JP2009136578A - Medical microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical microscope capable of irradiating excitation light corresponding to various fluorescent substances and capable of securely eliminating heat rays from illumination light. <P>SOLUTION: Since an optical filter 19 to cut the light on the infrared side is mounted in the fixed state in the internal optical path 13 of the microscope 1, the light in the infrared region to become heat rays can be securely eliminated. Since the optical filter 19 has characteristics to cut all the light on the infrared side from a threshold wavelength larger than 805 nm and smaller than 815 nm, heat rays on the infrared side including wavelengths around 825 nm, which is substantially the first peak P of the radiation intensity of a xenon lamp widely used as a light source, can be securely eliminated. Further, as the threshold of the optical filter 19 is larger than 805 nm, the optical filter can transmit excitation light for indocyanine green. As the optical filter 19 is one transmission type optical filter, the optical filter 19 can be fixed to a narrow irradiation port 16 of the microscope 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a medical microscope.

  In recent medicine, when a fluorescent substance is administered to a patient and the accumulation in the affected area has progressed, the excitation light having a wavelength that can excite the fluorescent substance is irradiated, and only the affected area is fluorescent while transmitting only the fluorescence. A technique for performing fluorescence observation or fluorescence imaging of an affected area via an optical filter is known.

  As the fluorescent substance, 5-aminolevulinic acid (5-ALA), talaporfin sodium (registered trademark Rezaphyrin), indocyanine green (ICG) and the like are known. 5-Aminolevulinic acid receives excitation light having a wavelength of about 380 nm and emits fluorescence having a wavelength of about 620 nm. Talaporfin sodium emits fluorescence having a wavelength of about 672 nm in response to excitation light having a wavelength of about 664 nm. Indocyanine green receives excitation light having a wavelength of about 805 nm and emits fluorescence having a wavelength of about 835 nm. Indocyanine green is the most infrared side.

  This type of excitation light is performed using illumination light from a microscope that observes the affected area. That is, since the affected part is originally irradiated with illumination light from the microscope for observation, it is convenient to use the illumination light. Illumination light is supplied to the microscope from an external light source device via an optical fiber. The illumination light introduced into the microscope is guided to an irradiation port formed on the bottom surface of the microscope through the internal optical path of the microscope. As a light source used in an external light source device, a xenon lamp capable of obtaining white light close to sunlight is common. A halogen lamp may be used.

  For the external light source device, only the heat protection optical filter that cuts the wavelength in the infrared region that becomes the heat ray from the illumination light to the affected part, and the excitation light of the wavelength corresponding to the fluorescent substance in the illumination light from the xenon lamp. A fluorescent optical filter that selectively transmits light is provided. These two optical filters are selectively interposed in the optical path of the illumination light from the xenon lamp by a slide type or a rotary type by an actuator. Normally, visible light is transmitted and infrared rays are cut by interposing a thermal protection optical filter. During fluorescence observation, the wavelength corresponding to the fluorescent material is interposed by interfering with the optical filter for fluorescence. Only the excitation light is selectively transmitted (see, for example, Patent Document 1).

JP 2004-163413 A

  However, in such a conventional technique, on the side of the external light source device that supplies illumination light to the microscope, the optical filter for thermal protection and the optical filter for fluorescence are made movable by the actuator, so that the failure of the actuator etc. As a result, any filter may be removed from the optical path of the illumination light in the external light source device, and illumination light from a xenon lamp or the like may be supplied to the microscope with 100% output, and may be directly irradiated to the affected part from the microscope. There is. Therefore, it is necessary to provide a sensor for detecting the displacement of the optical filter on the external light source device side, and the structure of the external light source device is complicated.

  The present invention has been made by paying attention to such a conventional technique, and can irradiate excitation light corresponding to various fluorescent materials and reliably remove heat rays from illumination light introduced inside. The present invention provides a medical microscope that can be used.

  The invention according to claim 1 is a medical microscope that introduces illumination light from outside, guides it to an irradiation port on the bottom surface through an internal optical path, and irradiates illumination light from the irradiation port toward an affected area, In the middle of the internal optical path, an optical means for cutting a light beam on a longer wavelength side than the threshold value with a wavelength larger than 805 nm and smaller than 815 nm as a threshold value is fixed.

  The invention described in claim 2 is characterized in that the illumination light is from a xenon lamp.

  The invention described in claim 3 is characterized in that the optical means is a single transmissive optical filter fixed to the irradiation port of the microscope.

  According to the first aspect of the present invention, since the optical means for cutting the infrared light is fixed in the internal optical path of the microscope, the light in the infrared region that becomes the heat ray can be surely removed. Can do. Due to the characteristic that the optical means cuts all the light beams on the longer wavelength side than the threshold with a wavelength larger than 805 nm and smaller than 815 nm as a threshold, the first peak of the radiation intensity of a xenon lamp widely used as a light source Infrared-side heat rays including around 825 nm can be reliably removed. Further, since the threshold value of the optical means is larger than 805 nm, indocyanine green excitation light having excitation light (wavelength 805 nm) on the most infrared side among various fluorescent materials can be transmitted.

  According to the second aspect of the present invention, since the illumination light is from the xenon lamp, the infrared rays including the vicinity of 825 nm, which is substantially the first peak, are reliably removed.

  According to the invention described in claim 3, since the optical means is a single transmission type optical filter, it can be fixed to a narrow irradiation port of the microscope.

  1 to 8 are views showing a preferred embodiment of the present invention. The operating microscope 1 is supported by an arm of a stand device (not shown) in the operating room. The microscope 1 is a stereoscopic microscope having two eyepieces 2, and a focus lens 3 is installed in the vertical direction and a zoom lens 4 is installed in the horizontal direction.

The light passing through the focus lens 3 is guided to the zoom lens 4 via the prism 5. The light that has passed through the zoom lens 4 is folded back to the eyepiece 2 via the two prisms 6 and 7. A beam splitter 8 is provided between the prism 7 and the eyepiece 2 to branch a part of the light. Then, the branched light can be photographed by an area camera (hereinafter referred to as a CCD camera) 9 using an image sensor such as a CCD image sensor. A filter 10 that transmits only the fluorescence wavelength is provided in front of the CCD camera 9.

  An optical fiber 12 from an external light source device 11 is connected below the zoom lens 4 in the microscope 1. The illumination light L from the optical fiber 12 is guided to the irradiation port 16 on the bottom surface through the lens 14 and the mirror 15 provided in the internal optical path 13 of the microscope 1, and can be irradiated toward the affected part T from the irradiation port 16.

  The external light source device 11 is provided with a xenon lamp 17 as a light source, and the illumination light L from the xenon lamp 17 is transmitted through a predetermined excitation filter 18 only to a necessary wavelength and supplied to the microscope 1. ing. The excitation filter 18 is movable up and down and can be freely inserted into and removed from the optical path of the xenon lamp 17. The excitation filter 18 is for indocyanine green and has a characteristic of transmitting only light having a wavelength of around 805 nm.

  A single transmission optical filter (optical means) 19 is fixed to the irradiation port 16 of the microscope 1. Since only one transmissive optical filter 19 is fixed, it can be fixed even in a narrow space of the irradiation port 16. The optical filter 19 is a heat ray cut filter, and has a characteristic of cutting all wavelengths larger than that of the illumination light L from the xenon lamp 17 with a threshold value of 810 nm.

  Next, the operation when indocyanine green is used as the fluorescent material will be described. The xenon lamp 10 emits illumination light L having a radiation spectrum distribution as shown in FIG. 6 as parallel light. The illumination light L emitted from the microscope 1 passes through the excitation filter 18 and has a wavelength near 805 nm necessary for excitation of indocyanine green.

  On the other hand, the optical filter 19 fixed to the irradiation port 16 of the microscope 1 has an infrared side larger than 810 nm (threshold) in the illumination light L, as is apparent from FIGS. 7 and 8 (enlarged main part in FIG. 6). It has a characteristic of cutting all the wavelengths. The optical filter 19 is always fixed in the optical path of the illumination light from the xenon lamp 17 through the microscope 1 (irradiation port 16) to the affected area T, and disposed so as to block the heat ray component of the illumination light beam L. Yes.

  Therefore, since the illumination light L from the xenon lamp 10 passes through the excitation filter 18 and has a wavelength smaller than 810 nm, it passes through the optical filter 19 of the irradiation port 16 as it is and is irradiated to the affected part T.

  Indocyanine green, which is a fluorescent substance, is accumulated in the affected area T in advance, and the reflected light L having a wavelength of 805 nm that excites the indocyanine green causes the affected area T to be fluorescent. The fluorescence is introduced into the microscope 1 from the focus lens 3, and a part of the fluorescence is branched from the beam splitter 8, and then photographed by the CCD camera 9 through the filter 10. And the state of the affected part T can be confirmed as a fluorescence image by displaying the photographed fluorescence image on a monitor (not shown).

  Here, in the unlikely event that the slide mechanism of the excitation filter 18 on the external light source device 11 side breaks down, the excitation filter 18 is out of the optical path of the xenon lamp 17 and 100% output illumination light L is introduced into the microscope 1 side. However, since the optical filter 19 is fixed to the irradiation port 16 of the microscope 1, light having a wavelength longer than 810 nm, which becomes a heat ray, is cut there, and the affected part T is not overheated. In particular, since the infrared side is cut from near 825 nm (810 nm), which is substantially the first peak P of the xenon lamp 10, it is possible to reliably remove heat rays in the xenon lamp 10. Even when the excitation filter 18 is intentionally removed and normal observation is performed with irradiation light including visible light, the same reliable heat ray removal as described above can be performed. In other words, the heat ray component is not irradiated toward the affected area T from the opening 16 of the microscope regardless of the type and presence of the excitation filter.

  Even when another type of excitation filter is used in the external light source device 11 when using a fluorescent material other than indocyanine green, the light transmitted therethrough passes through the optical filter 19 fixed to the microscope 1. It can be transmitted. That is, since indocyanine green having an excitation wavelength on the longest wavelength side (near 805 nm) can be transmitted, light for exciting other fluorescent materials can also pass through the optical filter 19.

  In the above embodiment, the transmissive optical filter 19 is taken as an example of the optical means, but a reflective mirror, a combination thereof, or other optical means may be used. The present invention can also be applied to illumination light from a halogen lamp or other light source.

1 is an overall perspective view showing a microscope according to an embodiment of the present invention. The perspective view which shows the bottom face of a microscope. The figure which shows the internal structure of a microscope. The perspective view of a partial fracture | rupture which shows the irradiation port vicinity of a microscope. Sectional drawing which shows the irradiation port vicinity of a microscope. The graph which shows the radiation spectrum distribution of a xenon lamp. The graph which shows the radiation spectrum distribution of 800 nm vicinity of a xenon lamp. The graph equivalent to FIG. 7 which shows the state by which the wavelength component longer wavelength side than 810 nm was cut with the optical filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microscope 11 External light source device 13 Internal optical path 16 Irradiation port 17 Xenon lamp 19 Optical filter (optical means)
T affected area L illumination light P peak

Claims (3)

A medical microscope that introduces illumination light from outside, guides it to the irradiation port on the bottom surface through an internal optical path, and irradiates illumination light toward the affected area from the irradiation port,
An optical means for cutting a light beam on a longer wavelength side than the threshold with a wavelength larger than 805 nm and smaller than 815 nm as a threshold is fixed in the middle of the internal optical path.   The medical microscope according to claim 1, wherein the illumination light is from a xenon lamp.   3. The medical microscope according to claim 1, wherein the optical means is a single transmissive optical filter and is fixed to an irradiation port of the microscope.

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