Every cardiac cycle of the human body comprises of two periods of activity: relaxation and contraction of the heart muscle. With the first, the human heart relaxes and refills
with blood (diastole), followed by a robust contraction (systole) that pumps the fluid throughout the cardiovascular system. This rhythm causes a time dependent pressure
pulse that drives a continuously changing volumetric flow, which can be detected due to the blood’s good light absorbance. Remote photoplethysmography (rPPG) is a novel, non-invasive and cost-effective method of detecting changes in blood volume by illuminating the dermal tissue and sensing infinitesimal intensity changes. Compared to conventional electrocardiography, rPPG does not require physical contact to determine a human’s heart rate. Using an ordinary digital camera, with a suitable rPPG algorithm, one can indirectly determine the heart rate by first measuring the pulse wave of the flowing blood. This way, an important physiology metric is obtained with information on the subjects’ health. With respect to the novel and highly contagious Coronavirus that evolved into a global health crisis, we have developed and tested a telemedicine application using a tele-operated mobile robot, outfitted with a high resolution camera. An experiment was conducted in three scenarios: living room lighting, direct sunlight and in a photography studio setting. In the case of former, the average error measured was less than 1 BPM. The gathered results clearly show that a rPPG algorithm on a mobile platform works not only as a functional alternative to other
conventional means of determining pulse rate, but also as a novel concept capable of decreasing the healthcare system’s workload.
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