Operating microscope with illumination device

Abstract

Operating microscope (100), especially for neurosurgery, with a lighting device (101) for providing illumination light in an operating area (117) examined with the operating microscope; which includes a high-performance light source (102) for generating a luminous field (118) located in the operating area (117); which includes an adjustable filter unit (112) for adjusting the intensity of the illumination light (116) directed to the operating area (117) between a maximum value and a minimum value; and with a control unit (170) for the lighting device (101) which has an operating module (172) by which the lighting device (101) can be activated and controlled, wherein the control unit (170) is operatively connected to the intensity adjustment means for adjusting the intensity of the illumination light directed to the operating area (117); characterized by the fact that For detecting the intensity of the illumination provided by the lighting device (101), a sensor (120) connected to the control unit (170) is provided, which is arranged on a deflecting mirror (115) for illumination light, which directs the illumination light to the operating area (117), in such a way that the sensor (120) receives a fraction of the illumination light from the lighting device (101) that is directed to the deflecting mirror (115), wherein a signal generator (175) is provided which emits a warning signal when an intensity of illumination light is set via the operating module (172) that exceeds a safety limit stored in a memory (171), and wherein the sensor (120) is located on the back of the deflecting mirror and receives the fraction of the illumination light via a corresponding bore.

Description

[0001] The invention relates to an operating microscope, in particular for neurosurgery, with an illumination device for providing illumination light in an operating area examined with the operating microscope, the illumination device comprising a high-performance light source, which includes an adjustable filter unit for adjusting the intensity of the illumination light directed to the operating area between a maximum value and a minimum value, wherein the operating microscope has a control unit for the illumination device, which has an operating module by means of which the illumination device can be activated and controlled, wherein the control unit for adjusting the intensity of the illumination light directed to the operating area is operatively connected with the intensity adjustment means.

[0002] An operating microscope of the type mentioned above is known from DE 195 38 382 A1.

[0003] To visualize the finest tissue structures with an operating microscope, adequate illumination is essential. This necessitates a powerful illumination system within the microscope. Therefore, high-power light sources are used in the illumination systems of operating microscopes for neurosurgery and ENT surgery. However, illumination light directed into the surgical area interacts with body tissue. This leads to heating and, if the illumination intensity is too high, can cause lasting damage to tissue structures, even when the UV and infrared light emitted by the high-power light sources is filtered out.

[0004] From DE 199 14 495 A1, a slit-lamp microscope is known that includes a sensor for detecting the luminous intensity of illumination light. This light is supplied to the sensor from the illumination beam path via a glass plate acting as a beam splitter. The sensor signal is used to regulate the luminous intensity of the light in the illumination beam path or to generate a warning signal. The operating microscope marketed by Carl Zeiss Surgical GmbH under the name OPMI® Pentero is designed for neurosurgery and has an illumination unit with a 300-watt high-performance xenon light source for illuminating the surgical area. The intensity of the illumination provided by the illumination unit can be adjusted almost continuously between a minimum and a maximum value using a diaphragm.The operating microscope allows the visualization of surgical areas with fluorescence light in the infrared and blue spectral range.

[0005] In order to optimally adjust an operating microscope for a surgical operation, it is advantageous if the surgeon has the possibility to vary, in particular, the intensity and spectral composition, but also the size of the illuminated field of the illumination light generated by the illumination device in the operating microscope, as well as the working position of the operating microscope in relation to the object area.

[0006] The object of the invention is to provide an operating microscope in which, despite a lighting device with high variability in terms of the intensity of the provided illumination light, damage to tissue structures of a patient due to incorrect operation is prevented.

[0007] This problem is solved by the operating microscope specified in claim 1.

[0008] In a further development of the invention, when the illumination device is activated via the operating module, the control unit sets the filter unit to a first illumination device activation value, at which the light from the high-power light source in the illumination device is attenuated. In this way, an operating microscope is created which, when the illumination device is switched on, does not subject the surgical area to excessive illumination.

[0009] In a further development of the invention, the operating module includes means for setting the first activation value of the lighting device. This allows the heat sensitivity of different body tissues undergoing surgery to be taken into account.

[0010] In a further development of the invention, a signal generator is provided that emits a warning signal when a first illumination activation value is set via the operating module that exceeds a safety limit for the first illumination activation value stored in a memory. In this way, the operator is informed that there is a risk of tissue damage when operating the surgical microscope with the current device setting.

[0011] In a further development of the invention, the lighting device includes a spectral filter for adjusting the spectral composition of the illumination light from the lighting device. In this way, it is possible to avoid exposing an operational area to illumination light that does not contribute to image formation.

[0012] In a further development of the invention, the spectral filter is designed as a heat protection filter. In this way, the exposure of an operating area to heat radiation can be prevented.

[0013] In a further development of the invention, the spectral filter is designed as an infrared fluorescence excitation filter. In this way, body tissue can be visualized using fluorescent dyes that emit infrared light when they fluoresce.

[0014] In a further development of the invention, the spectral filter is designed as a blue light fluorescence excitation filter. This enables the fluorescence examination of a surgical area in the blue spectral range.

[0015] In a further development of the invention, the operating module has an input unit for setting an infrared fluorescence operating mode in which the infrared fluorescence excitation filter is switched into the observation beam path of the illumination device. In this way, ergonomic operation of the operating microscope is possible.

[0016] In a further development of the invention, when the infrared fluorescence operating mode is selected via the input unit of the operating module, the control unit sets the filter unit to a second illumination device activation value. This prevents patient tissue from being exposed to excessively intense fluorescence excitation light when the operating microscope is switched to an infrared fluorescence operating mode.

[0017] In a further development of the invention, the operating module has means for setting the second illumination device activation value. In this way, the operating microscope can be configured according to the requirements of the operation to be performed.

[0018] In a further development of the invention, the operating microscope includes a signal generator that emits a warning signal when a second illumination activation value is set via the operating module that exceeds a safety limit stored in memory for the second illumination activation value. In this way, the operator is alerted to the danger that the illumination light of the operating microscope's illumination system could excessively stress patient tissue.

[0019] In a further development of the invention, the operating module of the surgical microscope has an input unit for setting a blue light fluorescence operating mode, in which the blue light fluorescence excitation filter is switched into the illumination beam path of the illumination device. In this way, the surgical microscope can be configured for a user-friendly blue light fluorescence operating mode.

[0020] In a further development of the invention, when the blue light fluorescence operating mode is selected via the input unit of the operating module, the control unit sets the filter unit to a third illumination device activation value. This prevents excessive tissue stress when operating the surgical microscope for blue light fluorescence.

[0021] In a further development of the invention, the operating module includes means for setting the third illumination device activation value. This makes it possible to configure the operating microscope for operations using dyes that fluorescently react to blue light and to quickly adjust it for use on body tissue with varying light sensitivity.

[0022] In a further development of the invention, a signal generator is provided in the operating microscope, which emits a warning signal when a third illumination activation value is set via the operating module that exceeds a safety limit for the third illumination activation value stored in a memory. This makes it possible to warn the operator of the risk of tissue damage during an operation in which the operating microscope is used.

[0023] In a further development of the invention, the operating module includes means for adjusting the filter unit between a value for minimum intensity of the illumination light from the lighting device and a second value for maximum intensity of the illumination light from the lighting device. This allows a surgeon to adjust the amount of light provided by the operating microscope's illumination device during a medical operation so that the surgical field is always clearly visible.

[0024] In a further development of the invention, the maximum adjustable value for the intensity of the illumination light in the operating microscope corresponds to the first, second, or third safety limit stored in the memory. This prevents a surgeon from accidentally operating the illumination device of the operating microscope in an area where there is a risk of tissue damage.

[0025] In a further development of the invention, the operating module has means for adjusting the second value for the maximum intensity of the illumination light of the lighting device. In this way, the aging process of a light source in an operating microscope can be taken into account, which leads to a decrease in the light output of a light source with increasing operating time.

[0026] In a further development of the invention, the operating microscope is equipped with a lamp change detection device, which is connected to the control unit and, upon detection of a lamp change, causes the filter unit to be set to a preset value. This ensures that the operating microscope illumination device does not emit excessively intense light immediately after a lamp change.

[0027] In a further development of the invention, the operating microscope includes a sensor for detecting the intensity of the illumination light provided by the lighting device. This makes it possible to automatically detect when it is advantageous to replace the lamp.

[0028] In a further development of the invention, the illumination device of the operating microscope includes means for adjusting the filter unit, which comprise a control loop that regulates the intensity of the illumination light emitted by the illumination device to a predetermined value. In this way, it is possible to automatically compensate for the decreasing light output with increasing operating time of a light source, thereby enabling a brightness impression of an operating area that is independent of the operating time of the light source.

[0029] Advantageous further developments of the invention are shown in the drawings and are described below.

[0030] They show: Fig. 1. An operating microscope for neurosurgery with a control unit that includes an operating module to control a lighting device; Fig. 2 a filter unit of the operating microscope designed as a sieve filter Fig. 1; Fig. 3 a filter wheel in the operating microscope Fig. 1 with multiple filter discs; Fig. 4 the filter characteristics of a first filter disc; Fig. 5 the filter characteristics of a second filter disc; Fig. 6 the filter characteristics of a third filter disc; and Fig. 7 an input menu of the control unit for the lighting system.

[0031] In Fig. Figure 1 shows an operating microscope 100 with an illumination device 101. The illumination device 101 contains a high-power light source 102 in the form of a high-power xenon lamp. The high-power light source 102 generates illumination light 103, which is supplied to a light guide 104 in the illumination device 101. The illumination device 101 has an adjustable illumination optic 105 with four lenses 106, 107, 108, and 109. An adjustable filter unit 112 is arranged between the illumination optic 105 and an exit end 110 of the light guide 104. The adjustable filter unit 112 is designed as a sieve filter. It acts as a means of adjusting the intensity of the illumination light from the lighting device 101. The filter unit attenuates the illumination light 113 emerging from the light guide according to an adjustable attenuation factor, which lies between 0% and 100%.

[0032] The filter unit 112 is associated with a filter wheel 114 with filters for adjusting the spectral composition of the illumination light 113, which is guided to the illumination optics 105 in the illumination device 101.

[0033] The lighting device 101 further comprises a deflecting mirror 115. The illumination light 116 emerging from the lighting optics 105 is directed by means of the deflecting mirror 115 to an object area 117. The illumination light 116 forms a luminous field 118 there.

[0034] An illumination light intensity detector 120 is arranged on the back side 119 of the deflecting mirror 115. The illumination light intensity detector 120 receives a fraction of the illumination light, which is directed from the illumination optics 105 to the deflecting mirror 115, via a bore 121 in the deflecting mirror 115.

[0035] The operating microscope 100 further comprises a main microscope objective 130, which is intersected by a left observation beam path 131 and a right observation beam path 132. On the side of the main microscope objective 130 facing away from the object, an adjustable zoom system 133, 134 is arranged in the left and right observation beam paths 131, 132. The operating microscope has a binocular tube with eyepieces 135, 136, which is shown in more detail.

[0036] A viewer looking with his eyes 137, 138 into the eyepieces 135, 136 can magnify the object area 117 and see it stereoscopically under a stereo angle 139 in relation to the optical axis 1000 of the microscope main objective 130.

[0037] A beam splitter 140 is arranged in the left observation beam path 131 of the operating microscope 100. This beam splitter 140 couples out part of the observation light 141 from the observation beam path 131 and directs it via an imaging optic 142 to a first camera 143.

[0038] In the right observation beam path 132 of the operating microscope there is a beam splitter 150. The beam splitter 150 couples out part of the observation light 151 from the right observation beam path 132 and directs it through a filter 152, which is tuned for fluorescence light of the fluorescent dye indocyanine green (ICG) and is essentially only transparent to light from the wavelength range between 820 nm and 870 nm, via an imaging optic 153 onto a camera 154.

[0039] A beam splitter 160 is provided in the right observation beam path 132 of the microscope 100. This beam splitter 160 serves to couple image and display signals from a display 161, to which an imaging optic 162 is assigned.

[0040] The operating microscope 100 is designed for examining object area 117 with white light. However, object area 117 can also be examined with the operating microscope 100 by observing fluorescence light generated in object area 117.

[0041] To generate fluorescent light within the object, a fluorescent dye is required, which must be located within the object. A fluorescent dye can be excited to fluorescence by illumination with a suitable spectral composition. This produces light whose spectral characteristics differ from those of the excitation light.

[0042] The lighting device 101 is designed so that the illuminating light 116, which forms the luminous field 118 in the object area, can stimulate the dyes ICG and 5-ALA, which are suitable for enriching body tissue of a patient in a surgical operation, to fluoresce.

[0043] The dye ICG can be excited to fluorescence by light with a wavelength of 780 nm in the red spectral range. The fluorescence emitted by the dye lies at 835 nm in the infrared spectral range and is not visible to the human eye.

[0044] To visualize an image of object area 117 based on the fluorescence of the dye ICG in the operating microscope, image conversion is required. This is achieved using the camera 154 in the operating microscope 100. The camera 154 is supplied with light from a wavelength range whose spectral composition corresponds to that of the fluorescence of ICG, via the filter 152. The camera 154 is connected to the display 161. This converts the image signal captured by the camera 154, which is invisible to the human eye, into an image signal that the human eye can see. This image is made visible by coupling it into the right observation beam path when the illumination device for exciting the fluorescence of ICG is activated.

[0045] Images of object area 117 produced using fluorescence light, based on the fluorescence of the dye Blue 400, can be observed with the naked eye in the operating microscope 100. To put the operating microscope 100 into an operating mode for observing the fluorescence of the dye Blue 400, a filter is inserted into the observation beam path by adjusting the filter wheel 114 in the illumination device 101. This filter is transparent to light that can excite the fluorescence of the dye Blue 400, but does not transmit light at the fluorescence wavelengths of this dye.

[0046] Fig. Figure 2 shows the filter unit 112 for attenuating the intensity of the illumination light produced by the high-power light source 102 of the lighting device. The filter unit 112 is designed as a screen filter and comprises an opaque screen filter disk 200 in which apertures 201 are provided for light of different sizes. By moving the disk 200 about its axis 202 in the direction of the double arrow 203 in the illumination beam path 204 of the lighting device, it controls the light flow according to the number and size of the light apertures 201 located in the illumination beam path 204.

[0047] Fig. Figure 3 shows the filter wheel 114 of the lighting device 101. Fig. 1 for adjusting the spectral composition of the illumination light produced by the high-power light source 102. The filter wheel 114 can be moved about an axis 301 in the illumination beam path according to the double arrow 310. It contains filter disks 302, 303 and 304, which filter the illumination light from the high-power light source 102. Fig. 1 for operation of the operating microscope in white light mode and in a mode in which the dye ICG can be excited to fluorescence, as well as in a mode that makes it possible to excite the dye 5-ALA to fluorescence.

[0048] The Fig. Figure 4 shows the filter characteristic 400 of the filter disc 302, which is connected to the illumination beam path when the operating microscope is in white light mode. The filter disc 302 acts as a heat protection filter. The filter disc 302 is transparent to illumination light in the visible spectral range with wavelengths between 400 nm and 720 nm. The filter characteristic 400 decreases for light with wavelengths below 450 nm. At 720 nm, there is a filter edge 401. Light in the UV range with wavelengths below 400 nm and light with wavelengths >720 nm in the infrared spectral range is blocked by the filter disc 301. Fig. 4 blocked. This ensures that when operating the operating microscope in white light mode, patient tissue is not unnecessarily exposed to heat radiation and UV radiation, which make no contribution to the image of an object area that can be observed with the operating microscope.

[0049] The Fig. Figure 5 shows the filter characteristic 500 of the filter disc 303. Fig. 3. The filter disc 303 acts as an infrared fluorescence excitation filter. This filter disc is inserted into the illumination beam path during operation of the operating microscope for the visualization of images based on ICG fluorescence. The filter characteristic 500 has a steep filter edge 501 at a wavelength of 780 nm. This ensures that the illumination system directs light whose wavelength lies within the excitation band for ICG fluorescence to the object area, while simultaneously preventing the object area from being illuminated by light whose wavelength lies within the range of the ICG fluorescence wavelength.

[0050] Fig. Figure 6 shows the filter characteristic 600 of the filter disc 304 in the filter wheel 114. Fig. 3. The filter disc 304 acts as a blue light fluorescence excitation filter. The filter disc 304 is used for operating the operating microscope in a mode for exciting the fluorescence of the dye 5-ALA in the illumination beam path of the illumination device 101 from the operating microscope 100. Fig. 1 switched on. The filter characteristic 600 ensures the transmission of light in the UV range below the wavelength of 400nm, where the fluorescence of the dye 5-ALA can be excited.

[0051] The illumination light from an operating microscope can damage patient tissue through thermal and phototoxic stress. The risk of tissue damage increases with the intensity of the illumination light used to light up the surgical area. To expose the dyes ICG and 5-ALA to the high-performance light source 102 in the illumination unit 101 of the operating microscope 100, Fig. To stimulate fluorescence, very intense illumination must be provided.

[0052] So that during routine operation of the operating microscope 100 Fig. 1. To avoid accidental damage to patient tissue, the lighting device 101 has a control unit 170 which allows the intensity of the illumination light directed to the operating area to be adjusted, but which, depending on the operating mode of the lighting device, ensures that the maximum illumination light intensity does not exceed a predetermined, adjustable threshold.

[0053] The control unit 170 comprises a data storage device 171 and an operating module 172 with a touch-sensitive screen 173 as an input and output interface. The operation of the operating microscope 100 can be activated via the touch-sensitive screen 173 for illumination of the operating area with white light, for illumination of the operating area with light to excite the fluorescence of ICG, and for illumination of the operating area with light to excite the fluorescence of the dye 5-ALA. For this purpose, the operator must touch the corresponding control fields on the screen.

[0054] The Fig. Figure 7 shows an input menu 700 of the touch-sensitive screen 173 in the operating microscope 100. Fig. 1. The values ​​for the light source intensity activation value and for the intensity of the illuminance emitted by the lighting device can be set using sliders 701 and 702. The input menu also includes a numeric keypad 703. This numeric keypad 703 allows the entry of personalized device configurations. These configurations are entered by entering a personal data code via the touch-sensitive screen 173 of the lighting device's control unit 101. Fig. 1. A personal device preset can be accessed. Using the numeric keypad 703, it is possible to set the activation values ​​stored in the data memory for the intensity of the illumination provided by the lighting unit 101 in the case of white light, light for exciting the fluorescence of ICG, and light for exciting the fluorescence of the dye 5-ALA. For security reasons, a license key must first be entered via the keypad. This activates the control unit 170. Fig. 1. put into a service operating mode and called up an input menu to set the activation values.

[0055] A patient harm warning device 174 is assigned to the control unit 170. If operating parameters for the lighting system are set that do not preclude patient harm from the lighting, a warning signal generator 175 in the patient harm warning device 174 is activated. This then emits an audible and a visual warning signal. Alternatively, the warning signal generator 175 can also be configured to emit only an audible warning signal or only a visual warning signal. It is also possible to configure the warning signal generator to emit a haptically detectable warning signal.

[0056] When the "white light" is activated, the filter disc 302 is turned by rotating the filter wheel 114. Fig. 3 moved into the lighting beam path. The sieve filter disc 200 is then placed on it. Fig. 2 of the filter unit 112 is set to a white light activation value. Only then is the high-performance light source 102 activated. The white light activation value corresponds to a setting value for the disc 200 of the filter unit 112 stored in the data memory 171. This setting value is stored by the manufacturer in the data memory 171. It preferably has a value for attenuating the light from the high-performance light source 102 to 25% of the amount of light provided by the high-performance light source 102.

[0057] The touch-sensitive screen 173 allows a white light operation activation value to be set. If the white light operation activation value is set to a value that exceeds the manufacturer's value for the white light operation activation value stored in the data memory 171, a warning signal is output by the warning signal generator 175 in the patient harm warning device 174.

[0058] The touch-sensitive screen 173 also allows the intensity of the illumination provided by the lighting device to be adjusted when the lighting device is in white light mode. By controlling the disc 200 from Fig. 2 of the filter unit 112 can adjust the intensity of the illumination light supplied by the high-power light source 102 of the illumination device 101 in the operating microscope 100. Fig. 1 originates from a value between 0 and a maximum value that corresponds to the white light operation activation value.

[0059] A similar process is possible in the operating mode of the illumination device 101 for the excitation of ICG fluorescence. When this operating mode is activated via the touch-sensitive screen 173, the filter disc 303 first moves into the illumination beam path, and the sieve filter disc 200 is set to an initial value favorable for the excitation of ICG fluorescence, at which there is no risk of damaging patient tissue. This activation value of the sieve filter disc 200 in the operating mode for the excitation of ICG fluorescence is, in turn, a value pre-programmed by the manufacturer into the data memory 171.

[0060] For example, it corresponds to an attenuation of the light from the high-performance light source 102 by means of the sieve filter disc 200. Fig. 2 to 50% of the light provided by the high-performance light source 102.

[0061] The touch-sensitive screen 173 allows this activation value for illumination light to stimulate the fluorescence of ICG to be set. If this activation value is set, the warning signal generator 175 in the patient harm warning device 174 generates a warning signal if an activation value is selected that is higher than the manufacturer-stored activation value stored in the data memory 171.

[0062] In the operating mode of the illumination device for the excitation of ICG fluorescence, the intensity of the supplied illumination light can be adjusted between a minimum and a maximum value via the touch-sensitive screen 173. The maximum value of the sieve filter disc 200 setting corresponds to the intensity value of the illumination light supplied by the illumination device 101 when the operating mode for ICG fluorescence is activated.

[0063] If the operating microscope is activated for fluorescence of 5-ALA operation, for which a corresponding input option is provided on the touch-sensitive screen 173, the filter disc 303 is adjusted. Fig. 3 in the lighting beam path. The sieve filter disc 200 made of Fig. 2 is set to a 5-ALA activation value. Then the high-performance source 102 in the operating microscope 100 is switched off. Fig. 1 put into operation.

[0064] The 5-ALA activation value is a setting value for the screen filter disc 200 stored in data memory 171. This setting value is configured by the manufacturer and stored in data memory 171. It corresponds, for example, to an attenuation of light from the high-power light source of 0, i.e., a setting of the screen filter disc for maximum illumination intensity.

[0065] It is possible to adjust this attenuation value again using the touch-sensitive screen 173 when activating the operating microscope mode for observing the fluorescence of the dye 5-ALA. If the activation value stored by the manufacturer in the data memory 171 is exceeded, a warning signal is again emitted by the warning signal generator 174 in the patient harm warning device 174.

[0066] About the in Fig. 7 Input menu shown on the touch-sensitive screen 173 of the operating microscope Fig. 1. The safety limit value of the light emitted by the lighting device 101 can be set using the slider 702. Fig. The emitted light can be varied within a set range. This safety limit can only be changed after entering a security code via the keypad 703 on the input menu 700 of the touch-sensitive screen 173. Fig. 1. be modified.

[0067] Slider 701 is used to adjust the activation value of the intensity of the illumination light emitted when the lighting device 101 is activated, for white light operation, for operation to excite the fluorescence of ICG, and for operation to excite the fluorescence of the dye 5-ALA. The corresponding setting is only accessible after entering a security code via keypad 703 in input menu 700. Fig. 7 possible.

[0068] If an operator sets a different threshold value than the one stored by the device manufacturer in the data memory 171 of the control unit 170, the patient harm warning device 174 of the lighting unit 101 will be activated. Fig. 1. A warning signal is emitted. Preferably, this warning signal is combined with a display on the touch-sensitive screen 173, which reads as follows: “Caution: High light intensity can cause tissue damage! Please consider using the lowest possible light output.” Only when this warning has been acknowledged via a corresponding input on the touch-sensitive screen can the relevant threshold be changed.

[0069] Preferably, this warning should be issued whenever the operator of the operating microscope changes and intends to set a different value than recommended by the manufacturer.

[0070] In the event that an operator sets the maximum value for the intensity of the illuminance emitted by the lighting device to a value that is lower than the relevant activation value when the lighting device is activated in one of the possible operating modes for the lighting device 101, then the control unit 170 will Fig. 1 The value of the light intensity emitted when the lighting device 101 is activated is reduced to the value set by the operator for the maximum emitted light output.

[0071] The control unit 170 contains a control loop 190. This control loop 190 enables the lighting device 101 to operate in a controlled operating mode. The control loop 190 is connected to the lighting intensity detector 120. It sends a control signal to the adjustable filter unit 112.

[0072] The standard operating mode can be set by input on the touch-sensitive screen 173. It allows the intensity of the light emitted by the illumination unit 101 in the operating microscope 100 to be adjusted. Fig. to regulate the illumination light provided by the operating microscope 100 to a predetermined value. For this purpose, the illumination light intensity detector 120, which is located on the back 119 of the deflecting mirror 116 in the operating microscope 100, is used. Fig. The currently measured value for the light intensity is fed to the control loop 190 in the control unit 170. This value is compared there with a setpoint. Depending on the deviation between the actual value and the setpoint, a control signal is then sent to the filter unit 112 to attenuate the intensity of the illumination light from the high-power source 102 in the lighting device 101. Fig. 1 submitted.

[0073] Finally, the illumination unit 101 of the operating microscope 100 contains Fig. 1. A lamp change detection device 180. The lamp change detection device 180 is connected to the control unit 170. When the lamp change detection device 180 detects a lamp change, a lamp change information signal is sent to the control unit 170. Based on this lamp change information signal, the control unit 170 adjusts the activation value for each possible operating mode of the lighting device 101: The respective activation value for white light operation, for excitation of ICG fluorescence, and for excitation of 5-ALA fluorescence is then set to an output value stored in a data memory and preset by the manufacturer.

[0074] After each lamp change, the control unit 170 independently of the current user settings made by an operator via the touch-sensitive screen 173 sets the activation values ​​for the light intensity when operating the lighting device in white light mode, in the ICG dye excitation mode and in the 5-ALA dye excitation mode, as well as the corresponding maximum adjustable light intensity values ​​for the lighting device 101. Fig. 1. The threshold values ​​stored in data memory 171 are reset. However, the values ​​set by the respective operator for the output light intensity and the light intensity at which a patient damage warning is triggered are retained in data memory 171. The operator also has the option, after a lamp change and the automatic reset of the light output from the illumination unit 101, to reset the illuminance to the setting used before the lamp change.

[0075] The operating microscope from Fig. Furthermore, 1 is designed for emergency operation. In the event that the operating module 171 with the touch-sensitive screen 173 fails, the control unit 170 causes the filter unit 112 to adjust the intensity of the illuminance emitted by the lighting device to a value of 70% of the maximum possible luminous flux.

[0076] To select an operator for the operating microscope 100 from Fig. 1. To warn of the possibility of harm to the patient from the lighting device, the light intensity emitted by the lighting device is displayed on the touch-sensitive screen, preferably in red text, if it corresponds to or exceeds the set threshold value. If the intensity of the light emitted by the lighting device 101 Fig. Furthermore, if the emitted illumination light is greater than or equal to the set threshold value, it is also detected in the observation beam path 132 of the operating microscope 101. Fig. 1. A warning indicator is displayed in the eyepiece 136 using the display 161. This warning indicator includes a numerical display of the light intensity in conjunction with additional exclamation marks. A good warning effect can be achieved by flashing the indicator, preferably at a frequency of 0.5 Hz for a period of 5 seconds.

[0077] If the currently set intensity threshold is undershot by the intensity of the illumination actually emitted by the lighting device 101, the display of the warning message on the touch-sensitive screen and on the display 161, which is visible in the observation beam path 132, is terminated.

[0078] Displaying information via the display 161 in the observation beam path 132 is disadvantageous when the operating microscope is used for observing fluorescence. Compared to normal light, the light generated by fluorescence in a surgical area is relatively low in intensity. This means that a fluorescence-based image in an operating microscope is typically dark. In such cases, additional display information in an eyepiece is distracting. Therefore, in the operating modes of the operating microscope 100 for fluorescence, warning messages are not displayed via the display 161 in the right observation beam path 132, but only on the touchscreen 173.

[0079] Furthermore, the described lighting device 101 makes it possible to issue a warning message at system start-up if the light intensity provided by the lighting device 101 exceeds 25% of a device-specific maximum value.

[0080] It should be noted that the intensity of the illumination provided by the lighting device 101 can be varied not only by adjusting the screen filter disc 200, but also by changing the lamp current for the high-power light source 102.

Claims

[1] Operating microscope (100), especially for neurosurgery, with a lighting device (101) for providing illumination light in an operating area (117) examined with the operating microscope; which includes a high-performance light source (102) for generating a luminous field (118) located in the operating area (117); which includes an adjustable filter unit (112) for adjusting the intensity of the illumination light (116) directed to the operating area (117) between a maximum value and a minimum value; and with a control unit (170) for the lighting device (101) which has an operating module (172) by which the lighting device (101) can be activated and controlled, wherein the control unit (170) is operatively connected to the intensity adjustment means for adjusting the intensity of the illumination light directed to the operating area (117); characterized by , that For detecting the intensity of the illumination provided by the lighting device (101), a sensor (120) connected to the control unit (170) is provided, which is arranged on a deflecting mirror (115) for illumination light, which directs the illumination light to the operating area (117), in such a way that the sensor (120) receives a fraction of the illumination light from the lighting device (101) that is directed to the deflecting mirror (115), wherein a signal generator (175) is provided which emits a warning signal when an intensity of illumination light is set via the operating module (172) that exceeds a safety limit stored in a memory (171), and wherein the sensor (120) is located on the back of the deflecting mirror and receives the fraction of the illumination light via a corresponding bore. [2] Operating microscope according to claim 1, characterized by, that the control unit (170) contains a control loop (190), and the control loop (190) sends a setting signal to the adjustable filter unit (112) to control the intensity of the illumination light provided by the lighting device (101) to a setpoint. [3] Operating microscope according to one of claims 1 or 2, characterized by , that when the lighting device (101) is activated via the operating module (172), the control unit (170) causes the filter unit (112) to be set to a first lighting device activation value, at which the light from the light source (102) in the lighting device (101) is attenuated. [4] Operating microscope according to claim 3, characterized by , that the control module (172) has means (173) for setting the first lighting device activation value. [5] Operating microscope according to claim 3, characterized by, that the signal generator (175) emits a warning signal when a first lighting device activation value is set via the operating module (172) that exceeds a safety limit value for the first lighting device activation value stored in a memory (171). [6] Operating microscope according to any one of claims 1 to 5, characterized by , that the lighting device (101) has a filter (302, 303, 304) for adjusting the spectral composition of the illumination light (116) from the lighting device. [7] Operating microscope according to claim 6, characterized by , that the spectral filter is designed as a heat protection filter (302). [8] Operating microscope according to claim 6, characterized by , that the spectral filter is designed as an infrared fluorescence excitation filter (303). [9] Operating microscope according to claim 6, characterized by, that the spectral filter is designed as a blue light fluorescence excitation filter (304). [10] Operating microscope according to claim 8, characterized by , that the operating module has an input unit (173) for setting an infrared fluorescence operating mode in which the infrared fluorescence excitation filter (303) is switched into the illumination beam path (113) of the illumination device (101). [11] Operating microscope according to claim 10, characterized by , that when the infrared fluorescence operating mode is set via the input unit (173) of the operating module (172), the control unit (170) causes the filter unit (112) to be set to a second lighting device activation value. [12] Operating microscope according to any one of claims 1 to 11, characterized by , that the operating module (172) has means (173) for setting a second lighting device activation value. [13] Operating microscope according to claim 12, characterized by , that a signal generator (175) is provided which emits a warning signal when a second lighting device activation value is set via the operating module (172) which exceeds a safety limit value for the second lighting device activation value stored in a memory (171). [14] Operating microscope according to claim 9, characterized by , that the operating module (172) has an input unit (173) for setting a blue light fluorescence operating mode in which the blue light fluorescence excitation filter (303) is switched into the illumination beam path (113) of the illumination device (101). [15] Operating microscope according to claim 14, characterized by, that when the blue light fluorescent operating mode is set via the input unit (173) of the operating module (172), the control unit (170) causes the filter unit (112) to be set to a third lighting device activation value. [16] Operating microscope according to claim 15, characterized by , that the operating module (172) has means (173) for setting the third lighting device activation value. [17] Operating microscope according to claim 16, characterized by , that a signal generator (175) is provided which emits a warning signal when a third lighting device activation value is set via the operating module (172) which exceeds a safety limit value for the third lighting device activation value stored in a memory (171). [18] Operating microscope according to any one of claims 1 to 17, characterized by, that the operating module (172) has means (173) for adjusting the filter unit (112) between a first value for minimum intensity of the illumination light of the lighting device and a second value for maximum intensity of the illumination light of the lighting device. [19] Operating microscope according to claim 18, characterized by , that the value for maximum intensity of the lighting light corresponds to the first, second or third lighting device activation value. [20] Operating microscope according to claim 19, characterized by , that the control module (172) has means (173) for setting the second value for maximum intensity of the illumination light of the lighting device. [21] Operating microscope according to any one of claims 1 to 20, characterized by, that a lamp change detection device (180) is provided which is connected to the control unit (170) and, upon detection of a lamp change, causes the filter unit (112) to be set to an output value. [22] Operating microscope according to any one of claims 1 to 21, characterized by , that the sensor (120) receives illumination light via a bore (121) in the deflecting mirror (115).

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