According to
our test results, we got the systolic BP (SBP) value is
corresponding to the position that the peak-to-peak value of
AC pulse is around 0.42 Pmax, and the diastolic BP (DBP)
value is corresponding to the position that the peak-to-peak
value of AC pulse is around 0.77 Pmax. Fig. 4 demonstrates
AC and DC of cuff pressure signals and the peak detection
results. After the DBP′ is detected or the cuff pressure value is
smaller than Threshold 2, the cuff pressure is released by a
deflation valve.