Study on automatic ECT data evaluation by using neural network

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

Komatsu, H.; Matsumoto, Y.; Badics, Z.

1994-12-31

At the in--service inspection of the steam generator (SG) tubings in Pressurized Water Reactor (PWR) plant, eddy current testing (ECT) has been widely used at each outage. At present, ECT data evaluation is mainly performed by ECT data analyst, therefore it has the following problems. Only ECT signal configuration on the impedance trajectory is used in the evaluation. It is an enormous time consuming process. The evaluation result is influenced by the ability and experience of the analyst. Especially, it is difficult to identify the true defect signal hidden in background signals such as lift--off noise and deposit signals. Inmore » this work, the authors performed the study on the possibility of the application of neural network to ECT data evaluation. It was demonstrated that the neural network proved to be effective to identify the nature of defect, by selecting several optimum input parameters to categorize the raw ECT signals.« less

Simplified Numerical Analysis of ECT Probe - Eddy Current Benchmark Problem 3

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

Sikora, R.; Chady, T.; Gratkowski, S.

2005-04-09

In this paper a third eddy current benchmark problem is considered. The objective of the benchmark is to determine optimal operating frequency and size of the pancake coil designated for testing tubes made of Inconel. It can be achieved by maximization of the change in impedance of the coil due to a flaw. Approximation functions of the probe (coil) characteristic were developed and used in order to reduce number of required calculations. It results in significant speed up of the optimization process. An optimal testing frequency and size of the probe were achieved as a final result of the calculation.

Application of ECT inspection to the first wall of a fusion reactor with wavelet analysis

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

Chen, G.; Yoshida, Y.; Miya, K.

1994-12-31

The first wall of a fusion reactor will be subjected to intensive loads during fusion operations. Since these loads may cause defects in the first wall, nondestructive evaluation techniques of the first wall should be developed. In this paper, we try to apply eddy current testing (ECT) technique to the inspection of the first wall. A method based on current vector potential and wavelet analysis is proposed. Owing to the use of wavelet analysis, a new theory developed recently, the accuracy of the present method is shown to be better than a conventional one.

Investigating electrical resonance in eddy-current array probes

NASA Astrophysics Data System (ADS)

Hughes, R.; Fan, Y.; Dixon, S.

2016-02-01

The sensitivity enhancing effects of eddy-current testing at frequencies close to electrical resonance are explored. Var-ied techniques exploiting the phenomenon, dubbed near electrical resonance signal enhancement (NERSE), were experimentally investigated to evaluate its potential exploitation for other interesting applications in aerospace materials, in particular its potential for boosting the sensitivity of standard ECT measurements. Methods for setting and controlling the typically unstable resonant frequencies of such systems are discussed. This research is funded by the EPSRC, via the Research Centre for Non-Destructive Evaluation RCNDE, and Rolls-Royce plc.

Real time flaw detection and characterization in tube through partial least squares and SVR: Application to eddy current testing

NASA Astrophysics Data System (ADS)

Ahmed, Shamim; Miorelli, Roberto; Calmon, Pierre; Anselmi, Nicola; Salucci, Marco

2018-04-01

This paper describes Learning-By-Examples (LBE) technique for performing quasi real time flaw localization and characterization within a conductive tube based on Eddy Current Testing (ECT) signals. Within the framework of LBE, the combination of full-factorial (i.e., GRID) sampling and Partial Least Squares (PLS) feature extraction (i.e., GRID-PLS) techniques are applied for generating a suitable training set in offine phase. Support Vector Regression (SVR) is utilized for model development and inversion during offine and online phases, respectively. The performance and robustness of the proposed GIRD-PLS/SVR strategy on noisy test set is evaluated and compared with standard GRID/SVR approach.

Real time groove characterization combining partial least squares and SVR strategies: application to eddy current testing

NASA Astrophysics Data System (ADS)

Ahmed, S.; Salucci, M.; Miorelli, R.; Anselmi, N.; Oliveri, G.; Calmon, P.; Reboud, C.; Massa, A.

2017-10-01

A quasi real-time inversion strategy is presented for groove characterization of a conductive non-ferromagnetic tube structure by exploiting eddy current testing (ECT) signal. Inversion problem has been formulated by non-iterative Learning-by-Examples (LBE) strategy. Within the framework of LBE, an efficient training strategy has been adopted with the combination of feature extraction and a customized version of output space filling (OSF) adaptive sampling in order to get optimal training set during offline phase. Partial Least Squares (PLS) and Support Vector Regression (SVR) have been exploited for feature extraction and prediction technique respectively to have robust and accurate real time inversion during online phase.

Comparison of current distributions in electroconvulsive therapy and transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Sekino, Masaki; Ueno, Shoogo

2002-05-01

We compared current density distributions in electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS) by numerical calculations. The model consisted of an air region and three types of tissues with different conductivities representing the brain, the skull, and the scalp. In the ECT model, electric currents were applied through electrodes with a voltage of 100 V. In the TMS model, a figure-eight coil (6 cm diameter per coil) was placed on the vertex of the head model. An alternating current with a peak intensity of 3.0 kA and a frequency of 4.2 kHz was applied to the coil. The maximum current densities inside the brain in ECT (bilateral electrode position) and TMS were 234 and 322 A/m2, respectively. The results indicate that magnetic stimulators can generate comparable current densities to ECT. While the skull significantly affected current distributions in ECT, TMS efficiently induced eddy currents in the brain. In addition, TMS is more beneficial than ECT because the localized current distribution reduces the risk of adverse side effects.

Metallic Bead Detection by Using Eddy-Current Probe with SV-GMR Sensor

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

Yamada, S.; Chomsuwan, K.; Hagino, T.

2005-04-09

The progress of the ECT probe with micro magnetic sensor becomes possible to apply to various applications. The detection of micro metallic bead used for electric packaging has been reported in this paper. We proposed micro ECT probes with meander coil as exciter and spin-valve giant magneto-resistance (SV-GMR) as receiver. Micro metallic bead(solder ball) with the diameter of 0.25 to 0.76 mm is used as a measuring object. We discuss the detection and alignment of metallic bead by using ECT technique.

Evaluation of machine learning tools for inspection of steam generator tube structures using pulsed eddy current

NASA Astrophysics Data System (ADS)

Buck, J. A.; Underhill, P. R.; Morelli, J.; Krause, T. W.

2017-02-01

Degradation of nuclear steam generator (SG) tubes and support structures can result in a loss of reactor efficiency. Regular in-service inspection, by conventional eddy current testing (ECT), permits detection of cracks, measurement of wall loss, and identification of other SG tube degradation modes. However, ECT is challenged by overlapping degradation modes such as might occur for SG tube fretting accompanied by tube off-set within a corroding ferromagnetic support structure. Pulsed eddy current (PEC) is an emerging technology examined here for inspection of Alloy-800 SG tubes and associated carbon steel drilled support structures. Support structure hole size was varied to simulate uniform corrosion, while SG tube was off-set relative to hole axis. PEC measurements were performed using a single driver with an 8 pick-up coil configuration in the presence of flat-bottom rectangular frets as an overlapping degradation mode. A modified principal component analysis (MPCA) was performed on the time-voltage data in order to reduce data dimensionality. The MPCA scores were then used to train a support vector machine (SVM) that simultaneously targeted four independent parameters associated with; support structure hole size, tube off-centering in two dimensions and fret depth. The support vector machine was trained, tested, and validated on experimental data. Results were compared with a previously developed artificial neural network (ANN) trained on the same data. Estimates of tube position showed comparable results between the two machine learning tools. However, the ANN produced better estimates of hole inner diameter and fret depth. The better results from ANN analysis was attributed to challenges associated with the SVM when non-constant variance is present in the data.

Subminiature eddy-current transducers designed to study welded joints of titanium alloys

NASA Astrophysics Data System (ADS)

Malikov, V. N.; Dmitriev, S. F.; Katasonov, A. O.; Sagalakov, A. M.; Ishkov, A. V.

2017-12-01

Eddy current transducers (ECT) are used to construct a sensor for investigating titanium sheets connected by a welded joint. The paper provides key technical information about the eddy current transducer used and describes the procedure of measurements that makes it possible to control defects in welded joints of titanium alloys. It is capable of automatically changing the filtering cutoff frequency and operating frequency of the device. Experiments were conducted on welded VT1-0 titanium plates. The paper contains the results of these measurements. The dependence data facilitates the assessment of the quality of the welded joints and helps make an educated conclusion about welding quality.

Advanced eddy current test signal analysis for steam generator tube defect classification and characterization

NASA Astrophysics Data System (ADS)

McClanahan, James Patrick

Eddy Current Testing (ECT) is a Non-Destructive Examination (NDE) technique that is widely used in power generating plants (both nuclear and fossil) to test the integrity of heat exchanger (HX) and steam generator (SG) tubing. Specifically for this research, laboratory-generated, flawed tubing data were examined. The purpose of this dissertation is to develop and implement an automated method for the classification and an advanced characterization of defects in HX and SG tubing. These two improvements enhanced the robustness of characterization as compared to traditional bobbin-coil ECT data analysis methods. A more robust classification and characterization of the tube flaw in-situ (while the SG is on-line but not when the plant is operating), should provide valuable information to the power industry. The following are the conclusions reached from this research. A feature extraction program acquiring relevant information from both the mixed, absolute and differential data was successfully implemented. The CWT was utilized to extract more information from the mixed, complex differential data. Image Processing techniques used to extract the information contained in the generated CWT, classified the data with a high success rate. The data were accurately classified, utilizing the compressed feature vector and using a Bayes classification system. An estimation of the upper bound for the probability of error, using the Bhattacharyya distance, was successfully applied to the Bayesian classification. The classified data were separated according to flaw-type (classification) to enhance characterization. The characterization routine used dedicated, flaw-type specific ANNs that made the characterization of the tube flaw more robust. The inclusion of outliers may help complete the feature space so that classification accuracy is increased. Given that the eddy current test signals appear very similar, there may not be sufficient information to make an extremely accurate (>95%) classification or an advanced characterization using this system. It is necessary to have a larger database fore more accurate system learning.

Non destructive technique for cracks detection by an eddy current in differential mode for steel frames

NASA Astrophysics Data System (ADS)

Harzalla, S.; Belgacem, F. Bin Muhammad; Chabaat, M.

2014-12-01

In this paper, a nondestructive technique is used as a tool to control cracks and microcracks in materials. A simulation by a numerical approach such as the finite element method is employed to detect cracks and eventually; to study their propagation using a crucial parameter such as the stress intensity factor. This approach has been used in the aircraft industry to control cracks. Besides, it makes it possible to highlight the defects of parts while preserving the integrity of the controlled products. On the other side, it is proven that the reliability of the control of defects gives convincing results for the improvement of the quality and the safety of the material. Eddy current testing (ECT) is a standard technique in industry for the detection of surface breaking flaws in magnetic materials such as steels. In this context, simulation tools can be used to improve the understanding of experimental signals, optimize the design of sensors or evaluate the performance of ECT procedures. CEA-LIST has developed for many years semi-analytical models embedded into the simulation platform CIVA dedicated to non-destructive testing. The developments presented herein address the case of flaws located inside a planar and magnetic medium. Simulation results are obtained through the application of the Volume Integral Method (VIM). When considering the ECT of a single flaw, a system of two differential equations is derived from Maxwell equations. The numerical resolution of the system is carried out using the classical Galerkin variant of the Method of Moments. Besides, a probe response is calculated by application of the Lorentz reciprocity theorem. Finally, the approach itself as well as comparisons between simulation results and measured data are presented.

Motion-induced eddy current thermography for high-speed inspection

NASA Astrophysics Data System (ADS)

Wu, Jianbo; Li, Kongjing; Tian, Guiyun; Zhu, Junzhen; Gao, Yunlai; Tang, Chaoqing; Chen, Xiaotian

2017-08-01

This letter proposes a novel motion-induced eddy current based thermography (MIECT) for high-speed inspection. In contrast to conventional eddy current thermography (ECT) based on a time-varying magnetic field created by an AC coil, the motion-induced eddy current is induced by the relative motion between magnetic field and inspected objects. A rotating magnetic field created by three-phase windings is used to investigate the heating principle and feasibility of the proposed method. Firstly, based on Faraday's law the distribution of MIEC is investigated, which is then validated by numerical simulation. Further, experimental studies are conducted to validate the proposed method by creating rotating magnetic fields at different speeds from 600 rpm to 6000 rpm, and it is verified that rotating speed will increase MIEC intensity and thereafter improve the heating efficiency. The conclusion can be preliminarily drawn that the proposed MIECT is a platform suitable for high-speed inspection.

Simulation and design of ECT differential bobbin probes for the inspection of cracks in bolts

NASA Astrophysics Data System (ADS)

Ra, S. W.; Im, K. H.; Lee, S. G.; Kim, H. J.; Song, S. J.; Kim, S. K.; Cho, Y. T.; Woo, Y. D.; Jung, J. A.

2015-12-01

All Various defects could be generated in bolts for a use of oil filters for the manufacturing process and then may affect to the safety and quality in bolts. Also, fine defects may be imbedded in oil filter system during multiple forging manufacturing processes. So it is very important that such defects be investigated and screened during the multiple manufacturing processes. Therefore, in order effectively to evaluate the fine defects, the design parameters for bobbin-types were selected under a finite element method (FEM) simulations and Eddy current testing (ECT). Especially the FEM simulations were performed to make characterization in the crack detection of the bolts and the parameters such as number of turns of the coil, the coil size and applied frequency were calculated based on the simulation results.

Eddy current analysis of cracks grown from surface defects and non-metallic particles

NASA Astrophysics Data System (ADS)

Cherry, Matthew R.; Hutson, Alisha; Aldrin, John C.; Shank, Jared

2018-04-01

Eddy current methods are sensitive to any discrete change in conductivity. Traditionally this has been used to determine the presence of a crack. However, other features that are not cracks such as non-metallic inclusions, carbide stringers and surface voids can cause an eddy current indication that could potentially lead to a reject of an in-service component. These features may not actually be lifelimiting, meaning NDE methods could reject components with remaining useful life. In-depth analysis of signals from eddy current sensors could provide a means of sorting between rejectable indications and false-calls from geometric and non-conductive features. In this project, cracks were grown from voids and non-metallic inclusions in a nickel-based super-alloy and eddy current analysis was performed on multiple intermediate steps of fatigue. Data were collected with multiple different ECT probes and at multiple frequencies, and the results were analyzed. The results show how cracks growing from non-metallic features can skew eddy current signals and make characterization a challenge. Modeling and simulation was performed with multiple analysis codes, and the models were found to be in good agreement with the data for cracks growing away from voids and non-metallic inclusions.

Evaluation of steam generator WWER 440 tube integrity criteria

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

Splichal, K.; Otruba, J.; Burda, J.

1997-02-01

The main corrosion damage in WWER steam generators under operating conditions has been observed on the outer surface of these tubes. An essential operational requirement is to assure a low probability of radioactive primary water leakage, unstable defect development and rupture of tubes. In the case of WWER 440 steam generators the above requirements led to the development of permissible limits for data evaluation of the primary-to-secondary leak measurements and determination of acceptable values for plugging of heat exchange tubes based on eddy current test (ECT) inspections.

On an image reconstruction method for ECT

NASA Astrophysics Data System (ADS)

Sasamoto, Akira; Suzuki, Takayuki; Nishimura, Yoshihiro

2007-04-01

An image by Eddy Current Testing(ECT) is a blurred image to original flaw shape. In order to reconstruct fine flaw image, a new image reconstruction method has been proposed. This method is based on an assumption that a very simple relationship between measured data and source were described by a convolution of response function and flaw shape. This assumption leads to a simple inverse analysis method with deconvolution.In this method, Point Spread Function (PSF) and Line Spread Function(LSF) play a key role in deconvolution processing. This study proposes a simple data processing to determine PSF and LSF from ECT data of machined hole and line flaw. In order to verify its validity, ECT data for SUS316 plate(200x200x10mm) with artificial machined hole and notch flaw had been acquired by differential coil type sensors(produced by ZETEC Inc). Those data were analyzed by the proposed method. The proposed method restored sharp discrete multiple hole image from interfered data by multiple holes. Also the estimated width of line flaw has been much improved compared with original experimental data. Although proposed inverse analysis strategy is simple and easy to implement, its validity to holes and line flaw have been shown by many results that much finer image than original image have been reconstructed.

Pulsed eddy current inspection of broach support plates in steam generators

NASA Astrophysics Data System (ADS)

Mokros, Sarah Gwendolyn

Steam Generators (SGs) are a critical component of nuclear reactors, employing thousands of SG tubes to convert heat generated in the reactor core into useable energy. SG tubes are supported at numerous locations by Broach Support Plates (BSPs) that have trefoil shaped holes, which prevent excessive tube vibrations, while allowing water to easily flow through the support structures. A number of degradation modes occur in SGs, such as SG tube fretting, cracking or denting, requiring periodic inspection. Currently, conventional Eddy Current Testing (ECT) is used to non-destructively assess the condition of SG tubes and components. However, as reactors age, new modes of degradation will likely appear that may be difficult to detect and characterize using conventional ECT, such as wall loss in BSPs and build-up of corrosion products, which typically form as a hard sludge called magnetite. Pulsed Eddy Current (PEC) technologies are an emerging technique that is presented in this work as a method to further advance inspection techniques used in CANDURTM nuclear reactors. A PEC probe was designed to inspect the unique shape of the trefoil shaped hole to detect and characterize wall loss and the presence of magnetite in A516 carbon steel BSPs with trefoil shaped holes from within 15.9 mm (5/8") Alloy-800 SG tubes. PEC was also used to observe how measurements of wall loss were affected by the presence of magnetite. This work presents Finite Element Method (FEM) simulations and experimental results collected to observe these degradation modes. The probe was demonstrated to be capable of detecting far side wall loss as low as 20%, locating and characterizing the relative permeability of magnetite, and of detecting wall loss when magnetite was present. FEM simulations and experimental results were found to be in good agreement, suggesting that additional investigations of the effects of BSP degradation on PEC signal response may also be performed using FEM models.

SRF test facility for the superconducting LINAC ``RAON'' — RRR property and e-beam welding

NASA Astrophysics Data System (ADS)

Jung, Yoochul; Hyun, Myungook; Joo, Jongdae; Joung, Mijoung

2015-02-01

Equipment, such as a vacuum furnace, high pressure rinse (HPR), eddy current test (ECT) and buffered chemical polishing (BCP), are installed in the superconducting radio frequency (SRF) test facility. Three different sizes of cryostats (diameters of 600 mm for a quarter wave resonator (QWR), 900 mm for a half wave resonator (HWR), and 1200 mm for single spoke resonator 1&2 (SSR 1&2)) for vertical RF tests are installed for testing cavities. We confirmed that as-received niobium sheets (ASTM B393, RRR300) good electrical properties because they showed average residual resistance ratio (RRR) values higher than 300. However, serious RRR degradation occurred after joining two pieces of Nb by e-beam welding because the average RRR values of the samples were ˜179, which was only ˜60% of as-received RRR value. From various e-beam welding experiments in which the welding current and a speed at a fixed welding voltage were changed, we confirmed that good welding results were obtained at a 53 mA welding current and a 20-mm/s welding speed at a fixed welding voltage of 150 kV.

Short- and long-term neurocognitive functioning after electroconvulsive therapy in depressed elderly: a prospective naturalistic study.

PubMed

Verwijk, Esmée; Comijs, Hannie C; Kok, Rob M; Spaans, Harm-Pieter; Tielkes, Caroline E M; Scherder, Erik J A; Stek, Max L

2014-02-01

It is generally assumed that the elderly patients are more vulnerable to cognitive side effects after electroconvulsive therapy (ECT) than younger depressed patients. The current study aims to evaluate the nature and extent of changes across multiple domains of neurocognitive functioning in a group of elderly depressed patients after ECT. In this prospective naturalistic study, we included 42 depressed patients aged ≥55 years. Global cognitive function, memory, and executive function were assessed before ECT treatment and within one week (short-term post-ECT) and six months after ECT (long-term post-ECT). Associations between cognitive functioning and electrode placement, total number of treatment sessions, age, and the severity of depression at the time of cognitive measurement were studied. Our data offered no evidence of decline for any of the neurocognitive tests after ECT, given its power to detect the difference. Post-ECT improvement of neurocognitive functioning was statistically significant for the Mini-Mental State Examination, Visual Association Test, 10 Words Verbal Learning Test, and Expanded Mental Control Test. Effect sizes were medium to large. After six months, compared with post-ECT performance, statistically significant improvement was found only for the Trail Making Test-A and the Letter Fluency Test with small to medium effect sizes. In our severely depressed elderly patients, neurocognitive performance improved or did not change after ECT. Patients with poor cognitive function were not able to participate in neuropsychological assessment before ECT started. Consequently these results may not apply to patients with more severe cognitive impairment prior to the start of ECT.

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

Harzalla, S., E-mail: harzallahozil@yahoo.fr; Chabaat, M., E-mail: mchabaat@yahoo.com; Belgacem, F. Bin Muhammad, E-mail: fbmbelgacem@gmail.com

In this paper, a nondestructive technique is used as a tool to control cracks and microcracks in materials. A simulation by a numerical approach such as the finite element method is employed to detect cracks and eventually; to study their propagation using a crucial parameter such as the stress intensity factor. This approach has been used in the aircraft industry to control cracks. Besides, it makes it possible to highlight the defects of parts while preserving the integrity of the controlled products. On the other side, it is proven that the reliability of the control of defects gives convincing resultsmore » for the improvement of the quality and the safety of the material. Eddy current testing (ECT) is a standard technique in industry for the detection of surface breaking flaws in magnetic materials such as steels. In this context, simulation tools can be used to improve the understanding of experimental signals, optimize the design of sensors or evaluate the performance of ECT procedures. CEA-LIST has developed for many years semi-analytical models embedded into the simulation platform CIVA dedicated to non-destructive testing. The developments presented herein address the case of flaws located inside a planar and magnetic medium. Simulation results are obtained through the application of the Volume Integral Method (VIM). When considering the ECT of a single flaw, a system of two differential equations is derived from Maxwell equations. The numerical resolution of the system is carried out using the classical Galerkin variant of the Method of Moments. Besides, a probe response is calculated by application of the Lorentz reciprocity theorem. Finally, the approach itself as well as comparisons between simulation results and measured data are presented.« less

The role of APOE-ɛ4 and beta amyloid in the differential rate of recovery from ECT: a review

PubMed Central

Sutton, T A; Sohrabi, H R; Rainey-Smith, S R; Bird, S M; Weinborn, M; Martins, R N

2015-01-01

Individual biological differences may contribute to the variability of outcomes, including cognitive effects, observed following electroconvulsive treatment (ECT). A narrative review of the research literature on carriage of the apolipoprotein E ɛ4 allele (APOE-ɛ4) and the protein biomarker beta amyloid (Aβ) with ECT cognitive outcome was undertaken. ECT induces repeated brain seizures and there is debate as to whether this causes brain injury and long-term cognitive disruption. The majority of ECT is administered to the elderly (over age 65 years) with drug-resistant depression. Depression in the elderly may be a symptom of the prodromal stage of Alzheimer's disease (AD). Carriage of the APOE-ɛ4 allele and raised cerebral Aβ are consistently implicated in AD, but inconsistently implicated in brain injury (and related syndromes) recovery rates. A paucity of brain-related recovery, genetic and biomarker research in ECT responses in the elderly was found: three studies have examined the effect of APOE-ɛ4 allele carriage on cognition in the depressed elderly receiving ECT, and two have examined Aβ changes after ECT, with contradictory findings. Cognitive changes in all studies of ECT effects were measured by a variety of psychological tests, making comparisons of such changes between studies problematic. Further, psychological test data-validity measures were not routinely administered, counter to current testing recommendations. The methodological issues of the currently available literature as well as the need for well-designed, hypothesis driven, longitudinal studies are discussed. PMID:25826114

The role of APOE-ɛ4 and beta amyloid in the differential rate of recovery from ECT: a review.

PubMed

Sutton, T A; Sohrabi, H R; Rainey-Smith, S R; Bird, S M; Weinborn, M; Martins, R N

2015-03-31

Individual biological differences may contribute to the variability of outcomes, including cognitive effects, observed following electroconvulsive treatment (ECT). A narrative review of the research literature on carriage of the apolipoprotein E ɛ4 allele (APOE-ɛ4) and the protein biomarker beta amyloid (Aβ) with ECT cognitive outcome was undertaken. ECT induces repeated brain seizures and there is debate as to whether this causes brain injury and long-term cognitive disruption. The majority of ECT is administered to the elderly (over age 65 years) with drug-resistant depression. Depression in the elderly may be a symptom of the prodromal stage of Alzheimer's disease (AD). Carriage of the APOE-ɛ4 allele and raised cerebral Aβ are consistently implicated in AD, but inconsistently implicated in brain injury (and related syndromes) recovery rates. A paucity of brain-related recovery, genetic and biomarker research in ECT responses in the elderly was found: three studies have examined the effect of APOE-ɛ4 allele carriage on cognition in the depressed elderly receiving ECT, and two have examined Aβ changes after ECT, with contradictory findings. Cognitive changes in all studies of ECT effects were measured by a variety of psychological tests, making comparisons of such changes between studies problematic. Further, psychological test data-validity measures were not routinely administered, counter to current testing recommendations. The methodological issues of the currently available literature as well as the need for well-designed, hypothesis driven, longitudinal studies are discussed.

Anti-solvent crystallization of L-threonine in Taylor crystallizers and MSMPR crystallizer: Effect of fluid dynamic motions on crystal size, shape, and recovery

NASA Astrophysics Data System (ADS)

Lee, Sooyun; Lee, Choul-Ho; Kim, Woo-Sik

2017-07-01

The influence of the fluid dynamic motions of a periodic Taylor vortex and random turbulent eddy on the anti-solvent crystallization of L-threonine was investigated. The Taylor vortex flow and random turbulent eddy flow were generated by the inner cylinder rotation in a Couette-Taylor (CT) crystallizer and the impeller agitation in a mixed-suspension mixed product removal (MSMPR) crystallizer, respectively. Furthermore, the circumferentially sinusoidal fluctuation of a Taylor vortex was induced in an elliptical Couette-Taylor (ECT) crystallizer . The periodic Taylor vortex flows in the CT and ECT crystallizers resulted in a smaller crystal size and higher crystal recovery ratio of L-threonine than the random turbulent flow in the MSMPR crystallizer due to induction of a higher supersaturation, resulting in a higher nucleation in the CT and ECT crystallizers than in the MSMPR crystallizer. Thus, the crystal size was reduced and the crystal recovery ratio enhanced when increasing the rotation/agitation speed and feed flow rate in the CT, ECT, and MSMPR crystallizers. When increasing the temperature, the crystal size and crystal recovery ratio were both increased due an enhanced mass transfer for crystal growth. The crystal morphology changes according to the fluid dynamic motion with various crystallization conditions were well correlated in terms of the supersaturation.

Episodic Visual Learning/Memory and Attentional Flexibility in Patients With Major Depressive Disorder After Clinically Effective Electroconvulsive Therapy.

PubMed

Kalogerakou, Stamatina; Oulis, Panagiotis; Anyfandi, Eleni; Konstantakopoulos, George; Papakosta, Vasiliki-Maria; Kontis, Dimitrios; Theochari, Eirini; Angelopoulos, Elias; Zervas, Ioannis M; Mellon, Robert C; Papageorgiou, Charalambos C; Tsaltas, Eleftheria

2015-12-01

This study is a follow-up of a previous one reporting that the neuropsychological profile of pharmacoresistant patients with major depressive disorder referred for electroconvulsive therapy (ECT, ECT group) contrasted with that of their pharmacorespondent counterparts (NECT group). The NECT group exhibited severe visuospatial memory and minor executive deficits; the ECT group presented the reverse pattern. In that same ECT group, the current follow-up study examined the effects of clinically effective ECT on both cognitive domains 2 months later. Fifteen ECT patients were administered Hamilton Depression (HAMD-24), Hamilton Anxiety (HAMA), Mini-Mental State Examination Scales and 5 tests of Cambridge Neuropsychological Test Automated Battery at intake (pre-ECT), end of ECT course (post-ECT), and 2 months thereafter (follow-up). Electroconvulsive therapy was effective in relieving clinical depression. After a post-ECT decline, the patients exhibited significant improvement in both Cambridge Neuropsychological Test Automated Battery, paired associate learning, and Stockings of Cambridge. By contrast, their major pre-ECT deficit in intra/extradimensional set shifting remained virtually unaffected. Our findings suggest that attentional flexibility deficits may constitute a neuropsychological trait-like feature of pharmacoresistant, ECT-referred major depressive disorder patients. However, this deficit does not seem generalized, given patient improvement in episodic visual learning/memory and some indication of improvement in spatial planning after ECT.

Seasonal cycle of volume transport through Kerama Gap revealed by a 20-year global HYbrid Coordinate Ocean Model reanalysis

DTIC Science & Technology

2015-11-10

the mean inflow into the ECS does not Z. Yu et al. / Ocean Modelling 96 (2015) 203–213 207 1995 1997 2000 2002 2005 2007 2010 2012 −20 −10 0 10 20 T...performed and the leading mode of the annual steric ef- ect ( Stammer , 1997) was also removed. Depending on the eddy lo- ation, the same type of eddy

Novel Deployment of Mobile Eddy Covariance Tower Observations Across Variations in the Built Environment in a Desert Urban Area

DTIC Science & Technology

2015-11-03

author(s) and should not contrued as an official Department of the Army position, policy or decision, unless so designated by other documentation. 9...Grass; 6 Undeveloped-Open Land (generally gravel or bare soil); Pavement ; Buildings and Concrete; and Residential Buildings (TG-ECT site only...pervious surfaces, while pavement , buildings and concrete, and residential buildings represent impervious surfaces. 2.3. Mobile Eddy Covariance Tower

Eddy Current Testing, RQA/M1-5330.17.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

As one in the series of classroom training handbooks, prepared by the U.S. space program, instructional material is presented in this volume concerning familiarization and orientation on eddy current testing. The subject is presented under the following headings: Introduction, Eddy Current Principles, Eddy Current Equipment, Eddy Current Methods,…

Testing the Theory of Embodied Cognition with Subliminal Words

ERIC Educational Resources Information Center

Ansorge, Ulrich; Kiefer, Marcus; Khalid, Shah; Grassl, Sylvia; Konig, Peter

2010-01-01

In the current study, we tested the embodied cognition theory (ECT). The ECT postulates mandatory sensorimotor processing of words when accessing their meaning. We test that prediction by investigating whether invisible (i.e., subliminal) spatial words activate responses based on their long-term and short-term meaning. Masking of the words is used…

The acute and medium-term effects of treatment with electroconvulsive therapy on memory in patients with major depressive disorder.

PubMed

Maric, N P; Stojanovic, Z; Andric, S; Soldatovic, I; Dolic, M; Spiric, Z

2016-03-01

Current literature provides insufficient information on the degree of cognitive impairment during and after electroconvulsive therapy (ECT), mostly due to the fact that applied tests lacked sensitivity and flexibility. Our goal was to evaluate cognitive functioning in adult depressed patients treated with bi-temporal ECT, using tests sensitive for detection of possible acute and medium-term memory changes. Thirty adult patients with major depressive disorder, treated with a course of bi-temporal ECT, underwent clinical and cognitive measurements three times: at baseline, immediately after a course of ECT, and 1 month later. For cognition assessment, we used learning and visual, spatial and figural memory tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Bi-temporal ECT has proven to be an effective treatment. The linear mixed model, used to analyze changes in depression severity and patients' cognitive performances over time and to assess dynamic correlations between aforementioned features, did not show any significant memory impairment as a potential acute or medium-term ECT effect. However, it yielded significant improvement on visual memory and learning at the follow-up, which positively correlated with the improvement of depression. Good progress is being made in the search for ECT-related acute and medium-term cognitive side-effects by using the tests sensitive to detect memory dysfunction with parallel forms of the tasks (to counter practice effects on repeat testing). Our results on learning and memory in relation to ECT during treatment of depression did not bring forth any prolonged and significant bi-temporal ECT-related memory deficit.

Intelligent technologies in process of highly-precise products manufacturing

NASA Astrophysics Data System (ADS)

Vakhidova, K. L.; Khakimov, Z. L.; Isaeva, M. R.; Shukhin, V. V.; Labazanov, M. A.; Ignatiev, S. A.

2017-10-01

One of the main control methods of the surface layer of bearing parts is the eddy current testing method. Surface layer defects of bearing parts, like burns, cracks and some others, are reflected in the results of the rolling surfaces scan. The previously developed method for detecting defects from the image of the raceway was quite effective, but the processing algorithm is complicated and lasts for about 12 ... 16 s. The real non-stationary signals from an eddy current transducer (ECT) consist of short-time high-frequency and long-time low-frequency components, therefore a transformation is used for their analysis, which provides different windows for different frequencies. The wavelet transform meets these conditions. Based on aforesaid, a methodology for automatically detecting and recognizing local defects in bearing parts surface layer has been developed on the basis of wavelet analysis using integral estimates. Some of the defects are recognized by the amplitude component, otherwise an automatic transition to recognition by the phase component of information signals (IS) is carried out. The use of intelligent technologies in the manufacture of bearing parts will, firstly, significantly improve the quality of bearings, and secondly, significantly improve production efficiency by reducing (eliminating) rejections in the manufacture of products, increasing the period of normal operation of the technological equipment (inter-adjustment period), the implementation of the system of Flexible facilities maintenance, as well as reducing production costs.

Detecting defects in marine structures by using eddy current infrared thermography.

PubMed

Swiderski, W

2016-12-01

Eddy current infrared (IR) thermography is a new nondestructive testing (NDT) technique used for the detection of cracks in electroconductive materials. By combining the well-established inspection methods of eddy current NDT and IR thermography, this technique uses induced eddy currents to heat test samples. In this way, IR thermography allows the visualization of eddy current distribution that is distorted in defect sites. This paper discusses the results of numerical modeling of eddy current IR thermography procedures in application to marine structures.

Non-destructive testing of composite materials used in military applications by eddy current thermography method

NASA Astrophysics Data System (ADS)

Swiderski, Waldemar

2016-10-01

Eddy current thermography is a new NDT-technique for the detection of cracks in electro conductive materials. It combines the well-established inspection techniques of eddy current testing and thermography. The technique uses induced eddy currents to heat the sample being tested and defect detection is based on the changes of induced eddy currents flows revealed by thermal visualization captured by an infrared camera. The advantage of this method is to use the high performance of eddy current testing that eliminates the known problem of the edge effect. Especially for components of complex geometry this is an important factor which may overcome the increased expense for inspection set-up. The paper presents the possibility of applying eddy current thermography method for detecting defects in ballistic covers made of carbon fiber reinforced composites used in the construction of military vehicles.

Test and Evaluation of an Eddy Current Clutch/Brake Propulsion System

DOT National Transportation Integrated Search

1975-01-01

This report covers the Phase II effort of a program to develop and test a 15 hp eddy-current clutch propulsion system. Included in the Phase 2 effort are the test and evaluation of the eddy-current clutch propulsion system on board a test vehicle. Th...

Improved Imaging With Laser-Induced Eddy Currents

NASA Technical Reports Server (NTRS)

Chern, Engmin J.

1993-01-01

System tests specimen of material nondestructively by laser-induced eddy-current imaging improved by changing method of processing of eddy-current signal. Changes in impedance of eddy-current coil measured in absolute instead of relative units.

Observation of Intralaminar Cracking in the Edge Crack Torsion Specimen

NASA Technical Reports Server (NTRS)

Czabaj, Michael W.; Ratcliffe, James G.; Davidson, Barry D.

2013-01-01

The edge crack torsion (ECT) test is evaluated to determine its suitability for measuring fracture toughness associated with mode III delamination growth onset. A series of ECT specimens with preimplanted inserts with different lengths is tested and examined using nondestructive and destructive techniques. Ultrasonic inspection of all tested specimens reveals that delamination growth occurs at one interface ply beneath the intended midplane interface. Sectioning and optical microscopy suggest that the observed delamination growth results from coalescence of angled intralaminar matrix cracks that form and extend across the midplane plies. The relative orientation of these cracks is approximately 45 deg with respect to the midplane, suggesting their formation is caused by resolved principal tensile stresses arising due to the global mode-III shear loading. Examination of ECT specimens tested to loads below the level corresponding to delamination growth onset reveals that initiation of intralaminar cracking approximately coincides with the onset of nonlinearity in the specimen's force-displacement response. The existence of intralaminar cracking prior to delamination growth onset and the resulting delamination extension at an unintended interface render the ECT test, in its current form, unsuitable for characterization of mode III delamination growth onset. The broader implications of the mechanisms observed in this study are also discussed with respect to the current understanding of shear-driven delamination in tape-laminate composites.

Nondestructive examination of recovery stage during annealing of a cold-rolled low-carbon steel using eddy current testing technique

NASA Astrophysics Data System (ADS)

Seyfpour, M.; Ghanei, S.; Mazinani, M.; Kashefi, M.; Davis, C.

2018-04-01

The recovery process in steel is usually investigated by conventional destructive tests that are expensive, time-consuming and also cumbersome. In this study, an alternative non-destructive test technique (based on eddy current testing) is used to characterise the recovery process during annealing of cold-rolled low-carbon steels. For assessing the reliability of eddy current results corresponding to different levels of recovery, X-ray line broadening analysis is also employed. It is shown that there is a strong relationship between eddy current outputs and the extent to which recovery occurs at different annealing temperatures. Accordingly, the non-destructive eddy current test technique represents the potential to be used as a reliable process for detection of the occurrence of recovery in the steel microstructure.

A Modified Edge Crack Torsion Test for Measurement of Mode III Fracture Toughness of Laminated Tape Composites

NASA Technical Reports Server (NTRS)

Czabaj, Michael W.; Davidson, Barry D.; Ratcliffe, James G.

2016-01-01

Modifications to the edge crack torsion (ECT) test are studied to improve the reliability of this test for measuring the mode-III fracture toughness, G (sub IIIc), of laminated tape fiber-reinforced polymeric (FRP) composites. First, the data reduction methods currently used in the ECT test are evaluated and deficiencies in their accuracy are discussed. An alternative data reduction technique, which uses a polynomial form to represent ECT specimen compliance solution, is evaluated and compared to FEA (finite element analysis) results. Second, seven batches of ECT specimens are tested, each batch containing specimens with a preimplanted midplane edge delamination and midplane plies with orientations of plus theta divided by minus theta, with theta ranging from 0 degrees to 90 degrees in 15-degree increments. Tests on these specimens show that intralaminar cracking occurs in specimens from all batches except for which theta = 15 degrees and 30 degrees. Tests on specimens of these two batches are shown to result in mode-III delamination growth at the intended ply interface. The findings from this study are encouraging steps towards the use of the ECT test as a standardized method for measuring G (sub IIIc), although further modification to the data reduction method is required to make it suitable for use as part of a standardized test method.

Neuropsychological effects and attitudes in patients following electroconvulsive therapy.

PubMed

Feliu, Miriam; Edwards, Christopher L; Sudhakar, Shiv; McDougald, Camela; Raynor, Renee; Johnson, Stephanie; Byrd, Goldie; Whitfield, Keith; Jonassaint, Charles; Romero, Heather; Edwards, Lekisha; Wellington, Chante'; Hill, LaBarron K; Sollers, James; Logue, Patrick E

2008-06-01

The current study examined the effects of electroconvulsive therapy (ECT) on neuropsychological test performance. Forty-six patients completed brief neuropsychological and psychological testing before and after receiving ECT for the treatment of recalcitrant and severe depression. Neuropsychological testing consisted of the Levin Selective Reminding Test (Levin) and Wechsler Memory Scale-Revised Edition (WMS-R). Self-report measures included the Beck Depression Inventory (BDI), the Short-Term Memory Questionnaire (STMQ), and several other measures of emotional functioning and patient attitudes toward ECT. The mean number of days between pre-ECT and post-ECT testing was 24. T-test revealed a significant decrease in subjective ratings of depression as rated by the BDI, t(45) = 9.82, P < 0.0001 (Pre-BDI = 27.9 +/- 20.2; post-BDI = 13.5 +/- 9.7). Objective ratings of memory appeared impaired following treatment, and patients' self-report measures of memory confirmed this decline. More specifically, repeated measures MANOVA [Wilks Lambda F(11,30) = 4.3, p < 0.001] indicated significant decreases for measures of immediate recognition memory (p < 0.005), long-term storage (p < 0.05), delayed prose passage recall (p < 0.0001), percent retained of prose passages (p < 0.0001), and percent retained of visual designs (p < 0.0001). In addition, the number of double mentions on the Levin increased (p < 0.02). This study suggests that there may be a greater need to discuss the intermittent cognitive risks associated with ECT when obtaining informed consent prior to treatment. Further that self-reports of cognitive difficulties may persist even when depression has remitted. However, patients may not acknowledge or be aware of changes in their memory functioning, and post-ECT self-reports may not be reliable.

Controlling stimulation strength and focality in electroconvulsive therapy via current amplitude and electrode size and spacing: comparison with magnetic seizure therapy.

PubMed

Deng, Zhi-De; Lisanby, Sarah H; Peterchev, Angel V

2013-12-01

Understanding the relationship between the stimulus parameters of electroconvulsive therapy (ECT) and the electric field characteristics could guide studies on improving risk/benefit ratio. We aimed to determine the effect of current amplitude and electrode size and spacing on the ECT electric field characteristics, compare ECT focality with magnetic seizure therapy (MST), and evaluate stimulus individualization by current amplitude adjustment. Electroconvulsive therapy and double-cone-coil MST electric field was simulated in a 5-shell spherical human head model. A range of ECT electrode diameters (2-5 cm), spacing (1-25 cm), and current amplitudes (0-900 mA) was explored. The head model parameters were varied to examine the stimulus current adjustment required to compensate for interindividual anatomical differences. By reducing the electrode size, spacing, and current, the ECT electric field can be more focal and superficial without increasing scalp current density. By appropriately adjusting the electrode configuration and current, the ECT electric field characteristics can be made to approximate those of MST within 15%. Most electric field characteristics in ECT are more sensitive to head anatomy variation than in MST, especially for close electrode spacing. Nevertheless, ECT current amplitude adjustment of less than 70% can compensate for interindividual anatomical variability. The strength and focality of ECT can be varied over a wide range by adjusting the electrode size, spacing, and current. If desirable, ECT can be made as focal as MST while using simpler stimulation equipment. Current amplitude individualization can compensate for interindividual anatomical variability.

Eddy Current System for Material Inspection and Flaw Visualization

NASA Technical Reports Server (NTRS)

Bachnak, R.; King, S.; Maeger, W.; Nguyen, T.

2007-01-01

Eddy current methods have been successfully used in a variety of non-destructive evaluation applications including detection of cracks, measurements of material thickness, determining metal thinning due to corrosion, measurements of coating thickness, determining electrical conductivity, identification of materials, and detection of corrosion in heat exchanger tubes. This paper describes the development of an eddy current prototype that combines positional and eddy-current data to produce a C-scan of tested material. The preliminary system consists of an eddy current probe, a position tracking mechanism, and basic data visualization capability. Initial test results of the prototype are presented in this paper.

Expanding the Role of School Psychologists to Support Early Career Teachers: A Mixed-Method Study

ERIC Educational Resources Information Center

Shernoff, Elisa S.; Frazier, Stacy L.; Maríñez-Lora, Ané M.; Lakind, Davielle; Atkins, Marc S.; Jakobsons, Lara; Hamre, Bridget K.; Bhaumik, Dulal K.; Parker-Katz, Michelle; Neal, Jennifer Watling; Smylie, Mark A.; Patel, Darshan A.

2016-01-01

School psychologists have training and expertise in consultation and evidence-based interventions that position them well to support early career teachers (ECTs). The current study involved iterative development and pilot testing of an intervention to help ECTs become more effective in classroom management and engaging learners, as well as more…

Mechanical properties and eddy current testing of thermally aged Z3CN20.09M cast duplex stainless steel

NASA Astrophysics Data System (ADS)

Liu, Tonghua; Wang, Wei; Qiang, Wenjiang; Shu, Guogang

2018-04-01

To study the thermal aging embrittlement of Z3CN20.09M duplex stainless steel produced in China, accelerated thermal aging experiments were carried out at 380 °C up to 9000 h. Microhardness measurements, Charpy impact and eddy current tests were performed on aged samples to characterize their thermal aging embrittlement. The results showed that the signal amplitude of eddy current decreased with the increase in aging time. Two quantitative correlations of the eddy current signal amplitude with both the Charpy impact energy, and the Vickers microhardness of the ferrite phase are obtained. The study showed that eddy current testing could be used to non-destructively evaluate the thermal aging embrittlement of cast duplex stainless steels.

Is there a decline in cognitive functions after combined electroconvulsive therapy and antipsychotic therapy in treatment-refractory schizophrenia?

PubMed

Pawełczyk, Agnieszka; Kołodziej-Kowalska, Emilia; Pawełczyk, Tomasz; Rabe-Jabłońska, Jolanta

2015-03-01

An analysis of literature shows that there is still little evidence concerning the efficacy of electroconvulsive therapy (ECT) combined with antipsychotic therapy in a group of treatment-resistant schizophrenia patients. More precisely, its influence on cognitive functions is still equivocal. The aim of this study was to assess the influence of ECT combined with antipsychotic therapy on working memory, attention, and executive functions in a group of treatment-refractory schizophrenia patients. Twenty-seven patients completed the study: 14 men and 13 women, aged 21 to 55 years (mean age, 32.8 years), diagnosed with treatment-resistant schizophrenia. Each patient underwent a course of ECT sessions and was treated with antipsychotic medications. Before the ECT and within 3 days after the last ECT session, the participants were assessed with the following neuropsychological tests: Trail Making Test (TMT) and Wisconsin Cart Sorting Test (WCST). There were no significant differences in the TMT and WCST results after combined ECT and antipsychotic therapy in treatment-refractory schizophrenia patients. According to the results of the neuropsychological tests, there was no decline in attention, executive functions, or working memory. The current study shows no significant difference in attention, working memory, or executive functions after treatment with a combination of electroconvulsive and antipsychotic therapy. This suggests that combined electroconvulsive therapy may not have a negative influence on the neuropsychological functioning of patients with treatment resistant schizophrenia.

The Radiation Belt Storm Probes (RBSP) Energetic Particle, Composition, and Thermal plasma (ECT) Suite: Upcoming Opportunties for Testing Radiation Belt Acceleration Mechanisms

NASA Astrophysics Data System (ADS)

Spence, Harlan; Reeves, Geoffrey

2012-07-01

The Radiation Belt Storm Probes (RBSP) mission will launch in late summer 2012 and begin its exploration of acceleration and dynamics of energetic particles in the inner magnetosphere. In this presentation, we discuss opportunities afforded by the RBSP Energetic Particle, Composition, and Thermal plasma (ECT) instrument suite to advance our understanding of acceleration processes in the radiation belts. The RBSP-ECT instrument suite comprehensively measures the electron and major ion populations of the inner magnetosphere, from the lowest thermal plasmas of the plasmasphere, to the hot plasma of the ring current, to the relativistic populations of the radiation belts. Collectively, the ECT measurements will reveal the complex cross-energy coupling of these colocated particle populations, which along with concurrent RBSP wave measurements, will permit various wave-particle acceleration mechanisms to be tested. We review the measurement capabilities of the RBSP-ECT instrument suite, and demonstrate several examples of how these measurements will be used to explore candidate acceleration mechanisms and dynamics of radiation belt particles.

Characterization of the Edge Crack Torsion (ECT) Test for Mode III Fracture Toughness Measurement of Laminated Composites

NASA Technical Reports Server (NTRS)

Ratcliffe, James G.

2004-01-01

The edge crack torsion (ECT) test is designed to initiate mode III delamination growth in composite laminates. The test has undergone several design changes during its development. The objective of this paper was to determine the suitability of the current ECT test design a mode III fracture test. To this end, ECT tests were conducted on specimens manufactured from IM7/8552 and S2/8552 tape laminates. Three-dimensional finite element analyses were performed. The analysis results were used to calculate the distribution of mode I, mode II, and mode III strain energy release rate along the delamination front. The results indicated that mode IIIdominated delamination growth would be initiated from the specimen center. However, in specimens of both material types, the measured values of GIIIc exhibited significant dependence on delamination length. Load-displacement response of the specimens exhibited significant deviation from linearity before specimen failure. X-radiographs of a sample of specimens revealed that damage was initiated in the specimens prior to failure. Further inspection of the failure surfaces is required to identify the damage and determine that mode III delamination is initiated in the specimens.

Nondestructive Testing Eddy Current Basic Principles RQA/M1-5330.12 (V-I).

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

As one in the series of programmed instruction handbooks, prepared by the U.S. space program, home study material is presented in this volume concerning familiarization and orientation on basic eddy current principles. The subject is presented under the following headings: Basic Eddy Current Concepts, Eddy Current Generation and Distribution,…

Non-Destructive Techniques Based on Eddy Current Testing

PubMed Central

García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

2011-01-01

Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

Non-destructive techniques based on eddy current testing.

PubMed

García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

2011-01-01

Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future.

Influence of magnet eddy current on magnetization characteristics of variable flux memory machine

NASA Astrophysics Data System (ADS)

Yang, Hui; Lin, Heyun; Zhu, Z. Q.; Lyu, Shukang

2018-05-01

In this paper, the magnet eddy current characteristics of a newly developed variable flux memory machine (VFMM) is investigated. Firstly, the machine structure, non-linear hysteresis characteristics and eddy current modeling of low coercive force magnet are described, respectively. Besides, the PM eddy current behaviors when applying the demagnetizing current pulses are unveiled and investigated. The mismatch of the required demagnetization currents between the cases with or without considering the magnet eddy current is identified. In addition, the influences of the magnet eddy current on the demagnetization effect of VFMM are analyzed. Finally, a prototype is manufactured and tested to verify the theoretical analyses.

Generation de chemins de couverture pour des operations automatisees de controle non destructif appliquees dans l'industrie aerospatiale

NASA Astrophysics Data System (ADS)

Olivieri, Pierre

Non destructive testing (NDT) plays an important role in the aerospace industry during the fabrication and maintenance of the structures built and is used, among other useful applications, to detect flaws such as cracks at an early stage. However, NDT techniques are still mainly done manually, especially on complex aeronautical structures, which then results in several drawbacks. In addition to be difficult and time-consuming, reliability and repeatability of inspection results are likely to be affected, since they rely on each operator's experience and dexterity. The present thesis is part of a larger project (MANU-418) of the Consortium for Research and Innovation in Aerospace in Quebec (CRIAQ). In this project, it has been proposed to develop a system using a 6-DOF manipulator arm to automate three particular NDT techniques often needed in the aerospace industry: eddy current testing (ECT), fluorescent penetrant inspection (FPI), and infrared thermography (IRT). The main objective of the MANU-418 project is to demonstrate the efficiency of the developed system and provide inspection results of surface and near surface flaws (cracks usually) at least as reliably and repeatably as inspection results from a human operator. One specific objective stemming from the main objective of the project is to develop a methodology and a software tool to generate covering paths adapted for the three aforementioned NDT techniques to inspect the complex surfaces of aerospace structures. The present thesis aims at reaching this specific objective. At first, geometrical and topological properties of the surfaces considered in this project are defined (flat surfaces, round and straight edges, cylindrical or near cylindrical surfaces, holes). It is also assumed that the 3D model of the surface to inspect is known in advance. Moreover, it has been decided within the framework of the MANU-418 project to give priority to the automation of ECT compared with the other techniques (FPI and IRT). As a result, the methodology developed to generate inspection paths is more closely focused on path constraints relative to the manual operations of ECT using a differential eddy current probe (named here EC probe), but it is developed to be flexible enough to be used with the other techniques as well. Common inspection paths for ECT are usually defined by a sweeping motion using a zigzag pattern with the EC probe in mild contact with the inspected surface. Moreover, the main axis of the probe must keep a normal orientation with the surface, and the alignment of its two coils must always be oriented along the direction of its motion. A first methodology is then proposed to generate covering paths on the whole surface of interest while meeting all EC probe motion constraints. First, the surface is meshed with triangular facets, and then it is subdivided into several patches such that their geometry and topology are simpler than the whole surface. Paths are then generated on each patch by intersecting their facets with offset section planes defined along a sweeping direction. Furthermore, another methodology is developed to generate paths around an indication (namely a small area where the presence of a flaw is suspected) whose position and orientation are assumed to be known a priori.. Then, a software tool with a graphical user interface has been developed in the MATLAB environment to generate inspection paths based on these methodologies. A set of path parameters can be changed by the user to get desired paths (distance between passes, sweep direction, etc.). Once paths are computed, an ordered list of coordinates (positions and orientations) of the tool is exported in an EXCEL spreadsheet so that it could be used with a real robot. In this research, these data are then used to perform simulations of trajectories (path described as a function of the time) with a MotoMan robot (model SV3XL) using the MotoSim software. After validation of these trajectories in this software (absence of collisions, positions are all reachable, etc.), they are finally converted into instructions for the real MotoMan robot to proceed with experimental tests. These first simulations and experimentations on a MotoMan robot of the generated paths have given results close to the expected inspection trajectories used manually in the NDT techniques considered, especially for the ECT technique. Nevertheless, it is strongly recommended to validate this path generation method with more experimental tests. For instance, a "test" tool could be manufactured to measure errors of position and orientation of this tool with respect to expected trajectories on a typical complex aeronautical structure. (Abstract shortened by UMI.).

Eddy-current testing of fatigue degradation upon contact fatigue loading of gas powder laser clad NiCrBSi-Cr3C2 composite coating

NASA Astrophysics Data System (ADS)

Savrai, R. A.; Makarov, A. V.; Gorkunov, E. S.; Soboleva, N. N.; Kogan, L. Kh.; Malygina, I. Yu.; Osintseva, A. L.; Davydova, N. A.

2017-12-01

The possibilities of the eddy-current method for testing the fatigue degradation under contact loading of gas powder laser clad NiCrBSi-Cr3C2 composite coating with 15 wt.% of Cr3C2 additive have been investigated. It is shown that the eddy-current testing of the fatigue degradation under contact loading of the NiCrBSi-15%Cr3C2 composite coating can be performed at high excitation frequencies 72-120 kHz of the eddy-current transducer. At that, the dependences of the eddy-current instrument readings on the number of loading cycles have both downward and upward branches, with the boundary between the branches being 3×105 cycles in the given loading conditions. This is caused, on the one hand, by cracking, and, on the other hand, by cohesive spalling and compaction of the composite coating, which affect oppositely the material resistivity and, correspondingly, the eddy-current instrument readings. The downward branch can be used to monitor the processes of crack formation and growth, the upward branch - to monitor the degree of cohesive spalling, while taking into account in the testing methodology an ambiguous character of the dependences of the eddy-current instrument readings on the number of loading cycles.

Development of and Improved Magneto-Optic/Eddy-Current Imager

DOT National Transportation Integrated Search

1997-04-01

Magneto-optic/eddy-current imaging technology has been developed and approved for inspection of cracks in aging aircraft. This relatively new nondestructive test method gives the inspector the ability to quickly generate real-time eddy-current images...

The Impact of A "Brief ECT Orientation Module" on The Knowledge and Attitudes of Medical Students Towards ECT in India.

PubMed

Balhara, Yps; Yadav, T; Mathur, S; Kataria, Dk

2012-07-01

Electroconvulsive therapy (ECT) continues to be an intervention that attracts controversy in spite of its proven efficacy. There is limited literature on attitude and knowledge of medical students towards ECT from Asian and African countries. The current study assesses the impact of a "Brief ECT Orientation Module" on the knowledge of and attitudes of Indian medical students towards modified ECT. The study was conducted at a tertiary care multi-specialty hospital associated with a government medical college. The students were administered the study questionnaire on Day 1 of Psychiatry clerkship. Following this, they were administered the Brief ECT Orientation Module. Assessment was made using a questionnaire with items related to knowledge and attitude towards ECT before and after "Brief ECT Orientation Module." Fifty-nine students completed the study. There was a significant improvement in knowledge of medical students on all the three domains of the questionnaire for assessment of knowledge about ECT-related facts. A change in attitudes towards ECT was also observed following Brief ECT Orientation Module, especially among those who witnessed ECT administration. The findings of the current study suggest that the Brief ECT Orientation Module is effective in improving the knowledge and attitude of medical students towards ECT.

Maintained Improvement of Neurocognitive Function in Major Depressive Disorders 6 Months after ECT.

PubMed

Mohn, Christine; Rund, Bjørn Rishovd

2016-01-01

Both impaired and improved cognitive function after electroconvulsive therapy (ECT) in major depressive disorder (MDD) patients may occur. We have previously found improved cognitive function 6 weeks after ECT in this group. The aim of this study was to report 6-month follow-up results from the same prospective project monitoring cognitive effects of ECT. Thirty-one patients with MDD were assessed with the MATRICS Consensus Cognitive Battery (MCCB), the Everyday Memory Questionnaire (EMQ), and the Montgomery-Åsberg Depression Rating Scale prior to, 6 weeks, and 6 months after ECT. Compared to baseline, the speed of processing, attention/vigilance, and reasoning/problem solving test results were significantly improved. The depression score was significantly reduced. There were no changes in subjective memory complaint. There was no significant relationship between the EMQ and the MCCB subtests, but a significant correlation between current depression level and the EMQ. Six months after ECT the cognitive improvement reported at 6-week follow-up was maintained and extended. The corresponding decrease in depressive symptoms and stability in subjectively reported memory complaints suggest that the antidepressant effects of ECT do not occur at the expense of cognitive function.

49 CFR Appendix C to Part 180 - Eddy Current Examination With Visual Inspection for DOT 3AL Cylinders Manufactured of Aluminum...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Eddy Current Examination With Visual Inspection... PACKAGINGS Pt. 180, App. C Appendix C to Part 180—Eddy Current Examination With Visual Inspection for DOT 3AL... procedure applicable to the test equipment it uses to perform eddy current examinations. 2. Visual...

Audit of thrice- versus twice-weekly ECT.

PubMed

Roche, Eric; Lope, Jasmin; Hughes, Helen; McCullagh, Niamh; Larkin, Terence; Feeney, Larkin

2012-09-01

There is a lack of knowledge regarding some basic differences between different electroconvulsive therapy (ECT) treatment schedules. To examine differences, including ECT technical parameters and length of stay, between thrice- and twice-weekly ECT treatment schedules. Prospective audit of the changeover period of administering thrice- to twice-weekly ECT in a Dublin psychiatric hospital. Twice-weekly ECT was associated with significantly lower total electricity dosage administered, a tendency toward shorter overall hospital stay and fewer ECT treatments compared to thrice-weekly ECT. Our results support the current international trend toward giving ECT twice weekly.

Using the Cambridge Neuropsychological Test Automated Battery (CANTAB) to assess the cognitive impact of electroconvulsive therapy on visual and visuospatial memory.

PubMed

Falconer, D W; Cleland, J; Fielding, S; Reid, I C

2010-06-01

The cognitive impact of electroconvulsive therapy (ECT) is rarely measured systematically in everyday clinical practice even though patient and clinician acceptance is limited by its adverse affect on memory. If patients are tested it is often with simple paper and pencil tests of visual or verbal memory. There are no reported studies of computerized neuropsychological testing to assess the cognitive impact of ECT on visuospatial memory. Twenty-four patients with severe depression were treated with a course of bilateral ECT and assessed with a battery of visual memory tests within the Cambridge Neuropsychological Test Automated Battery (CANTAB). These included spatial and pattern recognition memory, pattern-location associative learning and a delayed matching to sample test. Testing was carried out before ECT, during ECT, within the week after ECT and 1 month after ECT. Patients showed significant impairments in visual and visuospatial memory both during and within the week after ECT. Most impairments resolved 1 month following ECT; however, significant impairment in spatial recognition memory remained. This is one of only a few studies that have detected anterograde memory deficits more than 2 weeks after treatment. Patients receiving ECT displayed a range of visual and visuospatial deficits over the course of their treatment. These deficits were most prominent for tasks dependent on the use of the right medial temporal lobe; frontal lobe function may also be implicated. The CANTAB appears to be a useful instrument for measuring the adverse cognitive effects of ECT on aspects of visual and visuospatial memory.

The Impact of A “Brief ECT Orientation Module” on The Knowledge and Attitudes of Medical Students Towards ECT in India

PubMed Central

Balhara, YPS; Yadav, T; Mathur, S; Kataria, DK

2012-01-01

Background: Electroconvulsive therapy (ECT) continues to be an intervention that attracts controversy in spite of its proven efficacy. There is limited literature on attitude and knowledge of medical students towards ECT from Asian and African countries. Aim: The current study assesses the impact of a “Brief ECT Orientation Module” on the knowledge of and attitudes of Indian medical students towards modified ECT. Subjects and Methods: The study was conducted at a tertiary care multi-specialty hospital associated with a government medical college. The students were administered the study questionnaire on Day 1 of Psychiatry clerkship. Following this, they were administered the Brief ECT Orientation Module. Assessment was made using a questionnaire with items related to knowledge and attitude towards ECT before and after “Brief ECT Orientation Module.” Results: Fifty-nine students completed the study. There was a significant improvement in knowledge of medical students on all the three domains of the questionnaire for assessment of knowledge about ECT-related facts. A change in attitudes towards ECT was also observed following Brief ECT Orientation Module, especially among those who witnessed ECT administration. Conclusion: The findings of the current study suggest that the Brief ECT Orientation Module is effective in improving the knowledge and attitude of medical students towards ECT. PMID:23440565

Study of eddy current probes

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Wang, Morgan

1992-01-01

The recognition of materials properties still presents a number of problems for nondestructive testing in aerospace systems. This project attempts to utilize current capabilities in eddy current instrumentation, artificial intelligence, and robotics in order to provide insight into defining geometrical aspects of flaws in composite materials which are capable of being evaluated using eddy current inspection techniques.

Eddy Current Assessment of Engineered Components Containing Nanofibers

NASA Astrophysics Data System (ADS)

Ko, Ray T.; Hoppe, Wally; Pierce, Jenny

2009-03-01

The eddy current approach has been used to assess engineered components containing nanofibers. Five specimens with different programmed defects were fabricated. A 4-point collinear probe was used to verify the electrical resistivity of each specimen. The liftoff component of the eddy current signal was used to test two extreme cases with different nano contents. Additional eddy current measurements were also used in detecting a missing nano layer simulating a manufacturing process error. The results of this assessment suggest that eddy current liftoff measurement can be a useful tool in evaluating the electrical properties of materials containing nanofibers.

Characterization of the Edge Crack Torsion (ECT) Test for Mode III Fracture Toughness Measurement of Laminated Composites

NASA Technical Reports Server (NTRS)

Ratcliffe, James G.

2004-01-01

The edge crack torsion (ECT) test is designed to initiate mode III delamination growth in composite laminates. An ECT specimen is a rectangular laminate, containing an edge delamination at the laminate mid-plane. Torsion load is applied to the specimens, resulting in relative transverse shear sliding of the delaminated faces. The test data reduction schemes are intended to yield initiation values of critical mode III strain energy release rate, G(sub IIIc), that are constant with delamination length. The test has undergone several design changes during its development. The objective of this paper was to determine the suitability of the current ECT test design as a mode III fracture test. To this end, ECT tests were conducted on specimens manufactured from IM7/8552 and specimens made from S2/8552 tape laminates. Several specimens, each with different delamination lengths are tested. Detailed, three-dimensional finite element analyses of the specimens were performed. The analysis results were used to calculate the distribution of mode I, mode II, and mode III strain energy release rate along the delamination front. The results indicated that mode III-dominated delamination growth would be initiated from the specimen center. However, in specimens of both material types, the measured values of G(sub IIIc) exhibited significant dependence on delamination length. Furthermore, there was a large amount of scatter in the data. Load-displacement response of the specimens exhibited significant deviation from linearity before specimen failure. X-radiographs of a sample of specimens revealed that damage was initiated in the specimens prior to failure. Further inspection of the failure surfaces is required to identify the damage and determine that mode III delamination is initiated in the specimens.

The Clonic Phase of Seizures in Patients Treated with Electroconvulsive Therapy is Related to Age and Stimulus Intensity.

PubMed

Wang, Chao-Chih; Lin, Ching-Hung; Chiu, Yao-Chu; Tseng, Chih-Chieh

2013-01-01

Electroconvulsive therapy (ECT) is effective in the treatment of major depressive disorder and schizophrenia in patients who are drug-naïve or less-receptive to antipsychotic drugs. Several studies have discussed the correlation between patient characteristics, input-current volume, and seizure duration. According to the present principle of ECT guidelines, the therapeutic effect of ECT mostly correlates with seizure duration. As the tonic phase is different from the clonic phase with respect to brain function and activity, it is informative to analyze both the tonic and clonic phases. Thus, this study sought to clarify the relationship between the features of the two phases, and to re-examine and refine guidelines regarding ECT treatment. ECT-course data from 44 schizophrenia or bipolar I patients were recollected, including the number of treatments that they had received, their gender, age, and the association of these characteristics with motor seizure duration was analyzed. A two-factor correlation was employed to test the relationship between each of the two factors. The post-analysis results indicate that seizure duration and age are significantly correlated. Older patients had relatively short seizure durations after ECT-treatment. Notably, a negative correlation was only found between age and the clonic phase of the seizure, not between age and the tonic phase. Furthermore, this study also found an inverse relationship between ECT-intensity and the clonic phase, but not between ECT-intensity and the tonic phase. This study demonstrated that age and ECT-intensity are negatively correlated with seizure duration, particularly in the clonic phase. The present observations are not fully consistent with the basic guidelines of the APA-ECT practical manual. Accordingly, the predictions regarding the therapeutic effect of ECT can be based on both the seizure duration and the clonic phase.

Magnetic evaluation of the external surface in cast heat-resistant steel tubes with different aging states

NASA Astrophysics Data System (ADS)

Arenas, Mónica P.; Silveira, Rosa M.; Pacheco, Clara J.; Bruno, Antonio C.; Araujo, Jefferson F. D. F.; Eckstein, Carlos B.; Nogueira, Laudemiro; de Almeida, Luiz H.; Rebello, João M. A.; Pereira, Gabriela R.

2018-06-01

Heat-resistant austenitic stainless steels have become the principal alloys for use in steam reformer tubes in the petrochemical industry due to its mechanical properties. These tubes are typically exposed to severe operational conditions leading to microstructural transformations such as the aging phenomenon. The combination of high temperatures and moderate stresses causes creep damages, being necessary to monitor its structural condition by non-destructive techniques. The tube external wall is also subjected to oxidizing atmospheres, favoring the formation of an external surface, composed by an oxide scale and a chromium depleted zone. This external surface is usually not taken into account in the tube evaluation, which can lead to erroneous estimations of the service life of these components. In order to observe the magnetic influence of this layer, two samples, exposed to different operational temperatures, were characterized by non-destructive eddy current testing (ECT), scanning DC-susceptometer and magnetic force microscopy (MFM). It was found that the external surface thickness influences directly in the magnetic response of the samples.

Study protocol for the randomised controlled trial: Ketamine augmentation of ECT to improve outcomes in depression (Ketamine-ECT study).

PubMed

Trevithick, Liam; McAllister-Williams, R Hamish; Blamire, Andrew; Branton, Tim; Clark, Ross; Downey, Darragh; Dunn, Graham; Easton, Andrew; Elliott, Rebecca; Ellwell, Clare; Hayden, Katherine; Holland, Fiona; Karim, Salman; Lowe, Jo; Loo, Colleen; Nair, Rajesh; Oakley, Timothy; Prakash, Antony; Sharma, Parveen K; Williams, Stephen R; Anderson, Ian M

2015-10-21

There is a robust empirical evidence base supporting the acute efficacy of electroconvulsive therapy (ECT) for severe and treatment resistant depression. However, a major limitation, probably contributing to its declining use, is that ECT is associated with impairment in cognition, notably in anterograde and retrograde memory and executive function. Preclinical and preliminary human data suggests that ketamine, used either as the sole anaesthetic agent or in addition to other anaesthetics, may reduce or prevent cognitive impairment following ECT. A putative hypothesis is that ketamine, through antagonising glutamate receptors, protects from excess excitatory neurotransmitter stimulation during ECT. The primary aim of the ketamine-ECT study is to investigate whether adjunctive ketamine can attenuate the cognitive impairment caused by ECT. Its secondary aim is to examine if ketamine increases the speed of clinical improvement with ECT. The ketamine ECT study is a multi-site randomised, placebo-controlled, double blind trial. It was originally planned to recruit 160 moderately to severely depressed patients who had been clinically prescribed ECT. This recruitment target was subsequently revised to 100 patients due to recruitment difficulties. Patients will be randomly allocated on a 1:1 basis to receive either adjunctive ketamine or saline in addition to standard anaesthesia for ECT. The primary neuropsychological outcome measure is anterograde verbal memory (Hopkins Verbal Learning Test-Revised delayed recall task) after 4 ECT treatments. Secondary cognitive outcomes include verbal fluency, autobiographical memory, visuospatial memory and digit span. Efficacy is assessed using observer and self-report efficacy measures of depressive symptomatology. The effects of ECT and ketamine on cortical activity during cognitive tasks will be studied in a sub-sample using functional near-infrared spectroscopy (fNIRS). The ketamine-ECT study aims to establish whether or not adjunctive ketamine used together with standard anaesthesia for ECT will significantly reduce the adverse cognitive effects observed after ECT. Potential efficacy benefits of increased speed of symptom improvement and a reduction in the number of ECT treatments required will also be assessed, as will safety and tolerability of adjunctive ketamine. This study will provide important evidence as to whether adjunctive ketamine is routinely indicated for ECT given for depression in routine NHS clinical practice. Current Controlled Trials: ISRCTN14689382 (assigned 30/07/2012); EudraCT Number: 2011-005476-41.

Electroconvulsive Therapy Practice in Spain: A National Survey.

PubMed

Vera, Ignacio; Sanz-Fuentenebro, Javier; Urretavizcaya, Mikel; Verdura, Ernesto; Soria, Virginia; Martínez-Amorós, Erika; Bernardo, Miquel

2016-03-01

The use of electroconvulsive therapy (ECT) in Spain has not been systematically evaluated since 2000 to 2001. The aim of this study is to assess the current use of ECT in Spain. A cross-sectional survey was conducted covering every psychiatric unit in Spain as of December 31, 2012. About 93.2% of the centers answered the questionnaire. About 54.9% of the psychiatric units applied ECT at a rate of 0.66 patients per 10,000 inhabitants. Wide variations existed among the different autonomous communities and provinces. Written informed consent was obtained in all the facilities. About 38.2% of ECT-treated patients were 65 years or older. About 55.7% were women. Depressive episodes were the main indication for ECT (80.2%). All the facilities applied modified ECT. No sine wave current devices are currently used in Spain. Bifrontotemporal ECT was elective in 85% of the hospitals, bifrontal in 13.3%, and unilateral in 1.8%. Stimulus titration methods were elective in 8.6% of the centers. The decision to end ECT relied on the psychiatrist's clinical impression in 89.4% of the centers and on rating scales in 10.6%. The ECT training was mandatory in 56.5% of the centers. The ECT practice has significantly improved in Spain in recent years. Overall, Spanish facilities seem to comply with established clinical guidelines; however, specific concerns were identified, meaning there is still further scope for improvement.

Contrasting patterns of deficits in visuospatial memory and executive function in patients with major depression with and without ECT referral.

PubMed

Tsaltas, E; Kalogerakou, S; Papakosta, V-M; Kontis, D; Theochari, E; Koutroumpi, M; Anyfandi, E; Michopoulos, I; Poulopoulou, C; Papadimitriou, G; Oulis, P

2011-05-01

The pretreatment neuropsychological profile of drug-resistant patients with major depressive disorder (MDD) referred for electroconvulsive therapy (ECT) may differ from that of their drug-respondent MDD counterparts. Such differences could help in identifying distinct MDD subtypes, thus offering insights into the neuropathology underlying differential treatment responses. Depressed patients with ECT referral (ECTs), depressed patients with no ECT referral (NECTs) and non-psychiatric Controls (matched groups, n=15) were assessed with memory and executive function tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB). ECTs scored significantly lower than NECTs in the Mini-Mental State Examination (MMSE; p=0.01). NECTs performed worse than Controls in the Paired Associates Learning (PAL) task (p<0.03; Control/NECT p<0.01) and the Spatial Recognition Memory (SRM) task (p<0.05; Controls/NECTs p<0.05); ECTs performed between Controls and NECTs, not differing from either. In the Intra/Extradimensional (IED) set-shifting task, ECTs performed worse that Controls and NECTS (IED: p<0.01; Controls/ECTs p<0.01), particularly in the shift phases, which suggests reduced attentional flexibility. In Stockings of Cambridge (SOC), ECTs abandoned the test early more often than Controls and NECTs (H=11, p<0.01) but ECTs who completed SOC performed comparably to the other two groups. A double dissociation emerged from the comparison of cognitive profiles of ECT and NECT patients. ECTs showed executive deficits, particularly in attentional flexibility, but mild deficits in tests of visuospatial memory. NECTs presented the opposite pattern. This suggests predominantly frontostriatal involvement in ECT versus temporal involvement in NECT depressives.

Eddy current imaging for electrical characterization of silicon solar cells and TCO layers

NASA Astrophysics Data System (ADS)

Hwang, Byungguk; Hillmann, Susanne; Schulze, Martin; Klein, Marcus; Heuer, Henning

2015-03-01

Eddy Current Testing has been mainly used to determine defects of conductive materials and wall thicknesses in heavy industries such as construction or aerospace. Recently, high frequency Eddy Current imaging technology was developed. This enables the acquirement of information of different depth level in conductive thin-film structures by realizing proper standard penetration depth. In this paper, we summarize the state of the art applications focusing on PV industry and extend the analysis implementing achievements by applying spatially resolved Eddy Current Testing. The specific state of frequency and complex phase angle rotation demonstrates diverse defects from front to back side of silicon solar cells and characterizes homogeneity of sheet resistance in Transparent Conductive Oxide (TCO) layers. In order to verify technical feasibility, measurement results from the Multi Parameter Eddy Current Scanner, MPECS are compared to the results from Electroluminescence.

Modelling of eddy currents related to large angle magnetic suspension test fixture

NASA Technical Reports Server (NTRS)

Britcher, Colin P.; Foster, Lucas E.

1994-01-01

This report presents a preliminary analysis of the mathematical modelling of eddy current effects in a large-gap magnetic suspension system. It is shown that eddy currents can significantly affect the dynamic behavior and control of these systems, but are amenable to measurement and modelling. A theoretical framework is presented, together with a comparison of computed and experimental data related to the Large Angle Magnetic Suspension Test Fixture at NASA Langley Research Center.

Fast solver for large scale eddy current non-destructive evaluation problems

NASA Astrophysics Data System (ADS)

Lei, Naiguang

Eddy current testing plays a very important role in non-destructive evaluations of conducting test samples. Based on Faraday's law, an alternating magnetic field source generates induced currents, called eddy currents, in an electrically conducting test specimen. The eddy currents generate induced magnetic fields that oppose the direction of the inducing magnetic field in accordance with Lenz's law. In the presence of discontinuities in material property or defects in the test specimen, the induced eddy current paths are perturbed and the associated magnetic fields can be detected by coils or magnetic field sensors, such as Hall elements or magneto-resistance sensors. Due to the complexity of the test specimen and the inspection environments, the availability of theoretical simulation models is extremely valuable for studying the basic field/flaw interactions in order to obtain a fuller understanding of non-destructive testing phenomena. Theoretical models of the forward problem are also useful for training and validation of automated defect detection systems. Theoretical models generate defect signatures that are expensive to replicate experimentally. In general, modelling methods can be classified into two categories: analytical and numerical. Although analytical approaches offer closed form solution, it is generally not possible to obtain largely due to the complex sample and defect geometries, especially in three-dimensional space. Numerical modelling has become popular with advances in computer technology and computational methods. However, due to the huge time consumption in the case of large scale problems, accelerations/fast solvers are needed to enhance numerical models. This dissertation describes a numerical simulation model for eddy current problems using finite element analysis. Validation of the accuracy of this model is demonstrated via comparison with experimental measurements of steam generator tube wall defects. These simulations generating two-dimension raster scan data typically takes one to two days on a dedicated eight-core PC. A novel direct integral solver for eddy current problems and GPU-based implementation is also investigated in this research to reduce the computational time.

Ketamine-based anesthesia improves electroconvulsive therapy outcomes: a randomized-controlled study.

PubMed

Gamble, Jonathan J; Bi, Henry; Bowen, Rudy; Weisgerber, Grahme; Sanjanwala, Rohan; Prasad, Renuka; Balbuena, Lloyd

2018-06-01

Major depressive disorder (MDD) is a common and debilitating condition that can be challenging to treat. Electroconvulsive therapy (ECT) is currently the therapeutic gold standard for treatment-resistant MDD. We tested our hypothesis that ketamine-based anesthesia for ECT results in superior improvement in treatment-resistant MDD outcomes compared with propofol-based anesthesia. Patients with treatment-resistant MDD were enrolled in a randomized clinical trial with assignment to ketamine- or propofol-based anesthesia arms. Using a modified intention-to-treat analysis, we compared the median number of ECT treatments required to achieve a 50% reduction (primary outcome) and a score ≤ 10 (secondary outcome) on the Montgomery-Asberg depression rating scale (MADRS) between anesthesia groups. The study was terminated as significant results were found after the first planned interim analysis with 12 patients in each of the ketamine (intervention) and propofol (control) groups. All ketamine patients achieved at least a 50% MADRS reduction after a median of two ECT treatments whereas ten propofol patients (83%) achieved the same outcome after a median of four ECT treatments. All ketamine patients and seven propofol patients (58%) achieved MDD remission (MADRS ≤ 10). Log rank tests showed that both time-to-50% reduction and remission differed significantly between groups. Adverse events and recovery time were similar between groups. In this early-terminated small-sized study, ketamine-based anesthesia compared with propofol-based anesthesia provided response and remission after fewer ECT sessions. www.clinicaltrials.gov (NCT01935115). Registered 4 September 2013.

3-D residual eddy current field characterisation: applied to diffusion weighted magnetic resonance imaging.

PubMed

O'Brien, Kieran; Daducci, Alessandro; Kickler, Nils; Lazeyras, Francois; Gruetter, Rolf; Feiweier, Thorsten; Krueger, Gunnar

2013-08-01

Clinical use of the Stejskal-Tanner diffusion weighted images is hampered by the geometric distortions that result from the large residual 3-D eddy current field induced. In this work, we aimed to predict, using linear response theory, the residual 3-D eddy current field required for geometric distortion correction based on phantom eddy current field measurements. The predicted 3-D eddy current field induced by the diffusion-weighting gradients was able to reduce the root mean square error of the residual eddy current field to ~1 Hz. The model's performance was tested on diffusion weighted images of four normal volunteers, following distortion correction, the quality of the Stejskal-Tanner diffusion-weighted images was found to have comparable quality to image registration based corrections (FSL) at low b-values. Unlike registration techniques the correction was not hindered by low SNR at high b-values, and results in improved image quality relative to FSL. Characterization of the 3-D eddy current field with linear response theory enables the prediction of the 3-D eddy current field required to correct eddy current induced geometric distortions for a wide range of clinical and high b-value protocols.

Catatonia with schizophrenia: From ECT to rTMS.

PubMed

Stip, E; Blain-Juste, M-E; Farmer, O; Fournier-Gosselin, M-P; Lespérance, P

2018-04-01

Electroconvulsive therapy is indicated in cases of catatonic schizophrenia following a failure of the challenge test with lorazepam or Zolpidem ® . Some patients need maintenance treatment with ECT. Repetitive Transcranial Magnetic Stimulation (rTMS) and anodal Transcranial direct-current stimulation (tDCS) might be effective against catatonia. Consider an alternative to ECT for a refractory patient. Twenty-one articles were identified mainly based on case reports series were found using search on Medline, Google Scholar, PsychInfo, CAIRNS. Key words were:"catatonia", and "rTMS", and more generally with"ECT","tDCS","Zolpidem ® ". At the end there were only six case reports with rTMS and three with tDCS. We discussed the alternative to ECT and follow up rTMS strategies illustrated by these case reports. Patients mean age was 35; numbers of previous ECT vary from zero to 556; the most common motor threshold (MT) is 80%, with two patients with 110%, the most common treatment placement is L DLPFC. In one of them, ECT was the only acute-state or maintenance treatment effective in this patient, who underwent 556 ECT sessions over 20 years. High-frequency rTMS was considered as a possible alternative, given the potential adverse effects of chronic maintenance ECT in a patient with comorbid epilepsy. rTMS treatment was 3-4×/week and over time extended to once every two weeks. A persistent objective improvement in catatonia was observed on the Bush-Francis Catatonia Rating Scale. rTMS is helpful for acute and maintenance treatment for catatonic schizophrenia who both failed multiple pharmacologic interventions and had safety concerns with continuing maintenance ECT. Clinicians should consider rTMS as a potential treatment option for refractory catatonia. Copyright © 2017 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Nondestructive examination of the Tropical Rainfall Measuring Mission (TRMM) reaction control subsystem (RCS) propellant tanks

NASA Technical Reports Server (NTRS)

Free, James M.

1993-01-01

This paper assesses the feasibility of using eddy current nondestructive examination to determine flaw sizes in completely assembled hydrazine propellant tanks. The study was performed by the NASA Goddard Space Flight Center for the Tropical Rainfall Measuring Mission (TRMM) project to help determine whether existing propellant tanks could meet the fracture analysis requirements of the current pressure vessel specification, MIL-STD-1522A and, therefore be used on the TRMM spacecraft. After evaluating several nondestructive test methods, eddy current testing was selected as the most promising method for determining flaw sizes on external and internal surfaces of completely assembled tanks. Tests were conducted to confirm the detection capability of the eddy current NDE, procedures were developed to inspect two candidate tanks, and the test support equipment was designed. The non-spherical tank eddy current NDE test program was terminated when the decision was made to procure new tanks for the TRMM propulsion subsystem. The information on the development phase of this test program is presented in this paper as a reference for future investigation on the subject.

The eddy current probe array for Keda Torus eXperiment.

PubMed

Li, Zichao; Li, Hong; Tu, Cui; Hu, Jintong; You, Wei; Luo, Bing; Tan, Mingsheng; Adil, Yolbarsop; Wu, Yanqi; Shen, Biao; Xiao, Bingjia; Zhang, Ping; Mao, Wenzhe; Wang, Hai; Wen, Xiaohui; Zhou, Haiyang; Xie, Jinlin; Lan, Tao; Liu, Adi; Ding, Weixing; Xiao, Chijin; Liu, Wandong

2016-11-01

In a reversed field pinch device, the conductive shell is placed as close as possible to the plasma so as to balance the plasma during discharge. Plasma instabilities such as the resistive wall mode and certain tearing modes, which restrain the plasma high parameter operation, respond closely with conditions in the wall, in essence the eddy current present. Also, the effect of eddy currents induced by the external coils cannot be ignored when active control is applied to control instabilities. One diagnostic tool, an eddy current probe array, detects the eddy current in the composite shell. Magnetic probes measuring differences between the inner and outer magnetic fields enable estimates of the amplitude and angle of these eddy currents. Along with measurements of currents through the copper bolts connecting the poloidal shield copper shells, we can obtain the eddy currents over the entire shell. Magnetic field and eddy current resolutions approach 2 G and 6 A, respectively. Additionally, the vortex electric field can be obtained by eddy current probes. As the conductivity of the composite shell is high, the eddy current probe array is very sensitive to the electric field and has a resolution of 0.2 mV/cm. In a bench test experiment using a 1/4 vacuum vessel, measurements of the induced eddy currents are compared with simulation results based on a 3D electromagnetic model. The preliminary data of the eddy currents have been detected during discharges in a Keda Torus eXperiment device. The typical value of toroidal and poloidal eddy currents across the magnetic probe coverage rectangular area could reach 3.0 kA and 1.3 kA, respectively.

Individualized Low-Amplitude Seizure Therapy: Minimizing Current for Electroconvulsive Therapy and Magnetic Seizure Therapy.

PubMed

Peterchev, Angel V; Krystal, Andrew D; Rosa, Moacyr A; Lisanby, Sarah H

2015-08-01

Electroconvulsive therapy (ECT) at conventional current amplitudes (800-900 mA) is highly effective but carries the risk of cognitive side effects. Lowering and individualizing the current amplitude may reduce side effects by virtue of a less intense and more focal electric field exposure in the brain, but this aspect of ECT dosing is largely unexplored. Magnetic seizure therapy (MST) induces a weaker and more focal electric field than ECT; however, the pulse amplitude is not individualized and the minimum amplitude required to induce a seizure is unknown. We titrated the amplitude of long stimulus trains (500 pulses) as a means of determining the minimum current amplitude required to induce a seizure with ECT (bilateral, right unilateral, bifrontal, and frontomedial electrode placements) and MST (round coil on vertex) in nonhuman primates. Furthermore, we investigated a novel method of predicting this amplitude-titrated seizure threshold (ST) by a non-convulsive measurement of motor threshold (MT) using single pulses delivered through the ECT electrodes or MST coil. Average STs were substantially lower than conventional pulse amplitudes (112-174 mA for ECT and 37.4% of maximum device amplitude for MST). ST was more variable in ECT than in MST. MT explained 63% of the ST variance and is hence the strongest known predictor of ST. These results indicate that seizures can be induced with less intense electric fields than conventional ECT that may be safer; efficacy and side effects should be evaluated in clinical studies. MT measurement could be a faster and safer alternative to empirical ST titration for ECT and MST.

Eddy Current, Magnetic Particle and Hardness Testing, Aviation Quality Control (Advanced): 9227.04.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

This unit of instruction includes the principles of eddy current, magnetic particle and hardness testing; standards used for analyzing test results; techniques of operating equipment; interpretation of indications; advantages and limitations of these methods of testing; care and calibration of equipment; and safety and work precautions. Motion…

Minimum Electric Field Exposure for Seizure Induction with Electroconvulsive Therapy and Magnetic Seizure Therapy.

PubMed

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

2017-05-01

Lowering and individualizing the current amplitude in electroconvulsive therapy (ECT) has been proposed as a means to produce stimulation closer to the neural activation threshold and more focal seizure induction, which could potentially reduce cognitive side effects. However, the effect of current amplitude on the electric field (E-field) in the brain has not been previously linked to the current amplitude threshold for seizure induction. We coupled MRI-based E-field models with amplitude titrations of motor threshold (MT) and seizure threshold (ST) in four nonhuman primates (NHPs) to determine the strength, distribution, and focality of stimulation in the brain for four ECT electrode configurations (bilateral, bifrontal, right-unilateral, and frontomedial) and magnetic seizure therapy (MST) with cap coil on vertex. At the amplitude-titrated ST, the stimulated brain subvolume (23-63%) was significantly less than for conventional ECT with high, fixed current (94-99%). The focality of amplitude-titrated right-unilateral ECT (25%) was comparable to cap coil MST (23%), demonstrating that ECT with a low current amplitude and focal electrode placement can induce seizures with E-field as focal as MST, although these electrode and coil configurations affect differently specific brain regions. Individualizing the current amplitude reduced interindividual variation in the stimulation focality by 40-53% for ECT and 26% for MST, supporting amplitude individualization as a means of dosing especially for ECT. There was an overall significant correlation between the measured amplitude-titrated ST and the prediction of the E-field models, supporting a potential role of these models in dosing of ECT and MST. These findings may guide the development of seizure therapy dosing paradigms with improved risk/benefit ratio.

Eddy current correction in volume-localized MR spectroscopy

NASA Technical Reports Server (NTRS)

Lin, C.; Wendt, R. E. 3rd; Evans, H. J.; Rowe, R. M.; Hedrick, T. D.; LeBlanc, A. D.

1994-01-01

The quality of volume-localized magnetic resonance spectroscopy is affected by eddy currents caused by gradient switching. Eddy currents can be reduced with improved gradient systems; however, it has been suggested that the distortion due to eddy currents can be compensated for during postprocessing with a single-frequency reference signal. The authors propose modifying current techniques for acquiring the single-frequency reference signal by using relaxation weighting to reduce interference from components that cannot be eliminated by digital filtering alone. Additional sequences with T1 or T2 weighting for reference signal acquisition are shown to have the same eddy current characteristics as the original signal without relaxation weighting. The authors also studied a new eddy current correction method that does not require a single-frequency reference signal. This method uses two free induction decays (FIDs) collected from the same volume with two sequences with opposite gradients. Phase errors caused by eddy currents are opposite in these two FIDs and can be canceled completely by combining the FIDs. These methods were tested in a phantom. Eddy current distortions were corrected, allowing quantitative measurement of structures such as the -CH = CH- component, which is otherwise undetectable.

Individualized Low-Amplitude Seizure Therapy: Minimizing Current for Electroconvulsive Therapy and Magnetic Seizure Therapy

PubMed Central

Peterchev, Angel V; Krystal, Andrew D; Rosa, Moacyr A; Lisanby, Sarah H

2015-01-01

Electroconvulsive therapy (ECT) at conventional current amplitudes (800–900 mA) is highly effective but carries the risk of cognitive side effects. Lowering and individualizing the current amplitude may reduce side effects by virtue of a less intense and more focal electric field exposure in the brain, but this aspect of ECT dosing is largely unexplored. Magnetic seizure therapy (MST) induces a weaker and more focal electric field than ECT; however, the pulse amplitude is not individualized and the minimum amplitude required to induce a seizure is unknown. We titrated the amplitude of long stimulus trains (500 pulses) as a means of determining the minimum current amplitude required to induce a seizure with ECT (bilateral, right unilateral, bifrontal, and frontomedial electrode placements) and MST (round coil on vertex) in nonhuman primates. Furthermore, we investigated a novel method of predicting this amplitude-titrated seizure threshold (ST) by a non-convulsive measurement of motor threshold (MT) using single pulses delivered through the ECT electrodes or MST coil. Average STs were substantially lower than conventional pulse amplitudes (112–174 mA for ECT and 37.4% of maximum device amplitude for MST). ST was more variable in ECT than in MST. MT explained 63% of the ST variance and is hence the strongest known predictor of ST. These results indicate that seizures can be induced with less intense electric fields than conventional ECT that may be safer; efficacy and side effects should be evaluated in clinical studies. MT measurement could be a faster and safer alternative to empirical ST titration for ECT and MST. PMID:25920013

Continuation and Maintenance Electroconvulsive Therapy for Mood Disorders: Review of the Literature

PubMed Central

Petrides, Georgios; Tobias, Kristen G.; Kellner, Charles H.; Rudorfer, Matthew V.

2011-01-01

Background Electroconvulsive therapy (ECT) is a highly effective treatment for mood disorders. Continuation ECT (C-ECT) and maintenance ECT (M-ECT) are required for many patients suffering from severe and recurrent forms of mood disorders. This is a review of the literature regarding C- and M-ECT. Methods We conducted a computerized search using the words continuation ECT, maintenance ECT, depression, mania, bipolar disorder and mood disorders. We report on all articles published in the English language from 1998 to 2009. Results We identified 32 reports. There were 24 case reports and retrospective reviews on 284 patients. Two of these reports included comparison groups, and 1 had a prospective follow-up in a subset of subjects. There were 6 prospective naturalistic studies and 2 randomized controlled trials. Conclusions C-ECT and M-ECT are valuable treatment modalities to prevent relapse and recurrence of mood disorders in patients who have responded to an index course of ECT. C-ECT and M-ECT are underused and insufficiently studied despite positive clinical experience of more than 70 years. Studies which are currently under way should allow more definitive recommendations regarding the choice, frequency and duration of C-ECT and M-ECT following acute ECT. PMID:21811083

Development and Test of an Eddy-Current Clutch-Propulsion System

DOT National Transportation Integrated Search

1973-10-01

This report covers the Phase 1 effort which is to develop and to test an/AC-propulsion system for personal rapid- transit vehicles. This propulsion system incorporates an AC-induction motor in conjunction with an eddy-current clutch and brake. Also i...

Correlation of eddy current responses between fatigue cracks and electrical-discharge-machining notches

NASA Astrophysics Data System (ADS)

Seo, Sukho; Choi, Gyudong; Eom, Tae Jhoun; Lee, Bokwon; Lee, Soo Yeol

2017-07-01

The eddy current responses of Electrical Discharge Machining (EDM) notches and fatigue cracks are directly compared to verify the reliability of eddy current inspection. The fatigue crack growth tests using a constant load range control mode were conducted to obtain a variety of edge crack sizes, ranging from 0.9 to 6.6 mm for Al alloy and from 0.1 to 3 mm for Ti alloy. EDM notch specimens of Al and Ti alloys were accordingly prepared in lengths similar to that of the fatigued specimen. The crack length was determined by optical microscope and scanning electron microscope. The eddy current responses between the EDM and fatigued specimens with varying notch/crack length were examined using probe sensors at (100-500) kHz and (1-2) MHz for Al and Ti alloys, respectively. The results show a significant difference in the eddy current signal between the two specimens, based on the correlation between the eddy current response and notch/crack length. This suggests that eddy current inspection using the EDM reference specimen is inaccurate in determining the precise crack size, unless the eddy current response data base is obtained from a fatigue-cracked specimen.

Dual optimization method of radiofrequency and quasistatic field simulations for reduction of eddy currents generated on 7T radiofrequency coil shielding.

PubMed

Zhao, Yujuan; Zhao, Tiejun; Raval, Shailesh B; Krishnamurthy, Narayanan; Zheng, Hai; Harris, Chad T; Handler, William B; Chronik, Blaine A; Ibrahim, Tamer S

2015-11-01

To optimize the design of radiofrequency (RF) shielding of transmit coils at 7T and reduce eddy currents generated on the RF shielding when imaging with rapid gradient waveforms. One set of a four-element, 2 × 2 Tic-Tac-Toe head coil structure was selected and constructed to study eddy currents on the RF coil shielding. The generated eddy currents were quantitatively studied in the time and frequency domains. The RF characteristics were studied using the finite difference time domain method. Five different kinds of RF shielding were tested on a 7T MRI scanner with phantoms and in vivo human subjects. The eddy current simulation method was verified by the measurement results. Eddy currents induced by solid/intact and simple-structured slotted RF shielding significantly distorted the gradient fields. Echo-planar images, B1+ maps, and S matrix measurements verified that the proposed slot pattern suppressed the eddy currents while maintaining the RF characteristics of the transmit coil. The presented dual-optimization method could be used to design RF shielding and reduce the gradient field-induced eddy currents while maintaining the RF characteristics of the transmit coil. © 2014 Wiley Periodicals, Inc.

A novel eddy current damper: theory and experiment

NASA Astrophysics Data System (ADS)

Ebrahimi, Babak; Khamesee, Mir Behrad; Golnaraghi, Farid

2009-04-01

A novel eddy current damper is developed and its damping characteristics are studied analytically and experimentally. The proposed eddy current damper consists of a conductor as an outer tube, and an array of axially magnetized ring-shaped permanent magnets separated by iron pole pieces as a mover. The relative movement of the magnets and the conductor causes the conductor to undergo motional eddy currents. Since the eddy currents produce a repulsive force that is proportional to the velocity of the conductor, the moving magnet and the conductor behave as a viscous damper. The eddy current generation causes the vibration to dissipate through the Joule heating generated in the conductor part. An accurate, analytical model of the system is obtained by applying electromagnetic theory to estimate the damping properties of the proposed eddy current damper. A prototype eddy current damper is fabricated, and experiments are carried out to verify the accuracy of the theoretical model. The experimental test bed consists of a one-degree-of-freedom vibration isolation system and is used for the frequency and transient time response analysis of the system. The eddy current damper model has a 0.1 m s-2 (4.8%) RMS error in the estimation of the mass acceleration. A damping coefficient as high as 53 Ns m-1 is achievable with the fabricated prototype. This novel eddy current damper is an oil-free, inexpensive damper that is applicable in various vibration isolation systems such as precision machinery, micro-mechanical suspension systems and structure vibration isolation.

Eddy-Current Detection of Weak Bolt Heads

NASA Technical Reports Server (NTRS)

Messina, C. P.

1987-01-01

Electronic test identifies flawed units passing hardness tests. Eddy-current test detects weakness in head-to-shank junctions of 1/4-28 cup-washer lock bolts. Developed for alloy A286 steel bolts in Space Shuttle main engine fuel turbo-pump. Test examines full volume of head, including head-to-shank transition and nondestructively screens out potentially defective units. Test adapts to any other alloys.

A combined experimental and finite element analysis method for the estimation of eddy-current loss in NdFeB magnets.

PubMed

Fratila, Radu; Benabou, Abdelkader; Tounzi, Abdelmounaïm; Mipo, Jean-Claude

2014-05-14

NdFeB permanent magnets (PMs) are widely used in high performance electrical machines, but their relatively high conductivity subjects them to eddy current losses that can lead to magnetization loss. The Finite Element (FE) method is generally used to quantify the eddy current loss of PMs, but it remains quite difficult to validate the accuracy of the results with complex devices. In this paper, an experimental test device is used in order to extract the eddy current losses that are then compared with those of a 3D FE model.

Balance and gait in older electroconvulsive therapy recipients: a pilot study

PubMed Central

Plakiotis, Chris; Barson, Fay; Vengadasalam, Bharathi; Haines, Terry P; O’Connor, Daniel W

2013-01-01

Background Electroconvulsive therapy (ECT) is commonly used to treat depression in older adults. Despite its efficacy in this regard, an associated increase in the risk of falls in this population is a downside of treatment. ECT research has focused on the incidence of falls, but its effect on balance and gait – intrinsic factors in instability and falls – has not been studied. Our aim was to examine changes in balance and gait among older adults before and after a single ECT session and explore the effect of patient-related and treatment factors on any changes found. Methods Participants were 21 older adults requiring ECT for depression in public psychiatric services. Patients with clinically overt mobility problems (impairing test participation or increasing the risk of falls) were excluded. Balance and gait testing 1 hour pre-ECT and 1, 2 and 3 hours post-ECT included: (1) steady standing test; (2) perturbation of standing balance by self-initiated movements; (3) perturbation of standing balance by an external perturbation; and (4) timed up and go test. Results No deterioration in test performance was found, using one-way repeated measures analysis of variance. Conclusion Balance and gait did not deteriorate immediately after ECT. Exclusion of participants with clinically overt mobility problems and falls being better attributable to factors unrelated to balance and gait (such as post-ECT confusion) may account for our findings. This research does not repudiate the occurrence of ECT-related falls but calls into question the utility of introducing routine balance and gait assessment among older ECT recipients without pre-existing mobility problems as a means of preventing them. PMID:23766650

Estimation of stress distribution in ferromagnetic tensile specimens using low cost eddy current stress measurement system and BP neural network.

PubMed

Li, Jianwei; Zhang, Weimin; Zeng, Weiqin; Chen, Guolong; Qiu, Zhongchao; Cao, Xinyuan; Gao, Xuanyi

2017-01-01

Estimation of the stress distribution in ferromagnetic components is very important for evaluating the working status of mechanical equipment and implementing preventive maintenance. Eddy current testing technology is a promising method in this field because of its advantages of safety, no need of coupling agent, etc. In order to reduce the cost of eddy current stress measurement system, and obtain the stress distribution in ferromagnetic materials without scanning, a low cost eddy current stress measurement system based on Archimedes spiral planar coil was established, and a method based on BP neural network to obtain the stress distribution using the stress of several discrete test points was proposed. To verify the performance of the developed test system and the validity of the proposed method, experiment was implemented using structural steel (Q235) specimens. Standard curves of sensors at each test point were achieved, the calibrated data were used to establish the BP neural network model for approximating the stress variation on the specimen surface, and the stress distribution curve of the specimen was obtained by interpolating with the established model. The results show that there is a good linear relationship between the change of signal modulus and the stress in most elastic range of the specimen, and the established system can detect the change in stress with a theoretical average sensitivity of -0.4228 mV/MPa. The obtained stress distribution curve is well consonant with the theoretical analysis result. At last, possible causes and improving methods of problems appeared in the results were discussed. This research has important significance for reducing the cost of eddy current stress measurement system, and advancing the engineering application of eddy current stress testing.

Estimation of stress distribution in ferromagnetic tensile specimens using low cost eddy current stress measurement system and BP neural network

PubMed Central

Li, Jianwei; Zeng, Weiqin; Chen, Guolong; Qiu, Zhongchao; Cao, Xinyuan; Gao, Xuanyi

2017-01-01

Estimation of the stress distribution in ferromagnetic components is very important for evaluating the working status of mechanical equipment and implementing preventive maintenance. Eddy current testing technology is a promising method in this field because of its advantages of safety, no need of coupling agent, etc. In order to reduce the cost of eddy current stress measurement system, and obtain the stress distribution in ferromagnetic materials without scanning, a low cost eddy current stress measurement system based on Archimedes spiral planar coil was established, and a method based on BP neural network to obtain the stress distribution using the stress of several discrete test points was proposed. To verify the performance of the developed test system and the validity of the proposed method, experiment was implemented using structural steel (Q235) specimens. Standard curves of sensors at each test point were achieved, the calibrated data were used to establish the BP neural network model for approximating the stress variation on the specimen surface, and the stress distribution curve of the specimen was obtained by interpolating with the established model. The results show that there is a good linear relationship between the change of signal modulus and the stress in most elastic range of the specimen, and the established system can detect the change in stress with a theoretical average sensitivity of -0.4228 mV/MPa. The obtained stress distribution curve is well consonant with the theoretical analysis result. At last, possible causes and improving methods of problems appeared in the results were discussed. This research has important significance for reducing the cost of eddy current stress measurement system, and advancing the engineering application of eddy current stress testing. PMID:29145500

Eddy current inspection of graphite fiber components

NASA Technical Reports Server (NTRS)

Workman, G. L.; Bryson, C. C.

1990-01-01

The recognition of defects in materials properties still presents a number of problems for nondestructive testing in aerospace systems. This project attempts to utilize current capabilities in eddy current instrumentation, artificial intelligence, and robotics in order to provide insight into defining geometrical aspects of flaws in composite materials which are capable of being evaluated using eddy current inspection techniques. The unique capabilities of E-probes and horseshoe probes for inspecting probes for inspecting graphite fiber materials were evaluated and appear to hold great promise once the technology development matures. The initial results are described of modeling eddy current interactions with certain flaws in graphite fiber samples.

Nondestructive Testing Eddy Current Equipment, Methods and Applications RQA/M1-5330.12 (V-II).

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

As one in the series of programmed instruction handbooks, prepared by the U. S. space program, home study material is presented in this volume concerning familiarization and orientation on eddy current testing. The subject is presented under the following headings: Test Coils, Methods and Indications, and Applications. High product quality and…

What we have learned about electroconvulsive therapy and its relevance for the practising psychiatrist.

PubMed

Sienaert, Pascal

2011-01-01

In this narrative review, the current knowledge base on the efficacy and the practice of electroconvulsive therapy (ECT) is reviewed, and its relevance for the practising psychiatrist is appreciated. In the past decade, several large-scale studies have confirmed the significant superiority of ECT in the treatment of severe and refractory psychiatric conditions, such as major depressive disorder and bipolar disorder. However, the efficacy of ECT is not reflected in current treatment algorithms, where ECT is often reserved as a last resort. However, clinical characteristics, such as the presence of psychotic symptoms, suicidality, or catatonic signs, should prompt the clinician to consider ECT earlier in the treatment course. ECT is a safe procedure, without absolute contraindications for its use. Nevertheless, patients' fears and complaints should be acknowledged, and patients should be adequately informed about expected benefits and possible risks, such as memory problems, that are generally transient. Research focusing on further minimizing memory problems, while maintaining a superior efficacy, is ongoing. Adequate continuation treatment, either pharmacotherapy or continuation ECT, after a successful ECT course is of vital importance to maintain the benefits achieved and should be the focus of future research.

Method for removal of random noise in eddy-current testing system

DOEpatents

Levy, Arthur J.

1995-01-01

Eddy-current response voltages, generated during inspection of metallic structures for anomalies, are often replete with noise. Therefore, analysis of the inspection data and results is difficult or near impossible, resulting in inconsistent or unreliable evaluation of the structure. This invention processes the eddy-current response voltage, removing the effect of random noise, to allow proper identification of anomalies within and associated with the structure.

Long-Term Cognitive and Psychological Functioning in Post-Electroconvulsive Therapy Patients.

PubMed

Miller, Michelle L; Luu, Hien; Gaasedelen, Owen; Hahn-Ketter, Amanda E; Elmore, Alexis; Dezhkam, Naseem; Bayless, John; Moser, David J; Whiteside, Douglas M

2018-05-01

Electroconvulsive therapy (ECT) is associated with positive outcomes for treatment-resistant mood disorders in the short term. However, there is limited research on long-term cognitive or psychological changes beyond 1 year after -ECT. This study evaluated long-term outcomes in cognitive functioning, psychiatric symptoms, and quality of life for individuals who had undergone ECT. Eligible participants (N = 294) who completed a brief pre-ECT neuropsychological assessment within the last 14 years were recruited for a follow-up evaluation; a limited sample agreed to follow-up testing (n = 34). At follow-up, participants were administered cognitive measures (Repeatable Battery for the Assessment of Neuropsychological Status [RBANS], Wide Range Achievement Test-4 Word Reading, Trail Making Test, Wechsler Adult Intelligence Scale-Fourth Edition Letter Number Sequence and Digit Span, and Controlled Oral Word Association Test), along with emotional functioning measures (Beck Depression Inventory-Second Edition [BDI-II] and Beck Anxiety Inventory) and the World Health Organization Quality of Life-BREF quality of life measure. Follow-up-testing occurred on average (SD) 6.01 (3.5) years after last ECT treatment. At follow-up, a paired t test showed a large and robust reduction in mean BDI-II score. Scores in cognitive domains remained largely unchanged. A trend was observed for a mean reduction in RBANS visual spatial scores. Lower BDI-II scores were significantly associated with higher RBANS scores and improved quality of life. For some ECT patients, memory, cognitive functioning, and decreases in depressive symptoms can remain intact and stable even several years after ECT. However, the selective sampling at follow-up makes these results difficult to generalize to all post-ECT patients. Future research should examine what variables may predict stable cognitive functioning and a decline in psychiatric symptoms after ECT.

Representations of ECT in English-Language Film and Television in the New Millennium.

PubMed

Matthews, Avery Madeleine; Rosenquist, Peter B; McCall, William Vaughn

2016-09-01

The aim of the study was to survey the media landscape to determine whether visual depictions of electroconvulsive therapy (ECT) are becoming more or less medically accurate in the new millennium. English-language film and television shows depicting ECT were analyzed for patient demographics, administrator roles, indication, consent, anesthesia, paralytics, bite block, lead placement, electroencephalogram, and outcome. Thirty-nine ECT scenes were viewed, and just 3 included all 5 essential tools of modern ECT: anesthesia, paralytic, electrodes, electroencephalogram, and a bite block. Media depictions of ECT do not reflect current practice. Too often, ECT is portrayed as a torture technique rather than an evidenced-based therapy, and even in a therapeutic setting, it is too often shown with outdated techniques.

Eddy current testing probe with dual half-cylindrical coils

NASA Astrophysics Data System (ADS)

Bae, Byung-Hoon; Choi, Jung-Mi; Kim, Soo-Yong

2000-02-01

We have developed a new eddy current probe composed of a dual half-cylindrical (2HC) coil as an exciting coil and a sensing coil that is placed in the small gap of the 2HC coil. The 2HC coil induces a linear eddy current on the narrow region within the target medium. The magnitude of eddy current has a maximum peak with the narrow width, underneath the center of the exciting 2HC coil. Because of the linear eddy current, the probe can be used to detect not only the existence of a crack but also its direction in conducting materials. Using specimen with a machined crack, and varying the exciting frequency from 0.5 to 100 kHz, we investigated the relationships between the direction of crack and the output voltage of the sensing coil.

Effectiveness and clinical predictors of response to combined ECT and antipsychotic therapy in patients with treatment-resistant schizophrenia and dominant negative symptoms.

PubMed

Pawełczyk, Tomasz; Kołodziej-Kowalska, Emilia; Pawełczyk, Agnieszka; Rabe-Jabłońska, Jolanta

2014-12-15

The effectiveness and predictors of response to electroconvulsive therapy (ECT) combined with antipsychotics (AP) in treatment-resistant schizophrenia patients with the dominance of negative symptoms (TRS-NS) have not been studied systematically so far. 29 patients aged 21-55 years diagnosed with TRS-NS underwent ECT combined with antipsychotics (ECT+AP). Prior to the ECT, the symptom profile and severity were evaluated using Positive and Negative Syndrome Scale (PANSS). Demographic and medical data was collected; ECT parameters and pharmacotherapy results were evaluated. After the combined ECT+AP therapy a significant decrease in symptom severity was found. A response to treatment was achieved by 60% of patients. The greatest reductions were obtained in general and positive PANSS subscale (median change: 11 and 7 pts.) and the smallest, but still significant, ones in negative symptoms subscale (median: 3.5 pts.). Patients who responded to ECT+AP demonstrated a significantly shorter duration of the current episode in comparison with patients who did not experience at least a 25% reduction in symptom severity (median: 4 vs. 8 months). A combination of ECT and antipsychotic therapy can provide a useful treatment option for patients with TRS-NS. The only significant predictor of response to treatment was a shorter duration of the current episode. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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

PubMed Central

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

2017-01-01

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

[Selective alteration of the declarative memory systems in patients treated with a high number of electroconvulsive therapy sessions].

PubMed

Rami-González, L; Boget-Llucià, T; Bernardo, M; Marcos, T; Cañizares-Alejos, S; Penadés, R; Portella, M J; Castelví, M; Raspall, T; Salamero, M

The reversible electrochemical effects of electroconvulsive therapy (ECT) on specific areas of the brain enable the neuroanatomical bases of some cognitive functions to be studied. In research carried out on memory systems, a selective alteration of the declarative ones has been observed after treatment with ECT. Little work has been done to explore the differential alteration of the memory subsystems in patients with a high number of ECT sessions. AIM. To study the declarative and non declarative memory system in psychiatric patients submitted to maintenance ECT treatment, with a high number of previous ECT sessions. 20 patients submitted to treatment with ECT (10 diagnosed as having depression and 10 with schizophrenia) and 20 controls, who were paired by age, sex and psychopathological diagnosis. For the evaluation of the declarative memory system, the Wechsler Memory Scale (WMS) logical memory test was used. The Hanoi Tower procedural test was employed to evaluate the non declarative system. Patients treated with ECT performed worse in the WMS logical memory test, but this was only significant in patients diagnosed as suffering from depression. No significant differences were observed in the Hanoi Tower test. A selective alteration of the declarative systems was observed in patients who had been treated with a high number of ECT sessions, while the non declarative memory systems remain unaffected.

Eddy Current Testing for Detecting Small Defects in Thin Films

NASA Astrophysics Data System (ADS)

Obeid, Simon; Tranjan, Farid M.; Dogaru, Teodor

2007-03-01

Presented here is a technique of using Eddy Current based Giant Magneto-Resistance sensor (GMR) to detect surface and sub-layered minute defects in thin films. For surface crack detection, a measurement was performed on a copper metallization of 5-10 microns thick. It was done by scanning the GMR sensor on the surface of the wafer that had two scratches of 0.2 mm, and 2.5 mm in length respectively. In another experiment, metal coatings were deposited over the layers containing five defects with known lengths such that the defects were invisible from the surface. The limit of detection (resolution), in terms of defect size, of the GMR high-resolution Eddy Current probe was studied using this sample. Applications of Eddy Current testing include detecting defects in thin film metallic layers, and quality control of metallization layers on silicon wafers for integrated circuits manufacturing.

Erythropoietin as an add-on treatment for cognitive side effects of electroconvulsive therapy: a study protocol for a randomized controlled trial.

PubMed

Schmidt, Lejla Sjanic; Petersen, Jeff Zarp; Vinberg, Maj; Hageman, Ida; Olsen, Niels Vidiendal; Kessing, Lars Vedel; Jørgensen, Martin Balslev; Miskowiak, Kamilla Woznica

2018-04-19

Electroconvulsive therapy (ECT) is the most effective treatment for severe depression, but its use is impeded by its cognitive side effects. Novel treatments that can counteract these side effects may therefore improve current treatment strategies for depression. The present randomized trial investigates (1) whether short-term add-on treatment with erythropoietin (EPO) can reduce the cognitive side -effects of ECT and (2) whether such effects are long-lasting. Further, structural and functional magnetic resonance imaging (MRI) will be used to explore the neural underpinnings of such beneficial effects of EPO. Finally, the trial examines whether potential protective effects of EPO on cognition are accompanied by changes in markers of oxidative stress, inflammation, and neuroplasticity. The trial has a double-blind, randomized, placebo-controlled, parallel group design. Patients with unipolar or bipolar disorder with current moderate to severe depression referred to ECT (N = 52) are randomized to receive four high-dose infusions of EPO (40,000 IU/ml) or placebo (saline). The first EPO/saline infusion is administered within 24 h before the first ECT. The following three infusions are administered at weekly intervals immediately after ECT sessions 1, 4, and 7. Cognition assessments are conducted at baseline, after the final EPO/saline infusion (3 days after eight ECT sessions), and at a 3 months follow-up after ECT treatment completion. The neuronal substrates for potential cognitive benefits of EPO are investigated with structural and functional MRI after the final EPO/saline infusion. The primary outcome is change from baseline to after EPO treatment (3 days after eight ECT sessions) in a cognitive composite score spanning attention, psychomotor speed, and executive functions. With a sample size of N = 52 (n = 26 per group), we have ≥ 80% power to detect a clinically relevant between-group difference in the primary outcome measure at an alpha level of 5% (two-sided test). Behavioral, mood, and blood-biomarker data will be analyzed using repeated measures analysis of covariance. Functional MRI data will be preprocessed and analyzed using the FMRIB Software Library. If EPO is found to reduce the cognitive side effects of ECT, this could have important implications for future treatment strategies for depression and for the scientific understanding of the neurobiological etiology of cognitive dysfunction in patients treated with ECT. ClinicalTrials.gov, NCT03339596 . Registered on 10 November 2017.

Electric field characteristics of electroconvulsive therapy with individualized current amplitude: a preclinical study.

PubMed

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

2013-01-01

This study examines the characteristics of the electric field induced in the brain by electroconvulsive therapy (ECT) with individualized current amplitude. The electric field induced by bilateral (BL), bifrontal (BF), right unilateral (RUL), and frontomedial (FM) ECT electrode configurations was computed in anatomically realistic finite element models of four nonhuman primates (NHPs). We generated maps of the electric field strength relative to an empirical neural activation threshold, and determined the stimulation strength and focality at fixed current amplitude and at individualized current amplitudes corresponding to seizure threshold (ST) measured in the anesthetized NHPs. The results show less variation in brain volume stimulated above threshold with individualized current amplitudes (16-36%) compared to fixed current amplitude (30-62%). Further, the stimulated brain volume at amplitude-titrated ST is substantially lower than that for ECT with conventional fixed current amplitudes. Thus individualizing the ECT stimulus current could compensate for individual anatomical variability and result in more focal and uniform electric field exposure across different subjects compared to the standard clinical practice of using high, fixed current for all patients.

Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-5, Fundamentals of Eddy Current Testing.

ERIC Educational Resources Information Center

Espy, John

This fifth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II describes the fundamental concepts applicable to eddy current testing in general. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to…

Nondestructive examination of decarburised layer of steels using eddy current and magnetic Barkhausen noise testing techniques

NASA Astrophysics Data System (ADS)

Falahat, S.; Ghanei, S.; Kashefi, M.

2018-04-01

Eddy current and Barkhausen noise nondestructive testing techniques were considered to evaluate the magnetic properties of the decarburised steels as a function of microstructure. To make changes in decarburising depth, carbon steel samples were austenitised at 890 °C for 120-270 min. Considering different decarburised depths, height, position and width of the noise profiles were extracted in order to analyse the magnetic Barkhausen noise measurements. Next, the eddy current test was performed to detect the changes in the microstructure through decarburising of the steel taking into account the impedance variations. According to the results, both techniques allow us to detect changes in the magnetic properties of the decarburised steels and link them with their microstructural changes, nondestructively.

Computational models of Bitemporal, Bifrontal and Right Unilateral ECT predict differential stimulation of brain regions associated with efficacy and cognitive side effects.

PubMed

Bai, S; Gálvez, V; Dokos, S; Martin, D; Bikson, M; Loo, C

2017-03-01

Extensive clinical research has shown that the efficacy and cognitive outcomes of electroconvulsive therapy (ECT) are determined, in part, by the type of electrode placement used. Bitemporal ECT (BT, stimulating electrodes placed bilaterally in the frontotemporal region) is the form of ECT with relatively potent clinical and cognitive side effects. However, the reasons for this are poorly understood. This study used computational modelling to examine regional differences in brain excitation between BT, Bifrontal (BF) and Right Unilateral (RUL) ECT, currently the most clinically-used ECT placements. Specifically, by comparing similarities and differences in current distribution patterns between BT ECT and the other two placements, the study aimed to create an explanatory model of critical brain sites that mediate antidepressant efficacy and sites associated with cognitive, particularly memory, adverse effects. High resolution finite element human head models were generated from MRI scans of three subjects. The models were used to compare differences in activation between the three ECT placements, using subtraction maps. In this exploratory study on three realistic head models, Bitemporal ECT resulted in greater direct stimulation of deep midline structures and also left temporal and inferior frontal regions. Interpreted in light of existing knowledge on depressive pathophysiology and cognitive neuroanatomy, it is suggested that the former sites are related to efficacy and the latter to cognitive deficits. We hereby propose an approach using binarised subtraction models that can be used to optimise, and even individualise, ECT therapies. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Analytical modeling and analysis of magnetic field and torque for novel axial flux eddy current couplers with PM excitation

NASA Astrophysics Data System (ADS)

Li, Zhao; Wang, Dazhi; Zheng, Di; Yu, Linxin

2017-10-01

Rotational permanent magnet eddy current couplers are promising devices for torque and speed transmission without any mechanical contact. In this study, flux-concentration disk-type permanent magnet eddy current couplers with double conductor rotor are investigated. Given the drawback of the accurate three-dimensional finite element method, this paper proposes a mixed two-dimensional analytical modeling approach. Based on this approach, the closed-form expressions of magnetic field, eddy current, electromagnetic force and torque for such devices are obtained. Finally, a three-dimensional finite element method is employed to validate the analytical results. Besides, a prototype is manufactured and tested for the torque-speed characteristic.

Technique for temperature compensation of eddy-current proximity probes

NASA Technical Reports Server (NTRS)

Masters, Robert M.

1989-01-01

Eddy-current proximity probes are used in turbomachinery evaluation testing and operation to measure distances, primarily vibration, deflection, or displacment of shafts, bearings and seals. Measurements of steady-state conditions made with standard eddy-current proximity probes are susceptible to error caused by temperature variations during normal operation of the component under investigation. Errors resulting from temperature effects for the specific probes used in this study were approximately 1.016 x 10 to the -3 mm/deg C over the temperature range of -252 to 100 C. This report examines temperature caused changes on the eddy-current proximity probe measurement system, establishes their origin, and discusses what may be done to minimize their effect on the output signal. In addition, recommendations are made for the installation and operation of the electronic components associated with an eddy-current proximity probe. Several techniques are described that provide active on-line error compensation for over 95 percent of the temperature effects.

CORROSION FILM REMOVAL AS AN INDICATION OF DECONTAMINATION EFFECTIVENESS

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

Weed, R.D.

1958-11-10

The decontamination of high-temperature, highpressure recirculation loops and components is being investigated. The Turco-4501 process and certain promising modificatibns of this process are being evaluated according to their film-removing qualities. Two of the processes exhibited more promise than others. These were the Turco-4501 process, substituting either oxalic acid or a chromic acid solution lor the nitric acid. Other variations were also tested and results are reported. (W.L.H.) l8636 The dissipation of effluent into sea water by initial dilution eddy diffusion and residual currents was originally assessed by Seligman and Scott in 1948. Further experimental work is described which has enabledmore » a new urement of the initial dilution of fresh water from the pipe line, and a study of the movement of water as indicated by driff bottles. It is now envisaged that initial dilution by a factor of 10/sup 4/, will be followed by eddy diffusion with the coefficients as measured by Seligman and bulk movement primarily due to the force of the wind Exceptions will occur when defined calm conditions exist. The discharged effluent will then tend to float on the surface with an initial dilution factor of only a few diffussing remains of the previous activity there being no incations of residual currents. No work has been done a see if this more concentrated effluent can come ashore without further dilution. It is recommended that, a avoid floating effluent, water should not be discharged July. Thc p1imhry ob!ect of this inveBtigation was 10 gtudy during very calm weather. Maximum storage space can he assured by normaally pumping effluent to sea at the rffi hQh tide affer treatment. (auth) during very calm weather. Maximum storage space can be assured by normally pumping effluent to sea at the« less

The Clinical Practice of Assessing Cognitive Function in Adults Receiving Electroconvulsive Therapy: Whom Are We Missing?

PubMed

Obbels, Jasmien; Vanbrabant, Koen; Bouckaert, Filip; Verwijk, Esmée; Sienaert, Pascal

2016-06-01

Cognition can be affected by electroconvulsive therapy (ECT). Good clinical practice includes neuropsychological assessment, although this is seldom a part of routine clinical practice. It looks like a substantial part of patients fail to complete cognitive assessments. This constitutes a problem in the generalizability of published clinical research on cognitive side effects. Most studies of ECT-related cognitive adverse effects do not discuss this important issue of so-called cognitive test nonparticipants. Recent findings suggest that cognitive test nonparticipants are more severely ill, and probably more vulnerable to cognitive side effects. To examine the feasibility of a neuropsychological test battery in daily clinical practice, in an adult population referred for ECT. We reviewed the clinical records of 84 patients referred for ECT. Demographic and clinical characteristics of those patients who were able to complete our routine cognitive testing at baseline are compared with those who could not complete the assessment. From 84 ECT patients, 60 (71%) completed a pre-ECT cognitive assessment, whereas 24 (29%) did not. Patients with a unipolar depression, with psychotic symptoms, who started their treatment with a bitemporal electrode placement were more likely to be test noncompleters than test completers. Patients with a unipolar depression, with psychotic features, who are treated with a bitemporal electrode placement, have a higher likelihood of not completing a pre-ECT cognitive assessment. These patients probably represent a subgroup more vulnerable to cognitive side effects.

The use of fractional order derivatives for eddy current non-destructive testing

NASA Astrophysics Data System (ADS)

Sikora, Ryszard; Grzywacz, Bogdan; Chady, Tomasz

2018-04-01

The paper presents the possibility of using the fractional derivatives for non-destructive testing when a multi-frequency method based on eddy current is applied. It is shown that frequency characteristics obtained during tests can be approximated by characteristics of a proposed model in the form of fractional order transfer function, and values of parameters of this model can be utilized for detection and identification of defects.

Quantification and Compensation of Eddy-Current-Induced Magnetic Field Gradients

PubMed Central

Spees, William M.; Buhl, Niels; Sun, Peng; Ackerman, Joseph J.H.; Neil, Jeffrey J.; Garbow, Joel R.

2011-01-01

Two robust techniques for quantification and compensation of eddy-current-induced magnetic-field gradients and static magnetic-field shifts (ΔB0) in MRI systems are described. Purpose-built 1-D or 6-point phantoms are employed. Both procedures involve measuring the effects of a prior magnetic-field-gradient test pulse on the phantom’s free induction decay (FID). Phantom-specific analysis of the resulting FID data produces estimates of the time-dependent, eddy-current-induced magnetic field gradient(s) and ΔB0 shift. Using Bayesian methods, the time dependencies of the eddy-current-induced decays are modeled as sums of exponentially decaying components, each defined by an amplitude and time constant. These amplitudes and time constants are employed to adjust the scanner’s gradient pre-emphasis unit and eliminate undesirable eddy-current effects. Measurement with the six-point sample phantom allows for simultaneous, direct estimation of both on-axis and cross-term eddy-current-induced gradients. The two methods are demonstrated and validated on several MRI systems with actively-shielded gradient coil sets. PMID:21764614

Quantification and compensation of eddy-current-induced magnetic-field gradients.

PubMed

Spees, William M; Buhl, Niels; Sun, Peng; Ackerman, Joseph J H; Neil, Jeffrey J; Garbow, Joel R

2011-09-01

Two robust techniques for quantification and compensation of eddy-current-induced magnetic-field gradients and static magnetic-field shifts (ΔB0) in MRI systems are described. Purpose-built 1-D or six-point phantoms are employed. Both procedures involve measuring the effects of a prior magnetic-field-gradient test pulse on the phantom's free induction decay (FID). Phantom-specific analysis of the resulting FID data produces estimates of the time-dependent, eddy-current-induced magnetic field gradient(s) and ΔB0 shift. Using Bayesian methods, the time dependencies of the eddy-current-induced decays are modeled as sums of exponentially decaying components, each defined by an amplitude and time constant. These amplitudes and time constants are employed to adjust the scanner's gradient pre-emphasis unit and eliminate undesirable eddy-current effects. Measurement with the six-point sample phantom allows for simultaneous, direct estimation of both on-axis and cross-term eddy-current-induced gradients. The two methods are demonstrated and validated on several MRI systems with actively-shielded gradient coil sets. Copyright © 2011 Elsevier Inc. All rights reserved.

Modulation of Limbic and Prefrontal Connectivity by Electroconvulsive Therapy in Treatment-resistant Depression: A Preliminary Study.

PubMed

Cano, Marta; Cardoner, Narcís; Urretavizcaya, Mikel; Martínez-Zalacaín, Ignacio; Goldberg, Ximena; Via, Esther; Contreras-Rodríguez, Oren; Camprodon, Joan; de Arriba-Arnau, Aida; Hernández-Ribas, Rosa; Pujol, Jesús; Soriano-Mas, Carles; Menchón, José M

2016-01-01

Although current models of depression suggest that a sequential modulation of limbic and prefrontal connectivity is needed for illness recovery, neuroimaging studies of electroconvulsive therapy (ECT) have focused on assessing functional connectivity (FC) before and after an ECT course, without characterizing functional changes occurring at early treatment phases. To assess sequential changes in limbic and prefrontal FC during the course of ECT and their impact on clinical response. Longitudinal intralimbic and limbic-prefrontal networks connectivity study. We assessed 15 patients with treatment-resistant depression at four different time-points throughout the entire course of an ECT protocol and 10 healthy participants at two functional neuroimaging examinations. Furthermore, a path analysis to test direct and indirect predictive effects of limbic and prefrontal FC changes on clinical response measured with the Hamilton Rating Scale for Depression was also performed. An early significant intralimbic FC decrease significantly predicted a later increase in limbic-prefrontal FC, which in turn significantly predicted clinical improvement at the end of an ECT course. Our data support that treatment response involves sequential changes in FC within regions of the intralimbic and limbic-prefrontal networks. This approach may help in identifying potential early biomarkers of treatment response. Copyright © 2015 Elsevier Inc. All rights reserved.

Intelligent Software for System Design and Documentation

NASA Technical Reports Server (NTRS)

2002-01-01

In an effort to develop a real-time, on-line database system that tracks documentation changes in NASA's propulsion test facilities, engineers at Stennis Space Center teamed with ECT International of Brookfield, WI, through the NASA Dual-Use Development Program to create the External Data Program and Hyperlink Add-on Modules for the promis*e software. Promis*e is ECT's top-of-the-line intelligent software for control system design and documentation. With promis*e the user can make use of the automated design process to quickly generate control system schematics, panel layouts, bills of material, wire lists, terminal plans and more. NASA and its testing contractors currently use promis*e to create the drawings and schematics at the E2 Cell 2 test stand located at Stennis Space Center.

Historical essay: electroconvulsive therapy, memory, and self in America.

PubMed

Hirshbein, Laura

2012-01-01

Electroconvulsive Therapy (ECT) practitioners and anti-ECT activists have divergent interpretations of both the treatment and its history. Despite claims by ECT opponents that practitioners do not acknowledge memory side effects, the published literature on the procedure demonstrates psychiatrists' awareness of this issue. And though current ECT practitioners claim that memory side effects were mostly the result of outmoded methods, investigators continue to publish studies that indicate ongoing memory problems. This article explores the conflict between pro- and anti-ECT groups around the issue of memory side effects in the broader context of changes in American psychiatry and society.

Non-destructive Testing (NDT) of metal cracks using a high Tc rf-SQUID and eddy current method

NASA Technical Reports Server (NTRS)

Lu, D. F.; Fan, Chang-Xin; Ruan, J. Z.; Han, S. G.; Wong, K. W.; Sun, G. F.

1995-01-01

A SQUID is the most sensitive device to detect change in magnetic field. A nondestructive testing (NDT) device using high temperature SQUID's and eddy current method will be much more sensitive than those currently used eddy current systems, yet much cheaper than one with low temperature SQUID's. In this paper, we present our study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDT device will have a significant impact on metal corrosion or crack detection technology.

"Side effects" of ECT are mainly depressive phenomena and are independent of age.

PubMed

Brodaty, H; Berle, D; Hickie, I; Mason, C

2001-10-01

The aetiology of reported side effects of electroconvulsive therapy (ECT) is unclear. We examined the interaction of depression and age on adverse neuropsychological and putative side effects of ECT. Inpatients (N=81; median age 70 years) with major depression were assessed prospectively pre-ECT, immediately post-ECT and 1-3 years later. Patients were administered the Hamilton Rating Scale for Depression (HRSD), the Global Assessment of Functioning scale (GAF) and neuropsychological tests from the Wechsler Memory Scale. Side effects and total burden scores were rated pre- and post-treatment. HRSD and GAF scores improved with treatment after ECT, but the prevalence and total burden of side effects were unchanged. Side effect burden was related to depression level before and after ECT. Improvement in depression correlated with reduction in side effect burden. There was a significant decline in side effect burden after controlling for change in depression. Patients' scores on neuropsychological measures did not appear to change after ECT or between pre-ECT and follow-up. Re-analysis, allowing for age, chronicity of depression, medication use and development of dementia, did not alter the findings. lack of a control group, lack of information on ECT technique, incomplete data sets and limited neuropsychological testing. ECT, an effective treatment for depression, does not cause significant side effects or neuropsychological impairment, which are more likely to be depressive phenomena. ECT appears to be safe for old (> or =65 years) and very old (> or =75 years) patients, who do not appear to be more susceptible to adverse effects.

Safety of electroconvulsive therapy in patients with asthma.

PubMed

Mueller, P S; Schak, K M; Barnes, R D; Rasmussen, K G

2006-12-01

Patients with depression and other psychiatric disorders being considered for electroconvulsive therapy (ECT) may also have asthma. Since ECT requires the administration of general anaesthesia, it is assumed that extra care should be taken with asthmatic patients before and during ECT. We sought to investigate the safety of ECT in asthmatic patients. A retrospective review was conducted of the medical records of all of the patients with currently active and managed asthma who underwent ECT for severe depressive syndromes at Mayo Clinic, Rochester, Minnesota, between 1 January 1998, and 30 June 2006. Thirty-four patients with asthma who also underwent ECT were identified. Of these, 27 (79%) were women. The median age was 45 years (range 23-84 years). All 34 patients were using asthma medications daily at the time of ECT. The 34 patients underwent a total of 459 ECT sessions. Four (12%) patients experienced exacerbation of their asthma on a total of five occasions. Each exacerbation was successfully treated with standard asthma medications, and all four patients completed their courses of ECT. ECT in patients with asthma appears to be safe. Although exacerbation of asthma after ECT was rare in our series, a prospective study would be needed to determine the precise risk of pulmonary complications of ECT in asthmatic patients.

Use of electroconvulsive therapy (ECT) in postpartum psychosis--a naturalistic prospective study.

PubMed

Babu, Girish N; Thippeswamy, Harish; Chandra, Prabha S

2013-06-01

Postpartum psychosis (PPP) is a severe psychiatric condition requiring rapid restoration of health in view of significant risks to both mother and the infant. Electroconvulsive therapy (ECT) is often used for treatment of severe PPP. The aims of the study were to describe the indications for ECT among women admitted with PPP to a psychiatric hospital in India. It also aimed at assessing whether women with PPP who received ECT differed in their clinical history, diagnosis, severity of illness, psychopathology, drug dosage, and duration of hospital stay, compared to women who did not receive ECT. Infants of mothers who were breast-feeding their infants while receiving ECT were assessed for adverse effects. This was a naturalistic prospective study of 78 women admitted with PPP, 34 (43.6 %) of whom received ECT. Presence of catatonia, augmentation of medications, and suicidality were common indications for ECT. Catatonic symptoms were significantly higher among women who received ECT. There was no significant difference in duration of hospitalization or severity of psychopathology between women who did and did not receive ECT. Transient side effects to ECT were observed in few women, with no adverse effects noted in infants who were breast-fed. The current study supports the use of ECT as an effective and safe treatment for women with severe PPP.

Electroconvulsive therapy: Part I. A perspective on the evolution and current practice of ECT.

PubMed

Payne, Nancy A; Prudic, Joan

2009-09-01

The concept of inducing convulsions, mainly through chemical means, to promote mental wellness has existed since the 16th century. In 1938, Italian scientists first applied electrically induced therapeutic seizures. Although electroconvulsive therapy (ECT) is employed in the treatment of several psychiatric disorders, it is most frequently used today to treat severe depressive episodes and remains the most effective treatment available for those disorders. Despite this, ECT continues to be the most stigmatized treatment available in psychiatry, resulting in restrictions on and reduced accessibility to a helpful and potentially life-saving treatment. The psychiatric and psychosocial ramifications of this stigmatization may include the exacerbation of the increasingly serious, global health problem of major depressive disorders as well as serious consequences for individual patients who may not be offered, or may refuse, a potentially beneficial treatment. The goal of this first article in this two-part series is to provide an overview of ECT's historical development and discuss the current state of knowledge about ECT, including technical aspects of delivery, patient selection, its side-effect profile, and factors that may contribute to underuse of ECT.

Effects of desmopressin (DDAVP) on memory impairment following electroconvulsive therapy (ECT).

PubMed

Abdollahian, Ebrahim; Sargolzaee, Mohammad R; Hajzade, Moosareza; Mohebbi, Mohammad D; Javanbakht, Arash

2004-06-01

Memory impairment is a common adverse effect of electroconvulsive therapy (ECT). Studies on animals and humans suggest that vasopressin improves the cognitive function, and positive effects of desmopressin on memory and learning have been reported. This research was performed for evaluation of the effects of desmopressin in the prevention of memory impairment following ECT. This randomized, double-blind controlled clinical trial with placebo administration was performed on 50 patients with psychiatric disorders who were candidates for ECT. Subjects in the case group received 60 µm of intranasal desmopressin daily (in three doses of 20 µm). For the control group 0.9% saline solution was administered in the same way. Memory function was evaluated using Wechsler's Memory Scale three times a week (the first time before the start of ECT and the second and third times after the third and sixth sessions, respectively). Results were analyzed by t-test and Paired t-test. The mean age of patients was 29 years (range 20-40). During the course of ECT, patients in the control group demonstrated a meaningful decrease in memory scores (from a base score of 80.15-75.45 in the second test and 72.60 in the third test). Despite this, a meaningful increase in memory scores was observed during the treatment with desmopressin in the case group (from a base score of 73.27-75.70 and 79.13 in the second and the third tests, respectively). There was a meaningful difference between the two groups (P < 0.0001). This study confirms the protective effect of desmopressin against memory impairment. The results confirm that memory impairment is a common side-effect of ECT and suggest that desmopressin may prevent ECT-induced memory impairment by its effects on memory and the learning process.

Eddy-current system for the vibration-testing of blades

DOEpatents

Jacobs, Martin E.

1977-01-01

This invention is an improved system for the vibration-testing of cantilevered non-ferrous articles by inducing eddy currents therein. The principal advantage of the system is that relatively little heat is generated in the article being vibrated. Thus, a more accurate measurement of the fatigue characteristics of the article is obtained. Furthermore, the generation of relatively little heat in the blade permits tests to be conducted in low-pressure atmospheres simulating certain actual processes environments. Heat-generation in the vibrated article is minimized by utilizing eddy currents which are generated by an electromagnet whose magnetic field varies but does not change polarity. The typical winding for the electromagnet is excited with pulsating d.c. That is, the winding is alternately charged by connecting it across a d.c. power supply and then discharged by connecting it across a circuit for receiving current generated in the winding by self-induction. Preferably, the discharge circuit is designed so that the waveform of the discharging current approximates that of the charging current.

Memantine in the prevention or alleviation of electroconvulsive therapy induces cognitive disorders: A placebo controlled trial.

PubMed

Abbasinazari, Mohammad; Adib-Eshgh, Ladan; Rostami, Azin; Beyraghi, Narges; Dabir, Shideh; Jafari, Reyhaneh

2015-06-01

The purpose of this study was to evaluate the effect of memantine administration on the adverse cognitive effects of electroconvulsive therapy (ECT). Forty patients diagnosed with a major depressive disorder for which ECT was indicated as a treatment for their current episode were randomly allocated to either the memantine (5mg/day) group or the placebo group. All patients underwent the same protocol for anaesthesia and ECT procedures. The patients received memantine or the placebo for the whole period of ECT treatment, starting the day before ECT and continuing until the fourth session of ECT. The Modified Mental State Examination (MMSE) was used for the assessment of cognition before and after the trial. Regarding MMSE and item 3 MMSE (related to recent memory), the memantine group scored significantly higher at the end of ECT sessions than the control group (P=0.02, P<0.001, respectively). Our data support the hypothesis that memantine may reduce cognitive impairment following ECT. Memantine could be both a safe and well-tolerated treatment for use with ECT. Copyright © 2015 Elsevier B.V. All rights reserved.

Is electroconvulsive therapy (ECT) effective and safe for treatment of depression in dementia? A short review.

PubMed

Oudman, Erik

2012-03-01

Depression is one of the most frequently diagnosed psychiatric disorders in patients with dementia with a prevalence of up to 50%. The detrimental effects of depression in dementia include disability in daily living, worse quality of life, and faster cognitive decline. Although electroconvulsive therapy (ECT) is a well-established and effective treatment for depression in the elderly, it is currently an overlooked treatment option in the elderly with dementia and depression. The aim of this review was to provide a critical analysis of the efficacy and safety of ECT in depression superimposed on dementia by reviewing the current literature on this topic. Current evidence suggests that ECT is an effective treatment for depression in dementia, although the relatively small number of controlled studies hampers the comparison of effectiveness between healthy nongeriatric patients and those with dementia. Moreover, the systematic reports on cognitive side effects are very limited in number and currently only apply to moderately mild or mild dementia of nonvascular origin. Some studies do suggest that cognitive side effects are likely in later stages of dementia and in patients with vascular dementia. It is therefore of crucial relevance to prospectively study effects of ECT in different types and phases of dementia in controlled trials. From a clinical perspective, it is essential to inform and educate patients and family about the possible risks and benefits of ECT treatment for depression in dementia.

Evaluative studies in nuclear medicine research. Progress report, October 1, 1979-June 30, 1980

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

Potchen, E.J.

Effort since the last progress report (September 1979) has been directed toward assessing the potential short and long term benefits of continued development and application and medical research of emission computed tomograhy (ECT). This report contains a review of existing ECT technology, including functional descriptions of current and proposed image systems, for both sngle-photon ECT (SPECT) and positron ECT (PECT) approaches. Medical research and clinical topics to which ECT has been, or may be, applied are presented. One such area of investigation involves the effects of stroke. The application of ECT to laboratory research, and to clinical diagnosis and prognosis,more » of stroke may result in improved management of the disease. An illustration of the potential savings in the cost of management of stroke due to the effects of applied ECT research is included. The results represent a compilation of data collected from conversations with, and conference presentations by, ECT users, researchers and image system designers, and from a review of the literature.« less

The Role of Ect2 Nuclear RhoGEF Activity in Ovarian Cancer Cell Transformation

PubMed Central

Huff, Lauren P.; DeCristo, Molly J.; Trembath, Dimitri; Kuan, Pei Fen; Yim, Margaret; Liu, Jinsong; Cook, Danielle R.; Miller, C. Ryan; Der, Channing J.

2013-01-01

Ect2, a Rho guanine nucleotide exchange factor (RhoGEF), is atypical among RhoGEFs in its predominantly nuclear localization in interphase cells. One current model suggests that Ect2 mislocalization drives cellular transformation by promoting aberrant activation of cytoplasmic Rho family GTPase substrates. However, in ovarian cancers, where Ect2 is both amplified and overexpressed at the mRNA level, we observed that the protein is highly expressed and predominantly nuclear and that nuclear but not cytoplasmic Ect2 increases with advanced disease. Knockdown of Ect2 in ovarian cancer cell lines impaired their anchorage-independent growth without affecting their growth on plastic. Restoration of Ect2 expression rescued the anchorage-independent growth defect, but not if either the DH catalytic domain or the nuclear localization sequences of Ect2 were mutated. These results suggested a novel mechanism whereby Ect2 could drive transformation in ovarian cancer cells by acting as a RhoGEF specifically within the nucleus. Interestingly, Ect2 had an intrinsically distinct GTPase specificity profile in the nucleus versus the cytoplasm. Nuclear Ect2 bound preferentially to Rac1, while cytoplasmic Ect2 bound to RhoA but not Rac. Consistent with nuclear activation of endogenous Rac, Ect2 overexpression was sufficient to recruit Rac effectors to the nucleus, a process that required a functional Ect2 catalytic domain. Furthermore, expression of active nuclearly targeted Rac1 rescued the defect in transformed growth caused by Ect2 knockdown. Our work suggests a novel mechanism of Ect2-driven transformation, identifies subcellular localization as a regulator of GEF specificity, and implicates activation of nuclear Rac1 in cellular transformation. PMID:24386507

Incidence and risk factors for oxygen desaturation during recovery from modified electroconvulsive therapy: A prospective observational study.

PubMed

Surve, Rohini; Bansal, Sonia; Sriganesh, Kamath; Subbakrishna, Doddaballapur Kumaraswamy; Thirthalli, Jagadisha; Umamaheswara Rao, Ganne Sesha

2015-01-01

Electroconvulsive therapy (ECT) is an established modality of treatment for severe psychiatric illnesses. Among the various complications associated with ECT, oxygen desaturation is often under reported. None of the previous studies has evaluated the predictive factors for oxygen desaturation during ECT. The objective of this study was to evaluate the incidence of oxygen desaturation during recovery from anesthesia for modified ECT and evaluate its risk factors in a large sample. All patients aged above 15 years who were prescribed a modified ECT for their psychiatric illness over 1 year were prospectively included in this observational study. The association between age, body mass index (BMI), doses of thiopentone and suxamethonium, stimulus current, ECT session number, pre- and post-ECT heart rate and mean arterial pressure, seizure duration, and pre- and post ECT oxygen saturation, was systematically studied. The incidence of oxygen desaturation was 29% (93/316 patients). Seizure duration and BMI were found to be significantly correlated with post ECT desaturation. In this prospective observational study, the incidence of oxygen desaturation during recovery from anesthesia for ECT was high. The study identified obesity and duration of seizure as the independent predictors of this complication. This knowledge is likely to help in identifying and optimizing such patients before subsequent ECT sessions.

Electroconvulsive treatment during pregnancy: a systematic review.

PubMed

Pompili, Maurizio; Dominici, Giovanni; Giordano, Gloria; Longo, Lucia; Serafini, Gianluca; Lester, David; Amore, Mario; Girardi, Paolo

2014-12-01

Pharmacological treatment of severe psychiatric disorders during pregnancy is complicated by the potential harmful effects of treatment for the fetus. Electroconvulsive therapy (ECT) has been demonstrated to be effective for the treatment of several mental disorders. The aim of this study was to investigate the safety of ECT in the treatment of psychiatric disorders during pregnancy; to compare its efficacy with medication; and to identify the main indications for use in pregnancy. We performed a careful and systematic review of the literature on ECT and pregnancy was conducted. Almost all patients demonstrated total or at least partial remission of symptoms after ECT treatment. No deaths were reported in ECT-treated pregnant women. We conclude that ECT is probably currently under-used in many psychiatric settings because of its stigmatized perception by patients and by mental health professionals. ECT seems to be effective for treating major psychiatric disorders during pregnancy, and the risks of adverse events are low.

Eddy current crack detection capability assessment approach using crack specimens with differing electrical conductivity

NASA Astrophysics Data System (ADS)

Koshti, Ajay M.

2018-03-01

Like other NDE methods, eddy current surface crack detectability is determined using probability of detection (POD) demonstration. The POD demonstration involves eddy current testing of surface crack specimens with known crack sizes. Reliably detectable flaw size, denoted by, a90/95 is determined by statistical analysis of POD test data. The surface crack specimens shall be made from a similar material with electrical conductivity close to the part conductivity. A calibration standard with electro-discharged machined (EDM) notches is typically used in eddy current testing for surface crack detection. The calibration standard conductivity shall be within +/- 15% of the part conductivity. This condition is also applicable to the POD demonstration crack set. Here, a case is considered, where conductivity of the crack specimens available for POD testing differs by more than 15% from that of the part to be inspected. Therefore, a direct POD demonstration of reliably detectable flaw size is not applicable. Additional testing is necessary to use the demonstrated POD test data. An approach to estimate the reliably detectable flaw size in eddy current testing for part made from material A using POD crack specimens made from material B with different conductivity is provided. The approach uses additional test data obtained on EDM notch specimens made from materials A and B. EDM notch test data from the two materials is used to create a transfer function between the demonstrated a90/95 size on crack specimens made of material B and the estimated a90/95 size for part made of material A. Two methods are given. For method A, a90/95 crack size for material B is given and POD data is available. Objective of method A is to determine a90/95 crack size for material A using the same relative decision threshold that was used for material B. For method B, target crack size a90/95 for material A is known. Objective is to determine decision threshold for inspecting material A.

Theory and application of high temperature superconducting eddy current probes for nondestructive evaluation

NASA Astrophysics Data System (ADS)

Claycomb, James Ronald

1998-10-01

Several High-T c Superconducting (HTS) eddy current probes have been developed for applications in electromagnetic nondestructive evaluation (NDE) of conducting materials. The probes utilize high-T c SUperconducting Quantum Interference Device (SQUID) magnetometers to detect the fields produced by the perturbation of induced eddy currents resulting from subsurface flaws. Localized HTS shields are incorporated to selectively screen out environmental electromagnetic interference and enable movement of the instrument in the Earth's magnetic field. High permeability magnetic shields are employed to focus flux into, and thereby increase the eddy current density in the metallic test samples. NDE test results are presented, in which machined flaws in aluminum alloy are detected by probes of different design. A novel current injection technique performing NDE of wires using SQUIDs is also discussed. The HTS and high permeability shields are designed based on analytical and numerical finite element method (FEM) calculations presented here. Superconducting and high permeability magnetic shields are modeled in uniform noise fields and in the presence of dipole fields characteristic of flaw signals. Several shield designs are characterized in terms of (1) their ability to screen out uniform background noise fields; (2) the resultant improvement in signal-to-noise ratio and (3) the extent to which dipole source fields are distorted. An analysis of eddy current induction is then presented for low frequency SQUID NDE. Analytical expressions are developed for the induced eddy currents and resulting magnetic fields produced by excitation sources above conducting plates of varying thickness. The expressions derived here are used to model the SQUID's response to material thinning. An analytical defect model is also developed, taking into account the attenuation of the defect field through the conducting material, as well as the current flow around the edges of the flaw. Time harmonic FEM calculations are then used to model the electromagnetic response of eight probe designs, consisting of an eddy current drive coil coupled to a SQUID surrounded by superconducting and/or high permeability magnetic shielding. Simulations are carried out with the eddy current probes located a finite distance above a conducting surface. Results are quantified in terms of shielding and focus factors for each probe design.

Non-destructive testing (NDT) of metal cracks using a high Tc rf-SQUID and eddy current method

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

Lu, D.F.; Fan, C.; Ruan, J.Z.

1994-12-31

A SQUID is the most sensitive device to detect change in magnetic field. A non-destructive testing (NDT) device using high temperature SQUIDs and eddy current method will be much more sensitive than those currently used eddy current systems, yet much cheaper than one with low temperature SQUIDs. In this paper, we present our study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDTmore » device will have a significant impact on metal corrosion or crack detection technology.« less

European Credit Transfer and Accumulation System: An Alternative Way to Calculate the ECTS Grades

ERIC Educational Resources Information Center

Grosges, Thomas; Barchiesi, Dominique

2007-01-01

The European Credit Transfer and Accumulation System (ECTS) has been developed and instituted to facilitate student mobility and academic recognition. This paper presents, discusses, and illustrates the pertinence and the limitation of the current statistical distribution of the ECTS grades, and we propose an alternative way to calculate the ECTS…

Differences in Cognitive Outcomes After ECT Depending on BDNF and COMT Polymorphisms.

PubMed

Bennett, Daniel Mark; Currie, James; Fernie, Gordon; Perrin, Jennifer S; Reid, Ian C

2016-12-01

The study aimed to explore cognitive outcomes after electroconvulsive therapy (ECT) depending on which version of common single nucleotide polymorphisms the patient expressed for brain-derived neurotrophic factor (BDNF) and catechol-O-methyltransferase (COMT). A total of 87 patients from the clinical ECT service in Aberdeen, Scotland, were included in the study. Cognitive function testing (using Spatial Recognition Memory task from the Cambridge Neuropsychological Test Automated Battery and Mini-Mental State Examination) and mood ratings (Montgomery-Åsberg Depression Rating Scale) were performed before ECT, after 4 treatments, at the end of ECT and 1 and 3 months after the end of treatment. These scores were compared depending on BDNF and COMT variant at each time point using the Student t test and using a time series generalized least squares random effects model. No differences were found between the val and met versions of the BDNF or COMT polymorphism in either cognitive or mood outcomes at any time point during ECT treatment or up to 3 months of follow-up. This study did not detect significant differences in cognitive or mood outcomes between patients who have the val66val or met versions of the BDNF polymorphism. Our results suggest that these polymorphisms will not be helpful in clinical practice for predicting cognitive outcomes after ECT.

Improvement of cycloid psychosis following electroconvulsive therapy.

PubMed

Holm, Jonas; Brus, Ole; Båve, Ullvi; Landen, Mikael; Lundberg, Johan; Nordanskog, Pia; von Knorring, Lars; Nordenskjöld, Axel

2017-08-01

The treatment of choice for cycloid psychosis has traditionally been electroconvulsive therapy (ECT), but there is a lack of studies on its effectiveness. The primary aim of this register study was to determine the rates of remission and response after ECT for cycloid psychosis. The secondary aim was to examine possible predictors of outcome. Data were obtained from the National Quality Register for ECT in Sweden. The study population was patients (n = 42) who received ECT for acute polymorphic psychotic disorder without symptoms of schizophrenia or for cycloid psychosis between 2011-2015 in 13 hospitals. Remission and response rates were calculated using Clinical Global Impression-Severity (CGI-S) and -Improvement scores, respectively. Variables with possible predictive value were tested using Chi-square and Fisher's exact test. The response rate was 90.5%. The remission rate was 45.2%. Of 42 patients, 40 improved their CGI-S score after ECT (p < 0.001). The mean number of ECT treatments was 2.5 for non-responders and 7.0 for responders (p = 0.010). The mean number of ECT treatments did not differ significantly between remitters and non-remitters (7.2 vs 6.1, p = 0.31). None of the other investigated potential predictors was statistically significantly associated with outcome. ECT is an effective treatment for cycloid psychosis. Future studies need to compare the outcome of ECT to that of other treatment strategies. The high response rate with ECT indicates that cycloid psychosis is a clinically useful diagnosis.

Eddy current standards - Cracks versus notches

NASA Astrophysics Data System (ADS)

Hagemaier, D. J.; Collingwood, M. R.; Nguyen, K. H.

1992-10-01

Eddy current tests aimed at evaluating cracks and electron-discharge machined (EDM) notches in 7075-T6 aluminum specimens are described. A comparison of the shape and amplitude of recordings made from both transverse and longitudinal scans of small EDM notches and fatigue cracks showd almost identical results. The signal amplitude and phase angle increased with an increase of EDM notch and crak size. It is concluded that equivalent eddy current results obtained from similar-size surface cracks and notches in aluminum can be used to establish a desired sensitivity level for inspection.

Numerical modelling as a cost-reduction tool for probability of detection of bolt hole eddy current testing

NASA Astrophysics Data System (ADS)

Mandache, C.; Khan, M.; Fahr, A.; Yanishevsky, M.

2011-03-01

Probability of detection (PoD) studies are broadly used to determine the reliability of specific nondestructive inspection procedures, as well as to provide data for damage tolerance life estimations and calculation of inspection intervals for critical components. They require inspections on a large set of samples, a fact that makes these statistical assessments time- and cost-consuming. Physics-based numerical simulations of nondestructive testing inspections could be used as a cost-effective alternative to empirical investigations. They realistically predict the inspection outputs as functions of the input characteristics related to the test piece, transducer and instrument settings, which are subsequently used to partially substitute and/or complement inspection data in PoD analysis. This work focuses on the numerical modelling aspects of eddy current testing for the bolt hole inspections of wing box structures typical of the Lockheed Martin C-130 Hercules and P-3 Orion aircraft, found in the air force inventory of many countries. Boundary element-based numerical modelling software was employed to predict the eddy current signal responses when varying inspection parameters related to probe characteristics, crack geometry and test piece properties. Two demonstrator exercises were used for eddy current signal prediction when lowering the driver probe frequency and changing the material's electrical conductivity, followed by subsequent discussions and examination of the implications on using simulated data in the PoD analysis. Despite some simplifying assumptions, the modelled eddy current signals were found to provide similar results to the actual inspections. It is concluded that physics-based numerical simulations have the potential to partially substitute or complement inspection data required for PoD studies, reducing the cost, time, effort and resources necessary for a full empirical PoD assessment.

Non-Contact EDDY Current Hole Eccentricity and Diameter Measurement

NASA Technical Reports Server (NTRS)

Chern, E. James

1998-01-01

Precision holes are among the most critical features of a mechanical component. Deviations from permissible tolerances can impede operation and result in unexpected failure. We have developed an automated non-contact eddy current hole diameter and eccentricity measuring system. The operating principle is based on the eddy current lift-off effect, which is the coil impedance as a function of the distance between the coil and the test object. An absolute eddy current probe rotates in the hole. The impedance of each angular position is acquired and input to the computer for integration and analysis. The eccentricity of the hole is the profile of the impedance as a function of angular position as compared to a straight line, an ideal hole. The diameter of the hole is the sum of the diameter of the probe and twice the distance-calibrated impedance. An eddy current image is generated by integrating angular scans for a plurality of depths between the top and bottom to display the eccentricity profile. This system can also detect and image defects in the hole. The method for non-contact eddy current hole diameter and eccentricity measurement has been granted a patent by the U.S. Patent and Trademark Office.

Thin film eddy current impulse deicer

NASA Technical Reports Server (NTRS)

Smith, Samuel O.; Zieve, Peter B.

1990-01-01

Two new styles of electrical impulse deicers has been developed and tested in NASA's Icing Research Tunnel. With the Eddy Current Repulsion Deicing Boot (EDB), a thin and flexible spiral coil is encapsulated between two thicknesses of elastomer. The coil, made by an industrial printed circuit board manufacturer, is bonded to the aluminum aircraft leading edge. A capacitor bank is discharged through the coil. Induced eddy currents repel the coil from the aluminum aircraft structure and shed accumulated ice. A second configuration, the Eddy Current Repulsion Deicing-Strip (EDS) uses an outer metal erosion strip fastened over the coil. Opposite flowing eddy currents repel the strip and create the impulse deicing force. The outer strip serves as a surface for the collection and shedding of ice and does not require any structural properties. The EDS is suitable for composite aircraft structures. Both systems successfully dispelled over 95 percent of the accumulated ice from airfoils over the range of the FAA icing envelope.

Mouse repeated electroconvulsive seizure (ECS) does not reverse social stress effects but does induce behavioral and hippocampal changes relevant to electroconvulsive therapy (ECT) side-effects in the treatment of depression

PubMed Central

Sigrist, Hannes; Seifritz, Erich; Fikse, Lianne; Bosker, Fokko J.; Schoevers, Robert A.; Klein, Hans C.

2017-01-01

Electroconvulsive therapy (ECT) is an effective treatment for depression, but can have negative side effects including amnesia. The mechanisms of action underlying both the antidepressant and side effects of ECT are not well understood. An equivalent manipulation that is conducted in experimental animals is electroconvulsive seizure (ECS). Rodent studies have provided valuable insights into potential mechanisms underlying the antidepressant and side effects of ECT. However, relatively few studies have investigated the effects of ECS in animal models with a depression-relevant manipulation such as chronic stress. In the present study, mice were first exposed to chronic social stress (CSS) or a control procedure for 15 days followed by ECS or a sham procedure for 10 days. Behavioral effects were investigated using an auditory fear conditioning (learning) and expression (memory) test and a treadmill-running fatigue test. Thereafter, immunohistochemistry was conducted on brain material using the microglial marker Iba-1 and the cholinergic fibre marker ChAT. CSS did not increase fear learning and memory in the present experimental design; in both the control and CSS mice ECS reduced fear learning and fear memory expression. CSS induced the expected fatigue-like effect in the treadmill-running test; ECS induced increased fatigue in CSS and control mice. In CSS and control mice ECS induced inflammation in hippocampus in terms of increased expression of Iba-1 in radiatum of CA1 and CA3. CSS and ECS both reduced acetylcholine function in hippocampus as indicated by decreased expression of ChAT in several hippocampal sub-regions. Therefore, CSS increased fatigue and reduced hippocampal ChAT activity and, rather than reversing these effects, a repeated ECS regimen resulted in impaired fear learning-memory, increased fatigue, increased hippocampal Iba-1 expression, and decreased hippocampal ChAT expression. As such, the current model does not provide insights into the mechanism of ECT antidepressant function but does provide evidence for pathophysiological mechanisms that might contribute to important ECT side-effects. PMID:28910337

Mouse repeated electroconvulsive seizure (ECS) does not reverse social stress effects but does induce behavioral and hippocampal changes relevant to electroconvulsive therapy (ECT) side-effects in the treatment of depression.

PubMed

van Buel, Erin M; Sigrist, Hannes; Seifritz, Erich; Fikse, Lianne; Bosker, Fokko J; Schoevers, Robert A; Klein, Hans C; Pryce, Christopher R; Eisel, Ulrich Lm

2017-01-01

Electroconvulsive therapy (ECT) is an effective treatment for depression, but can have negative side effects including amnesia. The mechanisms of action underlying both the antidepressant and side effects of ECT are not well understood. An equivalent manipulation that is conducted in experimental animals is electroconvulsive seizure (ECS). Rodent studies have provided valuable insights into potential mechanisms underlying the antidepressant and side effects of ECT. However, relatively few studies have investigated the effects of ECS in animal models with a depression-relevant manipulation such as chronic stress. In the present study, mice were first exposed to chronic social stress (CSS) or a control procedure for 15 days followed by ECS or a sham procedure for 10 days. Behavioral effects were investigated using an auditory fear conditioning (learning) and expression (memory) test and a treadmill-running fatigue test. Thereafter, immunohistochemistry was conducted on brain material using the microglial marker Iba-1 and the cholinergic fibre marker ChAT. CSS did not increase fear learning and memory in the present experimental design; in both the control and CSS mice ECS reduced fear learning and fear memory expression. CSS induced the expected fatigue-like effect in the treadmill-running test; ECS induced increased fatigue in CSS and control mice. In CSS and control mice ECS induced inflammation in hippocampus in terms of increased expression of Iba-1 in radiatum of CA1 and CA3. CSS and ECS both reduced acetylcholine function in hippocampus as indicated by decreased expression of ChAT in several hippocampal sub-regions. Therefore, CSS increased fatigue and reduced hippocampal ChAT activity and, rather than reversing these effects, a repeated ECS regimen resulted in impaired fear learning-memory, increased fatigue, increased hippocampal Iba-1 expression, and decreased hippocampal ChAT expression. As such, the current model does not provide insights into the mechanism of ECT antidepressant function but does provide evidence for pathophysiological mechanisms that might contribute to important ECT side-effects.

The Role of Electroconvulsive Therapy (ECT) in Bipolar Disorder: Effectiveness in 522 Patients with Bipolar Depression, Mixed-state, Mania and Catatonic Features.

PubMed

Perugi, Giulio; Medda, Pierpaolo; Toni, Cristina; Mariani, Michela Giorgi; Socci, Chiara; Mauri, Mauro

2017-04-01

We evaluated the effectiveness of Electroconvulsive Therapy (ECT) in the treatment of Bipolar Disorder (BD) in a large sample of bipolar patients with drug resistant depression, mania, mixed state and catatonic features. 522 consecutive patients with DSM-IV-TR BD were evaluated prior to and after the ECT course. Responders and nonresponders were compared in subsamples of depressed and mixed patients. Descriptive analyses were reported for patients with mania and with catatonic features. Of the original sample only 22 patients were excluded for the occurrence of side effects or consent withdrawal. After the ECT course, 344 (68.8%) patients were considered responders (final CGIi score ≤2) and 156 (31.2%) nonresponders. Response rates were respectively 68.1% for BD depression, 72.9% for mixed state, 75% for mania and 80.8% for catatonic features. Length of current episode and global severity of the illness were the only statistically significant predictors of nonresponse. ECT resulted to be an effective and safe treatment for all the phases of severe and drug-resistant BD. Positive response was observed in approximately two-thirds of the cases and in 80% of the catatonic patients. The duration of the current episode was the major predictor of nonresponse. The risk of ECT-induced mania is virtually absent and mood destabilization very unlikely. Our results clearly indicate that current algorithms for the treatment of depressive, mixed, manic and catatonic states should be modified and, at least for the most severe patients, ECT should not be considered as a "last resort".

Health Related Quality of Life after ECT for depression: A study exploring the role of different electrode-placements and pulse-widths.

PubMed

Gálvez, Verònica; Li, Adrienne; Oxley, Cristal; Waite, Susan; De Felice, Nick; Hadzi-Pavlovic, Dusan; Kumar, Divya; Page, Andrew C; Hooke, Geoff; Loo, Colleen K

2016-12-01

Prior research has shown large improvements in HRQOL after a course of ECT for depression. However, the effect of different types of ECT on HRQOL outcomes has not been explored. This is important due to the considerable range of ECT treatment modalities that currently exist in clinical practice. HRQOL data from 355 depressed patients in three Australian clinical hospitals, who received ECT given with a range of treatment modalities (combinations of pulse-width and electrode-placement), were analysed. HRQOL was measured at baseline and after ECT, using the Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form (Q-LES-Q-SF). The association between type of ECT and HRQOL after ECT was examined by regression analysis, controlling for variables that may affect HRQOL outcomes. There was a significant increase in HRQOL scores after ECT (p<0.0001; t=-23.4). The magnitude of change was large (54% increase, Cohen's d=1.43). Multiple regression analysis yielded a significant model (P<0.001, R 2 =0.18). Baseline HRQOL score (t=4.83; p<0.0001), age (t=2.75, p<0.01) and type of ECT received [Right Unilateral brief vs Bitemporal Ultrabrief (t=-2.99; p<0.01) and Right Unilateral brief vs Bifrontal Ultrabrief (t=-2.70; p<0.01)] were significant predictors of HRQOL after the ECT course. Data was collected naturalistically from clinical services, thus ECT modality was not randomly assigned. Site could have confounded results. An acute course of ECT for depression produced statistically and clinically significant improvements in HRQOL. ECT treatment modality can substantially impact HRQOL outcomes, with the possibility of bilateral ultrabrief forms of ECT being less beneficial. Copyright © 2016 Elsevier B.V. All rights reserved.

78 FR 21079 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-09

... accomplished. The initial inspection may be either a detailed inspection or a bolt- hole eddy current (BHEC... inspection or a bolt-hole eddy current (BHEC) test for cracking of each nacelle lower longeron, in accordance...-39, Revision A, dated August 2, 2012, specify to contact the manufacturer for instructions to repair...

Eddy current inspection tool. [Patent application

DOEpatents

Petrini, R.R.; Van Lue, D.F.

1980-10-29

A miniaturized inspection tool, for testing and inspection of metal objects in locations with difficult accessibility, which comprises eddy current sensing equipment with a probe coil, and associated coaxial coil cable, oil energizing means, and circuit means responsive to impedance changes in the coil as effected by induced eddy currents in a test object to produce a data output signal proportional to such changes. The coil and cable are slideably received in the utility channel of the flexible insertion tube of a fiberoptic scope. The scope is provided with light transmitting and receiving fiberoptics for viewing through the flexible tube, and articulation means for articulating the distal end of the tube and permitting close control of coil placement relative to a test object. The eddy current sensing equipment includes a tone generator for generating audible signals responsive to the data output signal. In one selected mode of operation, the tone generator responsive to the output signal above a selected level generates a constant single frequency tone for signalling detection of a discontinuity and, in a second selected mode, generates a tone whose frequency is proportional to the difference between the output signal and a predetermined selected threshold level.

Electroconvulsive Therapy Part I: A Perspective on the Evolution and Current Practice of ECT

PubMed Central

Payne, Nancy A.; Prudic, Joan

2010-01-01

The concept of inducing convulsions, mainly through chemical means, to promote mental wellness has existed since the 16th century. In 1938, Italian scientists first applied electrically induced therapeutic seizures. Although electroconvulsive therapy (ECT) is employed in the treatment of several psychiatric disorders, it is most frequently used today to treat severe depressive episodes and remains the most effective treatment available for those disorders. Despite this, ECT continues to be the most stigmatized treatment available in psychiatry, resulting in restrictions on and reduced accessibility to a helpful and potentially life-saving treatment. The psychiatric and psychosocial ramifications of this stigmatization may include the exacerbation of the increasingly serious, global health problem of major depressive disorders as well as serious consequences for individual patients who may not be offered, or may refuse, a potentially beneficial treatment. The goal of this first article in this two-part series is to provide an overview of ECT's historical development and discuss the current state of knowledge about ECT, including technical aspects of delivery, patient selection, its side-effect profile, and factors that may contribute to underuse of ECT. PMID:19820553

How Electroconvulsive Therapy Works?: Understanding the Neurobiological Mechanisms

PubMed Central

Singh, Amit; Kar, Sujita Kumar

2017-01-01

Electroconvulsive therapy (ECT) is a time tested treatment modality for the management of various psychiatric disorders. There have been a lot of modifications in the techniques of delivering ECT over decades. Despite lots of criticisms encountered, ECT has still been used commonly in clinical practice due to its safety and efficacy. Research evidences found multiple neuro-biological mechanisms for the therapeutic effect of ECT. ECT brings about various neuro-physiological as well as neuro-chemical changes in the macro- and micro-environment of the brain. Diverse changes involving expression of genes, functional connectivity, neurochemicals, permeability of blood-brain-barrier, alteration in immune system has been suggested to be responsible for the therapeutic effects of ECT. This article reviews different neurobiological mechanisms responsible for the therapeutic efficacy of ECT. PMID:28783929

Episodic memory following deep brain stimulation of the ventral anterior limb of the internal capsule and electroconvulsive therapy.

PubMed

Bergfeld, Isidoor O; Mantione, Mariska; Hoogendoorn, Mechteld L C; Horst, Ferdinand; Notten, Peter; Schuurman, P Richard; Denys, Damiaan

Electroconvulsive Therapy (ECT) and Deep Brain Stimulation (DBS) are effective treatments for patients with treatment-resistant depression (TRD). However, a common side effect of ECT is autobiographical memory loss (e.g., personal experiences), whereas the impact of DBS on autobiographical memories has never been established. Comparing autobiographical memories following DBS and ECT. In two hospitals in The Netherlands, we interviewed 25 TRD patients treated with DBS of the ventral anterior limb of the internal capsule (vALIC), 14 TRD patients treated with ECT and 22 healthy controls (HC) with the Autobiographical Memory Inventory - Short Form (AMI-SF) in a prospective, longitudinal study between March 2010 and August 2016. Patients treated with DBS were interviewed before surgery, after surgery, and twice during treatment over 122.7 (SD: ±22.2) weeks. Patients treated with ECT were tested before ECT, after six right unilateral (RUL) ECT sessions and twice following ECT over 65.1 (±9.3) weeks. Controls were tested four times over 81.5 (±15.6) weeks. Compared to HC, the AMI-SF score decreased faster in both TRD groups (P < 0.001). More specifically, AMI-SF score decreased in a comparable rate as HC after DBS surgery, but decreased more during treatment. The AMI-SF decrease in the ECT group was larger than both the DBS and HC groups. Both ECT and vALIC DBS result in a faster autobiographical memory decline compared to HC. DBS might have a negative impact on autobiographical memories, although less so than ECT. Future work should dissect whether DBS or characteristics of TRD cause this decline. Copyright © 2017 Elsevier Inc. All rights reserved.

Heparin removal by ecteola-cellulose pre-treatment enables the use of plasma samples for accurate measurement of anti-Yellow fever virus neutralizing antibodies.

PubMed

Campi-Azevedo, Ana Carolina; Peruhype-Magalhães, Vanessa; Coelho-Dos-Reis, Jordana Grazziela; Costa-Pereira, Christiane; Yamamura, Anna Yoshida; Lima, Sheila Maria Barbosa de; Simões, Marisol; Campos, Fernanda Magalhães Freire; de Castro Zacche Tonini, Aline; Lemos, Elenice Moreira; Brum, Ricardo Cristiano; de Noronha, Tatiana Guimarães; Freire, Marcos Silva; Maia, Maria de Lourdes Sousa; Camacho, Luiz Antônio Bastos; Rios, Maria; Chancey, Caren; Romano, Alessandro; Domingues, Carla Magda; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis

2017-09-01

Technological innovations in vaccinology have recently contributed to bring about novel insights for the vaccine-induced immune response. While the current protocols that use peripheral blood samples may provide abundant data, a range of distinct components of whole blood samples are required and the different anticoagulant systems employed may impair some properties of the biological sample and interfere with functional assays. Although the interference of heparin in functional assays for viral neutralizing antibodies such as the functional plaque-reduction neutralization test (PRNT), considered the gold-standard method to assess and monitor the protective immunity induced by the Yellow fever virus (YFV) vaccine, has been well characterized, the development of pre-analytical treatments is still required for the establishment of optimized protocols. The present study intended to optimize and evaluate the performance of pre-analytical treatment of heparin-collected blood samples with ecteola-cellulose (ECT) to provide accurate measurement of anti-YFV neutralizing antibodies, by PRNT. The study was designed in three steps, including: I. Problem statement; II. Pre-analytical steps; III. Analytical steps. Data confirmed the interference of heparin on PRNT reactivity in a dose-responsive fashion. Distinct sets of conditions for ECT pre-treatment were tested to optimize the heparin removal. The optimized protocol was pre-validated to determine the effectiveness of heparin plasma:ECT treatment to restore the PRNT titers as compared to serum samples. The validation and comparative performance was carried out by using a large range of serum vs heparin plasma:ECT 1:2 paired samples obtained from unvaccinated and 17DD-YFV primary vaccinated subjects. Altogether, the findings support the use of heparin plasma:ECT samples for accurate measurement of anti-YFV neutralizing antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

Current status of electroconvulsive therapy for mood disorders: a clinical review.

PubMed

Kolar, Dusan

2017-02-01

Electroconvulsive therapy (ECT) is an effective treatment for mood disorders and a viable treatment option especially when urgency of clinical situation requires a prompt treatment response. After acute series of ECT, the ECT long-term treatment may be considered, although this practice may vary significantly between countries or even within the same country, because there is no universal consensus about its indications, duration and frequency of administration. Continuation or maintenance ECT is common in routine clinical practice and clinicians should be aware of the risks of using ECT long term. Neuropsychological assessment should be an essential part of a good clinical practice in ECT services. Cognitive side effects of ECT are sometimes underestimated and may last much longer after completed treatment than it is usually expected. These cognitive impairments associated with ECT may cause significant functional difficulties and prevent patients to return to work. Cognitive assessment during ECT treatment is usually not comprehensive enough and is limited to bedside assessment. A more proactive approach to careful neuropsychological assessment and consideration of combined maintenance medication treatment after ECT are essential. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Trends in use of electroconvulsive therapy in South London from 1949 to 2006.

PubMed

Lambe, Sinéad; Mogg, Andrew; Eranti, Savitha; Pluck, Graham; Hastilow, Sarah; McLoughlin, Declan M

2014-12-01

Electroconvulsive therapy (ECT) remains the most acutely effective treatment for severe depression, but its use has declined since its introduction more than 70 years ago. To provide some historical perspective on changes in ECT practice, the objective of the present study was to identify trends in ECT practice in selected teaching hospitals in South London, UK, between 1949 and 2006. Annual rates of ECT for 1949-1970 were estimated from the contemporary hospital reports of the Maudsley and Bethlem Royal hospitals in South London, UK. Case notes were also retrospectively reviewed to calculate annual rates of ECT administration and extract demographic and clinical information for approximately every 5 years between 1987 and 2006. The annual rate of ECT peaked at 35% of total admission in 1956 and declined gradually thereafter to 10.8% by 1970 and fell below 2.2% from 1991 onward. Depressed and female patients were more likely to receive ECT. Compared to previous years, patients were more severely ill and treatment resistant in 2006, whereas ethnic minorities made up 30% of patients receiving ECT compared to approximately 14% in the preceding years. Currently, ECT seems to be provided increasingly late in more severe illness episodes. The ethnicity of patients receiving ECT in South London may be becoming more representative of the background population, but ECT is being used relatively more frequently for nonaffective disorders in ethnic minorities.

Extension to the dynamic modeling of the large angle magnetic suspension test fixture. M.S. Thesis - Old Dominion Univ., May 1995 Progress Report, 1 Nov. 1994 - 30 Apr. 1995

NASA Technical Reports Server (NTRS)

Foster, Lucas E.; Britcher, Colin P.

1995-01-01

The Large Angle Magnetic Suspension Test Fixture (LAMSTF) is a laboratory scale proof-of-concept system. The configuration is unique in that the electromagnets are mounted in a circular planar array. A mathematical model of the system had previously been developed, but was shown to have inaccuracies. These inaccuracies showed up in the step responses. Eddy currents were found to be the major cause of the modeling errors. In the original system, eddy currents existed in the aluminum baseplate, iron cores, and the sensor support frame. An attempt to include the eddy current dynamics in the system model is presented. The dynamics of a dummy sensor ring were added to the system. Adding the eddy current dynamics to the simulation improves the way it compares to the actual experiment. Also presented is a new method of determining the yaw angle of the suspended element. From the coil currents the yaw angle can be determined and the controller can be updated to suspend at the new current. This method has been used to demonstrate a 360 degree yaw angle rotation.

Maintenance ECT as a therapeutic approach to medication-refractory epilepsy in an adult with mental retardation: case report and review of literature.

PubMed

Shah, Nilesh; Pande, Nikhil; Bhat, Tushar; Murke, Mukund; Andrade, Chittaranjan

2012-06-01

Electroconvulsive therapy (ECT) raises the seizure threshold. This physiological change may benefit patients with seizure disorders. Whereas ECT has recently been used to terminate medication-refractory status epilepticus, there is little current literature on its planned administration as a specific maintenance treatment for medication-refractory epilepsy. We used maintenance ECT to treat an 18-year-old man with a long-standing generalized tonic-clonic seizure disorder who had shown poor response to several antiepileptic drugs administered in combination with antiepileptic medication compliance confirmed through drug level monitoring. A total of 52 ECTs were administered across nearly 20 months at a mean frequency of once in nearly 12 days. From the very outset, ECT dramatically decreased the frequency of spontaneous seizures from approximately 6 to 24 per week at baseline to approximately 1 to 2 per week after ECT initiation. The efficacy of maintenance ECT in spontaneous seizure prophylaxis was greater when the ECT treatment interval was narrower. Improvement with ECT was associated with improved behavior and improved psychosocial functioning on clinical report. No cognitive or other adverse effects were reported or clinically ascertained. The ECT charge administered at the last 10 treatment sessions was 1434 millicoulombs. This is probably the highest electrical stimulus dose recorded in literature. Maintenance ECT may reduce the frequency of breakthrough seizures in patients with seizure disorder that is inadequately responsive to antiepileptic medication regimes. Very high ECT seizure thresholds may be observed when many antiepileptic drugs are concurrently administered in high doses.

Eddy current testing for blade edge micro cracks of aircraft engine

NASA Astrophysics Data System (ADS)

Zhang, Wei-min; Xu, Min-dong; Gao, Xuan-yi; Jin, Xin; Qin, Feng

2017-10-01

Based on the problems of low detection efficiency in the micro cracks detection of aircraft engine blades, a differential excitation eddy current testing system was designed and developed. The function and the working principle of the system were described, the problems which contained the manufacture method of simulated cracks, signal generating, signal processing and the signal display method were described. The detection test was carried out by taking a certain model aircraft engine blade with simulated cracks as a tested specimen. The test data was processed by digital low-pass filter in the computer and the crack signals of time domain display and Lissajous figure display were acquired. By comparing the test results, it is verified that Lissajous figure display shows better performance compared to time domain display when the crack angle is small. The test results show that the eddy current testing system designed in this paper is feasible to detect the micro cracks on the aeroengine blade and can effectively improve the detection efficiency of micro cracks in the practical detection work.

Impedance testing on cochlear implants after electroconvulsive therapy.

PubMed

McRackan, Theodore R; Rivas, Alejandro; Hedley-Williams, Andrea; Raj, Vidya; Dietrich, Mary S; Clark, Nathaniel K; Labadie, Robert F

2014-12-01

Cochlear implants (CI) are neural prostheses that restore hearing to individuals with profound sensorineural hearing loss. The surgically implanted component consists of an electrode array, which is threaded into the cochlea, and an electronic processor, which is buried under the skin behind the ear. The Food and Drug Administration and CI manufacturers contend that electroconvulsive therapy (ECT) is contraindicated in CI recipients owing to risk of damage to the implant and/or the patient. We hypothesized that ECT does no electrical damage to CIs. Ten functional CIs were implanted in 5 fresh cadaveric human heads. Each head then received a consecutive series of 12 unilateral ECT sessions applying maximum full pulse-width energy settings. Electroconvulsive therapy was delivered contralaterally to 5 CIs and ipsilaterally to 5 CIs. Electrical integrity testing (impedance testing) of the electrode array was performed before and after CI insertion, and after the first, third, fifth, seventh, ninth, and 12th ECT sessions. Electroconvulsive therapy was performed by a staff psychiatrist experienced with the technique. Explanted CIs were sent back to the manufacturer for further integrity testing. No electrical damage was identified during impedance testing. Overall, there were statistically significant decreases in impedances (consistent with no electrical damage) when comparing pre-ECT impedance values to those after 12 sessions. There was no statistically significant difference (P > 0.05) in impedance values comparing ipsilateral to contralateral ECT. Manufacturer testing revealed no other electrical damage to the CIs. Electroconvulsive therapy does not seem to cause any detectable electrical injury to CIs.

Eddy-current non-inertial displacement sensing for underwater infrasound measurements.

PubMed

Donskoy, Dimitri M; Cray, Benjamin A

2011-06-01

A non-inertial sensing approach for an Acoustic Vector Sensor (AVS), which utilizes eddy-current displacement sensors and operates well at Ultra-Low Frequencies (ULF), is described here. In the past, most ULF measurements (from mHertz to approximately 10 Hertz) have been conducted using heavy geophones or seismometers that must be installed on the seafloor; these sensors are not suitable for water column measurements. Currently, there are no readily available compact and affordable underwater AVS that operate within this frequency region. Test results have confirmed the validity of the proposed eddy-current AVS design and have demonstrated high acoustic sensitivity. © 2011 Acoustical Society of America

Electromechanical Apparatus Measures Residual Stress

NASA Technical Reports Server (NTRS)

Chern, Engmin J.; Flom, Yury

1993-01-01

Nondestructive test exploits relationship between stress and eddy-current-probe resistance. Yields data on residual stress or strain in metal tension/compression specimen (stress or strain remaining in specimen when no stress applied from without). Apparatus is assembly of commercial equipment: tension-or-compression testing machine, eddy-current probe, impedance gain-and-phase analyzer measuring impedance of probe coil, and desktop computer, which controls other equipment and processes data received from impedance gain-and-phase analyzer.

Nondestructive Crack Detection in a Fuel System Component

NASA Technical Reports Server (NTRS)

Koshti, Ajay; Ruffino, Norman; Wincheski, Russell; Prosser, William; Winfree, William; Russell, Richard; Bryson, Craig; Devries, Robert; Engel, James; Landy, James

2010-01-01

The presentation examines the background and objective of nondestructive crack detection, flow control valve assembly and poppet post flight evaluation, poppet properties. magnetic property characterization of lab data, NDE, eddy current inspection, simulation, eddy current criteria, poppet cycle testing and NDE criteria, and the use of ultrasonic surface wave for crack detection.

Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

NASA Astrophysics Data System (ADS)

Okafor, A. C.; Natarajan, S.

2007-03-01

Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

Automated measurement system employing eddy currents to adjust probe position and determine metal hardness

DOEpatents

Prince, J.M.; Dodson, M.G.; Lechelt, W.M.

1989-07-18

A system for measuring the hardness of cartridge cases employs an eddy current probe for inducing and sensing eddy currents in each cartridge case. A first component of the sensed signal is utilized in a closed loop system for accurately positioning the probe relative to the cartridge case both in the lift off direction and in the tangential direction, and a second component of the sensed signal is employed as a measure of the hardness. The positioning and measurement are carried out under closed loop microprocessor control facilitating hardness testing on a production line basis. 14 figs.

Automated measurement system employing eddy currents to adjust probe position and determine metal hardness

DOEpatents

Prince, James M.; Dodson, Michael G.; Lechelt, Wayne M.

1989-01-01

A system for measuring the hardness of cartridge cases employs an eddy current probe for inducing and sensing eddy currents in each cartridge case. A first component of the sensed signal is utilized in a closed loop system for accurately positioning the probe relative to the cartridge case both in the lift off direction and in the tangential direction, and a second component of the sensed signal is employed as a measure of the hardness. The positioning and measurement are carried out under closed loop microprocessor control facilitating hardness testing on a production line basis.

Measurement of Spindle Rigidity by using a Magnet Loader

NASA Astrophysics Data System (ADS)

Yamazaki, Taku; Matsubara, Atsushi; Fujita, Tomoya; Muraki, Toshiyuki; Asano, Kohei; Kawashima, Kazuyuki

The static rigidity of a rotating spindle in the radial direction is investigated in this research. A magnetic loading device (magnet loader) has been developed for the measurement. The magnet loader, which has coils and iron cores, generates the electromagnetic force and attracts a dummy tool attached to the spindle. However, the eddy current is generated in the dummy tool with the spindle rotation and reduces the attractive force at high spindle speed. In order to understand the magnetic flux and eddy current in the dummy tool, the electromagnetic field analysis by FEM was carried out. Grooves on the attraction surface of the dummy tool were designed to cut the eddy current flow. The dimension of the groove were decided based on the FEM analysis, and the designed tool were manufactured and tested. The test result shows that the designed tool successfully reduces the eddy current and recovers the attractive force. By using the magnet loader and the grooved tool, the spindle rigidity can be measured when the spindle rotates with a speed up to 10,000 min-1.

Application of Eddy Current Techniques for Orbiter Reinforced Carbon-Carbon Structural Health Monitoring

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Simpson, John

2005-01-01

The development and application of advanced nondestructive evaluation techniques for the Reinforced Carbon-Carbon (RCC) components of the Space Shuttle Orbiter Leading Edge Structural Subsystem (LESS) was identified as a crucial step toward returning the shuttle fleet to service. In order to help meet this requirement, eddy current techniques have been developed for application to RCC components. Eddy current technology has been found to be particularly useful for measuring the protective coating thickness over the reinforced carbon-carbon and for the identification of near surface cracking and voids in the RCC matrix. Testing has been performed on as manufactured and flown RCC components with both actual and fabricated defects representing impact and oxidation damage. Encouraging initial results have led to the development of two separate eddy current systems for in-situ RCC inspections in the orbiter processing facility. Each of these systems has undergone blind validation testing on a full scale leading edge panel, and recently transitioned to Kennedy Space Center to be applied as a part of a comprehensive RCC inspection strategy to be performed in the orbiter processing facility after each shuttle flight.

Informed consent and ECT: how much information should be provided?

PubMed

Torrance, Robert

2015-05-01

Obtaining informed consent before providing treatment is a routine part of modern clinical practice. For some treatments, however, there may be disagreement over the requirements for 'informed' consent. Electroconvulsive therapy (ECT) is one such example. Blease argues that patients 'should surely be privy to the matters of fact that: (1) there is continued controversy over the effectiveness of ECT; (2) there is orthodox scientific consensus that there is currently no acknowledged explanation for ECT and (3) there is a serious (mainstream) debate over whether the response to ECT may be a placebo response.' Before embracing these suggestions, two key questions must be asked. Are these claims a reasonable representation of current ECT research? And if so, will this information be of benefit to patients? The evidence-based support for ECT from both National Institute for Health and Care Excellence and the Royal College of Psychiatrists appears to undermine the validity of claims (1) and (3), and therefore the rationale for providing this information. Concerning assertion (2), it is true that the mechanism by which ECT has its therapeutic effect is not yet established, although the importance of conveying this fact to the patient is questionable. Of greater certainty is that the same irresolution surrounds the mechanism of action of pharmaceutical antidepressants, and so a double standard in patient care should be mindfully avoided if provision of this information is deemed a prerequisite for proper 'informed' consent. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The Role of Electroconvulsive Therapy (ECT) in Bipolar Disorder: Effectiveness in 522 Patients with Bipolar Depression, Mixed-state, Mania and Catatonic Features

PubMed Central

Perugi, Giulio; Medda, Pierpaolo; Toni, Cristina; Mariani, Michela Giorgi; Socci, Chiara; Mauri, Mauro

2017-01-01

Objective: We evaluated the effectiveness of Electroconvulsive Therapy (ECT) in the treatment of Bipolar Disorder (BD) in a large sample of bipolar patients with drug resistant depression, mania, mixed state and catatonic features. Method: 522 consecutive patients with DSM-IV-TR BD were evaluated prior to and after the ECT course. Responders and nonresponders were compared in subsamples of depressed and mixed patients. Descriptive analyses were reported for patients with mania and with catatonic features. Results: Of the original sample only 22 patients were excluded for the occurrence of side effects or consent withdrawal. After the ECT course, 344 (68.8%) patients were considered responders (final CGIi score ≤2) and 156 (31.2%) nonresponders. Response rates were respectively 68.1% for BD depression, 72.9% for mixed state, 75% for mania and 80.8% for catatonic features. Length of current episode and global severity of the illness were the only statistically significant predictors of nonresponse. Conclusion: ECT resulted to be an effective and safe treatment for all the phases of severe and drug-resistant BD. Positive response was observed in approximately two-thirds of the cases and in 80% of the catatonic patients. The duration of the current episode was the major predictor of nonresponse. The risk of ECT-induced mania is virtually absent and mood destabilization very unlikely. Our results clearly indicate that current algorithms for the treatment of depressive, mixed, manic and catatonic states should be modified and, at least for the most severe patients, ECT should not be considered as a “last resort”. PMID:28503107

Research of Steel-dielectric Transition Using Subminiature Eddy-current Transducer

NASA Astrophysics Data System (ADS)

Dmitriev, S. F.; Malikov, V. N.; Sagalakov, A. M.; Ishkov, A. V.

2018-05-01

The research aims to develop a subminiature transducer for electrical steel investigation. The authors determined the capability to study steel characteristics at different depths based on variations of eddy-current transducer amplitude at the steel-dielectric boundary. A subminiature transformer-type transducer was designed, which enables to perform local investigations of ferromagnetic materials using an eddy-current method based on local studies of the steel electrical conductivity. Having the designed transducer as a basis, a hardware-software complex was built to perform experimental studies of steel at the interface boundary. Test results are reported for a specimen with continuous and discrete measurements taken at different frequencies. The article provides the key technical information about the eddy current transformer used and describes the methodology of measurements that makes it possible to control steel to dielectric transition.

[Quantitative experiment and analysis of gradient-induced eddy currents on magnetic resonance imaging].

PubMed

He, Wenjing; Zhu, Yuanzhong; Wang, Wenzhou; Zou, Kai; Zhang, Kai; He, Chao

2017-04-01

Pulsed magnetic field gradients generated by gradient coils are widely used in signal location in magnetic resonance imaging (MRI). However, gradient coils can also induce eddy currents in final magnetic field in the nearby conducting structures which lead to distortion and artifact in images, misguiding clinical diagnosis. We tried in our laboratory to measure the magnetic field of gradient-induced eddy current in 1.5 T superconducting magnetic resonance imaging device; and extracted key parameters including amplitude and time constant of exponential terms according to inductance-resistance series mathematical module. These parameters of both self-induced component and crossing component are useful to design digital filters to implement pulse pre-emphasize to reshape the waveform. A measure device that is a basement equipped with phantoms and receiving coils was designed and placed in the isocenter of the magnetic field. By applying testing sequence, contrast experiments were carried out in a superconducting magnet before and after eddy current compensation. Sets of one dimension signal were obtained as raw data to calculate gradient-induced eddy currents. Curve fitting by least squares method was also done to match inductance-resistance series module. The results also illustrated that pulse pre-emphasize measurement with digital filter was correct and effective in reducing eddy current effect. Pre-emphasize waveform was developed based on system function. The usefulness of pre-emphasize measurement in reducing eddy current was confirmed and the improvement was also presented. All these are valuable for reducing artifact in magnetic resonance imaging device.

Development of Ground Coils with Low Eddy Current Loss by Applying the Compression Molding Method after the Coil Winding

NASA Astrophysics Data System (ADS)

Suzuki, Masao; Aiba, Masayuki; Takahashi, Noriyuki; Ota, Satoru; Okada, Shigenori

In a magnetically levitated transportation (MAGLEV) system, a huge number of ground coils will be required because they must be laid for the whole line. Therefore, stable performance and reduced cost are essential requirements for the ground coil development. On the other hand, because the magnetic field changes when the superconducting magnet passes by, an eddy current will be generated in the conductor of the ground coil and will result in energy loss. The loss not only increases the magnetic resistance for the train running but also brings an increase in the ground coil temperature. Therefore, the reduction of the eddy current loss is extremely important. This study examined ground coils in which both the eddy current loss and temperature increase were small. Furthermore, quantitative comparison for the eddy current loss of various magnet wire samples was performed by bench test. On the basis of the comparison, a round twisted wire having low eddy current loss was selected as an effective ground coil material. In addition, the ground coils were manufactured on trial. A favorable outlook to improve the size accuracy of the winding coil and uneven thickness of molded resin was obtained without reducing the insulation strength between the coil layers by applying a compression molding after winding.

The Use of Electroconvulsive Therapy in Atypical Psychotic Presentations

PubMed Central

Vasu, Devi

2007-01-01

Convulsive therapy and its progeny, electroconvulsive therapy (ECT), were originally used for the treatment of catatonic schizophrenia, and there is little doubt that ECT remains an effective intervention for the treatment of schizophrenia. However, current practice tends to favor the use of ECT in severe or treatment refractory affective disorders, and its use in schizophrenia and other nonaffective (atypical) psychotic disorders has become controversial. Case reports have suggested a role for ECT in two specific atypical psychotic disorders: Cotard's syndrome and cycloid psychosis. In this article, we review the atypical psychotic disorders and report a series of five case examples that signify the role of ECT in atypical psychotic presentations, particularly when the symptoms resemble those found in Cotard's syndrome and cycloid psychosis. PMID:20428309

The use of electroconvulsive therapy in atypical psychotic presentations: a case review.

PubMed

Montgomery, John H; Vasu, Devi

2007-10-01

Convulsive therapy and its progeny, electroconvulsive therapy (ECT), were originally used for the treatment of catatonic schizophrenia, and there is little doubt that ECT remains an effective intervention for the treatment of schizophrenia. However, current practice tends to favor the use of ECT in severe or treatment refractory affective disorders, and its use in schizophrenia and other nonaffective (atypical) psychotic disorders has become controversial.CASE REPORTS HAVE SUGGESTED A ROLE FOR ECT IN TWO SPECIFIC ATYPICAL PSYCHOTIC DISORDERS: Cotard's syndrome and cycloid psychosis. In this article, we review the atypical psychotic disorders and report a series of five case examples that signify the role of ECT in atypical psychotic presentations, particularly when the symptoms resemble those found in Cotard's syndrome and cycloid psychosis.

Internal and forced eddy variability in the Labrador Sea

NASA Astrophysics Data System (ADS)

Bracco, A.; Luo, H.; Zhong, Y.; Lilly, J.

2009-04-01

Water mass transformation in the Labrador Sea, widely believed to be one of the key regions in the Atlantic Meridional Overturning Circulation (AMOC), now appears to be strongly impacted by vortex dynamics of the unstable boundary current. Large interannual variations in both eddy shedding and buoyancy transport from the boundary current have been observed but not explained, and are apparently sensitive to the state of the inflowing current. Heat and salinity fluxes associated with the eddies drive ventilation changes not accounted for by changes in local surface forcing, particularly during occasional years of extreme eddy activity, and constitute a predominant source of "internal" oceanic variability. The nature of this variable eddy-driven restratification is one of the outstanding questions along the northern transformation pathway. Here we investigate the eddy generation mechanism and the associated buoyancy fluxes by combining realistic and idealized numerical modeling, data analysis, and theory. Theory, supported by idealized experiments, provides criteria to test hypotheses as to the vortex formation process (by baroclinic instability linked to the bottom topography). Ensembles of numerical experiments with a high-resolution regional model (ROMS) allow for quantifying the sensitivity of eddy generation and property transport to variations in local and external forcing parameters. For the first time, we reproduce with a numerical simulation the observed interannual variability in the eddy kinetic energy in the convective region of the Labrador Basin and along the West Greenland Current.

Current electroconvulsive therapy practice and research in the geriatric population

PubMed Central

Kerner, Nancy; Prudic, Joan

2014-01-01

SUMMARY Electroconvulsive therapy (ECT) is utilized worldwide for various severe and treatment-resistant psychiatric disorders. Research studies have shown that ECT is the most effective and rapid treatment available for elderly patients with depression, bipolar disorder and psychosis. For patients who suffer from intractable catatonia and neuroleptic malignant syndrome, ECT can be life saving. For elderly patients who cannot tolerate or respond poorly to medications and who are at a high risk for drug-induced toxicity or toxic drug interactions, ECT is the safest treatment option. Organic causes are frequently associated with late-life onset of neuropsychiatric conditions, such as parkinsonism, dementia and stroke. ECT has proven to be efficacious even when these conditions are present. During the next decade, research studies should focus on the use of ECT as a synergistic therapy, to enhance other biological and psychological treatments, and prevent symptom relapse and recurrence. PMID:24778709

Does Gender Influence Electroconvulsive Therapy Sessions Required across Psychiatric Diagnoses? A 5-Year Experience from a Single Center

PubMed Central

Manohar, Harshini; Subramanian, Karthick; Menon, Vikas; Kattimani, Shivanand

2017-01-01

Context: There is a paucity of systematic data reflecting the practice of electroconvulsive therapy (ECT) from developing countries. Aim: We aimed to identify the number of ECT sessions required to yield response and gender diffeferences in the number of sessions across various diagnostic categories. Setting and Design: A record-based study from a teaching cum tertiary care hospital in South India. Subjects and Methods: Case records of patients who received modified ECT from January 2011 to January 2016 were reviewed. The sociodemographic details and ECT-related data were collected. Psychiatric diagnoses were ascertained as per the International Classification of Diseases, 10th Revision criteria. Statistical Analysis Used: Kruskal–Wallis test and Mann–Whitney U-test. Results: Among 148 patients, 82 (55.4%) had mood disorder (bipolar disorder and recurrent depressive disorder), 43 (29.1%) had schizophrenia, and 22 (14.9%) had other acute and transient psychotic disorders (ATPDs). Patients with mood disorders, schizophrenia, and other ATPD received 7.3 (± 3.8), 9.7 (± 6.1), and 5.4 (± 2.0) ECT sessions, respectively, to achieve response. There was no gender difference in the number of sessions received. Conclusion: Our findings show that number of ECT sessions required to yield response may be disorder-specific. Gender does not influence the ECT dose requirement. Variations in ECT parameters across settings may limit the generalizability of results. PMID:28694625

Improvement in verbal memory performance in depressed in-patients after treatment with electroconvulsive therapy.

PubMed

Biedermann, S V; Bumb, J M; Demirakca, T; Ende, G; Sartorius, A

2016-12-01

Electroconvulsive therapy (ECT) is a highly effective and well-tolerated therapy for severe and treatment-resistant depression. Cognitive side-effects are still feared by some patients and clinicians. Importantly, cognitive impairments are among the most disabling symptoms of depression itself. Patients suffering from a severe episode of depression were treated with either ECT or treatment as usual (TAU) in an in-patient setting. Matched healthy participants served as controls (HC). Verbal memory was tested with the California Verbal Learning Test (CVLT) before the specific treatment started (ECT = 15, TAU = 16, HC = 31) and 2 months after the last ECT session or 2 months after discharge respectively. Before the specific treatment started, depressed patients performed substantially worse compared with HC in total, short- and long-delay recall in the CVLT, while the ECT group showed the worst performance. More severely depressed patients showed worse performances in these measures. Intriguingly, verbal memory showed a significant improvement in ECT-treated patients, but not in the other groups. No differences between the groups were found at follow-up. Contrary to the widely feared assumption that ECT has long-term impact on memory functions, we found evidence that ECT is superior to TAU in improving verbal memory in depressed patients. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Randomized Controlled Trial of Brief and Ultrabrief Pulse Right Unilateral Electroconvulsive Therapy

PubMed Central

Katalinic, Natalie; Smith, Deirdre J.; Ingram, Anna; Dowling, Nathan; Martin, Donel; Addison, Kerryn; Hadzi-Pavlovic, Dusan; Simpson, Brett; Schweitzer,, Isaac

2015-01-01

Background: Some studies suggest better overall outcomes when right unilateral electroconvulsive therapy (RUL ECT) is given with an ultrabrief, rather than brief, pulse width. Methods: The aim of the study was to test if ultrabrief-pulse RUL ECT results in less cognitive side effects than brief- pulse RUL ECT, when given at doses which achieve comparable efficacy. One hundred and two participants were assigned to receive ultrabrief (at 8 times seizure threshold) or brief (at 5 times seizure threshold) pulse RUL ECT in a double-blind, randomized controlled trial. Blinded raters assessed mood and cognitive functioning over the ECT course. Results: Efficacy outcomes were not found to be significantly different. The ultrabrief group showed less cognitive impairment immediately after a single session of ECT, and over the treatment course (autobiographical memory, orientation). Conclusions: In summary, when ultrabrief RUL ECT was given at a higher dosage than brief RUL ECT (8 versus 5 times seizure threshold), efficacy was comparable while cognitive impairment was less. PMID:25522389

Baseline cognitive function does not predict the treatment outcome of electroconvulsive therapy (ECT) in late-life depression.

PubMed

Bjølseth, Tor Magne; Engedal, Knut; Benth, Jūratė Šaltytė; Dybedal, Gro Strømnes; Gaarden, Torfinn Lødøen; Tanum, Lars

2015-10-01

No prior study has investigated whether impairment of specific cognitive functions at baseline may predict the short-term treatment outcome of electroconvulsive therapy (ECT) in elderly non-demented patients with major depression (MD). This longitudinal cohort study included 65 elderly patients with unipolar or bipolar MD, aged 60-85 years, treated with formula-based ECT. Treatment outcome was assessed using the 17-item Hamilton Rating Scale for Depression (HRSD17). Cognitive function at baseline was assessed using nine neuropsychological tests or subtests measuring information processing speed, verbal learning and memory, and aspects of executive function. A poorer performance on the word reading task of the Color Word Interference Test rendered higher odds of achieving remission during the ECT course (p=0.021). Remission was defined as an HRSD17 score of 7 or less. There were no other significant associations between the treatment outcome of ECT and cognitive performance parameters assessed at baseline. The limited number of subjects may have reduced the generalizability of the findings. Multiple statistical tests increase the risk for making a type I error. How well patients perform on neuropsychological tests at baseline is most likely not a predictor of, or otherwise not significantly associated with the treatment outcome of formula-based ECT in elderly patients with MD. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Computational Analysis of Static and Dynamic Behaviour of Magnetic Suspensions and Magnetic Bearings

NASA Technical Reports Server (NTRS)

Britcher, Colin P. (Editor); Groom, Nelson J.

1996-01-01

Static modelling of magnetic bearings is often carried out using magnetic circuit theory. This theory cannot easily include nonlinear effects such as magnetic saturation or the fringing of flux in air-gaps. Modern computational tools are able to accurately model complex magnetic bearing geometries, provided some care is exercised. In magnetic suspension applications, the magnetic fields are highly three-dimensional and require computational tools for the solution of most problems of interest. The dynamics of a magnetic bearing or magnetic suspension system can be strongly affected by eddy currents. Eddy currents are present whenever a time-varying magnetic flux penetrates a conducting medium. The direction of flow of the eddy current is such as to reduce the rate-of-change of flux. Analytic solutions for eddy currents are available for some simplified geometries, but complex geometries must be solved by computation. It is only in recent years that such computations have been considered truly practical. At NASA Langley Research Center, state-of-the-art finite-element computer codes, 'OPERA', 'TOSCA' and 'ELEKTRA' have recently been installed and applied to the magnetostatic and eddy current problems. This paper reviews results of theoretical analyses which suggest general forms of mathematical models for eddy currents, together with computational results. A simplified circuit-based eddy current model proposed appears to predict the observed trends in the case of large eddy current circuits in conducting non-magnetic material. A much more difficult case is seen to be that of eddy currents in magnetic material, or in non-magnetic material at higher frequencies, due to the lower skin depths. Even here, the dissipative behavior has been shown to yield at least somewhat to linear modelling. Magnetostatic and eddy current computations have been carried out relating to the Annular Suspension and Pointing System, a prototype for a space payload pointing and vibration isolation system, where the magnetic actuator geometry resembles a conventional magnetic bearing. Magnetostatic computations provide estimates of flux density within airgaps and the iron core material, fringing at the pole faces and the net force generated. Eddy current computations provide coil inductance, power dissipation and the phase lag in the magnetic field, all as functions of excitation frequency. Here, the dynamics of the magnetic bearings, notably the rise time of forces with changing currents, are found to be very strongly affected by eddy currents, even at quite low frequencies. Results are also compared to experimental measurements of the performance of a large-gap magnetic suspension system, the Large Angle Magnetic Suspension Test Fixture (LAMSTF). Eddy current effects are again shown to significantly affect the dynamics of the system. Some consideration is given to the ease and accuracy of computation, specifically relating to OPERA/TOSCA/ELEKTRA.

Predictors of regained occupational functioning after electroconvulsive therapy (ECT) in patients with major depressive disorder--a population based cohort study.

PubMed

Nordenskjöld, Axel; von Knorring, Lars; Brus, Ole; Engström, Ingemar

2013-10-01

The aim of the present study is to investigate the rate of regained occupational functioning among patients treated with electroconvulsive therapy (ECT) for major depression and to define predictors of time to regained occupational functioning. A nested cohort study was performed of patients treated by ECT for unipolar major depressive disorder registered in the Quality register for ECT and in the Swedish Social Insurance Agency registry. Predictive values of single clinical variables and their relative importance were tested with Cox regression analysis. 394 patients were identified. Of those, 266 were on non-permanent sick leave and 128 on disability pension during ECT. Within 1 year post-ECT, 71% of the patients with non-permanent sick leave regained occupational functioning. Factors independently associated with a statistically significant increased time to regained occupational functioning were longer duration of sick leave pre-ECT, milder depression pre-ECT, less complete improvement with ECT, benzodiazepine treatment after ECT and co-morbid substance dependence. A large proportion of the patients do not return to work within several months post-ECT. Paradoxically, patients with more severe depression pre-ECT had a reduced time to regained occupational functioning, indicating a larger effect in this patients group of the treatment. Moreover, the period with sick leave compensation might be reduced if ECT is initiated within the first 3 months of sick leave. Most patients on non-permanent sick leave regain occupational functioning after ECT. However, it usually takes a few months even in symptomatically improved patients.

Eddy current inspection tool which is selectively operable in a discontinuity detection mode and a discontinuity magnitude mode

DOEpatents

Petrini, Richard R.; Van Lue, Dorin F.

1983-01-01

A miniaturized inspection tool, for testing and inspection of metal objects in locations with difficult accessibility, which comprises eddy current sensing equipment (12) with a probe coil (11), and associated coaxial coil cable (13), coil energizing means (21), and circuit means (21, 12) responsive to impedance changes in the coil as effected by induced eddy currents in a test object to produce a data output signal proportional to such changes. The coil and cable are slideably received in the utility channel of the flexible insertion tube 17 of fiberoptic scope 10. The scope 10 is provided with light transmitting and receiving fiberoptics for viewing through the flexible tube, and articulation means (19, 20) for articulating the distal end of the tube and permitting close control of coil placement relative to a test object. The eddy current sensing equipment includes a tone generator 30 for generating audibly signals responsive to the data output signal. In one selected mode of operation, the tone generator responsive to the output signal above a selected level generates a constant single frequency tone for signalling detection of a discontinuity and, in a second selected mode, generates a tone whose frequency is proportional to the difference between the output signal and a predetermined selected threshold level.

Eddy current inspection tool which is selectively operable in a discontinuity detection mode and a discontinuity magnitude mode

DOEpatents

Petrini, R.R.; Van Lue, D.F.

1983-10-25

A miniaturized inspection tool, for testing and inspection of metal objects in locations with difficult accessibility, which comprises eddy current sensing equipment with a probe coil, and associated coaxial coil cable, coil energizing means, and circuit means responsive to impedance changes in the coil as effected by induced eddy currents in a test object to produce a data output signal proportional to such changes. The coil and cable are slideably received in the utility channel of the flexible insertion tube of fiberoptic scope. The scope is provided with light transmitting and receiving fiberoptics for viewing through the flexible tube, and articulation means for articulating the distal end of the tube and permitting close control of coil placement relative to a test object. The eddy current sensing equipment includes a tone generator 30 for generating audibly signals responsive to the data output signal. In one selected mode of operation, the tone generator responsive to the output signal above a selected level generates a constant single frequency tone for signaling detection of a discontinuity and, in a second selected mode, generates a tone whose frequency is proportional to the difference between the output signal and a predetermined selected threshold level. 5 figs.

Evaluation of eddy-current proximity devices for measuring thin potassium film thicknesses

NASA Technical Reports Server (NTRS)

Asadourian, A. S.

1972-01-01

Two eddy current proximity probe systems were tested over a range of 0 to 508 micrometers (0 to 20 mils) of simulated potassium film thicknesses for simulated temperatures of 66 C (150 F), 232 C (450 F), and 666 C (1230 F). The results of short time calibration tests are presented. Instrument drift was a problem throughout the testing and, without correction, may limit the use of such systems to short periods of time. Additional development will be required prior to their being usable as practical instrumentation systems.

Nine time steps: ultra-fast statistical consistency testing of the Community Earth System Model (pyCECT v3.0)

NASA Astrophysics Data System (ADS)

Milroy, Daniel J.; Baker, Allison H.; Hammerling, Dorit M.; Jessup, Elizabeth R.

2018-02-01

The Community Earth System Model Ensemble Consistency Test (CESM-ECT) suite was developed as an alternative to requiring bitwise identical output for quality assurance. This objective test provides a statistical measurement of consistency between an accepted ensemble created by small initial temperature perturbations and a test set of CESM simulations. In this work, we extend the CESM-ECT suite with an inexpensive and robust test for ensemble consistency that is applied to Community Atmospheric Model (CAM) output after only nine model time steps. We demonstrate that adequate ensemble variability is achieved with instantaneous variable values at the ninth step, despite rapid perturbation growth and heterogeneous variable spread. We refer to this new test as the Ultra-Fast CAM Ensemble Consistency Test (UF-CAM-ECT) and demonstrate its effectiveness in practice, including its ability to detect small-scale events and its applicability to the Community Land Model (CLM). The new ultra-fast test facilitates CESM development, porting, and optimization efforts, particularly when used to complement information from the original CESM-ECT suite of tools.

The Global ECT-MRI Research Collaboration (GEMRIC): Establishing a multi-site investigation of the neural mechanisms underlying response to electroconvulsive therapy.

PubMed

Oltedal, Leif; Bartsch, Hauke; Sørhaug, Ole Johan Evjenth; Kessler, Ute; Abbott, Christopher; Dols, Annemieke; Stek, Max L; Ersland, Lars; Emsell, Louise; van Eijndhoven, Philip; Argyelan, Miklos; Tendolkar, Indira; Nordanskog, Pia; Hamilton, Paul; Jorgensen, Martin Balslev; Sommer, Iris E; Heringa, Sophie M; Draganski, Bogdan; Redlich, Ronny; Dannlowski, Udo; Kugel, Harald; Bouckaert, Filip; Sienaert, Pascal; Anand, Amit; Espinoza, Randall; Narr, Katherine L; Holland, Dominic; Dale, Anders M; Oedegaard, Ketil J

2017-01-01

Major depression, currently the world's primary cause of disability, leads to profound personal suffering and increased risk of suicide. Unfortunately, the success of antidepressant treatment varies amongst individuals and can take weeks to months in those who respond. Electroconvulsive therapy (ECT), generally prescribed for the most severely depressed and when standard treatments fail, produces a more rapid response and remains the most effective intervention for severe depression. Exploring the neurobiological effects of ECT is thus an ideal approach to better understand the mechanisms of successful therapeutic response. Though several recent neuroimaging studies show structural and functional changes associated with ECT, not all brain changes associate with clinical outcome. Larger studies that can address individual differences in clinical and treatment parameters may better target biological factors relating to or predictive of ECT-related therapeutic response. We have thus formed the Global ECT-MRI Research Collaboration (GEMRIC) that aims to combine longitudinal neuroimaging as well as clinical, behavioral and other physiological data across multiple independent sites. Here, we summarize the ECT sample characteristics from currently participating sites, and the common data-repository and standardized image analysis pipeline developed for this initiative. This includes data harmonization across sites and MRI platforms, and a method for obtaining unbiased estimates of structural change based on longitudinal measurements with serial MRI scans. The optimized analysis pipeline, together with the large and heterogeneous combined GEMRIC dataset, will provide new opportunities to elucidate the mechanisms of ECT response and the factors mediating and predictive of clinical outcomes, which may ultimately lead to more effective personalized treatment approaches.

Compact probing system using remote imaging for industrial plant maintenance

NASA Astrophysics Data System (ADS)

Ito, F.; Nishimura, A.

2014-03-01

Laser induced breakdown spectroscopy (LIBS) and endoscope observation were combined to design a remote probing device. We use this probing device to inspect a crack of the inner wall of the heat exchanger. Crack inspection requires speed at first, and then it requires accuracy. Once Eddy Current Testing (ECT) finds a crack with a certain signal level, another method should confirm it visually. We are proposing Magnetic particle Testing (MT) using specially fabricated the Magnetic Particle Micro Capsule (MPMC). For LIBS, a multichannel spectrometer and a Q-switch YAG laser were used. Irradiation area is 270 μm, and the pulse energy was 2 mJ. This pulse energy corresponds to 5-2.2 MW/cm2. A composite-type optical fiber was used to deliver both laser energy and optical image. Samples were prepared to heat a zirconium alloy plate by underwater arc welding in order to demonstrate severe accidents of nuclear power plants. A black oxide layer covered the weld surface and white particles floated on water surface. Laser induced breakdown plasma emission was taken into the spectroscope using this optical fiber combined with telescopic optics. As a result, we were able to simultaneously perform spectroscopic measurement and observation. For MT, the MPMC which gathered in the defective area is observed with this fiber. The MPMC emits light by the illumination of UV light from this optical fiber. The size of a defect is estimated with this amount of emission. Such technology will be useful for inspection repair of reactor pipe.

High resolution eddy current microscopy

NASA Astrophysics Data System (ADS)

Lantz, M. A.; Jarvis, S. P.; Tokumoto, H.

2001-01-01

We describe a sensitive scanning force microscope based technique for measuring local variations in resistivity by monitoring changes in the eddy current induced damping of a cantilever with a magnetic tip oscillating above a conducting sample. To achieve a high sensitivity, we used a cantilever with an FeNdBLa particle mounted on the tip. Resistivity measurements are demonstrated on a silicon test structure with a staircase doping profile. Regions with resistivities of 0.0013, 0.0041, and 0.022 Ω cm are clearly resolved with a lateral resolution of approximately 180 nm. For this range of resistivities, the eddy current induced damping is found to depend linearly on the sample resistivity.

Passive eddy-current damping as a means of vibration control in cryogenic turbomachinery

NASA Technical Reports Server (NTRS)

Cunningham, R. E.

1986-01-01

Lateral shaft vibrations produced by a rotating unbalance weight were damped by means of eddy currents generated in copper conductors that were precessing cyclicly in the gap formed by the pole faces of C-shaped, permanent magnets. The damper assembly, which was located at the lower bearing support of a vertically oriented rotor was completely immersed in liquid nitrogen during the test run. The test rotor was operated over a speed range from 800 to 10,000 rpm. Three magnet/conductor designs were evaluated. Experimental damping coefficients varied from 180 to 530 N sec/m. Reasonable agreement was noted for theoretical values of damping for these same assemblies. Values of damping coefficients varied from 150 to 780 N sec/m. The results demonstrate that passive eddy-current damping is a viable candidate for vibration control in cryogenic turbomachinery.

Efficacy and cognitive side effects of electroconvulsive therapy (ECT) in depressed elderly inpatients with coexisting mild cognitive impairment or dementia.

PubMed

Hausner, Lucrezia; Damian, Marinella; Sartorius, Alexander; Frölich, Lutz

2011-01-01

To study cognitive performance in depressed geriatric inpatients with or without preexisting cognitive impairment who received a first course of electroconvulsive therapy (ECT). Forty-four elderly inpatients with major depressive disorder (ICD-10 criteria) were included in a prospective consecutive case series of a university hospital. The patients were divided into 3 groups (no cognitive impairment [NCI], mild cognitive impairment [MCI], dementia) and rated for cognitive performance with the MMSE before first ECT, after sixth ECT, and 6 weeks and 6 months after ECT termination. Affective symptoms were rated by 21-item Hamilton Depression Rating Scale (HDRS-21) before and 6 weeks after ECT. Analysis of variance or Kruskal-Wallis tests on ECT-induced MMSE and HDRS-21 score changes were compared to baseline. Binary logistic regression was used for predictor analysis. The study was conducted from April 2004 to April 2008. After initial nonsignificant cognitive deterioration in all 3 groups, the NCI group improved cognitively 6 weeks (P = .018) and 6 months (P = .027) after ECT. The MCI group improved in cognition 6 months (P = .036) after ECT. In the dementia group, mean MMSE scores also improved numerically over the course of ECT without significance. Dementia patients with antidementia treatment improved in cognition to a clinically relevant extent after the sixth ECT. Dementia subjects without antidementia treatment deteriorated. After the sixth ECT, 70.0% of dementia patients (P = .004) presented a cognitive decline, and 68.8% of MCI patients (P < .001) presented a decline 6 weeks after ECT. Six months after ECT, one-third of the dementia patients (P < .036) still had a cognitive decline. Affective symptoms remitted after ECT in all 3 groups (P < .001). Pre-ECT cognitive deficits were the best predictor of MMSE decline (6 weeks after ECT, P = .007; 6 months after ECT, P = .055). ECT is effective and well tolerated in geriatric depressed inpatients regardless of preexisting cognitive impairment. Cognitive deficits were transient. © Copyright 2011 Physicians Postgraduate Press, Inc.

A quantitative comparison of two methods to correct eddy current-induced distortions in DT-MRI.

PubMed

Muñoz Maniega, Susana; Bastin, Mark E; Armitage, Paul A

2007-04-01

Eddy current-induced geometric distortions of single-shot, diffusion-weighted, echo-planar (DW-EP) images are a major confounding factor to the accurate determination of water diffusion parameters in diffusion tensor MRI (DT-MRI). Previously, it has been suggested that these geometric distortions can be removed from brain DW-EP images using affine transformations determined from phantom calibration experiments using iterative cross-correlation (ICC). Since this approach was first described, a number of image-based registration methods have become available that can also correct eddy current-induced distortions in DW-EP images. However, as yet no study has investigated whether separate eddy current calibration or image-based registration provides the most accurate way of removing these artefacts from DT-MRI data. Here we compare how ICC phantom calibration and affine FLIRT (http://www.fmrib.ox.ac.uk), a popular image-based multi-modal registration method that can correct both eddy current-induced distortions and bulk subject motion, perform when registering DW-EP images acquired with different slice thicknesses (2.8 and 5 mm) and b-values (1000 and 3000 s/mm(2)). With the use of consistency testing, it was found that ICC was a more robust algorithm for correcting eddy current-induced distortions than affine FLIRT, especially at high b-value and small slice thickness. In addition, principal component analysis demonstrated that the combination of ICC phantom calibration (to remove eddy current-induced distortions) with rigid body FLIRT (to remove bulk subject motion) provided a more accurate registration of DT-MRI data than that achieved by affine FLIRT.

Concurrent Electroconvulsive Therapy and Bupropion Treatment.

PubMed

Takala, Christopher R; Leung, Jonathan G; Murphy, Lauren L; Geske, Jennifer R; Palmer, Brian A

2017-09-01

Bupropion is associated with a dose-dependent increased risk of seizures. Use of concomitant bupropion and electroconvulsive therapy (ECT) remains controversial because of an increased risk of prolonged seizures. This is the first systematic evaluation of the effect of bupropion on ECT. A case group (n = 119), patients treated with concomitant ECT and bupropion, was compared with an age and gender frequency-matched control group (n = 261), treated with only ECT. Electroconvulsive therapy treatment data including seizure length, number of treatments, and concurrent medications were extracted. Longitudinal mixed models examined ECT versus ECT + bupropion group differences over the course of treatments measured by seizure duration (electroencephalogram [EEG] and motor). Multivariable models examined the total number of treatments and first and last seizure duration. All models considered group differences with ECT treatment measures adjusted for age, gender, benzodiazepine treatment, lead placement, and setting. Electroconvulsive therapy treatment with bupropion led to shorter motor seizure duration (0.047) and EEG seizure duration (P = 0.001). The number of ECT treatments (7.3 vs 7.0 treatments; P = 0.23), respectively, or the probability of a prolonged seizure (P = 0.15) was not significantly different. Benzodiazepine use was significantly more common in control subjects (P = 0.01). This is a retrospective analysis limited in part by unavailable variables (seizure threshold, nature of EEG and motor seizure monitoring, type of ECT device, dosing and formulation of bupropion, and duration of the current depressive illness). This study revealed a significantly shorter duration in seizure length with ECT + concomitant bupropion, but not in the number of required treatments in those treated compared with ECT without bupropion. There remains a critical need to reevaluate the efficacy of concomitant use of psychotropic medications + ECT.

Eddy current nondestructive testing device for measuring variable characteristics of a sample utilizing Walsh functions

DOEpatents

Libby, Hugo L.; Hildebrand, Bernard P.

1978-01-01

An eddy current testing device for measuring variable characteristics of a sample generates a signal which varies with variations in such characteristics. A signal expander samples at least a portion of this generated signal and expands the sampled signal on a selected basis of square waves or Walsh functions to produce a plurality of signal components representative of the sampled signal. A network combines these components to provide a display of at least one of the characteristics of the sample.

Cognitive training to improve memory in individuals undergoing electroconvulsive therapy: Negative findings.

PubMed

Choi, Jimmy; Wang, Yuanjia; Feng, Tianshu; Prudic, Joan

2017-09-01

Although electroconvulsive therapy (ECT) remains the most effective treatment for severe depression, some patients report persistent memory problems following ECT that impact their quality of life and their willingness to consent to further ECT. While cognitive training has been shown to improve memory performance in various conditions, this approach has never been applied to help patients regain their memory after ECT. In a double-blind study, we tested the efficacy of a new cognitive training program called Memory Training for ECT (Mem-ECT), specifically designed to target anterograde and retrograde memory that can be compromised following ECT. Fifty-nine patients with treatment-resistant depression scheduled to undergo ultra-brief right unilateral ECT were randomly assigned to either: (a) Mem-ECT, (b) active control comprised of nonspecific mental stimulation, or (c) treatment as usual. Participants were evaluated within one week prior to the start of ECT and then again within 2 weeks following the last ECT session. All three groups improved in global function, quality of life, depression, and self-reported memory abilities without significant group differences. While there was a decline in verbal delayed recall and mental status, there was no decline in general retrograde memory or autobiographical memory in any of the groups, with no significant memory or clinical benefit for the Mem-ECT or active control conditions compared to treatment as usual. While we report negative findings, these results continue to promote the much needed discussion on developing effective strategies to minimize the adverse memory side effects of ECT, in hopes it will make ECT a better and more easily tolerated treatment for patients with severe depression who need this therapeutic option. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pattern of electroconvulsive therapy use in Spain: Proposals for an optimal practice and equitable access.

PubMed

Sanz-Fuentenebro, Javier; Vera, Ignacio; Verdura, Ernesto; Urretavizcaya, Mikel; Martínez-Amorós, Erika; Soria, Virginia; Bernardo, Miquel

The main aims of our study were to estimate the current rates and pattern of electroconvulsive therapy (ECT) use in Spain, as well as exploring the causes that may be limiting its use in our country. A cross-sectional survey was conducted covering every psychiatric unit in Spain as of 31 December 2012. More than half (54.9%) of the psychiatric units applied ECT at a rate of 0.66 patients per 10,000 inhabitants. There are wide variations with regard to ECT application rates between the different autonomous communities (0.00-1.39) and provinces (0.00-3.90). ECT was prescribed to a mean of 25.5 patients per hospital that used the technique and 4.5 in referral centre (P=.000), but wide differences were reported in the number of patients who were prescribed ECT from hospital to hospital. Although the percentage of psychiatric units applying ECT in our country is among the highest in the world, the ECT application rate in Spain is among the lowest within western countries. Large differences in ECT use have been reported across the various autonomous communities, provinces and hospitals. Thus, health planning strategies need to be implemented, as well as promoting training in ECT among health professionals, if these differences in ECT use are to be reduced. Copyright © 2016 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

Significantly improved neurocognitive function in major depressive disorders 6 weeks after ECT.

PubMed

Mohn, Christine; Rund, Bjørn Rishovd

2016-09-15

Cognitive side effects may occur after electroconvulsive treatment (ECT) in depressive disorder patients. Previous studies have been limited by small numbers of cognitive functions assessed. The present study reports the first results from a prospective project monitoring cognitive effects of ECT using a comprehensive neuropsychological test battery and subjective report of everyday cognitive function. Thirty-one patients with major depressive disorder were assessed with the MATRICS Consensus Cognitive Battery (MCCB). Subjective cognitive complaints were described with the Everyday Memory Questionnaire (EMQ). Severity of depression symptoms were assessed with the Montgomery-Åsberg Depression Rating Scale (MADRS). These assessments were performed prior to and 6 weeks after non-standardized ECT. Compared to baseline, the mean depression severity level was nearly halved and there were significant improvements in mean levels of Speed of Processing, Attention/Vigilance, and Visual Learning 6 weeks after ECT. The other cognitive domains were not altered from baseline. There was no significant change in subjective cognitive complaints. At baseline, there were several significant correlations between the MADRS and MCCB scores. There was no strong association between the EMQ and MCCB scores at either assessment point, but the post-ECT EMQ score was significantly correlated with depression severity. Major limitations were low N and lack of uniform ECT procedure. There was significant improvement in Speed of Processing, Attention/Vigilance, and Visual Learning 6 weeks after ECT. Cognitive tests scores were related to severity of depression, but not to subjective memory complaints. Copyright © 2016 Elsevier B.V. All rights reserved.

Focal Electrically Administered Seizure Therapy (FEAST): A novel form of ECT illustrates the roles of current directionality, polarity, and electrode configuration in seizure induction

PubMed Central

Spellman, Timothy; Peterchev, Angel V.; Lisanby, Sarah H.

2009-01-01

Electroconvulsive therapy (ECT) is a mainstay in the treatment of severe, medication resistant depression. The antidepressant efficacy and cognitive side effects of ECT are influenced by the position of the electrodes on the head and by the degree to which the electrical stimulus exceeds the threshold for seizure induction. However, surprisingly little is known about the effects of other key electrical parameters such as current directionality, polarity, and electrode configuration. Understanding these relationships may inform the optimization of therapeutic interventions to improve their risk/benefit ratio. To elucidate these relationships, we evaluated a novel form of ECT (focal electrically administered seizure therapy, FEAST) that combines unidirectional stimulation, control of polarity, and an asymmetrical electrode configuration, and contrasted it with conventional ECT in a nonhuman primate model. Rhesus monkeys had their seizure thresholds determined on separate days with ECT conditions that crossed the factors of current directionality (unidirectional or bidirectional), electrode configuration (standard bilateral or FEAST (small anterior and large posterior electrode)), and polarity (assignment of anode and cathode in unidirectional stimulation). Ictal expression and post-ictal suppression were quantified via scalp EEG. Findings were replicated and extended in a second experiment with the same subjects. Seizures were induced in each of 75 trials, including 42 FEAST procedures. Seizure thresholds were lower with unidirectional than with bidirectional stimulation (p<0.0001), and lower in FEAST than in bilateral ECS (p=0.0294). Ictal power was greatest in posterior-anode unidirectional FEAST, and post-ictal suppression was strongest in anterior-anode FEAST (p=0.0008 and p=0.0024, respectively). EEG power was higher in the stimulated hemisphere in posterior-anode FEAST (p=0.0246), consistent with the anode being the site of strongest activation. These findings suggest that current directionality, polarity, and electrode configuration influence the efficiency of seizure induction with ECT. Unidirectional stimulation and novel electrode configurations such as FEAST are two approaches to lowering seizure threshold. Furthermore, the impact of FEAST on ictal and post-ictal expression appeared to be polarity-dependent. Future studies may examine whether these differences in seizure threshold and expression have clinical significance for patients receiving ECT. PMID:19225453

Focal electrically administered seizure therapy: a novel form of ECT illustrates the roles of current directionality, polarity, and electrode configuration in seizure induction.

PubMed

Spellman, Timothy; Peterchev, Angel V; Lisanby, Sarah H

2009-07-01

Electroconvulsive therapy (ECT) is a mainstay in the treatment of severe, medication-resistant depression. The antidepressant efficacy and cognitive side effects of ECT are influenced by the position of the electrodes on the head and by the degree to which the electrical stimulus exceeds the threshold for seizure induction. However, surprisingly little is known about the effects of other key electrical parameters such as current directionality, polarity, and electrode configuration. Understanding these relationships may inform the optimization of therapeutic interventions to improve their risk/benefit ratio. To elucidate these relationships, we evaluated a novel form of ECT (focal electrically administered seizure therapy, FEAST) that combines unidirectional stimulation, control of polarity, and an asymmetrical electrode configuration, and contrasted it with conventional ECT in a nonhuman primate model. Rhesus monkeys had their seizure thresholds determined on separate days with ECT conditions that crossed the factors of current directionality (unidirectional or bidirectional), electrode configuration (standard bilateral or FEAST (small anterior and large posterior electrode)), and polarity (assignment of anode and cathode in unidirectional stimulation). Ictal expression and post-ictal suppression were quantified through scalp EEG. Findings were replicated and extended in a second experiment with the same subjects. Seizures were induced in each of the 75 trials, including 42 FEAST procedures. Seizure thresholds were lower with unidirectional than with bidirectional stimulation (p<0.0001), and lower in FEAST than in bilateral ECS (p=0.0294). Ictal power was greatest in posterior-anode unidirectional FEAST, and post-ictal suppression was strongest in anterior-anode FEAST (p=0.0008 and p=0.0024, respectively). EEG power was higher in the stimulated hemisphere in posterior-anode FEAST (p=0.0246), consistent with the anode being the site of strongest activation. These findings suggest that current directionality, polarity, and electrode configuration influence the efficiency of seizure induction with ECT. Unidirectional stimulation and novel electrode configurations such as FEAST are two approaches to lowering seizure threshold. Furthermore, the impact of FEAST on ictal and post-ictal expression appeared to be polarity dependent. Future studies may examine whether these differences in seizure threshold and expression have clinical significance for patients receiving ECT.

Post-tensioning tendon force loss detection using low power pulsed eddy current measurement

NASA Astrophysics Data System (ADS)

Kim, Ji-Min; Lee, Jun; Sohn, Hoon

2018-04-01

In the field of bridge engineering, pre-fabrication of a bridge member and its construction in site have been issued and studied, which achieves improved quality and rapid construction. For integration of those pre-fabricated segments into a structural member (i.e., a concrete slab, girder and pier), post-tensioning (PT) technique is adopted utilizing a high-strength steel tendon, and an effective investigation of the remaining PT tendon force is essential to assure an overall structural integrity. This study proposes a pulsed eddy current based tendon force loss detection system. A compact eddy current sensor is designed to be installed on the surface of an anchor holding a steel PT tendon. The intensity of the induced eddy current varies with PT tendon force alteration due to the magnetostriction effect of a ferromagnetic material. The advantages of the proposed system are as follows: (1) low power consumption, (2) rapid inspection, and (3) simple installation. Its performance was validated experimentally in a full-scale lab test of a 3.3-m long, 15.2-mm diameter mono-tendon that was tensioned using a universal testing machine. Tendon force was controlled from 20 to 180 kN with 20 kN interval, and eddy current responses were measured and analyzed at each force condition. The proposed damage index and the amount of force loss of PT tendon were monotonically related, and an excessive loss as much as 30 % of an initially-introduced tendon force was successfully predicted.

Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-6, Operation of Eddy Current Test Equipment.

ERIC Educational Resources Information Center

Espy, John; Selleck, Ben

This sixth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II details eddy current examination of steam generator tubing. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

Influence of GRIK4 genetic variants on the electroconvulsive therapy response.

PubMed

Minelli, Alessandra; Congiu, Chiara; Ventriglia, Mariacarla; Bortolomasi, Marco; Bonvicini, Cristian; Abate, Maria; Sartori, Riccardo; Gainelli, Giulio; Gennarelli, Massimo

2016-07-28

Several lines of evidence have shown the involvement of the glutamatergic system in the function of electroconvulsive therapy (ECT). In particular, patients with treatment resistant depression (TRD) and chronic depression have lower levels of glutamate/glutamine than controls, and ECT can reverse this deficit. Genetic factors might contribute to modulating the mechanisms underlying ECT. This study aimed to evaluate the relationship between three polymorphisms (rs1954787, rs4936554 and rs11218030) of the glutamate receptor ionotropic kainate 4 (GRIK4) gene and responsiveness to ECT treatment in a sample of one hundred individuals, TRD or depressive Bipolar Disorder patients resistant to pharmacological treatments. The results revealed that GRIK4 variants were significantly associated with the response to ECT. In particular, we found that patients carrying the G allele of the GRIK4 rs11218030 had a significantly poorer response to ECT (p=2.71×10(-4)), showing five times the risk of relapse after ECT compared to the AA homozygotes. Analogously, patients carrying the GG rs1954787 genotype and rs4936554A allele carriers presented a double risk of lack of response after ECT (p=0.013 and p=0.040, respectively). In conclusion, the current study provides new evidence, indicating that some GRIK4 variants modulate the response to ECT in patients with depression resistant to treatment, suggesting a role for kainate receptor modulation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

Deng, Zhi-De

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

Is electroconvulsive therapy safe in the presence of an intracranial metallic object?: case report and review of the literature.

PubMed

Mortier, Philippe; Sienaert, Pascal; Bouckaert, Filip

2013-09-01

Little is known about the use of electroconvulsive therapy (ECT) in patients with intracranial metallic objects. Theoretically, electric current might cause heating of the metal and damage of the surrounding brain tissue. Moreover, intracranial foreign objects increase the risk for epileptic phenomena and could thus complicate the treatment course. The case of a man with intracranial bullet fragments as a result of a headshot, treated with ECT for mania, is presented. We conducted a PubMed literature search for other relevant cases. In our patient, ECT was completed without complication. Electroconvulsive therapy was safely administered in 22 published cases of patients with intracranial metallic objects. After carefully weighing benefits and risks in each individual case, psychiatrists should not be reluctant to use ECT in patients with intracranial metallic objects. Apart from avoiding empirical dosage titration to minimize the exposure to current, positioning the electrodes to avoid the electric current of heating the metal, and continuing antiepileptic agents in high-risk patients, no precautions need to be considered.

State of the art: nursing knowledge and electroconvulsive therapy.

PubMed

Froimson, L; Creed, P; Mathew, L

1995-09-01

Nursing services attempting to develop standards for their own facilities will find limited literature specific to nursing and electroconvulsive therapy (ECT) in American publications. From 1966 to December 1994, there were only 19 publications in American nursing journals that provide a specific focus on nursing and ECT. Only one of these articles reported research findings. Twenty-seven citations in Convulsive Therapy included nurse contributors. While the APA Task Force on the Practice of ECT has addressed educational needs of nursing and technical elements of the procedure, there do not currently exist specific standards for nursing practice in ECT. Concerns salient to nursing that have generated articles by nurses include instruction of patients, support to patients and families, safety of patients, assessment of clinical status, informed consent, and nurses' and patients' attitudes about ECT. Nurses are encouraged to join their physician-colleagues in developing and disseminating the information needed for the field of nursing to contribute its own expertise to the care of patients receiving ECT.

Improving relapse prevention after successful electroconvulsive therapy for patients with severe depression: completed audit cycle involving 102 full electroconvulsive therapy courses in West Sussex, United kingdom.

PubMed

Atiku, Leonard; Gorst-Unsworth, Caroline; Khan, Barkath Ulla; Huq, Fuad; Gordon, Jackie

2015-03-01

The aim of this study was to determine whether current guidance or consensus regarding continuation pharmacotherapy after successful electroconvulsive therapy (ECT) was being followed by referring clinicians in West Sussex, United Kingdom. A complete audit cycle examining psychotropic medication after successful ECT for patients with severe depression was performed. Clinical and ECT records (electronic and paper) were reviewed, and relapse rates in the 4 commonly prescribed psychotropic medication groups were compared. The pattern of relapse in the 4 groups was similar for both audits 1 and 2. Taking the 102 patients as a whole, the lowest relapse rates were recorded for patients taking a combination of an antidepressant and lithium (16% relapsed within 6 months of successful ECT). Patients taking a combination of antipsychotic and antidepressants fared the worst with 75% relapse rate. This was followed by those taking a combination of antidepressant and a mood stabilizer (other than lithium) (69%). Patients taking antidepressant(s) only were associated with a relapse rate of 60%. Audit 2 demonstrated that clinicians did not change their prescribing practices for their patients after successful ECT despite the efforts made in widely disseminating the results of audit 1. In particular, there was no increase in the use of lithium. Not all psychotropic medication prescribing for patients receiving ECT for depression followed available and current guidance or consensus. More needs to be done to understand the reasons for the reluctance to use lithium if relapse rates after ECT are to improve.

Corrosion Detection in Airframes Using a New Flux-Focusing Eddy Current Probe

NASA Technical Reports Server (NTRS)

Fulton, James P.; Wincheski, Buzz; Nath, Shridhar; Namkung, Min

1994-01-01

A new flux-focusing eddy current probe was recently developed at NASA Langley Research Center. The new probe is similar in design to a reflection type eddy current probe, but is unique in that it does not require the use of an impedance bridge for balancing. The device monitors the RMS output voltage of a pickup coil and, as a result, is easier to operate and interpret than traditional eddy current instruments. The unique design feature of the probe is a ferromagnetic cylinder, typically 1020 steel, which separates a concentrically positioned drive and pickup coil. The increased permeability of the steel causes the magnetic flux produced by the drive coil to be focused in a ring around the pickup coil. At high frequencies the eddy currents induced in both the sample and the cylinder allow little or no flux to link with the pickup coil. This results in a self-nulling condition which has been shown to be useful for the unambiguous detection of cracks in conducting materials. As the frequency is lowered the flux produced by the drive coil begins to link with the pickup coil causing an output which, among other things, is proportional to the thickness of the test specimen. This enables highly accurate measurements of the thickness of conducting materials and helps to facilitate the monitoring of thickness variations in a conducting structure such as an aircraft fuselage. Under ideal laboratory conditions the probe can sense thickness changes on the order of 1% as illustrated. However, this is highly dependent upon the thickness, and the geometric complexity of the sample being tested and for practical problems the sensitivity is usually much less. In this presentation we highlight some of the advantages and limitations in using the probe to inspect aircraft panels for corrosion and other types of material nonuniformities. In particular, we present preliminary results which illustrate the probes capabilities for detecting first and second layer corrosion in aircraft panels which may contain air gaps between the layers. Since the probe utilized eddy currents its corrosion detection capabilities are similar to convectional eddy current techniques, but the new probe is much easier to use.

Testing the predictions of the existential constructivist theory of suicide in a college student sample.

PubMed

Lockman, Jennifer D; Servaty-Seib, Heather L

2018-04-01

There is a lack of empirically supported theories explaining suicidal ideation and few theories describe how suicidal ideation can be prevented in the context of normative human development. Rogers (2001) proposed an existential constructivist theory of suicide (ECTS) wherein existential distress and the inability to reconstruct meaning from adverse life events contribute to suicidal ideation. The ECTS includes a distinct focus on meaning reconstruction from adverse life events, which is congruent with existing research on college students and developmental frameworks used by counseling psychologists. Thus, in the present study, we tested the predictions of the ECTS in a college student sample. We collected data online from 195 college students (i.e., ages 18-25) attending a large, Midwestern university and analyzed the data using structural equation modeling. Findings provided partial support for the original ECTS. Post hoc analyses of an alternate ECTS model indicated that existential distress mediated the negative association between meaning reconstruction and suicidal ideation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Propofol interruption of ECT seizure to reduce side-effects: a pilot study.

PubMed

Warnell, Ronald L; Swartz, Conrad M; Thomson, Alice

2010-01-30

Fifteen depressed subjects received six bitemporal electroconvulsive therapy (ECT) treatments under etomidate anesthesia. They were randomized to blindly either receive propofol 0.5mg/kg 15s post-stimulus or not. Propofol infusion significantly prevented long seizures, and prevented cognitive decrements in most neuropsychological tests, several significantly. Propofol interruption may clinically help reduce ECT side-effects.

Flowpath evaluation and reconnaissance by remote field Eddy current testing (FERRET)

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

Smoak, A.E.; Zollinger, W.T.

1993-12-31

This document describes the design and development of FERRET (Flowpath Evaluation and Reconnaisance by Remote-field Eddy current Testing). FERRET is a system for inspecting the steel pipes which carry cooling water to underground nuclear waste storage tanks. The FERRET system has been tested in a small scale cooling pipe mock-up, an improved full scale mock-up, and in flaw detection experiments. Early prototype designs of FERRET and the FERRET launcher (a device which inserts, moves, and retrieves probes from a piping system) as well as the field-ready design are discussed.

Early effects of modern electroconvulsive therapy on subjective memory in patients with mania or depression

PubMed Central

Bag, Sevda; Canbek, Ozge; Atagun, Ilhan Murat; Kutlar, Tarik Mehmet

2016-01-01

Context: Although electroconvulsive therapy (ECT) is considered a very effective tool for the treatment of psychiatric diseases, memory disturbances are among the most important adverse effects. Aims: This study aimed to assess prospectively early subjective memory complaints in depressive and manic patients due to bilateral, brief-pulse ECT, at different stages of the treatment, compare the associations between psychiatric diagnosis, sociodemographic characteristics, and ECT characteristics. Settings and Design: This prospective study was done with patients undergoing ECT between November 2008 and April 2009 at a tertiary care psychiatry hospital of 2000 beds. Materials and Methods: A total of 140 patients, scheduled for ECT with a diagnosis of bipolar disorder (depressive or manic episode) or unipolar depression according to Diagnostic and Statistical Manual of Mental Disorders IV diagnostic criteria, were included in the study and invited to complete the Squire Subjective Memory Questionnaire (SSMQ) before ECT, after the first and third sessions and end of ECT treatment. Statistical Analysis: Mean values were compared with the Kruskal–Wallis test and comparison of the longitudinal data was performed with a nonparametric longitudinal data analysis method, F1_LD_F1 design. Results: SSMQ scores of the patients before ECT were zero. SSMQ scores showed a decrease after the first and third ECT sessions and before discharge, showing a memory disturbance after ECT and were significantly less severe in patients with mania in comparison to those with depression. Conclusions: These findings suggest an increasing degree of subjective memory complaints with bilateral brief-pulse ECT parallel to the increasing number of ECT sessions. PMID:27385854

Fast valve based on double-layer eddy-current repulsion for disruption mitigation in Experimental Advanced Superconducting Tokamak.

PubMed

Zhuang, H D; Zhang, X D

2015-05-01

A fast valve based on the double-layer eddy-current repulsion mechanism has been developed on Experimental Advanced Superconducting Tokamak (EAST). In addition to a double-layer eddy-current coil, a preload system was added to improve the security of the valve, whereby the valve opens more quickly and the open-valve time becomes shorter, making it much safer than before. In this contribution, testing platforms, open-valve characteristics, and throughput of the fast valve are discussed. Tests revealed that by choosing appropriate parameters the valve opened within 0.15 ms, and open-valve times were no longer than 2 ms. By adjusting working parameter values, the maximum number of particles injected during this open-valve time was estimated at 7 × 10(22). The fast valve will become a useful tool to further explore disruption mitigation experiments on EAST in 2015.

[Efficacy of continuation and maintenance electroconvulsive therapy (c/m ECT) in the treatment of patients with therapy-resistant affective disorders: a retrospective analysis].

PubMed

Post, Thomas; Kemmler, Georg; Krassnig, Tristan; Brugger, Anita; Hausmann, Armand

2015-01-01

Continuation and maintenance electroconvulsive therapy (c/m ECT) is a long-term treatment option in severely and chronically ill patients with mood disorders, who are unresponsive or intolerant to medication. Due to the current lack of empirical studies, c/m ECT is still a clinical tool with little evidence. We conducted a retrospective analysis of patients' charts who received c/m ECT over a 10-year period. Outcome was measured by comparing the number of pre-c/m ECT and post-c/m ECT hospitalizations, as well as inpatient days per year and mean duration of hospital stays. In 19 patients (63% female; mean age 53.5 ± 12.0 years) with either bipolar (42%) or unipolar (58%) mood disorder, with the majority of patients suffering from a depressive episode at hospital admission (95%), c/m ECT was initiated after a successful series of ECT. In a 5-year interval before and after starting c/m ECT the number of hospitalizations per year (0.87 vs. 0.28, p < 0.001), inpatient days per year (30.8 vs. 4.5 days, p < 0.001), as well as the mean duration of hospital days (30.5 vs. 16.7 days, p = 0.02) decreased significantly. Our data support previous results showing that c/m ECT is an efficacious option in treating and favourably altering the course of therapy-resistant affective disorders. Further research using a controlled study design and larger sample sizes are needed to convincingly define indication and performance of c/m ECT.

Are reports of cognitive testing among older electroconvulsive therapy recipients clinically valid?

PubMed

Plakiotis, Chris; Chin, Loi Fei; O'Connor, Daniel W

2014-03-01

Electroconvulsive therapy (ECT) administration rises in frequency with age, with older depressed adults often showing clinical features predictive of good response. Recent reviews suggest that older people experience few if any long-term cognitive adverse effects after contemporary ECT, despite their increased vulnerability to these. However, the broader clinical validity of research findings is not assured as most studies of ECT-related cognitive effects do not discuss cognitive test nonparticipants. This study examines whether cognitive test participants and nonparticipants are comparable. We recently completed a study of cognition in depressed patients 65 years and older treated with ECT. Only 35% of eligible patients completed neuropsychological testing at 2 time points, the remainder either refusing or unable to consent. To examine whether exclusion of most eligible patients from cognitive testing might have affected the clinical applicability of findings, we compared demographic and clinical characteristics of patients who participated with those who did not based on a subset of patients from our original study. The 2 patient groups differed in several respects. Most notably, nonparticipants were significantly more likely to be involuntary patients; to refuse food and fluids; and to require treatment with a bitemporal or mixed electrode placement. Our findings suggest cognitive test nonparticipants to be more severely psychiatrically unwell than test participants. As their exclusion might bias results and confound understanding of this important ECT-related topic, special mention of participation rates and comparison of participants and nonparticipants is recommended to establish the clinical relevance of future study findings.

Eddy current testing of composite pressure vessels

NASA Astrophysics Data System (ADS)

Casperson, R.; Pohl, R.; Munzke, D.; Becker, B.; Pelkner, M.

2018-04-01

The use of composite pressure vessels instead of conventional vessels made of steel or aluminum grew strongly over the last decade. The reason for this trend is the tremendous weight saving in the case of composite vessels. However, the long-time behavior is not fully understood for filling and discharging cycles and creep strength and their influence on the CFRP coating (carbon fiber reinforced plastics) and the internal liner (steel, aluminum, or plastics). The CFRP ensures the pressure resistance while the inner liner is used as a container for liquid or gas. To overcome the missing knowledge of aging, BAM started an internal project to investigate degradation of these material systems. Therefore, applicable testing methods like eddy current testing are needed. Normally, high-frequency eddy current testing (HF-ET, f > 10 MHz) is deployed for CFRP due to its low conductivity of the fiber, which is in the order of 0.01 MS/s, and the capacitive coupling between the fibers. Nevertheless, in some cases conventional ET can be applied. We show a concise summary of studies on the application of conventional ET of composite pressure vessels.

Rocuronium-sugammadex use for electroconvulsive therapy in a hemodialysis patient: a case report.

PubMed

Kurita, Shigeaki; Moriwaki, Katsuyuki; Shiroyama, Kazuhisa; Sanuki, Mikako; Toyota, Yukari; Takebayashi, Minoru

2016-01-01

Recently, rocuronium with subsequent use of sugammadex was proposed for electroconvulsive therapy (ECT) as an alternative to succinylcholine. Because sugammadex is cleared via the kidney with no metabolism, it is unknown that rocuronium-sugammadex use is safe in hemodialysis patients who received ECT. In this case report, we used rocuronium with subsequent administration of sugammadex in a 69-year-old female, hemodialysis patient, scheduled for ten ECT sessions for severe major depression. In the initial eight sessions, we tested the feasibility of rocuronium-sugammadex use for ECT. During the series of four ECT sessions, we measured plasma concentrations for the sum of sugammadex and sugammadex-rocuronium complex and observed whether possible residual sugammadex affected muscle relaxation during subsequent sessions of ECT. The results showed the feasibility of rocuronium-sugammadex use as muscle relaxants for ECT in patients undergoing hemodialysis. However, an accumulation of sugammadex did occur even after two sessions of hemodialysis, and residual sugammadex decreased the effect of the rocuronium given in the subsequent ECT sessions. Rocuronium-sugammadex was successfully utilized as muscle relaxants for ECT in this patient. Our experience in this case may indicate that if succinylcholine is contraindicated, rocuronium-sugammadex can be an alternative method for muscle relaxation during ECT in patients undergoing hemodialysis. When this rocuronium-sugammadex procedure is used, the effect of residual sugammadex after hemodialysis on the subsequently administered rocuronium should be considered.

Development of Eddy Current Techniques for Detection of Deep Fatigue Cracks in Multi-Layer Airframe Components

NASA Technical Reports Server (NTRS)

Wincheski, Russell A.

2008-01-01

Thick, multi-layer aluminum structure has been widely used in aircraft design in critical wing splice areas. The multi-layer structure generally consists of three or four aluminum layers with different geometry and varying thickness, which are held together with fasteners. The detection of cracks under fasteners with ultrasonic techniques in subsurface layers away from the skin is impeded primarily by interlayer bonds and faying sealant condition. Further, assessment of such sealant condition is extremely challenging in terms of complexity of structure, limited access, and inspection cost. Although Eddy current techniques can be applied on in-service aircraft from the exterior of the skin without knowing sealant condition, the current eddy current techniques are not able to detect defects with wanted sensitivity. In this work a series of low frequency eddy current probes have been designed, fabricated and tested for this application. A probe design incorporating a shielded magnetic field sensor concentrically located in the interior of a drive coil has been employed to enable a localized deep diffusion of the electromagnetic field into the part under test. Due to the required low frequency inspections, probes have been testing using a variety of magnetic field sensors (pickup coil, giant magneto-resistive, anisotropic magneto-resistive, and spin-dependent tunneling). The probe designs as well as capabilities based upon a target inspection for sub-layer cracking in an airframe wing spar joint is presented.

Electroconvulsive Therapy in Women: A Retrospective Study from a Mental Health Hospital in Turkey.

PubMed

Özdemir, Armağan; Poyraz, Cana Aksoy; Erten, Evrim; Çırakoğlu, Emre; Tomruk, Nesrin

2016-12-01

The aim was to evaluate the clinical profile and effectiveness of ECT in women. A retrospective chart review was carried out to identify female patients who had received ECT during the period September 2013-February 2015. Details regarding their sociodemographic, clinical, and treatment data were extracted from these records for the present study. The total number of patients, admitted to our psychiatry inpatient clinic during the survey period, was 802. During this period, 26 (3.24 %) female patients received ECT. Patients who received ECT were mostly in age group of 25-44 years (76.9 %). Twenty percent of patients were in the postpartum period. Psychotic disorders (46.1 %) was the most common diagnosis for which ECT was used, followed by bipolar affective disorder, current episode manic (19.2 %). At the end of ECT courses, 70 % of the patients showed good response with a CGI-I of 1 or 2, and 30 % showed minimal response with a CGI-I score of 3. The most common side effects were post-ECT confusion (15.4 %) and prolonged seizure (11.5 %). This rate of prolonged seizure was higher the rates reported in the literature. The bronchospasm related with remifentanil, post-ECT bradycardia, hypertensive crisis and oligohydramnios were also reported in one case each. ECT is a safe and effective treatment option in women with severe psychiatric disorders and disorders in the perinatal/postpartum period are a major area of ECT use. The female gender may be a contributing factor for the higher rates of prolonged seizure.

Electroconvulsive Therapy Hasn’t Negative Effects on Short-Term Memory Function, as Assessed Using a Bedside Hand-Held Device

PubMed Central

Müller, Helge H.O.; Reike, Mareen; Grosse-Holz, Simon; Röther, Mareike; Lücke, Caroline; Philipsen, Alexandra; Kornhuber, Johannes; Grömer, Teja W.

2017-01-01

Electroconvulsive therapy (ECT) is effective in the treatment of treatment-resistant major depression. The fear of cognitive impairment after ECT often deters patients from choosing this treatment option. There is little reliable information regarding the effects of ECT on overall cognitive performance, while short-term memory deficits are well known but not easy to measure within clinical routines. In this pilot study, we examined ECT recipients’ pre- and post-treatment performances on a digital ascending number tapping test. We found that cognitive performance measures exhibited good reproducibility in individual patients and that ECT did not significantly alter cognitive performance up to 2 hours after this therapy was applied. Our results can help patients and physicians make decisions regarding the administration of ECT. Digital measurements are recommended, especially when screening for the most common side effects on cognitive performance and short-term memory. PMID:28748058

Electroconvulsive Therapy Hasn't Negative Effects on Short-Term Memory Function, as Assessed Using a Bedside Hand-Held Device.

PubMed

Müller, Helge H O; Reike, Mareen; Grosse-Holz, Simon; Röther, Mareike; Lücke, Caroline; Philipsen, Alexandra; Kornhuber, Johannes; Grömer, Teja W

2017-03-22

Electroconvulsive therapy (ECT) is effective in the treatment of treatment-resistant major depression. The fear of cognitive impairment after ECT often deters patients from choosing this treatment option. There is little reliable information regarding the effects of ECT on overall cognitive performance, while short-term memory deficits are well known but not easy to measure within clinical routines. In this pilot study, we examined ECT recipients' pre- and post-treatment performances on a digital ascending number tapping test. We found that cognitive performance measures exhibited good reproducibility in individual patients and that ECT did not significantly alter cognitive performance up to 2 hours after this therapy was applied. Our results can help patients and physicians make decisions regarding the administration of ECT. Digital measurements are recommended, especially when screening for the most common side effects on cognitive performance and short-term memory.

The Depth Limits of Eddy Current Testing for Defects: A Computational Investigation and Smooth-Shaped Defect Synthesis from Finite Element Optimization

DTIC Science & Technology

2015-04-22

AND SUBTITLE 5a. CONTRACT NUMBER W56HZV-07-2-0001 W56HZV-08- C - 0236 The Depth Limits of Eddy Current Testing for Defects: A...Unlimited b. ABSTRACT Unlimited c . THIS PAGE Unlimited Unlimited 12 19b. TELEPHONE NUMBER (include area code) 586-282-6471 Standard Form 298...Dave Gunter, Acting Associate Director, Analytics, US Army TARDEC  Dr. Dave Horner, Director, DoD HPC Mod Program  Mr. Steve Knott , Deputy

Eddy current X-Y scanner system

NASA Technical Reports Server (NTRS)

Kurtz, G. W.

1983-01-01

The Nondestructive Evaluation Branch of the Materials and Processes Laboratory became aware of a need for a miniature, portable X-Y scanner capable of performing eddy current or other nondestructive testing scanning operations such as ultrasonic, or small areas of flat plate. The technical description and operational theory of the X-Y scanner system designed and built to fulfill this need are covered. The scanner was given limited testing and performs according to its design intent, which is to scan flat plate areas of approximately 412 sq cm (64 sq in) during each complete cycle of scanning.

PSF mapping-based correction of eddy-current-induced distortions in diffusion-weighted echo-planar imaging.

PubMed

In, Myung-Ho; Posnansky, Oleg; Speck, Oliver

2016-05-01

To accurately correct diffusion-encoding direction-dependent eddy-current-induced geometric distortions in diffusion-weighted echo-planar imaging (DW-EPI) and to minimize the calibration time at 7 Tesla (T). A point spread function (PSF) mapping based eddy-current calibration method is newly presented to determine eddy-current-induced geometric distortions even including nonlinear eddy-current effects within the readout acquisition window. To evaluate the temporal stability of eddy-current maps, calibration was performed four times within 3 months. Furthermore, spatial variations of measured eddy-current maps versus their linear superposition were investigated to enable correction in DW-EPIs with arbitrary diffusion directions without direct calibration. For comparison, an image-based eddy-current correction method was additionally applied. Finally, this method was combined with a PSF-based susceptibility-induced distortion correction approach proposed previously to correct both susceptibility and eddy-current-induced distortions in DW-EPIs. Very fast eddy-current calibration in a three-dimensional volume is possible with the proposed method. The measured eddy-current maps are very stable over time and very similar maps can be obtained by linear superposition of principal-axes eddy-current maps. High resolution in vivo brain results demonstrate that the proposed method allows more efficient eddy-current correction than the image-based method. The combination of both PSF-based approaches allows distortion-free images, which permit reliable analysis in diffusion tensor imaging applications at 7T. © 2015 Wiley Periodicals, Inc.

A Novel Strategy for Continuation ECT in Geriatric Depression: Phase 2 of the PRIDE Study.

PubMed

Kellner, Charles H; Husain, Mustafa M; Knapp, Rebecca G; McCall, W Vaughn; Petrides, Georgios; Rudorfer, Matthew V; Young, Robert C; Sampson, Shirlene; McClintock, Shawn M; Mueller, Martina; Prudic, Joan; Greenberg, Robert M; Weiner, Richard D; Bailine, Samuel H; Rosenquist, Peter B; Raza, Ahmad; Kaliora, Styliani; Latoussakis, Vassilios; Tobias, Kristen G; Briggs, Mimi C; Liebman, Lauren S; Geduldig, Emma T; Teklehaimanot, Abeba A; Dooley, Mary; Lisanby, Sarah H

2016-11-01

The randomized phase (phase 2) of the Prolonging Remission in Depressed Elderly (PRIDE) study evaluated the efficacy and tolerability of continuation ECT plus medication compared with medication alone in depressed geriatric patients after a successful course of ECT (phase 1). PRIDE was a two-phase multisite study. Phase 1 was an acute course of right unilateral ultrabrief pulse ECT, augmented with venlafaxine. Phase 2 compared two randomized treatment arms: a medication only arm (venlafaxine plus lithium, over 24 weeks) and an ECT plus medication arm (four continuation ECT treatments over 1 month, plus additional ECT as needed, using the Symptom-Titrated, Algorithm-Based Longitudinal ECT [STABLE] algorithm, while continuing venlafaxine plus lithium). The intent-to-treat sample comprised 120 remitters from phase 1. The primary efficacy outcome measure was score on the 24-item Hamilton Depression Rating Scale (HAM-D), and the secondary efficacy outcome was score on the Clinical Global Impressions severity scale (CGI-S). Tolerability as measured by neurocognitive performance (reported elsewhere) was assessed using an extensive test battery; global cognitive functioning as assessed by the Mini-Mental State Examination (MMSE) is reported here. Longitudinal mixed-effects repeated-measures modeling was used to compare ECT plus medication and medication alone for efficacy and global cognitive function outcomes. At 24 weeks, the ECT plus medication group had statistically significantly lower HAM-D scores than the medication only group. The difference in adjusted mean HAM-D scores at study end was 4.2 (95% CI=1.6, 6.9). Significantly more patients in the ECT plus medication group were rated "not ill at all" on the CGI-S compared with the medication only group. There was no statistically significant difference between groups in MMSE score. Additional ECT after remission (here operationalized as four continuation ECT treatments followed by further ECT only as needed) was beneficial in sustaining mood improvement for most patients.

Rapid amelioration of severe manic episodes with right unilateral ultrabrief pulse ECT: a case series of four patients.

PubMed

Sidorov, Alexey; Mayur, Prashanth

2017-02-01

The aim of this small case series is to describe four cases of severe mania, where ultrabrief pulse electroconvulsive therapy (ECT) was used as a primary mode of treatment. A retrospective file review was undertaken of four patients identified as having received ultrabrief pulse ECT for severe mania. The outcome measures for treatment efficacy were the Young Mania Rating Scale (YMRS) and Clinical Global Impression (CGI). All the patients showed significant clinical improvement. A comparison of pre- and post-treatment YMRS and CGI scores showed a dramatic decrease in all four cases. However, one patient was shifted to brief pulse ECT due to inadequate response. Ultrabrief pulse ECT may be an effective treatment in cases of severe mania. Due to the very small number of cases in the current case series, no specific conclusions regarding efficacy may be drawn; however, larger, controlled studies would be indicated.

Reducing Falls After Electroconvulsive Therapy: A Quality Improvement Project.

PubMed

Brown, Allana Marie

2017-07-01

Falls after electroconvulsive therapy (ECT) in patients 60 and older have been long recognized as a major clinical care issue across many mental health care settings. The evidence base for fall prevention strategies after receiving ECT is sparse. The risk factors for falls after ECT are vast and complex in nature, especially considering existing comorbid medical conditions. The dearth of research in guiding practitioners on fall reduction interventions for this patient population illuminates a gap in mental health care quality and safety. The purpose of the current nurse-led quality improvement project was to reduce falls in patients undergoing ECT by enhancing safety measures through education and a post-ECT treatment protocol. The project did not prove to be as efficacious as anticipated as measured by fall rate outcomes. Several factors that may account for the project's findings are discussed. [Journal of Psychosocial Nursing and Mental Health Services, 55(7), 20-29.]. Copyright 2017, SLACK Incorporated.

Determining confounding sensitivities in eddy current thin film measurements

NASA Astrophysics Data System (ADS)

Gros, Ethan; Udpa, Lalita; Smith, James A.; Wachs, Katelyn

2017-02-01

Eddy current (EC) techniques are widely used in industry to measure the thickness of non-conductive films on a metal substrate. This is done by using a system whereby a coil carrying a high-frequency alternating current is used to create an alternating magnetic field at the surface of the instrument's probe. When the probe is brought near a conductive surface, the alternating magnetic field will induce ECs in the conductor. The substrate characteristics and the distance of the probe from the substrate (the coating thickness) affect the magnitude of the ECs. The induced currents load the probe coil affecting the terminal impedance of the coil. The measured probe impedance is related to the lift off between coil and conductor as well as conductivity of the test sample. For a known conductivity sample, the probe impedance can be converted into an equivalent film thickness value. The EC measurement can be confounded by a number of measurement parameters. It was the goal of this research to determine which physical properties of the measurement set-up and sample can adversely affect the thickness measurement. The eddy-current testing was performed using a commercially available, hand-held eddy-current probe (ETA3.3H spring-loaded eddy probe running at 8 MHz) that comes with a stand to hold the probe. The stand holds the probe and adjusts the probe on the z-axis to help position the probe in the correct area as well as make precise measurements. The signal from the probe was sent to a hand-held readout, where the results are recorded directly in terms of liftoff or film thickness. Understanding the effect of certain factors on the measurements of film thickness, will help to evaluate how accurate the ETA3.3H spring-loaded eddy probe was at measuring film thickness under varying experimental conditions. This research studied the effects of a number of factors such as i) conductivity, ii) edge effect, iii) surface finish of base material and iv) cable condition.

Experimental and analytical study on vibration control effects of eddy-current tuned mass dampers under seismic excitations

NASA Astrophysics Data System (ADS)

Lu, Zheng; Huang, Biao; Zhang, Qi; Lu, Xilin

2018-05-01

Eddy-current tuned mass dampers (EC-TMDs) are non-contacting passive control devices and are developed on the basis of conventional tuned mass dampers. They comprise a solid mass, a stiffness element, and a damping element, wherein the damping mechanism originates from eddy currents. By relative motion between a non-magnetic conductive metal and a permanent magnet in a dynamic system, a time-varying magnetic field is induced in the conductor, thereby generating eddy currents. The eddy currents induce a magnetic field with opposite polarity, causing repulsive forces, i.e., damping forces. This technology can overcome the drawbacks of conventional tuned mass dampers, such as limited service life, deterioration of mechanical properties, and undesired additional stiffness. The experimental and analytical study of this system installed on a multi-degree-of-freedom structure is presented in this paper. A series of shaking table tests were conducted on a five-story steel-frame model with/without an EC-TMD to evaluate the effectiveness and performance of the EC-TMD in suppressing the vibration of the model under seismic excitations. The experimental results show that the EC-TMD can effectively reduce the displacement response, acceleration response, interstory drift ratio, and maximum strain of the columns under different earthquake excitations. Moreover, an analytical method was proposed on the basis of electromagnetic and structural dynamic theories. A comparison between the test and simulation results shows that the simulation method can be used to estimate the response of structures with an EC-TMD under earthquake excitations with acceptable accuracy.

A Systematic Review of the Combined Use of Electroconvulsive Therapy and Psychotherapy for Depression

PubMed Central

McClintock, Shawn M.; Brandon, Anna R.; Husain, Mustafa M.; Jarrett, Robin B.

2011-01-01

Objective Electroconvulsive therapy (ECT) is one of the most effective treatments for severe Major Depressive Disorder (MDD). However, after acute phase treatment and initial remission, relapse rates are significant. Strategies to prolong remission include continuation phase ECT, pharmacotherapy, psychotherapy, or their combinations. This systematic review synthesizes extant data regarding the combined use of psychotherapy with ECT for the treatment of patients with severe MDD and offers the hypothesis that augmenting ECT with depression-specific psychotherapy represents a promising strategy for future investigation. Methods The authors performed two independent searches in PsychInfo (1806 – 2009) and MEDLINE (1948 – 2009) using combinations of the following search terms: Electroconvulsive Therapy (including ECT, ECT therapy, electroshock therapy, EST, shock therapy) and Psychotherapy (including cognitive behavioral, interpersonal, group, psychodynamic, psychoanalytic, individual, eclectic, and supportive). We included in this review a total of six articles (English language) that mentioned ECT and psychotherapy in the abstract, and provided a case report, series, or clinical trial. We examined the articles for data related to ECT and psychotherapy treatment characteristics, cohort characteristics, and therapeutic outcome. Results Although research over the past seven decades documenting the combined use of ECT and psychotherapy is limited, the available evidence suggests that testing this combination has promise and may confer additional, positive functional outcomes. Conclusions Significant methodological variability in ECT and psychotherapy procedures, heterogeneous patient cohorts, and inconsistent outcome measures prevent strong conclusions; however, existing research supports the need for future investigations of combined ECT and psychotherapy in well-designed, controlled clinical studies. Depression-specific psychotherapy approaches may need special adaptations in view of the cognitive effects following ECT. PMID:21206376

Effects of combined elcatonin and alendronate treatment on the architecture and strength of bone in ovariectomized rats.

PubMed

Ogawa, Koko; Hori, Masayuki; Takao, Ryoko; Sakurada, Toyozo

2005-01-01

We examined the combined effects of elcatonin (ECT) and alendronate (ALN) on bone mass, architecture, and strength in ovariectomized (OVX) rats. Fifty female Sprague Dawley rats, aged 13 weeks, were divided into Sham, OVX, OVX+ECT, OVX+ALN, and OVX+ECT+ALN groups (n = 10). Immediately after ovariectomy, ECT was administered at a dose of 15 units (U)/kg three times a week, and ALN was administered daily at a dose of 2.0 microg/kg, subcutaneously for 12 weeks. The three-dimensional architecture of the bone in the distal femoral metaphysis was analyzed using a microfocus X-ray computed tomography system (microCT), and bone strength was measured using a material-testing machine. Trabecular bone volume (BV/TV) and number (Tb.N) were significantly greater in the OVX+ECT and OVX+ALN groups than in the OVX group. In the OVX+ECT+ALN group, BV/TV and Tb.N were significantly greater when compared with those in the OVX+ECT and OVX+ALN groups. Trabecular thickness (Tb.Th) was significantly greater in the OVX+ECT+ALN group than in the OVX+ALN group. With regard to bone strength, the compression strength in the femoral metaphysis was significantly lower in the OVX group than in the Sham group. The reduction of compression strength was slightly lower in the OVX+ECT and OVX+ALN groups. In the OVX+ECT+ALN group, the compression strength in the femoral metaphysis significantly increased when compared with the OVX and OVX+ECT groups. These results suggest that the combined treatment of ECT and ALN does not alter the individual effects of each drug and that it exerts an additive effect on trabecular architecture and bone strength in OVX rats.

Reynolds Stress Distributions and the Measurement and Calculation of Eddy Viscosity in Gravity Currents

NASA Astrophysics Data System (ADS)

Kelly, R. W.; Chalk, C.; Dorrell, R. M.; Peakall, J.; Burns, A. D.; Keevil, G. M.; Thomas, R. E.; Williams, G.

2016-12-01

In the natural environment, gravity currents transport large volumes of sediment great distances and are often considered one of the most important mechanisms for sediment transport in ocean basins. Deposits from many individual submarine gravity currents, turbidites, ultimately form submarine fan systems. These are the largest sedimentary systems on the planet and contain valuable hydrocarbon reserves. Moreover, the impact of these currents on submarine technologies and seafloor infrastructure can be devastating and therefore they are of significant interest to a wide range of industries. Here we present experimental, numerical and theoretical models of time-averaged turbulent shear stresses, i.e. Reynolds stresses. Reynolds stresses can be conceptually parameterised by an eddy viscosity parameter that relates chaotic fluid motion to diffusive type processes. As such, it is a useful parameter for indicating the extent of internal mixing and is used extensively in both numerical and analytical modelling of both open-channel and gravity driven flows. However, a lack of knowledge of the turbulent structure of gravity currents limits many hydro- and morphodynamic models. High resolution 3-dimensional experimental velocity data, gathered using acoustic Doppler profiling velocimetry, enabled direct calculation of stresses and eddy viscosity. Comparison of experimental data to CFD and analytical models allowed the testing of eddy viscosity-based turbulent mixing models. The calculated eddy viscosity profile is parabolic in nature in both the upper and lower shear layers. However, an apparent breakdown in the Boussinesq hypothesis (used to calculate the eddy viscosity and upon which many numerical models are based) is observed in the region of the current around the velocity maximum. With the use of accompanying density data it is suggested that the effect of stratification on eddy viscosity is significant and alternative formulations may be required.

Automated detection and location of indications in eddy current signals

DOEpatents

Brudnoy, David M.; Oppenlander, Jane E.; Levy, Arthur J.

2000-01-01

A computer implemented information extraction process that locates and identifies eddy current signal features in digital point-ordered signals, signals representing data from inspection of test materials, by enhancing the signal features relative to signal noise, detecting features of the signals, verifying the location of the signal features that can be known in advance, and outputting information about the identity and location of all detected signal features.

Eddy-Current Detection of Cracks in Tubes

NASA Technical Reports Server (NTRS)

Parent, R.; Kettering, D.

1987-01-01

Nondestructive device tests narrow, sharply-bent metal tubes. Eddycurrent probe detects incipient cracks inside small metal tubes. Tube-centering device consisting of pair of opposed bars ensures tube centered on eddy-current coil. Probe moves along length of bent tube to inspect repeatably for cracks. Compatible with tubes of different cross sections, oval, flattened, square, rectangular,or irregular. Adapts for inspecting formed tubes in petrochemical, automotive, nuclear, and medical equipment.

Factors associated with relapse after a response to electroconvulsive therapy in unipolar versus bipolar depression.

PubMed

Itagaki, Kei; Takebayashi, Minoru; Shibasaki, Chiyo; Kajitani, Naoto; Abe, Hiromi; Okada-Tsuchioka, Mami; Yamawaki, Shigeto

2017-01-15

While electroconvulsive therapy (ECT) treatment for depression is highly effective, the high rate of relapse is a critical problem. The current study investigated factors associated with the risk of relapse in mood disorders in patients in which ECT was initially effective. The records of 100 patients with mood disorders (61 unipolar depression, 39 bipolar depression) who received and responded to an acute ECT course were retrospectively reviewed. Associations between clinical variables and relapse after responding to acute ECT were analyzed. The Ethics Committee of NHO Kure Medical Center approved the study protocol. After one year, the percentage of relapse-free patients was 48.7%. There was no significant difference between patients with either unipolar or bipolar depression who were relapse-free (unipolar: 51.1%, bipolar: 45.5%, P=0.603). Valproate maintenance pharmacotherapy in unipolar depression patients was associated with a lower risk of relapse compared to patients without valproate treatment (multivariate analysis, hazard ratio: 0.091; P=0.022). Lithium treatment, reportedly effective for unipolar depression following a course of ECT, tended to lower the risk of relapse (hazard ratio: 0.378; P=0.060). For bipolar depression, no treatment significantly reduced the risk of relapse. The current findings were retrospective and based on a limited sample size. The relapse-free rate was similar between unipolar and bipolar depression. Valproate could have potential for unipolar depression patients as a maintenance therapeutic in preventing relapse after ECT. Copyright © 2016 Elsevier B.V. All rights reserved.

ECT and Pronounced Impairment in Spatial Cognition: The Fallacy of Drawing Conclusions From a Single Case.

PubMed

Andrade, Chittaranjan; Prasad, Yameni; Devaraj, Aathira; Pinto, Ekta Franscina; Shukla, Lekhansh

2018-06-01

Electroconvulsive therapy (ECT) is associated with memory deficits on neuropsychological assessment. The association of ECT with nonmemory cognitive deficits has been poorly studied. We present a 40-year-old woman who showed a bizarre form of spatial cognition impairment on a subtest of the Tactual Performance Test (TPT) after recovering from depression with 6 alternate day, thrice-weekly, inpatient ECT treatments. This woman was part of a naturalistic, nonblind study that examined nonmemory cognitive deficits in antidepressant-treated depressed patients who did and did not receive ECT. The impairment was in the form of bizarrely drawn reproductions of differently shaped wooden blocks that had been presented to the patient when she was blindfolded. The impairment was still evident when she was retested (3 hours later) under substantially simplified conditions but was much attenuated approximately 2.5 weeks later. On the surface, it seems that ECT had induced severe impairment in spatial cognition and that the impairment showed the familiar pattern of attenuation with the passage of time. However, another recovered patient in the study, who did not receive ECT, also showed substantial spatial deficits on the same subtest of the TPT, and the attenuation of the deficits across time in the ECT-treated patient was probably a result of repeated exposure to the task. We suggest that not all patients who seem to experience spectacular cognitive impairment after ECT have deficits that are attributable to ECT.

Cognitive Performance Under Electroconvulsive Therapy (ECT) in ECT-Naive Treatment-Resistant Patients With Major Depressive Disorder.

PubMed

Ziegelmayer, Christoph; Hajak, Göran; Bauer, Anne; Held, Marion; Rupprecht, Rainer; Trapp, Wolfgang

2017-06-01

Although electroconvulsive therapy (ECT) is considered a safe and highly effective treatment option for major depressive disorder, there are still some reservations with regard to possible adverse cognitive adverse effects. This is the case despite a large body of evidence showing that these deficits are transient and that there even seems to be a long-term improvement of cognitive functioning level. However, most data concerning cognitive adverse effects stem from studies using mixed samples of treatment-resistant and non-treatment-resistant as well as ECT-naive and non-ECT-naive subjects. Furthermore, neurocognitive measures might partly be sensitive to practice effects and improvements in depressive symptom level. We examined neurocognitive performance in a sample of 20 treatment-resistant and ECT-naive subjects using repeatable neurocognitive tests, whereas changes in depressive symptom level were controlled. Cognitive functioning level was assessed before (baseline), 1 week, and 6 months (follow-up 1 and 2) after (12 to) 15 sessions of unilateral ECT treatment. No adverse cognitive effects were observed in any of the cognitive domains examined. Instead, a significant improvement in verbal working memory performance was found from baseline to follow-up 2. When changes in depressive symptom levels were controlled statistically, this improvement was no longer seen. Although findings that ECT does not lead to longer lasting cognitive deficits caused by ECT were confirmed, our study adds evidence that previous results of a beneficial effect of ECT on cognition might be questioned.

The experience of electroconvulsive therapy and its impact on associated stigma: A meta-analysis.

PubMed

Aoki, Yuta; Yamaguchi, Sosei; Ando, Shuntaro; Sasaki, Natsuki; Bernick, Peter J; Akiyama, Tsuyoshi

2016-12-01

Despite its efficacy and safety, electroconvulsive therapy (ECT) is underutilized, in part due to stigma associated with the treatment. The aim of this study was to test the hypothesis that experiencing ECT has an impact on associated stigma, as measured by patient and family knowledge of and attitudes toward ECT. A comprehensive literature search was conducted using MEDLINE, EMBASE and PsycINFO. Studies with cross-sectional and/or longitudinal designs were identified. Studies were further categorized into subcategories based on participant type (patients or patient family members) and outcome domain (knowledge or attitudes). Effect size (Cohen's d) was calculated for each study and then integrated into each subcategory (participant type by outcome domain) using a random effect model. Eight studies were identified as being eligible for analysis. Two studies were cross-sectional, five were longitudinal and one incorporated both designs. Analysis of the longitudinal studies indicated that experiencing ECT both increased knowledge of and improved attitudes toward ECT in patients; in family members of patients, analysis showed significant positive change in knowledge of ECT, but no significant change in attitudes toward ECT. Experience with ECT may have a positive impact on knowledge of and attitudes toward ECT. However, the quality of evidence of included studies was low; further research is required in order to clarify the relationship and to identify information of use to individuals considering ECT as a treatment option. © The Author(s) 2016.

The role of ECT in posttraumatic stress disorder: A systematic review.

PubMed

Youssef, Nagy A; McCall, W Vaughn; Andrade, Chittaranjan

2017-02-01

Posttraumatic stress disorder (PTSD) is associated with a high burden of disability and mortality and frequently is treatment resistant. There is little to offer patients who are not responding to standard interventions. Thus, the objective of this report is to systematically review human data on whether electroconvulsive therapy (ECT) is effective in PTSD. We performed a systematic literature review from 1958 through August 2016 for clinical studies and case reports published in English examining the efficacy of ECT in improving PTSD symptoms. The literature search generated 3 retrospective studies, 1 prospective uncontrolled clinical trial, and 5 case reports. It is not clear, given the small sample size and lack of a large randomized trial, whether favorable outcomes were attributed to improvement in depression (as opposed to core PTSD symptoms). Current efficacy data do not separate conclusively the effects of ECT on PTSD symptoms from those on depression. Randomized controlled trials are necessary to examine the use of ECT in medication-refractory PTSD patients with and without comorbid depression. Subsequent studies may address response in PTSD subtypes, and the use of novel techniques, such as memory reactivation, before ECT.

Short- and long-term evaluation of cognitive functions after electroconvulsive therapy in a Japanese population.

PubMed

Takagi, Shunsuke; Takeuchi, Takashi; Yamamoto, Naoki; Fujita, Munehisa; Furuta, Ko; Ishikawa, Hiroyo; Motohashi, Nobutaka; Nishikawa, Toru

2018-02-01

While electroconvulsive therapy (ECT) is a well-established, safe, and effective treatment for mental illnesses, the potential for adverse effects on cognitive functions remains controversial. We aimed to evaluate multiple cognitive functions in different time periods before and after ECT in a Japanese population. A battery of five neurocognitive tests was administered to patients who underwent a course of ECT treatment at three time points: before, immediately after, and 4 weeks after ECT. A transient but significant decline in letter fluency function was observed immediately after ECT, but had recovered well by 4 weeks. We also observed a significant improvement in the trail-making task at 4 weeks after ECT. In a Japanese population, adverse effects of ECT on verbal fluency function-related and other cognitive impairments were transient. Over the longer term, we detected significant improvements in the performance of tasks that presumably reflected information processing speed and executive functions. © 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.

Multifactorial Determinants of the Neurocognitive Effects of Electroconvulsive Therapy

PubMed Central

McClintock, Shawn M.; Choi, Jimmy; Deng, Zhi-De; Appelbaum, Lawrence G.; Krystal, Andrew D.; Lisanby, Sarah H.

2014-01-01

For many patients with neuropsychiatric illnesses, standard psychiatric treatments with mono or combination pharmacotherapy, psychotherapy, and transcranial magnetic stimulation are ineffective. For these patients with treatment resistant neuropsychiatric illnesses, a main therapeutic option is electroconvulsive therapy (ECT). Decades of research have found ECT to be highly effective; however, it can also result in adverse neurocognitive effects. Specifically, ECT results in disorientation after each session, anterograde amnesia for recently learned information, and retrograde amnesia for previously learned information. Unfortunately, the neurocognitive effects and underlying mechanisms of action of ECT remain poorly understood. The purpose of this paper is to synthesize the multiple moderating and mediating factors that are thought to underlie the neurocognitive effects of ECT into a coherent model. Such factors include demographic and neuropsychological characteristics, neuropsychiatric symptoms, ECT technical parameters, and ECT associated neurophysiological changes. Future research is warranted to evaluate and test this model, so that these findings may support the development of more refined clinical seizure therapy delivery approaches and efficacious cognitive remediation strategies to improve the utility of this important and widely used intervention tool for neuropsychiatric diseases. PMID:24820942

Multifactorial determinants of the neurocognitive effects of electroconvulsive therapy.

PubMed

McClintock, Shawn M; Choi, Jimmy; Deng, Zhi-De; Appelbaum, Lawrence G; Krystal, Andrew D; Lisanby, Sarah H

2014-06-01

For many patients with neuropsychiatric illnesses, standard psychiatric treatments with mono or combination pharmacotherapy, psychotherapy, and transcranial magnetic stimulation are ineffective. For these patients with treatment-resistant neuropsychiatric illnesses, a main therapeutic option is electroconvulsive therapy (ECT). Decades of research have found ECT to be highly effective; however, it can also result in adverse neurocognitive effects. Specifically, ECT results in disorientation after each session, anterograde amnesia for recently learned information, and retrograde amnesia for previously learned information. Unfortunately, the neurocognitive effects and underlying mechanisms of action of ECT remain poorly understood. The purpose of this paper was to synthesize the multiple moderating and mediating factors that are thought to underlie the neurocognitive effects of ECT into a coherent model. Such factors include demographic and neuropsychological characteristics, neuropsychiatric symptoms, ECT technical parameters, and ECT-associated neurophysiological changes. Future research is warranted to evaluate and test this model, so that these findings may support the development of more refined clinical seizure therapy delivery approaches and efficacious cognitive remediation strategies to improve the use of this important and widely used intervention tool for neuropsychiatric diseases.

Recent and Future Enhancements in NDI for Aircraft Structures

DTIC Science & Technology

2015-11-30

accomplish NDI of aircraft structure. This includes improved eddy current probes, improved eddy current instrumentation, as well as other...Aircraft Structures,” which is currently in Revision C [8]. The document divides various inspection methods, such as eddy current and fluorescent...efforts at AFRL to address technology shortfalls include improved eddy current probes, improved eddy current instrumentation, as well as other

Recent and Future Enhancements in NDI for Aircraft Structures (Postprint)

DTIC Science & Technology

2015-11-30

accomplish NDI of aircraft structure. This includes improved eddy current probes, improved eddy current instrumentation, as well as other...Aircraft Structures,” which is currently in Revision C [8]. The document divides various inspection methods, such as eddy current and fluorescent...efforts at AFRL to address technology shortfalls include improved eddy current probes, improved eddy current instrumentation, as well as other

Recent and Future Enhancements in NDI for Aircraft Structures (Postprint)

DTIC Science & Technology

2015-11-01

accomplish NDI of aircraft structure. This includes improved eddy current probes, improved eddy current instrumentation, as well as other...Aircraft Structures,” which is currently in Revision C [8]. The document divides various inspection methods, such as eddy current and fluorescent...efforts at AFRL to address technology shortfalls include improved eddy current probes, improved eddy current instrumentation, as well as other

Recent and Future Enhancements in NDI for Aircraft Structures (POSTPRINT)

DTIC Science & Technology

2015-11-16

accomplish NDI of aircraft structure. This includes improved eddy current probes, improved eddy current instrumentation, as well as other...Aircraft Structures,” which is currently in Revision C [8]. The document divides various inspection methods, such as eddy current and fluorescent...efforts at AFRL to address technology shortfalls include improved eddy current probes, improved eddy current instrumentation, as well as other

NASA's RBSP-ECT Science Investigation of the Van Allen Probes Mission: Highlights of the Prime Mission Phase, Data Access Overview, and Opportunities to Collaborate in the Extended Mission Phase

NASA Astrophysics Data System (ADS)

Smith, S. S.; Friedel, R. H.; Larsen, B.; Reeves, G.; Spence, H. E.

2015-12-01

In this poster, we present a summary of access to the data products of the Radiation Belt Storm Probes - Energetic Particle Composition, and Thermal plasma (RBSP-ECT) suite of NASA's Van Allen Probes mission. The RBSP-ECT science investigation (http://rbsp-ect.sr.unh.edu) measures comprehensively the near-Earth charged particle environment in order to understand the processes that control the acceleration, global distribution, and variability of radiation belt electrons and ions. RBSP-ECT data products derive from the three instrument elements that comprise the suite, which collectively covers the broad energies that define the source and seed populations, the core radiation belts, and also their highest energy ultra-relativistic extensions. These RBSP-ECT instruments include, from lowest to highest energies: the Helium, Oxygen, Proton, and Electron (HOPE) sensor, the Magnetic Electron and Ion Spectrometer (MagEIS), and the Relativistic Electron and Proton Telescope (REPT). We provide a brief overview of their principles of operation, as well as a description of the Level 2-3 data products that the HOPE, MagEIS, and REPT instruments produce, both separately and together. We provide a summary of how to access these RBSP-ECT data products at our Science Operation Center and Science Data Center (http://www.rbsp-ect.lanl.gov/rbsp_ect.php ) as well as caveats for their use. Finally, in the spirit of efficiently and effectively promoting and encouraging new collaborations, we present a summary of past publications, current studies, and opportunities for your future participation in RBSP-ECT extended mission phase science.

NASA's Van Allen Probes RBSP-ECT Data Products and Access to Them: An Insider's Outlook on the Inner and Outer Belts (and We Don't Mean the Nation's Beltway...)

NASA Astrophysics Data System (ADS)

Smith, S. S.; Friedel, R. H. W.; Henderson, M. G.; Larsen, B.; Reeves, G. D.; Spence, H. E.

2014-12-01

In this poster, we present a summary of access to the data products of the Radiation Belt Storm Probes - Energetic Particle Composition, and Thermal plasma (RBSP-ECT) suite of NASA's Van Allen Probes mission. The RBSP-ECT science investigation (http://rbsp-ect.sr.unh.edu) measures comprehensively the near-Earth charged particle environment in order to understand the processes that control the acceleration, global distribution, and variability of radiation belt electrons and ions. RBSP-ECT data products derive from the three instrument elements that comprise the suite, which collectively covers the broad energies that define the source and seed populations, the core radiation belts, and also their highest energy ultra-relativistic extensions. These RBSP-ECT instruments include, from lowest to highest energies: the Helium, Oxygen, Proton, and Electron (HOPE) sensor, the Magnetic Electron and Ion Spectrometer (MagEIS), and the Relativistic Electron and Proton Telescope (REPT). We provide a brief overview of their principles of operation, as well as a description of the Level 1-3 data products that the HOPE, MagEIS, and REPT instruments produce, both separately and together. We provide a summary of how to access these RBSP-ECT data products at our Science Operation Center and Science Data Center (http://www.rbsp-ect.lanl.gov/rbsp_ect.php ) as well as caveats for their use. Finally, in the spirit of efficiently and effectively promoting and encouraging new collaborations, we present a summary of past publications, current studies, and opportunities for your future participation in RBSP-ECT science analyses.

Research of aluminum alloys with using eddy-current transducers on the basis of cores of various form

NASA Astrophysics Data System (ADS)

Dmitriev, S. F.; Ishkov, A. V.; Katasonov, A. O.; Malikov, V. N.; Sagalakov, A. M.

2018-01-01

The research aims to develop a microminiature eddy current transducer for aluminum alloys. The research topic is considered relevant due to the need for evaluation and forecasting of safe operating life of aluminum. A microminiature transformer-type transducer was designed, which enables to perform local investigations of unferromagnetic materials using eddy-current method based on local studies conductivity. Having the designed transducer as a basis, a hardware-software complex was built to perform experimental studies of aluminium. Cores with different shapes were used in this work. Test results are reported for a flaws in the form of hidden slits and apertures inside the slabs is derived for excitation coil frequencies of 300-700 Hz.

Remission of depression following electroconvulsive therapy (ECT) is associated with higher levels of brain-derived neurotrophic factor (BDNF).

PubMed

Freire, Thiago Fernando Vasconcelos; Fleck, Marcelo Pio de Almeida; da Rocha, Neusa Sica

2016-03-01

Research on the association between electroconvulsive therapy (ECT) and increased brain derived neurotrophic factor (BDNF) levels has produced conflicting result. There have been few studies which have evaluated BDNF levels in clinical contexts where there was remission following treatment. The objective of this study was to investigate whether remission of depression following ECT is associated with changes in BDNF levels. Adult inpatients in a psychiatric unit were invited to participate in this naturalistic study. Diagnoses were made using the Mini-International Neuropsychiatric Interview (MINI) and symptoms were evaluated at admission and discharge using the Hamilton Rating Scale for Depression (HDRS-17). Thirty-one patients who received a diagnosis of depression and were subjected to ECT were included retrospectively. Clinical remission was defined as a score of less than eight on the HDRS-17 at discharge. Serum BDNF levels were measured in blood samples collected at admission and discharge with a commercial kit used in accordance with the manufacturer's instructions. Subjects HDRS-17 scores improved following ECT (t = 13.29; p = 0.00). A generalized estimating equation (GEE) model revealed a remission × time interaction with BDNF levels as a dependent variable in a Wald chi-square test [Wald χ(2) = 5.98; p = 0.01]. A post hoc Bonferroni test revealed that non-remitters had lower BDNF levels at admission than remitters (p = 0.03), but there was no difference at discharge (p = 0.16). ECT remitters had higher serum BDNF levels at admission and the level did not vary during treatment. ECT non-remitters had lower serum BDNF levels at admission, but levels increased during treatment and were similar to those of ECT remitters at discharge. Copyright © 2016 Elsevier Inc. All rights reserved.

49 CFR 180.209 - Requirements for requalification of specification cylinders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Requalification period (years) Eddy current examination combined with visual inspection Eddy current—In accordance... performing eddy current must be familiar with the eddy current equipment and must standardize (calibrate) the system in accordance with the requirements provided in Appendix C to this part. 2 The eddy current must...

49 CFR 180.209 - Requirements for requalification of specification cylinders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Requalification period (years) Eddy current examination combined with visual inspection Eddy current—In accordance... performing eddy current must be familiar with the eddy current equipment and must standardize (calibrate) the system in accordance with the requirements provided in Appendix C to this part. 2 The eddy current must...

49 CFR 180.209 - Requirements for requalification of specification cylinders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Requalification period (years) Eddy current examination combined with visual inspection Eddy current—In accordance... performing eddy current must be familiar with the eddy current equipment and must standardize (calibrate) the system in accordance with the requirements provided in Appendix C to this part. 2 The eddy current must...

An Assessment of the ECTS in Software Engineering: A Teaching Experience

ERIC Educational Resources Information Center

Salas-Morera, L.; Berral-Yeron, J.; Serrano-Gomez, I.; Martinez-Jimenez, P.

2009-01-01

Spain is currently implementing the regulatory modifications promulgated by the Declaration of Bologna, which should result in the updating of the structure of university degrees, and the inclusion of the European Credit Transfer and Accumulation System (ECTS) methodology. In some Spanish universities, the experimental adoption of this methodology…

Low-dose right unilateral electroconvulsive therapy (ECT): effectiveness of the first treatment.

PubMed

Lapidus, Kyle A B; Shin, Joseph S W; Pasculli, Rosa M; Briggs, Mimi C; Popeo, Dennis M; Kellner, Charles H

2013-06-01

Electroconvulsive therapy (ECT) is a widely used, highly effective antidepressant treatment. Except for the most severely ill patients, right unilateral (RUL) electrode placement is the most frequent initial treatment choice. In current practice, RUL ECT is administered at several multiples of seizure threshold (ST) based on reports that lower stimulus intensity results in lower response/remission rates. Many patients, as part of an initial dose titration to determine ST, will receive a single treatment with low-dose RUL ECT and subsequent treatments with a stimulus at a multiple of ST. To assess response to the first ECT. A retrospective analysis of charts from clinical practice at Mount Sinai Medical Center was performed. A single treatment with low-dose (presumably near ST) RUL ECT had a significant and immediate antidepressant effect in our sample of patients with major depression. We determined that this response is similar to that of patients receiving a single initial treatment with high-dose RUL ECT (at a multiple of ST). These data suggest, contrary to commonly held belief, that RUL ECT may be effective at a low stimulus dose. This argues against restimulating at 6 times ST in the initial session, based on the belief that the near-threshold seizure has no antidepressant efficacy. Our findings suggest a need for further investigation of cases in which low-dose RUL ECT may be an effective antidepressant treatment. Further prospective studies, including larger numbers of patients who receive randomized treatment with low- or high-dose RUL with longer follow-up, are indicated.

Determination of eddy current response with magnetic measurements.

PubMed

Jiang, Y Z; Tan, Y; Gao, Z; Nakamura, K; Liu, W B; Wang, S Z; Zhong, H; Wang, B B

2017-09-01

Accurate mutual inductances between magnetic diagnostics and poloidal field coils are an essential requirement for determining the poloidal flux for plasma equilibrium reconstruction. The mutual inductance calibration of the flux loops and magnetic probes requires time-varying coil currents, which also simultaneously drive eddy currents in electrically conducting structures. The eddy current-induced field appearing in the magnetic measurements can substantially increase the calibration error in the model if the eddy currents are neglected. In this paper, an expression of the magnetic diagnostic response to the coil currents is used to calibrate the mutual inductances, estimate the conductor time constant, and predict the eddy currents response. It is found that the eddy current effects in magnetic signals can be well-explained by the eddy current response determination. A set of experiments using a specially shaped saddle coil diagnostic are conducted to measure the SUNIST-like eddy current response and to examine the accuracy of this method. In shots that include plasmas, this approach can more accurately determine the plasma-related response in the magnetic signals by eliminating the field due to the eddy currents produced by the external field.

Unsupervised classification of surface defects in wire rod production obtained by eddy current sensors.

PubMed

Saludes-Rodil, Sergio; Baeyens, Enrique; Rodríguez-Juan, Carlos P

2015-04-29

An unsupervised approach to classify surface defects in wire rod manufacturing is developed in this paper. The defects are extracted from an eddy current signal and classified using a clustering technique that uses the dynamic time warping distance as the dissimilarity measure. The new approach has been successfully tested using industrial data. It is shown that it outperforms other classification alternatives, such as the modified Fourier descriptors.

Dynamically Consistent Parameterization of Mesoscale Eddies This work aims at parameterization of eddy effects for use in non-eddy-resolving ocean models and focuses on the effect of the stochastic part of the eddy forcing that backscatters and induces eastward jet extension of the western boundary currents and its adjacent recirculation zones.

NASA Astrophysics Data System (ADS)

Berloff, P. S.

2016-12-01

This work aims at developing a framework for dynamically consistent parameterization of mesoscale eddy effects for use in non-eddy-resolving ocean circulation models. The proposed eddy parameterization framework is successfully tested on the classical, wind-driven double-gyre model, which is solved both with explicitly resolved vigorous eddy field and in the non-eddy-resolving configuration with the eddy parameterization replacing the eddy effects. The parameterization focuses on the effect of the stochastic part of the eddy forcing that backscatters and induces eastward jet extension of the western boundary currents and its adjacent recirculation zones. The parameterization locally approximates transient eddy flux divergence by spatially localized and temporally periodic forcing, referred to as the plunger, and focuses on the linear-dynamics flow solution induced by it. The nonlinear self-interaction of this solution, referred to as the footprint, characterizes and quantifies the induced eddy forcing exerted on the large-scale flow. We find that spatial pattern and amplitude of each footprint strongly depend on the underlying large-scale flow, and the corresponding relationships provide the basis for the eddy parameterization and its closure on the large-scale flow properties. Dependencies of the footprints on other important parameters of the problem are also systematically analyzed. The parameterization utilizes the local large-scale flow information, constructs and scales the corresponding footprints, and then sums them up over the gyres to produce the resulting eddy forcing field, which is interactively added to the model as an extra forcing. Thus, the assumed ensemble of plunger solutions can be viewed as a simple model for the cumulative effect of the stochastic eddy forcing. The parameterization framework is implemented in the simplest way, but it provides a systematic strategy for improving the implementation algorithm.

Imaging flaws in thin metal plates using a magneto-optic device

NASA Technical Reports Server (NTRS)

Wincheski, B.; Prabhu, D. R.; Namkung, M.; Birt, E. A.

1992-01-01

An account is given of the capabilities of the magnetooptic/eddy-current imager (MEI) apparatus in the case of aging aircraft structure-type flaws in 2024-T3 Al alloy plates. Attention is given to images of cyclically grown fatigue cracks from rivetted joints in fabricated lap-joint structures, electrical discharge machining notches, and corrosion spots. Although conventional eddy-current methods could have been used, the speed and ease of MEI's use in these tests is unmatched by such means. Results are displayed in real time as a test piece is scanned, furnishing easily interpreted flaw images.

Method and apparatus for correcting eddy current signal voltage for temperature effects

DOEpatents

Kustra, Thomas A.; Caffarel, Alfred J.

1990-01-01

An apparatus and method for measuring physical characteristics of an electrically conductive material by the use of eddy-current techniques and compensating measurement errors caused by changes in temperature includes a switching arrangement connected between primary and reference coils of an eddy-current probe which allows the probe to be selectively connected between an eddy current output oscilloscope and a digital ohm-meter for measuring the resistances of the primary and reference coils substantially at the time of eddy current measurement. In this way, changes in resistance due to temperature effects can be completely taken into account in determining the true error in the eddy current measurement. The true error can consequently be converted into an equivalent eddy current measurement correction.

Debunking EHEA Myths: Common ECTS Misconceptions and Why They Are Wrong

ERIC Educational Resources Information Center

Pérez Cañado, María Luisa

2009-01-01

The present article seeks to overcome some of the most common misconceptions which are currently proliferating in the application of the "European Credit Transfer System" (ECTS) at tertiary level. It presents and unpacks seven false myths affecting all the main curricular and organizational levels of the implementation of the new credit…

Electronic Current Transducer (ECT) for high voltage dc lines

NASA Astrophysics Data System (ADS)

Houston, J. M.; Peters, P. H., Jr.; Summerayes, H. R., Jr.; Carlson, G. J.; Itani, A. M.

1980-02-01

The development of a bipolar electronic current transducer (ECT) for measuring the current in a high voltage dc (HVDC) power line at line potential is discussed. The design and construction of a free standing ECT for use on a 400 kV line having a nominal line current of 2000 A is described. Line current is measured by a 0.0001 ohm shunt whose voltage output is sampled by a 14 bit digital data link. The high voltage interface between line and ground is traversed by optical fibers which carry digital light signals as far as 300 m to a control room where the digital signal is converted back to an analog representation of the shunt voltage. Two redundant electronic and optical data links are used in the prototype. Power to operate digital and optical electronics and temperature controlling heaters at the line is supplied by a resistively and capacitively graded 10 stage cascade of ferrite core transformers located inside the hollow, SF6 filled, porcelain support insulator. The cascade is driven by a silicon controlled rectifier inverter which supplies about 100 W of power at 30 kHz.

New type of eddy current sensor for large-displacement test

NASA Astrophysics Data System (ADS)

Pan, Haifeng; Zhu, Huizhong; Fu, Zhibin; Xu, Yuzheng; Feng, Guanping

2001-09-01

In this paper a new type of large displacement eddy current sensor is developed to overcome the three main disadvantages of the traditional eddy current senor. For a traditional sensor, the measurement range is limited and less than one half of the diameter of the measuring coil. The output is high sensitivity to the changes of the target material and the cable length connected between the probe and the preamplifier. When the material or the cable length changed, it is necessary to readjust the preamplifier. The probe of the new eddy current sensor has three coaxial measuring coils, one is an exciting coil and the other two are receiving coils. The diameter of measuring coils is (Phi) 11 mm. The measurement range of this sensor is 40mm and almost four times of the diameter of the coil. The form of differential input and feedback amplification is used in signal amplifier. Thus the effect of the common modules, such as the changes of the target material and the cable length, can be counteracted well.

Eddy Current Influences on the Dynamic Behaviour of Magnetic Suspension Systems

NASA Technical Reports Server (NTRS)

Britcher, Colin P.; Bloodgood, Dale V.

1998-01-01

This report will summarize some results from a multi-year research effort at NASA Langley Research Center aimed at the development of an improved capability for practical modelling of eddy current effects in magnetic suspension systems. Particular attention is paid to large-gap systems, although generic results applicable to both large-gap and small-gap systems are presented. It is shown that eddy currents can significantly affect the dynamic behavior of magnetic suspension systems, but that these effects can be amenable to modelling and measurement. Theoretical frameworks are presented, together with comparisons of computed and experimental data particularly related to the Large Angle Magnetic Suspension Test Fixture at NASA Langley Research Center, and the Annular Suspension and Pointing System at Old Dominion University. In both cases, practical computations are capable of providing reasonable estimates of important performance-related parameters. The most difficult case is seen to be that of eddy currents in highly permeable material, due to the low skin depths. Problems associated with specification of material properties and areas for future research are discussed.

Eddy Current COPV Overwrap and Liner Thickness Measurement System and Data Analysis for 40-Inch Kevlar COPVs SN002 and SN027

NASA Technical Reports Server (NTRS)

Wincheski, Russell A.

2008-01-01

As part of the health assessment of flight spare 40in diameter Kevlar composite overwrapped pressure vessels (COPVs) SN002 and SN027 an eddy current characterization of the composite and liner thickness change during pressurization was requested under WSTF-TP-1085-07.A, "Space Shuttle Orbiter Main Propulsion System P/N MC282-0082-0101 S/N 002 and Orbital Maneuvering System P/N MC282-0082-001 S/N 027 COPV Health Assessment." The through the thickness strains have been determined to be an important parameter in the analysis of the reliability and likelihood of stress rupture failure. Eddy current techniques provide a means to measure these thicknesses changes based upon the change in impedance of an eddy current sensor mounted on the exterior of the vessel. Careful probe and technique design have resulted in the capability to independently measure the liner and overwrap thickness changes to better than +/- 0.0005 in. at each sensor location. Descriptions of the inspection system and test results are discussed.

Design of permanent magnet eddy current brake for a small scaled electromagnetic launch model

NASA Astrophysics Data System (ADS)

Zhou, Shigui; Yu, Haitao; Hu, Minqiang; Huang, Lei

2012-04-01

A variable pole-pitch double-sided permanent magnet (PM) linear eddy current brake (LECB) is proposed for a small scaled electromagnetic launch model. A two-dimensional (2D) analytical steady state model is presented for the double-sided PM-LECB, and the expression for the braking force is derived. Based on the analytical model, the material and eddy current skin effect of the conducting plate are analyzed. Moreover, a variable pole-pitch double-sided PM-LECB is proposed for the effective braking of the moving plate. In addition, the braking force is predicted by finite element (FE) analysis, and the simulated results are in good agreement with the analytical model. Finally, a prototype is presented to test the braking profile for validation of the proposed design.

Levels of mania and cognitive performance two years after ECT in patients with bipolar I disorder - results from a follow-up study.

PubMed

Haghighi, Mohammad; Barikani, Reza; Jahangard, Leila; Ahmadpanah, Mohammad; Bajoghli, Hafez; Sadeghi Bahmani, Dena; Holsboer-Trachsler, Edith; Brand, Serge

2016-08-01

There is limited evidence on the long-term outcomes for patients with bipolar I disorder (BP-I-D) and treated with ECT. Therefore, we asked whether mania scores and cognitive performance at the end of ECT treatment (baseline/BL) predicted mania scores, cognitive performance, recurrence, treatment adherence, and mood (depression; hypomania) two years later (follow-up/FU). 38 patients with BP-I-D undergoing ECT at baseline were followed up two years later. A brief psychiatric and cognitive assessment (Mini Mental State Examination; short-term verbal memory test) was performed; patients completed questionnaires covering recurrence, treatment adherence, and mood (depression; hypomania). High cognitive performance at BL predicted high cognitive performance at FU; low mania scores at BL predicted low mania scores at FU. By FU, cognitive performance had increased and mania scores decreased. Mania scores and cognitive performance at BL did not predict recurrence, or adherence to medication, or mood (depression; hypomania). The pattern of results suggests that after two years of successful treatment of acute mania with ECT, cognitive impairment, measured by MMSE and a short-term verbal memory test, is not impaired and mood symptom recurrence seems to be improved. Mania scores and cognitive performance at the end of ECT treatment predicted neither mood (depression; hypomania), nor recurrence, or adherence to medication two years later. Copyright © 2016 Elsevier Inc. All rights reserved.

Electronic voltage and current transformers testing device.

PubMed

Pan, Feng; Chen, Ruimin; Xiao, Yong; Sun, Weiming

2012-01-01

A method for testing electronic instrument transformers is described, including electronic voltage and current transformers (EVTs, ECTs) with both analog and digital outputs. A testing device prototype is developed. It is based on digital signal processing of the signals that are measured at the secondary outputs of the tested transformer and the reference transformer when the same excitation signal is fed to their primaries. The test that estimates the performance of the prototype has been carried out at the National Centre for High Voltage Measurement and the prototype is approved for testing transformers with precision class up to 0.2 at the industrial frequency (50 Hz or 60 Hz). The device is suitable for on-site testing due to its high accuracy, simple structure and low-cost hardware.

Differential Mechanisms Associated with Vascular Disrupting Action of Electrochemotherapy: Intravital Microscopy on the Level of Single Normal and Tumor Blood Vessels

PubMed Central

Markelc, Bostjan; Sersa, Gregor; Cemazar, Maja

2013-01-01

Electropermeabilization/electroporation (EP) provides a tool for the introduction of molecules into cells and tissues. In electrochemotherapy (ECT), cytotoxic drugs are introduced into cells in tumors, and nucleic acids are introduced into cells in gene electrotransfer. The normal and tumor tissue blood flow modifying effects of EP and the vascular disrupting effect of ECT in tumors have already been determined. However, differential effects between normal vs. tumor vessels, to ensure safety in the clinical application of ECT, have not been determined yet. Therefore, the aim of our study was to determine the effects of EP and ECT with bleomycin on the HT-29 human colon carcinoma tumor model and its surrounding blood vessels. The response of blood vessels to EP and ECT was monitored in real time, directly at the single blood vessel level, by in vivo optical imaging in a dorsal window chamber in SCID mice with 70 kDa fluorescently labeled dextrans. The response of tumor blood vessels to EP and ECT started to differ within the first hour. Both therapies induced a vascular lock, decreased functional vascular density (FVD) and increased the diameter of functional blood vessels within the tumor. The effects were more pronounced for ECT, which destroyed the tumor blood vessels within 24 h. Although the vasculature surrounding the tumor was affected by EP and ECT, it remained functional. The study confirms the current model of tumor blood flow modifying effects of EP and provides conclusive evidence that ECT is a vascular disrupting therapy with a specific effect on the tumor blood vessels. PMID:23555705

Relapse following successful electroconvulsive therapy for major depression: a meta-analysis.

PubMed

Jelovac, Ana; Kolshus, Erik; McLoughlin, Declan M

2013-11-01

High rates of early relapse following electroconvulsive therapy (ECT) are typically reported in the literature. Current treatment guidelines offer little information to clinicians on the optimal nature of maintenance therapy following ECT. The aim of this study was to provide a systematic overview of the existing evidence regarding post-ECT relapse. A keyword search of electronic databases was performed for studies appearing in the peer-reviewed literature before January 2013 reporting on relapse rates in responders to an acute course of ECT administered for a major depressive episode. Meta-analyses were performed where appropriate. Thirty-two studies with up to 2 years' duration of follow-up were included. In modern era studies of continuation pharmacotherapy, 51.1% (95% CI=44.7-57.4%) of patients relapsed by 12 months following successful initial treatment with ECT, with the majority (37.7%, 95% CI=30.7-45.2%) relapsing within the first 6 months. The 6-month relapse rate was similar in patients treated with continuation ECT (37.2%, 95% CI=23.4-53.5%). In randomized controlled trials, antidepressant medication halved the risk of relapse compared with placebo in the first 6 months (risk ratio=0.49, 95% CI=0.39-0.62, p<0.0001, number needed to treat=3.3). Despite continuation therapy, the risk of relapse within the first year following ECT is substantial, with the period of greatest risk being the first 6 months. The largest evidence base for efficacy in post-ECT relapse prevention exists for tricyclic antidepressants. Published evidence is limited or non-existent for commonly used newer antidepressants or popular augmentation strategies. Maintenance of well-being following successful ECT needs to be improved.

Effects of small-dose dexmedetomidine on hyperdynamic responses to electroconvulsive therapy.

PubMed

Li, Xiang; Tan, Fang; Jian, Chao-Jun; Guo, Na; Zhong, Zhi-Yong; Hei, Zi-Qing; Zhou, Shao-Li

2017-08-01

Acute hemodynamic responses to electroconvulsive therapy (ECT) may increase the risk of cardiovascular complications in vulnerable patients. The aim of the current study was to assess the effect of small-dose dexmedetomidine on hyperdynamic responses to ECT. Seventy-eight patients were enrolled and randomly allocated to receive either 0.2 μg/kg dexmedetomidine (Dex group, n = 39) or saline (Control group, n = 39) prior to ECT. Heart rate (HR) and mean arterial pressure (MAP) were recorded immediately after the administration of dexmedetomidine (T1), and 0, 1, 3, 5 and 10 min after the electrical stimuli ended (T2, T3, T4, T5 and T6). In addition, the peak HR after ECT, seizure duration, recovery time, and incidence rates of post-ECT adverse effects (agitation, headache and nausea) were also recorded. HR and MAP in the Dex group were significantly lower than those in the Control group from T2 to T5. In addition, peak HR was significantly lower in the Dex group compared with that in the Control group. Seizure length and time to spontaneous breathing, eye opening, and obeying commands in the Dex group were similar to those in the Control group. The incidence rates of post-ECT agitation and headache in the Dex group were significantly lower than that in the Control group. The administration of 0.2 μg/kg dexmedetomidine to patients receiving ECT leads to a significant reduction in HR, MAP, and peak HR responses to ECT without altering seizure duration or delaying recovery. Furthermore, dexmedetomidine effectively reduced the incidence rates of post-ECT adverse effects such as agitation and headache. Copyright © 2017. Published by Elsevier Taiwan LLC.

Relapse Following Successful Electroconvulsive Therapy for Major Depression: A Meta-Analysis

PubMed Central

Jelovac, Ana; Kolshus, Erik; McLoughlin, Declan M

2013-01-01

High rates of early relapse following electroconvulsive therapy (ECT) are typically reported in the literature. Current treatment guidelines offer little information to clinicians on the optimal nature of maintenance therapy following ECT. The aim of this study was to provide a systematic overview of the existing evidence regarding post-ECT relapse. A keyword search of electronic databases was performed for studies appearing in the peer-reviewed literature before January 2013 reporting on relapse rates in responders to an acute course of ECT administered for a major depressive episode. Meta-analyses were performed where appropriate. Thirty-two studies with up to 2 years' duration of follow-up were included. In modern era studies of continuation pharmacotherapy, 51.1% (95% CI=44.7–57.4%) of patients relapsed by 12 months following successful initial treatment with ECT, with the majority (37.7%, 95% CI=30.7–45.2%) relapsing within the first 6 months. The 6-month relapse rate was similar in patients treated with continuation ECT (37.2%, 95% CI=23.4–53.5%). In randomized controlled trials, antidepressant medication halved the risk of relapse compared with placebo in the first 6 months (risk ratio=0.49, 95% CI=0.39–0.62, p<0.0001, number needed to treat=3.3). Despite continuation therapy, the risk of relapse within the first year following ECT is substantial, with the period of greatest risk being the first 6 months. The largest evidence base for efficacy in post-ECT relapse prevention exists for tricyclic antidepressants. Published evidence is limited or non-existent for commonly used newer antidepressants or popular augmentation strategies. Maintenance of well-being following successful ECT needs to be improved. PMID:23774532

Temperature sensitivity study of eddy current and digital gauge probes for nuclear fuel rod oxide measurement

NASA Astrophysics Data System (ADS)

Beck, Faith R.; Lind, R. Paul; Smith, James A.

2018-04-01

Novel fuels are part of the nationwide effort to reduce the enrichment of Uranium for energy production. Performance of such fuels is determined by irradiating their surfaces. To test irradiated samples, the instrumentation must operate remotely. The plate checker used in this experiment at Idaho National Lab (INL) performs non-destructive testing on fuel rod and plate geometries with two different types of sensors: eddy current and digital thickness gauges. The sensors measure oxide growth and total sample thickness on research fuels, respectively. Sensor measurement accuracy is crucial because even 10 microns of error is significant when determining the viability of an experimental fuel. One parameter known to affect the eddy current and thickness gauge sensors is temperature. Since both sensor accuracies depend on the ambient temperature of the system, the plate checker has been characterized for these sensitivities. The manufacturer of the digital gauge probes has noted a rather large coefficient of thermal expansion for their linear scale. It should also be noted that the accuracy of the digital gauge probes are specified at 20°C, which is approximately 7°C cooler than the average hot-cell temperature. In this work, the effect of temperature on the eddy current and digital gauge probes is studied, and thickness measurements are given as empirical functions of temperature.

Low eddy current RF shielding enclosure designs for 3T MR applications.

PubMed

Lee, Brian J; Watkins, Ronald D; Chang, Chen-Ming; Levin, Craig S

2018-03-01

Magnetic resonance-compatible medical devices operate within the MR environment while benefitting from the superior anatomic information of MRI. Avoiding electromagnetic interference between such instrumentation and the MR system is crucial. In this work, various shielding configurations for positron emission tomography (PET) detectors were studied and analyzed regarding radiofrequency (RF) shielding effectiveness and gradient-induced eddy current performances. However, the results of this work apply to shielding considerations for any MR-compatible devices. Six shielding enclosure configurations with various thicknesses, patterns, and materials were designed: solid and segmented copper, phosphor bronze mesh (PBM), and carbon fiber composite (CFC). A series of tests was performed on RF shielding effectiveness and the gradient-induced eddy current. For the shielding effectiveness, the solid copper with various thickness and PBM configurations yield significantly better shielding effectiveness (>15 dB) compared with CFC and segmented configurations. For the gradient-induced eddy current performance, the solid copper shielding configurations with different thicknesses showed significantly worse results, up to a factor of 3.89 dB, compared with the segmented copper, PBM, and the CFC configurations. We evaluated the RF shielding effectiveness and the gradient-induced eddy current artifacts of several shielding designs, and only the PBM showed positive outcomes for both aspects. Magn Reson Med 79:1745-1752, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

78 FR 27001 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-09

... one-time mid- frequency eddy current (MFEC) inspection, a low-frequency eddy current (LFEC) inspection... new AD instead requires repetitive external eddy current inspections for cracking of certain fuselage crown lap joints, and corrective actions if necessary; internal eddy current and detailed inspections...

Finite element analysis of gradient z-coil induced eddy currents in a permanent MRI magnet.

PubMed

Li, Xia; Xia, Ling; Chen, Wufan; Liu, Feng; Crozier, Stuart; Xie, Dexin

2011-01-01

In permanent magnetic resonance imaging (MRI) systems, pulsed gradient fields induce strong eddy currents in the conducting structures of the magnet body. The gradient field for image encoding is perturbed by these eddy currents leading to MR image distortions. This paper presents a comprehensive finite element (FE) analysis of the eddy current generation in the magnet conductors. In the proposed FE model, the hysteretic characteristics of ferromagnetic materials are considered and a scalar Preisach hysteresis model is employed. The developed FE model was applied to study gradient z-coil induced eddy currents in a 0.5 T permanent MRI device. The simulation results demonstrate that the approach could be effectively used to investigate eddy current problems involving ferromagnetic materials. With the knowledge gained from this eddy current model, our next step is to design a passive magnet structure and active gradient coils to reduce the eddy current effects. Copyright © 2010 Elsevier Inc. All rights reserved.

Overgeneral memory predicts stability of short-term outcome of electroconvulsive therapy for depression.

PubMed

Raes, Filip; Sienaert, Pascal; Demyttenaere, Koen; Peuskens, Joseph; Williams, J Mark G; Hermans, Dirk

2008-03-01

To investigate the predictive value of overgeneral memory (OGM) for outcome of electroconvulsive therapy (ECT) for depression. The Autobiographical Memory Test was used to measure OGM in 25 patients with depression before ECT. The Hamilton Rating Scale for Depression (HRSD) was administered weekly to 1 week posttreatment. Overgeneral memory did not predict HRSD scores from the last ECT treatment, but did predict HRSD change scores from the last treatment to 1-week follow-up: patients high in OGM experienced a relatively greater increase in HRSD scores after the last treatment. Results further extend the status of OGM as a predictor of an unfavorable course of depression to a previously unstudied ECT population.

Electroconvulsive Therapy for Agitation in Schizophrenia: Metaanalysis of Randomized Controlled Trials.

PubMed

Gu, Xiaojing; Zheng, Wei; Guo, Tong; Ungvari, Gabor S; Chiu, Helen F K; Cao, Xiaolan; D'Arcy, Carl; Meng, Xiangfei; Ning, Yuping; Xiang, Yutao

2017-02-25

Agitation poses a significant challenge in the treatment of schizophrenia. Electroconvulsive therapy (ECT) is a fast, effective and safe treatment for a variety of psychiatric disorders, but no meta-analysis of ECT treatment for agitation in schizophrenia has yet been reported. To systematically evaluate the efficacy and safety of ECT alone or ECT-antipsychotics (APs) combination for agitation in schizophrenia. Systematic literature search of randomized controlled trials (RCTs) was performed. Two independent evaluators selected studies, extracted data about outcomes and safety with available data, conducted quality assessment and data synthesis. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) was used to judge the level of the overall evidence of main outcomes. Seven RCTs from China, including ECT alone (4 RCTs with 5 treatment arms, n=240) and ECT-APs combination (3 RCTs, n=240), were identified. Participants in the studies were on average 34.3(4.5) years of age and lasted an average of 4.3(3.1) weeks of treatment duration. All 7 RCTs were non-blinded, and were rated as low quality based on Jadad scale. Meta-analysis of the pooled sample found no significant difference in the improvement of the agitation sub-score of the Positive and Negative Syndrome Scale (PANSS) when ECT alone (weighted mean difference=-0.90, (95% confidence interval (CI): -2.91, 1.11), p=0.38) or ECT-APs combination (WMD=-1.34, (95%CI: -4.07, 1.39), p=0.33) compared with APs monotherapy. However, ECT alone was superior to APs monotherapy regarding PANSS total score (WMD=-7.13, I 2 =0%, p =0.004) and its excitement sub-score (WMD=-1.97, p <0.0001) as well as the PANSS total score at 14 days (WMD=-7.13, I 2 =0%, p =0.004) and its excitement sub-score at 7 and 14 days (WMD=-1.97 to -1.92, p =0.002 to 0.0001) after ECT. The ECT-APs combination was superior to APs monotherapy with respect to the PANSS total score at treatment endpoint (WMD=-10.40, p=0.03) and 7 days (WMD=-5.01, p =0.02). Headache (number-needed-to-harm (NNH)=3, 95%CI=2-4) was more frequent in the ECT alone group compared to AP monotherapy. According to the GRADE approach, the evidence levels of main outcomes were rated as ''very low'' (37.5%) and "low" (50%). Pooling of the data based on 7 RCTs from China found no advantage of ECT alone or ECT-APs combination in the treatment of agitation related outcomes in schizophrenia patients. However, ECT alone or ECT-APs combination were associated with significant reduction in the PANSS total score. High-quality RCTs are needed to confirm the current interpretations.

Electroconvulsive therapy in Brazil after the "psychiatric reform": a public health problem--example from a university service.

PubMed

Ribeiro, Rafael Bernardon; Melzer-Ribeiro, Débora Luciana; Rigonatti, Sérgio Paulo; Cordeiro, Quirino

2012-09-01

The Brazilian public health system does not provide electroconvulsive therapy (ECT), which is limited to a few academic services. National mental health policies are against ECT. Our objectives were to analyze critically the public policies toward ECT and present the current situation using statistics from the Institute of Psychiatry of the University of São Paulo (IPq-HCFMUSP) and summary data from the other 13 ECT services identified in the country. Data regarding ECT treatment at the IPq-HCFMUSP were collected from January 2009 to June 2010 (demographical, number of sessions, and diagnoses). All the data were analyzed using SPSS 19, Epic Info 2000, and Excel. During this period, 331 patients were treated at IPq-HCFMUSP: 221 (67%) were from São Paulo city, 50 (15.2%) from São Paulo's metropolitan area, 39 (11.8%) from São Paulo's countryside, and 20 (6.1%) from other states; 7352 ECT treatments were delivered-63.0% (4629) devoted entirely via the public health system (although not funded by the federal government); the main diagnoses were a mood disorder in 86.4% and schizophrenia in 7.3% of the cases. There is an important lack of public assistance for ECT, affecting mainly the poor and severely ill patients. The university services are overcrowded and cannot handle all the referrals. The authors press for changes in the mental health policies.

Antidepressant and Neurocognitive Effects of Isoflurane Anesthesia versus Electroconvulsive Therapy in Refractory Depression

PubMed Central

Weeks, Howard R.; Tadler, Scott C.; Smith, Kelly W.; Iacob, Eli; Saccoman, Mikala; White, Andrea T.; Landvatter, Joshua D.; Chelune, Gordon J.; Suchy, Yana; Clark, Elaine; Cahalan, Michael K.; Bushnell, Lowry; Sakata, Derek; Light, Alan R.; Light, Kathleen C.

2013-01-01

Background Many patients have serious depression that is nonresponsive to medications, but refuse electroconvulsive therapy (ECT). Early research suggested that isoflurane anesthesia may be an effective alternative to ECT. Subsequent studies altered drug, dose or number of treatments, and failed to replicate this success, halting research on isoflurane's antidepressant effects for a decade. Our aim was to re-examine whether isoflurane has antidepressant effects comparable to ECT, with less adverse effects on cognition. Method Patients with medication-refractory depression received an average of 10 treatments of bifrontal ECT (n = 20) or isoflurane (n = 8) over 3 weeks. Depression severity (Hamilton Rating Scale for Depression-24) and neurocognitive responses (anterograde and retrograde memory, processing speed and verbal fluency) were assessed at Pretreatment, Post all treatments and 4-week Follow-up. Results Both treatments produced significant reductions in depression scores at Post-treatment and 4-week Follow-up; however, ECT had modestly better antidepressant effect at follow-up in severity-matched patients. Immediately Post-treatment, ECT (but not isoflurane) patients showed declines in memory, fluency, and processing speed. At Follow-up, only autobiographical memory remained below Pretreatment level for ECT patients, but isoflurane patients had greater test-retest neurocognitive score improvement. Conclusions Our data reconfirm that isoflurane has an antidepressant effect approaching ECT with less adverse neurocognitive effects, and reinforce the need for a larger clinical trial. PMID:23922809

Environmental control technology (ECT) for geothermal processes

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

Katz, G.

1982-01-01

The objectives of the environmental control technology (ECT) program are to develop research priorities, research new and alternative technologies and to improve economics and performance of ECT systems. The Interagency Geothermal Coordinating Council, Environmental Control Panel developed priorities and obtained industry input during 1980. H/sub 2/S controls, injection monitoring, solid waste characterization and control and subsidence were reviewed as high priority while noise controls were considered low priority. Since geothermal technology is still developing there is a need to continue researching new and alternative ECT. Often ECT systems must be designed for site specific applications and need modification for usemore » of other sites. Most of the US geothermal experience is found at the Geysers, California where H/sub 2/S abatement is required. Various systems have been tested with mixed results. The bottom line is that the economics and performance of H/sub 2/S abatement systems are less than desirable.« less

Detection of Fatigue Cracks at Rivets with Self-Nulling Probe

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Fulton, Jim; Nath, Shridhar; Namkung, Min

1994-01-01

A new eddy current probe developed at NASA Langley Research Center has been used to detect small cracks at rivets in aircraft lap splices [1]. The device has earlier been used to detect isolated fatigue cracks with a minimum detectable flaw size of roughly 1/2 to 1/3 the diameter of the probe [2]. The present work shows that the detectable flaw size for cracks originating at rivets can be greatly improved upon from that of isolated flaws. The use of a rotating probe method combined with spatial filtering has been used to detect 0.18 cm EDM notches, as measured from the rivet shank, with a 1.27 cm diameter probe and to detect flaws buried under the rivet head, down to a length of 0.076 cm, using a 0.32 cm diameter probe. The Self-Nulling Electromagnetic Flaw Detector induces a high density eddy current ring in the sample under test. A ferromagnetic flux focusing lens is incorporated such that in the absence of any inhomogeneities in the material under test only a minimal magnetic field will reach the interior of the probe. A magnetometer (pickup coil) located in the center of the probe therefore registers a null voltage in the absence of material defects. When a fatigue crack or other discontinuity is present in the test article the path of the eddy currents in the material is changed. The magnetic field associated with these eddy currents then enter into the interior of the probe, producing a large output voltage across the pickup coil leads. Further

Solution of magnetic field and eddy current problem induced by rotating magnetic poles (abstract)

NASA Astrophysics Data System (ADS)

Liu, Z. J.; Low, T. S.

1996-04-01

The magnetic field and eddy current problems induced by rotating permanent magnet poles occur in electromagnetic dampers, magnetic couplings, and many other devices. Whereas numerical techniques, for example, finite element methods can be exploited to study various features of these problems, such as heat generation and drag torque development, etc., the analytical solution is always of interest to the designers since it helps them to gain the insight into the interdependence of the parameters involved and provides an efficient tool for designing. Some of the previous work showed that the solution of the eddy current problem due to the linearly moving magnet poles can give satisfactory approximation for the eddy current problem due to rotating fields. However, in many practical cases, especially when the number of magnet poles is small, there is significant effect of flux focusing due to the geometry. The above approximation can therefore lead to marked errors in the theoretical predictions of the device performance. Bernot et al. recently described an analytical solution in a polar coordinate system where the radial field is excited by a time-varying source. A discussion of an analytical solution of the magnetic field and eddy current problems induced by moving magnet poles in radial field machines will be given in this article. The theoretical predictions obtained from this method is compared with the results obtained from finite element calculations. The validity of the method is also checked by the comparison of the theoretical predictions and the measurements from a test machine. It is shown that the introduced solution leads to a significant improvement in the air gap field prediction as compared with the results obtained from the analytical solution that models the eddy current problems induced by linearly moving magnet poles.

Electroconvulsive therapy for obsessive-compulsive disorder: a systematic review.

PubMed

Fontenelle, Leonardo F; Coutinho, Evandro S F; Lins-Martins, Natália M; Fitzgerald, Paul B; Fujiwara, Hironobo; Yücel, Murat

2015-07-01

Surgical therapies for treatment-refractory obsessive-compulsive disorder (OCD), such as deep brain stimulation or psychosurgery, remain unattainable for many patients. Despite the long-held view that electroconvulsive therapy (ECT) is an ineffective treatment for OCD, there is no systematic review to support or refute this claim, which is the basis of the current review. A systematic search of MEDLINE, Web of Science, Scopus, and LILACS databases was conducted on December 22, 2013, using the terms obsessive-compulsive disorder and electroconvulsive therapy. Reference lists, specific journals, and clinical trial registries were also scrutinized. No date or language limitation was imposed on the search. After irrelevant and redundant records from the 500 identified titles were excluded, the 50 articles reporting the acute treatment effects of ECT in OCD and related constructs (involving a total of 279 patients) were analyzed for this study. The relevant sociodemographic, clinical, and outcome data of individual cases were extracted. Data from individual cases were used to compare the characteristics of responders versus nonresponders to ECT. Most selected records were case reports/series; there were no randomized controlled trials. A positive response was reported in 60.4% of the 265 cases in which individual responses to ECT were available. ECT responders exhibited a significantly later onset of OCD symptoms (P = .003), were more frequently nondepressed (P = .009), more commonly reported being treated with ECT for severe OCD (P = .01), and received a fewer number of ECT sessions (P = .03). ECT responders were also less frequently previously treated with adequate trials of serotonin reuptake inhibitors (P = .05) and cognitive-behavioral therapy (P = .005). Although 60% of the reported cases reviewed exhibited some form of a positive response to ECT, it cannot be stated that this provides evidence that ECT is indeed effective for OCD. © Copyright 2015 Physicians Postgraduate Press, Inc.

Observational evidence of seasonality in the timing of loop current eddy separation

NASA Astrophysics Data System (ADS)

Hall, Cody A.; Leben, Robert R.

2016-12-01

Observational datasets, reports and analyses over the time period from 1978 through 1992 are reviewed to derive pre-altimetry Loop Current (LC) eddy separation dates. The reanalysis identified 20 separation events in the 15-year record. Separation dates are estimated to be accurate to approximately ± 1.5 months and sufficient to detect statistically significant LC eddy separation seasonality, which was not the case for previously published records because of the misidentification of separation events and their timing. The reanalysis indicates that previously reported LC eddy separation dates, determined for the time period before the advent of continuous altimetric monitoring in the early 1990s, are inaccurate because of extensive reliance on satellite sea surface temperature (SST) imagery. Automated LC tracking techniques are used to derive LC eddy separation dates in three different altimetry-based sea surface height (SSH) datasets over the time period from 1993 through 2012. A total of 28-30 LC eddy separation events were identified in the 20-year record. Variations in the number and dates of eddy separation events are attributed to the different mean sea surfaces and objective-analysis smoothing procedures used to produce the SSH datasets. Significance tests on various altimetry and pre-altimetry/altimetry combined date lists consistently show that the seasonal distribution of separation events is not uniform at the 95% confidence level. Randomization tests further show that the seasonal peak in LC eddy separation events in August and September is highly unlikely to have occurred by chance. The other seasonal peak in February and March is less significant, but possibly indicates two seasons of enhanced probability of eddy separation centered near the spring and fall equinoxes. This is further quantified by objectively dividing the seasonal distribution into two seasons using circular statistical techniques and a k-means clustering algorithm. The estimated spring and fall centers are March 2nd and August 23rd, respectively, with season boundaries in May and December.

Significant treatment effect of add-on ketamine anesthesia in electroconvulsive therapy in depressive patients: A meta-analysis.

PubMed

Li, Dian-Jeng; Wang, Fu-Chiang; Chu, Che-Sheng; Chen, Tien-Yu; Tang, Chia-Hung; Yang, Wei-Cheng; Chow, Philip Chik-Keung; Wu, Ching-Kuan; Tseng, Ping-Tao; Lin, Pao-Yen

2017-01-01

Add-on ketamine anesthesia in electroconvulsive therapy (ECT) has been studied in depressive patients in several clinical trials with inconclusive findings. Two most recent meta-analyses reported insignificant findings with regards to the treatment effect of add-on ketamine anesthesia in ECT in depressive patients. The aim of this study is to update the current evidence and investigate the role of add-on ketamine anesthesia in ECT in depressive patients via a systematic review and meta-analysis. We performed a thorough literature search of the PubMed and ScienceDirect databases, and extracted all relevant clinical variables to compare the antidepressive outcomes between add-on ketamine anesthesia and other anesthetics in ECT. Total 16 articles with 346 patients receiving add-on ketamine anesthesia in ECT and 329 controls were recruited. We found that the antidepressive treatment effect of add-on ketamine anesthesia in ECT in depressive patients was significantly higher than that of other anesthetics (p<0.001). This significance persisted in both short-term (1-2 weeks) and moderate-term (3-4 weeks) treatment courses (all p<0.05). However, the side effect profiles and recovery time profiles were significantly worse in add-on ketamine anesthesia group than in control group. Our meta-analysis highlights the significantly higher antidepressive treatment effect of add-on ketamine in depressive patients receiving ECT compared to other anesthetics. However, clinicians need to take undesirable side effects into consideration when using add-on ketamine anesthesia in ECT in depressive patients. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

Neuropsychological Effects of Neuromodulation Techniques for Treatment-Resistant Depression: A Review

PubMed Central

Moreines, Jared L.; McClintock, Shawn M.; Holtzheimer, Paul E.

2010-01-01

Electroconvulsive therapy (ECT) and ablative neurosurgical procedures are established interventions for treatment-resistant depression (TRD), but their use may be limited in part by neuropsychological adverse effects. Additional neuromodulation strategies are being developed that aim to match or exceed the efficacy of ECT/ablative surgery with a better neurocognitive side effect profile. In this review, we briefly discuss the neurocognitive effects of ECT and ablative neurosurgical procedures, then synthesize the available neurocognitive information for emerging neuromodulation therapies including repetitive transcranial magnetic stimulation, magnetic seizure therapy, transcranial direct current stimulation, vagus nerve stimulation, and deep brain stimulation. The available evidence suggests these procedures may be more cognitively benign relative to ECT or ablative neurosurgical procedures, though further research is clearly needed to fully evaluate the neurocognitive effects, both positive and negative, of these novel neuromodulation interventions. PMID:21255751

Dynamically consistent parameterization of mesoscale eddies. Part III: Deterministic approach

NASA Astrophysics Data System (ADS)

Berloff, Pavel

2018-07-01

This work continues development of dynamically consistent parameterizations for representing mesoscale eddy effects in non-eddy-resolving and eddy-permitting ocean circulation models and focuses on the classical double-gyre problem, in which the main dynamic eddy effects maintain eastward jet extension of the western boundary currents and its adjacent recirculation zones via eddy backscatter mechanism. Despite its fundamental importance, this mechanism remains poorly understood, and in this paper we, first, study it and, then, propose and test its novel parameterization. We start by decomposing the reference eddy-resolving flow solution into the large-scale and eddy components defined by spatial filtering, rather than by the Reynolds decomposition. Next, we find that the eastward jet and its recirculations are robustly present not only in the large-scale flow itself, but also in the rectified time-mean eddies, and in the transient rectified eddy component, which consists of highly anisotropic ribbons of the opposite-sign potential vorticity anomalies straddling the instantaneous eastward jet core and being responsible for its continuous amplification. The transient rectified component is separated from the flow by a novel remapping method. We hypothesize that the above three components of the eastward jet are ultimately driven by the small-scale transient eddy forcing via the eddy backscatter mechanism, rather than by the mean eddy forcing and large-scale nonlinearities. We verify this hypothesis by progressively turning down the backscatter and observing the induced flow anomalies. The backscatter analysis leads us to formulating the key eddy parameterization hypothesis: in an eddy-permitting model at least partially resolved eddy backscatter can be significantly amplified to improve the flow solution. Such amplification is a simple and novel eddy parameterization framework implemented here in terms of local, deterministic flow roughening controlled by single parameter. We test the parameterization skills in an hierarchy of non-eddy-resolving and eddy-permitting modifications of the original model and demonstrate, that indeed it can be highly efficient for restoring the eastward jet extension and its adjacent recirculation zones. The new deterministic parameterization framework not only combines remarkable simplicity with good performance but also is dynamically transparent, therefore, it provides a powerful alternative to the common eddy diffusion and emerging stochastic parameterizations.

Wire-inhomogeneity detector

DOEpatents

Gibson, G.H.; Smits, R.G.; Eberhard, P.H.

1982-08-31

A device for uncovering imperfections in electrical conducting wire, particularly superconducting wire, by detecting variations in eddy currents. Eddy currents effect the magnetic field in a gap of an inductor, contained in a modified commercial ferrite core, through which the wire being tested is passed. A small increase or decrease in the amount of conductive material, such as copper, in a fixed cross section of wire will unbalance a bridge used to measure the impedance of the inductor, tripping a detector and sounding an alarm.

Improved multi-directional eddy current inspection test apparatus for detecting flaws in metal articles

DOEpatents

Nance, Roy A.; Hartley, William H.; Caffarel, Alfred J.

1984-01-01

Apparatus is described for detecting flaws in a tubular workpiece in a single scan. The coils of a dual coil bobbin eddy current inspection probe are wound at a 45.degree. angle to the transverse axis of the probe, one coil having an angular position about the axis about 90.degree. relative to the angular position of the other coil, and the angle of intersection of the planes containing the coils being about 60.degree..

Comparative study of eddy current and Barkhausen noise nondestructive testing methods in microstructural examination of ferrite-martensite dual-phase steel

NASA Astrophysics Data System (ADS)

Ghanei, S.; Kashefi, M.; Mazinani, M.

2014-04-01

The magnetic properties of ferrite-martensite dual-phase steels were evaluated using eddy current and Barkhausen noise nondestructive testing methods and correlated with their microstructural changes. Several routes were used to produce different microstructures of dual-phase steels. The first route was different heat treatments in γ region to vary the ferrite grain size (from 9.47 to 11.12 in ASTM number), and the second one was variation in intercritical annealing temperatures (from 750 to 890 °C) in order to produce different percentages of martensite in dual-phase microstructure. The results concerning magnetic Barkhausen noise are discussed in terms of height, position and shape of Barkhausen noise profiles, taking into account two main aspects: ferrite grain size, and different percentages of martensite. Then, eddy current testing was used to study the mentioned microstructural changes by detection of impedance variations. The obtained results show that microstructural changes have a noticeable effect on the magnetic properties of dual-phase steels. The results reveal that both magnetic methods have a high potential to be used as a reliable nondestructive tool to detect and monitor microstructural changes occurring during manufacturing of dual-phase steels.

NASA's Van Allen Probes RBSP-ECT and NSF's FIREBIRD Data Products and Access to Them: An Insider's Outlook on the Inner and Outer Belts.

NASA Astrophysics Data System (ADS)

Smith, S. S.; Spence, H. E.; Geoffrey, R.; Klumpar, D. M.

2017-12-01

In this poster, we present a summary of access to data products Radiation Belt Storm Probes - Energetic Particle Composition, and Thermal plasma (RBSP-ECT) suite of NASA's Van Allen Probes mission. The RBSP-ECT science investigation (http://rbsp-ect.sr.unh.edu) measures comprehensively the near-Earth charged particle environment in order to understand the processes that control the acceleration, global distribution, and variability of radiation belt electrons and ions. RBSP-ECT data products derive from the three instrument elements that comprise the suite, which collectively covers the broad energies that define the source and seed populations, the core radiation belts, and also their highest energy ultra-relativistic extensions. These RBSP-ECT instruments include, from lowest to highest energies: the Helium, Oxygen, Proton, and Electron (HOPE) sensor, the Magnetic Electron and Ion Spectrometer (MagEIS), and the Relativistic Electron and Proton Telescope (REPT). We provide a brief overview of their principles of operation, as well as a description of the Level 1-3 data products that the HOPE, MagEIS, and REPT instruments produce, both separately and together. We provide a summary of how to access these RBSP-ECT data products at our Science Operation Center and Science Data Center (http://www.rbsp-ect.lanl.gov/rbsp_ect.php ) as well as caveats for their use. In addition, we also provide a summary of access to the data products from NSF's CubeSat mission called Focused Investigation of Relativistic Electron Burst: Intensity, Range, and Dynamics (FIREBIRD). The dual CubeSat FIREBIRD missions provide data on energetic radiation belt electrons precipitating into the atmosphere at low altitudes, which complements and is contemporary with RBSP-ECT measurements. We provide a similar summary of how to access these data (https://ssel.montana.edu/firebird2.html). Finally, in the spirit of efficiently and effectively promoting and encouraging new collaborations, we present a summary of past publications, current studies, and opportunities for your future participation in both RBSP-ECT and FIREBIRD science analyses.

A Systematic Review and Meta-Analysis of Brief Versus Ultrabrief Right Unilateral Electroconvulsive Therapy for Depression.

PubMed

Tor, Phern-Chern; Bautovich, Alison; Wang, Min-Jung; Martin, Donel; Harvey, Samuel B; Loo, Colleen

2015-09-01

Electroconvulsive therapy (ECT) is an effective depression treatment, but it has potential cognitive side effects. Ultrabrief pulse (UBP) right unilateral (RUL) ECT is an increasingly used treatment option that can potentially combine efficacy with lesser cognitive side effects. However, current trials are underpowered or have conflicting results. A systematic review and meta-analysis was conducted to evaluate the relative efficacy and cognitive effects of brief pulse (BP) and UBP RUL ECT. MEDLINE, EMBASE, PsycINFO, CENTRAL, DARE, and the International Clinical Trials Registry Platform were searched with the search terms ECT, electroconvulsive therapy, electroconvulsive shock, electroconvulsive shock therapy, electrical stimulation, electroconvulsive combined with brief, ultra*, pulse, and trial in English, all fields including title, abstract, subject heading, and full text up to June 20, 2013, for studies comparing BP and UBP RUL ECT in depressed patients that reported formalized mood ratings for depression. Six studies met the inclusion criteria, comprising a total of 689 patients. Efficacy, cognitive, response, and remission outcomes were extracted from each publication or obtained directly from authors. BP RUL ECT was significantly more efficacious in treating depression than UBP RUL ECT (standardized mean difference = 0.25; 95% CI, 0.08–0.41; P = .004) but showed significantly more cognitive side effects in all cognitive domains examined (global cognition, anterograde learning and recall, retrograde memory) (P < .01). The mean number of treatment sessions given was 8.7 for BP ECT and 9.6 for UBP ECT (P < .001). UBP had a lower remission rate (OR = 0.71; 95% CI, 0.51–0.99; P = .045), with a number needed to treat of 12.1. BP compared with UBP RUL ECT was slightly more efficacious in treating depression and required fewer treatment sessions, but led to greater cognitive side effects. The decision of whether to use BP or UBP RUL ECT should be made on an individual patient basis and should be based on a careful weighing of the relative priorities of efficacy versus minimization of cognitive impairment.

Serum BDNF as a peripheral biomarker of treatment-resistant depression and the rapid antidepressant response: A comparison of ketamine and ECT.

PubMed

Allen, A P; Naughton, M; Dowling, J; Walsh, A; Ismail, F; Shorten, G; Scott, L; McLoughlin, D M; Cryan, J F; Dinan, T G; Clarke, G

2015-11-01

Ketamine is associated with rapid antidepressant efficacy but the biological mechanisms underpinning this effect are unclear. Serum brain-derived neurotrophic factor (sBDNF) is a potential circulating biomarker of treatment-resistant depression (TRD) and ketamine response but it is unclear if this is a common target of both ketamine and electroconvulsive therapy (ECT), the current gold standard for TRD. Moreover, the impact of multiple ketamine infusions on sBDNF has not yet been established. Thirty five TRD patients with a current DSM-IV diagnosis of recurrent depressive disorder received up to 12 ECT sessions (N=17) or up to three intravenous infusions of low-dose (0.5mg/kg) ketamine (N=18). Blood samples were taken over the course of the study for assessment of sBDNF. Symptom severity and response were monitored using the 17-item Hamilton Depression Rating Scale (HDRS). sBDNF was assessed in 20 healthy controls to allow comparison with TRD patients. As expected, sBDNF was lower in TRD patients at baseline compared to healthy controls. Ketamine and ECT treatment were both associated with significant reductions in depressive symptoms. However, sBDNF was significantly elevated only at one week following the first ketamine infusion in those classified as responders one week later. sBDNF was not elevated following subsequent infusions. ECT reduced depressive symptoms, as expected, but was not associated with an enhancement in BDNF. Patients continued with their psychotropic medications throughout this trial. SBDNF normalisation does not appear to be a prerequisite for symptomatic improvement in TRD following ketamine or ECT treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

Unified Ultrasonic/Eddy-Current Data Acquisition

NASA Technical Reports Server (NTRS)

Chern, E. James; Butler, David W.

1993-01-01

Imaging station for detecting cracks and flaws in solid materials developed combining both ultrasonic C-scan and eddy-current imaging. Incorporation of both techniques into one system eliminates duplication of computers and of mechanical scanners; unifies acquisition, processing, and storage of data; reduces setup time for repetitious ultrasonic and eddy-current scans; and increases efficiency of system. Same mechanical scanner used to maneuver either ultrasonic or eddy-current probe over specimen and acquire point-by-point data. For ultrasonic scanning, probe linked to ultrasonic pulser/receiver circuit card, while, for eddy-current imaging, probe linked to impedance-analyzer circuit card. Both ultrasonic and eddy-current imaging subsystems share same desktop-computer controller, containing dedicated plug-in circuit boards for each.

Genetic and Environmental Influences on Two Measures of Speed of Information Processing and Their Relation to Psychometric Intelligence: Evidence from the German Observational Study of Adult Twins.

ERIC Educational Resources Information Center

Neubauer, Alioscha C.; Spinath, Frank M.; Riemann, Rainer; Angleitner, Alois; Borkenau, Peter

2000-01-01

Administered 2 elementary cognitive task (ECT) tests and 2 psychometric intelligence tests to 169 monozygotic and 131 dizygotic pairs of twins in Germany. Reaction times correlated negatively with psychometric intelligence, and habitability estimates were substantial for both psychometric intelligence and reaction times on the ECTs. Multivariate…

Eddy-Current Inspection Of Graphite-Fiber Composites

NASA Technical Reports Server (NTRS)

Workman, G. L.; Bryson, C. C.

1993-01-01

NASA technical memorandum describes initial research on, and proposed development of, automated system for nondestructive eddy-current inspection of parts made of graphite-fiber/epoxy-matrix composite materials. Sensors in system E-shaped or U-shaped eddy-current probes like those described in "Eddy-Current Probes For Inspecting Graphite-Fiber Composites" (MFS-26129).

76 FR 28632 - Airworthiness Directives; The Boeing Company Model 737-300, -400, and -500 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-18

... doing internal eddy current inspections, or repairing the crack. As an alternative to the external eddy current inspections, the AD provides for internal eddy current and detailed inspections for cracks in the... 5, 2011, we issued Emergency AD 2011-08-51, which requires repetitive external eddy current...

Determining Confounding Sensitivities In Eddy Current Thin Film Measurements

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

Gros, Ethan; Udpa, Lalita; Smith, James A.

Determining Confounding Sensitivities In Eddy Current Thin Film Measurements Ethan Gros, Lalita Udpa, Electrical Engineering, Michigan State University, East Lansing MI 48824 James A. Smith, Experiment Analysis, Idaho National Laboratory, Idaho Falls ID 83415 Eddy current (EC) techniques are widely used in industry to measure the thickness of non-conductive films on a metal substrate. This is done using a system whereby a coil carrying a high-frequency alternating current is used to create an alternating magnetic field at the surface of the instrument's probe. When the probe is brought near a conductive surface, the alternating magnetic field will induce ECs inmore » the conductor. The substrate characteristics and the distance of the probe from the substrate (the coating thickness) affect the magnitude of the ECs. The induced currents load the probe coil affecting the terminal impedance of the coil. The measured probe impedance is related to the lift off between coil and conductor as well as conductivity of the test sample. For a known conductivity sample, the probe impedance can be converted into an equivalent film thickness value. The EC measurement can be confounded by a number of measurement parameters. It is the goal of this research to determine which physical properties of the measurement set-up and sample can adversely affect the thickness measurement. The eddy current testing is performed using a commercially available, hand held eddy current probe (ETA3.3H spring loaded eddy probe running at 8 MHz) that comes with a stand to hold the probe. The stand holds the probe and adjusts the probe on the z-axis to help position the probe in the correct area as well as make precise measurements. The signal from the probe is sent to a hand held readout, where the results are recorded directly in terms of liftoff or film thickness. Understanding the effect of certain factors on the measurements of film thickness, will help to evaluate how accurate the ETA3.3H spring loaded eddy probe is at measuring film thickness under varying experimental conditions. This research will study the effects of a number of factors such as i) calibration, ii) conductivity, iii) edge effect, iv) surface finish of base material and v) cable condition and compare with the long term reproducibility of a standard measurement. This work was performed with support from the Department of Energy under the United States National Nuclear Security Administration (NNSA) at the Idaho National Laboratory.« less

Electroconvulsive therapy for schizophrenia.

PubMed

Tharyan, P; Adams, C E

2005-04-18

Electroconvulsive therapy (ECT) involves the induction of a seizure for therapeutic purposes by the administration of a variable frequency electrical stimulus shock via electrodes applied to the scalp. The effects of its use in people with schizophrenia are unclear. To determine whether electroconvulsive therapy (ECT) results in clinically meaningful benefit with regard to global improvement, hospitalisation, changes in mental state, behaviour and functioning for people with schizophrenia, and to determine whether variations in the practical administration of ECT influences outcome. We undertook electronic searches of Biological Abstracts (1982-1996), EMBASE (1980-1996), MEDLINE (1966-2004), PsycLIT (1974-1996),SCISEARCH (1996) and the Cochrane Schizophrenia Group's Register (July 2004). We also inspected the references of all identified studies and contacted relevant authors. We included all randomised controlled clinical trials that compared ECT with placebo, 'sham ECT', non-pharmacological interventions and antipsychotics and different schedules and methods of administration of ECT for people with schizophrenia, schizoaffective disorder or chronic mental disorder. Working independently, we selected and critically appraised studies, extracted data and analysed on an intention-to-treat basis. Where possible and appropriate we calculated risk ratios (RR) and their 95% confidence intervals (CI) with the number needed to treat (NNT). For continuous data Weighted Mean Differences (WMD) were calculated. We presented scale data for only those tools that had attained pre-specified levels of quality. We also undertook tests for heterogeneity and publication bias. This review includes 26 trials with 50 reports. When ECT is compared with placebo or sham ECT, more people improved in the real ECT group (n=392, 10 RCTs, RR 0.76 random CI 0.59 to 0.98, NNT 6 CI 4 to 12) and though data were heterogeneous (chi-square 17.49 df=9 P=0.04), its impact on variability of data was not substantial (I-squared 48.5%). There was a suggestion that ECT resulted in less relapses in the short term than sham ECT (n=47, 2 RCTs, RR fixed 0.26 CI 0.03 to 2.2), and a greater likelihood of being discharged from hospital (n=98, 1 RCT, RR fixed 0.59, CI 0.34 to 1.01). There is no evidence that this early advantage for ECT is maintained over the medium to long term. People treated with ECT did not drop out of treatment earlier than those treated with sham ECT (n=495, 14 RCTs, RR fixed 0.71 CI 0.33 to 1.52, I-squared 0%). Very limited data indicated that visual memory might decline after ECT compared with sham ECT (n=24, 1 RCT, WMD -14.0 CI -23 to -5); the results of verbal memory tests were equivocal. When ECT is directly compared with antipsychotic drug treatments (total n=443, 10 RCTs) results favour the medication group (n=175, 3 RCTs, RR fixed 'not improved at the end of ECT course' 2.18 CI 1.31 to 3.63). Limited evidence suggests that ECT combined with antipsychotic drugs results in greater improvement in mental state (n= 40, 1 RCT, WMD, Brief Psychiatric Rating Scale -3.9 CI - 2.28 to -5.52) than with antipsychotic drugs alone. One small study suggested more memory impairment after a course of ECT combined with antipsychotics than with antipsychotics alone (n=20, MD serial numbers and picture recall -4.90 CI -0.78 to -9.02), though this proved transient. When continuation ECT was added to antipsychotic drugs, the combination was superior to the use of antipsychotics alone (n=30, WMD Global Assessment of Functioning 19.06 CI 9.65 to 28.47), or CECT alone (n=30, WMD -20.30 CI -11.48 to -29.12). Unilateral and bilateral ECT were equally effective in terms of global improvement (n=78, 2 RCTs, RR fixed 'not improved at end of course of ECT' 0.79 CI 0.45 to 1.39). One trial showed a significant advantage for 20 treatments over 12 treatments for numbers globally improved at the end of the ECT course (n=43, RR fixed 2.53 CI 1.13 to 5.66). The evidence in this review suggests that ECT, combined with treatment with antipsychotic drugs, may be considered an option for people with schizophrenia, particularly when rapid global improvement and reduction of symptoms is desired. This is also the case for those with schizophrenia who show limited response to medication alone. Even though this initial beneficial effect may not last beyond the short term, there is no clear evidence to refute its use for people with schizophrenia. The research base for the use of ECT in people with schizophrenia continues to expand, but even after more than five decades of clinical use, there remain many unanswered questions regarding its role in the management of people with schizophrenia.

Determination of linear defect depths from eddy currents disturbances

NASA Astrophysics Data System (ADS)

Ramos, Helena Geirinhas; Rocha, Tiago; Pasadas, Dário; Ribeiro, Artur Lopes

2014-02-01

One of the still open problems in the inspection research concerns the determination of the maximum depth to which a surface defect goes. Eddy current testing being one of the most sensitive well established inspection methods, able to detect and characterize different type of defects in conductive materials, is an adequate technique to solve this problem. This paper reports a study concerning the disturbances in the magnetic field and in the lines of current due to a machined linear defect having different depths in order to extract relevant information that allows the determination of the defect characteristics. The image of the eddy currents (EC) is paramount to understand the physical phenomena involved. The EC images for this study are generated using a commercial finite element model (FLUX). The excitation used produces a uniform magnetic field on the plate under test in the absence of defects and the disturbances due to the defects are compared with those obtained from experimental measurements. In order to increase the limited penetration depth of the method giant magnetoresistors (GMR) are used to lower the working frequency. The geometry of the excitation planar coil produces a uniform magnetic field on an area of around the GMR sensor, inducing a uniform eddy current distribution on the plate. In the presence of defects in the material surface, the lines of currents inside the material are deviated from their uniform direction and the magnetic field produced by these currents is sensed by the GMR sensor. Besides the theoretical study of the electromagnetic system, the paper describes the experiments that have been carried out to support the theory and conclusions are drawn for cracks having different depths.

A comparison of the structure, properties, and water mass composition of quasi-isotropic eddies in western boundary currents in an eddy-resolving ocean model

NASA Astrophysics Data System (ADS)

Rykova, Tatiana; Oke, Peter R.; Griffin, David A.

2017-06-01

Using output from a near-global eddy-resolving ocean model, we analyse the properties and characteristics of quasi-isotropic eddies in five Western Boundary Current (WBC) regions, including the extensions of the Agulhas, East Australian Current (EAC), Brazil-Malvinas Confluence (BMC), Kuroshio and Gulf Stream regions. We assess the model eddies by comparing to satellite and in situ observations, and show that most aspects of the model's representation of eddies are realistic. We find that the mean eddies differ dramatically between these WBC regions - all with some unique and noteworthy characteristics. We find that the vertical displacement of isopycnals of Agulhas eddies is the greatest, averaging 350-450 m at depths of over 800-900 m. EAC (BMC) eddies are the least (most) barotropic, with only 50% (85-90%) of the velocity associated with the barotropic mode. Kuroshio eddies are the most stratified, resulting in small isopycnal displacement, even for strong eddies; and Gulf Stream eddies carry the most heat. Despite their differences, we explicitly show that the source waters for anticyclonic eddies are a mix of the WBC water (from the boundary current itself) and water that originates equatorward of the WBC eddy-field; and cyclonic eddies are a mix of WBC water and water that originates poleward of the WBC eddy-field.

[MK-801 or DNQX reduces electroconvulsive shock-induced impairment of learning-memory and hyperphosphorylation of Tau in rats].

PubMed

Liu, Chao; Min, Su; Wei, Ke; Liu, Dong; Dong, Jun; Luo, Jie; Liu, Xiao-Bin

2012-08-25

This study explored the effect of the excitatory amino acid receptor antagonists on the impairment of learning-memory and the hyperphosphorylation of Tau protein induced by electroconvulsive shock (ECT) in depressed rats, in order to provide experimental evidence for the study on neuropsychological mechanisms improving learning and memory impairment and the clinical intervention treatment. The analysis of variance of factorial design set up two intervention factors which were the electroconvulsive shock (two level: no disposition; a course of ECT) and the excitatory amino acid receptor antagonists (three level: iv saline; iv NMDA receptor antagonist MK-801; iv AMPA receptor antagonist DNQX). Forty-eight adult Wistar-Kyoto (WKY) rats (an animal model for depressive behavior) were randomly divided into six experimental groups (n = 8 in each group): saline (iv 2 mL saline through the tail veins of WKY rats ); MK-801 (iv 2 mL 5 mg/kg MK-801 through the tail veins of WKY rats) ; DNQX (iv 2 mL 5 mg/kg DNQX through the tail veins of WKY rats ); saline + ECT (iv 2 mL saline through the tail veins of WKY rats and giving a course of ECT); MK-801 + ECT (iv 2 mL 5 mg/kg MK-801 through the tail veins of WKY rats and giving a course of ECT); DNQX + ECT (iv 2 mL 5 mg/kg DNQX through the tail veins of WKY rats and giving a course of ECT). The Morris water maze test started within 1 day after the finish of the course of ECT to evaluate learning and memory. The hippocampus was removed from rats within 1 day after the finish of Morris water maze test. The content of glutamate in the hippocampus of rats was detected by high performance liquid chromatography. The contents of Tau protein which included Tau5 (total Tau protein), p-PHF1(Ser396/404), p-AT8(Ser199/202) and p-12E8(Ser262) in the hippocampus of rats were detected by immunohistochemistry staining (SP) and Western blot. The results showed that ECT and the glutamate ionic receptor blockers (NMDA receptor antagonist MK-801 and AMPA receptor antagonist DNQX) induced the impairment of learning and memory in depressed rats with extended evasive latency time and shortened space exploration time. And the two factors presented a subtractive effect. ECT significantly up-regulated the content of glutamate in the hippocampus of depressed rats which were not affected by the glutamate ionic receptor blockers. ECT and the glutamate ionic receptor blockers did not affect the total Tau protein in the hippocampus of rats. ECT up-regulated the hyperphosphorylation of Tau protein in the hippocampus of depressed rats, while the glutamate ionic receptor blockers down-regulated it, and combination of the two factors presented a subtractive effect. Our results indicate that ECT up-regulates the content of glutamate in the hippocampus of depressed rats, which up-regulates the hyperphosphorylation of Tau protein resulting in the impairment of learning and memory in depressed rats.

Is Electroconvulsive Therapy a Treatment for Depression Following Traumatic Brain Injury?

PubMed Central

Srienc, Anja; Sarai, Simrat; Xiong, Yee; Lippmann, Steven

2018-01-01

Traumatic brain injury (TBI) can be caused by blunt or penetrating injury to the head. The pathophysiological evolution of TBI involves complex biochemical and genetic changes. Common sequelae of TBI include seizures and psychiatric disorders, particularly depression. In considering pharmacologic interventions for treating post-TBI depression, it is important to remember that TBI patients have a higher risk of seizures; therefore, the benefits of prescribing medications that lower the seizure threshold need to be weighed against the risk of seizures. When post-TBI depression is refractory to pharmacotherapy, electroconvulsive therapy (ECT) could provide an alternative therapeutic strategy. Data remain sparse on using ECT in this seizure-prone population, but three case reports demonstrated good outcomes. Currently, not enough evidence exists to provide clinical recommendations for using ECT for treating post-TBI depression, and more research is needed to generate guidelines on how best to treat depression in TBI patients. However, the preliminary data on using ECT in patients with TBI are promising. If proven safe, ECT could be a powerful tool to treat post-TBI depression. PMID:29707426

Is Electroconvulsive Therapy a Treatment for Depression Following Traumatic Brain Injury?

PubMed

Srienc, Anja; Narang, Puneet; Sarai, Simrat; Xiong, Yee; Lippmann, Steven

2018-04-01

Traumatic brain injury (TBI) can be caused by blunt or penetrating injury to the head. The pathophysiological evolution of TBI involves complex biochemical and genetic changes. Common sequelae of TBI include seizures and psychiatric disorders, particularly depression. In considering pharmacologic interventions for treating post-TBI depression, it is important to remember that TBI patients have a higher risk of seizures; therefore, the benefits of prescribing medications that lower the seizure threshold need to be weighed against the risk of seizures. When post-TBI depression is refractory to pharmacotherapy, electroconvulsive therapy (ECT) could provide an alternative therapeutic strategy. Data remain sparse on using ECT in this seizure-prone population, but three case reports demonstrated good outcomes. Currently, not enough evidence exists to provide clinical recommendations for using ECT for treating post-TBI depression, and more research is needed to generate guidelines on how best to treat depression in TBI patients. However, the preliminary data on using ECT in patients with TBI are promising. If proven safe, ECT could be a powerful tool to treat post-TBI depression.

Acetylcholinesterase inhibitors for electroconvulsive therapy-induced cognitive side effects: a systematic review.

PubMed

Henstra, Marieke J; Jansma, Elise P; van der Velde, Nathalie; Swart, Eleonora L; Stek, Max L; Rhebergen, Didi

2017-05-01

Electroconvulsive therapy (ECT) is an effective treatment for severe late-life depression; however, ECT-induced cognitive side effects frequently occur. The cholinergic system is thought to play an important role in the pathogenesis. We systematically reviewed the evidence for acetylcholinesterase inhibitors (Ache-I) to prevent or reduce ECT-induced cognitive side effects. A systematic search was performed in Pubmed, EMBASE, PsychINFO, and the Cochrane database to identify clinical trials investigating the effect of Ache-I on ECT-induced cognitive side effects. Key search terms included all synonyms for ECT and Ache-I. Risk of bias assessment was conducted by using the Cochrane Collaboration's tool. Five clinical trials were eligible for inclusion. All studies focused on cognitive functioning as primary endpoint, but assessment of cognitive functioning varied widely in time point of assessment and in cognitive tests that were used. There was also great variety in study medication, route and time of administration and dosages, duration of drug administration, and ECT techniques. Finally, only two out of five studies were considered at low risk of bias. Despite the aforementioned shortcomings, without exception, all studies demonstrated significantly better cognitive performance in individuals treated with Ache-I. Despite large heterogeneity in studies, Ache-I appear to have beneficial effects on ECT-induced cognitive side effects, supporting an association with the cholinergic system in ECT-induced cognitive impairment. Methodological sound studies controlling for putative confounders are warranted. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Randomized comparison of ultra-brief bifrontal and unilateral electroconvulsive therapy for major depression: cognitive side-effects.

PubMed

Sienaert, P; Vansteelandt, K; Demyttenaere, K; Peuskens, J

2010-04-01

The cognitive side-effects of bifrontal (BF) and right unilateral (UL) ultra-brief pulse (0.3 ms) electroconvulsive therapy (ECT) were compared, in the treatment of patients with a depressive episode. Neuropsychological functioning in patients with a medication refractory depressive episode, that were treated with a course of BF ultra-brief ECT at 1.5 times seizure threshold (ST) or UL ultra-brief ECT at 6 times ST, by random assignment, was assessed before treatment, and 1 and 6 weeks after the treatment course, by a blinded rater. Of the 64 patients that were included, 32 (50%) received BF ECT, and 32 (50%) received UL ECT, by random assignment. Neuropsychological testing 1 and 6 weeks after treatment was performed by 30 (93.75%) and 19 (59.37%) patients, respectively, in the BF-group and 29 (90.62%) and 20 (62.50%), respectively, in the UL-group. There was no deterioration in any of the neuropsychological measures. Patients rated their memory as clearly improved after treatment. There were no significant differences between the patients given BF ECT and those given UL ECT. Ultrabrief pulse ECT, used either in combination with a UL electrode position and a stimulus of 6 times ST, or a BF electrode position with a stimulus of 1.5 times ST, are effective antidepressant techniques, that do not have a deleterious effect on cognitive function. Copyright 2009 Elsevier B.V. All rights reserved.

The current California drought through EDDI's eyes: early warning and monitoring of agricultural and hydrologic drought with the new Evaporative Demand Drought Index.

NASA Astrophysics Data System (ADS)

Hobbins, M.; McEvoy, D.; Huntington, J. L.; Wood, A. W.; Morton, C.; Verdin, J. P.

2015-12-01

We have developed a physically based, multi-scalar drought index—the Evaporative Demand Drought Index (EDDI)—to improve treatment of evaporative dynamics in drought monitoring. Existing popular drought indices—such as the Palmer Drought Severity Index that informs much of the US Drought Monitor (USDM)—have primarily relyied on precipitation and temperature (T) to represent hydroclimatic anomalies, leaving evaporative demand (E0) most often derived from poorly performing T-based parameterizations then used to derive actual evapotranspiration (ET) from LSMs. Instead, EDDI leverages the inter-relations of E0 and ET, measuring E0's physical response to surface drying anomalies due to two distinct land surface/atmosphere interactions: (i) in sustained drought, limited moisture availability forces E0 and ET into a complementary relation, whereby ET declines as E0 increases; and (ii) in "flash" droughts, E0 increases due to increasing advection or radiation. E0's rise in response to both drought types suggests EDDI's robustness as a monitor and leading indicator of drought. To drive EDDI, we use for E0 daily reference ET from the ASCE Standardized Reference ET equation forced by North American Land Data Assimilation System drivers. EDDI is derived by aggregating E0 anomalies from its long-term mean across a period of interest and normalizing them to a Z-score. Positive EDDI indicates drier than normal conditions (and so drought). We use the current historic California drought as a test-case in which to examine EDDI's performance in monitoring agricultural and hydrologic drought. We observe drought development and decompose the behavior of drought's evaporative drivers during in-drought intensification periods and wetting events. EDDI's performance as a drought leading indicator with respect to the USDM is tested in important agricultural regions. Comparing streamflow from several USGS gauges in the Sierra Nevada to EDDI, we find that EDDI tracks most major hydrologic droughts, with correlations to water-year streamflow that are highest at the 9- to 12-month aggregation periods, and during the summer. EDDI shows significant promise as a leading indicator of drought, thereby providing a valuable planning window for growers and water resource managers.

Electronic Voltage and Current Transformers Testing Device

PubMed Central

Pan, Feng; Chen, Ruimin; Xiao, Yong; Sun, Weiming

2012-01-01

A method for testing electronic instrument transformers is described, including electronic voltage and current transformers (EVTs, ECTs) with both analog and digital outputs. A testing device prototype is developed. It is based on digital signal processing of the signals that are measured at the secondary outputs of the tested transformer and the reference transformer when the same excitation signal is fed to their primaries. The test that estimates the performance of the prototype has been carried out at the National Centre for High Voltage Measurement and the prototype is approved for testing transformers with precision class up to 0.2 at the industrial frequency (50 Hz or 60 Hz). The device is suitable for on-site testing due to its high accuracy, simple structure and low-cost hardware. PMID:22368510

Development of Eddy Current Techniques for the Detection of Cracking in Space Shuttle Primary Reaction Control Thrusters

NASA Technical Reports Server (NTRS)

Wincheski, Buzz A.; Simpson, John W.; Koshti, Ajay

2007-01-01

A recent identification of cracking in the Space Shuttle Primary Reaction Control System (PRCS) thrusters triggered an extensive nondestructive evaluation effort to develop techniques capable of identifying such damage on installed shuttle hardware. As a part of this effort, specially designed eddy current probes inserted into the acoustic cavity were explored for the detection of such flaws and for evaluation of the remaining material between the crack tip and acoustic cavity. The technique utilizes two orthogonal eddy current probes which are scanned under stepper motor control in the acoustic cavity to identify cracks hidden with as much as 0.060 remaining wall thickness to the cavity. As crack growth rates in this area have been determined to be very slow, such an inspection provides a large safety margin for continued operation of the critical shuttle hardware. Testing has been performed on thruster components with both actual and fabricated defects. This paper will review the design and performance of the developed eddy current inspection system. Detection of flaws as a function of remaining wall thickness will be presented along with the proposed system configuration for depot level or on-vehicle inspection capabilities.

Development of Eddy Current Technique for the Detection of Stress Corrosion Cracking in Space Shuttle Primary Reaction Control Thrusters

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Simpson, John; Koshti, Ajay

2006-01-01

A recent identification of stress corrosion cracking in the Space Shuttle Primary Reaction Control System (PRCS) thrusters triggered an extensive nondestructive evaluation effort to develop techniques capable of identifying such damage on installed shuttle hardware. As a part of this effort, specially designed eddy current probes inserted into the acoustic cavity were explored for the detection of such flaws and for evaluation of the remaining material between the crack tip and acoustic cavity. The technique utilizes two orthogonal eddy current probes which are scanned under stepper motor control in the acoustic cavity to identify cracks hidden with as much as 0.060 remaining wall thickness to the cavity. As crack growth rates in this area have been determined to be very slow, such an inspection provides a large safety margin for continued operation of the critical shuttle hardware. Testing has been performed on thruster components with both actual and fabricated defects. This paper will review the design and performance of the developed eddy current inspection system. Detection of flaws as a function of remaining wall thickness will be presented along with the proposed system configuration for depot level or on-vehicle inspection capabilities.

Development of eddy current probe for fiber orientation assessment in carbon fiber composites

NASA Astrophysics Data System (ADS)

Wincheski, Russell A.; Zhao, Selina

2018-04-01

Measurement of the fiber orientation in a carbon fiber composite material is crucial in understanding the load carrying capability of the structure. As manufacturing conditions including resin flow and molding pressures can alter fiber orientation, verification of the as-designed fiber layup is necessary to ensure optimal performance of the structure. In this work, the development of an eddy current probe and data processing technique for analysis of fiber orientation in carbon fiber composites is presented. A proposed directional eddy current probe is modeled and its response to an anisotropic multi-layer conductor simulated. The modeling results are then used to finalize specifications of the eddy current probe. Experimental testing of the fabricated probe is presented for several samples including a truncated pyramid part with complex fiber orientation draped to the geometry for resin transfer molding. The inductively coupled single sided measurement enables fiber orientation characterization through the thickness of the part. The fast and cost-effective technique can be applied as a spot check or as a surface map of the fiber orientations across the structure. This paper will detail the results of the probe design, computer simulations, and experimental results.

Calculation of Eddy Currents In the CTH Vacuum Vessel and Coil Frame

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

A. Zolfaghari, A. Brooks, A. Michaels, J. Hanson, and G. Hartwell

2012-09-25

Knowledge of eddy currents in the vacuum vessel walls and nearby conducting support structures can significantly contribute to the accuracy of Magnetohydrodynamics (MHD) equilibrium reconstruction in toroidal plasmas. Moreover, the magnetic fields produced by the eddy currents could generate error fields that may give rise to islands at rational surfaces or cause field lines to become chaotic. In the Compact Toroidal Hybrid (CTH) device (R0 = 0.75 m, a = 0.29 m, B ≤ 0.7 T), the primary driver of the eddy currents during the plasma discharge is the changing flux of the ohmic heating transformer. Electromagnetic simulations are usedmore » to calculate eddy current paths and profile in the vacuum vessel and in the coil frame pieces with known time dependent currents in the ohmic heating coils. MAXWELL and SPARK codes were used for the Electromagnetic modeling and simulation. MAXWELL code was used for detailed 3D finite-element analysis of the eddy currents in the structures. SPARK code was used to calculate the eddy currents in the structures as modeled with shell/surface elements, with each element representing a current loop. In both cases current filaments representing the eddy currents were prepared for input into VMEC code for MHD equilibrium reconstruction of the plasma discharge. __________________________________________________« less

The Practice of Electroconvulsive Therapy in US Correctional Facilities: A Nationwide Survey.

PubMed

Surya, Sandarsh; McCall, W Vaughn; Iltis, Ana S; Rosenquist, Peter B; Hogan, Elizabeth

2015-09-01

There are little data regarding the practice of electroconvulsive therapy (ECT) in correctional settings in the United States. A survey was conducted to study the current practice of ECT in US prisons. We hypothesize that ECT is underutilized in the correctional setting. We also review the ethical aspects of using ECT for the treatment of mental illness in the prison population. A 12-question survey via a Survey Monkey link was emailed to chiefs of psychiatry, or the equivalent, of each state's department of corrections. We examined the frequency of Likert-type responses, tabulated individual comments for qualitative review, and grouped for comparison. Email contacts for chiefs of psychiatry, or the equivalent, for the department of corrections in 45 states (90%) were obtained and a survey link was sent. Thirty-one (68.9%) of 45 responded to the survey. Respondent estimates of the number of inmates with mental illness in 31 prison systems varied from less than 500 to more than 4500. Of these 31, 12 (38.7%) had more than 4500 inmates with mental illness. Four systems reported the use of ECT within the last 5 years. Of those, one reported use in the last 1 to 6 months, and 3 reported use in the last 2 to 5 years. Of these 4 prison systems, all felt that they had up to 10 patients who would benefit if ECT continued to be offered or became available in the future. None of these systems provided ECT within the prison. The inmates were referred to a local state psychiatric facility, a university hospital, or other institutions. The reasons for not using ECT as reported by the respondents are grouped under subheadings of stigma, ethical concerns, logistical concerns, and others. Considering the high prevalence of mental illness in prisons, one might expect a high prevalence of ECT responsive mental illness and, hence, provision of ECT to some prisoners with mental illness. However, our survey suggests that the use of ECT in prisons in the United States is low. Stigma, ethical concerns, and logistical concerns were the main hindrances for providing ECT to prisoners with mental illness. Given that ECT is the standard of care in certain clinical scenarios, physicians are obligated to offer such treatment to inmates when necessary. It can be argued that failure of the prison to offer the standard of care is unethical and unconstitutional.

A new early cognitive screening measure to detect cognitive side-effects of electroconvulsive therapy?

PubMed

Martin, Donel M; Katalinic, Natalie; Ingram, Anna; Schweitzer, Isaac; Smith, Deidre J; Hadzi-Pavlovic, Dusan; Loo, Colleen K

2013-12-01

Cognitive side-effects from electroconvulsive therapy (ECT) can be distressing for patients and early detection may have an important role in guiding treatment decisions over the ECT course. This prospective study examined the utility of an early cognitive screening battery for predicting cognitive side-effects which develop later in the ECT course. The screening battery, together with the Mini Mental Status Examination (MMSE), was administered to 123 patients at baseline and after 3 ECT treatments. A more detailed cognitive battery was administered at baseline, after six treatments (post ECT 6) and after the last ECT treatment (post treatment) to assess cognitive side-effects across several domains: global cognition, anterograde memory, executive function, speed and concentration, and retrograde memory. Multivariate analyses examined the predictive utility of change on items from the screening battery for later cognitive changes at post ECT 6 and post treatment. Results showed that changes on a combination of items from the screening battery were predictive of later cognitive changes at post treatment, particularly for anterograde memory (p < 0.01), after controlling for patient and treatment factors. Change on the MMSE predicted cognitive changes at post ECT 6 but not at post treatment. A scoring method for the new screening battery was tested for discriminative ability in a sub-sample of patients. This study provides preliminary evidence that a simple and easy-to-administer measure may potentially be used to help guide clinical treatment decisions to optimise efficacy and cognitive outcomes. Further development of this measure and validation in a more representative ECT clinical population is required. Copyright © 2013 Elsevier Ltd. All rights reserved.

The influence of eddy currents on magnetic actuator performance

NASA Technical Reports Server (NTRS)

Zmood, R. B.; Anand, D. K.; Kirk, J. A.

1987-01-01

The present investigation of the effects of eddy currents on EM actuators' transient performance notes that a transfer function representation encompassing a first-order model of the eddy current influence can be useful in control system analysis. The method can be extended to represent the higher-order effects of eddy currents for actuators that cannot be represented by semiinfinite planes.

Expert system for analyzing eddy current measurements

DOEpatents

Levy, Arthur J.; Oppenlander, Jane E.; Brudnoy, David M.; Englund, James M.; Loomis, Kent C.

1994-01-01

A method and apparatus (called DODGER) analyzes eddy current data for heat exchanger tubes or any other metallic object. DODGER uses an expert system to analyze eddy current data by reasoning with uncertainty and pattern recognition. The expert system permits DODGER to analyze eddy current data intelligently, and obviate operator uncertainty by analyzing the data in a uniform and consistent manner.

Effect of mesoscale eddies on the Taiwan Strait Current

NASA Astrophysics Data System (ADS)

Chang, Y. L.; Miyazawa, Y.; Guo, X.

2016-02-01

This study shows that mesoscale eddies can alter the Taiwan Strait current. The 20-year data-assimilated Japan Coastal Ocean Predictability Experiment 2 (JCOPE2) reanalysis data are analyzed, and the results are confirmed with idealized experiments. The leading wind-forced seasonal cycle is excluded to focus on the effect of the eddy. The warm eddy southwest of Taiwan is shown to generate a northward flow, whereas the cold eddy produces a southward current. The effect of the eddy penetrates onto the shelf through the Joint Effect of Baroclinicity and Relief (JEBAR). The cross-isobath fluxes lead to shelfward convergence and divergence, setting up the modulation of the sea level slope. The resulting along-strait current anomaly eventually affects a wide area of the Taiwan Strait. The stronger eddy leads to larger modification of the cross-shelf flows and sea level slope, producing a greater transport anomaly. The composite Sea-Viewing Wide Field-of-view Sensor chlorophyll-a (Chl-a) serves as an indicator to show the change in Chl-a concentration in the strait in response to the eddy-induced current. During the warm eddy period, the current carries the southern water of lower concentration northward, reducing Chl-a concentration in the strait. In contrast, Chl-a is enhanced because the cold eddy-induced southward current carries the northern water of higher concentration southward into the strait.

An audit of ECT in England 2011-2015: Usage, demographics, and adherence to guidelines and legislation.

PubMed

Read, John; Harrop, Christopher; Geekie, Jim; Renton, Julia

2017-10-20

Electroconvulsive therapy (ECT) continues to be used in England, but without comprehensive national auditing. Therefore, information was gathered on usage, demographics, consent, and adherence to the guidelines of the National Institute of Clinical Excellence (N.I.C.E.) and to the Mental Health Act. Freedom of Information Act requests were sent to 56 National Health Service Trusts. Thirty-two trusts provided some usable data. Only 10 were able to report how many people received psychological therapy prior to ECT in accordance with N.I.C.E. recommendations, with figures ranging from 0% to 100%. The number of people currently receiving ECT in England annually is between 2,100 and 2,700, and falling. There was a 12-fold difference between the Trusts with the highest and lowest usage rates per capita. Most recipients are still women (66%) and over 60 (56%). More than a third (39%) is given without consent, with 30% of Trusts not adhering to mental health legislation concerning second opinions. At least 44% were not using validated measures of efficacy, and at least 33% failed to do so for adverse effects. Only four provided any actual data for positive outcomes or adverse effects. None provided any data on efficacy beyond the end of treatment. National audits should be reinstated. Independent, objective monitoring of adverse effects is urgently required. An investigation into why ECT is still administered excessively to older people and women seems long overdue. Mental health staff should seek to ensure that all depressed people in their service are offered evidence-based psychological treatments before being offered E.C.T. Staff should lobby managers to ensure proper auditing of E.C.T. within their service Individuals receiving ECT should be closely monitored for adverse cognitive effects Overuse of ECT with women and older people should be avoided. © 2017 The British Psychological Society.

Use of electroconvulsive therapy for Asian patients with schizophrenia (2001-2009): Trends and correlates.

PubMed

Xiang, Yu-Tao; Ungvari, Gabor S; Correll, Christoph U; Chiu, Helen F K; Lai, Kelly Y C; Wang, Chuan-Yue; Si, Tian-Mei; Lee, Edwin H M; He, Yan-Ling; Yang, Shu-Yu; Chong, Mian-Yoon; Kua, Ee-Heok; Fujii, Senta; Sim, Kang; Yong, Michael K H; Trivedi, Jitendra K; Chung, Eun-Kee; Udomratn, Pichet; Chee, Kok-Yoon; Sartorius, Norman; Tan, Chay-Hoon; Shinfuku, Naotaka

2015-08-01

Little is known about electroconvulsive therapy (ECT) use in Asian inpatients with schizophrenia. This study examined trends of ECT use for schizophrenia patients in Asia between 2001 and 2009 and its independent demographic and clinical correlates. Data on 6761 hospitalized schizophrenia patients (2001 = 2399, 2004 = 2136, and 2009 = 2226) in nine Asian countries and territories were collected by either chart review or interviews during a 1-month period. Patients' sociodemographic and clinical characteristics, prescriptions of psychotropic drugs and ECT use were recorded using a standardized protocol and data-collection procedure. The frequency of ECT was 3.3% in the whole sample; rising from 1.8% in 2001 to 3.3% in 2004 and 4.9% in 2009 (P < 0.0001). However, this increased trend was driven solely by increased ECT use in China (P < 0.0001), and the inclusion of India in the 2009 survey. There were wide inter-country variations: 2001, 0% (Hong Kong, Korea) to 5.9% (China); 2004, 0% (Singapore) to 11.1% (China); 2009, 0% (Hong Kong) to 13.8% (India) and 15.2% (China). Multiple logistic regression analysis of the whole sample revealed that patients receiving ECT were less likely in the 35-64-year age group, had shorter length of current hospitalization and fewer negative symptoms, and were more likely to receive second-generation antipsychotic medications compared to those who were not treated with ECT (R(2)  = 0.264, P < 0.001). ECT use for schizophrenia has increased over the past decade in China, being low/relatively stable in other Asian countries/regions. Reasons for substantial variations in ECT frequency in Asia require further study. © 2015 The Authors. Psychiatry and Clinical Neurosciences © 2015 Japanese Society of Psychiatry and Neurology.

Detection and Inspection of Steel Bars in Reinforced Concrete Structures Using Active Infrared Thermography with Microwave Excitation and Eddy Current Sensors

PubMed Central

Szymanik, Barbara; Frankowski, Paweł Karol; Chady, Tomasz; John Chelliah, Cyril Robinson Azariah

2016-01-01

The purpose of this paper is to present a multi-sensor approach to the detection and inspection of steel bars in reinforced concrete structures. In connection with our past experience related to non-destructive testing of different materials, we propose using two potentially effective methods: active infrared thermography with microwave excitation and the eddy current technique. In this article active infrared thermography with microwave excitation is analyzed both by numerical modeling and experiments. This method, based on thermal imaging, due to its characteriatics should be considered as a preliminary method for the assessment of relatively shallowly located steel bar reinforcements. The eddy current technique, on the other hand, allows for more detailed evaluation and detection of deeply located rebars. In this paper a series of measurement results, together with the initial identification of certain features of steel reinforcement bars will be presented. PMID:26891305

Detection and Inspection of Steel Bars in Reinforced Concrete Structures Using Active Infrared Thermography with Microwave Excitation and Eddy Current Sensors.

PubMed

Szymanik, Barbara; Frankowski, Paweł Karol; Chady, Tomasz; John Chelliah, Cyril Robinson Azariah

2016-02-16

The purpose of this paper is to present a multi-sensor approach to the detection and inspection of steel bars in reinforced concrete structures. In connection with our past experience related to non-destructive testing of different materials, we propose using two potentially effective methods: active infrared thermography with microwave excitation and the eddy current technique. In this article active infrared thermography with microwave excitation is analyzed both by numerical modeling and experiments. This method, based on thermal imaging, due to its characteriatics should be considered as a preliminary method for the assessment of relatively shallowly located steel bar reinforcements. The eddy current technique, on the other hand, allows for more detailed evaluation and detection of deeply located rebars. In this paper a series of measurement results, together with the initial identification of certain features of steel reinforcement bars will be presented.

Cognitive side-effects of electroconvulsive therapy in elderly depressed patients.

PubMed

Dybedal, Gro Strømnes; Tanum, Lars; Sundet, Kjetil; Gaarden, Torfinn Lødøen; Bjølseth, Tor Magne

2014-01-01

Knowledge about cognitive side-effects induced by electroconvulsive therapy (ECT) in depressed elderly patients is sparse. In this study we investigated changes in the cognitive functioning of non-demented elderly depressed patients receiving ECT (n = 62) compared with healthy elderly people (n = 17). Neuropsychological tests were administered at the start of treatment and again within 1 week after treatment. We computed reliable change indices (RCIs) using simple regression methods. RCIs are statistical methods for analyzing change in individuals that have not yet been used in studies of the acute cognitive side-effects of ECT. At the group level, only letter fluency performance was found to be significantly reduced in the ECT group compared with the controls, whereas both groups demonstrated stable or improved performance on all other measures. At the individual level, however, 11% of patients showed retrograde amnesia for public facts post-ECT and 40% of the patients showed a significant decline in neuropsychological functioning. Decline on a measure of delayed verbal anterograde memory was most common. Our findings indicate that there are mild neurocognitive impairments in the acute phase for a substantial minority of elderly patients receiving ECT. Analysis of reliable change facilitated the illumination of cognitive side-effects in our sample.

Promising More Information

NASA Technical Reports Server (NTRS)

2003-01-01

When NASA needed a real-time, online database system capable of tracking documentation changes in its propulsion test facilities, engineers at Stennis Space Center joined with ECT International, of Brookfield, Wisconsin, to create a solution. Through NASA's Dual-Use Program, ECT developed Exdata, a software program that works within the company's existing Promise software. Exdata not only satisfied NASA s requirements, but also expanded ECT s commercial product line. Promise, ECT s primary product, is an intelligent software program with specialized functions for designing and documenting electrical control systems. An addon to AutoCAD software, Promis e generates control system schematics, panel layouts, bills of material, wire lists, and terminal plans. The drawing functions include symbol libraries, macros, and automatic line breaking. Primary Promise customers include manufacturing companies, utilities, and other organizations with complex processes to control.

Eddy current probe with foil sensor mounted on flexible probe tip and method of use

DOEpatents

Viertl, John R. M.; Lee, Martin K.

2001-01-01

A pair of copper coils are embedded in the foil strip. A first coil of the pair generates an electromagnetic field that induces eddy currents on the surface, and the second coil carries a current influenced by the eddy currents on the surface. The currents in the second coil are analyzed to obtain information on the surface eddy currents. An eddy current probe has a metal housing having a tip that is covered by a flexible conductive foil strip. The foil strip is mounted on a deformable nose at the probe tip so that the strip and coils will conform to the surface to which they are applied.

Electroconvulsive therapy-related cognitive impairment and choice of anesthesia: the tipping point.

PubMed

Sedighinejad, Abbas; Nabi, Bahram Naderi; Haghighi, Mohammad; Farzam, Alieh; Sayyah, Zahra; Kabiri, Majid; Soleimani, Robabeh; Alavi, Cyrus Emir

2015-06-01

Electroconvulsive therapy (ECT) is among the most effective treatments of several life-threatening psychiatric disorder. Despite effective therapy, ECT-induced seizure could cause several adverse effects including cognitive disorders and memory impairment. Drugs such as thiopental, which have been prescribed for anesthesia required for ECT, are known as drugs with cognitive effects. This pilot randomized clinical trial tried to assess the feasibility of using a lower dose of thiopental in combination with remifentanil instead of a higher challenging dose of a single drug with cognitive side effects such as thiopental. We evaluated post-ECT cognitive impairment in patients who received remifentanil-thiopental compared with thiopental-placebo group. One hundred twenty patients with psychiatric disorders between the ages of 18 and 60 years were enrolled. The patients were randomized into 2 groups who received either thiopental sodium (4 mg/kg) and remifentanil (1 μg/kg) or thiopental sodium (3 mg/kg, placebo). The psychiatric patients were examined using mini-mental state examination in terms of the cognitive deficits before ECT as well as 5 and 24 hours after ECT. Statistical analyses were done using Statistical Package for the Social Sciences version 16. Unpaired t test, χ2 test, and analysis of variance were used to determine the association of variables. All the patients completed the trial. There were no reports of adverse effects. In terms of depth of anesthesia measured by bispectral index, no significant difference was observed. Regarding mini-mental state examination scores, the difference was not statistically significant. Depth of anesthesia was similar between the groups.

A cryogenic scan mechanism for use in Fourier transform spectrometers

NASA Technical Reports Server (NTRS)

Hakun, Claef F.; Blumenstock, Kenneth A.

1995-01-01

This paper describes the requirements, design, assembly and testing of the linear Scan Mechanism (SM) of the Composite Infrared Spectrometer (CIRS) Instrument. The mechanism consists of an over constrained flexible structure, an innovative moving magnet actuator, passive eddy current dampers, a Differential Eddy Current (DEC) sensor, Optical Limit Sensors (OLS), and a launch lock. Although all the components of the mechanism are discussed, the flexible structure and the magnetic components are the primary focus. Several problems encountered and solutions implemented during the development of the scan mechanism are also described.

Wire inhomogeneity detector having a core with opposing pole pieces and guide pieces adjacent the opposing pole pieces

DOEpatents

Gibson, George H.; Smits, Robert G.; Eberhard, Philippe H.

1989-01-01

A device for uncovering imperfections in electrical conducting wire, particularly superconducting wire, by detecting variations in eddy currents. Eddy currents effect the magnetic field in a gap of an inductor, contained in a modified commercial ferrite core, through which the wire being tested is passed. A small increase or decrease in the amount of conductive material, such as copper, in a fixed cross section of wire will unbalance a bridge used to measure the impedance of the inductor, tripping a detector and sounding an alarm.

Experimental verification of an eddy-current bearing

NASA Technical Reports Server (NTRS)

Nikolajsen, Jorgen L.

1989-01-01

A new type of electromagnetic bearing was built and tested. It consists of fixed AC-electromagnets in a star formation surrounding a conducting rotor. The bearing works by repulsion due to eddy-currents induced in the rotor. A single bearing is able to fully support a short rotor. The rotor support is inherently stable in all five degrees of freedom. No feedback control is needed. The bearing is also able to accelerate the rotor up to speed and decelerate the rotor back to standstill. The bearing design and the experimentation to verify its capabilities are described.

Development of Geometry Normalized Electromagnetic System (GNES) instrument for metal defect detection

NASA Astrophysics Data System (ADS)

Zakaria, Zakaria; Surbakti, Muhammad Syukri; Syahreza, Saumi; Mat Jafri, Mohd. Zubir; Tan, Kok Chooi

2017-10-01

It has been already made, calibrated and tested a geometry normalized electromagnetic system (GNES) for metal defect examination. The GNES has an automatic data acquisition system which supporting the efficiency and accuracy of the measurement. The data will be displayed on the computer monitor as a graphic display then saved automatically in the Microsoft Excel format. The transmitter will transmit the frequency pair (FP) signals i.e. 112.5 Hz and 337.5 Hz; 112.5 Hz and 1012.5 Hz; 112.5 Hz and 3037.5 Hz; 337.5 Hz and 1012.5 Hz; 337.5 Hz and 3037.5 Hz. Simultaneous transmissions of two electromagnetic waves without distortions by the transmitter will induce an eddy current in the metal. This current, in turn, will produce secondary electromagnetic fields which are measured by the receiver together with the primary fields. Measurement of percent change of a vertical component of the fields will give the percent response caused by the metal or the defect. The response examinations were performed by the models with various type of defect for the master curves. The materials of samples as a plate were using Aluminum, Brass, and Copper. The more of the defects is the more reduction of the eddy current response. The defect contrasts were tended to decrease when the more depth of the defect position. The magnitude and phase of the eddy currents will affect the loading on the coil thus its impedance. The defect must interrupt the surface eddy current flow to be detected. Defect lying parallel to the current path will not cause any significant interruption and may not be detected. The main factors which affect the eddy current response are metal conductivity, permeability, frequency, and geometry.

Mitigation of eddy current heating during magnetic nanoparticle hyperthermia therapy.

PubMed

Stigliano, Robert V; Shubitidze, Fridon; Petryk, James D; Shoshiashvili, Levan; Petryk, Alicia A; Hoopes, P Jack

2016-11-01

Magnetic nanoparticle hyperthermia therapy is a promising technology for cancer treatment, involving delivering magnetic nanoparticles (MNPs) into tumours then activating them using an alternating magnetic field (AMF). The system produces not only a magnetic field, but also an electric field which penetrates normal tissue and induces eddy currents, resulting in unwanted heating of normal tissues. Magnitude of the eddy current depends, in part, on the AMF source and the size of the tissue exposed to the field. The majority of in vivo MNP hyperthermia therapy studies have been performed in small animals, which, due to the spatial distribution of the AMF relative to the size of the animals, do not reveal the potential toxicity of eddy current heating in larger tissues. This has posed a non-trivial challenge for researchers attempting to scale up to clinically relevant volumes of tissue. There is a relative dearth of studies focused on decreasing the maximum temperature resulting from eddy current heating to increase therapeutic ratio. This paper presents two simple, clinically applicable techniques for decreasing maximum temperature induced by eddy currents. Computational and experimental results are presented to understand the underlying physics of eddy currents induced in conducting, biological tissues and leverage these insights to mitigate eddy current heating during MNP hyperthermia therapy. Phantom studies show that the displacement and motion techniques reduce maximum temperature due to eddy currents by 74% and 19% in simulation, and by 77% and 33% experimentally. Further study is required to optimise these methods for particular scenarios; however, these results suggest larger volumes of tissue could be treated, and/or higher field strengths and frequencies could be used to attain increased MNP heating when these eddy current mitigation techniques are employed.

Development of eddy current microscopy for high resolution electrical conductivity imaging using atomic force microscopy.

PubMed

Nalladega, V; Sathish, S; Jata, K V; Blodgett, M P

2008-07-01

We present a high resolution electrical conductivity imaging technique based on the principles of eddy current and atomic force microscopy (AFM). An electromagnetic coil is used to generate eddy currents in an electrically conducting material. The eddy currents generated in the conducting sample are detected and measured with a magnetic tip attached to a flexible cantilever of an AFM. The eddy current generation and its interaction with the magnetic tip cantilever are theoretically modeled using monopole approximation. The model is used to estimate the eddy current force between the magnetic tip and the electrically conducting sample. The theoretical model is also used to choose a magnetic tip-cantilever system with appropriate magnetic field and spring constant to facilitate the design of a high resolution electrical conductivity imaging system. The force between the tip and the sample due to eddy currents is measured as a function of the separation distance and compared to the model in a single crystal copper. Images of electrical conductivity variations in a polycrystalline dual phase titanium alloy (Ti-6Al-4V) sample are obtained by scanning the magnetic tip-cantilever held at a standoff distance from the sample surface. The contrast in the image is explained based on the electrical conductivity and eddy current force between the magnetic tip and the sample. The spatial resolution of the eddy current imaging system is determined by imaging carbon nanofibers in a polymer matrix. The advantages, limitations, and applications of the technique are discussed.

Effects of electroconvulsive therapy and magnetic seizure therapy on acute memory retrieval.

PubMed

Polster, Julia D; Kayser, Sarah; Bewernick, Bettina H; Hurlemann, René; Schlaepfer, Thomas E

2015-03-01

Electroconvulsive therapy (ECT) is currently the most effective treatment for severe depression. However, it is frequently associated with negative cognitive side effects. Magnetic seizure therapy (MST) depicts an alternative, although experimental, convulsive treatment for major depression. Initial results suggest comparable antidepressant effects accompanied by a better side effect profile. However, no studies up to now have addressed acute retrieval disruption after MST in comparison to ECT. Therefore, we intended to broaden insight into the side effect profile of MST compared to ECT by examining the disruption of acute verbal memory processes after treatment. Twenty depressed patients were randomly assigned to either MST (10 patients) or ECT (10 patients) treatment. On 2 treatment days and 2 treatment-free days, the patients memorized words using a controlled learning paradigm derived from the Batchelder and Riefer storage retrieval model. Four hours after memorization, the patients were asked to retrieve words freely (delayed recall) and a second time with the help of an additional cue constructed out of a hypernymic category (cued recall). By comparing memory performance on treatment days to control days, treatment-induced memory disruption was evaluated. After ECT, delayed recall was disturbed, whereas after MST, it was not. However, this difference in performance was no longer apparent upon cue application (cued recall). This study demonstrates that ECT-induced acute memory disruption measured by delayed recall is absent after MST, confirming its superior side effect profile. We hope that confirming advantages of MST over ECT will improve therapy options for patients with severe depression.

Comparison of the effect of intravenous anesthetics used for anesthesia during electroconvulsive therapy on the hemodynamic safety and the course of ECT.

PubMed

Wojdacz, Rafał; Święcicki, Łukasz; Antosik-Wójcińska, Anna

2017-12-30

Electroconvulsive therapy (ECT) is the treatment method widely used in psychiatric disorders such as depression, bipolar disorder, schizophrenia and schizoaffective disorder. The advantage of ECT is therapeutic response that occurs significantly earlier than during pharmacotherapy. Initially ECTwas used without anesthesia. Then, in the 1950s procedures with general anesthesia were introduced to reduce the complications that may occur during a seizure caused by ECT, such as broken bones, teeth, tendon rupture, muscle damage. Currently, in general anesthesia for ECTseveral medications are used interchangeably: thiopental, propofol, etomidate and ketamine. In different resorts and different countries different anestethics are used, the choice is determined mainly by the experience of each resort and a kind of tradition. The authors provide an overview of objective data showing how various anesthetics affect the quality of ECT and the presence of any hemodynamic complications after ETC. Selection of articles included in this paper was made by searching Medline and PubMed databases using specific keywords: electroconvulsive therapy, general anesthesia, the risks and benefits of thiopental, ketamine, propofol and etomidate. The results of this review are inconclusive when it comes to the effect of intravenous anesthetics on the quality of the ECT treatment and side effects relating to respiratory and cardiovascular system. On this basis it is impossible to determine which of intravenous anesthetics is most advantageous from the point of view of the patient. To develop the optimum scheme of anesthesia for ECT, it is necessary to conduct further, methodologically correct studies.

Using eddy currents for noninvasive in vivo pH monitoring for bone tissue engineering.

PubMed

Beck-Broichsitter, Benedicta E; Daschner, Frank; Christofzik, David W; Knöchel, Reinhard; Wiltfang, Jörg; Becker, Stephan T

2015-03-01

The metabolic processes that regulate bone healing and bone induction in tissue engineering models are not fully understood. Eddy current excitation is widely used in technical approaches and in the food industry. The aim of this study was to establish eddy current excitation for monitoring metabolic processes during heterotopic osteoinduction in vivo. Hydroxyapatite scaffolds were implanted into the musculus latissimus dorsi of six rats. Bone morphogenetic protein 2 (BMP-2) was applied 1 and 2 weeks after implantation. Weekly eddy current excitation measurements were performed. Additionally, invasive pH measurements were obtained from the scaffolds using fiber optic detection devices. Correlations between the eddy current measurements and the metabolic values were calculated. The eddy current measurements and pH values decreased significantly in the first 2 weeks of the study, followed by a steady increase and stabilization at higher levels towards the end of the study. The measurement curves and statistical evaluations indicated a significant correlation between the resonance frequency values of the eddy current excitation measurements and the observed pH levels (p = 0.0041). This innovative technique was capable of noninvasively monitoring metabolic processes in living tissues according to pH values, showing a direct correlation between eddy current excitation and pH in an in vivo tissue engineering model.

Mesoscale Eddy Activity and Transport in the Atlantic Water Inflow Region North of Svalbard

NASA Astrophysics Data System (ADS)

Crews, L.; Sundfjord, A.; Albretsen, J.; Hattermann, T.

2018-01-01

Mesoscale eddies are known to transport heat and biogeochemical properties from Arctic Ocean boundary currents to basin interiors. Previous hydrographic surveys and model results suggest that eddy formation may be common in the Atlantic Water (AW) inflow area north of Svalbard, but no quantitative eddy survey has yet been done for the region. Here vorticity and water property signatures are used to identify and track AW eddies in an eddy-resolving sea ice-ocean model. The boundary current sheds AW eddies along most of the length of the continental slope considered, from the western Yermak Plateau to 40°E, though eddies forming east of 20°E are likely more important for slope-to-basin transport. Eddy formation seasonality reflects seasonal stability properties of the boundary current in the eastern portion of the study domain, but on and immediately east of the Yermak Plateau enhanced eddy formation during summer merits further investigation. AW eddies tend to be anticyclonic, have radii close to the local deformation radius, and be centered in the halocline. They transport roughly 0.16 Sv of AW and, due to their warm cores, 1.0 TW away from the boundary current. These findings suggest eddies may be important for halocline ventilation in the Eurasian Basin, as has been shown for Pacific Water eddies in the Canadian Basin.

3D Magnetic Field Analysis of a Turbine Generator Stator Core-end Region

NASA Astrophysics Data System (ADS)

Wakui, Shinichi; Takahashi, Kazuhiko; Ide, Kazumasa; Takahashi, Miyoshi; Watanabe, Takashi

In this paper we calculated magnetic flux density and eddy current distributions of a 71MVA turbine generator stator core-end using three-dimensional numerical magnetic field analysis. Subsequently, the magnetic flux densities and eddy current densities in the stator core-end region on the no-load and three-phase short circuit conditions obtained by the analysis have good agreements with the measurements. Furthermore, the differences of eddy current and eddy current loss in the stator core-end region for various load conditions are shown numerically. As a result, the facing had an effect that decrease the eddy current loss of the end plate about 84%.

Analysis and numerical modelling of eddy current damper for vibration problems

NASA Astrophysics Data System (ADS)

Irazu, L.; Elejabarrieta, M. J.

2018-07-01

This work discusses a contactless eddy current damper, which is used to attenuate structural vibration. Eddy currents can remove energy from dynamic systems without any contact and, thus, without adding mass or modifying the rigidity of the structure. An experimental modal analysis of a cantilever beam in the absence of and under a partial magnetic field is conducted in the bandwidth of 01 kHz. The results show that the eddy current phenomenon can attenuate the vibration of the entire structure without modifying the natural frequencies or the mode shapes of the structure itself. In this study, a new inverse method to numerically determine the dynamic properties of the contactless eddy current damper is proposed. The proposed inverse method and the eddy current model based on a lineal viscous force are validated by a practical application. The numerically obtained transfer function correlates with the experimental one, thus showing good agreement in the entire bandwidth of 01 kHz. The proposed method provides an easy and quick tool to model and predict the dynamic behaviour of the contactless eddy current damper, thereby avoiding the use of complex analytical models.

Measurement of eddy-current distribution in the vacuum vessel of the Sino-UNIted Spherical Tokamak.

PubMed

Li, G; Tan, Y; Liu, Y Q

2015-08-01

Eddy currents have an important effect on tokamak plasma equilibrium and control of magneto hydrodynamic activity. The vacuum vessel of the Sino-UNIted Spherical Tokamak is separated into two hemispherical sections by a toroidal insulating barrier. Consequently, the characteristics of eddy currents are more complex than those found in a standard tokamak. Thus, it is necessary to measure and analyze the eddy-current distribution. In this study, we propose an experimental method for measuring the eddy-current distribution in a vacuum vessel. By placing a flexible printed circuit board with magnetic probes onto the external surface of the vacuum vessel to measure the magnetic field parallel to the surface and then subtracting the magnetic field generated by the vertical-field coils, the magnetic field due to the eddy current can be obtained, and its distribution can be determined. We successfully applied this method to the Sino-UNIted Spherical Tokamak, and thus, we obtained the eddy-current distribution despite the presence of the magnetic field generated by the external coils.

The Change in Facial Emotion Recognition Ability in Inpatients with Treatment Resistant Schizophrenia After Electroconvulsive Therapy.

PubMed

Dalkıran, Mihriban; Tasdemir, Akif; Salihoglu, Tamer; Emul, Murat; Duran, Alaattin; Ugur, Mufit; Yavuz, Ruhi

2017-09-01

People with schizophrenia have impairments in emotion recognition along with other social cognitive deficits. In the current study, we aimed to investigate the immediate benefits of ECT on facial emotion recognition ability. Thirty-two treatment resistant patients with schizophrenia who have been indicated for ECT enrolled in the study. Facial emotion stimuli were a set of 56 photographs that depicted seven basic emotions: sadness, anger, happiness, disgust, surprise, fear, and neutral faces. The average age of the participants was 33.4 ± 10.5 years. The rate of recognizing the disgusted facial expression increased significantly after ECT (p < 0.05) and no significant changes were found in the rest of the facial expressions (p > 0.05). After the ECT, the time period of responding to the fear and happy facial expressions were significantly shorter (p < 0.05). Facial emotion recognition ability is an important social cognitive skill for social harmony, proper relation and living independently. At least, the ECT sessions do not seem to affect facial emotion recognition ability negatively and seem to improve identifying disgusted facial emotion which is related with dopamine enriched regions in brain.

Eddies on the boundary between the Kuroshio current and coastal waters observed by HF ocean surface radar

NASA Astrophysics Data System (ADS)

Nadai, A.

2016-02-01

The HF ocean surface radar (HFOSR) is one of the powerful tools to measure the ocean current parameters like surface currents. Three observations of the Kuroshio current in the Tokara straight using HFOSR had done by the National Institute of Information and Comunications Technology (NICT: the former name is the Communications Research Laboratory). The first-order echoes on Doppler spectra of HFOSR shows broaden and splitting shape in the region of the border between the Kuroshio currents and coastal waters. The surface velocity maps show the existence of eddy on the border. The investigation of the mechanism of broadening first order-echoes by Nadai (2006) revealed that the modulation of wave fields from surface currents like eddy is the cause of broadening and the measured current fields also influenced the modulated wave fields. Moreover, Nadai (2006) also suggested that the influence is able to reduce using the average of two radial velocities extracted by the first-order echoes. In this paper, the results of current field observation around the border between the Kuroshio current and coastal waters are presented. Many small scale eddies are observed at the border of the Kuroshio current and coastal waters. The typical radius of the eddies is about 10km. Usury the observation of such a small scale eddy is difficult, but the eddies with same scale are observed by airborne synthetic aperture radar in the same area at different time. The eddies shows strong rotation as the typical tangential speed is about 1m/s. While the typical speed of the Kuroshio current is about 1.5m/s, the typical speed of the eddy movements is about 0.7m/s. No eddies generated in the radar coverage, but one or two eddies entered in the radar coverage a day. Therefore the origin of these eddies will exist in the upstream area of the radar coverage. Using the compensation method for the influence of the modulated wave field suggested by Nadai (2006), the eddies shows weak divergence. It is important to consider the mixing between the water of Kuroshio region and East China Sea. However the vertical structure is needed for more precise discussion.

An Investigation of Patient Preferences for Music Played Before Electroconvulsive Therapy.

PubMed

Graff, Veena; Wingfield, Peter; Adams, David; Rabinowitz, Terry

2016-09-01

Patients often feel anxious before electroconvulsive therapy (ECT), which can lead to avoidance of treatments. Music is a noninvasive safe option to reduce anxiety in the preoperative setting. Therefore, we examined patients' preferences of listening to music while receiving ECT by providing music-by way of headphones or speakers-to participants before treatment. Patients receiving ECT were recruited for this study. Patients served as their own controls in 3 separate music intervention sessions: 1) randomization to music via headphones or speakers, 2) no music, 3) the remaining music intervention. Patients completed a questionnaire related to satisfaction and preferences of music being played before ECT. Patients received a final questionnaire at the end of the study asking which intervention they preferred. Thirty patients completed the study. Ninety percent enjoyed listening to music through speakers. Eighty percent liked listening to music through headphones. Seventeen percent preferred not having any music. The difference in preference between speakers and headphones was not significant (P = 0.563; McNemar-Bowker test). There was no association between preference at the end of the study and the initial assignment of speakers or headphones (P = 0.542 and P = 0.752, respectively; Pearson χ tests). No adverse events were reported. Music is a low-cost intervention with virtually no side effects that could be offered as an adjunctive therapy for patients receiving ECT. A significant proportion of patients liked hearing music before treatment.

Eddy Currents: Levitation, Metal Detectors, and Induction Heating

ERIC Educational Resources Information Center

Wouch, G.; Lord, A. E., Jr.

1978-01-01

A simple and accessible calculation is given of the effects of eddy currents for a sphere in the field of a single circular loop of alternating current. These calculations should help toward the inclusion of eddy current effects in upper undergraduate physics courses. (BB)

Eddy Current Damper for Cryogenic Applications

NASA Astrophysics Data System (ADS)

Starin, Scott; Crosno, Fred

2002-09-01

This presentation considers the following topics: the need for cryogenic energy absorption, high speed damper characteristics, gearbox characteristics, composite assembly characteristics, performance tests, simulation models.

Healing of Fatigue Crack in 1045 Steel by Using Eddy Current Treatment

PubMed Central

Yang, Chuan; Xu, Wenchen; Guo, Bin; Shan, Debin; Zhang, Jian

2016-01-01

In order to investigate the methods to heal fatigue cracks in metals, tubular specimens of 1045 steel with axial and radial fatigue cracks were treated under the eddy current. The optical microscope was employed to examine the change of fatigue cracks of specimens before and after the eddy current treatment. The results show that the fatigue cracks along the axial direction of the specimen could be healed effectively in the fatigue crack initiation zone and the crack tip zone under the eddy current treatment, and the healing could occur within a very short time. The voltage breakdown and the transient thermal compressive stress caused by the detouring of eddy current around the fatigue crack were the main factors contributing to the healing in the fatigue crack initiation zone and the crack tip zone, respectively. Eddy current treatment may be a novel and effective method for crack healing. PMID:28773761

Healing of Fatigue Crack in 1045 Steel by Using Eddy Current Treatment.

PubMed

Yang, Chuan; Xu, Wenchen; Guo, Bin; Shan, Debin; Zhang, Jian

2016-07-29

In order to investigate the methods to heal fatigue cracks in metals, tubular specimens of 1045 steel with axial and radial fatigue cracks were treated under the eddy current. The optical microscope was employed to examine the change of fatigue cracks of specimens before and after the eddy current treatment. The results show that the fatigue cracks along the axial direction of the specimen could be healed effectively in the fatigue crack initiation zone and the crack tip zone under the eddy current treatment, and the healing could occur within a very short time. The voltage breakdown and the transient thermal compressive stress caused by the detouring of eddy current around the fatigue crack were the main factors contributing to the healing in the fatigue crack initiation zone and the crack tip zone, respectively. Eddy current treatment may be a novel and effective method for crack healing.

The numeric calculation of eddy current distributions in transcranial magnetic stimulation.

PubMed

Tsuyama, Seichi; Hyodo, Akira; Sekino, Masaki; Hayami, Takehito; Ueno, Shoogo; Iramina, Keiji

2008-01-01

Transcranial magnetic stimulation (TMS) is a method to stimulate neurons in the brain. It is necessary to obtain eddy current distributions and determine parameters such as position, radius and bend-angle of the coil to stimulate target area exactly. In this study, we performed FEM-based numerical simulations of eddy current induced by TMS using three-dimentional human head model with inhomogeneous conductivity. We used double-cone coil and changed the coil radius and bend-angle of coil. The result of computer simulation showed that as coil radius increases, the eddy current became stronger everywhere. And coil with bend-angle of 22.5 degrees induced stronger eddy current than the coil with bendangle of 0 degrees. Meanwhile, when the bend-angle was 45 degrees, eddy current became weaker than these two cases. This simulation allowed us to determine appropriate parameter easier.

Equilibrium reconstruction with 3D eddy currents in the Lithium Tokamak eXperiment

DOE PAGES

Hansen, C.; Boyle, D. P.; Schmitt, J. C.; ...

2017-04-18

Axisymmetric free-boundary equilibrium reconstructions of tokamak plasmas in the Lithium Tokamak eXperiment (LTX) are performed using the PSI-Tri equilibrium code. Reconstructions in LTX are complicated by the presence of long-lived non-axisymmetric eddy currents generated by a vacuum vessel and first wall structures. To account for this effect, reconstructions are performed with additional toroidal current sources in these conducting regions. The eddy current sources are fixed in their poloidal distributions, but their magnitude is adjusted as part of the full reconstruction. Eddy distributions are computed by toroidally averaging currents, generated by coupling to vacuum field coils, from a simplified 3D filamentmore » model of important conducting structures. The full 3D eddy current fields are also used to enable the inclusion of local magnetic field measurements, which have strong 3D eddy current pick-up, as reconstruction constraints. Using this method, equilibrium reconstruction yields good agreement with all available diagnostic signals. Here, an accompanying field perturbation produced by 3D eddy currents on the plasma surface with a primarily n = 2, m = 1 character is also predicted for these equilibria.« less

Direct process estimation from tomographic data using artificial neural systems

NASA Astrophysics Data System (ADS)

Mohamad-Saleh, Junita; Hoyle, Brian S.; Podd, Frank J.; Spink, D. M.

2001-07-01

The paper deals with the goal of component fraction estimation in multicomponent flows, a critical measurement in many processes. Electrical capacitance tomography (ECT) is a well-researched sensing technique for this task, due to its low-cost, non-intrusion, and fast response. However, typical systems, which include practicable real-time reconstruction algorithms, give inaccurate results, and existing approaches to direct component fraction measurement are flow-regime dependent. In the investigation described, an artificial neural network approach is used to directly estimate the component fractions in gas-oil, gas-water, and gas-oil-water flows from ECT measurements. A 2D finite- element electric field model of a 12-electrode ECT sensor is used to simulate ECT measurements of various flow conditions. The raw measurements are reduced to a mutually independent set using principal components analysis and used with their corresponding component fractions to train multilayer feed-forward neural networks (MLFFNNs). The trained MLFFNNs are tested with patterns consisting of unlearned ECT simulated and plant measurements. Results included in the paper have a mean absolute error of less than 1% for the estimation of various multicomponent fractions of the permittivity distribution. They are also shown to give improved component fraction estimation compared to a well known direct ECT method.

The validity of using an electrocutaneous device for pain assessment in patients with cervical radiculopathy.

PubMed

Abbott, Allan; Ghasemi-Kafash, Elaheh; Dedering, Åsa

2014-10-01

The purpose of this study was to evaluate the validity and preference for assessing pain magnitude with electrocutaneous testing (ECT) compared to the visual analogue scale (VAS) and Borg CR10 scale in men and women with cervical radiculopathy of varying sensory phenotypes. An additional purpose was to investigate ECT sensory and pain thresholds in men and women with cervical radiculopathy of varying sensory phenotypes. This is a cross-sectional study of 34 patients with cervical radiculopathy. Scatterplots and linear regression were used to investigate bivariate relationships between ECT, VAS and Borg CR10 methods of pain magnitude measurement as well as ECT sensory and pain thresholds. The use of the ECT pain magnitude matching paradigm for patients with cervical radiculopathy with normal sensory phenotype shows good linear association with arm pain VAS (R(2) = 0.39), neck pain VAS (R(2) = 0.38), arm pain Borg CR10 scale (R(2) = 0.50) and neck pain Borg CR10 scale (R(2) = 0.49) suggesting acceptable validity of the procedure. For patients with hypoesthesia and hyperesthesia sensory phenotypes, the ECT pain magnitude matching paradigm does not show adequate linear association with rating scale methods rendering the validity of the procedure as doubtful. ECT for sensory and pain threshold investigation, however, provides a method to objectively assess global sensory function in conjunction with sensory receptor specific bedside examination measures.

Association of Electroconvulsive Therapy With Psychiatric Readmissions in US Hospitals.

PubMed

Slade, Eric P; Jahn, Danielle R; Regenold, William T; Case, Brady G

2017-08-01

Although electroconvulsive therapy (ECT) is considered the most efficacious treatment available for individuals with severe affective disorders, ECT's availability is limited and declining, suggesting that information about the population-level effects of ECT is needed. To examine whether inpatient treatment with ECT is associated with a reduction in 30-day psychiatric readmission risk in a large, multistate sample of inpatients with severe affective disorders. A quasi-experimental instrumental variables probit model of the association correlation of ECT administration with patient risk of 30-day readmission was estimated using observational, longitudinal data on hospital inpatient discharges from US general hospitals in 9 states. From a population-based sample of 490 252 psychiatric inpatients, a sample was drawn that consisted of 162 691 individuals with a principal diagnosis of major depressive disorder (MDD), bipolar disorder, or schizoaffective disorder. The key instrumental variable used in the analysis was ECT prevalence in the prior calendar year at the treating hospital. To examine whether ECT's association with readmissions was heterogeneous across population subgroups, analyses included interactions of ECT with age group, sex, race/ethnicity, and diagnosis group. The study was conducted from August 27, 2015, to March 7, 2017. Readmission within 30 days of being discharged. Overall, 2486 of the 162 691 inpatients (1.5%) underwent ECT during their index admission. Compared with other inpatients, those who received ECT were older (mean [SD], 56.8 [16.5] vs 45.9 [16.5] years; P < .001) and more likely to be female (65.0% vs 54.2%; P < .001) and white non-Hispanic (85.3% vs 62.1%; P < .001), have MDD diagnoses (63.8% vs 32.0%; P < .001) rather than bipolar disorder (29.0% vs 40.0%; P < .001) or schizoaffective disorder (7.1% vs 28.0%; P < .001), have a comorbid medical condition (31.3% vs 26.6%; P < .001), have private (39.4% vs 21.7%; P < .001) or Medicare (49.2% vs 39.4%; P < .001) insurance coverage, and be located in urban small hospitals (31.2% vs 22.3%; P < .001) or nonurban hospitals (9.0% vs 7.6%; P = .02). Administration of ECT was associated with a reduced 30-day readmission risk among psychiatric inpatients with severe affective disorders from an estimated 12.3% among individuals not administered ECT to 6.6% among individuals administered ECT (risk ratio [RR], 0.54; 95% CI, 0.28-0.81). Significantly larger associations with ECT on readmission risk were found for men compared with women (RR, 0.44; 95% CI, 0.20-0.69 vs 0.58; 95% CI, 0.30-0.88) and for individuals with bipolar disorder (RR, 0.42; 95% CI, 0.17-0.69) and schizoaffective disorder (RR, 0.44; 95% CI, 0.11-0.79) compared with those who had MDD (RR, 0.53; 95% CI, 0.26-0.81). Electroconvulsive therapy may be associated with reduced short-term psychiatric inpatient readmissions among psychiatric inpatients with severe affective disorders. This potential population health effect may be overlooked in US hospitals' current decision making regarding the availability of ECT.

Research and Development of Automated Eddy Current Testing for Composite Overwrapped Pressure Vessels

NASA Technical Reports Server (NTRS)

Carver, Kyle L.; Saulsberry, Regor L.; Nichols, Charles T.; Spencer, Paul R.; Lucero, Ralph E.

2012-01-01

Eddy current testing (ET) was used to scan bare metallic liners used in the fabrication of composite overwrapped pressure vessels (COPVs) for flaws which could result in premature failure of the vessel. The main goal of the project was to make improvements in the areas of scan signal to noise ratio, sensitivity of flaw detection, and estimation of flaw dimensions. Scan settings were optimized resulting in an increased signal to noise ratio. Previously undiscovered flaw indications were observed and investigated. Threshold criteria were determined for the system software's flaw report and estimation of flaw dimensions were brought to an acceptable level of accuracy. Computer algorithms were written to import data for filtering and a numerical derivative filtering algorithm was evaluated.

Effects of Angular Variation on Split D Differential Eddy Current Probe Response (Postprint)

DTIC Science & Technology

2016-02-10

AFRL-RX-WP-JA-2016-0327 EFFECTS OF ANGULAR VARIATION ON SPLIT D DIFFERENTIAL EDDY CURRENT PROBE RESPONSE (POSTPRINT) Ryan D...March 2014 – 22 September 2015 4. TITLE AND SUBTITLE EFFECTS OF ANGULAR VARIATION ON SPLIT D DIFFERENTIAL EDDY CURRENT PROBE RESPONSE (POSTPRINT...last few years have seen increased levels of complexity added to push the state-of-the-art modeling software used in eddy current NDE today. The added

Right Unilateral Ultrabrief Pulse ECT in Geriatric Depression: Phase 1 of the PRIDE Study.

PubMed

Kellner, Charles H; Husain, Mustafa M; Knapp, Rebecca G; McCall, W Vaughn; Petrides, Georgios; Rudorfer, Matthew V; Young, Robert C; Sampson, Shirlene; McClintock, Shawn M; Mueller, Martina; Prudic, Joan; Greenberg, Robert M; Weiner, Richard D; Bailine, Samuel H; Rosenquist, Peter B; Raza, Ahmad; Kaliora, Styliani; Latoussakis, Vassilios; Tobias, Kristen G; Briggs, Mimi C; Liebman, Lauren S; Geduldig, Emma T; Teklehaimanot, Abeba A; Lisanby, Sarah H

2016-11-01

The Prolonging Remission in Depressed Elderly (PRIDE) study evaluated the efficacy of right unilateral ultrabrief pulse electroconvulsive therapy (ECT) combined with venlafaxine for the treatment of geriatric depression. PRIDE was a two-phase multisite study. Phase 1 was an acute course of right unilateral ultrabrief pulse ECT, combined with open-label venlafaxine at seven academic medical centers. In phase 2 (reported separately), patients who had remitted were randomly assigned to receive pharmacotherapy (venlafaxine plus lithium) or pharmacotherapy plus continuation ECT. In phase 1, depressed patients received high-dose ECT (at six times the seizure threshold) three times per week. Venlafaxine was started during the first week of treatment and continued throughout the study. The primary outcome measure was remission, assessed with the 24-item Hamilton Depression Rating Scale (HAM-D), which was administered three times per week. Secondary outcome measures were post-ECT reorientation and safety. Paired t tests were used to estimate and evaluate the significance of change from baseline in HAM-D scores. Of 240 patients who entered phase 1 of the study, 172 completed it. Overall, 61.7% (148/240) of all patients met remission criteria, 10.0% (24/240) did not remit, and 28.3% (68/240) dropped out; 70% (169/240) met response criteria. Among those who remitted, the mean decrease in HAM-D score was 24.7 points (95% CI=23.4, 25.9), with a mean final score of 6.2 (SD=2.5) and an average change from baseline of 79%. The mean number of ECT treatments to remission was 7.3 (SD=3.1). Right unilateral ultrabrief pulse ECT, combined with venlafaxine, is a rapidly acting and highly effective treatment option for depressed geriatric patients, with excellent safety and tolerability. These data add to the evidence base supporting the efficacy of ECT to treat severe depression in elderly patients.

Birth of a Loop Current Eddy

NASA Image and Video Library

2010-05-24

The northern portion of the Gulf of Mexico Loop Current, shown in red, appears about to detach a large ring of current, creating a separate eddy. An eddy is a large, warm, clockwise-spinning vortex of water -- the ocean version of a cyclone.

Inflammation and Improvement of Depression Following Electroconvulsive Therapy in Treatment-Resistant Depression.

PubMed

Kruse, Jennifer L; Congdon, Eliza; Olmstead, Richard; Njau, Stephanie; Breen, Elizabeth C; Narr, Katherine L; Espinoza, Randall; Irwin, Michael R

Electroconvulsive therapy (ECT) is the most robust acute treatment for severe major depressive disorder, yet clinical response is variable. Inflammation is associated with depression, especially in women, and levels of C-reactive protein (CRP) and interleukin (IL)-6 predict response to antidepressant medications. This study evaluated whether markers of inflammation predicted response to electroconvulsive therapy (ECT) in patients with treatment-resistant depression and to what extent this association differed between men and women. In patients (N = 29) who had a current major depressive episode diagnosed using DSM-IV-TR criteria and were scheduled to undergo ECT at an academic referral center, levels of CRP, IL-6, IL-8, and tumor necrosis factor-α and severity of depressive symptoms (Montgomery-Asberg Depression Rating Scale [MADRS]) were prospectively evaluated before ECT treatment, after the second ECT session, and again at the completion of the index treatment series. Data were collected between December 2011 and December 2014. The primary outcome was end-of-treatment MADRS score. In multivariate analyses, higher levels of IL-6 at baseline, but not other inflammatory markers or clinical variables, were associated with lower end-of-treatment MADRS score (P = .01). When stratified by sex, IL-6 remained a significant predictor of end-of-treatment MADRS for women (P = .02) but not men (P = .1), and CRP emerged as a significant predictor for women (P = .04) but not men (P = .66). CRP and IL-6 increased from baseline to the second ECT session (P values < .01) and returned to baseline levels at end of treatment; these changes did not relate to MADRS score over the course of ECT. Levels of IL-6 prior to ECT treatment may be useful in identifying those depressed patients most likely to benefit from ECT treatment. In contrast, acute changes in IL-6 and CRP may reflect spikes in inflammatory response related to the initiation of seizure therapy, but not mood. Assessment of pretreatment inflammatory biomarkers, especially in women, might be useful in guiding treatment decision-making in treatment-resistant depression. © Copyright 2018 Physicians Postgraduate Press, Inc.

S -ketamine compared to etomidate during electroconvulsive therapy in major depression.

PubMed

Zavorotnyy, Maxim; Kluge, Ina; Ahrens, Kathrin; Wohltmann, Thomas; Köhnlein, Benjamin; Dietsche, Patricia; Dannlowski, Udo; Kircher, Tilo; Konrad, Carsten

2017-12-01

Objective of the study was to compare two commonly used anesthetic drugs, S-ketamine and etomidate, regarding their influence on seizure characteristics, safety aspects, and outcome of electroconvulsive therapy (ECT) in major depression. Treatment data of 60 patients who underwent a total number of 13 ECTs (median) because of the severe or treatment-resistant major depressive disorder (DSM-IV) were analyzed. Etomidate, mean dosage (SD) = 0.25 (0.04) mg/kg, was used for anesthesia in 29 participants; 31 patients received S-ketamine, mean dosage (SD) = 0.96 (0.26) mg/kg. Right unilateral brief pulse ECTs were performed. The number of ECTs was individually adjusted to clinical needs, mean (SD) = 13.0 (4.3). Seizure characteristics, adverse events, and the clinical global impression (CGI) scores were compared between the both groups during ECT series. In the S-ketamine group, a lower initial seizure threshold (p = 0.014), stimulation charge (p < 0.001), higher postictal suppression (p < 0.001), EEG ictal amplitude (p = 0.04), EEG coherence (p < 0.001) and maximum heart rate (p = 0.015) were measured. Etomidate was associated with more frequent abortive seizures (p = 0.02) and restimulations (p = 0.01). The CGI scores, the number of sessions within an ECT series, and the incidence of adverse events did not differ between groups. Due to its lower initial seizure threshold, S-ketamine might hold a potential to become a clinically favorable anesthetic agent during ECT. However, the current findings should be interpreted with caution, and further prospective randomized clinical trials are required. Also, specific adverse effects profile of S-ketamine, especially with regard to the cardiovascular risk, needs to be taken into account.

SAFETY AND UTILITY OF ACUTE ELECTROCONVULSIVE THERAPY FOR AGITATION AND AGGRESSION IN DEMENTIA

PubMed Central

Acharya, Deepa; Harper, David G.; Achtyes, Eric D.; Seiner, Stephen J.; Mahdasian, Jack A.; Nykamp, Louis J.; Adkison, Lesley; Van der Schuur White, Lori; McClintock, Shawn M.; Ujkaj, Manjola; Davidoff, Donald A.; Forester, Brent P.

2015-01-01

Objective Agitation and aggression are among the most frequent and disruptive behavioral complications of dementia that contribute to increased cost of care, hospitalization, caregiver burden, and risk of premature institutionalization. This current study examined the safety and efficacy of electroconvulsive therapy (ECT) as a treatment for behavioral disturbances in dementia. We hypothesized that ECT would result in reduced agitated and aggressive behaviors between baseline and discharge. Methods Twenty-three participants admitted to McLean Hospital (Belmont, MA) and Pine Rest Christian Mental Health Services (Grand Rapids, MI), with a diagnosis of dementia who were referred for ECT to treat agitation and/or aggression, were enrolled in the study. We administered the Cohen-Mansfield Agitation Inventory (CMAI)-short form, Neuropsychiatric Inventory (NPI)-Nursing Home Version, Cornell Scale for Depression in Dementia (CSDD), and the Clinical Global Impression Scale (CGI) at baseline, during, and after the ECT course. Results Regression analyses revealed a significant decrease from baseline to discharge on the CMAI (F(4, 8) =13.3; p=0.006) and NPI (F(4, 31)= 14.6; p<0.001). There was no statistically significant change in scores on the CSDD. The CGI scores on average changed from a rating of “markedly agitated/aggressive” at baseline to “borderline agitated/aggressive” at discharge. Treatment with ECT was well tolerated by most participants; discontinuation of ECT occurred for two participants due to recurrence of agitation and for three participants due to adverse events. Conclusions ECT may be a safe treatment option to reduce symptoms of agitation and aggression in patients with dementia whose behaviors are refractory to medication management. PMID:24838521

A Smart Eddy Current Sensor Dedicated to the Nondestructive Evaluation of Carbon Fibers Reinforced Polymers.

PubMed

Naidjate, Mohammed; Helifa, Bachir; Feliachi, Mouloud; Lefkaier, Iben-Khaldoun; Heuer, Henning; Schulze, Martin

2017-08-31

This paper propose a new concept of an eddy current (EC) multi-element sensor for the characterization of carbon fiber-reinforced polymers (CFRP) to evaluate the orientations of plies in CFRP and the order of their stacking. The main advantage of the new sensors is the flexible parametrization by electronical switching that reduces the effort for mechanical manipulation. The sensor response was calculated and proved by 3D finite element (FE) modeling. This sensor is dedicated to nondestructive testing (NDT) and can be an alternative for conventional mechanical rotating and rectangular sensors.

Gilles de la Tourette syndrome: response to electroconvulsive therapy.

PubMed

Karadenizli, Demet; Dilbaz, Nesrin; Bayam, Goksel

2005-12-01

Tourette syndrome is a chronic disease characterized by vocal and motor ticks. Self-injurious behavior is observed in one third of the patients and can be life-threatening. Current medical therapy includes dopamine receptor antagonists and atypical antipsychotics. In certain cases, there has been some evidence about the efficacy of electroconvulsive therapy (ECT). The case study below is a Tourette syndrome patient with self-injurious behavior and psychotic features and poor response to medical therapy. Two years of remission was achieved after 7 sessions of ECT and carbamezapine maintance therapy. In conclusion, ECT can be used as an efficacious treatment modality for Tourette patients with self-injurious behavior, psychotic features, or for those that are unresponsive to traditional methods.

Individualized Anesthetic Management for Patients Undergoing Electroconvulsive Therapy: A Review of Current Practice.

PubMed

Bryson, Ethan O; Aloysi, Amy S; Farber, Kate G; Kellner, Charles H

2017-06-01

Electroconvulsive therapy (ECT) remains an indispensable treatment for severe psychiatric illness. It is practiced extensively in the United States and around the world, yet there is little guidance for anesthesiologists involved with this common practice. Communication between the anesthesiologist and the proceduralist is particularly important for ECT, because the choice of anesthetic and management of physiologic sequelae of the therapeutic seizure can directly impact both the efficacy and safety of the treatment. In this review, we examine the literature on anesthetic management for ECT. A casual or "one-size-fits-all" approach may lead to less-than-optimal outcomes; customizing the anesthetic management for each patient is essential and can significantly increase treatment success rate and patient satisfaction.

An Interventional Study on the Clinical Usefulness and Outcomes of Electroconvulsive Therapy in Medication-Resistant Mental Disorders

PubMed Central

Manhas, Rameshwar S; Tarfarosh, Shah Faisal Ahmad; Shoib, Sheikh; Dar, Mohammad Maqbool; Hussain, Arshad; Shah, Tabindah; Shah, Sahil; Manzoor, Mushbiq

2016-01-01

Background Resistance to recommended medications has been an issue in dealing with a number of psychiatric ailments, and it is showing up as an ongoing challenge for contemporary mental health experts. Resistant psychiatric disorders not only increase the morbidity of patients suffering from such severe conditions but also intensify the problems of their caretakers. This has vigorously started to cause the costs to increase for healthcare services. Thanks to electroconvulsive therapy (ECT), we now have an effective method that is proving to be a fruitful final course of action in this micro-epidemic of resistant psychiatric diseases. However, the medical literature of case reports or studies in this niche is scarce. Also, no such comprehensive study has been carried out in the Southeast Asian region to date for the assessment of the effectiveness of electroconvulsive therapy in patients with medication-resistant psychiatric disorders. Aim To assess the effectiveness of ECT in medication-resistant psychiatric patients at the post-ECT course, three-month follow-up, and six-month follow-up. Materials and methods The study was a prospective and interventional study (without controls) conducted in the Institute of Mental Health and Neurosciences (IMHANS), Srinagar, India. Fifty-six patients with pharmacotherapy-resistant psychiatric disorders were included in the study. The patients were assessed at the end of the ECT course, at the three-month follow-up, and at the six-month follow-up by the Clinical Global Impression (CGI), Montgomery Asberg Depression Rating Scale (MADRS), Young Manic Rating Scale (YMRS) and the Yale-Brown Obsessive Compulsive Scale (YBOCS). Improvement was defined with the help of the CGI subscale by comparing the position of the patient at admission to the projected condition with ECT. Statistical analysis Analysis of Variance (ANOVA) was used for analysis of the quantitative data. For the pair-wise comparison of the groups, the post hoc tests were used. Pearson’s chi-square test was used for analysis of qualitative data. A p-value of < 0.05 was considered to be statistically significant, and all the data analysis was done using SPSS Version 20.0. Results The CGI scale revealed that statistically significant improvement occurred in patients at the end of ECT course, at the three-month follow-up as well as at the six-month follow-up. Conclusion ECT should be used for the treatment of pharmacotherapy-resistant psychiatric patients and the benefits can be seen even six months after an ECT course completion. Further work in this field should focus on educating the general public about the usefulness of ECT in the treatment of resistant mental illnesses. The myths related to the so-called psychiatric assault from ECT should be removed.  PMID:28003938

Best Practices for Evaluating the Capability of Nondestructive Evaluation (NDE) and Structural Health Monitoring (SHM) Techniques for Damage Characterization (Post-Print)

DTIC Science & Technology

2016-02-10

a wide range of part, environmental and damage conditions. Best practices of using models are presented for both an eddy current NDE sizing and...to assess the reliability of NDE and SHM characterization capability. Best practices of using models are presented for both an eddy current NDE... EDDY CURRENT NDE CASE STUDY An eddy current crack sizing case study is presented to highlight examples of some of these complex characteristics of

Evaluation of nonmemory cognitive parameters in psychiatric patients' pre- and post-electroconvulsive therapy: An observational study.

PubMed

Prakash, Jyoti; Srivastava, Kalpana; Manandhar, Pradeep; Saha, Amitabh

2015-01-01

Possibility of cognitive side effects has made electroconvulsive therapy (ECT) questionable. Variable deficits have been debated in memory cognition. Pattern of changes in nonmemory cognition pre- and post-ECT is not clear. Forty patients undergoing ECT were studied on nonmemory cognitive parameters before ECT, after a course of ECT, and after 4 weeks of last. ECT. Nonmemory cognition improved during the course of ECT and over 4 weeks of ECT. ECT does not affect the nonmemory cognition adversely.

Does comorbid alcohol and substance abuse affect electroconvulsive therapy outcome in the treatment of mood disorders?

PubMed

Moss, Lori; Vaidya, Nutan

2014-03-01

Antidepressant medications remain the principal agents used to treat patients with mood disorders, although 30% to 40% of these patients do not improve. One of the factors associated with poor medication response is alcohol and substance abuse. Persons with mood disorders are at the greatest risk for suicide, and alcoholism is a significant additional risk factor. Electroconvulsive therapy (ECT) is shown to be the most effective treatment for major depression especially when associated with psychosis, catatonia, and suicide intent. However, similar to most antidepressant trials, patients with depression and comorbid alcohol and substance abuse are excluded from ECT efficacy studies. Through a retrospective chart review, we compared response to ECT in patients with mood disorder and comorbid alcohol and drug abuse to those with mood disorder only. From 2004 to 2010, 80 patients with mood disorder received ECT. Fifty of these had comorbid alcohol or drug abuse. Using a 10-item psychopathology scale, we compared pre- and post-ECT symptom severity between the 2 groups. Outcome was determined by measuring a decrease in the pre-ECT and post-ECT score using Wilcoxon rank tests, with statistical significance at P = 0.05. There was no difference between the 2 groups in most demographics, ECT medication, or seizure quality. There was no difference in ECT outcome between those with comorbid alcohol abuse and those without based on percent decrease in pre- and post-ECT symptom scores (abuse: mean [SD], 0.89 [0.2] vs nonabuse: mean [SD], 0.93 [0.16]; Wilcoxon, 1332; P = 0.086). When we compared those who met the criteria for alcohol or drug dependence (19 patients) with those with no abuse, there was a trend for the dependence group to not do as well (dependence: mean [SD], 0.83 [0.25] vs nonabuse: mean [SD], 0.93 [0.16]; Wilcoxon, 405; P = 0.053). Those with combined drug and alcohol abuse (18 patients) did have a significantly worse outcome (combined: mean [SD], 0.82 [0.25] vs nonabuse: mean [SD], 0.93 [0.16]; Wilcoxon, 372; P = 0.033). Our results indicate that comorbid alcohol and drug abuse may influence the response to ECT in the treatment of mood disorders. Based on our results, patients with comorbid dependence and combined drug and alcohol abuse showed symptom improvement but did not do as well as those with nonabuse.

Modeling, design, and testing of a proof-of-concept prototype damper with friction and eddy current damping effects

NASA Astrophysics Data System (ADS)

Amjadian, Mohsen; Agrawal, Anil K.

2018-01-01

Friction is considered as one of the most reliable mechanisms of energy dissipation that has been utilized extensively in passive damping devices to mitigate vibration of civil engineering structures subjected to extreme natural hazards such as earthquakes and windstorms. However, passive friction dampers are well-known for having a highly nonlinear hysteretic behavior caused by stick-slip motion at low velocities, a phenomenon that is inherent in friction and increases the acceleration response of the structure under control unfavorably. The authors have recently proposed the theoretical concept of a new type of damping device termed as "Passive Electromagnetic Eddy Current Friction Damper" (PEMECFD) in which an eddy current damping mechanism was utilized not only to decrease the undesirable effects of stick-slip motion, but also to increase the energy dissipation capacity of the damping device as a whole. That study was focused on demonstration of the theoretical performance of the proposed damping device through numerical simulations. This paper further investigates the influence of eddy current damping on energy dissipation due to friction through modeling, design, and testing of a proof-of-concept prototype damper. The design of this damper has been improved over the design in the previous study. The normal force in this damper is produced by the repulsive magnetic force between two cuboidal permanent magnets (PMs) magnetized in the direction normal to the direction of the motion. The eddy current damping force is generated because of the motion of the two PMs and two additional PMs relative to a copper plate in their vicinity. The dynamic models for the force-displacement relationship of the prototype damper are based on LuGre friction model, electromagnetic theory, and inertial effects of the prototype damper. The parameters of the dynamic models have been identified through a series of characterization tests on the prototype damper under harmonic excitations of different frequencies in the laboratory. Finally, the identified dynamic models have been validated by subjecting the prototype damper to two different random excitations. The results indicate that the proposed dynamic models are capable of representing force-displacement behavior of the new type of passive damping device for a wide range of operating conditions.

Evaluation of the Self-Nulling Rotating Eddy Current Probe System

NASA Technical Reports Server (NTRS)

Hagemaier, Don; Rengel, Kent; Wincheski, Buzz; Namkung, Min

1999-01-01

In order to detect multi-site fatigue cracks located under flush-head rivets, automated eddy current equipment is required. To assure a reliable system, the eddy current probe must be centered easily over the installed rivets. To meet these requirements, the NDE Group at NASA LaRC developed the Self-Nulling Rotating Eddy Current Probe System (SNRECPS) which will be referred to as RPS in this document. The system was evaluated at the FAA, NDI Validation Center, in Albuquerque, New Mexico. The system was capable of detecting a 0.032 inch long crack with a 90/95% PoD. Further evaluations were conducted at Boeing in Long Beach, California. These evaluations included fatigue cracks and notches in a range from 0.025 to 0.100 inch long under flush-head aluminum rivets, and titanium or steel flush-head fasteners. The results of these tests are reported herein. Subsequently, the system was loaned to the USAF Structures Laboratory for the purpose of detecting and measuring short cracks under flush-head rivets in a variety of fatigue test specimens. The inspection task was to detect and plot crack growth from numbered fasteners in lettered rows. In January, 1998, the system was taken to Northwest Airlines Maintenance Base, in Atlanta, to inspect a DC-9, for multi-site cracks in three circumferential splices. The aircraft had 83,000 cycles. The inspection was conducted at 30 kHz from longeron 5 left to longeron 5 right. The system was calibrated using a 0,030 EDM first layer notch. The instrument gain was set to 19 mV from the notch. The reject level was set at 10 mV and the unflawed fasteners yielded a signal amplitude of 2 to 3 mV. Only one fastener location, out of about 2,500 tested, yielded a signal of 58 mV. The rivet was removed and visually evaluated. It appeared to be a slight gouge in the counter-sink zone. No fatigue cracks were detected. The same fastener locations were also inspected using the Boeing MAUS system at 60 kHz. No cracks were detected. Thus far, the rotating probe eddy current system has been found to be very user friendly and capable of detecting first layer cracks on the order of 0.030 inch long or longer.

Eddy current-nulled convex optimized diffusion encoding (EN-CODE) for distortion-free diffusion tensor imaging with short echo times.

PubMed

Aliotta, Eric; Moulin, Kévin; Ennis, Daniel B

2018-02-01

To design and evaluate eddy current-nulled convex optimized diffusion encoding (EN-CODE) gradient waveforms for efficient diffusion tensor imaging (DTI) that is free of eddy current-induced image distortions. The EN-CODE framework was used to generate diffusion-encoding waveforms that are eddy current-compensated. The EN-CODE DTI waveform was compared with the existing eddy current-nulled twice refocused spin echo (TRSE) sequence as well as monopolar (MONO) and non-eddy current-compensated CODE in terms of echo time (TE) and image distortions. Comparisons were made in simulations, phantom experiments, and neuro imaging in 10 healthy volunteers. The EN-CODE sequence achieved eddy current compensation with a significantly shorter TE than TRSE (78 versus 96 ms) and a slightly shorter TE than MONO (78 versus 80 ms). Intravoxel signal variance was lower in phantoms with EN-CODE than with MONO (13.6 ± 11.6 versus 37.4 ± 25.8) and not different from TRSE (15.1 ± 11.6), indicating good robustness to eddy current-induced image distortions. Mean fractional anisotropy values in brain edges were also significantly lower with EN-CODE than with MONO (0.16 ± 0.01 versus 0.24 ± 0.02, P < 1 x 10 -5 ) and not different from TRSE (0.16 ± 0.01 versus 0.16 ± 0.01, P = nonsignificant). The EN-CODE sequence eliminated eddy current-induced image distortions in DTI with a TE comparable to MONO and substantially shorter than TRSE. Magn Reson Med 79:663-672, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Automated eddy current analysis of materials

NASA Technical Reports Server (NTRS)

Workman, Gary L.

1991-01-01

The use of eddy current techniques for characterizing flaws in graphite-based filament-wound cylindrical structures is described. A major emphasis was also placed upon incorporating artificial intelligence techniques into the signal analysis portion of the inspection process. Developing an eddy current scanning system using a commercial robot for inspecting graphite structures (and others) was a goal in the overall concept and is essential for the final implementation for the expert systems interpretation. Manual scans, as performed in the preliminary work here, do not provide sufficiently reproducible eddy current signatures to be easily built into a real time expert system. The expert systems approach to eddy current signal analysis requires that a suitable knowledge base exist in which correct decisions as to the nature of a flaw can be performed. A robotic workcell using eddy current transducers for the inspection of carbon filament materials with improved sensitivity was developed. Improved coupling efficiencies achieved with the E-probes and horseshoe probes are exceptional for graphite fibers. The eddy current supervisory system and expert system was partially developed on a MacIvory system. Continued utilization of finite element models for predetermining eddy current signals was shown to be useful in this work, both for understanding how electromagnetic fields interact with graphite fibers, and also for use in determining how to develop the knowledge base. Sufficient data was taken to indicate that the E-probe and the horseshoe probe can be useful eddy current transducers for inspecting graphite fiber components. The lacking component at this time is a large enough probe to have sensitivity in both the far and near field of a thick graphite epoxy component.

Fatigue Crack Growth Behavior Evaluation of Grainex Mar-M 247 for NASA's High Temperature, High Speed Turbine Seal Test Rig

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.; Steinetz, Bruce M.; Rimnac, Clare M.; Lewandowski, John J.

2008-01-01

The fatigue crack growth behavior of Grainex Mar-M 247 is evaluated for NASA s Turbine Seal Test Facility. The facility is used to test air-to-air seals primarily for use in advanced jet engine applications. Because of extreme seal test conditions of temperature, pressure, and surface speeds, surface cracks may develop over time in the disk bolt holes. An inspection interval is developed to preclude catastrophic disk failure by using experimental fatigue crack growth data. By combining current fatigue crack growth results with previous fatigue strain-life experimental work, an inspection interval is determined for the test disk. The fatigue crack growth life of the NASA disk bolt holes is found to be 367 cycles at a crack depth of 0.501 mm using a factor of 2 on life at maximum operating conditions. Combining this result with previous fatigue strain-life experimental work gives a total fatigue life of 1032 cycles at a crack depth of 0.501 mm. Eddy-current inspections are suggested starting at 665 cycles since eddy current detection thresholds are currently at 0.381 mm. Inspection intervals are recommended every 50 cycles when operated at maximum operating conditions.

Effect of asymmetrical eddy currents on magnetic diagnosis signals for equilibrium reconstruction in the Sino-UNIted Spherical Tokamak.

PubMed

Jiang, Y Z; Tan, Y; Gao, Z; Wang, L

2014-11-01

The vacuum vessel of Sino-UNIted Spherical Tokamak was split into two insulated hemispheres, both of which were insulated from the central cylinder. The eddy currents flowing in the vacuum vessel would become asymmetrical due to discontinuity. A 3D finite elements model was applied in order to study the eddy currents. The modeling results indicated that when the Poloidal Field (PF) was applied, the induced eddy currents would flow in the toroidal direction in the center of the hemispheres and would be forced to turn to the poloidal and radial directions due to the insulated slit. Since the eddy currents converged on the top and bottom of the vessel, the current densities there tended to be much higher than those in the equatorial plane were. Moreover, the eddy currents on the top and bottom of vacuum vessel had the same direction when the current flowed in the PF coils. These features resulted in the leading phases of signals on the top and bottom flux loops when compared with the PF waveforms.

Practical considerations in the use of ultrabrief ECT in clinical practice.

PubMed

Galletly, Cherrie; Clarke, Patrick; Paterson, Tom; Rigby, Ashlee; Gill, Shane

2014-03-01

Electroconvulsive therapy (ECT) is the most effective treatment for major depression. Brief pulse width (BPW; pulse width, 1.0 m/s) ECT is often associated with cognitive impairment. Ultrabrief (UB; pulse width, 0.3 m/s) ECT is better tolerated and causes less cognitive impairment so has been introduced as an alternative. Previous research has shown that more treatments are needed with UB ECT; however, there has not been any previous research into the impact of prescribing UB ECT on length of stay. This study reports naturalistic data collected from 258 inpatients in a private psychiatric hospital for 2 years since the introduction of UB ECT. Clinician and self-rated scales of depression severity and hospital service data were used to evaluate the number of ECT treatments, length of stay, and efficacy. Patients prescribed UB ECT had, on average, 10.9 treatments compared to 8.8 for BPW ECT. They also spent more time in hospital; 30.3 days from the first ECT treatment to discharge compared to 24.7 days for patients prescribed BPW ECT. Excluding patients who switched treatments, 54% of patients prescribed UB ECT responded compared to 66.7% of patients prescribed BPW ECT. More patients (n = 42) switched from UB to BPW than from BPW to UB (n = 3). In the 4 years since the introduction of UB ECT, the number of patients prescribed ECT has increased, and the mean number of treatments per patient (for all patients receiving ECT) has increased from 7.7 to 11.6. Ultrabrief ECT has significant advantages, reflected in the increased use of ECT since UB ECT became available. However, the greater number of treatments and the increased length of stay have important implications for service delivery, costs, and bed accessibility.

Analysis of eddy current induced in track on medium-low speed maglev train

NASA Astrophysics Data System (ADS)

Li, Guanchun; Jia, Zhen; He, Guang; Li, Jie

2017-06-01

Electromagnetic levitation (EMS) maglev train relies on the attraction between the electromagnets and rails which are mounted on the train to achieve suspension. During the movement, the magnetic field generated by the electromagnet will induce the eddy current in the orbit and the eddy current will weaken the suspended magnetic field. Which leads to the attenuation of the levitation force, the increases of suspension current and the degradation the suspension performance. In this paper, the influence of eddy current on the air gap magnetic field is solved by theoretical analysis, and the correction coefficient of air gap magnetic field is fitted according to the finite element data. The levitation force and current are calculated by the modified formula, and the velocity curves of the levitation force and current are obtained. The results show that the eddy current effect increases the load power by 61.9% in the case of heavy loads.

Eddy Current Sensing of Torque in Rotating Shafts

NASA Astrophysics Data System (ADS)

Varonis, Orestes J.; Ida, Nathan

2013-12-01

The noncontact torque sensing in machine shafts is addressed based on the stress induced in a press-fitted magnetoelastic sleeve on the shaft and eddy current sensing of the changes of electrical conductivity and magnetic permeability due to the presence of stress. The eddy current probe uses dual drive, dual sensing coils whose purpose is increased sensitivity to torque and decreased sensitivity to variations in distance between probe and shaft (liftoff). A mechanism of keeping the distance constant is also employed. Both the probe and the magnetoelastic sleeve are evaluated for performance using a standard eddy current instrument. An eddy current instrument is also used to drive the coils and analyze the torque data. The method and sensor described are general and adaptable to a variety of applications. The sensor is suitable for static and rotating shafts, is independent of shaft diameter and operational over a large range of torques. The torque sensor uses a differential eddy current measurement resulting in cancellation of common mode effects including temperature and vibrations.

Factor Structure and Validity of Paper-and-Pencil Measures of Mental Speed: Evidence for a Higher-Order Model?

ERIC Educational Resources Information Center

Danthiir, Vanessa; Wilhelm, Oliver; Schulze, Ralf; Roberts, Richard D.

2005-01-01

This study explored the structure of elementary cognitive tasks (ECTs) and relations between the corresponding construct(s) with processing speed (Gs) and fluid intelligence (Gf). Participants (N=321) completed 14 ECTs, 3 Gs, and 6 Gf marker tests, all administered in paper-and-pencil format to reduce potential confounds evident when tasks are…

Preliminary Upper Estimate of Peak Currents in Transcranial Magnetic Stimulation at Distant Locations from a TMS Coil

PubMed Central

Makarov, Sergey N.; Yanamadala, Janakinadh; Piazza, Matthew W.; Helderman, Alex M.; Thang, Niang S.; Burnham, Edward H.; Pascual-Leone, Alvaro

2016-01-01

Goals Transcranial magnetic stimulation (TMS) is increasingly used as a diagnostic and therapeutic tool for numerous neuropsychiatric disorders. The use of TMS might cause whole-body exposure to undesired induced currents in patients and TMS operators. The aim of the present study is to test and justify a simple analytical model known previously, which may be helpful as an upper estimate of eddy current density at a particular distant observation point for any body composition and any coil setup. Methods We compare the analytical solution with comprehensive adaptive mesh refinement-based FEM simulations of a detailed full-body human model, two coil types, five coil positions, about 100,000 observation points, and two distinct pulse rise times, thus providing a representative number of different data sets for comparison, while also using other numerical data. Results Our simulations reveal that, after a certain modification, the analytical model provides an upper estimate for the eddy current density at any location within the body. In particular, it overestimates the peak eddy currents at distant locations from a TMS coil by a factor of 10 on average. Conclusion The simple analytical model tested in the present study may be valuable as a rapid method to safely estimate levels of TMS currents at different locations within a human body. Significance At present, safe limits of general exposure to TMS electric and magnetic fields are an open subject, including fetal exposure for pregnant women. PMID:26685221

Movement integration in elementary classrooms: Teacher perceptions and implications for program planning.

PubMed

Webster, Collin A; Zarrett, Nicole; Cook, Brittany S; Egan, Cate; Nesbitt, Danielle; Weaver, R Glenn

2017-04-01

Movement integration (MI), which involves infusing physical activity (PA) into regular classroom time in schools, is widely recommended to help children meet the national guideline of 60min of PA each day. Understanding the perspective of elementary classroom teachers (ECTs) toward MI is critical to program planning for interventions/professional development. This study examined the MI perceptions of ECTs in order to inform the design and implementation of a school-based pilot program that focused in part on increasing children's PA through MI. Twelve ECTs (Grades 1-3) from four schools were selected to participate based on their responses to a survey about their use of MI. Based on the idea that MI programming should be designed with particular attention to teachers who integrate relatively few movement opportunities in their classrooms, the intent was to select the teacher who reported integrating movement the least at her/his respective grade level at each school. However, not all of these teachers agreed to participate in the study. The final sample included two groups of ECTs, including eight lowest integrating teachers and four additional teachers. Each ECT participated in an interview during the semester before the pilot program was implemented. Through qualitative analysis of the interview transcripts, four themes emerged: (a) challenges and barriers (e.g., lack of time), (b) current and ideal resources (e.g., school support), (c) current implementation processes (e.g., scheduling MI into daily routines), and (e) teachers' ideas and tips for MI (e.g., stick with it and learn as you go). The themes were supported by data from both groups of teachers. This study's findings can inform future efforts to increase movement opportunities for children during regular classroom time. Copyright © 2017 Elsevier Ltd. All rights reserved.

A national survey of electroconvulsive therapy use in the Russian Federation.

PubMed

Nelson, Alexander I

2005-09-01

A survey of electroconvulsive therapy (ECT) throughout Russia was undertaken to understand the range of ECT usage and knowledge. A survey form was distributed by mail to 1648 Russian doctors and institutions expected to deal with ECT. A total of 114 replies were received. They indicated that ECT is available to 22.4% of the country's population. In available regions, ECT is given to 1.43% of hospital admissions and 0.54 per 10,000 persons per year. ECT is used in Russian psychiatry, neurology, and addictionology. Outdated ECT instruments are used in more than one third of sites, and EEG and seizure quality are virtually never monitored. Fewer than 20% of ECTs are modified with anesthesia. There is no system or expectation for ECT training or privileging, there is no national organization that aims to advance ECT practice, and ECT research is haphazard. Nevertheless, most respondents are enthusiastic and positive about ECT, and most institutions are eager to adopt modern ECT methods.

Evaluation of the Edge Crack Torsion (ECT) Test for Mode 3 Interlaminar Fracture Toughness of Laminated Composites

NASA Technical Reports Server (NTRS)

Li, Jian; Lee, Edward W.; OBrien, T. Kevin; Lee, Shaw Ming

1996-01-01

An analytical and experimental investigation was carried out on G40-800/R6376 graphite epoxy laminates to evaluate the Edge Crack Torsion (ECT) test as a candidate for a standard Mode 3 interlaminar fracture toughness test for laminated composites. The ECT test consists of a (90/(+/- 45)(sub 3)/(+/- 45)(sub 3)/90))(sub s) laminate with a delamination introduced by a non-adhesive film at the mid-plane along one edge and loaded in a special fixture to create torsion along the length of the laminate. Dye penetrate enhanced X-radiograph of failed specimens revealed that the delamination initiated at the middle of the specimen length and propagated in a self similar manner along the laminate mid-plane. A three-dimensional finite element analysis was performed that indicated that a pure Mode 3 delamination exists at the middle of specimen length away from both ends. At the ends near the loading point a small Mode 2 component exists. However, the magnitude of this Mode 2 strain energy release rate at the loading point is small compared to the magnitude of Mode 3 component in the mid-section of the specimen. Hence, the ECT test yielded the desired Mode 3 delamination. The Mode 3 fracture toughness was obtained from a compliance calibration method and was in good agreement with the finite element results. Mode 2 End-Notched Flexure (ENF) tests and Mode 1 Double Cantilever Beam (DCB) tests were also performed for the same composite material. The Mode 1 fracture toughness was much smaller than both the Mode 2 and Mode 3 fracture toughness. The Mode 2 fracture toughness was found to be 75% of the Mode 3 fracture toughness.

Does electroconvulsive therapy cause epilepsy?

PubMed

Ray, Anindya Kumar

2013-09-01

Electroconvulsive therapy (ECT) has been mentioned as a risk factor for epilepsy in some texts. This observation is based on isolated case reports and 2 studies done in 1980s. Since 1983, no study was done on this topic. The objective of the current study was to find out the incidence of spontaneous seizures after ECT. The study was done in Central Institute of Psychiatry, India. It was a retrospective cohort study where files of the patients receiving unmodified ECT during 1990 to 1995 were reviewed over approximately the next 10 years. Patients having the risk factors for spontaneous seizures like past and family history of seizure, substance abuse, and organicity were excluded from the study group. For minimizing the confounding effect of concurrent psychotropic drugs, an age-, sex-, and diagnosis-matched control group was selected. This group consisted of patients admitted during the same time and treated with similar drugs but no ECT. No report of spontaneous seizure was found in the study group of 619 patients. One patient who was excluded from the study group due to suspected neurosyphilis developed recurrent seizures 1 month after ECT. Two patients in the control group had single occasion convulsion with no further recurrence even with continuation of similar drugs. Electroconvulsive therapy has not been found to cause epilepsy. Patient's underlying organic condition may influence development of seizures.

A naturalistic study of high-dose unilateral ECT among severely depressed inpatients: how does it work in the clinical practice?

PubMed

Alves, Lucas P C; Freire, Thiago F V; Fleck, Marcelo P A; Rocha, Neusa S

2016-11-11

Naturalistic studies can be useful tools to understand how an intervention works in the real clinical practice. This study aims to investigate the outcomes in a naturalistically treated depressed inpatients cohort, who were referred, or not, to unilateral ECT. Depressed adults according to MINI admitted in a psychiatric unit were divided in unilateral ECT treated and non-ECT treated. Main outcomes were: depression improvement in Hamilton Rating Scale for Depression (HDRS-17) scores; response (HDRS-17 improvement ≥50 %); remission (HDRS-17 score ≤7); length of hospitalization. Forty-three patients were included in unilateral ECT group and 104 in non-ECT group. No differences of psychotic symptoms, melancholic features or past maniac episode were found between groups. Unilateral ECT group had a mean HDRS-17 score higher than non-ECT group at admission (ECT: 25.05 ± 1.03; non-ECT: 21.61 ± 0.69; p = 0.001), but no significant difference was found at discharge (ECT: 7.70 ± 0.81; non-ECT: 7.40 ± 0.51; p = 0.75). Unilateral ECT group had a larger HDRS-17 score reduction during treatment (ECT: 18.24 ± 1.18; non-ECT:14.20 ± 0.76; p = 0.004). There were no significant differences in response and remission rates between groups. Unilateral ECT group had longer mean duration of hospitalization in days (ECT: 35.48 ± 2.48; non-ECT: 24.57 ± 1.50; p < 0.001), but there were no difference in mean time of treatment (ECT group:27.66 ± 1.95; non-ECT: 24.57 ± 1.50; p = 0.25). Unilateral high-dose ECT is still a useful treatment option, in the real world clinical practice, to reduce the intensity of depressive symptoms in highly depressed inpatients.

Combined Wave and Current Bottom Boundary Layers: A Review

DTIC Science & Technology

2016-03-01

18 3.2 Wave and currents at arbitrary angles ....................................................................... 19 3.3 Eddy viscosity ...closure ................................................................................................. 22 3.3.1 Eddy viscosity for stratified fluids...23 3.3.2 Time-dependent eddy viscosities

Continuation of ECT after recovery from transient, ECT-induced, postictal cortical blindness.

PubMed

Sonavane, Sushma; Bambole, Vivek; Bang, Abha; Shah, Nilesh; Andrade, Chittaranjan

2012-03-01

Transient, postictal cortical blindness is a rare adverse effect of electroconvulsive therapy (ECT). There is no information on the safety of continuation of ECT in patients who recover from ECT-induced cortical blindness. An 18-year-old woman with paranoid schizophrenia experienced cortical blindness immediately after her first bifrontotemporal ECT treatment. There was complete, spontaneous recovery of vision after 6 hours. Neurological examination, computed tomography of the brain, and electroencephalographic study revealed no abnormality. A combination of circumstances suggested that continuation of ECT was desirable. After clearances from neurological and ophthalmological teams, she received 6 more ECT treatments, starting 9 days after the first. After resumption of ECT, there was marked improvement in psychopathology across the ECT course. There was no recurrence of visual symptoms. Patients who experience transient, ECT-induced, postictal cortical blindness may not necessarily experience the same adverse effect on rechallenge with ECT.

Detection and sizing of cracks in structural steel using the eddy current method

DOT National Transportation Integrated Search

2000-11-01

This report summarizes research pertaining to the application of the Eddy Current method as a means of crack detection in structural steel members of highway bridges. Eddy currents are induced when an energized coil is placed near the surface of a co...

78 FR 15281 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-11

... horizontal stabilizer. This AD requires repetitive high frequency eddy current (HFEC) inspections for... repetitive high frequency eddy current (HFEC) inspections for cracking of the left and right rib hinge... high frequency eddy current (HFEC) inspection for cracking of the left and right rib hinge bearing lugs...

78 FR 46536 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-01

... eddy current inspection of the fastener holes for defects and repair if necessary. We are proposing... also includes doing a high frequency eddy current inspection of the fastener holes for defects and... frequency eddy current inspection of the fastener holes for defects and all applicable repairs, in...

77 FR 26993 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-08

... high frequency eddy current (HFEC) inspections for cracking in holes common to the splice strap and... tasks required by this paragraph: Before further flight, do a high frequency eddy current (HFEC... approval must specifically refer to this AD. (h) Detailed and High Frequency Eddy Current Inspections...

78 FR 71998 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-02

... initial and repetitive [detailed or eddy current] inspections [for cracking and damage and replacement if... the detailed or eddy current inspection for cracking of the pilot-side rudder pedal tubes, specified... within 600 flight cycles thereafter. (2) If the most recent inspection was an eddy current inspection...

77 FR 61550 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-10

... inspection required by AD 2003-14-06 only terminates the external eddy current inspections required by..., which should not terminate the detailed or eddy current inspection, as specified. We find that... terminating action ``before the effective date of this AD'' terminates the eddy current inspections required...

Current induced domain wall motion in antiferromagnetically coupled (Co70Fe30/Pd) multilayer nanowires

NASA Astrophysics Data System (ADS)

Meng, Zhaoliang; He, Shikun; Huang, Lisen; Qiu, Jinjun; Zhou, Tiejun; Panagopoulos, Christos; Han, Guchang; Teo, Kie-Leong

2016-10-01

We investigate the current induced domain wall (DW) motion in the ultrathin CoFe/Pd multilayer based synthetically antiferromagnetic (SAF) structure nanowires by anomalous Hall effect measurement. The threshold current density (Jth) for the DW displacement decreases and the DW velocity (v) increases accordingly with the exchange coupling Jex between the top and bottom ferromagnetic CoFe/Pd multilayers. The lowest Jth = 9.3 × 1010 A/m2 and a maximum v = 150 m/s with J = 1.5 × 1012 A/m2 are achieved due to the exchange coupling torque (ECT) generated in the SAF structure. The strength of ECT is dependent on both of Jex and the strong spin-orbit torque mainly generated by Ta layer.

A new method to model electroconvulsive therapy in rats with increased construct validity and enhanced translational value.

PubMed

Theilmann, Wiebke; Löscher, Wolfgang; Socala, Katarzyna; Frieling, Helge; Bleich, Stefan; Brandt, Claudia

2014-06-01

Electroconvulsive therapy is the most effective therapy for major depressive disorder (MDD). The remission rate is above 50% in previously pharmacoresistant patients but the mechanisms of action are not fully understood. Electroconvulsive stimulation (ECS) in rodents mimics antidepressant electroconvulsive therapy (ECT) in humans and is widely used to investigate the underlying mechanisms of ECT. For the translational value of findings in animal models it is essential to establish models with the highest construct, face and predictive validity possible. The commonly used model for ECT in rodents does not meet the demand for high construct validity. For ECT, cortical surface electrodes are used to induce therapeutic seizures whereas ECS in rodents is exclusively performed by auricular or corneal electrodes. However, the stimulation site has a major impact on the type and spread of the induced seizure activity and its antidepressant effect. We propose a method in which ECS is performed by screw electrodes placed above the motor cortex of rats to closely simulate the clinical situation and thereby increase the construct validity of the model. Cortical ECS in rats induced reliably seizures comparable to human ECT. Cortical ECS was more effective than auricular ECS to reduce immobility in the forced swim test. Importantly, auricular stimulation had a negative influence on the general health condition of the rats with signs of fear during the stimulation sessions. These results suggest that auricular ECS in rats is not a suitable ECT model. Cortical ECS in rats promises to be a valid method to mimic ECT. Copyright © 2014 Elsevier Ltd. All rights reserved.

A pilot study of the comparative efficacy of 100 Hz magnetic seizure therapy and electroconvulsive therapy in persistent depression.

PubMed

Fitzgerald, Paul B; Hoy, Kate E; Elliot, David; McQueen, Susan; Wambeek, Lenore E; Chen, Leo; Clinton, Anne Maree; Downey, Glenn; Daskalakis, Zafiris J

2018-05-01

Magnetic seizure therapy (MST) is a novel brain stimulation technique that uses a high-powered transcranial magnetic stimulation device to produce therapeutic seizures. Preliminary MST studies have found antidepressant effects in the absence of cognitive side effects but its efficacy compared to electroconvulsive therapy (ECT) remains unclear. The aim of this study was to investigate the therapeutic efficacy and cognitive profile of MST compared to standard right unilateral ECT treatment. Thirty-seven patients completed a course of at least nine ECT or MST treatments in a randomized double-blind protocol. Assessments of depression severity and cognition were performed before and after treatment. No difference in the antidepressant effectiveness between the treatments was seen across any of the clinical outcome measures, although the overall response rates in both groups were quite low. In regards to cognition, following MST there were significant improvements in tests of psychomotor speed, verbal memory, and cognitive inhibition, with no reductions in cognitive performance. Following ECT there was significant improvement in only one of the cognitive inhibition tasks. With respect to the between-group comparisons, the MST group showed a significantly greater improvement on psychomotor speed than ECT. MST showed similar efficacy to right unilateral ECT in patients with treatment-resistant depression without cognitive side effects but in a sample that was only of sufficient size to demonstrate relatively large differences in response between the two groups. Future research should aim to optimize the methods of MST administration and compare its efficacy to ECT in large randomized controlled trials. © 2018 Wiley Periodicals, Inc.

46 CFR 151.03-38 - Nondestructive testing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... examination, radiographic examination, eddy current, and acoustic emission. [CGD 85-061, 54 FR 50965, Dec. 11... 46 Shipping 5 2011-10-01 2011-10-01 false Nondestructive testing. 151.03-38 Section 151.03-38... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-38 Nondestructive testing...

46 CFR 151.03-38 - Nondestructive testing.

Code of Federal Regulations, 2012 CFR

2012-10-01

... examination, radiographic examination, eddy current, and acoustic emission. [CGD 85-061, 54 FR 50965, Dec. 11... 46 Shipping 5 2012-10-01 2012-10-01 false Nondestructive testing. 151.03-38 Section 151.03-38... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-38 Nondestructive testing...

46 CFR 151.03-38 - Nondestructive testing.

Code of Federal Regulations, 2013 CFR

2013-10-01

... examination, radiographic examination, eddy current, and acoustic emission. [CGD 85-061, 54 FR 50965, Dec. 11... 46 Shipping 5 2013-10-01 2013-10-01 false Nondestructive testing. 151.03-38 Section 151.03-38... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-38 Nondestructive testing...

46 CFR 151.03-38 - Nondestructive testing.

Code of Federal Regulations, 2014 CFR

2014-10-01

... examination, radiographic examination, eddy current, and acoustic emission. [CGD 85-061, 54 FR 50965, Dec. 11... 46 Shipping 5 2014-10-01 2014-10-01 false Nondestructive testing. 151.03-38 Section 151.03-38... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-38 Nondestructive testing...

Acute electroconvulsive therapy followed by maintenance electroconvulsive therapy decreases hospital re-admission rates of older patients with severe mental illness.

PubMed

Shelef, Assaf; Mazeh, Doron; Berger, Uri; Baruch, Yehuda; Barak, Yoram

2015-06-01

Electroconvulsive therapy (ECT) is a highly effective treatment for patients with severe mental illness (SMI). Maintenance ECT (M-ECT) is required for many elderly patients experiencing severe recurrent forms of mood disorders, whereas M-ECT for schizophrenia patients is a poorly studied treatment. We report on the outcomes in aged patients with SMI: schizophrenia and severe affective disorders treated by M-ECT of varying duration to prevent relapse after a successful course of acute ECT. The study measured the effectiveness of M-ECT in preventing hospital readmissions and reducing admission days. A retrospective chart review of 42 consecutive patients comparing the number and length of psychiatric admissions before and after the start of M-ECT was used. We analyzed diagnoses, previous ECT treatments, number of ECT treatments, and number and length of psychiatric admissions before and after M-ECT. Mean age in our sample was 71.5 (6.9) years. Twenty-two (52%) patients experienced severe affective disorders and 20 (48%) experienced schizophrenia. Patients were administered 92.8 (85.9) M-ECT treatments. Average duration of the M-ECT course was 34 (29.8) months. There were on average 1.88 admissions before M-ECT and only 0.38 admissions in the M-ECT period (P < 0.001). Duration of mean hospitalization stay decreased from 215.9 to 12.4 days during the M-ECT (P < 0.01). Our findings suggest that acute ECT followed by M-ECT is highly effective in selected elderly patients with SMIs.

Measurement of toroidal vessel eddy current during plasma disruption on J-TEXT.

PubMed

Liu, L J; Yu, K X; Zhang, M; Zhuang, G; Li, X; Yuan, T; Rao, B; Zhao, Q

2016-01-01

In this paper, we have employed a thin, printed circuit board eddy current array in order to determine the radial distribution of the azimuthal component of the eddy current density at the surface of a steel plate. The eddy current in the steel plate can be calculated by analytical methods under the simplifying assumptions that the steel plate is infinitely large and the exciting current is of uniform distribution. The measurement on the steel plate shows that this method has high spatial resolution. Then, we extended this methodology to a toroidal geometry with the objective of determining the poloidal distribution of the toroidal component of the eddy current density associated with plasma disruption in a fusion reactor called J-TEXT. The preliminary measured result is consistent with the analysis and calculation results on the J-TEXT vacuum vessel.

3D analysis of eddy current loss in the permanent magnet coupling.

PubMed

Zhu, Zina; Meng, Zhuo

2016-07-01

This paper first presents a 3D analytical model for analyzing the radial air-gap magnetic field between the inner and outer magnetic rotors of the permanent magnet couplings by using the Amperian current model. Based on the air-gap field analysis, the eddy current loss in the isolation cover is predicted according to the Maxwell's equations. A 3D finite element analysis model is constructed to analyze the magnetic field spatial distributions and vector eddy currents, and then the simulation results obtained are analyzed and compared with the analytical method. Finally, the current losses of two types of practical magnet couplings are measured in the experiment to compare with the theoretical results. It is concluded that the 3D analytical method of eddy current loss in the magnet coupling is viable and could be used for the eddy current loss prediction of magnet couplings.

Longitudinal gradient coil optimization in the presence of transient eddy currents.

PubMed

Trakic, A; Liu, F; Lopez, H Sanchez; Wang, H; Crozier, S

2007-06-01

The switching of magnetic field gradient coils in magnetic resonance imaging (MRI) inevitably induces transient eddy currents in conducting system components, such as the cryostat vessel. These secondary currents degrade the spatial and temporal performance of the gradient coils, and compensation methods are commonly employed to correct for these distortions. This theoretical study shows that by incorporating the eddy currents into the coil optimization process, it is possible to modify a gradient coil design so that the fields created by the coil and the eddy currents combine together to generate a spatially homogeneous gradient that follows the input pulse. Shielded and unshielded longitudinal gradient coils are used to exemplify this novel approach. To assist in the evaluation of transient eddy currents induced within a realistic cryostat vessel, a low-frequency finite-difference time-domain (FDTD) method using the total-field scattered-field (TFSF) scheme was performed. The simulations demonstrate the effectiveness of the proposed method for optimizing longitudinal gradient fields while taking into account the spatial and temporal behavior of the eddy currents.

Kynurenine pathway metabolism and the neurobiology of treatment-resistant depression: Comparison of multiple ketamine infusions and electroconvulsive therapy.

PubMed

Allen, A P; Naughton, M; Dowling, J; Walsh, A; O'Shea, R; Shorten, G; Scott, L; McLoughlin, D M; Cryan, J F; Clarke, G; Dinan, T G

2018-05-01

Current first-line antidepressants can take weeks or months to decrease depressive symptoms. Low dose ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, shows potential for a more rapid antidepressant effect, with efficacy also evident in previously treatment-resistant populations. However, a greater understanding of the physiological mechanisms underlying such effects is required. We assessed the potential impact of ketamine infusion on neurobiological drivers of kynurenine pathway metabolism in major depression (HPA axis hyperactivity, inflammation) in patients with treatment-resistant depression compared to gender-matched healthy controls. Furthermore, we assessed these biomarkers before and after electroconvulsive therapy (ECT), which is currently the gold standard for management of treatment-resistant depression. As previously demonstrated, treatment with ketamine and ECT was associated with improved depressive symptoms in patients. At baseline, waking cortisol output was greater in the ECT cohort, kynurenine was greater in the ketamine cohort, and kynurenic acid was lower in patients compared to healthy controls, although inflammatory markers (IL-6, IL-8, IL-10 or IFN-γ) were similar in patients and controls. Furthermore, in patients who responded to ECT, the cortisol awakening response was decreased following treatment. Despite a trend towards reduced kynurenine concentrations in those who responded to ketamine, ketamine was not associated with significant alterations in any of the biomarkers assessed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Autism-Like Behavior in BTBR Mice Is Improved by Electroconvulsive Therapy.

PubMed

Hagen, Eunice; Shprung, Dana; Minakova, Elena; Washington, James; Kumar, Udaya; Shin, Don; Sankar, Raman; Mazarati, Andrey

2015-07-01

Autism is a developmental disorder characterized by impairments in social and communication abilities, as well as by restricted and repetitive behaviors. Incidence of autism is higher than earlier estimates, and treatments have limited efficacy and are costly. Limited clinical and experimental evidence suggest that patients with autism may benefit from electroconvulsive therapy (ECT). We examined the therapeutic potential of ECT in BTBR T+ tf/j mice, which represent a validated model of autism. A series of 13 electroconvulsive shocks (ECS) delivered twice a day over 7 days reversed core autism-like behavioral abnormalities-impaired sociability, social novelty, and repetitive behavior-when the animals were tested 24 h after the last ECS. The effect lasted up to 2 weeks after ECT. Neither single ECS nor a series of 6 ECS modified animals' behavior. Chronic infusion into the lateral brain ventricle of a preferential oxytocin receptor blocker (2S)-2-Amino-N-[(1S,2S,4R)-7,7-dimethyl-1-[[[4-(2-methylphenyl)-1-piperazinyl]sulfonyl]methyl]bicyclo[2.2.1]hept-2-yl]-4-(methylsulfonyl)butanamide hydrochloride abolished ECT-induced improvement of sociability and mitigated improvement of social novelty but did not affect ECT-induced reversal of repetitive behavior. These proof-of-principle experiments suggest that ECT may, indeed, be useful in the treatment of autism, and that its therapeutic effects may be mediated, in part, by central oxytocin signaling.

Eddy properties in the Southern California Current System

NASA Astrophysics Data System (ADS)

Chenillat, Fanny; Franks, Peter J. S.; Capet, Xavier; Rivière, Pascal; Grima, Nicolas; Blanke, Bruno; Combes, Vincent

2018-05-01

The California Current System (CCS) is an eastern boundary upwelling system characterized by strong eddies that are often generated at the coast. These eddies contribute to intense, long-distance cross-shelf transport of upwelled water with enhanced biological activity. However, the mechanisms of formation of such coastal eddies, and more importantly their capacity to trap and transport tracers, are poorly understood. Their unpredictability and strong dynamics leave us with an incomplete picture of the physical and biological processes at work, their effects on coastal export, lateral water exchange among eddies and their surrounding waters, and how long and how far these eddies remain coherent structures. Focusing our analysis on the southern part of the CCS, we find a predominance of cyclonic eddies, with a 25-km radius and a SSH amplitude of 6 cm. They are formed near shore and travel slightly northwest offshore for 190 days at 2 km day-1. We then study one particular, representative cyclonic eddy using a combined Lagrangian and Eulerian numerical approach to characterize its kinematics. Formed near shore, this eddy trapped a core made up of 67% California Current waters and 33% California Undercurrent waters. This core was surrounded by other waters while the eddy detached from the coast, leaving the oldest waters at the eddy's core and the younger waters toward the edge. The eddy traveled several months as a coherent structure, with only limited lateral exchange within the eddy.

78 FR 4042 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-18

... provides an option for a high frequency eddy current inspection for cracking of the critical fastener holes... for a high frequency eddy current inspection for cracking of the critical fastener holes, and repair..., August 9, 2007)), do a high frequency eddy current (HFEC) inspection for cracking of the four critical...

77 FR 5724 - Airworthiness Directives; Fokker Services B.V. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

... proposed AD would require repetitive low frequency eddy current inspections of the forward fuselage butt... repetitive [low frequency eddy current] inspections of the forward fuselage butt joints for cracks and, when... effective date of this AD, whichever occurs later, do a low frequency eddy current inspection of the forward...

76 FR 38072 - Airworthiness Directives; The Boeing Company Model 777 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-29

... above. This proposed AD would require repetitive detailed inspection and high frequency eddy current... high frequency eddy current (HFEC) inspection for cracks in the WCS web pockets of spanwise beams... = 160 frequency eddy current inspection per hour = $4,250 inspection cycle. airplanes x $4,250 of...

77 FR 37788 - Airworthiness Directives; Fokker Services B.V. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-25

... Model F.28 Mark 0100 airplane. This AD requires repetitive low frequency eddy current inspections of the... described above, this [EASA] AD requires repetitive [low frequency eddy current] inspections of the forward... eddy current inspection of the forward fuselage butt-joints for cracks, in accordance with the...

78 FR 40050 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-03

... inspections or high frequency eddy current inspections for cracks of the blended area of the fuselage skin... repetitive external detailed inspections or high frequency eddy current inspections for cracks of the blended..., 2009) is August 3, 2009. (h) Repetitive High Frequency Eddy Current (HFEC) Inspections For airplanes on...

Eddy current compensation for delta relaxation enhanced MR by dynamic reference phase modulation.

PubMed

Hoelscher, Uvo Christoph; Jakob, Peter M

2013-04-01

Eddy current compensation by dynamic reference phase modulation (eDREAM) is a compensation method for eddy current fields induced by B 0 field-cycling which occur in delta relaxation enhanced MR (dreMR) imaging. The presented method is based on a dynamic frequency adjustment and prevents eddy current related artifacts. It is easy to implement and can be completely realized in software for any imaging sequence. In this paper, the theory of eDREAM is derived and two applications are demonstrated. The theory describes how to model the behavior of the eddy currents and how to implement the compensation. Phantom and in vivo measurements are carried out and demonstrate the benefits of eDREAM. A comparison of images acquired with and without eDREAM shows a significant improvement in dreMR image quality. Images without eDREAM suffer from severe artifacts and do not allow proper interpretation while images with eDREAM are artifact free. In vivo experiments demonstrate that dreMR imaging without eDREAM is not feasible as artifacts completely change the image contrast. eDREAM is a flexible eddy current compensation for dreMR. It is capable of completely removing the influence of eddy currents such that the dreMR images do not suffer from artifacts.

Magnetic Field of Conductive Objects as Superposition of Elementary Eddy Currents and Eddy Current Tomography

NASA Astrophysics Data System (ADS)

Sukhanov, D. Ya.; Zav'yalova, K. V.

2018-03-01

The paper represents induced currents in an electrically conductive object as a totality of elementary eddy currents. The proposed scanning method includes measurements of only one component of the secondary magnetic field. Reconstruction of the current distribution is performed by deconvolution with regularization. Numerical modeling supported by the field experiments show that this approach is of direct practical relevance.

A report on the introduction of ultrabrief pulse width ECT in a private psychiatric hospital.

PubMed

Galletly, Cherrie; Paterson, Tom; Burton, Cassandra

2012-03-01

We report on 6 months of data since the introduction of ultrabrief pulse width electroconvulsive therapy (UB ECT) at a private psychiatric hospital in Adelaide. Results suggest that psychiatrists welcomed the availability of UB ECT, with an increase in prescription of ECT. About a quarter of UB ECT patients changed to standard pulse width (SPW) ECT, but those who did respond to UB ECT had an equivalent response to those who had SPW ECT. Courses of treatment were longer with UB ECT, which was reflected in an increased length of stay.

Nondestructive inspection assessment of eddy current and electrochemical analysis to separate inconel and stainless steel alloys

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

Moore, D.G.; Sorensen, N.R.

1998-02-01

This report presents a nondestructive inspection assessment of eddy current and electrochemical analysis to separate inconel alloys from stainless steel alloys as well as an evaluation of cleaning techniques to remove a thermal oxide layer on aircraft exhaust components. The results of this assessment are presented in terms of how effective each technique classifies a known exhaust material. Results indicate that either inspection technique can separate inconel and stainless steel alloys. Based on the experiments conducted, the electrochemical spot test is the optimum for use by airframe and powerplant mechanics. A spot test procedure is proposed for incorporation into themore » Federal Aviation Administration Advisory Circular 65-9A Airframe & Powerplant Mechanic - General Handbook. 3 refs., 70 figs., 7 tabs.« less

The metallic sphere in a uniform ac magnetic field: A simple and precise experiment for exploring eddy currents and non-destructive testing

NASA Astrophysics Data System (ADS)

Honke, Michael L.; Bidinosti, Christopher P.

2018-06-01

We describe a very simple experiment that utilizes standard laboratory equipment to measure the electromagnetic response of a metallic sphere exposed to a uniform ac magnetic field. Measurements were made for a variety of non-magnetic and magnetic metals, and in all cases the results fit very well with theory over the four orders of frequency (25 Hz to 102 kHz) explored here. Precise values of magnetic permeability and electrical conductivity can be extracted from fits to the data given the sphere radius only. The same apparatus is also used to explore the effects of geometry on eddy current generation as well as to demonstrate non-destructive testing through measurements on coins of different composition.

Influence of clamping plate permeability and metal screen structures on three-dimensional magnetic field and eddy current loss in end region of a turbo-generator by numerical analysis

NASA Astrophysics Data System (ADS)

Likun, Wang; Weili, Li; Yi, Xue; Chunwei, Guan

2013-11-01

A significant problem of turbogenerators on complex end structures is overheating of local parts caused by end losses in the end region. Therefore, it is important to investigate the 3-D magnetic field and eddy current loss in the end. In end region of operating large turbogenerator at thermal power plants, magnetic leakage field distribution is complex. In this paper, a 3-D mathematical model used for the calculation of the electromagnetic field in the end region of large turbo-generators is given. The influence of spatial locations of end structures, the actual shape and material of end windings, clamping plate, and copper screen are considered. Adopting the time-step finite element (FE) method and taking the nonlinear characteristics of the core into consideration, a 3-D transient magnetic field is calculated. The objective of this paper is to investigate the influence of clamping plate permeability and metal screen structures on 3-D electromagnetic field distribution and eddy current loss in end region of a turbo-generator. To reduce the temperature of copper screen, a hollow metal screen is proposed. The eddy current loss, which is gained from the 3D transient magnetic field, is used as heat source for the thermal field of end region. The calculated temperatures are compared with test data.

Software compensation of eddy current fields in multislice high order dynamic shimming.

PubMed

Sengupta, Saikat; Avison, Malcolm J; Gore, John C; Brian Welch, E

2011-06-01

Dynamic B(0) shimming (DS) can produce better field homogeneity than static global shimming by dynamically updating slicewise shim values in a multislice acquisition. The performance of DS however is limited by eddy current fields produced by the switching of 2nd and 3rd order unshielded shims. In this work, we present a novel method of eddy field compensation (EFC) applied to higher order shim induced eddy current fields in multislice DS. This method does not require shim shielding, extra hardware for eddy current compensation or subject specific prescanning. The interactions between shim harmonics are modeled assuming steady state of the medium and long time constant, cross and self term eddy fields in a DS experiment and 'correction factors' characterizing the entire set of shim interactions are derived. The correction factors for a given time between shim switches are shown to be invariable with object scanned, shim switching pattern and actual shim values, allowing for their generalized prospective use. Phantom and human head, 2nd and 3rd order DS experiments performed without any hardware eddy current compensation using the technique show large reductions in field gradients and offsets leading to significant improvements in image quality. This method holds promise as an alternative to expensive hardware based eddy current compensation required in 2nd and 3rd order DS. Copyright © 2011 Elsevier Inc. All rights reserved.

Characterization of Heat Treated Titanium-Based Implants by Nondestructive Eddy Current and Ultrasonic Tests

NASA Astrophysics Data System (ADS)

Mutlu, Ilven; Ekinci, Sinasi; Oktay, Enver

2014-06-01

This study presents nondestructive characterization of microstructure and mechanical properties of heat treated Ti, Ti-Cu, and Ti-6Al-4V titanium-based alloys and 17-4 PH stainless steel alloy for biomedical implant applications. Ti, Ti-Cu, and 17-4 PH stainless steel based implants were produced by powder metallurgy. Ti-6Al-4V alloy was investigated as bulk wrought specimens. Effects of sintering temperature, aging, and grain size on mechanical properties were investigated by nondestructive and destructive tests comparatively. Ultrasonic velocity in specimens was measured by using pulse-echo and transmission methods. Electrical conductivity of specimens was determined by eddy current tests. Determination of Young's modulus and strength is important in biomedical implants. Young's modulus of specimens was calculated by using ultrasonic velocities. Calculated Young's modulus values were compared and correlated with experimental values.

The Anaesthetic-ECT Time Interval in Electroconvulsive Therapy Practice--Is It Time to Time?

PubMed

Gálvez, Verònica; Hadzi-Pavlovic, Dusan; Wark, Harry; Harper, Simon; Leyden, John; Loo, Colleen K

2016-01-01

Because most common intravenous anaesthetics used in ECT have anticonvulsant properties, their plasma-brain concentration at the time of seizure induction might affect seizure expression. The quality of ECT seizure expression has been repeatedly associated with efficacy outcomes. The time interval between the anaesthetic bolus injection and the ECT stimulus (anaesthetic-ECT time interval) will determine the anaesthetic plasma-brain concentration when the ECT stimulus is administered. The aim of this study was to examine the effect of the anaesthetic-ECT time interval on ECT seizure quality and duration. The anaesthetic-ECT time interval was recorded in 771 ECT sessions (84 patients). Right unilateral brief pulse ECT was applied. Anaesthesia given was propofol (1-2 mg/kg) and succinylcholine (0.5-1.0 mg/kg). Seizure quality indices (slow wave onset, amplitude, regularity, stereotypy and post-ictal suppression) and duration were rated through a structured rating scale by a single blinded trained rater. Linear Mixed Effects Models analysed the effect of the anaesthetic-ECT time interval on seizure quality indices, controlling for propofol dose (mg), ECT charge (mC), ECT session number, days between ECT, age (years), initial seizure threshold (mC) and concurrent medication. Longer anaesthetic-ECT time intervals lead to significantly higher quality seizures (p < 0.001 for amplitude, regularity, stereotypy and post-ictal suppression). These results suggest that the anaesthetic-ECT time interval is an important factor to consider in ECT practice. This time interval should be extended to as long as practically possible to facilitate the production of better quality seizures. Close collaboration between the anaesthetist and the psychiatrist is essential. Copyright © 2015 Elsevier Inc. All rights reserved.

Efficacy of right unilateral ultrabrief pulse width ECT: a preliminary report.

PubMed

Magid, Michelle; Truong, Liz; Trevino, Kenneth; Husain, Mustafa

2013-12-01

Ultrabrief (right unilateral) electroconvulsive therapy (UB-RU ECT) is a newer form of ECT, which uses a shorter pulse width than the standard ECT (0.3 vs 1.0 millisecond, respectively). As a result, the use of UB ECT may provide a means of further decreasing ECT-related cognitive adverse effects. In 2011, the University of Texas Southwestern Department of ECT in Austin adopted a UB ECT protocol. The purpose of this study was to perform a preliminary evaluation of the effectiveness and efficiency of UB-RU ECT. This study also examined whether sex, age, or diagnosis affected response rates. This retrospective chart review identified 62 patients treated with the UB ECT protocol. An analysis of ECT response rates and demographic characteristics was conducted based on the data from clinical evaluations and Patient Health Questionnaire 9. Sixty-eight percent of patients in the study responded to ECT; 55% responded to UB pulse width RU ECT with another 13% responding when switched to standard pulse width bilateral ECT. The mean number of treatments in an index ECT series was 12.5. There was no statistically significant difference in response rates between bipolar and unipolar depressed patients. Men required progression to bilateral treatment more than women. This UB ECT protocol demonstrated a similar response rate when compared to standard ECT protocols; however, an increase in the number of treatments was required. Ultrabrief protocols are a viable option for both bipolar and unipolar depression. In men, UB ECT protocols may be less advantageous due to a need to overcome a potentially higher seizure threshold in men; however, additional research is needed to confirm this finding.

Observations of the interaction between near-inertial waves and mesoscale eddies

NASA Astrophysics Data System (ADS)

Martínez-Marrero, Antonio; Sangrá, Pablo; Caldeira, Rui; Aguiar-González, Borja; Rodríguez-Santana, Ángel

2014-05-01

Trajectories of eight drifters dragged below the surface mixed layer and current meter data from a mooring are used to analyse the interaction between near-inertial waves and mesoscale eddies. Drifters were deployed within eddies generated downstream of Canary and Madeira islands between 1998 and 2007. The mooring was installed in the passage of cyclonic eddies induced by Gran Canaria island during 2006. Rotatory wavelet analysis of Lagrangian velocities shows a clear relationship between the near-inertial waves' intrinsic frequencies and the eddy angular velocities. The results reveal that near-inertial waves reach a minimum frequency of half the planetary vorticity (f/2) in the inner core of young anticyclonic eddies rotating with its maximum absolute angular speed of f/2. The highest amplitudes of the observed inertial motions are also found within anticyclonic eddies evidencing the trapping of inertial waves. Finally, the analysis of the current meter series show frequency fluctuations of the near-inertial currents in the upper 500 meters that are related to the passage of cyclonic eddies. These fluctuations appear to be consistent with the variation of the background vorticity produced by the eddies.

Electrochemotherapy under tumescent local anesthesia for the treatment of cutaneous metastases.

PubMed

Kendler, Michael; Micheluzzi, Martin; Wetzig, Tino; Simon, Jan C

2013-07-01

The surgical management of cutaneous metastasis (CM) is challenging, particularly in elderly patients, in whom general anesthesia can be difficult because of comorbidity. To test the effectiveness of tumescent local anesthesia (TLA) to achieve adequate anesthesia during the treatment of extensive CM with electrochemotherapy (ECT), previously only performed under general anesthesia. We conducted five ECT treatments of CM with intralesional bleomycin under TLA. We examined pain scores before, during, and after treatment; analgesic use; and side effects. The intention of the treatment was palliative in all cases. We treated four patients (ages 75-88) with CM with a mean area of 126 cm(2) (range 12-198 cm(2) ) with 356 mL of TLA per treatment (range 180-450 mL). The ECT treatment under TLA demonstrated that anesthesia was adequate, with moderate pain during and slight pain after the procedure as measured on a visual analog scale (VAS). In this proof-of-principle study, we demonstrated that ECT can be performed under TLA; TLA might be a useful new anesthesia option for patients treated with ECT. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

NonDestructive Evaluation for Industrial & Development Applications

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

Hunter, James F.

2016-10-12

Provide overview of weld inspection for Non-Destructive Testing at LANL. This includes radiography (RT/DR/CR/CT for x-ray & neutron sources), ultrasonic testing (UT/PAUT), dye penetrant inspection (PT), eddy current inspection (ET) and magnetic particle testing (MT). Facilities and capabilities for weld inspection will be summarized with examples.

Key factors of eddy current separation for recovering aluminum from crushed e-waste.

PubMed

Ruan, Jujun; Dong, Lipeng; Zheng, Jie; Zhang, Tao; Huang, Mingzhi; Xu, Zhenming

2017-02-01

Recovery of e-waste in China had caused serious pollutions. Eddy current separation is an environment-friendly technology of separating nonferrous metallic particles from crushed e-waste. However, due to complex particle characters, separation efficiency of traditional eddy current separator was low. In production, controllable operation factors of eddy current separation are feeding speed, (ωR-v), and S p . There is little special information about influencing mechanism and critical parameters of these factors in eddy current separation. This paper provided the special information of these key factors in eddy current separation of recovering aluminum particles from crushed waste refrigerator cabinets. Detachment angles increased as the increase of (ωR-v). Separation efficiency increased with the growing of detachment angles. Aluminum particles were completely separated from plastic particles in critical parameters of feeding speed 0.5m/s and detachment angles greater than 6.61deg. S p /S m of aluminum particles in crushed waste refrigerators ranged from 0.08 to 0.51. Separation efficiency increased as the increase of S p /S m . This enlightened us to develop new separator to separate smaller nonferrous metallic particles in e-waste recovery. High feeding speed destroyed separation efficiency. However, greater S p of aluminum particles brought positive impact on separation efficiency. Greater S p could increase critical feeding speed to offer greater throughput of eddy current separation. This paper will guide eddy current separation in production of recovering nonferrous metals from crushed e-waste. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multipurpose Pressure Vessel Scanner and Photon Doppler Velocimetry

NASA Technical Reports Server (NTRS)

Ellis, Tayera

2015-01-01

Critical flight hardware typically undergoes a series of nondestructive evaluation methods to screen for defects before it is integrated into the flight system. Conventionally, pressure vessels have been inspected for flaws using a technique known as fluorescent dye penetrant, which is biased to inspector interpretation. An alternate method known as eddy current is automated and can detect small cracks better than dye penetrant. A new multipurpose pressure vessel scanner has been developed to perform internal and external eddy current scanning, laser profilometry, and thickness mapping on pressure vessels. Before this system can be implemented throughout industry, a probability of detection (POD) study needs to be performed to validate the system's eddy current crack/flaw capabilities. The POD sample set will consist of 6 flight-like metal pressure vessel liners with defects of known size. Preparation for the POD includes sample set fabrication, system operation, procedure development, and eddy current settings optimization. For this, collaborating with subject matter experts was required. This technical paper details the preparation activities leading up to the POD study currently scheduled for winter 2015/2016. Once validated, this system will be a proven innovation for increasing the safety and reliability of necessary flight hardware. Additionally, testing of frangible joint requires Photon Doppler Velocimetry (PDV) and Digital Image Correlation instrumentation. There is often noise associated with PDV data, which necessitates a frequency modulation (FM) signal-to-noise pre-test. Generally, FM radio works by varying the carrier frequency and mixing it with a fixed frequency source, creating a beat frequency which is represented by audio frequency that can be heard between about 20 to 20,000 Hz. Similarly, PDV reflects a shifted frequency (a phenomenon known as the Doppler Effect) from a moving source and mixes it with a fixed source frequency, which results in a beat frequency. However, for PDV, discerning the signal from the noise is difficult without a moving source to induce the modulation. A rotating wheel is currently being used as the moving source but its configuration is impractical and has cumbersome placement inside the current frangible joint test cell. As a way to combat this problem and verify a satisfactory signal-to-noise ratio, a reflective moving crystal piezo will be used to modulate a beat frequency, and an absorptive target will be used to block the signal in order to determine any back reflection coming from the probe and discern the true signal-to-noise ratio. The piezo will be mounted and inserted onto the test table on an extendable telescopic antenna grounded by a magnetic base in the test zone. This piezo configuration will be more compatible within the test zone and allow for easy removal of the disk following acceptable signal verification and prior to frangible joint tests.

A Novel Application of Eddy Current Braking for Functional Strength Training during Gait

PubMed Central

Washabaugh, Edward P.; Claflin, Edward S.; Gillespie, R. Brent; Krishnan, Chandramouli

2016-01-01

Functional strength training is becoming increasingly popular when rehabilitating individuals with neurological injury such as stroke or cerebral palsy. Typically, resistance during walking is provided using cable robots or weights that are secured to the distal shank of the subject. However, there exists no device that is wearable and capable of providing resistance across the joint, allowing over ground gait training. In this study, we created a lightweight and wearable device using eddy current braking to provide resistance to the knee. We then validated the device by having subjects wear it during a walking task through varying resistance levels. Electromyography and kinematics were collected to assess the biomechanical effects of the device on the wearer. We found that eddy current braking provided resistance levels suitable for functional strength training of leg muscles in a package that is both lightweight and wearable. Applying resistive forces at the knee joint during gait resulted in significant increases in muscle activation of many of the muscles tested. A brief period of training also resulted in significant aftereffects once the resistance was removed. These results support the feasibility of the device for functional strength training during gait. Future research is warranted to test the clinical potential of the device in an injured population. PMID:26817456

A Novel Application of Eddy Current Braking for Functional Strength Training During Gait.

PubMed

Washabaugh, Edward P; Claflin, Edward S; Gillespie, R Brent; Krishnan, Chandramouli

2016-09-01

Functional strength training is becoming increasingly popular when rehabilitating individuals with neurological injury such as stroke or cerebral palsy. Typically, resistance during walking is provided using cable robots or weights that are secured to the distal shank of the subject. However, there exists no device that is wearable and capable of providing resistance across the joint, allowing over ground gait training. In this study, we created a lightweight and wearable device using eddy current braking to provide resistance to the knee. We then validated the device by having subjects wear it during a walking task through varying resistance levels. Electromyography and kinematics were collected to assess the biomechanical effects of the device on the wearer. We found that eddy current braking provided resistance levels suitable for functional strength training of leg muscles in a package that is both lightweight and wearable. Applying resistive forces at the knee joint during gait resulted in significant increases in muscle activation of many of the muscles tested. A brief period of training also resulted in significant aftereffects once the resistance was removed. These results support the feasibility of the device for functional strength training during gait. Future research is warranted to test the clinical potential of the device in an injured population.

New Eddy Current Probe for Thickness Gauging of Conductive Materials

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Fulton, Jim; Nath, Shridhar; Namkung, Min

1993-01-01

The accurate measure of material thickness is important for many non-destructive evaluation applications. Factors such as corrosion damage can jeopardize structural integrity through material thinning and process control considerations often mandate strict limits on material dimensions. Access to the material under test can be limited to a single side and large areas may need to be examined in a small time period. In an effort to enhance the effectiveness of material thickness measurements a flux focusing eddy current probe has been developed at NASA Langley Research Center. The probe provides an accurate measure of the thickness of conducting materials from a single sided measurement. It is straight forward to use and can be easily automated for production line testing. The probe also requires only minimal instrumentation and power so that extremely portable units can be manufactured at a low cost. This new eddy current probe has been used to accurately measure the thickness of aluminum alloy plates with a resolution of greater than 0.001 in. (25 microns). Simulated corrosion damage has also been detected on both single layer and multi-layer samples. The present work will explain the output voltage dependence of the device as a function of material thickness and present experimental results for thickness gauging and corrosion detection.

Measurement of toroidal vessel eddy current during plasma disruption on J-TEXT

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

Liu, L. J.; Yu, K. X.; Zhang, M., E-mail: zhangming@hust.edu.cn

2016-01-15

In this paper, we have employed a thin, printed circuit board eddy current array in order to determine the radial distribution of the azimuthal component of the eddy current density at the surface of a steel plate. The eddy current in the steel plate can be calculated by analytical methods under the simplifying assumptions that the steel plate is infinitely large and the exciting current is of uniform distribution. The measurement on the steel plate shows that this method has high spatial resolution. Then, we extended this methodology to a toroidal geometry with the objective of determining the poloidal distributionmore » of the toroidal component of the eddy current density associated with plasma disruption in a fusion reactor called J-TEXT. The preliminary measured result is consistent with the analysis and calculation results on the J-TEXT vacuum vessel.« less

Bitemporal Versus High-Dose Unilateral Twice-Weekly Electroconvulsive Therapy for Depression (EFFECT-Dep): A Pragmatic, Randomized, Non-Inferiority Trial.

PubMed

Semkovska, Maria; Landau, Sabine; Dunne, Ross; Kolshus, Erik; Kavanagh, Adam; Jelovac, Ana; Noone, Martha; Carton, Mary; Lambe, Sinead; McHugh, Caroline; McLoughlin, Declan M

2016-04-01

ECT is the most effective treatment for severe depression. Previous efficacy studies, using thrice-weekly brief-pulse ECT, reported that high-dose (6× seizure threshold) right unilateral ECT is similar to bitemporal ECT but may have fewer cognitive side effects. The authors aimed to assess the effectiveness and cognitive side effects of twice-weekly moderate-dose (1.5× seizure threshold) bitemporal ECT with high-dose unilateral ECT in real-world practice. This was a pragmatic, patient- and rater-blinded, noninferiority trial of patients with major depression (N=138; 63% female; age=56.7 years [SD=14.8]) in a national ECT service with a 6-month follow-up. Participants were independently randomly assigned to bitemporal or high-dose unilateral ECT. The primary outcome was change in the 24-item Hamilton Depression Rating Scale (HAM-D) score after the ECT course; the prespecified noninferiority margin was 4.0 points. Secondary outcomes included response and remission rates, relapse status after 6 months, and cognition. Of the eligible patients, 69 were assigned to bitemporal ECT and 69 to unilateral ECT. High-dose unilateral ECT was noninferior to bitemporal ECT regarding the 24-item HAM-D scores after the ECT course (mean difference=1.08 points in favor of unilateral ECT [95% CI=-1.67 to 3.84]). There were no significant differences for response and remission or 6-month relapse status. Recovery of orientation was quicker following unilateral ECT (median=19.1 minutes versus 26.4 minutes). Bitemporal ECT was associated with a lower percent recall of autobiographical information (odds ratio=0.66) that persisted for 6 months. Twice-weekly high-dose unilateral ECT is not inferior to bitemporal ECT for depression and may be preferable because of its better cognitive side-effect profile.

Comparison of anesthetics in electroconvulsive therapy: an effective treatment with the use of propofol, etomidate, and thiopental.

PubMed

Zahavi, Guy Sender; Dannon, Pinhas

2014-01-01

Electroconvulsive therapy (ECT) is considered to be one of the most effective treatments in psychiatry. Currently, three medications for anesthesia are used routinely during ECT: propofol, etomidate, and thiopental. The objective of this study was to evaluate the effects of the anesthetics used in ECT on seizure threshold and duration, hemodynamics, recovery from ECT, and immediate side effects. Our study is a retrospective cohort study, in which a comparison was made between three groups of patients who underwent ECT and were anesthetized with propofol, etomidate, or thiopental. The main effect compared was treatment dose and seizure duration. All patients were chosen as responders to ECT. Data were gathered about 91 patients (39 were anesthetized with thiopental, 29 with etomidate, and 23 with propofol). Patients in the thiopental group received a lower electrical dose compared to the propofol and etomidate group (mean of 459 mC compared to 807 mC and 701 mC, respectively, P<0.001). Motor seizure duration was longer in the thiopental group compared to propofol and etomidate (mean of 40 seconds compared to 21 seconds and 23 seconds, respectively, P=0.018). Seizure duration recorded by electroencephalography was similar in the thiopental and etomidate groups and lower in the propofol group (mean of 57 seconds in both groups compared to 45 seconds, respectively, P=0.038). Patients who were anesthetized with thiopental received a lower electrical treatment dose without an unwanted decrease in seizure duration. Thiopental might be the anesthetic of choice when it is congruent with other medical considerations.

Eddy Current System and Method for Crack Detection

NASA Technical Reports Server (NTRS)

Wincheski, Russell A. (Inventor); Simpson, John W. (Inventor)

2012-01-01

An eddy current system and method enables detection of sub-surface damage in a cylindrical object. The invention incorporates a dual frequency, orthogonally wound eddy current probe mounted on a stepper motor-controlled scanning system. The system is designed to inspect for outer surface damage from the interior of the cylindrical object.

Eddy-Current Inspection of Ball Bearings

NASA Technical Reports Server (NTRS)

Bankston, B.

1985-01-01

Custom eddy-current probe locates surface anomalies. Low friction air cushion within cone allows ball to roll easily. Eddy current probe reliably detects surface and near-surface cracks, voids, and material anomalies in bearing balls or other spherical objects. Defects in ball surface detected by probe displayed on CRT and recorded on strip-chart recorder.

77 FR 64709 - Airworthiness Directives; MD Helicopters, Inc.

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-23

... visual inspection, and if necessary, an eddy current inspection of the main rotor lower hub assembly... specifies an initial 100-hour and recurring 300-hour visual and eddy current inspections of the lower hub... a total cost per helicopter of $85 and a total cost of $1,020 for the fleet. Eddy current inspecting...

77 FR 37332 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-21

... the high frequency eddy current inspection for cracking of the critical fastener holes, and repair if... of the bulkhead, and repair if necessary; and proposed an option to the high frequency eddy current...-15152 (72 FR 44753, August 9, 2007)), do a high frequency eddy current (HFEC) inspection for cracking of...

Revolving Eddy-Current Probe Detects Cracks Near Rivets

NASA Technical Reports Server (NTRS)

Namkung, Min; Wincheski, Buzz; Fulton, James P.; Nath, Shridhar; Simpson, John

1995-01-01

Scanning eddy-current probe in circular pattern increases sensitivity with which probe indicates fatigue cracks and other defects in metal surfaces in vicinity of rivets. Technique devised to facilitate inspection of riveted joints in aircraft. Eddy-current probe in question described in "Electro-magnetic Flaw Detector Is Easier To Use" (LAR-15046).

77 FR 43178 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

... eddy current high frequency (ETHF) inspections for cracking on the aft side of the left and right wing... NPRM proposed to require repetitive eddy current high frequency (ETHF) inspections for cracking on the...,000 flight cycles after the effective date of this AD, whichever occurs later, do an eddy current high...

76 FR 14349 - Airworthiness Directives; British Aerospace Regional Aircraft Model HP.137 Jetstream Mk.1...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-16

... (FC). For the reasons described above, this AD requires initial and repetitive eddy current... requires initial and repetitive eddy current inspections, and depending on findings, accomplishment of... (landings) on the MLG after the effective date of this AD, whichever occurs later, eddy current inspect all...

78 FR 73457 - Airworthiness Directives; the Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-06

... frequency eddy current inspections for cracking of the tension tie at BS 760 or 780, as applicable, and do... ties, including doing an open-hole high frequency eddy current inspection for cracks, as applicable...) and paragraph (i) of this AD, but not as AMOCs for the high frequency eddy current inspections...

76 FR 58094 - Airworthiness Directives; 328 Support Services GmbH (Type Certificate Previously Held by AvCraft...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-20

... subsequent Eddy Current inspection (NDI) [non-destructive inspection] of the same area to detect cracks... inspections are eddy current inspections. The modification includes cold expansion of the former lower wing... with consequent loss of control. * * * * * The new inspections are eddy current inspections. The...

76 FR 58416 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-21

... specifies a bolt hole eddy current inspection to verify the cracking. The corrective actions for cracking... specified in paragraph (k) of this AD, do eddy current non-destructive inspections (NDI) and detailed... secondary eddy current inspection to detect cracking of fastener holes with suspected crack indications; in...

77 FR 18963 - Airworthiness Directives; MD Helicopters, Inc.

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-29

...) Model MD900 helicopters. The existing AD requires a visual inspection, and if necessary, an eddy current... with an airworthy lower hub. If there is no crack as a result of the visual inspection, eddy current... nondestructive eddy current inspection of the lower hub. That AD was prompted by cracks found on four lower hubs...

77 FR 21402 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-10

... option is to conduct an eddy current inspection and the other option is to conduct a visual inspection... blade sanding inspection rather than the eddy current inspection, at an average labor rate of $85 per.... (1) Inspect by using either an eddy current inspection in accordance with paragraphs B.(1)(a) through...

Model development and validation of geometrically complex eddy current coils using finite element methods

NASA Astrophysics Data System (ADS)

Brown, Alexander; Eviston, Connor

2017-02-01

Multiple FEM models of complex eddy current coil geometries were created and validated to calculate the change of impedance due to the presence of a notch. Capable realistic simulations of eddy current inspections are required for model assisted probability of detection (MAPOD) studies, inversion algorithms, experimental verification, and tailored probe design for NDE applications. An FEM solver was chosen to model complex real world situations including varying probe dimensions and orientations along with complex probe geometries. This will also enable creation of a probe model library database with variable parameters. Verification and validation was performed using other commercially available eddy current modeling software as well as experimentally collected benchmark data. Data analysis and comparison showed that the created models were able to correctly model the probe and conductor interactions and accurately calculate the change in impedance of several experimental scenarios with acceptable error. The promising results of the models enabled the start of an eddy current probe model library to give experimenters easy access to powerful parameter based eddy current models for alternate project applications.

Solving time-dependent two-dimensional eddy current problems

NASA Technical Reports Server (NTRS)

Lee, Min Eig; Hariharan, S. I.; Ida, Nathan

1988-01-01

Results of transient eddy current calculations are reported. For simplicity, a two-dimensional transverse magnetic field which is incident on an infinitely long conductor is considered. The conductor is assumed to be a good but not perfect conductor. The resulting problem is an interface initial boundary value problem with the boundary of the conductor being the interface. A finite difference method is used to march the solution explicitly in time. The method is shown. Treatment of appropriate radiation conditions is given special consideration. Results are validated with approximate analytic solutions. Two stringent test cases of high and low frequency incident waves are considered to validate the results.

An avenue of eddies: Quantifying the biophysical properties of mesoscale eddies in the Tasman Sea

NASA Astrophysics Data System (ADS)

Everett, J. D.; Baird, M. E.; Oke, P. R.; Suthers, I. M.

2012-08-01

The Tasman Sea is unique - characterised by a strong seasonal western boundary current that breaks down into a complicated field of mesoscale eddies almost immediately after separating from the coast. Through a 16-year analysis of Tasman Sea eddies, we identify a region along the southeast Australian coast which we name ‘Eddy Avenue’ where eddies have higher sea level anomalies, faster rotation and greater sea surface temperature and chlorophyll a anomalies. The density of cyclonic and anticyclonic eddies within Eddy Avenue is 23% and 16% higher respectively than the broader Tasman Sea. We find that Eddy Avenue cyclonic and anticyclonic eddies have more strongly differentiated biological properties than those of the broader Tasman Sea, as a result of larger anticyclonic eddies formed from Coral Sea water depressing chl. a concentrations, and for coastal cyclonic eddies due to the entrainment of nutrient-rich shelf waters. Cyclonic eddies within Eddy Avenue have almost double the chlorophyll a (0.35 mg m-3) of anticyclonic eddies (0.18 mg m-3). The average chlorophyll a concentration for cyclonic eddies is 16% higher in Eddy Avenue and 28% lower for anticyclonic eddies when compared to the Tasman Sea. With a strengthening East Australian Current, the propagation of these eddies will have significant implications for heat transport and the entrainment and connectivity of plankton and larval fish populations.

Electroconvulsive therapy in the intensive care unit for the treatment of catatonia: a case series and review of the literature.

PubMed

Dessens, Femke M; van Paassen, Judith; van Westerloo, David J; van der Wee, Nic J; van Vliet, Irene M; van Noorden, Martijn S

2016-01-01

Catatonia is an underdiagnosed syndrome that may occur in severely ill patients. The malignant subtype, consisting of motor symptoms, autonomic instability and fever, is associated with high mortality rates, though exact current mortality rates are unknown. This subtype requires a fast detection and treatment with high doses of a benzodiazepine or electroconvulsive therapy (ECT), preferably in an intensive care unit (ICU) setting. Case series and qualitative literature review. This paper presents four patients admitted to the ICU of an academic hospital diagnosed with malignant catatonia. All patients received ECT after an ineffective trial of high-dose intravenous benzodiazepine treatment. The duration of ECT ranged from 6 to 23 treatments after which the catatonic features partially or fully remitted. In addition, we have reviewed the diagnostic challenges, neurobiology, possible causes, differential diagnosis and treatment options of catatonia, focusing on the treatment with ECT and the importance of detection and multidisciplinary collaboration. Malignant catatonia is an underdiagnosed, potentially life-threatening syndrome that requires fast recognition and prompt treatment, preferably in an ICU setting. Copyright © 2016 Elsevier Inc. All rights reserved.

A case of catatonia in a 14-year-old girl with schizophrenia treated with electroconvulsive therapy.

PubMed

Häßler, Frank; Reis, Olaf; Weirich, Steffen; Höppner, Jacqueline; Pohl, Birgit; Buchmann, Johannes

2013-01-01

This article presents a case of a 14-year-old female twin with schizophrenia who developed severe catatonia following treatment with olanzapine. Under a combined treatment with amantadine, electroconvulsive therapy (ECT), and (currently) ziprasidone alone she improved markedly. Severity and course of catatonia including treatment response were evaluated with the Bush-Francis Catatonia Rating Scale (BFCRS). This case report emphasizes the benefit of ECT in the treatment of catatonic symptoms in an adolescent patient with schizophrenic illness.

Impacts of the Mesoscale Ocean-Atmosphere Coupling on the Peru-Chile Ocean Dynamics: The Current-Induced Wind Stress Modulation

NASA Astrophysics Data System (ADS)

Oerder, V.; Colas, F.; Echevin, V.; Masson, S.; Lemarié, F.

2018-02-01

The ocean dynamical responses to the surface current-wind stress interaction at the oceanic mesoscale are investigated in the South-East Pacific using a high-resolution regional ocean-atmosphere coupled model. Two simulations are compared: one includes the surface current in the wind stress computation while the other does not. In the coastal region, absolute wind velocities are different between the two simulations but the wind stress remains very similar. As a consequence, the mean regional oceanic circulation is almost unchanged. On the contrary, the mesoscale activity is strongly reduced when taking into account the effect of the surface current on the wind stress. This is caused by a weakening of the eddy kinetic energy generation near the coast by the wind work and to intensified offshore eddy damping. We show that, above coherent eddies, the current-stress interaction generates eddy damping through Ekman pumping and eddy kinetic energy dissipation through wind work. This alters significantly the coherent eddy vertical structures compared with the control simulation, weakening the temperature and vorticity anomalies and increasing strongly the vertical velocity anomalies associated to eddies.

[Electroconvulsive therapy and level of evidence: From causality to dose-effect relationship].

PubMed

Micoulaud-Franchi, J-A; Quilès, C; Cermolacce, M; Belzeaux, R; Adida, M; Fakra, E; Azorin, J-M

2016-12-01

The first objective of this article is to summarize the history of electroconvulsive therapy (ECT) in psychiatry in order to highlight the transition from clinical level of evidence based on phenomenological descriptions to controlled trial establishing causal relationship. The second objective is to apply the criteria of causation for ECT, to focus on the dose-effect relationship criteria, and thus to analyze the conditions of application of these criteria for ECT. A literature review exploring the use of electricity, ECT and electroencephalography (EEG) in psychiatry was conducted. The publications were identified from the Pubmed and GoogleScholar electronic databases. The scientific literature search of international articles was performed in July 2016. In 1784, a Royal commission established in France by King Louis XVI tested Mesmer's claims concerning animal magnetism. By doing that, the commission, including such prominent scientists as the chemist Anton Lavoisier and the scientist and researcher on electricity and therapeutics Benjamin Franklin, played a central role in establishing the criteria needed to assess the level of evidence of electrical therapeutics in psychiatry. Surprisingly, it is possible to identify the classical Bradford Hill criteria of causation in the report of the commission, except the dose-effect relationship criteria. Since then, it has been conducted blinded randomized controlled trials that confirmed the effectiveness of ECT against ECT placebos for the treatment of psychiatric disorders. At present, the dose-effect relationship criteria can be analyzed through an EEG quality assessment of ECT-induced seizures. EEG quality assessment includes several indices: TSLOW (time to onset of seizure activity ≤5Hz, seconds), peak mid-ictal amplitude (mm), regularity (intensity or morphology of the seizure (0-6)), stereotypy (global seizure patterning, 0-3) and post-ictal suppression (0-3). A manual rating sheet is needed to score theses indices. Such manual rating with example of EEG segments recording is proposed in this article. Additional studies are needed to validate this manual, to better establish the dose-response relationship for the ECT, and thus strengthen the position of the EEG as a central element for clinical good practice for ECT. © L’Encéphale, Paris, 2016.

Successful use of right unilateral ECT for catatonia: a case series.

PubMed

Cristancho, Pilar; Jewkes, Delaina; Mon, Thetsu; Conway, Charles

2014-03-01

Catatonia is a neuropsychiatric syndrome involving motor signs in association with disorders of mood, behavior, or thought. Bitemporal electrode placement electroconvulsive therapy (ECT) is a proven effective treatment for catatonia, and this mode of ECT delivery is the preferred method of treatment in this condition. Studies in major depressive disorder have demonstrated that suprathreshold, nondominant (right) hemisphere, unilateral electrode placement ECT has fewer adverse effects, especially cognitive adverse effects, than bitemporal ECT. This case series describes the use of right unilateral (RUL) ECT in 5 patients with catatonia. Before ECT, all 5 patients in this series initially failed therapy with benzodiazepines and psychotropic medications. Each catatonic patient received a series of 8 to 12 RUL ECT in an every-other-day series. After ECT, 4 of the 5 patients had a full recovery from catatonia. One patient achieved only partial response to RUL ECT, and no additional benefit was obtained with bitemporal ECT. All patients in this case series tolerated RUL ECT without major adverse effects. This case series illustrates successful use of RUL ECT in patients with catatonia and adds to the early literature demonstrating its effective use in treating this complex condition.

Concomitant Anticonvulsants With Bitemporal Electroconvulsive Therapy: A Randomized Controlled Trial With Clinical and Neurobiological Application.

PubMed

Rakesh, Gopalkumar; Thirthalli, Jagadisha; Kumar, Channaveerachari Naveen; Muralidharan, Kesavan; Phutane, Vivek H; Gangadhar, Bangalore N

2017-03-01

Electroconvulsive therapy (ECT) is an effective treatment for major affective disorders. The combined use of ECT and anticonvulsant mood stabilizers is a common clinical scenario. There is dearth of systematic studies on the use of this combination with regard to clinical or cognitive outcomes. We aimed to compare clinical improvement and cognitive adverse effects between patients who received only ECT versus those who received ECT and anticonvulsants. We hypothesized that improvement would be fastest in patients who received only ECT. We conducted a randomized controlled trial in which patients prescribed ECT while being treated with anticonvulsants were randomized into 3 groups: full-dose (FD), half-dose (HD), and stop anticonvulsant. A blind rater assessed clinical improvement in patients using rating scales [Young's Mania Rating Scale (YMRS) and Clinical Global Impression] for clinical improvement and cognitive adverse effects (Postgraduate Institute memory scale). Analysis was done using mixed-effects modeling to delineate differences in clinical and cognitive outcomes across the 3 arms of the study over the course of ECT. Of the 54 patients recruited, 36 patients went into treatment allocation arms per the initial randomization plan. The main anticonvulsants prescribed were sodium valproate and carbamazepine. Patients in the 3 groups were comparable on clinical features. The most common diagnosis was bipolar affective disorder-with current episode of mania. Overall, there was no difference across the 3 groups in final clinical outcome scores (YMRS and Clinical Global Impression) when analyzed as intention to treat (ITT) or "as treated." In both analyses, group × time interaction was significant when comparing trend of YMRS scores between the FD anticonvulsant group and the HD group from baseline to last ECT (P = 0.0435 in ITT and P = 0.0055 in as treated). Patients in the FD group improved faster than those in the HD group. There were no differences across the 3 groups with regard to their cognitive adverse effects in the ITT analysis; "as-treated analysis" showed the HD patients to have performed poorly on some domains. Seizure parameters showed no significant difference across the 3 groups. This is a preliminary prospective study examining whether coprescription of anticonvulsants with ECT affected clinical or cognitive outcomes. The most important takeaway point from this study is the significant reduction in YMRS scores when ECT was given with FD anticonvulsant compared with halving the dose (HD) of anticonvulsant. This difference was shown in both ITT and as-treated analysis. There is a need for more prospective studies to examine this clinical question.

Eddy-Current Inspection Of Tab Seals On Beverage Cans

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

1994-01-01

Eddy-current inspection system monitors tab seals on beverage cans. Device inspects all cans at usual production rate of 1,500 to 2,000 cans per minute. Automated inspection of all units replaces visual inspection by microscope aided by mass spectrometry. System detects defects in real time. Sealed cans on conveyor pass near one of two coils in differential eddy-current probe. Other coil in differential eddy-current probe positioned near stationary reference can on which tab seal is known to be of acceptable quality. Signal of certain magnitude at output of probe indicates defective can, automatically ejected from conveyor.

Use of eddy current mixes to solve a weld examination application

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

Ward, R.C.; LaBoissonniere, A.

1995-12-31

The augmentation of typical nondestructive (i.e., ultrasound) weld inspection techniques by the use of eddy current tools may significantly enhance the quality and reliability of weld inspections. One recent example is the development of an eddy current technique for use in the examination of BWR core shroud welds, where multi-frequency mixes are used to eliminate signals coming from the weld material so that the examination of the heat affected zone is enhanced. An analysis tool most commonly associated with ultrasound examinations, the C-Scan based on gated information, may be implemented with eddy current data to enhance analysis.

Development of Interior Permanent Magnet Motors with Concentrated Windings for Reducing Magnet Eddy Current Loss

NASA Astrophysics Data System (ADS)

Yamazaki, Katsumi; Kanou, Yuji; Fukushima, Yu; Ohki, Shunji; Nezu, Akira; Ikemi, Takeshi; Mizokami, Ryoichi

In this paper, we present the development of interior magnet motors with concentrated windings, which reduce the eddy current loss of the magnets. First, the mechanism of the magnet eddy current loss generation is investigated by a simple linear magnetic circuit. Due to the consideration, an automatic optimization method using an adaptive finite element method is carried out to determine the stator and rotor shapes, which decrease the eddy current loss of the magnet. The determined stator and rotor are manufactured in order to proof the effectiveness by the measurement.

Practice of Acute and Maintenance Electroconvulsive Therapy in the Psychiatric Clinic of a University Hospital from Turkey: between 2007 and 2013

PubMed Central

Sengul, Melike Ceyhan Balci; Kenar, Ayse Nur Inci; Hanci, Ezgi; Sendur, İbrahim; Sengul, Cem; Herken, Hasan

2016-01-01

Objective Electroconvulsive therapy (ECT) can be given as the form of acute, continuation or maintenance ECT according to the process of administration. We report our 7 years’ observation with acute and maintenance ECT in a university hospital in Turkey. Methods The medical records of the hospitalized patients treated with acute or maintenance ECT between the years 2007 and 2013 was retrospectively analyzed. The sociodemographic characteristics, diagnosis, data of ECT and the co-administered psychotropic drugs were recorded. The frequency of ECT was calculated by identifying the total number of the hospitalized patients during the study period from the hospital records. Results A total number of 1,432 female and 1,141 male patients hospitalized in a period of 7 years, with a total number of 111 patients treated with ECT. The ratio of ECT was 4%, maintenance/acute ECT 11%. For acute ECT, affective disorders (65.3%) and psychotic disorders (21.6%) were among the leading diagnoses. Maintenance ECT, the diagnosis was; 6 affective disorders, 4 psychotic disorders and 1 obsessive compulsive disorder. There was a significant difference between the patients receiving acute and maintenance ECT in terms of age, duration of illness, and number of previous hospitalizations and ECTs. Conclusion The percentage of patients treated with acute ECT is lower in our institution than that in many other institutions from our country. Acute and maintenance ECT should be considered as an important treatment option particularly for patients with long disease duration, a high number of hospitalizations and a history of benefiting from previous ECTs. PMID:26792041

Cognitive Behavioral Therapy as a Treatment for Electroconvulsive Therapy Phobia: Case Report and Review of Literature.

PubMed

Wo, Nolan King Hop; Guyitt, Brendan; Owen, Richard

2015-12-01

Electroconvulsive therapy (ECT) can raise feelings of fear and anxiety in our patients. No documented cases of phobia regarding ECT or its treatment were found in the literature. We present a patient who developed anxiety regarding ECT that was severe enough to be classified as a phobia. She was successfully treated with cognitive behavioral therapy (CBT) for her phobia and was subsequently able to tolerate ECT. We conducted a literature review of ECT phobia, fear, and anxiety using MEDLINE, PsycINFO, and EMBASE. We outlined how CBT, in our specific case, was helpful in treating extreme and unrealistic fears concerning ECT. We could not find a case of phobia related to ECT in the literature; however, both qualitative and quantitative studies illustrate that ECT causes anxiety and fear. Although cases of ECT phobia are rare, feelings of fear and anxiety surrounding ECT are common. The experience of ECT is individualized for each patient, and CBT can be a successful treatment in those who have anxiety related to ECT.

A review of ultrabrief pulse width electroconvulsive therapy

PubMed Central

Katalinic, Natalie; Martin, Donel; Schweitzer, Isaac

2012-01-01

The effect of shortening the pulse width of the electrical stimulus when administering electroconvulsive therapy (ECT) has recently been systematically studied with promising results. This review examines reported outcomes from three randomized controlled trials which compared ultrabrief (≤0.3 ms) with brief (0.5–1.5 ms) pulse width ECT, and other recent clinical trials of ultrabrief pulse width ECT. The emerging evidence for ultrabrief pulse right unilateral (RUL) ECT suggests clinically meaningful efficacy and substantially reduced neuropsychological side effects compared with standard (brief) pulse ECT; this may represent a generational advance in the ECT technique. However, it is unclear if patients receiving ultrabrief pulse RUL ECT may have a slower speed of response and require additional treatments compared with brief pulse ECT. Therefore, until further data are available, clinicians may be well advised to use brief pulse ECT in situations requiring an urgent clinical response. The evidence base for ultrabrief bilateral ECT is limited, with findings that efficacy may be reduced compared with brief pulse width ECT. Thus ultrabrief bilateral ECT should not be used outside the research setting. PMID:23251770

A High-Sensitivity Flexible Eddy Current Array Sensor for Crack Monitoring of Welded Structures under Varying Environment.

PubMed

Chen, Tao; He, Yuting; Du, Jinqiang

2018-06-01

This paper develops a high-sensitivity flexible eddy current array (HS-FECA) sensor for crack monitoring of welded structures under varying environment. Firstly, effects of stress, temperature and crack on output signals of the traditional flexible eddy current array (FECA) sensor were investigated by experiments that show both stress and temperature have great influences on the crack monitoring performance of the sensor. A 3-D finite element model was established using Comsol AC/DC module to analyze the perturbation effects of crack on eddy currents and output signals of the sensor, which showed perturbation effect of cracks on eddy currents is reduced by the current loop when crack propagates. Then, the HS-FECA sensor was proposed to boost the sensitivity to cracks. Simulation results show that perturbation effect of cracks on eddy currents excited by the HS-FECA sensor gradually grows stronger when the crack propagates, resulting in much higher sensitivity to cracks. Experimental result further shows that the sensitivity of the new sensor is at least 19 times that of the original one. In addition, both stress and temperature variations have little effect on signals of the new sensor.

Thermal/optical methods for elemental carbon quantification in soils and urban dusts: equivalence of different analysis protocols.

PubMed

Han, Yongming; Chen, Antony; Cao, Junji; Fung, Kochy; Ho, Fai; Yan, Beizhan; Zhan, Changlin; Liu, Suixin; Wei, Chong; An, Zhisheng

2013-01-01

Quantifying elemental carbon (EC) content in geological samples is challenging due to interferences of crustal, salt, and organic material. Thermal/optical analysis, combined with acid pretreatment, represents a feasible approach. However, the consistency of various thermal/optical analysis protocols for this type of samples has never been examined. In this study, urban street dust and soil samples from Baoji, China were pretreated with acids and analyzed with four thermal/optical protocols to investigate how analytical conditions and optical correction affect EC measurement. The EC values measured with reflectance correction (ECR) were found always higher and less sensitive to temperature program than the EC values measured with transmittance correction (ECT). A high-temperature method with extended heating times (STN120) showed the highest ECT/ECR ratio (0.86) while a low-temperature protocol (IMPROVE-550), with heating time adjusted for sample loading, showed the lowest (0.53). STN ECT was higher than IMPROVE ECT, in contrast to results from aerosol samples. A higher peak inert-mode temperature and extended heating times can elevate ECT/ECR ratios for pretreated geological samples by promoting pyrolyzed organic carbon (PyOC) removal over EC under trace levels of oxygen. Considering that PyOC within filter increases ECR while decreases ECT from the actual EC levels, simultaneous ECR and ECT measurements would constrain the range of EC loading and provide information on method performance. Further testing with standard reference materials of common environmental matrices supports the findings. Char and soot fractions of EC can be further separated using the IMPROVE protocol. The char/soot ratio was lower in street dusts (2.2 on average) than in soils (5.2 on average), most likely reflecting motor vehicle emissions. The soot concentrations agreed with EC from CTO-375, a pure thermal method.

Grey matter volume increase following electroconvulsive therapy in patients with late life depression: a longitudinal MRI study

PubMed Central

Bouckaert, Filip; De Winter, François-Laurent; Emsell, Louise; Dols, Annemieke; Rhebergen, Didi; Wampers, Martien; Sunaert, Stefan; Stek, Max; Sienaert, Pascal; Vandenbulcke, Mathieu

2016-01-01

Background The evidence on the mechanisms of action of electroconvulsive therapy (ECT) has grown over the past decades. Recent studies show an ECT-related increase in hippocampal, amygdala and subgenual cortex volume. We examined grey matter volume changes following ECT using voxel-based morphometry (VBM) whole brain analysis in patients with severe late life depression (LLD). Methods Elderly patients with unipolar depression were treated twice weekly with right unilateral ECT until remission on the Montgomery–Åsberg Depression Rating Scale (MADRS) was achieved. Cognition (Mini Mental State Examination) and psychomotor changes (CORE Assessment) were monitored at baseline and 1 week after the last session of ECT. We performed 3 T structural MRI at both time points. We used the VBM8 toolbox in SPM8 to study grey matter volume changes. Paired t tests were used to compare pre- and post-ECT grey matter volume (voxel-level family-wise error threshold p < 0.05) and to assess clinical response. Results Twenty-eight patients (mean age 71.9 ± 7.8 yr, 8 men) participated in our study. Patients received a mean of 11.2 ± 4 sessions of ECT. The remission rate was 78.6%. Cognition, psychomotor agitation and psychomotor retardation improved significantly (p < 0.001). Right- hemispheric grey matter volume was increased in the caudate nucleus, medial temporal lobe (including hippocampus and amygdala), insula and posterior superior temporal regions but did not correlate with MADRS score. Grey matter volume increase in the caudate nucleus region correlated significantly with total CORE Assessment score (r = 0.63; p < 0.001). Limitations Not all participants were medication-free. Conclusion Electroconvulsive therapy in patients with LLD is associated with significant grey matter volume increase, which is most pronounced ipsilateral to the stimulation side. PMID:26395813

Detection of Cracks at Welds in Steel Tubing Using Flux Focusing Electromagnetic Probe

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Fulton, Jim; Nath, Shridhar; Simpson, John; Namkung, Min

1994-01-01

The inspection of weldments in critical pressure vessel joints is a major concern in the nuclear power industry. Corrosive environments can speed the fatigue process and access to the critical area is often limited. Eddy current techniques have begun to be used to help overcome these obstacles [1]. As direct contact and couplants are not required, remote areas can be inspected by simply snaking an eddy current coil into the intake tube of the vessel. The drawback of the eddy current method has been the high sensitivity to small changes in the conductivity and permeability of the test piece which are known to vary at weldments [1]. The flaw detection mechanism of the flux focusing electromagnetic probe can help alleviate these difficulties and provide a unique capability for detecting longitudinal fatigue cracks in critical tube structures. The Flux Focusing Electromagnetic Flaw Detector, originally invented for the detection of fatigue and corrosion damage in aluminum plates [2-3], has been adapted for use in testing steel tubing for longitudinal fatigue cracks. The modified design allows for the probe to be placed axisymmetrically into the tubing, inducing eddy currents in the tube wall. The pickup coil of the probe is fixed slightly below the primary windings and is rotated 90 so that its axis is normal to the tube wall. The magnetic flux of the primary coil is focused through the use of ferromagnetic material so that in the absence of fatigue damage there will be no flux linkage with the pickup coil. The presence of a longitudinal fatigue crack will cause the eddy currents induced in the tube wall to flow around the flaw and directly under the pickup coil. The magnetic field associated with these currents will then link the pickup coil and an unambiguous increase in the output voltage of the probe will be measured. The use of the flux focusing electromagnetic probe is especially suited for the detection of flaws originating at or near tube welds. The probe is shown to discriminate against signals due solely to the weld joint so that flaw signals are not hidden in the background in these locations. Experimental and finite element modeling results are presented for the flaw detection capabilities of the probe in stainless steel tubes.

Electroconvulsive Therapy in the Elderly: New Findings in Geriatric Depression.

PubMed

Geduldig, Emma T; Kellner, Charles H

2016-04-01

This paper reviews recent research on the use of electroconvulsive therapy (ECT) in elderly depressed patients. The PubMed database was searched for literature published within the past 4 years, using the search terms: "electroconvulsive elderly," "electroconvulsive geriatric," "ECT and elderly," and "ECT elderly cognition." The studies in this review indicate excellent efficacy for ECT in geriatric patients. Adverse cognitive effects of ECT in this population are usually transient and not typically severe. In addition, continuation/maintenance ECT (C/M-ECT) may be a favorable strategy for relapse prevention in the elderly after a successful acute course of ECT. ECT is an important treatment option for depressed geriatric patients with severe and/or treatment-resistant illness. New data add to the evidence demonstrating that ECT is a highly effective, safe, and well-tolerated antidepressant treatment option for geriatric patients.

Monitoring daily affective symptoms and memory function using interactive voice response in outpatients receiving electroconvulsive therapy.

PubMed

Fazzino, Tera L; Rabinowitz, Terry; Althoff, Robert R; Helzer, John E

2013-12-01

Recently, there has been a gradual shift from inpatient-only electroconvulsive therapy (ECT) toward outpatient administration. Potential advantages include convenience and reduced cost. But providers do not have the same opportunity to monitor treatment response and adverse effects as they do with inpatients. This can obviate some of the potential advantages of outpatient ECT, such as tailoring treatment intervals to clinical response. Scheduling is typically algorithmic rather than empirically based. Daily monitoring through an automated telephone, interactive voice response (IVR), is a potential solution to this quandary. To test feasibility of clinical monitoring via IVR, we recruited 26 patients (69% female; mean age, 51 years) receiving outpatient ECT to make daily IVR reports of affective symptoms and subjective memory for 60 days. The IVR also administered a word recognition task daily to test objective memory. Every seventh day, a longer IVR weekly interview included questions about suicidal ideation. Overall daily call compliance was high (mean, 80%). Most participants (96%) did not consider the calls to be time-consuming. Longitudinal regression analysis using generalized estimating equations revealed that participant objective memory functioning significantly improved during the study (P < 0.05). Of 123 weekly IVR interviews, 41 reports (33%) in 14 patients endorsed suicidal ideation during the previous week. Interactive voice response monitoring of outpatient ECT can provide more detailed clinical information than standard outpatient ECT assessment. Interactive voice response data offer providers a comprehensive, longitudinal picture of patient treatment response and adverse effects as a basis for treatment scheduling and ongoing clinical management.

The Role of Baseline Cognitive Function in the Neurocognitive Effects of Electroconvulsive Therapy in Depressed Elderly Patients.

PubMed

Dybedal, Gro Strømnes; Tanum, Lars; Sundet, Kjetil; Bjølseth, Tor Magne

2015-01-01

Electroconvulsive therapy (ECT) is an effective biological treatment option for severely depressed elderly patients; however, it can cause cognitive side effects, including anterograde and retrograde amnesia. Elderly patients with "cognitive impairment no dementia" (CIND) are reported as being more vulnerable to the cognitive side effects of ECT compared with patients with "no cognitive impairment" (NCI). The few studies that have reached this conclusion can be criticized for using insensitive outcome measures. The present study investigated cognitive side effects using standard neuropsychological tests before and after twice-weekly ECT. Patients were assessed at baseline (T1) and within one week after a course of ECT (consisting of a mean of 10 treatments) (T2), and were followed up for three months after T2 (T3). The sample included 54 patients with NCI (n = 36) or CIND (n = 18). For a control group, we recruited 17 healthy elderly persons. Tests of anterograde memory, information-processing speed, executive function, and retrograde memory were administered. We computed reliable change indices using simple regression methods. Short-term side effects were detected at T2 in a large minority of patients, with no significant differences between NCI and CIND patients. Considerable improvement in global cognitive function from T1 to T3 was observed in 44% of the CIND patients. At the group level, information-processing speed improved significantly in CIND vs. NCI patients. CIND patients were not more vulnerable to amnesia than were NCI patients. Long-term cognitive side effects of ECT were not detected.

Detection of fatigue cracks by nondestructive testing methods

NASA Technical Reports Server (NTRS)

Anderson, R. T.; Delacy, T. J.; Stewart, R. C.

1973-01-01

The effectiveness was assessed of various NDT methods to detect small tight cracks by randomly introducing fatigue cracks into aluminum sheets. The study included optimizing NDT methods calibrating NDT equipment with fatigue cracked standards, and evaluating a number of cracked specimens by the optimized NDT methods. The evaluations were conducted by highly trained personnel, provided with detailed procedures, in order to minimize the effects of human variability. These personnel performed the NDT on the test specimens without knowledge of the flaw locations and reported on the flaws detected. The performance of these tests was measured by comparing the flaws detected against the flaws present. The principal NDT methods utilized were radiographic, ultrasonic, penetrant, and eddy current. Holographic interferometry, acoustic emission monitoring, and replication methods were also applied on a reduced number of specimens. Generally, the best performance was shown by eddy current, ultrasonic, penetrant and holographic tests. Etching provided no measurable improvement, while proof loading improved flaw detectability. Data are shown that quantify the performances of the NDT methods applied.

A western boundary current eddy characterisation study

NASA Astrophysics Data System (ADS)

Ribbe, Joachim; Brieva, Daniel

2016-12-01

The analysis of an eddy census for the East Australian Current (EAC) region yielded a total of 497 individual short-lived (7-28 days) cyclonic and anticyclonic eddies for the period 1993 to 2015. This was an average of about 23 eddies per year. 41% of the tracked individual cyclonic and anticyclonic eddies were detected off southeast Queensland between about 25 °S and 29 °S. This is the region where the flow of the EAC intensifies forming a swift western boundary current that impinges near Fraser Island on the continental shelf. This zone was also identified as having a maximum in detected short-lived cyclonic eddies. A total of 94 (43%) individual cyclonic eddies or about 4-5 per year were tracked in this region. The census found that these potentially displaced entrained water by about 115 km with an average displacement speed of about 4 km per day. Cyclonic eddies were likely to contribute to establishing an on-shelf longshore northerly flow forming the western branch of the Fraser Island Gyre and possibly presented an important cross-shelf transport process in the life cycle of temperate fish species of the EAC domain. In-situ observations near western boundary currents previously documented the entrainment, off-shelf transport and export of near shore water, nutrients, sediments, fish larvae and the renewal of inner shelf water due to short-lived eddies. This study found that these cyclonic eddies potentially play an important off-shelf transport process off the central east Australian coast.

Three-dimensional eddy current solution of a polyphase machine test model (abstract)

NASA Astrophysics Data System (ADS)

Pahner, Uwe; Belmans, Ronnie; Ostovic, Vlado

1994-05-01

This abstract describes a three-dimensional (3D) finite element solution of a test model that has been reported in the literature. The model is a basis for calculating the current redistribution effects in the end windings of turbogenerators. The aim of the study is to see whether the analytical results of the test model can be found using a general purpose finite element package, thus indicating that the finite element model is accurate enough to treat real end winding problems. The real end winding problems cannot be solved analytically, as the geometry is far too complicated. The model consists of a polyphase coil set, containing 44 individual coils. This set generates a two pole mmf distribution on a cylindrical surface. The rotating field causes eddy currents to flow in the inner massive and conducting rotor. In the analytical solution a perfect sinusoidal mmf distribution is put forward. The finite element model contains 85824 tetrahedra and 16451 nodes. A complex single scalar potential representation is used in the nonconducting parts. The computation time required was 3 h and 42 min. The flux plots show that the field distribution is acceptable. Furthermore, the induced currents are calculated and compared with the values found from the analytical solution. The distribution of the eddy currents is very close to the distribution of the analytical solution. The most important results are the losses, both local and global. The value of the overall losses is less than 2% away from those of the analytical solution. Also the local distribution of the losses is at any given point less than 7% away from the analytical solution. The deviations of the results are acceptable and are partially due to the fact that the sinusoidal mmf distribution was not modeled perfectly in the finite element method.

76 FR 52901 - Airworthiness Directives; The Boeing Company Model 757-200, -200PF, and -200CB Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-24

... if necessary. This proposed AD would also add an option for the high frequency eddy current... also adds an optional ultrasonic inspection for the high frequency eddy current inspection to detect... proposed AD would also add an option for the high frequency eddy current inspection for cracking of the...

77 FR 21395 - Airworthiness Directives; Fokker Services B.V. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-10

... would require performing a low frequency eddy current inspection for cracks of the lap joint of the rear...-frequency eddy current inspection of the lap joint for cracks and, depending on findings, repair of the lap... AD: Do a low frequency eddy current (LFEC) inspection for cracks of the lap joint of the rear...

76 FR 41662 - Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-15

... different compliance time; adds an eddy current inspection; retains the requirement to replace a cracked... and recurring 300-hour visual and eddy current inspections of the lower hub for a crack and, if there... AD requires a visual inspection, and if necessary, an eddy current inspection of the lower hub for a...

ECT practices in Iraq: a national audit.

PubMed

Alhemiary, Nesif; Ali, Zainab; Abbas, Mohammed J

2015-12-01

Aims and method This national audit examined practice of electroconvulsive therapy (ECT) in Iraq against local standards. Data were collected by a questionnaire sent to heads of departments or medical directors in the 10 Iraqi hospitals which provide ECT and by examining case notes of all patients who had ECT in the first 6 months of 2013. Results Of the 26 psychiatric hospitals in Iraq, 10 provide ECT. There were some resource shortcomings in the ECT clinics (e.g. only 2 had a minimum of 2 rooms and all had no EEG monitoring). During the audit period, 251 patients had ECT. The mean age was 36.2 years and 51.8% were males. Bilateral ECT was used in all cases, general anaesthesia in 77.15%. The main indication for ECT was schizophrenia, followed by severe depression, resistant mania, catatonia and others. Clinical implications More work is needed to ensure all patients receive modified ECT. ECT is still used widely for schizophrenia. This needs further exploration and training.

Image reconstruction algorithms for electrical capacitance tomography based on ROF model using new numerical techniques

NASA Astrophysics Data System (ADS)

Chen, Jiaoxuan; Zhang, Maomao; Liu, Yinyan; Chen, Jiaoliao; Li, Yi

2017-03-01

Electrical capacitance tomography (ECT) is a promising technique applied in many fields. However, the solutions for ECT are not unique and highly sensitive to the measurement noise. To remain a good shape of reconstructed object and endure a noisy data, a Rudin-Osher-Fatemi (ROF) model with total variation regularization is applied to image reconstruction in ECT. Two numerical methods, which are simplified augmented Lagrangian (SAL) and accelerated alternating direction method of multipliers (AADMM), are innovatively introduced to try to solve the above mentioned problems in ECT. The effect of the parameters and the number of iterations for different algorithms, and the noise level in capacitance data are discussed. Both simulation and experimental tests were carried out to validate the feasibility of the proposed algorithms, compared to the Landweber iteration (LI) algorithm. The results show that the SAL and AADMM algorithms can handle a high level of noise and the AADMM algorithm outperforms other algorithms in identifying the object from its background.

Twice versus thrice weekly ECT in a clinical population: an evaluation of patient outcomes.

PubMed

Siskind, Dan; Charlson, Fiona; Saraf, Sudeep; Scheurer, Roman; Lie, David Charles

2012-10-30

Increasing demand on electroconvulsive therapy (ECT) services led to a recommendation that low risk patients be considered for twice weekly ECT rather than the usual thrice weekly. We evaluated whether practice changed and compared patient clinical outcomes for twice and thrice weekly ECT. Medical records for all patients receiving ECT in the 2-year study period (1/9/08 to 30/8/10) were reviewed to determine ECT protocol, diagnosis, admission duration and readmission rates. During the study period, 119 patients received 150 treatment courses. Patient outcomes were compared for twice weekly ECT and thrice weekly ECT protocols, as well as for 1 year before and after the recommendation (1/9/09). Twice weekly ECT courses increased (8-20) after the recommendation while thrice weekly ECT courses decreased (64-30). The recommendation had no significant effect on patient outcomes. Comparing twice and thrice weekly ECT, patient clinical outcomes were similar between the two groups, though non-affective twice weekly patients waited longer before starting ECT. In the context of resource constraints, psychiatrists can be influenced to examine and change their ECT prescribing practice. This bodes well for the implementation of evidence-based treatment into mental health services. Secondly, for adults, there appear to be no significant differences in clinical outcomes for twice versus thrice weekly ECT. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Electroconvulsive therapy (ECT) in schizophrenia: a review of recent literature.

PubMed

Sanghani, Sohag N; Petrides, Georgios; Kellner, Charles H

2018-05-01

ECT remains an important, yet underutilized, treatment for schizophrenia. Recent research shows that medication-resistant patients with schizophrenia, including those resistant to clozapine, respond well to ECT augmentation. The purpose of this article is to review recent studies of the use of ECT in the treatment of schizophrenia. We performed an electronic database search for articles on ECT and schizophrenia, published in 2017. The main themes of these articles are: epidemiological data on ECT use from various countries; retrospective studies, prospective studies and meta-analyses focusing on efficacy and cognitive side-effects of ECT in schizophrenia; ECT technical parameters and potential biomarkers. There is growing evidence to support the use of ECT for augmentation of antipsychotic response in the treatment of schizophrenia. Cognitive side-effects are generally mild and transient. In fact, many studies show improvement in cognition, possibly related to the improvement in symptoms. There is wide variation among countries in the use of ECT for the treatment of schizophrenia. There are also variations in the choice of ECT electrode placement, parameters and schedules. These technical differences are likely minor and should not interfere with the treatment being offered to patients. Further, long-term studies are needed to optimize ECT treatment parameters, to examine the effect of maintenance ECT and to investigate neuroimaging/biomarkers to understand the mechanism of action and identify potential response predictors to ECT.

Effect of eddy current damping on phononic band gaps generated by locally resonant periodic structures

NASA Astrophysics Data System (ADS)

Ozkaya, Efe; Yilmaz, Cetin

2017-02-01

The effect of eddy current damping on a novel locally resonant periodic structure is investigated. The frequency response characteristics are obtained by using a lumped parameter and a finite element model. In order to obtain wide band gaps at low frequencies, the periodic structure is optimized according to certain constraints, such as mass distribution in the unit cell, lower limit of the band gap, stiffness between the components in the unit cell, the size of magnets used for eddy current damping, and the number of unit cells in the periodic structure. Then, the locally resonant periodic structure with eddy current damping is manufactured and its experimental frequency response is obtained. The frequency response results obtained analytically, numerically and experimentally match quite well. The inclusion of eddy current damping to the periodic structure decreases amplitudes of resonance peaks without disturbing stop band width.

Lateral eddy diffusivity estimates from simulated and observed drifter trajectories: a case study for the Agulhas Current system

NASA Astrophysics Data System (ADS)

Rühs, Siren; Zhurbas, Victor; Durgadoo, Jonathan V.; Biastoch, Arne

2017-04-01

The Lagrangian description of fluid motion by sets of individual particle trajectories is extensively used to characterize connectivity between distinct oceanic locations. One important factor influencing the connectivity is the average rate of particle dispersal, generally quantified as Lagrangian diffusivity. In addition to Lagrangian observing programs, Lagrangian analyses are performed by advecting particles with the simulated flow field of ocean general circulation models (OGCMs). However, depending on the spatio-temporal model resolution, not all scale-dependent processes are explicitly resolved in the simulated velocity fields. Consequently, the dispersal of advective Lagrangian trajectories has been assumed not to be sufficiently diffusive compared to observed particle spreading. In this study we present a detailed analysis of the spatially variable lateral eddy diffusivity characteristics of advective drifter trajectories simulated with realistically forced OGCMs and compare them with estimates based on observed drifter trajectories. The extended Agulhas Current system around South Africa, known for its intricate mesoscale dynamics, serves as a test case. We show that a state-of-the-art eddy-resolving OGCM indeed features theoretically derived dispersion characteristics for diffusive regimes and realistically represents Lagrangian eddy diffusivity characteristics obtained from observed surface drifter trajectories. The estimates for the maximum and asymptotic lateral single-particle eddy diffusivities obtained from the observed and simulated drifter trajectories show a good agreement in their spatial pattern and magnitude. We further assess the sensitivity of the simulated lateral eddy diffusivity estimates to the temporal and lateral OGCM output resolution and examine the impact of the different eddy diffusivity characteristics on the Lagrangian connectivity between the Indian Ocean and the South Atlantic.

Conductive shield for ultra-low-field magnetic resonance imaging: Theory and measurements of eddy currents.

PubMed

Zevenhoven, Koos C J; Busch, Sarah; Hatridge, Michael; Oisjöen, Fredrik; Ilmoniemi, Risto J; Clarke, John

2014-03-14

Eddy currents induced by applied magnetic-field pulses have been a common issue in ultra-low-field magnetic resonance imaging. In particular, a relatively large prepolarizing field-applied before each signal acquisition sequence to increase the signal-induces currents in the walls of the surrounding conductive shielded room. The magnetic-field transient generated by the eddy currents may cause severe image distortions and signal loss, especially with the large prepolarizing coils designed for in vivo imaging. We derive a theory of eddy currents in thin conducting structures and enclosures to provide intuitive understanding and efficient computations. We present detailed measurements of the eddy-current patterns and their time evolution in a previous-generation shielded room. The analysis led to the design and construction of a new shielded room with symmetrically placed 1.6-mm-thick aluminum sheets that were weakly coupled electrically. The currents flowing around the entire room were heavily damped, resulting in a decay time constant of about 6 ms for both the measured and computed field transients. The measured eddy-current vector maps were in excellent agreement with predictions based on the theory, suggesting that both the experimental methods and the theory were successful and could be applied to a wide variety of thin conducting structures.

Conductive shield for ultra-low-field magnetic resonance imaging: Theory and measurements of eddy currents

PubMed Central

Zevenhoven, Koos C. J.; Busch, Sarah; Hatridge, Michael; Öisjöen, Fredrik; Ilmoniemi, Risto J.; Clarke, John

2014-01-01

Eddy currents induced by applied magnetic-field pulses have been a common issue in ultra-low-field magnetic resonance imaging. In particular, a relatively large prepolarizing field—applied before each signal acquisition sequence to increase the signal—induces currents in the walls of the surrounding conductive shielded room. The magnetic-field transient generated by the eddy currents may cause severe image distortions and signal loss, especially with the large prepolarizing coils designed for in vivo imaging. We derive a theory of eddy currents in thin conducting structures and enclosures to provide intuitive understanding and efficient computations. We present detailed measurements of the eddy-current patterns and their time evolution in a previous-generation shielded room. The analysis led to the design and construction of a new shielded room with symmetrically placed 1.6-mm-thick aluminum sheets that were weakly coupled electrically. The currents flowing around the entire room were heavily damped, resulting in a decay time constant of about 6 ms for both the measured and computed field transients. The measured eddy-current vector maps were in excellent agreement with predictions based on the theory, suggesting that both the experimental methods and the theory were successful and could be applied to a wide variety of thin conducting structures. PMID:24753629

A qualitative study of experience of parents of adolescents who received ECT.

PubMed

Grover, Sandeep; Varadharajan, Natarajan; Avasthi, Ajit

2017-12-01

To evaluate the experience of parents of adolescents who received ECT for severe mental illness. Using qualitative methods, 6 parents of 5 adolescents were interviewed by using a self-designed semi-structured interview after the completion of ECT course. The clinicians involved in the ECT procedure, i.e., seeking informed consent and administration of ECT were not aware about the study. All the interviews were recorded and the content was analysed and themes were generated. Parents of all the 5 adolescents expressed that their children were considered for ECT only after the patient had not responded to medication and were unmanageable. Prior to ECT the treating doctors did explain to them about the ECT procedure, they were given information booklet and they were not coerced to consent for ECT. Some of the parents reported that they had dilemma prior to giving consent and were scared prior to the first ECT. However, as the clinical condition of their children improved, they felt that ECT was a good treatment. Majority of the parents felt that ECT was delayed for their children. When asked about restriction in use of ECT in children and adolescents, the parents expressed that it is important for law makers to understand the distress of the parents,when their children are acutely ill. They expressed that decision of administration of ECT must be left to the family and the treating clinicians. Parents of adolescents considered for ECT are generally satisfied with the treatment procedure. Copyright © 2017 Elsevier B.V. All rights reserved.

Non-destructive inspection using HTS SQUID on aluminum liner covered by CFRP

NASA Astrophysics Data System (ADS)

Hatsukade, Y.; Yotsugi, K.; Sakaguchi, Y.; Tanaka, S.

2007-10-01

An eddy-current-based SQUID non-destructive inspection (NDI) system to detect deep-lying cracks in multi-layer composite-Al vessels was developed taking advantage of the uncontested sensitivity of HTS-SQUID in low-frequency range. An HTS-SQUID gradiometer was mounted in a pulse tube cryocooler. A pair of differential coils with C-shaped ferrite cores was employed to induce an enhanced eddy current in an Al vessel wrapped in a carbon fiber reinforced plastic (CFRP) cover. Ellipsoidal dome-shaped Al liners containing through cracks, which were made by pressure cycle tests, in the CFRP covers with total thickness of 6 mm (CFPR 3 mm, and Al 3 mm) were inspected by the system. While inducing eddy currents in the vessels with excitation fields at 100 Hz or 7 kHz, the vessels were rotated under the HTS-SQUID. Above the cracks, anomalous signals due to the cracks were clearly detected at both frequencies. These results suggested the SQUID-NDI technique would be a possible candidate for inspection of high-pressure multi-layer composite-Al vessels.

Modeling and analysis of a novel planar eddy current damper

NASA Astrophysics Data System (ADS)

Zhang, He; Kou, Baoquan; Jin, Yinxi; Zhang, Lu; Zhang, Hailin; Li, Liyi

2014-05-01

In this paper, a novel 2-DOF permanent magnet planar eddy current damper is proposed, of which the stator is made of a copper plate and the mover is composed of two orthogonal 1-D permanent magnet arrays with a double sided structure. The main objective of the planar eddy current damper is to provide two orthogonal damping forces for dynamic systems like the 2-DOF high precision positioning system. Firstly, the basic structure and the operating principle of the planar damper are introduced. Secondly, the analytical model of the planar damper is established where the magnetic flux density distribution of the permanent magnet arrays is obtained by using the equivalent magnetic charge method and the image method. Then, the analytical expressions of the damping force and damping coefficient are derived. Lastly, to verify the analytical model, the finite element method (FEM) is adopted for calculating the flux density and a planar damper prototype is manufactured and thoroughly tested. The results from FEM and experiments are in good agreement with the ones from the analytical expressions indicating that the analytical model is reasonable and correct.

Eddy-Current Measurement Of Turning Or Curvature

NASA Technical Reports Server (NTRS)

Chern, Engmin J.

1993-01-01

Rotatable conductive plate covers sensing coil to varying degree. Curvature of pipe at remote or otherwise inaccessible location inside pipe measured using relatively simple angular-displacement eddy-current probe. Crawler and sensor assemblies move along inside of pipe on wheels. Conductive plate pivots to follow curvature of pipe, partly covering one of eddy-current coils to degree depending on local curvature on pipe.

76 FR 9495 - Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-18

...-18, which requires you to repetitively inspect (using the eddy current method) the two outboard... through 0101 and AT-802A-0092 through 0101: To perform, using the eddy current method, two inspections at... through 0178 and AT-802A-0102 through 0178 to perform using the eddy current method, two inspections at 5...

76 FR 2281 - Airworthiness Directives; BAE SYSTEMS (OPERATIONS) LIMITED Model BAe 146 Airplanes, and Model...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-13

... this AD, perform an external eddy current inspection of the forward fuselage skin to detect cracking... paragraphs (j)(1), (j)(2), and (j)(3) of this AD, do an external eddy current inspection of the forward... this AD, do an external eddy current inspection of the forward fuselage skin to detect cracking, in...

76 FR 66209 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

... option is to conduct an eddy current inspection and the other option is to conduct a visual inspection... eddy current inspection, at an average labor rate of $85 per work hour. Required parts would cost about... using either an eddy current inspection in accordance with paragraphs B.(1)(a) through B.(1)(o) or using...

75 FR 5692 - Airworthiness Directives; The Boeing Company Model 747-200C and -200F Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-04

... all Model 747-200C and -200F series airplanes. This AD requires a high frequency eddy current (HFEC... on July 6, 2009 (74 FR 31894). That NPRM proposed to require a high frequency eddy current inspection..., whichever occurs later: Do an open-hole high frequency eddy current (HFEC) inspection of all the fastener...