Dissertations / Theses on the topic 'Electric stimulation'
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1
Suzuki, Ryuji Ph D. Massachusetts Institute of Technology. "Responses from electric stimulation of cochlear nucleus." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62518.
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Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references.
Cochlear nucleus (CN), the exclusive destination of the auditory nerve, is the gateway for all central processing of auditory information. The CN comprises three major subdivisions: anteroventral, posteroventral and dorsal (AVCN, PVCN and DCN, respectively), each of which contains anatomically and physiologically distinct neurons projecting onto different targets. This research used focal electric stimulation of small, confined parts of the CN in anesthetized guinea pigs to resolve the roles of the CN divisions, in two contexts. Part i explored the effect of stimulation on the gross neural potential (electrically evoked auditory brainstem response, EABR). In AVCN and PVCN away from the 8th nerve fibers entering the brainstem, stimulation consistently evoked waveforms comprising 3 waves, suggesting a diffuse distribution of cellular generator of the EABR. On the other hand, in vestibular structures (vestibular nerve root and Scarpa's ganglion), the characteristic waveform comprised only two waves. Stimulation of multiple neural structures, as seen with higher stimulus levels or stimulation in auditory nerve root area generally produced more complex and variable waveforms. Part 2 explored the effects of stimulation on the activation of one type of auditory reflex, medial olivocochlear (MOC) reflex. The reflex was monitored through its effects on distortion product otoacoustic emission (DPOAE). The MOC reflex was activated bilaterally by stimulating PVCN or AVCN shell, but not AVCN core. These results suggest that there are two groups of MOC interneurons in specific parts of CN.
by Ryuji Suzuki.
Ph.D.
2
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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Grumet, Andrew Eli. "Electric stimulation parameters for an epi-retinal prosthesis." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9336.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 138-144).
This work was undertaken to contribute to the development of an epi-retinal prosthesis which may someday restore vision to patients blinded by outer retinal degenerations like retinitis pigmentosa. By stimulating surviving cells in tens or hundreds of distinct regions across the retinal surface, the prosthesis might convey the visual scene in the same way that images are represented on a computer screen. The anatomical and functional arrangement of retinal neurons, however, poses a potential obstacle to the success of this approach. Stimulation of ganglion cell axons-which lie in the optic nerve fiber layer between stimulating electrodes and their intended targets, and which originate from a relatively diffuse peripheral region-would probably convey the perception of a peripheral blur, detracting from the usefulness of the imagery. Inspired by related findings in brain and peripheral nerve stimulation, experiments were performed in the isolated rabbit retina to determine if excitation thresholds for ganglion cell axons could be raised by orienting the stimulating electric field perpendicularly to the axons' path. Using a custom-designed apparatus, axon (and possibly dendrite) thresholds were measured for stimulation through a micro-fabricated array of disk electrodes each having a diameter of ten microns. The electrodes were driven singly versus a distant return (monopolar stimulation) and in pairs (bipolar stimulation) oriented along fibers (longitudinal orientation) or across fibers (transverse orientation). Transverse thresholds were measured for a range of fiber displacements between the two poles of the bipolar electrode pair, and compared in each case with the monopolar threshold for the closer pole. Transverse/ monopolar threshold ratios were near unity when one of the poles was directly over the fiber, but rose rapidly with improved centering of the bipolar pair. Longitudinal/monopolar threshold ratios were near unity over the same range of displacements. As in previous work by others, thresholds were highest for perpendicular stimulating fields. Practical application of this result will require electrode designs which minimize longitudinal fringing fields.
by Andrew Eli Grumet.
Ph.D.
4
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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Al-Mutawaly, Nafia DeBruin Hubert. "Neuro magnetic stimulation : engineering aspects /." *McMaster only, 2002.
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Schlepütz, Marco [Verfasser]. "Electric field stimulation of precision-cut lung slices / Marco Schlepütz." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2011. http://d-nb.info/101818919X/34.
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Druhan, Jonathan Peter. "Pharmacological assessment of the relationship between cue properties and rewarding effects of electrical stimulation of the ventral tegmental area." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25382.
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The present series of experiments was designed to assess the utility of a discrimination procedure for measuring the affective properties of rewarding brain-stimulation. If the rewarding and discriminative stimulus properties of electrical brain stimulation were related, they may share a common substrate and be affected similarly by the same pharmacological manipulations.
In Experiment 1, a discrimination procedure was developed to measure the cue properties of EBS delivered to the ventral tegmental area (VTA). Rats with VTA electrodes were trained to obtain food pellets by making a discriminated operant response on one of two levers following pulses of high intensity stimulation, or on the alternate lever after low intensity pulses. Following training, the rats were given tests in which generalized responding to intermediate intensities was measured. These tests were repeated either with conditions kept constant, or with the absolute intensities of the cues delivered within a sesion increased or decreased relative to baseline. The tests with higher or lower intensity ranges were intended to mimic the conditions that might prevail if the perceived intensities of the EBS were modified by drugs. The results of this experiment indicated that generalization gradients remained stable across three tests with conditions kept constant. When higher or lower current ranges were delivered, the discriminated responses were appropriately biased towards one lever or the other, resulting in lateral shifts in the generalization gradients. These results verified that the discrimination procedure provided a stable measure of the EBS stimulus properties, and that this measure was sensitive to changes in the intensities of the cues.
In Experiment 2, tests for EBS generalization and self-stimulation (ICSS) were given after injections of vehicle, d-amphetamine (1.0 mg/kg and 2.0 mg/kg) and haloperidol (.075 mg/kg and .10 mg/kg). The results indicated that these doses of amphetamine and haloperidol did not affect the EBS generalization. However, during ICSS sessions, 2.0 mg/kg amphetamine decreased threshold and increased rates for ICSS whereas .10 mg/kg haloperidol resulted in an increase in threshold. These results suggest a dissociation of the stimulus properties of EBS from the DA reward substrate.
In Experiment 3, the rats were tested for generalization after injections of physostigmine (.25 mg/kg and .50 mg/kg), scopolamine (.10 mg/kg and .25 mg/kg) and vehicle. Only the high dose of physostigmine (.50 mg/kg) produced significant differences in responding in this experiment. After injection of this drug, lower intensity stimuli elicited responding on the lever appropriate for the high current intensity, indicating a possible augmentation of the stimulus property of a fixed intensity of brain stimulation.
The results of this study indicate that the cue properties of VTA brain-stimulation are dissociable from EBS reward related to the activation of DA neurons. However, evidence is provided which suggests that cholinergic neurons may be involved in the mediation of the EBS cues. In as much as cholinergic neurons are also involved in the rewarding effects of VTA brain-stimulation, these results may indicate a relationship between the cue properties of VTA EBS and an acetylcholine reward system.Arts, Faculty of
Psychology, Department of
Graduate
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Hjeltnes, Nils. "Physical exercise and electrical stimulation in the management of metabolic, cardiovascular and skeletal-muscle alterations in people with tetraplegia /." Stockholm, 1998. http://diss.kib.ki.se/search/diss.se.cfm?19980529hjel.
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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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Shim, Ji Wook. "Development of 32-channel electrotactile stimulation system /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1426104.
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Mattar, Jessy. "Stimulation of the fermentation by pulsed electric fields : Saccharomyces cerevisiae case." Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2196/document.
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L’intégration croissante des procédés innovants comme les ultrasons, les champs magnétiques, et les champs électriques pulsés a pour but d’améliorer et de stabiliser le déroulement des procédés de fermentation. Le champ électrique pulsé (CEP) est un procédé athermique généralement utilisé pour l’inactivation des pathogènes (Barbosa-Cánovas et al., 2001) ainsi que pour l’extraction des composés intracellulaires d’intérêt (El Zakhem et al., 2006a; Vorobiev & Lebovka 2006). Dans ce travail de thèse, nous proposons d’évaluer l’activité microbienne des cellules soumises à un traitement électrique modéré. Un intérêt particulier est apporté à des aspects fondamentaux comme la croissance et le métabolisme des cellules. Sur le plan technologique, le but fondamentale est de mettre en place et optimiser des protocoles de stimulation de microorganismes pour intensifier les bioprocédés. La fermentation de microorganismes stimulés par CEP a montré des cinétiques plus rapides que les levures non traitées. La stimulation de l’activité fermentaire s’est révélée grâce au suivi de la masse du milieu, les solutés solubles, l’absorbance, les sucres... L’optimisation des protocoles de stimulation a permis de réveler deux comportements logarithmique et saturé. Il a été montré une dépendance importante de l’énergie spécifique sur certains aspects physiologiques notamment la taille et le nombre de coloniesThe continually increasing integration of innovative technologies such as ultrasound, magnetic fields, and pulsed electric fields aims to improve and stabilize the course of fermentation processes. The pulsed electric field (PEF) is an athermal process generally used for pathogen inactivation (Barbosa-Canovas et al., 2001) and for the extraction of intracellular compounds of interest (El Zakhem et al., 2006a; Vorobiev & Lebovka 2006). In this thesis, we propose to evaluate the microbial activity of cells subjected to a moderate electric treatment. Special consideration is given to key aspects such as growth and cell metabolism. Technologically, the fundamental purpose is to implement and optimize microorganisms’ stimulation protocols to intensify their bioprocesses. The positive impact of PEF pre-treatment on yeast cells was shown by their faster fermentation kinetics compared to the control. This was proven by monitoring the weight of the ferment, the soluble solutes, the UV absorbance, and sugar consumption profiles. Two behaviors of electrostimulation, “logarithmic” and “saturated”, were revealed by optimization of the stimulation protocols. Finally, a relationship between the growth rate, the size of the colonies and the applied specific energy is deduced
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Maezawa, Hitoshi. "Somatosensory evoked magnetic fields following electric tongue stimulation using pin electrodes." Kyoto University, 2009. http://hdl.handle.net/2433/124268.
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Hughes, Richard Owain. "Improving the focality of magnetic stimulation coils." Thesis, Swansea University, 2012. https://cronfa.swan.ac.uk/Record/cronfa43024.
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Lai, Sin-yi, and 賴善怡. "Effects of low current electrical stimulation of neck muscles on voicing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B46339188.
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Alcorn, Justin Dow. "Osteogenic effect of electric muscle stimulation as a countermeasure during hindlimb unloading." Texas A&M University, 2003. http://hdl.handle.net/1969.1/5816.
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Rats that undergo hindlimb unloading (HU) as a simulation for space flight
experience bone changes similar to astronauts in microgravity. The purpose of this
research was to assess whether an exercise countermeasure would be effective in
preventing or mitigating bone degradation during HU. Controlled electrical muscle
stimulation was applied to the lower left hindlimb to simulate resistive exercise.
Adult 6-mo. old male rats were assigned to 3 groups of 12 each: hindlimb
unloaded (HU), aging cage control (CC), and baseline (BL). The CC group was pair-fed
to match the nutritional intake of HU animals during the 28 days of the study. The left
leg was exercised 3 days a week for the duration of the study, with the unexercised right
leg serving as a contra-lateral control. Mechanical tests were conducted to assess the
strength of cancellous bone in the proximal tibia metaphysis. Although isolated
specimens of cancellous bone are not feasible, reduced platen compression (RPC) was
employed to directly load only the cancellous core region of each specimen.
There was no significant difference in ultimate stress or elastic modulus between
BL, CC, and HU-Ex (exercised). However, HU-Ex results were dramatically and
significantly higher than HU-No Ex (contra-lateral unexercised control) for both
ultimate stress (68%) and elastic modulus (81%). It is also notable that ultimate stress
was 32% higher (but not statistically significant) for HU-Ex compared to CC. The total
bone mineral density in the tibial metaphysis was significantly larger, 11%, in the HUEx
compared to the HU-No Ex group's values. The results clearly demonstrate the
efficacy of the exercise protocol in preventing the substantial mechanical deterioration
induced by HU.
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Polinkovsky, Arkady A. "Insertion Point Eccentricity Controlled Ankle Mechanism in Conjunction with Functional Electric Stimulation." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1279679194.
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Choi, Angela Sio-van. "The design of a versatile magnetic stimulator." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29928.
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A magnetic stimulator consisting of a capacitor discharge and associated control circuits was designed and constructed for use in research and practice. This stimulator is capable of delivering an output voltage of 1000 V and output peak current of 8 kA to a coil. Depending on the coil used, the rise time of the current pulse can be varied in steps of 30 µs or less. After each discharge, the stimulator measures the output current amplitude to within 0.2 kA and rise time to within 10 µs, and displays their values on a liquid crystal panel. The stimulator can operate in pulsed or in repetitive discharge mode (1 pulse per 5 seconds). With minor modifications, the stimulator can operate up to 1600 V and provide up to 16 kA. The rise time can be changed in steps of 10 µs or less.
The capability to provide output current of variable rise time makes this stimulator is a versatile instrument for both research and clinical use of magnetic stimulation. This feature, which is found in no other stimulating instrument, is important for studying the effect of current rise time on magnetically induced stimulation. With this device we can determine the optimum current pulse shape for effective stimulation with the minimum energy.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
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Lee, Dongchul C. "STRUCTURE-FUNCTION RELATIONSHIPS IN CENTRAL NERVOUS SYSTEM NEURONS ACTIVATED BY EXTRACELLULAR ELECTRIC FIELDS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=case1089749205.
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Rosie, Juliet. "The immediate effects of EMG-triggered neuromuscular electrical stimulation on cortical excitability and grip control in people with chronic stroke." Click here to access this resource online, 2009. http://hdl.handle.net/10292/731.
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AIM The aim of this study was to identify the immediate effects on cortical excitability and grip control of a short intervention of EMG-triggered neuromuscular electrical stimulation, compared to voluntary activation of the finger flexor muscles, in people with chronic stroke. STUDY DESIGN This experimental study used a within-subject design with experimental and control interventions. PARTICIPANTS Fifteen people with chronic stroke participated in the study. INTERVENTION Participants performed a simple force tracking task with or without EMG-triggered neuromuscular electrical stimulation of the finger flexor muscles. MAIN OUTCOME MEASURES Cortical excitability was measured by single and paired-pulse transcranial magnetic stimulation. Multi-digit grip control accuracy was measured during ramp and sine wave force tracking tasks. Maximal grip strength was measured before and after each intervention to monitor muscle fatigue. RESULTS No significant increases in cortico-motor excitability were found. Intracortical inhibition significantly increased following the EMG-triggered neuromuscular electrical stimulation intervention immediately post-intervention (t = 2.466, p = .036), and at 10 minutes post-intervention (t = 2.45, p = .04). Accuracy during one component of the force tracking tasks significantly improved (F(1, 14) = 4.701, p = .048), following both EMG-triggered neuromuscular electrical stimulation and voluntary activation interventions. Maximal grip strength reduced significantly following both interventions, after the assessment of cortical excitability (F(1, 8) = 9.197, p = .16), and grip control (F(1, 14) = 9.026, p = .009). CONCLUSIONS EMG-triggered neuromuscular electrical stimulation during short duration force tracking training does not increase cortical excitability in participants with chronic stroke. Short duration force tracking training both with and without EMG-triggered neuromuscular electrical stimulation leads to improvements in training-specific aspects of grip control in people with chronic stroke.
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Kara, Prakash. "Processing of transient stimuli by the visual system of the rat." Master's thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/26626.
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While three decades of intensive cortical electrophysiology using a variety of sustained visual stimuli has made a significant contribution to many aspects of visual function, it has not supported the existence of intracortical circuit operations in cortical processing. This study investigated cortical processing by a comparison of the response of primary visual cortical neurones to transient electrical and strobe-flash stimulation. Experiments were performed on 74 anaesthetised Long Evans rats. Standard stereotaxic and extracellular electrophysiological techniques were employed. Continuous (on-line) raster plots and peri-stimulus time histograms (PSTHs) of the extracellular spikes from 81 visual cortical and 55 lateral geniculate nucleus (LGN) neurones were compiled. The strobe-flash stimuli (0.05 ms) were applied to the contralateral eye while the monopolar or bipolar electrical stimuli (0.2 ms, 80-400 μA) were applied to the ipsilateral LGN. 60 of the 81 (74%) tested cortical units were found to be responsive to visual stimuli. A distinct and consistent difference in the cortical response to the two types of transient stimuli was found: (a) Electrical stimulation evoked a prolonged period (197 ± 61 ms) of inhibition in all cortical neurones tested (n=20). This was the case even in those cortical units that were completely unresponsive to visual stimulation. The protracted inhibition was usually followed by a 100-200 ms phase of rebound excitation. (b) Flash stimulation evoked a prominent excitatory discharge (5-30 ms duration) after a latency of 30-60 ms from the onset of the stimulus (n = 59). This was followed by either moderate inhibition or return to a firing rate similar to control activity, for a maximum of 40 ms. Thereafter, cortical neurones showed a sustained increased level of activity with superimposed secondary excitatory phases. The duration of this late re-excitatory phase was 200-300 ms. In 17 of 20 (85%) tested units, the temporal profile of the cortical response to flash stimulation was modulated by small changes in the level of background illumination. In 16 of the 17 units, this sensitivity was reflected primarily as an emergence of a brief secondary inhibitory phase at the lowest level of background illumination (0 lux). Only 1 of the 17 cortical units displayed a flash-evoked primary inhibitory phase at O lux. We explored the possibility that neurones in the lateral geniculate nucleus (LGN) of the thalamus were responsible for the late phase of cortical reexcitation. 49 of the 55 (89%) LGN neurones could be classified as either of the "ON type" i.e. excited by visual stimuli, or the "OFF type" i.e. inhibited by visual stimuli. The response of ON-like LGN neurones to strobe-flash stimulation of the contralateral eye was characterised by a primary excitatory or early discharge (ED) phase after a latency of 25-40 ms. Thereafter, a 200- 400 ms period of inhibition was observed. In 57% of the sample, a rebound excitatory or late discharge (LD) phase completed the response. OFF-like LGN neurones were inhibited by the strobe-flash stimuli after a latency of 30- 35 ms. This flash-evoked inhibition was maintained for 200-400 ms. The sensitivity of the flash-evoked LGN response to the level of background illumination was tested in 11 ON-like and 10 OFF-like neurones. No sustained secondary excitatory events, as observed in visual cortical neurones, were found in any of the ON- and OFF-like LGN neurones, irrespective of the level of background illumination. In conclusion, the data show that the late re-excitatory phase evoked in cortical neurones upon strobe-flash stimulation, is not due to sustained LGN (thalamic) input. Rather, it suggests that these re-excitatory phases are due to intracortical processing of the transient stimuli. These findings emphasize the independent role of the cortex in computing the response to visual stimuli, and cast doubt on traditional theories that have emphasised the role of the thalamus in shaping cortical responses. The difference in the flash and electrically evoked cortical response suggests that even though substantial inhibition is available to the cortex, only a small fraction of this inhibitory capacity is utilised during natural stimulation.
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Vu, Hung Quoc. "Short Term Effects of External Electric Fields on Electrical Activity of the Pineal Gland in Rats." Thesis, University of North Texas, 1996. https://digital.library.unt.edu/ark:/67531/metadc277728/.
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The effects of short term exposure (5 minutes) to EEFs at relatively high dosages (10, 25, 39, kV/m) on the electrical activity in rat pineal glands was studied.
Daytime and nighttime recordings were taken from an implanted microelectrode in the gland. The data show that (1) both the activity and frequency were enhanced when the
animals were exposed to EEFs at 39 kV/m continuously and discontinuously; (2) the later condition yielded a sustained increase (36%) whereas the former a brief (10 sec) increase. This enhancement was statistically significant under both conditions (day and night). The effects observed were thought to be due to membrane alterations either in the pineal gland itself or in the neural inputs to the gland.
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Zolj, Adnan. "Electrically Small Dipole Antenna Probe for Quasi-static Electric Field Measurements." Digital WPI, 2018. https://digitalcommons.wpi.edu/etd-theses/202.
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The thesis designs, constructs, and tests an electrically small dipole antenna probe for the measurement of electric field distributions induced by a transcranial magnetic stimulation (TMS) coil. Its unique features include high spatial resolution, large frequency band from 100 Hz to 300 kHz, efficient feedline isolation via a printed Dyson balun, and accurate mitigation of noise. Prior work in this area is thoroughly reviewed. The proposed probe design is realized in hardware; implementation details and design tradeoffs are described. Test data is presented for the measurement of a CW capacitor electric field, demonstrating the probe’s ability to properly measure conservative electric fields caused by a charge distribution. Test data is also presented for the measurement of a CW solenoidal electric field, demonstrating the probe’s ability to measure non-conservative solenoidal electric fields caused by Faraday’s law of induction. Those are the primary fields for the transcranial magnetic stimulation. Advantages and disadvantages of this probing system versus those of prior works are discussed. Further refinement steps necessary for the development of this probe as a valuable TMS instrument are discussed.
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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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Rader, Tobias [Verfasser]. "Speech Perception of Cochlear Implanted Patients with Combined Electric-Acoustic Stimulation / Tobias Rader." München : Verlag Dr. Hut, 2012. http://d-nb.info/102424282X/34.
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Smith, Zachary M. (Zachary Mark). "Binaural interactions in the auditory midbrain with bilateral electric stimulation of the cochlea." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36166.
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Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2006.Includes bibliographical references (p. 135-141).
Bilateral cochlear implantation seeks to restore the advantages of binaural hearing to the profoundly deaf by giving them access to binaural cues normally important for accurate sound localization and speech reception in noise. This thesis characterizes binaural interactions in auditory neurons using a cat model of bilateral cochlear implants. Single neuron responses in the inferior colliculus (IC), the main nucleus of the auditory midbrain, were studied using electric stimulation of bilaterally implanted intracochlear electrode arrays. Neural tuning to interaural timing difference (ITD) was emphasized since it is an important binaural cue and is well represented in IC neural responses. Stimulation parameters were explored in an effort to find stimuli that might result in the best ITD sensitivity for clinical use. The majority of IC neurons were found to be sensitive to ITD with low-rate constant-amplitude pulse trains. Electric ITD tuning was often as sharp as that with acoustic stimulation in normal-hearing animals, but many neurons had dynamic ranges of ITD sensitivity limited to a few decibels. Consistent with behavioral results in bilaterally implanted humans, neural ITD discrimination thresholds degraded with increasing pulse rates above 100 pulses per second (pps).
(cont.) Since cochlear implants typically encode sounds by amplitude modulation (AM) of pulse-train carriers, ITD tuning of IC neurons was also studied using AM pulse trains. Many IC neurons were sensitive to ITD in both the amplitude envelope and temporal fine structure of the AM stimulus. Sensitivity to envelope ITD generally improved with increasing modulation frequency up to 160 Hz. However, the best sensitivity was to fine structure ITD of a moderate-rate (1000 pps) AM pulse train. These results show that bilateral electric stimulation can produce normal ITD tuning in IC neurons and suggest that the interaural timing of current pulses should be accurately controlled if one hopes to design a bilateral cochlear implant processing strategy that provides salient ITD cues. In additional experiments, we found that evoked potentials may be clinically useful for assigning frequency-channel mappings in bilateral implant recipients, such as pediatric patients, for which existing psychophysical methods of matching interaural electrodes are unavailable.
by Zachary M. Smith.
Ph.D.
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Guduru, Rakesh. "Bionano Electronics: Magneto-Electric Nanoparticles for Drug Delivery, Brain Stimulation and Imaging Applications." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/979.
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Nanoparticles are often considered as efficient drug delivery vehicles for precisely dispensing the therapeutic payloads specifically to the diseased sites in the patient’s body, thereby minimizing the toxic side effects of the payloads on the healthy tissue. However, the fundamental physics that underlies the nanoparticles’ intrinsic interaction with the surrounding cells is inadequately elucidated. The ability of the nanoparticles to precisely control the release of its payloads externally (on-demand) without depending on the physiological conditions of the target sites has the potential to enable patient- and disease-specific nanomedicine, also known as Personalized NanoMedicine (PNM). In this dissertation, magneto-electric nanoparticles (MENs) were utilized for the first time to enable important functions, such as (i) field-controlled high-efficacy dissipation-free targeted drug delivery system and on-demand release at the sub-cellular level, (ii) non-invasive energy-efficient stimulation of deep brain tissue at body temperature, and (iii) a high-sensitivity contrasting agent to map the neuronal activity in the brain non-invasively. First, this dissertation specifically focuses on using MENs as energy-efficient and dissipation-free field-controlled nano-vehicle for targeted delivery and on-demand release of a anti-cancer Paclitaxel (Taxol) drug and a anti-HIV AZT 5’-triphosphate (AZTTP) drug from 30-nm MENs (CoFe2O4-BaTiO3) by applying low-energy DC and low-frequency (below 1000 Hz) AC fields to separate the functions of delivery and release, respectively. Second, this dissertation focuses on the use of MENs to non-invasively stimulate the deep brain neuronal activity via application of a low energy and low frequency external magnetic field to activate intrinsic electric dipoles at the cellular level through numerical simulations. Third, this dissertation describes the use of MENs to track the neuronal activities in the brain (non-invasively) using a magnetic resonance and a magnetic nanoparticle imaging by monitoring the changes in the magnetization of the MENs surrounding the neuronal tissue under different states.
The potential therapeutic and diagnostic impact of this innovative and novel study is highly significant not only in HIV-AIDS, Cancer, Parkinson’s and Alzheimer’s disease but also in many CNS and other diseases, where the ability to remotely control targeted drug delivery/release, and diagnostics is the key.
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Rosen, Andrew M. "Effects of paired-pulse electrical stimulation of the chorda tympani nerve on cells in the nucleus of the solitary tract of the rat." Diss., Online access via UMI:, 2008.
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Widerström-Noga, Eva. "Analgesic effects of somatic afferent stimulation a psychobiological perspective /." Göteborg : Dept. of Physiology, University of Göteborg, 1993. http://catalog.hathitrust.org/api/volumes/oclc/30761064.html.
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Schroeder, Mark James. "Acquisition and quantitative analyses of EEG during CES and during concurrent use of CES and neurofeedback /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Meacham, Kathleen Williams. "Selective surface activation of motor circuitry in the injured spinal cord." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26571.
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Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2009.Committee Co-Chair: Shawn Hochman; Committee Co-Chair: Stephen P. DeWeerth; Committee Member: Lena Ting; Committee Member: Robert J. Butera; Committee Member: Robert Lee; Committee Member: Vivian K. Mushahwar. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Sundeen, Garfield Byron. "The effect of electrical stimulation on some parameters of postmortem avian muscle." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/29435.
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Four studies were conducted to assess the use of electrical shock on several parameters of avian muscle that contribute to its ultimate quality.
In the preliminary study, the effect of preslaughter electric stunning on the tenderness of broilers processed and handled in a standard commercial manner was assessed. The tenderness of cooked breast muscle samples was evaluated by Kramer single blade shear force values. This evaluation indicated that samples from the electrically stunned birds were significantly more tender than those from the no stun controls (p<0.01).
The effects of varying the duration, frequency and voltage of a
post-exsanguination stimulatory current on the development of rigor mortis and the postmortem glycolytic rate were investigated in Study One. The pH of muscle homogenates at various postmortem sampling times was used as an index of glycolysis whereas rigor development was monitored by the isometric tension technique. Postmortem glycolysis in Biceps femoris and Pectoral is major samples was accelerated by electrical stimulation, as was the time course of rigor development. Pectoral is major samples from treated carcasses required significantly less time to develop maximum tension than control samples (p<0.05). Although Biceps femoris samples from stimulated carcasses also exhibited decreases in the time required to achieve maximum tension when compared to controls, these differences were not significant.
Pectoral is maj or samples from carcasses treated with 70V for 2 minutes at either 40 or 80 pulses/s developed significantly lower tension than control samples (p<0.05). No significant differences due to the voltage or total number of pulses were observed for either the time required to achieve maximum tension or the maximum tension developed.
The influence of electrical stimulation on the development of rigor was further examined in Study Two. Rigor development again was monitored by the isometric tension technique and changes in metabolite contents for both muscle types were determined by enzymatic analytical techniques. Electrical stimulation reduced the time required by Biceps femoris and Pectoral is major samples to reach maximum tension but this decrease was only significant for the latter (p<0.05). The amount of isometric tension developed by both muscle types was similarly reduced by electrical stimulation.
The initial glycogen and ATP contents of both muscles were reduced by electrical stimulation, as were their ATP contents at subsequent sampling periods. Several correlations between the parameters of isometric tension and metabolite contents were noted and regression equations were developed to express the significant relationships. No significant differences due to electrical stimulation in the rate of isometric tension release were observed, but Pectoralis major samples from stimulated carcasses released their developed tension more rapidly than their respective Biceps femoris samples.
In the final study, Study Three, the effect of electrical stimulation on muscle proteolytic activity was assessed by two analytical methods for TCA soluble material. In addition, changes in protein extractability, dispersibility and hydrophobicity were followed in control and treated samples during storage for one day at 2°C.
Electrical stimulation significantly reduced the time required to reach maximum tension (p<0.05) and decreased the maximum tension achieved for Pectoralis major and Biceps femoris muscle samples. Pectoralis major samples from treated carcasses again released their developed tension faster than their respective Biceps femoris samples.
When the muscle samples were analysed for nonprotein nitrogen, neither measure indicated a significant treatment effect. In a similar manner, neither extractable protein, protein dispersibility nor protein hydrophobicity were affected by electrical stimulation.Land and Food Systems, Faculty of
Graduate
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Maladen, Ryan D. "Effect of stimulation train characteristics on the dynamic performance of human skeletal muscle." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 0.38 Mb., 57 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:1435807.
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Andersson, Stina. "Gastric electrical stimulation studies in patients with intractable nausea and comiting /." Göteborg : Dept. of Internal Medicine, Institute of Medicine at Sahlgrenska Academy, Sahlgrenska University Hospital, University of Gothenburg, 2010. http://hdl.handle.net/2077/21862.
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Macdougall, Hamish G. "The human eye-movement response to maintained surface galvanic vestibular stimulation." Phd thesis, School of Psychology, 2003. http://hdl.handle.net/2123/10402.
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Suaning, Gregg J????rgen Graduate School of Biomedical Engineering Faculty of Engineering UNSW. "Engineering and acute physiological testing of a retinal neurostimulator." Awarded by:University of New South Wales. Graduate School of Biomedical Engineering, 2003. http://handle.unsw.edu.au/1959.4/19203.
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Electrical stimulation of retinal neurons is known to elicit visual sensations. When applied to the retina in a spatial pattern, electrical stimulation may be capable of providing rudimentary patterned vision that may be of benefit to sufferers of degenerative retinal disorders. No such device has yet been devised to provide for chronic study of the psychophysical perceptions elicited from a prosthesis for retinal stimulation. In this study, steps towards achieving this goal have been successfully carried out. Foregoing research was reviewed such that appropriate stimulation parameters were incorporated in the design of a 100 stimulation channel, complimentary metal oxide semiconductor (CMOS) integrated circuit, small enough in size so as to be capable of being implanted within the ocular anatomy or surrounding orbit. The device, and its associated external hardware and software were designed, modeled, fabricated, and interfaced with stimulating electrodes in acute testing in a highorder mammal (Ovis aries) so as to assess the capabilities of the device to elicit cortical potentials as a direct result of stimulation of the neural retina. Testing was performed under conditions similar to those anticipated in chronic in-situ configurations wherein radio-frequency telemetry was used to deliver power and configuration parameters to the device thus avoiding the passage of wires through tissue in order to communicate to the implant circuit. The results of the testing indicate that the circuit is indeed capable of eliciting physiological responses in the animal and evidence is present that these responses could be elicited in patterned form. Further work undertaken includes the development of surgical methods for implantation, and application of the prosthesis circuit in functional electronic stimulation.
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LEEMING, MICHAEL NEWBOLD. "CARDIOPULMONARY AND EPIDERMAL EFFECTS OF ELECTRICAL STIMULATION IN THE CANINE: A STUDY IN ENGINEERING PSYCHOLOGY." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184077.
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The well-known field of engineering psychology, also known as human factors engineering, utilizes psychologists to solve Engineering's problems that concern the behavior of humans in their operation and control of engineering systems such as military aircraft. To limit psychology's relation to engineering this way is, however, counterproductive. Psychology requires a broader conceptualization of engineering psychology, a subfield of psychology, within which the psychologist's major concern is with the behavior of psychoengineering systems that affect the reliability, validity and safety of psychological research and practice. In contrast with human-factor systems, the psychoengineering systems include healthy and unhealthy, human and animal subjects. The affiliated problems are not those of the engineering industry. This study in engineering psychology concerned the safety of two electrical stimulation systems that are used on animals, chiefly dogs, in punishment and escape/avoidance conditioning procedures of psychology. The study referenced two safety questions. First, is the electricity, when applied externally to the ventral neck of the animal, capable of stimulating carotide sinus and vagus nerves to the point of dangerously disrupting systemic blood pressure and sinus rhythm? Second, is the electricity capable of damaging the epidermis when it is applied repeatedly to the same two points of contact? Of forty-two anesthetized dogs, half were tested with a punishment system; the remainder were tested with an escape/avoidance system. Each was stimulated for five seconds, five times, at each of five intensities. Inter-stimulus interval was about thirty seconds. Systemic blood pressures and electrocardiograms (ECG) were recorded. Control and experimental biopsies were taken for histological examinations of electrified and unelectrified specimens. Each animal's neck was examined grossly each day for ten days following the stimulation runs. None of the gross examination reports was positive. An exact binomial test supported the hypothesis that tissue samples from control and experimental biopsies did not differ histologically. Repeated measure ANOVAs were used to detect significant differences in systolic pressures, diastolic pressures, and R to R intervals of the ECG throughout stimulation runs. While there were some statistically significant results, there was no clinical significance, especially with regard to safety hazards.
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Harvey, Mordecai Micah. "Characterization of an in vitro exercise model and the effects of a metabolic endotoxemia on skeletal muscle adaptation to electric pulse stimulation." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/78235.
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The prevalence of obesity and type II diabetes is increasing. Although exercise is widely accepted for prevention and treatment, evidence of resistance to exercise in patients with these diseases is also mounting. Muscle contraction during exercise stimulate cellular responses important for adaptation. These responses include the release of myokines and the subsequent increase in substrate metabolism. This study aimed to define a culture model for simulating exercise in human primary skeletal muscle cells. We hypothesized that chronic electric pulse stimulation (EPS) of human myotubes in vitro would emulate cellular and molecular responses to exercise observed in vivo. To define this model, we applied EPS to human myotubes for varied lengths of time and measured interleukin-6 (Il-6), peroxisome proliferator-activated receptor gamma coactivator 1- (PGC1-), superoxide dismutase 2 (SOD2), substrate metabolism, metabolic enzyme activity, heat stress markers, and pH. To recreate the inflammatory milieu observed in metabolic disease states we treated the myotubes with a low dose of 20 EU lipopolysaccharide (LPS). Following the 24-hour stimulation we observed significant increases in transcription of Il-6, PGC1-, and SOD2. Basal glucose and fatty acid oxidation were also markedly increased in the cells after EPS. Cells treated with LPS elicited a blunted transcriptional, metabolic, and enzymatic response to EPS. These findings suggest that EPS is a viable model for simulating the effects of exercise. Our observations also indicate that an inflammatory environment could play a role in interfering with the adaptations to exercise.Ph. D.
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Hanekom, Tania. "Modelling of the electrode-auditory nerve fibre interface in cochlear prosthesis." Pretoria : [s.n.], 2001. http://upetd.up.ac.za/thesis/available/etd-09052001-132021.
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Taghian, Toloo. "Interaction of an Electric Field with Vascular Cells." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439309071.
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Hunold, Alexander [Verfasser], Jari Akademischer Betreuer] Hyttinen, Alexander [Akademischer Betreuer] Opitz, and Jens [Gutachter] [Haueisen. "Transcranial electric stimulation : modeling, application, verification / Alexander Hunold ; Gutachter: Jens Haueisen ; Jari Hyttinen, Alexander Opitz." Ilmenau : TU Ilmenau, 2021. http://d-nb.info/1241044961/34.
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Rubinstein, Jay T. "Quasi-static analytical models for electrical stimulation of the auditory nervous system /." Thesis, Connect to this title online; UW restricted, 1988. http://hdl.handle.net/1773/8073.
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Кіріл'єва, А. В., Ірина Миколаївна Сотник, Ирина Николаевна Сотник, and Iryna Mykolaivna Sotnyk. "Electric car market: problems and prospects of development." Thesis, Teadmus OÜ, 2021. https://essuir.sumdu.edu.ua/handle/123456789/84259.
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Проаналізовано динаміку розвитку світового ринку електромобілів. Визначено переваги і недоліки електротранспорту. Проаналізовано механізми економічного стимулювання розвитку ринку електромобілів у різних країнах світу на перспективу.Проанализирована динамика развития мирового рынка электромобилей. Определены преимущества и недостатки электротранспорта. Проанализированы механизмы экономического стимулирования развития рынка электромобилей в разных странах мира на перспективу.
The dynamics of the electric cars world market development is analyzed. The advantages and disadvantages of electric vehicles are identified. The mechanisms of economic stimulation of the electric car market development in different countries worldwide for the future are analyzed.
The publication was prepared in the framework of the research projects "Formation of economic mechanisms for sustainable development of renewable energy in the conditions of global and local threats to energy security of Ukraine" (№ 0120U104806) funded by the National Research Foundation of Ukraine and "Fundamentals of the phase transition to the additive economy: from disruptive technologies to institutional sociologization of decisions" (No. 0121U109557) funded by a grant from the state budget of Ukraine.
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Chou, Li-Wei. "New strategies to maintain paralyzed skeletal muscle force output during repetitive electrical stimulation." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 147 p, 2007. 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:3247571.
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Johnson, Lise. "DECODING ELECTRIC FIELDS OF THE NERVOUS SYSTEM: INVESTIGATIONS OF INFORMATION STORAGE AND TRANSFER IN THE CENTRAL AND PERIPHERAL NERVOUS SYSTEM." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/193574.
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Electrical potentials are the fundamental currency of communication in the nervous system. The advanced executive functions of the prefrontal cortex and the motor commands delivered to the neuromuscular junction, though involved with very different aspects of behavior, both rely on time-varying electrical signals. It is possible to "listen to" the internal communications of the nervous system by measuring the electrical potentials in the extra-cellular space. However, this is only meaningful if there is some way to interpret these signals, which are incredibly complicated and information rich. This dissertation represents an attempt to decode some of these signals in order to reveal their significance for behavior and function. The first study is an investigation of the relationship between different elements of the local field potential in the prefrontal cortex and memory consolidation. It is shown that certain electrographic signatures of non-rapid eye movement sleep, namely K-complexes and low-voltage spindles, are correlated with neuronal replay of recent experiences. It is also shown that the global fluctuations of activity in the population of cells, known as up/down states, is correlated with neuronal replay. Finally, it is shown that high-voltage spindles are not correlated with memory replay, and are therefore functionally different from low-voltage spindles. The second study focuses on the relationship between movements of the upper limb and the coordinated neural control, as measured by the electromyogram (EMG), of the muscles generating that movement. We show that different probability-based models can be used to predict what the pattern of EMG in the different muscles will be for any given kinematic state of the hand. In the third study it is demonstrated that the kinematic output associated with a particular pattern of EMG can be reproduced with electrical stimulation. Thus, it is not only possible to understand the commands issued by the nervous system, it is also possible to issue commands by interfacing with the nervous system directly. Finally, the design for an experiment that would combine EMG prediction with translation of EMG into electrical stimulus patterns is presented. The objective of this study would be to use these methods to fully control the upper limb in a way that would be useful for a functional electrical stimulation-based neuroprosthetic for spinal cord injured patients.
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LIMA, Mayara Fernanda Campêlo Borba de. "Neuromodulação por estimulação não invasiva do sistema nervoso central associada ao exercício físico: Estudo da excitabilidade medular." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/18282.
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CNPQ
O exercício físico e as estimulações não invasivas do sistema nervoso central (SNC) são capazes de promover neuroplasticidade do SNC. Dentre as estimulações não invasivas destaca-se a estimulação transcraniana magnética repetitiva (EMTr) e, mais recentemente, a estimulação transcutânea medular por corrente contínua (ETMCC). O uso associado do exercício físico com a EMT ou com a ETMCC parece modular reflexos medulares. Contudo, não há evidência sistemática quanto aos efeitos da ETMCC sobre a excitabilidade da medula espinal, nem evidência comparativa das associações da ETMCC e da EMTr com o exercício físico. Portanto, essa dissertação apresenta dois artigos originais. O primeiro estudo é uma revisão sistemática com meta-análise que teve por objetivo sumarizar e avaliar o nível de evidência da eficácia da ETMCC em modificar a atividade medular. Dos sete estudos da revisão sistemática, cinco foram incluídos na meta-análise do efeito da ETMCC anódica e quatro na meta-análise do efeito da ETMCC catódica. Não houve efeito significante da ETMCC anódica e catódica, quando comparadas à ETMCC sham. Com isso, o estudo 1 conclui que não há evidência da eficácia da ETMCC em modular a excitabilidade medular. O segundo estudo é um crossover, triplo-cego, sham controlado, randomizado e contrabalanceado realizado com adultos saudáveis. Seu objetivo foi investigar as repercussões, nas excitabilidades medular e cortical, da associação da EMTr e da ETMCC com o exercício físico. Doze voluntários (24,75±2,77) foram submetidos a seis sessões experimentais, intercaladas por um período de 5 a 7 dias. Em cada sessão, um tipo de estimulação não invasiva do SNC (ETMCC anódica, ETMCC catódica, ETMCC sham, EMTr 20 Hz, EMTr1 Hz e EMTr sham) foi isoladamente associado a 20 minutos de exercício físico na esteira (EFE), em intensidade moderada. As repercussões das associações foram investigadas por meio de dois desfechos, avaliados antes (baseline), imediatamente (T0), 30 (T1) e 60 minutos (T2) após as intervenções. A excitabilidade medular (desfecho primário) e a excitabilidade cortical (desfecho secundário) foram mensuradas, respectivamente, por meio do componente doloroso do reflexo de retirada da perna (RIII) e de potenciais evocados motores (PEM). O estudo dois revelou que as intervenções ETMCC catódica/EFE (baseline/T0) e ETMr 20Hz/EFE (baseline/T0) aumentaram a excitabilidade medular, enquanto a aplicação da ETMr 1Hz/EFE (baseline/T2) e da ETMr 20Hz/EFE (baseline/T0, baseline/T1, e baseline/T2 ) aumentaram os níveis de excitabilidade cortical. Com isso, o estudo crossover demonstra que as associações EMTr/EFE e ETMCC/EFE podem interferir na atividade do SNC, mas apenas a ETMr 20Hz/EFE foi capaz de, simultaneamente, modular as excitabilidades cortical e medular. Portanto, a associação de estimulações não invasivas/EFE é capaz de modular o SNC e os efeitos decorrentes parecem depender do tipo de estimulação não invasiva aplicada.
Physical exercise and central nervous system (CNS) non invasive stimulation techniques, including repetitive transcranial magnetic stimulation (rTMS) and transcutaneous spinal direct current stimulation (tsDCS), are able to promote CNS plasticity. Furthermore, the association between physical exercise and rTMS or tsDCS appears to promote spinal reflexes modulation. However, there are not systematic evidence about tsDCS effects on spinal reflexes. Similarly, there are no comparative study about an associative intervention of physical exercise and rTMS or tsDCS.Thus, this masters dissertation presents two originals articles. The first one is a systematic review with meta-analysis aimed to summarize and evaluate the level of evidence of tsDCS efficacy to modify spinal cord excitability. Seven studies were included on this systematic review. From these, five using anodal tsDCS and four using cathodal tsDCS were included on meta-analysis. The results indicated that there were not significant effects of anodal and cathodal tsDCS, when compared to sham tsDCS. Therefore, the first article concluded that there are not evidence of tsDCS efficacy to modulate spinal cord excitability. The second article is a crossover, triple-blind, sham controlled, randomized and counterbalanced study with healthy individuals. The aim of this study was to investigate the repercussions of the association between rTMS or tsDCS and physical exercise over CNS excitability. Twelve volunteers performed six experimental sessions. On each session, one type of CNS non invasive stimulation technique (anodal tsDCS, cathodal tsDCS, sham tsDCS, rTMS 20 Hz, rTMS 1 Hz or rTMS sham) was associated with 20 minutes of treadmill. An interval between five and seven days was assumed as washout period. The physical exercise (treadmill) was perfomed on moderate intensity and the CNS excitability was investigated by two outcomes measures, assessed at four different time points: before (baseline), immediately (T0), 30 (T1) and 60 (T2) minutes after the interventions. Spinal cord (primary outcome) and cortical (secondary outcome) excitabilities were assessed by the painful component of withdrawal reflex (RIII) and by motor evoked potentials (MEP), respectively. The result reveled that cathodal tsDCS/treadmill (baseline/T0) and rTMS 20HZ/treadmill (baseline/T0) increased spinal cord excitability. Additionally, rTMS1 Hz/treadmill (baseline/T2) and rTMS 20Hz/treadmill (baseline/T0, baseline/T1 and baseline/T2) increased cortical excitability. Thereby, the crossover study demonstrated that rTMS/treadmill and TsDCS/treadmill associative intervention are able to interfere on CNS excitability. However, only rTMS 20Hz/treadmill was able to modulate cortical and spinal cord activity. Therefore, CNS non invasive technique and physical exercise associative intervention can modify CNS excitability and the after effects seems to be dependent on the type of stimulation.
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Kinoshita, Masako. "Electric cortical stimulation suppresses epileptic and background activities in neocortical epilepsy and mesial temporal lobe epilepsy." Kyoto University, 2005. http://hdl.handle.net/2433/144790.
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Kyoto University (京都大学)0048
新制・課程博士
博士(医学)
甲第11466号
医博第2889号
新制||医||900(附属図書館)
23109
UT51-2005-D216
京都大学大学院医学研究科脳統御医科学系専攻
(主査)教授 福山 秀直, 教授 林 拓二, 教授 河野 憲二
学位規則第4条第1項該当
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Noury, Nima Verfasser], and Markus [Akademischer Betreuer] [Siegel. "Properties of transcranial electric stimulation artifacts in EEG and MEG recordings / Nima Noury ; Betreuer: Markus Siegel." Tübingen : Universitätsbibliothek Tübingen, 2018. http://d-nb.info/1173700021/34.
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Joseph, Laveeta. "Conduction block in peripheral nerves: effect of high frequency stimulation on different fiber types." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42723.
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Selective stimulation and conduction block of specific nerve fibers has been a major area of research in neuroscience. The potential clinical and neurophysiological applications have warranted reliable techniques for transiently blocking conduction through nerves. High Frequency Alternating Current (HFAC) waveforms have been found to induce a reversible and repeatable block in peripheral nerves; however the effect of these waveforms on the neural activity of individual fiber types is currently unknown. Understanding this effect is critical if clinical applications are to be pursued. This dissertation work utilized extracellular electrophysiological techniques to characterize the activity of different fiber type populations in peripheral nerves during application of HFAC waveforms. First, we investigated the phenomenon in the homogeneous unmyelinated nerves of the sea-slug, Aplysia californica. Although complete reversible block was demonstrated in these nerves, a non-monotonic relationship of block threshold to frequency was found which differed from previously published work in the field. We then investigated the effect of HFAC waveforms on amphibian mixed nerves and studied the response of specific fiber types by isolating different components of the compound action potential. We validated our results from the Aplysia nerves by determining the block thresholds of the larger diameter, myelinated A-fibers and comparing them with those of the smaller diameter, unmyelinated C-fibers. We also showed that block threshold behavior during application of the HFAC waveform depends on the nerve fiber type, and this property can be used to selectively block specific fiber types. Finally, we examined the recovery time after block induction in unmyelinated nerves and found that recovery from block was dependent on the duration of application of the HFAC waveform. The time-dependent distribution of the recovery time and the non-monotonic threshold behavior in the smaller diameter unmyelinated nerves indicate that multiple mechanisms are involved in block induction using HFAC waveforms, and these mechanisms are dependent not only on the blocking stimulus but also on the characteristics of the nerve fiber. Overall, this work demonstrates that HFAC waveforms may enable inherent peripheral nerve properties to be exploited for potential clinical applications related to the treatment of unwanted neural activity.
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Lund, Iréne. "Pain, its assessment and treatment using sensory stimulation techniques : methodological considerations /." Stockholm : Department of physiology and pharmacology, Karolinska institutet, 2006. http://diss.kib.ki.se/2006/91-7140-786-3/.
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Vargas, Estevez Carolina. "Suspended Micro/nanogenerators for cell stimulation." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/666193.
Full textAbstract:
Our bodies are complex machines whose functioning depends on multiple electrical signals controlled mainly by the nervous system. Afterwards, it is not illogical to think that one day artificial electrical impulses would replace those signals offering supports of medical treatments. Nowadays electrical stimulation is used in many therapeutic applications to modulate cellular activity, restore biological lost functions or even improve the performance of certain tissues. However, these systems still carry side effects link to the surgical interventions to place them or place their electrodes, their inherent bulkiness or lack in specificity to target only the cells involved in the condition to treat. The future to transcend these constrains would be possible in the extent that technology ease the path to improve precision, autonomy and miniaturization of the actual therapeutic tools. In this context, micro- and nanogenerators play a key role as self-powered devices with high spatial resolution and acute cell specificity.
This thesis aims to provide micro/nanogenerators to stimulate single cells in its own liquid media. This work explored two technological branches based on photovoltaic and on magnetoelastic (piezoelectric/magnetostrictive) devices to harvest energy. Their fabrication was accomplished through semiconductors microfabrication technologies and their performance was characterized through several tests to ensure their correct power generation. As these devices were intended to interface biological media, direct cytotoxicity studies were conducted to guarantee their safety. Both branches were biologically validated with in vitro models of excitable cells (embryonic mouse neurons and human osteoblast- like cells) analyzing the electrostimulation effects through morphological changes and through instantaneous ionic responses as calcium signaling. The results gathered in this research demonstrated the feasibility of these micro- and nanogenerators as self-powered electrical stimulators. Furthermore, their reduce size and capability to be suspended in liquid media open the door to further developments towards injected or ingested minimally invasive medical tools.Nuestros cuerpos son máquinas complejas cuyo funcionamiento depende de múltiples señales eléctricas controladas principalmente por el sistema nervioso. Así pues, no es ilógico pensar que un día los impulsos eléctricos artificiales reemplazarían aquellas señales dando soporte a los tratamientos médicos. En la actualidad, la estimulación eléctrica se utiliza en muchas aplicaciones terapéuticas para modular la actividad celular, restaurar funciones biológicas perdidas o incluso mejorar el rendimiento de ciertos tejidos. Sin embargo, estos sistemas aún presentan efectos secundarios ligados a las intervenciones quirúrgicas para colocarlos o colocar sus electrodos, a su volumen intrínseco o a la falta de especificidad para solo focalizar su actividad sobre las células involucradas en la enfermedad a tratar. El futuro para trascender estas limitaciones será posible en la medida en que la tecnología facilite el camino para mejorar la precisión, la autonomía y la miniaturización de las actuales herramientas terapéuticas. En este contexto, los micro/nanogeneradores juegan un papel clave como dispositivos autoalimentados con alta resolución especial y especificidad celular fina. Esta tesis pretende proporcionar micro/nanogeneradores de energía para estimular eléctricamente células individuales en su propio medio líquido. Este trabajo exploró dos ramas tecnológicas basadas en dispositivos fotovoltaicos y magnetoelásticos (piezoeléctricos / magnetoestrictivos) para transducir energía. Su fabricación se llevó a cabo a través de tecnologías de microfabricación de semiconductores y su rendimiento se caracterizó a través de varias pruebas para garantizar su correcta generación de energía. Como estos dispositivos estaban destinados a interconectar medios biológicos, se realizaron estudios de citotoxicidad directa para garantizar su seguridad. Ambas ramas se validaron biológicamente con modelos in vitro de células excitables (neuronas embrionarias de ratón y células de tipo óseo humanas) analizando los efectos de la electroestimulación a través de cambios morfológicos y a través de respuestas iónicas instantáneas como la señalización de calcio. Los resultados reunidos en esta investigación demostraron la viabilidad de estos micro/nanogeneradores como estimuladores eléctricos autoalimentados. Además, su reducido tamaño y la capacidad de estar en suspensión en medios líquidos abren la puerta a nuevos desarrollos hacia herramientas médicas mínimamente invasivas inyectadas o ingeridas.