The Research And Design Of Multi-Lead Ecg Monitoring System Based On Wireless Sensor Network

Cardiovascular disease is the first human health killer in our county for a long time, the converntional ECG equipment in the hospital can achieve the ECG signal testing for a short period, hardly capture the sporadic disorders ECG signal on the human body. The holter can store the ECG data in the Flash memory, the medical personnel can do the analyzing work after the device complete the ECG recording. It is impossible for the holter device to upload the ECG data on real-time,let alone achieve real-time monitoring、ECG data analysis and Crisis warning. So, it is necessary to develop a portable、low power cosuming、ECG monitoring products which can diagnose the human signal dynamically on real-time.In the paper, we design a set of multi-lead ECG monitor system based on ZigBee wireless sensor network, complete the project evaluation and development. Acocording to the fact that the ECG captured from the human body is weak and mixed with strong noise, we carry on the ECG lead system research work, design the three lead ECG acquistion module on the front, finish the PCB board design and testing work,and finially we get the ideal ECG waveform signal. We adopt the open design ideas on the ADC part, an idea of using conventional multipler and ADC core module integrated in the MSP430micro control unit, achieve the ECG signal switch and conversion. Another train of thought is that make use of the. high-precision component to complete the analog-to-digital conversion separately, we choose the AD7691manufacturered by Analog Devices,which can transimit the digital data to the MCU through the SPI interface to acomplish the acquisition work synchronously. Both the design thought scheme can realize the multi-lead swich、real-time acquisition、synchronous convert.In the second way of design, omit the filter circuit and notch circuit to reduce the PCB board area.After being coverted by the ADC7691, the digital ECG signal can be processed by the digital filter.A large number of hardware processing workis transformed to software filter to enforce, which fufill the low power consuming, protabe need.In the reseach of short distance wireless communication technology, on the basis of the application situation and system feature, we choose the ZigBee wireless communication technology. After a deep study of the Z-stack, this paper introduce the process of network initialization> network setings network join, and use CC2430to set up a wireless ECG signal sensing network. Though the verification, the network can transimit the reliable ECG signal on real-time. The experiment proves that the distance can reach15m through interior wall, hundreds of meters outdoor open congdition, which meet the design expected requirements.After finishing the design of system, we carry on the necessary test.The ECG system base on ZigBee network can continue to run stably. The feature of low power consumption, portabilty stability and reliability can satisfy the requirement of application in the family or commnunity. This system can accomplish the real-time ECG monitoring, qualify the requirement, has a positive meaning on the domestic ECG monitoring work.