Spirometer Flow Sensing with Disposable Resistive Elements

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Solution Overview

Problem

Conventional spirometers face issues with complex construction, unreliable readings, high costs, and difficulty in cleaning, especially due to the use of fixed resistive elements which can lead to microbial contamination and require periodic recalibration, while also struggling with data transfer and battery management.

Innovation Solution

An electronic spirometer with removably arranged disc-shaped air-resistive elements featuring hexagonal perforations for uniform airflow resistance, connected to pressure/temperature sensors, and an electronic control module for real-time data logging and wireless transmission, allowing for easy cleaning and replacement of resistive elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If fixed metallized tube bundles are used as resistive elements, then accurate flow measurements are achieved, but device cost increases and cleaning becomes difficult

Engineering Contradiction:
Improveflow measurement accuracyVSAvoidconstruction complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs disposable fabric screens instead of permanent metallized tube bundles. These fabric resistive elements are inexpensive, easily replaceable, and designed for single-use or limited-use scenarios, eliminating the need for complex sterilization and recalibration procedures while maintaining adequate measurement accuracy.

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

Solution Approach 2:

The patent utilizes fabric screens with controlled porosity as resistive elements. The porous fabric structure provides consistent flow resistance characteristics suitable for flow measurement, replacing the solid tube bundle structure with a porous material that achieves similar functional results with simpler construction.

Inventive Principle:
Principle #31Porous materials

2Ease of manufacture

If fabric resistive elements are used, then device cost decreases, but reading reliability deteriorates due to non-uniform airflow

Engineering Contradiction:
Improvedevice costVSAvoidreading reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent divides the airflow path into multiple segments by using multiple fabric screens arranged in series within the air tube. This segmentation creates multiple staged resistance points, ensuring more uniform airflow distribution across each fabric element and improving measurement reliability while keeping individual screens simple and inexpensive.

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If resistive elements are placed in slant position, then airflow stabilization is improved, but device complexity increases

Engineering Contradiction:
Improveairflow stabilityVSAvoidair tube design complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent combines the support function and the airflow stabilization function into the same structural feature. The fabric screens are supported by simple radial struts that simultaneously provide mechanical support and create the intended airflow path, eliminating the need for separate complex positioning mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

4Productivity

If repeated use of flow sensors is allowed, then device productivity increases, but calibration accuracy decreases due to microbial contamination

Engineering Contradiction:
Improveusage frequencyVSAvoidcalibration accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent employs disposable fabric screens instead of permanent metallized tube bundles. These fabric resistive elements are inexpensive, easily replaceable, and designed for single-use or limited-use scenarios, eliminating the need for complex sterilization and recalibration procedures while maintaining adequate measurement accuracy.

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

Solution Approach 2:

The patent implements a discard-and-replace strategy for the fabric resistive elements. After a certain number of uses or when contamination is detected, the fabric screens are discarded and replaced with new ones, ensuring consistent measurement accuracy without requiring complex in-situ sterilization or recalibration systems.

Inventive Principle:
Principle #34Discarding and recovering

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 spirometer provides accurate and linear airflow measurements across high and low flow rates, facilitates easy cleaning, and enables continuous data tracking and reporting through mobile applications, improving user convenience and clinical monitoring.

Implementation Method 1

at least two disc-shaped air-resistive elements are removably-arranged within the tubular member to resist the air-flow

Methodology Applied
Scientific EffectFlow resistance: Drag

Implementation Method 2

at least two ports extend radially outwards through a wall of said tubular member, each of said two ports located within the tubular-member near the resistive-elements to cause determination of at least a pressure-difference there-between

Methodology Applied
Scientific EffectDifferential pressure measurement: Pressure Gradient

Data Source

PatentEP3658022B1Flow sensing arrangement for spirometer and method thereof
Publication Date: 2024.09.04 CIPLA LTD
  • EP3658022B1 patent drawingFigure 1(a)~1(b)
  • EP3658022B1 patent drawingFigure 2(a)~2(b)
  • EP3658022B1 patent drawingFigure 3

AI summary

The present subject matter describes a flow-sensing arrangement within a spirometer (100). The arrangement comprises a tubular-member (202) for allowing an air-passage along a longitudinal-axis thereof. At-least two disc-shaped air-resistive elements (204) are removably-arranged within the tubular member (202) to resist the air-flow. Each of said resistive-elements comprises perforations for allowing the air-passage through the resistive- element. At-least two ports (206) extend radially outward through a wall of said tubular member (202), such that each of said two ports (206) are located within the tubular-member (202) near the resistive-elements (204) to cause determination of at least a pressure- difference there-between.