Flexible Surgical Shaft With One Opening for Easier Assembly

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Solution Overview

Problem

The manufacturing and assembly of flexible surgical tube shaft instruments, particularly flexible endoscopes, are complicated due to the need for forming multiple small through-holes for steering cables, which are difficult and time-consuming.

Innovation Solution

A flexible shaft design featuring a single through-opening for receiving a working channel, optical image device, and at least two steering wires, allowing for easier assembly and manufacturing through injection molding, eliminating the need for separate openings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If multiple separate through-holes are formed for steering cables in the flexible shaft, then each cable can be individually guided, but the manufacturing process becomes difficult and time-consuming

Engineering Contradiction:
Improveease of assemblyVSAvoidstructural complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines multiple separate through-holes into a single integrated through-opening that accommodates multiple steering wires simultaneously. This merging of separate structural elements into one unified feature simplifies the manufacturing process by requiring only one opening operation instead of multiple precise hole formations, directly resolving the contradiction between ease of manufacture and device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single through-opening is designed to serve multiple functions: it receives and guides multiple steering wires (at least two) simultaneously, while also accommodating the working channel and optical image device. This multi-functional design eliminates the need for separate openings for each component, reducing manufacturing steps while maintaining the ability to individually guide each steering wire

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

2Productivity

If multiple separate through-holes are formed for steering cables, then precise cable positioning is achieved, but manufacturing time increases

Engineering Contradiction:
Improvemanufacturing speedVSAvoidcable positioning precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

By merging multiple cable guide holes into a single through-opening, the manufacturing process is accelerated as only one opening operation is required. The internal structure of this opening is designed with positioning features that maintain precise cable positioning, thus improving productivity without sacrificing manufacturing precision

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The through-opening is pre-configured with internal structures (such as protrusions or positioning features) that guide and position the steering wires during assembly. This preliminary preparation of the opening structure ensures that precise cable positioning is achieved automatically during assembly, eliminating the need for time-consuming post-manufacturing adjustments

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4588421A1Flexible shaft, surgical instrument, method for manufacturing a flexible shaft and method for assembling a steering wire to a flexible shaft
Publication Date: 2025.07.23 KARL STORZ SE & CO KG
  • EP4588421A1 patent drawingFigure 1~2
  • EP4588421A1 patent drawingFigure 3~4
  • EP4588421A1 patent drawingFigure 5~5B-B

AI summary

The present invention provides a flexible shaft (1) for a surgical instrument, in particular for a flexible endoscope, comprising: a distal end (2) and a proximal end (3); and a plurality of shaft sections (4), which are arranged in series between the distal end (2) and the proximal end (3); wherein the plurality of shaft sections (4) is articulatable at least in one plain and comprises a through-opening (5), which is configured for receiving a working channel and an optical image device, wherein the through-opening (5) is further configured for receiving at least two steering wires (6), wherein the through-opening (5) extends through the plurality of shaft sections (4) from the proximal end (3) to the distal end (2). Further the present invention provides a surgical instrument comprising such a flexible shaft as well as a method for manufacturing a flexible shaft for a surgical instrument and a method for assembling a steering wire to a flexible shaft for a surgical instrument.