Based On Virtual Instrument Ecg Machine Design And Development

On statistics, heart disease is the major illness threatening human's life and the death rate of heart disease is still the highest in the world. Thus, the medicine circles all over the world always attach importance to diagnose and cure heart disease. It is an important and meaningful task to extraet ECG precisely and provide auxiliary analytical devices for doctors. In this thesis, the designed virtual ECG instrument can be used widely in the small hospitals, even families, it will be very significant for improving the people's health level.Firstly, on the basis of introduces of the ECG knowledge, this thesis tells the ECG detection circuit and gives the ECG acquisition circuit, especially the specific design and some circuits .These circuits includes a pre amplifier, second-order Butterworth low-pass filter, high-pass filter, and 50Hz trap circuit, which depresses various kinds of interference effeetively. Then, the design proposal of ECG contants a control core of AT89S52 CPU, A/D conversion's ADC0809, and USB transport interface. And then, the thesis states the ECG pretreatments and test way of R-wave.Finaly,the thesis introducesthe process of developing of up machine software which is based on the virtual device software LabVIEW.The system was made up of up and down machine.Down machine was controlledby AT89S52 single chip micyoco. The amplified and filered ECG signal was collected by down machine, then the analog signals was transformed to digital signals, and transferred to up machine by USB interface.Up machine is used for receiving the ECG datas, the relative machining (such as digital filtering pretreatment), and displaying of the ECG datas.The hardware and software of the ECG instrument was completely designed by the thesis. If the collecting part and communication part of this digital electrocardiograph are cooperated with other type sensors(such as blood pressure sensor), the digital medical treatment will be realized.