Dialyzer Priming Pressure Control for Membrane Air Removal

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Solution Overview

Problem

Existing dialysis machines lack efficient and automated methods for removing air bubbles from the semipermeable membrane of the dialyzer, posing a risk of air embolism and complicating the priming process.

Innovation Solution

An extracorporeal blood treatment machine with a control unit that alternately sets transmembrane pressures with pressure gradients between the dialysis fluid side and blood side to efficiently remove air bubbles, utilizing pumps and valves to create directed flows and turbulent conditions within the dialyzer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual priming methods are used to remove air bubbles from the dialyzer, then the operator can directly manipulate the dialyzer, but the process requires manual rotation and tapping which is time-consuming and less effective

Engineering Contradiction:
Improvemanual manipulation of dialyzerVSAvoidpriming process duration
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical operations (rotation and tapping) with an automated pressure control system. The control unit automatically adjusts pressure gradients across the semipermeable membrane to create fluid flow that removes air bubbles, eliminating the need for manual manipulation while reducing priming time and improving consistency.

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

2Device complexity

If conventional priming procedures are used, then the process can be performed with simple equipment, but air bubbles cannot be effectively removed from the semipermeable membrane increasing air embolism risk

Engineering Contradiction:
Improvepriming equipment simplicityVSAvoidair bubble removal effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs pressure gradient control across the semipermeable membrane to drive fluid flow that removes air bubbles. By controlling pressure differences between the blood side and dialysate side, the system creates directed flow that effectively evacuates air from the membrane pores, enhancing safety without requiring complex additional equipment.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The control unit dynamically adjusts pressure parameters across the membrane during priming. By varying pressure gradients in controlled sequences, the system optimizes air bubble removal effectiveness while maintaining equipment simplicity and ensuring reliable operation.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the dialyzer is filled on the blood side first as in conventional procedures, then the filling sequence is simple, but manual rotation is required to fill the dialysis fluid side which complicates the process

Engineering Contradiction:
Improvefilling sequence simplicityVSAvoidmanual rotation requirement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical rotation step with automated pressure control. The control unit manages pressure gradients that automatically direct fluid flow to fill both the blood side and dialysis fluid side of the dialyzer in the correct sequence, eliminating manual rotation while maintaining filling simplicity.

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

4Extent of automation

If automated priming is implemented, then the process can be performed without manual intervention, but the system requires complex control mechanisms to manage pressure gradients

Engineering Contradiction:
Improvepriming process automationVSAvoidcontrol system complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The control unit performs multiple functions: it manages pressure gradient establishment, maintains pressure differences across the membrane, controls fluid flow direction, and monitors priming completion. By consolidating these functions in a single control system, the patent achieves high automation while managing complexity through functional integration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 automated priming process effectively removes air bubbles, enhancing safety and efficiency by ensuring a clean dialyzer membrane for optimal blood treatment, reducing the need for manual handling and minimizing patient risk.

Implementation Method 1

it successively or alternately sets a transmembrane pressure with a pressure gradient from the dialysis fluid side to the blood side and from the blood side to the dialysis fluid side in order to remove/drain/promote/flush out air, especially air bubbles, from the semipermeable membrane during priming

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

The dialysis fluid circuit further comprises a dialysis fluid inlet with an inlet valve, a dialysis fluid outlet with a drain valve, and a pump, in particular an ultrafiltration pump

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 3

The principle of dialysis is based on the diffusion process, in which waste products and excess fluids pass through the membrane into a dialysate

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 4

a hollow-fiber dialyzer with a blood side and a dialysate side separated by a semipermeable membrane

Methodology Applied
Scientific EffectSemipermeable membrane: Semipermeable Membrane

Data Source

PatentEP4699627A1Extracorporeal blood treatment machine and method for automatically priming a dialyzer
Publication Date: 2026.02.25 B BRAUN AVITUM
  • EP4699627A1 patent drawingFigure 1~2
  • EP4699627A1 patent drawingFigure 3a~4
  • EP4699627A1 patent drawingFigure 5

AI summary

The disclosure relates to an extracorporeal blood treatment machine with a dialyzer (19) having hollow fibers (2) and a blood side (4) and a dialysis fluid side (6), an extracorporeal blood circuit, and a dialysis fluid circuit. The extracorporeal blood treatment machine has a control unit (48) which is configured and prepared to perform automatic priming of the blood treatment machine such that it successively or alternately sets a transmembrane pressure (10) with a pressure gradient from the dialysis fluid side (6) to the blood side (4) and from the blood side (4) to the dialysis fluid side (6) in order to remove air from the semipermeable membrane (8) during priming.The dialysis fluid circuit comprises a dialysis fluid inlet (30) with an inlet valve (32), a dialysis fluid outlet (36) with an outlet valve (38), and a pump (42). The control unit (48) is configured and prepared to adjust the transmembrane pressure (10) with a pressure gradient from the blood side (4) to the dialysis fluid side (6) by opening the outlet valve (38) and/or by actuating the pump (42). The disclosure further relates to a method for priming a dialyzer (19) comprising hollow fibers (2) and to a computer program.