Dual Flow Restriction Device for Infusion Occlusion Detection

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Solution Overview

Problem

Current infusion systems, particularly manual and syringe pump-based systems, face challenges in accurately measuring and regulating fluid flow rates and detecting occlusions, leading to low dosing accuracy and potential safety risks, especially at low infusion rates.

Innovation Solution

A device with two flow restrictions and pressure sensors arranged behind these restrictions allows for precise measurement of flow rates and immediate detection of occlusions by measuring pressure differences across defined flow resistances, enabling accurate dosing and reducing the need for drip chambers, thus enhancing dosing accuracy and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual gravity infusion is used, then the system is simple and easy to operate, but the dosing accuracy is low (±20-50%)

Engineering Contradiction:
Improveease of operationVSAvoiddosing accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical manual regulation system (roller clamp) with a motorized drive unit that provides precise rotational control of the syringe. This mechanical-to-electrical substitution enables accurate dosing control while maintaining operational simplicity through electronic control interfaces.

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

Solution Approach 2:

The patent implements feedback through sensors that detect the position of the drive unit, flow rate measurement devices, and occlusion detection mechanisms. This feedback is processed by a control unit that adjusts the drive unit's operation to maintain accurate dosing rates and detect abnormalities, resolving the contradiction between simple operation and precise measurement.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If syringe pump infusion is used, then the dosing accuracy and constant delivery are improved, but the device complexity increases

Engineering Contradiction:
Improvedosing accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions into a single compact device: the drive unit serves both as a pumping mechanism and a positioning system; sensors detect both flow rate and occlusion conditions; the control unit manages dosing calculations, real-time monitoring, and alarm functions. This multi-functionality reduces overall system complexity while maintaining high dosing accuracy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the drive unit, sensors, flow restrictions, and control electronics into an integrated infusion device. The merging of these components into a unified system reduces the complexity associated with multiple separate devices while preserving the dosing accuracy benefits of pump-based infusion.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If traditional manual occlusion detection is used, then the device complexity is low, but the detection time is delayed (up to one hour)

Engineering Contradiction:
Improvedevice complexityVSAvoidocclusion detection time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent implements real-time feedback through sensors that continuously monitor flow conditions and pressure changes. When an occlusion occurs, the sensor detects the abnormal condition immediately and signals the control unit, which can then trigger an alarm or adjust the drive unit. This continuous feedback loop reduces occlusion detection time from hours to seconds while adding minimal complexity through integrated sensing.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent maintains continuous monitoring of the infusion process through constantly active sensors and real-time data processing. This continuous action ensures that occlusions are detected immediately upon occurrence rather than through periodic manual checks, dramatically reducing detection time while the sensors remain integrated within the existing device structure.

Inventive Principle:
Principle #20Continuity of useful action

4Measurement precision

If drip chamber is used for flow measurement, then the measurement is direct, but the manufacturing cost increases

Engineering Contradiction:
Improveflow measurement accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical drip chamber counting method with electronic flow rate sensors and motorized position tracking. The drive unit's position and speed are measured electronically to calculate flow rate, eliminating the need for physical drip chambers while providing continuous digital measurement data. This substitution reduces manufacturing costs by removing complex disposable components.

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

Solution Approach 2:

The patent introduces electronic sensors and control algorithms as intermediaries between the syringe movement and flow rate measurement. Instead of directly observing drops in a chamber, the system uses the drive unit's rotational position and speed data to calculate flow rate mathematically. This intermediary approach provides accurate measurement without requiring expensive drip chamber manufacturing.

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 solution provides significantly improved dosing accuracy and immediate occlusion detection, reducing the risk of errors and costs associated with conventional infusion systems, while allowing for precise control of infusion rates and reducing the need for costly disposable components.

Implementation Method 1

precise measurement of flow rates and immediate detection of occlusions by measuring pressure differences across defined flow resistances

Methodology Applied
Scientific EffectPressure difference measurement: Pressure Drop

Implementation Method 2

measuring pressure differences across defined flow resistances

Methodology Applied
Scientific EffectFlow resistance: Pressure Drop

Data Source

PatentEP2349405B1Device for determining at least one flow parameter
Publication Date: 2019.11.20 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP2349405B1 patent drawingFigure 1~2
  • EP2349405B1 patent drawingFigure 3A~3B
  • EP2349405B1 patent drawingFigure 4A~4C

AI summary

The invention relates to a device for capturing at least one flow parameter, comprising a series fluid circuit (10), a first flow restriction (12), a first measurement area (14), a second flow restriction (16), and a second measurement area (18). A first sensor (20) is provided in order to capture a first quantitative dimension for a pressure present in the first measurement area. A second sensor is provided in order to capture a second quantitative dimension for a pressure present in the second measurement area. An evaluation device (24) is provided, designed for determining a flow rate of a fluid flowing through the series circuit by using the dimensions captured by the first and second sensor (20, 22), and/or for determining whether a stoppage of the first flow restriction (12), the second flow restriction (16), or a fluid area adjacent to the second fluid area is present.