Two universities today announced separate developments in prosthetics that will make life easier for amputees. The University of the Witwatersrand (Wits) said that a team of postgraduates had developed a brainwave-operated prosthetic hand, while Walter Sisulu University (WSU) said two students had developed a an adjustbale prosthetic leg and a pneumatic prosthesis. Although the projects were carried out separately, both of them will greatly reduce the cost of prosthetics, making them more affordable for South Africa’s 1 million amputees.

Bionic hand

Biomedical engineers at the University of the Witwatersrand (Wits) have researched how to use brainwaves to control a robotic prosthetic hand. The hand uses a brain computer interface (BCI) that will enable amputees to control a prosthetic hand as well as allowing people with motor impairments such as stroke victims to regain some hand mobility.

The research group consists of six students studying different aspects of potentially controlling a robotic hand. Most BCI experiments to date have centered on basic hand movements such as finger taps, button presses or simple finger grasps. 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. BCls can use electroencephalograms (EEGs) brainwaves to interpret human intentions from electrical signals in the brain and use these to control an external device such as a prosthetic hand, computer, or speech synthesizer.

The prosthetic robotic hand relies on electrodes on the skull that are able to pick up signals that the BCI interprets and translates to control the movements of the artificial hand.

As well as being a big technological advancement, the team have also drastically reduced the cost. According to team, a prosthetic hand currently costs around $100,000 (R1.47million), compared to the Wits team’s cost of just $78 (R1,150) to 3D-print a prosthetic hand, making it more affordable and more freely available to amputees.

Adjustable legs & pneumatic feet

At WSU, two final year students were awarded the WSU Vice-Chancellor’s Recognition Award for their significant contributions to the university in the field of prosthetics.

Final year medical orthotics and prosthetic students Zanodumo Godlimpi and Siphosethu Mgwili’s inventions are expected to save children and adolescent amputees thousands of rands in upgrades as they grow up. Mgwili’s innovation will allow amputees the ability to adjust their own height and functionality at home.

Godlimpi has developed a pneumatic prosthesis for below the knee that uses pressurised air and a pneumatic cylinder to achieve a 360-degree range of motion. This means the artificial leg uses compressed air to perform basic motions like heel up and heel down.

“This prosthetic foot uses certain characteristics of the normal walking pattern as mechanical signals which are then used to instruct the ankle joint to move,” said Zanodumo.

Mgwili said that the main purpose behind this study was to help prosthetic users and suppliers by making them more functional, affordable and available to people.

“Due to financial constraints and lack of insurance, less than 10% of these amputees in developing regions have access to a prosthetic limb. Even simple devices without dynamic features are expensive, resulting in amputees settling for an ill-fitting device, or going without one at all. This causes serious health and mobility concerns for the amputees since there is a 50%, five-year mortality rate for amputees who remain sedentary,” said Mgwili.

The duo recently received the WSU Vice-Chancellor’s Recognition Award for their significant contributions to the university.