Granted Patent
Utility
US 4,852,565 · App. 07/171,708
Fenestrated tracheostomy tube
Inventor:
Robert F. Eisele
Patented Case
View Patent ↗
Granted: Aug 1, 1989
Filed: Mar 22, 1988
Inventor
Robert F. Eisele
Assignee (at issue)
Shiley Incorporated
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.