The loss of body parts due to accidents or premature natural wear and tear is a dramatic event for those affected and results in severe restrictions in their daily lives. Passive prostheses, which only fulfill basic functions, are currently being used. Automatic adjustments to new environmental conditions or changes in function are usually not possible with these elements. This has a significant impact on the daily life of the person wearing the prosthesis and results in frequent visits to the doctor or hospital for observation and, if necessary, manual adjustments. Continuous observation is not only a requirement for the reliable function of prostheses – it is also advantageous for the treatment or prevention of many diseases, but can hardly be realized in clinical routine.
Therapy and diagnosis with a single device
Intelligent implants combine diagnosis and therapy in a single medical device. This enables the production of prostheses that are more comfortable due to their natural behavior and continuous use. These functions can only be realized through complex systems that are developed in multidisciplinary collaborative projects. This process includes the latest insights gained by medicine and results from materials science, electrical engineering, and biochemistry, as well as signal processing and computer science.
The “Theranostic Implants” project is composed of three demonstrators:
Skeletal system demonstrator: the smart hip joint prosthesis allows constant monitoring of bone ingrowth without surgical intervention and enables readjustment of the position of the implant if necessary.
Cardiovascular demonstrator: a sensor implant for monitoring blood circulation allows long-term data collection in patients suffering from high blood pressure or strokes and transmits these data to an external receiver.
Neuromuscular demonstrator: a myoelectric prosthetic hand controller enables the prosthesis to be controlled through detection of the wearer’s intended movements and allows adjustments to be made via the feedback of signals through nerve stimulation.
The contribution made by Fraunhofer IIS
The Fraunhofer IIS is developing the electronics for a myoelectric prosthetic hand controller in the subproject on the neuromuscular demonstrator. Power is supplied to the implant using wireless technology. The active implant is controlled using a microcontroller and can exchange data with external components via an RF link. Data transfer is bidirectional. In addition to the standard components that are used, two application-specific ICs (ASICs) have also been developed for the multichannel registration of muscle and nerve signals and the stimulation of nerves. The sensory feedback system sends information to the wearer of the hand prosthesis on what things feel like. This makes it easier to control the prosthetic device and also allows complex movements. Furthermore, the ASICs permit a high level of integration and extremely low energy consumption.
More information on the project Theranostic Implants