Apparatus for measurement of expiration fluids
US4233842A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1978 |
| Grant date | Nov 18, 1980 |
| Priority date | — |
| Expiry date | Oct 20, 1998 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2230/435
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A dynamic method and apparatus for determining the rate of expiration of a selected fluid constituent expired by a living subject during respiration. The apparatus includes a fluid path system which conducts the expired air to a first fluid detector which produces a first signal operable as a function of concentration for the selected fluid constituent. The signal registered by the detector is used for later comparison with a second signal which provides the basis for determining the expiration rate of fluid constituent originally present in the expired air. To make this determination, the fluid constituent is removed from the expired air, with the expired air being advanced to a mixing chamber where a second detection means senses the fluid concentration. The respective signals from the first and second detection means are compared and integrated and additional fluid constituent is added to the expired air at the mixing chamber by a metering pump until the respective signals are equal, indicating equivalent concentrations. Since the flow rate of fluid constituent replenished is a function of rate of expiration for the selected fluid constituent, this value can be used to obtain th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.