Fluid Control System with Inline Flow Sensor

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Solution Overview

Problem

Current intravenous infusion methods lack precise control over flow rates, flexibility in fluid volumes, and electronic recording capabilities, often relying on human observation or complex and costly positive displacement pumps, which can lead to safety issues and inefficiencies.

Innovation Solution

A sensor-based infusion platform using a fluid pathway assembly with closed-loop quasi-static pressure adjustment and a low-pressure pneumatic pump, combined with wireless communication for device software updates and alarm broadcasting, allowing for precise control and electronic recording of infusion data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If positive displacement pumps are used to control flow rate, then flow control precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improveflow control precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical positive displacement pumps with a simpler system using a mechanical occluder that adjusts flow resistance by occluding the fluid pathway. This substitution maintains flow control capability while significantly reducing device complexity and cost.

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

Solution Approach 2:

The patent employs a balloon occluder inflated with fluid or gas to control flow rate. By using pneumatic/hydraulic principles to create variable resistance through balloon inflation, the system achieves precise flow control without complex mechanical pumping mechanisms.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Measurement precision

If positive displacement pumps are used to control flow rate, then flow control precision is improved, but financial cost increases

Engineering Contradiction:
Improveflow control precisionVSAvoidfinancial cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive positive displacement pumps with a cost-effective mechanical occluder system that uses simple components like balloons and tubing to achieve flow control, significantly reducing manufacturing costs.

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

Solution Approach 2:

The patent employs disposable components such as balloons and tubing in the flow control system. These inexpensive, single-use parts replace expensive durable pumps, reducing both initial cost and maintenance expenses.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If flow stop mechanisms are incorporated to prevent runaway infusion, then patient safety is improved, but flow continuity is compromised

Engineering Contradiction:
Improvepatient safetyVSAvoidflow continuity
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent uses a dynamically adjustable mechanical occluder that can be continuously adjusted to modulate flow rate rather than simply stopping flow. This dynamic control allows the system to respond to safety conditions by reducing flow gradually while maintaining system readiness, balancing safety with flow continuity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent incorporates feedback mechanisms that monitor infusion conditions and automatically adjust the mechanical occluder position. When safety thresholds are approached, the system provides feedback to reduce flow rate, creating a continuous safety loop that maintains both patient safety and flow continuity.

Inventive Principle:
Principle #23Feedback

4Reliability

If air detection systems are incorporated to prevent air infusion, then patient safety is improved, but nuisance alarms increase

Engineering Contradiction:
Improvepatient safetyVSAvoidoperator inefficiency
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent incorporates preliminary air removal actions through the mechanical occluder system that can trap and hold air pockets before they reach the patient. By addressing air issues proactively rather than reactively, the system reduces false alarms while maintaining safety.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback-based air detection that distinguishes between genuine air infusion hazards and benign air pockets. The system provides intelligent feedback to differentiate true alarms from nuisance conditions, reducing operator inefficiency while maintaining high patient safety standards.

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 accurate and flexible control over intravenous fluid flow, reduces the risk of air infusion and nuisance alarms, and enhances patient safety and caregiver efficiency by enabling electronic data recording and communication.

Implementation Method 1

an optical detector to detect a position of the flow element

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

a light source array to illuminate a flow channel

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Data Source

PatentEP3068464B1Fluid control system and disposable assembly
Publication Date: 2024.04.10 FRESENIUS KABI USA LLC
  • EP3068464B1 patent drawingFigure 1a
  • EP3068464B1 patent drawingFigure 1b
  • EP3068464B1 patent drawingFigure 2

AI summary

A system for controlled delivery of medicinal fluid includes a fluid pathway assembly. The fluid pathway assembly has an inline flow sensor element received within the fluid pathway movable in response to fluid flowing in the fluid pathway. A flow control device is removably attached to the fluid pathway assembly and has a sensor for sensing a position of the inline flow sensor element in the fluid pathway, the position of the inline flow sensor element being representative of a second calculated fluid flow rate. The fluid pathway assembly includes a variable flow resistor adjustable to regulate a rate of fluid flow in the fluid pathway assembly. A drive mechanism attached to the flow control device is operably coupled to the variable flow resistor when the flow control device is attached to the fluid pathway assembly.