Wits biomedical students are creating a prosthetic hand with 3D-printing that works with brainwaves – and it won't cost an arm and a leg
Wits University postgraduates recently made mobility more accessible to the one million amputees in South Africa with a lightweight 3D-printed hand that costs just R20 000 —down from the R500 000 cost of similar prosthetics.
Engineering pivotal mobility
Biomedical engineers at Wits have developed a system that allows a robotic prosthetic hand to be controlled via brainwaves. The impact of this Brain Computer Interface (BCI) is immense, offering amputees and people with motor impairments the chance to regain some hand mobility.
A prosthetic hand usually costs around R500 000, an investment that is way out of reach for most South Africans. This research will use 3D-printing to create a prosthetic hand for R20 000, thereby increasing access for many.
“In South Africa, stroke victims may benefit significantly from this technology,” says Abdul-Khaallq Mohamed, lecturer and PhD candidate in the Wits School of Electrical and Information Engineering. “Stroke afflicts an estimated 132 000 South Africans per year.”
Mohamed co-ordinates a research group of students studying different methods of control for robotic hands. Most BCI experiments to date have centered on basic hand movements such as finger taps, button presses or simple finger grasps, but he envisages a BCI capable of controlling a robotic prosthetic hand so well that it enables people with motor dlsabilities to write, hold a glass or shake hands.
The Wits-based research group focuses uniquely on a combination of hand movements including wrist extension, wrist flexion, finger flexion, finger extension and the tripod pinch.
The biotech of interpreting brainwaves
BCls utilise electroencephalograms (EEGs) to interpret human intentions from electrlcal signals produced in the brain, and use them to control external devices such as prosthetic hands, computers and speech synthesizers.
The prosthetic robotic hand relies on EEGs extracted via electrodes on the skull or electromyography obtained from electrodes that record muscle signals for information. A BCI will interpret these signals and translate them to instruct the movements of the artificial hand.
Other life-changing research within biotech and engineering is being done at the globally ranked university, where 97% of its graduates are employed within six months of graduation. These advances include postgraduate projects that are developing eye-gaze devices, an assistive tech that empowers people with disabilities by improving their independence at home, such as postgraduate projects led by Wits biomedical engineer Adam Pantanowitz.
The brain as a network device
Pantanowitz discovered he had a neuromuscular condition as a teenager and since then, the lecturer in the School of Electrical and Information Engineering has researched the potential of technology to empower people with disabilities. In particular, he has explored the untapped potential of the brain through BCIs.
In February 2019, in an experiment believed to be a world first, Pantanowitz and his colleagues incorporated the human brain into a computer network. Dubbed “BrainConnect”, the proof-of-concept innovation saw the researchers connect two computers through the human brain and successfully transmit words like “hello” and “apple” passively, without the user being aware that a message was present.
“We don’t know of anywhere else where the brain has been used to connect two disconnected computers, so this presents an interesting theoretical system, with a human literally being ‘in the loop’,” says Pantanowitz, co-author of the paper with Wits alumni Rushil Daya and Michael Dukes, which is under review for publication in the journal Communications in Information Systems.
Morse code via light signals
BrainConnect links light, signal transmission, the visual cortex of the human brain, and two computers.
It works by attaching a device to a person’s head, which links the two computers. The person passively stares at a flashing light while a word is encoded in the light signal. The flashing light stimulates the visual cortex in the brain and an electroencephalogram wirelessly transmits information to a second computer, which decodes the signals.
“You can think of it like Morse Code via light signals,” says Pantanowitz. BrainConnect can decipher up to 17 symbols at a rate of four seconds per symbol. The more relaxed the person is, the greater the possibility of invoking a response through this “steady state visually evoked potential”.
Realising visionary assistive tech
Although BrainConnect is still fledgling research, Pantanowitz says this BCI may have applications in eye-gaze devices, which allow for the control of the environment by detecting where the gaze is focused.
In a similar project, Wits students Kimoon Kim and Chelsey Chewins worked with Pantanowitz to create an eye-tracking system to interface more naturally with a computer. This project enables PC users to control their computers with a mouse controlled with the eyes.
“BrainConnect works through light stimulus of the visual cortex. Similar eye-gaze devices already serve as assistive tech to empower motor-impaired people or paraplegics,” he says.
Pantanowitz cites futurists who predict greater human-tech integration by 2030. The fourth industrial revolution (4IR) is a feature of 21st century society — humans are now deeply connected to tech through smartphones and other close-contact devices. Research in South Africa and Africa, similar to this engineering innovation at Wits University, has the potential to advance 4IR.
“Africa’s challenges need unique solutions. The brain research is being conducted under what’s known as a ‘frugal innovation’, where low-cost equipment and innovative approaches keep costs down,” concludes Pantanowitz.
Join one of the leading teams of researchers at Wits University and position yourself at the top of engineering and biotech fields. For more information about the world-changing work being done by Witsies, go to www.wits.ac.za/future/ and www.wits.ac.za/news/latest-news/research-news/.