Device ISO standards: turning worries into confidence

15 November 2021

Product developers must innovate continually to maintain a competitive advantage. When bringing a new idea from early R&D into detailed design, the developers must strike a balance between many trade-offs, such as:

• Lower cost versus more features
• Better portability versus easier maintenance
• Higher power versus more comfortable ergonomics

If the product is to comply with legislation, it is essential for product developers to know the acceptable bounds of these trade-offs. For example, is the ingress protection rating of the product relevant only to marketing claims, or does legislation stipulate a minimum? Must the product pass drop tests? What must its user instructions contain? Further, how can the developers be confident there are no “unknown unknowns”, that is, that they have not neglected any important aspects? These questions apply to all products but are particularly critical for medical devices: failure of, say, a ventilator or autoinjector may conceivably result in serious harm or death.

Part of the answer is in standards. It has been said that engineering is organised worrying, and standards can be seen as an example of that philosophy. The appropriate use of standards can transmute opaque worries into a clear plan of action, and confidence that one’s product will work, be safe, and comply with the relevant legislation. This post gives a brief introduction to what standards are, and how they can help developers build that confidence.

What are standards?

Standards are essentially documents that lay out the best practice for doing something. Each one is a rich source of information and guidance drafted by a collection of experts on the matter, and they are kept updated by periodic revision. A broad set of these are device standards, which relate to the product itself and help ensure that devices perform their basic useful functions safely (see for example  ISO 80601-2-12 on critical care ventilators). As an example, Table 1 illustrates a small fraction of the information that might be available in a device ISO standard.

Table 1: Examples of information contained in a device ISO standard.

Area	Specified requirements
Labelling	Information that must be on the product, such as default settings and port labels The minimum font size for certain information
Information for use	What must be contained in the instruction manual, which could include a list of consumables and where they can be purchased, warnings, maintenance procedures and disposal instructions
Alarms	System states that must trigger an alarm Alarm priorities. For example, for a medical device in which several alarms trigger simultaneously, which alarm sound will be played and allow physicians to easily identify and deal with high priority alarms first Alarm sounds and noise level Connectivity to internal alarm systems
Connections	Some devices (such as ventilators) must have standardised patient outlet and inlet ports to which consumables are connected Inlet ports such as oxygen and air inlets on ventilators are also standardised and have been specified in a manner that prevents misuse and accidents
Ingress protection	The conditions under which the device must be resistant to ingress of solids and liquids
Device testing	Test setups, device settings and pass criteria. This could include ensuring it is robust to the failure of any single component Operation of the device while wearing gloves, which might affect the responsivity of a touch screen

 

How are standards used?

The application of standards is jurisdiction-dependent. ISO standards are predominantly European but have also been in part adopted by the USA, which for historic reasons also has rules laid out by the Consumer Product Safety Commission (CPSC).

The fastest and most cost-effective way to get a product to market is to use standards to guide the development process, and weave the aspects specified by standards into the fabric of a design early in its development. This is typically done as follows:

1. Identify the applicable standards

The applicable standards will typically depend on the territory in which the device will be used, rather than the territory that will manufacture or sell it. Once jurisdiction(s) are identified, the standards that apply can be identified by a thorough search of a standards catalogue. For a novel device it may not be obvious which standards apply, in which case expert advice can be useful.

2. Interpret the standards

Each standard must be read and interpreted to make it apply to the specific device under question. For example, ISO 11608 covers a broad range of needle-based medical injection systems, and its interpretation will be different for an autoinjector and for a patch injector.

3. Act on the standards

It is usually useful to then create from each standard a set of specifications and checklists: for example, this could turn into individual checklists for alarms, safety tests, risk analysis and device markings.

4. Build the required documentation along the way

For some types of devices, in particular medical devices, building documentation during development is essential for approval as a way of evidencing a rigorous process. It can also prove critical for the protection of intellectual property.

5. Submit the device for certification

The responsibility of testing and ensuring a product is functional and safe ultimately rests with the manufacturer, who can use certified test houses and technical consultants to assist in the certification process.

Following the above steps naturally produces a significant flux of data and documentation, and quality management systems have been developed (naturally specified by their own standards) to manage the process in a systematic way. Springboard is certified to one such standard, ISO 13485, which is specially for the development of medical devices, and it helps us develop and test devices regularly for our clients to a wide range of standards. If you would like some guidance in this area, or would like to know more, just get in touch.

– Michael Madekurozwa and Gabriel Villar