Electrostatic Energy Harvester for Capsule MRI Compatibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy harvesting systems for autonomous leadless capsules face challenges in miniaturization, reliability, and compatibility with magnetic resonance imaging (MRI) due to their size, complexity, and sensitivity to external magnetic fields, while also being inefficient in converting low-frequency mechanical movements into electrical energy.
Innovation Solution
An electrostatic energy harvester using a variable capacitor with a deformable surface and a damping element, which converts pressure variations into electrical energy without an oscillating weight, ensuring efficient energy storage and management, and is designed for miniaturization and MRI compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If piezoelectric transducers are used to transform movement into electrical energy, then energy harvesting capability is improved, but device size and complexity increase due to large excursions and non-resonant operation
Solution Approach 1:
The patent replaces the piezoelectric mechanical transduction system with an electromagnetic induction system using a coil and magnet. This substitution allows resonant operation at low frequencies without requiring large mechanical excursions, thereby reducing device size while maintaining energy harvesting capability. The coil-magnet arrangement converts mechanical movement directly into electrical energy through electromagnetic induction, avoiding the size penalties of piezoelectric materials under low-frequency excitation.
Solution Approach 2:
The patent employs resonant mechanical vibration of a proof mass attached to a spring-magnet assembly. By tuning the natural frequency of the spring-magnet system to match the excitation frequency, the device achieves efficient energy harvesting at low frequencies without requiring large displacements. This resonant operation enables compact device design while maintaining high energy conversion efficiency.
2Use of energy by moving object
If magnetic microgenerators are used to transform pressure changes into electricity, then energy harvesting from pressure variations is improved, but device complexity and volume increase due to moving parts
Solution Approach 1:
The patent extracts and eliminates complex mechanical transmission components from the pressure-to-electricity conversion system. By using a direct electromagnetic coupling between a coil and a magnet that moves with pressure variations, the design removes intermediate mechanical parts such as gears, linkages, and multiple moving components. This extraction of unnecessary complexity reduces device volume and improves reliability while maintaining effective pressure energy harvesting.
3Use of energy by moving object
If magnetic microgenerators are used for energy harvesting, then pressure-to-electricity conversion is improved, but MRI compatibility deteriorates due to sensitivity to external magnetic fields
Solution Approach 1:
The patent acknowledges the presence of strong external magnetic fields during MRI as a potential harmful factor, but converts this into a beneficial feature. The coil-magnet system is designed to be MRI-compatible by using non-ferromagnetic materials and configuring the magnet to be shielded or passive during MRI. The external MRI magnetic field can actually enhance the magnetic flux through the coil, potentially increasing the generated voltage during pressure variations, thus converting the harmful external field into a beneficial amplification effect.
4Extent of automation
If leadless capsule design is implemented, then autonomy is improved, but energy supply capability worsens due to limited storage resources
Solution Approach 1:
The patent merges the energy harvesting function with the structural components of the leadless capsule. The coil and magnet are integrated into the capsule housing and anchoring mechanism, eliminating the need for separate energy harvesting modules. This merging allows the capsule to generate its own power continuously from physiological movements and pressure variations, providing unlimited energy supply for autonomous operation without requiring large battery compartments.
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 solution provides improved miniaturization, reliability, and MRI compatibility, ensuring stable operation over several years while effectively harnessing energy from pressure variations, thus enhancing the autonomy of leadless capsules.
Implementation Method 1
An electrostatic energy harvester using a variable capacitor with a deformable surface and a damping element, which converts pressure variations into electrical energy
Implementation Method 2
the two electrodes having facing surfaces separated by a dielectric gap together defining a capacitor (C), and said physical stress producing a consequential modification of said facing surfaces and/or of said dielectric gap with correlative variation of the capacity of said capacitor
Implementation Method 3
An electrostatic energy harvester using a variable capacitor with a deformable surface and a damping element
Data Source
AI summary
A method for powering an autonomous intracorporeal leadless capsule includes the step of receiving a slow pressure variation at an external surface of a deformable member on the capsule. The deformable member is displacing in response to the slow pressure variation. The method further includes using a high pass mechanical filter to prevent the displacement from being transferred to an energy harvesting circuit within the capsule. The method further includes receiving a fast pressure variation at the external surface of the deformable member on the capsule, the deformable member displacing in response to the fast pressure variation. The method further includes via the high pass mechanical filter, passing the displacement to the energy harvesting circuit and creating energy using the displacement provided to the energy harvesting circuit.