Design and Simulation of a Modular Single-Lead ECG Analog Front-End for Low-Noise Biomedical Signal Acquisition

Electrocardiography (ECG) is an important non-invasive technique for monitoring cardiac electrical activity and is increasingly incorporated into portable, wearable, and long-term monitoring systems. Reliable ECG acquisition is challenging because the desired biological signal is relatively weak and can be affected by baseline variations, electrode-related disturbances, common-mode interference, and environmental electrical noise. The analog front-end (AFE) consequently has a major influence on the quality of the acquired signal. This paper presents the design and simulation of a modular single-lead ECG analog front-end intended for portable and research-oriented biomedical signal acquisition. The proposed architecture integrates differential signal acquisition, precision amplification, frequency-selective signal conditioning, common-mode interference reduction, and ADC-compatible signal buffering. The design emphasizes a practical balance between signal quality, implementation complexity, flexibility, and low-voltage operation. Unlike highly integrated ECG solutions, the proposed approach separates the major signal-conditioning functions into independently analyzable stages, enabling straightforward modification and optimization. A -based system-level numerical simulation is performed to evaluate the overall frequency response, signal gain, low-frequency baseline suppression, high-frequency attenuation, and power-line interference rejection. The simulated response demonstrates that the proposed architecture provides an effective ECG passband while maintaining the required signal-conditioning characteristics for subsequent digital acquisition. The results indicate that the proposed architecture can serve as a flexible platform for ECG acquisition research and prototype development.

کلیدواژه ها:

ECG ، electrocardiography ، analog front-end ، biomedical signal acquisition ، instrumentation amplifier ، common-mode rejection ، signal conditioning ، wearable electronics