Granted Patent
Utility
US 4,851,195 · App. 07/086,423
Carbon dioxide sensor
Inventors:
Richard S. Matthews, Frederick E. Witherell, Jr.
Patented Case
View Patent ↗
Granted: Jul 25, 1989
Filed: Aug 17, 1987
Inventors
Richard S. Matthews
Frederick E. Witherell, Jr.
Assignee (at issue)
Pfizer Hospital Products Group, Inc.
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.