Tracheal Intubation Stylet Sheath Moulding

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Solution Overview

Problem

Current methods for manufacturing tracheal intubation stylets with plastic coverings are costly and inefficient, particularly in achieving a smooth and even thickness, and none have successfully utilized injection moulding effectively.

Innovation Solution

A method involving a first and second injection moulding tool with sheath projections to accurately position and mould a sheath around a malleable insert, ensuring a smooth exterior and reducing the risk of trauma during intubation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional methods (extrusion, dipping, spraying, compression moulding) are used to cover the stylet rod, then the plastic covering can be applied, but the manufacturing process is costly and inefficient, and achieving even thickness and smooth surface is difficult

Engineering Contradiction:
Improvemanufacturing cost and efficiencyVSAvoidplastic covering thickness uniformity and surface smoothness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The injection moulding tool is segmented into multiple components including a fixed component, a movable component, and a core component that can be independently positioned. This segmentation allows precise control of the moulding cavity geometry, enabling production of sheaths with uniform wall thickness and smooth surfaces while maintaining manufacturing efficiency through the injection moulding process

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a third dimensional aspect by using a movable component that can be positioned at different locations within the moulding cavity. This allows dynamic control of the sheath formation process, enabling even thickness distribution and smooth surface finish that were not achievable with traditional single-step methods

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If injection moulding is used to manufacture the sheath, then manufacturing efficiency and cost-effectiveness improve, but achieving accurate positioning of the insert and even thickness of the sheath has been unsuccessful in prior art

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidinsert positioning accuracy and sheath thickness uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The core component is pre-positioned within the moulding cavity before the injection process begins. This preliminary positioning ensures that the sheath material will be deposited uniformly around the insert from the start of the process, achieving both accurate insert positioning and even sheath thickness in a single injection moulding operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The movable component acts as an intermediary element between the fixed component and the insert. It facilitates precise positioning of the insert and controls the flow of sheath material, enabling the injection moulding process to achieve both high productivity and high precision simultaneously

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If the sheath has openings from support projections, then the insert can be positioned, but the exterior surface is not smooth and may catch on patient anatomy causing trauma

Engineering Contradiction:
Improveinsert positioning accuracyVSAvoidsurface roughness causing patient trauma
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The harmful feature (openings in the sheath surface) is extracted and removed by designing the movable component to fill these openings during the injection moulding process. The result is a sheath with a completely smooth exterior surface that eliminates the risk of catching on patient anatomy, while the insert positioning function is maintained through the core component

Inventive Principle:
Principle #2Taking out (Extraction)

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 method provides a more accurate and cost-effective manufacturing process for tracheal intubation devices with a smooth exterior, reducing the risk of trauma and kinks, and enabling the use of both stylet and bougie functions.

Implementation Method 1

injection moulding a second sheath about the inner sheath body and the at least one insert

Methodology Applied
Scientific EffectInjection moulding:

Implementation Method 2

injection moulding a second sheath about the inner sheath body and the at least one insert

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3370937B1Manufacture of medical devices and such a medical devices
Publication Date: 2022.07.20 INTERSURGIGAL AG
  • EP3370937B1 patent drawingFigure 1~4
  • EP3370937B1 patent drawingFigure 5~6(d)

AI summary

Improvements relating to the Manufacture of Medical Devices The present invention relates to medical devices and methods of manufacturing medical devices. The application describes method of manufacturing a medical device where at least one insert (20,22) is provided with a first sheath including an inner sheath body (24) and one or more sheath projections (26), such that the insert (20,22) and the first sheath can be supported by the one or more sheath projections (24) within a mould chamber, and a second sheath (28) is injection moulded about the inner sheath body (24) and the at least one insert (20,22), between the one or more sheath projections (26).