Drainage Tube Pressure Control for Clearing Dependent Loops

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Solution Overview

Problem

Existing fluid drainage systems suffer from fluid pooling in dependent loops, leading to complications such as catheter-associated urinary tract infections (CAUTI) due to bacteria and microbes, which are detrimental to patients and increase healthcare costs.

Innovation Solution

A dynamic pressure response system with a drainage tube, sensor, and controller logic that automatically detects fluid states and adjusts air pressure to clear fluid from dependent loops into a collection container, using solenoid valves and pumps to manage airflow between 0% and 100% pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous high airflow is applied to clear dependent loops, then fluid pooling is prevented, but patient trauma and system damage occur

Engineering Contradiction:
Improveprevention of fluid poolingVSAvoidpatient trauma
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system applies airflow intermittently rather than continuously, using periodic bursts of air to clear fluid from dependent loops. The controller activates the airflow source only when fluid presence is detected by the sensor, and deactivates it when the loop is clear, preventing continuous high pressure exposure that causes trauma.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts airflow characteristics based on real-time sensor feedback. The controller modulates airflow rate and duration according to the detected fluid state, transitioning between different airflow levels to effectively clear fluid while avoiding excessive pressure that would cause patient trauma or system damage.

Inventive Principle:
Principle #15Dynamics

2Productivity

If high airflow rate is used to clear fluid rapidly, then productivity increases, but system damage and patient trauma occur

Engineering Contradiction:
Improvefluid clearing speedVSAvoidsystem durability
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The system uses periodic airflow bursts rather than sustained high airflow. The controller activates high airflow only for the minimum duration needed to clear detected fluid, then stops airflow to allow pressure equalization, preventing cumulative stress on the system and patient while maintaining effective fluid clearing capability.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The sensor provides real-time feedback on fluid presence in the dependent loop, allowing the controller to adjust airflow rate and duration. When fluid is detected, high airflow is applied; when the loop is clear, airflow is reduced or stopped. This feedback mechanism ensures rapid fluid clearing only when necessary, preserving system durability.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If automated clearing system is implemented, then ease of operation improves, but device complexity increases

Engineering Contradiction:
Improveautomation of clearingVSAvoidsystem components
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system performs self-monitoring and self-clearing of dependent loops. The sensor automatically detects fluid presence, and the controller autonomously activates the airflow source to clear the loop without requiring manual intervention. This self-service capability maintains ease of operation while the added components provide necessary automation functions.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The integrated system combines sensing, control, and airflow generation into a multi-functional unit. The same device that monitors fluid drainage also automatically clears dependent loops, eliminating the need for separate manual clearing procedures. This consolidation improves ease of operation while the shared components help manage overall system complexity.

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

Effectively prevents fluid pooling by rapidly transitioning between low and high airflow rates to clear fluid without causing trauma to the patient or damaging the system, thereby reducing infection risks and system damage.

Implementation Method 1

The sensor is configured to detect one of an air pressure within the drainage lumen, or a state of the drainage fluid within the drainage lumen

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 2

a connector providing pressurized air to the drainage lumen, the controller logic configured to modify a pressure level of the pressurized air provided by the connector

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP4240458B1Dynamic pressure response system
Publication Date: 2026.04.01 CR BARD INC
  • EP4240458B1 patent drawingFigure 1
  • EP4240458B1 patent drawingFigure 2A~2B
  • EP4240458B1 patent drawingFigure 3

AI summary

Embodiments disclosed herein are directed to a dynamic pressure response system for fully automated clearing of dependent loops from a fluid drainage system. Fluid drainage systems include a flexible drainage tube providing fluid communication with a collection container. Dependent loops can form within the tube leading to pooling of urine and provide an increased risk in CAUTI. Dynamic pressure response systems can automatically detect the presence of dependent loops and provide a low-rate positive air pressure to clear the columnized fluid. Further, the system can automatically detect mixed fluid states when a noise level of pressure signals increases, the system can then provide high-rate positive air pressure to clear mixed fluid state liquid from the tube lumen.