Granted Patent
Utility
US 5,917,135 · App. 08/873,645
Gas concentration sensor and control for oxygen concentrator utilizing gas concentration sensor
Inventors:
Gregory A. Michaels, Homayoun Birangi
Patented Case
View Patent ↗
Granted: Jun 29, 1999
Filed: Jun 12, 1997
Inventors
Gregory A. Michaels
Homayoun Birangi
Assignee (at issue)
INVACARE CORPORATION
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.