JPH01145080A - Apparatus for imaging irradiation intensity distribution of near infrared laser beam - Google Patents

Abstract

PURPOSE:To realize the visualization of the image of the intensity distribution of the near infrared laser beam in an object to be irradiated, by irradiating the object with near infrared laser beam to take the image of the laser beam distribution on a split surface parallel to an optical axis. CONSTITUTION:An object A to be irradiated such as the tissue of a living body is irradiated with the near infrared laser beam from a laser device 1 and the beam distribution region of the object A is received as an image by a television camera 2 having a solid-state imaging element. The image signal from this television camera 2 is inputted to a computer 7 through an A/D converter 5 to perform the step gradation processing or contour processing of the intensity distribution of laser beam. The intensity distribution of the near infrared beam allowed to irradiate the object A is displayed on a monitor 9 through a D/A converter 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention) When examining the effect of a laser on an object to be irradiated, it is most important to understand the intensity distribution of the laser light on the object [ff]. In particular, in the medical application of lasers, it is important to accurately understand the effects and areas of action that laser light has on irradiated targets such as living tissues, both from the standpoint of examining therapeutic effects and the like, as well as from the standpoint of treatment safety. This is an extremely important issue, and it is clear that if the above-mentioned effects and areas of action can be visually observed, the quality of clinical applications of laser light can be dramatically improved.

In the case of a visible light laser such as an argon laser, the above action and action area can be directly observed with the naked eye as a visible image. In addition, even if laser light is in the invisible region, in addition to methods such as using a phosphor in the case of an ultraviolet laser, or using an infrared image sensor such as an image converter or silicon vidicon in the case of an infrared laser, there are other methods such as infrared phosphorescence and observation. Methods that measure the spatial intensity distribution of a laser, that is, the mode pattern, by a method that applies a two-photon process are conventionally known, but these methods are not necessarily clinically appropriate.

Furthermore, in the case of near-infrared lasers, it is no exaggeration to say that there is currently no equipment that can accurately grasp the intensity distribution of laser light irradiated onto a target.

In recent years, the value of near-infrared laser light has rapidly increased in various fields, and in the medical field in particular, near-infrared lasers such as Nd-YAG lasers and semiconductor lasers are becoming mainstream. However, due to the above-mentioned actual situation, conventional treatments such as irradiation with invisible near-infrared laser light have been performed based on empirical rules and guesswork. Therefore,
There have been very serious problems with the therapeutic efficacy and safety of near-infrared laser light irradiation.

In view of this, an object of the present invention is to provide an apparatus that realizes visualization of the intensity distribution of near-infrared laser light on an irradiation target.

(Means for Achieving the Object) According to the present invention, when an irradiation target such as a living tissue is irradiated with near-infrared laser light, the light distribution area of the target, that is, the area of action of the laser light is solid-state imaged. After the image is received by a television camera having an element, the image is converted from analog to digital (hereinafter referred to as A/D conversion) and input into a computer, and within this computer, according to processing instructions given from the outside, Step gradation processing and contour processing of the intensity distribution of laser light are performed.

After that, a digital-to-analog converter (hereinafter referred to as D/A
The intensity distribution and action area of the near-infrared laser beam irradiated onto the target will be displayed on the monitor through the converter (referred to as a converter).

(Description of the Apparatus) FIG. 1 is a block diagram showing the overall configuration of the near-infrared laser irradiation light intensity distribution imaging apparatus according to the present invention. This laser device irradiates external laser light, and as this laser device 1, an Nd-YAG laser or a semiconductor laser having a wavelength range of 1.271 m or less is used. Reference numeral 2 denotes a television camera having a solid-state image sensor 3, which receives, through an optical system lens 4, a two-dimensional image of laser light on an object A irradiated with near-infrared laser light by the laser device 1. The image sensor 3 used in this television camera 2 may be an x-y address type MOS or a charge transfer type CCD, but it has various functions such as image pickup, transfer, M product, and readout. CCD (Charge Co
It is best to use upled[16vice]. An A/D converter 5 converts the two-dimensional image detected by the television camera 2 into a binary digital video signal. A video amplifier 6 as shown by the imaginary line in FIG. 1 may be inserted on the input stage side of the A/D converter 5. 7 is a personal computer (computer), and this personal computer 7 has a memory 7A that stores the output of the A/D converter 5, and provides processing instructions such as step gradation processing of light intensity distribution and contour processing to the stored image. The controller 7B includes a personal computer main body 7B to which a keyboard 7b is connected, and a controller 7C having control functions such as capturing images, switching one screen, and switching input channels. A D/A converter 8 converts the digital image signal processed by the personal computer 7 into an analog signal. A video monitor 9 displays the analog image signal output from the D/A converter 8 as an image.

The main image processing performed by the computer 7 is to set a certain value of the output of the CCD television camera 2 as a reference intensity level, and then perform step gradation processing according to the magnitude of the output from the reference intensity level. This allows images to be displayed on the video monitor 9 in color-specific gradations corresponding to the intensity of the near-infrared laser light. Also,
Image contour processing can also be performed.

(Effects of the Invention) As is clear from the above explanation, if the device according to the present invention is used, the distribution of laser light in an irradiated object such as a biological tissue when irradiated with near-infrared laser light, which is invisible light, can be improved. A television camera equipped with a solid-state image sensor captures the actual working area of near-infrared laser light, which cannot be observed with the naked eye, such as the depth of the light, and a visible image that shows the intensity distribution in gradations. It can be displayed on a monitor. Therefore, by observing the above-mentioned visible image, it is possible to easily and accurately examine the action and action area of near-infrared laser light irradiation on the irradiated object.Especially in medical applications, near-infrared laser light irradiation can be performed based on the data. It is possible to examine the therapeutic effects and safety of light irradiation.
It is possible to achieve an appropriate therapeutic effect. Additionally, this device can be used to accurately perform laser treatment while monitoring the intensity distribution of laser light in the living body.

(Example) In the near-infrared laser irradiation light intensity distribution imaging device configured as described above, a near-infrared laser beam is emitted from the laser device l onto an object A such as a living tissue from the normal direction of its irradiation surface. The object of near-infrared laser light e1
The distribution within can be observed with the naked eye.

In addition, the depth of penetration of the near-infrared laser beam can be measured by capturing an image of the back surface of the object A, such as a biological tissue, irradiated with the near-infrared laser beam using the television camera 2.

In addition to the above, it can also be used to measure the distribution and depth of light when laser light is irradiated on the crown surface of a tooth, and the area of action of laser light when guided laser light is irradiated into the root canal of a tooth. can also be applied.

(Industrial Application Field) This device can be used not only for medical purposes but also in a wide range of fields.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an apparatus according to an embodiment of the present invention. (Explanation of symbols) 1...Laser device, 2...TV camera, 3...
・Solid-state image sensor (CCD), 5...A/D converter, 7
・・・Computer (PC), 8・-D/A
conversion! , 9... video monitor. one or more one

Claims (4)

[Claims] (1) A television camera with a solid-state image sensor that detects a two-dimensional image of the laser light distribution on an object irradiated with near-infrared laser light, and an analog-digital converter that converts the two-dimensional image detected by the television camera from analog to digital. a converter;
a computer including means for storing the output of the converter and applying processing instructions to the stored image; a digital-to-analog converter for digital-to-analog converting the image processed by the computer; 1. A near-infrared laser irradiation light intensity distribution imaging device, comprising a monitor that displays the output of the converter, and displays a visible image that displays the intensity distribution of the laser light on an irradiation target in gradations. (2) The solid-state image sensor used in the above television camera is C
The near-infrared laser irradiation light intensity distribution imaging device according to claim 1, which is a CD or MOS. (3) The near-infrared laser irradiation light intensity distribution imaging device according to claim 1, wherein the laser irradiated to the target is a near-infrared laser such as a GaAlAs semiconductor laser or a YAG laser. (4) The near-infrared laser irradiation light intensity distribution image according to any one of claims 1 to 3, wherein the image processing by the computer includes step gradation processing of the laser light intensity distribution on the irradiation target. Device.