and may partially explain the interactions resultant of pulse type and hemisphere for experiential elicitations during the golden age of surgical stimulations. The results also indicate that there may be an essential "hardwiring" within the human brain that is maintained for decades when it is fixed appropriately.

  16. The impact of calcium current reversal on neurotransmitter release in the electrically stimulated retina

    NASA Astrophysics Data System (ADS)

    Werginz, Paul; Rattay, Frank

    2016-08-01

    Objective. In spite of intense theoretical and experimental investigations on electrical nerve stimulation, the influence of reversed ion currents on network activity during extracellular stimulation has not been investigated so far. Approach. Here, the impact of calcium current reversal on neurotransmitter release during subretinal stimulation was analyzed with a computational multi-compartment model of a retinal bipolar cell (BC) that was coupled with a four-pool model for the exocytosis from its ribbon synapses. Emphasis was laid on calcium channel dynamics and how these channels influence synaptic release. Main results. Stronger stimulation with anodic pulses caused transmembrane voltages above the Nernst potential of calcium in the terminals and, by this means, forced calcium ions to flow in the reversed direction from inside to the outside of the cell. Consequently, intracellular calcium concentration decreased resulting in a reduced vesicle release or preventing release at all. This mechanism is expected to lead to a pronounced ring-shaped pattern of exocytosis within a group of neighbored BCs when the stronger stimulated cells close to the electrode fail in releasing vesicles. Significance. Stronger subretinal stimulation causes failure of synaptic exocytosis due to reversal of calcium flow into the extracellular space in cells close to the electrode.

  17. Effects of Electrical Stimulation in Sympathetic Neuron-Cardiomyocyte Co-cultures

    NASA Astrophysics Data System (ADS)

    Takeuchi, Akimasa; Tani, Hiromasa; Mori, Masahide; Moriguchi, Hiroyuki; Kotani, Kiyoshi; Lee, Jong-Kook; Noshiro, Makoto; Jimbo, Yasuhiko

    The sympathetic nervous system is one of the principal sources for regulating cardiovascular functions. Little is known, however, about the network-level interactions between sympathetic neurons and cardiomyocytes. In this study, a semi-separated co-culture system of superior cervical ganglion (SCG) neurons and ventricular myocytes (VMs) was developed by using a polydimethylsyloxane (PDMS) chamber placed on a microelectrode-array (MEA) substrate. Neurites of SCG neurons passed through a conduit of the chamber and reached VMs. Evoked activities of SCG neurons were observed from several electrodes immediately after applying constant-voltage stimulation (1 V, 1 ms, biphasic square pulses) to SCG neurons by using 32 electrodes. Furthermore, this stimulation was applied to SCG neurons at the frequency of 1, 5 and 10 Hz. After applying these three kinds of stimulations, mean minute contraction rate of VMs increased with an increase in the frequency of stimulation. These results suggest that changes in contraction rate of VMs after applying electrical stimulations to SCG neurons depend on frequencies of these stimulations and that the heart-regulating mechanisms as well as that in the body were formed in this co-culture system.

  18. Quasi-monopolar electrical stimulation of the retina: a computational modelling study

    NASA Astrophysics Data System (ADS)

    Abramian, Miganoosh; Lovell, Nigel H.; Habib, Amgad; Morley, John W.; Suaning, Gregg J.; Dokos, Socrates

    2014-04-01

    Objective. In this study we investigated the feasibility of quasi-monopolar (QMP) electrical stimulation for retinal implant devices, using a computational model of the retinal ganglion cell layer. Approach. When used with hexagonally arrayed multiple electrodes, QMP stimulation is a hybrid of hexapolar and conventional monopolar stimulus modes. In hexapolar mode, each active electrode is surrounded by six guards which collectively return the stimulus current, whereas in monopolar mode the injected stimulus current is returned through a distant return electrode. The QMP paradigm, on the other hand, distributes the return current between the guard electrodes as well as the distant return. The electrodes tested were 25, 50 and 100 µm in diameter, with hexagonally arranged centre-to-centre spacing of either double or quadruple this diameter. Main results. Simulation results indicated that electrode size had minimal effects on subretinal threshold currents, whilst electrode configuration and centre-to-centre spacing played major roles in determining thresholds and spatial activation patterns. Threshold charge densities for 50 and 100 µm electrodes were generally within the safe limit. Significance. We found that QMP stimulation offers greater advantages compared to monopolar and hexapolar stimulation, in that it combines the low thresholds of monopolar stimulation with the localized spatial activation achieved with hexapolar electrodes during parallel stimulation.

  19. Electrical Impedance Myography to Detect the Effects of Electrical Muscle Stimulation in Wild Type and Mdx Mice

    PubMed Central

    Li, Jia; Yim, Sung; Pacheck, Adam; Sanchez, Benjamin; Rutkove, Seward B.

    2016-01-01

    Objective Tools to better evaluate the impact of therapy on nerve and muscle disease are needed. Electrical impedance myography (EIM) is sensitive to neuromuscular disease progression as well as to therapeutic interventions including myostatin inhibition and antisense oligonucleotide-based treatments. Whether the technique identifies the impact of electrical muscle stimulation (EMS) is unknown. Methods Ten wild-type (wt) C57B6 mice and 10 dystrophin-deficient (mdx) mice underwent 2 weeks of 20 min/day EMS on left gastrocnemius and sham stimulation on the right gastrocnemius. Multifrequency EIM data and limb girth were obtained before and at the conclusion of the protocol. Muscle weight, in situ force measurements, and muscle fiber histology were also assessed at the conclusion of the study. Results At the time of sacrifice, muscle weight was greater on the EMS-treated side than on the sham-stimulated side (p = 0.018 for wt and p = 0.007 for mdx). Similarly, in wt animals, EIM parameters changed significantly compared to baseline (resistance (p = 0.009), reactance (p = 0.0003) and phase (p = 0.002); these changes were due in part to reductions in the EIM values on the EMS-treated side and elevations on the sham-simulated side. Mdx animals showed analogous but non-significant changes (p = 0.083, p = 0.064, and p = 0.57 for resistance, reactance and phase, respectively). Maximal isometric force trended higher on the stimulated side in wt animals only (p = 0.06). Myofiber sizes in wt animals were also larger on the stimulated side than on the sham-stimulated side (p = 0.034); no significant difference was found in the mdx mice (p = 0.79). Conclusion EIM is sensitive to stimulation-induced muscle alterations in wt animals; similar trends are also present in mdx mice. The mechanisms by which these EIM changes develop, however, remains uncertain. Possible explanations include longer-term trophic effects and shorter-term osmotic effects. PMID:26986564

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

    PubMed

    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.

  1. The Morphological and Molecular Changes of Brain Cells Exposed to Direct Current Electric Field Stimulation

    PubMed Central

    Pelletier, Simon J.; Lagacé, Marie; St-Amour, Isabelle; Arsenault, Dany; Cisbani, Giulia; Chabrat, Audrey; Fecteau, Shirley; Lévesque, Martin

    2015-01-01

    Background: The application of low-intensity direct current electric fields has been experimentally used in the clinic to treat a number of brain disorders, predominantly using transcranial direct current stimulation approaches. However, the cellular and molecular changes induced by such treatment remain largely unknown. Methods: Here, we tested various intensities of direct current electric fields (0, 25, 50, and 100V/m) in a well-controlled in vitro environment in order to investigate the responses of neurons, microglia, and astrocytes to this type of stimulation. This included morphological assessments of the cells, viability, as well as shape and fiber outgrowth relative to the orientation of the direct current electric field. We also undertook enzyme-linked immunosorbent assays and western immunoblotting to identify which molecular pathways were affected by direct current electric fields. Results: In response to direct current electric field, neurons developed an elongated cell body shape with neurite outgrowth that was associated with a significant increase in growth associated protein-43. Fetal midbrain dopaminergic explants grown in a collagen gel matrix also showed a reorientation of their neurites towards the cathode. BV2 microglial cells adopted distinct morphological changes with an increase in cyclooxygenase-2 expression, but these were dependent on whether they had already been activated with lipopolysaccharide. Finally, astrocytes displayed elongated cell bodies with cellular filopodia that were oriented perpendicularly to the direct current electric field. Conclusion: We show that cells of the central nervous system can respond to direct current electric fields both in terms of their morphological shape and molecular expression of certain proteins, and this in turn can help us to begin understand the mechanisms underlying the clinical benefits of direct current electric field. PMID:25522422

  2. Transcutaneous Electrical Nerve Stimulation (TENS) A Possible Aid for Pain Relief in Developing Countries?

    PubMed Central

    Tashani, O; Johnson, MI

    2009-01-01

    Transcutaneous electrical nerve stimulation (TENS) refers to the delivery of electrical currents through the skin to activate peripheral nerves. The technique is widely used in developed countries to relieve a wide range of acute and chronic pain conditions, including pain resulting from cancer and its treatment. There are many systematic reviews on TENS although evidence is often inconclusive because of shortcomings in randomised control trials methodology. In this overview the basic science behind TENS will be discussed, the evidence of its effectiveness in specific clinical conditions analysed and a case for its use in pain management in developing countries will be made. PMID:21483510

  3. Transcutaneous Electrical Nerve Stimulation (TENS) A Possible Aid for Pain Relief in Developing Countries?

    PubMed

    Tashani, O; Johnson, Mi

    2009-06-01

    Transcutaneous electrical nerve stimulation (TENS) refers to the delivery of electrical currents through the skin to activate peripheral nerves. The technique is widely used in developed countries to relieve a wide range of acute and chronic pain conditions, including pain resulting from cancer and its treatment. There are many systematic reviews on TENS although evidence is often inconclusive because of shortcomings in randomised control trials methodology. In this overview the basic science behind TENS will be discussed, the evidence of its effectiveness in specific clinical conditions analysed and a case for its use in pain management in developing countries will be made.

  4. Electrical stimulation promotes the survival of oligodendrocytes in mixed cortical cultures.

    PubMed

    Gary, Devin S; Malone, Misti; Capestany, Paul; Houdayer, Thierry; McDonald, John W

    2012-01-01

    Oligodendrocyte (OLG) death plays a major role in white matter dysfunction and demyelination following injury to the CNS. Axonal contact, communication, and neuronal activity appear to promote OLG survival and function in cell culture and during development. The application of electrical stimulation to mixed neural cultures has been shown to promote OLG differentiation and the formation of myelin in vitro. Here we show that OLG viability can be significantly enhanced in mixed cortical cultures by applying biphasic pulses of electrical stimulation (ESTIM). Enhanced survival via ESTIM requires the presence of neurons and is suppressed by inhibition of voltage-gated sodium channels. Additionally, contact between the axon and OLG is necessary for ESTIM to promote OLG survival. This report suggests that patterned neuronal activity could repress delayed progression of white matter injury and promote CNS repair in neurological conditions that involve white matter damage.

  5. Analytical theory for extracellular electrical stimulation of nerve with focal electrodes. II. Passive myelinated axon.

    PubMed Central

    Rubinstein, J T

    1991-01-01

    The cable model of a passive, myelinated fiber is derived using the theory of electromagnetic propagation in periodic structures. The cable may be excited by an intracellular source or by an arbitrary, time-varying, applied extracellular field. When the cable is stimulated by a distant source, its properties are qualitatively similar to an unmyelinated fiber. Under these conditions relative threshold is proportional to the cube of the source distance and inversely proportional to the square of the fiber diameter. Electrical parameters of the model are chosen where possible, from mammalian peripheral nerve and anatomic parameters from cat auditory nerve. Several anatomic representations of the paranodal region are analyzed for their effects on the length and time constants of the fibers. Sensitivity of the model to parameter changes is studied. The linear model reliably predicts the effects of fiber size and electrode-fiber separation on threshold of cat dorsal column fibers to extracellular electrical stimulation. Images FIGURE 2 PMID:1932546

  6. The will to persevere induced by electrical stimulation of the human cingulate gyrus.

    PubMed

    Parvizi, Josef; Rangarajan, Vinitha; Shirer, William R; Desai, Nikita; Greicius, Michael D

    2013-12-18

    Anterior cingulate cortex (ACC) is known to be involved in functions such as emotion, pain, and cognitive control. While studies in humans and nonhuman mammals have advanced our understanding of ACC function, the subjective correlates of ACC activity have remained largely unexplored. In the current study, we show that electrical charge delivery in the anterior midcingulate cortex (aMCC) elicits autonomic changes and the expectation of an imminent challenge coupled with a determined attitude to overcome it. Seed-based, resting-state connectivity analysis revealed that the site of stimulation in both patients was at the core of a large-scale distributed network linking aMCC to the frontoinsular and frontopolar as well as some subcortical regions. This report provides compelling, first-person accounts of electrical stimulation of this brain network and suggests its possible involvement in psychopathological conditions that are characterized by a reduced capacity to endure psychological or physical distress. PMID:24316296

  7. Tremor suppression using functional electrical stimulation: a comparison between digital and analog controllers.

    PubMed

    Gillard, D M; Cameron, T; Prochazka, A; Gauthier, M J

    1999-09-01

    In this study, we compared digital and analog versions of a functional electrical stimulator designed to suppress tremor. The device was based on a closed-loop control system designed to attenuate movements in the tremor frequency range, without significantly affecting slower, voluntary movements. Testing of the digital filter was done on three patients with Parkinsonian tremor and the results compared to those of a functional electrical stimulation device based on an analog filter evaluated in a previous study. Additional testing of both the analog and digital filters was done on three subjects with no neurological impairment performing tremor-like movements and slow voluntary movements. We found that the digital controller provided a mean attenuation of 84%, compared to 65% for the analog controller.

  8. A point process framework for modeling electrical stimulation of the auditory nerve

    PubMed Central

    Rubinstein, Jay T.; Shea-Brown, Eric

    2012-01-01

    Model-based studies of responses of auditory nerve fibers to electrical stimulation can provide insight into the functioning of cochlear implants. Ideally, these studies can identify limitations in sound processing strategies and lead to improved methods for providing sound information to cochlear implant users. To accomplish this, models must accurately describe spiking activity while avoiding excessive complexity that would preclude large-scale simulations of populations of auditory nerve fibers and obscure insight into the mechanisms that influence neural encoding of sound information. In this spirit, we develop a point process model of individual auditory nerve fibers that provides a compact and accurate description of neural responses to electric stimulation. Inspired by the framework of generalized linear models, the proposed model consists of a cascade of linear and nonlinear stages. We show how each of these stages can be associated with biophysical mechanisms and related to models of neuronal dynamics. Moreover, we derive a semianalytical procedure that uniquely determines each parameter in the model on the basis of fundamental statistics from recordings of single fiber responses to electric stimulation, including threshold, relative spread, jitter, and chronaxie. The model also accounts for refractory and summation effects that influence the responses of auditory nerve fibers to high pulse rate stimulation. Throughout, we compare model predictions to published physiological data of response to high and low pulse rate stimulation. We find that the model, although constructed to fit data from single and paired pulse experiments, can accurately predict responses to unmodulated and modulated pulse train stimuli. We close by performing an ideal observer analysis of simulated spike trains in response to sinusoidally amplitude modulated stimuli and find that carrier pulse rate does not affect modulation detection thresholds. PMID:22673331

  9. [ELECTRIC STIMULATION OF VAGUS NERVE MODULATES A PROPAGATION OF OXYGEN EPILEPSY IN RABBITS].

    PubMed

    Zhilyaev, S Yu; Moskvin, A N; Platonova, T F; Demchenko, I T

    2015-11-01

    The activation of autonomic afferents (achieved through the vagus nerve (VN) electrical stimulation) on CNS O2 toxicity and cardiovascular function was investigated. In conscious rabbits at 5 ATA 02, prodromal signs of CNS O2 toxicity and convulsion latency were determined with and without vagus nerve (VN) stimulation. EEG, ECG and respiration were also recorded. In rabbits at 5 ATA, sympathetic overdrive and specific patterns on the EEG (synchronization of slow-waves), ECG (tachycardia) and respiration (respiratory minute volume increase) preceded motor convulsions. Vagus nerve stimulation increased parasympathetic component of autonomic drive and significantly delayed prodromal signs of oxygen toxicity and convulsion latency. Autonomic afferent input to the brain is a novel target for preventing CNS toxicity in HBO2. PMID:26995956

  10. Focal electrical stimulation of major ganglion cell types in the primate retina for the design of visual prostheses.

    PubMed

    Jepson, Lauren H; Hottowy, Pawel; Mathieson, Keith; Gunning, Deborah E; Dabrowski, Wladyslaw; Litke, Alan M; Chichilnisky, E J

    2013-04-24

    Electrical stimulation of retinal neurons with an advanced retinal prosthesis may eventually provide high-resolution artificial vision to the blind. However, the success of future prostheses depends on the ability to activate the major parallel visual pathways of the human visual system. Electrical stimulation of the five numerically dominant retinal ganglion cell types was investigated by simultaneous stimulation and recording in isolated peripheral primate (Macaca sp.) retina using multi-electrode arrays. ON and OFF midget, ON and OFF parasol, and small bistratified ganglion cells could all be activated directly to fire a single spike with submillisecond latency using brief pulses of current within established safety limits. Thresholds for electrical stimulation were similar in all five cell types. In many cases, a single cell could be specifically activated without activating neighboring cells of the same type or other types. These findings support the feasibility of direct electrical stimulation of the major visual pathways at or near their native spatial and temporal resolution.

  11. Growth characteristics of different heart cells on novel nanopatch substrate during electrical stimulation.

    PubMed

    Stout, David A; Raimondo, Emilia; Marostica, Giuliano; Webster, Thomas J

    2014-01-01

    During a heart attack, the heart's oxygen supply is cut off, and cardiomyocytes perish. Unfortunately, once these tissues are lost, they cannot be replaced and results in cardiovascular disease-the leading cause of deaths worldwide. Advancements in medical research have been targeted to understand and combat the death of these cardiomyocytes. For example, new research (in vitro) has demonstrated that one can expand cardiomyocyte adhesion and proliferation using polylactic-co-glycolic acid (PLGA) (50:50 (weight percent)) supplemented with carbon nanofibers (CNFs) to create a cardiovascular patch. However, the examination of other cardiovascular cell types has not been investigated. Therefore, the purpose of this present in vitro study was to determine cell growth characteristics of three different important cardiovascular cell types (aortic endothelial, fibroblast and cardiomyocyte) onto the substrate. Cells were seeded onto different PLGA:CNF ratio composites to determine if CNF density has an effect on cell growth, both in static and electrically stimulated environments. During continuous electrical stimulation (rectangle, 2 nm, 5 V/cm, 1 Hz), cardiomyocyte cell density increased in comparison to its static counterparts after 24, 72 and 120 hours. A minor rise in Troponin I excretion in electrical stimulation compared to static conditions indicated nominal cardiomyocyte cell function during cell experiments. Endothelial and fibroblast cell growth experiments indicated the material hindered or stalled proliferation during both static and electrical stimulation experiments, thus supporting the growth of cardiomyocytes onto the dead tissue zone. Furthermore, the results specified that CNF density did have an effect on PLGA:CNF composite cytocompatibility properties with the best results coming from the 50:50 [PLGA:CNF (weight percent:weight percent)] composite. Therefore, this study provides further evidence that a conductive scaffold using nanotechnology should be

  12. Effect of Electrical Stimulation on Fruit Body Formation in Cultivating Mushrooms

    PubMed Central

    Takaki, Koichi; Yoshida, Kohei; Saito, Tatsuya; Kusaka, Tomohiro; Yamaguchi, Ryo; Takahashi, Kyusuke; Sakamoto, Yuichi

    2014-01-01

    The effect of high-voltage electrical stimulation on fruit body formation in cultivating mushrooms was evaluated using a compact pulsed power generator designed and based on an inductive energy storage system. An output voltage from 50 to 130 kV with a 100 ns pulse width was used as the electrical stimulation to determine the optimum amplitude. The pulsed high voltage was applied to a sawdust-based substrate of Lyophyllum decastes and natural logs hosting Lentinula edodes, Pholiota nameko, and Naematoloma sublateritium. The experimental results showed that the fruit body formation of mushrooms increased 1.3–2.0 times in terms of the total weight. The accumulated yield of Lentinula edodes for four cultivation seasons was improved from 160 to 320 g by applying voltages of 50 or 100 kV. However, the yield was decreased from 320 to 240 g upon increasing the applied voltage from 100 to 130 kV. The yield of the other types of mushrooms showed tendencies similar to those of Lentinula edodes when voltage was applied. An optimal voltage was confirmed for efficient fruit body induction. The hypha activity was evaluated by the amount of hydrophobin release, which was mainly observed before the fruit body formation. The hydrophobin release decreased for three hours after stimulation. However, the hydrophobin release from the vegetative hyphae increased 2.3 times one day after the stimulation.

  13. Motor Skill Acquisition and Retention after Somatosensory Electrical Stimulation in Healthy Humans

    PubMed Central

    Veldman, Menno P.; Zijdewind, Inge; Maffiuletti, Nicola A.; Hortobágyi, Tibor

    2016-01-01

    Somatosensory electrical stimulation (SES) can increase motor performance, presumably through a modulation of neuronal excitability. Because the effects of SES can outlast the period of stimulation, we examined the possibility that SES can also enhance the retention of motor performance, motor memory consolidation, after 24 h (Day 2) and 7 days (Day 7), that such effects would be scaled by SES duration, and that such effects were mediated by changes in aspects of corticospinal excitability, short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF). Healthy young adults (n = 40) received either 20 (SES-20), 40 (SES-40), or 60 min (SES-60) of real SES, or sham SES (SES-0). The results showed SES-20 increased visuomotor performance on Day 2 (15%) and Day 7 (17%) and SES-60 increased visuomotor performance on Day 7 (11%; all p < 0.05) compared with SES-0. Specific responses to transcranial magnetic stimulation (TMS) increased immediately after SES (p < 0.05) but not on Days 2 and 7. In addition, changes in behavioral and neurophysiological parameters did not correlate, suggesting that paths and structures other than the ones TMS can assay must be (also) involved in the increases in visuomotor performance after SES. As examined in the present study, low-intensity peripheral electrical nerve stimulation did not have acute effects on healthy adults' visuomotor performance but SES had delayed effects in the form of enhanced motor memory consolidation that were not scaled by the duration of SES. PMID:27014043

  14. 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.

  15. Myocardial Scaffold-based Cardiac Tissue Engineering: Application of Coordinated Mechanical and Electrical Stimulations

    PubMed Central

    Wang, Bo; Wang, Guangjun; To, Filip; Butler, J. Ryan; Claude, Andrew; McLaughlin, Ronald M.; Williams, Lakiesha N.; de Jongh Curry, Amy L.; Liao, Jun

    2013-01-01

    Recently, we have developed an optimal decellularization protocol to generate 3D porcine myocardial scaffolds, which preserved natural extracellular matrix structure, mechanical anisotropy, and vasculature templates, and also showed good cell recellularization and differentiation potential. In this study, a multi-stimulation bioreactor was built to provide coordinated mechanical and electrical stimulations for facilitating stem cell differentiation and cardiac construct development. The acellular myocardial scaffolds were seeded with mesenchymal stem cells (106 cells/ml) by needle injection and subjected to 5-azacytidine treatment (3 μmol/L, 24 h) and various bioreactor conditioning protocols. We found that, after 2-day culture with mechanical (20% strain) and electrical stimulation (5 V, 1 Hz), high cell density and good cell viability were observed in the reseeded scaffold. Immunofluorescence staining demonstrated that the differentiated cells showed cardiomyocyte-like phenotype, by expressing sarcomeric α-actinin, myosin heavy chain, cardiac troponin T, connexin-43, and N-cadherin. Biaxial mechanical testing demonstrated that positive tissue remodeling took place after 2-day bioreactor conditioning (20% strain + 5 V, 1 Hz); passive mechanical properties of the 2-day and 4-day tissue constructs were comparable to the tissue constructs produced by stirring reseeding followed by 2-week static culture, implying the effectiveness and efficiency of the coordinated simulations in promoting tissue remodeling. In short, the synergistic stimulations might be beneficial not only for the quality of cardiac construct development, but also for patients by reducing the waiting time in future clinical scenarios. PMID:23923967

  16. Cardiomyocyte behavior on biodegradable polyurethane/gold nanocomposite scaffolds under electrical stimulation.

    PubMed

    Ganji, Yasaman; Li, Qian; Quabius, Elgar Susanne; Böttner, Martina; Selhuber-Unkel, Christine; Kasra, Mehran

    2016-02-01

    Following a myocardial infarction (MI), cardiomyocytes are replaced by scar tissue, which decreases ventricular contractile function. Tissue engineering is a promising approach to regenerate such damaged cardiomyocyte tissue. Engineered cardiac patches can be fabricated by seeding a high density of cardiac cells onto a synthetic or natural porous polymer. In this study, nanocomposite scaffolds made of gold nanotubes/nanowires incorporated into biodegradable castor oil-based polyurethane were employed to make micro-porous scaffolds. H9C2 cardiomyocyte cells were cultured on the scaffolds for one day, and electrical stimulation was applied to improve cell communication and interaction in neighboring pores. Cells on scaffolds were examined by fluorescence microscopy and scanning electron microscopy, revealing that the combination of scaffold design and electrical stimulation significantly increased cell confluency of H9C2 cells on the scaffolds. Furthermore, we showed that the gene expression levels of Nkx2.5, atrial natriuretic peptide (ANF) and natriuretic peptide precursor B (NPPB), which are functional genes of the myocardium, were up-regulated by the incorporation of gold nanotubes/nanowires into the polyurethane scaffolds, in particular after electrical stimulation. PMID:26652343

  17. Electrical acupoint stimulation changes body composition and the meridian systems in postmenopausal women with obesity.

    PubMed

    Lin, Chia-Hsien; Lin, Yu-Min; Liu, Chi-Feng

    2010-01-01

    This study evaluates the effects of electrical stimulation on body composition and the meridian system in postmenopausal women with obesity. Forty-one postmenopausal women were recruited in Taiwan. The body composition was used as a screening test for obesity (percentage of body fat: > 30%, waist circumference: > 80 cm). The experimental group (EG, n = 20) received modulated middle-frequency electrical stimulation treatment for 20 min twice a week for 12 consecutive weeks at the Zusanli (ST36) and Sanyinjiao (SP6) acupoints. The control group (CG, n = 21) did not receive any intervention. The measurements of body composition and the meridian system were recorded for both groups in the pre- and post-study. The results showed that the data of body composition (weight, waist and hip circumference, percentage of body fat, and percentage of lean muscle mass) changed considerably in the EG (p < 0.05); however, no significant difference was observed in the CG. The left triple burner meridian changed notably in both EG and CG throughout the study (p < 0.05), however there was no difference between the two groups in the overall mean value, up-down ratio, qi and blood ratio, and yin-yang ratio. Our findings suggest that modulated middle-frequency electrical stimulation could help to improve body composition in postmenopausal women with obesity, potentially providing them with better care and health by integrating Western medicine and traditional Chinese medicine.

  18. Conditioning the middle ear reflex at sensation levels below reflex threshold: air jet and electrical stimulation.

    PubMed

    McDaniel-Bacon, L; Fulton, R T; Laskowski, R P

    1980-01-01

    An ABAB functional analysis, conditioning and generalization, design was used in 3 experiments (2 were formal studies and 1 was empirical in nature) to investigate the conditionability of the middle ear reflex. The conditioned stimuli were subreflex threshold pure tones of various frequencies and intensities. The unconditioned stimulus (UCS) was an auricular air jet to the contralateral ear in the first experiment and cutaneous electrical stimulation to the ipsolateral, probe ear in the last 2 experiments. Reflexes were monitored by an otoadmittance meter, storage oscilloscope, and strip chart recorder. In the first experiment (air jet UCS), no subjects met the conditioning criterion within the maximum presentation of 400 paired trials, despite pilot evidence which indicated conditioning was feasible. In the second experiment (electrical stimulation UCS), 2 subjects met conditioning criterion; however, only one subject reconditioned and demonstrated partial generalization to other conditioned stimuli. In the third experiment (electrical stimulation UCS), one of 3 subjects who had previously been unconditionable with the air jet UCS met conditioning and reconditioning criterion and demonstrated partial generalization. Results indicate that the middle ear reflex can be conditioned to be elicited by subreflex threshold pure tones, however, results are limited.

  19. The effects of whirlpool bath and neuromuscular electrical stimulation on complex regional pain syndrome.

    PubMed

    Devrimsel, Gul; Turkyilmaz, Aysegul Kucukali; Yildirim, Murat; Beyazal, Munevver Serdaroglu

    2015-01-01

    [Purpose] The aim of the present study was to investigate and compare the effects of whirlpool bath and neuromuscular electrical stimulation on complex regional pain syndrome. [Subjects and Methods] Sixty outpatients (30 per group) with complex regional pain syndrome participated. They received 15 treatment 5 days per week for 3 weeks. The outcome measures were the visual analogue scale for pain, edema, range of motion of the wrist (flexion and extension), fingertip-to-distal palmar crease distance, hand grip strength, and pinch strength. All parameters were measured at baseline (week 0) and at the trial end (week 3). [Results] There were significant improvements in all parameters after therapy in both groups. The whirlpool bath group showed significantly better improvements in the visual analogue score, hand edema, hand grip strength, wrist range of motion (both flexion and extension), fingertip-to-distal palmar crease distance, and the three-point and fingertip pinch strengths than the neuromuscular electrical stimulation group; however, the lateral pinch strengths were similar. [Conclusion] Both whirlpool bath and neuromuscular electrical stimulation are effective in the treatment of complex regional pain syndrome, but the efficacy of the whirlpool bath treatment was better.

  20. Rebuilding motor function of the spinal cord based on functional electrical stimulation

    PubMed Central

    Shen, Xiao-yan; Du, Wei; Huang, Wei; Chen, Yi

    2016-01-01

    Rebuilding the damaged motor function caused by spinal cord injury is one of the most serious challenges in clinical neuroscience. The function of the neural pathway under the damaged sites can be rebuilt using functional electrical stimulation technology. In this study, the locations of motor function sites in the lumbosacral spinal cord were determined with functional electrical stimulation technology. A three-dimensional map of the lumbosacral spinal cord comprising the relationship between the motor function sites and the corresponding muscle was drawn. Based on the individual experimental parameters and normalized coordinates of the motor function sites, the motor function sites that control a certain muscle were calculated. Phasing pulse sequences were delivered to the determined motor function sites in the spinal cord and hip extension, hip flexion, ankle plantarflexion, and ankle dorsiflexion movements were successfully achieved. The results show that the map of the spinal cord motor function sites was valid. This map can provide guidance for the selection of electrical stimulation sites during the rebuilding of motor function after spinal cord injury.

  1. Cardiomyocyte behavior on biodegradable polyurethane/gold nanocomposite scaffolds under electrical stimulation.

    PubMed

    Ganji, Yasaman; Li, Qian; Quabius, Elgar Susanne; Böttner, Martina; Selhuber-Unkel, Christine; Kasra, Mehran

    2016-02-01

    Following a myocardial infarction (MI), cardiomyocytes are replaced by scar tissue, which decreases ventricular contractile function. Tissue engineering is a promising approach to regenerate such damaged cardiomyocyte tissue. Engineered cardiac patches can be fabricated by seeding a high density of cardiac cells onto a synthetic or natural porous polymer. In this study, nanocomposite scaffolds made of gold nanotubes/nanowires incorporated into biodegradable castor oil-based polyurethane were employed to make micro-porous scaffolds. H9C2 cardiomyocyte cells were cultured on the scaffolds for one day, and electrical stimulation was applied to improve cell communication and interaction in neighboring pores. Cells on scaffolds were examined by fluorescence microscopy and scanning electron microscopy, revealing that the combination of scaffold design and electrical stimulation significantly increased cell confluency of H9C2 cells on the scaffolds. Furthermore, we showed that the gene expression levels of Nkx2.5, atrial natriuretic peptide (ANF) and natriuretic peptide precursor B (NPPB), which are functional genes of the myocardium, were up-regulated by the incorporation of gold nanotubes/nanowires into the polyurethane scaffolds, in particular after electrical stimulation.

  2. Transcutaneous Electrical Retinal Stimulation Therapy for Age-Related Macular Degeneration

    PubMed Central

    Shinoda, Kei; Imamura, Yutaka; Matsuda, Sayaka; Seki, Maiko; Uchida, Atsuro; Grossman, Terry; Tsubota, Kazuo

    2008-01-01

    This reports the preliminary outcome of a transpalpebral electrical retinal stimulation therapy for age-related macular degeneration (ARMD). Twenty-one patients consisting of 16 with wet-type (Group-W) and 5 with dry-type (Group-D) ARMD with a mean age of 73.9 ± 9.5 years (range 51 to 85 years) were recruited for this study. Transpalpebral electrical retinal stimulation (20 minutes, 800 μA) was applied on the patients 4 times per day for up to 1 month. The mean best-corrected visual acuity (Early Treatment Diabetic Retinopathy Study [ETDRS] score) changed from 29.5±5.1 to 31.8±5.0 in Group-W and from 39.8±4.7 to 42.9±4.9 in Group-D. Neither ocular nor systemic adverse effects were observed with the exception of one patient who developed contact dermatitis. Due to several limitations such as lack of control, patients’ learning effect, etc, the efficacy of the therapy could not be drawn. This preliminary study, however, showed that the transpalpebral electrical retinal stimulation therapy can be non-invasively applied on wet-type ARMD patients. PMID:19526044

  3. Rebuilding motor function of the spinal cord based on functional electrical stimulation.

    PubMed

    Shen, Xiao-Yan; Du, Wei; Huang, Wei; Chen, Yi

    2016-08-01

    Rebuilding the damaged motor function caused by spinal cord injury is one of the most serious challenges in clinical neuroscience. The function of the neural pathway under the damaged sites can be rebuilt using functional electrical stimulation technology. In this study, the locations of motor function sites in the lumbosacral spinal cord were determined with functional electrical stimulation technology. A three-dimensional map of the lumbosacral spinal cord comprising the relationship between the motor function sites and the corresponding muscle was drawn. Based on the individual experimental parameters and normalized coordinates of the motor function sites, the motor function sites that control a certain muscle were calculated. Phasing pulse sequences were delivered to the determined motor function sites in the spinal cord and hip extension, hip flexion, ankle plantarflexion, and ankle dorsiflexion movements were successfully achieved. The results show that the map of the spinal cord motor function sites was valid. This map can provide guidance for the selection of electrical stimulation sites during the rebuilding of motor function after spinal cord injury. PMID:27651782

  4. 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

  5. Rebuilding motor function of the spinal cord based on functional electrical stimulation.

    PubMed

    Shen, Xiao-Yan; Du, Wei; Huang, Wei; Chen, Yi

    2016-08-01

    Rebuilding the damaged motor function caused by spinal cord injury is one of the most serious challenges in clinical neuroscience. The function of the neural pathway under the damaged sites can be rebuilt using functional electrical stimulation technology. In this study, the locations of motor function sites in the lumbosacral spinal cord were determined with functional electrical stimulation technology. A three-dimensional map of the lumbosacral spinal cord comprising the relationship between the motor function sites and the corresponding muscle was drawn. Based on the individual experimental parameters and normalized coordinates of the motor function sites, the motor function sites that control a certain muscle were calculated. Phasing pulse sequences were delivered to the determined motor function sites in the spinal cord and hip extension, hip flexion, ankle plantarflexion, and ankle dorsiflexion movements were successfully achieved. The results show that the map of the spinal cord motor function sites was valid. This map can provide guidance for the selection of electrical stimulation sites during the rebuilding of motor function after spinal cord injury.

  6. Rebuilding motor function of the spinal cord based on functional electrical stimulation

    PubMed Central

    Shen, Xiao-yan; Du, Wei; Huang, Wei; Chen, Yi

    2016-01-01

    Rebuilding the damaged motor function caused by spinal cord injury is one of the most serious challenges in clinical neuroscience. The function of the neural pathway under the damaged sites can be rebuilt using functional electrical stimulation technology. In this study, the locations of motor function sites in the lumbosacral spinal cord were determined with functional electrical stimulation technology. A three-dimensional map of the lumbosacral spinal cord comprising the relationship between the motor function sites and the corresponding muscle was drawn. Based on the individual experimental parameters and normalized coordinates of the motor function sites, the motor function sites that control a certain muscle were calculated. Phasing pulse sequences were delivered to the determined motor function sites in the spinal cord and hip extension, hip flexion, ankle plantarflexion, and ankle dorsiflexion movements were successfully achieved. The results show that the map of the spinal cord motor function sites was valid. This map can provide guidance for the selection of electrical stimulation sites during the rebuilding of motor function after spinal cord injury. PMID:27651782

  7. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    NASA Astrophysics Data System (ADS)

    Albaugh, Daniel L.; Salzwedel, Andrew; van den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-09-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action.

  8. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    PubMed Central

    Albaugh, Daniel L.; Salzwedel, Andrew; Van Den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-01-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action. PMID:27601003

  9. Temporal Code-Driven Stimulation: Definition and Application to Electric Fish Signaling

    PubMed Central

    Lareo, Angel; Forlim, Caroline G.; Pinto, Reynaldo D.; Varona, Pablo; Rodriguez, Francisco de Borja

    2016-01-01

    Closed-loop activity-dependent stimulation is a powerful methodology to assess information processing in biological systems. In this context, the development of novel protocols, their implementation in bioinformatics toolboxes and their application to different description levels open up a wide range of possibilities in the study of biological systems. We developed a methodology for studying biological signals representing them as temporal sequences of binary events. A specific sequence of these events (code) is chosen to deliver a predefined stimulation in a closed-loop manner. The response to this code-driven stimulation can be used to characterize the system. This methodology was implemented in a real time toolbox and tested in the context of electric fish signaling. We show that while there are codes that evoke a response that cannot be distinguished from a control recording without stimulation, other codes evoke a characteristic distinct response. We also compare the code-driven response to open-loop stimulation. The discussed experiments validate the proposed methodology and the software toolbox. PMID:27766078

  10. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens.

    PubMed

    Albaugh, Daniel L; Salzwedel, Andrew; Van Den Berge, Nathalie; Gao, Wei; Stuber, Garret D; Shih, Yen-Yu Ian

    2016-01-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action.

  11. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens.

    PubMed

    Albaugh, Daniel L; Salzwedel, Andrew; Van Den Berge, Nathalie; Gao, Wei; Stuber, Garret D; Shih, Yen-Yu Ian

    2016-01-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action. PMID:27601003

  12. Electrical stimulation directs engineered cardiac tissue to an age-matched native phenotype

    PubMed Central

    Lasher, Richard A; Pahnke, Aric Q; Johnson, Jeffrey M; Sachse, Frank B

    2012-01-01

    Quantifying structural features of native myocardium in engineered tissue is essential for creating functional tissue that can serve as a surrogate for in vitro testing or the eventual replacement of diseased or injured myocardium. We applied three-dimensional confocal imaging and image analysis to quantitatively describe the features of native and engineered cardiac tissue. Quantitative analysis methods were developed and applied to test the hypothesis that environmental cues direct engineered tissue toward a phenotype resembling that of age-matched native myocardium. The analytical approach was applied to engineered cardiac tissue with and without the application of electrical stimulation as well as to age-matched and adult native tissue. Individual myocytes were segmented from confocal image stacks and assigned a coordinate system from which measures of cell geometry and connexin-43 spatial distribution were calculated. The data were collected from 9 nonstimulated and 12 electrically stimulated engineered tissue constructs and 5 postnatal day 12 and 7 adult hearts. The myocyte volume fraction was nearly double in stimulated engineered tissue compared to nonstimulated engineered tissue (0.34 ± 0.14 vs 0.18 ± 0.06) but less than half of the native postnatal day 12 (0.90 ± 0.06) and adult (0.91 ± 0.04) myocardium. The myocytes under electrical stimulation were more elongated compared to nonstimulated myocytes and exhibited similar lengths, widths, and heights as in age-matched myocardium. Furthermore, the percentage of connexin-43-positive membrane staining was similar in the electrically stimulated, postnatal day 12, and adult myocytes, whereas it was significantly lower in the nonstimulated myocytes. Connexin-43 was found to be primarily located at cell ends for adult myocytes and irregularly but densely clustered over the membranes of nonstimulated, stimulated, and postnatal day 12 myocytes. These findings support our hypothesis and reveal that the

  13. Randomised sham-controlled trial of transcutaneous electrical stimulation in obstructive sleep apnoea

    PubMed Central

    Pengo, Martino F; Xiao, Sichang; Ratneswaran, Culadeeban; Reed, Kate; Shah, Nimish; Chen, Tao; Douiri, Abdel; Hart, Nicholas; Luo, Yuanming; Rossi, Gian Paolo; Williams, Adrian; Polkey, Michael I; Moxham, John; Steier, Joerg

    2016-01-01

    Introduction Obstructive sleep apnoea (OSA) is characterised by a loss of neuromuscular tone of the upper airway dilator muscles while asleep. This study investigated the effectiveness of transcutaneous electrical stimulation in patients with OSA. Patients and methods This was a randomised, sham-controlled crossover trial using transcutaneous electrical stimulation of the upper airway dilator muscles in patients with confirmed OSA. Patients were randomly assigned to one night of sham stimulation and one night of active treatment. The primary outcome was the 4% oxygen desaturation index, responders were defined as patients with a reduction >25% in the oxygen desaturation index when compared with sham stimulation and/or with an index <5/hour in the active treatment night. Results In 36 patients (age mean 50.8 (SD 11.2) years, male/female 30/6, body mass index median 29.6 (IQR 26.9–34.9) kg/m2, Epworth Sleepiness Scale 10.5 (4.6) points, oxygen desaturation index median 25.7 (16.0–49.1)/hour, apnoea-hypopnoea index median 28.1 (19.0–57.0)/hour) the primary outcome measure improved when comparing sham stimulation (median 26.9 (17.5–39.5)/hour) with active treatment (median 19.5 (11.6–40.0)/hour; p=0.026), a modest reduction of the mean by 4.1 (95% CI −0.6 to 8.9)/hour. Secondary outcome parameters of patients' perception indicated that stimulation was well tolerated. Responders (47.2%) were predominantly from the mild-to-moderate OSA category. In this subgroup, the oxygen desaturation index was reduced by 10.0 (95% CI 3.9 to 16.0)/hour (p<0.001) and the apnoea-hypopnoea index was reduced by 9.1 (95% CI 2.0 to 16.2)/hour (p=0.004). Conclusion Transcutaneous electrical stimulation of the pharyngeal dilators during a single night in patients with OSA improves upper airway obstruction and is well tolerated. Trial registration number NCT01661712. PMID:27435610

  14. [Percutaneous electric and magnetic stimulation of the motor cortex in man. Physiological aspects and clinical applications].

    PubMed

    Maertens de Noordhout, A; Rothwell, J C; Day, B L; Thompson, P D; Delwaide, P J; Marsden, C D

    1989-01-01

    The new techniques of percutaneous electric and magnetic stimulation of the motor cortex in conscious man provide a unique opportunity of functional testing of the central motor pathways. These techniques seem to be safe and no immediate or delayed adverse reactions have been reported. The physiological studies so far performed suggest that the structures which are preferentially excited by these methods are the fast conducting pyramidal neurones. It has been shown that a single cortical stimulus is able to activate spinal motoneurones repeatedly. This phenomenon can easily be explained if the cortical stimulus generates multiple descending volleys in the central motor pathways. By comparison with experiments of stimulation of the exposed motor cortex in animals, it is likely that electric brain stimulation directly activates the axons of the pyramidal neurons at their origin and to a lesser extent also recruits these neurons transsynaptically, via some cortical interneurones. Magnetic stimulation of the brain at the vertex seems to act mostly by the latter mechanism. These different modes of action of the two methods of cortical stimulation explain the latency differences of the EMG responses obtained with either technique. Increased excitability of the spinal motoneurones and the existence of multiple descending volleys in response to a single cortical stimulus result in shortening of the latencies and greater amplitude of the responses recorded during voluntary contraction of the target muscle. Stimulation of the motor cortex has been used in pilot studies conducted on patients suffering from various disorders of the central motor pathways, such as multiple sclerosis, cervical spondylosis, motor neurone disease or stroke. The sensitivity of the technique looks promising. In M.S., the EMG responses usually show an increased central conduction latency, a reduced amplitude and a prolonged duration. The severity of the electrophysiological abnormalities is not very

  15. Gut pain reactions in man: an experimental investigation using short and long duration transmucosal electrical stimulation.

    PubMed

    Arendt-Nielsen, L; Drewes, A M; Hansen, J B; Tage-Jensen, U

    1997-02-01

    Visceral pain is a substantial, clinical problem but unfortunately few experimental models are available to study this phenomenon in man. In the present study we inserted a stimulation catheter 5-10 cm into the ileo-sigmoidostomy of nine patients. The catheter contained six small, flexible electrodes separated by 4 mm. The gut was stimulated by single burst, repeated burst (five stimuli delivered at 2 Hz), or continuous burst stimuli (4 Hz for 30, 60, 90, and 120 s). The sensation (ST), pain detection (PDT), and pain tolerance (PTT) thresholds to single/repeated burst stimuli were determined. The location/size/sensitivity of referred pain after repeated/continuous stimulation were characterized. The brain potentials to single burst stimuli and to increasing stimulus intensity were measured. ST to single burst stimuli was easy to determine (8 mA) and to reproduce. The patients found it difficult to determine the PDT and PTT to single burst stimuli, however both thresholds were easily determined for repeated burst stimuli. The pain thresholds to single burst stimuli were twice as high as the thresholds to repeated burst stimuli, indicating the importance of central temporal summation for visceral pain. Minor changes in the stimulus location resulted in changes of the referred pain projection site. The words most frequently selected (78%) from the McGill Pain Questionnaire to describe repeated burst stimulations were shooting, pricking, flashing, and boring. The amplitude of the brain potentials increased at increasing stimulus intensity. A stimulus intensity giving an initial pain rating of around 5 on a 0-10 visual analog scale (VAS) was used for continuous stimulation. A general increase of the pain intensity and the area of referred pain was found during this stimulation. It was concluded that electrical stimulation of the human gut provokes pain and especially long sequences of visceral stimuli are adequate to evoke referred pain mimicking pain profiles of

  16. Effect of Electrical Stimulation of the Suprahyoid Muscles in Brain-Injured Patients with Dysphagia.

    PubMed

    Beom, Jaewon; Oh, Byung-Mo; Choi, Kyoung Hyo; Kim, Won; Song, Young Jin; You, Dae Sang; Kim, Sang Jun; Han, Tai Ryoon

    2015-08-01

    The purpose of this study is to determine whether neuromuscular electrical stimulation of the suprahyoid muscle is effective compared to that of the infrahyoid muscle in brain-injured patients with dysphagia. A total of 132 patients with stroke, traumatic brain injury, or brain tumor in 2 university hospitals were allocated to 2 groups: those who received electrical stimulation therapy (EST) on the suprahyoid muscles (SM group, n = 66) and those who received EST with one pair of electrodes on the suprahyoid muscle and the other pair on the infrahyoid muscle (SI group, n = 66). Patients received 11.2 ± 3.4 sessions of electrical stimulation in the SM group and 11.9 ± 3.4 sessions in the SI group. The functional dysphagia scale (FDS), swallow function score (SFS), supraglottic penetration, and subglottic aspiration were measured using videofluoroscopic swallowing study. FDS scores decreased from 42.0 ± 19.1 to 32.3 ± 17.8 in the SM group and from 44.8 ± 17.4 to 32.9 ± 18.8 in the SI group by per-protocol (PP) analysis, and those decreased from 41.2 ± 20.9 to 34.5 ± 20.3 in the SM group and from 44.3 ± 19.1 to 35.7 ± 20.5 in the SI group by intention-to-treat (ITT) analysis, after electrical stimulation (p < 0.001 for each). SFSs increased from 3.3 ± 1.8 to 4.2 ± 1.6 in the SM group and from 2.8 ± 1.8 to 4.0 ± 1.8 in the SI group by PP analysis, and those increased from 3.3 ± 1.6 to 3.9 ± 1.6 in the SM group and from 2.8 ± 1.9 to 3.6 ± 2.0 in the SI group by ITT analysis, after electrical stimulation (p < 0.001, respectively). However, changes in FDS scores, SFSs, penetration, and aspiration were comparable between the SM and the SI groups. The results suggest that both SM and SI therapies induced similar improvements in swallowing function in brain-injured patients.

  17. The assessment of a novel electrical stimulation waveform recently introduced for the treatment of overactive bladder.

    PubMed

    Slovak, M; Barker, A T; Chapple, C R

    2013-05-01

    Transdermal amplitude modulated signal (TAMS) is a novel electrical stimulus which has been recently introduced for the treatment of overactive bladder (OAB) syndrome. It has been suggested that it has advantages over conventional waveforms by providing more effective penetration of the skin to enhance the efficacy of therapy. As there is no literature which supports this, we performed this study to evaluate potential advantages of the TAMS signal for electrical stimulation of subcutaneous nerves as compared to conventional stimuli. The stimuli were applied on forearms of ten healthy volunteers and electrical parameters of stimuli and sensation measurements were recorded. None of the recorded electrical parameters showed significant differences (paired t-test p ≥ 0.250) between the TAMS and conventional waveforms. Similarly, the mean sensation recorded at motor threshold level and at 50% of maximal motor response level showed no differences (paired t-test p = 0.242 and p = 0.687 respectively). It is unlikely, based on the results of this study, that TAMS provides any enhancement of the efficacy of conventional stimuli. We would recommend that further studies are carried out to clearly demonstrate in man what, if any, advantages the TAMS waveform has over conventional stimulation before it is widely deployed into clinical practice. PMID:23571145

  18. [Negative air ions generated by plants upon pulsed electric field stimulation applied to soil].

    PubMed

    Wu, Ren-ye; Deng, Chuan-yuan; Yang, Zhi-jian; Weng, Hai-yong; Zhu, Tie-jun-rong; Zheng, Jin-gui

    2015-02-01

    This paper investigated the capacity of plants (Schlumbergera truncata, Aloe vera var. chinensis, Chlorophytum comosum, Schlumbergera bridgesii, Gymnocalycium mihanovichii var. friedrichii, Aspidistra elatior, Cymbidium kanran, Echinocactus grusonii, Agave americana var. marginata, Asparagus setaceus) to generate negative air ions (NAI) under pulsed electric field stimulation. The results showed that single plant generated low amounts of NAI in natural condition. The capacity of C. comosum and G. mihanovichii var. friedrichii generated most NAI among the above ten species, with a daily average of 43 ion · cm(-3). The least one was A. americana var. marginata with the value of 19 ion · cm(-3). When proper pulsed electric field stimulation was applied to soil, the NAI of ten plant species were greatly improved. The effect of pulsed electric field u3 (average voltage over the pulse period was 2.0 x 10(4) V, pulse frequency was 1 Hz, and pulse duration was 50 ms) was the greatest. The mean NAI concentration of C. kanran was the highest 1454967 ion · cm(-3), which was 48498.9 times as much as that in natural condition. The lowest one was S. truncata with the value of 34567 ion · cm(-3), which was 843.1 times as much as that in natural condition. The capacity of the same plants to generate negative air ion varied extremely under different intensity pulsed electric fields. PMID:26094455

  19. [Negative air ions generated by plants upon pulsed electric field stimulation applied to soil].

    PubMed

    Wu, Ren-ye; Deng, Chuan-yuan; Yang, Zhi-jian; Weng, Hai-yong; Zhu, Tie-jun-rong; Zheng, Jin-gui

    2015-02-01

    This paper investigated the capacity of plants (Schlumbergera truncata, Aloe vera var. chinensis, Chlorophytum comosum, Schlumbergera bridgesii, Gymnocalycium mihanovichii var. friedrichii, Aspidistra elatior, Cymbidium kanran, Echinocactus grusonii, Agave americana var. marginata, Asparagus setaceus) to generate negative air ions (NAI) under pulsed electric field stimulation. The results showed that single plant generated low amounts of NAI in natural condition. The capacity of C. comosum and G. mihanovichii var. friedrichii generated most NAI among the above ten species, with a daily average of 43 ion · cm(-3). The least one was A. americana var. marginata with the value of 19 ion · cm(-3). When proper pulsed electric field stimulation was applied to soil, the NAI of ten plant species were greatly improved. The effect of pulsed electric field u3 (average voltage over the pulse period was 2.0 x 10(4) V, pulse frequency was 1 Hz, and pulse duration was 50 ms) was the greatest. The mean NAI concentration of C. kanran was the highest 1454967 ion · cm(-3), which was 48498.9 times as much as that in natural condition. The lowest one was S. truncata with the value of 34567 ion · cm(-3), which was 843.1 times as much as that in natural condition. The capacity of the same plants to generate negative air ion varied extremely under different intensity pulsed electric fields.

  20. The Effects of Neuromuscular Electrical Stimulation Training on Abdominal Strength, Endurance, and Selected Anthropometric Measures

    PubMed Central

    Porcari, John P.; Miller, Jennifer; Cornwell, Kelly; Foster, Carl; Gibson, Mark; McLean, Karen; Kernozek, Tom

    2005-01-01

    We studied the effects of self-administered neuromuscular electrical stimulation (NMES) on changes in strength, endurance, selected anthropometric measures, and subject’s perceived shape and satisfaction of the abdominal wall. Twenty-four adults (experimental group) stimulated their abdominals 5 days per week (20-40 minutes per session) for 8 weeks and refrained from engaging in any additional exercise during the study. A control group (N=16) refrained from exercising the abdominals or engaging in any other exercise training during the study. Subjects were tested at the beginning, mid-point, and end of the study. Isometric strength of the abdominal muscles was tested using a isokinetic dynamometer, endurance was measured using the ACSM curl-up test, abdominal circumference was measured using a steel tape measure, and body shape and satisfaction were assessed via questionnaire. The stimulation group had a 58% increase in abdominal strength, whereas the control group did not change. The stimulation group also had a 100% increase in abdominal endurance versus a 28% increase in the control group. Waist circumference decreased by of 3.5 cm in the stimulation group compared to no significant change in the control group. All 24 subjects in the stimulation group felt that their midsections were more “toned” and “firmed” and 13/24 (54%) felt that their posture had improved as a result of the stimulation. None of the control group subjects reported changes in these parameters. There were no significant differences in body weight, BMI, or skinfold thickness over the course of the study in either group. NMES, as used in the current study, resulted in significant improvements in the muscular strength and endurance of the abdominal region, as well as subject’s perceived shape and satisfaction of the mid-section. Key Points Electrical muscle stimulation (EMS) was effective in increasing muscle strength and endurance All subjects perceived their abdominal muscles to be

  1. 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

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

    PubMed

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

    2016-07-14

    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

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

    PubMed

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

    2016-07-14

    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

  4. Properties and application of a multichannel integrated circuit for low-artifact, patterned electrical stimulation of neural tissue

    PubMed Central

    Hottowy, Paweł; Skoczeń, Andrzej; Gunning, Deborah E.; Kachiguine, Sergei; Mathieson, Keith; Sher, Alexander; Wiącek, Piotr; Litke, Alan M.; Dąbrowski, Władysław

    2012-01-01

    Objective Modern multielectrode array (MEA) systems can record the neuronal activity from thousands of electrodes, but their ability to provide spatio-temporal patterns of electrical stimulation is very limited. Furthermore, the stimulus-related artifacts significantly limit the ability to record the neuronal responses to the stimulation. To address these issues, we designed a multichannel integrated circuit for patterned MEA-based electrical stimulation and evaluated its performance in experiments with isolated mouse and rat retina. Approach The Stimchip includes 64 independent stimulation channels. Each channel comprises an internal digital-to-analog converter that can be configured as a current or voltage source. The shape of the stimulation waveform is defined independently for each channel by the real-time data stream. In addition, each channel is equipped with circuitry for reduction of the stimulus artifact. Main results Using a high-density MEA stimulation/recording system, we effectively stimulated individual retinal ganglion cells (RGCs) and recorded the neuronal responses with minimal distortion, even on the stimulating electrodes. We independently stimulated a population of RGCs in rat retina and, using a complex spatio-temporal pattern of electrical stimulation pulses, we replicated visually-evoked spiking activity of a subset of these cells with high fidelity. Significance Compared with current state-of-the-art MEA systems, the Stimchip is able to stimulate neuronal cells with much more complex sequences of electrical pulses and with significantly reduced artifacts. This opens up new possibilities for studies of neuronal responses to electrical stimulation, both in the context of neuroscience research and in the development of neuroprosthetic devices. PMID:23160018

  5. Effect of Patterned Electrical Neuromuscular Stimulation on Vertical Jump in Collegiate Athletes

    PubMed Central

    Gulick, Dawn T.; Castel, John C.; Palermo, Francis X.; Draper, David O.

    2011-01-01

    Background: Patterned electrical neuromuscular stimulation (PENS) uses the electrical stimulation of sensory and motor nerves to achieve a skeletal muscle contraction using an electromyogram-derived functional pattern. PENS is used extensively for neuromuscular reeducation and treatment of muscle disuse atrophy. Purpose: To explore the effectiveness of PENS as applied to the quadriceps muscles on the vertical jump of an athletic population. Study Design: Experimental with control and repeated measures over time. Methods: Healthy college athletes (54 women, 75 men) were divided into 3 groups (control, n = 30; jump, n = 33; and jump with PENS, n = 63). There was no difference among groups’ height and weight. Athletes performed a baseline standing vertical jump using a vertical jump system. The control group continued its normal daily activities with no jumping tasks included. The jump groups performed 3 sets of 12 repetitions with a 2-minute rest between sets at a frequency of 3 times per week. The PENS group did the jumping with the coordination of an electrical stimulation system. Vertical jump was retested after 6 weeks of intervention and 2 weeks after cessation. Results: A 3-way repeated measures analysis of variance for time (control, jump alone, jump with PENS) revealed a significant difference (P < 0.05) for time and an interaction between time and treatment, as well as a significant difference for the PENS group from baseline to posttest and for the jump group from posttest to follow-up jump. There was no significant difference between groups for the baseline vertical jump. Conclusions: This study demonstrated that 6 weeks of vertical jump training coordinated with PENS resulted in a greater increase than jumping only or control. This pattern of stimulation with PENS in combination with jump training may positively affect jumping. PMID:23016002

  6. Synaptic Plasticity after Chemical Deafening and Electrical Stimulation of the Auditory Nerve in Cats

    PubMed Central

    Ryugo, D.K.; Baker, C.A.; Montey, K.L.; Chang, L.Y.; Coco, A.; Fallon, J.B.; Shepherd, R.K.

    2010-01-01

    The effects of deafness on brain structure and function have been studied using animal models of congenital deafness that include surgical ablation of the organ of Corti, acoustic trauma, ototoxic drugs, and hereditary deafness. This report describes the morphologic plasticity of auditory nerve synapses in response to ototoxic deafening and chronic electrical stimulation of the auditory nerve. Normal kittens were deafened by neonatal administration of neomycin that eliminated auditory receptor cells. Some of these cats were raised deaf, whereas others were chronically implanted with cochlear electrodes at two months of age and electrically stimulated for up to 12 months. The large endings of the auditory nerve, endbulbs of Held, were studied because they hold a key position in the timing pathway for sound localization, are readily identifiable, and exhibit deafness-associated abnormalities. Compared to normal hearing cats, synapses of ototoxically deafened cats displayed expanded postsynaptic densities, a decrease in synaptic vesicle (SV) density, and a reduction in the somatic size of spherical bushy cells (SBCs). When compared to normal hearing cats, endbulbs of ototoxically deafened cats that received cochlear stimulation expressed postsynaptic densities (PSDs) that were statistically identical in size, showed a 32.8% reduction in SV density, and whose target SBCs had a 25.5% reduction in soma area. These results demonstrate that electrical stimulation via a cochlear implant in chemically-deafened cats preserves PSD size but not other aspects of synapse morphology. The results further suggest that the effects of ototoxic deafness are not identical to those of hereditary deafness. PMID:20127807

  7. Effect of early treatment with transcutaneous electrical diaphragmatic stimulation (TEDS) on pulmonary inflammation induced by bleomycin

    PubMed Central

    Santos, Laisa A.; Silva, Carlos A.; Polacow, Maria L. O.

    2013-01-01

    Background Bleomycin (B) is an antineoplastic drug that has pulmonary fibrosis as a side effect. There are few experimental studies about the effects of physical therapy treatment in this case. Objective The objective was to study rat lungs treated with B and precocious intervention by transcutaneous electrical diaphragmatic stimulation (TEDS). Method Wistar rats were divided into 4 groups (n=5): a control group (C); a stimulated group (TEDS); a group treated with a single dose of B (intratracheally, 2.5 mg/kg) (B); and a group treated with B and electric stimulation (B + TEDS). After the B instillation, the electrical stimulation was applied for 7 days, for a duration of 20 minutes. Lung fragments were histologically processed with hematoxylin and eosin (HE) and 8-isoprostane-PGF2α (8-iso-PGF2α). The density of the alveolar area was determined by planimetry, the inflammatory profile was defined by the number of cells, and the level of oxidative stress in the pulmonary tissue was evaluated by 8-iso-PGF2α. For statistical analysis of the data, the Shapiro-Wilk test was used, followed by a one-way ANOVA with the post-hoc Bonferroni test (p≤0.05). Results The B group exhibited a significant reduction in the area density, and the acute treatment with B + TEDS prevented this reduction. There were increased numbers of fibroblasts, leukocytes, and macrophages in the B group, as well as increased lipid peroxidation, which was observed only in this group. Conclusion B promoted a reduction in the alveolar density area, thereby inducing the inflammatory process and increasing the production of free radicals. These effects were minimized by the application of TEDS at the initial treatment stage. PMID:24346295

  8. Salivary alpha-amylase and cortisol responsiveness following electrical stimulation stress in major depressive disorder patients.

    PubMed

    Tanaka, Yoshihiro; Ishitobi, Yoshinobu; Maruyama, Yoshihiro; Kawano, Aimi; Ando, Tomoko; Okamoto, Shizuko; Kanehisa, Masayuki; Higuma, Haruka; Ninomiya, Taiga; Tsuru, Jusen; Hanada, Hiroaki; Kodama, Kensuke; Isogawa, Koichi; Akiyoshi, Jotaro

    2012-03-30

    Major depressive disorder (MDD) is often associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis by chronic stress. In comparison, psychosocial stress-induced activation of salivary α-amylase (sAA) functions as a marker of sympathoadrenal medullary system (SAM) activity. However, in contrast to salivary cortisol, sAA has been less extensively studied in MDD patients. The present study measured sAA and salivary cortisol levels in patients with MDD. The authors determined Profile of Mood State (POMS) and State-Trait anxiety Inventory (STAI) scores, Heart Rate Variability (HRV), and sAA and salivary cortisol levels in 88 patients with MDD and 41 healthy volunteers following the application of electrical stimulation stress. Patients with major depressive disorder were 8 points or more on Hamilton Depression Scale (HAM-D) scores. Tension-Anxiety, Depression-Dejection, Anger-Hostility, Fatigue, and Confusion scores in patients with major depressive disorder were significantly increased compared to healthy controls. In contrast, Vigor scores in patients with MDD were significantly decreased compared with healthy controls. There was no difference in heart rate variability measures between MDD patients and healthy controls. The threshold of electrical stimulation applied in MDD patients was lower than that in healthy controls. SAA levels in female MDD patients were significantly elevated relative to controls both before and after electrical stimulation. Finally, there were no differences in salivary cortisol levels between major depressive patients and controls. In the present study only three time points were explored. Furthermore, the increased secretion of sAA before and after stimulation could allude to an increased responsiveness of novel and uncontrollable situations in patients with MDD. These preliminary results suggest that sAA might be a useful biological marker of MDD. PMID:22063648

  9. A Phenomenological Model of the Electrically Stimulated Auditory Nerve Fiber: Temporal and Biphasic Response Properties.

    PubMed

    Horne, Colin D F; Sumner, Christian J; Seeber, Bernhard U

    2016-01-01

    We present a phenomenological model of electrically stimulated auditory nerve fibers (ANFs). The model reproduces the probabilistic and temporal properties of the ANF response to both monophasic and biphasic stimuli, in isolation. The main contribution of the model lies in its ability to reproduce statistics of the ANF response (mean latency, jitter, and firing probability) under both monophasic and cathodic-anodic biphasic stimulation, without changing the model's parameters. The response statistics of the model depend on stimulus level and duration of the stimulating pulse, reproducing trends observed in the ANF. In the case of biphasic stimulation, the model reproduces the effects of pseudomonophasic pulse shapes and also the dependence on the interphase gap (IPG) of the stimulus pulse, an effect that is quantitatively reproduced. The model is fitted to ANF data using a procedure that uniquely determines each model parameter. It is thus possible to rapidly parameterize a large population of neurons to reproduce a given set of response statistic distributions. Our work extends the stochastic leaky integrate and fire (SLIF) neuron, a well-studied phenomenological model of the electrically stimulated neuron. We extend the SLIF neuron so as to produce a realistic latency distribution by delaying the moment of spiking. During this delay, spiking may be abolished by anodic current. By this means, the probability of the model neuron responding to a stimulus is reduced when a trailing phase of opposite polarity is introduced. By introducing a minimum wait period that must elapse before a spike may be emitted, the model is able to reproduce the differences in the threshold level observed in the ANF for monophasic and biphasic stimuli. Thus, the ANF response to a large variety of pulse shapes are reproduced correctly by this model.

  10. Acute Response to Unilateral Unipolar Electrical Carotid Sinus Stimulation in Patients With Resistant Arterial Hypertension.

    PubMed

    Heusser, Karsten; Tank, Jens; Brinkmann, Julia; Menne, Jan; Kaufeld, Jessica; Linnenweber-Held, Silvia; Beige, Joachim; Wilhelmi, Mathias; Diedrich, André; Haller, Hermann; Jordan, Jens

    2016-03-01

    Bilateral bipolar electric carotid sinus stimulation acutely reduced muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in patients with resistant arterial hypertension but is no longer available. The second-generation device uses a smaller unilateral unipolar disk electrode to reduce invasiveness while saving battery life. We hypothesized that the second-generation device acutely lowers BP and MSNA in treatment-resistant hypertensive patients. Eighteen treatment-resistant hypertensive patients (9 women/9 men; 53±11 years; 33±5 kg/m(2)) on stable medications have been included in the study. We monitored finger and brachial BP, heart rate, and MSNA. Without stimulation, BP was 165±31/91±18 mm Hg, heart rate was 75±17 bpm, and MSNA was 48±14 bursts per minute. Acute stimulation with intensities producing side effects that were tolerable in the short term elicited interindividually variable changes in systolic BP (-16.9±15.0 mm Hg; range, 0.0 to -40.8 mm Hg; P=0.002), heart rate (-3.6±3.6 bpm; P=0.004), and MSNA (-2.0±5.8 bursts per minute; P=0.375). Stimulation intensities had to be lowered in 12 patients to avoid side effects at the expense of efficacy (systolic BP, -6.3±7.0 mm Hg; range, 2.8 to -14.5 mm Hg; P=0.028 and heart rate, -1.5±2.3 bpm; P=0.078; comparison against responses with side effects). Reductions in diastolic BP and MSNA (total activity) were correlated (r(2)=0.329; P=0.025). In our patient cohort, unilateral unipolar electric baroreflex stimulation acutely lowered BP. However, side effects may limit efficacy. The approach should be tested in a controlled comparative study.

  11. A Phenomenological Model of the Electrically Stimulated Auditory Nerve Fiber: Temporal and Biphasic Response Properties

    PubMed Central

    Horne, Colin D. F.; Sumner, Christian J.; Seeber, Bernhard U.

    2016-01-01

    We present a phenomenological model of electrically stimulated auditory nerve fibers (ANFs). The model reproduces the probabilistic and temporal properties of the ANF response to both monophasic and biphasic stimuli, in isolation. The main contribution of the model lies in its ability to reproduce statistics of the ANF response (mean latency, jitter, and firing probability) under both monophasic and cathodic-anodic biphasic stimulation, without changing the model's parameters. The response statistics of the model depend on stimulus level and duration of the stimulating pulse, reproducing trends observed in the ANF. In the case of biphasic stimulation, the model reproduces the effects of pseudomonophasic pulse shapes and also the dependence on the interphase gap (IPG) of the stimulus pulse, an effect that is quantitatively reproduced. The model is fitted to ANF data using a procedure that uniquely determines each model parameter. It is thus possible to rapidly parameterize a large population of neurons to reproduce a given set of response statistic distributions. Our work extends the stochastic leaky integrate and fire (SLIF) neuron, a well-studied phenomenological model of the electrically stimulated neuron. We extend the SLIF neuron so as to produce a realistic latency distribution by delaying the moment of spiking. During this delay, spiking may be abolished by anodic current. By this means, the probability of the model neuron responding to a stimulus is reduced when a trailing phase of opposite polarity is introduced. By introducing a minimum wait period that must elapse before a spike may be emitted, the model is able to reproduce the differences in the threshold level observed in the ANF for monophasic and biphasic stimuli. Thus, the ANF response to a large variety of pulse shapes are reproduced correctly by this model. PMID:26903850

  12. Acute Response to Unilateral Unipolar Electrical Carotid Sinus Stimulation in Patients With Resistant Arterial Hypertension.

    PubMed

    Heusser, Karsten; Tank, Jens; Brinkmann, Julia; Menne, Jan; Kaufeld, Jessica; Linnenweber-Held, Silvia; Beige, Joachim; Wilhelmi, Mathias; Diedrich, André; Haller, Hermann; Jordan, Jens

    2016-03-01

    Bilateral bipolar electric carotid sinus stimulation acutely reduced muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in patients with resistant arterial hypertension but is no longer available. The second-generation device uses a smaller unilateral unipolar disk electrode to reduce invasiveness while saving battery life. We hypothesized that the second-generation device acutely lowers BP and MSNA in treatment-resistant hypertensive patients. Eighteen treatment-resistant hypertensive patients (9 women/9 men; 53±11 years; 33±5 kg/m(2)) on stable medications have been included in the study. We monitored finger and brachial BP, heart rate, and MSNA. Without stimulation, BP was 165±31/91±18 mm Hg, heart rate was 75±17 bpm, and MSNA was 48±14 bursts per minute. Acute stimulation with intensities producing side effects that were tolerable in the short term elicited interindividually variable changes in systolic BP (-16.9±15.0 mm Hg; range, 0.0 to -40.8 mm Hg; P=0.002), heart rate (-3.6±3.6 bpm; P=0.004), and MSNA (-2.0±5.8 bursts per minute; P=0.375). Stimulation intensities had to be lowered in 12 patients to avoid side effects at the expense of efficacy (systolic BP, -6.3±7.0 mm Hg; range, 2.8 to -14.5 mm Hg; P=0.028 and heart rate, -1.5±2.3 bpm; P=0.078; comparison against responses with side effects). Reductions in diastolic BP and MSNA (total activity) were correlated (r(2)=0.329; P=0.025). In our patient cohort, unilateral unipolar electric baroreflex stimulation acutely lowered BP. However, side effects may limit efficacy. The approach should be tested in a controlled comparative study. PMID:26831195

  13. Evaluation of electric field distribution in electromagnetic stimulation of human femoral head.

    PubMed

    Su, Yukun; Souffrant, Robert; Kluess, Daniel; Ellenrieder, Martin; Mittelmeier, Wolfram; van Rienen, Ursula; Bader, Rainer

    2014-12-01

    Electromagnetic stimulation is a common therapy used to support bone healing in the case of avascular necrosis of the femoral head. In the present study, we investigated a bipolar induction screw system with an integrated coil. The aim was to analyse the influence of the screw parameters on the electric field distribution in the human femoral head. In addition, three kinds of design parameters (the shape of the screw tip, position of the screw in the femoral head, and size of the screw insulation) were varied. The electric field distribution in the bone was calculated using the finite element software Comsol Multiphysics. Moreover, a validation experiment was set up for an identical bone specimen with an implanted screw. The electric potential of points inside and on the surface of the bone were measured and compared to numerical data. The electric field distribution within the bone was clearly changed by the different implant parameters. Repositioning the screw by a maximum of 10 mm and changing the insulation length by a maximum of 4 mm resulted in electric field volume changes of 16% and 7%, respectively. By comparing the results of numerical simulation with the data of the validation experiment, on average, the electric potential difference of 19% and 24% occurred when the measuring points were at a depth of approximately 5 mm within the femoral bone and directly on the surface of the femoral bone, respectively. The results of the numerical simulations underline that the electro-stimulation treatment of bone in clinical applications can be influenced by the implant parameters.

  14. 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

  15. 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.

  16. Rapid systemic up-regulation of genes after heat-wounding and electrical stimulation

    NASA Technical Reports Server (NTRS)

    Davies, E.; Vian, A.; Vian, C.; Stankovic, B.

    1997-01-01

    When one leaf of a tomato plant is electrically-stimulated or heat-wounded, proteinase inhibitor genes are rapidly up-regulated in distant leaves. The identity of the systemic wound signal(s) is not yet known, but major candidates include hormones transmitted via the phloem or the xylem, the electrically-stimulated self-propagating electrical signal in the phloem (the action potential, AP), or the heat-wound-induced surge in hydraulic pressure in the xylem evoking a local change in membrane potential in adjacent living cells (the variation potential, VP). In order to discriminate between these signals we have adopted two approaches. The first approach involves applying stimuli that evoke known signals and determining whether these signals have similar effects on the "model" transcripts for proteinase inhibitors (pin) and calmodulin (cal). Here we show that a heat wound almost invariably evokes a VP, while an electrical stimulation occasionally evokes an AP, and both of these signals induce accumulation of transcripts encoding proteinase inhibitors. The second approach involves identifying the array of genes turned on by heat-wounding. To this end, we have constructed a subtractive library for heat-wounded tissue, isolated over 800 putatively up-regulated clones, and shown that all but two of the fifty that we have analyzed by Northern hybridization are, indeed, up-regulated. Here we show the early kinetics of up-regulation of three of these transcripts in the terminal (4th) leaf in response to heat-wounding the 3rd leaf, about 5 cm away. Even though these transcripts show somewhat different time courses of induction, with one peaking at 30 min, another at 15 min, and another at 5 min after flaming of a distant leaf, they all exhibit a similar pattern, i.e., a transient period of transcript accumulation preceding a period of transcript decrease, followed by a second period of transcript accumulation.

  17. FREQUENCY-PLACE MAP FOR ELECTRICAL STIMULATION IN COCHLEAR IMPLANTS: CHANGE OVER TIME

    PubMed Central

    Vermeire, Katrien; Landsberger, David M.; Van de Heyning, Paul H.; Voormolen, Maurits; Punte, Andrea Kleine; Schatzer, Reinhold; Zierhofer, Clemens

    2015-01-01

    The relationship between the place of electrical stimulation from a cochlear implant and the corresponding perceived pitch remains uncertain. Previous studies have estimated what the pitch corresponding to a particular location should be. However, perceptual verification is difficult because a subject needs both a cochlear implant and sufficient residual hearing to reliably compare electric and acoustic pitches. Additional complications can arise from the possibility that the pitch corresponding to an electrode may change as the auditory system adapts to a sound processor. In the following experiment, five subjects with normal or near-to-normal hearing in one ear and a cochlear implant with a long electrode array in the other ear were studied. Pitch matches were made between single electrode pulse trains and acoustic tones before activation of the speech processor to gain an estimate of the pitch provided by electrical stimulation at a given insertion angle without the influence of exposure to a sound processor. The pitch matches were repeated after 1, 3, 6, and 12 months of experience with the sound processor to evaluate the effect of adaptation over time. Pre-activation pitch matches were lower than would be estimated by a spiral ganglion pitch map. Deviations were largest for stimulation below 240° degrees and smallest above 480°. With experience, pitch matches shifted towards the frequency-to-electrode allocation. However, no statistically significant pitch shifts were observed over time. The likely explanation for the lack of pitch change is that the frequency-to-electrode allocations for the long electrode arrays were already similar to the pre-activation pitch matches. Minimal place pitch shifts over time suggest a minimal amount of perceptual remapping needed for the integration of electric and acoustic stimuli, which may contribute to shorter times to asymptotic performance. PMID:25840373

  18. Frequency-place map for electrical stimulation in cochlear implants: Change over time.

    PubMed

    Vermeire, Katrien; Landsberger, David M; Van de Heyning, Paul H; Voormolen, Maurits; Kleine Punte, Andrea; Schatzer, Reinhold; Zierhofer, Clemens

    2015-08-01

    The relationship between the place of electrical stimulation from a cochlear implant and the corresponding perceived pitch remains uncertain. Previous studies have estimated what the pitch corresponding to a particular location should be. However, perceptual verification is difficult because a subject needs both a cochlear implant and sufficient residual hearing to reliably compare electric and acoustic pitches. Additional complications can arise from the possibility that the pitch corresponding to an electrode may change as the auditory system adapts to a sound processor. In the following experiment, five subjects with normal or near-to-normal hearing in one ear and a cochlear implant with a long electrode array in the other ear were studied. Pitch matches were made between single electrode pulse trains and acoustic tones before activation of the speech processor to gain an estimate of the pitch provided by electrical stimulation at a given insertion angle without the influence of exposure to a sound processor. The pitch matches were repeated after 1, 3, 6, and 12 months of experience with the sound processor to evaluate the effect of adaptation over time. Pre-activation pitch matches were lower than would be estimated by a spiral ganglion pitch map. Deviations were largest for stimulation below 240° degrees and smallest above 480°. With experience, pitch matches shifted towards the frequency-to-electrode allocation. However, no statistically significant pitch shifts were observed over time. The likely explanation for the lack of pitch change is that the frequency-to-electrode allocations for the long electrode arrays were already similar to the pre-activation pitch matches. Minimal place pitch shifts over time suggest a minimal amount of perceptual remapping needed for the integration of electric and acoustic stimuli, which may contribute to shorter times to asymptotic performance. PMID:25840373

  19. Acupuncture with manual and electrical stimulation for labour pain: a longitudinal randomised controlled trial

    PubMed Central

    2014-01-01

    Background Acupuncture is commonly used to reduce pain during labour despite contradictory results. The aim of this study is to evaluate the effectiveness of acupuncture with manual stimulation and acupuncture with combined manual and electrical stimulation (electro-acupuncture) compared with standard care in reducing labour pain. Our hypothesis was that both acupuncture stimulation techniques were more effective than standard care, and that electro-acupuncture was most effective. Methods A longitudinal randomised controlled trial. The recruitment of participants took place at the admission to the labour ward between November 2008 and October 2011 at two Swedish hospitals . 303 nulliparous women with normal pregnancies were randomised to: 40 minutes of manual acupuncture (MA), electro-acupuncture (EA), or standard care without acupuncture (SC). Primary outcome: labour pain, assessed by Visual Analogue Scale (VAS). Secondary outcomes: relaxation, use of obstetric pain relief during labour and post-partum assessments of labour pain. The sample size calculation was based on the primary outcome and a difference of 15 mm on VAS was regarded as clinically relevant, this gave 101 in each group, including a total of 303 women. Results Mean estimated pain scores on VAS (SC: 69.0, MA: 66.4 and EA: 68.5), adjusted for: treatment, age, education, and time from baseline, with no interactions did not differ between the groups (SC vs MA: mean difference 2.6, 95% confidence interval [CI] -1.7-6.9 and SC vs EA: mean difference 0.6 [95% CI] -3.6-4.8). Fewer number of women in the EA group used epidural analgesia (46%) than women in the MA group (61%) and SC group (70%) (EA vs SC: odds ratio [OR] 0.35; [95% CI] 0.19-0.67). Conclusions Acupuncture does not reduce women’s experience of labour pain, neither with manual stimulation nor with combined manual and electrical stimulation. However, fewer women in the EA group used epidural analgesia thus indicating that the effect of

  20. 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

  1. Effects of oculo-motor exercise, functional electrical stimulation and proprioceptive neuromuscular stimulation on visual perception of spatial neglect patients

    PubMed Central

    Park, Si-Eun; Oh, Dae-Sik; Moon, Sang-Hyun

    2016-01-01

    [Purpose] The purpose of this study was to identify the effects of oculo-motor exercise, functional electrical stimulation (FES), and proprioceptive neuromuscular facilitation (PNF) on the visual perception of spatial neglect patients. [Subjects and Methods] The subjects were randomly allocated to 3 groups: an oculo-motor exercise (OME) group, a FES with oculo-motor exercise (FOME) group, and a PNF with oculo-motor exercise (POME) group. The line bisection test (LBT), motor free visual test (MVPT), and Catherine Bergego Scale (CBS) were used to measure visual perception. These were performed 5 times per week for 6 weeks. [Results] The OME group and POME group showed significant improvements according to the LBT and MVPT results, but the FOME group showed no significant improvement. According to the CBS, all 3 groups showed significant improvements. The OME and POME groups showed improvement over the FOME group in the LBT and MVPT. However, there was no significant difference among the three groups according to the CBS. [Conclusion] These results indicate that oculo-motor exercise and PNF with oculo-motor exercise had more positive effects than FES with oculo-motor exercise on the visual perception of spatial neglect patients. PMID:27190436

  2. Effects of oculo-motor exercise, functional electrical stimulation and proprioceptive neuromuscular stimulation on visual perception of spatial neglect patients.

    PubMed

    Park, Si-Eun; Oh, Dae-Sik; Moon, Sang-Hyun

    2016-04-01

    [Purpose] The purpose of this study was to identify the effects of oculo-motor exercise, functional electrical stimulation (FES), and proprioceptive neuromuscular facilitation (PNF) on the visual perception of spatial neglect patients. [Subjects and Methods] The subjects were randomly allocated to 3 groups: an oculo-motor exercise (OME) group, a FES with oculo-motor exercise (FOME) group, and a PNF with oculo-motor exercise (POME) group. The line bisection test (LBT), motor free visual test (MVPT), and Catherine Bergego Scale (CBS) were used to measure visual perception. These were performed 5 times per week for 6 weeks. [Results] The OME group and POME group showed significant improvements according to the LBT and MVPT results, but the FOME group showed no significant improvement. According to the CBS, all 3 groups showed significant improvements. The OME and POME groups showed improvement over the FOME group in the LBT and MVPT. However, there was no significant difference among the three groups according to the CBS. [Conclusion] These results indicate that oculo-motor exercise and PNF with oculo-motor exercise had more positive effects than FES with oculo-motor exercise on the visual perception of spatial neglect patients.

  3. Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients.

    PubMed

    Schwab, B; Durisin, M; Kontorinis, G

    2010-01-01

    Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (n = 50) was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest) was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed. PMID:20671908

  4. Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients

    PubMed Central

    Schwab, B.; Durisin, M.; Kontorinis, G.

    2010-01-01

    Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (n = 50) was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest) was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed. PMID:20671908

  5. Gastric Electrical Stimulation Is an Option for Patients with Refractory Cyclic Vomiting Syndrome

    PubMed Central

    Grover, Inderpreet; Kim, Richard; Spree, Danielle C; Lahr, Christopher J; Kedar, Archana; Kothari, Shivangi; Fleisher, David; Abell, Thomas L

    2016-01-01

    Background/Aims Cyclic vomiting syndrome (CVS) is a disabling migraine variant manifesting as severe episodes of nausea and vomiting and often refractory to many therapies. Gastric electrical stimulation (GES), which can reduce nausea and vomiting in gastroparesis, may provide symptomatic relief for drug-refractory CVS. This study assessed the utility GES in reducing the symptoms of CVS and improving the quality of life. Methods A one-year, non-randomized, clinical study was conducted. Eleven consecutive patients with drug refractory, cyclic vomiting syndrome based on Rome III criteria and North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN), underwent treatment with temporary GES (Temp GES) and permanent GES (Perm GES). Post-treatment follow up was done up to one year after permanent gastric electrical stimulation therapy. Results Total symptom score decreased by 68% and 40% after temporary and permanent GES therapies, respectively. Hospital admission events significantly decreased to 1.50 (± 1.00) events from 9.14 (± 7.21) annual admissions prior to treatment with permanent GES. Vomiting episodes fell by 83% post Temp GES and 69% after Perm GES treatments. Mucosal electrogram values also changed after temporary stimulation. Conclusions In a small group of drug-refractory CVS patients, treatments with temporary and permanent GES significantly reduced the severity of gastrointestinal symptoms and frequency of hospital admissions. PMID:27241799

  6. In vitro electrical properties for iridium oxide versus titanium nitride stimulating electrodes.

    PubMed

    Weiland, James D; Anderson, David J; Humayun, Mark S

    2002-12-01

    Stimulating electrode materials must be capable of supplying high-density electrical charge to effectively activate neural tissue. Platinum is the most commonly used material for neural stimulation. Two other materials have been considered: iridium oxide and titanium nitride. This study directly compared the electrical characteristics of iridium oxide and titanium nitride by fabricating silicon substrate probes that differed only in the material used to form the electrode. Electrochemical measurements indicated that iridium oxide had lower impedance and a higher charge storage capacity than titanium nitride, suggesting better performance as a stimulating electrode. Direct measurement of the electrode potential in response to a biphasic current pulse confirmed that iridium oxide uses less voltage to transfer the same amount of charge, therefore using less power. The charge injection limit for titanium nitride was 0.87 mC/cm2, contradicting other reports estimating that titanium nitride was capable of injecting 22 mC/cm2. Iridium oxide charge storage was 4 mC/cm2, which is comparable to other published values for iridium oxide. Electrode efficiency will lead to an overall more efficient and effective device.

  7. Effectiveness of daily eccentric contractions induced via kilohertz frequency transcutaneous electrical stimulation on muscle atrophy.

    PubMed

    Tanaka, Minoru; Nakanishi, Ryosuke; Murakami, Shinichiro; Fujita, Naoto; Kondo, Hiroyo; Ishihara, Akihiko; Roy, Roland R; Fujino, Hidemi

    2016-01-01

    The effects of daily repeated bouts of concentric, isometric, or eccentric contractions induced by high frequency (kilohertz) transcutaneous electrical stimulation in ameliorating atrophy of the soleus muscle in hindlimb unloaded rats were determined. Five groups of male rats were studied: control, hindlimb unloaded for 2 weeks (HU), or HU plus two daily bouts of concentric, isometric, or eccentric high-frequency electrical stimulation-induced contractions of the calf musculature. Soleus mass and fiber size were smaller, the levels of phosphorylated Akt1 and FoxO3a lower, and atrogin-1 and ubiquitinated proteins higher in the HU, and the HU plus concentric or isometric contraction groups than in the control group. In contrast, daily bouts of eccentric contractions maintained these values at near control levels and all measures were significantly different from all other HU groups. These results indicate that daily bouts of eccentric contractions induced by high-frequency stimulation inhibited the ubiquitin-proteasome catabolic pathway and enhanced the Akt1/FoxO3a anabolic pathway that resulted in a prevention of the atrophic response of the soleus muscle to chronic unloading.

  8. Augmented visual feedback counteracts the effects of surface muscular functional electrical stimulation on physiological tremor

    PubMed Central

    2013-01-01

    Background Recent studies suggest that surface muscular functional electrical stimulation (FES) might suppress neurological upper limb tremor. We assessed its effects on upper limb physiological tremor, which is mainly driven by mechanical-reflex oscillations. We investigated the interaction between FES and augmented visual feedback, since (a) most daily activities are performed using visual cues, and (b) augmented visual feedback exacerbates upper limb tremor. Methods 10 healthy subjects (23.4 ± 7.7 years) performed 2 postural tasks with combinations of FES (4 sites; frequency of stimulation: 30 Hz; pulse width: 300 microsec; range of current delivered 10–34 mAmp) and augmented visual feedback. Results Spectral analysis of tremor showed a decrease of power spectral density to 62.18% (p = 0.01), of the integral in the 8-12 Hz frequency band to 57.67% (p = 0.003), and of tremor root mean square (RMS) to 57.16% (p = 0.002) during FES, without any changes in tremor frequency. Augmented visual feedback blocked the beneficial effect of FES, as confirmed by power spectral analysis (p = 0.01). We found a statistically significant interaction between augmented visual feedback and electrical stimulation (p = 0.039). Conclusions Augmented visual feedback antagonizes the effects of FES on physiological tremor. The absence of changes of peak frequency argues against an effect of FES on mechanical properties of the upper limb. PMID:24063436

  9. Myocardial scaffold-based cardiac tissue engineering: application of coordinated mechanical and electrical stimulations.

    PubMed

    Wang, Bo; Wang, Guangjun; To, Filip; Butler, J Ryan; Claude, Andrew; McLaughlin, Ronald M; Williams, Lakiesha N; de Jongh Curry, Amy L; Liao, Jun

    2013-09-01

    Recently, we developed an optimal decellularization protocol to generate 3D porcine myocardial scaffolds, which preserve the natural extracellular matrix structure, mechanical anisotropy, and vasculature templates and also show good cell recellularization and differentiation potential. In this study, a multistimulation bioreactor was built to provide coordinated mechanical and electrical stimulation for facilitating stem cell differentiation and cardiac construct development. The acellular myocardial scaffolds were seeded with mesenchymal stem cells (10(6) cells/mL) by needle injection and subjected to 5-azacytidine treatment (3 μmol/L, 24 h) and various bioreactor conditioning protocols. We found that after 2 days of culturing with mechanical (20% strain) and electrical stimulation (5 V, 1 Hz), high cell density and good cell viability were observed in the reseeded scaffold. Immunofluorescence staining demonstrated that the differentiated cells showed a cardiomyocyte-like phenotype by expressing sarcomeric α-actinin, myosin heavy chain, cardiac troponin T, connexin-43, and N-cadherin. Biaxial mechanical testing demonstrated that positive tissue remodeling took place after 2 days of bioreactor conditioning (20% strain + 5 V, 1 Hz); passive mechanical properties of the 2 day and 4 day tissue constructs were comparable to those of the tissue constructs produced by stirring reseeding followed by 2 weeks of static culturing, implying the effectiveness and efficiency of the coordinated simulations in promoting tissue remodeling. In short, the synergistic stimulations might be beneficial not only for the quality of cardiac construct development but also for patients by reducing the waiting time in future clinical scenarios.

  10. Electrical stimulation for gastroesophageal reflux disease: current state of the art

    PubMed Central

    Kim, Sharon E; Soffer, Edy

    2016-01-01

    Patients with gastroesophageal reflux disease (GERD) who are not satisfied with acid suppression therapy can benefit primarily from fundoplication, a surgical intervention. Fundoplication has been the standard surgical procedure for GERD. It is effective but is associated with adverse effects, resulting in a declining number of interventions, creating a need for alternative interventions that are effective, yet have a better adverse effect profile. One such alternative involves the application of electrical stimulation to the lower esophageal sphincter. A number of animal studies showed that such stimulation can increase resting lower esophageal sphincter pressure. An acute human study confirmed this effect, and was followed by two open-label studies, with a follow-up of up to 3 years. Results thus far show that the therapy is associated with a significant improvement in symptoms, a significant reduction in esophageal acid exposure, and a very good safety profile. This review will describe the evolution of electrical stimulation therapy for GERD, as well as the safety and efficacy of this intervention. PMID:26834494

  11. 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.

  12. Peripheral electrical stimulation to induce cortical plasticity: a systematic review of stimulus parameters.

    PubMed

    Chipchase, L S; Schabrun, S M; Hodges, P W

    2011-03-01

    Peripheral electrical stimulation (ES) is commonly used as an intervention to facilitate movement and relieve pain in a variety of conditions. It is widely accepted that ES induces rapid plastic change in the motor cortex. This leads to the exciting possibility that ES could be used to drive cortical plasticity in movement disorders, such as stroke, and conditions where pain affects motor control. This paper aimed to critically review the literature to determine which parameters induced cortical plasticity in healthy individuals using ES. A literature search located papers that assessed plasticity in the primary motor cortex of adult humans. Studies that evaluated plasticity using change in the amplitude of potentials evoked by transcranial magnetic stimulation of the motor cortex were included. Details from each study including sample size, ES parameters and reported findings were extracted and compared. Where data were available, Cohen's standardised mean differences (SMD) were calculated. Nineteen studies were located. Of the parameters evaluated, variation of the intensity of peripheral ES appeared to have the most consistent effect on modulation of excitability of corticomotor pathway to stimulated muscles. There was a trend for stimulation above motor threshold to increase excitability (SMD 0.79 mV, CI -0.10 to 1.64). Stimulation below motor threshold, but sufficient to induce sensory perception, produced conflicting results. Further studies with consistent methodology and larger subject numbers are needed before definitive conclusions can be drawn. There also appeared to be a time effect. That is, longer periods of ES induced more sustained changes in cortical excitability. There is insufficient evidence to determine the effect of other stimulation parameters such as frequency and waveform. Further research is needed to confirm whether modulation of these parameters affects plastic change. PMID:20739217

  13. Vertical electric field stimulated neural cell functionality on porous amorphous carbon electrodes.

    PubMed

    Jain, Shilpee; Sharma, Ashutosh; Basu, Bikramjit

    2013-12-01

    We demonstrate the efficacy of amorphous macroporous carbon substrates as electrodes to support neuronal cell proliferation and differentiation in electric field mediated culture conditions. The electric field was applied perpendicular to carbon substrate electrode, while growing mouse neuroblastoma (N2a) cells in vitro. The placement of the second electrode outside of the cell culture medium allows the investigation of cell response to electric field without the concurrent complexities of submerged electrodes such as potentially toxic electrode reactions, electro-kinetic flows and charge transfer (electrical current) in the cell medium. The macroporous carbon electrodes are uniquely characterized by a higher specific charge storage capacity (0.2 mC/cm(2)) and low impedance (3.3 kΩ at 1 kHz). The optimal window of electric field stimulation for better cell viability and neurite outgrowth is established. When a uniform or a gradient electric field was applied perpendicular to the amorphous carbon substrate, it was found that the N2a cell viability and neurite length were higher at low electric field strengths (≤ 2.5 V/cm) compared to that measured without an applied field (0 V/cm). While the cell viability was assessed by two complementary biochemical assays (MTT and LDH), the differentiation was studied by indirect immunostaining. Overall, the results of the present study unambiguously establish the uniform/gradient vertical electric field based culture protocol to either enhance or to restrict neurite outgrowth respectively at lower or higher field strengths, when neuroblastoma cells are cultured on porous glassy carbon electrodes having a desired combination of electrochemical properties.

  14. Endogenous and exogenous electric fields as modifiers of brain activity: rational design of noninvasive brain stimulation with transcranial alternating current stimulation.

    PubMed

    Fröhlich, Flavio

    2014-03-01

    Synchronized neuronal activity in the cortex generates weak electric fields that are routinely measured in humans and animal models by electroencephalography and local field potential recordings. Traditionally, these endogenous electric fields have been considered to be an epiphenomenon of brain activity. Recent work has demonstrated that active cortical networks are surprisingly susceptible to weak perturbations of the membrane voltage of a large number of neurons by electric fields. Simultaneously, noninvasive brain stimulation with weak, exogenous electric fields (transcranial current stimulation, TCS) has undergone a renaissance due to the broad scope of its possible applications in modulating brain activity for cognitive enhancement and treatment of brain disorders. This review aims to interface the recent developments in the study of both endogenous and exogenous electric fields, with a particular focus on rhythmic stimulation for the modulation of cortical oscillations. The main goal is to provide a starting point for the use of rational design for the development of novel mechanism-based TCS therapeutics based on transcranial alternating current stimulation, for the treatment of psychiatric illnesses.

  15. Estimation of Optical Stimulus Amplitude for Balance Training Using Electrical Stimulation of the Vestibular System

    NASA Technical Reports Server (NTRS)

    Goel, R.; De Dios, Y. E.; Cohen, H. S.; Bloomberg, J. J.; Mulavara, A. P.

    2016-01-01

    Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts following gravitational transitions. By training astronauts preflight with supra-threshold noisy stochastic vestibular stimulation (SVS), the central nervous system can be trained to reweight sensory information by utilizing veridical information from other sensory inputs, such as vision and proprioception, for postural and gait control. This, in turn, can enhance functional performance in novel gravitational environments. The optimal maximum amplitude of stimulation to simulate the effect of deterioration in vestibular inputs for preflight training or for evaluating vestibular contribution in functional tests in general, however, has not yet been identified. Most studies have used arbitrary but fixed maximum current amplitudes from 3 to 5 mA in the medio-lateral (ML) direction to disrupt balance function in both ML and anterior-posterior directions in healthy adults. The goal of this study was to determine the minimum SVS level that yields an equivalently degraded balance performance. Fourteen subjects stood on a compliant surface with their eyes closed and were instructed to maintain a stable upright stance. Measures of stability of the head, trunk, and whole body were quantified in the ML direction. Objective perceptual motion thresholds, were estimated ahead of time by having subjects sit on a chair with their eyes closed and giving 1 Hz bipolar binaural sinusoidal electrical stimulation at various current amplitudes. Results from the balance task suggest that using stimulation amplitudes of 280% of motion-perceptual threshold (2.2 mA on average) significantly degraded balance performance and increasing the stimulation amplitude did not lead to further degradation. We anticipate that preflight training using supra-threshold SVS stimulation will be a component of preflight sensorimotor adaptability training designed to improve adaptability to novel

  16. Swing-through gait with free-knees produced by surface functional electrical stimulation.

    PubMed

    Heller, B W; Granat, M H; Andrews, B J

    1996-01-01

    The swing-through gait is often the gait of choice for those crutch walkers who can perform it. However, a practical (sufficiently low energy and sufficiently fast) gait is usually not achievable by paraplegic individuals with thoracic lesions. Functional electrical stimulation (FES) was used to assist three spinal cord injured (SCI) subjects with complete thoracic lesions at T11, T11 and T6 to ambulate with a swing-through gait patten. Eight channels of surface stimulation were used to bilaterally stimulate knee extensors, knee flexors, hip extensors and hip flexors. The stimulation sequence was controlled by a computer that implemented a finite-state, rule-based control strategy according to sensor inputs. Over a long, level walkway, the T11 subjects averaged 0.40 m/s and 0.38 m/s for distances of 56 m and 51 m; the T6 subject averaged 0.30 m/s for 43 m. Using a motion analysis system, the gait patterns of two of the subjects were compared to those of a trained, non-impaired subject. The SCI subjects spent more time in both double support phases (when both crutches and both feet contact the floor) than did the non-impaired subjects, leading to a loss of momentum and hence a slower and less efficient gait. In conclusion, an FES assisted swing-through gait is shown to be a potentially useful mode of FES gait.

  17. Autogenic EMG-controlled functional electrical stimulation for ankle dorsiflexion control.

    PubMed

    Yeom, Hojun; Chang, Young-Hui

    2010-10-30

    Our objectives were to develop and test a new system for the potential for stable, real-time cancellation of residual stimulation artefacts (RSA) using surface electrode autogenic electromyography-controlled functional electrical stimulator (aEMGcFES). This type of closed-loop FES could be used to provide more natural, continuous control of lower extremity paretic muscles. We built upon work that has been done in the field of FES with one major technological innovation, an adaptive Gram-Schmidt filtering algorithm, which allowed us to digitally cancel RSA in real-time. This filtering algorithm resulted in a stable real-time estimation of the volitional intent of the stimulated muscle, which then acted as the direct signal for continuously controlling homonymous muscle stimulation. As a first step toward clinical application, we tested the viability of our aEMGcFES system to continuously control ankle dorsiflexion in a healthy subject. Our results indicate positively that an aEMGcFES device with adaptive filtering can respond proportionally to voluntary EMG and activate forceful movements to assist dorsiflexion during controlled isometric activation at the ankle. We also verified that normal ankle joint range of movement could be maintained while using the aEMGcFES system. We suggest that real-time cancellation of both primary and RSA is possible with surface electrode aEMGcFES in healthy subjects and shows promising potential for future clinical application to gait pathologies such as drop foot related to hemiparetic stroke.

  18. The sodium channel band shapes the response to electric stimulation in retinal ganglion cells

    PubMed Central

    Jeng, J; Tang, S; Molnar, A; Desai, N J; Fried, S I

    2011-01-01

    To improve the quality of prosthetic vision, it is desirable to understand how targeted retinal neurons respond to stimulation. Unfortunately, the factors that shape the response of a single neuron to stimulation are not well understood. A dense band of voltage gated sodium channels within the proximal axon of retinal ganglion cells is the site most sensitive to electric stimulation, suggesting that band properties are likely to influence the response to stimulation. Here, we examined how three band properties influence sensitivity using a morphologically realistic ganglion cell model in NEURON. Longer bands were more sensitive to short-duration pulses than shorter bands and increasing the distance between band and soma also increased sensitivity. Simulations using the known limits of band length and location resulted in a sensitivity difference of approximately two. Additional simulations tested how changes to sodium channel conductance within the band influenced threshold and found that the sensitivity difference increased to a factor of nearly three. This is close to the factor of 5 difference measured in physiological studies suggesting that band properties contribute significantly to the sensitivity differences found between different types of retinal neurons. PMID:21558602

  19. Autogenic EMG-Controlled Functional Electrical Stimulation for Ankle Dorsiflexion Control

    PubMed Central

    Yeom, Hojun; Chang, Young-Hui

    2010-01-01

    Our objectives were to develop and test a new system for the potential for stable, real-time cancellation of residual stimulation artefacts (RSA) using surface electrode autogenic electromyography-controlled functional electrical stimulator (aEMGcFES). This type of closed-loop FES could be used to provide more natural, continuous control of lower extremity paretic muscles. We built upon work that has been done in the field of FES with one major technological innovation, an adaptive Gram-Schmidt filtering algorithm, which allowed us to digitally cancel RSA in real-time. This filtering algorithm resulted in a stable real-time estimation of the volitional intent of the stimulated muscle, which then acted as the direct signal for continuously controlling homonymous muscle stimulation. As a first step toward clinical application, we tested the viability of our aEMGcFES system to continuously control ankle dorsiflexion in a healthy subject. Our results indicate positively that an aEMGcFES device with adaptive filtering can respond proportionally to voluntary EMG and activate forceful movements to assist dorsiflexion during controlled isometric activation at the ankle. We also verified that normal ankle joint range of movement could be maintained while using the aEMGcFES system. We suggest that real-time cancellation of both primary and RSA is possible with surface electrode aEMGcFES in healthy subjects and shows promising potential for future clinical application to gait pathologies such as drop foot related to hemiparetic stroke. PMID:20713086

  20. The control of neural cell-to-cell interactions through non-contact electrical field stimulation using graphene electrodes.

    PubMed

    Heo, Chaejeong; Yoo, Jeongwan; Lee, Siyoung; Jo, Areum; Jung, Susie; Yoo, Hyosun; Lee, Young Hee; Suh, Minah

    2011-01-01

    Electric field stimulation has become one of the most promising therapies for a variety of neurological diseases. However, the safety and effectiveness of the stimulator are critical in determining the outcome. Because there are few safe and effective in vivo and/or in vitro stimulator devices, we demonstrate a method that allows for non-contact electric field stimulation with a specific strength that is able to control cell-to-cell interaction in vitro. Graphene, a form of graphite, and polyethylene terephthalate (PET) was used to create a non-cytotoxic in vitro graphene/PET film stimulator. A transient non-contact electric field was produced by charge-balanced biphasic stimuli through the graphene/PET film electrodes and applied to cultured neural cells. We found that weak electric field stimulation (pulse duration of 10 s) as low as 4.5 mV/mm for 32 min was particularly effective in shaping cell-to-cell interaction. Under weak electric field stimulation, we observed a significant increase in the number of cells forming new cell-to-cell couplings and in the number of cells strengthening existing cell-to-cell couplings. The underlying mechanism of the altered cellular interactions may be related to an altered regulation of the endogenous cytoskeletal proteins fibronectin, actin, and vinculin. In conclusion, this technique may open a new therapeutic approach for augmenting cell-to-cell coupling in cell transplantation therapy in the central nervous system.

  1. Detection of pulse trains in the electrically stimulated cochlea: Effects of cochlear healtha

    PubMed Central

    Pfingst, Bryan E.; Colesa, Deborah J.; Hembrador, Sheena; Kang, Stephen Y.; Middlebrooks, John C.; Raphael, Yehoash; Su, Gina L.

    2011-01-01

    Perception of electrical stimuli varies widely across users of cochlear implants and across stimulation sites in individual users. It is commonly assumed that the ability of subjects to detect and discriminate electrical signals is dependent, in part, on conditions in the implanted cochlea, but evidence supporting that hypothesis is sparse. The objective of this study was to define specific relationships between the survival of tissues near the implanted electrodes and the functional responses to electrical stimulation of those electrodes. Psychophysical and neurophysiological procedures were used to assess stimulus detection as a function of pulse rate under the various degrees of cochlear pathology. Cochlear morphology, assessed post-mortem, ranged from near-normal numbers of hair cells, peripheral processes and spiral ganglion cells, to complete absence of hair cells and peripheral processes and small numbers of surviving spiral ganglion cells. The psychophysical and neurophysiological studies indicated that slopes and levels of the threshold versus pulse rate functions reflected multipulse integration throughout the 200 ms pulse train with an additional contribution of interactions between adjacent pulses at high pulse rates. The amount of multipulse integration was correlated with the health of the implanted cochlea with implications for perception of more complex prosthetic stimuli. PMID:22225050

  2. 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.

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

    PubMed Central

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

    2016-01-01

    [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. PMID:27190439

  4. Effects of electrical stimulation therapy on the blood flow in chronic critical limb ischemia patients following regenerative therapy

    PubMed Central

    Yamabata, Shiho; Shiraishi, Hirokazu; Munechika, Mai; Fukushima, Hideki; Fukuoka, Yoshiyuki; Hojo, Tatsuya; Shirayama, Takeshi; Horii, Motoyuki; Matoba, Satoaki; Kubo, Toshikazu

    2016-01-01

    Objectives: We investigated the effects of electrical stimulation therapy on cutaneous and muscle blood flow in critical limb ischemia patients following regenerative therapy. Methods: Three groups were studied: 10 healthy young subjects, 10 elderly subjects, and 7 critical limb ischemia patients after regenerative therapy. After 5 min rest, electrical stimulation was applied at 5 Hz on the tibialis anterior muscle for 10 min. We estimated the relative changes in oxyhemoglobin and total hemoglobin compared to the basal values at rest (Δ[HbO2], Δ[Hbtot]), which reflected the blood flow in the skin and muscle layer, and we simultaneously measured the tissue O2 saturation (StO2) throughout the electrical stimulation and recovery phase by near-infrared spectroscopy. Results: The Δ[HbO2] and Δ[Hbtot] values of the muscle layer in critical limb ischemia patients increased gradually and remained significantly higher at the 5-min and 10-min recovery periods after the electrical stimulation without reducing the StO2, but there is no significant change in the other two groups. Skin blood flow was not influenced by electrical stimulation in three groups. Conclusion: This improvement of the peripheral circulation by electrical stimulation would be beneficial as the adjunctive therapy after regenerative cell therapy. PMID:27504185

  5. 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