FIBEROPTIC PH SENSOR FOR IN VIVO MEASUREMENTS

THE DEVELOPMENT OF A FIBEROPTIC PH PROBE IS PROPOSED USING A FLUORESCENT DYE IMMOBILIZED IN A HYDROPHILIC GEL MATRIX. THE MAIN TASKS IN THIS PROJECT ARE: (1) SET-UP OF RESEARCH INSTRUMENTATION FOR MEASURING AND CHARACTERIZING EXPERIMENTAL PROBES, (2) SELECTION AND IMMOBILIZATION OF DYES AT THE TIP OF THE OPTICAL FIBER, AND (3) TEST PH PROBESFOR SIGNAL INTENSITY, PH SENSITIVITY, TIME RESPONSE, PHOTOSTABILITY, AND LEACHING STABILITY. THE IMMOBILIZATION PROCEDURES WILL BE IMPROVED AND OPTIMIZED, IF NECESSARY, TO PROVIDE IN VIVO PATIENT BLOOD MONITORING FOR UP TO 3 DAYSWITHOUT RECALIBRATION. IN PHASE II, THIS PH PROBE WILL BE INCORPORATED WITH A SECOND CATHETER CONTAINING A GAS PERMEABLE MEMBRANE. THIS SECOND CATHETER WILL WITHDRAW O2 AND CO2 GAS FROM THE PATIENT'S BLOOD AND THE GAS CONCENTRATIONS WILL BE QUANTITATED USING GAS-SENSING LASER RAMAN SPECTROSCOPY. THE LASER LIGHT SOURCE WILL ALSO BE USED TO EXCITE THE PH-SENSING FLUORESCENCE PROBE. THIS APPROACH WILL PROVIDE REAL-TIME PH, PO2, AND PCO2 MEASUREMENTS FOR CRITICAL CARE MONITORING.