Innovative Surgery- Introducing The World’s First Prosthetic Arm That Can Feel

February 19, 2014

A fireworks accident in 2005 left Denmark-based Dennis Aabo Sørensen with a severely wounded left arm that had to be amputated eventually. Today, Sørensen has a bionic arm in its place. This bionic arm does more than just help Sørensen perform everyday functions. In a first of its kind, this bionic arm has restored an individual’s ability to feel.

Students during on-placement clinical teaching In a post-surgery statement that was released, Sørensen stated that he was able to feel things that he had not been able to feel in the 9 years since his accident. To date, Sørensen is the only one to have tested this prosthesis. He has only been using it for a very short span of time. It is expected to take some more testing by more people for it to be eventually put to wider use. Once it does, it will go a long way in improving the quality of life for many people with prosthetic limbs.

Sørensen’s bionic arm was developed by a team of neural engineers with Silvestro Micera leading this development. Micera is a neural engineer at Italy’s Scuola Superiore Sant’Anna and the Swiss Federal Institute of Technology at Lausanne in Switzerland.

To create this bionic arm, electrodes were first embedded in Sørensen’s arm. The prosthetic hand contains touch sensors that stimulate the rest of the nerves enabling him to recognize various objects based on how they feel and allowing him to grasp them accordingly.

The team connected the touch sensors in the artificial limb to electrodes that had been surgically embedded in the remaining nerves of Sørensen’s upper arm. Computer algorithms converted signals from these sensors into a form that could be detected by the nerves. A month-long clinical trial was then carried out, during which the hand was tested by Sørensen. A range of tests were carried out and the ability of the bionic arm was ascertained. Sørensen was able to differentiate between soft, medium and hard objects and could also feel their stiffness and shape. He told researchers that the touch sense from the artificial limb was very similar to the natural feeling that his other hand had. The “anatomically appropriate feedback” approach was used by researchers in the development and testing of this bionic arm.  

An electrical engineer at Chicago’s Rehabilitation Institute, Levi Hargrove said that by stimulating the nerves directly, it is possible to restore sensory feedback appropriately. Another important factor is that this device has to able to be fully implanted under the skin and that it is the only way to ensure that it will be useful and safe. It also has to work consistently over a longer period of time said Hargrove, adding that it was expected to be a while before the device was actually ready to be put to widespread clinical use, but it definitely was a step in the right direction.

All these details regarding this revolutionary surgery have been outlined in the Science Translational Medicine journal dated 5 February 2014.

Currently, a lot of research is being conducted around the development of prosthetic limbs and the aim is to help restore the ability of people to control their legs or arms after amputation. Researchers are now focusing on touch-sensitive feedback.