Wireless Neuromodulation Power Management via Parallel Current Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for powering implantable medical devices, such as electrostimulators, face inefficiencies in power transfer and data communication, particularly due to variations in resonance frequencies and limited battery capacity, leading to potential malfunctions and increased power consumption.
Innovation Solution
An external control unit (ECU) with a power unit comprising parallel current paths and a storage capacitor, along with a microcontroller, is used to manage power transmission to an implantable electrostimulator, optimizing power delivery during stimulation and non-stimulation periods, and encoding data through burst patterns to ensure efficient energy use and communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If power is transmitted continuously to the implant, then the implant remains powered, but battery consumption increases and operational efficiency decreases
Solution Approach 1:
The system transmits power in periodic bursts synchronized with stimulation periods rather than continuously. The external control unit delivers power during stimulation periods when the implant requires energy, and reduces or stops power transmission during non-stimulation periods, thereby maintaining implant operation while significantly reducing battery consumption.
Solution Approach 2:
The system prepares and transmits power in advance during non-stimulation periods to charge the implant's capacitor, so that sufficient energy is available when stimulation periods begin. This preliminary charging ensures the implant remains powered during critical stimulation periods without requiring continuous power transmission.
2Productivity
If power transmission efficiency is increased during stimulation periods, then stimulation effectiveness improves, but energy consumption during these periods increases
Solution Approach 1:
The system dynamically adjusts power transmission parameters including voltage, current, and duration based on the specific stimulation requirements. By optimizing these parameters for each stimulation event rather than using fixed high-power transmission, the system achieves effective stimulation while minimizing energy consumption during these critical periods.
3Productivity
If data communication is performed during power transmission, then communication efficiency improves, but power transfer stability deteriorates due to resonance frequency variations
Solution Approach 1:
The system separates data communication and power transmission into distinct time periods. Data communication is performed during non-stimulation periods when power transmission is reduced or suspended, while power transmission occurs during dedicated stimulation periods. This temporal segmentation eliminates interference between communication and power transfer, maintaining both communication efficiency and power transfer stability.
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
The ECU efficiently powers the implant by storing energy for high-power stimulation periods and minimizing energy consumption during non-stimulation times, while ensuring reliable data transmission and synchronization, thus enhancing the operational stability and reducing power requirements.
Implementation Method 1
A current flowing through a coil produces a magnetic field, which, in turn, will induce a current in a second coil. A coil inside a medical implant can therefore act as a receiving coil, while a coil outside a patient's body can act as a transmitting coil.
Implementation Method 2
A current can be driven through the transmitting coil in order to induce an induced current in the receiving coil, thereby powering the medical implant.
Data Source
AI summary
An external control unit is provided that includes a power unit, which includes a power amplifier arranged to provide current to an antenna circuit; first and second parallel current paths; and a storage capacitor, connected to the first parallel current path and not to the second parallel current path. A microcontroller is configured to drive the power unit to charge the storage capacitor with the power from the battery at times other than during stimulation periods; during one or more non-stimulation periods, drive the power unit to provide the power from the battery to the power amplifier via the second parallel current path and not via the first parallel current path; and during the stimulation periods, drive the power unit to provide power from the storage capacitor to the power amplifier via the first parallel current path and not via the second parallel current path. Other embodiments are also described.