How the new ANSI/AAMI HE75 updates impact your Medical Device design development and usability process

As of Nov 18, 2025, the Association for the Advancement of Medical Instrumentation (AAMI) has updated its primary human factors engineering guidance for the medical device industry, ANSI/AAMI HE75, for the first time in over fifteen years. This article summarizes the key updates and offers practical insights for applying these changes to create safer, more user-centered products.

Introduction

As of Nov 18, 2025, the Association for the Advancement of Medical Instrumentation (AAMI) has updated its primary human factors engineering guidance for the medical device industry, ANSI/AAMI HE75, for the first time in over fifteen years.

The purpose of HE75 is to provide relevant and useful Human Factors Engineering (HFE) information, design criteria, and guidelines for medical devices and combination products to optimize usability, minimize use errors, and enhance patient safety.

Since 2012, Wayne Ho, our HHF Directing Manager, has been a member of the AAMI Human Factors Committee and is a co-chair of the committee as of January 2025. This group worked to develop the updated ANSI/AAMI HE75.

The updated sections to focus on in HE75:2025 are:

Managing the risk of use error: Updated to align with FDA guidance.
Usability testing: Updated to align with FDA guidance and ISO/IEC 62366 and updated acceptance criteria recommendations.
1. Selection of use tasks for inclusion in a usability test: Updates to the selection of use tasks to indicate when non-critical tasks may need to be evaluated to ensure full workflows are performed.
2. Training: Updated guidance to include a variation of training provided through a “train-the-trainer” model and updates to expected minimum training decay.
3. Knowledge tasks: Updates to align with the FDA’s revised expectations for knowledge tasks and information comprehension assessment.
Instructional and training materials: Updates to include newer technologies such as digital labelling, embedded help, QRGs, videos, websites, and QR codes.
Transportable devices: Updates to design guidelines related to user and use environment considerations for handheld devices, mobile environments, and wearable devices.
Integrated systems: Outlines considerations related to the digital connectivity of devices and interoperability of multiple devices used in conjunction.
Combination products: Includes design guidelines and considerations for various combination products.

Managing the risk of use error

This section has been revised to align with FDA guidance and outlines the following considerations for managing medical device use-related risks:

Estimating use-related risk

Risks generally should be evaluated based on the severity of harm alone, not by the probability of occurrence. To determine an accurate probability would require large amounts of historical data from complaints and adverse events to be collected.

Methods of identifying, evaluating and understanding use errors

Potential design flaws and use errors can be identified through various means including reporting systems like the MAUDE database, performing task analysis, performing heuristic analysis or expert reviews, conducting interviews and focus groups, through contextual inquiry, and/or formative usability evaluation.

Control of use related risk

Multiple strategies may be needed to successfully mitigate each use-related risk. This may include creating inherently safe designs with forcing functions or automation where appropriate, designing protective measures like physical safeguards and warnings/alerts into devices, information for safety through effective labelling, and training.

Human factors validation testing

To confirm the effectiveness of the use-related risk control measures and to demonstrate there are not unacceptable use-related risks, human factors validation testing should be performed.

Post-market surveillance

Manufacturers should establish a post-market surveillance program to identify and manage use errors in the field. HE75 recommends device manufacturers to create customer complaint categories based on the URRA to help with internal tracking and trending, to prepare detailed call center scripts that align with IFU, to develop an escalation process for complaints, and to collect human factors supplemental data and determining root causes if a critical event occurs.

Leveraging post-market data for future product development

Any data gathered can be used to improve the design of existing and next-generation devices.

Selection of use tasks for inclusion in a usability test

HE75 has provided updates on the selection of use tasks:

The use scenarios and associated tasks selected for usability testing should include all the critical tasks as identified in a comprehensive use-related risk analysis. While the human factors validation testing is constructed to evaluate critical tasks, it needs to do so in a representative manner, which may require non-critical tasks that occur in sequence during use be included to ensure that the use scenarios will be performed in their entirety. Non-critical tasks may be included in the test to ensure that the hazard-related use scenarios will be performed in their entirety.

Training

Train-the-trainer

HE75 has outlined new guidance for the training variation “train-the-trainer” model:

For example, a diabetes educator or other HCP might train a patient with diabetes in the use of their insulin pump. The manufacturer could decide that the training, intended to minimize use errors by the patient, would best be conducted with materials designed by the manufacturer. In this situation, the participants’ training for the human factors validation test should be comparable to the training that actual users will receive. In this case, the test methodology could include training a diabetes educator to train the lay caregiver and patient participants in the validation study.

In cases like the example provided above, the FDA may expect the trainer to be a real-world trainer who has been trained by the manufacturer prior to the usability study. This differs from the approach of a manufacturer employee providing the training for the usability study.

Training Decay

Training decay should be representative of the expected delay between training and actual use. As such, it is recommended that a minimum training decay period of one hour be provided prior to testing. The break should not involve using the device and it should involve activities unrelated to testing to interfere with memory.

Image of a simulated neonate OR. There are overhead lights and devices in a lab with a neonate manikin set up to look like they are prepared for surgery. This is for a usability study, in which healthcare providers will work with a device in a simulated operating room.

FDA’s New expectations for Knowledge tasks

The updated HE75 guidance has added a section around what is expected for information comprehension assessment and knowledge tasks, which aligns with additional guidance that has been provided by the FDA.

In the case that a participant who did not look at the labelling provides an incorrect response; it is generally best practice to complete all the knowledge tasks before asking a series of follow up questions to determine possible factors contributing to the incorrect response. It is recommended to use a process of progressive prompting as follows:

Determine why the participant answered as they did.
Determine what the participant would do in real life if they wanted to know that information.
Determine whether the participant was aware that some of the materials in the room (i.e., the labeling) might provide the information they needed to answer the questions.
Invite the participant to look at the element of labeling – but not the specific section of that labeling – that contains the information needed to answer the question correctly.

That explains how to conduct the knowledge task section of a validation usability study. However, now that you have collected data from progressive prompting, how do you document and report on this?

While not specified by the guidance, these knowledge task issues would need to be reported as use errors (as the participant answered incorrectly). The information gained from further prompting could either be included in a separate information comprehension assessment section and/or included in the description of the participant’s subjective feedback for the use error.

Instructional and Training Materials

The section ‘User documentation’ has been updated to ‘Instructional and training materials’ in HE75:2025 to include design guidance of newer instructional technologies and methods. This includes:

Printed/PDF manuals and IFUs – Considerations for appropriate text highlighting and use of colors are discussed. The section also describes best practices for fonts, navigational aids, illustrations, tables, warnings and cautions, and how to effectively delineate different types of information.
Quick Start Guides and reminder cards – Consider the location or placement of such cards (e.g., attached to device, separate) and the material’s durability. This section recommends limiting content to essential information needed to operate the device safely and to reference the main IFU, so users are reminded to review it if they need more information. Further, consider whether graphics can play a role in conveying the necessary information effectively.
Device-embedded instructions and training – This section outlines considerations for instructions embedded within the user interface. Key points include:
1. To consider whether the content or layout should differ for novice versus experienced users (i.e., amount of detail, technical level);
2. When device is operating, ensure these instructions do not interfere with the user’s ability to safely operate the device. For example, avoid pop-ups that cover a critical patient parameter at the moment it changes in a significant way;
3. When the device is not being used to treat a patient (e.g., setup, between uses), embedded instructions, like a setup wizard, can take a primary role on the interface. But ensure there is flexibility to bypass these in emergency situations.
Passive audiovisual instructional and training materials – This form of training can be useful when users’ literacy and/or health literacy is low, when formal training or access to a trainer is low, and so users can observe product use demonstrations. Consider accessibility features including closed captions and audio descriptions. Ensure the content focuses on task performance sequences and memorable warnings. Further, the narrator should convey information at the appropriate level for the expected audience.
Interactive digital training and instructional materials – Ensure the content is designed for different screen sizes (i.e., mobile phones, computers) and for interactions on a touchscreen versus with mouse and keyboard. Consider how to provide consistent navigation throughout the interface that allows users to access specific sections, to design so users can identify where they are within the broader application and enable users to search for specific content. For video instructions, it is recommended to break each step into a separate video, then enable users to manually move to the next step.
Simulation and training devices – While developing a simulation / training mode for a device, consider what tasks need to occur based on the users’ needs and product requirements. Ensure the simulation mode has the same behaviors as the real device, but simulation mode should be clearly differentiated to prevent accidental use on patients. As well, consider environmental factors that can impact how users learn the device and try to emulate those during training (i.e., lighting levels, motion if in transport). Determine how users can repeat or restart tasks and how to integrate assessments so users can gauge whether they need more practice with a given task.

Transportable Devices

The “design of mobile devices” has been revised and relabeled “transportable devices.” Updates have been made to the user and use environment considerations for handheld devices, mobile environments, and wearable devices, specifically reframing the user considerations, and expanding on the questions to ask when considering environmental factors.

The general design guidelines have been expanded to include:

Hand-held devices should generally be operable using only one hand.
Devices should include appropriate safety or lock-out mechanisms in order to prevent inadvertent activation as a result of increased access by multiple individuals (e.g., family members, children, laypersons) or use under crowded conditions.
Transportable medical devices that contain displays, indicator lights, or speakers should allow the user to modify the intensity of the feedback (e.g., the display brightness, the speaker volume) to accommodate a range of environmental conditions.
A portable device should incorporate storage of any necessary accessories or supplies to ensure their availability at the time and location of use.
Portable devices should be designed to be positioned in several different ways and still support use. For example, a device might be placed on a patient’s bed, mounted on a bed rail, placed on a cart, set on a floor, or held by the user. The design should facilitate use in all likely positions by providing easy access to handles, controls, accessories, and labels.

The weight considerations have been expanded to include the following guidelines:

Hand-held devices should not have excess weight to impede effective use or to prevent transporting during storage.
Wearable devices should not have excess weight to compromise user mobility (e.g., walking, running) during use or leave users fatigued.
Heavier devices should incorporate features that facilitate lifting and carrying, such as a harness or shoulder strap.

And the mobility mechanisms have been expanded to include the following guidelines:

If a wearable device includes an adhesive to attach to the skin, the design should take into consideration user motion, including walking, running, jumping, bathing, sleeping, or other activities.
The design of body-worn devices should take into account the impact of clothing on device use, including access to displays and controls.

When a transportable device is carried on the user but is not actively being used (such as a blood glucose meter, injector, or inhaler), a means of “temporary” storage to protect the device should be considered. For example, carrying the device in a pocket or purse could expose the medical device to chemicals, particles, or other materials that could affect and/or compromise the labeling, user interface characteristics, or other aspects of use.

Integrated Systems

This is a new section in HE75:2025 which discusses considerations related to digital connectivity of devices and interoperability of multiple devices used in conjunction.

Considerations include how the device(s) should interact with a network. This includes discussion surrounding data transfer and presenting real-time data, remote control capabilities, information security and privacy, and network connectivity during in-hospital transport.

Further, considerations have been included regarding users’ experience while using the device(s) / remote monitoring system(s). For instance, ensuring the user is provided enough data to remain in the loop while devices can also provide decision support, early warning systems, and determining when users need to intervene / override versus when devices can perform functions automatically.

Combination Products

This is a new section in HE75:2025 which discusses considerations related to medical products that meet the FDA definition of combination product, such as those that combine a drug and/or a biologic with a delivery device (e.g., prefilled syringes, auto-injectors, inhalers).

This includes design guidance related to aspects such as product labelling, packaging, and IFU design to meet the needs of your specific user group(s). As well, design considerations related to physical tasks (e.g., product assembly, administration, cleaning, storage) and cognitive tasks (e.g., reducing the burden on users’ memory, calculations being performed by the device) have been included.

Conclusion

So, what do these updates mean for you and your usability engineering process?

Be familiar with the FDA guidance for managing the risk of use error. Keep in mind that risk management does not end once a device comes to market but continues throughout the lifecycle of the device.

Keep in mind that changes have been made in the standards for how to select use tasks.

Consider whether training for your medical device would be more realistically represented with a “train-the-trainer” model.

Make sure your validation usability studies moving forward follow the new FDA expectations for knowledge tasks and information comprehension assessment. Keep in mind that information comprehension assessments can be conducted separately.

Consider what mode(s) of instructional and training materials may best suit the needs for your users and device. Also review the design guidelines to determine how to best develop and integrate these materials.

Make sure to review the updated design guidelines if applicable to your transportable device. Keep in mind the different use environments, the different users who might operate the device, and that users might wear the device or use it while in motion.

Review the new design guidelines for device interoperability. Keep in mind how to provide sufficient data so clinicians can effectively remotely monitor the device and how they can respond to various conditions and alerts.

Review the new design guidance for combination products, if applicable to your combination product.

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