Diode Laser Raman Scattering Prototype for Gas Phase Environmental Monitoring

We propose to determine the feasibility of using diode-laser-based, full-spectrum Raman scattering technology incorporating fiber-optic coupling for rapid, continuous, on-line detection and monitoring of key intravenous (IV) drugs. Raman's narrow, well-defined peaks and insensitivity to water offers potential for full-spectrum Raman detection of drug levels in blood with parts per millions (ppm) sensitivity for many commonly administered drugs within 30 to 60 seconds. Traditional Raman scattering performed with visible light excitation is not compatible with physiological samples because of background fluorescence. Conventional gas lasers have too short of a life and are too expensive for routine commercial instrumentation. A semiconductor laser diode offers longer life than conventional lasers and can operate at near-IR wavelengths where sample fluorescence is minimized while taking advantage of the very sensitive and full-spectrum detection. Fiber-optic coupling allows the safe application of Raman scattering in medical environments by isolating (optically) the patient from electronic equipment and offers the potential for multiplexing several patients within a multiple bed recovery room. Phase I will demonstrate through bench studies the feasibility of applying diode-laser-based Raman technology to the measurement of commonly administered drug formulations and will determine the commercial market opportunity provided by closed-loop control of important IV drugs such as anticoagulants (heparin) and injectable aesthetics (propofol).| Benefits: Currently, the dosage of most drugs such as anticoagulants and anesthetics is determined by the patient response or effect rather than actual drug levels in the patient's blood. Raman scattering technology offers a method to continuously measure these and other drugs during surgery in over 3 millions procedures performed in the U.S. each year.|