Circuit design of portable ECG equipment based on LM124 operational amplifier

In this work, a portable ECG signal amplification and processing circuit were designed based on the lm124 chip. The circuit consists of a high CMRR measurement amplifier, a lowpass filter, a high-pass filter, and a band stop filter to suppress power frequency interference. The circuit is simulated and tested by Multisim software under different input voltage and frequency. The test results show that the differential mode amplification factor of the circuit is 147 times, and the common-mode rejection ratio is 110dB. At the same time, the condition of portability was considered, which made the package of the circuit small and portable. The designed circuit has the potential to measure and analyze the user's ECG signal 24 hours a day.