Fig. 4.

Demonstrations of waterproofing and continuous cuffless blood pressure measurement. (A) EMGs recording when the on-skin device was fully submerged in water. (B) A schematic diagram of the assembled piezoresistive on-skin pressure sensor. (C) Schematic illustrations of the simultaneous recording of ECG signals and arterial pulse waveforms for blood pressure monitoring. (D) Recorded concurrent ECG signals and arterial pulse waveforms with the pulse transit time (PTT) indicated. (E) The calculated beat-to-beat systolic blood pressures (red) and diastolic blood pressures (black) based on the PTT method.