Usability Validation Plan

Pattern Attributes

Intervention Process
Domain Medical
Work Programme SPRTMDRC
Research Area Any
Evidence Type Standard
Evidence Source Standard
Evidence Strength Hypothetical
Trigger product_domain == medical, doing_usability_engineering == true

Problem

You need to validate the usability of a medical device after its development. This validation should be carried out in line with a usability validation plan, as required by IEC 62366. The usability validation plan outlines the process to be used for the validation, the role of representative end users in the validation and the scenarios in which the medical device will be validated.

Analysis

When operating in the medical device domain, it is important to maintain documentation on all aspects of a software development project. During the validation of the medical device it is important to ensure that all aspects that can affect usability are considered. This includes user profiles, frequent use scenarios, worst case use scenarios, and the methods and settings used for the validation. To ensure that all of these aspects are considered a medical device organisation should carefully plan the validation and prepare a usability validation plan that can be used to guide the validation.

Solution

  1. Define the methods to be used for usability validation. For most effective results multiple methods should be used for validation. These may include, cognitive walkthrough, expert review, simulated clinical environments and field tests.
  2. Define the role of representative end users in the validation. To ensure the accuracy of validation end users should participate in the final validation of the device. The number and type of users should be defined as well as the tasks they will be required to complete.
  3. Define the criteria for successful validation of the medical device. The criteria for successful validation is given in the form of usability goals such as “80% of users should be able to calibrate the device within 5 minutes on their first try”.
  4. Define the setting for the usability validation. Usability validation can be performed in a number of locations such as Laboratory, simulated or actual use environment. The setting selected for validation can impact the exhaustiveness of the results. For example factors that can occur in an actual use environment may not be replicated in an laboratory environment.
  5. Define the scenarios to be used during validation. The scenarios selected for the validation may impact on the results obtained therefore a range of scenarios should be used. These should include frequent and worse case scenarios. Failure to test in a range of scenarios may leave some usability issues undetected.
  6. The usability validation plan should be recorded or referenced in the usability engineering file. This requirement is specified in the IEC 62366 standard.

References

  1. IEC 62366:2007 “Medical Devices - Application of usability engineering to medical devices”

  2. Flood, D., Mc Caffery, F., Casey, V., Regan, G.,(2013) “A Methodology for Software Process Improvement Roadmaps for Regulated Domains - Example with ISO 62366”, European System, Software & Service Process Improvement & Innovation (EuroSPI 2013)

  3. Flood, D., Mc Caffery, F., Casey, V., Regan, G.,(2013) “MeD UD - A Process Reference Model for Usability Design in Medical Devices”, South CHI 2013 International Conference on Human Factors in Computing & Informatics, Maribor, Slovenia.