CleanCTG: A Deep Learning Model for Multi-Artefact Detection and Reconstruction in Cardiotocography

TL;DR

CleanCTG is a deep learning model that detects and reconstructs artefacts in cardiotocography signals, significantly improving the accuracy and reliability of fetal monitoring by reducing noise and artefacts.

Contribution

The paper introduces an end-to-end dual-stage deep learning model for comprehensive artefact detection and correction in CTG signals, outperforming existing methods.

Findings

Achieved perfect artefact detection (AU-ROC = 1.00) on synthetic data.

Reduced mean squared error in reconstruction to 2.74 x 10^-4.

Improved clinical decision-making metrics, increasing specificity and reducing decision time.

Abstract

Cardiotocography (CTG) is essential for fetal monitoring but is frequently compromised by diverse artefacts which obscure true fetal heart rate (FHR) patterns and can lead to misdiagnosis or delayed intervention. Current deep-learning approaches typically bypass comprehensive noise handling, applying minimal preprocessing or focusing solely on downstream classification, while traditional methods rely on simple interpolation or rule-based filtering that addresses only missing samples and fail to correct complex artefact types. We present CleanCTG, an end-to-end dual-stage model that first identifies multiple artefact types via multi-scale convolution and context-aware cross-attention, then reconstructs corrupted segments through artefact-specific correction branches. Training utilised over 800,000 minutes of physiologically realistic, synthetically corrupted CTGs derived from expert-verified "clean" recordings. On synthetic data, CleanCTG achieved perfect artefact detection (AU-ROC = 1.00) and reduced mean squared error (MSE) on corrupted segments to 2.74 x 10^-4 (clean-segment MSE = 2.40 x 10^-6), outperforming the next best method by more than 60%. External validation on 10,190 minutes of clinician-annotated segments yielded AU-ROC = 0.95 (sensitivity = 83.44%, specificity 94.22%), surpassing six comparator classifiers. Finally, when integrated with the Dawes-Redman system on 933 clinical CTG recordings, denoised traces increased specificity (from 80.70% to 82.70%) and shortened median time to decision by 33%. These findings suggest that explicit artefact removal and signal reconstruction can both maintain diagnostic accuracy and enable shorter monitoring sessions, offering a practical route to more reliable CTG interpretation.