Blood Pressure Monitor Based On New MCU And Improved Pulse Wave Measurement

With the gradual improvement of people’s living standard,the increase of fatty food in the diet leads to the increase of blood lipid,which further leads to the increase of blood pressure.In recent years,the disease and death rate caused by hypertension have been increasing gradually,so blood pressure has been paid more and more attention.Blood pressure is one of the important physiological indicators of the human body.Normal blood pressure provides normal blood supply to the internal organs of the human body to ensure the normal metabolic process.Blood pressure values in disease diagnosis,treatment effect observation and reflect the status of the cardiovascular function of the human body to provide an important basis.The demand for blood pressure testing is not only in the hospital,but also on a daily basis.Daily home blood pressure monitoring and recording can effectively tell whether there is an underlying disease in the cardiovascular system,so that prevention and treatment can be carried out earlier.In China,because people have a shallow understanding of the significance of blood pressure,and the electronic sphygmomanometer is more expensive on the market,the sphygmomanometer has not been widely popularized.Therefore,it is of great significance to design a low cost portable electronic blood pressure monitor.This paper mainly studies an oscillographic sphygmomanometer based on a new MCU and pulse wave algorithm.Firstly,the basic physiological mechanism and characteristics of blood pressure signal generation were analyzed,and the blood pressure value was calculated according to pulse wave.Because the pulse wave signal directly measured contains a lot of noise,a method of denoising based on wavelet transform is proposed.The threshold function of this method is the soft threshold,and the wavelet decomposition and reconstruction are carried out based on Mallat algorithm.After the processing,the signal is greatly improved compared with the previous one.In terms of hardware,a self-developed 32-bit MCU is used for portable medical electronic devices.The architecture of this microprocessor is different from the mainstream MCU in the market,which reduces the cost and area at the expense of performance.This paper discusses the key voltage conversion pulse circuit and the denoising circuit based on wavelet denoising algorithm.The former is an analog to digital conversion mode,and the latter is a signal processing circuit.It also designs the circuit of each module of the blood pressure monitor system,draws PCB,and completes the whole assembly of the system.C language is used to write the system’s algorithm program and each module program,and the embedded software design is completed,so that the hardware circuit can work normally.After the completion of the system,the test is carried out in modules.It is considered that the modules of the system work normally and are connected well with each other.When testing system measuring accuracy,used for comparison after professional certification of sphygmomanometer,measured data by Bland Altman consistency analysis processing,experience,this paper design the sphygmomanometer accuracy is better,compared to the mainstream of blood pressure cuff on the market at the same time,this design used on hardware components are less,the cost is low.