Reflective PPG-based noninvasive continuous pulse rate measurement and remote monitoring system

Abstract

Noninvasive continuous pulse rate (PR) monitoring has recently become a budding topic in the field of remote healthcare monitoring. Photoplethysmography (PPG) based PR measurement is a continuous, unobtrusive, reliable, patient-friendly and low-cost solution. In this paper, a novel reflective type PPG sensing technique has been described in order to eliminate the limitations of a typical reflective type PPG sensor. Here, the angular incidence of the light is introduced to minimize the impact of motion artifacts and maximize the signal to noise ratio of the PPG signal. A complete PR monitoring system has been developed which can easily be integrated with the remote healthcare system. Also, this system can be very useful to monitor the PR of infants, elderly aged people, patients having a wound or burn injury or in the intensive care unit environment. The overall accuracy is achieved 99% and the percentage of error is around 1% for red light at 65° angle of incidence and the Signal-to-Noise Ratio (SNR) is increased up to 26% for 65° angle of incidence with respect to the perpendicular incidence. Hence, experimental results demonstrate that by using the developed reflective PPG-based sensing system, the measurement accuracy of the PR and the SNR of the PPG signal is significantly increased whereas the impact of motion artifact is considerably decreased.