Medical Inflation Device Plunger Coupling Mechanism

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Solution Overview

Problem

Existing medical devices for inflating balloons in procedures like angioplasty and valvuloplasty face challenges in efficiently generating and controlling high fluid pressure, particularly in coupling and decoupling plungers to syringe bodies, which affects the precision and ease of fluid displacement.

Innovation Solution

The design involves a handle that rotates to selectively couple and decouple a plunger to a syringe body through threaded mechanisms, allowing for precise control over fluid displacement by altering the engagement of plunger threads with internal nut threads, enabling both quick fluid displacement and locking the plunger in place to manage high pressures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a plunger is manually pushed to displace fluid in a syringe body, then fluid displacement can be achieved, but it requires excessive manual effort and cannot efficiently generate high fluid pressure

Engineering Contradiction:
Improvefluid pressure generation capabilityVSAvoidmanual effort required
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

The patent employs a mechanical advantage system using a lever arm and fulcrum to amplify the user's manual input force, transforming it into high fluid pressure through hydraulic principles. The force applied to the lever arm is mechanically amplified to generate sufficient pressure to advance the plunger against high resistance in the syringe body, eliminating the need for excessive direct manual pushing effort.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Reliability

If the plunger is securely coupled to the syringe body to maintain position under high pressure, then pressure stability is improved, but the device complexity increases due to coupling and decoupling mechanisms

Engineering Contradiction:
Improvepressure stabilityVSAvoidcoupling mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent utilizes a dynamic coupling mechanism where the plunger's engagement with the syringe body can be selectively changed between coupled and decoupled states. The lever arm system provides a mechanical locking effect during the coupled state to maintain pressure stability, while allowing easy decoupling when needed. This dynamic state change capability enables both reliable pressure maintenance and operational flexibility without excessive complexity.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the plunger is decoupled from the syringe body to release pressure, then pressure control is improved, but the time required for pressure adjustment increases

Engineering Contradiction:
Improvepressure control capabilityVSAvoidpressure adjustment time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent incorporates a pre-positioned lever arm system that is ready to be actuated for quick pressure release. The mechanical advantage system is pre-configured so that a simple lever movement can rapidly decouple the plunger from the syringe body, enabling fast pressure adjustment without requiring complex multi-step operations or significant time investment.

Inventive Principle:
Principle #10Preliminary action

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 solution provides a method for efficiently inflating medical devices by allowing precise control over fluid pressure and displacement, facilitating procedures like angioplasty and valvuloplasty with reduced manual effort, even under high pressure conditions.

Implementation Method 1

The inflation device includes a handle selectively coupleable to a plunger. Rotation of the handle from a first position to a second position about a longitudinal axis of the plunger causes the plunger to be longitudinally displaced with respect to the syringe body.

Methodology Applied
Scientific EffectScrew mechanism: Screw

Data Source

PatentEP2897680B1Inflation devices and methods of use thereof
Publication Date: 2019.12.18 MERIT MEDICAL SYSTEMS INC
  • EP2897680B1 patent drawingFigure 1A
  • EP2897680B1 patent drawingFigure 1B
  • EP2897680B1 patent drawingFigure 2A~2B

AI summary

Inflation devices and methods to inflate medical devices are disclosed. Certain embodiments enable the selective coupling of a plunger to a syringe body through manipulation of a handle. Other embodiments facilitate the generation of relatively high fluid pressures through inflation device designs that incorporate multiple plungers.