Fluid Type Detection System Using Voltage Drop Measurement

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Solution Overview

Problem

During apheresis procedures, there is a risk of accidental connection of anticoagulant instead of saline, which can be harmful or fatal to the donor, as existing technologies lack effective means to reliably differentiate between these fluids in real-time.

Innovation Solution

A system that applies a voltage across electrodes in contact with the fluid, measuring the voltage drop to determine whether the fluid is saline or anticoagulant, and includes a circuit to control valves and generate alarms to prevent incorrect fluid delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a voltage measurement system is implemented to differentiate between saline and anticoagulant, then fluid type detection accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvefluid type detection accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical fluid analysis systems with a simple electrical voltage measurement system. By applying a voltage across electrodes immersed in the fluid and measuring the resulting voltage drop, the system can differentiate between saline and anticoagulant based on their different electrical properties (conductivity/resistance). This substitution of electrical measurement for mechanical/chemical analysis simplifies the device while maintaining detection accuracy.

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

2Reliability

If real-time fluid detection is implemented during apheresis, then donor safety is improved, but system complexity increases

Engineering Contradiction:
Improvedonor safetyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements preliminary detection of fluid type before the fluid is delivered to the donor. The voltage measurement system is positioned in the fluid line upstream of the donor connection, allowing the system to identify whether saline or anticoagulant is present before it can reach the donor. This preliminary action prevents harmful fluid delivery while keeping the system relatively simple.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from voltage measurements to control fluid delivery. The voltage drop measurement provides real-time information about fluid type, which feeds back to the control system to determine whether to allow fluid delivery or trigger an alarm. This feedback mechanism ensures donor safety while maintaining operational simplicity.

Inventive Principle:
Principle #23Feedback

3Loss of time

If voltage measurement is used to detect fluid type, then detection speed is improved, but energy consumption increases

Engineering Contradiction:
Improvedetection speedVSAvoidenergy consumption
Core Design Contradiction:
Loss of timeVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic voltage measurements rather than continuous measurement. The system applies voltage and measures the voltage drop at specific intervals or trigger points in the apheresis procedure, such as when fluid connection is established or before donor delivery. This periodic action achieves rapid detection when needed while minimizing overall energy consumption compared to continuous monitoring.

Inventive Principle:
Principle #19Periodic 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 effectively differentiates between saline and anticoagulant, preventing harmful anticoagulant from being returned to the donor by controlling fluid flow and alerting operators, thus ensuring safer apheresis procedures.

Implementation Method 1

a voltage source configured for electrical connection to a first electrode and to a second electrode, and configured to apply a voltage across the first and second electrodes

Methodology Applied
Scientific EffectElectrical field: Electric Field

Implementation Method 2

a voltage detector electrically connected to the resistor and configured to measure a voltage drop across the resistor

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP3175229B1System for detecting fluid type
Publication Date: 2023.06.07 HAEMONETICS CORP
  • EP3175229B1 patent drawingFigure 1A
  • EP3175229B1 patent drawingFigure 1B~1C
  • EP3175229B1 patent drawingFigure 2A

AI summary

A system for detecting a fluid type within a blood processing device includes a voltage source for electrical connection to a first electrode and to a second electrode, and a resistor in series between the voltage source and the first and/or second electrode. The voltage source may apply a voltage across the first and second electrodes. The system also includes a voltage detector that is electrically connected to the resistor and measures a voltage drop across the resistor. A circuit electrically connected to the voltage detector determines the type of fluid in contact with the first and second electrode based, at least in part, upon the measured voltage drop.