Endoscopic Stapler with Rotating Cam Firing Mechanism
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Solution Overview
Problem
Current surgical staplers for laparoscopic or endoscopic procedures face challenges in using small diameter staples effectively due to the complexity of existing designs and staple size requirements, necessitating a solution for efficient suturing through small diameter cannulas.
Innovation Solution
A surgical stapler design featuring a shaft with a tool assembly including an anvil and cartridge assembly, where the cartridge body has notches and staples with curved legs, and a firing cam system that rotates the staples into the anvil for firing, allowing for the use of small diameter staples suitable for insertion through a 5 mm cannula.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional surgical staplers are used for endoscopic procedures, then stapling function is achieved, but the device diameter is too large to pass through small diameter cannulas
Solution Approach 1:
The cartridge assembly is rotatably nested within the anvil assembly, allowing the entire tool assembly to be compacted to a small diameter for cannula insertion while maintaining full functional capability when deployed
Solution Approach 2:
The cartridge assembly transitions from a static, fixed-position design to a dynamic, rotatable configuration that can be positioned at different angles relative to the anvil, enabling the stapler to pass through small cannulas while maintaining stapling function
2Length of moving object
If staple size is reduced to fit through small diameter cannulas, then cannula compatibility is improved, but stapling effectiveness on thicker tissues deteriorates
Solution Approach 1:
The staple legs are formed with curved configurations that allow them to flex and conform to tissue contours, distributing clamping forces more effectively and maintaining holding strength despite reduced staple size
Solution Approach 2:
The staple design incorporates optimized geometric parameters including leg curvature radius, leg thickness, and crown height ratios that maximize holding strength for the given small diameter constraints
3Length of moving object
If the firing mechanism is simplified for small diameter construction, then device diameter is reduced, but the precision of staple formation deteriorates
Solution Approach 1:
A cam mechanism serves as an intermediary between the simple rotational input and the complex staple deformation process, translating the rotational motion into precise linear and angular movements that ensure accurate staple formation
Solution Approach 2:
The cartridge assembly is pre-positioned and pre-oriented relative to the anvil before firing, with the cam mechanism pre-configured to guide the staple legs through the exact deformation path required for precise staple formation
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
Enables efficient suturing of thicker tissues with small diameter staples, facilitating faster and less traumatic surgical procedures by providing a compact and effective stapling mechanism.
Implementation Method 1
At least one firing cam includes a distal end defining a cam member which is movable within the tool assembly into sequential engagement with each of the plurality of staples. Engagement between the cam member and a staple effects rotational movement of the staple into the anvil member to fire the staple from the cartridge body.
Data Source
AI summary
A surgical stapler is described herein which includes a shaft portion and a tool assembly supported on a distal end of the shaft portion. The too assembly includes an anvil and a cartridge body which rotatably supports a plurality of staples within notches. At least one firing cam is provided to sequentially to engage and rotate each of the staples to fire the staples from the cartridge body. In embodiments, the cartridge body includes two spaced legs which support two linear rows of staples. Each of the spaced legs of the cartridge body is supported within one of a first and a second cartridge channel. The cartridge channels are fixed to opposite sides of a pivot member which is pivotally supported at a distal end of the shaft portion between the shaft portion and the tool assembly such that translation of the first and second cartridge channels in opposite directions effects articulation of the tool assembly in relation to the shaft portion.