Measurement of Body Vitals Using Photoplethysmography (PPG) and Smartphone Sensors

Abstract

Every day, millions of individuals use portable health devices to keep track of health metrics such as heart rate, blood oxygen, and other body vitals. However, this can also be facilitated using a commonly available smartphone and its capabilities. The outcome of this chapter is a framework to measure vital signals such as blood oxygen, heart rate, respiratory rate, and blood pressure using in-built sensors in a smartphone, namely the camera, flashlight, and accelerometer. Vitals are captured by analyzing the photoplethysmography (PPG) signals obtained from the red intensities of the images of the fingertip or the deviation in the values obtained in the accelerometer readings during measurement, and then performing further arithmetic calculations on the same. The authors also compare the values for the vitals measured on pulse oximeters, blood pressure monitors, health bands, and the smartphone itself. Comparisons are made on a sample size of 100 measurements, and the mean percentage error for each type of body vital measurement is calculated with respect to each measuring device.