The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 26, 1996
Filed:
Mar. 24, 1994
David M Anderson, St. Paul, MN (US);
Shawn McCutcheon, White Bear Lake, MN (US);
Medical Graphics Corporation, St. Paul, MN (US);
Abstract
A method is described for dynamically calibrating a flowmeter used in cardiopulmonary performance analyzing equipment which takes into account the ambient conditions at the test site in terms of relative humidity, barometric pressure and temperature. At the time of factory calibration, a density factor is computed and stored in a nonvolatile memory along with a calibration factor obtained by passing a known volume of gas at a known relative humidity, temperature and pressure through a pneumotach mouthpiece in a predetermined time span. When the system is being used in the field to evaluate a patient, a new density factor is computed that takes into account the relative humidity, barometric pressure and temperature at the test site and this new density factor along with the density factor previously computed and stored at factory calibration are used to compute a new flow calibration factor for use in obtaining an accurate flow parameter from the system flowmeter.