Perfusion monitoring by contactless photoplethy smography imaging

The flow of blood, or perfusion, of the skin can be indicative of the local but also systemic health of an individual. The noncontact Photoplethysmography (PPG) imaging is a recently emerging technology able to monitor skin perfusion. Using an off-the-shelf camera and a light source, it is possible to remotely detect the dynamic changes in blood volume beneath the skin and derive a map correlated to the blood perfusion. In this paper we empirically investigate perfusion monitoring by camera-based PPG imaging. Laser Speckle Contrast Analysis (LASCA), a well-known technique for perfusion monitoring, is used as reference. We design an experimental setup that allows simultaneous PPG imaging and laser speckle measurements. We conduct experiments with different local and temporary perfusion perturbation of the skin and show that camera-based PPG imaging can detect the perfusion changes in the tissue. Results correlate well with the laser speckle measurements, suggesting that non-contact PPG imaging is capable of providing a realistic map of skin perfusion.