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![A typical one-cycle ECG tracing [1]](profile/Dominique-Mery/publication/224920657/figure/fig2/AS:302848932892682@1449216220801/A-typical-one-cycle-ECG-tracing-1.png)
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![Fig. 2. Heart or Natural Pacemaker [27]](profile/Dominique-Mery/publication/224920657/figure/fig1/AS:302848932892680@1449216220580/Heart-or-Natural-Pacemaker-27_Q320.jpg)
![Fig. 3. A typical one-cycle ECG tracing [1]](profile/Dominique-Mery/publication/224920657/figure/fig2/AS:302848932892682@1449216220801/A-typical-one-cycle-ECG-tracing-1_Q320.jpg)
![Fig. 6. Time Intervals and Impulse Propagation in the ECG signal [1]](profile/Dominique-Mery/publication/224920657/figure/fig3/AS:667683255230474@1536199501286/Time-Intervals-and-Impulse-Propagation-in-the-ECG-signal-1_Q320.jpg)
Formal methods based tools and techniques have been recognised to be a promising approach to support the process of verification and validation of a critical system in early stage of the development. Specially, medical devices are very prone to show an unexpected behavior of the system in operating due to stochastic nature of the system and when a...
Contexts in source publication
Context 1
... records are obtained by sampling the bio- electric currents sensed by several electrodes, known as leads. A typical one-cycle ECG tracing is shown in Fig.-3. Electrocardiogram term is introduced by Willem Einthoven in 1893 at a meeting of the Dutch Medical Society. ...
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... normal electrocardiogram (ECG or EKG) is depicted in Fig.-3. All kinds of segments and intervals are represented in this ECG diagram. ...
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... node A in Fig. 5(a). The sinoatrial (SA) node is the physiological pacemaker of the normal heart, responsible for setting the rate and rhythm. The electrical impulse spreads through the walls of the atria, caus- ing them to contract. The conduction of the electrical impulse throughout the left and right atria is seen on the ECG as the P wave (see Fig. 3). From the sinus node, electrical impulse propagates throughout the atria and reach to the nodes B and C, but cannot propagate directly across the boundary between atria and ventricles. The electrical im- pulse travels outward into atrial muscle fibers and reached at the end of muscle fibers, which is represented by the node C in the ...
Context 4
... AV node functions as a critical delay in the conduction system. Without this delay, the atria and ventricles would contract at the same time, and blood wouldn't flow effectively from the atria to ventricles. The delay in the AV node forms much of the PR segment on the ECG. Part of atrial repolarization can be represented by the PR segment (see Fig. 3). Propagation from the atrioventricular (AV) node (A) to the ventricles is provided by a specialized conduction system. The distal portion of AV node is composed of a com- mon bundle, called the bundle of His is denoted as a landmark node D (see Fig. 4(b)). The bundle of His splits into two branches in the inter-ventricular septum, the ...
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Citations
This chapter concludes the book through summarising important points of each chapter. The main contribution of this book is to propose the formal methods based development life-cycle and associated techniques and tools, that are exemplified by the grand challenge related to the cardiac pacemaker. Additionally, this book provides a technique for identifying anomalies in the standard ECG protocol through incremental formalisation in Event-B.
Building high quality and zero defects medical software-based devices is a critical task, and formal modelling techniques can effectively help to achieve this target at the certain level. Formal modelling of a high-confidence medical device, such as that is too much error prone in operating, is an international Grand Challenge in the area of Verified Software. Modelling a cardiac pacemaker is one of the proposed challenges, and we consider the complete description of pacemaker’s functionalities using an incremental proof-based approach. To assess the effectiveness of our proposed development methodology and associated techniques and tools, we select this case study. This chapter presents the development of a cardiac pacemaker using our proposed development life-cycle methodology from requirement analysis to automatic code generation. In this development, we use formal verification to verify the correctness of the requirements for a simple and closed-loop model, model checking to verify the correctness of the system behaviours, real-time animator to check the system behaviours according to the domain experts (i.e. medical experts), and finally the code generation tool EB2ALL for generating the codes into several programming languages. The refinement charts are used to handle the complexity of the system, where it helps to organise the code structure according to the different operating modes. Formal models are expressed in the Event-B modelling language, which integrates conditions (called proof obligations) for checking their internal consistency with respect to the invariants and safety properties. The generated proof obligations of models are proved by the Rodin tool and desired behaviour of the system is validated by the ProB tool and real-time animator according to the medical experts.
A closed-loop model of a system is considered as a de facto standard in the area of system engineering for validating a system model. Cardiac pacemakers and implantable cardioverter-defibrillators (ICDs) are the most critical of these medical devices, requiring closed-loop modelling (integrated system and environment modelling) for verification purposes before obtaining a certificate from the certification bodies. This chapter presents a methodology for modelling a biological system, such as the heart, to enable modelling in a biological environment. The heart model is based mainly on electrocardiography analysis, which models the heart system at the cellular level. This heart model will be used for modelling the closed-loop system of a cardiac pacemaker.
The development of critical medical systems requires high levels of confidence in increasingly complex software systems. Formal methods have been identified as a means of contributing to assurance in this domain. We present a closed-loop modeling approach between an electrocardiography analysis based heart model and pacemaker. This stem is a step towards a modeling approach for medical systems at early stage of the system development. Implantable devices like cardiac pacemakers and implantable cardioverter-defibrillators require closed-loop modeling (integrated system and environment modeling) to qualify the certification standards. The industry has long sought such an approach to validating a system model in a virtual biological environment. This approach involves a pragmatic combination of formal specifications of the system and the biological environment to model a closed-loop system that enables verification of the correctness of the system and helps to improve the quality of the system.
Tools and techniques based on formal methods have been recognized as a promising approach to supporting the process of verification and validation of critical systems in the early stages of their development. In particular, medical devices are very prone to showing unexpected system behaviour in operation because of the stochastic nature of the systems and when traditional methods are used for system testing. Device-related problems have been responsible for a large number of serious injuries. Officials of the US Food and Drug Administration (FDA) have found that many deaths and injuries related to these devices are caused by flaws in product design and engineering. Cardiac pacemakers and implantable cardioverter–defibrillators (ICDs) are the most critical of these medical devices, requiring closed-loop modelling (integrated system and environment modelling) for verification purposes before obtaining a certificate from the certification bodies. No technique is available to provide environment modelling for verifying the developed system models. This paper presents a methodology for modelling a biological system, such as the heart, to enable modelling in a biological environment. The heart model is based mainly on electrocardiography analysis, which models the heart system at the cellular level. The main objective of this methodology is to model the heart system and integrate it with a model of a medical device such as a cardiac pacemaker to specify a closed-loop model. To build an environment model for a closed-loop system is currently an open problem. The industry has long sought such an approach to validating a system model in a virtual biological environment. Our approach involves a pragmatic combination of formal specifications of the system and the biological environment to model a closed-loop system that enables verification of the correctness of the system and helps to improve the quality of the system.
This report documents the program and the outcomes of Dagstuhl Seminar 14062 “The Pacemaker
Challenge: Developing Certifiable Medical Devices”. The aim of the seminar was to bring
together leading researchers and industrial partners of this field; the seminary ended up with 24
participants from 8 countries: Canada, Denmark, France, The Unites States, Germany, United
Kingdom, Brazil. Through a series of presentations, discussions, and working group meetings,
the seminar attempted to get a general view of the field of medical devices and certification issues
through the pacemaker challenge. The seminar brought together, on the one hand, researchers
from the different notations and various tools. The main outcome of the seminar is the exchange
of information between different groups and the project of a book.
