Microfluidic Manifold for Shear-Sensitive Blood Transport

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Solution Overview

Problem

Microfluidic medical devices face challenges in distributing blood to non-coplanar processing channels, as traditional methods like plenums require large priming volumes and lack control over flow distribution, while single planar manifolds cannot handle non-coplanar channels effectively.

Innovation Solution

A microfluidic device with multiple manifold channels configured to carry blood at varying wall shear rates, including a transition region with specific cross-sectional shapes and mathematical functions to control shear rate gradients, ensuring safe ranges for blood health and efficient flow distribution to non-coplanar channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a plenum is used to distribute blood to non-coplanar processing channels, then flow distribution to multiple channels is achieved, but the device requires large priming volumes and lacks control over flow distribution to individual conduits

Engineering Contradiction:
Improveflow distribution controlVSAvoidpriming volume
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The manifold is segmented into multiple separate channels (first manifold channel, second manifold channel, third manifold channel) instead of using a single plenum chamber. Each channel can be independently configured to deliver blood to non-coplanar processing channels with controlled flow rates, eliminating the need for large priming volumes while maintaining flow distribution control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The manifold channels are configured in three-dimensional space to reach non-coplanar processing channels. The channels extend in different spatial dimensions (x, y, z) to connect to processing channels that are not in the same plane, enabling flow distribution to non-coplanar channels without requiring a large plenum volume.

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

2Adaptability or versatility

If a single planar manifold is used to distribute blood, then the structure is simple, but it is incapable of distributing blood to non-coplanar processing channels

Engineering Contradiction:
Improvecapability to distribute to non-coplanar channelsVSAvoidmanifold structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The manifold transitions from a two-dimensional planar structure to a three-dimensional configuration. Multiple manifold channels are arranged in three-dimensional space with different orientations and positions, allowing them to connect to non-coplanar processing channels while maintaining a relatively simple overall structure.

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

Solution Approach 2:

Different regions of the manifold have different local configurations optimized for their specific functions. Each manifold channel can have different cross-sectional areas, lengths, and orientations tailored to deliver blood to specific non-coplanar processing channels with appropriate flow rates and shear rates.

Inventive Principle:
Principle #3Local quality

3Reliability

If high wall shear rates are used in manifold channels to maintain blood health, then clot formation is prevented, but the shear rate may be excessive for certain processing channels

Engineering Contradiction:
Improveblood health maintenanceVSAvoidexcessive shear rate damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Different manifold channels are configured with different cross-sectional areas and flow rates to provide locally optimized wall shear rates. The first manifold channel can maintain higher shear rates (4500-10000 s⁻¹) for blood health, while transition regions and downstream channels (second and third manifold channels) reduce shear rates to appropriate levels (100-800 s⁻¹) for specific processing channel requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The manifold channels incorporate transition regions where geometric parameters (cross-sectional area, length) are varied to control the wall shear rate profile. By adjusting these parameters, the shear rate can be transformed from higher values in upstream channels to lower values in downstream channels, preventing both clot formation and excessive shear damage.

Inventive Principle:
Principle #35Parameter changes

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 device effectively maintains healthy wall shear rates and flow properties, preventing clot formation and inflammation, while reducing priming volume and enabling efficient blood processing in non-coplanar channels.

Implementation Method 1

The first manifold channel is further configured to carry blood at a first wall shear rate. The second manifold channel is further configured to carry blood at a second wall shear rate, lower than the first wall shear rate.

Methodology Applied
Scientific EffectWall shear rate control: Shear Stress

Implementation Method 2

A transition region can be configured to change the wall shear rate experienced by blood transported through the at least one channel such that the wall shear rate experienced by blood upstream from the transition region is lower than a wall shear rate experienced by blood downstream from the transition region.

Methodology Applied
Scientific EffectShear rate gradient control: Shear Stress

Data Source

PatentEP3107597B1Microfluidic manifold for shear sensitive fluids
Publication Date: 2018.12.05 THE CHARLES STARK DRAPER LABORATORY INC
  • EP3107597B1 patent drawingFigure 1
  • EP3107597B1 patent drawingFigure 2A
  • EP3107597B1 patent drawingFigure 2B

AI summary

A microfluidic device is provided. A manifold having a first channel, a second channel, and a third channel configured to transport blood can be coupled to a substrate defining an artificial vasculature. The first channel can be configured to carry blood in a first direction. Each of the second and third channels can couple to the first channel at a first junction and can be configured to receive blood from the first channel. The second channel can be configured to carry blood in a second direction away from the first direction. The third channel can be configured to carry blood in a third direction away from the second direction. The first, second, and third channels can be non-coplanar.