End Effector Stop Members for Tissue Sealing Gap Control
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Solution Overview
Problem
Existing electrosurgical instruments fail to consistently and uniformly seal larger vessels or thick tissues due to inadequate control over pressure and gap distance between electrodes, leading to ineffective or non-uniform seals.
Innovation Solution
The development of a bipolar forceps with an end effector assembly featuring stop members that control the gap distance between opposing jaw members, ensuring a consistent gap of 0.001 to 0.010 inches, and an insulative member with an electrically conductive sealing surface, which is coated and trimmed to form stop members, allowing precise control over tissue sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If stop members are added to control gap distance, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The stop members are integrated within the jaw members themselves, with insulative stop members nested inside the first jaw member and conductive stop members nested inside the second jaw member. This nesting approach allows the stop members to be contained within the existing jaw structure, providing precise gap control without adding external components that would increase overall device complexity.
Solution Approach 2:
Insulative stop members are used as intermediary elements between the conductive sealing surfaces to maintain the required gap distance. These insulative stop members act as mediators that physically separate the opposing jaw members while allowing electrical insulation, thus achieving precise gap control without requiring direct mechanical adjustment mechanisms.
2Reliability
If pressure control is improved for sealing, then reliability is improved, but device complexity increases
Solution Approach 1:
Conductive stop members are nested within the jaw members to provide internal pressure distribution structures. These stop members are positioned to contact the tissue along with the sealing surfaces, creating multiple contact points that distribute clamping pressure uniformly across the tissue-vessel interface, thereby improving seal reliability without requiring external pressure control mechanisms.
Solution Approach 2:
The jaw members are designed with different local properties - the sealing surfaces have high friction coefficients for gripping, while the stop members provide localized pressure distribution. This differentiation of local qualities allows the same jaw member to perform multiple functions: sealing, gripping, and pressure distribution, improving reliability without adding separate pressure control devices.
3Reliability
If friction coefficient is increased for tissue gripping, then reliability is improved, but ease of operation worsens
Solution Approach 1:
The jaw members are designed with spatially varying friction coefficients - the sealing surfaces have high friction to ensure reliable tissue gripping and prevent slippage during sealing, while other portions of the jaw have lower friction to allow smooth tissue insertion and removal. This local differentiation of friction properties enables reliable gripping without requiring excessive closure force throughout the entire jaw surface.
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 solution enables reproducible and effective tissue sealing by maintaining optimal pressure and gap distance, preventing tissue shredding or incomplete sealing, and ensuring a consistent seal thickness for various tissue types.
Implementation Method 1
The insulative material is deposited onto the electrically conductive sealing surface using plasma deposition
Implementation Method 2
The insulative material is cured onto the inwardly facing electrically conductive sealing surface
Implementation Method 3
The insulative material is trimmed from the inwardly facing electrically conductive sealing surface to form a series of stop members arranged thereacross
Data Source
AI summary
A method for manufacturing an end effector assembly for sealing tissue includes the initial step of providing a pair of first and second jaw members each including an inwardly facing electrically conductive sealing surface. The method also includes the steps of: coating the inwardly facing electrically conductive sealing surface of one or both jaw members with an insulative material, the coating having a thickness within the range of about 0.001 inches to about 0.010 inches; allowing the insulative material to cure onto the inwardly facing electrically conductive sealing surface; removing a portion of the insulative material from the inwardly facing electrically conductive sealing surface to form a series of stop members arranged thereacross; and assembling the pair of first and second jaw members about a pivot such that the two inwardly facing electrically conductive sealing surfaces are substantially opposed to each other in pivotal relation relative to one another.