Cuffless Continuous Blood Pressure Monitoring Technology Research And System Development

Cardiovascular disease has become a common health problem for mankind.Its prevalence and mortality have been increasing year by year.Hypertension is one of the main risk factors for cardiovascular disease,which seriously endangers human health.Therefore,the accurate and reliable blood pressure measurement is particularly important.However,blood pressure levels are always fluctuating,and a single measurement of a cuff-type blood pressure measurement system cannot reflect the dynamic changes of blood pressure.Besides,the use of a cuff can cause restraint and discomfort.In addition,as people’s requirement for places of blood pressure measurement increases,home monitoring has become a new solution.Therefore,the study of a cuffless continuous blood pressure monitoring technology and system that can be used at home to achieve accurate assessment of hypertension has important clinical application value for the early prevention of cardiovascular disease.This paper designs a chair-type cuffless blood pressure continuous monitoring system for home use,which extracts pulse wave translation time(PWTT)by synchronously collecting electrocardiograph(ECG)and pulse(Photoplethysmography,PPG)signals and sets up a multiple linear regression blood pressure estimation model and builds a monitoring mode integrating collection terminal,Android client and cloud to achieve dynamic and reliable blood pressure monitoring.The main research contents and results are as follows:(1)Built a hardware of chair-type and cuffless blood pressure continuous monitoring system.By fixing the hardware system on the seat,high-quality signal acquisition is realized through the synchronous acquisition and conditioning circuit of ECG and PPG,the processing and integration of the acquired signals are realized in the main controller module,and the wireless data transmission is realized in the Bluetooth module.(2)Designed a continuous monitoring system software for cuffless blood pressure.The acquisition terminal software can realize the real-time collection,processing and transmission of the signal.The Android client can realize the signal preprocessing and blood pressure calculation,and simultaneously display the signal waveform and blood pressure value.The cloud database can realize the permanent storage of the data.(3)Put forward an ECG quality evaluation algorithm based on multi-index threshold evaluation.SQI parameters extracted from ECG waveform features are introduced as evaluation indicators to evaluate the quality of ECG signals.At the same time,an ECG de-noising algorithm based on wavelet threshold cycle shift is proposed.The wavelet threshold is used to denoise the noisy ECG caused by cyclic translation,which can effectively filter the noise interference in the signal.(4)Constructed a blood pressure estimation model method based on multiple linear regression,performed Pearson correlation coefficient analysis on the characteristic parameters of the blood pressure model,and constructed a blood pressure estimation model based on 5 characteristic parameters such as PWTT.The OMRON cuff sphygmomanometer is used to synchronize the parameter calibration and system verification with the system of this paper,and the results are in line with the AAMI standard.At the same time,the Pearson and Bland-Altman analysis diagrams are used to evaluate the consistency,which verifies the reliability of the method and system in this paper.The chair-type cuffless blood pressure continuous monitoring system designed in this paper realizes the real-time detection and analysis of blood pressure,provides early warning for a precursor of hypertension,and users can complete long-term effective monitoring at home.