A Distributed Ecg Monitoring System Based On Wireless Difference

The rapid urbanization and aging of the population,as well as unhealthy diet,lack of exercise and excessive stress,have contributed to the increasing damage of cardiovascular disease.Heart disease has become a major disease endangering human health.At present,ECG detection is one of the reliable detection methods for the diagnosis of cardiovascular diseases,which is of great significance for the prevention and treatment of cardiovascular diseases.In recent years,with the development of electronic technology,wearable medical devices and household portable medical devices have been gradually developed to meet the needs of monitoring ECG signals for a long time in daily life.In this paper,based on the existing wearable ECG monitoring devices,wireless sensor network synchronization technology is applied to ECG monitoring.We have established a distributed ECG monitoring system based on wireless difference.The purpose of the system is to get rid of the shackles of the lead wire in the traditional wired way and overcome the contradiction between the wearable design and the continuous monitoring design in the multi-lead ECG monitoring.The specific work of this paper is as follows:Firstly,according to the formation principle and signal characteristics of ECG signal,the hardware circuit of the sensor node and the coordinator are designed respectively.The charge sensor module,ADS1298 analog-digital conversion module,Zig Bee RF module,MSP430 master control module and power module of the sensor node are introduced in detail.The design of PCB board of sensor node and coordinator are completed.Then,a Zig Bee wireless sensor network based on TIMAC protocol stack is built,and two key parts of synchronous acquisition design of sensor nodes are analyzed:synchronous acquisition trigger and synchronous cumulative error suppression.For these two parts,the synchronization method based on beacon-enabled Zig Bee network is introduced respectively.Finally,the average trigger error of synchronous acquisition is measured to 44.06 μs.Finally,the performance of the system designed in this paper is tested.First,the basic performance parameters of the sensor nodes are measured.The equivalent input short-circuit noise of the nodes is about 4.2 μV,and the common mode rejection ratio is 89.9 dB.The second is to use the designed system to detect human ECG signals,and the results verify the feasibility of the proposed distributed ECG monitoring system.