A Robust Current-Feedback Operational Amplifier-Based Front-End Amplifier for Electrocardiogram Signal Noise Removal

Area of Science:

• Biomedical Engineering
• Electronics Engineering

Background:

• Electrocardiogram (ECG) signals are crucial for cardiac monitoring but are susceptible to various noise sources.
• Common ECG noise includes baseline wander (BW), powerline interference (PLI), and motion artifacts, which can obscure vital diagnostic information.

Purpose of the Study:

• To develop and validate a novel front-end amplifier circuit for ECG noise removal.
• To enhance the fidelity of ECG signals for improved diagnostic accuracy, particularly in wearable applications.

Main Methods:

• Design of a current-feedback operational amplifier (CFOA)-based ECG pre-amplifier utilizing the AD844 operational amplifier.
• Implementation of a balancing instrumentation amplifier architecture for superior noise rejection.
• Integration of a novel cascaded low-pass filter (LPF) stage for effective high-frequency interference suppression.

Main Results:

• The proposed CFOA-based amplifier achieved a high common-mode rejection ratio (CMRR) of 75.4 dB.
• A mid-band gain of 46.5 dB was obtained, demonstrating effective signal amplification.
• The circuit successfully eliminated baseline wander (BW) and powerline interference (PLI).

Conclusions:

• The developed ECG noise removal front-end amplifier demonstrates robust performance suitable for high-fidelity wearable ECG monitoring.
• The innovative architecture and filtering stages effectively denoise ECG signals, improving diagnostic signal quality.