Bipolar End Effector Cam Assembly for Precise Jaw Actuation
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Solution Overview
Problem
Existing flexible surgical instruments for robotic surgery lack an efficient mechanism to convert rotational motion into linear motion for bipolar end effectors, limiting their effectiveness in endoluminal and single-incision procedures.
Innovation Solution
A bipolar end effector assembly with a unique actuation mechanism that converts rotational motion into linear motion using a yoke, pulley, and cam member system, allowing for precise movement of jaw members between open and closed positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional cable actuation mechanism is used in flexible surgical instruments, then the instrument can be controlled from the proximal end, but the conversion of rotational motion to linear motion for jaw actuation is inefficient and imprecise
Solution Approach 1:
A cam member acts as an intermediary between the rotatable element (actuated by control wire) and the jaw members. The cam member's cam surface converts the rotational motion of the control wire into precise linear motion of the jaw carriers, achieving accurate jaw positioning without direct mechanical linkage
Solution Approach 2:
The patent replaces traditional direct mechanical cable actuation with a cam-based motion conversion system. The cam mechanism provides more precise control over jaw movement compared to simple cable pull, transforming the actuation method while maintaining flexibility
2Ease of operation
If a cam-based motion conversion mechanism is implemented, then precise linear motion of jaw members is achieved, but the structural complexity of the end effector assembly increases
Solution Approach 1:
The cam member is integrated with the yoke structure, and the control wire routing is combined with the cam actuation mechanism. Multiple functions (motion conversion, jaw actuation, structural support) are merged into unified components, reducing overall system complexity despite the sophisticated motion control achieved
3Power
If bipolar electrodes are integrated into the jaw members, then electrical energy can be applied to tissue, but the risk of electrical injury to surrounding structures increases
Solution Approach 1:
The bipolar electrodes are integrated specifically into the jaw members that directly contact the tissue, concentrating the electrical energy delivery precisely where needed. The insulating properties of the jaw carrier and selective electrode placement ensure that electrical current is localized to the clamped tissue, minimizing risk to surrounding structures
Data Source
AI summary
An end effector including a yoke arms, a pivot pin extending between the yoke arms, a pulley mounted on the pivot pin and having a drive pin extending laterally outward from a first side surface thereof, a cam member adjacent the first side surface and including a proximal body having a drive arm, wherein a cam pin is provided at a distal end of the drive arm, and wherein the proximal body has a cam slot that includes a vertical cam path and a horizontal cam path, wherein the vertical cam path is associated with the drive pin and the horizontal cam path is associated with the pivot pin, a first jaw carrier having a cam slot for a first portion of the cam pin and a second jaw carrier having a cam slot for a second portion of the cam pin.