JPH01320042A - Non-contact tonometer - Google Patents

Abstract

PURPOSE:To prevent a cloud of optical parts to compose a chamber and to reduce an unpleasant feeling depending on the release of a cool compressed gas by heating the compressed gas accumulated airtight. CONSTITUTION:A space heater 1A is provided in a cylinder 1. The space heater 1A functions as a heating device to heat a compressed gas accumulated in an airtight chamber 6, and a current is fed when the temperature of the compressed gas is lower than the outer air temperature, to heat the compressed gas. By adjusting the alignment of a meter main body to a coronea C to inspect, and feeding a current to a coil 56, a movable iron core 58 is moved in the direction of the arrow against the enforced power of a spring 62, a valve body 11 opens a linking hole 9, and the compressed gas is released to the coronea C to inspect from a nozzle 18. In this case, since the compressed gas is heated, a cloud of the optical parts to compose a chamber 13, and an unpleasant feeling to a person to inspect can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a non-contact tonometer that measures the intraocular pressure of an eye to be examined using compressed gas contained in a cylinder.

(Prior art) Conventionally, compressed gas contained in a cylinder is introduced into an airtight chamber communicating with a chamber, the airtight chamber is opened, and the compressed gas is released from a nozzle communicating with the chamber toward the cornea of the eye to be examined. However, a non-contact tonometer that measures the intraocular pressure of the eye to be examined is known.

This type of non-contact tonometer measures the intraocular pressure value based on the time from when compressed gas starts to be discharged toward the subject's eye until the subject's eye undergoes a predetermined deformation.

(Problems to be Solved by the Invention) By the way, in this type of non-contact tonometer, if the airtight chamber is opened and the compressed gas stagnant in the airtight chamber is directly guided into the chamber, the compressed gas ejected from the cylinder is Since the compressed gas cools due to its expansion, the temperature of the airtight chamber becomes lower than the outside temperature, which causes a problem that optical components such as window glass forming the chamber become foggy. Furthermore, depending on the environmental conditions, fogging may occur in the optical components when the compressed gas is discharged from the airtight chamber toward the chamber.

Furthermore, since the cold compressed gas is emitted towards the subject's eye, there is also the problem of causing discomfort to the subject.The present invention has been made in view of the above circumstances, and its purpose is to Another object of the present invention is to provide a non-contact tonometer that can prevent fogging of optical components constituting a chamber and can reduce discomfort to a subject.

(Means for Solving the Problems) A feature of the non-contact tonometer according to the present invention is that it is provided with a heating means for heating the compressed gas retained in the airtight chamber.

(Function) According to the non-contact tonometer according to the present invention, since the compressed gas retained in the airtight chamber is heated, it is possible to prevent fogging of the optical components constituting the chamber, and the gas is discharged from the nozzle. Since the compressed gas is warm, discomfort due to the release of cold compressed gas can be avoided.

(Example) Hereinafter, an example of a non-contact tonometer according to the present invention will be described with reference to the drawings.

1 and 2 are diagrams showing a compressed gas release system of a non-contact tonometer according to the present invention, and in FIG.
is the cylinder, 2 is the cylinder, 3 is the case for installing the cylinder,
4 is a nozzle head section.

The cylinder 1 has a cylinder wall 5. The inside of this cylinder wall 5 is an airtight chamber 6. A connecting cylinder part 7 is formed in the upper part of the cylinder wall 5.
The bottom part is a connecting cylinder part 8. The connecting cylinder portion 7 has a communication port 9 that communicates with the airtight chamber 6 . The communication port 9 is a valve device 11
0 is opened and closed, and 11 is a valve body. This valve device 1
The configuration and operation of 0 will be described again.

The nozzle head portion 4 has a support 12 . The support body 12 has a chamber 13 and a connecting cylinder portion 14 .

A nozzle receiver tube 15 is attached to the support body 12. In this nozzle receiver, a cover glass 16 is fixed to the cylinder 15,
A window glass 17 is attached to the support 12 so as to face the cover glass 16 .

A nozzle 18 is provided between the cover glass 16 and the window glass 17.
The stake has been passed. The connecting cylinder part 14 and the connecting cylinder part 7 are connected via a tube 19.

In addition, 20 is a set screw for fixing the window glass 17 to the support body 12, 21 is a window glass that constitutes a part of the chamber 13, and the light beam of the optical system (not shown) is the window glass 21.17, The light flux guided to the cornea C of the eye to be examined via the cover glass 16 or reflected by the cornea C of the eye to be examined is transmitted to the window glass 21.17 and the cover glass 1.
6 to an optical system (not shown).

The cylinder mounting case 3 functions as a pressure maintaining means located between the cylinder 2 and the airtight chamber 6, and is composed of a main body case 22 and a presser cover member 23. has a flange 24. A diaphragm 25 is provided between the presser cover member 23 and the main body case 22. The periphery of this diaphragm 25 is held between the flanges 24, and the cylinder mounting case 3 is defined as a double AS B. Room A is communication port 2
It communicates with the atmosphere via 3a. Note that 26 is a set screw for fixing the presser lid member 23 to the main body case 22, and 27 is a sealing member.

The main case 22 includes a cylinder mounting cylinder 28 and a connecting cylinder part 2.
9 is provided. The connecting cylinder part 29 is connected to the connecting cylinder part 8 via a tube 30. tube 3
Tube holding members 31 and 32 are provided at both ends of the tube. The tube holding members 31, 32 are fixed to both ends of the tube 30 by holding screws 33, 34. The tube 30 has its tube holding member 31.
32, fixed to the connecting cylinder part 8.29 by set screws 35.36. Note that 37 and 38 are seal members.

The cylinder mounting cylinder 28 has a flange portion 39 .

The cylinder mounting cylinder 28 is defined into a cylinder part 40 and a cylinder part 41 with this flange part 39 as a boundary. A threaded portion 42 is formed on the outer periphery of the cylindrical portion 40 . A threaded portion 43 is formed on the inner periphery of the cylindrical portion 41 . The threaded portion 42 is screwed into a threaded portion 45 formed on the wall portion 44 of the main body case 22 . The flange portion 39 of the cylinder mounting cylinder 28 is connected to the wall portion 44.
It is fixed to the main body case 22 by screwing together the threaded parts 42 and 45 until they come into contact with the main body case 22.

The cylindrical portion 40 has a wall portion 46 . The wall portion 46 faces the diaphragm 25, and a spout 47 and a guide hole are formed in the wall portion 46. A movable shaft 49 is inserted through the guide hole 48 . A joint portion 50 is provided at one end of the movable shaft 49, and a spring holder 51 is provided at the other end.

The spring holder 51 inserts the movable shaft 49 into the guide hole 48,
After the spring 52 is inserted into the movable shaft 49, it is fixed to the other end of the movable shaft 49.

The joint portion 50 is connected to the diaphragm 25 using an adhesive. The cylinder 2 has a valve stem 53 on its head and a threaded portion 54 on the outside of its head. The cylinder 2 is screwed onto the cylinder mounting tube 28 by screwing the threaded portion 54 into the screw portion 43. Note that 55 is a sealing member.

At the beginning when the pressure in chamber B is low, the diaphragm 25
It is relaxed as shown in FIG. Valve stem 53 is cylinder 2
By attaching the cylinder to the cylinder mounting cylinder 28, the cylinder comes into contact with the spring holder 51 and is pushed into the cylinder. As a result, compressed air is blown out from the cylinder 2. This ejection of compressed air increases the pressure in the chamber B, causing the diaphragm 25 to swell as shown in FIG. 2, and the movable shaft 49 to move in the direction of the arrow against the biasing force of the spring 52. At the same time, compressed gas flows into the airtight chamber 6 via the tube 30. that time,
The gas in chamber A is exhausted to the atmosphere. This expansion 11 of the diaphragm 25 causes the valve stem 53 and the spring holder 5 to
1 and are separated. As a result, the valve rod 53 closes the mouth of the cylinder 2, and discharge of compressed air from the cylinder 2 is stopped.

Note that a return urging force is stored in the spring 52 due to the expansion of the diaphragm 25.

The cylinder 1 is provided with a space heater IA. This space heater IA has a flat plate shape. The space heater IA is connected to a power source (not shown) by a cord IB. This space heater IA functions as a heating means for heating the compressed gas retained in the airtight chamber 6, and the space heater IA is energized when the temperature of the compressed gas is lower than the outside temperature. to warm up. Note that instead of providing the space heater IA in the airtight chamber 6, a configuration may be adopted in which a heater is provided in the chamber 13.

The valve device 10 includes a coil 56, a coil holder 57, a movable iron core, a coil lid 59, and a shaft member 60. Valve body 11
is attached to the tip of the shaft member 60. Shaft member 60
The rear end is a movable iron core 58. This movable iron core 58
has entered the coil holder 57. The coil holder 57 is supported by a support portion (not shown). Shaft member 6
A spring holder 61 is fixed to the coil holder 0, and a spring 62 is interposed between the spring holder 61 and the coil holder 57. The valve body 11 is connected to the communication port 9 by this spring 62.
is biased in the direction of closing. Note that 63 is a sealing member that is attached to the cylinder wall 5.

Therefore, when the alignment of the instrument body with respect to the cornea C of the eye to be examined is adjusted and the coil 56 is energized, the movable core 58 is moved in the direction of the arrow against the biasing force of the spring 62.
The valve body 11 opens the communication port 9, whereby compressed gas is discharged from the nozzle 18 toward the cornea C of the eye to be examined. Here, since the compressed gas is heated, fogging of the optical components constituting the chamber 13 and discomfort to the subject are prevented when the compressed air is released. When the coil 56 is de-energized, the return urging force of the spring 52 moves the valve body 11 in the direction opposite to the direction of the arrow, and the communication port 9 is closed again. Due to the release of this compressed gas, the pressure in the airtight chamber 6 decreases,
Along with this, the pressure in chamber B also gradually decreases. Therefore,
The force that moves the movable shaft 49 in the direction opposite to the arrow direction due to the return urging force of the spring 62 gradually becomes larger than the force that moves the movable shaft 49 in the direction of the arrow based on the pressure in the chamber B, and the spring holder 61 By contacting the valve stem 53, the valve stem 53 is pushed into the cylinder again. Therefore, the mouth of the cylinder 2 is opened again, and the compressed air in the cylinder 2 flows into the chamber B.

In addition, in this embodiment, if the amount of compressed gas in the cylinder 2 becomes extremely small, it becomes impossible to maintain the pressure in the airtight chamber 6 constant; A pressure sensor 64 is provided on the cylinder wall 5 to detect this. Therefore, by using a warning means to inform the operator that the pressure in the airtight chamber 6 has fallen below a predetermined level, it is possible to prompt the operator to replace the cylinder 2.

As described above, in the embodiment, the cylinder mounting case 3 as a pressure maintaining means has the diaphragm 25, but instead of providing the diaphragm 25, a valve is provided in the connecting cylinder part 29 and the valve is adjusted based on the signal from the pressure sensor 64. It is also possible to maintain a constant pressure in the airtight chamber 6 by opening and closing a valve and controlling the amount of compressed gas flowing into the airtight chamber 6.

(Effects of the Invention) As explained above, the present invention heats the compressed gas retained in the airtight chamber, thereby reducing fogging of the optical components constituting the chamber and discomfort to the subject. This has the effect of making it possible to achieve the following.

[Brief explanation of the drawing]

FIGS. 1 and 2 are sectional views of essential parts showing a compressed gas release system of a non-contact tonometer according to the present invention.

Claims (1)

[Claims] (1) The compressed gas contained in the cylinder is guided into an airtight chamber communicating with the chamber, the airtight chamber is opened, and the compressed gas retained in the airtight chamber is delivered to the cornea of the eye to be examined through a nozzle communicating with the chamber. A non-contact tonometer that measures the intraocular pressure of the eye to be examined by emitting gas toward the subject's eye, characterized in that the non-contact tonometer is provided with a heating means for heating the compressed gas guided into the airtight chamber. Pressure gauge.