Fig. 2From: History and evolution of blood pressure measurement(A) Heartguide, a miniaturized version of an oscillometric device (B) Galaxy watch, a smartwatch requiring regular calibration with a cuff-based device (C) Aktiia, a bracelet using PPG signal (D) BPro, a wrist-worn device using modified applanation tonometry (E) Volume clamping, a cuff-based ring-type device applying the Peñáz principleBack to article page