Robotic End Effector Clevis Cam Mechanism for Tissue Severing
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Solution Overview
Problem
Existing surgical forceps, particularly those used in robotic surgical systems, face challenges in efficiently severing treated tissue after mechanical clamping and energy-based treatments.
Innovation Solution
The end effector assembly incorporates a clevis with a pivot pin, cam pin, and jaw members, featuring flags and cam slots that allow for precise pivoting and cutting action, enabling effective tissue grasping, treatment, and severing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional surgical forceps are used for tissue manipulation, then mechanical clamping and energy-based treatment can be applied, but the efficiency of severing treated tissue is insufficient
Solution Approach 1:
The end effector assembly is divided into distinct functional segments: jaw members for clamping, a cutting element for severing, and a cam mechanism for controlled movement. This segmentation allows each component to specialize in its function, improving overall productivity while maintaining ease of operation through dedicated functional zones.
Solution Approach 2:
The cam mechanism enables dynamic movement of the cutting element relative to the jaw members. The cam slot and cam pin arrangement allows the cutting element to move between retracted and advanced positions, providing adaptive capability that improves both severing efficiency and operational ease by allowing precise control during different phases of tissue manipulation.
2Productivity
If a cutting element is incorporated into electrosurgical forceps, then treated tissue can be effectively severed, but the device complexity increases
Solution Approach 1:
The cutting element is merged with the existing jaw member structure through the cam mechanism. The cutting element is positioned within the end effector assembly and actuated by the same cam pin and slot system that controls jaw movement, combining multiple functions (clamping and cutting) into a unified mechanism that reduces overall device complexity while maintaining severing capability.
Solution Approach 2:
The end effector assembly is designed as a multi-functional unit where the jaw members provide both mechanical clamping and support for the cutting element. The cam mechanism serves dual purposes: controlling jaw closure and actuating the cutting element, thereby achieving multiple functions without proportionally increasing device complexity.
3Measurement precision
If precise pivoting mechanism is implemented, then tissue manipulation precision is enhanced, but the device complexity increases
Solution Approach 1:
The cam pin acts as an intermediary element between the cam mechanism and the jaw members. It transmits the cam's motion through the cam slot to produce precise pivoting of the jaw members, achieving high precision tissue manipulation without requiring complex direct actuation mechanisms. The cam slot geometry serves as an intermediary that converts simple cam motion into precise jaw pivoting.
Data Source
AI summary
An end effector assembly includes a clevis having first and second spaced-apart arms, a ceiling, a floor, pivot and cam pins extending between the arms, and first and second jaw members. Each jaw member includes a proximal portion and a distal body extending distally from the clevis. The proximal portion of the first jaw member includes a first flag disposed between the first and second arms of the clevis, operably coupled to both the pivot pin and the cam pin, extending vertically at least partially through openings defined within the ceiling and floor. The proximal portion of the second jaw member includes second and third flags disposed between the first and second arms of the clevis in spaced-apart relative to one another and between the ceiling and the floor. The second and third flags are fixedly engaged to the clevis.