Cannula Device With Pivoting Trocar-Tip Shielding During Removal

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Solution Overview

Problem

Existing cannula devices pose a safety risk during removal of the puncture device due to the potential for user injury and infection from the exposed trocar tip.

Innovation Solution

A cannula device with a protection element that automatically covers the trocar tip upon removal, featuring pivotable shielding legs connected to the puncture trocar, which are moved to shield the tip when the device is withdrawn from the housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the puncture device is removed from the housing after use, then the cannula can be placed within the body cavity for long-term feeding, but the exposed trocar tip poses a safety risk causing user injury and infection

Engineering Contradiction:
Improvesafety during removalVSAvoiduser injury and infection risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A protection element with shielding legs is introduced as an intermediary component between the trocar tip and the user. The shielding legs pivot from an open position during insertion to a closed position during removal, automatically covering the trocar tip to prevent injury and infection while allowing the puncture device to be removed for cannula placement

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a protection element with pivotable shielding legs is added to cover the trocar tip during removal, then user safety is improved, but the device complexity increases

Engineering Contradiction:
Improveprotection during removalVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The shielding legs are designed to be pivotable rather than fixed, allowing them to dynamically change position between open (during insertion) and closed (during removal) states. This dynamic mechanism provides automatic protection without requiring additional actuators or complex control systems, as the pivoting action is driven by the natural removal motion of the puncture device

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The protection element with its pivotable shielding legs is nested within the housing structure, utilizing the existing spatial arrangement of the puncture device. The connection portion of the protection element attaches to the puncture trocar, integrating the protective function into the existing device architecture rather than adding separate external components

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4044944B1Cannula device
Publication Date: 2025.09.24 FRESENIUS KABI DEUTSCHLAND GMBH
  • EP4044944B1 patent drawingFigure 1
  • EP4044944B1 patent drawingFigure 2~4
  • EP4044944B1 patent drawingFigure 5~6

AI summary

A cannula device (1) comprises a housing (11), a cannula (10) arranged on the housing (11), and a puncture device (17) which, in a use state, is arranged on the housing (11) and comprises a puncture trocar (18) received in the cannula (10). The puncture trocar (18) is displaceable with respect to the cannula (10) and comprises a trocar tip (180) which, by displacing the puncture trocar (18) with respect to the cannula (10) in a puncturing direction (P), is movable to protrude from the cannula (10) in said puncturing direction (P), wherein the puncture device (17) is removable from the housing (11) in a removal direction (A) opposite the puncturing direction (P). A protection element (15) is received in the housing (11) and comprises a connection portion (150) arranged on the puncture trocar (18) and at least one shielding leg (152, 153) pivotably connected to the connection portion (150), wherein the puncture trocar (18) is configured to carry the protection element (15) along when the puncture trocar (18) is removed from the housing (11) in said removal direction (A), the at least one shielding leg (152, 153) being configured to be pivotably moved with respect to the connection portion (150) to approach the trocar tip (180) when the protection element (15) is carried along by the puncture trocar (18).