Noninvasive Detection System Of Cardiovascular Parameters Based On Finger-tip Pulse Wave

With the improvement of living standards and the increasingly serious population aging problem,cardiovascular disease has become a serious problem that seriously endangers people's health.Blood pressure,blood oxygen and heart rate are important physical parameters for the prevention and diagnosis of cardiovascular diseases,and noninvasive detection can help people to understand their own physical condition at any time.However,at present,there are shortcomings of single function,low precision and complicated operation.In view of the above background and significance,a noninvasive detection system for cardiovascular parameters based on finger pulse wave is proposed to detect the physiological indexes such as blood oxygen,blood pressure,heart rate,respiratory rate,blood perfusion index and so on.Secondly,based on the pre processed PPG signals,a high precision cardiovascular parameter detection algorithm is designed to achieve non-invasive physiological indexes such as blood oxygen,blood pressure,heart rate,respiratory frequency,blood perfusion index and so on.When calculating the blood oxygen value,two kinds of blood oxygen eigenvalue extraction algorithms are adopted:the extraction algorithm of blood oxygen eigenvalue based on linear regression and the extraction algorithm of blood oxygen based on moving average,and we choose the optimal algorithm by the calibration test in this paper.The PWTT extraction algorithm based on the accelerated pulse wave is first built in the calculation of the blood pressure value,and the linear relationship model of PWTT and systolic pressure is established.Then the diastolic pressure fitting method is used to improve the calculation method of diastolic pressure.On the basis of PWTT,a kind of BP neural network based BP neural network is designed to estimate the blood pressure,which combines the multiple individual characteristics(sex,age,height,body weight,heart rate)as input to the neural network.Finally,the PWTT algorithm is combined with the BP neural network algorithm to further optimize the systolic and diastolic pressure.When calculating the respiratory rate and heart rate,a calculation method of respiratory frequency and heart rate is proposed by FFT-BHR algorithm.A blood perfusion index(PI)method is designed by calculating the blood perfusion index through the PPG signal envelope algorithm.Finally,the realization scheme of the whole cardiovascular parameter noninvasive detection system is elaborated,and the hardware circuit of the pulse wave signal acquisition front end and the design of the data analysis algorithm system are introduced.Firstly,the hardware system of thedetection system is briefly introduced,including the PPG signal acquisition and processing module and the whole circuit.Then,in the software aspect,the GUI signal analysis software based on the MATLAB system is introduced,which functions include the waveform display,the calculation of the physiological parameters and the data communication.