Air Elimination Assembly Using Negative Pressure

Solution Overview

Problem

Infusion pumps face challenges in preventing air embolism during infusion therapy, leading to delays in life-sustaining drug delivery, potential contamination, and 'alarm fatigue' due to frequent false alarms from bubble detectors, which are triggered by air bubbles in the liquid path.

Innovation Solution

An air elimination assembly using negative pressure and a hydrophobic membrane to actively remove air from the liquid path, ensuring that the liquid delivered is substantially void of gases, thereby preventing air embolism and reducing false alarms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bubble detectors are used to sense air in the liquid path, then air embolism is prevented, but infusion delivery is delayed and alarm fatigue occurs

Engineering Contradiction:

Improveprevention of air embolismVSAvoiddelay in infusion delivery

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary air removal by applying negative pressure to collapse bubbles before they can travel to the patient. The collapse chamber with its hydrophobic membrane and negative pressure actively draws out and collapses air bubbles upstream, preventing them from reaching the infusion line and triggering false alarms, thus eliminating the need to stop infusion for air purging

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system extracts air bubbles from the liquid path by applying negative pressure through the collapse chamber. The hydrophobic membrane selectively allows air to be drawn out while preventing liquid loss, separating the harmful air phase from the therapeutic liquid phase before infusion delivery

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If bubble detectors are used to sense air in the liquid path, then air embolism is prevented, but connection site contamination and infection risk increase

Engineering Contradiction:

Improveprevention of air embolismVSAvoidconnection site contamination and infection risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary air removal by applying negative pressure to collapse bubbles before they can travel to the patient. The collapse chamber with its hydrophobic membrane and negative pressure actively draws out and collapses air bubbles upstream, preventing them from reaching the infusion line and triggering false alarms, thus eliminating the need to stop infusion for air purging

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system extracts air bubbles from the liquid path by applying negative pressure through the collapse chamber. The hydrophobic membrane selectively allows air to be drawn out while preventing liquid loss, separating the harmful air phase from the therapeutic liquid phase before infusion delivery

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If low thresholds for bubble detectors are set, then air embolism risk is reduced, but false alarms and alarm fatigue increase

Engineering Contradiction:

Improveair embolism risk reductionVSAvoidalarm reliability and clinician attention

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The system performs preliminary air removal by applying negative pressure to collapse bubbles before they can travel to the patient. The collapse chamber with its hydrophobic membrane and negative pressure actively draws out and collapses air bubbles upstream, preventing them from reaching the infusion line and triggering false alarms, thus eliminating the need to stop infusion for air purging

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system extracts air bubbles from the liquid path by applying negative pressure through the collapse chamber. The hydrophobic membrane selectively allows air to be drawn out while preventing liquid loss, separating the harmful air phase from the therapeutic liquid phase before infusion delivery

Inventive Principle:

Principle #2Taking out (Extraction)

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 air elimination assembly effectively removes air from the liquid path, preventing air embolism, reducing delays in therapy, and minimizing false alarms, thus enhancing the reliability and safety of infusion pumps.

Implementation Method 1

a hydrophobic (or oleophobic) vent membrane

Methodology Applied

Scientific EffectHydrophobic membrane effect: Hydrophobe

Implementation Method 2

removal of air entrained in a liquid flow path by use of negative gauge pressure applied on the air side of a hydrophobic (or oleophobic) vent membrane

Methodology Applied

Scientific EffectNegative pressure suction: Suction

Data Source

PatentUS20230126860A1Pressure-assisted air elimination

Publication Date: 2023.04.27 FRESENIUS KABI USA LLC

AI summary

A liquid delivery system includes an air elimination assembly disposed in a pathway between a liquid source and a recipient. As its name suggests, the air elimination assembly removes gas from the liquid as it flows between an input port and output port of the air elimination assembly. A magnitude of pressure at the gas output port of the air elimination assembly is controlled to expel gas from the liquid passing from the input port to the output port. The gas expelled from the liquid is outputted from the gas output port. The liquid delivered to the recipient is void of any gases.