Granted Patent
Utility
US 5,771,890 · App. 08/265,844
Device and method for sampling of substances using alternating polarity
Inventor:
Janet Tamada
Patented Case
View Patent ↗
Granted: Jun 30, 1998
Filed: Jun 24, 1994
Inventor
Janet Tamada
Assignee (at issue)
Cygnus, LLC
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.