Two-stage Amplifier Design for ECG Signal Processing

The electrocardiogram (ECG) is a widely used medical diagnostic tool for assessing the electrical activity of the heart. This study focuses on the signal processing aspect of ECG analysis, encompassing signal generation, filtering, amplification, and denoising. After investigating the generation of ECG signals, this passage applies a cascade of filtering techniques, including Low-pass Filtering, high-pass Filtering, and notch filters, to preprocess the acquired ECG signals. Subsequently, a two-stage amplifier is employed to enhance the weak ECG signals, making them more observable for subsequent analysis. To further improve the signal quality, denoising techniques such as Wavelet Denoising, Empirical Mode Decomposition, and Empirical Wavelet Transform are applied. The design and simulation of the two-stage amplifier using CoolSpice resulted in an 80 dB DC gain and a -3dB bandwidth of approximately 3 kHz, while maintaining a stable phase margin of approximately 50 degrees, ensuring reliable amplification. The favorable characteristics observed in the simulation results demonstrate the viability of integrating the two-stage amplifier into future ECG signal processing applications.