Laparoscopic Pliers Kinematic Assembly Variable Tendon Geometry
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Solution Overview
Problem
Current robotic laparoscopic surgical pliers are mechanically complex due to the need for transmission cables to pass through articulated bodies, requiring additional pulleys and complicating the movement transmission mechanism.
Innovation Solution
The design incorporates a kinematic assembly with tendons formed from multiple steel cables arranged in a variable cross-sectional geometry, allowing efficient power transmission and eliminating the need for idler pulleys or gears by using rotating drums and changing orientation modules to adapt tendon geometry for smooth movement through joints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If transmission cables are used to pass through articulated bodies, then movement transmission is achieved, but device complexity increases due to additional pulleys and complicated mechanisms
Solution Approach 1:
The patent removes the articulated body and intermediate pulleys from the transmission system. Instead of passing cables through complex articulated mechanisms, the cables are routed directly from the drive mechanism to the distal end of the pliers, extracting the unnecessary intermediate components while maintaining the essential movement transmission function.
Solution Approach 2:
The cable routing system is designed to perform multiple functions: it transmits movement from the drive mechanism, navigates around the rotating body, and actuates the jaws at the distal end, all without requiring separate articulated components. The same cable path serves both as a simple transmission medium and as a mechanism to accommodate rotational movement.
2Ease of manufacture
If additional pulleys are added to accommodate cable routing through articulated bodies, then cable transmission is enabled, but manufacturing costs and assembly complexity increase
Solution Approach 1:
The patent eliminates the need for additional pulleys by removing the articulated body that necessitated them. The cable routing is redesigned to pass directly through the main body structure, extracting the unnecessary pulley components while maintaining cable transmission capability through a simplified path.
3Device complexity
If a simplified mechanism without articulated bodies is used, then device complexity is reduced, but flexibility and durability may be compromised
Solution Approach 1:
The patent incorporates a rotating body that can actively rotate to accommodate changes in cable tension and routing. This dynamic component allows the simplified mechanism to adapt to operational demands, maintaining flexibility and durability despite the reduction in overall mechanical complexity. The rotating body compensates for the absence of articulated bodies by providing active movement adjustment.
Data Source
AI summary
Laparoscopic surgical pliers include jaws mounted on a rotating body and first and second transmissions each including at least one tendon including several cables, and each transmission adapted to transmit movement of the jaws and the rotating body, respectively. The tendons of the first and second transmissions are each respectively formed of several cables arranged so that a cross-section of at least one tendon associated with the first transmission has a variable geometry therealong formed by a first arrangement in which the cables are arranged, in cross-section, with their longitudinal axes in a radial distribution, a second arrangement in which said axes are arranged in a first orientation, and a third arrangement in which said axes are arranged in a second orientation, perpendicular to the first orientation.