Schirmer i tear test
CA 2029204 C · Owner: Wong, Vernon G. · Inventors: Wong, Vernon G.; Gin, Jerry
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved Schirmer I Tear Test is provided. The improvement comprises a strip having a graduated migration scale printed an the test strip and the presence of a water soluble marker dye that comigrates with the tear migration front. Both improvements serve to increase the reproducibility of the test and ease which with the results are read.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed November 2, 1990 and granted December 31, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 2, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 2, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.