Peritoneal Dialysis Pressure Sensing for Safe Fluid Fill Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Automated peritoneal dialysis machines lack the ability to accurately determine the residual volume of dialysis fluid within a patient's peritoneal cavity, leading to uncertainty and potential overfilling, which can cause patient discomfort and adverse cardiopulmonary effects.

Innovation Solution

The system employs pressure sensors and a control unit to monitor and control both positive and negative pressures during fluid delivery and removal, using pressure readings to determine when the patient is full or empty, thereby preventing overfilling by stopping the pumping process when a pressure spike is sensed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the APD machine pumps dialysis fluid into the patient's peritoneal cavity without pressure monitoring, then the fluid delivery volume can be increased, but the patient may become overfilled causing discomfort and adverse cardiopulmonary effects

Engineering Contradiction:
Improvedialysis fluid delivery volumeVSAvoidpatient overfilling and discomfort
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The system continuously monitors pressure within the patient's peritoneal cavity during fluid delivery and uses this feedback to dynamically adjust or terminate pumping. The control unit receives pressure readings from the pressure sensor and automatically stops fluid delivery when a predetermined pressure threshold is reached, preventing overfilling while maximizing safe fluid delivery volume.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual mechanical monitoring and control with an automated electronic system that uses a pressure sensor and control unit to monitor pressure and regulate fluid delivery. This substitution enables precise, real-time pressure-based control that prevents overfilling while allowing maximum safe fluid delivery.

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

2Ease of operation

If the APD machine uses fixed fill volumes based on predictions, then the treatment process is simple, but the actual residual volume remains uncertain leading to potential overfilling

Engineering Contradiction:
Improvetreatment process simplicityVSAvoidresidual volume determination accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system uses real-time pressure feedback during the drain and fill cycles to automatically determine when the patient is full or empty. This eliminates the need for manual prediction of residual volumes and ultrafiltration amounts, providing accurate volume determination while maintaining automated operation that remains simple for the patient.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically monitoring pressure and determining optimal fill volumes based on actual patient conditions rather than fixed predictions. The control unit autonomously manages the complexity of volume calculations and pressure-based termination, keeping the patient interface simple while achieving precise volume control.

Inventive Principle:
Principle #25Self-service

3Reliability

If the APD machine implements pressure monitoring and control, then patient safety is improved, but the device complexity increases

Engineering Contradiction:
Improvepatient safetyVSAvoidsystem structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system implements a relatively simple feedback loop where a pressure sensor provides pressure readings to a control unit that automatically adjusts or terminates pumping. This straightforward feedback mechanism significantly improves patient safety by preventing overfilling without requiring complex multi-component control systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The pressure sensor acts as an intermediary that provides simple, direct pressure information to the control unit, enabling safe fluid delivery control without complex sensing or processing systems. This intermediary approach maintains system reliability while minimizing the added complexity of pressure monitoring.

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 allows for precise control of fluid delivery, reducing the risk of overfilling and enhancing patient comfort by ensuring accurate fluid management, thereby maximizing fluid delivery volume while maintaining patient safety.

Implementation Method 1

measuring a pressure within the patient with the pressure sensor

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 2

pumping is stopped for a period of time to allow pressure of the fluid... to reflect the pressure of fluid inside the patient

Methodology Applied
Scientific EffectPressure-driven fluid transport:

Data Source

PatentEP3641849B1Systems and methods for incorporating patient pressure into medical fluid delivery
Publication Date: 2023.11.08 BAXTER INT INC
  • EP3641849B1 patent drawingFigure 1
  • EP3641849B1 patent drawingFigure 2~3
  • EP3641849B1 patent drawingFigure 4~5

AI summary

A medical fluid delivery machine includes a pump interface having an actuation area for delivering positive or negative pressure to a medical fluid handling device; a pressure sensor positioned to measure pressure within the actuation area; a valve positioned to selectively vent the actuation area to atmosphere; and a control unit in signal communication with the pressure sensor and control communication with the valve, the control unit performing a sequence during pumping, wherein (i) application of positive pressure or negative pressure to the actuation area is stopped, the valve is switched to vent the actuation area to atmosphere, then switched to close the actuation area to atmosphere, and at least one pressure signal reading is taken via the pressure sensor, and (ii) a determination is made whether positive pressure or negative pressure to the chamber should be resumed based on the at least one pressure signal reading.