A novel approach to classification of ECG arrhythmia types with latent ODEs
Angelina Yan, Matt L. Sampson, Peter Melchior
TL;DR
This work tackles the challenge of arrhythmia detection from wearable ECG data by introducing an end-to-end pipeline that uses a path-minimized latent ODE to encode high-frequency ECG waveforms into compact latent vectors, which are then classified by a gradient boosted decision tree. The model is trained on the MIT-BIH Arrhythmia dataset at 360 Hz and evaluated under downsampled conditions of 90 Hz and 45 Hz, showing minimal degradation in macro-averaged AUC-ROC across frequencies (0.984, 0.978, 0.976). The approach leverages SMOTE balancing and mode aggregation over multiple latent samples to handle class imbalance and produce robust predictions. The results suggest that high-fidelity arrhythmia classification can be achieved with lower-frequency wearable data, enabling smaller, longer-lasting devices for continuous cardiac monitoring, though limitations include dataset size and minority-class performance. Overall, the work demonstrates that latent-ODE encodings can preserve essential morphology for reliable downstream classification even when signal fidelity is reduced, which has practical implications for proactive health monitoring.
Abstract
12-lead ECGs with high sampling frequency are the clinical gold standard for arrhythmia detection, but their short-term, spot-check nature often misses intermittent events. Wearable ECGs enable long-term monitoring but suffer from irregular, lower sampling frequencies due to battery constraints, making morphology analysis challenging. We present an end-to-end classification pipeline to address these issues. We train a latent ODE to model continuous ECG waveforms and create robust feature vectors from high-frequency single-channel signals. We construct three latent vectors per waveform via downsampling the initial 360 Hz ECG to 90 Hz and 45 Hz. We then use a gradient boosted tree to classify these vectors and test robustness across frequencies. Performance shows minimal degradation, with macro-averaged AUC-ROC values of 0.984, 0.978, and 0.976 at 360 Hz, 90 Hz, and 45 Hz, respectively, suggesting a way to sidestep the trade-off between signal fidelity and battery life. This enables smaller wearables, promoting long-term monitoring of cardiac health.
