Wearable sensor for continuously vigilant spatial and depth-resolved perfusion imaging

Direct characterization of blood perfusion in tissue is critical to a broad spectrum of applications in assessing circulatory disorders, wound conditions and ensuring outcomes of treatment. The rapid evolution of these conditions and their great risk for subjects require a continuously vigilant monitoring technology. This paper presents a wireless health platform providing the first wearable blood perfusion imager. This system, the Perfusion Oxygenation Monitor (POM), introduces sensing diversity by combining array methods and multispectral methods, as well as sensor and emitter distribution and operation scheduling. The principles of photoplethysmographic (PPG) sensing exploited by new methods will enable care providers to actively monitor blood perfusion at multiple anatomical sites for characterization and tracking of perfusion critical to tissue health, wound status and healing, formation of pressure ulcers, and circulation conditions. The POM system is described here along with its experimental validation. Experimental validation has been provided by a direct probing method based on physiological thermoregulatory response that induces perfusion change and is directly measured by POM. The demonstration of the POM system will also be supplemented by an analysis of the end to end system including sensor information processing, feature detection, Wireless Health data transport, and archive structure.