Dynamic Rectification for Deep Implant Wireless Recharging
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Solution Overview
Problem
Implantable medical devices face challenges in efficient wireless recharging due to increased depth and size, leading to slow and inefficient charging, particularly for devices implanted deeply or at non-ideal angles.
Innovation Solution
The implementation of dynamic rectification modes, such as fullwave and halfwave rectification, adjusted based on battery charge current levels and hysteresis thresholds, to optimize charging efficiency and prevent overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the implant depth is increased to meet patient needs for deeper implantation, then the device can be placed in optimal anatomical positions, but the wireless recharging efficiency decreases and charging time increases
Solution Approach 1:
The system dynamically switches between fullwave and halfwave rectification modes based on real-time coupling conditions. When the implant is at greater depth or suboptimal position, the system detects reduced coupling and transitions to halfwave rectification, which maintains charging efficiency by adapting to the degraded magnetic coupling environment between the external charger and implanted device
Solution Approach 2:
The rectification mode parameter is changed based on charge current levels and hysteresis thresholds. The system monitors the charge current and switches rectification modes when current crosses threshold boundaries, thereby optimizing the charging process for different implant depths and positions without requiring physical reconfiguration
2Volume of moving object
If the device size is reduced to meet patient desires for smaller implants, then the implantable device becomes less invasive, but the recharging coil efficiency decreases leading to slower charging
Solution Approach 1:
The dynamic rectification mode switching compensates for the reduced coil size by adapting the rectification process to the actual coupling conditions. Smaller coils naturally have reduced magnetic coupling, but the system maintains charging efficiency by switching to halfwave rectification when coupling is weak, thereby offsetting the limitations imposed by miniaturization
Solution Approach 2:
The system changes operational parameters (rectification mode) based on the actual charge current received, which is influenced by device size and coil configuration. This allows smaller devices to achieve adequate charging performance by operating in the appropriate rectification mode rather than being constrained by fixed parameters
3Loss of time
If the recharging power is increased to reduce charging time, then the convenience of the system improves, but the medical device temperature rise increases causing thermal stress
Solution Approach 1:
The system employs periodic monitoring of charge current and temperature, switching rectification modes based on hysteresis thresholds. This periodic adjustment allows the system to deliver high power when conditions permit (reducing charging time) while switching to lower power modes when thermal limits are approached, thereby managing thermal stress through rhythmic power modulation
Solution Approach 2:
The system uses feedback from charge current measurements and temperature sensors to control the rectification mode. When temperature rise or charge current indicates excessive power delivery, the system switches to halfwave rectification to reduce power and thermal stress, creating a closed-loop control system that balances charging speed with thermal safety
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
Enables efficient wireless recharging of implantable devices at deeper depths and non-ideal angles, extending the duration between charging sessions and reducing thermal stress.
Implementation Method 1
a transcutaneous recharge signal produced by one or more field-producing coils external to the patient
Implementation Method 2
dynamic adjustment of rectification mode... fullwave or halfwave rectification
Data Source
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AI summary
Devices and methods described herein relate to wireless recharging from a distance, and increasing the efficiency of such charging by intelligently or autonomously changing the rectification mode of the implanted device.