Semantic NLP Pipelines for Interoperable Patient Digital Twins from Unstructured EHRs
Rafael Brens, Yuqiao Meng, Luoxi Tang, Zhaohan Xi
TL;DR
The paper addresses the challenge of converting unstructured EHR content into interoperable patient digital twins using a semantic NLP pipeline aligned to the FHIR standard. It combines transformer-based NER, ontology-grounded normalization, and relation extraction to build minimal FHIR-compliant digital twins. Evaluation on the MIMIC-IV Demo with reference mappings shows significant gains in entity and relation extraction, semantic completeness, and interoperability. The work demonstrates the feasibility of end-to-end automated mapping from free-text to standards-based digital twins and outlines directions for extending longitudinal, multi-modal, and cross-institution generalization.
Abstract
Digital twins -- virtual replicas of physical entities -- are gaining traction in healthcare for personalized monitoring, predictive modeling, and clinical decision support. However, generating interoperable patient digital twins from unstructured electronic health records (EHRs) remains challenging due to variability in clinical documentation and lack of standardized mappings. This paper presents a semantic NLP-driven pipeline that transforms free-text EHR notes into FHIR-compliant digital twin representations. The pipeline leverages named entity recognition (NER) to extract clinical concepts, concept normalization to map entities to SNOMED-CT or ICD-10, and relation extraction to capture structured associations between conditions, medications, and observations. Evaluation on MIMIC-IV Clinical Database Demo with validation against MIMIC-IV-on-FHIR reference mappings demonstrates high F1-scores for entity and relation extraction, with improved schema completeness and interoperability compared to baseline methods.
