Heart modelling for closed-loop validation of implantable cardiac devices
Implantable cardiac devices are recommended by physicians to sustain life while improving the overall quality of life of the patients. However, a large number of safety recalls have taken place with the rapid increase of implantations, which suggests rigorous and novel validation approaches.
We propose a closed-loop validation framework with a heart model, which includes synchronous observers acting both as an automated oracle and also as a requirements coverage monitor. The observer combines an on-line testing adequacy evaluation module together with a heuristic learning module, which has the potential to guide the on-line test generation and execution to meet the required requirements coverage criteria.
In addition, significant improvements were made to an existing cardiac cell model to stabilise its activation behaviour and to an existing path model to capture the behaviour of continuous electrical propagation. Moreover, a new pacemaker cell model has been developed with the capability of capturing rate-dependent dynamics such as action potential duration (APD) restitution, conduction velocity (CV) restitution and overdrive suppression. With the improvements, we are able to explore a wide range of arrhythmias to exercise the devices in order to achieve high validation coverage.
Weiwei Ai received the B.S. degree in 2003 from Qingdao University, China, and the M.E. degree in 2006 from Beijing University of Technology, China. From 2006 to 2013, she worked as a reliability and failure analysis engineer in CEC Huada Electronic Design Co.,Ltd. She is currently working towards the Ph.D. degree at the the University of Auckland, New Zealand. Her research interests are in verification and validation with a focus on medical devices.