Peritoneal Dialysis Flow Control for Patient-Specific Cycle Timing

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Solution Overview

Problem

Existing peritoneal dialysis systems lack patient-specific estimation of total treatment duration, leading to uncertainties due to non-accounted-for catheter quality deterioration and position changes, which affect inflow and outflow behavior.

Innovation Solution

A peritoneal dialysis device with a control unit that determines a patient-specific delay factor based on measured inflow and outflow behavior over multiple cycles, adjusting treatment parameters and providing real-time feedback for improved estimation and catheter monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed delay factor is used for all patients, then the device complexity is reduced, but the measurement precision of treatment duration estimation deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidtreatment duration estimation precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The control unit continuously monitors actual inflow and outflow durations, compares them with theoretical values, and automatically updates the delay factor for each patient based on measured data. This feedback mechanism enables the system to adapt to individual patient conditions and catheter performance changes over time, significantly improving treatment duration estimation precision without requiring complex manual calibration procedures

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-calibration by automatically determining the delay factor from its own operational data. The control unit uses the measured inflow and outflow behavior from the patient's own treatment cycles to calculate and update the patient-specific delay factor, eliminating the need for external calibration equipment or manual intervention while maintaining high measurement precision

Inventive Principle:
Principle #25Self-service

2Measurement precision

If patient-specific delay factors are determined through multiple measurements, then the treatment duration estimation precision is improved, but the loss of time for calibration increases

Engineering Contradiction:
Improvetreatment duration estimation precisionVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs delay factor determination during routine treatment cycles rather than requiring separate calibration sessions. By integrating the measurement process into normal inflow and outflow phases, the system accumulates necessary data over several standard treatment cycles, achieving accurate patient-specific calibration without dedicating additional calibration time that would extend treatment duration

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The measurement and calibration process continues uninterrupted during regular treatment cycles. The control unit collects data during each inflow and outflow phase, continuously refining the delay factor without stopping or pausing the dialysis treatment, thereby maintaining continuous useful action while improving measurement precision over time

Inventive Principle:
Principle #20Continuity of useful action

3Reliability

If the device monitors inflow and outflow behavior continuously, then the reliability of catheter quality monitoring is improved, but the use of energy increases

Engineering Contradiction:
Improvecatheter quality monitoring reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The measuring device performs measurements at periodic intervals during inflow and outflow phases rather than continuously. The control unit analyzes flow characteristics at key moments in each treatment cycle, sufficient to detect catheter quality changes and position variations while minimizing energy consumption by keeping measurement functions dormant during holding phases and between cycles

Inventive Principle:
Principle #19Periodic action

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

Enables more reliable estimation of total treatment duration, monitors catheter quality, and adapts treatment parameters to individual patient conditions, reducing uncertainties and improving treatment efficiency.

Implementation Method 1

small molecules from the blood can pass into the dialysis solution via the capillaries of the peritoneum due to a concentration gradient

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

water can also be removed from the body in this way, provided the dialysis solution has a higher concentration of osmotically active substances than the blood

Methodology Applied
Scientific EffectOsmosis: Osmosis

Implementation Method 3

This step, as well as the drainage from the abdominal cavity, can be performed gravimetrically

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3624871B1Peritoneal dialysis machine
Publication Date: 2025.11.26 FRESENIUS MEDICAL CARE DEUTSCHLAND GMBH
  • EP3624871B1 patent drawingFigure 1
  • EP3624871B1 patent drawingFigure 2
  • EP3624871B1 patent drawingFigure 3

AI summary

The invention relates to a peritoneal dialysis appliance for carrying out peritoneal dialysis treatment with recurring cycles, the cycles comprising a fill phase, a dwell period and a drain phase for the dialysis liquid, wherein the appliance has a control unit and a measurement device for determining the filling and/or drainage behaviour of the dialysis liquid from a patient, wherein the control unit is configured, on the basis of the measured values collected over several fill and/or drain phases, to determine a delay factor which sets a theoretical fill and/or drain duration in relation to the actual fill and/or drain duration of dialysis liquid to/from the patient.