Medical Device Human Factors
510k Submission, ANSI/AAMI IEC 62366 compliance
As the complexity of medical devices increases, so does the need to identify and mitigate use errors in order to ensure the safety of device users and patients alike. Medical device manufacturers must now demonstrate to the FDA that human factors / usability engineering techniques are part of their product development cycle in the early requirements, design, and validation phases of development and that use errors have been prevented and corrected.*
Contextual Field Research / User Interviews
There is no substitute for the invaluable insights and information that can be learned through user interviews and in-context observation of use. Data gained from these techniques are the foundation for persona and scenario development, task and error analysis and a solid safe, effective and usable design.
Formative research describes user testing conducted in the early and mid-stages of the design process. These research sessions are crucial to ensuring a design that is safe, easy to use, and effective is being developed. Formative research sessions can be formal or informal and might involve a small or large number of participants. Low- or high fidelity prototypes are used in these task-based sessions. Formative research should be done iteratively until the product design has matured to an acceptable level of safety and effectiveness..
Summative Research / Validation Testing
Summative research or Validation Testing is conducted near the end of the design and development process to validate the safety and effectiveness of a product. In most cases, validation testing is a formal simulated-use study involving a minimum of 15 participants who represent typical users. In these studies the product interface, documentation and labeling are evaluated against pre-specified pass/fail criteria. The nearly-final product should be used in summative testing. Errors and failures identified in these tests will need to be documented, mitigated, and re-tested.
Heuristic Evaluation / Cognitive Walkthrough
Inspection techniques such as Heuristic Evaluation and Cognitive Walkthroughs are an important complement to user research during the design phase. Heuristic Evaluations are conducted by a small team of human factors experts who evaluate the design against a set of heuristics for safe and usable medical devices. A cognitive walkthrough is conducted by a multi-disciplinary team who step through the tasks or scenarios while asking themselves key questions about the product design’s usability. Both reveal usability and safety issues not always uncovered by other methods.
Understanding the task steps users must perform and the situation in which the tasks are performed is crucial when specifying a product’s features and creating its design. There are several valid functional analysis methods such as Task Analysis, PCA (Perception, Cognition, Action), and UTP (User Technical Process). Functional analyses should be based on field research and user interviews. The final analysis includes each task the product will support , the associated steps needed for task completion, step inputs and outputs, and the surrounding context in which the task is performed.
Use Error Analysis
A use error analysis is a critical component of the Usability Engineering Process. In this analysis a new layer is added to the functional analysis – anticipated and observed us errors. Listed with each use error is its associated hazard, consequence and mitigation strategy. The Use Error Analysis is used to create Hazard-Related Use Scenarios, Hazard and Hazardous Situations and should feed into the Validation Testing Plan.
Specifications, Plans & Files
The Usability Engineering Process as specified in 62366, calls for several specifications to be created such as a Use Specification, a User Interface Specification, and a User Interface Evaluation Plan including a plan for Summative Evaluation. The key information from all these documents will need to be captured in the Usability Engineering File. We have experience creating all these document types and providing the clear traceability back to use error and mitigation that the FDA requires.
*See sections 820.30(c), 820.30(g) and 820.100 in the Code of Federal Regulations (CFR) Title 21, Food and Drugs, Chapter 1 – Food and Drug Administration, Department of Health and Human Services, Subchapter H- Medical Devices, Part 820 – Quality System Regulation. Alternatively, see this Basic Introduction to the QFR Quality System Regulation 21 CFR 820 for an easy-to-digest read.