A portable non-invasive technology for monitoring surface and deep tissue oxygenation will be identified and proven during Phase I of this project. During Phase II this technology will be demonstrated and production-prototyped as a system. The device, as envisioned, will facilitate in-field monitoring of personnel under physiologic stress caused by activity, environmental conditions and direct trauma or injury. Infrared spectral technology for measuring oxygenation has been proven and commercially available systems will be surveyed to locate suitable products. Simultaneously, other techniques for measuring oxygenation that have proven useful in other fields will be examined to determine their possible utility. Particular attention will be paid to techniques such as photo-acoustic spectroscopy that may integrate well with other physiologic parameter measurement systems such as acoustic Doppler. The various technologies will be evaluated with respect to their ability to interface with standard computers, and to record, store and transmit the oxygenation data. Tests will be devised and executed, within the scope of a Phase I program, to demonstrate the feasibility of the proposed sensor approach. A design for Phase II will be produced that will integrate of all components into a pre-production prototype for testing with tissues simulating battlefield hemorrhage and shock. Engineering Technology Incorporated has experience in developing dual use applications of military technology; this insures successful commercialization during Phase III.