Surgical Robot Sterile Interface and Magnetic Coupling

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Solution Overview

Problem

Surgical robots are difficult to sterilize due to the presence of lubricants and other components, posing challenges in maintaining sterility during medical procedures, especially when used with surgical instruments that require precise and sterile conditions.

Innovation Solution

A surgical robotic system with a detachable instrument arrangement that includes a drive unit and instrument interface, where the drive unit is designed as an independent module separate from the robot, allowing for easy adaptation and replacement, and featuring a sterile interface that encases the drive unit to prevent contamination, while the instrument and drive unit are connected via a magnetic or frictional coupling that can be easily detached and sterilized.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the robot is integrated with the drive unit and instrument, then the system structure is compact and unified, but the robot becomes difficult to sterilize due to lubricants and wear components

Engineering Contradiction:
Improvesystem structureVSAvoidsterility maintenance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system is divided into separate sterilizable components (instrument, drive unit, adapter) and a non-sterilizable robot. The instrument and adapter can be sterilized independently, while the robot remains outside the sterile field, resolving the contradiction between integrated structure and sterilization capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The drive unit is extracted from the robot and placed in a separate adapter that interfaces with the robot's flange. This extraction allows the adapter and instrument to be sterilized separately while the robot remains non-sterile, maintaining both system integration and sterilization capability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Device complexity

If the drive unit is integrated into the robot, then the system is unified, but adapting different instruments becomes complex

Engineering Contradiction:
Improvesystem integrationVSAvoidinstrument adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The adapter serves multiple functions: it interfaces with the robot's flange, houses the drive unit, provides sterile barrier, and accommodates different instruments. This universal adapter design enables easy adaptation of various instruments while maintaining system integration.

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

Solution Approach 2:

The adapter acts as an intermediary component between the robot and the instrument. It provides a standardized interface that simplifies instrument adaptation while isolating the robot from direct contact with sterile components, enabling both unity and versatility.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Duration of action of stationary object

If the robot arm and instrument are continuously connected, then the system operates smoothly, but maintaining sterility throughout the connection is difficult

Engineering Contradiction:
Improvecontinuous operationVSAvoidsterility maintenance
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

A flexible sterile film or balloon is used to create a sterile barrier between the non-sterile robot arm and the sterile instrument. This flexible barrier can accommodate the continuous connection and movement while maintaining sterility, allowing smooth operation without compromising sterile conditions.

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If the drive unit is separate and detachable, then sterilization is easier, but the coupling mechanism becomes complex

Engineering Contradiction:
Improvesterilization capabilityVSAvoidcoupling mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Magnetic coupling is used to replace complex mechanical coupling mechanisms. The magnetic coupling provides a simple yet effective way to detachably connect the drive unit and instrument while maintaining precise alignment, reducing mechanical complexity while enabling easy sterilization.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This design allows for improved sterility of the surgical environment, reduces the complexity of sterilizing the robot, and enables the use of different instruments with various degrees of freedom, enhancing the versatility and reliability of the surgical robotic system.

Implementation Method 1

The instrument interface 500 comprises a sterile foil sleeve 501 that encloses the housing of the drive unit 2

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Implementation Method 2

the instrument and drive unit are connected via a magnetic or frictional coupling that can be easily detached and sterilized

Methodology Applied
Scientific EffectMagnetic coupling: Magnetism

Implementation Method 3

the instrument and drive unit are connected via a magnetic or frictional coupling that can be easily detached and sterilized

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2881069B1Surgical robot system and surgical instrument
Publication Date: 2020.03.11 KUKA DEUT GMBH
  • EP2881069B1 patent drawingFigure 1~2
  • EP2881069B1 patent drawingFigure 3~4
  • EP2881069B1 patent drawingFigure 5

AI summary

According to one aspect, a surgical robot system according to the invention comprises a robot and an instrument arrangement with a drive unit having at least one rotary drive (7, 8, 9) with an electric motor and a drive shaft (10, 13, 15; 106, 107, 108) with a coupling part (31, 32, 33; 200, 201, 202; 300, 301, 302) for coupling to a drive shaft of the instrument, an instrument with an instrument shaft (3) and a drive shaft (16, 17, 18; 109, 110, 111; 404, 405, 406) with a coupling part (34, 35, 36; 203, 204, 205; 303, 304, 305) for coupling to a drive shaft of the drive unit, and a Instrument interface with a housing enclosing the drive unit (5, 501).