Method and apparatus for determining a pulmonary function parameter for gas exchange
US6302851A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 2000 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | May 15, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/083
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method and apparatus for determining a pulmonary function parameter, EVG, indicative of a living subject's effective lung volume, namely the lung volume in which gas exchange between respiratory air and pulmonary blood takes place efficiently. The apparatus carries out the steps of the method: (1) determining for a first breath during normal steady state breathing of the subject the end-tidal carbon dioxide or oxygen concentration P.sub.et1 and the average rate of flow V.sub.a1, over the duration T.sub.1 of the breath, of expired carbon dioxide or oxygen, (2) determining for a second breath comprising a breath-hold period the end-tidal carbon dioxide or oxygen concentration P.sub.et2 and the average rate of flow V.sub.a2, over the duration T.sub.2 of the breath, of expired carbon dioxide or oxygen, and (3) determining EVG as a quantity proportional to the ratio of the difference between said average flow rates V.sub.a1 and V.sub.a2 to the difference between said end-tidal concentrations P.sub.et2 and P.sub.et1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.