Cannula Insertion Device Needle Protection Mechanism

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Solution Overview

Problem

Existing insertion devices for medical cannulas are complex and not user-friendly, particularly when handling and disposing of infusion devices under sterile conditions, and they often expose patients to the needle during insertion and retraction.

Innovation Solution

A simple, cost-effective insertion device with a cylindrical design featuring a first and second insertion part, where the second part is connected to the injection needle and can move between activated and non-activated positions, using an elastic element for needle retraction and guiding means for slidable movement, ensuring the needle is never visible to the patient.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a complex automatic injection apparatus with multiple springs and plunger-syringe-combination is used, then the injection can be performed automatically, but the device complexity increases and it becomes unsuitable for simple cannula insertion under sterile conditions

Engineering Contradiction:
Improveautomatic injectionVSAvoiddevice complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex liquid injection mechanism (plunger, syringe, driver spring, return spring) from the system, retaining only the essential needle insertion and retraction functions. This simplifies the device while maintaining automatic operation for cannula insertion.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a disposable insertion device that is used once and then discarded, eliminating the need for complex reusable mechanisms. The simple structure can be manufactured cheaply as a single-use sterile device, combining automation with simplicity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Loss of information

If the injection needle is exposed during insertion and retraction, then the insertion process can be observed, but the patient is exposed to the needle creating safety hazards

Engineering Contradiction:
Improvevisibility of insertion processVSAvoidneedle exposure to patient
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The insertion device features a protective outer housing that contains the needle during insertion and retraction. The needle is nested within the device structure, visible to the operator through controlled openings but protected from direct patient exposure, resolving the contradiction between observation and safety.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The device introduces an intermediary protective structure between the needle and the patient. This mediator allows the insertion process to proceed while preventing direct needle contact with the patient, maintaining safety without completely obscuring the process.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If a simple insertion device structure is used, then the device is easy to manufacture and dispose, but it may lack the automation and control features of complex devices

Engineering Contradiction:
Improveease of manufactureVSAvoidautomation features
Core Design Contradiction:
Ease of manufactureVSExtent of automation

Solution Approach 1:

The insertion device is designed to be self-actuating through a simple trigger mechanism that automatically drives the needle forward and then retracts it using spring-loaded components. This provides automatic insertion and retraction without complex control systems, maintaining ease of manufacture while achieving necessary automation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The device uses dynamic spring-loaded mechanisms that automatically adjust during operation. The driver spring provides forward motion, and the return spring provides retraction, creating automatic dynamic operation without complex electronic or mechanical control systems.

Inventive Principle:
Principle #15Dynamics

4Loss of substance

If the insertion device is designed for multiple-use with reusable components, then cost is reduced, but sterilization and handling under sterile conditions becomes more complicated

Engineering Contradiction:
Improvecost reductionVSAvoidsterile handling
Core Design Contradiction:
Loss of substanceVSEase of operation

Solution Approach 1:

The patent designs the insertion device as a complete disposable unit that is discarded after single use. This eliminates sterilization requirements and simplifies sterile handling, while the low cost of the simple structure makes the disposable approach economically viable.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 device provides a safe, easy-to-use, and disposable solution for inserting cannulas, ensuring the needle is always protected from the user and patient, facilitating single or multiple-use scenarios while minimizing exposure risks.

Implementation Method 1

an elastic element for bringing the second insertion part from a forward to a retracted position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2046420B1Insertion device
Publication Date: 2014.03.26 UNOMEDICAL AS
  • EP2046420B1 patent drawingFigure 1~2
  • EP2046420B1 patent drawingFigure 3~4A
  • EP2046420B1 patent drawingFigure 4B~4C

AI summary

The invention relates to a device for insertion of a cannula of e.g. and infusion set for intermittent or continuous administration of a therapeutical 5 substance, such as e.g. insulin. The insertion device assures that before, during and after insertion the insertion needle is not visible to the patient. The insertion device according to the invention comprises a first insertion part (1) and a second insertion part (2), a cannula holding part (5) provided with a 10 cannula (4), and an injection needle (6) where - the second insertion part (2) is connected to the injection needle (6) and the injection needle (6) is releasably combined with the cannula (4) of the cannula holding part (5), - the first insertion part (1) covers the injection needle (6) in a non-activated 15 position and in an activated position the injection needle (6) projects beyond the first insertion part (1), - at least a part of the second insertion part (2) and the first insertion part (1) can be moved in relation to each other between at least one activated position and at least one non-activated position, 20 wherein the second insertion part (2) exceeds the distal end of the first insertion part (1) when the device is in an activated position.