Short-Term Photoplethysmography Embedded in Household Appliances

This paper opens new insights into short-term photoplethysmography (PPG) in dynamic condition when opening a refrigerator. Five hundred twelve PPG signals from fingers of 7 healthy volunteers were acquired simultaneously and analysed for heartbeats. Parallel referential electrocardiogram recordings confirmed the heartbeat detection sensitivity and precision of 97.62% and 90.31%, respectively. We also assessed the mean blood pressure, firstly, by measuring pulse transit times and, secondly, by our novel method based on the blood inflow times at the door opening instants. The models derived with exponential fitting proved the inflow times a robust and accurate blood pressure indicator; the mean absolute error was 1.2 +/- 0.9 mmHg.