Contrast Everything: A Hierarchical Contrastive Framework for Medical Time-Series

Published: 21 Sept 2023, Last Modified: 19 Dec 2023NeurIPS 2023 posterEveryoneRevisionsBibTeX
Keywords: Deep Learning, Contrastive Learning, Self-supervised Learning, Time Series, Healthcare
TL;DR: A novel self-supervised contrastive representation learning framework that harnesses four levels of data consistency (observation, sample, trial, and patient) to enhance medical time series analysis.
Abstract: Contrastive representation learning is crucial in medical time series analysis as it alleviates dependency on labor-intensive, domain-specific, and scarce expert annotations. However, existing contrastive learning methods primarily focus on one single data level, which fails to fully exploit the intricate nature of medical time series. To address this issue, we present COMET, an innovative hierarchical framework that leverages data consistencies at all inherent levels in medical time series. Our meticulously designed model systematically captures data consistency from four potential levels: observation, sample, trial, and patient levels. By developing contrastive loss at multiple levels, we can learn effective representations that preserve comprehensive data consistency, maximizing information utilization in a self-supervised manner. We conduct experiments in the challenging patient-independent setting. We compare COMET against six baselines using three diverse datasets, which include ECG signals for myocardial infarction and EEG signals for Alzheimer’s and Parkinson’s diseases. The results demonstrate that COMET consistently outperforms all baselines, particularly in setup with 10% and 1% labeled data fractions across all datasets. These results underscore the significant impact of our framework in advancing contrastive representation learning techniques for medical time series. The source code is available at
Supplementary Material: pdf
Submission Number: 5476