Non-Contact Vital Sensing with a Red-Green-Blue Color Camera

Abstract

A quantitative evaluation of peripheral hemodynamics is important to monitor tissue metabolism and health status. Optical spectroscopy provides functional and morphological information of living tissues based on optical absorption and scattering properties. Red-green-blue (RGB) camera-based diffuse reflectance imaging, which can be　achieved with a simple, robust optical system, has been widely applied to in vivo measurements and for imaging biological tissues. This article describes an RGB camera- based functional imaging technique and its applications to vital sign monitoring. The method estimated volume concentrations of oxygenated blood, deoxygenated blood, and melanin in skin tissue quantitatively based on a numerical simulation model for light transport in tissues. In vivo experiments with human subjects and rats demonstrate that the method has the ability to measure and visualize tissue oxygen saturation, plethysmogram, heart rate, peripheral vasomotion, and percutaneous arterial oxygen saturation.