Throughout the sterilized medical device packaging validation process, a medical device manufacturer’s (MDM) primary focus is on making sure that the sterile barrier remains intact. A variety of studies are performed to ensure that the sterile barrier won’t be compromised during transit or as the packaging ages. However, none of these tests are focused on whether or not the packaging configuration is usable once it gets into the hands of the intended user. This is where usability evaluations come in. A new addition to ISO 11607 as of 2019, usability evaluations test how well a packaging design will perform in the real world with real users.
The Importance of Usability Evaluations
Keeping the sterile barrier intact until the time of use is imperative. Usability evaluations can point out flaws in a packaging design that other packaging validation testing will not highlight. A couple of examples include, a seal that is too strong for the end user to open and confusion surrounding the opening features. If a surgical nurse is unable to safely open the package correctly and breaches the sterile barrier, they will be forced to open another package. Frequent sterile barrier breaches would create a higher cost for the hospital to use that device. Usability evaluations could help with sustainability by pointing out this flaw before the device goes to market.
Formative vs. Summative Usability Studies
A formative usability study is similar to feasibility testing. These are less formal tests that you can build on as you go. These tests can be performed by anyone and do not require a specific sample size. By the end of a formative usability study, you should have a clear timeline of the results and adjustments made along the way. Summative usability studies can be costly, so formative studies are often a desirable choice for MDMs who might not want to make a large investment in extra packaging materials and recruiting healthcare participants.
Summative studies comply with ISO 11607 and involve fifteen end users, standardized project plans, and a full results report. The MDM may consult with a usability partner, defining the intended use and environment while the usability partner recruits suitable participants to conduct the study within a simulated use environment. The usability partner reviews the study and provides the findings to the MDM.
Understanding Usability Evaluation Results
Unlike other packaging validation tests that give clear pass/fail results, usability outcomes are often ambiguous because ISO 11607 does not currently define a pass/fail standard. For example, if one of fifteen participants cannot identify the opening, a root-cause investigation is required to understand why. Such investigations matter because products can still go to market despite usability failures, if the FDA accepts the justification. For example, if a failure is attributed to a participant’s limited experience where they were unable to recognize a chevron seal opening feature on a flexible pouch, that may be considered acceptable.
However, if five of fifteen participants fail to aseptically open the package due to the seal being too strong on a flexible pouch and causes the device to fling out upon opening, the results become harder to justify. In that case, the MDM will need to analyze the root cause investigation and may need to modify the packaging or manufacturing process. Any design change(s) to the packaging will require a new usability study.
“Medical professionals will not compromise patient safety. If they even suspect that they won’t be able to aseptically open the packaging, it will be rejected,” says Johnny Kieu, Senior Packaging Engineer at PCL. If your usability evaluation reveals flaws in the packaging design that might deem the device unusable by a medical professional, it would be incredibly beneficial to consider redesigning and retesting your packaging design.
Key Takeaways
Usability evaluations for aseptic presentation are gaining traction in the sterile medical device packaging industry by filling a bit of a void in the validation journey. Taking the time to determine whether a formative or summative study will be most beneficial to your packaging design and finding a trusted usability partner are the keys to success. Since medical devices are so expensive to produce and validate, it’s beneficial to any medical device manufacturer to consider performing a usability evaluation.
