Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on Jan. 20, 2010. Major professor: Dr. Lynne Slivovsky. "Presented to the faculty of the College of Engineering, California Polytechnic State University." "In partial fulfillment of the requirements for the degree [of] Master of Science in Electrical Engineering." "July 2009." Includes bibliographical references (p. 102-104).

Thesis (D. Phil.(Biokinetics, Sport and Leisure Sciences))--University of Pretoria, 2003. / Includes bibliographical references.

Neuromuscular electrical stimulation (NMES) has been shown to be effective for recovery of motor function following injury or pathology, however, NMES can impart rapid fatigue and the specific parameters of stimulation that maximize force output and delay the onset of fatigue remain unclear. Frequency, intensity, and pulse pattern are a few of the parameters that can be manipulated to achieve desired outcomes. Strong evidence supports the use of higher frequencies of stimulation to maximize performance of fatigued or paralyzed muscle. Likewise, several studies advocate the use of varied pulse patterns, rather than constant pulses, to maximize force output as well. Much of the research literature regarding NMES use with a pathological population involves spinal injured individuals. Much less is known about the effect of NMES on motor recovery, especially when delivered through varied pulse patterns, in the post-stroke population. The three studies contained herein addressed these issues. In Study 1, submaximal and supramaximal intensities of two variable frequency stimulation patterns and one constant frequency pattern were applied to the thenar muscles of a young healthy population. Results showed marked differences in force output between the two intensities. Submaximal stimulation enhanced the effect of the variable pulses and a greater force response was produced. In Study 2, the same three patterns were applied to the thenar muscles of a post-stroke group and an age-matched able-bodied group at submaximal intensities. Again, differences in force output were evident between the healthy and pathological group, and the variable pulses may have further depressed already weakened hemiplegic muscle. Study 3 compared the effects of a NMES rehabilitation program using a high (40 Hz) and a low (20 Hz) frequency to determine if task-specific improvements were related to frequency used. Results showed that those in the high frequency condition demonstrated greater improvements in strength, dexterity and force accuracy; those in the low frequency condition showed improvements in motor endurance. The results of this work suggest that the intensity, frequency and stimulation pattern of NMES used have a significant impact on the resultant muscle contraction and functional skills gained following stroke and should be carefully considered when implementing a clinical regimen for motor recovery.

Recorded on July 27, 2007 by Eugene Barsky, Physiotherapy Outreach Librarian, UBC / N/A

Access to and subsequent control of spinal cord function are critical considerations for design of optimal therapeutic strategies for SCI patients. Electrical stimulation of the spinal cord is capable of activating behaviorally-relevant populations of neurons for recovery of function, and is therefore an attractive target for potential devices. A promising method for accessing these spinal circuits is through their axons, which are organized as longitudinal columns of white matter funiculi along the cord exterior. For this thesis, I hypothesized that these funiculi can be selectively recruited via electrodes appropriately placed on the surface of the spinal cord, for functional activation of relevant motor circuitry in a chronically-transected spinal cord. My tandem design goal was to fabricate and implement a conformable multi-electrode array (MEA) that would enable this selective stimulation. To accomplish this design goal, I participated in the design, fabrication, and electromechanical testing of a conformable MEA for surface stimulation of spinal tracts. I then assessed the fundamental capability of this MEA technology to stimulate white matter tracts in a precise, controlled, and functionally-relevant manner. This was accomplished via in vitro experiments that explored the ability of this MEA to locally activate axons via single- and dual-site surface stimulation. The results from these evaluation studies suggest that spinal-cord surface stimulation with this novel MEA technology can provide discrete, minimally-damaging activation of spinal systems via their white matter tracts. To test my hypothesis that surface stimulation can be used to recruit distinct populations in the spinal cord, I performed studies that stimulated lateral funiculi in both chronically-transected and intact in vitro spinal cords. Results from these studies reveal that selective surface stimulation of white matter tracts in the ventrolateral funiculus (VLF) elicit motor outputs not elicited in intact cords. In addition, I was able to demonstrate that the spinal systems activated by this surface stimulation involve synaptic components and are responsive to spatial, temporal, and pharmacologic facilitation. Corresponding labeling of the axonal tracts projecting through the T12 VLF indicate that, after chronic transection, the remaining spinal neurons whose axons travel through the VLF include those with cell bodies in both the intermediate region and dorsal horn. These electrophysiological results show that surface-stimulating technologies used to control motor function after injury should include focal activation of interneuronal systems with axons in the ventrolateral funiculus. As a whole, these studies provide essential starting points for further use of conformable MEAs to effectively activate and control spinal cord function from the surface of the spinal cord.

Listeners with severe-sloping losses often don’t perceive high-frequency sound cues. Conventional amplification fails to provide these cues due to loudness discomfort experienced by the listener, and/or acoustic feedback. Alternative signal-processing solutions include shifting higher frequencies down to lower frequencies, or providing electrical stimulation via a speech processor. Three experiments were carried out on adult hearing-impaired listeners to determine the best way of providing high-frequency information: conventional amplification, frequency compression or cochlear implantation.

Thesis (Ph. D.)--University of Virginia, 2008. / Includes bibliographical references. Also available online through Digital Dissertations.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Additional advisors: Susan Bellis, Vladimir Fast, Chi-Tsou Huang, Donald Muccio. Description based on contents viewed June 23, 2009; title from PDF t.p. Includes bibliographical references.

Thesis--Copenhagen. / Summary in Danish. "Publications 1742-1801 by Christian Gottlieb Kratzenstein": p. 175-182. Bibliography: p. 183-199.

Thesis (M.S.)--School of Bioengineering, Georgia Institute of Technology, 2005. Directed by Thomas Burkholder. / Thomas Burkholder, Committee Chair ; Cheng Zhu, Committee Member ; Grace Pavlath, Committee Member. Includes bibliographical references.