Development and Validation of CPX-MATE: An End-to-End Medical Education Platform Integrating Voice-Based Virtual Patient Simulation and Automated Real-time Evaluation

ABSTRACT Background Objective Structured Clinical Examination (OSCE; Clinical Performance Examination [CPX] in South Korea) is a high-stakes assessment of clinical performance, communication, and reasoning during time-limited patient encounters. As AI-enabled virtual standardized patient (VSP) simulation and automated scoring are introduced for OSCE-like training, prospective evidence is needed on how such systems perform and are perceived when embedded in real educational workflows. Methods We developed CPX with Medical students’ Assistant for Training and Evaluation (CPX-MATE), a web-based platform integrating (1) CPX with Virtual Standardized Patient (CPX-VSP), real-time voice dialogue with a VSP using speech-to-speech (STS) models, and (2) CPX with Real-Time Evaluator (CPX-RTE), automated transcription, checklist-based scoring, and feedback from encounter audio using a Speech-to-Text model and a large language model. During an emergency medicine clerkship (Nov 2025-Jan 2026), 60 senior medical students completed two 12-min CPX encounters (VSP with acute pancreatitis; HSP with ureteral stone) with immediate CPX-RTE feedback. For CPX-VSP, students were assigned to either a full-capacity or a resource-limited STS configuration (n=30 each). Dialogue fidelity was evaluated by turn-by-turn analysis of student–VSP exchanges, classifying responses into clinically meaningful error types (tangential, oversharing, role-breaking, off-script). CPX-RTE performance was assessed by agreement (Gwet’s AC1) with professor real-time and resident video-based ratings using a 45-item checklist. Usability of CPX-VSP and CPX-RTE, with overall system usability scale (SUS), were surveyed, and mean per-session costs for CPX-VSP and CPX-RTE were calculated. Results Across 3,282 dialogue turns, overall error rates were 1.77% versus 9.43% for full-capacity versus resource-limited STS configurations (p