MINIATURIZED RAMAN CLINICAL GAS ANALYZER

A NEED EXISTS TO QUANTITATE ANESTHETIC AND RESPIRATORY GASES(O2, CO2, N2) IN THE OPERATING ROOM. PREVIOUS WORK HAS SHOWN THAT RAMAN LIGHT SCATTERING CAN BE SUCCESSFULLY UTILIZED FOR MOLECULAR GAS ANALYSIS. THE RAMAN SIGNAL FOR EACH GAS CAN BE SEPARATED FROM THE LASER BEAM RAYLEIGH SCATTER VIA FILTER COMBINATIONS, THUS ELIMINATING THE NEED FOR LARGE, EXPENSIVE MONOCHROMATORS. THIS PROPOSAL ADDRESSES THE FEASIBILITY OF UTILIZING A SMALL, LIGHT, INTRACAVITY, FREQUENCY-DOUBLED, DIODE-PUMPED ND:YAG LASER AS AN ALTERNATIVE TO THE LARGE, INEFFICIENT AR(+) LASER USED IN PREVIOUS WORK. A RESEARCH PROTOTYPE WILL BE CONSTRUCTED THAT USES SUCH A COMMERCIALLY AVAILABLE SOLID-STATE LASER. A MULTICHANNEL GAS CELL WILL BE INSERTEDINTO AN INTRACAVITY SPACE, WHICH WILL BE PUMPED BY THIS LASER. THE RAMAN SIGNAL INTENSITY WILL BE DETERMINED FOR THE ABOVE NOTED GASES AND COMPARED TO THE VALUES CALCULATED FROM A SYSTEM-MODELING EQUATION. ACCURACY, SENSITIVITY, SPECIFICITY, AND LINEARITY WILL ALSO BE EVALUATED FOR EACH GAS. SHOULD THIS APPROACH PROVE FEASIBLE, THE USE OF SUCH A LASER WOULD GREATLY REDUCE INSTRUMENT SIZE, WEIGHT, AND COST, THUS MAKING IT MORE WIDELY AVAILABLE TO THE ANESTHESIOLOGY COMMUNITY.