non-contact tonometer

Abstract

In a contactless tonometer having a mechanism of puffing compressed air by moving a piston in a cylinder, puffing of unnecessary air against the eye to be inspected is suppressed. An apparatus includes a corneal shape changing unit configured to change a shape of a cornea of an eye to be inspected by compressing air in a cylinder by using a piston, and puffing the compressed air from the nozzle to the cornea, a piston control unit configured to control operation of the piston, and an intraocular pressure measurement unit configured to measure an intraocular pressure of the eye by detecting a state of a changed shape of the cornea. This apparatus includes a piston volume changing unit configured to change an initial volume when the piston compresses the air in the cylinder.

Description

technical field

[0001] The present invention relates to a non-contact tonometer that calculates an intraocular pressure value based on a corneal shape change signal obtained by an optical detection unit when the corneal shape is changed by jetting air against an eye to be inspected. Background technique

[0002] The non-contact tonometer is typified by the air jet tonometer developed by Bernard Grolman. This tonometer optically detects applanation of the cornea when air is sprayed on the cornea of ​​the subject's eye from a nozzle about 11 mm away from the cornea. Then, the contact Goldman type tonometer calculates the intraocular pressure value by calibrating the time until applanation. Many tonometers of this type use a mechanism that compresses the air in the cylinder by moving a piston inside the cylinder attached to the air injection nozzle section and ejects the air from the nozzle. In addition, the driving mechanism of the piston generally uses a solenoid because th...

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