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:
Mar. 26, 2002
Filed:
Feb. 07, 2000
Bernard Grolman, Worcester, MA (US);
Leica Microsystems Inc., Depew, NY (US);
Abstract
A hand-held non contact tonometer includes a piston having a transparent plane parallel window normal to a measurement axis of the tonometer along which the piston travels to discharge a fluid pulse without interfering with optical alignment functions of the instrument. In a first embodiment intended for home use by a patient, an alignment guidance system utilizing a concave mirror and a target source in a plane containing the center of curvature of the concave mirror present an alignment image to the patient for guiding self-alignment. An infra-red light source at the focal point of the concave mirror irradiates the concave mirror so that a collimated beam is reflected along the measurement axis and focused by an objective lens. When the focal point of the objective lens coincides with the center of curvature of the cornea, the infra-red light is retro-reflected through the system and diverted orthogonally from measurement axis to a masked detector to passively monitor alignment and trigger release of the piston. A second embodiment for office use by a general medical practitioner includes an eyepiece in place of the concave mirror for allowing operator observation along the measurement axis during alignment.