Abstract:Large language models (LLMs) exhibit remarkable capabilities in visual inspection of medical time-series data, achieving proficiency comparable to human clinicians. However, their broad scope limits domain-specific precision, and proprietary weights hinder fine-tuning for specialized datasets. In contrast, small specialized models (SSMs) excel in targeted tasks but lack the contextual reasoning required for complex clinical decision-making. To address these challenges, we propose ConMIL (Conformalized Multiple Instance Learning), a decision-support SSM that integrates seamlessly with LLMs. By using Multiple Instance Learning (MIL) to identify clinically significant signal segments and conformal prediction for calibrated set-valued outputs, ConMIL enhances LLMs' interpretative capabilities for medical time-series analysis. Experimental results demonstrate that ConMIL significantly improves the performance of state-of-the-art LLMs, such as ChatGPT4.0 and Qwen2-VL-7B. Specifically, \ConMIL{}-supported Qwen2-VL-7B achieves 94.92% and 96.82% precision for confident samples in arrhythmia detection and sleep staging, compared to standalone LLM accuracy of 46.13% and 13.16%. These findings highlight the potential of ConMIL to bridge task-specific precision and broader contextual reasoning, enabling more reliable and interpretable AI-driven clinical decision support.
Abstract:Time series probabilistic forecasting with multi-dimensional and sporadic data (known as sparse data) has potential to implement monitoring kinds of physiological indices of patients in Intensive Care Unit (ICU). In this paper, we propose Transformer-based Diffusion probabilistic model for Sparse Time series Forecasting (TDSTF), a new model to predict distribution of highly sparse time series. There are many works that focus on probabilistic forecasting, but few of them avoid noise that come from extreme sparsity of data. We take advantage of Triplet, a data organization that represents sparse time series in a much efficient way, for our model to bypass data redundancy in the traditional matrix form. The proposed model performed better on MIMIC-III ICU dataset than the current state-of-the-art probabilistic forecasting models. We obtained normalized average continuous ranked probability score (CRPS) of $\mathbf{0.4379}$, and mean squared error (MSE) of $\mathbf{0.4008}$ when adopting the median of the model samplings as the deterministic forecasting. Our code is provided at https://github.com/PingChang818/TDSTF.