Medical imaging device and method for medical imaging

Abstract

The invention relates to a medical imaging device (410) comprising: an illumination unit (412) having at least one light source (414) configured to provide illumination light (416) for illuminating an object (418) to be depicted; an image acquisition unit (420) which is designed to capture at least one calibration image (422, 423) of the object (418) to be depicted and to capture at least one object image (424) of the object (418) to be depicted; and an image correction unit (426). The image correction unit (426) is configured to: determine depth information from the calibration image (422, 423); determining a correction for the object image (424), wherein the correction comprises taking into account a positional correlation, in particular a distance correlation, of a light intensity of the illumination light (416) and / or a distance correlation of a light intensity of the object light (428) in accordance with the depth information; and generating a corrected object image (430) in accordance with the correction. The invention also relates to a method, program code and computer program product (438) for medical imaging.

Description

Technical Field

[0001] The invention relates to a medical imaging device, in particular an endoscopic device, an exoscopic device and / or a microscopic device, a method for medical imaging, a program code for executing such a method, and a computer program product having such a program code. Background Art

[0002] Imaging devices for performing fluorescence imaging are known from the prior art, which can record fluorescence images and white light images. Suitable excitation light is used to excite fluorescent dyes or, if necessary, naturally fluorescent substances in a targeted manner, and the emitted light is detected and used for imaging. In order to be able to simultaneously display the anatomical structures in the image area to the user, white light images are usually recorded in parallel or sequentially. The user can evaluate whether the anatomical structure is depicted based on the white light image. Fluorescence images and white light images can also be superimposed, whereby the user can perceive and analyze anatomical information and fluorescence information simultaneously.

[0003] Imaging devices, such as endoscopes or exoscopic devices, which generate multispectral or hyperspectral images are also known from the prior art. Multispectral or hyperspectral images have a spectral dimension in addition to two spatial dimensions (such as the spatial dimensions of a conventional image of a camera). The spectral dimension includes a plurality of spectral bands (wavelength bands). Multispectral and hyperspectral images differ primarily in the number and width of their spectral bands. Such systems can in principle also be suitable for performing fluorescence recordings.

[0004] In particular, in the context of medical applications, some imaging devices are known for generating such multi-spectral or hyperspectral images. For example, a device for capturing a hyperspectral image of an examination area of ​​a body is described in DE 20 2014 010 558 U1. An input lens for generating an image in an image plane and a slit-shaped aperture for hiding a slit-shaped area of ​​the image in the image plane are arranged in the device. The light passing through the aperture is fanned out with the aid of a dispersion element and captured with the aid of a camera sensor. As a result, a large number of spectra can be captured by the camera sensor along the longitudinal direction of the slit-shaped aperture, and the spectra have correspondingly associated spatial coordinates. The described device is further configured to capture other 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 for generating a multi-spectral or hyperspectral image based on this disclosure is also referred to as a so-called push-scan method.

[0005] In addition to the push-scan method, there are other methods for generating multispectral or hyperspectral images. In the so-called swing-scan method, the inspection area or object is scanned point by point, and a spectrum is acquired for each point. In contrast, the staring method captures multiple images with the same spatial coordinates. Here, different spectral filters and / or illumination sources are used between the individual images to distinguish the spectral information. There is also a method according to which a two-dimensional multicolor image is decomposed into multiple spectral single images by suitable optical elements, such as optical slicers, lenses and prisms, which are collected simultaneously on different detectors or detector areas. This is sometimes called a snapshot method.

[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 used, for example, in the basic field of application for diagnosis and for evaluating the success or quality of an operation.

[0007] Multimodal imaging devices allow selectively recording of white light images and / or multispectral images and / or fluorescence images and / or hyperspectral images. Examples of imaging devices of this type are multimodal endoscopes and multimodal exoscopes.

[0008] In general, in the imaging methods mentioned, light of a certain spectrum is directed onto the object to be observed and is then reflected, absorbed, transmitted or emitted due to fluorescence excitation. Ultimately, the light reaches the image sensor and, if necessary, passes through one or more suitable observation filters. The image sensor is used to acquire image data, from which a view can be generated for the user. There is no identification of which light interaction the detected light originates. Summary of the invention

[0009] Starting from the prior art, the object of the invention is to improve the interpretability of image data.

[0010] According to the invention, this object is achieved by an imaging device, a method for medical imaging, a program code and a computer program product, as described herein and defined in the following technical solutions.

[0011] According to the present invention, a medical imaging device, in particular an endoscope device, an exoscope device and / or a microscope device, comprises an illumination unit having at least one light source, which is configured to provide illumination light for illuminating an object to be depicted; and an image acquisition unit, which is configured to capture at least one calibration image of the object to be depicted and capture at least one object image of the object to be depicted. In addition, the imaging device comprises an image correction unit. The image correction unit is configured to determine depth information from the calibration image. In addition, the image correction unit is configured to determine a correction for the object image, wherein the correction comprises taking into account the positional dependency, in particular the distance dependency, of the light intensity of the illumination light and / or the distance dependency of the light intensity of the object light according to the depth information. In addition, the image correction unit is configured to generate a corrected object image according to the correction.

[0012] Furthermore, a method for medical imaging is provided according to the present invention. The method can be performed in some embodiments using a medical imaging device according to the present invention. The method comprises providing illumination light for illuminating an object to be depicted. Furthermore, the method comprises taking at least one calibration image of the object to be depicted. Furthermore, the method comprises taking at least one object image of the object to be depicted. Furthermore, the method comprises determining depth information from the calibration image. Furthermore, the method comprises determining a correction for the object image, wherein the correction comprises taking into account the distance dependency of the light intensity of the illumination light and / or the distance dependency of the light intensity of the object light according to the depth information. The method also comprises generating a corrected object image according to the correction.

[0013] The features according to the invention enable to improve the interpretability of image data. The inventors have recognized that in the case of common fluorescence imaging, multispectral imaging or hyperspectral imaging, the signal intensity varies with distance, and this can cause the image data to be interpreted incorrectly in some cases. The distance dependence mentioned may lead to the following situation, that is, within the scope of multispectral imaging and / or hyperspectral imaging, the reflectivity value cannot be absolutely measured. The inventors have also recognized that if the fluorescence signal is attenuated by the superimposed tissue and / or if it is not known how deep the observed fluorescent dye is in the observed tissue or how far the distance from the anatomical surface to the fluorescent dye is, the correctness of the interpretation of the image data may be impaired. In addition, the inventors have confirmed that the following situation is another problem of traditional multispectral imaging and / or hyperspectral imaging, that is, for specific applications, especially for calculating physiological parameters such as tissue oxygen saturation (StO2 parameter), so far, a simple assumption is made about the penetration depth of light, based on which distorted measurement results may be obtained. By determining the depth information from the calibration image according to the present invention and using it to correct the object image, the mentioned influence can be compensated. The physical interaction of the illuminating light, the diffusely reflected light and / or the emitted light with the observed object can be taken into account, whereby the available information can be interpreted in a more precise manner.

[0014] The imaging device can be constructed as a microscope, a macroscope and / or an exoscope and / or include such a microscope, a macroscope and / or an exoscope. In some embodiments, the imaging device is an endoscopic imaging device. It can include an endoscope and / or an endoscope system and / or be constructed as such an endoscope and / or an endoscope system, and / or constitute at least a part and preferably at least a large part and / or a main component of an endoscope and / or an endoscope system. "At least a large part" can mean at least 55%, preferably at least 65%, preferably at least 75%, particularly preferably at least 85% and very particularly preferably at least 95%, specifically especially in terms of the volume and / or mass of the object.

[0015] In some embodiments, the imaging device is configured to be introduced into a cavity for identification and / or observation, for example, an artificial and / or natural cavity, such as the interior of the body, a body organ, a tissue, etc.

[0016] In particular, when the imaging device is an exoscopic imaging device, it may be configured to capture tissue parameters, images of wounds, images of body parts, etc. For example, the imaging device may be configured to depict a surgical field of view.

[0017] The imaging unit comprises, in particular, an imaging sensor system and / or at least one optical element, in particular an objective.

[0018] The image acquisition sensing mechanism can be configured to detect light in the visible range and in the near infrared range. In some embodiments, the minimum detectable wavelength can be at most 500nm, at most 450nm, or even at most 400nm. In some embodiments, the maximum detectable wavelength can be at least 800nm, at least 900nm, or even at least 1000nm. For example, the image acquisition sensing mechanism can include at least one white light image sensor and at least one near infrared image sensor. In some embodiments, the imaging device includes a sensing mechanism and / or a white light camera for white light image acquisition. The imaging device can be configured for white light imaging. Anatomical images can be captured with the aid of a sensing mechanism and / or a white light camera for white light image acquisition.

[0019] The image acquisition unit may have a filter unit having an optical observation filter. The filter unit may define a plurality of observation modes and / or fluorescence modes defined by different observation filters. For example, different edge filters may be used which absorb / block the correspondingly used spectrum for exciting the associated light-emitting element used and at least substantially transmit only fluorescence. In some embodiments, the observation filter may also be switchable between a multispectral mode and / or a hyperspectral mode and a fluorescence mode.

[0020] The imaging device and in particular the optical device and / or the image acquisition sensor mechanism of the image acquisition unit can be set for multispectral and / or hyperspectral imaging, in particular for acquiring and / or generating multispectral and / or hyperspectral image data. Multispectral imaging or multispectral image data can in particular refer to such imaging in which at least two, in particular at least three, and in some cases at least five spectral bands are acquired and / or can be acquired independently of each other. Hyperspectral imaging or hyperspectral image data can in particular refer to such imaging in which at least 20, at least 50 or even at least 100 spectral bands are acquired and / or can be acquired independently of each other. The imaging device can work according to the push-sweep method and / or the swing-sweep method and / or the stare method and / or the snapshot principle.

[0021] For some applications, it may be advantageous to use a large spectral resolution. Thus, this is suitable for hyperspectral imaging. It may be combined with white light imaging. Thus, even if only spectrally resolved image data are collected substantially in real time (i.e., for example, it takes a few seconds to create a spectrally resolved image), it is still possible to observe in real time through a white light image. For some applications, it may be advantageous to generate spectral image data in real time. For example, this includes the generation of spectrally resolved images that are performed in less than one second or even multiple times per second. It may be appropriate here to adopt multispectral imaging. Thus, a possibly lower spectral resolution is offset by a higher refresh rate. Depending on the application, it may be sufficient to consider only a small number of different spectral ranges and / or wavelengths, such as two or three or four or generally less than ten. Additional white light imaging may be selectively abandoned here. The spectrally resolved image data acquired in real time or the multiple images delivered per second may also be used for monitoring purposes, wherein it is not necessary to compulsorily create an image to be reproduced for the user, but the image data may also be processed in the background.

[0022] The medical imaging device may have at least one proximal section, a distal section and / or an intermediate section. The distal section is particularly configured to be introduced and / or located in the cavity to be examined in the operating state, for example during the diagnosis and / or treatment action. The proximal section is particularly configured to be arranged outside the cavity to be examined in the operating state, for example during the diagnosis and / or treatment action. "Distal" should be understood in particular as being close to the patient and / or away from the user when in use. "Proximal" should be understood in particular as being away from the patient and / or close to the user when in use. The proximal side is particularly opposite to the distal side. In particular, the medical imaging device has at least one, preferably flexible rod. The rod can be an elongated object. In addition, the rod can at least partially and preferably at least mostly constitute the distal section. "Elongated object" should be understood in particular as an object whose main extension (Haupterstreckung) is at least five times, preferably at least ten times and particularly preferably at least twenty times larger than the maximum extension of the object perpendicular to its main extension, that is, in particular the diameter of the object. The "main extension" of an object is to be understood in particular as the longest extension of the object along its main extension direction. The "main extension direction" of a component is to be understood here in particular as a direction running parallel to the longest side of the smallest imaginary cube that completely surrounds the component.

[0023] The image acquisition unit can be at least partially and preferably at least mostly arranged in the area of ​​the proximal section and / or constitute the proximal section. In other embodiments, the image acquisition unit can be at least partially and preferably at least mostly arranged in the distal section and / or constitute the distal section. In addition, the image acquisition unit can be arranged to be at least partially distributed to the proximal section and the distal section. The image acquisition sensor mechanism has at least one image sensor in particular. In addition, the image acquisition sensor mechanism can also have at least two and preferably more image sensors, which can be arranged one after another. In addition, two and preferably more image acquisition sensors can have spectral acquisition sensitivities that are constructed differently from each other, so that, for example, the first sensor in the red spectral range, the second sensor in the blue spectral range, and the third sensor in the green spectral range are particularly sensitive or relatively more sensitive than other sensors. The image sensor can be constructed, for example, as a CCD sensor and / or a CMOS sensor.

[0024] The optics of the image acquisition unit may include suitable optical elements, such as lenses, mirrors, gratings, prisms, optical fibers, etc. The optics may be configured to direct object light from the imaged object to the image acquisition sensor mechanism, for example to focus and / or project it.

[0025] The image acquisition unit is particularly configured to acquire spatially and spectrally resolved image data. The image acquisition unit can be configured to generate at least two-dimensional spatial image data. The image acquisition unit can be spatially resolved as described below, i.e. it supplies a resolution of at least 100 pixels, preferably at least 200 pixels, preferably at least 300 pixels and advantageously at least 400 pixels in at least two different spatial directions, respectively. The image data is preferably at least three-dimensional, wherein at least two dimensions are spatial dimensions and / or wherein at least one dimension is a spectral dimension. A plurality of spatially resolved images of the object area can be obtained from the image data, which are respectively associated to different spectral bands. The spatial and spectral information of the image data can be characterized in that associated spectra can be obtained therefrom for a plurality of spatial pixels.

[0026] In some embodiments, the image acquisition unit is configured to generate continuously updated image data. For example, the image acquisition unit can be configured to generate image data substantially in real time, including, for example, generating updated image data at least every 30 seconds, in some cases at least every 20 seconds, and in some cases even at least every 10 seconds or at least every 5 seconds. Preferably, the image acquisition unit is configured to generate at least anatomical images and fluorescent images and views based thereon in real time, for example, at a frame rate of at least 5 fps, at least 10 fps, at least 20 fps, or even at least 30 fps.

[0027] The lighting unit may be configured to be multi-mode and include a plurality of light emitting elements which can be selectively activated in a mutually independent manner and which are configured to emit light according to different emission spectra to supply illumination light.

[0028] The image acquisition unit can be operated in a calibration mode and in at least one imaging mode. In the calibration mode, at least one calibration image can be captured. In the imaging mode, at least one object image can be captured. The object image can be a white light image, a fluorescence image, a multispectral image and / or a hyperspectral image. The image segments of the calibration image can correspond to the image segments of the object image and / or at least overlap with them. In particular, the calibration image can define image segments, which are at least partially contained in the image segments of the object image. In particular, correction can be performed for areas of the object image, which are also depicted in the calibration image. The image correction unit can be set to compare the image segments of the calibration image with the object image to identify correctable image areas. Thereby, correction can be performed even in the case where the calibration image and the object image are inconsistent.

[0029] The image acquisition unit may be configured to record a plurality of calibration images with different image acquisition parameters and / or illumination parameters. The depth information may be based on a plurality of calibration images, in particular those recorded with different parameters.

[0030] The image acquisition unit can be configured to record stereo images. For example, the image acquisition unit can include at least one pair of image sensors for this purpose, so that a stereo pair of images can be recorded.

[0031] In the context of the present disclosure, object light generally refers to light from the object to be observed. As mentioned above, this may be diffusely reflected or emitted light, depending on the nature of the object and / or the type of imaging. In some embodiments, the correction comprises associating the position coordinates x, y, z to the acquired pixels according to the depth information. Based on this, the correction for a particular pixel may be based on a function f(x, y, z) that depends on the position coordinates x, y, z of the particular pixel. If the correction takes into account distance dependence, the mentioned function may depend on x 2 +y 2 +z 2 The sum and / or the square root of the sum, i.e. sqrt(x 2 +y 2 +z 2 ). The correction may be performed point by point and / or image region by image and / or image by image.

[0032] The corrected object image can be corrected point by point and / or image region by image and / or image by image. The corrected object image is based in particular on the object image and the calibration image.

[0033] The method steps mentioned can be performed in the order mentioned in the method steps. However, it is understood that different orders are also possible according to the present invention, and the list of method steps does not necessarily limit the predetermined order.

[0034] A comprehensive correction can be performed in particular when the depth information includes at least one depth map. A depth map can be understood here in particular as position-resolved depth information, which associates a series of pixels, in particular all pixels, of a calibration image, which can be defined by coordinates x and y, respectively, with at least one depth value, for example defined by coordinate z. In other words, the morphology of the object to be depicted can be derived from the calibration image to obtain depth information. This depth information may be specific to the image acquisition parameters and / or illumination parameters used. The depth information may include a plurality of depth maps involving different wavelength ranges and / or tissue types and / or anatomical structures. Different depth maps can also be ascertained from a plurality of calibration images as an alternative or in addition. In particular, at least one calibration image with specific parameters can be captured respectively to obtain a specific depth map.

[0035] The image capture of the calibration image may include the detection of diffusely reflected light. Thus, by utilizing light with a very low penetration depth in a specific spectral range in the tissue, depth information can be obtained in a simple manner. Preferably, in this case, the calibration image is captured by means of stereoscopic imaging or 3D imaging. The calibration image may be a 3D image. Then, a depth map may be obtained by a stereo reconstruction algorithm. For example, a semi-global matching algorithm may be used for this purpose, such as the article "Accurate and efficient stereo processing by semi-global matching and mutualinformation" published by Hirschmüller at the IEEE Conference on Computer Vision and Pattern Recognition in 2005, described on pages 807-814. Alternatively, a 3D image or a topographic surface may be calculated from two-dimensional image data. For example, an artificial intelligence algorithm may be trained in advance with suitable 2D and 3D image data. The acquisition and / or evaluation of a 3D image may include the calibration of an image acquisition unit, which is intended to determine distortion parameters and / or relative spatial posture of an image sensor. The light used to capture such a calibration image is diffusely reflected substantially directly from the surface of the object to be depicted, whereby the calibration image mainly or at least substantially only includes image information relating to the surface of the object to be depicted. For example, a depth map can be ascertained from a white light calibration image. White light generally has a very low penetration depth into the tissue, so that the diffusely reflected light approximately comes from the surface of the anatomy. Alternatively or additionally, a depth map can be obtained from a monochrome calibration image or a false color calibration image, for which illumination light is used that is only in one or more sub-ranges of visible light. For example, illumination can be performed only with blue light, green light, yellow light and / or red light to obtain depth information based on the diffusely reflected light. A mixture of specific colors and / or spectral ranges different from white light can also be used. Preferably, a wavelength range is used here for which the light has the lowest possible penetration depth into the object to be depicted, thereby ensuring that the diffusely reflected light comes from the surface of the object. Alternatively or in addition, different calibration images can be taken for different wavelength ranges and depth maps can be calculated separately. This can then be used for correction at different wavelengths, whereby wavelength-dependent penetration depths can be taken into account in particular.

[0036] In some embodiments, the image capture of the calibration image may include the detection of fluorescence. This creates a basis for a comprehensive and accurate evaluation of the fluorescence image. Preferably, at least one 3D fluorescence image is captured here. As described above, light with a suitable wavelength can be injected as excitation light, and the light emitted by the object to be depicted can be detected through a suitable observation filter. Depth information, in particular a depth map, can be obtained with the aid of stereo reconstruction. Alternatively, similar to the above case, a 2D image can be used as a basis and depth information can be obtained with the aid of an artificial intelligence algorithm. In particular, a depth map can be obtained from the calibration image, which depth map relates to an area of ​​the object to be depicted that is located inside the object and / or below the surface of the object. In particular, the depth map can be derived from a stained area covered by unstained tissue. Then, the fluorescence reaches the objective lens and / or image sensor of the image acquisition unit from a position that is further away from the surface of the object to be depicted than the objective lens and / or image sensor of the image acquisition unit.

[0037] In particular, a wide range of corrections that allow a correct interpretation of the image data in different depiction modes can be achieved if the illumination unit is configured to be operable in different illumination modes, in which illumination light can be provided in different spectral ranges, and the image acquisition unit is configured to record a plurality of calibration images, the image recording of which is based on the different illumination modes of the illumination unit. For example, a first illumination mode can be used to obtain a calibration image based on diffusely reflected light, while a second illumination mode can be used to obtain a calibration image based on emitted light, in particular fluorescence. At least one first depth map and at least one second depth map can thereby be obtained, wherein the first depth map relates to the surface of the object to be depicted, and wherein the second depth map relates to a region of the object to be depicted that is dyed with at least one fluorescent dye and is located below the surface of the object to be depicted.

[0038] The image acquisition unit can be configured to simultaneously and / or sequentially record a plurality of calibration images in different spectral ranges, in particular using different optical filters. For example, in the case of multispectral imaging and / or hyperspectral imaging, the plurality of calibration images can originate from different spectral ranges.

[0039] In some embodiments, the correction comprises a distance correction, which is based on the inverse of a power of the length of the optical path, in particular based on the inverse of a power of the length of the optical path between the image acquisition unit (in particular the objective lens and / or the image sensor of the image acquisition unit) and the object to be depicted and / or the optical path inside the object to be depicted. The distance correction can be based on, for example, the distance square law. In particular, in this case, the lighting unit can be roughly regarded as a point light source. By using one of two different indices, deviations from a point light source can be taken into account.

[0040] Furthermore, the correction can include an absorption correction based on the attenuation, in particular exponential attenuation, of light along an optical path having a certain length, in particular the length of the optical path inside the object to be depicted. Alternatively or additionally, the absorption correction can take into account the attenuation of the illumination light and / or the attenuation of the object light.

[0041] Generally speaking, for the 0 The incident light has a wavelength λ 1 The distance correction for fluorescence imaging of the emitted light can be based on the following attenuation, which is caused by the distance from the objective of the image acquisition unit to the object to be imaged and the positioning of the area stained with the fluorescent dye in the object to be imaged:

[0042] I 探测 =I(λ 0 ) / (d 0 +d 1 ) α ·exp(-μ(λ 0 )·d 1 )·exp(-μ(λ 1 )·d 1 )·R

[0043] Among them I 探测 refers to the detected light intensity, I(λ 0 ) refers to a 0 The intensity of the incident light, d 0 Refers to the distance between the objective lens and the surface of the object to be depicted, d 1 is the distance between the surface of the object to be imaged and the area in the object to be imaged that is stained with the fluorescent dye, α is an exponent that defines the inverse square law and can be selected, for example, as 2 to perform the calculation according to the distance square law, μ(λ 0 ) refers to the wavelength λ when penetrating the object to be depicted 0 The attenuation factor of the light attenuation, μ(λ 1 ) refers to the wavelength λ when penetrating the object to be depicted 1 The attenuation factor of the light attenuation.

[0044] Particularly high accuracy can be achieved if the image correction unit is configured to determine spatial and / or spectral properties, in particular inhomogeneities, of the lighting unit from at least one calibration image and to take the determined spatial and / or spectral properties into account during the correction. In other words, the recording of the calibration image can be used to perform a calibration of the lighting device or to take into account the actual properties of the lighting device for the calculation of the object image for the correction.

[0045] In some embodiments, it can be provided that, in the corrected object image, at least one image area is enhanced and / or attenuated in at least one parameter according to the correction relative to at least one other image area, such as hue, brightness and / or color saturation. Thus, a corrected object image that is intuitively understandable to the user can be generated. In general, for example, the following intensity differences can be compensated, which originate from different lighting conditions but not from differences in the depicted tissue. Then, for example, the corrected object image can be calculated in a manner that the intensity differences cannot be recognized. Then, for the user, the same area can be distinguished, even if it is not depicted in the same way. For example, a fluorescent area partially or completely covered by unstained tissue can also be shown as if it is not covered. Alternatively, distance information can also be transmitted to the user by using false colors. For example, although a fluorescent area covered by unstained tissue can be shown with enhanced brightness so that it can be well identified, the color can be changed, for example, according to the distance between the fluorescent area and the surface of the object to be depicted, so that the user can recognize whether the fluorescent area is inside the object to be depicted and how far away it is. Thus, the user can be supported, for example, during dissection.

[0046] In some embodiments, the medical imaging device includes an illumination device including an illumination unit. The illumination device may include an optical interface portion for optical attachment of an imaging device. The illumination unit may be configured to supply illumination light to the optical interface portion. The illumination unit may be configured to be multi-mode and include a plurality of light-emitting elements that can be optionally activated independently of each other, which are configured to emit light according to different emission spectra to supply illumination light. The illumination unit may operate in at least one multi-spectral mode, in which a first group of light-emitting elements is at least temporarily activated, and in which the illumination unit supplies illumination light for multi-spectral imaging. In addition, the illumination unit may operate in at least one fluorescence mode, in which a second group of light-emitting elements is at least temporarily activated, and in which the illumination unit supplies illumination light for fluorescence imaging. The light-emitting elements may include at least one light-emitting element that is included in the first group and the second group.

[0047] In addition, a method for generating illumination light for an imaging device by means of an illumination device can be provided. The illumination device here comprises an optical interface portion for optical attachment of the imaging device and an illumination unit, the illumination unit being configured to supply illumination light to the optical interface portion, wherein the illumination unit comprises a plurality of light-emitting elements that can be optionally activated independently of one another, and they are configured to emit light according to different emission spectra to supply illumination light. The method comprises the steps of at least temporarily activating a first group of light-emitting elements to supply illumination light for multi-spectral imaging and at least temporarily activating a second group of light-emitting elements to supply illumination light for fluorescent imaging. At least one of the light-emitting elements is at least temporarily activated both when the first group of light-emitting elements is at least temporarily activated and when the second group of light-emitting elements is at least temporarily activated.

[0048] The optical interface part may optionally be detachable and connectable.In addition, the optical interface part may be combined with the mechanical interface part, so that the optical connection is automatically established when the imaging device is mechanically coupled, for example.

[0049] The light-emitting elements may comprise monochromatic LEDs (light-emitting diodes) and / or laser diodes. Furthermore, at least one of the light-emitting elements may be a white light LED or another white light source. In some embodiments, the lighting unit comprises at least one blue light-emitting element, at least one red light-emitting element, at least one deep red light-emitting element and at least one Nah-IR-light-emitting element (near infrared light-emitting element), in particular LEDs or laser diodes, respectively. Additionally, the lighting unit may comprise at least one white light LED or another white light source.

[0050] The first group may include at least two light-emitting elements that emit in spectrally different ways. When the multispectral mode includes different states, in which specific light-emitting elements or specific types of light-emitting elements are at least temporarily activated, a high degree of efficiency can be achieved in the case of multispectral imaging. Thereby, targeted illumination can be performed within a specific spectral range, so that different spectral images can be collected. Different light-emitting elements activated in different states can be used as different support points for multispectral imaging. At least one of the support points can be selected so that it is adapted to a characteristic point of the absorption spectrum of a physiologically relevant component, such as an isosbestic point of a hemoglobin oxidation curve. Multispectral imaging can additionally include the use of a suitable observation filter.

[0051] In addition, the second group may include at least two light-emitting elements that emit in different ways in terms of the spectrum. The fluorescence mode may include different sub-modes and / or states, in which a specific light-emitting element or a specific type of light-emitting element is at least temporarily activated. This allows targeted excitation within a specific spectral range, so that fluorescence imaging can be performed for a specifically selected dye. In other words, at least one light-emitting element included in the first group and the second group can be used both for multi-spectral mode and for fluorescence mode.

[0052] In some embodiments, the first group includes only some but not all of the light-emitting elements. Alternatively or additionally, in some embodiments, the second group includes only some but not all of the light-emitting elements. In multi-spectral mode, in particular only the light-emitting elements of the first group are at least temporarily activated, while the light-emitting elements that do not belong to the first group are deactivated. In fluorescence mode, in particular only the light-emitting elements of the second group are at least temporarily activated, while the light-emitting elements that do not belong to the second group are deactivated. It is generally understood that the light-emitting elements may include different types of light-emitting elements, and in different types of light-emitting elements, in particular there is exactly one light-emitting element. It is understood that according to the present invention, mixed operating modes may occur, in which the mentioned modes are used in sequence. For example, multi-spectral imaging and fluorescence imaging may be performed in sequence.

[0053] When at least one light-emitting element included in the first group and the second group emits light in the red spectral range, in particular when emitting light in the spectral range between 600nm and 680nm, for example between 610nm and 650nm or between 620nm and 660nm or between 630nm and 670nm, synergy in terms of using the light-emitting elements for different modes and the efficiency gains associated therewith can be achieved. The spectral range can be narrowband and include a wavelength of 660nm. "Narrowband" can include a spectral width of at most 80nm, in particular at most 40nm or even at most 20nm. The at least one light-emitting element can be configured to excite a dye that absorbs in the red spectral range and contribute to the supply of illumination for multi-spectral imaging in the red spectral range.

[0054] In some embodiments, the lighting unit can be operated in at least one white light mode, in which the lighting unit supplies illumination light for white light imaging. The illumination light for white light imaging can be broadband white light. Alternatively, the illumination light for white light imaging can include multiple narrow bands separated from each other, such as blue, red and deep red bands. "Deep red" can be understood here as "long wave is red" and refers to the spectral position rather than the light intensity. The illumination light for white light imaging can be a mixture of light from different light-emitting elements.

[0055] In the white light mode, the third group of light-emitting elements can be at least temporarily activated to supply illumination light for white light imaging. The light-emitting elements can include at least one light-emitting element, which is included in the first group and / or the second group and the third group. In some cases, the third group may include only some of the light-emitting elements but not all of them. In the white light mode, in particular only the light-emitting elements of the third group are at least temporarily activated, while the light-emitting elements that do not belong to the third group are deactivated. In other words, the lighting unit can include light-emitting elements, which are used for one, two or all three of the mentioned lighting modes. Thus, multiple light-emitting elements can be used multiple times.

[0056] At least one light-emitting element included in the first group and / or the second group and the third group can emit light in the red spectral range, in particular between 600nm and 680nm, for example between 610nm and 650nm or between 620 and 660nm or between 630 and 670nm. The advantages of using light-emitting elements in combination are particularly evident when at least one red light-emitting element can be used in all three modes.

[0057] At least one light emitting element included in the first group and / or the second and third groups can emit light in the blue spectral range, in particular in the spectral range between 440 and 480 nm. The at least one blue light emitting element can be suitably used in the fluorescent mode and the white light mode.

[0058] In general, as described above, the light-emitting element may include at least one, especially blue, light-emitting element, which emits light in a spectral range between 440 and 480 nm. In addition, as described above, the light-emitting element may include at least one, especially red, light-emitting element, which emits light in a spectral range between 600 and 680 nm, for example between 610 nm and 650 nm or between 620 and 660 nm or between 630 and 670 nm. Alternatively or additionally, the light-emitting element may include at least one, especially deep red, light-emitting element, which emits light in a spectral range between 750 and 790 nm. Alternatively or additionally, the light-emitting element may include at least one, especially near-infrared emitting light-emitting element, which emits light in a spectral range between 920 and 960 nm. In addition, the light-emitting element may include a white light-emitting element. In particular, when at least one light-emitting element is present in the mentioned light-emitting element types, a compact and universal lighting unit can be provided. For example, in a fluorescent mode, blue and red light-emitting elements may be used, and deep red light-emitting elements may also be used if necessary in the case of suitable dyes. In multispectral mode, deep red and near infrared emitting light elements can be used. In white light mode, white light elements can be used. They can be supplemented in white light mode by blue light elements and, if necessary, red light elements. Thus, the wavelength range can be supplemented by colored light elements, wherein the white light elements, for example due to their structure, but in particular due to filters and optical elements of the lighting unit, provide a reduced intensity. In addition, colored light elements can be used to adjust the color temperature during white light imaging.

[0059] In some embodiments, the second group includes a single light emitting element and / or a single type of light emitting element. For example, a white light emitting element, a red light emitting element and an infrared emitting light emitting element may be provided, wherein in particular the above values ​​are referred to in terms of the possible spectral range. Thus, the first group may include, for example, red and infrared emitting light emitting elements. The second group may include infrared emitting light emitting elements, in particular as a single light emitting element or as a single type of light emitting element.

[0060] In particular, when the lighting unit includes at least one cross beam splitter, a beneficial arrangement of light-emitting elements can be achieved, by means of which light can be deflected from the relative entrance side to the exit side, wherein correspondingly at least one light-emitting element is arranged on the relative entrance side of the cross beam splitter. In some embodiments, two or more cross beam splitters can be provided, which are arranged one after another in optical terms. The at least one cross beam splitter may include two beam splitter elements, whose light transmittance is adapted to the light-emitting elements associated accordingly. The beam splitter elements particularly include notch filters, respectively, so that they are reflected in narrow spectral bands, respectively, but transmitted in other cases. The spectral position and / or width of the corresponding notch can be adapted to the spectral range of the light-emitting elements associated accordingly, so that its light is diverted, but the light of other light-emitting elements is at least transmitted as much as possible.

[0061] In some embodiments, the light-emitting element may include at least four narrow-band emission monochromatic light-emitting elements and at least one broadband emission white light-emitting element, wherein the narrow-band emission monochromatic light-emitting elements have different spectral ranges. For related contents, please refer to the above embodiments regarding the color light-emitting element.

[0062] In particular, a large functional range combined with a compact design and the use of synergistic effects when using light-emitting elements can be achieved if the lighting unit can be operated in at least one hyperspectral mode, in which a plurality of light-emitting elements are activated, whose emission spectra jointly cover at least one spectral range from 450 nm to 850 nm, and in which the lighting unit supplies illumination light for hyperspectral imaging. In particular, all light-emitting elements can be used here.

[0063] It is understood that, in particular when laser diodes are used for the optical filters mentioned herein, suitable polarization filters can be used. Furthermore, in particular when laser diodes are used, at least one cross beam splitter can be used, the beam splitter elements of which are equipped with polarization filters. Selective light transmission can then be achieved by a combination of different polarizations.

[0064] The invention further relates to a program code which is designed to cause the execution of the method according to the invention when it is executed in a processor.

[0065] The invention also relates to a program code, comprising a computer readable medium, on which the program code according to the invention is stored.

[0066] Here, the device according to the invention and the method according to the invention should not be limited to the above-mentioned applications and embodiments. In particular, the device according to the invention and / or the method according to the invention for realizing the working principle described herein can have quantities different from the quantities mentioned herein of the individual elements, components and units and method steps. In addition, within the value range given in the present disclosure, the values ​​within the mentioned limits are also considered to be disclosed and can be used arbitrarily.

[0067] In particular, it should be pointed out that all features and characteristics described with reference to the device, as well as method approaches, can be transferred to the method in an alternative manner and can be used within the scope of the present invention and are considered to be jointly disclosed. This also applies in reverse. In other words, the structures mentioned with reference to the method, i.e., the features according to the device, can be considered, protected and also belong to the disclosure within the scope of the technical solution related to the device.

[0068] The present invention will be described exemplarily below with reference to the accompanying drawings. The drawings, the specification and the claims contain many combined features. Those skilled in the art will also appropriately consider these features individually and use these features in meaningful combinations within the scope of the claims.

[0069] If a particular object has more than one example, only one of them is provided with a reference numeral in the drawings and in the description, if necessary. The description of this example can be transferred to the other examples of the object accordingly. If the objects are named in particular with the aid of ordinal numbers, such as the first, second, third object, etc., they are used to name and / or associate these objects. Thus, for example, the first object and the third object can be included, but the second object is not included. However, in addition, the number and / or order of the objects can also be derived from the ordinal numbers. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In the attached picture:

[0071] Figure 1 A schematic diagram of an imaging device with an illumination device is shown;

[0072] Figure 2 A schematic diagram of a lighting device is shown;

[0073] Figure 3 shows a schematic transmission curve of a beam splitter element of an illumination device;

[0074] Figure 4 A schematic diagram of an imaging device is shown;

[0075] Figure 5 A schematic diagram showing another embodiment of an imaging device;

[0076] Figure 6A schematic diagram showing yet another embodiment of an imaging device;

[0077] Figure 7 A schematic perspective view of another embodiment of an imaging device is shown;

[0078] Figure 8 A schematic flow chart of a method for generating illumination light for an imaging device by means of an illumination device is shown;

[0079] Fig. 9 A schematic flow chart of a method for operating an imaging device is shown;

[0080] Fig.10 A schematic flow chart of a method for operating an imaging device is shown;

[0081] Fig.11 A schematic diagram of a medical imaging device is shown;

[0082] Fig.12 A schematic diagram showing an imaging situation is shown;

[0083] Fig.13 A schematic diagram of a first calibration image is shown;

[0084] Fig.14 shows a schematic diagram of a second calibration image;

[0085] Fig.15 A schematic diagram of a first depth map is shown;

[0086] Fig.16 A schematic diagram of a second depth map is shown;

[0087] Fig.17 A schematic diagram of an object image is shown;

[0088] Fig.18 A schematic diagram showing a corrected object image;

[0089] Fig.19 A schematic diagram showing another corrected object image;

[0090] Fig. 20 A schematic diagram showing a plurality of calibration images and associated depth maps;

[0091] Fig.21 A schematic flow chart showing a method for medical imaging; and

[0092] Fig. 22 A schematic diagram of a computer program product is shown. DETAILED DESCRIPTION

[0093] Figure 1A schematic diagram of an imaging device 10 is shown. In the exemplary case, the imaging device 10 is an endoscopic imaging device, in particular an endoscopic device. Alternatively, the imaging device 10 may be an exoscopic imaging device, a microscopic imaging device or a macroscopic imaging device. The imaging device 10 is exemplarily shown as a medical imaging device. The imaging device 10 is, for example, configured to inspect a cavity.

[0094] The imaging device 10 has a medical imaging device 14. In the case shown, this is an endoscope here.

[0095] In addition, the imaging device 10 includes an illumination device 12 having an optical interface 16 and an illumination unit 18. The imaging device 14 can be optically attached to the optical interface 16. The optical interface 16 can be part of an optical-mechanical interface that is optionally detachable and connectable. The illumination device 14 can be optionally disconnected from the illumination device 12. The illumination unit 18 is configured to supply illumination light to the optical interface 16. When imaging with the aid of the imaging device 14, the illumination unit 18 can correspondingly provide the required illumination light, which is guided to the illumination device 14 and outputted from there to the object to be depicted, such as a part.

[0096] In the case shown, the imaging device 10 also includes a display unit on which images can be displayed that are based on the image data acquired by means of the imaging device 14. These can be video images, still images, superpositions of different images, partial images, image sequences, etc.

[0097] The imaging device 10 is multi-mode. By way of example, the imaging device can be operated in three basic modes, namely a multi-spectral mode, a fluorescence mode and a white light mode. Furthermore, it can be provided that the imaging device 10 can be operated in a hyperspectral mode in addition to or as an alternative to the multi-spectral mode.

[0098] The lighting device 12 is multi-mode. The lighting device 12 can be operated in different lighting modes, in which the lighting device supplies light for different imaging modes. Currently, the lighting device 12 can be operated in three basic modes, namely a multi-spectral mode, a fluorescent mode and a white light mode. Similarly, the imaging device 14 can be operated in different operating modes, specifically also at least in a multi-spectral mode, a fluorescent mode and a white light mode. In the corresponding operating modes of the imaging device 10, the modes of the lighting device 12 are coordinated with each other.

[0099] Figure 21 shows a schematic diagram of a lighting device 12. The lighting unit 18 comprises a plurality of light emitting elements 20, 22, 24, 26, 28 which can be activated independently of each other. These light emitting elements are set to emit light according to different emission spectra to supply illumination light, i.e. the corresponding emission spectra are different between the light emitting elements.

[0100] Exemplarily, the light emitting elements 20, 22, 24, 26, 28 are configured as LEDs. Specifically, the first light emitting element 20 is configured as a red LED, the second light emitting element 22 is configured as a deep red LED, the third light emitting element 24 is configured as a blue LED, and the fourth light emitting element 26 is configured as a near-infrared LED. The colored light emitting elements 20, 22, 24, 26 are respectively emitted in a narrow band manner, such as at wavelengths of 660nm (first light emitting element 20), 770nm (second light emitting element 22), 460nm (third light emitting element 24) and 940nm (fourth light emitting element 26).

[0101] Furthermore, a fifth light emitting element 28 is provided, which is a white light emitting element, such as a white light LED. The fifth light emitting element 28 emits, for example, in a spectral range of about 400 to 700 nm. In other embodiments, laser diodes can also be used, in particular as colored light emitting elements.

[0102] Depending on the lighting mode, some of the light emitting elements 20, 22, 24, 26, 28 are at least temporarily activated, while other light emitting elements 20, 22, 24, 26, 28 are not used in the lighting mode in question, if necessary.

[0103] Currently, the first group includes a first light-emitting element 20 and a fourth light-emitting element 26. The first group may additionally include a light-emitting element 22 and / or a light-emitting element 24. The first group is used for multispectral imaging, wherein the light-emitting elements 20, 26 and, if necessary, the light-emitting elements 22 and 24 contained therein are respectively used as support points. In multispectral mode, for example, the first light-emitting element 20 is first used for illumination and an image is taken. Next, the fourth light-emitting element 26 is used for illumination and an image is taken. These images are respectively based on diffuse reflection, i.e., observation of light scattered back from the object to be depicted. Due to these two different support points, spectral information about the object to be depicted can be obtained. For example, specific tissue types, perfusion states, tissue properties, etc. can be evaluated thereby.

[0104] In addition, the second group includes a first light-emitting element 20, a second light-emitting element 22 and a third light-emitting element 24. The second group is used for illumination during fluorescence imaging. Here, for example, an object stained with a suitably selected dye can be observed. Different dyes can also be introduced into different tissue types, etc., and observed at the same time. A specific dye is excited to be excited to fluorescence by targeted excitation. The fluorescence is then depicted. The first light-emitting element 20 is suitable for exciting the dye cyanine 5.5 (Cy5.5), for example. The second light-emitting element 22 is suitable for exciting the dye indocyanine green (ICG). The third light-emitting element 24 is suitable for exciting the dye dihydrofluorescein.

[0105] In addition, the third group includes a fifth light-emitting element 28. In this embodiment, the third group also includes a first light-emitting element 20 and a third light-emitting element 24. The third group is used to provide illumination light for white light imaging. To this end, the white light of the fifth light-emitting element 28 can be mixed with the light of a specific color light-emitting element, thereby compensating for spectral loss and / or adjusting the color temperature in a targeted manner.

[0106] It can be seen that some of the lighting elements 20 , 22 , 24 , 26 , 28 are assigned to multiple groups, by way of example the first lighting element 20 is assigned to all three groups, and the third lighting element 24 and optionally also the second lighting element 22 are assigned to the second and third groups.

[0107] Alternatively or additionally, it can also be provided that some or all of the light-emitting elements 20, 22, 24, 26, 28 are applied in a hyperspectral mode. A wide excitation spectrum is then generated. Then, in combination with a suitable hyperspectral detector, spectral information about the entire visible and near-infrared spectrum of the object to be depicted can be collected. The imaging device 14 can include a push-broom arrangement (Pushbroom-Anordnung) as a hyperspectral detector for this purpose. In other embodiments, a swing-broom arrangement (Whiskbroom-Anordnung), a staring arrangement (Staring-Anordnung) and / or a snapshot arrangement (Schnappschuss-Anordnung) are used. The imaging device 14 can be a hyperspectral imaging device. For different methods of hyperspectral imaging and the components required for this purpose, see the professional article “Review of spectral imaging technology in biomedical engineering: achievements and challenges” by Quingli Li et al., published in Journal of Biomedical Optics 18(10), 100901, October 2013, and the professional article “Medical hyperspectral imaging: a review” by Guolan Lu and Baowei Fei, published in Journal of Biomedical Optics 19(1), 010901, January 2014.

[0108] The lighting unit 18 includes two cross beam splitters 30, 32. They include outlet sides 42, 44, respectively, include inlet sides 37, 41 opposite to the outlet sides 42, 44, respectively, and include two inlet sides 34, 36, 38, 40 opposite to each other. All inlet sides 34, 36, 37, 38, 40, 41 guide the incident light to the corresponding outlet sides 42, 44. The outlet side 42 of the first cross beam splitter 30 is close to the inlet side 41 of the second cross beam splitter 32. The outlet side 44 of the second cross beam splitter 32 is close to the optical interface 16. The two cross beam splitters 30, 32 are preferably arranged in a coaxial manner to each other and / or coaxial with the optical interface.

[0109] The lighting unit 18 may include suitable optical elements, such as lenses and / or mirrors (not shown). Figure 2, multiple lenses 78, 80, 82, 84, 86, 88 are shown by way of example. Lens 78 is, for example, associated with the optical interface portion 16 and inputs light from the exit side 44 of the second cross beam splitter 32 into the optical interface portion 16. In addition, each of the light emitting elements 20, 22, 24, 26, 28 is associated with a corresponding lens 80, 82, 84, 86, 88. In particular, when the light emitting elements 20, 22, 24, 26, 28 do not have a mirror located therebetween at the entrance side 34, 36, 37, 38, 40 of at least one cross beam splitter 30, 32, a particularly high degree of compactness can be achieved. Therefore, the light emitting elements 20, 22, 24, 26, 28 can be made very close to at least one cross beam splitter 30, 32.

[0110] The cross beam splitters 30, 32 each comprise two beam splitter elements 90, 92, 94, 96. They can in principle be semi-transparent so that light from all inlet sides 34, 36, 37, 38, 40, 41 is diverted to the corresponding outlet side 42, 44. In this embodiment, the beam splitter elements 90, 92, 94, 96 are selectively transparent. Further reference Figure 3 This point will be explained. The beam splitter elements 90, 92, 94, 96 may be filters that are reflective only within a limited range, but are highly transmissive otherwise. Figure 3 , the transmission curves 98, 100, 102, 104 of the beam splitter elements 90, 92, 94, 96 of the two cross beam splitters 30, 32 are shown. Each of the colored light-emitting elements 20, 22, 24, 26 or each of the opposite entrance sides 34, 36, 38, 40 is associated with one of the beam splitter elements 90, 92, 94, 96. The beam splitter elements 90, 92, 94, 96 are selected here so that they reflect in the wavelength range in which the associated light-emitting element 20, 22, 24, 26 emits, but transmit as much as possible otherwise. For this purpose, a band stop filter can be used in the intermediate wavelength range, which can have transmission spectra 100 and 102 for example. Instead of a band stop filter, a high-pass filter or a low-pass filter can be used at the edge of the spectrum, see transmission spectra 98 and 104.

[0111] Due to the specific transmission spectra 98, 100, 102, 104 of the cross beam splitters 30, 32, the light of the fifth light-emitting element 28 is spectrally cut off. Therefore, the light blocked by the beam splitters 30, 32 can be appropriately supplemented in the aforementioned manner and in a targeted manner with the help of light-emitting elements 20 and 24, and if necessary, also with the help of light-emitting elements 22 and / or 26. Thus, it is possible to supplement specifically in the spectral range in which the beam splitters 30, 32 absorb and / or reflect the light of the fifth light-emitting element 28 (but in any case not transmit to the optical interface 16). The light-emitting elements 20, 24 used in supplementation and the light-emitting element 22 used when necessary are preferably operated at a lower power or at an adapted power. The purpose here can be to restore the original spectrum of the fifth light-emitting element 28 at least as much as possible.

[0112] In some embodiments, the fifth light-emitting element 28 can alternatively be a green light-emitting element, or a generally colored light-emitting element that emits primarily in the spectral range transmitted by at least one beam splitter 30, 32. For example, in these embodiments, the fifth light-emitting element 26 can be an LED with an emission peak at about 530 nm. Green laser diodes can also be considered for this purpose. It can be provided here that color mixing is performed in white light mode and in particular not a single white light source such as a white light LED is used, but white light from separate light-emitting elements is mixed in a targeted manner.

[0113] It is understood that, given a suitable dye, such a green light emitting element can also be used in fluorescence mode. Alternatively or additionally, it can be used in multispectral mode.

[0114] The lighting unit 18 defines a common optical path 54 into which the emitted light of the light emitting elements 20, 22, 24, 26, 28 can be input. The common optical path 54 extends from the exit side 44 of the second cross beam splitter 32 to the optical interface. The common optical path 54 is currently arranged coaxially with the fifth light emitting element 26.

[0115] In the embodiment shown, the light emitting elements 20, 26 of the first group are arranged so that the light emitted from the light emitting elements 20, 26 passes through a light path of at least substantially the same length from the corresponding light emitting elements 20, 26 to the optical interface 16. The light emitting elements 20, 26 of the first group have light emitting surfaces 56, 58, respectively. The light emitting surfaces 56, 62 are arranged equidistantly with reference to the common optical path 54. This is currently achieved by arranging the two light emitting elements 20, 26 at the same distance from the beam splitter 32 (currently, exemplarily, the second beam splitter 32) associated with them, in particular, the entrance sides 28, 40 opposite thereto. The light is input into the common optical path 54 by the cross beam splitter 32.

[0116] The beam splitters 30 , 32 are arranged in particular such that the light emission surfaces 56 , 58 , 60 , 62 , 64 of the light emitting elements 20 , 22 , 24 , 26 , 28 are arranged equidistantly with respect to the cross beam splitter 30 , 32 associated therewith.

[0117] By using cross beam splitters 30, 32 and light elements 20, 22, 24, 26, 28 that can be used together for different modes, the lighting unit 18 or the lighting device 12 has a high degree of compactness. In addition, the equidistant arrangement makes it possible to achieve that when the imaging device 14 or its optical waveguide is twisted relative to the optical interface 16, no spectral shift occurs.

[0118] It is understood that different numbers of light emitting elements 20, 22, 24, 26, 28 and / or different numbers of cross beam splitters 30, 32 may be used. The use of cross beam splitters 30, 32 has proven to be particularly suitable. However, in other embodiments, other types of beam splitters and / or other optical elements may be used to input light from the light emitting elements 20, 22, 24, 26, 28 into the optical interface 16.

[0119] Figure 4 Shown is a schematic diagram of an imaging apparatus 10. An imaging device 14 is optically coupled to an optical interface 16, for example via an optical conductor 106, such as at least one optical fiber.

[0120] The imaging device 10 has a control section 66, which is configured so that the operating state of the imaging device 14 and the lighting mode of the lighting unit 18 are automatically coordinated with each other. Currently, the user can predetermine the operating mode of the imaging device 14 through user operation. Then, the control section 66 can adjust the lighting mode of the lighting unit 18 to match this. Alternatively or additionally, the user can adjust a specific lighting mode of the lighting unit 18 through user operation. Then, the control section 66 can adjust the operating mode of the imaging device 14 to match this. For example, the lighting device 12 and / or the imaging device 10 has a user interface, and the user can submit corresponding commands via the user interface.

[0121] The imaging device 14 comprises a camera unit 68 and a distal rod 76. The distal rod 76 is optically coupled to the camera unit 68. The camera unit 68 may have a joint for the distal rod 76, wherein the distal rod 76 may be optionally disconnected and coupled. The distal rod 76 may also be permanently optically and / or mechanically coupled to the camera unit 68. The camera unit 68 is arranged proximally with reference to the rod 76. The camera unit 68 comprises an imaging sensor mechanism 108, which in the present case is exemplarily a white light sensor 110 and a near infrared sensor 112. The imaging sensor mechanism 108 may generally have one or more at least spatially resolved light sensors / image sensors, such as at least one CMOS sensor and / or at least one CCD sensor. The rod 76 comprises an optical element, not shown, by means of which light can be guided to the camera unit 68 so that the object to be depicted can be optically captured. Furthermore, the rod 76 comprises at least one optical path 114 , for example defined by an optical conductor such as an optical fiber, which extends to a distal section 116 of the rod 76 and by means of which illumination light from the optical interface 16 of the illumination device 12 can be output to the object to be depicted.

[0122] The camera unit 68 has different operating states, specifically, for example, at least one multi-spectral operating state and a fluorescence operating state, and additionally in the present embodiment a white light operating state, and, if necessary, a hyperspectral operating state. The control unit 66 automatically adapts the lighting mode of the lighting unit 18 to the current operating state of the camera unit 68. Here, the control unit 66 can adjust the image capture behavior of the camera unit 68. For example, the control unit 66 can adjust the illumination duration, sensitivity / enhancement / gain (Gain) and / or other operating parameters of the camera unit 68, or in particular its image acquisition sensor 108 and, if necessary, its optical device, and thereby define different operating states of the imaging device 14. In the present case, the control unit 66 triggers the lighting unit 18 for camera synchronization.

[0123] The imaging device 14 comprises a filter unit 46 having optical filters 48, 50, 52. Three optical filters are shown by way of example, but it is understood that a different number of optical filters can be used. The filter unit 46 can be switched between a multispectral mode and a fluorescence mode. Furthermore, the filter unit 46 can additionally be switched into a white light mode and / or a hyperspectral mode. The optical filters 48, 50, 52 can optionally be brought into the observation beam path 70 of the camera unit 68, thereby defining different observation modes. They currently define the operating state of the camera unit 68.

[0124] A basic imaging mode can be assigned to multiple optical filters 48, 50, 52. In particular, for fluorescence imaging, other suitable optical filters can be used according to the light-emitting elements 20, 22, 24, 26, 28 used for excitation. For example, the current first light-emitting element 20 (red) is combined with an optical filter that transmits wavelengths greater than 730nm but blocks shorter wavelengths. This can especially achieve the detection of only fluorescence without detecting the excitation light itself. For example, the optical filter can absorb at least in the range of 600nm to 730nm. In addition, the current second light-emitting element 22 (deep red) is combined with the following filter that absorbs in the range of 700 to 850nm or transmits significantly only above 850nm.

[0125] The user can select a specific filter 48, 50, 52 and then select the associated observation mode or operating state of the camera unit 68. For this purpose, the camera unit 68 has a filter sensor 72, which can automatically detect the optical filter currently introduced into the observation beam path 70. Therefore, the user can manually introduce the selected filter 48, 50, 52 into the observation beam path 70. In the example shown, the optical filters 48, 50, 52 are arranged on the filter carrier 118. The filter carrier can be moved to different positions, whereby one of the optical filters 48, 50, 52 can be selected accordingly. Subsequently, the filter sensor 72 detects the currently selected optical filter 48, 50, 52. Then, the control unit can determine the current operating state of the camera unit 68 and therefore also the imaging device 14 according to the sensor signal of the filter sensor 72, and automatically adapt the lighting mode of the lighting unit 18 to it. Thus, the user places the entire imaging device 10 in the desired mode by a simple user operation, such as manually selecting the optical filter 48, 50, 52. In principle, the user can combine different filters with different illumination modes and thus produce different types of contrast.

[0126] In the case shown, the imaging device 14 and in particular the rod 76 comprises a broadband transmission optical device 77, which can be used in a consistent manner in different illumination modes. In the present case, the broadband optical device 77 is designed for a spectral range of at least 400nm to 1000nm. It is used in a consistent manner for different illumination and / or observation spectral ranges.

[0127] In some embodiments, the imaging device 14 can be configured as a stereo endoscope including stereo eyepieces with two sides. Different optical filters can be connected in series with these sides in an independent manner, thereby allowing different contrast images to be superimposed on each other.

[0128] In the following, the same reference numerals as above are used in the context of other embodiments and variants for the same or similar components. Regarding their description, in principle, reference is made to the above-mentioned embodiments, and the differences between the embodiments are mainly explained below. In addition, for the sake of clarity, the reference numerals are partially omitted in the following figures.

[0129] Figure 5 A schematic diagram of another embodiment of an imaging device 10 is shown. The imaging device 10 comprises an illumination device 12 and an illumination unit 18 having an optical interface 16 and an imaging device 14 attached to the optical interface 16. The imaging device 14 comprises a camera unit 68 having an automatic filter unit 210. The automatic filter unit 210 comprises a plurality of optical filters 48, 50, 52 which can be automatically brought into an observation beam path 70 of the camera unit 68 according to an observation mode predetermined by a user.

[0130] The automatic filter unit 210 comprises a filter drive 212 which is configured to automatically move the optical filters 48, 50, 52 into or out of the observation beam path 70. The optical filters 48, 50, 52 may be arranged on a filter carrier 118 attached to the filter drive 212. The filter drive 212 may be configured to move, e.g., displace and / or rotate and / or pivot, the filter carrier 118.

[0131] The imaging device 14 has a user interface 214 by means of which the user can adjust the desired observation mode. For example, the desired position of the filter carrier 118 can be predetermined by means of the user interface 214.

[0132] The imaging device 14 further comprises a control unit 66. The control unit 66 is coupled to the filter driver 212 and the user interface 214. The control unit 66 is configured in particular to process user-defined values ​​for the observation mode and to control the filter unit 210 and the illumination unit 18 according to the user-defined values. The control unit 66 can thus adjust the operating state of the imaging device 14 and the illumination mode of the illumination unit 18 coordinated therewith according to the observation mode selected by the user.

[0133] Figure 6A schematic diagram of yet another embodiment of the imaging device 10 is shown. The imaging device 10 includes an illumination device 12 and an illumination unit 18 having an optical interface portion 16, and an imaging device 14 attached to the optical interface portion 16. The imaging device 14 includes a proximal base unit 310. The proximal base unit 310 is attached to the optical interface portion 16 of the illumination device 12. Therefore, the illumination light generated by the illumination device 12 is supplied to the proximal base unit 310. The imaging device 14 also includes a control portion 66, which may be integrated into the base unit 310 in some embodiments.

[0134] Optionally, different replacement rods 312, 314 can be optically and electronically coupled to the proximal base unit 310. The base unit 310 has an interface portion 316 for coupling different replacement rods 312, 314. The interface portion 316 supplies illumination light from the illumination device 12 to the coupled replacement rods 312, 314. In addition, the interface portion 316 is configured to supply power to the coupled replacement rods 312, 314 and / or electronically attach them to the control portion 66 of the imaging device 14.

[0135] The replacement rods 312, 314 each have an integrated camera 318, 320 and an integrated optical filter 322, 324. The integrated cameras 318, 320 are configured as Tipcams. Currently, the integrated camera 318 of the first replacement rod 312 is set for multispectral imaging. In addition, the integrated camera 310 of the second replacement rod 314 is set for fluorescence imaging. Optional existing optical filters 322, 324 can be adapted thereto.

[0136] In other embodiments, replacement rods can also be used, which only include optical filters but no integrated camera. They can then be connectable to the proximal camera unit. In some cases, the proximal camera unit can then be constructed without an additional filter unit. A specific optical filter or a specific observation mode can be selected by selecting a suitable equipped replacement rod.

[0137] The control unit 66 is configured to identify the connected replacement rods 312, 314. This can be achieved based on software, mechanically and / or by sensor recognition. Then, the control unit 66 can find out in which operating state or which observation mode the imaging device 14 should operate based on the identified replacement rods 312, 314. The control unit 66 is also configured to adjust the lighting mode of the lighting unit 18. Therefore, the control unit 66 is configured to adjust the lighting mode of the lighting unit 18 according to the observation mode defined by the currently connected replacement rods 312, 314.

[0138] The replacement rods 312, 314 and the imaging device 10 are in the present case part of a medical imaging system 316. The medical imaging system 316 allows the user to select a suitable replacement rod 312, 314, connect it to the base unit 310, and thereby determine the mode for the entire imaging device 10. It is thus achieved by a simple replacement of the replacement rods 312, 314 that the lighting device 18 is automatically adapted to the image acquisition mode to be adopted.

[0139] Figure 7 A schematic stereogram of another embodiment of an imaging device 10' is shown. The reference numerals of this embodiment are provided with a prime to distinguish them. In this embodiment, the imaging device 10' is configured as an exoscopic imaging device. It includes an illumination device 12' and an imaging device 14'. Their basic operating principles correspond to those described above, however, in this embodiment the imaging device 14' is configured as an exoscope.

[0140] The aspects described above may also be summarized or described as follows. Figure 8 A schematic flow chart of a method for generating illumination light for an imaging device 14 by means of an illumination device 12 is shown. The flow of the method is also derived from the above embodiment. The illumination device 12 here comprises an optical interface portion 16 for optical attachment of the imaging device 14 and an illumination unit 18, which is configured to supply illumination light to the optical interface portion 16, wherein the illumination unit 18 comprises a plurality of light emitting elements 20, 22, 24, 26, 28 which can be optionally activated independently of each other, and which are configured to emit light according to different emission spectra to supply illumination light.

[0141] The method includes a step S11 of at least temporarily activating a first group of light emitting elements 20, 22, 24, 26, 28 to supply illumination light for multispectral imaging. In addition, the method includes a step S12 of at least temporarily activating a second group of light emitting elements 20, 22, 24, 26, 28 to supply illumination light for fluorescence imaging. One of the light emitting elements 20, 22, 24, 26, 28 is at least temporarily activated both when the first group of light emitting elements 20, 22, 24, 26, 28 is at least temporarily activated and when the second group of light emitting elements 20, 22, 24, 26, 28 is at least temporarily activated.

[0142] Fig. 9 1 shows a schematic flow chart of a method for operating the imaging device 10. The flow of the method is also derived from the above embodiments. In step S21, the imaging device 10 is provided with an imaging device 14. In step S22, illumination light is supplied to the imaging device 14. According to the reference Figure 8 The described method supplies illumination light to the imaging device 14 .

[0143] Fig.10 A schematic flow chart of a method for operating an imaging device 10 is shown. The flow of the method is also derived from the above embodiments. The method includes a step S31 of providing a lighting device 12 to provide illumination light for an imaging device 14. The imaging device 14 here includes an optical interface portion 16 for optical attachment of the imaging device 14 and a lighting unit 18, which is configured to supply illumination light to the optical interface portion 16. The lighting unit 18 is constructed to be multi-mode and can operate in a variety of different lighting modes. In addition, the method includes a step S32 of providing an imaging device 14, which can be connected to the optical interface portion 16 of the lighting device 12. In addition, the method includes a step S33 of automatically coordinating the operating state of the imaging device 14 and the lighting mode of the lighting unit 18.

[0144] Hereinafter, an aspect will be described which involves correcting an object image according to depth information that can be obtained from a calibration image. Fig.11 Schematic diagram of a medical imaging device 410 according to this aspect is shown. The medical imaging device 410 can in principle be formed and / or constructed as the imaging device 10 described above or as the imaging device 10 ′ described above. In particular, reference is made to the above description with regard to details of the operating principle and design of the components of the imaging device 410. For the purpose of explaining the present aspect, it is appropriate to refer to the purely schematic illustrations for understanding. Fig.11 And other drawings are used to describe the technical situation.

[0145] In the specific example, the imaging device 410 is an endoscopic device, but it can also be an exoscopic device and / or a microscope device. The imaging device 410 includes an illumination unit 412 having at least one light source 414. For example, the illumination unit 412 can be constructed as described above with reference to the illumination device 12. For the following description, it is assumed that the illumination unit 412 is constructed in this way. However, this is purely exemplary for understanding. In principle, the illumination unit 412 is configured to provide an illumination light 416, by means of which an object 418 to be depicted can be illuminated.

[0146] The imaging device 410 further comprises an image acquisition unit 420 having an objective lens 442, which is only schematically shown, and a suitable image acquisition sensor system 444. The image acquisition unit 420 is configured to detect object light 428 from the object 418. This may be diffusely reflected illumination light 416 and / or light emitted by the object 418, for example fluorescence.

[0147] The image acquisition sensor mechanism 444 is currently configured to capture images both in the visible range and in the near infrared range. For example, the image acquisition sensor mechanism 444 is sensitive at least in the range between 450nm and 950nm, and in some embodiments is sensitive in the range between 400nm and 1000nm.

[0148] In the following, it is assumed that the image acquisition unit 420 can be operated in combination with the illumination unit 412 at least in white light mode and fluorescence mode. In white light mode, the illumination light 416 is injected broadband, such as at least in the range of 480nm to 750nm, for example by means of a white light emitting element. The illumination light 416 diffusely reflected by the object 418 is then observed. However, in fluorescence mode, the illumination light 416 with a specific wavelength is injected, which is suitable for exciting the fluorescent dye used. In addition, the light emitted by the fluorescent dye is detected, which is emitted by the object 418 and in particular by the excited dye molecules.

[0149] In the present case, the image acquisition unit 420 is configured to capture stereo images and may include suitable stereo optics and / or suitable stereo image acquisition sensor means 444 for this purpose.

[0150] The object 418 to be depicted is, for example, an anatomical structure, such as an anatomical structure in a cavity of a patient. The anatomical structure includes an area 454 marked with a fluorescent dye. The object 418 includes an area 448 stained with a fluorescent dye. For example, indocyanine green is used as a dye. In addition, the object 418 includes a tissue 450 covering the stained area 448. For example, the stained area 448 is a vessel, and the tissue 450 is a fat tissue covering the vessel, wherein this is purely exemplary for understanding. Fig.12 Schematic diagram of the imaging situation is shown. The surface of the tissue 450 is located at a distance d from the imaging device 410, in particular from the objective lens 442 of the image acquisition unit 420. 0 The stained area 448 is located inside the tissue 450 and is located at a distance d from its surface. 1 It is assumed hereinafter that the illumination light is output in the region of the objective lens 442.

[0151] This has a number of effects on the imaging. If working with illumination light 416 with a low penetration depth into object 418, it is essentially reflected and / or scattered by the surface of fabric 450. The intensity of the diffusely reflected light then depends on the distance d according to the inverse square law, roughly according to the known distance square law. 0 It is assumed here that at a distance d 0 There is air in the region of , which is located in a cavity within which imaging is performed.

[0152] We need to take into account two effects when working with illumination light 416, which can penetrate tissue 450 and is suitable, for example, to reach dyeing area 448 and excite the dye molecules there to fluoresce. Firstly, the intensity of the injection is also subject to the inverse square law. Furthermore, inside tissue 450, attenuation of illumination light 416 occurs through interaction with tissue 450. Therefore, the intensity actually available for fluorescence excitation is less than the intensity emitted by illumination unit 412.

[0153] The object light 428 emitted from the stained area 448 is also subject to a certain attenuation in the tissue 450. In addition, the intensity of the emitted object light 428 also follows the inverse square law, where the total distance d needs to be taken into account. 0 +d 1 Therefore, the fluorescence intensity detectable by the image acquisition unit 420 is less than the fluorescence intensity emitted by the stained area 448 .

[0154] Therefore, as mentioned above, the detectable intensity I 探测 as follows:

[0155] I 探测 =I(λ 0 ) / (d 0 +d 1 ) α ·exp(-μ(λ 0 )·d 1 )·exp(-μ(λ 1 )·d 1 )·R

[0156] Among them I 探测 refers to the detected light intensity, I(λ 0 ) refers to a 0 The intensity of the incident light, d 0 Refers to the distance between the objective lens and the surface of the object to be depicted, d 1 is the distance between the surface of the object to be depicted and the area stained with the fluorescent dye in the object to be depicted, α is an exponent that defines the inverse square law and can be selected as 2, for example, to perform calculations according to the distance square law, μ(λ 0 ) refers to the wavelength λ when penetrating the object to be depicted 0 The attenuation factor of the light attenuation, μ(λ 1 ) refers to the wavelength λ when penetrating the object to be depicted 1 The attenuation factor of the light attenuation.

[0157] In order to take these effects into account and correct the image accordingly, the imaging device 410 includes an image correction unit 426. Figures 13 to 18 Describe in detail how they work.

[0158] First, in this example, two calibration images 422, 423 are taken. They can be stereo images here respectively. For example, the first calibration image 422 is obtained by illuminating with white light and detecting the dissipated light. Since white light has a low penetration depth into the object 418, the first calibration image 422 basically shows the surface of the object 418. The light that penetrates into the object 418 and is diffusely reflected by the layers located deeper can be ignored, because the intensity of the diffuse reflection is significantly lower than the intensity of the diffuse reflection by the surface of the object 418 due to both the attenuation of the incident light and the attenuation of the light diffusely reflected in the tissue.

[0159] Furthermore, a second calibration image 423 is recorded, for which purpose light is irradiated with a wavelength that excites the dye used. The second calibration image 423 is passed through a suitable observation filter and / or recorded in a suitable wavelength range to detect fluorescence. This comes from the dyed area 448.

[0160] In this example, the image correction unit 426 is configured to determine a depth map 432, 434 from each of the two calibration images 422, 423. For this purpose, a stereo reconstruction algorithm is used in each case. The depth maps 432, 434 therefore include information relating to the observed surface of the respective object, i.e., in the case of the depth map 432 determined from the first calibration image, information relating to the surface of the object 418 to be observed, and in the case of the depth map 434 determined from the second calibration image, information relating to the surface of the stained region 448 located in the tissue 450.

[0161] From this, it can be determined Fig.12 The distance d schematically shown in 0 and d 1 It is understood that this type of distance can be determined point by point. The depth maps 432, 434 contain in particular point by point depth information, so that corrections can be performed on a pixel by pixel basis.

[0162] It should be noted that due to the scattering effect, the distance d from the second calibration image 423 may be calculated taking into account the scattering factor. 1 Due to the scattering effect, the stereo reconstruction can produce a depth d for the stained area 448 0 +x·d 1 , where x is a factor to be determined empirically between 0 and 1. For example, the factor x can be determined empirically by suitable calibration and then taken into account by the image correction unit 426 to ascertain the actual distance value d 1 .

[0163] In the present case, the correction involves taking into account the above equation, ie taking into account both the distance and the attenuation.The position of the stained area 448 in the tissue 450 can then be determined by using the two depth maps 432 , 434 .

[0164] Next, an object image 424 of the object 418 can be taken. This can be based on a plurality of individual images and can be, for example, a superimposed view shown in the form of a superimposed white light image and a fluorescence image. Due to the distance and attenuation effects described, the stained area 448 may appear to be significantly lighter in the object image 424 than the actual fluorescence emission would correspond to. Therefore, the image correction unit 426 is configured to generate a corrected object image 430 according to the correction. For example, in the corrected object image 430, the intensity of the fluorescence from the stained area 448 is currently shown in an enhanced manner, for example, according to the correction. Therefore, the corrected object image 430 includes at least one image area 436, which is enhanced and / or attenuated in at least one parameter relative to another image area 437 according to the correction, such as hue, brightness and / or color saturation. Then, although the position of the stained area 448 is inside the tissue 450, the user can still recognize the stained area well.

[0165] Corrected object image 430 may be output to a user via a schematically shown display 446 of imaging device 410 .

[0166] Fig.19 Another example of a corrected object image 430 is shown. In order to additionally provide the user with information about at what depth the stained region 448 is located in the tissue 450, in this case the stained region 448 is shown with the corrected brightness / intensity as described above, but in false color according to a color scale 452. The color scale 452 contains information about the depth of the stained region 448 in the object 418. The color scale 452 can be displayed to the user so that he can directly understand the specific depth from the displayed staining of the stained region 448.

[0167] The above-described embodiments with reference to the multi-mode lighting device 12 can generally be understood as that, depending on the dye used, different wavelengths or wavelength mixtures can be used as the illumination light 416 to capture the calibration image. In addition, illumination can also be performed with wavelengths that can be expected when the dye is emitted to analyze the absorption characteristics / attenuation characteristics of the observed tissue. If, for example, indocyanine green is used as a dye, a calibration image can be captured by emitting light with a wavelength of approximately 940 nm (see the fourth light-emitting element 26). Then, fluorescence is not detected as described above, but diffusely reflected light is detected. The depth map determined in this way then provides insights into the penetration depth and absorption behavior of the observed tissue in the following spectral range, in which the dye is emitted when the object is later imaged.

[0168] If, for example, Cy5.5 is used as the dye, a calibration image can be recorded in order to ascertain the absorption in the tissue that is decisive for its fluorescence, wherein, for example, deep red light with a wavelength of 770 nm is radiated (see second light-emitting element 22 ).

[0169] Alternatively or additionally, a calibration image can also be obtained by means of monochromatic and / or narrow-band illumination, which allows conclusions to be drawn about the surface of object 418. It is also possible to record a plurality of calibration images in different spectral ranges in order to create a spectrally dependent depth map.

[0170] Fig. 20 Another application is shown. Here, imaging device 410 is set for multi-spectral and / or hyperspectral imaging. For example, this type of imaging can be used to measure specific tissue parameters, such as perfusion. To this end, the intensity of a specific pixel associated with a specific tissue type, such as a blood vessel, is observed at a suitable wavelength. For example, perfusion measurement can be performed by comparing the intensity at 680nm and 930nm. However, if the above-mentioned influence on the intensity of the detection is not taken into account here, the distorted parameters can be found.

[0171] Therefore, the imaging device 410 can be configured to capture multiple calibration images 422-1, 422-2, 422-3, 422-4 for different spectral ranges. For example, these images can be obtained by using each of the light emitting elements 20, 22, 24, 26 described above as an illumination light source to capture corresponding calibration images. Preferably, a stereo image is captured again.

[0172] Depth maps 432-1, 432-2, 432-3, 432-4 can be calculated from calibration images 422-1, 422-2, 422-3, 422-4, for example, with the aid of stereo reconstruction. They are in turn associated with a specific spectral range. Depth maps 432-1, 432-2, 432-3, 432-4 contain information about the average penetration depth of the light involved. In addition, a white light image can be taken or an image using short-wave illumination light, such as blue light, as another calibration image can be used. Another depth map can be determined from another calibration image in the manner described above, which corresponds at least substantially to the surface of the object to be depicted due to the low penetration depth of the light. If depth maps 432-1, 432-2, 432-3, 432-4 are subtracted from this other depth map, the average penetration depth in the corresponding spectral range can be estimated. Then, absorption losses in the observed tissue can be taken into account accordingly.

[0173] Additionally or alternatively, as described above, the inverse square law may be considered to account for intensity loss due to distance from the lighting unit 412 .

[0174] Fig.21 A schematic flow chart of a method for medical imaging is shown. The flow of the method is also derived from the above-mentioned embodiments. The method is performed, for example, with the aid of an imaging device 410. Step S41 includes providing an illumination light 416 for illuminating an object 418 to be depicted. Step S42 includes taking at least one calibration image 422, 423 of the object 418 to be depicted. Step S43 includes taking at least one object image 424 of the object 418 to be depicted. Step S44 includes determining depth information from the calibration images 422, 423. Step S45 includes determining a correction for the object image 424, wherein the correction includes taking into account the positional dependency of the light intensity of the illumination light 416 and / or the distance dependency of the light intensity of the object light 428 according to the depth information. Step S46 includes generating a corrected object image 430 according to the correction.

[0175] Fig. 22 A schematic diagram of a computer program product 438 having a computer-readable medium 440 is shown. A program code is stored on the computer-readable medium, which program code is configured to cause the execution of one and / or all of the described methods when it is executed in a processor.

[0176] Description of Reference Numerals

[0177] 10 Imaging equipment

[0178] 12 Lighting Equipment

[0179] 14 Imaging device

[0180] 16 Optical interface

[0181] 18 Lighting units

[0182] 20 Light-emitting element

[0183] 22 Light-emitting element

[0184] 24 Light-emitting element

[0185] 26 Light-emitting element

[0186] 28 Light-emitting element

[0187] 30 Beam splitter

[0188] 32 Beam splitter

[0189] 34 Inlet side

[0190] 36 Entrance side

[0191] 37 Entrance side

[0192] 38 Entrance side

[0193] 40 Inlet side

[0194] 41 Entrance side

[0195] 42 Exit side

[0196] 44 Exit side

[0197] 46 filter units

[0198] 48 Filter

[0199] 50 Filters

[0200] 52 Filter

[0201] 54 Optical Path

[0202] 56 Light emitting surface

[0203] 58 light emitting surface

[0204] 60 Light emitting surface

[0205] 62 light emitting surface

[0206] 64 Light emitting surface

[0207] 66 Control Department

[0208] 68 Camera Unit

[0209] 70 Observation beam path

[0210] 72 filter sensor

[0211] 74 Display Unit

[0212] 76

[0213] 77 Optical Devices

[0214] 78 Lens

[0215] 80 lens

[0216] 82 lenses

[0217] 84 lenses

[0218] 86 lens

[0219] 88 lens

[0220] 90 Beam Splitter Element

[0221] 92 beam splitter elements

[0222] 94 beam splitter elements

[0223] 96 beam splitter elements

[0224] 98 Transmission Spectrum

[0225] 100 Transmission spectrum

[0226] 102 Transmission Spectrum

[0227] 104 Transmission Spectrum

[0228] 106 Photoconductor

[0229] 108 Imaging sensor mechanism

[0230] 110 White light sensor

[0231] 112 Near infrared sensor

[0232] 114 Light Path

[0233] 116 Distal segment

[0234] 210 filter unit

[0235] 212 Filter Driver

[0236] 214 User Interface

[0237] 310 Base Unit

[0238] 312 Replacement Rod

[0239] 314 Replacement Rod

[0240] 316 Imaging System

[0241] 318 Camera

[0242] 320 Camera

[0243] 322 Filter

[0244] 324 Filter

[0245] 410 Imaging Equipment

[0246] 412 Lighting Unit

[0247] 414 Light Source

[0248] 416 illumination light

[0249] 418 Object

[0250] 420 Image Acquisition Unit

[0251] 422 Calibration Image

[0252] 423 Calibration Image

[0253] 424 Object Image

[0254] 426 Image Correction Unit

[0255] 428 Object Light

[0256] 430 Corrected object image

[0257] 432 Depth Map

[0258] 434 Depth Map

[0259] 436 Image Area

[0260] 437 Image Area

[0261] 438 Computer program products

[0262] 440 Computer readable medium

[0263] 442 Objective

[0264] 444 Image acquisition sensor mechanism

[0265] 446 Display

[0266] 448 dyeing area

[0267] 450 Organization

[0268] 452nd level

Claims

1. A medical imaging device (410), in particular an endoscope, an exoscopic device and / or a microscope, include: an illumination unit (412) having at least one light source (414) configured to provide illumination light (416) for illuminating an object (418) to be depicted; An image acquisition unit (420) configured to capture at least one calibration image (422, 423) of the object (418) to be depicted and to capture at least one object image (424) of the object (418) to be depicted; and The image correction unit (426) is configured as follows: determining depth information from the calibration images (422, 423); determining a correction for the object image (424), wherein the correction comprises taking into account a position dependency, in particular a distance dependency, of the light intensity of the illumination light (416) and / or a distance dependency of the light intensity of the object light (428) according to the depth information; as well as A corrected object image is generated according to the correction (430).

2. The medical imaging device (410) according to claim 1, The depth information includes at least one depth map (432, 434).

3. The medical imaging device (410) according to claim 1 or 2, The image acquisition of the calibration image (422, 423) includes the detection of diffusely reflected light.

4. The medical imaging device (410) according to any one of the preceding claims, The image acquisition of the calibration image (422, 423) includes the detection of fluorescence.

5. The medical imaging device (410) according to any one of the preceding claims, The lighting unit (412) is configured to operate in different lighting modes, and to provide lighting light in different spectral ranges in different lighting modes, and The image acquisition unit (420) is configured to capture a plurality of calibration images (422, 423), wherein the capturing of the plurality of calibration images is based on different illumination modes of the illumination unit (412).

6. The medical imaging device (410) according to any one of the preceding claims, The image acquisition unit (412) is configured to simultaneously and / or sequentially record a plurality of calibration images (422, 423) in different spectral ranges, in particular using different optical filters.

7. The medical imaging device (410) according to any one of the preceding claims, The correction comprises a distance correction which is based on the inverse of a power of the length of the optical path, in particular based on the inverse of a power of the length of the optical path between the image acquisition unit (420) and the object (418) to be depicted and / or the optical path inside the object (418) to be depicted.

8. The medical imaging device (410) according to any one of the preceding claims, The correction comprises an absorption correction which is based on an attenuation, in particular an exponential attenuation, of light along a light path having a certain length, in particular the length of the light path inside the object (418) to be depicted.

9. The medical imaging device (410) according to claim 8, The absorption correction takes into account the attenuation of the illumination light (416) and / or the attenuation of the object light (428).

10. The medical imaging device (410) according to any one of the preceding claims, The image correction unit (426) is configured to determine spatial and / or spectral characteristics, in particular inhomogeneities, of the lighting unit (412) from the at least one calibration image (422, 423) and to take the determined spatial and / or spectral characteristics into account during the correction.

11. The medical imaging device (410) according to any one of the preceding claims, The image correction unit (426) is configured to determine the depth information based on stereo reconstruction.

12. The medical imaging device (410) according to any one of the preceding claims, In the corrected object image (430), at least one image region (436) is enhanced and / or attenuated in accordance with the correction relative to at least another image region (437) in terms of at least one parameter, such as hue, brightness and / or color saturation.

13. The medical imaging device (410) according to any one of the preceding claims, The lighting unit (412) and / or the image acquisition unit (420) are configured for multi-spectral imaging.

14. Method for medical imaging, in particular a method for medical imaging using a medical imaging device (410) according to any one of the preceding claims, include: providing illumination light (416) for illuminating an object to be depicted (418); Taking at least one calibration image (422, 423) of the object (418) to be depicted; capturing at least one object image (424) of the object (418) to be depicted; determining depth information from the calibration images (422, 423); determining a correction for the object image (424), wherein the correction comprises taking into account the position dependency of the light intensity of the illumination light (416) and / or the distance dependency of the light intensity of the object light (428) according to the depth information; as well as A corrected object image is generated according to the correction (430).

15. Program code, which is designed to cause the execution of the method according to claim 14 when it is executed in a processor.

16. Computer program product (438) comprising a computer readable medium (440) on which the program code according to claim 15 is stored.

Images