Device and method for calibrating pulmonary function testing equipment
US4203316A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 9, 1979 |
| Grant date | May 20, 1980 |
| Priority date | — |
| Expiry date | May 9, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F25/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device and method for calibrating pulmonary function testing equipment by discharging a precise volume of compressed gas at reproducible and substantially exponentially diminishing flow rates through an orifice of a selected size into such equipment. The device includes a container defining a chamber for containing a predetermined volume of gas at a preselected pressure, a gas discharge conduit, which may serve as a conversion or expansion chamber, communicating with the container and having a flow-restricting fixed orifice of predetermined size for the discharge of gas, and a mechanism normally preventing the discharge of gas from the device but being selectively operable to release the gas through the orifice at reproducible and substantially exponentially diminishing flow rates into a spirometer for calibrating that instrument. In one form of the invention, there is provided an isolation housing having a pair of chambers, one of which communicates with the gas-discharging device and the other with the remainder of the pulmonary function testing equipment, the chambers of the housing being separated by a flexible barrier which prevents intermixing of the gaseous contents of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.