Simultaneous Energy and Data Wireless Transfer Attenuation in Biological Channel of Deep Implantable Medical Devices: Characteristic Analysis and Modeling

The scheme of energy and data wireless transmission with the same carrier based on Mary Differentially-Encoded Amplitude and Phase Shift Keying (MDAPSK) technology is an effective method to implement energy supply and data communication for implantable medical devices. In this paper, based on a large number of finite-difference time-domain simulation analyses, combined with knowledge of the clinical demand for implantable medical devices, the 13.56–402MHz band is selected as the biological channel frequency band, and attenuation characteristic analysis and mathematical modeling are carried out. Based on massive amounts of simulation data, the Levenberg-Marquardt and general global optimization methods are adopted to build a homogeneous and heterogeneous biological channel model in the aforementioned frequency band. In order to verify the reliability and versatility of the mathematical model, an adult male rabbit is employed for a living implantation experiment. Using a vector network analyzer, different frequency electromagnetic wave receiving efficiencies in different biological channels are measured. The measured data are highly consistent with the simulation data, which fully verifies the rationality of the proposed biological channel model. This work provides a theoretical basis and model reference for the clinical application of an implantable medical device wireless transmission system.