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Closed-loop verification of medical devices with model abstraction and refinement

  • Zhihao JiangEmail author
  • Miroslav Pajic
  • Rajeev Alur
  • Rahul Mangharam
TACAS 2012

Abstract

The design and implementation of software for medical devices is challenging due to the closed-loop interaction with the patient, which is a stochastic physical environment. The safety-critical nature and the lack of existing industry standards for verification make this an ideal domain for exploring applications of formal modeling and closed-loop analysis. The biggest challenge is that the environment model(s) have to be both complex enough to express the physiological requirements and general enough to cover all possible inputs to the device. In this effort, we use a dual chamber implantable pacemaker as a case study to demonstrate verification of software specifications of medical devices as timed-automata models in UPPAAL. The pacemaker model is based on the specifications and algorithm descriptions from Boston Scientific. The heart is modeled using timed automata based on the physiology of heart. The model is gradually abstracted with timed simulation to preserve properties. A manual Counter-Example-Guided Abstraction and Refinement (CEGAR) framework has been adapted to refine the heart model when spurious counter-examples are found. To demonstrate the closed-loop nature of the problem and heart model refinement, we investigated two clinical cases of Pacemaker Mediated Tachycardia and verified their corresponding correction algorithms in the pacemaker. Along with our tools for code generation from UPPAAL models, this effort enables model-driven design and certification of software for medical devices.

Keywords

Medical devices Implantable pacemaker Software verification Cyber-physical systems Model abstraction and refinement CEGAR 

Notes

Acknowledgments

The authors would like to thank Ashutosh Trivedi, from the University of Pennsylvania and the Indian Institute of Technology, Mumbai, for fruitful discussions during the preparation of this paper.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Zhihao Jiang
    • 1
    Email author
  • Miroslav Pajic
    • 1
  • Rajeev Alur
    • 1
  • Rahul Mangharam
    • 1
  1. 1.University of PennsylvaniaPhiladelphiaUSA

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