Real-time Heart Model for Implantable Cardiac Device Validation and Verification

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Conference Paper

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author={Zhihao Jiang and Pajic, M. and Connolly, A. and Dixit, S. and Mangharam, R.},
booktitle={Real-Time Systems (ECRTS), 2010 22nd Euromicro Conference on},
title={Real-Time Heart Model for Implantable Cardiac Device Validation and Verification},
keywords={cardiology;defibrillators;formal verification;medical computing;pacemakers;bug-free medical device software;closed-loop experimentation;electrophysiological operation;firmware problems;formal validation;formal verification;implantable cardiac device validation;pacemakers;real-time heart model;timed-automata model;Automata;Electric potential;Heart;Pacemakers;Probes;Software;Timing;Medical Devices;cyber-physical systems;formal verification;pacemaker;real-time systems;safety-critical systems;sotware validation},


Designing bug-free medical device software is challenging, especially in complex implantable devices that may be used in unanticipated contexts. Safety recalls of pacemakers and implantable cardioverter defibrillators due to firmware problems between 1990 and 2000 affected over 200, 000 devices. This encompasses 41% of the devices recalled and continues to increase in frequency. There is currently no formal methodology or open experimental platform to validate and verify the correct operation of medical device software. To this effect, a real-time Virtual Heart Model (VHM) has been developed to model the electrophysiological operation of the functioning (i.e. during normal sinus rhythm) and malfunctioning (i.e. during arrhythmia) heart. We present a methodology to construct a timed-automata model by extracting timing properties of the heart. The platform employs functional and formal interfaces for validation and verification of implantable cardiac devices. We demonstrate the VHM is capable of generating clinically-relevant response to intrinsic (i.e. premature stimuli) and external (i.e. artificial pacemaker) signals for a variety of common arrhythmias. By connecting the VHM with a pacemaker model, we are able to pace and synchronize the heart during the onset of irregular heart rhythms. The VHM has also been implemented on a hardware platform for closed-loop experimentation with existing and virtual medical devices. This integrated functional and formal device design approach has potential to help expedite medical device certification for safe operation.


cardiology, formal verification, medical computing, pacemakers, bug-free medical device software, closed-loop experimentation, electrophysiological operation, firmware problems, formal validation, formal verification, implantable cardiac device validation, pacemakers, real-time heart model, timed-automata model, Automata, Electric potential, Heart, Timing, Medical Devices, cyber-physical systems, safety-critical systems



Date Posted: 20 August 2012

This document has been peer reviewed.