An Overview of Remote Photoplethysmography Methods for Vital Sign Monitoring

Abstract

Vital signs such as heart rate, respiratory rate, blood pressure, body temperature, and oxygen saturation are essential for early detection of any related significant illness. Many of the existing methods that are used to monitor the aforementioned vital signs are camera-based. In these methods, sensors are fixed to the body that are not sturdy to the motion of the subject. Another method to monitor vital signs is photoplethysmography (PPG), an emerging noncontact technique that maps, spatial blood volume variation in living tissue from the images captured through a video. Most of the camera-based methods are driven by three remote photoplethysmography algorithms. The camera-based methods are useful for detecting vital signs with an objective AAA, i.e., anyone, anywhere, and anytime. However, there exist few challenges in r-ppg methods and make it an open research problem. This paper presents an overview of the signal processing challenges faced by remote photoplethysmography for calculating the vital signs with a focus on heart rate estimation.