Energy harvesting from the hip

Although artificial joints are already much more durable than they used to be, they still need to be replaced after a certain period of time. This is often due to wear and tear of the implant and overuse of the replacement joint. Daniel Klüß, Managing Director and owner of Innoproof GmbH, believes that the problem of overuse is solvable. 

The Collaborative Research Centre (CRC) 1270 ELAINE at the University of Rostock is developing electrically active implants. One question that the researchers there are working on is how to generate electrical voltage from the mechanical energy generated when running or walking. According to Klüß, this is an important prerequisite for providing the hip joint of the future with intelligence.

To this end, the hip endoprosthesis is equipped with piezo-ceramics. „In the laboratory test, the mechanical energy of the deformation of the ceramic material used is converted into electrical energy. This deformation of the ceramic is brought about by the patient when the implant is regularly loaded, for example when walking. The resulting electrical energy is collected – in technical jargon we speak of energy harvesting – to supply sensors and electrical circuits in the implant.This should make it possible, for example, to measure the quality of the surrounding bone and how firmly the implant is still anchored in the bone.

However, further steps are needed before the ceramic in the hip joint replacement can actually generate electricity at some point. For example, a new implant design must be developed in which the ceramic can be integrated without causing problems with the stability of the implants. Even after this change, the implants must of course last for years and fulfil their function reliably.

„Energy self-sufficient, electrically active implants for intelligent implants for the regeneration of bone and cartilage and the treatment of movement disorders are the central goal of ELAINE. Our interdisciplinary research team aims to contribute to a higher quality of life for young and old with new findings and innovations. Daniel Klüß's research results are a very good example of successful interdisciplinary basic research,

said Prof. Dr Ursula van Rienen, spokesperson for the Collaborative Research Centre.

In parallel to numerous promising simulations and calculations for the intelligent hüft joint, mechanical tests are being carried out in the Innoproof test laboratory. „The test standards were also passed in a double run“, says Klüß. „With the new energy harvesting technology, there is now also a source of electrical energy in the hip prosthesis.

The SFB ELAINE is now initially investigating how this energy source can also be used as a sensor for bone quality and implant loosening, and the newly developed diagnostic system should also provide information about the patient's activities. Doctors will then be able to recognise whether the implant has been overloaded by physical exertion or whether the patient has moved too little. Klüß could also imagine that the electrical energy is used to stimulate bone growth. This is an important point for patients who have already undergone several hip operations.

For everyone who wants to know
On the occasion of its 15th anniversary, the Interdisciplinary Faculty of the University of Rostock and the Hanseatic and University City of Rostock are organising a new series of talks in the town hall. It is aimed at „anyone who simply wants to know“. The extent to which „bones under electricity“ or electrically active implants can help or heal will be discussed on 10 November 2022 from 6 pm  by Prof. Ursula van Rienen and Prof. Rainer Bader from the ELAINE Collaborative Research Centre with Andreas Markschies from Medizintechnik Rostock GmbH at Rostock Town Hall. Admission is free

Source: medtech-zwo from 04 November 2022