Surgical Instrument Gearbox Assembly for Multi-Axis Robotic Actuation

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Solution Overview

Problem

Robotic surgical systems face challenges in providing additional functionality to surgical instruments due to constraints in the number, type, and configuration of inputs provided by the robotic arm, limiting the ability to achieve desired functionalities.

Innovation Solution

A gearbox assembly with a carriage and differential gear systems that can receive and process multiple inputs to perform specific functions, including articulation and translation, allowing for independent operation of surgical instruments with a robotic surgical system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple gear systems and differential assemblies are added to increase functionality, then the surgical instrument can perform complex tasks, but the device complexity increases

Engineering Contradiction:
ImprovefunctionalityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The gearbox assembly is divided into four separate gear systems (first, second, third, and fourth gear systems), each capable of receiving inputs independently. This segmentation allows each subsystem to handle specific functions, enabling complex surgical tasks to be broken down into manageable mechanical operations while maintaining overall system versatility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The differential gear assemblies serve multiple functions: they combine inputs from different gear systems, enable independent operation of surgical instruments, and provide mechanical advantage for various surgical tasks. The third differential gear assembly, for example, can process inputs from both first and second differential assemblies, creating a universal interface that handles multiple operational modes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If four gear systems are used to enable independent operation, then the surgical instrument achieves desired functionality, but the device complexity increases

Engineering Contradiction:
Improveindependent operation capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The four gear systems are merged through three differential gear assemblies that combine their outputs. The first differential assembly merges inputs from the first and second gear systems, the second differential assembly merges inputs from the third and fourth gear systems, and the third differential assembly merges the outputs from both previous assemblies. This merging strategy reduces the number of independent output paths while maintaining the ability to process multiple inputs independently.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The differential gear assemblies act as intermediary mechanisms between the four input gear systems and the final output to the surgical instrument. These intermediaries process and combine inputs in controlled ways, allowing independent operation capability to be achieved without directly connecting all four inputs to multiple outputs, thereby managing complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If differential gear assemblies are used to process inputs, then the surgical instrument can utilize available inputs effectively, but the device complexity increases

Engineering Contradiction:
Improveinput utilization efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The differential gear assemblies provide dynamic input processing where the mechanical advantage and output characteristics can vary based on the relative inputs from different gear systems. This dynamic behavior allows the system to adaptively utilize available inputs from the robotic arm, maximizing productivity by efficiently converting different input combinations into useful surgical motions without requiring complex electronic control systems.

Inventive Principle:
Principle #15Dynamics

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 the surgical instrument to perform complex tasks such as articulation, jaw movement, and tissue cutting by effectively utilizing the inputs from the robotic arm, enhancing the functionality of surgical instruments within the constraints of the robotic surgical system.

Implementation Method 1

The output gear assembly is a lead screw assembly. Each lead screw assembly may include a lead screw longitudinally fixed and rotatable coupled to the carriage, and a hub operably engaged about the lead screw such that rotation of the lead screw translates the hub.

Methodology Applied
Scientific EffectLead screw mechanism: Screw

Implementation Method 2

a first differential gear assembly operably coupled between the first and second gear systems; a second differential gear assembly operably coupled between the third and fourth gear systems; and a third differential gear assembly operably coupled between the first and second differential gear assemblies

Methodology Applied
Scientific EffectDifferential gear mechanism: Gear

Data Source

PatentEP3689283B1Geared actuation mechanisms for surgical instruments such as for use in robotic surgical systems
Publication Date: 2021.08.18 COVIDIEN LP
  • EP3689283B1 patent drawingFigure 1
  • EP3689283B1 patent drawingFigure 2A~2B
  • EP3689283B1 patent drawingFigure 3

AI summary

A surgical instrument configured for use with a robotic surgical system includes a housing, a shaft extending distally from the housing and including an articulating portion, an end effector assembly extending distally from the shaft and including first and second jaw members, a knife configured for translation between the jaw members, and a gearbox assembly disposed within the housing and operably coupled to the articulating portion of the shaft, the end effector assembly, and the knife. The gearbox assembly includes four rotational input gears each adapted to receive a rotational input from a robotic arm. The gearbox assembly is configured to independently articulate the end effector assembly about a first axis, articulate the end effector assembly about a second axis, move the jaw member(s) relative to the other, and translate the knife between the jaw members based upon the rotational inputs received by the four rotational input gears.