Surgical Stapler End Effector Snap-Fit Anvil Fixation
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Solution Overview
Problem
Existing surgical stapling devices suffer from anvil assembly misalignment and frame weakening due to rivet fixation, leading to staple malformation and deflection.
Innovation Solution
The anvil assembly is secured to the end effector frame via a snap-fit connection, using a cut plate sandwiched between the anvil and a proximally facing surface, with resilient fingers or protrusions for secure attachment without weakening the frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If rivets are used to secure the anvil assembly to the second transverse portion, then the anvil assembly is fixedly secured, but the through holes weaken the second transverse portion causing increased deflection
Solution Approach 1:
A reinforcement element is introduced as an intermediary component between the anvil assembly and the second transverse portion. This reinforcement element provides the necessary fixation for the anvil assembly while distributing loads away from the transverse portion, thereby preventing the deflection issues caused by direct rivet fixation.
2Stability of the object's composition
If rivets are used to secure the anvil assembly, then the anvil assembly is fixedly secured, but riveting tolerances result in misalignment of the anvil assembly with the cartridge assembly
Solution Approach 1:
Alignment features such as alignment pins or guided slots are incorporated into the reinforcement element or the anvil assembly before final fixation. These preliminary alignment mechanisms ensure precise positioning of the anvil assembly relative to the cartridge assembly during assembly, eliminating misalignment issues that arise from rivet tolerances.
3Device complexity
If the second transverse portion is supported in cantilevered fashion, then the end effector frame structure is simplified, but the second transverse portion deflects during firing causing anvil assembly misalignment
Solution Approach 1:
The reinforcement element serves as a mediator that supports the anvil assembly on the cantilevered second transverse portion. It provides the necessary structural support to prevent deflection-induced misalignment while maintaining the simplified cantilevered frame structure, effectively decoupling the structural simplicity from the stability requirement.
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 minimizes frame deflection, ensures precise alignment, and facilitates easy assembly, reducing costs and time compared to conventional riveting processes.
Implementation Method 1
The anvil assembly is secured to the distal transverse portion of the end effector frame via a snap-fit connection such that the cut plate is sandwiched between the anvil and the proximally facing surface of the distal transverse portion
Implementation Method 2
each of the brackets includes a resilient finger and the distal transverse portion of the end effector frame defines openings that receive the resilient fingers in snap-fit fashion to secure the anvil to the distal transverse portion of the end effector frame
Data Source
AI summary
A surgical stapling device includes an end effector having an end effector frame with a cantilevered portion and an anvil assembly supported on the cantilevered portion of the end effector frame. The anvil assembly and the cantilevered portion of the end effector frame are adapted to be secured together in a manner to minimize weakening of the cantilevered portion of the end effector frame to minimize deflection of the anvil assembly during firing of the stapling device.