Respirator Flow Sensor Self-Calibration via Reference Component

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing respirators actuated pneumatically and controlled electrically require additional flow velocity measuring instruments for calibration, limiting convenience, safety, and reliability, as users often lack matching instruments for accurate calibration.

Innovation Solution

Incorporating a flow measuring reference component between the inspiratory valve and check valve in the respirator, allowing for calibration based on the corresponding relationship between gas flow rates through this component and the flow sensor, enabling self-calibration without external instruments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional flow velocity measuring instruments are used for calibration, then measurement precision is improved, but device complexity increases and ease of operation deteriorates

Engineering Contradiction:

Improveflow sensor calibration accuracyVSAvoidcalibration system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The flow measuring reference component enables the respirator to perform self-calibration without requiring external flow velocity measuring instruments. The system uses its own built-in reference component to calibrate the flow sensor, making the calibration process self-contained and eliminating the need for additional external equipment.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The flow measuring reference component serves multiple functions: it acts as both a reference standard for calibration and as part of the normal gas flow measurement system. This multi-functional design eliminates the need for separate calibration equipment while maintaining measurement precision.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If additional flow velocity measuring instruments are used for calibration, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:

Improveflow sensor calibration accuracyVSAvoidcalibration operation convenience

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The system performs automatic self-calibration using the built-in flow measuring reference component, eliminating the need for users to manually operate external calibration instruments. The microprocessor controls the calibration process automatically, making it convenient for users while maintaining high measurement precision.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The manual calibration process using external mechanical flow velocity measuring instruments is replaced by an electronic automatic calibration system. The microprocessor electronically controls the calibration process based on signals from the flow measuring reference component, replacing complex manual mechanical operations with automated electronic control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If flow sensor is used in patient circuit, then measurement precision is improved, but object-affected harmful factors increase due to condensation and secretion interference

Engineering Contradiction:

Improvegas flow rate measurement accuracyVSAvoidcondensation and secretion interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The gas flow measurement system is divided into two separate components: the flow measuring reference component located in the driver gas circuit (free from patient secretions) and the flow sensor located in the patient circuit. This segmentation allows the reference component to provide clean reference measurements while the flow sensor directly measures patient circuit flow, and the two are combined through calibration to achieve accurate measurements despite the harsh environment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flow measuring reference component acts as an intermediary that provides a clean reference measurement free from condensation and secretion interference. By calibrating the flow sensor against this reference, the system compensates for the harmful effects in the patient circuit while maintaining measurement precision.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8776791B2Respirator and method for calibrating flow rate measuring component thereof

Publication Date: 2014.07.15 SHENZHEN MINDRAY BIO MEDICAL ELECTRONICS CO LTD

AI summary

A respiration apparatus and a method for calibrating respiration parameters thereof are provided. A flow measuring reference component arranged behind the inspiratory valve in the ventilator is used as a flow measuring reference sensor for calibrating the flow sensor so that the flow rates of the gas through the flow measuring reference component and the flow sensor to be calibrated are identical or in a corresponding relation. Electrical parameters output from the flow sensor and the flow measuring reference component are respectively acquired and processed to obtain a relation curve of the gas flow rate and the electrical parameter of the flow sensor on the basis of the read gas flow rate and the electrical parameters of the flow sensor. The present invention enables automatic calibration for a flow sensor without using any measuring instrument.