Implantable Cuff Electrode Self-Sealing Longitudinal Slot
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Solution Overview
Problem
Existing cuff electrode technologies fail to effectively address the requirements of being soft enough to avoid mechanical irritation, providing good electrical insulation, and accommodating nerve swelling for nerves with diameters smaller than 1 mm, as they often require hard materials and manual craftsmanship, leading to mechanical stress and deformation issues.
Innovation Solution
A flexible cuff electrode with a tube shape and a self-sealing mechanism using silicone material, featuring a longitudinal slot with movable lips for adjustable sealing and elastic deformation, allowing for variation in inner diameter and reducing mechanical irritation, along with an electrode array embedded in a silicone carrier for improved electrical coupling and nerve compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If soft materials are used for the cuff to avoid mechanical irritation, then mechanical compatibility with the nerve is improved, but manufacturing precision and geometrical accuracy deteriorate because soft cuffs typically require hand-making
Solution Approach 1:
The patent changes the material parameter from soft (hand-made) to rigid (photolithographic), enabling precise geometric control while maintaining nerve compatibility through controlled flexibility in the final device design
Solution Approach 2:
The patent replaces manual hand-making processes with photolithographic fabrication, substituting mechanical craftsmanship with a precision manufacturing process that can accurately define geometries for small-diameter nerves
2Reliability
If spiral cuffs are used to seal tightly against the nerve, then electrical insulation is improved, but the embedded metal structures are subjected to mechanical stress during rolling
Solution Approach 1:
The patent performs preliminary sealing of the longitudinal slot before the nerve swelling occurs, ensuring electrical insulation is established in advance while the metal structures remain stress-free during the sealing process
Solution Approach 2:
The patent divides the sealing function into separate components (lips sealing the longitudinal slot) rather than relying on the entire spiral structure, allowing the metal elements to remain isolated from sealing-related mechanical stresses
3Ease of operation
If larger rolling forces are applied to open the cuff for smaller diameters, then the cuff can be opened for implantation, but the material thickness must increase which increases flexural rigidity
Solution Approach 1:
The patent extracts the opening function from the rolling process itself, using a separate mechanism (lips at the longitudinal slot) to open the cuff, thereby eliminating the need for large rolling forces and avoiding increased material thickness
4Reliability
If the cuff diameter is fixed to ensure good electrical coupling, then electrical contact quality is improved, but the nerve cannot swell without causing blood vessel pinching and nerve damage
Solution Approach 1:
The patent introduces dynamic adjustability to the cuff diameter through the longitudinal slot mechanism, allowing the cuff to transition from a fixed initial diameter (ensuring good electrical coupling) to an adjustable larger diameter (accommodating nerve swelling)
Solution Approach 2:
The patent establishes good electrical coupling through precise initial positioning and sealing before nerve swelling occurs, then enables diameter adjustment afterward to prevent nerve damage while maintaining the initial electrical contact quality
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 reliable electrical coupling, minimizes mechanical irritation, and accommodates nerve swelling without compressing the nerve, ensuring effective sealing and ease of handling with a reduced risk of deformation and improved accuracy for smaller nerve diameters.
Implementation Method 1
the second lip retains the first lip in position on the cuff jacket by surface pressure
Implementation Method 2
The second lip may be movable upon modifying the width of the longitudinal slot, while maintaining the sealing of the longitudinal slot
Data Source
AI summary
An implantable cuff electrode having a flexible cuff in form of a tube having a longitudinal slot, wherein the longitudinal slot defines a first edge and a second edge on the cuff, wherein a first lip is arranged at the first edge of the longitudinal slot, and a second lip is arranged at the second edge of the longitudinal slot, and wherein the longitudinal slot can be sealed by the first lip and the second lip in that the first lip and the second lip extend at least partially on the cuff jacket of the cuff one lying on top of the other, and the second lip holds the first lip in position by means of a surface pressure onto the cuff jacket.