Gone are the days when mechanical engineering only focus on planes, trains and automobiles. A new generation of engineers from the Nelson Mandela University and their counterparts at the University of KwaZulu-Natal are changing the lives of amputees.
They designed a robotic prosthetic hand to perform day-to-day functions.
Detecting electrical signals from arm muscles, the battery-operated prosthesis is able to imitate natural hand functions.
Lungile Dick lost his hand in an accident, leading to a life of frustration and anger.
“You get frustrated because you can’t tie your own shoelaces, you can’t pick up something that you want to pick up. It affects me literally when I write sometimes because my mind works faster than my hand and I was not left-handed, I was right-handed. So you get those depressions and frustrations that you used to be able to do your own thing, but now you can’t,” says Dick.
He had to learn to navigate life without the use of his strongest hand, but that may be a thing of the past.
The prosthetic hand device picks up the neuro-electrical signals from Dick’s forearm muscles and operates like a hand, performing tasks under his guidance. He can now move his fingers and even make a fist.
“If you understand the psychology of a person with a disability, the small things are appreciated. With this hand, it’s not just a small thing. I mean I can do things that ordinarily I can’t do. I mean I would be able to pick up something. In life we use a hammer, we were cutting bread and we were doing all these things, and all these things are possible. This is small as it is in somebody else’s eyes, but for someone with a disability, that is a huge thing. Even if I can pick up a jug to drink water, that is huge thing.”
User-friendly prosthesis
Dick attaches the prosthesis to a 3D printed socket that covers and keeps his forearm stable. One of the primary aims was to create a safe, light and user-friendly prosthesis, which is perfect for him when he does technical work at an automotive company.
Many amputees struggle to use current prostheses because they are heavy and cumbersome. The upper-limb amputees tend to abandon their prostheses because of poor functionality.
There were challenges to put the device together because of COVID-19, but the students overcame the challenges.
The device was placed 11th out of 13 competitors at the 2020 invention Global Cybathlon in Switzerland.
NMU student Zaahid Imran says it was sad to see people struggling to perform many tasks.
“It was very sad to see someone struggling to do so many tasks that we could do easily because, obviously, we have our hands. It just shows how grateful we must be that we have hands. But then we have the knowledge in engineering to produce devices that can help him to perform tasks, maybe not as good us, but at least he will be able to perform the task.”
Another student, Jode Fourie says he has learned a lot about design.
“I have learned a lot about design and I’ve learned that engineering isn’t just designing machine parts and going into a certain specific direction; there’s actually a vast array of directions you can go into, like you can go into medical and it can actually help a lot of people in ways you wouldn’t think. Engineering could help a lot of people can touch them personally, and for me it was really cool seeing that.”
Potential improvement
The group says identifying areas of potential improvement was one of the most important things they gleaned from the competition.
They noticed that a simpler prosthesis with fewer electric parts, performed better and faster. After fixing a few mechanical bugs, they hope to start producing devices locally for under privileged amputees.
“Our main target with the hand is to look at a local option because these guys, the amputees have to normally bring these devices from overseas at exorbitant costs. So if we can produce something locally, not only is it good in terms of the guys that are going to use it, but it’s also good for our country as well because it’s another avenue where we can effectively promote engineering and manufacture in a very focused area for the country and the betterment of the community,” says Advanced Engineering Design Group Lecturer, Clive Hands.
Dick is now impatiently waiting to take ownership of this prosthetic hand but it is not a complete unit yet.
The team is now working to reduce the level of electronics and making it more robust for day-to-day use.
A new generation of engineers changing lives of amputees:
