Spirometer with multi-stage fixed orifice
US4991591A · kind A · utility
Inventor
Key dates
| Filing date | Jun 22, 1989 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Jun 22, 2009 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/097
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A spirometer for measuring breathing functions of a human subject includes a housing and a hollow elongate body with a first opening through which the subject inhales or exhales, a second opening through which the breath enters the elongate body when the subject inhales or discharges from the body when the subject exhales, and a third opening disposed between said first and second openings. The spirometer also includes a pressure transducer in fluid communication with the third opening of the elongate body. This transducer measures the pressure of the breath moving through the elongate body. A plug member disposed proximate the second opening of the elongate body closes a predetermined portion of the second opening when the rate of flow of the breath through the elongate body reaches a predetermined level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.