Circular Stapler Reload Knife Carrier Retention
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Solution Overview
Problem
Conventional circular stapling devices lack an effective mechanism to reliably retain the knife carrier in a retracted position after firing, posing a risk of injury to clinicians during reload assembly manipulation and disposal.
Innovation Solution
A reload assembly with a shell housing, staple cartridge, pusher, and knife carrier featuring flexible arms with hook portions that engage a holder to securely maintain the knife carrier in a retracted position, utilizing a tapered surface and ramped design to facilitate controlled movement between positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional circular stapling devices are used without improved retainment structure, then the device structure remains simple, but the knife carrier cannot be reliably retained in a retracted position after firing, creating safety risks
Solution Approach 1:
The holder acts as an intermediary component between the knife carrier and the shell housing. It provides a dedicated retention mechanism through openings that receive the flexible arms, serving as a mediator that ensures reliable knife carrier retainment without requiring complex integration into the existing stapling device structure.
Solution Approach 2:
The holder is designed as a separate, modular component with distinct features (openings for flexible arms, cavity for chip reception) that can be independently manufactured and assembled. This segmentation allows the retainment function to be added without redesigning the entire stapling device, maintaining simplicity while improving reliability.
2Object-affected harmful factors
If the knife carrier is allowed to move freely after firing, then manipulation of the reload assembly is easier, but the knife may expose and cause injury to the clinician
Solution Approach 1:
The holder is pre-configured with openings positioned to automatically receive the flexible arms when the knife carrier is in the retracted position. This preliminary arrangement ensures that as long as the knife carrier remains retracted, the clinician can safely manipulate and dispose of the reload assembly without risk of knife exposure.
Solution Approach 2:
The holder structure provides preliminary anti-action by preventing the knife carrier from moving forward beyond the retracted position. The openings act as mechanical stops that counteract any forward movement tendency, ensuring the knife remains concealed and cannot cause injury during subsequent manipulation steps.
Data Source
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Figure 3
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AI summary
A reload assembly includes a shell housing, and a staple cartridge supported on a distal portion of the shell housing. The reload assembly further includes a pusher, a knife carrier supported, and a holder, each of which is supported within the annular cavity. The pusher is movable from a retracted position, through a partially advanced position, to a fully advanced position. The knife carrier includes at least one flexible arm having a free end. The at least one flexible arm has a hook portion on the free end. A housing of the holder defines at least one opening for receiving the hook portion of the at least one flexible arm of the knife carrier which is received within the at least one opening of the holder when the pusher is in the retracted position and is deflected from within the at least one opening when the pusher is in the partially advanced position.