Research And Implementation Of Chest Wear ECG And Respiration Acquisition Device

In recent years,cardiovascular diseases and respiratory diseases have become chronic diseases with a high mortality rate,which seriously threatens people's life and health.Electrocardiograph and respiratory signals is important body signal that are rich in physiological information of the human body and are also important for the diagnosis of cardiovascular diseases and respiratory diseases.At present,the popular portable medical monitors in the market have the problems of large volume,high price,and inconvenience of long-time monitoring.In order to solve the above problems,this paper designs a portable,low-cost,portable electrocardiographic respiratory monitoring device that can be monitored for a long time based on physical parameters monitoring.The mobile terminal is used as a physical sign display platform to perform good data interaction with the device.The hardware platform also has extended functions that can add more human body information.This article combines the advantages of wearable detection schemes in signal acquisition methods.Abandoning the traditional way of detecting the ECG signal by the CM5 lead of the wet electrode,a single-lead chest strap type detection method is adopted.This method is a chest strap type device made of conductive silicone rubber as a signal acquisition sensor,which is convenient and flexible to collect and controllability.The signal core processor STM32L151CBT6 has an ARM cortex3 core which can simultaneously interact with ADS1292 R and ADXL345 to realize stable acquisition of ECG,respiration and acceleration signals,high-accuracy sampling,and reasonable signal scheduling.A circuit board is made by PCB layout,and a physical package is combined with an epoxy resin circuit box to form a wearable device to realize synchronous detection of electrocardiographic respiration and human posture.For the common high-frequency,power-frequency and baseline noise interference in ECG and respiration signals that article studies the removal of low-pass digital filters,traps and morphology,which can effectively eliminate mixed noise signal from ECG respiration signals.After the digital filtering is completed,the QRS complex of the ECG signal is identified by a differential threshold method with a small amount of computation that found the RR interval for calculating the heart rate.According to the characteristics of the respiratory signal waveform,the point-by-point discrimination method is used to find the maximum value and calculate the extreme point interval calculation respiratory frequency.The above signal processing methods and parameter value calculation methods do not rely on the high-performance processing of the mobile phone background,and rely only on the core processor on the hardware.According to design requirements,this article needs to test the power consumption,data measurement accuracy and stability of the entire acquisition device.The result showed that the power consumption of the device is 66.6mw.In the quiescent state,the average error rate of heart rate is controlled within 2% and the respiratory rate is controlled within 4%.And in normaly active state,the average error rate of heart rate control within 5% and the respiratory rate control within 6%.The above tests show that the design of the physical parameters of the acquisition device meets the design requirements.