Implantable Coil Detuning for Wireless Charging Heat Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable medical devices face the challenge of excessive heat buildup during charging, particularly due to large magnetic or electromagnetic fields from industrial, scientific, and medical equipment, which can damage components and reduce battery longevity.
Innovation Solution
The implementation of a resonant tank circuit with an implantable coil and a rechargeable battery that uses an inductive link for charging, where a controller determines the end-of-charge condition and signals the external charger to terminate charging through a predetermined detuning sequence, and then disconnects the battery from the resonant tank circuit, shifting the frequency to reduce heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the resonant tank circuit remains tuned to the charging frequency after battery charging is complete, then the external charging device continues to transmit power, but excessive heat builds up in the implantable components
Solution Approach 1:
The controller detects the end-of-charge condition and initiates the detuning sequence before significant heat buildup occurs. By preliminarily changing the resonant frequency of the tank circuit, the system signals the external charger to stop power transmission, preventing excessive heat accumulation in the implantable components.
Solution Approach 2:
The system applies preliminary anti-action by detuning the resonant tank circuit to prevent the harmful effect of continuous power transmission. The controller intentionally shifts the resonant frequency away from the charging frequency, which creates a detectable change that causes the external charger to terminate power transmission, thereby counteracting the potential heat buildup before it becomes problematic.
2Reliability
If the resonant tank circuit is detuned to signal end-of-charge, then power transmission is terminated, but the charging process must be carefully controlled to avoid incomplete charging
Solution Approach 1:
The controller continuously monitors the battery charge level and provides feedback to determine the end-of-charge condition. This feedback mechanism ensures that the detuning action is triggered at the appropriate moment, preventing both incomplete charging and overcharging. The system adjusts the resonant frequency based on real-time charge status, optimizing both charging completeness and time efficiency.
3Use of energy by moving object
If the implantable coil remains coupled to the external coil, then power can be continuously received, but magnetic and electromagnetic fields from external equipment can damage components
Solution Approach 1:
The system dynamically adjusts the resonant frequency of the tank circuit based on charging status. During active charging, the circuit is tuned to the charging frequency for optimal power transfer. After charging completion, the controller dynamically shifts the frequency away from the charging frequency, which terminates power reception and simultaneously protects the implantable components from harmful magnetic and electromagnetic fields by changing the coupling conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively prevents excessive heat buildup, protects the implantable components from damage, and ensures efficient battery charging while maintaining compatibility with standard charging protocols and ISM radio bands.
Implementation Method 1
an implantable coil that receives power from an external charging device via an inductive link
Implementation Method 2
a resonant tank circuit including an implantable coil coupled to an external coil of an external charging device via an inductive link
Data Source
AI summary
Presented herein are techniques for protecting an implantable component of a medical device from the buildup of excessive heat following a charging process. In one embodiment, the implantable component includes a resonant tank circuit that includes an implantable coil that receives power from the external charging device via an inductive link. The implantable component includes a rechargeable battery that is electrically connected to the resonant tank circuit and that can be recharged using the power received from the external charging device. A controller in the implantable component is configured to determine when charging of the rechargeable battery should be terminated and, in response, detune the resonant tank circuit in accordance with a predetermined pattern to signal to the external charging device that charging of the rechargeable battery should be terminated.