Design And Implementation Of Cardiovascular Parameter Detection System Based On Multi-channel PPG

With economic development and changes in people's living habits,staying up late and increasing the rate of obesity has become a common social phenomenon.If the prevention of cardiovascular diseases can be strengthened,early monitoring of cardiovascular physiological parameters can greatly reduce the pressure on medical resources and the suffering of patients.Based on the multi-channel photoelectric volume pulse wave,the health monitoring equipment designed in this thesis obtains the pulse wave signals of multiple parts of the human body in real time.The equipment not only provides daily blood pressure and heart rate,but also has the measurement function of the pulse wave velocity that the usual equipment does not have.It solves a dilemma that cardiovascular examinations are usually only completed in hospitals,not in ordinary communities.The system has low cost,does not require the operator to have professional knowledge,and can provides a reference for early cardiovascular prevention.So,it has important practical value.There is noise jamming in the collected original signal.After analyzing the common noise and the possible effect of the noise on the data,several methods of filtering out noise are presented in the thesis,and different filtering methods are used to process the signal and verification simulation results and analysis are obtained.Finally,the filtering process used in the system are selected.Based on the filtered signal,the waveform peak labeling algorithm is selected,and the heart rate and pulse wave conduction time parameters are successfully extracted,which lays the foundation for the subsequent calibration and measurement of blood pressure and pulse wave velocity.At the same time,the morphological waveform of the signal was extracted,and the comparison of the symmetric position waveform images has a guiding role in early warning of cardiovascular obstruction.The hardware mainly implements the function of collection,filtering and amplification of the ECG signal and pulse wave signal,and transmits the amplitude data of the amplified analog signal after analog-to-digital conversion to the upper computer.The software of the host computer mainly implements functions such as file creation,waveform drawing,data storage,and scheduling of various algorithms,which provides users with a simple interactive experience.After comparing and verifying with the measurement results of standard instruments,the system designed in this thesis has high accuracy in the measurement of heart rate and blood pressure,the difference between the center rate and the standard result is within ±1 bpm,and the average absolute error of systolic pressure is 4.59 mmHg,the average absolute error of diastolic blood pressure is 2.95 mmHg.In this paper,the stability of the pulse wave conduction velocity measurement results is verified by multiple measurements in continuous time.The results show that the standard deviation of the pulse wave conduction velocity measurement results of 6 locations in 5 consecutive measurements is within 0.25 m/s,which has a high Repeatability.