Date of Award
Master of Science in Electrical Engineering (MSEE)
Electrical, Computer, and Biomedical Engineering
This master thesis pertains to a systematic testing and evaluation of three neuroscience instruments previously developed at the Biomedical Engineering Laboratory of the University of Rhode Island. The three instruments are the Universal Clamp (UC), the Neuron Emulator (NE), and the Cell Capacitance Emulator (CCE). The UC is an innovative instrument that employs a fast-digital signal processor to deliver and integrate various experimental tools for electrophysiology. The NE is an electronic device that uses a capacitance source to represent the passive and active electrical properties of a neuron. The CCE presents a dynamic resistance-capacitance model of a neuron with the capability of switching between two capacitances that have a small difference to represent the activity of a vesicle crossing the cell membrane.
A platform for conducting a systematic testing on the functionality of the UC by use of the NE and the CCE was developed. The main objective was to explore the possibilities and drawbacks of using such a platform to test neuroscience instruments without the need for a wet experiment involving live neurons. The functions of the UC under evaluation included voltage clamp, current clamp, and cell capacitance measurement. The contributions of this research include the hardware and software improvements on the NE and CCE necessary for integrating them into the testing platform. An attempt to reduce of the rise time of the action potential spike by adding a low-pass filter at the output circuitry made the action potential waveform more realistic; however, the low-pass filter also reduced the speed for the feedback currents and resulted in an unsuccessful voltage clamp. The representation of the cell capacitance changes due to a vesicle activity on the order of 10 fF with a 2-ms pulse width was challenging. The parasitic capacitance from the wiring and the breadboard was often on the order of 10 pF. The existing algorithm based on short-time Fourier transform for detecting the vesicle capacitance was insufficient to detect such a small and fast capacitance change.
In summary, this thesis research has demonstrated an instrumentation platform and testing methods for electrophysiological instruments using only electronic devices. While the system does not completely replace the need for using live neurons, many standard experimental protocols such as current clamp and voltage clamp can be tested in an efficient and effective way.
Al Zowelei, Mosa, "INSTRUMENTATION OF MEASURING CELLULAR CAPACITANCE VIA SIGNAL PROCESSING TOOL" (2018). Open Access Master's Theses. Paper 1300.