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:
Apr. 29, 1997
Filed:
Mar. 16, 1995
Bruce W McCaul, Palo Alto, CA (US);
David E Doggett, Sunnyvale, CA (US);
Other;
Abstract
The absorption of laser radiation by a gas (such as oxygen and/or carbon dioxide) in human breath is detected on-airway by generating laser radiation using a laser diode, passing the laser radiation through a volume containing human breath multiple times, and detecting the laser radiation which is not absorbed by gases in the volume. To reduce the amount of energy required to control the laser diode, a laser diode is selected which generates laser radiation having a wavelength which is reasonably close to the wavelength of an absorption line of a desired gas when the laser diode is at or near normal body temperature. By passing the laser radiation through the sample gas multiple times, a longer path through the sample gas is provided for absorption thereby allowing the concentration of a gas having weak absorption lines (such as oxygen) to be determined using on-airway absorption detection. A two piece on-airway spectroscopy device is disclosed having a disposable mouthpiece portion and a reusable sensor assembly portion having a laser diode and a photodetector.