Breath Alcohol Sensor Using Flow Rate Integration

Solution Overview

Problem

Existing breath detection systems using electrochemical fuel cell sensors lack accuracy and specificity, particularly in accounting for varying breath volumes and are prone to errors from contaminants like smoke, which requires a method to calculate blood alcohol content (BAC) without active sampling and to detect error conditions.

Innovation Solution

A method utilizing an electrochemical fuel cell gas sensor in conjunction with a flow rate sensor to measure breath flow and time, calculating gaseous component levels and detecting error conditions by integrating flow rate over time, eliminating the need for a sampling mechanism and accounting for breath volume, while alerting users of potential errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If an electrochemical fuel cell sensor is used without an active sampling mechanism, then cost and device complexity are reduced, but measurement precision deteriorates due to inability to account for varying breath volumes

Engineering Contradiction:

Improvesampling mechanismVSAvoidalcohol content calculation

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical sampling mechanism (pump and valve system) with an electronic integration method. The microprocessor integrates the analog output signal from the fuel cell sensor over time to calculate total breath volume, eliminating moving mechanical parts while maintaining measurement precision through computational methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from fixed-volume sampling to time-integrated volume measurement. By integrating the sensor output signal over the duration of breath exposure and multiplying by a calibration factor, the system adapts to varying breath volumes without requiring predetermined volume sampling.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If an electrochemical fuel cell sensor is used without a sampling mechanism, then power consumption is reduced, but reliability deteriorates due to error conditions from contaminants like smoke

Engineering Contradiction:

Improvepower consumptionVSAvoidreading accuracy

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements feedback by continuously monitoring the fuel cell sensor output and comparing it against expected breath alcohol concentration ranges. The microprocessor detects abnormal readings that may indicate contamination (such as from cigarette smoke) and can trigger error conditions or request retesting, improving reliability through automated quality control.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs self-diagnosis by analyzing the temporal and magnitude characteristics of the sensor output signal. The microprocessor identifies error conditions based on the breath sample characteristics and sensor response patterns, allowing the system to self-validate reading quality without external intervention.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If traditional active sampling mechanism is used, then measurement precision is maintained, but device complexity and cost increase

Engineering Contradiction:

Improvealcohol content measurementVSAvoidsampling mechanism

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical sampling mechanism (pump and valve system) with an electronic integration method. The microprocessor integrates the analog output signal from the fuel cell sensor over time to calculate total breath volume, eliminating moving mechanical parts while maintaining measurement precision through computational methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system performs self-diagnosis by analyzing the temporal and magnitude characteristics of the sensor output signal. The microprocessor identifies error conditions based on the breath sample characteristics and sensor response patterns, allowing the system to self-validate reading quality without external intervention.

Inventive Principle:

Principle #25Self-service

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 approach enhances accuracy and specificity in BAC measurement, reduces power consumption and costs, and effectively discriminates ethanol from other gases, providing reliable breath alcohol level calculations and error detection.

Implementation Method 1

an output signal from the electrochemical fuel cell gas sensor

Methodology Applied

Scientific EffectElectrochemical reaction: Fuel Cell

Data Source

PatentUS9901288B2Methods of detecting gaseous component levels in a breath

Publication Date: 2018.02.27 OMEGAPOINT SYST

AI summary

Method for detecting gaseous component levels in a breath, comprising: receiving a breath through a breath channel, wherein the breath channel is in fluid communication with a flow rate sensor and an electrochemical fuel cell gas sensor; measuring a flow rate of the breath received through the breath channel; measuring a first time, wherein the first time corresponds to an amount of time elapsed while receiving the breath in the breath channel; and calculating a current gaseous component level utilizing the flow rate, first time and an output from the gas sensor. Methods for detecting an error condition while measuring gaseous component levels in a breath comprising: determining if the peak output occurs while breath is still being received in the breath channel; and if the peak output occurs while breath is still being received in the breath channel, alerting a user of an error condition.