Liquid Administration Device Cover Member Movement Restriction

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Solution Overview

Problem

Existing liquid administration devices face challenges in maintaining operability and safety, particularly when the pressing force is weakened during administration, leading to potential needle tube exposure and interruption of the administration process.

Innovation Solution

A liquid administration device with a cover member that can expose the needle tube while being restricted by a movement amount restriction unit, allowing for resumed administration without premature exposure, ensuring safety and operability by preventing the cover member from moving to the exposure position until the administration is complete.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cover member is biased by a spring to cover the needle tube after administration, then safety is enhanced by preventing erroneous puncturing, but the needle tube may be covered during administration if pressing force is weakened, making it difficult to continue administration

Engineering Contradiction:
ImprovesafetyVSAvoidoperability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cover member is designed to be movable between a retracted state (during administration) and a covering state (after administration) through spring biasing. The dynamic positioning allows the cover member to adapt to different operational phases, being pushed forward during administration and automatically retracting when pressing force is released, thus maintaining both safety and operability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring constant and pre-compression force are carefully selected to create a threshold effect: normal pressing force during administration overcomes the spring bias to keep the cover member retracted, while release of pressing force allows the spring to push the cover member forward. This parameter optimization ensures the cover member responds appropriately to operational states without interfering with administration

Inventive Principle:
Principle #35Parameter changes

2Reliability

If an exposure restriction unit is provided to restrict movement of the cover member, then the needle tube is covered after administration, but the exposure restriction unit operates prematurely if pressing force is weakened during administration, preventing continuation of administration

Engineering Contradiction:
ImprovesafetyVSAvoidadministration continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The exposure restriction unit incorporates a movable cover member that transitions between states based on operational phase. During administration, the cover member is dynamically positioned in a retracted state allowing needle exposure. After administration completes and pressing force releases, the cover member dynamically moves to the covering state, activating the exposure restriction function at the appropriate time

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring-biased cover member system provides mechanical feedback about the administration state. The position of the cover member reflects whether pressing force is being applied, creating a feedback mechanism that prevents premature operation of the exposure restriction unit during administration while enabling it after administration completes

Inventive Principle:
Principle #23Feedback

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 ensures safety by preventing needle tube exposure during administration and allows for resumed operation even if the administration is suspended, enhancing user experience and preventing wastage of medication.

Implementation Method 1

a second coil spring which biases the cover member in a distal direction

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP2918299B1Liquid administration device
Publication Date: 2021.09.29 TERUMO KK
  • EP2918299B1 patent drawingFigure 1
  • EP2918299B1 patent drawingFigure 2
  • EP2918299B1 patent drawingFigure 3

AI summary

[Problem] Provided is a liquid administration device with which it is possible to improve operability while securing safety by providing a cover member that covers a needle tube in a manner in which the needle tube can be exposed, and to resume administration even if the administration operation is suspended in the middle of the administration. [Means for Resolution] Provided is a liquid administration device 10 including: an operation unit 20; a structure 40 which includes a syringe 60 and a needle tube 66; a cover member 30 movable between a protection position at which the needle tube 66 is covered, and an exposure position from which the needle tube is exposed; a second coil spring 11 which biases the cover member 30 in a distal direction; an exposure restriction unit E which restricts movement of the cover member 30 to the exposure position when the movement amount of the cover member 30, which moves from the exposure position to the protection position, with respect to the structure 40 reaches a predetermined exposure restriction operation amount; and a movement amount restriction unit 95 which restricts the movement amount of the cover member 30 such that the movement amount of the cover member 30 with respect to the structure 40 does not reach the exposure restriction operation amount until the movement amount of the operation unit 20 with respect to the structure 40 reaches a predetermined movement amount for completion of the administration.