A paired stretchable printed sensor system for ambulatory blood pressure monitoring

Blood pressure is an important daily bio-signal but continuous monitoring of blood pressure is not an easy task. Continuous measurement of blood pressure can be provided with pulse arrival time (PAT) which is calculated by electrocardiogram (ECG) and blood pulse wave. In this study, dry conformable and stretchable ECG electrodes and a printed accelerometer are assembled into a wearable device which is aiming for continuous monitoring of blood pressure. Clear ECG signals which are comparable in shape and strength with those from the conventional wet electrode have been obtained. And reliable blood pulse wave with valid peripheral augmentation index is registered by the printed accelerometer. By utilizing paired printed sensors, the PAT is extracted from time difference between R-peak of the ECG signal and starting point of the pulse wave. Finally, a fitting line which is obtained from the graph of PAT vs. reference blood pressure estimates blood pressure reliably with intermittent exercises.