Tissue Resecting Instrument With Nested Drive Wire
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Solution Overview
Problem
Existing tissue resection instruments face challenges in efficiently removing tissue from internal surgical sites, such as the uterus, while maintaining a clear visual working space and effectively managing fluid distension.
Innovation Solution
The development of an end effector assembly for a tissue-resecting device, which includes an outer shaft with a cutting edge, a drive wire, a distal cutting tip, a hub housing, and a driver. This assembly allows for the rotation or oscillation of the distal cutting tip relative to the outer shaft, facilitating tissue resection and fluid management through a defined outflow path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a tissue resection instrument is inserted through an endoscope to perform endoscopic tissue resection, then the procedure can be performed minimally invasively, but the instrument complexity increases due to the need to integrate cutting mechanisms within a narrow shaft
Solution Approach 1:
The cutting tip is nested within the outer shaft, and the drive wire runs through the outer shaft to engage the cutting tip. This nested configuration allows the cutting mechanism to be housed within a compact endoscopic instrument, reducing invasiveness while maintaining functional capability
Solution Approach 2:
The instrument is divided into distinct functional segments: the outer shaft for fluid flow and structural support, the drive wire for power transmission, and the cutting tip for tissue resection. This segmentation allows each component to be optimized independently while working together within the constrained endoscopic environment
2Ease of operation
If fluid is used to distend the uterus and flush debris during the procedure, then the working space becomes visible and accessible, but the fluid management complexity increases requiring precise control of inflow and outflow
Solution Approach 1:
The outer shaft serves multiple functions: it provides structural support for the instrument, acts as a conduit for fluid flow to distend the uterus, and serves as a pathway for debris removal. This multi-functionality reduces the need for separate components, simplifying fluid management while maintaining working space visibility
Solution Approach 2:
The inflow and outflow paths are merged through the outer shaft structure, with the outflow path specifically designed to pass through the driver component. This integration allows coordinated fluid management where distension and debris removal occur simultaneously through a unified fluid pathway
3Productivity
If the distal cutting tip is made to rotate or oscillate relative to the outer shaft, then cutting efficiency is enhanced, but the mechanical complexity increases due to the need for rotation transmission mechanisms
Solution Approach 1:
The rotation of the cutting tip is achieved by replacing complex mechanical gear systems with a simpler drive wire mechanism. The drive wire, when actuated, directly rotates the cutting tip through wire-based power transmission, eliminating the need for traditional mechanical rotation transmission components within the constrained endoscopic shaft
Solution Approach 2:
The cutting tip is designed to be dynamically rotatable or oscillatable relative to the outer shaft through the drive wire mechanism. This dynamic capability allows the cutting tip to adapt its motion during the cutting process, enhancing cutting efficiency through rotational or oscillating motion while maintaining a relatively simple static structure when not in operation
4Productivity
If the outer shaft includes a cutting edge with cutting teeth to facilitate tissue resection, then the resection capability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The cutting functionality is localized to specific cutting teeth positioned at the distal end of the outer shaft and on the cutting tip. Rather than requiring the entire shaft to meet high precision standards, only the localized cutting surfaces and teeth require precise manufacturing to ensure effective tissue resection, while other portions of the instrument can be manufactured with standard tolerances
Data Source
AI summary
An end effector assembly of a tissue-resecting device includes an outer shaft defining a window, a drive wire extending through the outer shaft, and a distal cutting tip disposed within the outer shaft. The drive wire includes a cylindrical body and a distal end portion defining a semi-cylindrical configuration including a semi-cylindrical bottom surface and a planar top surface having a semi-cylindrical cut-out defined therein. The distal cutting tip at least partially overlaps the window and has a semi-cylindrical 1Pumen defined by a semi-cylindrical bottom surface and an open top. The distal end portion of the drive wire is at least partially received and within the semi-cylindrical lumen with the semi-cylindrical surfaces substantially mating. The drive wire is configured to drive rotation or oscillation of the distal cutting tip relative to the outer shaft.