What does a submarine operating underwater have in common with a metal stent propping open a human artery? More than you’d think initially.
Despite dramatic differences in scale and environment—obviously people ride inside submarines while stents are implanted inside people—both sub and stent are subject to the same laws of physics governing the behavior of fluids, structures and the interactions between them. Whether cruising the ocean depths or resisting the turbulence of pulsing blood, these two human inventions are subject to continuous wear and tear—and must protect human lives during decades of hopefully trouble-free operation.
Makers of submarines, airplanes, cars and other performance-critical products have for decades embraced computer simulation as an invaluable tool for product design and analysis that fosters innovation within the constraints of the physical world and can predict performance over a lifetime.
Medical device manufacturers are now catching up.
The FDA’s enthusiastic support is accelerating the drive to harness digital methods, such as FEA, CFD, topology optimization, virtual human modeling and so on for life sciences. And the same drive toward personalization that lets consumers specify unique details in their new cars is now empowering physicians and researchers to customize medical solutions for individual patients.
Take the arterial stent, one of the earlier examples of a manufactured medical device that has reached a stage of fine-tuning that would have been impossible without computer-aided engineering. Simulated fatigue prediction has now become necessary to ensure the safe performance of a new stent design over its lifetime, and is also recommended by the FDA.
What’s more, computer models of a living, beating heart, or components of it—based on scans of a particular patient—can be used to design and virtually test the configuration of the stent that best fits that same person’s unique anatomy and disease state. “One size fits all” is becoming a thing of the past in medical device development and manufacturing.
But what does all this customization cost? The answer is that the very same tools that allow personalization also help shorten that critical time-to-market equation. The FDA’s MDDT (medical device development tools) program is encouraging the industry to move forward rapidly with developing virtual animal and human models that can be used to evaluate medical devices. Computational models, in many instances, may be able to better represent aspects of a device’s performance than traditional sources of evidence, the FDA has concluded.
Think of it this way: Digital tools can be used to virtually “bench test” multiple solutions to a medical device design challenge. With the ongoing advancement of simulation solutions and corresponding availability of simulation expertise, companies of all sizes—from the largest manufacturer to the smallest startup—can use simulation to zoom in on those designs that have the most promise. This can save significant costs in early design evaluation and testing, helping rule out dead-end products before companies have invested heavily in trials or even production.
In moving to digital design, manufacturers will need access to expertise for simulating a broad range of physics, including everything from deformations of solids and fluid flow to heat transfer and electromagnetism. Often, the necessary methods and tools are already in use in completely separate fields and industries. The medical industry has much to gain by drawing on existing resources.
Which brings us back to our submarine: Methods for the stochastic and probabilistic assessment of the kinds of physical events that could impact its hull and endanger the occupants have been proven over decades—and are available to support the medical device manufacturer working to create products for that most variable entity of all: the human body.