| Aiming at the characteristics of weak ECG and low signal-to-noise ratio, a signal extraction system is designed, which is composed of multi-stage amplification and step-by-step filtering. The design principle of circuit at all levels is introduced, and the key problems involved in the design process are analyzed in detail. At the same time, the core filter circuit of the system is simulated by Multisim, and the results show that the filtering effect is good. Finally, the ECG signal is obtained from the prototype, and compared with the standard ECG, the ECG signal can be extracted clearly and completely, which can meet the design requirements and can be used as the ECG signal extraction. |