Design Of Continuous Blood Pressure Monitoring System Based On Pulse Wave

With the improvement of modern medical technology and social health care system,people’s attention to their own health has also been raised to a new level.Human body blood pressure,as one of the important vital signs parameters of human body,has great reference significance of cardiovascular disease prevention,diagnosis and treatment,so blood pressure measurement method research is also in the continuous development and improvement.Compared with the traditional blood pressure cuff type measurement can only get a short period of time,intermittent blood pressure data,in order to meet the new demand for continuous blood pressure measurement,the continuous blood pressure measurement method based on pulse wave transit time has become a new research hotspot.In this study,we design a set of continuous blood pressure monitoring system based on pulse wave transit time.the first target of this system is accurately continuous blood pressure measurement,and considering portable and practical.The main contents of the paper are as follows: 1.The design of hardware systemHardware design choose the STM32 microprocessor as the master control chip,medical electrode slices pick up ECG signal,AM2520 light source and APDS-9008 light sensors pick up the pulse signals.With the help of corresponding signal filtering,amplifying circuit,complete acquisition of ECG and PPG signal.ESP8266 wireless communication module is responsible for the data sent.2.The design of software systemThe software design includes the embedded software and Android App.The embedded software is responsible for the collection and transmission of the ECG and PPG signals.The android App is responsible for data reception,feature point recognition,PTT calculation,calculation of blood pressure value,and final data storage and waveform display.3.Establishment of blood pressure estimation modelThis paper establishes a personalized blood pressure estimation model for 8 testers.Everyone collects 12 groups of ECG and PPG,as well as blood pressure data.The first order difference and threshold value method is used to identify the signal feature points,the least square method is used to establish model between pulse wave transit time and systolic pressure,diastolic pressure.4.Test system prototype performance testThe system prototype was used to measure the systolic and diastolic blood pressure of 8 testers.Everyone collects 20 groups of data,Compared with the results of another electronic blood pressure measurement device,the absolute error is within 5mmHg,which proves that the prototype system has high accuracy and repeatability.