Contactless ophthalmotonometer and contactless ophthalmotonometer actuating method

Patent metadata

Field	Value
Publication number	US-2025072753-A1
Application number	US-202418817301-A
Country	US
Kind code	A1
Filing date	Aug 28, 2024
Priority date	Sep 1, 2023
Publication date	Mar 6, 2025
Grant date	—

Abstract

A contactless ophthalmotonometer includes a cylinder, a piston movably provided inside the cylinder, an actuator (solenoid) configured to move the piston inside the cylinder by applying current to compress air inside the cylinder, a nozzle configured to spray the air compressed with the piston to a subject eye, and a current application control unit (measurement control unit) configured to apply the current to the actuator, wherein the current application control unit performs first application processing for applying the current of a first current value to the actuator and, when a predetermined switching condition is satisfied while the first application processing is being performed, the first application processing is switched to second application processing for applying the current of a second current value higher than the first current value to the actuator.

First claim

What is claimed is:

1 . A contactless ophthalmotonometer, comprising:
a cylinder; a piston movably provided inside the cylinder; an actuator configured to move the piston inside the cylinder with current applied to the actuator to compress air inside the cylinder with the piston; a nozzle in communication with the inside of the cylinder, the nozzle configured to spray the air compressed with the piston to a subject eye; and a current application control unit configured to apply the current to the actuator, wherein the current application control unit performs first application processing for applying the current of a first current value to the actuator and, when a predetermined switching condition is satisfied while the first application processing is being performed, the first application processing is switched to second application processing for applying the current of a second current value higher than the first current value to the actuator.

2 . The contactless ophthalmotonometer according to claim 1 ,
wherein the nozzle is in communication with the inside of the cylinder through a chamber in communication with the inside of the cylinder, the contactless ophthalmotonometer further comprises a pressure sensor configured to detect pressure inside the chamber, and the current application control unit determines whether the switching condition is satisfied or not based on whether the pressure detected by the pressure sensor achieves a predetermined pressure threshold.

3 . The contactless ophthalmotonometer according to claim 1 , further comprising:
a detection sensor configured to detect a displaced amount of the actuator, wherein the current application control unit determines whether the switching condition is satisfied or not based on whether the displaced amount detected by the detection sensor achieves a predetermined displaced amount threshold.

4 . The contactless ophthalmotonometer according to claim 1 ,
wherein the current application control unit increases the second current value in a stepwise manner while the second application processing is being performed.

5 . The contactless ophthalmotonometer according to claim 4 ,
wherein the nozzle is in communication with the inside of the cylinder through a chamber in communication with the inside of the cylinder, the contactless ophthalmotonometer further comprises a pressure sensor configured to detect pressure inside the chamber, and the current application control unit increases the second current value in a stepwise manner in accordance with an increase in the pressure detected by the pressure sensor while the second application processing is being performed.

6 . The contactless ophthalmotonometer according to claim 4 , further comprising:
a detection sensor configured to detect a displaced amount of the actuator, wherein the current application control unit increases the second current value in a stepwise manner in accordance with an increase in the displaced amount detected by the detection sensor while the second application processing is being performed.

7 . The contactless ophthalmotonometer according to claim 1 ,
wherein the current application control unit stops the second application processing when a defined period of time determined in advance passes from start of the first application processing.

8 . The contactless ophthalmotonometer according to claim 1 , further comprising:
a projecting optical system configured to project a luminous flux to the subject eye while the air is being sprayed from the nozzle to the subject eye; and a receiving optical system configured to receive reflected light of the luminous flux reflected at the subject eye and outputs an applanation signal while the air is being sprayed from the nozzle to the subject eye, wherein the current application control unit stops the second application processing when a peak of the applanation signal output from the receiving optical system is detected while the second application processing is being performed.

9 . The contactless ophthalmotonometer according to claim 1 ,
wherein the actuator is a rotary actuator configured to cause the piston to move inside the cylinder through a crank mechanism.

10 . A method for actuating a contactless ophthalmotonometer, the contactless ophthalmotonometer including:
a cylinder; a piston movably provided inside the cylinder; an actuator configured to move the piston inside the cylinder with current applied to the actuator to compress air inside the cylinder with the piston; a nozzle in communication with the inside of the cylinder, the nozzle configured to spray the air compressed with the piston to a subject eye, the method including: performing first application processing for applying the current of a first current value to the actuator when the current is to be applied to the actuator; and switching the first application processing to second application processing for applying the current of a second current value higher than the first current value to the actuator when a predetermined switching condition is satisfied while the first application processing is being performed.

Assignees

• Topcon Corp

Inventors

• Koshihara Shiori
• Nakamura Satoshi
• FURUGAICHI Taketo
• Harada Akihiro

Classifications

• A61B3/165 Primary

  Non-contacting tonometers · CPC title

• A61B3/0025

  characterised by electronic signal processing, e.g. eye models · CPC title