Surgical Instrument Drive Unit with Compact Multi-Motor Gear Layout

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Solution Overview

Problem

Surgical robotic systems lack a handle assembly to actuate the functions of end effectors, requiring an instrument drive unit to interface with each surgical instrument, which is typically coupled to the robotic arm via a slide, limiting flexibility and efficiency.

Innovation Solution

An instrument drive unit with a carriage, electric motors, drive shafts, and gears is introduced, allowing for a compact design that enables bottom-loading of surgical instruments and independent actuation of functions through vertically stacked and offset gears, reducing the overall height and improving usability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an instrument drive unit is introduced to interface with each surgical instrument, then the system can actuate functions of end effectors, but the device complexity increases

Engineering Contradiction:
Improveactuation of end effector functionsVSAvoidsystem complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The instrument drive unit is segmented into multiple independent electric motors (first electric motor, second electric motor, third electric motor) that can independently actuate different functions of the surgical instrument. This segmentation allows for modular control where each motor handles a specific function, simplifying the control architecture while maintaining operational capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The instrument drive unit is designed as a universal interface that can actuate multiple functions of the surgical instrument through a single integrated unit. The multiple electric motors within the drive unit can collectively perform various operations (e.g., firing, articulation, grasping) that would otherwise require separate mechanisms, reducing overall system complexity.

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

2Length of moving object

If the instrument drive unit uses traditional coupling via slide, then the axial position can be adjusted, but the system footprint increases

Engineering Contradiction:
Improveaxial position adjustabilityVSAvoidsystem footprint
Core Design Contradiction:
Length of moving objectVSArea of stationary object

Solution Approach 1:

The instrument drive unit utilizes vertical stacking of electric motors and drive shafts in the vertical dimension rather than extending horizontally along the axial dimension. This dimensional reorganization allows the drive unit to maintain axial position adjustability through the slide mechanism while minimizing the horizontal footprint of the stationary components.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The drive shafts are rotationally supported within the carriage in a nested arrangement, with multiple drive shafts and their corresponding electric motors compactly organized within the confined space of the instrument drive unit. This nesting allows multiple functional components to occupy minimal space while maintaining full operational capability.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If multiple drive shafts are rotationally supported in the carriage, then independent actuation is enabled, but the height of the drive unit increases

Engineering Contradiction:
Improveindependent actuation capabilityVSAvoiddrive unit height
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The drive shafts and electric motors are arranged in the horizontal plane rather than being stacked vertically. This dimensional change allows multiple drive shafts to be rotationally supported within the carriage without increasing the vertical height of the drive unit, while still enabling independent actuation of each surgical instrument function.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Area of stationary object

If vertically stacked electric motors are used, then the horizontal footprint is reduced, but the vertical height increases

Engineering Contradiction:
Improvehorizontal footprintVSAvoidvertical height
Core Design Contradiction:
Area of stationary objectVSLength of stationary object

Solution Approach 1:

The electric motors are arranged horizontally within the carriage rather than being stacked vertically. This dimensional reorganization reduces the vertical height of the drive unit while maintaining compact horizontal dimensions, effectively trading vertical space for horizontal space optimization.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 instrument drive unit enhances the usability and safety of surgical robotic systems by enabling efficient actuation of surgical instruments, reducing the system's footprint, and simplifying emergency instrument removal.

Implementation Method 1

a plurality of electric motors disposed about the plurality of drive shafts... Each rotor is configured to rotate a corresponding drive gear in response to an activation of a respective electric motor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a plurality of drive gears. Each drive gear is fixed to a corresponding drive shaft and is configured for interfacing with a corresponding driven member... Each rotor is configured to rotate a corresponding drive gear

Methodology Applied
Scientific EffectMechanical advantage through gear engagement: Gear

Data Source

PatentEP3852666B1Surgical robotic systems
Publication Date: 2025.07.09 COVIDIEN LP
  • EP3852666B1 patent drawingFigure 1
  • EP3852666B1 patent drawingFigure 2~3
  • EP3852666B1 patent drawingFigure 4~5

AI summary

An instrument drive unit for use in a robotic surgical system includes a carriage configured to be coupled to a robotic arm, a plurality of drive shafts rotationally supported in the carriage, a plurality of electric motors disposed about the plurality of drive shafts, and a plurality of drive gears. Each electric motor includes a stator and a rotor disposed within the stator. Each drive gear is fixed to a corresponding drive shaft and is configured for interfacing with a corresponding driven member of the electromechanical surgical instrument. Each rotor is configured to rotate a corresponding drive gear in response to an activation of a respective electric motor to actuate a function of the electromechanical surgical instrument.