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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Akviziční systém pro povrchovou elektromyografii / The acquisition system for surface electromyography

Milek, Jakub January 2017 (has links)
At the beginning of this work the physiological nature of electromyographic signal is described. Design of miniature, portable EMG amplifier for surface measurement is presented. Creation of program for data visualization is described, followed by description of practical EMG amplifier realization.
102

Kineziologická analýza úderu horní končetinou ve sportovním karate / Kinesiological analysis of upper limb punch strike in sports karate

Pavelka, Radim January 2012 (has links)
I ABSTRACT Title: Kinesiological analysis of upper limb punch strike in sports karate. Aim of work: The aim of this thesis to describe and characterize the muscle involement in direct punch strike in karate. Then compared with the exercises, which are characteristic to karate - strikes with resistence and push-up exercise. Methods: Work is processed by a comparative analysis of selected movements based on the determination of muscle activation. The surface electromyography method synchronized with video and accelerometer was used in this work. Results: The result is describtion of selcted movements on the basis of muscle activation and function of selected muscles. The prove that the forearm extensors are activated as the last of the selcted muscles was managed. On the basis of karate technique and anatomy we confirmed important role of forearm extensor by direct punch in karate. The difference between onset time muscle activation by strikes and push up was found. Maximum speed of acral part of the upper limb by direct punch was established. Keywords: Electromyography (EMG), karate, direct punch - gyakucuki, accelrometer
103

Sledování změn zapojení svalů ve vybraných oblastech pohybové soustavy člověka při chůzi a nordic walking / Monitoring of changes regarding muscle involvement in specific areas of human motion system when walking and nordic walking

Škopek, Martin January 2012 (has links)
The Dissertation is concerned with monitoring of changes regarding muscle involvement in specific areas of human motion system when walking and Nordic walking (NW) with focus on adults and by means of electromyography method. Within the process of field testing there were 9 randomly selected individuals at the age of 50 - 60 tested to elicit differences in the motion system. There was an effort to find certain differences within involvement of specific muscle groups in the area of shoulder girdle, pelvic girdle and lower limbs and retrieval of similarities of coordination attributes concerning locomotion at horizontal presented by paradigm of kinesiological content of reflexive crawling according to Vojta's principle. Kinematic analyses was used to discover a difference in involvement of specific muscles between Nordic (v = 5 kph) and regular walking (v = 4, 75 kph) up to 10˚ of ascent. Muscles where their MVC was diagnosed the difference in individual muscle involvement was monitored expressed in percentage. The values found were consequently related to their referential value of MVC and tested by means of Wilcoxon test for dependent selection. Muscles where MVC value was not diagnosed the intraindividual comparative analyses of activation muscle pair similarity was carried out on the grounds of...
104

Probabilistic Control: Implications For The Development Of Upper Limb Neuroprosthetics

Anderson, Chad January 2007 (has links)
Functional electrical stimulation (FES) involves artificial activation of paralyzed muscles via implanted electrodes. FES has been successfully used to improve the ability of tetraplegics to perform upper limb movements important for daily activities. The variety of movements that can be generated by FES is, however, limited to a few movements such as hand grasp and release. Ideally, a user of an FES system would have effortless command over all of the degrees of freedom associated with upper limb movement. One reason that a broader range of movements has not been implemented is because of the substantial challenge associated with identifying the patterns of muscle stimulation needed to elicit additional movements. The first part of this dissertation addresses this challenge by using a probabilistic algorithm to estimate the patterns of muscle activity associated with a wide range of upper limb movements.A neuroprosthetic involves the control of an external device via brain activity. Neuroprosthetics have been successfully used to improve the ability of tetraplegics to perform tasks important for interfacing with the world around them. The variety of mechanisms which they can control is, however, limited to a few devices such as special computer typing programs. Because motor areas of the cerebral cortex are known to represent and regulate voluntary arm movements it might be possible to sense this activity with electrodes and decipher this information in terms of a moment-by-moment representation of arm trajectory. Indeed, several methods for decoding neural activity have been described, but these approaches are encumbered by technical difficulties. The second part of this dissertation addresses this challenge by using similar probabilistic methods to extract arm trajectory information from electroencephalography (EEG) electrodes that are already chronically deployed and widely used in human subjects.Ultimately, the two approaches developed as part of this dissertation might serve as a flexible controller for interfacing brain activity with functional electrical stimulation systems to realize a brain-controlled upper-limb neuroprosthetic system capable of eliciting natural movements. Such a system would effectively bypass the injured region of the spinal cord and reanimate the arm, greatly increasing movement capability and independence in paralyzed individuals.
105

Decoding the Language of Hypoglossal Motor Control

Laine, Christopher January 2011 (has links)
To effect movement, the central nervous system must appropriately coordinate the activities of pools of motoneurons (MNs), the cells which control muscle fibers. Sources of neural drive are often distributed to many MNs of a pool, and thus can synchronize the activities of targeted MNs. In this thesis, synchronization among MNs is used to investigate the strength, temporal progression, and anatomical distribution of neural drive to the hypoglossal motor nucleus (HMN), which controls muscles of the tongue. The HMN is an ideal target for such an investigation because it processes a host of functionally diverse inputs, such as those related to breathing, speaking, and swallowing. Study 1 characterizes motor unit (MU) synchronization within and across bellies of the human genioglossus (GG) muscle when MUs are activated by cortical drive (during voluntary tongue protrusion) or by automatic, brainstem-mediated drive (during rest breathing). We show that voluntary tongue protrusion synchronizes MU spike timing and firing rates within but not across bellies of the GG, whereas during rest breathing, MU firing rates are moderately synchronized both within and across muscle bellies. Study 2 documents respiratory-related synchronization of MU activities in muscles of the tongue and respiratory pump using an anesthetized rat model. The results of this study indicate that upper airway and respiratory pump MN pools share a low frequency respiratory-related drive, but that higher frequency (>8 Hz) synchronization is strongest in MU pairs of the chest-wall. Finally, Study 3 examines the potential for GG multi-unit and single MU activities to be entrained by cortical input. We show that during voluntary tongue protrusion, cortical oscillations in the 15-40 Hz range weakly synchronize MU population activity, and that EEG oscillations in this range intermittently influence the spike timing of individual GG MUs. These studies are the first to characterize MU synchronization by different sources of neural input to the HMN and establish a broad foundation for further investigation of hypoglossal motor control.
106

Novel Methods in SEMG-Force Estimation

Hashemi, Javad 29 August 2013 (has links)
An accurate determination of muscle force is desired in many applications in different fields such as ergonomics, sports medicine, prosthetics, human-robot interaction and medical rehabilitation. Since individual muscle forces cannot be directly measured, force estimation using recorded electromyographic (EMG) signals has been extensively studied. This usually involves interpretation and analysis of the recorded EMG to estimate the underlying neuromuscular activity which is related to the force produced by the muscle. Although invasive needle electrode EMG recordings have provided substantial information about neuromuscular activity at the motor unit (MU) level, there is a risk of discomfort, injury and infection. Thus, non-invasive methods are preferred and surface EMG (SEMG) recording is widely used. However, physiological and non-physiological factors, including phase cancelation, tissue filtering, cross-talk from other muscles and non-optimal electrode placement, affect the accuracy of SEMG-based force estimation. In addition, the relative movement of the muscle bulk and the innervation zone (IZ) with respect to the electrode attached to the skin are two major challenges to overcome in force estimation during dynamic contractions. The objective of this work is to improve the accuracy of SEMG-based force estimation under static conditions, and devise methods that can be applied to force estimation under dynamic conditions. To achieve this objective, a novel calibration technique is proposed, which corrects for variations in the SEMG with changing joint angle. In addition, a modeling technique, namely parallel cascade identification (PCI) that can deal with non-linearities and dynamics in the SEMG-force relationship is applied to the force estimation problem. Finally, a novel integrated sensor that senses both SEMG and surface muscle pressure (SMP) is developed and the two signal modalities are used as input to a force prediction model. The experimental results show significant improvement in force prediction using data calibrated with the proposed calibration method, compared to using non-calibrated data. Joint angle dependency and the sensitivity to the location of the sensor in the SEMG-force relationship is reduced with calibration. The SEMG-force estimation error, averaged over all subjects, is reduced by 44\% for PCI modeling compared to another modeling technique (fast orthogonal search) applied to the same dataset. Significantly improved force estimation results are also achieved for dynamic contractions when joint angle based calibration and PCI are combined. Using SMP in addition to SEMG leads to significantly better force estimation compared to using only SEMG signals. The proposed methods have the potential to be combined and used to obtain better force estimation in more complicated dynamic contractions and for applications such as improved control of remote robotic systems or powered prosthetic limbs. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2013-08-20 20:46:56.897
107

Calcium Alleviates Symptoms in Hyperkalemic Periodic Paralysis by Reducing the Abnormal Sodium Influx

DeJong, Danica 02 November 2012 (has links)
Hyperkalemic periodic paralysis, HyperKPP, is an inherited progressive disorder of the muscles caused by mutations in the voltage gated sodium channel (NaV1.4). The objectives of this thesis were to develop a technique for measurement symptoms in vivo using electromyography (EMG) and to determine the mechanism by which Ca2+ alleviates HyperKPP symptoms, since this is unknown. Increasing extracellular [Ca2+] ([Ca2+]e) from 1.3 to 4 mM did not result in any increases in45Ca2+ influx suggesting no increase in intracellular [Ca2+] ([Ca2+]i) acting on an intracellular signaling pathway or on an ion channel such as the Ca2+sensitive K+ channels. HyperKPP muscles have larger TTX-sensitive22Na+ influx than wild type muscles because of the defective NaV1.4 channels. When [Ca2+] was increased from 1.3 to 4 mM, the abnormal 22Na+ influx was completely abolished. Thus, one mechanism by which Ca2+alleviates HyperKPP symptoms is by reducing the abnormal Na+ influx caused by the mutation in the NaV1.4 channel.
108

An examination of glove attributes and their respective contributions to force decrement and increased effort in power grip at maximal and submaximal levels

Willms, Kirsten January 2006 (has links)
Gloved work has been shown to increase the effort required to perform manual tasks. In power grip tasks, these differences have been observed as reductions in strength and increases in muscular effort. Decreases in force output have been attributed to a number of factors, including loss of tactile sensitivity, glove flexibility or suppleness, thickness, changes in hand geometry, and friction at the glove-object interface. Glove research has rarely quantified glove attributes, and often compared gloves of varying material and physical properties. This research had the unique opportunity to control for a number of these properties by using three sets of identical gloves (powerline maintainers? insulating rubber gloves), differing only in thickness. <br /><br /> Administering the Von Frey Hair Test indicated that the gloves did indeed decrease tactile sensitivity. This research showed that increasing glove thickness led to large decreases in maximum power grip force. Small changes in hand geometry, such as increased interdigital space or grip span, affected force output. In the same hand posture, participants increased their grip force with increasing glove thickness for the object lifting task but were able to maintain a fixed submaximal force with visual feedback. The decrease in tactile sensitivity is a likely cause of this difference. <br /><br /> Muscular activity was affected by wearing the gloves while performing manual tasks. Inconsistent responses of muscular activation were seen in gloved maximum grip effort, while overall increases in electromyographic activity were recorded for tasks at submaximal levels when wearing gloves. <br /><br /> Interdigital spacing had different effects on maximal and submaximal tasks. For maximum effort power grip, interdigital spacing decreased force output by as much as 10%, with no significant changes in muscle activation. For submaximal tasks, no significant differences were seen in muscular activity or in force output. The overall force capability of the gloved user is hindered by changes in interdigital spacing at near maximal effort, but does not appear to be for tasks requiring lower grip force, such as the lifting task which required roughly 20%MVC. Overall, the effect of wearing these gloves on the users, the powerline maintainers, is a substantially increased effort to work. This research contributes to a greater understanding of why and how gloves inhibit performance.
109

NANOCOMPOSITE BIOELECTRONICS FOR BIOPOTENTIAL ENABLED PROSTHESIS

Lee, Dong Sup 01 January 2017 (has links)
Soft material-enabled electronics can demonstrate extreme mechanical flexibility and stretchability. Such compliant, comfortable electronics allow continuous, long-term measurement of biopotentials on the skin. Manufacturing of the stretchable electronic devices is enabled by the recent development combining materials transfer printing and microfabrication. However, the existing method using inorganic materials and multi-layered polymers requires long material preparation time and expensive processing cost due to the requirement of microfabrication tools and complicated transfer printing steps. Here, this study develops a new fabrication method of soft electronics via a micro-replica-molding technique, which allows fast production, multiple use, and low cost by avoiding microfabrication and multiple transfer printing. The core materials, carbon nanomaterials integrated with soft elastomers, further reduces the entire production cost, compared to costly metals such as gold and silver, while offering mechanical compliance. Collectively, skin-wearable electrodes, designed by optimized materials and fabrication method enable a high-fidelity measurement of non-invasive electromyograms on the skin for advanced human-machine interface, targeting prosthesis.
110

Biofeedback Training: Avoidance Conditioning of Frontal EMG

Catalanello, Michael S. 12 1900 (has links)
The present study was designed to evaluate the efficacy of utilizing an avoidance conditioning paradigm in EMG biofeedback training and to compare this method to the standard biofeedback training paradigm. Frontalis EMG levels of 20 college students were monitored during non-stress and stress conditions. Half then received standard EMG biofeedback training. The other half received biofeedback with contingent aversive stimulation. Both groups received training to a relaxation criterion of 3 microvolts for 100 seconds or, for a maximum of two 20 minute sessions. Subjects were then monitored again during non-stress and stress conditions. Both groups obtained significant EMG reductions due to training with no significant differences between them. Standard biofeedback training required less time for subjects to achieve the relaxation criterion than did biofeedback with a shock-avoidance contingency. Possible applications of avoidance contingent biofeedback were suggested.

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