In-Situ Dehydration Monitoring via a Stable Diffusion-Aided Single-Lead ECG IoMT: ML/DL Models Shine While LLMs Hallucinate

This study introduces a novel, non-invasive approach to monitor hydration status using single-lead electrocardiogram (ECG) signals. MAX86150 internet of medical things (IoMT) module is utilized to collect raw 1-lead ECG data from 65 subjects under fasting and exercise conditions, creating a labeled ECG dataset. To augment the dataset, white Gaussian noise is added to the ECG segments. In addition, synthetic ECG data is generated using STABLE DIFFUSION models trained on the conditioned ECG segments. The augmented data is then fed into various machine learning and deep learning models as part of a baseline evaluation. Two classification tasks are performed: binary classification (hydrated vs. dehydrated) and four-class classification, categorizing hydration level of subjects on a one to four scale. The models report a high accuracy that is up to 98.73% for binary classification, 97.41% for four-class classification in fasting subjects, and 98.32% for sportspeople, showing the potential of using single-lead ECG for hydration monitoring. Additionally, the models decisions are interpreted using LIME-based explainable artificial intelligence (AI) technique, which identifies ECG features such as the RR interval and QRS intervals as relevant biomarkers for dehydration. The study also investigates the use of large language models (LLMs) and large vision models (LVMs) to analyze sequential ECG data for hydration assessment. However, LLMs and LVMs struggle due to the time-series nature of the ECG data and fail to accurately interpret ECG graphs. While LLM and LVM results are not favorable due to hallucinations, this study provides valuable insights into the limitations of these models, paving the way for future research in this area.