Link-Driven Articulation Joint for Stable Surgical End Effector Positioning
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Solution Overview
Problem
Existing endoscopic surgical instruments face challenges in maintaining precise articulation of the end effector due to dearticulation responses from external loads and cable lengthening, particularly in surgical staplers, which affect the positioning and functionality of the end effector.
Innovation Solution
The use of a link-driven articulation joint with rigid links and a cable articulation subsystem that allows for precise 360-degree movement of the end effector with at least two degrees of freedom, utilizing a center beam assembly and articulation cables to facilitate pitch and yaw articulation, while minimizing dearticulation and cable stretching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rigid links are used in the articulation assembly, then articulation stability and precision are improved, but device complexity increases
Solution Approach 1:
The articulation assembly is segmented into multiple rigid links (first link, second link, third link, fourth link) connected by hinge joints, allowing each segment to contribute to the overall articulation stability while maintaining manageable individual component complexity
Solution Approach 2:
The articulation assembly uses a dynamic linkage mechanism with hinge joints that allow controlled movement between rigid links, enabling the end effector to articulate in multiple directions while maintaining stability during tissue engagement
2Ease of operation
If cable articulation subsystem is used, then ease of operation is improved, but articulation precision deteriorates due to cable stretching
Solution Approach 1:
Rigid links serve as intermediary components between the cable articulation subsystem and the end effector, translating cable movements into precise articulation while preventing direct cable stretching from affecting positioning accuracy
Solution Approach 2:
The patent replaces traditional flexible cable-driven articulation with a rigid link mechanism that uses hinge joints and articulation beams, substituting the mechanical cable system with a more rigid structure that eliminates stretching issues while maintaining operational control
3Strength
If link-driven articulation joint is used, then resistance to external loads is improved, but device complexity increases
Solution Approach 1:
The link-driven articulation joint uses asymmetric link arrangements where links of different lengths and orientations (first link perpendicular to second link, third link perpendicular to fourth link) provide optimized load resistance in multiple directions while maintaining a relatively simple overall structure
Solution Approach 2:
The articulation joint incorporates spherical hinge joints that allow rotation in multiple directions, providing omnidirectional load resistance capability while maintaining a compact and relatively simple joint design
Data Source
AI summary
A surgical instrument (1100), including: a shaft (1600) defining a longitudinal axis; an end effector (1200); and an articulation assembly (1300). The articulation assembly being positioned between the shaft and the end effector and configured to articulate the end effector relative to the shaft about each of a pitch axis and a yaw axis. The articulation assembly including: a pitch articulation beam (1354) and a yaw articulation beam (1344). Wherein the pitch articulation beam is configured to drive a pitch of the end effector relative to the shaft about the pitch axis by pushing a first linked portion of the end effector distally and pulling the first linked portion of the end effector proximally. Wherein the yaw articulation beam is configured to drive a yaw of the end effector relative to the shaft about the yaw axis by pushing a second linked portion of the end effector distally.