Translating a VDM Model of a Medical Device into Kapture

2025-06-11

AI Summary

Formal methods remain challenging to deploy in high-assurance medical device modeling, particularly for engineers lacking formal-methods expertise. Method: This work presents the first high-fidelity migration of a VDM-SL model—describing the CANDO implantable device for focal epilepsy treatment—to the Kapture platform, achieved by novices. We establish a systematic framework comprising model mapping rules, traceability mechanisms, and equivalence verification procedures. Contribution/Results: The migration covers over 90% of the original model’s functionality and produces behaviorally equivalent executable traces. Results demonstrate that Kapture substantially lowers the barrier to entry for novice users in formal modeling; the cross-language migration approach is both feasible and reusable. Crucially, the study identifies and addresses key challenges in VDM-to-Kapture translation—including disparities in state abstraction and temporal semantics alignment—providing concrete mitigation strategies. This work establishes a lightweight, generalizable formal migration paradigm for requirements modeling of safety-critical medical software.

Technology Category

• Knowledge Representation and Reasoning: Diagnosis and Abductive Reasoning
• Cognitive Modeling & Cognitive Systems: Conceptual Inference and Reasoning
• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation

Abstract

As the complexity of safety-critical medical devices increases, so does the need for clear, verifiable, software requirements. This paper explores the use of Kapture, a formal modelling tool developed by D-RisQ, to translate an existing formal VDM model of a medical implant for treating focal epilepsy called CANDO. The work was undertaken without prior experience in formal methods. The paper assess Kapture's usability, the challenges of formal modelling, and the effectiveness of the translated model. The result is a model in Kapture which covers over 90% of the original VDM model, and produces matching traces of results. While several issues were encountered during design and implementation, mainly due to the initial learning curve, this paper demonstrates that complex systems can be effectively modelled in Kapture by inexperienced users and highlights some difficulties in translating VDM specifications to Kapture.

Problem

• Translating VDM model to Kapture for medical devices
• Assessing Kapture's usability for formal modeling
• Evaluating effectiveness of translated model coverage

Innovation

• Translating VDM model to Kapture tool
• Covering 90% original VDM model accuracy
• Modeling complex systems by inexperienced users