Capacitance Approximation System for Implantable Medical Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional capacitive sensors in implantable medical devices (IMDs) face challenges in efficiently approximating differential capacitance, which is crucial for detecting positioning, posture, and motion, due to limitations in power consumption and component miniaturization, leading to suboptimal performance and increased complexity.
Innovation Solution
A capacitance approximation system that includes a control module, capacitance comparison module, and capacitance adjustment module, utilizing a bank of capacitors to iteratively approximate differential capacitance by modifying sampling intervals and selecting capacitors based on capacitance differences, allowing for reduced power consumption and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional capacitive sensors are used with multiple components for detecting differential capacitance, then measurement precision is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent combines multiple capacitive sensing elements into a single integrated capacitive sensor structure. The sensor includes a first capacitive component and a second capacitive component that are integrated together, allowing differential capacitance measurement without requiring separate, discrete components. This merging reduces the overall number of components while maintaining the ability to detect differential capacitance changes accurately.
Solution Approach 2:
The capacitive sensor is designed to perform multiple functions through its differential capacitance measurement capability. The same sensor structure can detect various physical quantities (position, posture, motion) by measuring changes in differential capacitance, eliminating the need for separate sensors for each function and thereby reducing device complexity.
2Measurement precision
If conventional capacitive sensors with multiple components are used, then measurement precision is improved, but power consumption increases
Solution Approach 1:
By integrating the capacitive components into a single sensor unit with shared readout circuitry, the patent reduces the total power consumption compared to using separate discrete components. The merged structure allows for more efficient signal processing and reduces the cumulative power requirements of multiple independent components.
3Device complexity
If the number of components in the IMD package is reduced, then device complexity is decreased, but measurement precision may deteriorate
Solution Approach 1:
The patent achieves component reduction while maintaining measurement precision by merging the capacitive sensing functionality into a single integrated unit. The first and second capacitive components are combined in a way that preserves differential measurement capability, ensuring that the reduced component count does not compromise the accuracy of differential capacitance detection.
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 system effectively approximates differential capacitance with reduced power consumption and component count, enhancing the accuracy and efficiency of IMDs in detecting physical activity and motion while minimizing the number of components and power usage.
Implementation Method 1
the sensors may include a sensing element that includes two parallel plate capacitive components acting in a differential manner in which acceleration of the sensor causes one of the capacitive components to increase in capacitance and the other capacitive component to decrease in capacitance
Data Source
AI summary
Techniques and circuits are described for approximation of the differential capacitance of a capacitive sensor to, among other things, optimize device operation and power consumption. In particular, feedback techniques are utilized for measurement and approximation of the differential capacitance of the capacitive sensor. In accordance with the disclosure, the capacitance approximation value for a test cycle preceding a given test cycle is utilized to reduce the number of iterations to be performed in a continuous series of test cycles. The capacitance approximation value for the given test cycle is reported as being equivalent to that of the preceding test cycle if the variance between the selected capacitance and the unselected capacitance is less than or equal to a first predefined value.