Student creates 3D-printed prosthetics to help people in need Wednesday, 14 December 2016

A biomedical engineering student at Monash University is using 3D printing to create low-cost assistive hand devices for people who are missing fingers.

Gabi Newman is carrying out the work as a member of the Melbourne chapter of e-NABLE, a charity that was set up to use 3D printing to help lower the cost of building prosthetics.

The community comprises people from all over the world, including teachers, students and engineers, who use 3D printers and open source designs to create their own prosthetics.

“[As the design is open source], other people can come and update them and make the models better. Then we offer the prosthetics pro bono to people in need,” Newman said.

Newman has been working on the project for six months, and emphasized that she started from scratch and traveled on a steep learning curve to work out how to use a 3D printer, such as how to use the software and what factors made a good or bad print.

“When you’re trying to print different parts, you can’t just all print them [in a uniform manner]. Some need to be stronger than others, some need to be thicker,” Newman said. “You’ve got to change to make the model as effective as possible.”

Another challenge has been finding the right amount of rigidity in the prosthetic and working around limitations in regards to detail and strength.

For example, plastic can break, which places limitations on how light it can be without snapping.

There are also constraints on the materials used, with Newman using ABS and PLA for the project.

“ABS is a slightly stronger material than PLA, so a lot of people find that PLA gives the better detail and the joints are better and the actual printing quality is better,” she said.

Deciding what material to use can depend on the person who needs the prosthetic based on their needs and asking whether they want something stronger or a better quality, Newman said.

There are also limitations on how much strength the prosthetic has. This means the hands are low-mechanical load bearing, so while they can withstand low loads like picking up a glass of water, the prosthetics can’t handle carrying a heavy shopping bag.

“You can’t have a hand that’s really strong but also very light. That just can’t happen. You have to constantly compromise,” Newman said.

A solution for kids

3D-printed prosthetics can provide a more cost-effective solution for children, Newman said.

She said due to their fast growth, children often need to have their prosthetic replaced, which can be expensive.

But if their 3D scan or measurements are kept on file, a new one could easily and cheaply be made when they outgrow their current one.

“We're talking $20 to $30 a prosthetic. All of a sudden it’s not that expensive to go and make a new one every few months when a child grows,” Newman said.

“That’s why this option is more viable than say, getting a proper carbon-fibre reinforced [prosthetic].”

This is because options like carbon-fibre prosthetics can be cost prohibitive and regularly need changing for children, which can make them unsuitable for them.

3D prosthetics can also be printed in a variety of colours, and while Newman said creating colour variations is an area she’s hoping to develop her skills in, she has experimented with variations such as a zebra pattern.

“All of a sudden, a prosthetic doesn’t become something they’re ashamed of, but something really cool,” Newman said.

She has now printed and assembled 20 prosthetics in a range of sizes, all of which have been given to e-NABLE.

Newman said there are already about 20 people on the waiting list here. But so far the Melbourne chapter of e-NABLE has been unable to provide their prosthetics to people in Australia, so they can only be used in other countries, including the United States and India.

“The issue is that to be able to give out a prosthetic in Australia, we have to have public liability insurance, which is very expensive. Without public liability insurance, it means that the maker themselves can be liable, and ultimately when you’re giving something pro bono, you want the organisation to be liable, not the individual maker,” Newman said.

While there is a group in Australia who is dedicated to building 3D prosthetics for e-NABLE, they are limited to helping Australians until they can raise the money for the insurance.

As well as working to overcome the insurance issue, Newman has her sights set on designing her own prosthetic and plans to continue developing her modelling skills over the summer.

One aspect in particular she hopes to improve is the degree of freedom a prosthetic hand has.

“If I were to go to a more basic level, the one thing I see in a lot of designs that need to change is that the thumb is rigid, and I think the thumb needs to be able to turn,” Newman said. “I would design it to be more of a ball-and-socket [structure] for the thumb.”

Newman also hopes to continue to be involved in projects at Monash, with several of her prosthetics recently on display at Future Finders, an exhibition curated by Monash University’s Faculty of Engineering.

“I’ve been able to do a couple other 3D projects with Monash, and I hope I keep getting that opportunity, because once I learn, I can do it myself. At the moment, I just need to keep learning and become better,” she said.