RFID Fluid Level Detection Using Conductive Elements

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Solution Overview

Problem

Current fluid containers lack an effective and reliable method for accurately detecting fluid levels, which is crucial in medical applications where timely monitoring of fluid volume is essential to prevent overfilling or emptying, leading to potential patient safety issues.

Innovation Solution

A fluid container system equipped with conductive elements and RFID tags that use RF signals to detect fluid levels, transmitting alerts to a patient monitor when specific volume thresholds are reached, ensuring accurate and continuous monitoring of fluid volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If manual fluid level monitoring is used, then device complexity is reduced, but measurement precision and reliability of fluid level detection deteriorate

Engineering Contradiction:
ImprovestructureVSAvoidfluid level detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces manual visual inspection of fluid levels with an automated RFID-based detection system. Conductive elements are positioned at specific volume levels within the fluid container, and an RFID reader wirelessly detects which conductive elements are in contact with the fluid, providing automated and precise fluid level monitoring without requiring manual observation.

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

Solution Approach 2:

The patent introduces conductive elements as intermediaries between the fluid and the RFID detection system. These conductive elements serve as mediators that enable wireless communication of fluid level information to the RFID reader, allowing accurate detection without direct physical contact between the reader and the fluid.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If automated RFID-based fluid level detection is implemented, then measurement precision and reliability are improved, but device complexity increases

Engineering Contradiction:
Improvefluid level monitoring reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The RFID reader is designed to perform multiple functions: it reads the unique identifier from the RFID tag to identify the specific fluid container, detects which conductive elements are activated to determine fluid level, and can trigger alerts when thresholds are reached. This multi-functionality reduces the need for separate dedicated components for each function.

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

Solution Approach 2:

The system uses the fluid itself as part of the detection mechanism. When fluid reaches a conductive element, the conductive element becomes part of the RFID antenna circuit, automatically changing the electrical characteristics that the RFID reader detects. The fluid essentially serves itself as the sensing medium without requiring additional sensors.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If multiple conductive elements are disposed at different volume levels, then measurement precision is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvefluid level detection accuracyVSAvoidconductive element positioning accuracy
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent divides the fluid container into multiple discrete volume levels by placing conductive elements at specific heights. Each conductive element represents a segmented threshold level, allowing the system to detect fluid level ranges rather than requiring continuous measurement. This segmentation approach simplifies the positioning requirements compared to continuous measurement systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses more conductive elements than the minimum single threshold would require. By implementing multiple conductive elements at different levels, the system provides graduated fluid level information (e.g., low, medium, high levels) rather than just a single threshold alert. This excessive action of adding multiple elements provides richer information while maintaining relatively simple positioning requirements.

Inventive Principle:
Principle #16Partial or excessive action

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

The system provides real-time and accurate fluid level detection, enabling healthcare providers to manage fluid levels effectively, reducing the risk of overfilling or emptying and enhancing patient safety by alerting staff promptly.

Implementation Method 1

The RFID tag and a common conductive element. The conductive element has a portion disposed within the volume and a portion external to the volume. Both the common conductive element and the conductive element are connected to the RFID tag via a respective conductive wire.

Methodology Applied
Scientific EffectRF (Radio Frequency) signal detection: Electromagnetic Induction

Data Source

PatentEP3601964B1Fluid containers and systems and methods for detecting a fluid level therein
Publication Date: 2021.03.10 INTEGRA LIFESCI SWITZERLAND SARL
  • EP3601964B1 patent drawingFigure 1A~1B
  • EP3601964B1 patent drawingFigure 2
  • EP3601964B1 patent drawingFigure 3A~3B

AI summary

Fluid containers having a volume marking(s) and conductive element(s) disposed at the volume marking(s) and a common conductive element are provided. For example, the fluid container has a wall forming the volume. The conductive element(s) and the common conductive element have a portion disposed within the volume and a portion external to the volume. The container further has a RFID tag, where the conductive element(s) and the common conductive element are connected thereto via respective conductive wires. A fluid detection system having the fluid containers is also provided. The system comprises one or more containers and a patient site monitor having a RF reader that interrogates the RFID tag at a preset interval. Responsive to the signal, the tag supplies a predetermined current to the conductive element and the common conductive element and detects a voltage and generates an alert based on the same.