Self-adaptive segmental recognition of Korotkoff sound for blood pressure measurement method

In order to improve the measurement accuracy of electronic sphygmogram, a measure scheme using self-adaptive segmental recognition of Korotkoff sound was proposed based on the principle of Korotkoff sound method. Firstly, the dual ADC was used to collect sound and pressure signals, and the static pressure equation was fitted in real time. Then, the abrupt point in the pressure signal was identified and the signal of Korotkoff sound was segmtioned. Then, the threshold value is calculated adaptively based on the normal distribution 3σ principle, and the feature points of the middle segment Korotkoff sound were extracted. Finally, heart rate was used as the search step to identify systolic and diastolic blood pressure points. The experimental results show that the standard deviation of systolic blood pressure based on this method is 2.18 mmHg (1 mmHg=133.322 Pa), the standard deviation of systolic blood pressure is 2.74 mmHg, the standard deviation of diastolic blood pressure is −0.93 mmHg, and the standard deviation of diastolic blood pressure is 2.24 mmHg, which prove that the scheme has higher accuracy and stability, and provide a direction for the optimization and improvement of electronic measurement of Korotkoff sound.