Microfluidic Dialysis Device with Pressurizing Feature for Solute Clearance

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Solution Overview

Problem

Conventional dialysis devices face challenges in increasing convective clearance of solutes within a compact design, leading to reduced patient mobility due to larger device sizes required for enhanced clearance.

Innovation Solution

A microfluidic device with a network of channels separated by a permeable membrane, featuring a pressurizing feature that creates a non-linear pressure profile along the channels, allowing for increased convective transport of solutes by maintaining a high pressure upstream and low pressure downstream, thereby enhancing solute clearance without increasing device size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the length of channels is increased to enhance convective clearance, then solute clearance is improved, but device size increases leading to reduced patient mobility

Engineering Contradiction:
Improvesolute clearanceVSAvoiddevice size
Core Design Contradiction:
ProductivityVSVolume of moving object

Solution Approach 1:

The patent applies parameter changes by modifying the pressure distribution along the channel length. Instead of uniform pressure, a non-linear pressure profile is created with higher pressure at the inlet and lower pressure at the outlet, increasing the transmembrane pressure gradient and thus enhancing convective clearance without extending channel length.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a vertical dimension to the pressure profile by creating different pressure levels at different heights within the channel. The pressurizing feature generates elevated pressure in the upper portion of the channel, adding a vertical pressure gradient component that enhances solute transport across the membrane without increasing horizontal channel length.

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

2Productivity

If channel dimensions are increased to improve flow and clearance, then convective transport is enhanced, but device complexity and size increase

Engineering Contradiction:
Improveconvective transportVSAvoidchannel structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating localized high-pressure zones within specific regions of the channel using pressurizing features. Instead of uniformly increasing channel dimensions throughout, the pressure is concentrated in specific local areas to enhance clearance where most needed, maintaining simple overall channel geometry.

Inventive Principle:
Principle #3Local quality

3Productivity

If transmembrane pressure is increased uniformly along channels to enhance clearance, then solute removal is improved, but device size and complexity increase

Engineering Contradiction:
Improvesolute removalVSAvoidchannel length
Core Design Contradiction:
ProductivityVSLength of stationary object

Solution Approach 1:

The patent transforms the pressure parameter from a uniform distribution to a non-linear distribution along the channel. By implementing a pressure profile that decreases from inlet to outlet, the system achieves enhanced average transmembrane pressure and convective clearance without extending the channel length.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent adds a vertical dimension to pressure distribution within the channel cross-section. Pressurizing features create elevated pressure in the upper channel region, generating a vertical pressure gradient that enhances solute transport across the membrane without increasing the horizontal footprint or length of the device.

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 microfluidic device effectively increases convective transport of solutes, maintaining a pressure gradient across the membrane to enhance solute clearance, while maintaining a compact device size, thus improving patient mobility.

Implementation Method 1

a non-linear pressure profile exists along the length of the at least one Second Channel and a pressure gradient exists across the membrane separating the one or more First Channels from the at least one complimentary Second Channel

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

The pressurizing feature can include a partial wall configured to restrict fluid flow in the at least one Second Channel, yielding the high pressure at an upstream portion of the at least one Second Channel and the low pressure at a downstream portion

Methodology Applied
Scientific EffectFluid flow restriction: Pressure Drop

Implementation Method 3

Convective clearance of solutes from blood in the device is determined by the transmembrane pressure in the device

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

a filtration membrane separating the one or more First Channels from the at least one Second Channel

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 5

a pressure gradient exists across the membrane separating the one or more First Channels from the at least one complimentary Second Channel

Methodology Applied
Scientific EffectPressure gradient driven filtration: Pressure Gradient

Data Source

PatentEP2943282B1Systems and methods for increasing convective clearance of undesired particles in a microfluidic device
Publication Date: 2017.11.08 THE CHARLES STARK DRAPER LABORATORY INC
  • EP2943282B1 patent drawingFigure 1A
  • EP2943282B1 patent drawingFigure 1B
  • EP2943282B1 patent drawingFigure 2~3

AI summary

A microfluidic device for increasing convective clearance of particles from a liquid is provided. A network of first channels can be separated from a network of second channels by a membrane. The network of second channels can include a pressurizing feature to create a high pressure at an upstream portion of the second channels and a low pressure at a downstream portion of the second channels. Liquid containing an analyte can be introduced in the network of first channels. Filtrate can be flowed through the pressurizing feature in the second channels, such that the pressure difference in between the first and second channels causes at least some of the analyte in the first liquid is transported into the second channels through the membrane.