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Computer simulation has increasingly established itself as a valuable tool for medical device companies in testing new product design. In conjunction, FDA is receiving a growing number of submissions that include simulation data, leading the agency to believe that computer modeling and simulation (M&S) has potential to supplement traditional models used to evaluate devices.
To connect the interest in M&S with the device approval process, the Center for Device and Radiological Health (CDRH) and the American Society of Mechanical Engineers (ASME) are drafting verification and validation guidelines expected out later in 2013.
“The message from FDA is, ‘You are already using this kind of tool for your design evaluation; why don’t you provide that information to us when you submit the data so that we can better understand your design,’ ” says Cheryl Liu, Life Sciences Senior Product Experience Technical Specialist at Dassault Systèmes SIMULIA, which worked with CDRH to develop the organization’s internal framework for validating and regulating industry-submitted simulations. “From FDA’s perspective, they want the manufacturers to include those data so that they can see the performance of the device better through simulation results (rather) than just physical testing and animal testing itself. Basically the two components really come together.”
Most device companies use simulation as a development and design optimization tool, whether for manufacturing, stress analysis or fatigue life predictions, Liu says. A ten-year life cycle bench test of a knee implant can take three months, but with simulation it can take less than a week. Device companies have embraced simulation due to its savings in cost and time.
FDA recently listed challenges with the current uses of M&S for reporting, including:
- A lack of sufficient details for adequate assessment, because there aren’t reporting standards for computational modeling
- A lack of sensitivity and uncertainty analyses for parameters such as geometry, physical properties and boundary conditions
- A lack of adequate validation to support computational model usage
- A lack of understanding of physiological loads and variations in patient populations
These challenges have led FDA to work on outlining strategies that assess M&S’ credibility and use, and to determine how medical device regulatory submissions should report these modeling studies.
Liu sees medical device companies adopting simulation even more in the future. FDA requires simulation for stent analysis, and the organization’s forthcoming guidelines could drive more manufacturers to adopt M&S models. A sign suggesting that FDA sees benefit in simulation data is the new publicly-available Virtual Physiological Patient, which presents human body computer models in different disease states and provides shared references to understand model attributes, limitations, data and simulation validation for regulatory evaluation. The Virtual Physiological Patient was launched in conjunction with the Medical Device Innovation Consortium in December 2012.
Manufacturers can join the discussion at the next workshop, Computer Models and Validation for Medical Devices, that will take place June 11-12 at FDA’s campus in White Oaks, Maryland. Registration information can be found on FDA’s Medical Devices News & Events—Workshops & Conferences calendar. Electronic comments can be made at www.regulations.gov.
REFERENCE
Public Meeting – FDA/NIH/NSF Workshop on Computer Models and Validation for Medical Devices, June 11-12, 2013, www.fda.gov/MedicalDevices/NewsEvents/WorkshopsConferences/ucm346375.htm, Accessed April 2013.
Photo via Smith & Nephew
