EAAI Journal 2026 Journal Article
Unsupervised electrocardiogram signal denoising and quality assessment using spectrum-constrained cycle-consistent generative adversarial network
- Meng Chen
- Yongjian Li
- Mingsen Du
- Wenzhuo Shi
- Yali Shi
- Shoushui Wei
Electrocardiograms hold strong promise for noninvasive health monitoring, yet their reliability in wearable systems is frequently undermined by motion artifacts and complex real-world noise. Existing denoising approaches often assume additive or independent noise, limiting their ability to handle the nonstationary interference observed in practice. In this study, we propose a spectrum-constrained cycle-consistent generative adversarial network that performs electrocardiogram denoising using real, unpaired noisy and clean signals, thereby overcoming the dependence on simplified noise models. A spectrum-consistency loss based on the Wasserstein–Fourier distance is introduced to preserve frequency characteristics, while feature-attention and temporal-attention modules enhance the generator's representational capacity. Instance normalization in the discriminator further stabilizes adversarial training. Beyond denoising, the proposed method leverages the latent representations of the clean-domain generator and discriminator to estimate noise severity and to perform signal quality assessment. This enables automatic identification and exclusion of severely degraded segments, which is essential for reliable downstream tasks such as monitoring key electrocardiographic peaks and arrhythmia classification. Extensive experiments on synthetic data, wearable long-term electrocardiograms, and twelve-lead clinical recordings demonstrate that our method achieves competitive reconstruction accuracy and spectral fidelity. Compared with competitive supervised and unsupervised baselines, our method improves the median signal-to-noise ratio from 11. 54–26. 39 dB–28. 98 dB. Incorporating signal quality assessment produces additional gains by preventing low-quality segments from propagating errors into subsequent analyses. With only 0. 86 million parameters and a throughput of 170, 616 samples per second, the proposed method is computationally efficient and well suitable for real-world wearable and clinical monitoring scenarios.