Multi-modal fusion model for Time-Varying medical Data: Addressing Long-Term dependencies and memory challenges in sequence fusion.

Abstract

Multi-modal time-varying data continuously generated during a patient's hospitalization reflects the patient's disease progression. Certain patient conditions may be associated with long-term states, which is a weakness of current medical multi-modal time-varying data fusion models. Daily ward round notes, as time-series long texts, are often neglected by models. This study aims to develop an effective medical multi-modal time-varying data fusion model capable of extracting features from long sequences and long texts while capturing long-term dependencies. We proposed a model called medical multi-modal fusion for long-term dependencies (MMF-LD) that fuses time-varying and time-invariant, tabular, and textual data. A progressive multi-modal fusion (PMF) strategy was introduced to address information loss in multi-modal time series fusion, particularly for long time-varying texts. With the integration of the attention mechanism, the long short-term storage memory (LSTsM) gained enhanced capacity to extract long-term dependencies. In conjunction with the temporal convolutional network (TCN), it extracted long-term features from time-varying sequences without neglecting the local contextual information of the time series. Model performance was evaluated on acute myocardial infarction (AMI) and stroke datasets for in-hospital mortality risk prediction and long length-of-stay prediction. area under the receiver operating characteristic curve (AUROC), area under the precision-recall curve (AUPRC), and F1 score were used as evaluation metrics for model performance. The MMF-LD model demonstrated superior performance compared to other multi-modal time-varying data fusion models in model comparison experiments (AUROC: 0.947 and 0.918 in the AMI dataset, and 0.965 and 0.868 in the stroke dataset; AUPRC: 0.410 and 0.675, and 0.467 and 0.533; F1 score: 0.658 and 0.513, and 0.684 and 0.401). Ablation experiments confirmed that the proposed PMF strategy, LSTsM, and TCN modules all contributed to performance improvements as intended. The proposed medical multi-modal time-varying data fusion architecture addresses the challenge of forgetting time-varying long textual information in time series fusion. It exhibits stable performance across multiple datasets and tasks. It exhibits strength in capturing long-term dependencies and shows stable performance across multiple datasets and tasks.