Conductive Fiber Patch for Implantable Medical Devices
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Solution Overview
Problem
Existing implantable medical devices that use electrodes for electrical stimulation of human tissue often cause tissue damage and scarring during implantation, leading to increased fibrotic tissue formation and impaired energy efficiency due to concentrated electrical energy at the attachment points.
Innovation Solution
An implantable medical device featuring a patch made of entangled, electrically conductive fibers that can be interwoven with soft tissue, providing a low-impedance interface and secure mechanical attachment without causing scarring, achieved through a felting process using needles with barbs, allowing for efficient energy transfer and signal sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a hook or screw is used to fixate the electrode in situ, then mechanical attachment is achieved, but tissue damage and scarring occur during implantation
Solution Approach 1:
The patent replaces the traditional mechanical fixation system (hooks or screws) with a biological integration system. The electrode is constructed with a core surrounded by an insulating layer and outer conductive layers that are directly sutured to the tissue, eliminating the need for separate mechanical fixatives that cause tissue damage. The electrode itself becomes the structural element that integrates with the tissue through surgical suturing rather than invasive mechanical anchoring.
Solution Approach 2:
The electrode is divided into distinct functional segments: a core element for mechanical strength, an insulating layer for electrical isolation, and outer conductive layers for electrical contact. This segmentation allows each layer to perform its specific function optimally while the entire structure can be sutured as a unit to the tissue, avoiding the need for separate fixation mechanisms that would cause tissue damage.
2Strength
If a hook or screw is used for electrode fixation, then mechanical attachment is achieved, but fibrotic tissue formation increases at the stimulation site
Solution Approach 1:
The patent eliminates the mechanical fixation system that generates harmful fibrotic responses. By directly suturing the electrode structure to the tissue, the system avoids creating concentrated stress points and foreign body reactions that lead to fibrosis. The electrode's own structure serves as the fixation mechanism, removing the need for separate mechanical elements that would otherwise trigger fibrotic tissue formation.
3Strength
If electrical energy is concentrated at the hook or screw, then mechanical attachment is achieved, but energy efficiency is impaired due to increased excitation threshold
Solution Approach 1:
The electrode is segmented into multiple conductive layers that distribute electrical contact across a larger surface area. This segmentation prevents concentration of electrical energy at single points (hooks or screws) and instead spreads the current through multiple contact interfaces with the tissue, reducing the excitation threshold and improving energy efficiency.
Solution Approach 2:
The patent transitions from point-contact fixation (zero-dimensional hooks or screws) to surface-contact fixation (two-dimensional sutured electrode layers). This dimensional change distributes electrical energy across a larger area, reducing current density at any single point and thereby lowering the excitation threshold while maintaining secure mechanical attachment through suturing.
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 enables efficient electrical stimulation and sensing with reduced tissue scarring and fibrosis, maintaining device functionality by lowering the voltage threshold for polarization and electrical resistance, while providing a strong mechanical connection.
Implementation Method 1
The first patch comprises fibers that are electrically conductive such that the soft tissue can be electrically stimulated
Implementation Method 2
The technique of interweaving the fibers with soft tissues is described in the related application PCT/CH2019/000015. The fibers of the patch can be pushed or pulled into the soft tissue by means of a needle, pin or blade comprising barbs.
Data Source
AI summary
An implantable medical device including a first patch for electrical stimulation and/or electrical sensing of human or animal soft tissue is disclosed. The first patch includes a felt material. The felt material has a multitude of fibers that are entangled with each other. The felt material is suitable to be felted with fibers of human or animal soft tissue. The first patch includes fibers that are electrically conductive such that the soft tissue can be electrically stimulated and or electrical signals of the soft tissue can be sensed.