Micro-Surgical Tool Coupling with Rotational Locking

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Solution Overview

Problem

Micro-invasive surgical instruments with curved shafts face challenges in rotating easily within body cavities, and existing coupling mechanisms for tools and shafts are not fully satisfactory for easy assembly, disassembly, and rotation.

Innovation Solution

A micro-invasive surgical instrument with a tool detachably coupled to a shaft featuring a joint device, a connecting component with a bayonet coupling mechanism, and a locking device that allows rotational movement while preventing axial displacement, enabling easy assembly and disassembly and facilitating the tool's orientation within the body cavity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a bayonet coupling mechanism is used for detachable connection, then assembly and disassembly become easy, but rotational movement may be unintentional or unstable

Engineering Contradiction:
Improveassembly and disassemblyVSAvoidrotational stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The locking device is designed to be movable between a locked position (where it engages with the transmission rod to prevent rotation) and an unlocked position (where rotation is permitted during assembly/disassembly). This dynamic positioning allows the system to switch between operational stability and operational flexibility as needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The locking device utilizes the rotational movement itself to engage or disengage from the transmission rod. When the connecting component rotates into the locked position, the locking device automatically engages with the transmission rod without requiring additional actuators or complex mechanisms, making the locking action self-activating.

Inventive Principle:
Principle #25Self-service

2Reliability

If the locking device is fixed to the transmission rod, then rotational stability is improved, but assembly and disassembly become difficult

Engineering Contradiction:
Improverotational stabilityVSAvoidassembly and disassembly
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The locking device is separated from the transmission rod as an independent component that can move relative to it. This segmentation allows the locking device to remain engaged with the transmission rod for stability during operation, while simultaneously allowing the connecting component to be easily attached or detached by moving the locking device between locked and unlocked positions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking device acts as an intermediary element between the connecting component and the transmission rod. It provides the locking function during operation while allowing the connecting component to be freely attached or detached when in the unlocked position, mediating between the needs for stability and ease of assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the tool is rotatable relative to the shaft, then orientation flexibility is improved, but coupling reliability deteriorates

Engineering Contradiction:
Improveorientation flexibilityVSAvoidcoupling reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The coupling system dynamically switches between two states: a locked state where the locking device engages the transmission rod to prevent rotation and ensure coupling reliability, and an unlocked state where the locking device disengages to allow rotational movement for orientation flexibility. This dynamic state change resolves the contradiction between stability and flexibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the rotational parameter from unrestricted (when unlocked for assembly/disassembly) to restricted (when locked for operation). By controlling the engagement state of the locking device, the rotational freedom parameter is adjusted to match the operational requirements, achieving both flexibility and reliability at different times.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2510887B1Tool for a micro-surgical instrument
Publication Date: 2016.03.23 KARL STORZ SE & CO KG
  • EP2510887B1 patent drawingFigure 1~2
  • EP2510887B1 patent drawingFigure 3~5
  • EP2510887B1 patent drawingFigure 6~9

AI summary

The tool (20) has hinge to which jaw portion (25,26) or other active device is attached. A connecting component is connected to rotate with hinge. A transmission rod (40) is provided to transmit force or torque from proximal end of shaft (30) in micro-invasive surgical instrument (10). A locking device is coupled with rod, such that locking device is rotatable in relation to rod while axial sliding is prohibited. The locking device is mechanically mounted in connecting component, such that it is made to slide axially in relation to connecting component while rotation is prohibited. An independent claim is included for micro-invasive surgical instrument.