Respiratory gas monitor
US5285794A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1992 |
| Grant date | Feb 15, 1994 |
| Priority date | — |
| Expiry date | Dec 14, 2012 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/083
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method and apparatus for monitoring the respiratory gas of a patient includes an adjustable volume gas mixing chamber which allows for the differences in lung capacity of patients from neonate to adult. A constant flow of a therapeutic gas mixture is measured by a flow meter in a supply line leading to a face mask breathing device. The mask is by-pass connected to the supply line such that the patient inspires from and exhales into the flow from the supply line. Both by-pass and expired gas mix and enter the adjustable-volume chamber, which contains an internal fan and sensors for detecting percentage content of oxygen and carbon dioxide. The chamber is adjusted to a volume where the sensor readings become stable rather than pulsatile. The change in percentages of oxygen and carbon dioxide content in the chamber, as compared to the content in the supply gas, is then entirely due to total-body consumption and production. Whole body rates can be determined by multiplying the percentage change by the flow rate in the supply line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.