Electrosurgical Pivot Joint Sealing for Cleanable Sterile Instruments

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Solution Overview

Problem

Existing electrosurgical instruments with pivotally mounted branches face challenges in cleaning and sterilization due to the presence of gaps that can harbor impurities, making them difficult to maintain effectively.

Innovation Solution

An electrosurgical instrument with a swivel joint featuring a seal that completely surrounds the bearing journal in the circumferential direction, providing a sealing effect in the axial direction while allowing for a gap to facilitate cleaning and sterilization, and including spacer elements to maintain joint stability and accessibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a seal is provided at the pivot joint to prevent contaminant ingress, then protection against harmful factors is improved, but cleaning accessibility deteriorates

Engineering Contradiction:
Improvecontaminant ingressVSAvoidcleaning accessibility
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

A flexible seal element is provided at the pivot joint that can be compressed axially to create a sealing effect. The seal is made of elastically deformable material that allows it to be compressed between the first and second branches, creating a sealing effect that prevents contaminant ingress while maintaining flexibility for cleaning access

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The seal is designed to be dynamically compressible axially, allowing it to adapt between sealed and accessible states. During normal operation, the seal is compressed to prevent contaminant ingress. During cleaning, the dynamic nature of the seal allows cleaning tools to access the pivot joint area despite the presence of the seal

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If the seal completely surrounds the bearing journal circumferentially, then sealing effectiveness is improved, but the gap for cleaning access is reduced

Engineering Contradiction:
Improvesealing effectivenessVSAvoidcleaning access
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The seal is implemented as a flexible ring-shaped element that can be compressed axially. When compressed, it creates an effective seal that completely surrounds the bearing journal circumferentially. The flexibility of the seal material allows it to maintain complete circumferential contact while still permitting cleaning access through the compressed state

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The seal's axial thickness is specifically designed to be greater than the axial distance between contact surfaces, allowing it to be compressed to a thickness that is equal to or less than the axial distance. This parameter change enables the seal to provide complete circumferential sealing while maintaining a gap for cleaning access

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If spacer elements are added to maintain joint stability and accessibility, then ease of operation is improved, but device complexity increases

Engineering Contradiction:
Improvejoint stability and accessibilityVSAvoidnumber of components
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The spacer elements serve multiple functions: they maintain the axial distance between contact surfaces, provide a reference for seal compression, and contribute to joint stability. By combining multiple functions into a single component, the overall device complexity is minimized while achieving the desired ease of operation

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

Solution Approach 2:

The spacer elements act as intermediary components that mediate between the first and second branches, maintaining the appropriate axial distance and allowing the seal to function effectively. These intermediaries enable joint stability and accessibility without requiring complex adjustment mechanisms

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution ensures effective sealing against impurities while maintaining accessibility for cleaning and sterilization, improving the instrument's hygiene and usability by preventing contamination and ensuring reliable operation.

Implementation Method 1

The seal is elastically deformed in the axial direction, causing it to be compressed between the branches

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The seal has a sealing effect in an axial direction... The seal bears against the first branch and the second branch in a sealing manner

Methodology Applied
Scientific EffectSealing effect: Physical Containment

Implementation Method 3

the seal is permeable to water vapor and ethylene oxide (ETO). This ensures that sterilization by the seal is not impeded

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP3725250B1Electrical surgical instrument with joint sealing
Publication Date: 2022.04.20 ERBE ELEKTROMEDIZIN GMBH
  • EP3725250B1 patent drawingFigure 1~2
  • EP3725250B1 patent drawingFigure 3~4
  • EP3725250B1 patent drawingFigure 5~6

AI summary

The invention relates to an electrosurgical instrument (10) with two branches (11, 12) which are pivotally mounted to one another by means of a pivot joint (13). The pivot joint (13) has a bearing pin (34) and a bearing recess (37). The bearing pin (34) is preferably rotationally fixed to one of the branches (11 or 12) and rotatably mounted in the bearing recess (37) of the other branch (12 or 11). A seal (45) is provided between the branches (11, 12), which seals against both branches (11, 12) and completely surrounds the bearing pin (34) in the circumferential direction. Preferably, the bearing pin (34) is sealed to the respective branch (11, 12) at both axial ends. This prevents or at least reduces the ingress of contaminants into the area between the bearing pin (34) and the bearing recess (37).