Medical Device & Diagnostic Industry

part (ANSI/AAMI HE74:2001, “Human Factors Design Process for Medical Devices”) in 2001. This document aims to help manufacturers respond properly to FDA’s quality system regulation pertaining to human factors. In short, the process guide calls for manufacturers to conduct an appropriately scaled set of human factors research, design, and user testing activities en route to producing a final, validated medical device that resists use errors. But the document does not include applied design guidelines. For example, it will not help a mechanical engineer determine the proper size and spacing of control panel components to ensure ease of use and prevent accidental actuations. The forthcoming companion document does.

Notably, ANSI/AAMI HE-2001 formed the basis for the International Electrotechnical Commission’s collateral standard, IEC 60601-1-6, “ Medical Electrical Equipment—Part 1-6: General Requirements for Safety— Collateral Standard: Usability,” which was released in 2004.⁵ The current plan is to revise IEC 60601-1-6 to fully align it with IEC 62366 by replacing most of the current content of IEC 60601-1-6 with a normative reference to IEC 62366.

Eventually, the IEC committee plans to withdraw IEC 60601-1-6. That could happen by incorporating the reference to IEC 62366 directly into IEC 60601-1 or by amending IEC 62366 to add a normative annex that contains the necessary bridging requirements.

Content

The new standard addresses 22 topics (see the sidebar, “Breaking Down AAMI HE75:200X,” below for a list of the topics included in the document). Readers will discover some inconsistency in how the standard addresses each topic.

Vibrations in a moving ambulance make

it harder to read displays. AAMI HE75

advises designers to make display characters (e.g., heart rate and blood pressure)

larger than normal.

By intent, some topics cross the line between providing detailed design guidance and addressing design methodology issues, such as conducting usability tests. Some sections contain reference data, such as the dimensions of small and large hands that can inform the design of a surgical instrument. Other sections focus on user interface details, such as the proper size of characters appearing on a critical display (e.g., a patient monitor) that users will view from across a room. Readers should keep in mind that the standard includes design guidelines, not rigid requirements. Ed Israelski, the AAMI HFE committee cochair and a human factors program