Resectoscope Probe Sealing Assembly for Low-Friction Precision Movement

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Solution Overview

Problem

Conventional resectoscope sealing devices require force to connect, leading to involuntary movements and increased friction, which can injure patients and hinder precise movement of the probe assembly.

Innovation Solution

A probe device with a sealing device made of non-elastic materials like metal or ceramic, allowing the probe shaft to be displaced parallel to the longitudinal axis, eliminating the need for compression and reducing friction and involuntary movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an elastic sealing device is used to seal the proximal end of the resectoscope shaft, then fluid-tight sealing is achieved, but force is required to compress the sealing device causing involuntary movements and friction

Engineering Contradiction:
Improvefluid-tight sealingVSAvoidinvoluntary movements and friction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The sealing device material is changed from elastic to non-elastic (metal or ceramic), fundamentally altering the physical parameter of elasticity. This allows the sealing device to maintain fluid-tight sealing through precise geometric fit and compression-resistant structure rather than elastic deformation, thereby eliminating the harmful compressive force and friction associated with elastic materials

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs composite construction where the sealing device is made of non-elastic material (metal or ceramic) combined with the probe shaft assembly. This composite approach allows the sealing function to be decoupled from elastic deformation, achieving reliable sealing through the rigidity and precision of the non-elastic material while avoiding the harmful effects of elastic compression

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If friction between the elastic sealing device and probe assembly shaft is reduced, then precise movement is improved, but sealing reliability may be compromised

Engineering Contradiction:
Improveprecise movementVSAvoidsealing effect
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

By changing the material parameter from elastic to non-elastic, the sealing device eliminates friction-based sealing mechanisms. The precise movement is maintained through the rigid, low-friction contact of metal or ceramic surfaces, while sealing reliability is achieved through geometric precision and compression resistance rather than friction

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the friction-based sealing mechanism of elastic materials with a rigid, geometry-based sealing mechanism using metal or ceramic. This substitution eliminates the trade-off between friction and sealing reliability, as the non-elastic material provides both low friction and reliable sealing through its inherent rigidity and precise fit

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

Data Source

PatentEP3363395B1Probe device for resectoscope or other micro-invasive instrument
Publication Date: 2025.11.19 KARL STORZ SE & CO KG
  • EP3363395B1 patent drawingFigure 1~3
  • EP3363395B1 patent drawingFigure 4~6
  • EP3363395B1 patent drawingFigure 7~9

AI summary

A probe assembly (50) for a resectoscope (10) or other microinvasive instrument for processing or manipulating tissue comprises a probe shaft (60) with a cylindrical section (66) for placement within an instrument shaft (20) and a distal end for placement near a distal end of the instrument shaft (20), an action device at the distal end of the probe shaft (60), and a sealing device (70) with a probe shaft channel (76) in which the cylindrical section (66) of the probe shaft (60) is arranged, wherein the probe shaft (60) is displaceable relative to the sealing device (70) parallel to the longitudinal axis of the probe shaft (60) and parallel to the longitudinal axis of the probe shaft channel (76). The sealing device (70) is made of metal or ceramic or of another non-elastic material and is permanently connected to the probe shaft (60).