Charged Membrane Urea Separation in Regenerative Dialysis

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Solution Overview

Problem

Existing dialysis systems face challenges in efficiently removing urea from blood without producing toxic byproducts, which can contaminate the dialysis fluid and require costly sorbents for removal.

Innovation Solution

A regenerative dialysis fluid system using a charged membrane to separate urea from the dialysis fluid circuit, allowing urea to be filtered into a secondary fluid circuit where it can be safely removed, thereby preventing toxic byproducts from entering the dialysis fluid.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If urea is removed from dialysis fluid using conventional methods, then urea clearance is achieved, but toxic byproducts are generated and dialysis fluid constituents are depleted

Engineering Contradiction:

Improveurea clearanceVSAvoidtoxic byproducts

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system divides the urea removal process into two separate circuits: a dialysis fluid circuit and a secondary fluid circuit. The charged membrane separates these circuits, allowing urea to be removed from the dialysis fluid into the secondary circuit where it can be safely degraded without contaminating the dialysis fluid with toxic byproducts.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The charged membrane acts as an intermediary barrier that selectively transports urea from the dialysis fluid circuit to the secondary fluid circuit while blocking charged dialysis fluid constituents. This intermediary structure enables urea removal while preventing the contamination of the dialysis fluid with toxic byproducts.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If sorbents are used to bind toxic end products, then urea removal is achieved, but system complexity and cost increase

Engineering Contradiction:

Improveurea removalVSAvoidsystem complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/chemical sorbent-based urea removal system with an electrostatic field-based system using a charged membrane. This substitution eliminates the need for complex sorbent materials and associated binding mechanisms, simplifying the overall system while maintaining effective urea removal.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of substance

If dialysis fluid is reused, then resource efficiency is improved, but accumulation of toxic byproducts occurs

Engineering Contradiction:

Improveresource efficiencyVSAvoidtoxic byproduct accumulation

Core Design Contradiction:

Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The charged membrane continuously extracts urea from the dialysis fluid circuit and transfers it to the secondary fluid circuit. This extraction process prevents urea accumulation in the dialysis fluid, enabling safe reuse of the dialysis fluid without toxic byproduct buildup.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The charged membrane serves as an intermediary that facilitates the continuous removal of urea from the dialysis fluid circuit while maintaining the integrity of the dialysis fluid composition. This intermediary function enables prolonged reuse of dialysis fluid without contamination.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 approach effectively reduces the risk of toxic byproducts in the dialysis fluid, extends the life of the dialysis fluid by preventing depletion of constituents, and allows for multiple treatments without the need for frequent component replacement.

Implementation Method 1

The charged membrane of the present disclosure uses the principles of electrostatic repulsion and/or size exclusion to separate urea from used dialysis fluid. The charged membrane may include a negative charge to prevent negative ions from penetrating the membrane and/or a positive charge to prevent positive ions from penetrating the membrane.

Methodology Applied

Scientific EffectElectrostatic repulsion: Ion Repulsion/Attraction

Implementation Method 2

These types of dialysis treatment rely on diffusion of urea across a membrane and/or enzymatic degradation of urea.

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 3

The charged membrane of the present disclosure uses the principles of electrostatic repulsion and/or size exclusion to separate urea from used dialysis fluid.

Methodology Applied

Scientific EffectSize exclusion: Molecular Sieve

Data Source

PatentUS20250177623A1Methods and apparatuses using urea permselective diffusion through charged membranes

Publication Date: 2025.06.05 BAXTER INT INC

AI summary

Systems and apparatuses for regenerating used dialysis fluid are described herein. In an embodiment, a regenerative dialysis fluid system includes a dialysis unit configured to generate used dialysis fluid including urea and a urea separation unit configured to separate at least a portion of the urea from the used dialysis fluid into a secondary fluid. The urea separation unit includes a membrane separating a dialysis fluid chamber from a urea chamber. The membrane includes at least one of a positive charge to prevent positive ions from transporting across the membrane and a negative charge to prevent negative ions from transporting across the membrane.