Cable-Driven End Effector Jaw Closure Mechanism
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Solution Overview
Problem
Existing robotic surgical instruments lack efficient and compact mechanisms for opening and closing the jaws of end effectors, which are crucial for various surgical treatments.
Innovation Solution
A cable-driven end effector mechanism with a rotatably coupled first and second jaw, a central pulley, and a pivot link, where a jaw cable looped around the central pulley operates on a 'pull-pull' strategy to open and close the jaws, facilitated by individual actuation mechanisms for each end of the jaw cable to enhance control and minimize wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a cable-driven motion system is used to articulate the end effector, then degrees of freedom in movement are improved, but the complexity of the mechanism for opening and closing jaws increases
Solution Approach 1:
The jaw closure mechanism is segmented into distinct functional components: a first jaw, a second jaw, a pivot link, and a cable assembly. Each component performs a specific function, allowing the complex motion control to be divided into manageable segments that can be independently optimized and assembled.
Solution Approach 2:
A cable assembly acts as an intermediary element between the actuation mechanism and the jaw components. The cable transmits force from the actuator to the pivot link and jaws, enabling remote operation while simplifying the direct mechanical connection and reducing the complexity of the closure mechanism itself.
2Measurement precision
If individual actuation mechanisms are used for each end of the jaw cable, then control precision is improved, but the device complexity increases
Solution Approach 1:
The actuation system is segmented into separate actuation mechanisms for each end of the jaw cable. This segmentation allows independent control of each cable end, enabling precise control of jaw movement while distributing the mechanical load and reducing the complexity of any single actuation mechanism.
3Volume of moving object
If a compact mechanism is used for opening and closing jaws, then the size of the end effector is reduced, but the reliability of the mechanism decreases
Solution Approach 1:
The compact jaw closure mechanism uses segmented components (first jaw, second jaw, pivot link, cable assembly) that can be efficiently packaged within a reduced volume. Each segment is optimized for its specific function, maintaining reliability while minimizing the overall size of the end effector.
Solution Approach 2:
The cable-driven system utilizes flexible cable transmission that can be routed through compact pathways. The cable assembly acts as a flexible conduit that transmits force efficiently through tight spaces, enabling compact mechanism design while maintaining the reliability of force transmission through the cable connection points and pivot joints.
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 precise and durable operation of the end effector jaws, allowing for effective surgical procedures with reduced load and stretch on the cables, thereby extending the device's lifespan and improving control over jaw movement.
Implementation Method 1
A jaw cable is looped around a central pulley and operatively coupled to the pivot link such that linear movement of the jaw cable correspondingly causes the first jaw to rotate relative to the second jaw on the jaw axle
Data Source
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AI summary
An end effector includes a first jaw rotatably coupled to a second jaw at a jaw axle, a central pulley rotatably mounted to the jaw axle, and a pivot link rotatably coupled to the first jaw at a pivot axle. A jaw cable is looped around the central pulley and operatively coupled to the pivot link such that linear movement of the jaw cable correspondingly causes the first jaw to rotate relative to the second jaw on the jaw axle and between open and closed positions.