? A collaborative effort between ASL Analytical, Inc. and a research team at the University of Iowa is proposed to development a noninvasive nocturnal hypoglycemic alarm. The goal for the alarm system is to provide continuous noninvasive measurements during the sleep period of an individual with diabetes, sounding an audible alarm to wake the person if an impending hypoglycemic event is detected. The system will be based on continuous spectral measurements in the combination near infrared region. Through the use of a customized Fourier transform spectrometer and novel fiber-optic interface, transmission measurements will be made through the thin skin on the back of the hand of the sleeping person. The patient will initiate the monitoring session by performing a conventional finger-stick glucose measurement and acquiring a corresponding reference spectrum. Subsequent spectra will be referenced to this initial spectrum, and a novel pattern classification algorithm will be used to detect hypoglycemic events. Both in vitro and in vivo experiments are proposed in this Phase I application to optimize the hardware and software components of the alarm system. Glucose clamp experiments performed with Sprague-Dawley rats will be used to establish the performance characteristics of the spectrometer hardware, fiber-optic interface, and alarm algorithm. In addition, optimization of the fiber-optic interface will be aided by experiments performed with a population of human subjects. Through these studies, the feasibility of the proposed nocturnal alarm will be evaluated in preparation for a potential Phase II development effort. ? Hypoglycemia is a potentially life-threatening condition where blood glucose concentrations drop below normal values. Episodes of severe hypoglycemia contribute significantly to the morbidity and mortality of individuals with type I diabetes and recurrent hypoglycemia can result in long-lasting damage to brain function including memory loss and degradation of other cognitive functions. Nocturnal hypoglycemia is particularly troublesome for many individuals with type I diabetes because it can go undetected and it is one component in the progression of hypoglycemic unawareness. The proposed nocturnal alarm represents an innovative approach to reduce significantly the frequency of hypoglycemic occurrences. Our approach is noninvasive, thereby avoiding confounding issues associated with biocompatibility and infection that plague implantable biosensor technologies. ? ?
