Artificial Lung Hollow Fiber Membrane Design for Gas Exchange

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing artificial lungs face challenges in achieving high gas exchange and heat exchange performance while minimizing blood filling amount and blood side pressure loss, with previous improvements made to individual elements independently rather than in conjunction.

Innovation Solution

The design and evaluation method for artificial lungs involves measuring gas exchange performance, heat exchange performance coefficient, and blood side pressure loss, and calculating performance factors such as Fp, Fp3, and Fp4 to unify the evaluation of different types and structures, ensuring optimal performance by balancing these factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the surface area of the gas exchanging hollow fiber membrane or the heat exchanging element is reduced to minimize blood filling amount, then the blood filling amount is reduced, but the gas exchange performance and heat exchange performance are deteriorated

Engineering Contradiction:
Improveblood filling amountVSAvoidgas exchange performance
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent applies parameter changes by optimizing the inner diameter, outer diameter, and length of the hollow fiber membrane to achieve high gas exchange performance with reduced surface area. Specifically, the membrane has an inner diameter of 0.15-0.25mm, outer diameter of 0.20-0.30mm, and length of 100-200mm, which allows efficient gas exchange with minimal blood filling amount.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by creating uneven thickness distribution in the hollow fiber membrane, with the thickness being 10-20μm at the inner circumference and 5-15μm at the outer circumference. This non-uniform thickness optimization enhances gas exchange performance while maintaining reduced surface area and blood filling amount.

Inventive Principle:
Principle #3Local quality

2Productivity

If the gas exchanging hollow fiber membrane is densely installed to acquire high performance through small surface area, then the gas exchange performance is improved, but the blood side pressure loss increases and damage to blood cells occurs

Engineering Contradiction:
Improvegas exchange performanceVSAvoidblood side pressure loss
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent optimizes the membrane parameters (inner diameter 0.15-0.25mm, outer diameter 0.20-0.30mm, length 100-200mm) to achieve high gas exchange performance without requiring dense installation. The optimized parameters allow sufficient gas exchange area while maintaining low blood side pressure loss and preventing blood cell damage.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The uneven thickness distribution (10-20μm inner, 5-15μm outer) creates optimal local flow characteristics that reduce turbulence and pressure loss while maintaining high gas exchange efficiency, allowing the membrane to be installed without excessive density.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If the surface area of the heat exchanging element is reduced to minimize blood filling amount, then the blood filling amount is reduced, but the heat exchange performance is deteriorated

Engineering Contradiction:
Improveblood filling amountVSAvoidheat exchange performance
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent optimizes the heat exchanging element parameters (outer diameter 2-5mm, length 50-150mm) to achieve high heat exchange performance with reduced surface area and minimal blood filling amount. The optimized dimensions allow efficient heat transfer without requiring large surface area.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If various elements of the artificial lung are improved independently rather than in conjunction, then individual element performance is enhanced, but the overall system performance cannot be uniformly evaluated and compared

Engineering Contradiction:
Improveindividual element performanceVSAvoidsystem evaluation capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent establishes a universal evaluation system that can assess different types and structures of artificial lungs using standardized performance factors. The system measures gas exchange performance, heat exchange performance coefficient, blood filling amount, and blood side pressure loss, then calculates comprehensive performance factors (Fp, Fp3, Fp4) that enable uniform comparison across diverse artificial lung designs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 method allows for the general evaluation and comparison of artificial lungs, achieving high performance across various types and structures, with Fp values ranging from 1.5 to 2.5 and Fp3/Fp4 values indicating excellent performance, thus optimizing the design and operation of artificial lungs.

Implementation Method 1

an external circulation-type gas exchanging hollow fiber membrane bundle

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

a wound heat exchanger portion that is provided with a heat exchanging element comprised of a resin tube

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 3

heat exchange performance coefficient of the artificial lung

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3202438B1Artificial lung and artificial heart-lung circuit device
Publication Date: 2019.10.23 TERUMO KK
  • EP3202438B1 patent drawingFigure 1A~1B
  • EP3202438B1 patent drawingFigure 2
  • EP3202438B1 patent drawing

AI summary

The present invention is an invention that aims to provide a technology of designing and evaluating an artificial lung in which performance of each of elements of the artificial lung can be uniformly examined and a generally excellent performance can be exhibited. The present invention provides an artificial lung including a gas exchanger portion that is provided with an external circulation-type gas exchanging hollow fiber membrane bundle and a heat exchanger portion that is provided with a heat exchanging element. A heat exchange performance coefficient of the artificial lung, a blood filling amount of the artificial lung, and a blood side pressure loss of the artificial lung are measured, and when Fp3=heat exchange performance coefficient of artificial lung/(blood filling amount of artificial lungxblood side pressure loss of artificial lung) is calculated, a value of Fp3 is equal to or greater than 0.15.