JPH0588607B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a non-contact device that deforms the cornea by blowing gas onto the cornea of the eye to be examined, and optically detects the deformation to measure intraocular pressure. This relates to a type tonometer.

[Prior Art] For example, in a conventional non-contact tonometer that uses air pulses, an air pulse is blown onto the cornea of the eye to be examined from the axial direction of the device, and the intraocular pressure is determined by the time it takes for the cornea to be applanated. Measuring.

This air pulse injection mechanism rotates a rotary solenoid 1 by a certain angle as shown in FIG.
is moved to position 4', thereby compressing the air in cylinder 5 in chamber 6, and moving objective lens 7 to position 4'.
Air pulses are ejected toward the eye E from a nozzle 8 provided at the center of the eye. After the air is injected, the piston 4 returns from the position 4' to its original position, and at that time external air is automatically sucked in from the nozzle 8 to be used for the next injection. In addition, in Fig. 3, 9 is the chamber 6.
It shows a transparent member that is part of the optical axis L and is placed on the optical axis L.

In this case, the air blown onto the cornea Ec is sucked in from the nozzle 20 as described above, so it sucks in dust as well, and this dust blows onto the cornea.
If sprayed onto Ec, this dust may damage the cornea Ec.

[Object of the Invention] An object of the present invention is to provide a non-contact tonometer that eliminates the drawbacks of the conventional example and can use clean gas without damaging the cornea.

[Summary of the invention] The gist of the present invention for achieving the above object is as follows:
A non-contact tonometer that sprays gas onto the cornea of the eye to be examined and measures intraocular pressure based on the deformation of the cornea, comprising a supply source of the spraying gas and a gas storage means connected to the supply source, The non-contact tonometer is characterized in that the gas from the supply source is once stored in the gas storage means, and then the gas is blown onto the subject's eye from the gas storage means.

[Embodiments of the Invention] The present invention will be explained in detail based on the embodiments shown in FIGS. 1 and 2.

FIG. 1 shows only the gas injection mechanism of the non-contact tonometer according to the first embodiment, and the measurement optical system and other members arranged on the optical axis L are not shown. In FIG. 1, numeral 10 indicates a high-pressure tank, in which a gas such as carbon dioxide, which does not contain dust and has a specific gravity greater than air, is compressed to about 100 atmospheres or more and stored. A secondary tank 12 is connected thereto. This secondary tank 12 is for filling gas necessary for one measurement, and the output of the pressure detection means 13 provided on the side thereof is connected to the controller 14, and the outlet of the secondary tank 12 is connected to the controller 14. The side is connected via a valve 15 to a chamber 16 . A solenoid 17 that opens and closes the valve 11 and a solenoid 18 that opens and closes the valve 15 are each operated by an output from the controller 14. Further, for example, an objective lens 19 is disposed in a portion of the chamber 16 facing the eye E to be examined, and a nozzle 20 is attached to the center thereof.

At the measurement preparation stage, the valve 15 is closed, and the valve 11 is opened by the solenoid 17, and the secondary tank 12 is filled with several atmospheres of gas necessary for one measurement, and the pressure is maintained at a predetermined level. This is detected by the pressure detection means 13 and the valve 11 is closed. At the start of measurement, when the valve 15 is opened by the solenoid 18, the gas in the secondary tank 12 is discharged into the chamber 16 while being controlled by the valve 15, and is injected from the nozzle 20 toward the eye E to be examined.

This series of operations is all controlled by the controller 14. The secondary tank 12 is provided in consideration of ensuring safety for the eye E to be examined and facilitating control of the valve 15.

By doing so, clean gas that does not contain dust can be blown onto the cornea Ec, and there is no possibility that the cornea Ec will be damaged by dust.

In addition, in order to applanate an area with a diameter of approximately 3.6 mm at the center of the cornea using such a conventional mechanism, nozzle 2 must be used.
It is necessary to bring the distance between the tip of the nozzle 20 and the cornea Ec close to about 12 mm, and because the distance is so close, the eyelashes of the eye E to be examined may touch the tip of the nozzle 20, making the measurement inaccurate, or the examiner On the other hand, there is also the problem that sufficient care must be taken to prevent the nozzle 20 from coming into contact with the cornea Ec of the eye E to be examined.

In this case, if a gas with a higher specific gravity than air is used as in the example, the nozzle and cornea
The distance between Ec and Ec can be made larger than before,
There is also less risk that the eyelashes will swing to the tip of the nozzle 20 and adversely affect the measurement, or that the nozzle 20 will come into contact with the eye E to be examined.

In FIG. 2, a rotary solenoid 30 is used to compress gas, and a high-pressure tank 3 filled with clean gas via a valve 31 is installed in the chamber 16.
2 are connected. The actuation of the rotary solenoid 30 drives the piston 35 within the cylinder 36 via the arm 33 and piston rod 34.
Compressing the gas is similar to the conventional example shown in FIG. The rotary solenoid 30 is actuated by a command from a controller 37, and the valve 31 is actuated via a solenoid 38 which similarly moves in synchronization with the rotary solenoid 30 by a command from the controller 37.

In this case as well, clean gas can be used as in the previous embodiment, and there is no risk of damaging the cornea Ec.

In addition, instead of using the high-pressure tank 10 in FIG. 1 and the high-pressure tank 32 in FIG. 2, in hospitals etc., the oxygen pipes etc. that are piped to examination rooms etc. are connected directly to the chamber via a valve. It's fine.

[Effects of the Invention] As explained above, the non-contact tonometer according to the present invention can use clean gas that does not contain dust, and there is no risk of blowing dust onto the cornea and damaging the cornea. Further, the gas from the supply source can be converted into a suitable state and sprayed onto the subject's eye.

[Brief explanation of the drawing]

1 and 2 are block diagrams of a gas injection mechanism according to an embodiment of the non-contact tonometer according to the present invention, and FIG. 3 is a block diagram of a conventional example. Codes 10, 32 are high pressure tanks, 11, 15, 3
1 is a valve, 12 is a secondary tank, 13 is a pressure detection means, 14, 37 are controllers, 16 is a chamber, 17, 18, 38 are solenoids, 19 is an objective lens, 20 is a nozzle, 30 is a rotary solenoid, 36 is It is a cylinder.

Claims (1)

[Claims] 1. A non-contact tonometer that measures intraocular pressure based on the deformation of the cornea by blowing gas onto the cornea of the eye to be examined,
The method includes a supply source of the spraying gas and a gas storage means connected to the supply source, and after the gas from the supply source is once stored in the gas storage means, the gas is sprayed from the gas storage means onto the subject's eye. A non-contact tonometer characterized by: 2. The non-contact tonometer according to claim 1, wherein the gas is supplied in a pre-compressed state from a high-pressure tank as the supply source. 3. The non-contact tonometer according to claim 1, wherein the gas has a higher specific gravity than air.