Stratasys Additive Manufacturing Technologies Transforming Orthotics
Orthoses, often referred to as orthotics, are passive devices worn to support an injured or weakened body part. Whilst many people will be familiar with the use of temporary braces after an injury or surgery, a significant proportion of orthotics are used for long term care to address multiple conditions. These conditions include foot drop (from muscle weakness or neural damage caused by a stroke), multiple sclerosis, peripheral nerve injuries, and other disease states requiring artificial support. Another common application for orthoses are also used to assist stabilizing a painful osteoarthritic joint, and correcting a joint deformity.
With aging populations worldwide, the number of people who utilize orthoses has grown significantly in the past three decades. Projections indicate that 7.3 million people in the United States will utilize orthoses to combat the effects of paralysis, deformity or orthopedic impairments by 2020. However, while the demand for custom orthotics increases, there has been no dramatic change to the manufacturing techniques used to create these devices in decades.
The University of Michigan has partnered with Altair Engineering and Stratasys to form the CYBER team. And the CYBER Team was recently selected and funded by America Makes (the National Additive Manufacturing Innovation Institute) to work together on a solution that will leverage additive manufacturing and Industry 4.0 to transform the design, comfort, utility and customization of Ankle Foot Orthotics (AFO). This solution will incorporate digital design, additive manufacturing through 3D printing, and leverage industry leaders at the University of Michigan Orthotics and Prosthetics Center to deliver on emerging Industry 4.0 trends.
In order to accomplish this, the CYBER team will create the digital workflow for additive manufacturing (AM) design, while connecting the digital thread in a cloud-based cyber physical system which will connect fused deposition modeling (FDM) additive manufacturing technology and Altair® OptiStruct® software for the production of customized ankle-foot orthoses (AFO).
The Pain Point of Ankle Foot Orthotic Manufacturing Today
The traditional process for making a patient a customized AFO uses (A & B, see image below) skilled orthotists and technicians to take an “impression” of an individual’s lower leg with fiberglass cast tape; (C) pouring liquid plaster into this impression to create a positive model; (D) modifying the plaster model by hand to account for bony prominences as well as pressure tolerant areas (E) vacuum forming a thermoplastic sheet around the model; (F) hand-trimming the plastic orthosis to final shape; and then adding any necessary padding and straps before fitting the AFO to the patient1.
The pain points of this process starts with a typical delivery time of two to four weeks due to the skilled labor required, insurance authorization processes, and the demand on this resource from the numerous patients requiring this care in orthotic centers. The process uses a significant amount of disposable plaster materials, has limited capability to optimize the structure or the weight due to a constant sheet thickness across the orthosis, and does not incorporate modern analytical techniques that ensure optimization of the strength and flex of the AFO to maximize a patient’s mobility.
- Jeff Wensman, BSME, CPO, Clinical/Technical Director, University of Michigan, Orthotics and Prosthetics Center.
The CYBER Solution: Making Industry 4.0 Real in Ankle Foot Orthotic Manufacturing
The CYBER team has come together to directly address these pain points that affect patients and care-givers, while accelerating and reducing the cost of delivery of optimized ankle foot orthoses.
This future cloud-based cyber physical system will allow clinicians to create Ankle Foot Orthoses by utilizing an online portal, combining clinician expertise with automated tools to create the patient’s prescription. The engineered cyber-physical system provides the seamless integration of the cloud based algorithms with the physical component manufacture to optimize overall part geometry and its corresponding tool-paths.
The advantages of an additive manufacturing solution for Ankle-Foot Orthoses are compelling:
- Reduce the long delivery time: Typical delivery time is 2-4 weeks for AFOs. The team plans to reduce this delivery time to 1 day through the cyber-physical system.
- Enhance the level of accuracy: Plaster shrinks after drying so plaster molds do not accurately duplicate the patient’s ankle and foot shape without iterations or the skill of a certified orthotist. The team plans to utilize precise, 3-dimensional scanning to provide exact dimensions for instant, exact AFO accuracy while utilizing design for additive manufacturing compensation techniques.
- Eliminate multiple visits: This is taxing for users and caregivers, and drives cost.
The team plans to improve the manufacturing process to provide single-visit patient care.
- Enhance the limited design freedom: Shapes of AFOs are limited by current manufacturing practices, which cannot fabricate orthoses that require more intricate, functional designs.
The team plans on allowing computational model and tool path based optimization to drive future AFO design, while encouraging clinician input to provide personalized care. The average age of a lower extremity orthotic wearer is 70 years old; light-weighting and ease of use are paramount in this project.
Of course, no one person can properly execute all of the required knowledge to operate the current workflow needed to achieve this cyber-physical system. Engineers, such as those at Stratasys and Altair, along with clinicians at orthotics & prosthetics centers, are the only people knowledgeable enough to execute each specific task. Between multiple file types, the creation of structural and tool path optimization files, design for additive manufacturing considerations, and orthotic best practices, the amount of manual computational analysis is daunting. Adding to the expertise needed, the current additive manufacturing workflow has drawbacks:
- Machine throughput: The current additive manufacturing technologies do not provide high enough throughput to enable the one-day visit for ankle-foot orthotics. A new design methodology is required to increase throughput and lower material usage, while maintaining structural integrity and functionality.
- Multiple materials: Both stiff material for structural functionality and a soft material for comfortable interfacing are needed in one custom orthosis.
- Lack of clinical interface and system integration: There is no software system that can seamlessly process all the data from the patient’s 3D scan geometry to shape of the orthosis, and to the printable command file.
Only through collaboration between the realm of health sciences, industry partners, and ultimately, patients, will facilitate the developments required to overcome such obstacles. For over 22 years, Cimetrix has been the leader in 3D Printing Technologes within , providing innovative additive manufacturing solutions to revolutionize workflows through partnerships the nations's industry leaders. With Applications Specialists decidated to specific verticals, and unparalleled experience working with some of Canada's most innovative groups and institutions, Cimetrix has the tools to make your ideas become a reality. To learn more, please contact our team of Applications Specialists.
Originally adapted from the Stratasys Blog Transforming Orthotics with 3D Printing and Industry 4.0