DE3S: Dual-Enhanced Soft-Sparse-Shape Learning for Medical Early Time-Series Classification

Abstract: Early time-series classification (ETSC) in medical applications is crucial for time-sensitive scenarios such as sepsis prediction in intensive care units (ICUs), where a large number of deaths are caused by delayed prediction. ETSC can significantly improve ICU resource utilization efficiency and healthcare precision. However, it faces conflicting goals of accuracy and earliness, with existing methods often trading one for the other, struggling to capture subtle early-stage patterns due to weak initial signals and class imbalance. The key to solve these challenges is to find shapelets, which are discriminative subsequences (or shapes) with high interpretability in time-series classification. This paper proposes Dual-Enhanced Soft-Sparse-Shape Learning for Medical Early Time-Series Classification (DE3S), which introduces a novel Dual-Enhanced Soft-Shape Learning framework to figure out shapelets precisely through three innovations: (1) a comprehensive dual-enhancement strategy combines traditional temporal augmentation with attention-based global temporal enhancement for robust representation learning, (2) an attention-score-based soft shapelet sparsification mechanism dynamically preserves discriminative patterns while aggregating less important shapelets into representative tokens, and (3) a dual-path Mixture of Experts Network (MoE) and Inception modules fusion architecture where MoE performs local learning within shapelets and multi-scale Inception modules capture global patterns across shapelets. The framework employs weighted cross-entropy loss for class imbalance handling and demonstrates robustness on subject-consistency datasets. Extensive experiments on six real-world medical datasets show state-of-the-art performance, with ablation studies confirming component efficacy.