Wits researchers interpret brainwaves to give amputees a hand

Date:28 October 2019 Tags:, , , , , ,

Biomedical engineers at Wits have found a way to make mobility more accessible to the 1 million amputees in South Africa through research into brainwaves.

These engineers have researched how brainwaves can be used to control a robotic prosthetic hand. Using a Brain Computer Interface (BCI), amputees and people with motor impairments will be able to regain some hand mobility.

“In South Africa, stroke victims may benefit significantly from this technology,” says Abdul-Khaallq Mohamed, Lecturer and PhD candidate in the School of Electrical and Information Engineering at Wits. “Stroke afflicts an estimated 132 000 South Africans per year.”

Currently, a prosthetic hand costs around R1.4 million ($100,000), which is well beyond the price most South Africans can afford. This research will use 3D-printing to create a prosthetic hand for just R1,130 ($73), making it much more affordable.

Interpreting brainwaves

BCl’s  work by using electroencephalograms (EEGs) brainwaves to interpret human intentions from electrical signals in the brain. They then use these to control an external device such as a prosthetic hand, computer, or speech synthesizer.

The prosthetic robotic hand relies on EEGs extracted via electrodes on the skull or electromyography (EMG) obtained from electrodes recording muscle signals, for information. A BCI will interpret these signals and translate them to instruct the movements of the artificial hand.

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 brain as a network device

Wits is not only working on BCIs, other biotech and engineering research is also ongoing. This includes incorporating the brain as a computer network, completed by Wits biomedical engineer Adam Pantanowitz and his teams. Dubbed ‘BrainConnect’, the researchers connected two computers through the human brain and successfully transmitted words like ‘hello’ and ‘apple’ passively, without the user being aware that a message was present.

BrainConnect works by linking light, signal transmission- in the visual cortex of the brain- and two computers together.

A device is attached to a person’s head, which links the two computers. The person passively stares at a flashing light whilst a word, for example, ‘apple’, is encoded in the light signal. The flashing light stimulates the visual cortex in the brain and an EEG wirelessly transmits information to a second computer, which decodes the signals to appear on the second computer.

“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’.

Although BrainConnect is fledgling research, Pantanowitz says this BCI may have applications in eye-gaze devices, which allow for the control of the environment by detecting where gaze is focused.


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/.


Image: Supplied

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