Master of Science

thesisCurrent testing methods of capnometers do not test for a capnometer's ability to accurately calculate clinical parameters such as respiratory rate (RR) and end-tidal CO2 (ETCO2). Ideal standards should test capnometers with changing flow rates and frequencies of respiration, as well as with capnograms with complex shapes and trends. Simulators have been used in recent years as a solution for standardizing the testing of medical devices and dynamically evaluating their performance. A CO2 waveform simulator was designed that continuously changes the flow rate of CO2 being injected into a constant flow of 02, in order to create varying CO2 partial pressures over time that mimic capnograms. The CO2 flow rate is computer-controlled through a variable orifice solenoid valve that outputs higher flow rates for higher input currents. Once the CO2 in injected into the O2 stream, the mixed gas is diverted to the reference capnometer, which is used to calibrate the CO2 valve and measure the simulator's performance. Clinically recorded capnograms were used to validate the performance of the simulator by measuring how well the simulator reproduced the waveforms