Table of Content
A successful Human Factors Validation or Human Factors Validation Study is an essential part of the approval process for medical devices according to FDA standards. In this article, we would like to give you an initial overview of the components of a Human Factors Validation.
We hope you enjoy reading it!
Fundamentals of human factors engineering:
Human factors engineering aims to ensure the safe and user-friendly use of medical devices. By taking into account human capabilities and limitations in the development process, the occurrence of application errors should be minimized. At the end of this process is the HRV test, which is intended to ensure that the product can be used safely and effectively.
Implementation support through “Applying Human Factors”:
The FDA provides a valuable resource in the document “Applying Human Factors and Usability Engineering to Medical Devices“. Chapter 8 of this document specifically highlights the requirements and recommendations for the HFV test.
General information on testing:
Successful HFV requires the involvement of representative test participants, the consideration of all critical tasks, the use of the final user interface and the creation of realistic test conditions. Sensitive testing is necessary in order to detect even unconscious user errors and to avoid overlooking serious dangers due to design flaws.
The conditions for simulated use must be realistic enough to allow valid conclusions to be drawn for actual use. This includes environmental factors such as lighting or distractions. The independence of the participants and the consideration of real usage scenarios are crucial.
The selection of test participants is of fundamental importance. At least 15 participants per user group, representing the actual target group, are recommended. A broad coverage of characteristics, including possible functional limitations, is essential.
Tasks and use scenarios:
The HFV test must cover all critical tasks and pre-identified usage scenarios. Defining successful user performance and considering rare, high-risk scenarios is essential.
Various approaches can be taken to reduce the number of scenarios to be tested while still ensuring comprehensive coverage of critical tasks and usage scenarios. This includes the prioritization and categorization of scenarios, the selection of edge cases and the use of heuristics and empirical values. The automation of tests also plays an important role in increasing efficiency. By applying these approaches, test coverage can be optimized by avoiding unnecessary duplication and focusing on relevant scenarios.
Instructions for Use (IFUs):
IFUs should reflect the final design. The evaluation of the instructions for use takes place in the context of actual device use. Deficiencies in the labeling or IFUs are revealed through participant performance or subjective feedback.
Training of users:
The training provided in the HRV test should correspond to the real user situation. This means that your human factors validation must have the same conditions of use as in real-life use – for example, if there are disturbing noises in the real application that can cause stress in the user, these must also be simulated. Mitigation of usage errors through additional training is only acceptable if it is proven to be effective. The use of training content, formats and methods should reflect the actual user situation.
The HFV test should record observable data as well as participants’ knowledge and subjective experiences. Observable data includes participants’ performance on critical tasks and errors of use. Knowledge data, especially for complex tasks, is collected by interviewing participants. Post-test interviews provide insights into subjective assessments and perspectives.
The data collected is analyzed qualitatively. The aim is to identify the roots of any usage errors or difficulties that have occurred. The identified causes are analyzed with regard to the associated risks in order to determine the potential for possible damage and the urgency of further risk management measures.
Assessment of the residual risk:
After the HFV analysis, a residual risk remains. The assessment of this risk is crucial. Results that show serious usage errors are acceptable if it is demonstrated that further reduction is not possible and the benefits of the device outweigh the remaining risks.
Testing for modified products:
For modified devices that are already on the market, the review of HRA requires a comprehensive risk analysis. A new HRA may be necessary, focusing on the areas affected by design changes. The assessment by comparing the old and new design is particularly effective.
Testing through real use:
Real-use tests are required for particularly complex devices. They should follow previous simulated tests and take into account representative test participants and realistic environments. User self-reports should be supplemented by observational data.
The documentation of all HRV tests and analyses is of central importance for the FDA review. A detailed Human Factors Report is required to ensure compliance with FDA standards.
The successful implementation of an HFT test requires the simulation of realistic usage scenarios, the selection of representative test participants and the consideration of all critical tasks. The evaluation of the instructions for use and the training of the users should correspond to the real user situation.
Data collection during the test includes observable data, knowledge data and subjective experiences of the participants, while the analysis aims to identify causes of usage errors that occur and to assess the residual risk. Comprehensive documentation of all HRV testing and analysis is critical to complying with FDA standards and ensuring product safety.
You need to pay special attention to all of these components. You can find out how to deal with the individual points in detail in our articles: “Human Factors Validation – the basics at a glance (Part 1)” and “Human Factors Validation – the basics at a glance (Part 2)“.
Do you need help with the planning, implementation and documentation of your Human Factors Validation? Please get in touch using our contact form. We look forward to hearing from you.