JP4097569B2 - Laser therapy device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser treatment apparatus that performs treatment by irradiating an affected area with laser light.
[0002]
[Prior art]
There is known a laser treatment device that selectively guides treatment laser beams of different wavelengths such as green, yellow, and red to the fundus of a patient's eye and coagulates them. In this type of apparatus, the laser wavelength is selected according to the case of the patient's eye and the state of the patient's eye. When the aiming light of the same color (same wavelength) is aimed at the selected therapeutic laser, the wavelength selected during observation can be visually confirmed. In addition, it is convenient because the transmission characteristics of the actual therapeutic laser beam can be observed with the aiming beam. For example, when an intermediate translucent material such as a crystalline lens or a vitreous body is clouded, a large difference in transmission characteristics occurs due to the difference in laser wavelength, so observe the aiming light of the same color as the treatment laser light of each wavelength. By doing so, an appropriate laser wavelength can be selected. As a method of obtaining aiming light having the same color as the treatment laser light, there is a method in which an attenuation filter is detachably disposed on the optical path of the treatment laser light (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-87304
[Problems to be solved by the invention]
However, in an apparatus that obtains aiming light of the same color by inserting and removing the attenuation filter in the optical path of the therapeutic laser beam, if the attenuation filter is dropped or damaged due to some trouble, the laser beam is irradiated with the therapeutic output. End up. Further, when the output of the therapeutic laser light source is constant, it has been difficult to increase or decrease the aiming light amount by the attenuation filter on the optical path. In addition, when a laser capable of emitting a plurality of wavelengths is used as a therapeutic light source, it is necessary to create a broadband attenuation filter.
[0005]
In view of the above-described problems of the conventional technology, the present invention provides a laser treatment apparatus that can obtain aiming light having the same color as the treatment laser light by a simple method and can obtain the treatment laser light with low loss. And
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by having the following configuration.
[0007]
(1) In a laser treatment apparatus that guides and irradiates an affected area with therapeutic laser light having a visible wavelength, P-polarized light having a polarization ratio higher than that of S-polarized light is a light separating member disposed in the optical path of the therapeutic laser light. A light separating member that is transmitted at a Brewster angle so as to reflect S-polarized light and separates the transmitted first laser light and the second laser light for aiming the reflected S-polarized light ; The shutter driving means having an openable / closable shutter disposed in the optical path of the first laser light separated by the light separating member, and the first laser light and the second laser light passing through the shutter are coaxially arranged. A light synthesizing member to be synthesized, a light guide optical system for guiding the laser light synthesized by the light synthesizing member to the affected part, and closing the shutter when aiming at the affected part, and the second laser light by the light guiding optical system Light guide, During chromatography The treatment characterized in that it comprises a control means for controlling the shutter driving unit to open only the irradiation time set the shutter on the basis of a trigger signal of the laser irradiation, the.
[0008]
(2) In a laser treatment apparatus that guides and irradiates a laser beam to an affected area, a laser light source that emits laser light having a visible wavelength, an incident angle of the laser light from the laser light source are arranged at a Brewster angle, and P-polarized light A light separating member that separates the first laser light of the transmitted light and the second laser light of the reflected light containing S-polarized light, and an openable and closable element disposed in the optical path of the first laser light separated by the light separating member A shutter, a first half-wave plate arranged in the optical path of the first laser light and changing P-polarized light to S-polarized light, and a second half-wave plate arranged in the optical path of the second laser light and changing S-polarized light to P-polarized light Reflecting the first laser beam changed to S-polarized light by the half-wave plate and the first half-wave plate and transmitting the second laser light changed to P-polarized light by the second half-wave plate, Polarization synthesis to synthesize 1 laser beam and 2nd laser beam again To Photosynthesis member as wood, and a light guide optical system for guiding to the affected area of the laser light combined by the light combining member, characterized Rukoto equipped with.
[0009]
(3) In the laser treatment apparatus of (2), the first half-wave plate and the second half-wave plate are each provided with a driving unit that rotationally drives the first half-wave plate and the second half-wave plate.
[0010]
(4) In a laser treatment apparatus that guides and irradiates laser light to an affected area, a laser light source that emits laser light having a visible wavelength, and an incident angle so as to reflect a part of the P-polarized component in the laser light from the laser light source. Is arranged shifted from the Brewster angle and separates the first laser beam of the transmitted light and the second laser beam of the reflected light, and an openable / closable shutter disposed in the optical path of the first laser beam, A half-wave plate disposed in the optical path of the first laser beam, and the half-wave plate reflects the laser beam in which the P-polarized component of the first laser beam is changed to the S-polarized component and reflects the P of the second laser beam. A polarization combining member that transmits a polarization component, and a light guide optical system that guides laser light combined by the polarization combining member to an affected part.
[0011]
(5) In the laser treatment apparatus according to claim 4, a half-wave plate rotating unit that rotates the half-wave plate, a first polarizing plate that is disposed in an optical path of the second laser light and passes only a P-polarized component, and A second polarizing plate disposed in the optical path of the second laser beam and rotatable, and a polarizing plate rotating means for rotating the second polarizing plate are provided.
[0012]
(6) The light separating member according to claim 4 is arranged so that the incident angle is shifted from the Brewster angle so that the P-polarized light of the laser light from the laser light source is reflected by 0.1 to 0.5% of the whole. It is characterized by that.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an external configuration of a laser photocoagulation apparatus. Reference numeral 1 denotes an apparatus main body, which stores a laser light source and an optical system that allows laser light to enter the optical fiber 2. Reference numeral 3 denotes a control box for setting and displaying photocoagulation conditions such as laser output, irradiation time and wavelength switching, and displaying the state of the apparatus. Reference numeral 4 denotes a slit lamp delivery for irradiating the affected part of the patient's eye with the laser light while observing the patient's eye. The laser irradiating part 5 for irradiating the laser light guided to the optical fiber 2 and the illumination part 6 for illuminating the patient's eye. The binocular microscope unit 4a for observing the patient's eyes is provided. Reference numeral 7 denotes a foot switch for sending a laser irradiation trigger signal.
[0014]
FIG. 2 is a diagram for explaining an optical system of the apparatus main body 1, and FIG. 3 is a control system block diagram of the apparatus. A laser light source 9 includes an Nd: YAG crystal that is a solid laser medium, a semiconductor laser that is an excitation light source, and a nonlinear crystal that is a wavelength converter. The Nd: YAG crystal emits light having a plurality of oscillation lines (peak wavelengths) in the near-infrared region by excitation light from the excitation light source. By generating second harmonics in three oscillation lines of about 1064 nm, about 1123 nm, and about 1319 nm, which have a high output among a plurality of oscillation lines, using a nonlinear crystal, a wavelength of about 532 nm (green) ), Laser beams of three colors having a wavelength of about 561 nm (yellow) and a wavelength of about 659 nm (red) are emitted.
[0015]
Reference numeral 11 denotes a transparent glass plate as a light splitting member arranged so that the incident angle of the laser light from the laser light source 9 becomes a Brewster angle (56.3 °). Of the laser light from the laser light source 9, P-polarized light is emitted. Almost all and about 80% of the S-polarized component are transmitted, and about 20% of the S-polarized component is reflected and separated. Many of the laser light sources used for treatment are linearly polarized light having a polarization ratio of about 1000: 1, and therefore, about 1/5000 of S-polarized light components can be extracted.
[0016]
Nearly all of the P-polarized component and about 80% of the S-polarized component used as therapeutic laser light pass through the glass plate 11 and pass through the optical path of the optical axis L1. On the optical axis L1, a half-wave plate 32 corresponding to three wavelengths of a wavelength of about 532 nm (green), a wavelength of about 561 nm (yellow), and a wavelength of about 659 nm (red) is provided. Thus, the P-polarized light is changed to the S-polarized light component, and the S-polarized light is changed to the P-polarized light component.
[0017]
A therapeutic light shutter 17 is disposed on the optical axis L1, and when the therapeutic laser light is not required, the therapeutic light shutter 17 is inserted into the optical path by driving the driving device 67 to block the therapeutic laser light. To do. The opening and closing of the therapeutic light shutter 17 is detected by a shutter sensor 17a.
[0018]
Further, a polarizer 15 that transmits the P-polarized component and reflects the S-polarized component is provided on the optical axis L <b> 1, and the P-polarized component that has passed through the polarizer 15 enters the diffuser 33. The diffuser 33 serves to absorb unnecessary laser light in order to reduce the output of the therapeutic laser light. The half-wave plate 32 is rotated by the drive unit 32a, and the light amount of the S-polarized component reflected by the polarizer 15 changes depending on the rotation angle of the half-wave plate 32 and the polarizer 15, and the treatment laser light The amount of light (output) is adjusted.
[0019]
A beam splitter 36 and a polarizer 16 as an optical polarization combining member that reflects S-polarized light and transmits P-polarized light are disposed in the optical path reflected by the polarizer 15. The beam splitter 36 reflects a part of the S-polarized component and transmits the remaining part. On the optical path reflected by the beam splitter 36, a polarizing plate 38 and an output sensor 37 that allow only the S-polarized light component to pass therethrough are disposed. The output of the treatment laser light is monitored by the output sensor 37.
[0020]
The S-polarized component used for the aiming light reflects off the glass plate 11 and then reflects off the mirror 12 and travels along the optical axis L2. A half-wave plate 31 is provided on the optical axis L2, and S-polarized light is changed to P-polarized light components. A correction lens 13 for correcting a difference in optical path length between the optical axis L1 and the optical axis L2 is placed on the optical axis L2 along which the S-polarized light travels. A polarizing plate 34 that cuts the S-polarized light component is disposed on the optical axis L2. The polarizing plate 34 is disposed so as to have a polarization direction that transmits only the P-polarized light component and cuts all the S-polarized light component. The half-wave plate 31 is rotated by the drive unit 31 a, and the light amount of the P-polarized component transmitted through the polarizing plate 34 is changed depending on the rotation angle of the half-wave plate 31, and the light amount (output) of the aiming light is adjusted.
[0021]
Most of the P-polarized component aiming light that has passed through the polarizing plate 34 passes through the polarizer 16 and is combined with the therapeutic laser light on the optical axis L1 side, but about 10% is reflected by the polarizer 16 and is aiming light. Is incident on the output sensor 35.
[0022]
A safety shutter 10 is detached from the optical path by driving the driving device 61 to allow the laser light to pass therethrough, and is inserted into the optical path in a predetermined case such as when an abnormality occurs to block the laser light. The opening / closing of the safety shutter 10 is detected by a shutter sensor 10a.
[0023]
A condensing lens 22 condenses and enters the laser light on the incident end face of the optical fiber 2. The laser light guided to the slit lamp delivery 4 by the optical fiber 2 is irradiated to the affected part of the patient's eye through the laser irradiation unit 5.
[0024]
In FIG. 3, reference numeral 60 denotes a control unit, to which a laser light source 9, a foot switch 7, a control box 3, sensors, driving devices and the like are connected. The control box 3 includes a rotary knob 3a for setting the laser output, a switch 3b for setting the amount of aiming light, a color switch 3c for selecting the wavelength (color) of the treatment laser light, and a laser irradiation enabled / disabled state. A switch 3d for switching is provided. In addition, the control box 3 is provided with a switch and a display unit for setting the laser irradiation conditions such as the laser irradiation time and the laser irradiation interval time, which are not shown in FIG. The therapeutic light shutter 17 is opened for a set laser irradiation time when the foot switch 7 is pressed.
[0025]
The operation of the apparatus having the above configuration will be described. At the time of laser irradiation, the surgeon operates each switch of the control box 3 to set the coagulation conditions such as wavelength selection of laser light, laser output, and coagulation time. The wavelength of the laser light is selected according to the purpose of treatment (red, yellow, green) using the color switch 3c. Here, description will be made assuming that the laser beam is set to yellow. When a laser beam is selected, a laser beam having a selected wavelength is emitted from the laser light source 9. When the power is turned on, the therapeutic light shutter 17 is closed. When the switch 3b is turned on (aiming light is not 0), the control unit 60 opens the safety shutter 10 by driving the driving device 61. Of the laser light emitted from the laser light source 9, a part of the S-polarized component is reflected by the glass plate 11. Further, the control unit 60 rotates the half-wave plate 31 by the half-wave plate driving unit 31 a based on the signal from the aiming light output sensor 35 so that the aiming light amount adjusted by the switch 3 b is obtained. The amount of the P-polarized component of the aiming laser beam guided to the output end is changed. The P-polarized component of the aiming laser beam passes through the optical fiber 2 and is guided to the laser irradiation unit 5 of the slit lamp delivery 4.
[0026]
The surgeon observes the eye fundus of the patient and aiming light with the slit lamp delivery 4, and aims at the affected area. Thereafter, the switch 3d is pressed to change the operation mode of the apparatus from the STANDBY state to the READY state, so that the therapeutic laser beam can be irradiated. When the surgeon depresses the foot switch 7, the therapeutic light shutter 17 is opened. If the therapeutic laser light irradiation state that is in the READY state is not enabled, the therapeutic light shutter 17 is controlled so as not to open even if the foot switch 7 is stepped on.
[0027]
Of the laser light emitted from the laser light source 9, all of the P-polarized component and about 80% of the S-polarized component are transmitted through the glass plate 11. The half-wave plate 32 changes P-polarized light into an S-polarized component and S-polarized light into a P-polarized component. Based on the detection signal of the output sensor 37, the controller 60 rotates the half-wave plate 32 by the half-wave plate driver 32a so that the laser output set by the rotary knob 3a is obtained. The S-polarized component of the therapeutic laser beam reflected from the polarizer 15 is also reflected by the polarizer 16 and guided to the output end.
[0028]
In the above apparatus, the aiming is performed with aiming light of the same color as the therapeutic laser beam, so that the actual transmission characteristics of the therapeutic laser beam can be observed. In the above description, the yellow laser beam is selected. However, if there is a large difference in the transmission characteristics due to the difference in the laser wavelength, the green, yellow, and red colors are observed by observing the same-color aiming light that has passed through the intermediate transparent body. An appropriate laser wavelength can be selected from the laser beams.
[0029]
Further, by separating the treatment laser light and the aiming treatment laser light by the glass plate 11 arranged at the Brewster angle, the light is separated into the S-polarized component and the P-polarized component by a polarizer such as a polarizing beam splitter. The output loss in the optical path of the therapeutic laser beam can be suppressed as much as possible. In other words, when the therapeutic laser beam is separated by a polarizer such as a polarizing beam splitter, the transmission of the P-polarized component becomes about 90%. However, in the glass plate 11 arranged at the Brewster angle, the laser beam of the P-polarized component Can be separated by almost 100% permeation.
[0030]
Further, the S-polarized component treatment laser light is reflected by the polarizer 16 and synthesized with the aiming light, so that the P-polarized treatment laser light is transmitted through the polarizer 16 and synthesized with the aiming light. The output loss in the optical path of the therapeutic laser beam can be suppressed as much as possible.
[0031]
Further, when the output of the S polarization component used for the aiming light is low, the optical system shown in FIG. 4 may be used. In FIG. 4, the same members in the above embodiment are denoted by the same symbols. In this modification example, the incident angle of the glass plate 11 ′ is shifted from the Brewster angle (56.8 °) by the angle θ = 4.8 ° to 52 °. By shifting the incident angle by the angle θ = 4.8 °, a part of the P-polarized light component is reflected by about 0.1 to 0.5% on the glass plate 11 ′. In this modification example, the reflection amount is about 0.1%. Further, the S-polarized component reflected by the glass plate 11 ′ is cut by the polarizing plate 40 arranged so as to pass only the P-polarized component. Reference numeral 41 denotes a polarizing plate that is rotationally driven by the polarizing plate driving unit 41a. Based on the signal from the aiming light output sensor 35, the control unit 60 rotates the polarizing plate 41 by the polarizing plate driving unit 41a and transmits the polarizing plate 40 so that the aiming light amount adjusted by the switch 3b is obtained. Aiming light of the P-polarized component is attenuated, and the amount of aiming laser light guided to the output end is changed.
[0032]
【The invention's effect】
As described above, according to the present invention, the aiming light having the same color as the treatment laser beam can be obtained by a simple method without using the conventionally used attenuation filter and its insertion / removal mechanism, and the treatment laser beam can be reduced in loss. Can be obtained at
[Brief description of the drawings]
FIG. 1 is a diagram showing an external appearance of an apparatus main body.
FIG. 2 is a diagram showing an optical system inside the apparatus.
FIG. 3 is a block diagram showing a control system.
FIG. 4 is a diagram illustrating an optical system of a modification example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Optical fiber 9 Laser light source 11 Glass plate 11 'Glass plate 16 Polarizer 17 Treatment light shutter 31 1/2 wavelength plate 31a Drive part 32 1/2 wavelength plate 32a Drive part 40 Polarizing plate 41 Polarizing plate 41a Polarized light Plate drive unit

Claims (6)

In a laser treatment apparatus that guides and irradiates an affected area with a therapeutic laser beam having a visible wavelength, the light separation member is disposed in the optical path of the therapeutic laser beam and transmits P-polarized light having a higher polarization ratio than S-polarized light. A light separating member that is arranged at a Brewster angle so as to reflect S-polarized light, and that separates the first laser light of transmitted light and the second laser light for aiming of reflected light of S-polarized light ; The shutter driving means having an openable / closable shutter disposed in the optical path of the first laser light separated by the separating member, and the first laser light and the second laser light passing through the shutter are combined coaxially . A light synthesizing member, a light guide optical system for guiding laser light synthesized by the light synthesizing member to the affected area, and closing the shutter when aiming at the affected area, and guiding the second laser light by the light guiding optical system. ,laser Laser treatment apparatus, characterized in that it comprises a control means for controlling the shutter driving unit to open only the irradiation time set the shutter on the basis of a trigger signal of the laser irradiation, the on療時. In a laser treatment apparatus that guides and irradiates an affected area with laser light, a laser light source that emits laser light having a visible wavelength, and an incident angle of the laser light from the laser light source that is arranged at a Brewster angle, and transmitted light including P-polarized light A light separating member for separating the first laser light and the second laser light reflected by S-polarized light, an openable / closable shutter disposed in the optical path of the first laser light separated by the light separating member, A first half-wave plate arranged in the optical path of the first laser light and changing P-polarized light to S-polarized light, and a second half-wave plate arranged in the optical path of the second laser light and changing S-polarized light to P-polarized light And reflecting the first laser light converted to S-polarized light by the first half-wave plate and transmitting the second laser light changed to P-polarized light by the second half-wave plate, And a polarization combining member that combines the second laser beam and the second laser beam again. Laser treatment apparatus for photosynthesis member, a light guide optical system that guides the affected part with a laser beam which is synthesized by the light synthesizing member, wherein Rukoto with the Te.   3. The laser treatment apparatus according to claim 2, further comprising drive means for rotating and driving each of the first half-wave plate and the second half-wave plate.   In a laser treatment apparatus for guiding and irradiating an affected area with laser light, a laser light source that emits laser light having a visible wavelength, and an incident angle of Brewster so as to reflect a part of the P-polarized component in the laser light from the laser light source. A light separating member arranged to be shifted from the corner and separating the first laser light of the transmitted light and the second laser light of the reflected light, an openable / closable shutter disposed in the optical path of the first laser light, and the first A half-wave plate disposed in the optical path of the laser beam, and the half-wave plate reflects the laser beam in which the P-polarized component of the first laser beam is changed to the S-polarized component, and the P-polarized component of the second laser beam is reflected. A laser treatment apparatus comprising: a polarization combining member that transmits light; and a light guide optical system that guides laser light combined by the polarization combining member to an affected area.   5. The laser treatment apparatus according to claim 4, a half-wave plate rotating unit that rotates the half-wave plate, a first polarizing plate that is disposed in an optical path of the second laser light and passes only a P-polarized component, and the second laser. A laser treatment apparatus comprising: a second polarizing plate that is disposed in a light path of light and is rotatable; and a polarizing plate rotating unit that rotates the second polarizing plate.   The light separating member according to claim 4 is arranged such that the incident angle is shifted from the Brewster angle so that the P-polarized light of the laser light from the laser light source is reflected by 0.1 to 0.5% of the whole. Laser treatment device.

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