Tissue Resecting Instrument Outflow Control Seal
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Solution Overview
Problem
Current tissue resection instruments face challenges in effectively managing fluid outflow during endoscopic procedures, which can lead to incomplete tissue resection and debris removal due to inadequate sealing mechanisms.
Innovation Solution
The design incorporates an inner core drive assembly with a seal member and a connector that reciprocates between proximal and distal positions, allowing for controlled fluid outflow and resection of tissue, featuring a threaded coupler and follower mechanism to amplify or attenuate rotational inputs for precise cutting and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a seal member is continuously engaged to block outflow, then fluid sealing is improved, but tissue resection and debris removal are hindered due to inability to flush debris
Solution Approach 1:
The seal member is designed to dynamically transition between sealed and open states based on the reciprocating motion of the inner shaft. During the retraction stroke, the seal member engages with the connector to block outflow and maintain sealing. During the advancement stroke, the seal member disengages to allow outflow and debris removal. This dynamic behavior resolves the contradiction by making the sealing function conditional rather than continuous.
Solution Approach 2:
The system employs periodic reciprocating motion of the inner shaft to alternately establish and release the seal. Each complete cycle of reciprocation creates a periodic pattern of sealing and flushing, allowing both tissue resection (during open phase) and fluid sealing (during closed phase) to occur in sequence, thereby resolving the contradiction between continuous sealing and periodic debris removal.
2Productivity
If the connector remains in the distal position to permit outflow, then debris removal is improved, but fluid sealing is compromised leading to loss of distension
Solution Approach 1:
The connector is designed to reciprocate between proximal and distal positions in response to inner shaft motion. When the inner shaft retracts, the connector moves distally to open the outflow path for debris removal. When the inner shaft advances, the connector moves proximally to seal the outflow path and maintain distension. This dynamic positioning resolves the contradiction by making outflow permission conditional on the surgical phase.
Solution Approach 2:
The reciprocating motion creates periodic phases of outflow permission and sealing. During the retraction phase, the connector permits outflow for debris removal. During the advancement phase, the connector establishes sealing to maintain distension. This periodic alternation allows both debris removal and fluid sealing to be achieved at appropriate times in the surgical cycle.
3Reliability
If the seal member is designed to fully block outflow, then sealing reliability is improved, but control over fluid outflow is reduced
Solution Approach 1:
The seal member's blocking action is made dynamic rather than static. It fully blocks outflow when engaged (during retraction) to ensure sealing reliability, and fully opens when disengaged (during advancement) to permit complete debris removal. The transition between these two extreme states is driven by the reciprocating motion, providing adaptability without compromising sealing reliability when needed.
Data Source
AI summary
A tissue resecting end effector includes a housing, a shaft extending from the housing, and a drive assembly operably coupled to the shaft such that a rotational input provided to the drive assembly effects the rotation and reciprocation of the shaft relative to the housing. The assembly includes a proximal portion translationally fixed and rotatably coupled to the housing and configured to receive the rotational input and to rotate relative to the housing in response thereto, a distal portion translationally and rotatably coupled to the housing and operably coupled to the proximal portion such that the rotation of the proximal portion relative to the housing effects rotation and reciprocation of the distal portion relative to the housing to thereby rotate and reciprocate the first shaft relative to the housing, and a seal member disposed on the proximal portion or the distal portion and configured to selectively establish a seal therebetween.