DRT proposes to research, design and develop a novel, low cost, reliable, accurate, fluidic -technology-based multiple medical gas monitor (MMGM) for CO2, O2, N2O and volatile anesthetics made possible by the development of miniature fluidic integrated circuitry. Gasses are separated and identified by a unique system of scrubbers (e.g., zeolites for N2O and O2 and soda lime for CO2) and because each anesthetic will be known a priori a non-specific scrubber (activated charcoal) will be used and logic in a PC will pick the calibration. Gas concentrations are determined from the tiny pressure changes (due to changes in density and viscosity) at the junction of an orifice-capillary bridge. A fluidic laminar proportional amplifier raises these pressures to useful levels. Sensor outputs will be processed and displayed on a PC. Real-time gas monitoring with clinical accuracies (equals approximately 0.1%) and ranges (0 - 99%) will be possible. The system will have performance better than conventional full- function gas monitors at substantially reduced costs because no complex (e.g., chromatography) techniques are used. The Phase I proof-of-concept will demonstrate monitoring of three gasses, O2,CO2 and N2O and one example anesthetic. Based on this, a nine-channel system will be designed for fabrication and demonstration in the Phase Il effort.
The innovation of reliable, low cost, continuous gas monitoring would greatly improve anesthesia administration. This system could reduce medical/clinical acquisition and life-cycle costs of current gas sensors by a factor of as much as two compared with conventional full-function IR machines and as much as a factor of three over chromatography-based devices.
