Nov 9, 2016
At the University of Victoria, a team of engineers, designers and volunteers is hard at work, providing 3D printed prosthetic hands to amputees in some of the world’s most deprived areas. There are challenges, but the difference they’re making is remarkable. They are the Victoria Hand Project, and this is their story.
In the late 90’s, Dr. Nikolai Dechev was working on his Masters project creating a prosthetic hand with a ground-breaking technology which he called Adaptive Grasp. Adaptive Grasp allows the fingers to conform around an object as the hand closes. At the time, the hand was designed to be fabricated on a CNC machine. The high cost of manufacturing the hand made it not a viable option. That’s where 3D printing came in. After seeing the potential of this technology, Dechev and his colleague Joshua Coutts modified the design and started the Victoria Hand Project.
Prosthetics aren’t often available in developing countries, due to limited resources, restricted access in rural areas, lack of expertise and expense. 3D printing provided a solution to the problem, enabling the team to print and assemble locally in each country, at a reduced cost. With a 3D printer and right filament, a clinic can print personalized medical devices or replacement parts, even in remote locations. For example, in Nepal, a team of engineers traveled with their 3D printer, creating medical devices and replacement parts for machines. It’s easier and cheaper than transporting big boxes of specific parts.
They needed a printer that offered a high-quality finish, with strong bonds between each plastic layer. The Ultimaker 2 was ideal, thanks to the quality, ease of use and available resources for maintenance and troubleshooting.
How it works
Firstly, the amputee meets the prosthetist for measurements. A mold is created of their residual limb, then the prosthetist creates interfaces between the device and the human body. The Victoria Hand Project team captures the prosthetist’s skill through custom 3D scanning of the plaster mold. This scan is then used to create a customized, 3D printed socket for the amputee.
The hand and wrist components are printed in around 48 hours, then assembled and attached to the custom socket. The final step is to paint the prosthesis to match the natural skin tone. This aesthetic touch helps the amputee to feel more confident.
Training is provided to all 3D print lab staff, plus the prosthetists and clinicians.
3D printing challenges
In 2014, the Victoria Hand Project team researched different 3D printers, and found the Ultimaker 2 was best suited to the task. Initially, they ordered an SLA 3D printer as well, but it resulted in many failed prints and didn’t offer the clean environment required. The parts were also too brittle for practical use. Ultimaker proved to be far easier to use, which meant clinicians and prosthetists could quickly grasp how to operate them.
There were a few issues along the way, but Ultimaker’s guides and forums helped them learn how to use and repair the printers. The quality of prints improved and the manufacturing process sped up. Over the years, the team gained valuable experience using 3D printers, and were able to provide technical support to other clinics. They train medical workers in person, to ensure they know how to assemble and fit the prosthesis. This encourages a closer relationship with the clinic staff.
The team also learned how different 3D printing in clinics can be from printing in the University of Victoria lab. In Nepal, for example, there are daily power-cuts. Without a UPS, no sockets could be printed. In other clinics, it’s hot and humid, which can alter material properties. In Kathmandu, the air is dusty, which means the build plate needs to be cleaned more often, and this makes the process more expensive. Plus, shipping and importing fees make it expensive to replace even something as small as a nozzle.
Sometimes, it’s challenging knowing what the best print settings are for the job. With Ultimaker 2+ printers, the Victoria Hand team tested print speeds and layer heights to find the optimum settings, and also tested different materials, such as PLA, ABS, Nylon and PET. Engineering student volunteers undertook tensile tests and failure analysis in each case. These tests allowed Victoria Hand Project to further improve their designs.
The students determined that black PLA was the best. It was strong and required less pre-processing time. Other materials were harder to print with – for example, ABS was stronger, but didn’t stick to the build plate as well. This would have been problematic for less experienced 3D printers (such as the staff at the clinics). PLA offered great quality and was easy to use – so it was the ideal material for the job.
From Guatemala to Cambodia and beyond
After receiving a grant from Grand Challenges Canada, the Victoria Hand Project joined forces with the Range of Motion Project in Guatemala. Short and long-term trials were conducted – which confirmed that people desperately needed high-quality prostheses, without the expense. Joshua Coutts, a designer, recalls his third visit, when he realized the 3D printer’s full potential.
Until then, he’d focused on developing the hand functionality. In the third trial, the function, ease of use and aesthetics were all improved, which made the world of difference. It felt like the hard work was paying off, and they were finally delivering life-changing results.
Since then, the Victoria Hand Project have teamed with other clinical partners in Nepal, Haiti, Cambodia and Ecuador. The clinics find the amputees, print and assemble the hands, and fit the prosthesis. The Victoria Hand Project team sets up the equipment, trains local staff, and offers support and follow-up.
Sponsors and supporters
It wouldn’t have been possible without several generous donations. Grand Challenges Canada funded the initial development and trials, and extended their help to establish additional clinics. Ultimaker donated four Ultimaker 2+ printers – a crucial component of the operation. The Enable Community Foundation funded the clinic in Haiti, and other donations have come through via crowdfunding and fundraising.
Although Victoria Hand Project have collaborated with E-nable, the design teams are now separate. E-nable runs off an open-source model, allowing people to download designs and print them anywhere with a 3D printer. The Victoria Hand Project provides STL files and Gcode files to collaborators only. This ensures the 3D printed prosthetic is exceptional quality and maintains a good reputation.
In addition to the 3D printed hands, the team has started to develop other medical devices using 3D printing; such as an adjustable club-foot brace, ankle brace and finger brace. They used the same hardware and materials, so the new design is simply emailed to the clinic and printing can begin.
The parts are heat-formed using a heat-gun or hot water, as PLA is a thermoplastic. As the material becomes soft, it can be formed around the limb; then as it cools it becomes rigid and provides support.
Victoria Hand Project aims to reach more amputees by improving their system further, raising funds, and building more partnerships worldwide.
Spreading the word and gaining financial support are major factors in making this happen. Watch this space to learn more about this amazing project. We will keep you posted on their progress!