Thursday, December 12, 2019

Submission of the Human Engineering File to the FDA and Other Regulatory Bodies, Sections 6 and 7: Part V

I cover Sections 6 and 7 in this article as shown below:

6Summary of preliminary analyses and evaluations
  • Evaluation methods used
  • Key results and design modifications implemented in response
  • Key findings that informed the human factors validation test protocol
7Description and categorization of critical tasks 
  • Process used to identify critical tasks
  • List and descriptions of critical tasks
  • Categorization of critical tasks by severity of potential harm
  • Descriptions of use scenarios that include critical tasks
I consider Sections 6 and 7 together because the information for these two sections should have come from the formative stage of the research and design process. These two sections could be combined into a single section. However, it is apparent that the FDA (and probably other regulatory bodies as well) considers Section 7, Description and categorization of critical tasks, as important enough to have its own, separate section. 

Importance of Getting It Right


The contents of these sections, the descriptions and explanations provided, can be the difference between: 

  • An easy, unquestioned acceptance of what you've done or
  • A difficult, question-riddled review of the work that you performed resulting in:
    • Approval delays, 
    • A reworking of the submitted materials 
    • Requests for additional research to be performed, or 
    • Rejection of the human engineering file 

To fully address what should be included in Sections 6 and 7, you need to examine your entire HE process in the context of the research and development program of your medical device or system and determine whether your HE process can adequately address reporting requirements of these two sections. These sections form the core of the report of your research and design process up to the point immediately before you begin your final phase of testing, namely verification and validation (summative) testing.


Section 6: Summary of the Preliminary Analysis and Evaluations


What Should be in Section 6

I briefly cover the points of what should be included in Section 6. Assuming that you are a human engineering professional, you should already have a reasonable understanding of the meaning of each of three requirements listed below. 

1. Evaluation methods used

This comprises the entire body of research performed including all of the data collected before the implementing a foundational or initial design, and all of the testing performed on the design.

2. Key results and design modifications implemented in response

What findings from your research lead to you to creating your initial design and what where the factors that lead you to modifying your design?

3. Key findings that informed the human factors validation test protocol

How did your arrive at creating your research protocol for summative/validation testing? How do you know that your validation protocol is appropriate and will verify that your system or device is safe for use?

That's the brief overview of what should be in Section 6. However, what should be included in Section 6 are the logical threads of justifications for doing what you did: for creating your research and development plan, the initial/foundational design and how you went about modifying that design. 
   
Don't be deceived by the seeming simplicity of Section 6. It is far more complicated and demands much more investigative and design process rigor than one might imagine. 


Human Engineering (HE): Research and Development


Section 6 is the section where you lay out all research and development performed in relationship to human engineering. Thus, Section 6 becomes the place where you make your case for the research that you performed and the design choices that you made. After reading Section 6, the reviewer should have a clear understanding and be in agreement with the research and design process that was undertaken. This includes the rationale for the research plan as proposed and undertaken including the rationale for any changes made to the plan on the basis of research findings. It will include the rationale for the design process, including the initial or foundational design and the reasons for changes made through the design iteration process.

Human factors is the study of how human interact with or operate systems and devices. Its fundamentally research. Human engineering incorporates the human factors, but encompasses and  incorporates design and the design process that should be at its foundation, driven by research. The research that directs and informs design and the design process includes field, laboratory, library, risk or research-based standards. And in the absence of the ability to collect empirical data: scenarios and interaction walk-throughs and analysis. 


You will need to defend your rationale for the specific research projects undertaken and the design choices made. Because the narrative is an overview, it's often a good place to explain the much of the logic for the research undertaken and the design choices made.


Defending HE Research and Design Planning and Choices


Adequate and effective justification of your research and development plan and design choices will often be the key to insuring unquestioned acceptance of your submission. Here are some suggestions:

  1. Justifying the Research and Development Plan -- the means for creating a usable and low-likelihood use-error and low risk system or device. Reasoning and justifications for the creating a research and development plan for this system or device include:
    • Compliance with IEC 62366 (part 1).
    • Conformance to FDA HE program guidance (on the FDA website).
    • Guidance from AAMI/ANSI HE-75
    • Guidance from previous, similar and accepted plans 
    • This system or device is a next generation release of a currently, commercially available product. Thus the research and development performed along with field collected data provide guidance for research and design plan for this next generation product.
  2. Justification for performing specific research include:
    • Planned research
    • Research fits within the guidelines set within the research plan.
    • Research is designed to answer specific research questions. Often during a research program, questions arise that may be human performance, design specific, etc. that may not have been specified in the research plan. Often times these types of studies are applicable to the research and development of a variety of device and systems. In this case the research is "question-driven." Those research questions need to be clearly defined out within the research protocol and become the clear justification for the research and the applicability and potential value of the findings.
    • Findings from planned research suggest the need for new research not originally planned.
  3. Justification for the foundational design: is initial design that is prototyped, usability tested and then iterated. The foundational design establishes the basic design philosophy (appearance and operation) that will likely be commercialized. While the foundational design will likely be updated and improved throughout the research and development process; fundamentally, it will likely maintain the same design philosophy. Thus, establishment of the foundational design maybe the most consequential step in the research and development process. Justifications for the foundational design include:
    • Updated version of an earlier, accepted design: using the same design philosophy. Updates and improvement driven-by field research, customer feedback, research on the use of the system under actual conditions.
    • Findings from formative research as defined by the research and development plan undertaken before initiating a design.
    • Compliance with accepted design standards, e.g., AAMI HE75. (There are a wide array of design standards issued and accepted by the US agencies as well as other agencies of a variety of countries. When localization of a design is required, the design standards issued by the targeted country should be considered and referenced.)
  4. Justification for changes made to the foundational and modified designs.
    • Findings from prototype testing.
    • Findings from expert reviewers: resulting from design walkthroughs/reviews and/or interactions with the device or system.
    • Limited field tests of prototypes.
  5. Justification that the design has reached the stage for verification and validation (summative) testing. And that a research protocol can be written that can effectively and realistically test the system or device to demonstrate that the system or device will be safe for use by members of the targeted population in the intended use environment(s).
    • This is the hand-off point to the summative testing phase.
    • Justification that that the system or device is read to hand off: The formative testing up to this point should have subjected the system or device to the all of the testing that it would be subjected-to multiple times. And the system or device should have passed those tests multiple times. Thus, if the research and development plan was properly executed nothing of any concern should come from verification and validation testing. If there are findings that are the least bit concerning, then it is time to reexamine your research and development planning and protocols. 
    • Finally, if your formative testing, meaning all of the testing performed up to this point, has been comprehensive,  rigorous and complete, then that testing should dictate the verification and validation research protocols.

What Should be Included in the Section 6 Narrative


I suggest that your narrative should be written in the form of a story. It should be a narration that describes in a linear fashion (from the beginning to immediately before the validation step) what you did, why you did it: 

  • if it's research, summarize what you did and what you found, 
  • if it's your foundational design, provide an high level description of how you arrived at this design (include enough figures to be sure that a reviewer will understand your description) and
  • if it's a design update, explain what change or changes were made and why.
Be sure to include references to your submitted materials in your HE file.



Section 7: Description and categorization of critical tasks


Identifying the critical tasks that will be performed on your system or device should be part of formative research. Often the ability to identify the set of critical tasks is beyond the expertise of the human engineering professional and identifying as well as categorizing the critical tasks requires the support of subject-matter experts (who should be included from the beginning of the formative research stage). My experience has been to integrate subject-matter experts into the research and design process from product inception.  

The list of requirements for Section 7 include:

1. Process used to identify critical tasks

With your subject-matter experts, describe the process used to identify your critical tasks. 

2. List and descriptions of critical tasks

Include with this your justifications and reasoning for this list. 

3. Categorization of critical tasks by severity of potential harm

In addition, if any of your critical tasks have the possibility of inflicting moderate to critical harm, I suggest that mitigations developed to minimize the likelihood that harm would ever occur. 


4. Descriptions of use scenarios that include critical tasks

These use scenarios should form a fundamental part of both your testing as well as justification and rationale for your design (and updates to your design.)

Section 7 Narrative


I suggest that in your narrative that you include a table with the information from items 2 and 3 above. I would add a brief summary of the process that was used to identify your critical tasks. Finally, include a reference to the use scenarios that include the critical tasks. You don't need to include them in your narrative, a reference should be sufficient. 

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Note: I plan on periodically updating this article as I learn more and reconsider what I have written. With each update, I'll include at the top of this article, when it was updated and list some of the changes that I have made. 

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