Charge-Balancing Coupling Circuit for Miniaturized Stimulation Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electrical stimulation devices face challenges in miniaturization due to the physical size of coupling capacitors required for effective energy delivery, which increases the device's size and prevents the inclusion of a greater number of capacitors without substantial increases in space.
Innovation Solution
The use of coupling circuits that capacitively couple stimulation generators to electrodes, featuring miniaturized discrete or integrated circuit capacitors, and a processing module that controls the orientation of capacitors to maintain voltage within a threshold range, allowing for reduced capacitor size and increased capacitors without size increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional coupling capacitors are used for electrical stimulation, then effective energy delivery is achieved, but the device size increases substantially
Solution Approach 1:
The device is divided into multiple independent stimulation channels, each with its own coupling capacitor. This segmentation allows the total capacitance to be distributed across multiple smaller capacitors rather than requiring one large capacitor, thereby reducing the overall device volume while maintaining the required energy delivery capability across multiple electrodes
Solution Approach 2:
A single coupling capacitor is designed to serve multiple functions: it provides charge balancing for the stimulation waveform, blocks DC components, and enables bidirectional current flow through polarity switching. This multi-functionality eliminates the need for separate capacitors for each function, reducing the total number and size of capacitors required in the device
2Adaptability or versatility
If more coupling capacitors are included to increase stimulation channels, then more electrodes can be stimulated, but the device size increases substantially
Solution Approach 1:
Multiple stimulation channels share common components including the battery, control circuitry, and coupling capacitors. By merging these resources across channels, the device achieves multi-electrode stimulation capability without proportionally increasing the total component count and device volume
Solution Approach 2:
The device employs dynamic polarity switching of the coupling capacitors during stimulation delivery. This dynamic operation allows a single capacitor to handle bidirectional current flow for multiple electrodes through controlled reversal of polarity, effectively multiplying the utility of each capacitor and reducing the number needed
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 approach enables the miniaturization of electrical stimulation devices, allowing for a greater number of capacitors and efficient energy delivery while maintaining charge balance, applicable across various stimulation applications.
Implementation Method 1
coupling circuits that capacitively couple stimulation generators to electrodes
Implementation Method 2
a processing module that controls the orientation of capacitors to maintain voltage within a threshold range
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In some examples, a device for delivering electrical stimulation to a medical patient includes an electrical stimulation generator, a coupling circuit, and a processing module. The electrical stimulation generator is configured to generate electrical stimulation. The coupling circuit includes a first node connected to the electrical stimulation generator, a second node configured to deliver the electrical stimulation to the patient, and a capacitor. The coupling circuit is configured to operate in a first state to couple the capacitor between the first and second nodes in a first orientation and operate in a second state to couple the capacitor between the first and second nodes in a second orientation that is opposite to the first orientation. The processing module is configured to set the state of the coupling circuit to one of the first and second states.