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:
Dec. 13, 1983
Filed:
Jun. 27, 1980
William E Humphrey, San Leandro, CA (US);
Humphrey Instruments, Inc., San Leandro, CA (US);
Abstract
An analysis of the corneal shape through the combination of several keratometer measurements is disclosed. The eye is preferably scanned to a nasal angular position, a central angular position and a temporal angular position. The central position is straight ahead along the patient's line of sight. The temporal and nasal positions are in the broad range of up to 5.degree. to 22.degree.; the intermediate range of 10 to 15.degree.; and the narrow range of 12.degree. to 14.degree. on either side. Measurements in sphere, cylinder and axes are taken. Astigmatism is in the more preferable format of 0.degree.-90.degree. astigmatism and 45.degree.-135.degree. astigmatism. When each individual point is measured with its respective estimate for sphere and cylinder components, these measurements are fitted to an idealized parameter. Then the three sets of curvature measurements taken at the specified locations are reduced to a set of adjusted, idealized curvatures all fitted to an elliptical model. Thereafter, these fitted values create final corneal shaped parameters, the particular process here including the creation of intermediate parameters. Finally, readings of central 'k', corneal shape, apex position, cap size, vault height, corrected central 'k' and goodness of fit are all set forth.