The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 2020
Filed:
Mar. 19, 2018
Applicant:
Precision Vision, Inc., Woodstock, IL (US);
Inventor:
John Robson, Cambridge, GB;
Assignee:
PRECISION VISION, INC., Woodstock, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
A61B 3/02 (2006.01); A61B 3/032 (2006.01); A61B 3/06 (2006.01);
U.S. Cl.
CPC ...
A61B 3/022 (2013.01); A61B 3/032 (2013.01); A61B 3/063 (2013.01);
Abstract
An apparatus and method for evaluating a patient's contrast sensitivity. The apparatus including a table or chart with a plurality of shaded marks printed in cells in the table or chart. The shaded marks printed with a various contrasts with a log of Weber contrast ranging from −0.20 to −2.15. Where a subject marks an observed position of the shaded marks and a key is used to check the observed position against an actual position of the shaded mark to determine a threshold contrast of the subject.