Novel method of automatic auscultation for blood pressure measurement using pulses in cuff pressure and korotkoff sound

In the NIBP (Non-Invasive Blood Pressure) measurement, we need well trained observer and there are differences in reading values between observers. We suggest new automated auscultation algorithms to select the proper epoch of K-sound for each heart beat. The sound for each epoch is converted into frequency domain and total power was calculated. We decided SBP(Systolic Blood Pressure) point when there was abrupt jump from the baseline. DBP (Diastolic blood pressure) was decided when there was the biggest drop in total power of successive beats. For the validation of our suggested method, human observer assessed SBP/DBP according to EHS (European Hypertension Society) recommendation. The mean differences between the automatic method and traditional auscultation method were 2.0 mmHg for SBP and 3.1 mmHg for DBP. We also took the paired t-test with the two results, and there was no statistically significant difference between these two methods.