The broader impact/commercial potential of this Small Business Innovations Research (SBIR) Phase I project is the potential to overcome some of the current lack of similar devices for screening and monitoring of PAD and will allow greater access at lower cost for current and future patients suffering from PAD. Today, hospitalization costs for diagnosis and treatment of PAD patients exceed $10,000 per patient for 8 to 10 million Americans suffering from lower-extremity PAD. The current options for PAD diagnosis are too expensive and impractical to monitor or diagnose the condition in its early stages before it is too late to initiate therapy to reverse or slow progress. Regular screening as well as monitoring of PAD after an initial diagnosis by medical professionals has the potential to significantly reduce the current cost of managing PAD patients, including prevention of many of the 150,000 ischemic amputations performed annually in the US through early intervention. <br/><br/>The proposed project addresses the need for a more practical, accessible, user-friendly, and inexpensive technique, for monitoring PAD. The proposed our transdermal gasotransmitter sensor employs an innovative, patented gas-phase detector to non-invasively provide real-time measure of the target molecule. It is anticipated that this approach would provide accurate, cost-effective monitoring of onset and severity through monitoring plasma H2S levels, which could also enable subsequent therapeutic measures in real-time. During this Phase I study, a prototype of a TGS module will be developed and its performance will be demonstrated. Prior data and results will be utilized to design and develop a breadboard prototype for remote gasotransmitter monitoring. Key technical challenges of developing a disposable sensor will be addressed, including size, cost, and ease of use. Feasibility will be tested under simulated laboratory conditions with membranes and animal skin. Furthermore, the breadboard prototype will be implemented in ongoing studies on healthy and diabetic rats. Building on Phase I findings, more advanced prototype development and further testing is planned for Phase II efforts.