Electromagnetic field modeling of implantable telemetry systems

Implantable telemetry systems are used to establish a communication link between an external instrument and an implanted tissue stimulator. This link can be adequately used to control and acquire data from the implant. The telemetry system uses inductively coupled electromagnetic energy at low frequencies. The communication between the external instrument and the implant have been achieved using pulse width modulation. Appropriate electronics exist in both the implant and the external instrument to encode and decode binary O´s and l´s. In order to prevent RFI and EMI from disrupting data transmission, digital encoding schemes are used. A numerical model to be used in the solution of the electromagnetic field problem associated with the above mentioned system is presented. The developed numerical model can be used as a powerful tool for telemetry system designs as well as the improvement of telemetry systems performance through optimization studies. Further applications are discussed.