An Improved Nerve Recording Configuration for FES Feedback Control Systems that Utilize Natural Sensors

Functional Electrical Stimulation (FES), using the intact functionality of the muscles, has been applied to a number of different handicap aids and rehabilitation systems. However, in most cases such rehabilitation systems have not met technical and user requirements: Technically they tend to be unstable and fragile, and the users often find them impractical. One purpose of the research at the Center for Sensory-Motor Interaction is to develop individual, functional, and reliable implantable devices (Neural Prosthesis) which are fully or partly invisible for the patient. The methods are based on the neural coding in the human sensory-motor system together with new technologies for registration and processing of electrical signals from muscles and nerve tissue. A technique in which the information retained in the natural sensory-motor system is used to activate the paralyzed muscles. The natural sensory signal is captured by a cuff electrode, fed to an amplifier/controller unit and led to the paralyzed muscles. An improved neuro-amplifier configuration and circuit design has been developed in a cooperation between the Institute of Biomedical Engineering (TU Graz) and the Center for Sensory-Motor Interaction (SMI, University Aalborg). This new amplifier configuration has been tested in several animal experiments, which showed that this configuration possesses a by far better interference rejection ability and an improved signals to noise ratio.