A Statistical Comparative Study of Photoplethysmographic Signals in Wrist-Worn and Fingertip Pulse-Oximetry Devices

Prolonged time-matching continuous recordings of electrocardiogram and photoplethysmographic waveforms from fingertip pulse oximeter and wrist-worn devices obtained from stroke patients admitted to the intensive care unit were analyzed. Heart rate and pulse rate variability indices and signal complexity were estimated and statistically compared to investigate the reliability of heart rate estimation using photoplethymography and whether fingertip pulse oximetry and radial photoplethymography reflect the same pulse rate variability. Heart rates were generally found to be accurately estimated by both photoplethysmographic modalities when using the electrocardiogram as a reference. Pulse rate variability analysis showed statistically comparable properties between photoplethysmographic modalities, suggesting that fingertip pulse oximetry and wrist photoplethymography reflect the same cardiovascular changes.