Granted Patent
Utility
US 5,407,581 · App. 08/032,487
Filter medium having a limited surface negative charge for treating a blood material
Inventors:
Hirokazu Onodera, Makoto Yoshida
Patented Case
View Patent ↗
Granted: Apr 18, 1995
Filed: Mar 17, 1993
Inventors
Hirokazu Onodera
Makoto Yoshida
Assignee (at issue)
ASAHI MEDICAL CO., LTD
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.