Dissertations / Theses on the topic 'Electrical stimulation'
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Kuhn, Andreas. "Modeling transcutaneous electrical stimulation /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17948.
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Philley, Lindsey M. "The Effects of Cold, Electrical Stimulation, and Combination Cold and Electrical Stimulation on Sensory Perception." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1305058527.
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Woodcock, Alan. "Electrical stimulation of chronically denervated muscle." Thesis, University of Surrey, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301288.
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Hasegawa, Satoshi. "CLINICAL APPLICATIONS OF ELECTRICAL MUSCLE STIMULATION." Kyoto University, 2011. http://hdl.handle.net/2433/142294.
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Kyoto University (京都大学)0048
新制・課程博士
博士(人間・環境学)
甲第16166号
人博第549号
新制||人||133(附属図書館)
22||人博||549(吉田南総合図書館)
28745
京都大学大学院人間・環境学研究科共生人間学専攻
(主査)教授 森谷 敏夫, 教授 津田 謹輔, 准教授 林 達也
学位規則第4条第1項該当
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Evans, Nancy C. "Determination of the most effective stimulation parameters for functional electrical stimulation." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/20028.
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Szlavik, Robert Bruce. "In vivo electrical stimulation of motor nerves." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0032/NQ66239.pdf.
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Moen, Lars Lyse. "An Implantable Device for Electrical Nerve Stimulation." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-26850.
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Neural stimulation is currently subject to heavy research for the control of obesity using Vagus Nerve Stimulation (VNS). The available devices for such research is however developed for human use only, causing unnecessary complications when testing in smaller animals models due to the physical size of the device. A device for use in small animal models based on commercially available components would serve as a low-cost and more optimal solution to VNS research and similar disciplines.The design of an small electrical nerve stimulator was developed based on a comprehensive literature study combined with a detailed analysis of the requirements given by the end user. The system is described using a modular architecture with explicit interfaces, supporting easy verification and reproduction of the essential parts of the system.The result is a prototype design for an implantable electrical nerve stimulator with the ability to be miniaturized into 1/4 of the size of similar stimulating systems. The design meets the requirements from the end user, but must be miniaturized and encapsulated together with a connector for the electrode pin to be ready for implementation in animals.This thesis describes a novel prototype design of an implantable stimulator with a primary use in VNS applications, compatible with the bipolar 304 leads from Cyberonics Inc. The stimulator is designed with commercially available components resulting in a low-cost and portable solution. A modular architecture describes the system with respect to specifications given by end user and limitations from a literature study.
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Grumet, Andrew Eli. "Extracellular electrical stimulation of retinal ganglion cells." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/42559.
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Tandon, Nina. "Biomimetic electrical stimulation for cardiac tissue engineering." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/38323.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (leaves 66-69).
A major challenge of tissue engineering is directing cells to establish the physiological structure and function of the tissue being replaced. Electrical stimulation has been used to induce synchronous contractions of cultured cardiac constructs. The hypothesis adopted for this study is that functional cardiac constructs can be engineered by "mimicking" the conditions present during cardiac development, and in particular, electrical stimulation using supra-threshold signals. For this Master's Thesis research, I have compared the material properties and charge-transfer characteristics at the electrode-electrolyte interface of various biocompatible materials, including carbon, stainless steel, titanium and titanium nitride, for use as electrodes in a biomimetic system for cardiac tissue engineering. I have also designed and implemented an electrical stimulator which is capable of modulating several important parameters of electrical stimulation, including stimulus amplitude and frequency.
(cont.) In addition, I have built an experimental setup incorporating this electrical stimulator and used it for experiments with C2C12 mouse myoblast cells and neonatal rat cardiomyocytes. Lastly, I have analyzed cell morphology as well as functional performance of engineered tissue by assessing excitation thresholds and maximum capture rates.
by Nina Tandon.
S.M.
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Almashaikhi, Talal. "Electrical brain stimulation and human insular connectivity." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10174/document.
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Le cortex insulaire est le cinquième lobe du cerveau en charge de l'intégration de nombreuses fonctions cognitives, sous-tendues par une organisation cytoarchitectonique etune connectivité aussi riche que complexe. Ce travail vise à évaluer la connectivité fonctionnelle insulaire du cerveau humain par le biais de stimulation électrique intra-cérébrale et de potentiels évoqués cortico-corticaux (PECC) réalisés chez des patients explorés en stéréoélectroencéphalographie (SEEG) pour une épilepsie partielle réfractaire. Nous avons développé un protocole automatisé permettant destimuler successivement l’ensemble des bipoles d’enregistrement intracérébraux (deux plots contigus d’une même électrode) disponibles chez les patients explorés en SEEG. Deux sériesde 20 stimulations monophasiques d’une durée unitaire de 1 ms et d’une intentisté de 1 mA, étaient délivrés à une fréquence de 0,2 Hz au niveau de chaque bipole (105 en moyenne,produisant un total d’environ 11.000 PECC par patient). Un premier travail a consisté dans lamise au point d’une méthode fiable d’analyse statistique objective des PECC significatifs, encomplement de l’analyse visuelle, sur un échantillon de 33017 enregistrements chez trois patients. L’analyse a porté sur les quatre fenêtres temporelles post-stimulation suivantes: 10-100 ms, 100-300 ms, 300-500 ms, 500-1000 ms. La seconde partie de notre thèse a appliquéces méthodes à l’étude des connections intra-insulaires sur un échantillon de10 patients présentant au moins deux éléctrodes intra-insulaires. La dernière partie de notre travail s’est intéressé aux efférences insulaires sur un échantillon de 11 patients. L’étude des PECC apporte des éléments de connectivité fonctionnelle derésolution spatiale et temporelle inégalée, complémentaires de ceux découlant des techniquesde neuroimagerie. La gestion complexe du volume de données à gérer pour chaque patientpeut être résolu par des procédures d’analyse statistiques automatisée de sensibilité etspécificité satisfaisante. Le pattern des connections intra- et extra-insulaires révélé par cetteapproche permet une meilleure compréhension de la physiologie de l’insula chez l’Homme etdes modalités de propagations des décharges épileptiques impliquant ce lobeThe insular cortex is the fifth lobe of the brain and is in charge of the integration of many cognitive functions, underpinned by a rich cytoarchitectonic organization and a complex connectivity. Our work aims to evaluate the insular functional connectivity of the human brain using intracerebral electrical stimulation and recording of cortico-cortical evoked potentials (CCEPs) in patients investigated with stereoelectroencephalography (SEEG) for refractory partial epilepsy. We first developed an automated protocol to stimulate successively all intracerebral recorded bipoles (two contiguous leads of the same electrode) available in patients undergoing SEEG. Two sets of 20 monophasic stimulation of 1 ms duration and 1mA intensity were delivered at a frequency of 0.2 Hz at each bipole (105 on average, producing a total of about 11,000 recordings per patient). We then develop a reliable and objective statistical method to detect significant CCEPs as a complement to visual analysis, and validate this approach on a sample of 33017 recordings in three patients. The analysis was performed over four distinct post-stimulus epochs: 10-100 ms, 100-300 ms, 300-500 ms, 500-1000 ms. In the second part of our thesis, we applied these methods to the study of intrainsular connections on a sample of 10 patients with at least two intra-insular electrodes. The last part of our work used the same approach to investigate insular efferents in a sample of 11 patients. The study of CCEPs provides novel and important findings regarding the human brain functional connectivity, with unmatched spatial and temporal resolutions as compared to neuroimaging techniques. The complex management of large volume of data in each patient can be solved by automated statistical analysis procedures with satisfactory sensitivity and specificity. The pattern of connections within and outside the insula revealed by this approach provides a better understanding of the physiology of the Human insula as well as of the propagation of epileptic discharges involving this lobe
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Ly, Mai Thanh Graduate School of Biomedical Engineering Faculty of Engineering UNSW. "Electrical stimulation of cells involved in wound healing." Publisher:University of New South Wales. Graduate School of Biomedical Engineering, 2008. http://handle.unsw.edu.au/1959.4/41523.
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Problem investigated: Chronic wounds are not only a major burden to the patient arising from general pain and discomfort but also generate economic costs to both these individuals and the health care system. Various electrical stimulation regimes have been employed to study the effects of electrical stimulation on wound healing both in vivo and in vitro. In was hypothesised that electrical stimulation using various waveforms can modulate cell function, particularly cell migration. The aim of this thesis was to study the effects of electrical stimulation on cellular migration, in particular endothelial cells and fibroblasts, key cell types involved in wound healing. The impact of collagen matrix on cell migration was also assessed. Methods: Cells were seeded on either glass or collagen I substrate and stimulated with various electrical regimes via platinum electrodes connected to a constant current source. Cell migration was accessed by manual tracking of cell nuclei over a period of 3 hours from digital time-lapse images acquired during stimulation. Data from cell tracking were analysed for directional migration, migration rates and mean square displacement. Results: No directional cell migration for both endothelial cells and fibroblasts were observed when stimulated with either alternating or biphasic currents. However, surface substrate had impacted on cell motility with opposite effects being observed for the two cell types. Endothelial cells tended to migrate at a faster rate on collagen I substrate than on glass, compared with fibroblasts, which displayed a slower rate of migration on collagen I substrate. Significant changes in mean square displacement of biphasic current stimulated cells on collagen I substrate compared to unstimulated cells were also observed. Conclusion: This thesis has illustrated cell migration can be modulated by electrical stimulation, in particular asymmetric biphasic current. It has also been demonstrated surface substrate can impact cell migration.
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Luo, Yuanming. "Assessment of diaphragm electrical activity using electrical and magnetic phrenic nerve stimulation." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270379.
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Yue, Zhang. "Opto-Magneto-Electrical Nanoactuators for Wireless Cell Stimulation." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/670924.
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Clinical treatments based on electrical stimulation of excitable cells have been efficacious for a variety of diseases. However, these devices are often limited by their bulkiness, need for wiring electrodes and inability to target specific cells. Implantable devices that can directly convert optical or magnetic energy to localized electrical output to actuate cells are promising alternatives. This thesis focused on the development of opto-electric and magneto-opto-electric nanomaterials for wireless cell stimulation. Currently, the opto-electric stimulators usually require low penetration visible light and high intensities, the magneto-electric stimulators usually provide poor spatial and temporal precision. In this thesis, two types of nanomaterials have been developed to overcome these challenges.
The first nanomaterial was based on Si/Au nanopillars to achieve opto-electric stimulation in the first and second NIR biological windows with ultralow light intensities. We started with the rational design and analysis, the FDTD simulations predicted that Si nanopillars capped by Au nanodiscs exhibited 6-fold enhancement of the light absorption compared with the plain Si wafer, such enhancement is due to the excitation of novel hybrid metal/dielectric resonances. Next, an exhaustive experimental opto-electric-chemical analysis of Si/Au nanostructures was presented. In particular, the short Si/Au nanopillars gave the highest opto-electric performance, achieving a photovoltage of 80 mV at ultralow light intensity of 0.44 µW/mm2, showing a frequency window of 50-200 Hz to maximize the photovoltage and photocurrent. Finally, the biocompatibility of the Si/Au nanostructures was validated by cell viability assays.
The second nanomaterial was composed of arrays of hollow FeGa/ZnO nanodomes integrated onto soft, flexible and biocompatible elastomeric film. The proposed magneto-electric stimulation is based on the magnetostriction of FeGa and the piezoelectricity of ZnO, the opto-electric stimulation is based on the NIR light absorption of FeGa and the pyroelectric response of ZnO. The magnetic behaviour results revealed that the hexagonal-close-packed arrays with 400 nm diameter provided the lowest saturation magnetic field and minimal remanence. The photothermal test showed intense optical heating for light wavelengths of 808 nm and 1064 nm. The biocompatibility was proved by evaluating the bone Saos-2 cells viability.
Therefore, the Si/Au and FeGa/ZnO nanoactuators present new platforms for wireless cell modulation through NIR light and magnetic field, which may be broadly applicable to both fundamental biological studies and clinical therapeutics.Los tratamientos clínicos basados en la estimulación eléctrica de células excitables han sido eficaces y ampliamente utilizados para una variedad de enfermedades. Sin embargo, estos dispositivos a menudo están limitados por su volumen, la necesidad de electrodos con cableado externo y la incapacidad de actuar en células específicas. Los dispositivos implantables que pueden convertir la energía óptica o magnética en estímulos localizados eléctricos o térmicos para activar las células, son alternativas prometedoras. Esta tesis se centró en el desarrollo de nanomateriales opto-eléctricos y magneto-opto-eléctricos para la estimulación celular inalámbrica. Actualmente, los estimuladores opto-eléctricos generalmente requieren luz visible de baja penetración y altas intensidades, y los estimuladores magnetoeléctricos generalmente proporcionan una precisión espacial y temporal deficiente. En esta tesis, se han desarrollado dos tipos de nanomateriales para superar estos desafíos. El primer nanomaterial se basó en nanopilares Si/Au para lograr la estimulación opto-eléctrica en la primera y segunda ventanas biológicas del infrarrojo cercano con intensidades de luz ultrabajas. Las simulaciones teóricas predijeron que los nanopilares de Si coronados por nanodiscos Au exhiben una mejora de 6 veces en la absorción de luz en comparación con la oblea de Si simple. Tal mejora se debe a la excitación de nuevas resonancias híbridas de metal/dieléctrico. A continuación, se presentó un exhaustivo análisis experimental opto-eléctrico-químico de los nanopilares de Si/Au. Los nanopilares cortos de Si/Au dieron el mayor rendimiento opto-eléctrico, logrando un fotovoltaje de 80 mV a una intensidad de luz ultrabaja de 0,44 µW/mm2, que fue 11 veces mayor que la oblea p-n Si simple. La fotocorriente también mostró una mejora sustancial de 2.5 veces, mostrando una combinación de corrientes capacitivas y faradaicas inducidas por la luz que pueden ajustarse con la densidad de los nanopilares Si/Au. Además, los nanopilares cortos de Si/Au mostraron una ventana de frecuencia de 50-200 Hz para maximizar la fotovoltaje y la fotocorriente. Finalmente, la biocompatibilidad de las nanoestructuras Si/Au fue validada por ensayos de viabilidad celular. El segundo nanomaterial estaba compuesto por matrices de nanocúpulas huecas de FeGa/ZnO integradas en una película elastomérica flexible y biocompatible. La estimulación magnetoeléctrica propuesta se basa en la magnetostricción del FeGa y la piezoelectricidad del ZnO. La estimulación optoeléctrica se basa en la absorción de luz infrarroja por el FeGa y la respuesta piroeléctrica del ZnO. Los resultados del comportamiento magnético revelaron que las matrices hexagonales empaquetadas con un diámetro de 400 nm proporcionaron el campo magnético de saturación más bajo y una remanencia mínima. El análisis fototérmico mostró un intenso calentamiento óptico para longitudes de onda de luz de 808 nm y 1064 nm. La biocompatibilidad se demostró evaluando la viabilidad de las células Saos-2 óseas. En conclusión, los actuadores celulares nanoestructurados de Si/Au y FeGa/ZnO constituyen nuevas plataformas para la modulación electrofisiológica inalámbrica mediante luz infrarroja y campo magnético. Mirando hacia el futuro, son prometedores como nanoactuadores inyectables e implantables in vivo debido a las posibles optimizaciones, como la fabricación en sustratos flexibles y la funcionalización de su superficie para su unión a tipos celulares específicos, que podrían ser ampliamente aplicables tanto a los estudios biológicos fundamentales como a terapias clínicas.
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Honhold, Nick. "Paracetamol, percutaneous electrical stimulation and rat spinal neurones." Thesis, Royal Veterinary College (University of London), 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522587.
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Stone, Barry A. "Control strategies for functional electrical stimulation induced cycling." Thesis, University of Glasgow, 2005. http://theses.gla.ac.uk/1533/.
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Functional Electrical Stimulation cycling ergometers and mobile cycling systems have been developed over a number of years to allow Spinal Cord Injured persons to exercise. Standard able bodied exercise tests are adapted and applied to paraplegic cyclists. A modified recumbent tricycle is instrumentated with an electric motor and sensors to measure cadence and the power produced by the cyclist at the crank. They are then integrated to a stimulator and a laptop computer. The tricycle is mounted on an indoor cycling trainer to provide a novel test bed for the implementation of exercise testing. Controllers are desired to control cadence and power during cycling. Identification of input-output data for the cadence-motor loop and the power-stimulation loop is undertaken. Three muscle groups are stimulated on a paraplegic subject to produce power. Models are identified of the power and cadence systems. Thereafter controllers are designed, via polynomial methods. The results show that the controllers are robust during cadence tracking, power tracking and for disturbance rejection. The controllers can be accurately applied to exercise testing protocols. The concept of VO2 control is induced. VO2 is the rate of oxygen uptake during exercise. VO2-power dynamics are identified and as before a model is fitted to the measured data. Controllers are designed and further modified, as the understanding of the VO2 dynamics is developed. This is through a series of tests to improve the accuracy of the control. The results illustrate that VO2 control is a novel and practical application. These findings develop the field of functional Electrical Stimulation Induced Cycling within the laboratory. However further work is required to develop this application outside laboratory conditions.
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Boyle, Derek John. "Electrical stimulation in the treatment of faecal incontinence." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/3365.
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Background There is a delay between obstetric injury and the onset of faecal incontinence (FI) for most females, yet traditional surgical management has focussed on the obstetric injury when treating FI. Recently, electrical stimulation has been used in a number of treatments however the modes of action and efficacies are unknown. This study aimed to assess the aetiology of FI, while exploring the efficacy of the three main modalities of electrical stimulation for FI, namely sacral nerve stimulation (SNS), percutaneous tibial nerve stimulation (PTNS) and electrically stimulated gracilis neosphincter (ESGN). Methods Data was analysed for 999 females, who had undergone anorectal physiology testing (ARP) excluding confounding factors other than aging and childbirth. Patients treated for FI with PTNS or SNS were investigated with ARP to assess their efficacy and any potential indicators of success. Patients with ESGN were evaluated to assess efficacy in the short, mid and long term. Results The function of the external anal sphincter is affected by childbirth, while the internal anal sphincter deteriorates with age. SNS can be effective in the treatment of FI, but only 26% of patients experience a resolution of symptoms with 74% remaining incontinent. PTNS performs slightly better with 32% of patients experiencing apparent continence; however this is significantly cheaper and less invasive than SNS. Outcome for ESGN also revealed a high failure rate, yet in the long term, this outperforms SNS and PTNS with 43% of patients being successfully treated. Discussion Both aging and childbirth contribute via different mechanisms to produce decreased anal sphincteric function. Symptomatic patients can be treated with electrical stimulation therapies however, a high failure rate is noted for all modalities. A treatment “ladder” is emerging, starting with minimally invasive PTNS, through SNS and finally the costly and demanding ESGN for highly motivated patients.
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Lane, Rodney. "Control of upper-limb functional neuromuscular electrical stimulation." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/419062/.
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Functional electrical stimulation (FES) is the name given for the use of neuromuscular electrical stimulation to achieve patterns of induced movement which are of functional benefit to the user. System are available that use FES to aid persons who have suffered an insult to the motor control region of the brain and been left with movement impairment. The aim of this research was to investigate methods of providing an FES system that could have a beneficial effect in restoring arm function. The techniques for applying upper-limb stimulation are well established, however the methods of controlling it to provide functional use remain lacking. This is because upper-limb movement can be difficult to measure and quantify as the starting point for any movement may not be well defined. Moreover the movements needed to complete a useful function such as reaching and grasping requires the coordinated control of a number of muscle groups, and that relies on being able to track the position of the limb. Effective control of FES for the arm requires reliable feedback about the position and state of the limb. Electromyograms (EMG) are a measure of the very small electrical signals that are emitted whenever a muscle is ‘fired’ to move. EMG can be used to detect muscle activity and so can be a useful feedback control input. It does however have a number of drawbacks that this research sought to address by combining the method with external motion sensors. The intension had been to use the motion sensors to track the position of the limb and then use the EMG measurements to detect the wearer’s movements. FES could then be used to assist the wearer in making a desired movement. Initial studies were done to separately investigate the motion sensing and the EMG measurement components of the system. However before these could be combined a more interesting observation was made relating to bioimpedance. A study of bioimpedance measurements found a relationship between tissue impedance changes and muscle activity. Different methods for measuring bioimpedance where investigated and the results compared, before a practical technique for capturing measurements was developed and demonstrated. A new set of test equipment was made using these finding. Subsequent results using this equipment were able to demonstrate that bioimpedance measurement could be taken from a limb while FES was being used, and that these measurement could be used as a feedback signal to control the FES to maintain a target limb position. This work forms the basis of a novel approach to the control of FES that uses feedback from the user’s limb to determine the position of the limb in free space without need for additional sensors.
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Parikh, Ketul M. "Modeling the electrical stimulation of peripheral vestibular nerves." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/41621.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (p. 137-143).
The research conducted for this thesis investigated the theoretical placement of electrodes for a proposed implantable vestibular prosthesis to aid patients suffering from balance related disorders. The most likely sites of stimulation for the first-generation of such a device are the peripheral nerves responsible for transmitting rotational information to the brain. Although stimulation of such nerves has been performed in human and animal patients, little is known about the mechanisms responsible for the eliciting nerve responses. Models of the inferior and superior divisions of peripheral vestibular nerve were created to characterize the stimulus threshold behavior across the parameters of fiber diameter and location within the nerve. Current-distance relations were derived for nerve fibers excited by six commonly used electrode configurations. The threshold relations were used as a guide to determine the electrode configuration and location best-suited to stimulate the inferior vestibular nerve and selectively stimulate the branches of the superior vestibular nerve. The criteria used determine optimal placement included minimum current thresholds, configuration simplicity, and distance to the electrode. For the inferior nerve case, a cathodal stimulus located at a distance of 100 pm or 200 ym from the nerve and driven with a stimulus current of 56 pA or 76 pIA was recommended. For the superior vestibular nerve case we were interested in selectively stimulating each branch, imposing a further criteria to maximize the threshold ratio between stimulation of the respective branches. A transverse dipole electrode configurations was suggested that allowed selective stimulation of either branch. The configuration included a cathode located 300m from Branch 1 and an anode centrally located between both branches.
(cont.) When driven with a cathodal stimulus of strength 51 pA, only Branch I was excited, while driving both electrodes with a magnitude of 106 jIA excited only Branch II. The proximity to the facial nerve was considered in the choices
by Ketul M. Parikh.
M.Eng.
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Kim, Sun Wook. "Modulation of Stem Cell Fate by Electrical Stimulation." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1383812480.
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Wang, Lei. "Hsp70 response to electrical stimulation in C2C12 cells." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-64223.
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Byrne, Elizabeth Mary. "Working memory training and transcranial electrical brain stimulation." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/277101.
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Working memory training improves performance on trained and untrained working memory tasks, but there is little consistent evidence that these gains benefit everyday tasks that rely on working memory. Evidence has shown that transcranial electrical stimulation (tES) may be an effective tool for enhancing cognitive training and promoting transfer. In the first study, participants completed Cogmed working memory training with either active or sham transcranial random noise stimulation (tRNS). Training was associated with substantial gains on the training activities and on transfer measures of working memory with common processing and storage demands to the training tasks. tRNS did not enhance gains on trained or untrained activities. The second study systematically investigated the boundary conditions to training transfer by testing whether gains following backward digit recall (BDR) training transferred within- and across-paradigm to untrained backward recall and n-back tasks with varying degrees of overlap with the training activity. A further aim was to test whether transcranial direct current stimulation (tDCS) enhanced training and transfer. Participants were allocated to one of three conditions: (i) BDR training with active tDCS, (ii) BDR training with sham tDCS, or (iii) visual search control training with sham tDCS. The results indicated that training transfer is constrained by paradigm, but not by stimuli domain or stimuli materials. There was no evidence that tDCS enhanced performance on the training or transfer tasks. The results of Study 1 and Study 2 provide no evidence that tES enhances the benefits of working memory training. The absence of transfer between backward recall training and n-back in Study 2 suggested the tasks might tap into distinct aspects of working memory. Consequently, the final study used a latent variable approach to explore the degree of overlap between different forms of backward recall and n-back tasks containing digits, letters, or spatial locations as stimuli. The best-fitting factor model included two distinct but related (r = .68) constructs corresponding to backward recall and n-back. Both categories of task were linked to a separate fluid reasoning construct, providing evidence that both are valid measures of higher-order complex cognition. Overall, the experiments in this thesis suggest that working memory tasks tap into separate processes and that training may be targeting and improving these distinct processes, explaining the absence of cross-paradigm transfer.
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Kesar, Trisha. "Effect of stimulation frequency and intensity on skeletal muscle fatigue during repetitive electrical stimulation." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 1.62 Mb., 85 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:1430768.
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Chin, Steven R. (Steven Richard). "Transcutaneous electrical nerve stimulation (TENS) : effects of duration of stimulation on antinociception in man." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68165.
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Transcutaneous electrical nerve stimulation (TENS) has been employed for over 2 decades in pain management, however, definitive analgesic parameters have yet to be determined. The objective of this study was to determine the influence of 10, 30 and 60 min of TENS on the time course and magnitude of modulation on flexion reflex (FR) and on subjective pain estimates (visual analogue scale, VAS), as well as determining the relationship between FR responses and VAS scores following TENS of different durations.Ten (10) normal subjects received electrical stimuli of maximal tolerable intensity to the sole of their foot. Our results indicated that TENS could suppress the FR in 50% to 70% of subjects. However, longer durations (30 and 60 min) of TENS have a small, but discernible difference in the number of subjects that show inhibition of FR area and significant maximal FR suppression when compared to 10 min of TENS. Moreover, the 60 min of TENS generated significant depression of VAS scores in more subjects than 10 and 30 min of TENS and ensured that any increase in pain perception would not reach significance when compared to the shorter (10 and 30 min) durations of TENS.
Our results suggested that longer durations of TENS could be applied to produce antinociceptive and analgesic effects. (Abstract shortened by UMI.)
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Kershaw, Robert Andrew. "Retrieved voluntary electromyogram signals for functional electrical stimulation control." Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295098.
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Jiang, Chong-He. "Prolonged Modulation of the Micturition Reflex by Electrical Stimulation." Doctoral thesis, Linköpings universitet, Cellbiologi, 1999. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4989.
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Intravesical electrical stimulation (IVES) has been used in treatment of patients with urinary bladder dysfunctions for more than four decades. While some investigators have reported excellent results others have observed less convincing effects or outright failures. The discrepancies may reflect differences in patient selection or stimulation procedure. A better theoretical understanding of the IVES working mechanism might help to improve the success rate of the treatment. The aims of the present study were to provide such information. Experiments were performed on adult female cats and rats under /alpha/-chloralose anesthesia. IVES was delivered by a catheter electrode in the bladder. At proper intensity and frequency, IVES evoked reflex detrusor contractions that were abolished by bilateral rhizotomy of sacral dorsal roots. Stimulation parameters and response characteristics revealed that bladder mechanoreceptor A/delta/ afferents were activated by the IVES, the same afferents that drive the normal micturition reflex. Five minutes of continues IVES at 20 Hz induced a prolonged, significant decrease in the micturition threshold volume of anesthetized rats. Similarly, selective bladder A/delta/ afferent stimulation induced a long-lasting enhancement of micturition reflex discharges in cats. A comparable prolonged inhibitory effect on the micturition reflex was demonstrated after ano-genital afferent stimulation. Both modulatory effects occurred without changes in response sensitivity of stimulated afferents. The IVES induced modulation was prevented by transient exposure of the bladder to a local anesthetic and by systemic administration of a glutamate NMDA receptor antagonist. In conclusion, IVES induces a prolonged modulation of the micturition reflex by an LTP like enhancement of excitatory synaptic transmission in the central micturition reflex pathway. The findings provide an experimental explanation for the neuronal mechanisms underlying the curative effect of IVES in patients with bladder evacuation problems.On the day of the public defence the status of article V was: Accepted.
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Collins, Amber Taylor Weinhold Paul S. "Electrical stimulation to improve proprioception in the normal knee." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,1343.
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Thesis (M.S.)--University of North Carolina at Chapel Hill, 2007.Title from electronic title page (viewed Apr. 25, 2008). "... in partial fulfillment of the requirements of the degree of Masters of Science in the Department of Biomedical Engineering." Discipline: Biomedical Engineering; Department/School: Medicine.
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Hale, Janet L. "Transcutaneous electrical nerve stimulation in the management of spasticity." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63995.
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Vanoncini, Michele. "Improving sitting posture in paraplegia via functional electrical stimulation." Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494804.
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This study is an experimental investigation on the application of Functional Electrical Stimulation (FES) to the trunk muscles in paraplegic subjects. The aim is to improve trunk balance during reaching/grasping activities, and to explore a potential use of FES for the prevention of pressure sores. The research comprises three parts: the development of a model of the human trunk, the synthesis of closed loop controllers for the stimulation, and the use of FES for pressure sore prevention. Biomechanical models of the trunk, available from previous studies, are not appropriate for the synthesis of FES controllers. They are difficult to identify due to the high number of prameters, and hence cannot be taken into account the daily variations of the muscle response to the stimulation. This study proposes a novel approach, based on a simple model, which can be identified prior to any stimulation session. The investigation on automatic control of FES aims at trunk stabilisation and rejection of disturbances. Two regulators are considered: a Proportional Integral Derivative (PID) and a Linear Quadratic Regulator (LQR). The results show that a development by trial and error of a PID controller is feasible, and hence should be considered in practical applications. The study also shows that the simple model previously developed and be employed in the synthesis of an LQR controller. Finally, the study considers the stimulation of the trunk extensors as a tool for pressure sore prevention. This is a novel FES application, potentially more practical than the stimulation of the gluteal or quadriceps muscles, proposed by other authors. The experimental study described in this thesis shows that the stimulation of the trunk extensors can be used to induce a periodic change of the pressure distribution on the buttocks, and hence can potentially be employed as a tool for prevention.
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Weber, Sonja A. "Electrical Characterisation of Wounds and Stimulation of Wound Healing." Thesis, University of Ulster, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516428.
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Kirtley, C. "Control of functional electrical stimulation with extended physiological proprioception." Thesis, University of Strathclyde, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292029.
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Valadao, Jaime Andre. "The effect of neuromuscular electrical stimulation on hamstring prehabilitation." University of the Western Cape, 2018. http://hdl.handle.net/11394/6566.
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Masters of ScienceBACKGROUND: Hamstring injuries remain a growing concern within a large variety of sports from the elite athlete to the weekend warrior. A copious amount of research has been performed in an attempt to reduce these injuries. The aim of this study was to understand the changes in lengthened state eccentric strength of the hamstrings following four separate protocols. METHODS: A quantitative research approach, using a true experimental design, was adopted for this study. A convenience sample of non-sedentary, 35 male participants, between the ages of 18 and 35 within the City of Cape Town was used. Participants were randomly allocated to one of four groups namely; Control group (C), resistance training alone (RT), neuromuscular electrical stimulation alone (NMES), or NMES superimposed with RT (NMES&RT). Participant’s eccentric hamstring strength was tested in a lengthened state, on the Biodex system 4 Pro™ for the pre- and post-test. The intervention spanned over four weeks. SPSS version 25 was used for data analysis. RESULTS: All groups demonstrated a mean increase in relative peak torque. However, a repeated-measures analysis of variance (ANOVA) showed no interaction effect (p = 0.411) between the four groups. Further analysis using Magnitude-based inferences (MBI), to identify the magnitude of changes, showed a small positive effect for both the NMES and NMES&RT group when compared to the C and RT groups. CONCLUSION: Although there are no statistically significant differences between the four groups employed in this study (C, RT, NMES, NMES&RT), NMES and NMES&RT did show small positive effects compared to C and RT with a very low likelihood of negative effects. Thus, using NMES either alone or superimposed with resistance training will be beneficial for trained athletes but it is not a necessity and the use of specific resistance training may be just as effective.
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Basson, Tobias Johannes. "Changes in hyo-laryngeal elevation post-pharyngeal electrical stimulation." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96764.
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Thesis (MScMedSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Swallowing disorders are prevalent in many elderly individuals and are common amongst individuals suffering from neurological diseases. These individuals are affected from slight swallowing difficulty to total swallowing inability. In severe cases this may cause aspiration pneumonia, dehydration, malnutrition and ultimately death. Swallowing disorders can be diagnosed and treated to increase quality of life. New treatment strategies to understand the pathophysiology and impaired swallowing response are needed. Neuromuscular electrical stimulation is used as rehabilitation method in various disciplines. This method of rehabilitation of physiological dysfunction is used in treating swallowing disorders and has become a focus for current research. To understand the effect of electrical stimulation to the swallowing centre it is proposed to study its mechanism on normal swallowing musculature. The outcome of the effect that electrical stimulation has on healthy individuals may possibly be used to extrapolate to clinical settings and its benefit for modern dysphagia rehabilitation. The purpose of this study was to report on the hyo-laryngeal movement pattern of young healthy, male and female, individuals and to measure the effect of a single neuromuscular electrical stimulation session on the hyo-laryngeal complex of 22 young healthy individuals. Lastly, the aim was to determine the detraining or lasting effect on the hyo-laryngeal swallowing complex of a single neuromuscular electrical stimulation session. The study reported on baseline hyo-laryngeal complex movement patterns by measuring the anterior movement and elevation of the hyo-laryngeal complex through the use of videofluoroscopy swallow study. Analysis of these measurements where done to report on the effect of electrical stimulation on the hyo-laryngeal complex movement pattern pre- and post- electrical stimulation. Significant changes were revealed with elevation of the hyo-laryngeal complex, however no significant effects could be found with anterior movement of the hyo-laryngeal complex pre- and post- electrical stimulation. It was found that elevation of the hyo-laryngeal complex lowered after a single electrical stimulation session. The hyo-laryngeal complex movement pattern remained similar between genders. Lastly it was found that a single electrical stimulation session showed significant reversibility towards baseline levels. This might be related to muscle fatigue and one would need to take into account muscle recovery for future research.
AFRIKAANSE OPSOMMING: Sluk versteurings is algemeen onder bejaardes asook individue wat ly aan neurologiese siektes. Hierdie individue word geaffekteer deur matige sluk probleme tot totale sluk onvermoë. In ernstige gevalle kan dit aanleiding gee tot aspirasie longontsteking, dehidrasie, wanvoeding en selfs dood. Sluk versteurings kan gediagnoseer en behandel word om die kwaliteit van lewe te verbeter. Dit is daarom noodsaaklik om die patofisiologiese en verswakte sluk reaksie te verstaan om sodoende nuwe behandeling strategieë te ontwikkel. Neuromuskulêre elektriese stimulasie word gebruik as rehabilitasie tegniek in verskeie dissiplines. Hierdie metode van behandeling van fisiologiese disfunksie word ook gebruik in die behandeling van sluk afwykings en geniet tans baie navorsings aandag. Om die effek van elektriese stimulasie op die sluk sentrum te verstaan word dit dus voorgestel dat die meganisme op die normale sluk spierstelsel bestudeer word. Hierdie bevindinge kan dus moontlik toegepas word op persone met sluk afwykings en sodoende meer effektiewe rehabilitasie tegnieke bevorder. Die doel van hierdie studie was om die effek op die hyo-laringeale bewegings patroon van jong, gesonde, manlike en vroulike individue te bestudeer, asook om verslag te doen oor die uitwerking van 'n enkele neuromuskulêre elektriese stimulasie sessie op die hyo-laringeale kompleks van 22 jong, gesonde individue. Laastens was die doel van hierdie studie ook om die blywende effek van 'n enkele sessie neuromuskulêre elektriese stimulasie op die sluk sentrum te bepaal. Die studie het basislyn hyo-laringeale kompleks bewegings patrone gerapporteer deur die voorwaartse asook opwaartse beweging van die hyo-laringeale kompleks te meet deur gebruik te maak van videofluoroskopie sluk studies. Ontleding van hierdie metings is gedoen om die uitwerking van elektriese stimulasie op die hyo-laringeale kompleks bewegings patroon voor en na elektriese stimulasie te bepaal. Beduidende veranderinge is in die opwaartse beweging van die hyo-laringeale kompleks gevind, alhoewel geen veranderinge gevind is in die voorwaartse beweging van die hyo-laringeale kompleks voor en na elektriese stimulasie nie. Daar is vasgestel dat die opwaartse beweging van die hyo-laringeale kompleks verlaag het na 'n enkele elektriese stimulasie sessie. Verder het die hyo-laringeale kompleks bewegings patroon geen beduidende verskille tussen geslagte getoon nie. Laastens is bevind dat 'n enkele elektriese stimulasie sessie beduidende omkeerbaarheid terug na basislyn vlakke van beweging toon. Dit kan verband hou met die uitputting van die hyo-laringeale spiere as gevolg van die elektriese stimulasie en toekomstige navorsing sal dus uitputting, asook die tempo van herstel in ag moet neem.
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Manidakis, Ioannis. "Paired pulse electrical stimulation in human intractable focal epilepsy." Thesis, King's College London (University of London), 2012. https://kclpure.kcl.ac.uk/portal/en/theses/paired-pulse-electrical-stimulation-in-human-intractable-focal-epilepsy(0cae49bb-f24e-4036-a465-10a4b034ed51).html.
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Objective: The purpose of this study was the identification of synaptic changes related to epileptogenesis in patients investigated with intracranial recordings during presurgical assessment. Hypothesis: The following hypotheses were tested: 1. Suppression, depression or facilitation is related to seizure onset area. 2. The removal of the cortex showing suppression, depression or facilitation is associated with better surgery outcome. Methods: A total of 79 patients with intractable focal epilepsy in whom intracranial electrodes were implanted for assessment prior to epilepsy surgery were analysed, using paired pulse electrical stimulation. The amplitude of the response elicited from the first pulse (1st response) was compared with the amplitude of the response elicited from the second pulse (2nd response). Depending on if the 2nd response was absent, of reduced, increased or similar amplitude to that of the 1st response four different conditions were emerged: a) suppression, b) depression, c) facilitation, or d) no change. Results: The following results were noted: a) Suppression showed better relation with SO lobe than depression and facilitation b) In patients with focal onset, suppression was observed in the area surrounding the focus and c) Resection of the suppressed areas was found to be an unreliable marker of surgical outcome. Discussion: The distribution of suppression in seizure onset lobe and more specifically in the area surrounding the focus can be of particular interest to identify the epileptogenic lobe and to study the pathophysiology of human focal epilepsy.
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Kelly, Shawn Kevin 1973. "A system for electrical retinal stimulation for human trials." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/50499.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (leaf 45).
The goal of the Retinal Implant Project is to restore useful vision to patients with degenerative diseases of the retina. Electrical stimulation of the retina via a microelectrode array is achieved using a battery powered stimulation system. This thesis describes the design of this system, including features that ensure the subject's safety from electrical shock. The stimulation system delivers charge balanced current pulses to the 100 electrodes in the array. The system has been tested in the laboratory setting as well as in rabbit experiments and one human retinal stimulation trial. It functions as specified, and is very robust.
by Shawn Kevin Kelly.
M.Eng.
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Hines, Anne Ewing. "Functional electrical stimulation for hand opening in spastic hemiplegia." Case Western Reserve University School of Graduate Studies / OhioLINK, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=case1061393914.
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Toprani, Sheela C. "MECHANISMS OF SEIZURE REDUCTION BY LOW FREQUENCY ELECTRICAL STIMULATION." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1399474125.
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Molema, Matlho Segopotso. "Improving meat tenderness with vitamin D3 and electrical stimulation." Diss., University of Pretoria, 2007. http://hdl.handle.net/2263/28115.
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Meat tenderness is regarded as the single most important characteristic of meat quality. Fifty Bonsmara feedlot steers were fed a commercial feedlot ration (10,5 MJ MElKg DM, 12% CP), supplemented with 0,15mg Zilmaxlkg live weight in the feed and with different levels of vitamin D3 (1 to 5 X 106 IU Vit D3 /day) for five days prior to slaughter. The steers were randomly allocated to the vitamin D3 treatments and a control group that received no vitamin D3 supplementation. The steers were fed from ca. 248 ± 3 kg live weight, while Zilmax was fed for the last 35 days to a target weight of ca 400kg. All steers were slaughtered at a commercial abattoir after a Zilmax withdrawal period of 7 days. Samples from m. longissimuss lumborum were collected 24h post-mortem for sheer force testing on an Instron apparatus equipped with a Wamer Bratzler shear blade. Cooking loss was determined by measuring the amount of fluid loss after cooking. Feedlot performance, carcass characteristics and drip loss of meat samples did not differ significantly between the different vitamin D3 treatments. The inclusion of 5 X 106 IU of vitamin. D3 resulted in significantly lower shear force (SF) values compared to the steers in the control group. The results suggest that dietary supplementation of 5 X 106 IU of vitamin. D3 may significantly improve the tenderness of meet from steers fed 0, IS mg Zilmax ®/kg live weight for the last 35 days in the feedlot. The aim of the second study was to explore the effectiveness of the use of electrical stimulation on tenderness of mutton. In this experiment 22 wethers of class AB weighing between 45 and 50kg were used. The carcasses were assigned to two treatment groups, of which group one was electrically stimulated (ES) and the other group was not electrically stimulated (NES). The results revealed that electrical stimulation did not significantly affect of the fatty acid content of meat and crude fat content. Treatment however, significantly (P< 0,038) influenced the moisture content of the samples. There was a variation in SF values between the two treatment groups; SF of samples from the ES group were lower compared to that of the NES group. This suggests that ES can be successfully applied to reduce the variation in tenderness within the class- AB mutton.Dissertation (MSc(Agric) : Meat Science)--University of Pretoria, 2008.
Animal and Wildlife Sciences
unrestricted
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Molema, Matlho Segopotso. "Improving meat tenderness with vitamin D₃ and electrical stimulation." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-09222008-124203.
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Fuller, Paula. "A physiological perspective: Electrical stimulation of post-mortem muscle." Thesis, Fuller, Paula (2016) A physiological perspective: Electrical stimulation of post-mortem muscle. PhD thesis, Murdoch University, 2016. https://researchrepository.murdoch.edu.au/id/eprint/34928/.
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Electrical stimulation of carcasses is a mainstay processing technique within the sheep meat industry. A primary use is to accelerate tenderisation of meat and to reduce the variation observed in its end products. Technological advances have resulted in a new generation of medium voltage electrical stimulation (MVES) units, which offer superior outcomes to previous high- and low-voltage systems. These new units allow precisely controlled electrical inputs to individual carcasses, thus providing processors with greater control over end product outcomes. Yet even with these new systems, significant variation in meat quality still remains. This variation likely results from an unidentified interaction between the electrical input and the carcass, as previously used electrical parameters were empirically defined, based on processor experience rather than an integrated understanding of the applied parameters and the induced response in the post-mortem muscle. Thus a scientific understanding of how the electrical input interacts with post-mortem muscle to improve meat quality is required. Given the use of electrical stimulation stems from its ability to engage muscle activity, this thesis sought to examine the effect of MVES on post-mortem muscle function using contractile characteristics as a means to identify how this type of system imparts its beneficial effects.
The first experimental chapter (Chapter 2) examined the effect of various MVES parameters on dressed sheep carcasses (under commercial processing conditions), using the ΔpH of the M. longissimus thoracis et lumborum as a means by which to define carcass response and determine which electrical parameters were most effective. We observed that stimulation parameters incorporating longer pulse widths (i.e. 5ms) or those with a modulated (increasing) frequency across the electrodes produced the largest carcass response (i.e. largest ΔpH). Interestingly, the effect of this electrical stimulation on pH was influenced by hot carcass weight, with lighter carcasses (<23Kg) more responsive to all stimulation parameters tested, in contrast to heavier carcasses that did not distinguish between the different electrical inputs. As part of this study, we also determined that pre-stimulation pH is an adequate marker of carcass responsiveness to MVES stimulation, offering a way in which to determine how carcasses will respond to the applied current. In a concurrent study, we took advantage of the positioning of the stimulation system in order to compare the effect of MVES on muscle pH within the immediate stimulation period (i.e. within five minutes) compared to a time period more reflective of that in the literature, documenting a significant difference. This, in conjunction with showing a significant difference between pH measuring techniques, highlights the requirement for consideration of both the timing and methodology when comparing pH responses to MVES.
Having determined the parameters that produced the biggest effect on carcass pH, the second experimental chapter (Chapter 3) undertook a closer examination as to how these parameters affected the contractile properties of post-mortem muscle. This was achieved by establishing an isolated nerve-muscle electrophysiology rig to examine their influence on muscle in a controlled environment. The electrical parameters identified in the previous chapter were examined, with a particular interest in the effect of longer pulse widths and modulated frequency on muscle contraction given their positive effect on ΔpH. The contractile characteristics of two different types of sheep muscle [M. semitendinosus (ST) and M. semimembranosus (SM)], were examined. This study revealed that electrical stimulation with longer pulse widths produced a greater contractile response in terms of both peak tension and the overall amount of contraction. Muscle response to modulated frequency stimulation was similar to that elicited by longer pulse widths, but likely arose from enhanced activity of different contractile elements. Comparison of the different muscle responses to simulated MVES showed that overall, the oxidative-glycolytic SM muscle produced a larger contractile response than the glycolytic ST, but did not distinguish between the electrical parameters. This study also revealed a difference in the way in which the electrical impulse was transmitted through the muscle bundle, i.e., direct stimulation of muscle vs. nerve-mediated (stimulation of residual nerve activity). It appeared that more of each parameter was transmitted via the nerves in SM, but more directly transmitted in ST.
The last observations from Chapter 3 were particularly interesting, as it suggested that electrical stimulation transmitted via the nervous system may a viable option for use within the MVES set up. This possibility would provide another avenue for whole carcass stimulation, as electrical transmission via the nervous system generates a consistent and more homogenous decline of pH in all carcass muscles. Thus the last experimental chapter (Chapter 4) examined if, and to what extent, post-mortem muscle could respond to nerve-mediated electrical stimulation. This study showed that under a defined post-mortem environment (i.e., anoxic conditions), post-mortem sheep muscle does retain contractile activity in response to nerve-mediated electrical stimulation, but in a muscle-specific manner - both in the magnitude of contraction and the ability to distinguish between stimuli frequencies. We also investigated the role of several neuromodulators in muscle contraction under these conditions, specifically those that are known to mediate muscle contraction arising from nerve stimulation (ATP, NO and CGRP). The neuromodulators ATP and NO appear to affect muscle response to nerve stimulation at the level of neurotransmission in ST, in contrast to E-C coupling processes in SM. These results suggest that post-mortem SM muscle is better able to respond to nerve-mediated parameters, and this response is likely directed by the physiological properties that dictate normal muscle function (i.e., the type of innervation). Overall this study suggests that nerve-mediated electrical parameters may be a viable option for incorporation into commercial processing environment if optimised in a muscle-specific manner, with the most advantage likely gained for the processing of muscle groups containing oxidative-glycolytic fibre types.
In summary, this thesis has provided a number of insights into the mechanisms by which various MVES inputs influence post-mortem muscle function. Identification of the biological changes that occur within stimulated nerve and muscle in post-mortem tissue may be used to refine electrical stimulation parameters for specific carcass applications to enhance overall meat quality. Furthermore, we identified a potential role for nerve-mediated responses as part of the stimulation strategy. It is hoped that these findings contribute to a more sophisticated understanding of the use of electrical stimulation, and may provide the commercial sector further opportunities for refining this technology for the benefit of both the producer and consumer.
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Vance, Carol Grace T. "Examination of parameters in transcutaneous electrical nerve stimulation effectiveness." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/4779.
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Pain is the oldest medical condition and has been referenced through the ages. TENS is a non-invasive treatment for pain. Despite conflicting reports of treatment outcomes, TENS has enjoyed widespread clinical utilization. Seminal work by Sluka and colleagues reported low frequency TENS produces anti-hyperalgesia through µ-opioid receptors and high frequency TENS produces anti-hyperalgesia through ä-opioid receptors in an animal model of inflammation. The experimental results suggested that pain can be reduced by both high and low frequency TENS but by differing opioid receptors. These important findings require translational experiments to be conducted in humans.
Providing an adequate placebo for experimental investigation of any physical intervention presents as a challenge. An improvement in the placebo intervention is critical to ascertain the true effects of TENS on painful conditions. Clinical TENS experiments often only examine a single outcome - resting pain. Recent work suggests TENS is less effective on resting pain as compared to movement pain. Investigation to determine which outcome measures (pain at rest, movement pain, pain sensitivity, and function) are most likely to be affected by TENS in human subjects with pain are critical to inform the design of future studies.
The least investigated parameter for application of TENS electrode site determination. One method of selection employs a technique of finding points on the skin with suspected lower impedance. To date, no literature exists to determine the effectiveness of this clinical practice and speculation has existed for decades regarding the existence of distinct electrical properties associated with specific points on the body.
This series of experiments accomplishes the goals of improving the TENS placebo, testing established parameters from basic science experiments in a patient population, testing multiple outcome measures to direct future investigation; and examined the effect of electrode site selection in TENS analgesia. These experiments were the first to establish a placebo that can 100% blind the TENS examiner, to test this placebo in a patient population, and to show that although there are differences in impedance between optimal and sham sites, that this difference had no effect in the amount of analgesia produced by TENS.
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Pegoraro, Roger V. "Electrical train stimulation to assess exercise associated muscle cramp." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2010. https://ro.ecu.edu.au/theses/1845.
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Muscle cramp is a forceful, involuntary contraction of skeletal muscle, but its underlying mechanisms are not well understood. Our limited understanding of muscle cramp may be due to its unreliable occurrence. Electrical train stimulation (ETS) has been reported to induce cramp in the small flexor muscles of the foot, and a relationship exists between the threshold frequency (TF) of ETS to induce cramp and muscle cramp susceptibility. The use of ETS to induce muscle cramp in the calf muscles however may be challenging, and the test-retest reliability of this method has not been examined in the calf muscles. Since athletes can experience muscle cramp in the calf muscles, in turn affecting their athletic performance, it is necessary to establish a method to assess calf muscle cramp. The first purpose of this study therefore was to determine the usefulness of the ETS application to the calf muscles, along with its reliability. Using a Compex 2 stimulator, ETS was applied to the calf muscles of both dominant and non-dominant legs in 10 men (33.5 ± 8.4 y) who reported experiencing cramp during training or competition. Each leg was treated separately in a counterbalanced order, with subjects in the supine position and legs supported by a bench that fixed the ankle at maximal plantarflexion. ETS consisted of 2 s (including 500 ms ramp time) of 300 μs square pulsed waves followed by 30 s rest. ETS commenced with two bouts of stimulation at 10 Hz during which the stimulation intensity was increased to the maximum tolerated, with values of 46.9 ± 6.5 and 45.4 ± 7.7 mA for the dominant and non-dominant legs, respectively. Subsequent stimulation trains increased by 3 Hz until cramp occurred, as confirmed by a spontaneous electromyograph (EMG) signal. The protocol was repeated 30 min after the first test, with the entire testing procedure repeated seven days later. Muscle cramp was induced in all subjects, but the TF varied amongst subjects (13-55 Hz). Mean TF value to induce muscle camp for the dominant leg was 25.0 ± 7.6 Hz for the first test and 23.7 ± 5.0 Hz for the second test. The non-dominant leg also showed similar values. Test-retest reliability, as indicated by the intraclass correlation coefficient (ICC), limits of agreement (LOA) and coefficient of variation (CV), were 0.94, 5.4 % and 9.2 %, respectively for the dominant leg, and 0.72, 9.8 % and 15.4 %, respectively for the non-dominant leg. These results show that ETS can induce muscle cramp in the calf muscles and that the TF of ETS was a reliable measure to assess the calf muscle cramp susceptibility. The second purpose of this thesis was to examine the influence of fatigue on the TF of ETS-induced muscle cramp in the calf muscles of 10 men (35.8 ± 9.2 y) who reported experiencing cramp during sporting activity. The previously described methods were used to assess muscle cramp in the calf muscles of the subject’s dominant leg with a stimulation intensity of 49.3 ± 4.9 mA before, immediately after, and 30 min after exercise. Exercise consisted of uphill treadmill walking, standing calf raises, skipping, drop jumps and cycling to fatigue, which was completed in 82.9 ± 2.0 min at an average heart rate of 141.7 ± 6.0 bpm. An isokinetic dynamometer was used to measure plantarflexor muscle torque of the dominant leg before and immediately after exercise, and following 30 mins of passive recovery. Blood and urine samples were obtained to assess electrolyte concentrations and hydration status before and immediately after exercise. Plantarflexor muscle torque decreased significantly (p < 0.05) approximately 20 % from the baseline (42.4 ± 17.1 Nm) immediately post exercise (34.6 ± 14.9 Nm), and was still significantly lower at 30 min post-exercise (37.4 ± 15.9 Nm). Serum (4.32 ± 0.35 vs 4.66 ± 0.38 mmol/L) and urine (56.3 ± 38.6 vs 87.2 ± 40.8 mmol/L) potassium concentrations, urine osmolality (551.1 ± 306.6 vs 683.9± 236.6 mmol/L), and urine specific gravity (1.014 ± 0.008 vs 1.022 ± 0.009) changed significantly from pre to post exercise, but serum osmolality, serum sodium and urine sodium concentrations remained unchanged. No significant changes in TF were evident before (23.2 ± 6.0 Hz), immediately after (22.6 ± 5.1 Hz) and 30 min post-exercise (25.3 ± 7.4 Hz). These results suggest that neither fatigue nor mild changes in hydration status affect the TF. Nevertheless, the duration of exercise used in this study might not have been sufficient to cause the physiological changes that may occur during training or racing. As muscle cramp can reliably be assessed by ETS, future investigations should use this method to uncover potential mechanisms related to muscle cramp, such as body temperature, hydration status and electrolyte concentrations.
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Busolin, Giorgia. "Transcriptional reprogramming of muscle fibers by chronic electrical stimulation." Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3423414.
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Background: Skeletal muscle fibers have a remarkable capacity to adjust their molecular, functional, and metabolic properties in response to developmental and environmental stimuli. A central role for neuromuscular activity in determining skeletal muscle fibers composition was demonstrated by cross-innervation and electrical stimulation experiments in adult skeletal muscle. A fast to slow transition can be induced by chronic low-frequency electrical stimulation (CLFS). In literature, CLFS studies have focused on the effects produced after days or weeks of stimulation. Here, I present the first transcriptome study that identifies the earliest genetic changes in this process.
Methods: The fast EDL muscle was subjected to CLFS for 6 and 12 hours. First, microarray experiments were performed using whole EDL muscle. Then, in order to reduce biological noise caused by different cell types, I applied microgenomic analyses at the level of single fibers (SF), isolated according to the protocol recently developed in my laboratory. Microarray experiments have been produced with updated platforms (Agilent SurePrint G3 Mouse GE 8x60K).
Results and discussion: The expression profiles of whole muscle after 6 and 12 hours of electrical stimulation identified about two hundred differentially expressed (DE) genes. The functional categories of blood vessel development and transcription regulation were most enriched. Genomic analyses of isolated fibers identified more than a thousand DE genes after 12 hours of stimulation. The functional category of blood vessel development was enriched also at the SF level, suggesting that myofibers are able to interact with other cell types in order to stimulate the angiogenesis process. In general, muscle structural genes were equally expressed between stimulated and unstimulated muscles, indicating that changes in fiber type require prolonged stimulation. On the contrary, genes involved in transcription, chromatin-remodeling genes and several myofibril genes acting as signaling molecule were early activated after CLFS.Introduzione: Le fibre del muscolo scheletrico possiedono una notevole capacità di modificare le loro proprietà molecolari, funzionali e metaboliche in risposta a stimoli di crescita e ambientali. Esperimenti di cross-innervazione e stimolazione elettrica hanno dimostrato il ruolo fondamentale dell’attività neuromuscolare nel determinare il tipo di fibra. La stimolazione cronica a bassa frequenza (CLFS) è in grado di indurre il processo di trasformazione di una fibra veloce verso un fenotipo lento. Fino ad ora, questi processi sono stati studiati dopo lunghi periodi di stimolazione. In questo lavoro, mi sono proposta di identificare i cambiamenti trascrizionali precoci di questo processo. Metodi: Il muscolo veloce EDL di topo è stato sottoposto a CLFS per 6 e 12 ore. Inizialmente ho utilizzato il muscolo intero per produrre i profili di espressione Successivamente, per ovviare al problema dell’eterogenea composizione del muscolo, ho utilizzato l’approccio microgenomico, producendo profili di espressione a livello di una singola fibra, isolata utilizzando il protocollo sviluppato nel mio laboratorio. Tutti i profili sono stati ottenuti mediante l’utilizzo di piattaforme Agilent (SurePrint G3 Mouse GE 8x60K). Risultati e discussione: I profili di espressione con il muscolo intero hanno identificato circa 200 geni differenzialmente espressi (DE). Lo sviluppo dei vasi sanguigni e la regolazione della trascrizione sono risultate le categorie funzionali più arricchite. Le analisi genomiche a livello di singola fibra hanno identificato più di mille geni DE dopo 12 ore di stimolazione. La categoria funzionale riguardante lo sviluppo dei vasi sanguigni risulta arricchita anche con questo approccio, suggerendo un’interazione tra le fibre muscolari e gli altri tipi cellulari al fine di stimolare il processo di angiogenesi. La maggiorparte dei geni strutturali risulta essere ugualmente espressa, suggerendo che i cambiamenti nel tipo di fibra richiedono un tempo prolungato. Al contrario, i geni coinvolti nella trascrizione, nel rimodellamento della cromatina e alcuni geni miofibrillari che agiscono come molecule di segnale, si attivano rapidamente in risposta a CLFS.
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Lacuey, Lecumberri Nuria. "Human autonomic and respiratory responses to direct cortical electrical stimulation." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/666840.
Full textAbstract:
Los pacientes con epilepsia son bien conocidos por tener un mayor riesgo de muerte súbita inesperada. El riesgo de muerte súbita inesperada en pacientes con epilepsia (SUDEP) varía de 0,35 a 2,3 por cada 1000 personas por año en las poblaciones de base comunitaria, a 6,3 a 9,3 en los candidatos a cirugía para la epilepsia. Los mecanismos agónicos precisos que desencadenan SUDEP son desconocidos, aunque la evidencia reciente del estudio de unidades de monitoreo de Epilepsia (MORTEMUS) apunta al colapso combinado respiratorio y cardiovascular que conduce al fatal evento.
Los signos adversos del sistema nervioso autónomo son prominentes durante las convulsiones. Arritmias cardíacas (bradicardia, asistolia, taquiarritmias) en aproximadamente el 72% de los pacientes con epilepsia, hipotensión post ictal, sensibilidad barorrefleja alterada (que puede comprometer el flujo sanguíneo cerebral), incremento del tono simpático, expresado como aumento de la sudoración y disminución de la variabilidad inter-ictal del ritmo cardíaco nocturno (HRV) son comunes. La alteración severa de la respiración se ve típicamente en las convulsiones clónicas tónicas generalizadas (GTCS). Las características del electroencefalograma (EEG), incluida la supresión generalizada post-ictal en el EEG (PGES), sugieren un alto riesgo de SUDEP, se correlacionan fuertemente con un aumento de la sudoración y una disminución de la HRV y pueden ir acompañadas de hipotensión profunda. Los mecanismos neuronales subyacentes a estos patrones necesitan ser definidos.
La epilepsia es un trastorno cortical prototípico, donde la mayoría de los síntomas se producen por la activación o inhibición de regiones específicas en la corteza. Las descargas epileptiformes que involucran un área específica en el cerebro pueden inducir síntomas relacionados con la funcionalidad de ese área. De manera similar, la estimulación eléctrica del cerebro se puede usar para mapear funciones cerebrales.
Aunque varios estudios que usan estimulación eléctrica cerebral han sugerido el posible papel de estructuras corticales en la respiración y el control autonómico, los informes de algunos investigadores han indicado hallazgos mixtos, de tal manera que no hay consenso sobre las áreas precisas de la corteza involucrada.
Nuestro objetivo fue identificar los sitios corticales con funciones en el control respiratorio y/o autonómico y correlacionar la activación inducida por las crisis epilepticas o la inhibición de estas estructuras, con particulares patrones autonómicos y respiratorios peri-ictales reconocidos como posibles índices de riesgo de muerte. Este estudio describe el papel de varias estructuras límbicas/paralímbicas en la respiración y el control de la presión arterial humana, y los mecanismos patogénicos de la respiración y las respuestas autonómicas durante las crisis epilépticas, proporcionando información sobre los mecanismos que pueden desencadenan la muerte súbita inesperada en los pacientes con epilepsia (SUDEP).Patients with epilepsy are well known to be at increased risk of sudden unexpected death. The risk of Sudden Unexpected Death in Epilepsy Patients (SUDEP) ranges from 0.35 to 2.3 per 1000 people per year in community-based populations, to 6.3 to 9.3 in epilepsy surgery candidates. SUDEP’s precise agonal mechanisms are unknown, although recent evidence from the Mortality in Epilepsy Monitoring Units Study (MORTEMUS) points to combined respiratory and cardiovascular collapse driving the fatal event. Adverse autonomic nervous system signs are prominent during seizures. Cardiac arrhythmias (bradycardia, asystole, tachyarrhythmias) in approximately 72% of epilepsy patients, post-ictal hypotension, impaired baroreflex sensitivity (potentially compromising cerebral blood flow), enhanced sympathetic outflow, expressed as increased sweating and decreased inter-ictal nocturnal heart rate variability (HRV) are common. Severe alteration of breathing is typically seen in generalized tonic clonic seizures (GTCS). Electroencephalogram (EEG) characteristics, including post-ictal generalized EEG suppression (PGES), are suggestive of high SUDEP-risk, strongly correlate with increased sweating and decreased HRV, and may be accompanied by profound hypotension. Neural mechanisms underlying these patterns need to be defined. Epilepsy is a prototypic cortical disorder, where most of the symptoms are produced by the activation or inhibition of specific regions in the cortex. Epileptiform discharges involving a specific area in the brain may induce symptoms related with that area’s functionality. In a similar manner, electrical brain stimulation can be used to map brain functions. Although several studies using brain electrical stimulation have suggested the possible role of cortical structures in respiration and autonomic control, reports from some investigators have indicated mixed findings, such that there is no consensus on the precise areas of cortex concerned. We aimed to identify cortical sites with roles in respiratory and/or autonomic control and to correlate seizure induced activation or inhibition of these structures to particular peri-ictal autonomic and breathing patterns recognized as potential indices of risk for death. This study describes the role of several limbic/paralimbic structures in respiration and human blood pressure control, and pathomechanisms of breathing and autonomic responses during epileptic seizures, providing insights into mechanisms of failure in SUDEP.
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Al-Majed, Abdulhakeem A. "Promoting peripheral nerve regeneration, functional electrical stimulation and pharmacological approaches." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0009/NQ59560.pdf.
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Thomas, Daniel Stewart. "Muscle preservation in denervation injury using continuous implantable electrical stimulation." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61297.
Full textAbstract:
Using a dog model, two experimental groups were defined. In group 1, the common peroneal nerve of the right hind limb was cut and repaired microsurgically 12 cm from the tibialis anterior muscle (fast muscle). Electrodes (applied to the muscle) and an Itrel pulse generator were implanted, and electrical stimulation (ES) was delivered at 85 Hz,.45 msec pulse duration, 10.5 V, 1.5 sec every 24 sec (n = 4). Group 2 was similar except there was no ES (n = 5).Comparing the experimental side to the normal contralateral muscle, ES versus no ES resulted in a preservation of muscle weight--73% vs 39% (p $<$.01); twitch tension--21% vs 7% (p $<$.001); nerve stimulated tetanic tension--23% vs 7% (p $<$.05); direct muscle stimulated tetanic tension--43% vs 11% (p $<$.01); Type I fiber area--69% vs 46% (p $<$.05); and Type II fiber area of 63% vs 34% (p $<$.05). There was no statistically significant difference between the two groups in the fiber type proportions.
The results of this project support the hypothesis that continuous, implantable ES delivered over an extended period of time has a positive functional and morphological impact on denervated muscle. (Abstract shortened by UMI.)
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Jaime, Ralf-Peter. "On the control of paraplegic standing using functional electrical stimulation." Thesis, University of Glasgow, 2002. http://theses.gla.ac.uk/1591/.
Full textAbstract:
This thesis is concerned with the restoration of upright standing after spinal cord injury (SCI) by the means of Functional Electrical Stimulation. In particular, the work presented in this thesis is concerned with unsupported standing, i.e. standing without any support by the arms for stabilisation. Firstly, the experimental apparatus and feedback control approach is described. Secondly, the experimental work is divided into three parts. The motivation, experimental setup and procedure as well as results and conclusions are given for each of them. The feasibility of the investigated approach was usually tested on a neurologically intact subject. The results were subsequently confirmed with a paraplegic subject. First the feasibility and fundamental limitations of unsupported standing were investigated. Assuming the subject as a single-link inverted pendulum, an improved fully dynamic control approach was employed in the first step, confirming existing results. Here, the voluntary influence by the central nervous system was minimised. However, it is naturally desirable to take advantage of the residual sensory-motor abilities of the paraplegic subject to ease the task of stabilising the body. Ankle stiffness control has been proposed in the literature to accomplish this task. Hitherto, ankle stiffness was provided by artificial actuators. In the second part we investigated the feasibility and limitations of ankle stiffness control by means of FES. The same single-link approach was employed as above. Ankle stiffness control by FES was used in the third part to enable paraplegic standing. Here, the subject was required to participate actively in the task of stable standing and, while doing so, behaving like a double-link inverted pendulum. It could be shown that FES-controlled ankle stiffness contributed crucially to the subject's ability to stand. The thesis concludes with propositions for future work.
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Rahal, Mouhamed. "Optimisation of nerve cuff recordings for functional electrical stimulation applications." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248136.
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Cramp, Alice Fiona Louise. "The physiological and hypoalgesic effects of transcutaneous electrical nerve stimulation." Thesis, University of Ulster, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314031.
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Mackenzie, Stuart William. "Reflexes evoked by electrical vestibular stimulation and their clinical application." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8594/.
Full textAbstract:
The vestibular system provides vital information about head position and motion; which is used for the control of balance through vestibulospinal reflexes. Chapter 2 explores the process of transforming head position to body coordinates, with and without vision. The results show when vision is available, the evoked response is less precise. Chapter 3 explores the transformation process before and after 60 days of bedrest. After this period of inactivity, participants swayed more, and their EVS-evoked sway response was less precise. This decrement in precision appears to begin recovery 6 days postbedrest. Chapter 4 focuses on vestibulo-ocular reflexes rather than postural reflexes. Electrical vestibular stimulation is used to evoke measurable torsional eye-movements. The magnitude of the response is modulated by stimulus frequency. Results suggest that CNS interprets electrical vestibular stimulation as a velocity signal rather than a position or acceleration signal. This technique is an ideal measure of pure vestibular function, Chapter 5 utilised the technique in a clinical environment. Vestibular schwannoma patients, with known unilateral vestibular deficit, were tested to identify if the proposed technique can detect this deficit. Results showed that asymmetries could be detected, and, the test may be more sensitive than previously used measures of vestibular asymmetries.
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Chen, Xisha. "Pulsatile electrical stimulation of auditory nerve fibres : a modelling approach." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/55936/.
Full textAbstract:
A stochastic leaky integrate-and-fire nerve model with a dynamical threshold (LIFDT) has been derived for the neural response to sinusoidal electrical stimulation. The LIFDT model incorporates both the refractory effects and the accommodation effects in the interpulse interactions. In this thesis, this phenomenological nerve model is extended for the neural response to pulsatile electrical stimulation, which is widely used in cochlear implants as it reduces inter channel interference. Neurophysiological data from adult guinea pigs were fitted to the LIFDT model. First, the parameters were constrained by the Input/output (I/O) curve analysis. Analysis of the data showed strong accommodation effects. The figures of I/O function for each pulse were plotted according to the physiological data. Fitting the I/O function of the data constrained the value of four variables of LIFDT model. The other five parameters were “optimised by eye”. Although the LIFDT is built with stimulus-dependent threshold, the response of short duration biphasic pulsatile stimuli exhibits weak accommodation effects. Then, in order to avoid the complication of full optimization, analytical approximation of the LIFDT model was derived for pulsatile electrical stimulation. It improves computational efficiency and provides information on how the parameters of the LIFDT model affect the accommodation effects. Theoretical predictions indicate that the LIFDT model could not capture the strong accommodation effects in the neurophysiological data due to structural problems. Alternatively, a Markov renewal process model was utilized to track the pulsetrain response. The stationary and non-stationary Markov renewal process models were fitted to the neurophysiological data. Both models can interpret the conventional PST histograms into conditional probabilities, which are directly related to the interpulse intervals. The consistent results from those two models provide a qualitative analysis of the accommodation characteristics.