Date of Award

Fall 1993

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)


Biomedical Engineering

First Advisor

Jeutter, Dean C.

Second Advisor

Ishii, Thomas K.

Third Advisor

Myklebust, Joel


This thesis presents a novel passive biotelemetry system. The system passively communicates the electrode load voltage from the receiver/stimulator to the transmitter using virtually no power from the internal receiver/stimulator battery. This is done by using the stimulator output waveform to modulate the VCO, which is used to turn on/off a MOSFET switch. This causes a change in the input impedance (when the switch is closed 26.5 Ohms to switch open 33.8 Ohms at a k of 0.3) seen from the external primary, and as a result, the primary voltage changes. This change in voltage, induces a voltage in the RF detector coil. After signal conditioning circuitry and scaling, the electrode voltage waveform is recovered as the system's output. This can be viewed by use of an oscilloscope, recorded on a paper chart, or ND converted for computer analysis.



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