Research on Design Method of Voltage Injection Test Circuit of Active Implantable Neurostimulator

A design method of electrode-tissue interface equivalent circuit for the voltage injection test of active implantable neurostimulator (INS) is presented and analyzed. In this proposed method, characteristic frequencies of the equivalent circuit are determined, based on the published data of human tissue permittivity and conductivity. The equivalent circuit structure is defined, according to "electrode-tissue" interface model. Appropriate values of electronic components are matched by simulation. In addition, a method of replacing the electrode-tissue interface equivalent circuit with purely resistance is also proposed. According to ISO14708-3, voltage injection tests are carried out with these different equivalent circuits and INS. Results showed that these design methods can meet test requirements with no significant difference. This study explored convenient and universal methods for the voltage injection test of INS, which is useful to improve the guarantee of the electromagnetic compatibility (EMC) safety of the INS.