Peritoneal Dialysis Pressure Control via Patient-End Sensor Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Peritoneal dialysis systems face challenges in accurately controlling pressure within the peritoneal cavity during fill and drain cycles, leading to potential over-pressurization and errors in fluid balance calculations due to the reliance on traditional methods that do not account for patient-cycler height differences and pressure drop in the fill line.

Innovation Solution

Incorporating pressure sensors at both ends of the fill/drain line, with one sensor located close to the patient to monitor pressure changes and prevent over-pressurization, and using a controller to regulate the flow rate based on continuous feedback, ensuring accurate pressure indication and minimizing errors from line pressure drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a pressure sensor is placed at the cycler to monitor pressure, then the system can detect pressure changes, but the measurement is inaccurate due to pressure drop in the fill line and patient-cycler height differences

Engineering Contradiction:
Improvepressure measurement accuracyVSAvoidpressure indication error
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

A pressure sensor is placed at the patient end of the fill line to directly measure the pressure at the point of interest (peritoneal cavity), eliminating the influence of pressure drop in the fill line and height differences. This intermediary measurement location provides accurate pressure feedback to the controller, which then regulates the pump to maintain safe pressure levels.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stress or pressure

If the dialysate container is elevated to control fill pressure, then gravity determines the fill pressure, but this method cannot prevent over-pressurization and introduces errors in fluid balance calculation

Engineering Contradiction:
Improvefill pressure controlVSAvoidpressure control safety
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The system uses a pressure sensor at the patient end to continuously monitor the actual pressure in the peritoneal cavity during filling. This pressure information is fed back to the controller, which dynamically adjusts the pump operation to maintain pressure within safe limits. This closed-loop feedback control replaces the open-loop gravity-based pressure control, ensuring both safety and accuracy in fluid balance calculation.

Inventive Principle:
Principle #23Feedback

3Extent of automation

If automated pumps are used to fill the peritoneal cavity, then the treatment can be automated, but the system cannot generate sufficient pressure control and may over-pressurize the cavity

Engineering Contradiction:
Improveautomated fill controlVSAvoidperitoneal cavity pressure
Core Design Contradiction:
Extent of automationVSStress or pressure

Solution Approach 1:

The automated pump system is enhanced with a pressure sensor at the patient end that provides real-time pressure feedback to the controller. The controller uses this feedback to dynamically regulate the pump's filling action, ensuring that the peritoneal cavity pressure remains within safe limits while maintaining automated operation. This feedback-controlled automation resolves the contradiction between automation and pressure control safety.

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 solution provides precise control over pressure within the peritoneal cavity, reducing the risk of over-pressurization and improving the accuracy of fluid balance calculations, thereby enhancing patient safety and treatment efficacy in peritoneal dialysis.

Implementation Method 1

a pressure sensor at either end

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 2

using a controller to regulate the flow rate based on continuous feedback

Methodology Applied
Scientific EffectFeedback control: Feedback

Implementation Method 3

Osmosis exchange with the patient's blood occurs across the peritoneal membrane

Methodology Applied
Scientific EffectOsmosis: Osmosis

Data Source

PatentEP3482786B1Peritoneal dialysis systems and devices
Publication Date: 2023.12.13 NXSTAGE MEDICAL INC
  • EP3482786B1 patent drawingFigure 1~2B
  • EP3482786B1 patent drawingFigure 3A~4B
  • EP3482786B1 patent drawingFigure 5A~5C

AI summary

A disposable unit for peritoneal dialysis is disclosed. The unit comprises a batch container and one or more concentrate containers interconnected by a flow switch.