Fig. 1. (Color online) (a) The shape of the major arteries through which blood flows from the human heart and the length (LA) from the aortic canal to the middle finger capillaries are indicated by thick dotted lines. The locations of the cuff for blood pressure measurement and the three electrodes (LA, RA, LL) for ECG measurement. Displays an LED light source and photodetector for measuring the two PPG waveforms of the radial artery near the wrist and in the capillaries near the middle finger, respectively. (b) The ECG waveform, which is a myocardial electrical signal formed according to the movement and size changes of the atrium and ventricle in the heart. (c) The actual shape and size of the heart's ventricles change as they periodically repeat diastole and systole, as well as the internal atria and ventricles. (d) The blood flow velocity waveform passing through the blood vessel according to periodic diameter changes of the radial artery. (e) A representative PPG waveform measured with a PPG sensor worn on the wrist and fingers.
© NPSM
