In an interview with MEDICA-tradefair.com, Prof. Oskar Aszmann talks about what bionic reconstruction actually means, how the novel prosthesis works and why the system can not only help patients after an amputation.
Prof. Aszmann, your newly developed prosthesis works according to the principle of bionic reconstruction. Can you explain this in more detail?
Prof. Oskar Aszmann: The word bionics is an acronym derived from biology and technics. In bionic reconstruction, we deal with the processing of biological signals to control a piece of technology – the prosthesis. These are nerve signals that we have to process in such a way that the prosthesis understands and implements them.
If a person has lost an arm, for example, all the corresponding nerves are still present but useless. We then have to perform a nerve transfer in a surgical procedure. In the process, we relocate the nerves to other muscles in the amputation stump so that they regain a certain functionality and the biosignals can be usefully used to control the prosthesis. With the help of a sensor – which can be placed on the skin or implanted – these signals are recorded and transmitted to the prosthesis. We have developed a system that is self-contained. The prosthesis also contains sensors that provide feedback to the patient.
We have currently found a technically useful solution to two important feedback problems: The patient knows when the prosthesis is in contact with an object. And he knows how intensive the force transmission is, i.e. how firmly he holds the object. There is therefore a closed feedback loop, which is made possible by a cuff electrode – a cuff that is placed around a nerve to stimulate it and thus in turn close the feedback loop. We call such a system bionic prosthesis.