Available at: http://digitalcommons.calpoly.edu/theses/875
Date of Award
MS in Biomedical Engineering
Biomedical and General Engineering
This paper outlines a surgical procedure for exposing and stimulating the sciatic nerve of an anesthetized rodent for purposes of obtaining conduction velocity readings. The ability to accurately quantify nerve conduction velocity has potential for use in the field of diagnostic medicine and disease characterization. An accurate reading depends on both the surgical method used to expose the desired nerve without imposing onto it any physical trauma as well as the stimulation protocol used to initiate action potentials. This paper contains the specific steps required to set up the necessary hardware and software for electrical stimulation as well as a detailed surgical and stimulation protocol. The animal model chosen to perform this experiment is the rat because it is the smallest animal model available with large enough nerve size to perform histology as a step toward validating the nerve size estimates obtained from this procedure. Based on repeated experimental runs, these methods are are expected to yield the most usable results while inflicting the least amount of physical trauma to the nerve. Upon isolating the sciatic nerve, the surgeon is to place an electrode cuff around the nerve and then initiate the stimulation protocol. The stimulation software is designed to slowly increment the current passing through the nerve to recruit increasing numbers of neurons one-at-a-time. The resulting data would theoretically offer researchers the actual threshold values for each individual neuron, uncovering information about the conduction characteristics of each one. The steps outlined in this thesis have been optimized to implement the theoretical model of group delay. Using the decomposition model introduced by Szlavik et al., the signal obtained from the entire nerve is broken down into individual action potentials associated with individual neurons.