Noncontact type tonometer

• US 5,092,334 A
• Filed: 06/29/1988
• Issued: 03/03/1992
• Est. Priority Date: 06/30/1987
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Topcon 1-GO 75-Ban Hasunuma-Cho Itabashi-Ku Tokyo-To
• Original Assignee: Tokyo Kogaku Kikai Kabushiki Kaisha (Topcon Corporation)
• Inventors: Nishio, Kouji, Hanamura, Yoshihiko
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): HANLEY, JOHN C
• Application Number:
  US07/325,944
• Time in Patent Office: 1,343 Days
• Field of Search: 128/645, 128/648, 128/652
• US Class Current: 600/401
• CPC Class Codes: A61B 3/165 Non-contacting tonometers
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence

Abstract

A noncontact type tonometer projects a fluid toward an eye-to-be-tested and obtains a measured value of eye pressure from a relation between transfigurations of the eye due to the fluid projection and the pressure projecting of the fluid. A detecting circuit senses a pulse wave of the person-to-be-tested and a calculating circuit determines at least one of the maximum eye pressure value, minimum eye pressure value and average pressure value of the eye dependent on the maximum fluctuation width of the detected pulse wave, a fluctuating quantity of the detected pulse wave, and the measured eye pressure value. The calculation circuit determines the pulse wave fluctuating quantity at the time point when the eye pressure is measured. The pulse wave of the person may be measured at a position remote from the eye. The tonometer may also include a display for displaying the pulse wave and a display controller for displaying the time point when the eye pressure is measured. The displayed eye pressure overlaps the displayed pulse wave to illustrate the relation between the measured eye pressure value and the pulse wave fluctuation.

Claims

1. A noncontact type tonometer comprising fluid projecting means for projecting a fluid toward an eye-to-be-tested, eye pressure measuring means for obtaining a measured value of the eye-to-be-tested from a relation between a transfiguring quantity of the eye-to-be-tested and the pressure of the fluid, pulse wave detecting means for detecting a pulse wave of a person-to-be-tested, and calculating means coupled to the pulse wave detecting means and said eye pressure measuring means for determining at least one of the maximum eye pressure value, minimum eye pressure value and average eye pressure value of the eye-to-be-tested through calculation with reference to the maximum fluctuation width of the pulse wave detected by the pulse wave detecting means, the pulse wave fluctuating quantity at the time point when the measurement of the eye pressure is carried out by the eye pressure measuring means, and the measured value of the eye pressure.

2. A noncontact type tonometer according to claim 1 and further comprising:

displaying means connected to said pulse wave detecting means for displaying the pulse wave.

3. A noncontact type tonometer comprising means for projecting fluid toward an eye-to-be-tested and measuring an eye pressure of the eye-to-be-tested from a relation between a transfiguring quantity of the eye-to-be-tested and the pressure of the fluid,

pulse wave detecting means for detecting a pulse wave of a person-to-be-tested, displaying means for displaying a pulse wave form detected by said pulse wave detecting means, and overlap display controlling means for displaying the time point when the measurement of the eye pressure is carried out in such a manner as to overlap with the pulse wave form displayed on said displaying means.