Misalignment analysis of resonance-based wireless power transfer to biomedical implants

Implantable RF telemetry for cardiac monitoring in the murine heart: a tutorial review

“…For two non-coaxial and non-parallel filamentary coils, the mutual inductance defined in [44] is For our case of multilayer helical coils with axial and angular misalignment, we apply the filament method [45] to (17) and calculate the mutual inductance, which produces the following equation:…”

Miniature implantable telemetry system for pressure-volume cardiac monitoring

“…This process is not trivial as all factors of the design must be accounted for including the tissue medium [113,[131][132][133]. Additional power transfer technologies exist including Ultrasound [134,135], Resonance based coupling where coils are resonant at a specific frequency allowing transfer range to increase versus traditional inductive coupling [131,136], RF [133,137], etc, each with their own advantages and drawbacks. A more recent field of research is in direct energy harvesting from within the body.…”

“…This is significantly important for small animal implant design as the size is severely limited, thus the applicable power sources are limited [4]. Nevertheless, small animal power transfer is an active area of research focusing on coil misalignment [136] and full power cage solutions [21,126,127,[144][145][146].…”

“…The first implementation would be to use inductive wireless power transfer. Future versions would utilize a full cage solution based on Helmholtz coils and magnetic resonance energy transfer, currently being explored by other members of this research group [136]. Furthermore, design and testing of custom power management circuits (LDO, Bandgap, and Rectifier) are also underway [130,271], which will be fully integrated with a wireless power solution, Fig.…”

Optimization of Wireless Power Transfer via Magnetic Resonance in Different Media

“…A comparison of the performance of two-coil inductive coupling methods with SCMR is performed in Table 2-1. In addition, an SCMR system for wireless power transfer to small biomedical implantable was presented in [88], it also examined axial and angular misalignments at 15 mm axial distance and misalignments angle of 50°. A miniaturized SCMR system operating at 6.78 MHz integrated with a Medical Implant Communication Service (MICS)…”