WO2006030622A1

WO2006030622A1 - Laser therapeutic device

Info

Publication number: WO2006030622A1
Application number: PCT/JP2005/015629
Authority: WO
Inventors: Isami Nitta
Original assignee: Niigata University
Priority date: 2004-09-01
Filing date: 2005-08-29
Publication date: 2006-03-23
Also published as: JPWO2006030622A1

Abstract

A laser therapeutic device capable of applying a laser beam uniformly and accurately only to a location to be treated with little thermal damage to normal tissues surrounding a lesion to be treated. The device comprises a laser oscillator (1) for generating a laser beam (30), a beam expander (10) for expanding the beam size of the laser beam (30) emitted from the laser oscillator (1), a laser scanning means (12) for scanning in an appropriate pattern the laser beam (30) incident via the beam expander (10), a condensing means (16) for finely narrowing down the laser beam (30) scanned by the laser scanning means (12), and an irradiation control means (6) for changing the irradiation time of the laser beam (30) finely condensed by the condensing means (16). A laser beam finely narrowed down is applied over the entire scanning area to enable a necessary amount to be applied effectively to only a location to be treated.

Description

Specification

Laser therapy device

Technical field

[0001] The present invention relates to a laser treatment apparatus that performs treatment by irradiating a living body tissue with laser light, particularly a tissue such as a nevi, skin tumor, or hemangioma.

Background art

In recent years, photothermal therapy and photochemotherapy using laser light have been performed in the treatment of lesion tissues such as nevus, skin tumors, and hemangiomas in dermatology and plastic surgery.

[0003] For example, a photothermal treatment method in which a lesioned tissue caused by a bruise is irradiated with laser light has been performed. Among the bruises, blue bruise and black bruise are skin diseases in which melanin increases locally and may increase in the epidermis or in the dermis. The principle of photothermia treatment for blue bruises and black bruises is a method that treats bruises by absorbing laser light into melanin, a lesion pigment, causing thermal destruction, and phagocytosing the destroyed melanin by macrophages. is there. On the other hand, red bruises are skin lesions that appear red due to the presence of a large number of red blood cells in the dermis or subcutaneous adipose tissue, where blood vessels dilate and grow. The principle of photothermia treatment for red bruises is that the hemoglobin in the red blood cells absorbs the laser light, the red blood cells are thermally coagulated 'thermally destroyed, and the blood vessels are shrunk to create a thrombus, thereby crushing the blood vessels and treating the bruises It is a method to do.

[0004] As described above, photothermal therapy is performed by irradiating a diseased tissue with laser light, causing the lesion cells that form the diseased tissue to absorb the light energy, and converting the absorbed light energy into heat. In this therapy, the diseased cells are destroyed by heat and the affected tissue is removed, coagulated and destroyed. In such a laser treatment method, the wavelength of the laser beam and the irradiation time of the laser beam are important parameters. For example, the laser absorptance of the lesion yarn and weave varies depending on the wavelength of the laser beam, and the depth (light penetration depth) at which the laser beam reaches the living tissue also varies. In addition, regarding the laser beam irradiation time, even if the laser beam is selectively absorbed by a diseased tissue such as a bruise, if the irradiation time is too long, a thermal effect is exerted on the surrounding tissue due to thermal diffusion, causing burns. Gatsutsu Therefore, it is necessary to select the wavelength and irradiation time of the laser beam according to the type of bruise, and the problem that the laser beam has to be irradiated in a shorter time than the time of heat diffusion (thermal relaxation time). was there.

[0005] Further, in the photothermal treatment method, in order to coagulate and denature the protein in the diseased tissue to cause thermal destruction, the temperature of the diseased tissue has to be about 60 to 65 ° C. This is because the temperature of the diseased tissue is lower than 60 ° C. In this case, the laser beam energy is only stimulated and mildly heated, and the structural change of the diseased tissue does not occur, and it is higher than 65 ° C and higher than 100 ° C. If the temperature is lower, the moisture of the living tissue is reduced, and the tissue is dried and contracted. Further, when the temperature exceeds 100 ° C, the living tissue is burned and carbonized, and the living tissue is lost.

[0006] Therefore, for example, a laser treatment apparatus disclosed in Patent Document 1 is known as a laser treatment apparatus capable of easily adjusting a desired irradiation energy density and performing appropriate treatment. This apparatus is a laser treatment apparatus that irradiates an affected area of a patient with a therapeutic laser beam, and variably sets the output energy setting means for variably setting the output energy of the laser beam and the beam diameter of the laser beam on the affected area. A beam diameter setting means, an energy density calculation means for calculating the energy density of the laser beam on the affected area based on the set output energy and beam diameter, and an energy density display means for displaying the obtained energy density It is equipped with. Patent Document 1 describes that, according to this apparatus, the irradiation beam diameter can be varied in the range of 3 to 10 mm by the beam diameter setting means for variably setting the beam diameter of the laser beam.

Patent Document 1: Japanese Unexamined Patent Publication No. 2000-60894

Non-Patent Document 1: "Laser treatment of bruises" by Hirayama Shun, Tezuka Tadashi, Ohara Kuniaki edited by Katsuseido Publishing (1st edition), 21-37, 131-147, 1997

Disclosure of the invention

Problems to be solved by the invention

[0007] However, in the apparatus described in Patent Document 1 and the conventional laser treatment apparatus (Non-Patent Document 1), the laser beam diameter (diameter: about 2 to: LOmm) is large. There was a problem that the tissue was also irradiated with laser. Therefore, it can treat bruises, but there is a risk of secondary burns. It has been protracted. Furthermore, since the conventional laser treatment apparatus has to manually irradiate a wide range of lesioned tissue with a laser beam a plurality of times, the amount of laser irradiation has become uneven.

[0008] Therefore, the present invention provides a laser treatment apparatus that reduces thermal injury to normal tissue around a lesion to be treated and can apply laser light accurately and uniformly only to the treatment site. For the purpose.

Means for solving the problem

[0009] The laser treatment device according to claim 1 of the present invention includes a laser oscillator that generates laser light, a beam expander that expands a beam size of the laser light emitted from the laser oscillator, and the beam extractor. Laser scanning means for scanning laser light incident through the panda in an arbitrary pattern, condensing means for finely narrowing the laser light scanned by the laser scanning means, and finely condensed by the condensing means And an irradiation control means for controlling the irradiation time of the laser beam.

[0010] The laser treatment device according to claim 2 of the present invention is the laser treatment device according to claim 1, wherein the condensing means includes an fΘ lens composed of a plurality of lenses, and the fΘ lens. It is characterized by comprising a lens barrel to be stored and a joining member for joining the fΘ lens and the lens barrel.

[0011] The laser treatment device according to claim 3 of the present invention is characterized in that, in claim 1, the laser scanning means includes a galvanometer mirror.

[0012] The laser treatment device according to claim 4 of the present invention is the laser treatment device according to claim 1, wherein the irradiation control means includes an acousto-optic element, and the acousto-optic element is used to reduce the irradiation time of the laser light. It is characterized by being configured to control in seconds.

[0013] The laser treatment device according to claim 5 of the present invention is the laser treatment device according to claim 1, wherein the spot diameter of the laser beam focused by the focusing means is 15 m or less. Features.

[0014] A laser treatment apparatus according to claim 6 of the present invention is the laser treatment apparatus according to any one of claims 1 to 5, wherein scanning by the laser scanning means is It is characterized by pine pattern scanning. [0015] The laser treatment device according to claim 7 of the present invention is the laser treatment device according to any one of claims 1 to 5, wherein the scanning by the laser scanning means is a line. A laser treatment apparatus characterized by interlaced scanning.

The invention's effect

[0016] According to the laser treatment device of claim 1 of the present invention, the necessary amount of laser is effectively applied only to the treatment site by irradiating the finely focused laser beam in the entire scanning region. Can be irradiated. In addition, there is no thermal injury to normal cells. Furthermore, by scanning the laser in an arbitrary pattern and irradiating the laser beam to a single point for a long time, it is possible to eliminate the thermal damage to the surrounding tissue caused by thermal diffusion and enhance the cooling effect.

[0017] According to the laser treatment device described in claim 2 of the present invention, it is possible to finely focus the laser beam. In addition, by irradiating a finely focused laser beam in the entire scanning region, it is possible to effectively irradiate only the treatment site with the necessary amount of laser. Furthermore, the use of the fΘ lens makes the linear velocity constant on the scanning plane and enables two-dimensional scanning at an arbitrary speed optimal for treatment.

[0018] According to the laser treatment device of claim 3 of the present invention, since the laser scanning device includes the galvanometer mirror, the galvanometer mirror can precisely detect even if the beam spot diameter is fine. The beam scanning position can be controlled. Further, since it is not manual, there is no possibility of unevenness in the laser irradiation amount.

[0019] According to the laser treatment device according to claim 4 of the present invention, the irradiation time of the laser beam is precisely controlled in nanosecond units, so that it is given to the local position of the affected part by fine time control. The laser energy can be precisely controlled. Furthermore, the laser beam can be irradiated in a shorter time than the time during which heat is diffused.

[0020] According to the laser treatment device of claim 5 of the present invention, since the beam diameter of the fine laser beam is used, it is possible to effectively irradiate the affected area with the necessary amount of laser. . In addition, the laser effect can be accurately applied only to the treatment site with a high cooling effect and a strong force. In addition, thermal injury to normal tissues around the lesion to be treated can be reduced.

[0021] According to the laser treatment apparatus of the sixth aspect of the present invention, a checkerboard pattern is scanned. Thus, by irradiating the laser beam to a single point for an optimal time for treatment, it is possible to eliminate the thermal injury to the surrounding tissue caused by thermal diffusion and enhance the cooling effect.

[0022] According to the laser treatment device of claim 7 of the present invention, by performing interlaced scanning, the portion of the laser light power ^ point is irradiated for a time optimal for the treatment, so that heat diffusion can be achieved. The cooling effect can be enhanced by eliminating the thermal injury to the surrounding tissue.

Brief Description of Drawings

FIG. 1 is a front view of a laser treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a laser treatment apparatus according to an embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a light collecting means in one embodiment of the present invention.

FIG. 4 is a block diagram showing a main configuration of a laser treatment apparatus according to an embodiment of the present invention.

FIG. 5 is a diagram showing a spot diameter measurement range in a laser scanning region.

FIG. 6 is an explanatory diagram of the spot diameter of the laser treatment apparatus according to one embodiment of the present invention.

FIG. 7 is a diagram showing a measurement result of a spot diameter of the laser treatment apparatus in one embodiment of the present invention.

FIG. 8 is an explanatory diagram of a mesh for analyzing the relationship between temperature and time.

FIG. 9 is a diagram showing a temperature change when laser irradiation with a diameter of lmm and a diameter of 12 m is performed.

FIG. 10 is a diagram showing an example of a laser scanning pattern of the laser treatment apparatus according to one embodiment of the present invention.

FIG. 11 is a diagram showing an example of a laser scanning pattern of the laser treatment apparatus according to one embodiment of the present invention.

FIG. 12 is a diagram showing an example of a laser scanning pattern of the laser treatment apparatus according to one embodiment of the present invention.

Explanation of symbols

[0024] 1 Laser oscillator (Nd: YAG laser oscillator)

6 Irradiation control means (AOM)

10 beam expander

12 Laser scanning means (galvanomirror) 16 Condensing means

30 Laser light

31, 32, 33, 34, 35, 36 lenses (f Θ lenses)

40, 41 Joining member

50 tube

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a laser treatment apparatus showing an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a schematic external view of the laser treatment apparatus, and FIG. 2 is a plan view of the schematic external view of the laser treatment apparatus. The laser treatment apparatus of this embodiment includes an Nd: YAG laser oscillator 1 as a laser oscillator that emits laser light, a beam expander 10 for expanding the beam size of the laser light emitted from the laser oscillator, A Ganolevano mirror 12 as a laser scanning means capable of scanning the laser light in an arbitrary pattern; a condensing means 16 for finely focusing the laser light scanned by the laser scanning means 12 on the treatment site; AOM (acousto-optic element) 6 as an irradiation control means for changing the irradiation time of the laser beam finely condensed by the XYZ stage 17 as a mounting table for the subject X, and the like. In the present invention, the term “fine” refers to a range of 15 / z m or less, preferably 10 m or less, and most preferably 5 μm or less.

The Nd: YAG laser oscillator body 1 is fixed to the upper part of the Nd: YAG laser tilt'height adjustment base 2. The Nd: YAG laser oscillator body 1 can be manufactured by ELFORLIGHT, and its specifications are a wavelength of 532 nm, an output of 200 mW, a beam diameter of 1 mm, continuous oscillation, and a spread angle of lmrad. Here, the Nd: YAG laser is taken as an example. Nd: YAG laser tilt 'height adjustment stand 2 is fixed to the system upper plate 19, and Nd: YAG laser oscillator 1 is fixed to the top, and is used to adjust the tilt and height to match the optical axis. This tilt / height is adjusted by a screw screw. Reference numeral 3 denotes a shutter for cutting off the laser when it is not necessary to irradiate the laser.

[0027] Reference numeral 4 denotes the front and rear lenses of AOM6 and a lens barrel that houses the front and rear lenses. In order to increase the rise time of AOM6, a concave lens and a convex lens are respectively provided before and after AOM6. Using this combination lens, the incident beam diameter to AOM6 is focused to a diameter of 0.1 mm, for example. As AOM6, for example, one manufactured by Crystal Technology can be used. The lens on the AOM entrance side is used to collect light, and the lens on the AOM exit side is used to return the expanded beam to parallel light. The specifications of the lenses used here are 12 mm for the outer diameter, 160 mm for the focal length, 50.5 mm for the back focus, and 0.1 mm for the spot diameter for both concave and convex lenses, but are not limited thereto. Reference numeral 5 denotes a holder for fixing the lens barrel 4 for the front and rear lenses of the AOM, and positioning pins are used for positioning the lens barrel holder 5 for the front and rear lenses of the AOM. There is a positioning pin on the top of the mounting base 7 for fixing the AOM 6 to the top, which is used to determine the center position of the AOM crystal. The pin is placed so that the optical axis passes through the center of this pin! The AOM 6 is installed at the Bragg's angle by the angle adjusting jig 15. It is a mechanism that pushes AOM6 with a spring from one side and finely adjusts the angle of AOM6 with the screw on the other side, and is fixed to the side surface of AOM mounting base 7. Reference numeral 13 denotes an AOM driver for supplying ultrasonic waves (high frequency) to the AOM6. The AOM6 is connected to the AOM6 by a cable.

[0028] Reference numeral 8 denotes a reflection mirror for changing the direction of the oscillated laser light by 180 ° to match the incident optical axis of the galvano mirror 12. The reflecting mirror 8 has a coating that reflects almost 100% of the laser beam. Fine adjustment of the tilting direction of the reflecting mirror 8 can be performed by the reflecting mirror holder 9.

[0029] A concave lens that expands the laser light is incorporated in the incident side of the beam expander 10, and a convex lens that collimates the laser light magnified by the concave lens on the exit side is incorporated in the lens barrel. . The position can be finely adjusted by using an XYZ stage. A pinhole plate 11 is used for aligning the optical axis of the laser beam. For example, a hole having a diameter of about lmm is provided in the metal pinhole plate 11, and the position of the pinhole plate 11 is determined by a positioning pin.

[0030] The maximum rotation angle of the galvanometer mirror 12 for scanning laser light is, for example, about ± 20 °, and the rotation angle is controlled by a personal computer or the like. The two rotatable galvanometer mirrors 12 are driven by two galvanometers and rotate the first galvanometer mirror 12. By scanning, the laser beam is scanned in the X-axis direction, and by rotating the second galvanometer mirror 12, the laser beam is scanned in the Y-axis direction. Therefore, by controlling the second galvanometer mirror 12 simultaneously, it is possible to scan the laser with respect to the XY plane. Reference numeral 14 denotes a light shielding plate for shielding laser light. As the galvanometer mirror 12, for example, a product made by GSI LUMONICS can be used.

Reference numeral 16 denotes a condensing unit that finely narrows the laser beam scanned by the laser scanning unit 12. Here, a description will be given with reference to FIG. 3 showing a longitudinal sectional view of an embodiment of the light collecting means 16. The light collecting means 16 includes f 0 lenses 31 to 36 including a plurality of lenses 31, 32, 33, 34, 35, and 36.

, F Θ lenses 31 to 36, and joining members (shrink filters) 40 and 41 for joining the f Θ lenses 31 to 36 and the lens barrel 50 are provided. The f 0 lens is a lens whose purpose is to convert the deflected light beam into a point image (spot) scan with a constant linear velocity on the running surface. The lenses are arranged in order from the laser incident direction (upper side in the figure).

, 35, 36. In this embodiment, a plurality of lenses 31 to 36 are provided.

The number can be changed as appropriate. Each lens 31 to 36 is joined to the bonding member 40 in the lens barrel 50.

41 is joined. The joining members 40 and 41 are made of a polymer material (for example, a resin such as polyimide, acrylic, or polyacetal) having a larger coefficient of thermal expansion than the material of the lens barrel 50 (for example, a metal such as aluminum). It is formed in a cylindrical shape. Since plastic joining members 40 and 41 are incorporated between the lenses 31 to 36 and the lens barrel 50, an interference fit can be achieved. Further, the optical axes of the lenses 31 to 36 coincide with each other, so that the laser can be finely narrowed down over the entire scanning region. Further, even when temperature fluctuation occurs, the lens is always fastened with a constant force due to the thermal expansion of the joining members 40 and 41, so that the optical performance such as the spot diameter can be kept constant. The joining member 41 has grooves 51, 52 in the circumferential direction of the outer periphery surrounding the lens group. The grooves 51, 52 join the lens group by passing a string or a wire. This is for fixing the joining member 41. In addition, since the lens 36 is concave on both sides and has a wide joint surface, the lens curved surface is easily deformed with a slight tightening pressure. In order to prevent such deformation, a joint surface 53 narrower than the outer peripheral thickness of the lens 36 is provided, and the joint width between the joint member 41 and the lens 36 is smaller than the lens thickness. It is trying to become. In this embodiment, the focal length is 166.5 mm, the design spot diameter is 15 μm, or the focal length is ll lmm, and the design spot diameter is 10 m, but is not limited thereto. When the spot diameter is 15 μm or less, it is possible to irradiate cells with a size of about 5 to: LOO μm.

[0032] The XYZ stage 17 is used to move the laser spot measuring device to the entire scanning region, and the Z stage is used to adjust the laser spot measuring device to the height at which the laser beam forms an image. The tilt of the XYZ stage 17 can be finely adjusted by the tilt stage 18. 22 is a galvano scan controller (base). When input data is sent from a personal computer, it is converted into an optimal signal and a rotation angle is given to the galvanometer. Reference numeral 24 denotes a YAG laser oscillator power supply unit (for example, manufactured by ELFORLIGHT), which is used to supply power to the YAG laser oscillator main body. Reference numeral 25 denotes an AOM control device that controls AOM 6 in accordance with a control signal from the galvano scan controller 22. With the AOM controller software, continuous output, one-shot output * Pulse output frequency, pulse width, etc. can be set, and in this embodiment, a short of approximately 12.5 ns (nanosecond) by pulse width modulation. Pulse irradiation is performed.

The operation of the laser treatment apparatus configured as described above will be described with reference to FIG. FIG. 4 is a block diagram showing the main configuration of the laser treatment apparatus according to this embodiment. The laser beam 30 emitted from the laser oscillator 1 passes through the irradiation control means 6. Then, the direction of the laser beam 30 that has passed through the irradiation control means 6 is changed by the reflecting mirror 8. The laser beam whose direction has been changed is expanded by the concave lens on the incident side of the beam expander 10 before being guided to the f 0 lens, and becomes parallel light by the convex lens on the output side. The laser light 30 that has become parallel light is scanned by the laser scanning means 12, and the laser light 30 is finely condensed by the condensing means 16, and then focused on the subject X on the XYZ stage 17.

In the laser treatment apparatus of the present invention described above, it is possible to accurately and uniformly irradiate only a treatment site with a necessary amount by irradiating a finely focused laser beam in the entire scanning region. . In addition, the effect of heat dissipation can be enhanced by irradiating a treatment site with no side effects on normal cells with a laser beam finely focused by the condensing means 16. Furthermore, the cooling effect can be further enhanced by scanning the laser with an arbitrary pattern. In addition, instantaneous laser irradiation is possible by passing laser beam 30 through AOM6. The laser beam 30 can be alternately turned on and off at a high speed on the order of nanoseconds. Further, since the laser spot diameter is reduced in inverse proportion to the beam diameter before incidence of the ί "θ lens, the beam expander 10 is used to expand the beam diameter of the laser beam 30, so that the minute laser Spots can be formed.

[0035] The laser treatment apparatus of the present invention includes skin tumors (mole, warts, xanthomas, seborrheic keratosis, etc.), nevus (Ota nevus, flat nevus, ectopic mongolia), It can be applied to hemangiomas, traumatic pigmentation, stains, senile plaques, and acne scars.

As described above, in this embodiment, the laser oscillator 1 that generates the laser light 30, the beam expander 10 that expands the beam size of the laser light 30 emitted from the laser oscillator 1, and the beam expander 10 are provided. Laser scanning means 12 that scans the laser beam 30 incident through the laser beam into an arbitrary pattern, a light collecting means 16 that finely narrows the laser light 30 scanned by the laser scanning means 12, and a light collecting means 16 And the irradiation control means 6 that changes the irradiation time of the focused laser beam 30, so that it is effective only for the treatment site by irradiating the laser beam that is finely focused over the entire scanning area. It is possible to irradiate the required amount of laser. In addition, there is no thermal injury to normal cells. Furthermore, by irradiating the laser in an arbitrary pattern and irradiating the laser beam to one spot for a long time, the thermal effect on the surrounding tissue caused by thermal diffusion can be eliminated and the cooling effect can be enhanced. it can.

Further, in the present embodiment, the light converging means 16 includes the f Θ lenses 31 to 36 including the plurality of lenses 31, 32, 33, 34, 3 5, and 36, and the f Θ lens 31 as described above. Since the lens barrel 50 that accommodates .about.36 and the joining members 40 and 41 that join the f.theta. Lenses 31 to 36 and the lens barrel 50 are provided, the laser beam 30 can be narrowed down finely. Further, by irradiating the laser beam 30 that is finely focused in the entire scanning region, it is possible to effectively irradiate only the treatment site with the necessary amount of laser. In addition, by using f 0 lenses 31 to 36, two-dimensional scanning can be performed with a constant linear velocity on the scanning surface.

[0038] Further, in this embodiment, since the laser scanning unit 12 includes the galvanometer mirror 12, the beam scanning position can be precisely controlled by the galvanometer mirror 12 even if the beam spot diameter is fine. it can. Furthermore, since it is not manual, there is no risk of unevenness in the amount of laser irradiation. [0039] Furthermore, in this embodiment, the acoustooptic device (AOM) 6 is provided as an irradiation control means as described above, and the acoustooptic device 6 causes the irradiation time of the laser light 30 to be about 12.5 ns (nanosecond). Since it is configured to control in units of seconds, the irradiation time of the laser beam 30 is precisely controlled in nanoseconds, so that the laser energy given to the local position of the affected area can be precisely controlled by fine time control. Furthermore, the laser beam 30 can be irradiated in a shorter time than the time during which heat is diffused.

[0040] Further, in this embodiment, since the spot diameter of the laser beam 30 condensed by the condensing means 16 is 15 m or less, a necessary amount of laser can be effectively irradiated onto the affected area. Is possible. In addition, the cooling effect is high and the laser treatment can be accurately performed only on the treatment site. In addition, thermal injury to normal tissues around the lesion to be treated can be reduced.

[0041] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, in this embodiment, an Nd: YAG laser light source is used. For example, CO

2 A variety of plastic light sources for plastic surgery, such as laser light sources, can be used. In the present embodiment, the joining members 40 and 41 may be integrated with the separated force. Furthermore, as another embodiment, the laser treatment apparatus of the present invention may be provided with an image observation means for specifying the position of the affected part such as a CCD camera or a laser microscope with high accuracy. By providing image observation means, for example, when laser treatment is applied to blood vessel types, only the position of the blood vessel is identified with high accuracy by performing CCD observation or laser scanning detection, and the laser beam is precisely detected by the galvanometer mirror 12. The scanning position can be controlled and only the blood vessels can be irradiated with laser, so there is no risk of damaging normal tissue.

Example 1

As shown in FIG. 5, the spot diameter in a 12 mm square laser scanning region was measured. The measurement positions are 13 points each in the upper right direction as shown by ◯ and in the lower right direction as shown by △. As shown in Fig. 6, the spot diameter is the beam diameter where the beam intensity is at the peak value of lZe ² (13.5%). A beam scan was used as a spot diameter measurement device. The spot diameter was measured on both the X-axis and y-axis, and the average value was taken. By inputting the rotation angle command value to the personal computer, the galvanometer mirror is rotated by a predetermined angle to measure the laser beam. Moved to position. Next, the XY stage was moved to the laser beam coordinates, and the spot diameter was measured with a beam scan. The diameter of the laser beam incident on the galvanometer mirror was 13 mm.

[0043] Fig. 7 shows the measurement results. From Fig. 7, it was confirmed that the laser spot diameter was about 11 to 13 m in all the measurement range.

Example 2

[0044] Next, the cooling effect after irradiation when laser light focused to a diameter of about 12 m and laser light with a diameter of 1 mm were irradiated was examined. The analysis was performed as a two-dimensional problem using the general-purpose finite element analysis software Marc (Ver. 7.3). Figure 8 shows a part of the mesh used in the analysis. The heat transfer coefficient, specific heat, and density were all the physical properties of the skin, the skin temperature was 36.5 ° C, and the heat application width was the spot diameter of 12 m or lmm. The depth of heat application was 0.25 mm from the skin surface, and the laser scanning speed was OmmZs, that is, no laser scanning was performed. The atmosphere temperature was 25 ° C, the atmosphere on the skin surface was ambient air conditioning, and the heat transfer coefficient was 3. OWZm ² 'K. Heat is given as laser energy (W / cm ² ), and the maximum power density of the laser treatment device of the present invention is 79.6 kWZ cm ² on the skin surface, and reflection on the skin surface, scattering in the skin 'absorption process is performed. In consideration, energy 51. Ok WZcm ² was given at a skin depth of 0.25 mm. In both cases, the laser was irradiated for 200 s.

[0045] The analysis results are shown in FIG. The vertical axis is temperature, and the horizontal axis is time. In both cases, the temperature increased from the start of laser irradiation to 200 s after the end of irradiation. In the case of laser irradiation with a diameter of 1 mm, the temperature rose to a maximum of approximately 67.5 ° C. In the case of laser irradiation with a diameter of about 12 m, the maximum temperature was about 65 ° C. After that, the temperature dropped, but in the case of laser irradiation with a diameter, the temperature dropped by about 5 ° C after 1 ms. In other words, it was confirmed that the cooling effect was higher when the laser beam was narrowed down. Furthermore, about 60-65 ° C was the temperature at which protein denaturation and coagulation began, and it was confirmed that the peripheral area where heat was applied was lower than the burn initiation temperature of 65 ° C. Therefore, it can be seen that the part that gives heat! / Swells rises to a temperature at which the affected tissue is thermally destroyed and does not affect the surrounding tissue.

Example 3 In the present embodiment, a pattern example of laser scanning is shown. The laser irradiation pattern shown below is an example, and the present invention is not limited to this. 10 to 12 show the laser irradiation region of the laser treatment apparatus of the present invention described in the above embodiment. If all of this area is the target to be treated, it is necessary to irradiate all of this area with the laser.

[0047] FIG. 10 shows an example of sequential scanning in which laser irradiation is performed in a spot shape and the laser is scanned linearly. The numbers in the circles in the figure represent the order of laser irradiation. In the example shown in the figure, the force drawn so that the laser spots do not overlap. The spots may partially overlap, or multiple spots may be overlapped, or the lasers may be irradiated continuously. You may shoot. When the scanning of one row is finished, it is shifted to the side and the second row is scanned linearly. In this case, the first and second rows do not overlap in the example in the figure, but they may overlap partially.

FIG. 11 shows an example of interlaced scanning with a gap between each row. By performing interlaced scanning in this manner, the laser beam can be irradiated at a single point for an optimal time for treatment, thereby eliminating the thermal injury to the surrounding tissue caused by thermal diffusion and enhancing the cooling effect. . In addition, the cooling effect produced by finely focusing the laser can be further enhanced. The gap is not limited to one row, and any gap can be made. In the above description, the laser scanning direction may be a scanning force that is a vertical force, or may be scanned at an arbitrary angle.

FIG. 12 shows an example of a pine pattern scanning in which a laser is irradiated like a pine pattern from the first spot as indicated by numerals. The laser spot spacing may be uniform or non-uniform. Further, the order of irradiation may be regular or random. By scanning like this, it is possible to eliminate the thermal injury to the surrounding tissue caused by thermal diffusion and improve the cooling effect by irradiating the laser beam to one point for the optimal time for treatment. You can. In addition, the cooling effect of the finely focused laser can be enhanced. Furthermore, conventionally, only the laser irradiation time and power were the control parameters, but by using the apparatus of the present invention, the spatial pattern of the laser irradiation can be changed, and an unprecedented treatment pattern can be obtained. Can be developed.

Claims

The scope of the claims

[1] A laser oscillator that generates laser light, a beam expander that expands the beam size of the laser light emitted from the laser oscillator force, and a laser beam incident through the beam expander is scanned in an arbitrary pattern. A laser scanning unit that performs focusing, a condensing unit that finely narrows the laser beam scanned by the laser scanning unit, and an irradiation control unit that controls the irradiation time of the laser beam finely condensed by the condensing unit. A laser treatment apparatus characterized by comprising.

[2] The condensing unit includes an fΘ lens composed of a plurality of lenses, a lens barrel that houses the fΘ lens, and a joining member that joins the fΘ lens and the lens barrel. 2. The laser treatment apparatus according to claim 1, wherein the laser treatment apparatus is characterized in that:

[3] The laser treatment device according to [1], wherein the laser scanning means includes a galvanometer mirror.

[4] The laser treatment according to claim 1, wherein the irradiation control means includes an acoustooptic device, and the acoustooptic device is configured to control the irradiation time of the laser beam in nanosecond units. apparatus.

5. The laser treatment apparatus according to claim 1, wherein the spot diameter of the laser beam condensed by the condensing means is 15 μm or less.

6. The laser treatment apparatus according to any one of claims 1 to 5, wherein the scanning by the laser scanning means is a checkered pattern scanning.

7. The laser treatment apparatus according to any one of claims 1 to 5, wherein the scanning by the laser scanning means is a line jump scanning.