Denoising + Fourier Spectrogram ECG CNN

Lightweight convolutional neural network for binary ECG classification that represents ECG beats as spectrograms (via short-time Fourier transform) rather than raw signals, after denoising and frequency filtration to reduce data volume while preserving diagnostically relevant information. Using the large public PTB-XL dataset, the spectrogram-based CNN reached 99.06% accuracy, outperforming an equivalent raw-signal CNN, while also reducing memory usage and computation by avoiding complex architectures; the authors additionally studied the effect of signal up/down-sampling on classification performance.