The goal of this research project is to develop instruments to noninvasively evaluate cutaneous perfusion and viability of skin grafts. In Phase I, fluorescein fluorescence and differential pulse blood volume digital video-imaging instruments were successfully constructed and tested. Software was written that used fluorescein images to evaluate spacial variations in regional circulation and predict skin viability. The device was correlated to laser Doppler velocimetry in a rat skin flap model and demonstrated the ability of the technique to visualize skin circulation. Comparison of fluorescence image characteristics with long-term skin viability established the system utility for evaluating skin grafts. Initial studies performed during Phase I demonstrate that 1) an enhanced instrument can produce valuable images of differential blood volume and 2) the current instrument's fluorescein fluorescence capabilities are ready for transfer to research/clinical testing. Phase II will consist of: 1) design, construction and evaluation of an enhanced unit for use in imaging differential blood volume; 2) construction of rugged, compact, portable systems for testing in a clinical research environment; 3) clinical evaluation of the fluorescence imager in the Vascular Laboratory of the Maricopa Medical Center, and 4) alteration of the instrument and expansion and integration of its software to incorporate needs and suggestions derived from clinical testing. These integration of its software to incorporate needs and suggestions derived from clinical testing. These imaging systems will provide enhanced viability predictive data for plastic and reconstructive surgeons and be applicable to perfusion-related disorders such as those found in diabetics and burn patients.
