Imaging device, in particular endoscopic, exoscopic, and / or microscopic imaging device

Abstract

The invention relates to an imaging device (10a-d), in particular an endoscopic, exoscopic, and / or microscopic imaging device, comprising: an illuminating device (12a-d) which is designed to illuminate an examination region (14a-d) and excite a first luminescent dye (16a-d) and at least one second luminescent dye (18a-d), an image capturing unit (20a-d) for capturing a set of images including at least one image of the examination region (14a-d), and an analysis unit (22a-d) which is designed to analyze the set of image and distinguish between, preferably identify, the at least two luminescent dyes (16a-d, 18a-d) using the respective luminescence spectrum (24a, 26a) thereof.

Description

[0001] Imaging device, in particular endoscopic, exoscopic and / or microscopic imaging device

[0002] The present invention relates to an imaging device, in particular an endoscopic, exoscopic and / or microscopic imaging device, and a method for operating an imaging device.

[0003] Imaging devices such as endoscopic or exoscopic devices that generate multispectral or hyperspectral images are known from the prior art. Multispectral or hyperspectral images have, in addition to two spatial dimensions, such as a conventional camera image, a spectral dimension. The spectral dimension encompasses several spectral bands (wavelength bands). Multispectral and hyperspectral images differ primarily in the number and width of their spectral bands.

[0004] Several imaging devices for generating such multispectral or hyperspectral images are known, particularly in the context of medical applications. For example, DE 20 2014 010 558 U1 describes a device for capturing a hyperspectral image of an examination region of a body. The device includes an input lens for generating an image in an image plane and a slit-shaped aperture in the image plane for masking out a slit-shaped region of the image. The light passing through the aperture is spread out by a dispersive element and recorded by a camera sensor. As a result, the camera sensor can record a plurality of spectra, each with an associated spatial coordinate, along the longitudinal direction of the slit-shaped aperture.The described device is further configured to record additional spectra along the longitudinal direction of the slit-shaped aperture in a direction different from the longitudinal direction of the slit-shaped aperture. The method underlying this disclosure for generating multispectral or hyperspectral images is also known as the so-called pushbroom method.

[0005] In addition to the pushbroom method, there are other methods for generating multispectral or hyperspectral images. In the so-called whiskbroom method, the examination area or object is scanned point by point, and a spectrum is obtained for each point. In contrast, the staring method acquires multiple images with the same spatial coordinates. Different spectral filters and / or illumination sources are used from image to image to resolve spectral information. Furthermore, there are methods in which a two-dimensional multicolor image is decomposed into several individual spectral images using suitable optical elements such as optical slicers, lenses, and prisms, which are simultaneously acquired on different detectors or detector areas. This is sometimes referred to as the snapshot approach.

[0006] As described in DE 10 2020 105 458 A1, multispectral and hyperspectral imaging devices are particularly suitable as endoscopic imaging devices. In this context, multispectral and / or hyperspectral imaging is a fundamental field of application, for example, for diagnostics and for assessing the success or quality of a procedure.

[0007] White light imaging is also used, particularly in medical imaging. Observed tissue is illuminated with white light, and images of the tissue are generated using a camera or other image capture sensor, which can then be displayed to a user.

[0008] Fluorescence imaging is also used, especially in medical imaging. Tissue is illuminated in a specific wavelength range to excite fluorescent dye molecules that are specifically introduced into specific entities, such as tissue regions. The resulting emitted light with a longer wavelength can be observed through a suitably selected filter, which can be used to filter out the excitation light.

[0009] Typical fluorescent dyes often have a similar excitation spectrum, so they can generally be used with the same imaging device. However, different fluorescent dyes generally require different camera system sensitivities. Furthermore, different fluorescent dyes in similar spectral ranges cannot be used simultaneously to detect different targets, for example, simultaneous visualization of tumors and perfusion.

[0010] Multimodal imaging devices allow the selective acquisition of white light images and / or multispectral images and / or fluorescence images and / or hyperspectral images. Examples of such imaging devices are multimodal endoscopes and multimodal exoscopes. To implement different modes, illumination devices may be required that can be operated in different illumination modes to generate illumination light in different spectral ranges as needed. US 10,481,095 B2 and US 11,668,922 B2 disclose imaging devices with multiple illumination sources, the light emitted by each of which can be combined using beam splitter elements.

[0011] Based on the prior art, the invention is based in particular, but not limited to, the object of advantageously further developing an imaging device.

[0012] This object is achieved according to the invention by an imaging device and a method for operating an imaging device as described herein and defined in the claims.

[0013] The invention relates to an imaging device, in particular an endoscopic, exoscopic and / or microscopic imaging device, comprising:

[0014] - a lighting device which is provided for illuminating an examination area and for exciting a first luminescent dye and at least one second luminescent dye,

[0015] - an image recording unit for recording an image set with at least one image of the examination area, and

[0016] - an analysis unit which is intended to analyse the image set and to distinguish, preferably to identify, the at least two luminescent dyes on the basis of their respective luminescence spectrum.

[0017] The invention further relates to a method for operating an imaging device, in particular an endoscopic, exoscopic and / or microscopic imaging device,

[0018] - wherein an examination area is irradiated by means of an illumination spectrum which is suitable for exciting a first luminescent dye and at least one second luminescent dye,

[0019] - wherein an image set with at least one image of the examination area is recorded and

[0020] - wherein the image set is analyzed and the at least two luminescent dyes are automatically differentiated, preferably identified.

[0021] The luminescent dyes can be either a phosphorescent dye or a fluorescent dye that can be added to a tissue, for example, cyanine 5.5 (Cy 5.5), indocyanine green (ICG), S0456, ZW800-1, or fluorescein and / or fluorescent dyes with excitation in the red or blue wavelength range, or that occur naturally in a tissue. The above-mentioned features allow for advantageous further development of an imaging device.In particular, different luminescent dyes, in particular fluorescent dyes, of various clinical markers can be differentiated and, in particular, identified, in particular to then automatically select a corresponding luminescence operating mode, in particular fluorescence operating mode, advantageously with the required sensitivity of a sensor and / or corresponding display properties of a display unit for the luminescent dye, in particular fluorescent dye. This can enable simultaneous medical visualization, for example, of tumors and perfusion, in particular by switching between two different luminescence operating modes, in particular fluorescence operating modes. This can be advantageous both from a regulatory perspective and from a sales model perspective.Given that it is anticipated that a large number of fluorescent marker substances will receive clinical approval, an existing imaging device can be adapted for these new fluorescent marker substances, for example by means of a corresponding software update and / or by means of an existing network connection to a server containing a database of approved fluorescent marker substances and / or by replacing an optical filter.

[0022] The imaging device can preferably be a medical imaging device. In addition to the illumination device, the imaging device can comprise an imaging device, for example, an endoscope, exoscope, and / or microscope, which can be optically connected to an optical interface of the illumination device. The optical interface can be selectively connectable and detachable. Furthermore, the optical interface can be combined with a mechanical interface, so that an optical connection is automatically established, for example, when the imaging device is mechanically coupled.

[0023] In some embodiments, the imaging device and in particular the imaging apparatus is configured to be insertable into a cavity for examination and / or observation, for example into an artificial and / or natural cavity, such as the interior of a body, a body organ, tissue, or the like. The imaging device and in particular the imaging apparatus can also be configured to be insertable into a housing, casing, shaft, pipe, or other, in particular artificial, structure for examination and / or observation. The imaging device and in particular the imaging apparatus can be configured to record tissue parameters, images of wounds, images of body parts, etc. For example, the imaging device can be configured to image a surgical field.

[0024] The illumination device is provided for providing illumination light for the imaging device. In some embodiments, the illumination device comprises an illumination unit configured to supply illumination light to the optical interface. The illumination unit can be multimodal and / or operable in a plurality of different illumination modes. The illumination unit can be configured to provide a broad, in particular continuous, emission spectrum. The illumination unit can be multimodal and comprise a plurality of independently selectably activatable lighting elements configured to emit light according to different emission spectra to supply the illumination light.The illumination unit can be operated in at least one multispectral mode, in which a first group of the luminous elements is at least temporarily activated and in which the illumination unit provides illumination light for multispectral imaging. Furthermore, the illumination unit can be operated in at least one luminescence mode, in particular a fluorescence mode, in which a second group of the luminous elements is at least temporarily activated and in which the illumination unit provides illumination light for luminescence imaging, in particular fluorescence imaging. The luminous elements can comprise at least one luminous element that is contained in both the first group and the second group.

[0025] The lighting elements can comprise single-color LEDs (light-emitting diodes) and / or laser diodes. Furthermore, at least one of the lighting elements can be a white light LED or another white light source. In some embodiments, the lighting unit comprises at least one blue lighting element, at least one red lighting element, at least one far-red lighting element, and at least one near-IR (near-infrared) lighting element, in particular LEDs or laser diodes. Additionally, the lighting unit can comprise at least one white light LED or another white light source.

[0026] The fact that the illumination device is intended to be provided "for exciting a first luminescent dye and at least one second luminescent dye" should be understood not only to mean that the illumination device excites both luminescent dyes simultaneously in one operating mode, but also that the two luminescent dyes can be excited sequentially one after the other in one operating mode. The image recording unit and / or the analysis unit can be at least partially part of the imaging device, such that individual elements of the image recording unit and / or the analysis unit are components of the imaging device. Alternatively, however, the image recording unit and / or analysis unit can also be provided as a separate unit from the imaging device, for example, connectable to the imaging device by means of a light guide and / or a cable connection.

[0027] The image acquisition unit can provide spatial and spectral information. The image acquisition unit can be configured with spatial and spectral resolution and can comprise at least one optical unit, for example, comprising a filter unit, and at least one image acquisition sensor coupled to the optical unit, for example, comprising a camera, which are configured to perform an image acquisition of an image region, generating spatial and spectral image data that includes both spatial and spectral information.

[0028] The image acquisition unit and in particular the optics and / or the image acquisition sensor system can be configured for multispectral and / or hyperspectral imaging, specifically for capturing and / or generating multispectral and / or hyperspectral image data. Multispectral imaging or multispectral image data can refer in particular to imaging in which at least two, in particular at least three, and in some cases at least five spectral bands can be and / or are captured independently of one another. Hyperspectral imaging or hyperspectral image data can refer in particular to imaging in which at least 20, at least 50, or even at least 100 spectral bands can be and / or are captured independently of one another.

[0029] For some applications, it may be advantageous to be able to use a high spectral resolution. In this case, hyperspectral imaging is a suitable option. This can be combined with white-light imaging and / or luminescence imaging, particularly fluorescence imaging. This enables real-time observation via a white-light image and / or a luminescence image, particularly a fluorescence image, even if the acquisition of spectrally resolved image data is essentially only real-time, meaning that, for example, several seconds are required to create a spectrally resolved image.

[0030] For some applications, it may be advantageous to generate spectral image data in real time. This includes, for example, generating a spectrally resolved image in less than one second or even multiple times per second. In this case, it may be appropriate to use multispectral imaging. A possibly lower spectral resolution is then offset by a higher frame rate. Depending on the application, it may be sufficient to consider only a few different spectral ranges and / or wavelengths, for example, two or three or four, or generally fewer than ten. In this case, additional white light imaging can optionally be omitted. Spectrally resolved image data that is acquired in real time ordeliver several images per second, can also be used for surveillance purposes, whereby it is not necessarily necessary to create an image for a user to display, but the image data can also be processed in the background.

[0031] The image recording unit can operate according to the pushbroom method and / or the whiskbroom method and / or the staring method and / or a snapshot principle.

[0032] In some embodiments, the image acquisition unit can have a filter unit by means of which certain light components can be filtered out from the examination area, for example, an excitation light and / or certain light components of a luminescent light, in particular fluorescent light. The filter unit can be controllable, in particular to change filter properties.

[0033] In some applications, the illumination device may provide different illumination levels sequentially, so that, for example, the first luminescent dye is excited during a first time interval and the second luminescent dye is excited during a second time interval. The image acquisition unit can then provide spatially resolved images of the examination area during the respective time intervals.

[0034] The imaging device may comprise a controller configured to automatically coordinate an operating state of the imaging device and / or the image acquisition unit with an illumination mode of the illumination device and / or the illumination unit. The controller may be configured to control the illumination device and / or the illumination unit and / or the imaging device and / or the image acquisition unit. The analysis unit may be part of this controller and / or integrated therein.

[0035] In some embodiments, the image acquisition unit comprises a white-light camera and / or sensors for white-light image acquisition. The image acquisition unit can be configured for white-light imaging in addition to spectrally resolved imaging. Separate optics and / or shared optics can be used for this purpose. The white-light imaging and the spectrally resolved imaging can be performed simultaneously or alternately, or at times simultaneously and at times sequentially.

[0036] In some embodiments, the image acquisition unit comprises sensors for luminescence imaging, in particular fluorescence imaging. The image acquisition unit can be configured for luminescence imaging, in particular fluorescence imaging, in addition to spectrally resolved imaging and optionally in addition to white light imaging. Separate optics and / or shared optics can be used for this purpose. The luminescence imaging, in particular fluorescence imaging, optionally the white light imaging, and the spectrally resolved imaging can be performed simultaneously or alternately, or at times simultaneously and at times sequentially. In particular, a dedicated sensor can be provided for each luminescent dye. Furthermore, a shared sensor can be provided for several or all luminescent dyes.

[0037] The image set can comprise precisely one image of the examination area or multiple images of the examination area, which can be acquired simultaneously, in particular using different image acquisition sensors, and / or preferably sequentially in one operating mode, in particular using the same image acquisition sensor. The image set can be provided for processing and displaying a single frame of an image of the examination area. The time interval between consecutive images is preferably a maximum of 1 s, preferably a maximum of 0.5 s, and particularly preferably a maximum of 0.1 s.

[0038] The fact that the analysis unit is intended to "distinguish" the at least two luminescent dyes based on their respective luminescence spectra in the image set should be understood to mean that the analysis unit is configured to distinguish the at least two luminescent dyes in the image set based on at least one property of the luminescence spectra, in particular to the extent that the at least two luminescent dyes are of different types and / or where the at least two luminescent dyes are arranged in the at least one image of the image set. The differentiation by the analysis unit can take place once, continuously, or in a specific test step, in particular also recurringly.

[0039] The fact that the analysis unit is provided to "identify" the at least two luminescent dyes based on their respective luminescence spectra in the image set should be understood to mean that the analysis unit is configured to recognize the type of the at least two luminescent dyes based on at least one property of the luminescence spectra. The analysis unit can, for example, be provided to compare certain properties of the recorded luminescence spectra or of the recorded luminescence spectrum with corresponding reference properties of a reference spectrum and / or to compare the recorded luminescence spectra or the recorded luminescence spectrum with reference spectra. For this purpose, the analysis unit can have a storage unit in which the corresponding properties of the reference spectrum and / or the reference spectrum itself are stored.Alternatively or additionally, the analysis unit can have a communication interface for communication via a network, in particular the Internet, with a database in which the corresponding properties of the reference spectrum and / or the reference spectrum are stored. Identification by the analysis unit can be performed once, continuously, or in a specific test step, in particular recurringly.

[0040] "Intended" should be understood as specifically equipped, configured, and / or programmed, and not merely as mere suitability. For simplicity, the same terms are used for objects in an image of the study area as for the corresponding objects in the study area.

[0041] Preferably, the analysis unit is provided to distinguish, preferably to identify, the at least two luminescent dyes even in the case of partially overlapping luminescence spectra, whereby a field of application of the imaging device can be particularly advantageously increased.

[0042] In some embodiments, the analysis unit can be provided to differentiate, preferably identify, the at least two luminescent dyes based on the same image of the image set. This makes it possible to achieve rapid differentiation, in particular identification, which can enable high temporal resolution. Overall, this can reduce the reaction time of the imaging device. In this case, the image set advantageously has only exactly one image, in particular for each frame of a recording of the examination region. In some embodiments, the image recording unit can have a hyperspectral camera, which enables separation and / or identification of the at least two luminescent dyes in the same image of the examination region, which can achieve high spectral resolution.Alternatively or additionally, in some embodiments the image recording unit may comprise a filter unit, in particular with a matrix of individual filter elements, which enables separation and / or identification of the at least two.

[0043] Luminescent dyes in the same image of the examination area.

[0044] Alternatively or additionally, the analysis unit can be provided to differentiate, preferably identify, the at least two luminescent dyes based on different images of the image set. In this case, the image set has at least two images, in particular for each frame of a recording of the examination area. This makes it advantageously possible to keep an imaging device simple and / or cost-effective. In particular, an advantageously high spatial resolution can be achieved. In principle, it would be conceivable that even in the case of the previously described application of a hyperspectral camera and / or a filter unit, in particular with a matrix of individual filter elements, several images and not just one image are used for an analysis.

[0045] In some embodiments, the analysis unit can be provided to control the illumination device and to provide a different illumination spectrum for illuminating the examination area in a first sub-test step of a test step than in a second sub-test step of the test step. This allows for a particularly simple differentiation, in particular identification, of the luminescent dyes. Furthermore, an advantageously high spatial resolution can be achieved.

[0046] In this case, it can be provided that in the first sub-test step, a first illumination spectrum is present for exciting the first luminescent dye, and in the second sub-test step, a second illumination spectrum is present for exciting the second luminescent dye. When differentiating, in particular identifying, the analysis unit can then utilize the fact that in the first sub-test step, luminescent light from the first luminescent dye is present, and in the second sub-test step, luminescent light from the second luminescent dye is present. This procedure would also be conceivable in principle with the previously described application of a hyperspectral camera and / or a filter unit, in particular with a matrix of individual filter elements.

[0047] Furthermore, it would be conceivable for a first illumination spectrum to be present in the first sub-test step for exciting the first luminescent dye, and for a second illumination spectrum to be present in the second sub-test step for exciting the first luminescent dye, or for a first illumination spectrum to be present in the first sub-test step for exciting the second luminescent dye, and for a second illumination spectrum to be present in the second sub-test step for exciting the second luminescent dye. It would also be conceivable for a first illumination spectrum to be present in the first sub-test step for exciting the first and second luminescent dyes, and for a second illumination spectrum to be present in the second sub-test step for exciting the first and second luminescent dyes.Since the luminescence spectra of the luminescent dyes differ for different excitation spectra, this can further improve the identification of the luminescent dyes, especially when the luminescence spectra of the luminescent dyes are very similar. For example, an examination area containing the fluorescent dyes indocyanine green (ICG) and S0456 could be illuminated, particularly alternately in the first sub-test step with a laser line at 770 nm and in the second sub-test step with a laser line at 780 nm. The luminescence spectra for these two lines are different, which can be used to distinguish between the two fluorescent dyes.

[0048] It would also be conceivable for the image recording unit to have a filter unit and for the analysis unit to be provided to control the filter unit. This can enable an advantageously high spatial resolution. Furthermore, a cost-effective solution can be provided. In some embodiments, the filter unit can have a plurality of filter elements and / or be switchable between a plurality of filter elements and / or filter properties, wherein each of the filter elements is assigned a luminescent dye. Consequently, the filter elements can each have a high transmittance for a luminescent dye, whereby the luminescent dyes can be distinguished, in particular identified. The filter unit can be designed as a filter wheel.Alternatively, instead of controlling the filter unit by the analysis unit, a constant rotation of a filter unit designed as a filter wheel and / or a temporally constant switching between different filter elements and / or properties of the filter unit would be conceivable, so that a corresponding assignment to a specific luminescent dye results over time.

[0049] It would also be conceivable for the image capture unit to have a filter unit with a matrix of individual filter elements, and for at least a first individual filter element of the filter unit to have a first transmission wavelength range that differs from a second transmission wavelength range of a second individual filter element of the filter unit, and for the first transmission wavelength range to comprise a maximum of a first luminescence spectrum of the first luminescent dye, and for the second transmission wavelength range to comprise a maximum of a second luminescence spectrum of the second luminescent dye. This allows a high discrimination capability of the luminescent dyes to be combined with high temporal resolution and sufficiently high spatial resolution.The filter unit can be part of a luminescence filter, which can be designed as a color filter array. The filter unit can be designed as a basic component of the luminescence filter that repeats periodically in two spatial directions, in particular similar to a Bayer filter. A sensor element, in particular a pixel, of a luminescence light sensor of the image recording unit can be assigned to each of the individual filter elements of the filter unit and / or the luminescence filter.

[0050] In some embodiments, the filter unit may comprise at least one dedicated individual filter element for each identifiable luminescent dye, thereby enabling simple design and / or evaluation.

[0051] The first transmission wavelength range can comprise wavelengths of at least 750 nm, preferably at least 800 nm, and at most 850 nm, preferably at most 825 nm. The second transmission wavelength range can comprise wavelengths of at least 800 nm, preferably at least 825 nm, and at most 900 nm, preferably at most 850 nm. This advantageously enables differentiation, in particular identification, of the fluorescent dyes indocyanine green (ICG) and another fluorescent dye in the NIR range, for example, S0456 or ZW800-1.

[0052] The analysis unit can be designed to use a first light component transmitted through the first individual filter element and a second light component transmitted through the second individual filter element for the differentiation, preferably the identification, of the luminescent dyes. This enables differentiation, in particular identification, of the luminescent dyes without making excessive compromises with regard to spatial resolution and / or sensitivity.

[0053] In some embodiments, the filter unit can have a plurality of third individual filter elements, each with a third transmission wavelength range, which can include a maximum of the first luminescence spectrum of the first luminescent dye and a maximum of the second luminescence spectrum of the second luminescent dye. This can advantageously open up further analysis possibilities. Furthermore, an advantageously good signal-to-noise ratio can be achieved.

[0054] The third transmission wavelength range can comprise wavelengths of at least 700 nm, preferably at least 750 nm, and at most 1000 nm, preferably at most 950 nm, thereby ensuring that maxima of luminescence spectra of current and future fluorescent dyes lie within the third transmission wavelength range. In some embodiments, the analysis unit can be provided to use third light components transmitted through the third individual filter elements to determine a luminescence signal strength. This can enable advantageous luminescence imaging, in particular fluorescence imaging.

[0055] In addition, it can be provided that a number of third individual filter elements of the filter unit corresponds to at least 50%, preferably at least 75%, of a total number of individual filter elements of the filter unit. This allows an advantageously high sensitivity with regard to luminescence imaging, in particular fluorescence imaging, to be achieved.

[0056] Preferably, the total number of individual filter elements in the filter unit is at least 4, preferably at least 9. This ensures high application flexibility. Furthermore, it enables differentiation between a beneficial number of different luminescent dyes. Furthermore, the relative number of individual filter elements unavailable for measuring a luminescence signal strength can be kept low.

[0057] Preferably, the analysis unit can be provided to consider at least one piece of position information of the at least two luminescent dyes, whereby differentiation, in particular identification, can be further improved. The analysis unit can be provided to consider surrounding regions in the image with regard to the identification of a luminescent dye at a position in an image of the image set. If, for example, a specific luminescent dye was detected in a region immediately adjacent to a position, it can be assumed with a high degree of probability that this luminescent dye is also present at that position. Furthermore, biologically typical geometries can be taken into account by the analysis unit.For example, nerve tracts or blood vessels tend to be elongated, which can be helpful in distinguishing and, in particular, identifying luminescent dyes, especially when considering where these typically accumulate in tissue. Furthermore, some embodiments may provide for spatial averaging of a spectral signal in the image, since the fluorescence distribution often covers a very large area in the image.

[0058] In some embodiments, the analysis unit can be configured to select appropriate settings for luminescence imaging tailored to the detected luminescent dye based on the detection of the presence of a specific luminescent dye. This can advantageously enhance the user experience. In particular, a high degree of automation can be achieved. Furthermore, operating errors and / or misjudgments can be avoided.

[0059] The devices and systems according to the invention, as well as the method according to the invention, are not intended to be limited to the application and embodiment described above. In particular, to fulfill a functionality described herein, they may comprise a number of individual elements, components, units, and method steps that differs from the number stated herein. Furthermore, in the value ranges specified in this disclosure, values ​​within the stated limits are also to be considered disclosed and can be used arbitrarily.

[0060] It is particularly noted that all features and properties described with reference to a device, as well as procedures, are transferable to methods and applicable within the meaning of the invention and are considered to be included in the disclosure. The same applies in reverse. This means that structural features mentioned with reference to methods, i.e., features related to the device, can also be considered, claimed, and included in the disclosure within the scope of the device claims.

[0061] The present invention is described below by way of example with reference to the accompanying figures. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will expediently consider the features individually and use them in meaningful combination within the scope of the claims.

[0062] If more than one instance of a particular object exists, only one of them may be provided with a reference symbol in the figures and in the description. The description of this instance can be applied accordingly to the other instances of the object. If objects are named, in particular, using numerical terms such as "first," "second," "third," etc., these serve to name and / or assign objects. Accordingly, a first object and a third object may be included, for example, but not a second object.

[0063] However, using number words, it might also be possible to derive a number and / or order of objects.

[0064] They show:

[0065] Fig. 1 an imaging device with an imaging device in the form of an endoscope for

[0066] Recording of an examination area and with an image recording unit, Fig. 2 a filter unit of the image recording unit,

[0067] Fig. 3 two exemplary fluorescence spectra of two fluorescent dyes,

[0068] Fig. 4 is an enlarged view of an image of the examination area,

[0069] Fig. 5. A flowchart of a method for operating the imaging device,

[0070] Fig. 6 shows an imaging device in a further embodiment,

[0071] Fig. 7 shows an imaging device in an alternative embodiment and

[0072] Fig. 8 shows an imaging device in a further alternative embodiment.

[0073] Fig. 1 shows a schematic representation of an imaging device 10a. In the exemplary case shown, the imaging device 10a is an endoscopic imaging device, specifically an endoscope device. Alternatively, the imaging device 10a could be an exoscopic, a microscopic, or a macroscopic imaging device. The imaging device 10a is shown as an example as a medical imaging device. The imaging device 10a is intended, for example, for examining a cavity. The imaging device 10a has a medical imaging device 46a. In the illustrated case, this is an endoscope.

[0074] The imaging device 10a further comprises an illumination device 12a with an optical interface 48a and an illumination unit 50a. The imaging device 46a can be optically connected to the optical interface 48a, for example, via a light guide 68a. The optical interface 48a can be part of an optical-mechanical interface that can be selectively connected and detachable. The imaging device 46a can be selectively decoupled from the illumination device 12a. The illumination unit 50a is configured to supply illumination light to the optical interface 48a. During imaging using the imaging device 46a, the illumination unit 50a can accordingly provide the required illumination light, which is guided to the imaging device 46a and from there coupled out onto an object to be imaged, such as a site.In the illustrated case, the imaging device 10a further comprises a display unit 44a, on which images based on image data acquired by the imaging device 46a can be displayed. These can be video images, still images, overlays of different images, partial images, image sequences, etc.

[0075] The imaging device 10a is multimodal. For example, the imaging device 10a can be operated in two basic modes: a luminescence mode and a white light mode, which can also occur together in a hybrid mode. Furthermore, the imaging device 10a can be additionally operated in a multispectral mode or a hyperspectral mode.

[0076] The illumination device 12a is multimodal. The illumination device 12a can be operated in different illumination modes, in which it provides light for different imaging modes. In the present case, the illumination device 12a can be operated in two basic modes: a luminescence mode and a white light mode, which can also occur together in a hybrid mode. Likewise, the imaging device 46a can be operated in different operating modes, specifically also a luminescence mode and a white light mode, which can also occur together in a hybrid mode. An additional multispectral mode or hyperspectral mode would also be conceivable here. In the corresponding operating mode of the imaging device 10a, the modes of the illumination device 12a and the imaging device 46a are coordinated with one another.

[0077] The illumination device 12a is provided for illuminating an examination region 14a and for exciting a first luminescent dye 16a and at least one second luminescent dye 18a. The luminescent dyes 16a, 18a are fluorescent dyes that can be added to a tissue 54a as markers or can occur naturally in the tissue 54. The illumination device 12a could also be provided for the simultaneous excitation of more than two luminescent dyes 16a, 18a. Furthermore, the luminescent dyes 16a, 18a could also be phosphorescent dyes. The illumination device 12a is provided for simultaneously exciting the first luminescent dye 16a and the second luminescent dye 18a.The illumination unit 50a of the illumination device 12a is therefore provided for emitting an illumination spectrum by which both luminescent dyes 16a, 18a can be excited simultaneously.

[0078] The imaging device 46a has an image acquisition unit 20a for acquiring an image set with at least one image of the examination area 14a. The image acquisition unit 20a has a sensor system for white light imaging (not shown).

[0079] This includes a white light camera for recording a reflection image of the

[0080] Examination area 14a and a corresponding white light optic.

[0081] The image acquisition unit 20a has a sensor system for luminescence imaging. This includes a luminescence light sensor 56a for recording a luminescence image of the examination region 14a and a correspondingly associated luminescence optics. The luminescence light sensor 56a has a matrix of sensor elements, which in this case are embodied as CMOS sensors. The luminescence optics include an observation filter for blocking excitation light (not shown). The luminescence optics include a luminescence filter 58a that interacts with the luminescence light sensor 56a and will be described in more detail later.

[0082] The image acquisition unit 28a has a beam splitter unit (not shown) that splits a beam path originating from the examination area 14a in a conventional manner between the sensor system for white light imaging and the sensor system for luminescence imaging. This could be done, for example, using a prism that supplies a visible light component to the sensor system for white light imaging and a near-infrared component to the sensor system for luminescence imaging.

[0083] If a user selects the white light mode of the imaging device 10a, only the white light imaging sensor is active. If, however, the luminescence mode is selected, the luminescence imaging sensor is activated. In hybrid mode, both sensors are active together.

[0084] The imaging device 10a comprises an analysis unit 22a, which is connected to the imaging device 46a via a cable 70a for power supply and data exchange. The analysis unit 22a is provided to analyze the image set, i.e., the individual image, and to identify the at least two luminescent dyes 16a, 18a based on their respective luminescence spectra 24a, 26a. Example luminescence spectra 24a, 26a are shown in Fig. 3. The analysis unit 22a is provided to identify the at least two luminescent dyes 16a, 18a even when the luminescence spectra 24a, 26a partially overlap, as shown in Fig. 3. The analysis unit 22a is provided to identify the at least two luminescent dyes 16a, 18a based on the same image of the image set. The analysis unit 22a utilizes the luminescence filter 58a. Figure 2 shows a section of the luminescence filter 58a.The luminescence filter 58a has a matrix of individual filter elements 30a, 32a, 34a, 36a that repeats periodically in two spatial directions. For the sake of clarity, only some of these elements are provided with reference numerals in Fig. 2. Fig. 2 shows a filter unit 28a as the basic component of the luminescence filter 58a. The filter unit 28a repeats periodically in both spatial directions of the drawing plane, thus forming the luminescence filter 58a. Each of the individual filter elements 30a, 32a, 34a, 36a is assigned a single sensor element of the luminescence light sensor 56a (not shown). The total number of individual filter elements 30a, 32a, 34a, 36a of the filter unit 28a is 16 in this case, and these are arranged in a 4*4 matrix. However, alternative numbers and arrangements, even non-square ones, would also be conceivable.

[0085] A first individual filter element 30a of the filter unit 28a has a first transmission wavelength range 38a, which differs from a second transmission wavelength range 40a of a second individual filter element 32a of the filter unit 28a. As illustrated in Fig. 3, the first transmission wavelength range 38a comprises a maximum of the first luminescence spectrum 24a of the first luminescent dye 16a, and the second transmission wavelength range 40a comprises a maximum of a second luminescence spectrum 26a of the second luminescent dye 18a. For each identifiable luminescent dye 16a, 18a, the filter unit 28a has such a dedicated individual filter element 30a, 32a. The first transmission wavelength range 38a comprises, for example, wavelengths of at least 800 nm and at most 825 nm. The second transmission wavelength range 40a comprises, for example, wavelengths of at least 825 nm and at most 850 nm.

[0086] The filter unit 28a comprises a plurality of third individual filter elements 34a, 36a, of which only two are provided with reference numerals in Fig. 2. As indicated in Fig. 3, the third individual filter elements 34a, 36a each have a third transmission wavelength range 42a, which comprises a maximum of the first luminescence spectrum 24a of the first luminescent dye 16a and a maximum of the second luminescence spectrum 26a of the second luminescent dye 18a. The third transmission wavelength range 42a comprises wavelengths of at least 780 nm and at most 950 nm.

[0087] A number of third individual filter elements 34a, 36a of the filter unit 28a corresponds in this case to a

[0088] A proportion of 87.5% of a total number of individual filter elements 30a, 32a, 34a, 36a of the filter unit 28a. The analysis unit 22a is designed to use a first light component transmitted through the first individual filter element 30a and a second light component transmitted through the second individual filter element 32a for the identification of the luminescent dyes 16a, 18a.

[0089] In the case of the first luminescent dye 16a and its first luminescence spectrum 24a, the sensor elements of the luminescent light sensor 56a assigned to the third individual filter elements 34a, 36a will register a high intensity. A sensor element of the luminescent light sensor 56a assigned to the first individual filter element 30a will register a medium intensity. A sensor element of the luminescent light sensor 56a assigned to the second individual filter element 32a will register a lowest intensity.

[0090] In the case of the second luminescent dye 18a and its second luminescence spectrum 26a, the sensor elements of the luminescent light sensor 56a assigned to the third individual filter elements 34a, 36a will also register a high intensity. A sensor element of the luminescent light sensor 56a assigned to the second individual filter element 32a will register a medium intensity. A sensor element of the luminescent light sensor 56a assigned to the first individual filter element 30a will register a lowest intensity.

[0091] In this way, the analysis unit 22a can determine the spatial distribution of the luminescent dyes 16a, 18a. The analysis unit 22a is designed to use third light components transmitted through the third individual filter elements 34a, 36a to determine a respective luminescence signal strength.

[0092] Fig. 4 shows an example image of the examination area 14a. For the sake of simplicity, the same reference symbols and terms are used for objects in the image as for the corresponding objects in the examination area 14a.

[0093] The identification of the luminescent dyes 16a, 18a can be further improved if the analysis unit 22a is provided to consider at least one piece of position information of the at least two luminescent dyes 16a, 18a. The analysis unit 22a can be provided to consider surrounding regions 62a, 64a in the image of the image set with regard to the identification of one of the luminescent dyes 16a, 18a at a position 60a. If a specific one of the luminescent dyes 16a, 18a has been detected in a region 62a immediately adjacent to the position 60a, it can be assumed with a high degree of probability that this luminescent dye 16a, 18a is also present at the position 60a. In white light mode, the analysis unit 22a is provided to display a reflection image of the examination region 14a via the display unit 44a.In luminescence mode, the analysis unit 22a is provided to display a luminescence image of the examination region 14a via the display unit 44a. In hybrid mode, the analysis unit 22a is provided to display a reflection image of the examination region 14a via the display unit 44a, overlaid with a luminescence image of the examination region 14a. The first luminescence dye 16a and the second luminescence dye 18a are displayed as differently colored overlays over the reflection image. The analysis unit 22a is provided to deactivate corresponding overlays of fluorescent dyes 16a, 18a not present in the examination region 14a.

[0094] Fig. 5 shows a diagram of a method for operating the imaging device 10a. In the luminescence mode or the hybrid mode, in a step 100a, the examination region 14a is illuminated using an illumination spectrum suitable for simultaneously exciting the first luminescent dye 16a and the second luminescent dye 18a. In a step 102a, an image set is acquired with exactly one image of the examination region 14a per frame. In a step 104a, the image set is analyzed, and the at least two luminescent dyes 16a, 18a are automatically identified. In a step 106a, the luminescence image is output.

[0095] Further embodiments of the invention are shown in Figs. 6 to 8. The following description is essentially limited to the differences between the embodiments. With regard to structural units and components with the same reference numerals, reference can generally be made to the description of the other embodiments, in particular to the embodiment of Figs. 1 to 5. For differentiation, the reference numerals of the embodiments of Figs. 6 to 8 are followed by one of the letters "b" to "d" instead of the letter "a" of the embodiment of Figs. 1 to 5.

[0096] Fig. 6 shows an imaging device 10b in a further exemplary embodiment. An imaging unit 46b of the imaging device 10b has an image acquisition unit 20a with a hyperspectral camera 66b, in which a sensor system for white light imaging and a sensor system for luminescence imaging are combined. Furthermore, the image acquisition unit 20a has broadband optics at an input of the hyperspectral camera 66b, whereby an observation filter is omitted. In both a white light mode and a luminescence mode or a hybrid mode, the hyperspectral camera 66b records spatial and spectral data from an examination area 14b. The hyperspectral camera 66b can operate according to the pushbroom method and / or the whiskbroom method and / or the staring method and / or a snapshot principle.

[0097] An analysis unit 22b of the imaging device 10b uses the pixel-by-pixel spectral data of the hyperspectral camera 66b to identify luminescence spectra 24b, 26b by comparing them with reference spectra of different fluorescent dyes 16b, 18b. The analysis unit 22b is thus designed to identify the luminescence dyes 16b, 18b based on the same image of the image set, namely a single image.

[0098] For this purpose, the imaging device 10b comprises a communication unit (not shown) for communicating with a central database via the Internet. Reference spectra of various fluorescent dyes 16b, 18b are stored in the central database. The database can be centrally expanded with additional reference spectra of other, newly approved fluorescent dyes 16b, 18b. Based on the comparison, the analysis unit 22b can identify the luminescent dyes 16b, 18b present in the examination area 14b.

[0099] In white light mode, the analysis unit 22b is provided to display a reflection image of the examination area 14b via a display unit 44b. In luminescence mode, the analysis unit 22b is provided to display a luminescence image of the examination area 14b via the display unit 44b. In hybrid mode, the analysis unit 22b is provided to display a reflection image of the examination area 14b via the display unit 44b, overlaid with a luminescence image of the examination area 14b. The first luminescent dye 16b and the second luminescent dye 18b are displayed as differently colored overlays over the reflection image. The analysis unit 22b is provided to deactivate corresponding overlays of fluorescent dyes 16b, 18b not present in the examination area 14b.

[0100] Fig. 7 shows an imaging device 10c in a further exemplary embodiment. An imaging device 46c of the imaging device 10c has, as in the exemplary embodiment of Figs. 1 to 5, a sensor system for white light imaging, a sensor system for luminescence imaging, and a beam splitter unit (not shown). The beam splitter unit is provided to split a beam path originating from an examination region 14c between the sensor system for white light imaging and the sensor system for luminescence imaging. The sensor system for white light imaging is basically configured as in the first exemplary embodiment.

[0101] The sensor system for luminescence imaging comprises a luminescence light sensor 56c for recording a luminescence image of the examination region 14c and correspondingly associated luminescence optics. The luminescence light sensor 56c has a matrix of sensor elements, which are embodied here as CMOS sensors. The luminescence optics comprise an observation filter for blocking excitation light (not shown). The luminescence optics comprise a filter unit 28c that interacts with the luminescence light sensor 56c. The filter unit 28c is embodied as a filter wheel with multiple filter elements (not shown), with a dedicated filter element for each luminescence dye 16c, 18c for which the imaging device 10c is intended and / or approved.

[0102] If a user selects a white light mode of the imaging device 10c, only the white light imaging sensor is active. If, however, a luminescence mode is selected, the luminescence imaging sensor is activated. In a hybrid mode, both sensors are active together.

[0103] An illumination device 12c of the imaging device 10c is provided to provide light for the simultaneous excitation of at least two luminescent dyes 16c, 18c in the examination region 14c.

[0104] In luminescence mode and hybrid mode, the image acquisition unit 20c, and in particular the sensor system for luminescence imaging, is provided in a test step to create a first and at least one second image of the examination region 14c, which together form an image set. The first image is created using a first filter element of the filter unit 28c, which has a first transmission wavelength range that includes a maximum of a first luminescence spectrum of a first luminescent dye 16b. The second image is created using a second filter element of the filter unit 28c, which has a second transmission wavelength range that includes a maximum of a second luminescence spectrum of a second luminescent dye 18b.

[0105] The imaging device 10c comprises an analysis unit 22c, which is provided in the test step to control the filter unit 28c accordingly, in particular via a cable 70c, in order to create the image set. The analysis unit 22c is provided to identify the at least two luminescent dyes 16c, 18c based on various images of the image set. Since each of the filter elements is assigned a luminescent dye, the analysis unit 22c can directly identify the luminescent dyes 16c, 18c from the position of the filter unit 28c. If no image is received for a filter element by the image acquisition unit 20c, the analysis unit 22c concludes that a correspondingly assigned luminescent dye 16c, 18c is not present in the examination area 14c. This filter element of the filter unit 28c is then no longer accessed for future recordings of the current operating mode.

[0106] The test step can be performed once at the beginning of the luminescence mode or the hybrid mode or recurringly over time, in particular periodically.

[0107] Based on the detected luminescent dyes 16c, 18c, the analysis unit 22c selects appropriate image acquisition parameters for the respective luminescent dyes 16c, 18c for the luminescence imaging sensors. In luminescence mode or hybrid mode, these image acquisition parameters are then used in sequential acquisitions of the examination area 14c to create separate luminescence images for each of the luminescent dyes 16c, 18c.

[0108] In white light mode, the analysis unit 22c is provided to display a reflection image of the examination area 14c via a display unit 44c. In luminescence mode, the analysis unit 22c is provided to display a luminescence image of the examination area 14c via the display unit 44c. In hybrid mode, the analysis unit 22c is provided to display a reflection image of the examination area 14c via the display unit 44c, overlaid with a luminescence image of the examination area 14c. The first luminescent dye 16c and the second luminescent dye 18c are displayed as differently colored overlays over the reflection image. The analysis unit 22c is provided to deactivate corresponding overlays of fluorescent dyes 16c, 18c not present in the examination area 14c.

[0109] Fig. 8 shows an imaging device 10d in a further exemplary embodiment. As in the previous exemplary embodiment, an imaging device 46d of the imaging device 10d has a sensor system for white light imaging, a sensor system for luminescence imaging, and a beam splitter unit (not shown). The beam splitter unit is provided to split a beam path originating from an examination region 14d between the sensor system for white light imaging and the sensor system for luminescence imaging. The sensor system for white light imaging is basically configured as in the previous exemplary embodiments.

[0110] The sensor system for luminescence imaging comprises a luminescence light sensor 56d for capturing a luminescence image of the examination area 14d and a corresponding luminescence optics. The luminescence light sensor 56d is designed as a multispectral camera 72d. The luminescence optics includes an observation filter for blocking excitation light (not shown).

[0111] If a user selects a white light mode of the imaging device 10d, only the white light imaging sensor is active. If, however, a luminescence mode is selected, the luminescence imaging sensor is activated. In a hybrid mode, both sensors are active together.

[0112] An illumination device 12d of the imaging device 10d is provided to provide light for the sequential excitation of at least two luminescent dyes 16d, 18d in the examination region 14d. For this purpose, the illumination device 12d has, in addition to a white light source (not shown), a first illumination unit 50d and a second illumination unit 52d. The first illumination unit 50d is provided to provide excitation light for a first luminescent dye 16d in the examination region 14d. The second illumination unit 52d is provided to provide excitation light for a second luminescent dye 18d in the examination region 14d.

[0113] The imaging device 10d is designed to perform a test step to determine which luminescent dyes 16d, 18d are present in the examination area. Based on this, a decision can then be made as to which of the illumination sources 50d, 52d are actually required in the luminescence mode or in the hybrid mode due to the presence of a correspondingly assigned luminescent dye 16d, 18d in the examination area, and also as to which image acquisition parameters should be selected for the respective luminescent dye 16d, 18d. The test step can be performed once at the beginning of the luminescence mode or the hybrid mode or recurringly, in particular periodically.

[0114] The imaging device 10d comprises an analysis unit 22d, which is provided in the test step to control the illumination device 12d and, in a first sub-test step of the test step, to provide a different illumination spectrum for illuminating the examination region 14d than in a second sub-test step of the test step. The analysis unit 22d is provided to create a first and at least one second image of the examination region 14d by means of the image acquisition unit 20d and, in particular, the sensor system for luminescence imaging, which together form an image set. The first image is created using the excitation light from the first illumination unit 50d. The second image is created using the excitation light from the second illumination unit 52d.

[0115] The analysis unit 22d is designed to identify the luminescent dyes 16d, 18d based on various images of the image set. Since each of the images is assigned a luminescent dye 16d, 18d, the analysis unit 22d can directly deduce the luminescent dyes 16c, 18c present from the images. The analysis unit 22d thereby identifies the illumination units 50d, 52d required for luminescence imaging, as well as the respective image acquisition parameters to be used.

[0116] In white light mode, the analysis unit 22d is provided to display a reflection image of the examination area 14d via a display unit 44d. In luminescence mode, the analysis unit 22d is provided to display a luminescence image of the examination area 14d via the display unit 44d. In hybrid mode, the analysis unit 22d is provided to display a reflection image of the examination area 14d via the display unit 44d, overlaid with a luminescence image of the examination area 14d. The first luminescent dye 16d and the second luminescent dye 18d are displayed as differently colored overlays over the reflection image. The analysis unit 22d is provided to deactivate corresponding overlays of fluorescent dyes 16d, 18d not present in the examination area 14d.

[0117] FE

[0118] List of reference symbols

[0119] 10 Imaging device

[0120] 12 Lighting device

[0121] 14 Study area

[0122] 16 first luminescent dye

[0123] 18 second luminescent dye

[0124] 20 Image acquisition unit

[0125] 22 Analysis unit

[0126] 24 first luminescence spectrum

[0127] 26 second luminescence spectrum

[0128] 28 Filter unit

[0129] 30 first single filter element

[0130] 32 second single filter element

[0131] 34 third single filter element

[0132] 36 third single filter element

[0133] 38 first transmission wavelength range

[0134] 40 second transmission wavelength range

[0135] 42 third transmission wavelength range

[0136] 44 display unit

[0137] 46 imaging device

[0138] 48 optical interface

[0139] 50 lighting units

[0140] 52 lighting unit

[0141] 54 fabrics

[0142] 56 Luminescence light sensor

[0143] 58 luminescence filters

[0144] 60 positions

[0145] 62 surrounding area

[0146] 64 surrounding area

[0147] 66 Hyperspectral camera

[0148] 68 light guides

[0149] 70 cables

[0150] 72 multispectral camera

[0151] 100 steps

[0152] 102 Step 104 Step

[0153] 106 steps

Claims

Claims 1. Imaging device (10a-d), in particular endoscopic, exoscopic and / or microscopic imaging device, comprising: - an illumination device (12a-d) which is provided for illuminating an examination area (14a-d) and for exciting a first luminescent dye (16a-d) and at least one second luminescent dye (18a-d), - an image recording unit (20a-d) for recording an image set with at least one image of the examination area (14a-d), and - an analysis unit (22a-d) which is provided to analyze the image set and to distinguish, preferably to identify, the at least two luminescent dyes (16a-d, 18a-d) on the basis of their respective luminescence spectrum (24a, 26a).

2. Imaging device (10a-d) according to claim 1, wherein the analysis unit (22a-d) is provided to distinguish, preferably to identify, the at least two luminescent dyes (16a-d, 18a-d) even in the case of partially overlapping luminescence spectra (24a, 26a).

3. Imaging device (10a-b) according to one of the preceding claims, wherein the analysis unit (22a-b) is provided to distinguish, preferably to identify, the at least two luminescent dyes (16a-b, 18a-b) on the basis of the same image of the image set.

4. Imaging device (10c-d) according to one of the preceding claims, wherein the analysis unit (22c-d) is provided to distinguish, preferably to identify, the at least two luminescent dyes (16c-d, 18c-d) on the basis of different images of the image set.

5. Imaging device (10d) according to one of the preceding claims, wherein the analysis unit (22d) is provided in a test step to control the illumination device (12d) and to provide a different illumination spectrum for illuminating the examination region (14d) in a first sub-test step of the test step than in a second sub-test step of the test step.

6. Imaging device (10c) according to one of the preceding claims, wherein the image recording unit (20c) has a filter unit (28c) and the analysis unit (22c) is provided to control the filter unit (28c).

7. Imaging device (10a) according to one of the preceding claims, wherein the image recording unit (20a) has a filter unit (28a) with a matrix of individual filter elements (30a, 32a, 34a, 36a) and at least a first individual filter element (30a) of the filter unit (28a) has a first transmission wavelength range (38a) which differs from a second transmission wavelength range (40a) of a second individual filter element (32a) of the filter unit (28a), and the first transmission wavelength range (38a) comprises a maximum of a first luminescence spectrum (24a) of the first luminescent dye (16a) and the second transmission wavelength range (40a) comprises a maximum of a second luminescence spectrum (26a) of the second luminescent dye (18a).

8. The imaging device (10a) of claim 7, wherein the filter unit (28a) comprises at least one dedicated individual filter element (30a, 32a) for each identifiable luminescent dye (16a, 18a).

9. Imaging device (10a) according to claim 7 or 8, wherein the first transmission wavelength range (38a) comprises wavelengths of at least 750 nm, preferably at least 800 nm, and at most 850 nm, preferably at most 825 nm.

10. Imaging device (10a) according to one of claims 7 to 9, wherein the second transmission wavelength range (40a) comprises wavelengths of at least 800 nm, preferably at least 825 nm, and at most 900 nm, preferably at most 850 nm.

11. Imaging device (10a) according to one of claims 7 to 10, wherein the analysis unit (22a) is provided to use a first light component transmitted through the first individual filter element (30a) and a second light component transmitted through the second individual filter element (32a) for the differentiation, preferably the identification, of the luminescent dyes (16a 18a).

12. Imaging device (10a) according to one of claims 7 to 11, wherein the filter unit (28a) has a plurality of third individual filter elements (34a, 36a), each having a third transmission wavelength range (42a) which comprises a maximum of the first luminescence spectrum (24a) of the first luminescent dye (16a) and a maximum of the second luminescence spectrum (26a) of the second luminescent dye (18a).

13. The imaging device (10a) of claim 12, wherein the third transmission wavelength range (42a) comprises wavelengths of at least 700 nm and at most 1000 nm.

14. Imaging device (10a) according to claim 12 or 13, wherein a number of third individual filter elements (34a, 36a) of the filter unit (28a) corresponds to at least 50% of a total number of individual filter elements (30a, 32a, 34a, 36a) of the filter unit (28a).

15. Imaging device (10a) according to one of claims 12 to 14, wherein the analysis unit (22a) is provided to use third light components transmitted through the third individual filter elements (34a, 36a) for determining a luminescence signal strength.

16. Imaging device (10a) according to one of claims 7 to 15, wherein a total number of individual filter elements (30a, 32a, 34a, 36a) of the filter unit (28a) is at least 4, preferably at least 9.

17. Imaging device (10a-d) according to one of the preceding claims, wherein the analysis unit (22a-d) is provided to take into account at least one item of position information of the at least two luminescent dyes (16a-d, 18a-d).

18. Imaging device (10c-d) according to one of the preceding claims, wherein the analysis unit (22c-d) is provided to select, based on a detection of the presence of a specific luminescent dye (16c-d, 18c-d), suitable settings for luminescence imaging tailored to the detected luminescent dye (16c-d, 18c-d).

19. Method for operating an imaging device (10a-d), in particular an endoscopic, exoscopic and / or microscopic imaging device, in particular according to one of the preceding claims, wherein an examination region (14a-d) is illuminated by means of an illumination spectrum which is suitable for exciting a first luminescent dye (16a-d) and at least one second luminescent dye (18a-d), wherein an image set with at least one image of the examination region (14a-d) is recorded and wherein the image set is analyzed and the at least two luminescent dyes (16a-d, 18a-d) are automatically differentiated, preferably identified.

Images