Wednesday, May 1, 2013

Human factors in the medical device industry

There has been a growing emphasis on human factors as a part of the product development process in the medical device industry, in the past few years. In fact, the human factors and ergonomics society even conducted a special symposium on human factors and health care, wherein medical device design was a special track. So, why the sudden demand for human factors in the medical device industry? A lot of this demand is driven by regulatory requirements and I attempt to describe some of this in this blog.

Several medical device directive (MDD) and active implantable medical device (AIMD) changes took place in 2010. This impacted multiple functions (e.g., Regulatory, risk management, technical communications) and had an effect on legacy, ongoing, and future products. For example, the crux of the MDD changes included:
  • Designing and manufacturing medical devices in such a way that when used under the conditions and for the purposes intended, they will not compromise the clinical condition or the safety of patients, or the safety and health of users.
  • Reducing the risk of use error due to the ergonomic features of the device and the environment in which the device is intended to be used.
  • Considering the technical knowledge, experience, education and training and where applicable the medical and physical conditions of intended users.
In summary, essential requirements related to human factors and ergonomics was added to MDD and AIMD.  As part of the MDD/AIMD work, two human factors engineering standards, EN 60601-1-6:2007 and EN 62366:2008 were harmonized and was in effect.

 So, what is EN 62366? 
  • This is a ‘process standard’, that tells a manufacturer the process to  analyze, specify, design, verify and validate usability, as it relates to the safety of a medical device.
  • The standard focuses on the need to provide adequate usability such that the “risks resulting from normal use and use error are acceptable”.
  • The standard focuses on identifying and mitigating design-induced use error.
  • The standard discusses the need to validate primary operating functions.
  • Overall, this standard emphasizes a more formal human factors process that combines analytical and empirical methods to detect as well as mitigate use error.
  • The standard also requires the maintenance of a usability engineering file and associated documentation that human factors work was done. However, the process is scalable.

In 2011, FDA published a draft guidance on “Applying Human Factors and Usability Engineering to Optimize Medical Device Design” for comment purposes. The comment period is complete but the effectivity date for the guidance is still TBD. Overall the FDA draft guidance is very similar to EN62366.  However, some key differences exist:
  • The FDA draft guidance focuses on using analytical and empirical methods very early in the project lifecycle to identify and mitigate sources of use error.
  • There are clear expectations for handling, documenting, and resolving use errors.
  • The guidance discusses a human factors engineering summary report, which is very elaborate and prescriptive.
As a human factors advocate, I believe that irrespective of the regulatory driven requirements, human factors should be an integral part of the product development lifecycle in medical device industries (or any industry) so as to create products that are not only safe but also improve user workflow and efficiency.