External factors that affect the photoplethysmography waveforms

Abstract Photoplethysmography (PPG) is a simple and inexpensive technology used in many smart devices to monitor cardiovascular health. The PPG sensors use LED lights penetrate into the bloodstream detect different blood volume changes tissue through skin contact by sensing amount of light that hits sensor. Typically, data are displayed on graph it forms pulse waveform. information from produced waveform can be useful calculating measurements help health, such as pressure. With more people beginning their health status devices, extremely important signal accurate. Designing experiment with standard laboratory equipment commercial sensors, we wanted find how external factors influence results. In this study, was found factors, touch force temperature, have large impact resulting waveform, so effects those need considered order for become reliable.