Surgical Stapling Instrument Cable-Driven Knife and Lever Arm Actuation
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Solution Overview
Problem
Existing endoscopic surgical staplers require high forces to operate due to low mechanical advantage in their firing and clamping systems, limiting their efficiency and effectiveness in surgical procedures.
Innovation Solution
A surgical cutting and stapling instrument with a cable-driven knife assembly and an anvil assembly that utilizes a distal closure tube segment to apply actuation motion to a closure ring, allowing for axial movement and improved clamping force through a pivotally attached articulation joint, enabling efficient stapling and cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a cable-driven firing system is used in surgical staplers, then the device can achieve compact design suitable for endoscopic applications, but the mechanical advantage is low requiring relatively high forces to operate
Solution Approach 1:
A lever arm is introduced as an intermediary component between the cable-driven firing system and the anvil closure mechanism. The lever arm pivots about an axis and transforms the linear cable tension into rotational moment, providing mechanical advantage while maintaining the compact cable-driven architecture suitable for endoscopic staplers
Solution Approach 2:
The firing mechanism transitions from direct linear cable tension to rotational motion through the lever arm pivot axis. This dimensional transformation allows the system to exploit torque and moment arms, converting a high-force linear pull into a more efficient rotational closure action
2Device complexity
If cables are threaded around pulleys and terminated at a closure ring for anvil closure, then the mechanism achieves simplified cable routing, but the capacity to generate clamping force is limited
Solution Approach 1:
The lever arm serves as a mechanical intermediary between the cable-driven closure ring and the anvil. By pivoting the lever arm about an axis positioned to create a favorable moment arm, the system amplifies the clamping force delivered to the anvil while preserving the simplified cable routing through the closure ring
Solution Approach 2:
The lever arm mechanism creates a mechanical advantage that counteracts the limited force capacity of the cable system. The pivot axis positioning and lever arm geometry are designed to multiply the input force from the cable, effectively compensating for the inherently limited clamping force of direct cable-driven systems
Data Source
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AI summary
A multi-axis surgical stapling and cutting instrument. In various embodiments, the instrument includes a tool assembly that operably supports a cable powered knife assembly and further has an anvil that is actuated by axial movement of a closure ring. The instrument may further include a disposable reload unit that may be attached to the reusable portion of the instrument without the use of tools. Various embodiments may also employ an active articulation control system for actively articulating the tool assembly.