This paper proposes a new electrocardiograph system based on GPRS standard. The system consists of a monitoring terminal (portable ECG monitor), a wireless network and a monitoring center station. The wireless network utilizes a modern communication network and a computer network to provide access devices at the monitoring terminal; the monitoring center is generally built in the hospital day monitoring center, and the ECG monitoring is a part of the center; the monitoring terminal is to implement wireless real-time monitoring. The essential.
ECG monitoring terminal hardware
The whole ECG monitoring terminal circuit mainly includes: 1 ECG signal acquisition and processing circuit, the part includes preamplifier circuit, filter circuit and post-amplifier circuit; 2 ECG monitoring circuit, QRS wave extraction detection circuit, MCU and liquid crystal display ; 3 remote communication part, including MCU, GSM / GPRS module, SIM card and RF circuit; 4 power circuit. The ECG signal is divided into two paths by the post-amplifier circuit. A path bandpass filtering and detection circuit enters the MCU to realize the judgment of abnormal arrhythmia and premature beat; the other path MCU enters the memory and is stored as a complete ECG signal.
Preamplifier stage
ECG preamplification requires very high input impedance and common mode rejection ratio, low zero drift, low offset, low power consumption, especially low 1/f noise voltage. Generally, the in-phase parallel differential three-op-amp instrumentation amplifier is used. In order to obtain good comprehensive performance, this design uses the low-cost instrumentation amplifier AD620 of American Analog Device Company, which has obtained good circuit effect. The circuit is shown in Figure 2. The preamplifier gain of this design is set to 7 times magnification. Comprising 300 times the channel gain with the successor amplifier.
Preamplifier circuit
Bone Glue,Bone Glue Gelatin,Animal Bone Glue,Industrial Grade Bone Glue
Hebei Haodong Biological Technology Co.,Ltd. , https://www.hdgelatin.com