JPS6225379B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a laser surgical treatment device, such as Nd:
This invention relates to a laser surgical treatment device that uses infrared laser light such as a YAG laser core grater.

In this type of surgical treatment apparatus, since the laser light is in the infrared region and is invisible light, visible light is required as a guide light in order to aim at the irradiated area and confirm the irradiated area with the naked eye.

First, an example of a conventional laser surgical treatment device will be explained with reference to FIG. 1. 1 is a YAG laser device that outputs a laser beam L with a wavelength of 1.06 μm, 2 is a laser rod, 3 and 4 are resonator reflectors, and 5 is the wavelength
A He-Ne laser device that outputs a laser beam L' of 0.6328 μm, 6 a reflecting mirror, and 7 an optical system that transmits the YAG laser beam L and reflects the He-Ne laser beam L' to align the optical axes of both laser beams. 8 is a condenser lens, 9 is a light guide system such as an optical fiber, a manipulator, a self-cleaning lens, etc., and 10 is an irradiated part. When aiming, the He-Ne laser device 5 is activated to emit He-Ne laser beam L. ' is used as a guide light, and during surgical treatment, the YAG laser device 1 is activated to irradiate the site with a strong YAG laser beam for photocoagulation (core grate). In addition, as shown in Fig. 2, there is a He-
A Ne laser device 5 is provided, and a He-Ne laser beam L' is emitted, for example, through a mirror 11 and an optical axis alignment mirror 12.
The mirrors 3' and 4' are placed on the optical axis of the YAG laser beam L, and mirrors 3' and 4' are formed to form a resonator of the YAG laser device and to transmit the He-Ne laser beam, and operate in the same manner as in Fig. 1. I'm letting you do it.

However, such a conventional device has the disadvantage that it is difficult to align the optical axes of the YAG laser beam L and the He--Ne laser beam L', and that a large number of adjustment steps are required to accurately align the two optical axes. moreover
Since the He--Ne laser beam L' is a red light, it is extremely difficult to see tissues in body cavities or under the epidermis, and therefore has the disadvantage that aiming operation is difficult.
Since two laser light sources, a Sarara YAG laser device and a He-Ne laser device, are used, the surgical treatment device has the disadvantage of being large, heavy, and expensive.

Furthermore, there are surgical procedures that use xenon arc lamps as guide light sources, but as mentioned above, many adjustment steps are required to align the optical axis, and the guide light has the same color as the endoscope field illumination light, making aiming operations difficult. It has the disadvantage of being.

The object of the present invention is to provide a laser surgical treatment device that eliminates the drawbacks of the conventional devices mentioned above.

Therefore, according to the present invention, in a laser surgical treatment device configured to condense invisible laser light from a laser device and guide it to an irradiated area via a light guide system,
In order to illuminate the irradiated area with visible light when aiming,
A harmonic generation device that generates harmonics in the visible range from the invisible laser light and an optical means that passes only the harmonics to the light guide system are inserted into the optical path of the invisible laser light, and during surgical treatment, In order to irradiate the irradiated portion with the invisible laser beam, only the optical means or both the optical means and the harmonic generation device are configured to exit from the optical path.

According to the laser surgical treatment apparatus of the present invention configured as described above, invisible laser light for surgical treatment is incident on the harmonic generator, and the harmonics generated therefrom, particularly the second harmonic, are used as guide light, In this case, due to the generation principle, the optical axes of the transmitted laser beam and the second harmonic do not shift, so the number of steps for aligning the optical axes as described above can be significantly reduced, and the laser beam at the output end of the light guide system can be adjusted. The magnitude of the deviation from the guide light depends only on the chromatic aberration of the condensing lens system, so the advantage is that the deviation between the position aimed by the guide light and the irradiation position of the surgical laser beam can be significantly reduced. play. Further, in the apparatus of the present invention, since the laser device for surgical treatment is also used as a guide light source, the entire surgical treatment apparatus can be made smaller and lighter, and can be manufactured at low cost. Furthermore, in the device of the present invention, if this laser device is, for example, a YAG laser device, the second
Since the harmonics are blue-green light with a wavelength of 0.53 μm, they are very easy to see, and the effect as a guide light is significantly improved, which has the advantage of making aiming operations extremely easy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The case of a core grater using a laser device will be explained with reference to FIGS. 3 and 4. In these figures, the same components as those in FIGS. 1 and 2 are designated by the same reference numerals.

FIG. 3 shows a state in which the laser surgical treatment apparatus of the present invention aims at the irradiated part 10, and FIG. 4 shows a state in which a surgical treatment is performed on the irradiated part 10.

In the embodiment shown in FIG. 3, between the YAG laser device 1 and the condenser lens 8,
In the optical path of the laser beam L with a wavelength of 1.06 μm output from the laser device 1, a second harmonic (wavelength of 0.53 μm) that passes through this laser beam L and serves as a guide light G.
The non-linear optical crystal 14 of the harmonic generator 13 that generates a high-power laser beam L absorbs the laser beam L or reflects it off the optical axis in order to prevent the high-power laser beam L from damaging the operator's eyes. An optical element 16, such as a filter or a beam splitter, is provided to allow only the second harmonic G to pass through to the condensing lens 8. Therefore, during aiming, a portion of the laser beam L output from the YAG laser device 1 excites the nonlinear optical crystal 14 and converts it into a second harmonic G, which is the same as the remaining laser beam L transmitted through this crystal. The laser beam is generated on the optical axis O, and the optical element 16 deflects the laser beam off the optical axis, and the second harmonic G is passed along the optical axis O to the condensing lens 8, and the condensing lens 8 and the light guide system It is possible to perform aiming operation while observing the reflected light with the naked eye through another light guide system or the like.

After this aiming operation is completed, as shown in FIG. 4, the optical element 16 is actuated by its driving device 17 to move the optical element 16 from the optical path of the laser beam L along the optical axis O (for example, from the position shown by the dotted line to the position shown by the solid line). The laser beam L and its second harmonic wave G can be guided to the aimed part of the irradiated part 10 via the condensing lens 8 and the light guiding system 9, and can be photocoagulated. still,
In the figure, reference numeral 15 denotes a control device for a nonlinear crystal 14 constituting a part of the harmonic generator, which will be described later.

Next, a harmonic generator used in the apparatus of the present invention will be explained with reference to FIGS. 5 and 6.

It is known that coherent and strong light such as laser light interacts with materials to cause nonlinear effects and generate harmonics of laser light. ADP, KDP, LiNbO ₃ ,
LiIO ₃ , BNN, D-CDA, and others are known. In order to effectively convert the energy of the incident laser beam L into the second harmonic G as a guide beam using these nonlinear optical crystals, the relationship between the refractive index and each wavelength must satisfy the so-called phase matching condition. This requires an angular tuning method that uses the anisotropy of the refractive index of the extraordinary ray to satisfy matching conditions by adjusting the direction of the birefringent nonlinear optical crystal.
There is a temperature tuning method in which the traveling direction of light is set perpendicular to the optical axis and matching is achieved by changing the temperature of the crystal.

FIG. 5 shows an example of a harmonic generator for the angle tuning method, in which a cut crystal 14 is used for angle tuning.
is fixed on a control device 15 such as a goniometer, and the angle α between the optical axis O of the laser beam L and the optical axis C of the crystal is adjusted with a fine adjustment screw 15' to control the laser beam L and the second
The direction of the crystal in which both refractive indices of the harmonic G are the same is made to coincide with the optical axis O. In this case, as an example, if the light source is an Nd:YAG laser device with a wavelength of 1.06 μm and the crystal is KDP (KH ₂ PO ₄ ), the optical axis c
By setting the incident angle α of the laser beam L to 40°31', the laser beam L with a wavelength of 1.06 μm and the wavelength
The second harmonic G of 0.53 μm can be extracted along the optical axis O.

FIG. 6 shows an example of a harmonic generator using the temperature tuning method, in which the crystal 14 is connected to the heat sink 18.
sandwich-like in a direction along the optical axis O, and housed in an oven 20 having an entrance window 19 and an exit window (not shown) for the laser beam L,
The temperature change of the refractive index of the crystal 14 is adjusted while monitoring the temperature of the crystal 14 obtained from the thermocouple 22 with an external temperature regulator 21. In this case, as an example, the light source has a wavelength of 1.06 μm.
Nd:YAG laser light source is used, and the crystal is D-CDA (C
_s D ₂ A _s O ₄ ), the wavelength is 1.06 μm at a temperature of 102°C.
The laser beam L and the second harmonic G having a wavelength of 0.53 μm can be extracted along the optical axis O.

In any of the harmonic generators described above, if the conversion efficiency of the laser beam to the second harmonic is set to about 0.1% or less, the second harmonic can be obtained with an intensity that does not interfere with aiming. This is compared to the conventional He
-Ne It can be used as a guide light in place of laser light or light from an arc lamp.

In the embodiment of the present invention explained with reference to FIGS. 3 and 4, the YAG laser beam is used as a laser beam for surgical treatment, and the second harmonic is used as a guide light for aiming.The YAG laser beam is cut during aiming. An optical element 16 such as a filter or a beam splitter is used to direct only the guide light to the irradiated area 10.
are using. In this case, when a beam splitter is used as the optical element 16, it generally has the shape of a parallel plane plate and is provided obliquely to the optical axis O.
The guide light transmitted through 6 is shifted from the optical axis O,
Therefore, it is necessary to correct this deviation. 7 and 8 show a simple mechanism for correcting this deviation, and the same components as those shown in FIG. 3 are denoted by the same reference numerals. 23 shown in Figure 7
is an optical axis correction plate for the guide light G, for example, a plate having the same optical properties and shape as the optical element 16, and when aiming, this correction plate 23 and the optical element 16 are used.
are arranged in the optical path between the nonlinear optical crystal 14 and the condensing lens 8 so that they are symmetrical with respect to a plane orthogonal to the optical axis o, and during surgical treatment, the correction plate 23 and the optical The configuration is such that the pair with element 16 is moved out of the optical path. With this configuration, the guide light G whose optical axis has shifted after passing through the optical element 16 is corrected by passing through the correction plate 23, and the condenser lens 8 has a shift in the optical axis. Since the beam enters without any deviation, it is possible to aim accurately. In addition, 24 is a condensing lens, which is provided on the emission side of the YAG laser device 1 in order to effectively utilize the laser beam when the beam diameter of the laser beam L output from the YAG laser device 1 is large. It is.

Figure 8 shows the deviation of the optical axis of the guide light by the condenser lens 8.
A mechanism for correcting by shifting and light guiding system 9 is shown,
In this case, the holding part 25 of the condenser lens 8 is coupled to the incident end 26 of the light guide system 9 so that their optical axes coincide, forming one incident system 27, and the optical element 16, for example, a beam splitter, is connected to the incident end 26 of the light guiding system 9. When the ivy is inserted into or removed from the optical path, the entrance system 27 is moved in the direction shown by the arrow a or b in synchronization with this, and the optical axis of the entrance system 27 is adjusted to the insertion or exit of the light receiving element 16. Displacement of optical axis due to exit (O → G
or G→O), and this follow-up drive is performed, for example, by an incident system drive device 29 connected to the drive device 17 of the light receiving element 16 via a synchronization system 28.

FIG. 9 shows an example of the structure of this entrance system driving device 29. In this embodiment, the step motor 30 is rotated in synchronization with the amount of drive of the light receiving element 16 (the rotation angle of the light receiving element 16 in the embodiment shown in FIG. 8), and the rack 32 is driven by a pinion 31 provided on its shaft. In this configuration, the incident system 27 is moved in a direction perpendicular to the optical axis O.

It is clear that the invention is not limited only to the embodiments described above, but can be subjected to many variations and modifications. For example, FIG. 10 shows an example in which the harmonic generator 13 is disposed between the reflecting mirror 4 and the laser rod 2 that constitute the resonator of the laser device 1, and in this case also, FIGS. The second harmonic can be generated similarly to the embodiment shown.

Furthermore, FIG. 11 shows an embodiment in which the laser surgical treatment apparatus is configured so that the optical axis of the guide light does not shift even when an optical element 16 such as a beam splitter is used. The guide light G generated from the harmonic generator 13 is transferred to the reflecting mirror 34, the beam splitter 16, and the two reflecting mirrors 3.
5 and 36, the optical axis of the guide light G is made to coincide with the optical axis O of the laser light L during surgical treatment, and the laser light L is made to enter the condenser lens 8, and the laser light L is transmitted through the beam splitter 16 to form the guide light. G and the frame 37 shown in broken lines during surgical procedures.
The laser beam output from the laser device 1 without removing the components 13, 34, and 36 shown in the figure from the optical path of the laser beam L is transmitted to the condensing lens 33 and the relay lens 3.
8 and enters the condenser lens 8.

Furthermore, as shown in FIG. 12, the laser beam L is deflected from the optical axis o by the beam splitter 16 during aiming.
It is also possible to guide the laser beam L to a power meter 39 and measure the output of the laser beam L at the same time as aiming, or to guide it to an absorber and absorb it to ensure safety.

Furthermore, in the embodiments shown in FIGS. 3 and 4, a condensing lens is provided on the emission side of the laser device 1 to effectively utilize the laser beam, as in the embodiments shown in FIGS. 7, 11, and 12. It is clear that it is possible to achieve this goal.

Furthermore, although the second harmonic of the laser beam was used as the guide light in the above-described embodiment, other harmonics within the visible range or optical mixed waves may be used.

Further, although the above-mentioned embodiments have been described with reference to a laser core grater, the present invention can also be used in other surgical treatment devices, and a condensing lens may be inserted between the light guide system 9 and the irradiated area 10. The light beam from the light guide system 9 may be focused on the irradiated portion 10.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams for explaining a conventional laser surgical treatment device, and FIGS. 3 and 4 are schematic diagrams illustrating an embodiment of the laser surgical device of the present invention, respectively. Figures 5 and 6 are schematic diagrams for explaining the harmonic generator used in the devices shown in Figures 3 and 4, and Figures 7 to 9 correct the deviation of the optical axis of the guide light. Schematic diagrams 10 to 12 each showing an example of a correction mechanism for
The figures are schematic diagrams respectively showing other embodiments of the invention. 1...Laser device, 2...Laser rod, 3,
4...Reflector (for resonator), 8, 24, 33...
... Condensing lens, 9 ... Light guide system, 10 ... Irradiated part, 13 ... Harmonic generator, 14 ... Nonlinear optical crystal, 15 ... Control device, 15' ... (Control device) slight movement Screw, 16... Optical element, 17... (Optical element) drive device, 18... Heat sink, 1
9...Incidence window, 20...Oven, 21...Temperature regulator, 22...Thermocouple, 23...Correction plate, 25
...Holding part (of the condensing lens), 26...Incidence end (of the light guiding system), 27...Incidence system, 28...Synchronization system,
29...Injection system drive device, 30...Step motor, 31...Pinion, 32...Rack, 34,
35, 36...reflector, 38...relay lens,
39...Power meter or absorber.

Claims (1)

[Claims] 1 In a laser surgical treatment device configured to condense invisible laser light from a laser device and guide it to the irradiated area via a light guide system, the invisible laser beam is used to illuminate the irradiated area with visible light when aiming. A harmonic generation device that generates harmonics in the visible range from this invisible laser light and an optical means that passes only the harmonics to the light guide system are inserted into the optical path of the invisible laser beam, and during surgical treatment, the irradiated area A laser surgical treatment apparatus characterized in that the optical means alone or both the optical means and the harmonic generation device are moved out of the optical path in order to irradiate the area with the invisible laser light.