Patent ID: 8500638
Filing Date: 2013-08-06
Classification: A61B

Abstract:
1. A non-contact ultrasonic tonometer for measuring an intraocular pressure of an examinee's eye in non-contact manner by use of an ultrasonic wave, comprising: an ultrasonic transducer including a transmitter which emits an ultrasonic transmission pulse wave to the eye and a receiver which detects an ultrasonic reflection pulse wave from the eye, the transducer being arranged to be placed in a position apart from the eye and to transmit and receive the pulse wave with respect to the eye through the medium of air; and a detection optical system for detecting an alignment state of the tonometer with respect to the eye in a working distance direction; a drive part to move a main unit in which the ultrasonic transducer is provided with respect to the eye; and a controller configured to detect an alignment state of the main unit in the working distance direction based on a detection result of the alignment detection optical system, determine whether a distance between the ultrasonic transducer and the eye is appropriate or not based on the detection result, and measure the intraocular pressure based on the ultrasonic reflection pulse wave when the distance is determined to be appropriate, wherein the distance between the ultrasonic transducer and the eye is appropriate if the distance falls within a predetermined range.