Communication in Implantable Medical Devices: FEM Simulation to Evaluate the Coating Effects on Transmission

Implantable medical devices hold great promise for treating nervous system disorders. However, their small size requires communication with an external device to process electrophysiological signals. The transmission of these signals is often hindered by biocompatible encapsulation materials and surrounding biological tissues. This study uses FEM simulations in COMSOL Multiphysics to assess how the device’s coating and biological tissues affect 2.4 GHz data transmission, a frequency within the ISM band for implantable device communications. A compact Planar Inverted-F Antenna (PIFA) is used, and S11/S22 parameters are calculated to assess transmission efficiency. Since the coating layer hinders transmission depending on its thickness and material properties, simulations were conducted using three different body types representing varying Body Mass Index (BMI) levels to account for inter-patient variability. Implant safety was evaluated by calculating the Specific Absorption Rate (SAR) and the local temperature increase. The results presented in this work serve as a pilot study to assess the effects of encapsulation materials on wireless communication in implantable devices, laying the groundwork for future ex vivo and in vivo research.