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Full-Text Articles in Computer Engineering
Cyber-Physical Modeling Of Implantable Cardiac Medical Devices, Zhihao Jiang, Miroslav Pajic, Rahul Mangharam
Cyber-Physical Modeling Of Implantable Cardiac Medical Devices, Zhihao Jiang, Miroslav Pajic, Rahul Mangharam
Rahul Mangharam
The design of bug-free and safe medical device software is challenging, especially in complex implantable devices that control and actuate organs in unanticipated contexts. Safety recalls of pacemakers and implantable cardioverter defibrillators between 1990 and 2000 affected over 600,000 devices. Of these, 200,000 or 41%, were due to firmware issues and their effect continues to increase in frequency. There is currently no formal methodology or open experimental platform to test and verify the correct operation of medical device software within the closed-loop context of the patient. To this effect, a real-time Virtual Heart Model (VHM) has been developed to model …
From Verification To Implementation: A Model Translation Tool And A Pacemaker Case Study, Miroslav Pajic, Zhihao Jiang, Insup Lee, Oleg Sokolsky, Rahul Mangharam
From Verification To Implementation: A Model Translation Tool And A Pacemaker Case Study, Miroslav Pajic, Zhihao Jiang, Insup Lee, Oleg Sokolsky, Rahul Mangharam
Rahul Mangharam
Model-Driven Design (MDD) of cyber-physical systems advocates for design procedures that start with formal modeling of the real-time system, followed by the model’s verification at an early stage. The verified model must then be translated to a more detailed model for simulation-based testing and finally translated into executable code in a physical implementation. As later stages build on the same core model, it is essential that models used earlier in the pipeline are valid approximations of the more detailed models developed downstream. The focus of this effort is on the design and development of a model translation tool, UPP2SF, and …
Modeling Cardiac Pacemaker Malfunctions With The Virtual Heart Model, Zhihao Jiang, Rahul Mangharam
Modeling Cardiac Pacemaker Malfunctions With The Virtual Heart Model, Zhihao Jiang, Rahul Mangharam
Rahul Mangharam
Implantable cardiac devices such as artificial pacemakers deliver therapies according to the timing information from the heart. Such devices work under the assumptions of perfect sensing, which are: (a) the pacemaker leads remain in place, and (b) the pacing therapy in one chamber (e.g. atrium) is insulated from the other chambers (e.g. ventricles). But there are common cases which violate these assumptions and the mechanisms for imperfect sensing cannot be captured by a simple signal generator. In this paper we use the Penn Virtual Heart Model (VHM) to investigate the spatial and temporal aspects of the electrical conduction system of …
Model-Based Closed-Loop Testing Of Implantable Pacemakers, Zhihao Jiang, Miroslav Pajic, Rahul Mangharam
Model-Based Closed-Loop Testing Of Implantable Pacemakers, Zhihao Jiang, Miroslav Pajic, Rahul Mangharam
Rahul Mangharam
The increasing complexity of software in implantable medical devices such as cardiac pacemakers and defibrillators accounts for over 40% of device recalls. Testing remains the principal means of verification in the medical device certification regime. Traditional software test generation techniques, where the tests are generated independently of the operational environment, are not effective as the device must be tested within the context of the patient's condition and the current state of the heart. It is necessary for the testing system to observe the system state and conditionally generate the next input to advance the purpose of the test. To this …