Characteristics of medical device software development

This paper aims to describe the software development settings of medical device domain focusing on the demands of the safety critical software processes. Medical device software developers have to adhere to a number of regulations and standards. This paper addresses the most important characteristics of a software development framework that could support medical device software developers in their efforts to comply with these regulations as well as to improve their software development processes

Challenges Experienced by Medical Device Software Organisations while following a Plan-driven SDLC

Medical device software organisations face challenges not faced by generic software development organisations. These challenges include the adherence to regulatory controls. Regulatory bodies require medical device software organisations to provide objective evidence that the software they are developing is safe and reliable. To produce this, regulatory bodies require a number of deliverables which must be achieved. However, they do not dictate which Software Development Life Cycle (SDLC) must be followed in order to achieve these deliverables. Despite not dictating which SDLC must be followed when developing medical device software, organisations typically develop their software in accordance with a Plan-Driven software development lifecycle. By conducting semi structured interviews with seven medical device software organisations, we gained a deeper insight into how the challenges experienced impact on the development of medical device software. The interviews also attempted to learn from the participants how they believe the challenges experienced can be overcome. The aim of this paper is to explain the methodology used to perform interviews with medical device software organisations and to present these interviews

High-Confidence Medical Device Software Development

The design of bug-free and safe medical device software is challenging, especially in complex implantable devices. This is due to the device\u27s closed-loop interaction with the patient\u27s organs, which are stochastic physical environments. The life-critical nature and the lack of existing industry standards to enforce software validation make this an ideal domain for exploring design automation challenges for integrated functional and formal modeling with closed-loop analysis. The primary goal of high-confidence medical device software is to guarantee the device will never drive the patient into an unsafe condition even though we do not have complete understanding of the physiological plant. There are two major differences between modeling physiology and modeling man-made systems: first, physiology is much more complex and less well-understood than man-made systems like cars and airplanes, and spans several scales from the molecular to the entire human body. Secondly, the variability between humans is orders of magnitude larger than that between two cars coming off the assembly line. Using the implantable cardiac pacemaker as an example of closed-loop device, and the heart as the organ to be modeled, we present several of the challenges and early results in model-based device validation. We begin with detailed timed automata model of the pacemaker, based on the specifications and algorithm descriptions from Boston Scientific. For closed-loop evaluation, a real-time Virtual Heart Model (VHM) has been developed to model the electrophysiological operation of the functioning and malfunctioning (i.e., during arrhythmia) hearts. By extracting the timing properties of the heart and pacemaker device, we present a methodology to construct timed-automata models for formal model checking and functional testing of the closed-loop system. The VHM\u27s capability of generating clinically-relevant response has been validated for a variety of common arrhythmias. Based on a set of requirements, we describe a framework of Abstraction Trees that allows for interactive and physiologically relevant closed-loop model checking and testing for basic pacemaker device operations such as maintaining the heart rate, atrial-ventricle synchrony and complex conditions such as avoiding pacemaker-mediated tachycardia. Through automatic model translation of abstract models to simulation-based testing and code generation for platform-level testing, this model-based design approach ensures the closed-loop safety properties are retained through the design toolchain and facilitates the development of verified software from verified models. This system is a step toward a validation and testing approach for medical cyber-physical systems with the patient-in-the-loop

An Agile V-Model for Medical Device Software Development to Overcome the Challenges with Plan Driven SDLCs

Through the use of semi structured interviews with medical device software organizations it emerged that medical device software organizations are experiencing difficulties when following plan driven Software Development Life Cycles (SDLC), particularly in the area of requirements management. To attempt to resolve these issues an examination of the non-regulated industry was performed to determine if lessons learned there could be applied to the development of medical device software. This examination revealed that agile methods are being widely adopted in the non-regulated software industry. To learn if agile methods could be adopted when developing medical device software a mapping study was performed which looked for instances of where agile methods have been used in regulated industries and where they have been adopted, to what success. This mapping study revealed that incorporating agile practices with the existing plan driven SDLC is the most favourable choice for medical device software organizations. This research aims to develop a SDLC which has a foundation of a plan driven SDLC which incorporates agile practices which can be followed when developing regulatory compliant software

Medical Device Software: From Requirements to Certification

The role of software in healthcare is getting more and more pervasive. Nevertheless, manufacturers sometimes forget that these software are medical devices and must be certified according to the EU Medical Device Regulation 2017/745. In this work we propose a pipeline for developing a Medical Device Software (MDS) compliant with the regulations and certifiable. The pipeline includes the phase of requirements elicitation, risk assessment and analysis of effectiveness as key elements. The preparation of the technical file should be carried out in parallel with the MDS development. In the overall, it can be stated that the certification process starts with the conceptualization of the MDS and proceeds all along its design and implementation

Integrating Agile Practices with a Medical Device SDLC.

The rate at which agile software development practices are being adopted is growing rapidly. Agile software development practices and methodologies appear to offer the silver bullet which can solve the problems associated with following plan driven software development lifecycles. Agile software development practices offer the possibility of achieving lower development costs, increased efficiency and improved software quality. However, there is currently a low rate of publicly available information that suggests there is widespread adoption of agile practices within the medical device software domain. This is largely due to the fact that software developed for medical devices includes challenges not faced when developing non safety critical software. As a result of these challenges, medical device software is typically developed using plan driven software development lifecycles. However, such lifecycles are quite rigid and cannot accommodate changes easily. Previous research has revealed that medical device software development projects can benefit from adopting agile practices whilst still maintaining the discipline associated with following plan driven development lifecycles. This paper outlines the challenges faced by developers when developing medical device software and how shortcomings in both agile and plan driven approaches can be resolved by following a mixed method approach to medical device software developmen

Medical device software as a subsystem of an overall medical device

Embedded software is a sub-system that needs to be integrated with the electrical and mechanical subsystems for a functional medical device to be developed and marketed. In order to be able to develop a medical device system through integrating its sub-systems, the complete system requirements should be known at the start of the project and managed throughout development. Software requirements are then derived from the systems requirements. We have developed and piloted a medical device software process assessment framework called MDevSPICE® that integrates processes from various medical device software standards as well as generic software development standards. This paper describes how the MDevSPICE® framework has been designed so as to enable medical device software developers to produce software that will be safe and easily integrated with other sub-systems of the overall medical device. We also describe the lessons learned from piloting MDevSPICE® in the medical device industry and challenges medical device software developers meet in tracing requirements and risks to and from the system level

Adopting Agile Practices when Developing Medical Device Software

Agile methods are gaining momentum amongst the developers of non-safety critical software. They offer the ability to improve development time, increase quality and reduce development costs. Despite this, the rate of adoption of agile methods within safety critical domains remains low. On face value agile methods appear to be contradictory to regulatory requirements. However while they may appear contradictory, they align on key values such as the development of the highest quality software. To demonstrate that agile methods could in fact be adopted when developing regulatory compliant software they were implemented on a medical device software development project. This implementation showed that not only can agile methods be successfully followed, but it also revealed that benefits were acquired. For example, the medical device software development project was completed 7% faster when following agile methods, when compared to if it had been completed in accordance with a plan-driven approach. While this implementation is confined to a single project, within a single organization it does strengthen the belief that adopting agile methods within regulated domains can reap the same benefits as those acquired in non-safety critical domains

Key Aspects to Teach Medical Device Software Certification

Certification of Medical Device Software (MDS) according to the EU Medical Device Regulation 2017/745 requires demonstrating safety and effectiveness. Thus, the syllabus of a course on MDS development must provide tools for addressing these issues. To assure safety, risk analysis has to be performed using a four-step procedure. Effectiveness could be demonstrated by literature systematic review combined with meta-analysis, to compare the MDS performances with those of similar tools