Optical Implant Depth Measurement for Resonant AIMD Charging

The patent introduces light as an intermediary substance to transmit depth information from the implant to the external charger. The light source embedded in the implant emits light that travels through tissue to the skin surface, where photodetectors detect it. This optical intermediary enables depth measurement without direct electrical contact or complex imaging systems, resolving the contradiction between maintaining simple system structure and achieving optimized power transfer efficiency.

The patent replaces complex mechanical or electronic depth measurement systems with an optical system. Instead of using mechanical probes, ultrasound, or complex electromagnetic imaging to determine implantation depth, the invention uses simple light emission and detection. This substitution maintains system simplicity while enabling the necessary depth information for optimizing power transfer efficiency through capacitance tuning.

The patent performs depth measurement and capacitance optimization in advance before the actual power transfer begins. The light-based depth measurement system determines the implantation depth first, then the external charger pre-adjusts its capacitance values based on this information. This preliminary action ensures that when charging starts, the system is already optimized for the specific implantation depth, minimizing charging time without requiring complex real-time adjustments during operation.

The patent implements a feedback mechanism where the light detection system continuously or periodically measures the implantation depth, and this information feeds back to the external charger's control system. The controller uses this feedback to automatically adjust capacitance values and optimize power transfer parameters, reducing charging time while maintaining ease of operation through automated control rather than manual intervention.

The patent performs capacitance tuning as a preliminary step before actual power transfer. The system first measures implantation depth using light, calculates the optimal capacitance values based on the measured depth, and configures the external charger's capacitance accordingly before initiating charging. This preliminary optimization ensures maximum resonance efficiency from the start, and while it adds an initial setup step, the automated calculation based on light-measured depth keeps this process rapid.

The patent changes the capacitance parameter of the external charger based on the measured implantation depth. The system uses the light-derived depth information to dynamically select or adjust capacitance values that match the specific implantation conditions. This parameter adaptation optimizes the resonant coupling between the external coil and implant coil, maximizing power transfer efficiency while the automated process keeps the time investment minimal.