DE102017216754A1 - Surgical microscope with a lighting device - Google Patents

Abstract

Surgical microscope (130) with a lighting device (100) for illuminating an object plane (132), comprising a light source (101) for emitting illumination light in a first wavelength range and an illumination optics with a coupling element (120). The illumination light is guided along a beam path (102) from the light source (101) to the optical coupling element (120) and guided via the illumination optics to the object plane (132). An illumination filter (110), which is arranged in the beam path (102) between the light source (101) and the optical injection element (120), has a transmission range in a second wavelength range, which is suitable as the excitation wavelength range of a fluorescent dye.
The beam path (102) is encapsulated in at least one area between the light source (101) and the optical coupling element (120).

Description

The invention relates to a surgical microscope with a lighting device for illuminating an object area in fluorescence diagnostics.

One way to make tumors visible to the surgeon using a surgical microscope is by fluorescence diagnostics.

For the study and treatment of tumors, it is known to administer to a patient a fluorescent dye which selectively accumulates in tumor cells. By illuminating the fluorescent dye with a certain wavelength, referred to as excitation wavelength or excitation light, its molecules are excited to fluoresce. Such a fluorescent light is detectable by an optical system so that a tumor can be localized. In healthy tissue, the fluorescent dyes do not accumulate, so that the diseased tissue can be detected by a significantly higher fluorescence. Examples of a fluorescent dye is protoporphyrin IX.

The fluorescent light emitted by the fluorescent dye lies in a different wavelength spectrum than the excitation light. In the observation beam path of the surgical microscope, therefore, at least one filter is arranged so that the emitted wavelength spectrum of the fluorescent light can be separated from the wavelength spectrum of the excitation light. Thus, the tumor tissue can be distinguished from the healthy tissue.

However, the intensity of the emitted fluorescent light is not the same for all fluorescent dyes or tumor types. There are tumors that fluoresce only very weakly. This very weakly emitted fluorescent light is not easy to visualize in the respective wavelengths in a surgical microscope. In some applications, detection and registration of this very weak fluorescent light is only possible with very sensitive camera chips.

If only a small part of the illumination light emitted by the light source, which lies in the wavelength spectrum of the fluorescent light, reaches the object plane, then an observer can no longer distinguish whether it is the weak fluorescent light emitted by the fluorescent dye or light from the illumination device is.

The object of the invention is to provide an improved surgical microscope, in which the observation of a very low intensity fluorescent tissue is possible.

The object is achieved by a device having the features of independent claim 1. Advantageous developments of the invention are described in the subclaims.

According to the invention, a surgical microscope with an illumination device for illuminating an object plane comprises a light source for irradiating illumination light in a first wavelength range, illumination optics having a coupling element, wherein the illumination light is guided along a beam path from the light source to the optical coupling element and via the illumination optics to the object plane is guided. An illumination filter is arranged in the beam path between the light source and the optical coupling element and has a passband in a second wavelength range, which is suitable as the excitation wavelength range of a fluorescent dye. The beam path is guided encapsulated in at least one area between the light source and the optical coupling element.

A light source generates illumination light in a first wavelength range. The illumination light is guided along an optical path to an object plane. In the beam path, an illumination filter, a coupling element and an illumination optical system are arranged. The illumination light is passed through the illumination filter. The illumination filter has a passband in a second wavelength range, so that a precisely defined second wavelength range is cut out of the first wavelength range. This second wavelength range forms an excitation wavelength range for fluorescence observation. The light emerging from the filter illumination light in this second wavelength range is coupled via a coupling element in the illumination optics and guided by the illumination optics for illuminating an object plane.

The illumination light directed onto the object plane is used as excitation light for fluorescence observation. For this purpose, only the illumination light guided through the illumination filter in the second wavelength range should be directed to the object plane. For this purpose, only the illumination light filtered through the illumination filter should enter the optical coupling element.

Therefore, the beam path is encapsulated in at least one area between the light source and the optical coupling element.

The encapsulation along a region of the beam path between the light source and the coupling element prevents light from being radiated into the illumination device by reflection or scattering, which could be coupled into the beam path at another point.

The encapsulation forms a complete enclosure for this region of the beam path, so that no light can penetrate out of the beam path to the outside or can penetrate from outside into the beam path. The penetration of stray light, reflection light, or other extraneous light that could get from the outside in this encapsulated portion of the beam path, is reliably prevented.

If the beam path is encapsulated in a section between the light source and the illumination filter, the illumination light emitted by the light source is conducted to the illumination filter in the first wavelength range within the encapsulation. The encapsulation thus precludes ambient light or extraneous light, which is not generated by the light source, from reaching the illumination filter. Only the light generated by the light source is directed along the beam path to the illumination filter.

An encapsulation in a section between the illumination filter and the coupling-in element ensures that only the illumination light emerging through the illumination filter can reach the coupling element in the second wavelength range. The penetration of scattered light, reflection light, or other extraneous light that could get from the outside into this section of the beam path between the illumination filter and coupling element is reliably prevented.

Thus, only light of the second wavelength range of the precisely defined illumination filter is coupled into the coupling element and passed through the illumination optics to the object plane so as to excite the fluorescent dye in a tumor. External light, which could penetrate in any way in the lighting device, passes through reflection or scattering in the lighting device or is generated by a possible further light source, can not reach the coupling element.

Advantageously, the surgical site is wavelength-selectively illuminated without disturbing ambient light, reflected light or scattered light. This ensures that the fluorescent light detectable by the observation of the surgical microscope is generated exclusively by the fluorescent dye in the tumor and is not generated by the illumination device. The light present in the object plane during fluorescence observation by the surgical microscope is present in two separate wavelength ranges. The first wavelength range represents the excitation light, the second wavelength range represents the fluorescence light detected in the observation. Thus, it is also possible to observe and detect a tissue which fluoresces in a very weak intensity.

In one embodiment of the invention, the beam path is encapsulated in a first region between the illumination filter and the optical coupling element.

The encapsulation between the illumination filter and the coupling element ensures that only the illumination light emerging through the illumination filter can reach the coupling element in the second wavelength range. The penetration of scattered light, reflection light, or other extraneous light that could get from the outside into this section of the beam path between the illumination filter and coupling element is reliably prevented.

In one embodiment of the invention, the beam path is formed encapsulated in a second region between the light source and the illumination filter.

The encapsulation in this second region precludes ambient light or extraneous light, which is not generated by the light source, from reaching the illumination filter. Only the light generated by the light source is directed along the beam path to the illumination filter. In addition, it is ensured that no light between the light source and the illumination filter is emitted by reflection or scattering in the illumination device.

In one embodiment of the invention, the beam path between the light source and the optical coupling element is guided by an encapsulation, wherein the encapsulation has a recess into which the illumination filter can be introduced.

The complete encapsulation between the light source and the optical coupling element can further improve the leakage of scattered light or reflection light and the penetration of extraneous light into the beam path.

The illumination light emitted by the light source is guided in the first wavelength range within the encapsulation to the illumination filter. The encapsulation thus precludes ambient light or extraneous light, which is not generated by the light source, from reaching the illumination filter. Only that from the light source generated light is conducted along the beam path to the illumination filter.

The further encapsulation between the illumination filter and the coupling element ensures that only the illumination light emerging through the illumination filter can reach the coupling element in the second wavelength range. The penetration of scattered light, reflection light, or other extraneous light that could get from the outside into this section of the beam path between the illumination filter and coupling element is reliably prevented.

The encapsulation has a recess into which the illumination filter can be introduced. The illumination filter can be introduced into the beam path and removed again. By this arrangement, the illumination filter can be exchanged advantageous. This is particularly advantageous if the illumination filter is arranged on a filter changer, for example a filter wheel. Advantageously, a wavelength-selective illumination of the object plane without disturbing reflection light or scattered light can be effected for several filters.

In one embodiment of the invention, the encapsulation is formed by a scattered light sleeve.

A scattered light sleeve forms an elongated and solid envelope of the beam path and causes an encapsulation of the beam path. A scattered light sleeve can have an arbitrarily shaped cross section. A round cross section has the advantage that the scattered light sleeve is easier to produce. Advantageously, the scattered light sleeve can be produced as a component that can be easily assembled or retrofitted in a beam path.

In one embodiment of the invention, the scattered light sleeve is formed in two parts.

By a two-part diffuser light simplifies the production of a recess into which the illumination filter can be introduced. Further advantages are easy assembly and simpler items, such as simple and inexpensive turned parts.

In one embodiment of the invention, the one surface of the scattered light sleeve is designed as a thread.

At the thread a multiple reflection can occur and so a reduction of the incident light and the scattered light can be achieved. By a thread also a solid mechanical and light-tight connection to another component, such as the coupling element or the light source can be made. Threads are easy to produce.

In one embodiment of the invention, the scattered light sleeve is designed as a cylinder.

A cylinder is inexpensive and easy to manufacture, for example by sawing a pipe.

In one embodiment of the invention, the scattered light sleeve is conical.

By a conical shape of the scattered light sleeve, this can be very well adapted to a convergent beam path.

In one embodiment of the invention, a surface of the scattered light sleeve is stepped.

By grading, a multiple reflection can occur and thus a reduction of the incident light and the scattered light can be achieved. By staging cylindrical outer and inner surfaces can be formed on the two end faces, which facilitate assembly and connection with another component, for example on the coupling element or on the light source.

In one embodiment of the invention, one end face of the scattered light sleeve has a bristle comb.

By the bristle comb, the gap between a fixed-mounted scattered light sleeve and a movable element, such as a filter wheel or a filter slide, be optically sealed, and still allow a relative movement of the components. The mobility of the filter wheel or filter slide is only slightly affected by the bristle friction.

In one embodiment of the invention, a surface of the scattered light sleeve is formed black.

A black surface absorbs light and thus reduces reflection and scattering. The black color can be applied by anodising, painting or plasma-chemically.

In one embodiment of the invention, a surface has grooves, grooves or scales, so that a rough surface with an arithmetic mean roughness Ra> 0.1 mm is formed.

On a rough surface, multiple reflection can occur and thus a reduction of the reflected light and the scattered light can be achieved.

In one embodiment of the invention, the illumination filter has a passband in a wavelength range of 400 nm to 435 nm.

Illumination light in this wavelength range is particularly suitable for fluorescence excitation for protoporphyrin IX.

In one embodiment of the invention, the illumination filter has a passband in a wavelength range of 400 nm to 800 nm.

Illumination light in this wavelength range or a subrange of this wavelength range is particularly suitable when using the fluorescent dye indocyanine green.

In one embodiment of the invention, the illumination filter has a passband in a wavelength range from 380 nm to 440 nm.

This excitation wavelength enables the fluorescent light examination of a tissue region in the blue spectral range. Illumination light in this wavelength range or a subregion of this wavelength range forms an excitation light for a fluorescent dye, which is particularly sensitive to a wavelength around 405 nm.

In one embodiment of the invention, the illumination filter is arranged on a filter changer.

A plurality of illumination filters can be arranged on a filter changer. Advantageously, different illumination modes can be set, each with different illumination wavelengths.

In one embodiment of the invention, the optical coupling element is a light guide.

When the illumination light is coupled into an optical waveguide, the illumination light can be generated outside the surgical microscope. The light source is easier to access, so easy to exchange. Heat generation of the light source is separated from the observation optics of the surgical microscope. The lighting device forms a cold light source. The surgical microscope can be constructed more compactly.

In one embodiment of the invention, the light source is lit continuously.

Under a continuously illuminated light source is understood to be a constant light source. A pulsed light source can only be regarded as continuously lit if an observer can optically not differentiate the pulses, so that an observer perceives the light source as continuous and constantly bright. For example, an LED can be controlled pulse width modulated to control the brightness of the light source. However, an observer does not perceive any pulses or flashes, but perceives the LED as constant and continuously lit. When considering a surgical site with the naked eye, a pulsating or flashing illumination light would be annoying and unpleasant.

• 1 eine Beleuchtungsvorrichtung für ein Operationsmikroskop in einer schematischen Darstellung;
• 2 die Beleuchtungsvorrichtung gemäß 1 mit einem Streulichtanteil in einer schematischen Darstellung;
• 3 die Beleuchtungsvorrichtung gemäß 1 mit einem durch Streulichthülsen gekapselten Strahlengang;
• 4 ein erstes Ausführungsbeispiel einer Streulichthülse in einer Schnittdarstellung;
• 5 ein zweites Ausführungsbeispiel einer Streulichthülse in einer Schnittdarstellung;
• 6 ein drittes Ausführungsbeispiel einer Streulichthülse in einer Schnittdarstellung.

Further advantages and features of the invention will be explained with reference to the following drawings, in which:

• 1 a lighting device for a surgical microscope in a schematic representation;
• 2 the lighting device according to 1 with a scattered light component in a schematic representation;
• 3 the lighting device according to 1 with a light path encapsulated by stray light sleeves;
• 4 a first embodiment of a scattered light sleeve in a sectional view;
• 5 a second embodiment of a scattered light sleeve in a sectional view;
• 6 a third embodiment of a scattered light sleeve in a sectional view.

The 1 shows a lighting device for a surgical microscope in a schematic representation.

A lighting device 100 includes a light source 101 , a filter changer that acts as a filter wheel 110 is formed with a first illumination filter 111 and a second illumination filter 112 , an optical coupling element 120 and a light guide 121 ,

That from the light source 101 radiated illumination light is in a convergent beam path 102 to the optical coupling element 120 guided. The illumination beam path 102 is through the first illumination filter 111 guided. The first illumination filter 111 is on the filter wheel 110 arranged. The filter wheel 110 includes the further illumination filter 112 , The filter wheel 110 is on an axis 113 rotatably mounted. This is by the arrow 114 shown schematically.

The in the optical coupling element 120 coupled illumination light is transmitted through a light guide 121 to a surgical microscope 130 guided. The surgical microscope 130 includes an unillustrated main objective, illumination optics, and viewing optics. That over the optical fiber 121 supplied illumination light is on the illumination optics of the surgical microscope 130 to a lighting beam 131 shaped and forms the lighting for an object plane 132 , The surgical microscope 130 is designed for the illumination and observation of an operation site. The surgical site includes a tumor.

The lighting device 100 may include other optical elements, not shown, for example, lenses, apertures, beam splitters and / or other filters.

The light source 101 can be a light bulb, a halogen or xenon light source. The light source 101 can also be formed by an LED light source.

The filter wheel 110 may include a single illumination filter or multiple illumination filters. The filter wheel 110 can also have an opening without a filter element, through which the illumination light directly to the optical coupling element 120 arrives. The filter wheel 110 Alternatively, it can also be formed by a filter slide, in which a single or several filters can be inserted linearly along an axis into the beam path.

The first illumination filter 111 has a passband in a well-defined wavelength range suitable for excitation of a fluorescent dye in the tumor. The first illumination filter 111 is therefore also referred to as an excitation filter. An example of a passband is a wavelength range from 400 nm to 435 nm as the excitation range for protoporphyrin IX. For this purpose, a dye is supplied to a body with the name 5-ALA, which is converted by metabolic processes in the body to protoporphyrin IX and thus forms a tumor marker.

The second illumination filter 112 has a passband that is different from the wavelength range of the first illumination filter 111 different. For example, the second illumination filter 112 a passband for another fluorescent dye. In an alternative embodiment, the filter wheel 110 instead of the second illumination filter 112 also have only one opening, for example if that by the light source 101 radiated illumination light without filtering to illuminate the surgical site.

The optical coupling element 120 may be formed by a lens or a light guide. It is also conceivable that the illumination light directly into the light guide 121 is coupled. The light guide 121 may be formed by an optical fiber or a light guide rod. A Lichtleitstab is advantageous because the entire rod as a solid material can pass on the light and thus low brightness losses occur. An optical fiber is advantageous because it can also transport the light along curved paths and thus a very flexible construction of the lighting device becomes possible.

The surgical microscope 130 may be a conventional stereo optical surgical microscope with a main objective, a magnifying optic and eyepieces, or a purely digital surgical microscope in which an object plane is captured by one or more cameras whose image is displayed on a screen. The surgical microscope 130 can also form a hybrid system, a mixture of a conventional surgical microscope and a digital surgical microscope.

The 2 shows the lighting device according to 1 with a scattered light component in a schematic representation.

In an ideal lighting device 100 is the entire illumination light, which is in the light source 101 is generated by the first illumination filter 111 directed. In this case, only light of the wavelength range of the well-defined illumination filter 111 via the coupling element 120 in the light guide 121 coupled and the illumination optics of the surgical microscope 130 illuminate the surgical site and thus stimulate the fluorescent dye in the tumor.

In one embodiment, a light source generates 101 , which is designed as a xenon light source, illumination light in a wavelength range of 370 nm to 800 nm. The illumination filter 111 has a passband of 400 nm to 435 nm as the excitation region for protoporphyrin IX. When all the illumination light through the illumination filter 111 is guided, the operation site is illuminated exclusively with illumination light in the wavelength range of 400 nm to 435 nm. This causes excitation of the fluorescent dye in the tumor.

However, already the light source 101 an interference source. Illumination light in a wavelength range outside the passband of the filter 111 is reflected and / or scattered within the lighting device on components or the housing. This reflected and / or scattered illumination light, not through the illumination filter 111 is guided, is schematically by a first scattered light 140 shown. The first scattered light 140 reaches the optical coupling element 120 and is over the light guide 121 and the Illumination optics of the surgical microscope 130 to the object level 132 directed the operation site. This also illuminating light in a wavelength range outside passes through the illumination filter 111 defined wavelength range from 400 nm to 435 nm in the object plane, on the operation site and on the tumor. Thus, too much illumination light, which previously did not pass through the illumination filter, is reached 111 was guided, the light guide and thus passes in addition to the excitation light on the fluorescent dye.

In the observation beam path of the surgical microscope 130 can thus look at the object plane 132 It can not be clearly distinguished whether the observed light is actually fluorescent light emitted by the excitation of the fluorescent dye in the tumor or the first scattered light 140 from the lighting device 100 is. This is true both when looking at the object plane 132 through the eyepieces of the surgical microscope 130 as well as to a viewing through a camera.

The 3 shows the lighting device according to 1 with an encapsulated by stray light tubes beam path.

A lighting device 180 according to 3 has the same components as the lighting device according to the 1 and the 2 , The lighting device 180 according to 3 differs from the lighting device 100 according to the 1 and the 2 in that the beam path 102 in a first area between the illumination filter 111 and the optical coupling element 120 encapsulated and additionally in a second area between the light source 101 and the illumination filter 111 encapsulated.

The encapsulation is formed by a scattered light sleeve, which is formed in two parts. The convergent first section of the beam path 102 between the light source 101 and that on the filter wheel 110 arranged first illumination filter 111 is through a first stray light tube 150 capsuled. The convergent second section of the beam path 102 between the first illumination filter 111 and the optical coupling element 120 is through a second stray light tube 151 capsuled.

Stray light or reflected light between the light source 101 and first illumination filter 111 arises is schematically as a second scattered light 141 shown. The second scattered light 141 is through the first stray light tube 150 either absorbed or reflected so that it is the first illumination filter 111 happens.

A third scattered light 142 schematically shows stray light or reflected light that is between the first illumination filter 111 and the coupling element 120 is produced. The third scattered light 142 is through the second stray light sleeve 151 either absorbed or reflected so that it is to the coupling element 120 to be led.

Light that from the outside to the second diffuser sleeve 151 is met schematically by a fourth scattered light 143 shown. Through the first scattered light sleeve 150 and the second diffuser sleeve 151 is effectively prevented, the ambient light, or in the lighting device 100 reflected or scattered light in the beam path 102 passes and into the light guide 121 via the optical coupling element 120 is coupled.

The first scattered light sleeve 150 can with the light source 101 be connected in a light-tight manner. Likewise, the second scattered light sleeve 151 with the coupling element 120 be connected in a light-tight manner. These connections are static because there is no mechanical relative movement between these components.

However, a mechanical movement takes place between the filter wheel 110 and a first end face of the first scattered light sleeve 150 , As well as a second end face of the second scattered light sleeve 151 instead of.

Therefore, between the first end face of the first scattered light sleeve 150 and the filter wheel 110 a first gap 160 available. Between the filter wheel 110 and the second end face of the second scattered light sleeve 151 is a second gap 161 educated. The first gap 160 and the second gap 161 are present so that the filter wheel 110 a rotation about the axis 113 can run and it is not clamped. This gap is very small, for example less than 0.1mm, to the ingress of stray light in the beam path 102 largely avoided.

Advantageously, on the first end face of the first scattered light sleeve 150 and on the second end face of the second scattered light sleeve 151 a bristle ring may be arranged to prevent the ingress of stray light through the first gap 160 or the second gap 161 effectively prevent. An example of such a bristle wreath is in 6 shown. As an alternative to the bristle rim, it is also possible to arrange a flexible sealing lip or a felt element which effects a light-tight seal and thereby only a low frictional force on the filter wheel 110 exercises.

The encapsulation can also be designed such that the filter wheel 110 completely or is at least partially included in the encapsulated area.

In one embodiment, the beam path 102 between the light source and the optical coupling element 120 guided by a one-piece encapsulation, wherein the encapsulation has a recess into which the filter wheel 110 with the illumination filter 111 can be introduced. The one-piece encapsulation thus comprises the first scattered light sleeve 150 and the second diffuser sleeve 151 ,

In one embodiment, only the second diffuser is 151 in the beam path 102 arranged. Thus, it is ensured that only through the illumination filter 111 emerging illumination light in the second wavelength range to the coupling element 120 can get. The intrusion of extraneous light, that from the outside into this section of the beam path 102 between the illumination filter 111 and the coupling element 120 could arrive reliably prevented. The scattered light sleeve 151 causes light that could enter the lighting device from the outside or lighting light that is scattered or reflected in the lighting device and not by the illumination filter 111 is guided, not in the coupling element 120 is coupled.

In a further embodiment, only the first scattered light sleeve 150 in the beam path 102 arranged. The first scattered light sleeve 150 prevents ambient light or extraneous light that is not from the light source 101 is generated to the illumination filter 111 arrives. Only that from the light source 101 radiated light is emitted along the beam path 102 to the illumination filter 111 directed. The first scattered light sleeve 150 prevents light along the beam path 102 between the light source 101 and the illumination filter 111 by reflection or scattering in the lighting device 180 is emitted.

The 4 shows a first embodiment of a scattered light sleeve in a sectional view.

A first scattered light sleeve 200 is designed as a cylinder. The width of the lateral surface 201 the first scattered light sleeve 200 claims about 10% of the diameter. As a result, the first scattered light sleeve 200 a relatively wide first end face 202 and a second end face 205 on. Advantageously, at the first end face 202 or at the second end 205 an additional sealing element, for example a flexible sealing lip, a felt element or a bristle element are arranged in order to improve the sealing effect even further. The outer lateral surface is as external thread 204 formed, the cylinder inside is as an internal thread 203 educated.

Advantageously, the first scattered light sleeve can thus be screwed to the light source or to the coupling element in order to further improve the light-tightness at this connection point. Advantageously, the internal thread 203 or the external thread 204 be designed as a light trap to effectively absorb stray light. In combination with a light-reducing surface, light is absorbed very well due to the multiple impact on the surface. The internal thread 203 and / or the external thread 204 can have a high roughness. The surface may have grooves, grooves or scales, so that the one rough surface is formed with an arithmetic mean roughness Ra> 0.1 mm.

The first scattered light sleeve 200 may be black anodized or painted to absorb incident light. The staining can also be done plasmachemisch.

The first scattered light sleeve 200 can be made of plastic or metal. Plastic is lightweight and can be produced already colored. Metal has good thermal conductivity. The mechanical processing of a cylindrical scattered light sleeve is possible on a lathe. A cylindrical scattered light sleeve can be inexpensively manufactured by the meter.

The 5 shows a second embodiment of a scattered light sleeve in a sectional view.

A second scattered light sleeve 300 is conical. A first diameter of a first end face 203 is larger than a second diameter of a second end face 205 , Due to the substantially conical shape of a lateral surface 301 is the second scattered light sleeve 300 particularly well adapted to a convergent beam path. The conical surface has on its outer surface 304 and on its inner surface 303 each step-shaped heels on. Thus, reflected light and scattered light can be absorbed more effectively. The surface can be light-colored black. The step-shaped shoulders may be formed such that the lateral surfaces of the steps are each cylindrical.

Due to the stepped formation, the respective adjacent step is at the first end face 203 and at the second end face 302 cylindrically shaped. Thus, the second scattered light sleeve 300 easily plugged onto the light source or to the optical coupling element or light-tightly inserted into a suitable bore.

The surface finish, the coloring and the material can be made exactly the same as with the first scattered light sleeve 200 according to 4 , The same advantages apply as with the first scattered light sleeve 200 ,

The 6 shows a third embodiment of a scattered light sleeve in a sectional view.

A third stray light sleeve 400 is designed as a cylinder. An outer cylinder 404 and an inner cylinder 403 are each executed plan. This is a cheap design. The width of a lateral surface 401 the third scattered light sleeve 400 is about 10% of the diameter. As a result, the third scattered light sleeve 400 as well as the first scattered light sleeve 200 according to 4 a relatively wide first end face 402 and a second end face 405 on.

At the first end 402 is a bristle comb 406 arranged. Through the bristle comb 406 can the gap between the third scattered light sleeve 400 and a filter wheel or a filter slide are optically sealed without significantly affecting the mobility of the filter wheel or filter slide.

The bristle comb 406 can also according to the first scattered light sleeve 4 or the second scattered light sleeve according to 5 be arranged.

The surface finish, the coloring and the material can be made exactly the same as with the first scattered light sleeve 200 according to 4 , The same advantages apply as with the first scattered light sleeve 200 ,

LIST OF REFERENCE NUMBERS

100

lighting device

101

light source

102

beam path

110

filter wheel

111

First lighting filter

112

Second illumination filter

113

axis

114

arrow

120

Optical coupling element

121

optical fiber

130

surgical microscope

131

Lighting beam

132

object level

140

First scattered light

141

Second scattered light

142

Third scattered light

143

Fourth scattered light

150

First scattered light sleeve

151

Second scattered light sleeve

160

First gap

162

Second gap

200

First scattered light sleeve

201, 301, 401

corpus

202, 302, 402

First front page

203

inner thread

204

external thread

205, 305, 405

Second front side

303

palm

304

outer surface

403

inner cylinder

404

outer cylinder

406

bristle comb

300

Second scattered light sleeve

400

Third scattered light sleeve

Claims (15)

Operating microscope (130) with a lighting device (100, 180) for illuminating an object plane (132), comprising a light source (101) for emitting illumination light in a first wavelength range, an illumination optical system with a coupling-in element (120), the illumination light being guided along a beam path (102) from the light source (101) to the optical coupling element (120) and guided via the illumination optical system to the object plane (132), an illumination filter (110) disposed in the beam path (102) between the light source (101) and the optical injection element (120) and having a transmission region in a second wavelength range suitable as the excitation wavelength region of a fluorescent dye, wherein the beam path (102) is guided encapsulated in at least one area between the light source (101) and the optical coupling element (120). Device after Claim 1 , wherein the beam path (102) in a first region between the illumination filter (110) and the optical coupling element (120) is formed encapsulated. Device according to one of the preceding claims, wherein the beam path (102) in a second Region between the light source (101) and the illumination filter (110) is formed encapsulated. Device according to one of the preceding claims, wherein the beam path (102) between the light source (101) and the optical coupling element (120) is guided by an encapsulation, wherein the encapsulation has a recess into which the illumination filter (111, 112) can be introduced , Device according to one of the preceding claims, wherein the encapsulation by a stray light sleeve (150, 151) is formed. Device according to one of the preceding claims, wherein the scattered light sleeve (150, 151) is formed in two parts. Device according to one of the preceding claims, wherein a surface of the scattered light sleeve (150, 151, 200) as a thread (203, 204) is formed. Device according to one of the preceding claims, wherein the scattered light sleeve (150, 151, 300) is conical. Device after Claim 5 wherein a surface of the scattered light sleeve (150, 151, 300) is stepped. Device according to one of the preceding claims, wherein an end face (402) of the scattered light sleeve (400) has a bristle comb (406). Device according to one of the preceding claims, wherein a surface of the scattered light sleeve (150, 151, 200, 300, 400) is formed black. Device according to one of the preceding claims, wherein a surface of the scattered light sleeve (150, 151, 200, 300, 400) grooves, grooves or scales, so that a rough surface is formed with an arithmetic mean roughness Ra> 0.1 mm. Device according to one of the preceding claims, wherein the illumination filter (111, 112) has a passband in a wavelength range of 400 nm to 435 nm. Apparatus according to any preceding claim, wherein the illumination filter (111, 112) is disposed on a filter changer (110). Device according to one of the preceding claims, wherein the optical coupling element (120) is a light guide.

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