The Design Of Portable ECG Signal Acquisition System

Fit of cardiovascular diseases expresses outburst, difficult to predictive, high risk of death and disability. But the discovery means of cardiovascular diseases mainly depends on ECG signal now. ECG signal is a bioelectrical signal, which is generated by the electrical activity of the heart and can reflect its changing information of physiological function. Therefore, acquisition of ECG information continuously, accurately and real time can provide a significant basis for the clinical diagnosis of cardiovascular diseases.Recently, the acquisition and processing technology of ECG signal is still a key to study Multi-functional ECG monitor. In this paper, according to the trend of medical monitoring equipment, we mainly research the solution of ECG acquisition system with convenience, real time and accuracy based on comprehensive analysis and references. This program applies Programmable Logical Device (FPGA) and USB2.0 technique to ECG signal acquisition system. It will have many advantages contrast to the ole analog ECG monitor: Using FPGA instead of the MCU of traditional design, not only reduces the cost of development, but also realizes intelligence, digitization and miniaturization of the system. Using interface of USB2.0, communicate with PC easily and can realize high-speed data acquisition with convenience of the system. Using MFC designed the client application, whose interface is more friendly and the content display is more abundant, coordinating with A/D circuit and the USB interface circuit, would form a powerful man-machine interaction system that more facilitate ECG signal accurate monitoring.Firstly, the theory and technology of ECG signal detection is studied and an overall design scheme of portable ECG signal acquisition system is proposed in this paper, lading the foundation of the hardware and software design. Then the overall hardware design of the system is introduced in detail, including analog circuit and digital circuit. Finally, software design of the system is presented, including the FPGA procedures, USB firmware, drivers and PC procedure, etc. The front-end of system is a signal conditioning circuit which can realizes the extraction of high-quality ECG data. The central part of system is the A/D acquisition control module, FLASH control module and USB transmission control module, which is designed by using Cyclone II EP2C8Q208C8 microcontroller as core, and it realizes data acquisition and cache of the ECG signal and transmission to the computer with USB2.0 interface. The System monitoring control interface is developed using MFC under Microsoft Visual C++6.0 software. The ECG signal acquisiting, receiving, and displaying are realized in the software system.The results of the client applications and data transmission rate test procedure validate this system design of the portable ECG signal acquisition system basically achieving anticipated target.