Date of Award
Fall 1972
Document Type
Dissertation - Restricted
Degree Name
Doctor of Philosophy (PhD)
Department
Biomedical Engineering
First Advisor
Sances, Anthony
Second Advisor
Hosek, Ronald
Third Advisor
Ackman, James J.
Abstract
This study examines two basic problems in the evaluation of EEG activity; namely, the development of effective procedures of analysis and computation for (1) monitoring slow changes in the complex structure of the EEG using parameters which correlate with physiological state, and (2) the detection of unique transient patterns of scalp EEG activity which are time-locked to spikes generated deep in the brain. The tracking parameter study is directed to the first problem and the matched digital filtering study is directed to the second problem. The tracking parameter study is based on the measurement pf moments of the power spectral density and average zero crossing rate. These measurements constituted the basis for evaluating state change in experiments involving (a) the effects of pharmacologic agents on the EEG, and (b) the computer discrimination of EEG sleep stages. A theoretical analysis is also presented to establish the relationship of zero crossing rate parameters to spectral density and correlation function parameters. The matched digital filtering study includes both theoretical and experimental research in the design of optimal digital filters to detect patterns of scalp EEG activity which correlate significantly with the occurrence of spiking activity recorded from deep brain structures in Macacus rhesus monkeys. Digital filters were designed to provide optimum detection of a transient pattern corresponding to the shape of the average time-locked EEG potential at the scalp. Experimentally the average time-locked potential at the scalp was computed by using subcortical spikes as the synchronizing trigger...