Granted Patent
Utility
US 4,655,980 · App. 06/839,793
Process of making collagen membranes for medical use
Inventor:
George H. Chu
Patented Case
View Patent ↗
Granted: Apr 7, 1987
Filed: Mar 13, 1986
Inventor
George H. Chu
Assignee (at issue)
COLLAGEN 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.