Non-invasive Blood-glucose Monitor using Terahertz Radiation

This Phase I SBIR proposal describes a research program to determine feasibility for using terahertz radiation to non-invasively monitor metabolic analytes such as glucose. Non-invasive monitoring is important for determining general physiological activity and health, and needed by diabetics for painless, rapid glucose measurement. Mid-infrared and far-infrared monitoring has been extensively explored, but after many years of research, no reliable instrument is available. Infrared glucose concentration data reliability is poor due to strong radiation scattering and overlapping signals arising from blood components that maski glucose signals. Based on published data, improved molecular discrimination may occur in the terahertz spectral region, where DNA and organic-molecule resonant absorption spectra dominate, where photon scattering is reduced, and where a new generation of miniature cascade-lasers is under development. Phase I will investigate terahertz absorption spectra in glucose-containing phantoms simulating blood, and in purchased laboratory blood solutions with known glucose concentrations. The measurements will be performed at the Brookhaven synchrotron source, using an FTIR spectrometer and terahertz radiation detector. The proposed project dovetails with a companion program to develop a miniature terahertz cascade-laser source at Spire Biomedical. Phase II will include tissue-measurements and develop a portable, non-invasive monitoring system using the terahertz cascade-laser.