Digital Compensation Method for Enhancing the Blood Pressure Estimation based on the Arterial Pulse Waveform

摘要

Blood pressure measurement method by using the PPG sensor and arterial pulse waveform has a prior condition that the sensor has to maintain constant pressure on the artery all over the measurement process, and it is very hard under the 24-hours continual measurement environment. To get the reliable blood pressure measurement result, we have to find a way to compensate the sensor pressure variation over the artery. In this work, we proposed the new digital compensation method that can measure the arterial pulse waveform and sensor pressure simultaneously and can compensate the blood pressure estimation equation along with the sensor pressure variation to find out more precise blood pressure. we also designed and implemented the arterial pulse waveform measurement system includes digital PPG sensor, ADC, Raspberry PI 3 and smartphone app that has new blood pressure estimation equation that can compensate the sensor pressure variation on the differential values of the arterial pulse waveform and BP-relation equation. The android smartphone app processes the arterial pulse waveform from the Raspberry PI 3 through the Bluetooth link and estimates more accurate blood pressure with the proposed estimation equation. To evaluate the estimation accuracy, we implemented the experimental environment and compared the experimental results to the commercial tonometer. The experimental results showed the proposed estimation equation can improve the estimation accuracy up to 5.5% on systolic and 30% on diastolic for hypertension and normal volunteers, and can make continuous estimation within 5% error rate for hypertension.