IEC 60601-1-6 is the usability collateral standard under the EN 60601-1 family. It does not define its own human factors process. It points directly to EN 62366-1:2015+A1:2020. For an electrical medical device under MDR, that means one usability engineering file, built to EN 62366-1, serves both the electrical safety standard and MDR Annex I §5 and §22.

By Tibor Zechmeister and Felix Lenhard.

TL;DR

  • IEC 60601-1-6 is a collateral standard to EN 60601-1 dealing exclusively with usability.
  • The collateral does not replicate a human factors process. It cross-references the generic usability engineering standard, currently EN 62366-1:2015+A1:2020.
  • Under MDR, ergonomic and use-related risk requirements live in Annex I GSPR §5 and §22 (devices for lay users).
  • Manufacturers of electrical medical devices produce one usability engineering file that satisfies the collateral standard, EN 62366-1, and the MDR GSPRs simultaneously.
  • Notified bodies expect to see a single, coherent usability file. Not one artefact per standard.
  • Use-related risk is integrated with EN ISO 14971:2019+A11:2021 risk management, not run in parallel.

Why this matters (Hook)

The first audit finding Tibor writes on usability is rarely about missing tests. It is about duplicated, inconsistent documentation. A startup building an infusion pump hands over three overlapping files: one labelled "60601-1-6 compliance," one labelled "62366 usability," and one labelled "Annex I §5 ergonomics." They contradict each other. The use specification lists five user groups in one file and three in another. The summative evaluation references tasks that do not appear in the use error analysis.

This happens because the team read each standard in isolation. They did not notice that IEC 60601-1-6 is not a standalone usability standard at all. It is a pointer. The collateral standard's entire job is to tell you: for usability, follow the generic process standard. Currently, that generic standard is EN 62366-1:2015+A1:2020.

Once a founder sees this, the workload halves. You build one usability engineering file. One use specification. One set of user interface specifications. One summative evaluation. And that single package answers the electrical safety standard, the usability standard, and MDR Annex I.

What MDR actually says (Surface)

MDR Annex I, the General Safety and Performance Requirements, contains two clauses that drive usability work for electrical medical devices.

Annex I GSPR §5 covers ergonomic features and the environment of use. It requires manufacturers to reduce, as far as possible, risks linked to the design of the user interface, ergonomic features, and the environment in which the device is used, taking into account the technical knowledge, experience, education, training and use environment, and medical and physical conditions of intended users.

Annex I GSPR §22 addresses devices intended to be used by lay persons. It requires that such devices be designed and manufactured to perform appropriately given the skills and means available to lay users, and to minimise the risk of incorrect handling.

MDR does not mandate any specific usability standard by name. Instead, it operates through harmonised standards: if you follow EN 62366-1:2015+A1:2020, you carry a presumption of conformity to the relevant parts of Annex I §5 and §22.

On the electrical safety side, EN 60601-1 is the basic safety and essential performance standard for medical electrical equipment. It carries a family of collateral standards. IEC 60601-1-6 is the collateral dedicated to usability. Rather than inventing a separate human factors process, 60601-1-6 normatively references the generic usability engineering process standard. IEC 62366-1, which in Europe is EN 62366-1:2015+A1:2020.

The practical consequence is unambiguous. If you apply EN 60601-1 and its usability collateral, you are applying EN 62366-1. There is no second process. There is no parallel file.

A worked example (Test)

Consider a Class IIa electrical medical device. A portable nerve stimulator used by physiotherapists and, in a separate product variant, by patients at home. The startup has six people. The founder wants to know how much usability work is actually required and what the deliverable stack looks like.

The single usability engineering file, built to EN 62366-1, contains:

  1. Use specification. Two user groups: licensed physiotherapists in clinical environments, and adult lay users at home following a clinician prescription. Two use environments: clinic treatment room and domestic living room. Intended medical indication defined precisely.

  2. User interface specification. All elements the user interacts with. Physical buttons, display icons, labelling on the device, packaging, quick-start guide, IFU, and the accompanying smartphone companion app used for session logs.

  3. Known use problems analysis. A structured review of post-market data for the predicate category, MAUDE-equivalent European sources, published literature on TENS device misuse, and internal complaints from earlier feasibility work.

  4. Hazard-related use scenarios. Tasks where use error could lead to harm: electrode placement over the carotid sinus, placement on broken skin, use during pregnancy, interaction with implanted cardiac devices, incorrect intensity escalation.

  5. Summative evaluation. A formal validation with representative users. Not the development team, not friends of the CEO, but real physiotherapists and real lay users matching the use specification. Performing the hazard-related tasks under realistic conditions.

That file satisfies EN 62366-1 directly. Because IEC 60601-1-6 references EN 62366-1, the same file also satisfies the collateral standard. And because the file demonstrates that use-related risks have been reduced as far as possible and that the lay-user variant performs appropriately for its intended users, it supports conformity with MDR Annex I §5 and §22.

The team does not write a separate "60601-1-6 compliance document." That document would be an index, not a deliverable. And an index is better expressed as a cross-reference table inside the technical documentation.

The Subtract to Ship playbook (Ship)

Subtract to Ship treats duplicated regulatory artefacts as the most expensive kind of waste. Every document you write you must also maintain, version, audit, and reconcile with every adjacent document. Two usability files are not twice the work. They are four times the work, because every change has to be mirrored and the mirroring has to be verified.

The startup playbook for electrical medical devices:

1. Declare the standard set once. In your technical documentation index, list EN 60601-1 and its collaterals (including IEC 60601-1-6), and list EN 62366-1:2015+A1:2020. Note explicitly that 60601-1-6 cross-references the generic usability standard and that a single usability engineering file is maintained.

2. Build one use specification. This is the foundation stone. If the use specification is wrong or incomplete, every downstream artefact. Risk analysis, verification, validation, labelling, training. Inherits the error. Get the user groups, use environments, and intended medical indications tight before anything else.

3. Integrate use-related risk with EN ISO 14971. Use errors and hazard-related use scenarios feed into the same risk management file that handles electrical, mechanical, and biological hazards. You do not run a second risk process for usability. EN ISO 14971:2019+A11:2021 is the risk spine; EN 62366-1 feeds it.

4. Map deliverables to MDR GSPR once. In the Annex I checklist you will submit to your notified body, point §5 and §22 to the single usability file. One reference per GSPR row. No splits.

5. Run summative evaluation with representative users, not proxies. The notified body will examine participant recruitment. A summative evaluation performed by engineers pretending to be lay users is a finding waiting to happen.

6. Link the usability file to IFU and training material. Use errors detected in formative evaluation become IFU warnings, quick-start steps, and training content. The feedback loop must be visible in documentation.

7. Plan post-market usability surveillance. Use errors observed in the field go into post-market surveillance under MDR Art. 83-86 and loop back into the usability file. The file is living, not archived.

The subtraction is this: you are not building two systems. You are building one system that answers three documents.

Reality Check

  1. Does your technical file contain one usability engineering file, or several overlapping ones?
  2. Is your use specification identical across your risk management file, your verification plan, and your IFU?
  3. Does your IEC 60601-1-6 documentation point to the same EN 62366-1 artefacts, or is it a separate deliverable?
  4. Are your summative evaluation participants drawn from the actual intended user groups in your use specification?
  5. For a lay-user device, have you addressed Annex I §22 explicitly. Not just §5?
  6. Are use-related hazards integrated into your EN ISO 14971 risk analysis, or maintained in a parallel document?
  7. Does your post-market surveillance plan capture use errors and feed them back into the usability file?
  8. Could a notified body auditor trace any single use-related risk control from hazard to summative evidence in one unbroken chain?

Frequently Asked Questions

Do we need to buy IEC 60601-1-6 if we already have EN 62366-1? Yes, because the collateral defines the linkage and specifies how the generic standard applies in the context of medical electrical equipment. But your usability process itself is built on EN 62366-1:2015+A1:2020.

Does following EN 62366-1 automatically cover Annex I §5 and §22? Following the harmonised version gives a presumption of conformity to the parts of Annex I the standard addresses. Annex I §5 and §22 contain requirements beyond user interface design (for example, environmental conditions), so the usability file contributes to, but does not alone prove, full §5 and §22 conformity.

Is formative evaluation required or just summative? EN 62366-1 expects both. Formative evaluation drives iterative design improvements. Summative evaluation validates that residual risks are acceptable. Skipping formative work is a common finding.

Can we use our development team as summative evaluation participants? No. Participants must represent the user groups in the use specification. Developers know the device too well; their performance does not reflect real-world use.

What about IEC 62366-2? Part 2 is a technical report providing guidance on applying the process standard. It is not a harmonised standard and you do not need to claim conformity to it. It is useful reading, not a deliverable.

How does this change for a home-use device? Annex I §22 kicks in. The use specification must treat lay users as the primary user group, the summative evaluation must include lay participants, and the IFU and labelling must meet the lay-user readability requirements in Annex I Chapter III.

Sources

  1. Regulation (EU) 2017/745 on medical devices, consolidated text. Annex I §5, §14, §17, §22.
  2. EN 62366-1:2015+A1:2020. Medical devices. Application of usability engineering to medical devices.
  3. EN 60601-1:2006+A1+A12+A2+A13:2024. Medical electrical equipment. Part 1: General requirements for basic safety and essential performance.
  4. EN ISO 14971:2019+A11:2021. Medical devices. Application of risk management to medical devices.