Microfluidic Heat Exchange for Dialysis Water Purification

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Solution Overview

Problem

Current dialysis systems are too large and energy-inefficient for home use, requiring excessive water and complex, expensive flow-balancing technology, which limits their suitability for home dialysis and results in demanding schedules for patients.

Innovation Solution

A compact, portable dialysis system utilizing a microfluidic heat exchange system for on-demand ultrapure water production, reducing energy consumption and water usage, and integrating a water purification subsystem capable of pasteurizing water using a single fluid stream without the need for a secondary fluid.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If current dialysis systems are used, then dialysis treatment can be performed, but the systems are too large and bulky to fit within a typical home

Engineering Contradiction:
Improvesystem sizeVSAvoidhome use suitability
Core Design Contradiction:
Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The dialysis system is divided into separate functional modules including a water purification subsystem, a dialysate preparation subsystem, and a dialyzer unit. This segmentation allows each component to be optimized independently and facilitates compact integration while maintaining full dialysis functionality for home use

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The microfluidic heat exchange system is integrated within the water purification subsystem, with multiple functional elements nested within each other. The heat exchange laminae are stacked and diffusion-bonded to create a compact structure that performs multiple functions in a minimal space, enabling the overall system to fit within a typical home environment

Inventive Principle:
Principle #7Nested doll (Nesting)

2Loss of energy

If current dialysis systems are used, then dialysis treatment can be performed, but they use large amounts of energy and require enormous amounts of water

Engineering Contradiction:
Improveenergy consumptionVSAvoiddialysis treatment capability
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The system performs preliminary purification of water before it enters the main dialysis process, using a compact microfluidic heat exchange system that pre-heats and pre-cools water efficiently. This preliminary action reduces the energy required during the actual dialysis treatment and minimizes water consumption by optimizing the dialysate preparation process

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The microfluidic heat exchange system changes the temperature parameters of water efficiently through controlled heat transfer across thin laminae. By optimizing temperature gradients and residence times, the system achieves effective water purification and heating with minimal energy input, enabling sustainable home dialysis operation

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If home dialysis systems are made compact, then they can be used at home, but they may require complex flow-balancing technology that is expensive to manufacture

Engineering Contradiction:
Improvesystem sizeVSAvoidmanufacturing cost
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The system replaces complex mechanical flow-balancing mechanisms with a microfluidic-based passive flow control design. The heat exchange laminae and diffusion barriers are engineered to naturally regulate fluid flow through pressure differentials and viscosity effects, eliminating the need for expensive solenoid valves and active flow control mechanisms while maintaining compact dimensions

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of operation

If home dialysis systems use solenoid valves for flow control, then flow management is achieved, but high noise levels are created

Engineering Contradiction:
Improveflow control capabilityVSAvoidnoise level
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The system substitutes mechanical solenoid valves with a microfluidic flow control mechanism that uses pressure differentials and viscous flow principles to manage fluid distribution. This non-mechanical approach eliminates the high noise levels associated with solenoid operation while maintaining precise flow control capability necessary for effective home dialysis

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 system provides reliable, efficient, and cost-effective ultrapure water for home dialysis, reducing the size and energy requirements, allowing for flexible scheduling and improved patient convenience while minimizing environmental impact.

Implementation Method 1

a heat exchange system adapted to pasteurize water for use in dialysis

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

The systems described herein use a microfluidics heat exchanger for heating, purifying and cooling water

Methodology Applied
Scientific EffectThermal energy transfer: Conduction (thermal)

Implementation Method 3

The water purification system may employ a heat exchange system adapted to pasteurize water for use in dialysis

Methodology Applied
Scientific EffectPasteurization: Heating

Implementation Method 4

The microfluidic heat exchange system may be formed of a plurality of lamina stacked atop one another and diffusion bounded

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP2763719B1Heat exchange fluid purification for dialysis system
Publication Date: 2017.08.09 OUTSET MEDICAL
  • EP2763719B1 patent drawingFigure 1
  • EP2763719B1 patent drawingFigure 2
  • EP2763719B1 patent drawingFigure 3

AI summary

Disclosed herein are small, lightweight, portable, systems that have the capability of reliably, reproducibly, highly efficiently and relatively inexpensively providing a source of purified water of sufficient volumes for home dialysis. In addition, the systems disclosed herein require much less purified water at any one time than the volumes typically needed for dialysis today, thereby further reducing the expense of running the system at home.