Researchers at the University of Michigan (UM) are implementing a new orthotics and prosthetics outfitting system: 3D printed assistive devices that will be customized to individual patients’ needs and reach them faster than ever before.
Engineers and clinicians at the UM College of Engineering and Orthotics and Prosthetics Center say their new cyber manufacturing system is a vast improvement over traditional production methods. Currently, assistive device users must wait days or even weeks for essential orthotics and prosthetics. The new UM system would reduce that wait time to one day. Even better, each device will be customized on a case-by-case basis, providing improved support, fit, and function.
Specialists working with a patient at the UM facility
Whereas prosthetics are assistive devices used to replace an arm or a leg, orthotics are braces that protect, align, or improve function or stability to injured limbs. For now, the UM team has begun working with ankle and foot orthotics, typically prescribed to stroke patients who are relearning how to walk. Children with cerebral palsy, myelomeningocele, and other medical conditions also benefit from foot orthotics, which help facilitate stability and minimize the struggle of walking.
“Eventually we envision that a patient could come in in the morning for an optical scan, and the clinician could design a high quality orthosis very quickly using the cloud-based software,” said Albert Shih, UM professor of mechanical and biomedical engineering. “By that afternoon, they could have a 3-D printed device that’s ready for final evaluation and use.”
The UM system starts with a 3D scan of the patient using state-of-the-art imaging technology. Orthotists then upload the individual scan to a cloud-based design centre, and begin designing the orthotic. Design files are then sent back to the UM facility, where an on-site 3D printer manufactures the assistive device, layer by layer. The whole process takes only a few hours.
3D printed orthotics
It’s a vast departure from current methods of manufacturing orthotics, which can be a costly and time-consuming process that requires fiberglass tape, plaster, heated plastic, and a hand-finish. The labour-intensive procedure requires highly trained staff and a large facility.
By contrast, UM’s alternative method only requires access to an optical scanner, a computer, and a 3D printer.
“Traditional hand-made orthotics are solid plastic, and they need to be a certain thickness because they have to be wrapped around a physical model during the manufacturing process,” said Jeff Wensman, director of clinical and technical services at the UM Orthotics and Prosthetics Center.
“3-D printing eliminates that limitation. We can design devices that are solid in some places and hollow in others and vary the thickness much more precisely. It gives us a whole new set of tools to work with.”
The traditional method of making orthotics
The UM 3D printing technique is known as “sparse structure,” and was developed by Robert Chisena, a mechanical engineering PhD student at UM. Sparse structure allows for the production of partially hollow orthotics, thanks to a wavy internal structure that saves weight and boosts strength.
Perhaps best of all, this system could open the door for widespread production of custom orthotics and prosthetics. Any clinic with a 3D printer would be able to produce assistive devices using UM’s technique, even small facilities in remote areas. Shih’s team eventually plans to make their software and specifications freely available, so other healthcare providers can implement similar systems independently.
“In a sense, we’re building a recipe that others can use to build their own systems,” Shih said.
The UM project is jointly funded between America Makes and the National Science Foundation. Statasys provided the 3D printer, and software is currently undergoing development by Altair and Standard Cyborg.