FIBER OPTIC REFLECTANCE/PHOSPHORESCENCE DECAY SPECTROMETRY

THIS RESEARCH PROJECT INVOLVES THE DEVELOPMENT OF OPTICAL METHODS TO QUANTIFY THE TOTAL AVAILABLE OXYGEN CONTENT OF OPICARDIAL TISSUE. EPICARDIAL OXYGEN IS FOUND IN THREE MAJOR POOLS-AS OXYGEN DISSOLVED IN AQUEOUS MEDIA, AS OXYGEN BOUND TO HEMOBLOBIN AND AS OXYGEN BOUND TO MYOGLOBIN. IN THIS PROJECT, INSTRUMENTATION WILL BE DEVELOPED TO SIMULTANEOUSLY OBTAIN REFLECTANCE SPECTRA AND PHOSPHORESCENCE FROM THE SAME REGION OF THE EPICARDIUM AND FROM THIS DATA DETERMINE PO2 INCARDIAC CIRCULATION AND OBTAIN CONCENTRATIONS OF THE OXY AND DEOXY HEMOPROTEINS. PREDICTIVE ABILITY OF THIS REFLECTANCE METHOD WILL BE TESTED WITH HEMOBLOBIN/MYOGLOBIN MIXTURES IN SCATTERING MEDIA AND IN BLOOD PERFUSED RATE HEARTS. AFTER DEMONSTRATION OF FEASIBILITY IN PHASE I, PHASE II WILL CONCENTRATE ON DEVELOPING THE INSTRUMENT FOR USE IN WORKING PERUSED HEARTS AND IN NMR MAGNETS TO INCREASE ITS UTILITY FOR CARDIAC BIOENERGETIC STUDIES. THE APPLICATION OF MULTIVARIATE STATISTICAL TECHNIQUES TO ANALYZE OPTICAL SPECTRA OPENS UP THE PROSPECT OF MONITORING MULTIPLE METABOLIC PARAMETERS SIMULTANEOUSLY FOR USE IN EVALUATING CARDIA ISCHEMIA AND HYPOXIA. THIS INSTRUMENT WILL QUANTIFY MULTIPLE ASPECTS OF TISSUE METABOLISM AND OXYGEN SUPPLY/DEMAND FOR RESEARCH AND CLINICAL PURPOSES.