Endoscopic Instrument Jaw Actuation and Electrical Isolation
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Solution Overview
Problem
Existing surgical instruments face challenges in transmitting clamping pressure and conducting electrical current effectively in minimally invasive procedures due to their small diameter, particularly below 2.8 mm, and ensuring electrical isolation of tissue-contacting surfaces.
Innovation Solution
The design includes a surgical instrument with a 2.4 mm diameter elongated shaft, featuring a drive assembly that translates a drive bar to move jaw members between spaced-apart and grasping positions, and uses high-temperature dielectric materials and pivot pins for electrical isolation, with a knife slot for tissue cutting, to apply pressure in the range of 3 kg/cm2 to 16 kg/cm2.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the diameter of the surgical instrument is reduced below 2.8 mm for minimally invasive procedures, then the ability to perform minimally invasive surgery is improved, but the transmission of clamping pressure between jaw members deteriorates
Solution Approach 1:
The drive bar is segmented into multiple sections (first drive bar section, second drive bar section, third drive bar section) that can be independently positioned and actuated. This segmentation allows the force transmission mechanism to be distributed along the length of the shaft, maintaining effective clamping pressure transmission despite the reduced overall diameter of the instrument.
2Length of moving object
If the diameter of the surgical instrument is reduced below 2.8 mm, then minimally invasive surgery capability is improved, but the conduction of electrical current deteriorates
Solution Approach 1:
The first and second jaw members are equipped with active electrodes that are electrically isolated from the shaft and from each other. This local quality modification allows electrical current to be conducted through the jaw members for tissue treatment while maintaining the small diameter of the shaft, as the electrical conduction path is localized to the jaw members rather than requiring the entire shaft to be a conductor.
3Length of moving object
If the diameter of the surgical instrument is reduced below 2.8 mm, then minimally invasive surgery capability is improved, but ensuring electrical isolation of tissue-contacting surfaces becomes more challenging
Solution Approach 1:
The shaft is designed as a dielectric (non-conductive) intermediary element that electrically isolates the active electrodes on the first and second jaw members from each other and from the rest of the instrument. This dielectric shaft acts as a mediator that maintains electrical isolation while still allowing mechanical force transmission, thereby ensuring safe electrical isolation in the minimally invasive instrument configuration.
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 configuration enables effective tissue grasping, sealing, and cutting while maintaining electrical isolation and efficient pressure transmission, suitable for minimally invasive surgeries, enhancing the performance of surgical instruments in small diameters.
Implementation Method 1
The active electrode seal plate may be bonded to the support surface with a high-temperature, dielectric epoxy. The support surface may be coated with a high-temperature dielectric material.
Implementation Method 2
The first link is pivotably connected to the clevis about a first pivot axis, and is pivotably connected to the first jaw member about a first jaw member pivot. The second link is pivotably connected to the clevis about a second pivot axis, and is pivotably connected to the second jaw member about a second jaw member pivot.
Data Source
AI summary
An endoscopic surgical instrument is provided. The instrument includes a housing, a handle, an elongated shaft extending distally from the housing and defining a longitudinal axis, an end effector assembly, a drive assembly, a clevis, a first link, and a second link. The end effector assembly is disposed adjacent a distal end of the elongated shaft and includes a first jaw member and a second jaw member. The first link is pivotably connected to the clevis about a first pivot axis, and is pivotably connected to the first jaw member about a first jaw member pivot. The second link is pivotably connected to the clevis about a second pivot axis, and is pivotably connected to the second jaw member about a second jaw member pivot. The first pivot axis and the second pivot axis are offset from the longitudinal axis.