JPH0649083B2 - Laser therapy equipment - Google Patents

Description

Description: FIELD OF THE INVENTION This invention relates to laser treatment devices.

2. Description of the Related Art For example, eye treatment is performed using laser light emitted from a laser light source. The spot size of this type of laser light is one of the treatment conditions, and it is necessary to change it according to the type and content of the treatment.

However, conventionally, the spot size has been changed by moving the optical fiber closer to or further from the diseased part.

Further, there is also one in which the tip size of the optical fiber is formed as a separate piece, and the spot size is changed by changing several kinds of optical fibers having different diameters to the tip part.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above-described method of changing the spot size by changing the distance between the optical fiber tip and the diseased part, if the aperture angle of emission from the optical fiber is set to be small, the optical fiber tip and the diseased part The change amount of the spot size with respect to the change of the distance is small, and the spot size does not change unless it is moved considerably.

On the other hand, when the exit aperture angle is set to a large value, the change in spot size can be easily obtained, but when the small spot size is desired, the tip of the optical fiber must be brought very close to the diseased part. In particular, intraocular photocoagulation is dangerous because it may damage the retina.

It is an object of the present invention to change the aperture angle of laser light emitted from a light guide optical system to change the spot diameter of laser irradiation without changing the distance between a diseased part of a patient and the tip of an optical fiber. The purpose is to have done.

SUMMARY OF THE INVENTION This invention has a laser treatment device as claimed in the claims.

Means for Solving the Problems Reference is made to FIG.

The condensing optical system is the zoom optical system 3, and the numerical aperture of the laser light flux when the laser light is incident on the optical fiber 10 which is the light guiding optical system is made variable.

Action By changing the aperture angle A of the laser light flux incident on the optical fiber 10 of the laser light 8 as shown in FIGS. 2 and 3, the aperture angle of emission from the tip portion 12 which is the laser light emission end is changed.
Therefore, the spot size is changed while keeping the distance between the tip portion 12 and the diseased portion 15 constant.

Example 1 Referring to FIG.

The output of the laser light source 1 is controlled by the laser control device 2.

The zoom optical system 3 is located between the condenser lens 4 and the laser light source 1. The zoom optical system 3 has concave lenses 5 and 6 and a convex lens 7. Movable part 20 including concave lens 6 and convex lens 7
Can be moved in the optical axis direction by the laser control device 2.

The concave lens 6 and the convex lens 7 can be moved separately.

The laser light 8 of the laser light source 1 passes through the zoom optical system 3 and is condensed by the condenser lens 4. The condensed laser light enters the entrance end of the optical fiber 10 and is irradiated from the tip 12 of the handpiece 11 to the diseased part 15 on the retina 14 of the fundus of the affected eye 13.

The tip portion 12 passes through the sclera 16 of the affected eye 13 and is inserted into the vitreous body 17.

When the light is focused and incident at a numerical aperture (NA) or less of the optical fiber 10, the aperture angle of the beam of the laser light 22 emitted from the optical fiber 10 is substantially equal to the numerical aperture of the laser light flux at the time of incidence. This is because the incident light passes through the inside of the core of the optical fiber 10 while being repeatedly reflected, and when it is emitted from the emission end, the light is emitted with an aperture angle substantially equal to the numerical aperture of the laser light flux when it is incident. Therefore, if the incident light has a small numerical aperture, it will have a small aperture angle, and if the numerical aperture is large, it will have a large aperture angle.

The opening angle of the laser beam 22 emitted from the optical fiber 10 is
By making the zoom optical system 3 changeable, when a small spot size is desired, the aperture angle A1 of the incident laser light beam can be reduced as shown in FIG.
The distance between the tip portion 12 of 0 and the diseased portion 15 can be increased as indicated by L, and safe treatment can be performed.

Further, when the spot size is preferably large as shown in FIG. 3, the distance L between the distal end portion 12 of the optical fiber 10 and the diseased portion 15 can be extremely increased by increasing the aperture angle A2 of the incident laser beam. You can get it without doing it.

In this way, the spot size can be changed without changing the distance L between the tip 12 of the optical fiber and the diseased part 15.

Example 2 Reference is made to FIG. 4 and FIG.

In this embodiment, the diaphragm 33 is used. The aperture changes the numerical aperture of the laser light. In FIG. 4, the diaphragm 33 is opened, and the aperture angle A of the incident laser beam is
3 is big. In FIG. 5, the diaphragm 33 is slightly closed, and the opening angle A4 of the incident laser beam is small. This method is optimal because it can be easily performed when the laser light has a margin.

The laser light 8 from the laser light source 1 is a beam expander 4
After passing through the lenses 30 and 31 of 0, the light is converged by the diaphragm 33 and condensed by the condenser lens 32 to enter the incident end of the optical fiber 10.

The present invention is not limited to the above embodiment. A mechanical diaphragm or an electric diaphragm can be adopted as the diaphragm.

Advantageous Effects of the Invention Since the distance between the diseased part of the patient and the emitting end of the laser beam can be kept constant and sufficiently without being affected by the size of the spot diameter, accidental damage to the diseased part is prevented and the safety of laser treatment is improved. Can be improved. Also, the size of the spot diameter can be easily changed.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a laser treatment apparatus of the present invention, FIGS. 2 and 3 are operation diagrams of the first embodiment, and FIGS.
The figure shows the second embodiment. 1 ... Laser light source 2 ... Laser control device 3 ... Zoom optical system 4 ... Condensing lens 10 ... Optical fiber 15 ... Disease part

Claims (1)

[Claims] 1. A laser treatment apparatus for guiding a laser beam emitted from a laser light source to a light guide optical system through a focusing optical system to irradiate and treat a diseased part of a patient, wherein the focusing optical system is a zoom optical system. The laser treatment device is characterized in that the numerical aperture of the laser beam when entering the light guiding optical system is variable.