Micro-valve Membrane Stiffening for Infusion Flow Control

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Solution Overview

Problem

Existing micro-pumps for therapeutic product infusion systems face challenges with filling efficiency and uncontrolled flow due to pressure dependencies and complex assembly processes, particularly in the design of one-way check-valves, which are prone to leaking and assembly issues.

Innovation Solution

A one-way valve design featuring a membrane with a stiffened outer peripheral portion, restricted to deflect only over a valve seat, allowing precise control of activation pressure and alignment, combined with a rigid frame and distinct material composition for the inner and outer membrane portions, to ensure consistent and accurate operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a one-way check-valve is used in a micro-pump for infusion systems, then uncontrolled flow can be prevented, but the filling efficiency is affected by outlet pressure and the valve is prone to leaking

Engineering Contradiction:
Improveflow control reliabilityVSAvoidfilling efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The membrane is designed with non-uniform thickness, having a first thickness in the central region and a second thickness in the peripheral region. This local quality variation allows the central region to be more compliant for efficient filling while the peripheral region provides structural support to prevent uncontrolled flow and leaking

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the physical parameter of membrane thickness to create different mechanical properties in different regions. By controlling the thickness ratio between central and peripheral regions, the valve achieves optimal balance between filling efficiency and flow control reliability

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the activation pressure of the inlet valve is increased to prevent leaking, then uncontrolled flow is reduced, but pumping efficiency is compromised

Engineering Contradiction:
Improvevalve sealing reliabilityVSAvoidpumping efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The membrane's non-uniform thickness creates local quality differences where the thinner central region opens at lower pressure for efficient pumping, while the thicker peripheral region maintains sealing at higher pressures to prevent leaking

Inventive Principle:
Principle #3Local quality

3Reliability

If a rubber membrane is glued to rigid layers during assembly, then the membrane is held in place and sealing is provided, but the manufacturing complexity increases and assembly problems occur

Engineering Contradiction:
Improvesealing reliabilityVSAvoidassembly simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the glue layer from the assembly process. The membrane is retained in position and sealing is achieved through its own structural design (non-uniform thickness and elasticity) rather than through adhesive bonding, significantly simplifying manufacturing

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The membrane structure itself provides the retention and sealing functions that previously required external adhesive. The elastic material and thickness distribution enable the membrane to self-retain in the valve assembly without additional bonding materials

Inventive Principle:
Principle #25Self-service

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 solution provides a micro-valve with accurately defined activation pressure, reduced complexity in manufacturing, and improved sealing, enabling efficient and controlled fluid flow while preventing uncontrolled therapeutic product delivery, suitable for disposable and variable-sized applications.

Implementation Method 1

increases the pressure differential across the inlet valve to beyond a predetermined activation pressure of the inlet valve which opens in response

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

a membrane with a stiffened outer peripheral portion, restricted to deflect only over a valve seat

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the stiffening of the outer peripheral membrane portion relative to the inner membrane portion is effected by a rigid frame embedded therein

Methodology Applied
Scientific EffectStructural stiffening:

Data Source

PatentEP2077888B1Micro-valve
Publication Date: 2015.12.09 CELLNOVO LIMITED
  • EP2077888B1 patent drawingFigure 1~3
  • EP2077888B1 patent drawingFigure 4

AI summary

A one-way valve (1 ) comprises a seat (5) and a membrane (4) having an inner portion (4a) that is stretched over the seat, wherein, in use, the inner membrane portion is selectively deflected from the seat such that a fluid path is created from one side of the membrane to the other so as to open the valve, and wherein an outer peripheral portion (4b) of the membrane is stiffer than the inner portion such that the membrane deflection is substantially restricted to only the inner portion. The one-way valve may be used in a pump for an infusion system.