Figure 7From: Detection of a and b waves in the acceleration photoplethysmogram Detected a and b waves in APG signals at rest (before exercise). It contains (a) stationary signals, (b) non-stationary signals, (c) low amplitudes, and (d) irregular heart rhythm. Here, ‘red asterisk’ represents the detected a wave and ‘black plus sign’ represents the detected b wave by the proposed algorithm.Back to article page