Fig. 2

Illustration of the concept of the derivation of BP from the distension and blood flow velocity waveform using ultrasound. a The acquired diameter and/or velocity waveform from the sensor is converted into the pressure waveform by applying validated models and initial mean arterial pressure (MAP) and diastolic BP (DBP) values. b Schematic of the wearable ultrasound that acquires the physiological signals of either the ulnar or radial artery. Simultaneously, the MAP and DBP values are measured at the brachial artery using the gold standard cuff sphygmomanometer for calibration