We can see a gray area with 3D-printed medical devices, especially when it comes to the medical industry actually printing those devices for their patients. The benefits behind hospitals and other medical organizations printed these parts cannot be ignored.
3D printing allows for great flexibility, multiple iterations, quick turnover and a lot of durable, versatile material options. The issue arises when we bring implants and prosthetics into the mix; in these cases, if the product is being printed at the medical facility, the hospital is somewhat left to its own devices when it comes down to quality management.
That was just one of the topics touched on by the MD&M BIOMEDigital Conference panel on applications of 3D printing in medtech. The panel, sponsored by Formlabs, Trelleborg and Protolabs, was composed of three individuals with extensive experience in healthcare:
- Beth Ripley, M.D., Ph.D., director, Veterans Health Administration (VHA) 3D printing network at VA Health Care Systems
- Sean McEligot, section head of medical device research and development at Mayo Clinic
- John Foody, manufacturing engineer at Corvia Medical
Ripley, whose organization uses additive manufacturing (AM) to create orthotics and prosthetics for veterans, discussed the distinct benefits of AM for those applications through a real-life example in which a veteran with a 3D-printed lower extremity prothesis experienced knee pain while rehabbing. The prosthetist wanted to carve out materials on the prosthetic to alleviate the pain.
“The prosthetist was able to hop on a computer and using software make those tweaks in about 20 minutes, reprint the prosthetic overnight and the next day, have the patient back into another prosthesis with no interruption to their rehab,” she said. “This is a huge space we’re interested in.”
Ripley also noted that orthosis is an interesting space for additive because it can allow for the digitalization of different braces to keep at the ready when these sometimes-brittle devices break.
Another perk of 3D printing medical devices is the variety of materials available. At the Mayo Clinic, McEligot noted they have a wide range of materials and machines—including a titanium printer—since they use additive manufacturing for many things from one-of-a-kind devices to lab equipment to a temporomandibular joint (TMJ) implant.
“The biocompatible materials are very interesting to us and we’re starting to use those,” he said. “We have challenges with each of the different materials. I’m most optimistic right now about the stereolithography [SLA] world.”
The double-edged sword to having wide array of materials is that there’s still a lot we don’t know about how different materials interact with humans and different sterilization methods used in the medical industry. For example, devices created using fused filament fabrication cannot be re-used because they cannot be cleaned to reduce risk of infection.
The surfaces have to be relatively non-porous so they can be cleaned,” said McEligot. “Historically, with stereolithography, the materials haven’t been true engineering materials, so they’ve been brittle and, in some cases, they haven’t been dimensionally stable.”
Ripley agreed with McEligot on materials limitations and considerations.
“You have to be very careful about the materials you’re putting in because the sterilization process itself may change those properties of the material,” she noted.
Ripley said the VHA primarily uses SLA and DLP methods—as long as they’re photo-curable materials. She also noted the hospital system is pursuing powder bed technology applications.
“We have pneumatic-based, syringe-based-type of printers that will allow you to load almost any material you can into a syringe and push it out under air compression,” Ripley explained.
Another issue facing medical organizations using 3D printers is the development of a quality management system (QMS), which is pretty new to the hospitals printing in-house.
“This has been wild and new for us, but quite important in terms of learning how to be a manufacturer,” Ripley said. “We are still learning. This is not something you just pull off the shelf. Each quality management system needs to be built for the organization.”
McEligot agreed about the need for a good QMS for medical organizations, but also highlighted how the Mayo Clinic is including the FDA in its research initiatives. The investigational device exemption (IDE) under the FDA allows it to monitor ongoing research. It’s under this exemption that allows many 3D-printed medical device research to happen.
“It’s a bit of a gray area from a regulatory standpoint,” McEligot said. He pointed out that the organization doesn’t have to be a medical device manufacturer to support an IDE, but a QMS is required. He went on to note that when the Mayo Clinic begins using its titanium printer for implants, it will have to become a registered medical device manufacturer per FDA regulations, regardless of its IDE status.
Of course, this isn’t a large issue for medical device manufacturers like Corvia Medical, which is known for manufacturing structural heart devices, and already has an established QMS.
“We’re probably a ways away from ever considering implementing 3D printed parts in any part of our actual producible device,” noted Foody. “There are so many limitations right now that are being worked on.”
Speed of production, materials, machines and software that can be validated and noted in a QMS, generational considerations and potential contamination are limitations that Foody noted.