Design and fabrication of neurostimulator implants-selected problems

In many therapeutic processes the future medicine will go away from the traditional pharmacological methods and will apply active stimulation of organs with implanted neurostimulators. The classical examples are nowadays the pacemakers. From the inspiration of Pathophysiology Department in Collegium Medicum of Jagiellonian University the Institute of Electron Technology undertook the research work in the field of implanted neurostimulators. The authors presented in the paper the hitherto achieved results of research works, including the analysis of electrical signals course in excited and non-excited vagus nerve and impedance measurement of nerve fibre, necessary for determining the parameters of neurostimulator such as the amplitude, duration and the repetition rate of stimulator pulses. From the point of view of circuit theory neurostimulator is a kind of self-excited or microprocessor controlled pulse generator. In the paper the structure of neurostimulator is presented and the choice of electrodes material and encapsulation resin is explained, taking into account the problem of biocompatibility. Some experimental results of laboratory tests on experimental animals with implanted neurostimulators are shown.