Method for measuring breath alcohol concentration and apparatus therefor
US11885795B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 2021 |
| Grant date | Jan 30, 2024 |
| Priority date | — |
| Expiry date | Aug 14, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/98
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to a method and apparatus for measuring breath alcohol concentration of a user. A flow of an expired breath sample is passed through a fuel cell sensor giving an output signal proportional to the amount of alcohol present in the breath sample. By measuring the flow rate, the volume of the breath sample may be calculated, whereas the breath alcohol concentration is calculated based on the fuel cell output signal. Both the sample volume and the breath alcohol concentration values are continually updated by integrating the measured instantaneous flow rate and the fuel cell output signal over time. If the user stops blowing, flow compensation is performed to obtain a compensated fuel cell output signal using a stored calibration volume. Hence, an improved method for accurately measuring the breath alcohol concentration of a test person is achieved, capable of handling varied expired volumes of breath, which obviates the need for a sampling mechanism.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.