Systems Engineering for Medical Devices

Systems engineering aims to systematically develop systems – in this context, medical devices – in the planned time and quality.

Definition of systems engineering

According to the ISO/IEC 15940 definition, systems engineering is …

… interdisciplinary approach governing the total technical and managerial effort required to transform a set of customer needs, expectations, and constraints into a solution and to support that solution throughout its life.

Wikipedia has also adopted this definition of systems engineering.

ISO/IEC/IEEE 21841 speaks of a process of planning, analysis, organization, development, and integration.

1. Articles on processes and activities

a) Processes

The V-model is a well-known model for the development process. It is suitable as a documentation model for the (agile) development of medical devices.

As part of this process, manufacturers carry out various activities for which further articles provide guidance. They can set up their development team for these activities and/or have activities carried out by third parties.

In the latter case, these articles are relevant:

• Outsourcing in medical technology
• Engineering service providers: successfully outsourcing development?

b) Formulate intended purpose and requirements

• Formulate intended use and purpose
• Stakeholder requirements, such as user requirements and regulatory requirements
• Create requirements specification and functional specification (be careful with this)
• Derive System Requirements or System Specification (SRS)

c) Designing systems

• Creating a system architecture for medical devices, ideally not a layered architecture
• Creating safety concepts to achieve functional safety
• Using modeling languages such as the Unified Modeling Language (UML)
• Creating designs using Computer-based Modeling & Simulation (CM&S)
• Performing threat modeling for systems that contain software for IT security
• Carrying out a design validation
• Developing software in compliance with the law

d) Verifying and validating systems

• Verification and validation: difference & definitions
• Verification and validation of IVD
• Combinatorial testing
• Clinical evaluation

e) Further phases in the life-cycle

• Design transfer to production
• Post-market phase, including post-market surveillance
• Subsequent design changes
• Recycling and disposal of medical devices

2. Articles on the IEC 60601-1 family and physical safety

a) Regulatory requirements

The regulatory requirements are based on EU regulations and directives:

• EU Regulation for Medical Devices MDR
• EU Regulation for In Vitro Diagnostic Medical Devices IVDR
• EU Machinery Directive
• EU Radio Equipment Directive
• EU Battery Regulation

The central standard is IEC 60601-1, which was extended by a 2nd amendment in 2019. IEC 61010-1 is relevant for IVDs.

The concepts of the standard(s) include:

• Basic safety, essential performance
• Functional safety
• MOPP, MOOP, MOP, and the IEC 60601 arithmetic

In addition to the basic standard, the particular standards are also relevant:

• IEC 60601-1-2: New edition on EMC of medical devices
• IEC 60601-1-8: Back to conformity in 12 steps
• IEC 60601-1-11 AMD1:2020 (2.1) – Medical devices in the home environment

Many manufacturers rely on the CB Reports to provide evidence.

b) Implementation of requirements for specific systems and situations

• Systems, devices
  • Medical device software PC: Software manufacturers take note!
  • Closed-loop systems for medical devices
  • Autonomous systems: 4 advantages for medical device manufacturers
  • Combination of medical devices: Legal and economic considerations
• Components, parts
  • PESS: Programmable electronic subsystems
  • Multiple socket-outlets for medical devices
  • Critical components/parts

3. Articles on biocompatibility, sterility, and reprocessing

There are special standards for devices that are intended to come into contact with the human body:

• ISO 10993 on biocompatibility
• ISO 10993-5 on cytotoxicity testing
• ISO 18562 on the biocompatibility evaluation of breathing gas pathways in healthcare applications

ISO 17664 is relevant for the reprocessing of medical devices.

Please also refer to our article on substance-based medical devices.