Prosthetic limbs have been available for quite some time, though with limited utility. However, over time, innovation and technology have greatly improved their usefulness. In today’s environment of 3-D digital design and simulation, the outlook for prosthetic limbs is advancing in unprecedented ways.
Fit, Function, and Comfort
Of key importance to any patient receiving a prosthetic limb, or other orthotic device, is the fit, function, and comfort that the newly designed prosthesis provides. This is becoming expedited with the use of simulation software that is experiential and allows key attributes of form, fit, and comfort to be incorporated in fabricated prototypes.
The process of creating such forms utilizes complex design software in concert with 3-D printing. 3-D printing allows
for rapid fabrication and iterative designs with different materials and topologies, so that the patient has a very precise fitting for adequate functionality and comfort.
Upper limb forequarter amputations often require the removal of an entire arm and/or scapula. To create a prosthetic for such patients, an intricate and customized prosthetic device may be designed and fabricated but is often expensive. They also require high maintenance by the patient and often do not provide an adequate comfort level for using such prosthetics for sustained periods of time.
When an artificial limb is designed to provide patients the appearance of a pre-amputated body part, with prices replication, the patient has a higher rate of continuous use, they have limitations in functional use.
At the Singapore University of Technology and Design’s (SUTD) Medical Engineering and Design Laboratory, engineers collaborated with Tan Tock Seng Hospital’s (TTSH) Foot Care and Limb Design Centre to fabricate a patient-specific upper limb prosthesis.
More Comfort, Less Cost
This resultant cosmetic prosthesis included a self-locking function to provide more comfort and a surprising 20 percent decrease in cost compared to comparable prosthetic limbs. This was made possible with accurate digital technology and 3-D printing.
By working collaboratively with the patient and prosthetist at the hospital, it was determined that the new prosthesis needed to be “lightweight, capable of dissipating heat, locking at 90° of flexion, and be comfortable to wear and void of metal components that would be detectable by airport scanners.” After the application of careful engineering design and collaboration, the team was able to create a remarkable limb.
“Digitalization and 3-D printing have been transforming the design and manufacture of complex medical devices, surgery planning, medical education, and care delivery,” said principal investigator, assistant professor Subburaj Karupppasamy from Singapore University of Technology and Design’s Product Development pillar.
“Even though 3-D printing technology has been around for more than three decades since the early ‘90s, it wasn’t until recently that people really began to appreciate and trust it for end-use fabrication. In this work, 3-D printing freed us from the manufacturing constraints and enabled us to optimize the design to suit the patient’s needs. More importantly, this work sets the groundwork for future patient-specific end-use 3-D printed parts for prosthetic needs.”
End-to-End Design
Such applications are fitting for high-performing digital design tools. Dassault Systèmes 3DEXPERIENCE solutions create an end-to-end journey for medical designers and manufacturers with the capability to efficiently manage product lifecycle management as well as quality issues. Digital tools are used to boost traceability and achieve full compliance with regulations and requirements. In addition, it has proven to be quite effective in reducing waste without sacrificing quality and safety in the design.
For example, Dassault Systemes an extended collaboration with the U.S. Food and Drug Administration to utilize its platform to expedite a review of cardiovascular and medical devices. Specifically, this second phase of their ongoing collaboration supports the 21st Century Cures Act, using virtual patients based on computational modeling and simulation to improve efficiency of clinical trials for new device designs. The intent of the collaboration is to put the power of digital innovation to work and blaze a new trial for patients to access safe, effective new treatments for heart disease, the world’s leading cause of death.
The New Frontier
Digital design tools are simply providing new possibilities for wellness. The uniqueness of highly accurate and complex digital design capabilities, when collaborating with all medical stakeholders—biomedical engineers, prosthetists, physicians, 3-D fabricators, researchers, and of course, patients—is creating a new cure for medical challenges that had inadequate solutions in the past.
The digital fabric and all that goes with it is a new frontier in medicine, and by some measures, a whole new metaphoric cure for prosthetics and medical orthotics.
Jim Romeo is a journalist focused on technology topics. He retired after a 30-year career as a mechanical engineer for the U.S.Department of Defense where he was a supervisory branch chief, and systems engineering division head. He has been covering technology topics as a freelance writer since 1991. He writes about all topics including manufacturing, robotics, plastics, 3-D printing, engineering software, design thinking, and many other related topics. He is a graduate of the United States Merchant Marine Academy and holds an MBA in Marketing from Columbia University. He lives in Chesapeake, Virginia.