When testing medical devices (or any new products) for usability, it’s important to test both the device and the manual/instructions that go along with it. Usability testing is meant to pinpoint sources of confusion, information that is missing or out of order, instructions that are open to interpretation and information that prompts unexpected behavior.

Usability testing is often performed twice: once at the early stages to look for design flaws and again at a later stage to test users’ ability to perform necessary tasks. Once usability goals have been determined, select tasks for testing and choose testers. For a medical device which is meant to be used by patients, the selected testers should be novices who have never used a similar device before. They should not have any particular knowledge about the device or its use and should not be especially skilled at reading comprehension or language skills. If the device is meant for use by medical personnel, the testers should belong to the profession for which the device was designed.

The next step is to set up the logistics. Video recording or screen capture is an effective way of seeing how testers use the device and testing whether they are able to use it properly. In order to ensure that each test is the same, the introductory explanations should be scripted and the procedure followed in the same order each time. The setting should also be the same for each test, with attention paid to lighting, temperature, noise and similar factors.

Having a designer present at the test can have a positive effect on the development process. Developers sometimes have a hard time believing that “regular” users don’t understand how to use the device they have developed, but seeing it with their own eyes will drive home the point. However, it is important that the designer not jump in and try to help the testers.

Once users have completed the test, they should also fill out a questionnaire about their experiences using the device. A review of the tests and the answers to the survey is then conducted to create a report on usability: missed steps, glaring errors and what the users said about ease of use. This data can then be used to make design changes to the device itself or to modify the instructions so they are clearer to the average user.

During Triode  last usability testing session for a medical device developer, we have found that a device function was not used by the nurse because the instruction label was hidden by a component. By changing the label position, the instruction for use is now available and the nurse can follow it easily.

Patrick Sirois


At Triode, we specialize in developing new products and services for complex industries like medical devices and transportation. We work with you closely to help define product strategy, with an emphasis on reducing the risks associated with innovating in these sophisticated and often regulated consumer-oriented environments.