Cam Locking Mechanism for Surgical Stapler Articulation
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Solution Overview
Problem
Existing surgical instruments with articulable tool assemblies lack a reliable mechanism to lock the tool assembly in desired positions, leading to potential deflection during procedures due to reliance on friction, which can be disrupted by accidental contact with body structures.
Innovation Solution
A locking articulation mechanism that includes an articulation housing, main shaft, cam lock, locking cover, and articulation lever, utilizing a cam mechanism and biasing member to securely lock the tool assembly in place without relying on friction, allowing for precise control and maintenance of articulation positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If friction-based positioning is used to maintain tool assembly position, then the device complexity is reduced, but the reliability deteriorates due to potential deflection from accidental contact
Solution Approach 1:
The patent replaces the friction-based mechanical positioning system with a cam-based locking mechanism. The cam lock engages with locking surfaces to provide positive positioning, eliminating reliance on friction alone. This substitution maintains the simplicity of the overall device while dramatically improving positioning reliability through mechanical interlocking.
Solution Approach 2:
The articulation mechanism is segmented into distinct functional components: the cam lock, locking surfaces, biasing member, and friction elements. This segmentation allows each component to perform its specific function optimally - the cam provides positive locking, the biasing member maintains engagement force, and friction elements provide secondary stabilization - thereby improving overall reliability without excessive complexity.
2Reliability
If a locking mechanism is added to prevent deflection, then the reliability improves, but the device complexity increases
Solution Approach 1:
The patent introduces a cam-based locking mechanism that replaces or augments the friction-based system. The cam lock with its engagement surfaces provides positive positioning, while the biasing member ensures continuous engagement. This targeted addition of locking elements improves positioning stability without requiring a complete redesign of the entire articulation mechanism.
Solution Approach 2:
The biasing member automatically maintains engagement force between the cam lock and locking surfaces, ensuring continuous positioning stability without requiring active control or additional complex mechanisms. The self-actuating nature of the biasing member improves reliability while minimizing added complexity.
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
The mechanism provides a secure and reliable locking system for surgical instruments, preventing unintended deflection during procedures and ensuring consistent positioning of the tool assembly, enhancing surgical precision and safety.
Implementation Method 1
A locking articulation mechanism is provided that includes an articulation housing, a main shaft, a cam lock, a locking cover, and an articulation lever
Implementation Method 2
utilizing a cam mechanism and biasing member to securely lock the tool assembly in place
Data Source
AI summary
A surgical stapler is provided and comprises a handle assembly, an elongated body, an articulable tool assembly, and an articulation mechanism. The articulation mechanism has: a main shaft member connected to an articulation linkage; a retainer having an opening for receiving a shaft portion of the main shaft member; a cam lock having cam locking surfaces and a locking tab; a locking cover defining recesses for receiving the locking tab; an articulation handle having cam surfaces configured to engage the cam locking surfaces of the cam lock.