Surgical Instrument Gearbox Assembly for Articulation and Jaw Force
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Solution Overview
Problem
Robotic surgical systems face constraints in designing surgical instruments due to limited inputs from the robotic arm, which hinders the achievement of desired functionalities in surgical instruments.
Innovation Solution
A surgical instrument with a gearbox assembly that includes an articulation sub-assembly and a jaw drive sub-assembly, utilizing lead screws, nuts, and guide bars to articulate the end effector and transition it between open and closed positions, allowing for precise control and alignment with robotic surgical systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a robotic arm provides limited inputs to a surgical instrument, then the robotic arm's structure is simplified and easier to control, but the surgical instrument cannot achieve desired functionalities such as articulation and jaw movement
Solution Approach 1:
The surgical instrument is divided into functionally independent sub-assemblies (articulation sub-assembly and jaw drive sub-assembly), each with its own drive mechanism. This segmentation allows the instrument to achieve multiple functionalities through separate input channels from the robotic arm, resolving the contradiction between versatility and complexity by organizing complexity into manageable modules.
Solution Approach 2:
The gearbox assembly is designed to perform multiple functions (articulation and jaw movement) through a unified mechanical structure that accepts multiple inputs. The lead screw mechanisms serve dual purposes in both sub-assemblies, creating a universal drive system that maximizes functionality while minimizing the number of unique components required.
2Measurement precision
If lead screws and nuts are used to articulate the end effector, then precise control and alignment are achieved, but the device complexity increases due to additional components
Solution Approach 1:
The articulation mechanism merges multiple lead screws and nuts into a compact integrated assembly where components share common mounting structures and alignment features. The guide bars are designed to serve multiple lead screws simultaneously, reducing the total number of independent guidance elements and simplifying the overall structure while maintaining precision.
3Manufacturing precision
If multiple lead screws are used in the articulation sub-assembly, then articulation accuracy is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The lead screws are designed with varying levels of precision based on their specific functional requirements within the articulation mechanism. Critical lead screws that directly control end effector positioning are manufactured with higher precision, while supporting lead screws use standard tolerances. This localized quality approach maintains articulation accuracy where needed while reducing manufacturing complexity elsewhere.
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
Enables efficient articulation and grasping of tissue, maintaining jaw force during articulation, and aligning components to enhance the functionality of surgical instruments compatible with robotic surgical systems.
Implementation Method 1
a first lead screw (302) including a gear portion (302g), a waist portion (302w), and an elongate threaded body portion (302t), and a second lead screw (304) including a gear portion (304g) and an elongate threaded body portion (304t). A first nut (312) is threadingly engaged with the elongate threaded body portion (302t) of the first lead screw (302) such that rotation of the first lead screw (302) effects longitudinal translation of the first nut (312).
Implementation Method 2
The distal gear portion of the proximal center gear is meshingly engaged with the gear portion of the first lead screw. Additionally, the distal gear portion of the distal center gear is meshingly engaged with the gear portion of the second lead screw
Implementation Method 3
A first nut is threadingly engaged with the elongate threaded body portion of the first lead screw such that rotation of the first lead screw effects longitudinal translation of the first nut. A second nut is threadingly engaged with the elongate threaded body portion of the second lead screw such that rotation of the second lead screw effects longitudinal translation of the second nut.
Data Source
AI summary
A gearbox assembly for a surgical instrument includes an articulation sub-assembly and a jaw drive sub-assembly. The articulation sub-assembly is configured to articulate an end effector of the surgical instrument and the jaw drive sub-assembly is configured to move jaw members of the end effector between an open and closed position. The articulation sub-assembly includes two input shafts, a proximal plate, a middle plate, two center gears, and four lead screws with four nuts. The jaw drive sub-assembly includes a drive rod coupled to at least one of the jaws and a spring force assembly to maintain a force between the jaws.