Medicine and Health Sciences Commons^™

Modeling Hrtf For Sound Localization In Normal Listeners And Bilateral Cochlear Implant Users, Douglas A. Miller

Electronic Theses and Dissertations

Mathematical models can be very useful for understanding complicated systems and for testing algorithms through simulation that would be difficult or expensive to implement. This dissertation presents a model that attempts to simulate the sound localization performance of persons using bilateral cochlear implants. The expectation is that this model could prove to be a useful tool in developing new signal processing algorithms for neural encoding strategies.

The head related transfer function (HRTF) is a critical component of this model, and in the ideal case, provides the base characteristics of head shadow, torso and pinna effects. This defines the temporal, intensity …

Impedance Changes In Biceps Brachii Due To Isometric Contractions And Muscle Fatigue Using Electrical Impedance Myography (Eim), Travis Orth

Electronic Theses and Dissertations

Electrical impedance myography (EIM) is a non-invasive technique used to evaluate neuromuscular conditions by using a quantitative parameter called impedance (Z). It relies upon the application and measurement of high-frequency, low-intensity electrical current imbedded over a localized muscle to determine its opposition to current flow. In brevity, impedance determines the resistance of muscle fibers due to changes in muscle composition. The objective of this thesis was to establish a relationship between muscles at rest and during isometric contractions at various force levels(25%, 50%, and 100% of maximum voluntary contraction) of the biceps brachii over a multifrequency spectrum. Impedance measurements due …