Tissue Resecting Instrument Dynamic Seal for Fluid Control
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Solution Overview
Problem
Endoscopic tissue resection procedures face challenges in maintaining a distended and clear working space within the uterus during fluid distension, as existing instruments lack effective control over fluid outflow, leading to potential fluid loss and debris accumulation.
Innovation Solution
The tissue resecting instrument features an end effector assembly with an inner core drive assembly that includes a proximal receiver with a seal member, allowing for controlled rotation and reciprocation of the inner shaft, which establishes a seal to block outflow and permits fluid communication for suction when necessary, ensuring effective tissue cutting and debris removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the inner shaft rotates and reciprocates continuously for tissue cutting, then tissue resection efficiency is improved, but fluid leaks from the interior of the inner shaft causing loss of distension and debris accumulation
Solution Approach 1:
The seal member is configured to dynamically transition between sealed and open states based on the rotational position of the inner shaft. During rotation, the seal member periodically opens to allow fluid communication with the outflow conduit, then closes to prevent fluid loss. This dynamic operation maintains distension while enabling continuous tissue cutting.
Solution Approach 2:
The system implements periodic sealing and opening actions synchronized with the rotational cycles of the inner shaft. The seal member closes during portions of rotation to prevent fluid loss, then opens periodically to allow debris removal, creating a rhythmic pattern of sealing and release that maintains overall fluid containment while enabling continuous operation.
2Loss of substance
If the seal member remains closed to prevent fluid loss, then fluid containment is improved, but debris and tissue cannot be removed from the interior of the inner shaft
Solution Approach 1:
The seal member transitions from a static closed state to a dynamic state that periodically opens during rotation. This allows the system to maintain fluid containment during most of the cycle while creating periodic openings that enable debris and tissue fragments to be flushed out through the outflow conduit.
Solution Approach 2:
The system maintains continuous fluid containment while implementing periodic debris removal. The seal member's periodic opening allows continuous operation of the tissue cutting function while intermittently clearing debris, ensuring that the useful action of tissue resection continues without interruption while harmful debris accumulation is prevented.
3Loss of substance
If the connector is fixed at the proximal position to maintain sealing, then fluid loss prevention is improved, but the inner shaft cannot reciprocate for effective tissue cutting
Solution Approach 1:
The connector is designed to move dynamically between proximal and distal positions during rotation. At the proximal position, it engages the seal member to prevent fluid loss. During rotation, it reciprocates to the distal position, allowing the inner shaft to reciprocate effectively for tissue cutting. This dynamic positioning resolves the conflict between sealing and operational effectiveness.
Solution Approach 2:
The connector implements periodic engagement and disengagement from the seal member synchronized with rotation. It engages the seal member periodically to prevent fluid loss, then disengages to allow inner shaft reciprocation for effective tissue cutting. This periodic action sequence ensures both fluid containment and cutting effectiveness are achieved during continuous operation.
Data Source
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AI summary
A tissue resecting instrument includes an end effector assembly having a proximal hub housing, outer and inner shafts extending therefrom, and an inner core drive assembly to rotate and reciprocate the inner shaft relative to the outer shaft. The inner core drive assembly includes a proximal receiver that receives a rotational input and rotates in response and includes a seal member disposed thereon. The rotation of the proximal receiver effects rotation of a connector and reciprocation of the connector between a proximal position and a distal position. The connector is operably coupled to the inner shaft such that the rotation and reciprocation of the connector effects the rotation and reciprocation of the inner shaft. In the proximal position, the connector and the seal member establish a seal that blocks outflow. In the distal position, the connector is displaced from the seal member to permit outflow.