Dual Check Valve Gap Staging for Backflow and Grit Control

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Solution Overview

Problem

Existing IV check valves are susceptible to grit lodging, leading to leaks and backflows when reverse flow is applied, rendering them useless, and current infusion pumps are not reliable, cost-effective, or quiet enough.

Innovation Solution

A dual check valve system with an upper housing, intermediate housing, and lower housing, featuring first and second disks that selectively contact valve seats to create distinct gaps for fluid flow and backflow prevention, ensuring the first gap is smaller than the second gap to prevent particulate lodging and leaks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the gap between the disk and the seat of the inlet port is made smaller to prevent grit lodging, then the reliability of the valve is improved, but the flow rate capability is reduced

Engineering Contradiction:
Improvevalve sealing reliabilityVSAvoidfluid flow rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The single valve is segmented into two separate check valves with distinct functions: the first check valve has a smaller gap optimized for preventing grit lodging and ensuring reliable sealing, while the second check valve has a larger gap optimized for maintaining adequate fluid flow rate. This segmentation allows each valve to specialize in one function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-dimension solution (one valve with compromise gap size) to a two-dimension solution (two valves in series with different gap sizes). By adding the dimensional aspect of having multiple valves with differentiated characteristics, the system can simultaneously achieve both small gap for reliability and large gap for flow rate capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If a single check valve is used to maintain normal flow, then the device complexity is reduced, but the valve becomes susceptible to grit lodging causing leaks and backflows

Engineering Contradiction:
Improvevalve structure complexityVSAvoidvalve performance under reverse flow
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single check valve is segmented into two separate check valves with distinct functions: the first check valve handles normal forward flow with a smaller gap to prevent grit lodging, while the second check valve handles reverse flow prevention with a larger gap. This segmentation allows each valve to specialize in one function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first check valve acts as an intermediary that filters out grit and particulates before they can reach the second check valve. By placing this protective element in the flow path, the system prevents grit from lodging in the second valve's larger gap, thereby maintaining reliability without requiring complex additional filtering mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the gap between the disk and the seat is increased to improve fluid flow, then the productivity is improved, but the valve becomes more susceptible to grit lodging

Engineering Contradiction:
Improvefluid flow rateVSAvoidresistance to grit lodging
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The single valve is segmented into two separate check valves with distinct functions: the first check valve has a smaller gap optimized for preventing grit lodging and ensuring reliable sealing, while the second check valve has a larger gap optimized for maintaining adequate fluid flow rate. This segmentation allows each valve to specialize in one function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-dimension solution (one valve with compromise gap size) to a two-dimension solution (two valves in series with different gap sizes). By adding the dimensional aspect of having multiple valves with differentiated characteristics, the system can simultaneously achieve both small gap for reliability and large gap for flow rate capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 dual check valve system effectively prevents backflow and particulate lodging, ensuring reliable and efficient fluid delivery while being more cost-effective and quieter than existing systems.

Implementation Method 1

when the fluid flows through the IV set, the flow pressure from the fluid movement deflects the disk and creates a gap between the disk and the seat of the inlet port allowing the fluid to flow through the check valve

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

the first disk deflects away from the first valve seat to create a first gap between an upper surface of the first disk and the first valve seat

Methodology Applied
Scientific EffectElastic deformation: Deformation

Implementation Method 3

when there is no movement of fluid, the disk in the chamber sits against the seat of the inlet port so that the check valve is sealed

Methodology Applied
Scientific EffectSealing:

Data Source

PatentEP4108288A1Dual check valve
Publication Date: 2022.12.28 CAREFUSION 303 INC
  • EP4108288A1 patent drawingFigure 1
  • EP4108288A1 patent drawingFigure 2
  • EP4108288A1 patent drawingFigure 3

AI summary

A dual check valve includes an upper housing, an intermediate housing, and a lower housing, and a first valve seat. The intermediate housing is coupled to the upper housing to define a first cavity, and includes a second valve seat. The lower housing is coupled to the intermediate housing to define a second cavity. A first disk is mounted in the first cavity and configured to selectively contact the first valve seat. A second disk is mounted in the second cavity and configured to selectively contact the second valve seat. When the dual check valve is in an open state, the first disk deflects away from the first valve seat to create a first gap, and the second disk deflects away from the second valve seat to create a second. The first gap is smaller than the second gap.