Dialysis Concentrate Refilling via Concentration Feedback

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Solution Overview

Problem

In dialysis treatments, the existing methods for producing a dialysis solution using a bag with solid sodium bicarbonate result in unnecessary waste as the concentration of the solution drops, leading to premature termination of treatment and discarding of still-useful bicarbonate solution, due to inadequate monitoring and refilling mechanisms.

Innovation Solution

Implementing a method that measures the concentration of the dissolved substance and temporarily or permanently prevents water refilling when the concentration falls below a certain limit, allowing the remaining bicarbonate to be fully utilized and extending the treatment duration by ensuring the solution is used until the bag is empty.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If water refilling is continuously performed based on pressure monitoring, then the bag is kept filled with liquid, but the concentration of bicarbonate solution decreases and waste occurs when concentration falls below critical value

Engineering Contradiction:
Improvebicarbonate solution concentrationVSAvoidbicarbonate waste
Core Design Contradiction:
Quantity of substanceVSLoss of substance

Solution Approach 1:

The system continuously monitors the concentration of bicarbonate in the bag using a measuring device and provides feedback to the control unit. When the concentration falls below a predetermined threshold, the control unit automatically stops the water refilling process, preventing further dilution and waste of bicarbonate. This closed-loop feedback mechanism ensures optimal utilization of the bicarbonate substance.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention changes the control parameter from pressure-based refilling to concentration-based refilling. By monitoring the actual bicarbonate concentration and adjusting the refilling process accordingly, the system prevents dilution beyond usable limits, thereby reducing waste while maintaining adequate fill levels throughout the dialysis treatment.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If treatment is terminated when bicarbonate alarm is triggered, then concentration control is maintained, but treatment duration is reduced and still-filled bag must be discarded

Engineering Contradiction:
Improvedialysis solution qualityVSAvoidtreatment duration
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The continuous concentration monitoring provides real-time feedback that allows the system to detect when bicarbonate levels are sufficient before alarm triggers. This enables proactive adjustment of water refilling to maintain concentration within acceptable ranges, ensuring treatment can continue for the full intended duration without premature termination or alarm conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system takes preliminary action by monitoring concentration trends and adjusting water refilling before the bicarbonate alarm is triggered. By maintaining concentration above critical thresholds through proactive control, the system prevents alarm conditions and ensures continuous treatment throughout the scheduled duration.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If pressure-controlled refilling is used, then water is automatically added when pressure drops, but concentration monitoring and control is insufficient

Engineering Contradiction:
Improveautomatic refilling operationVSAvoidconcentration measurement
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The invention merges pressure-controlled automatic refilling with concentration monitoring and control into a unified system. The control unit integrates both pressure signals (for fill level management) and concentration measurements (for quality control), coordinating water refilling to satisfy both volume and concentration requirements simultaneously.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system combines feedback from both pressure sensors (indicating fill level) and concentration sensors (indicating bicarbonate content). The control unit processes both feedback signals to make intelligent refilling decisions, ensuring that water is added only when both volume and concentration conditions warrant refilling, thereby achieving precise dual-parameter control.

Inventive Principle:
Principle #23Feedback

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 minimizes waste by fully utilizing the bicarbonate solution, allowing continuous dialysis until the bag is empty and potentially avoiding the need for a new bag, thus optimizing resource use and treatment duration.

Implementation Method 1

The conductivity of the produced solution is measured by means of a conductivity measuring device

Methodology Applied
Scientific EffectConductivity measurement: Conduction (electrical)

Data Source

PatentEP2950919B1Method for providing a concentrate
Publication Date: 2019.05.01 FRESENIUS MEDICAL CARE DEUTSCHLAND GMBH
  • EP2950919B1 patent drawingFigure 1
  • EP2950919B1 patent drawingFigure 2
  • EP2950919B1 patent drawingFigure 3

AI summary

The present invention relates to a method for providing at least one concentrate of at least one solute for the production of at least one dialysis solution, the method comprising the following steps: providing at least one container which contains at least one solid to be dissolved; supplying water to the container to dissolve the solid; removing the concentrate of the solute from the container and replenishing with water; measuring the concentration of the solute or of a parameter correlated with the concentration; and temporarily or permanently stopping replenishment with water if the measured concentration value of the solute falls below a first threshold value or the value of the parameter falls below or exceeds a first threshold value or if a change in the concentration value of the solute or in the value of the parameter exceeds a first threshold value.