Endoscopic and / or exoscopic imaging device for spectral imaging and method for its operation

Description

State of the art

[0001] The invention relates to an endoscopic and / or exoscopic imaging device according to the preamble of claim 1.

[0002] An endoscopic imaging device for spectral imaging is already known from DE 10 2014 115 738 A1. This device comprises a shaft and an imaging channel arranged in the shaft. The imaging channel has an imaging branch which includes at least one spectrally selective beam splitter that spectrally selectively divides an optical image into a spectral partial image of one spectral range and a further spectral partial image of another spectral range. The first spectral range is different from the second. The imaging branch includes an image sensor for capturing the spectral partial image. The imaging branch also includes a relay optic for transmitting the second partial image.

[0003] Furthermore, US2010 / 0079587 A1 discloses an endoscope which has two or three beam splitters arranged in series at a distal end of its shaft, as well as attenuation elements located between them, wherein each beam splitter is associated with an image sensor, and wherein the image sensors operate in different wavelength ranges. Image data is then transmitted from the distal end of the shaft to its proximal end via electrical conductors.

[0004] The object of the invention is, in particular, to provide a generic device with improved properties for multispectral and, in particular, hyperspectral imaging, taking into account a compact design. This object is achieved according to the invention by the features of claim 1, while advantageous embodiments and further developments of the invention can be found in the dependent claims. Advantages of the invention

[0005] The invention relates to an endoscopic and / or exoscopic imaging device for multispectral and, in particular, hyperspectral imaging of an examination area;with at least one shaft and with at least one imaging channel arranged at least partially, preferably at least to a large extent and particularly preferably completely, in the shaft, which has at least one first imaging branch comprising at least one spectrally selective beam splitter, which spectrally selectively divides an optical image of the area to be examined into at least one first spectral partial image of a first spectral range and at least one further first spectral partial image of a further first spectral range, wherein the first spectral range is different from the further first spectral range, and the first imaging branch comprises at least one image sensor for capturing the first spectral partial image, and the first imaging branch comprises at least one relay optic comprising a pair of rod lenses for forwarding the further first partial image.

[0006] It is proposed that the imaging channel has at least one second imaging branch, which includes at least one second spectrally selective beam splitter that spectrally selectively divides the further first partial image into at least one second spectral partial image of a second spectral range and at least one further second spectral partial image of a further second spectral range, wherein the second spectral range is different from the further second spectral range, and the second imaging branch includes at least one second image sensor for acquiring the second spectral partial image, and the second imaging branch includes at least one second relay optic for transmitting the further second partial image, which comprises a pair of rod lenses, wherein the first relay optic of the first imaging branch and the second relay optic of the second imaging branch are arranged one behind the other.so that an image plane of the first relay optic is identical to an object plane of the second relay optic.

[0007] This allows for a significant reduction in the installation space required for a multispectral, and especially hyperspectral, endoscopic and / or exoscopic imaging device. This is achieved primarily through the arrangement of the image sensors of the various imaging branches. This is particularly relevant for endoscopic applications of the imaging device, as this application requires only the installation space absolutely necessary for a minimally invasive surgical procedure. Furthermore, the spectral resolution can be advantageously increased, which can be multiplied by the number of imaging branches used. Additionally, the use of two image channels and their sensors allows for real-time spectral display via video, particularly stereo video.The term "endoscopic and / or exoscopic imaging device" refers in particular to a, preferably functional, component, especially a subassembly and / or a structural and / or functional component of an endoscope and / or exoscope. The endoscopic and / or exoscopic imaging device can constitute the endoscope and / or exoscope at least partially, preferably at least to a large extent, and particularly preferably completely. The "endoscopic imaging device" is specifically designed to be inserted, at least partially and preferably at least to a large extent, into an artificial cavity, such as a housing, and / or a natural cavity, such as a hollow space in a body organ or tissue, in order to examine these internally.The "exoscopic imaging device" is specifically designed to be positioned outside an artificial cavity, such as a housing, and / or a natural cavity, such as a hollow space in a body organ or tissue, in order to examine them from the outside. "Designed" is understood to mean specifically programmed, provided, designed, configured, and / or equipped. The fact that a component is designed for a specific function is understood to mean, in particular, that the component fulfills and / or performs this specific function in at least one application and / or operating state. The expression "at least to a large extent" is understood to mean, in particular, at least 50%, preferably at least 70%, preferably at least 90%, and most preferably completely, specifically with regard to a volume and / or mass of a component.The endoscopic and / or exoscopic imaging device has at least one proximal section and one distal section. The distal section is specifically designed to be inserted into a cavity to be examined during operation. "Distal" is understood to mean, in particular, that the device is positioned facing the patient and / or away from the operator. "Proximal" is the opposite of distal. The proximal section is specifically designed to be positioned outside the cavity to be examined during operation. The shaft can, for example, at least partially form the proximal section. The shaft is preferably designed as an elongated component. The shaft is preferably designed as a rigid shaft.Alternatively, the shaft could be flexible. An "elongated component" is understood to mean, in particular, a component whose principal extent is greater by at least a factor of five, preferably at least a factor of ten, and most preferably at least a factor of twenty than a maximum extent of the component perpendicular to its principal extent, i.e., in particular, a diameter of the component. A "principal extent" of a component is understood to mean, in particular, its longest extent along its principal direction of extension. A "principal direction of extension" of a component is understood to mean, in particular, a direction that runs parallel to the longest edge of the smallest imaginary cuboid that just completely encloses the component.

[0008] Spectral imaging is understood to mean, in particular, imaging in which at least one spectral image of a study area is generated, encompassing information of at least two spatial dimensions and at least one spectral dimension. The spectral image can thus be described by a data cube containing at least row and column entries, which include spatial information, and plane entries, which include spectral information. Furthermore, it is conceivable that the spectral image could also have higher dimensions, such as in the form of a data hypercube or data tesseract, and could encompass three spatial dimensions, one temporal dimension, and one spectral dimension. In this case, the spectral image would be represented as a 5-dimensional data hypercube.The spectral information of a spectral image is primarily derived from spectral parameters. Using these spectral parameters, the imaging device can identify at least one type and / or at least one property, such as a tissue type and / or a tissue property, of the area under investigation. The spectral parameters serve as reference points that can be compared with stored parameters characteristic of a specific type and / or property of the area under investigation in order to determine the at least one type and / or property of the area under investigation. "Multispectral imaging" is defined as spectral imaging in which at least three, preferably at least five, and particularly preferably at least nine spectrally offset parameters are acquired."Hyperspectral imaging" is understood to mean, in particular, spectral imaging in which a number of at least 10, preferably at least 40, and most preferably at least 120 spectrally offset spectral parameters are acquired. The acquired spectral parameters lie, in particular, in a wavelength range starting at least 10 nm, preferably at least 150 nm, and most preferably at least 300 nm, and / or up to a maximum of 3000 nm, preferably up to a maximum of 2000 nm, and most preferably up to a maximum of 1000 nm, thus, for example, also within the ultraviolet and infrared wavelength range.

[0009] An "imaging channel" is understood to be, in particular, an optical transmission path that contributes to the acquisition of the spectral image. An imaging branch of an imaging channel is, in particular, a section of the imaging channel along which it has a branch of an optical transmission path or beam path. A "relay optic" of an imaging branch is understood to be, in particular, an optic that extends an image along an optical transmission path and inverts an intermediate image of the image at least once along the transmission path. The relay optic of the imaging branch can comprise one or more lenses, preferably at least one gradient lens, as well as achromats, apochromats, or the like, for example, to correct chromatic aberrations.

[0010] A spectrally selective beam splitter is, in particular, an optical component that divides an optical image into at least one first spectral partial image of a first spectral range and at least one further first spectral partial image of a further first spectral range, whereby the spatial information of the image is also preserved in the respective partial images. The beam splitter can be designed as a reflection beam splitter, interference beam splitter, beam splitter cube, dichroic mirror, or the like. The phrase "one spectral range differs from another spectral range" means, in particular, that the spectral ranges do not overlap spectrally, at least partially, preferably at least to a large extent, and most preferably completely. The spectral ranges can, in particular, have different spectral widths.The first spectral sub-region preferably extends over the visible spectral range. The second spectral range particularly preferably extends over the near-infrared spectral range.

[0011] The term "image sensor" is understood to mean, in particular, a sensor comprising sensor pixels arranged in a two-dimensional matrix. The image sensor may be a CMOS sensor, a CCD sensor, or the like. The image sensor is specifically configured to capture images at a frame rate of at least 15, preferably at least 30, and particularly preferably at least 60 frames per second, thereby enabling the recording and / or playback of spectral information as video or in real time. The image sensor, in particular, possesses at least one spectral sensitivity, which defines the wavelength-dependent sensitivity of the image sensor and can be described by a sensitivity characteristic. The spectral sensitivity is specifically dependent on the quantum efficiency of a sensor pixel of the image sensor and / or on a filter spectrum of a sensor filter of the image sensor associated with the sensor pixel.Thus, by using different sensor filters or sensor pixels, the spectral sensitivity can be varied. When light from a partial image of a spectral range reaches the image sensor, the sensor registers this light depending on the specific spectral range of that partial image and the spectral sensitivity of the image sensor itself. The desired spectral characteristic is obtained by superimposing the transmitted light of the partial image, the spectral range of that partial image, and the spectral sensitivity of the sensor.

[0012] As described above, the number of support points determinable by the imaging device is scalable with the number of different spectrally selective beam splitters of the imaging branches. To advantageously further increase spectral resolution while maintaining a compact design, it is proposed that the imaging channel have at least one third imaging branch, which includes at least one third spectrally selective beam splitter that spectrally selectively divides the second partial image into at least one third spectral partial image of a third spectral range and at least one further third spectral partial image of a further third spectral range, wherein the third spectral range is different from the further third spectral range, and the third imaging branch includes at least one third image sensor, at least for acquiring the third spectral partial image.and the third imaging branch for forwarding the further third partial image comprises at least a third relay optic, wherein the second relay optic of the second imaging branch and the third relay optic of the third imaging branch are arranged one behind the other, such that an image plane of the second relay optic is identical to an object plane of the third relay optic. The third spectral range preferably extends over the infrared spectral range. The spectral resolution can be particularly advantageously increased further by cascading a plurality of imaging branches one behind the other according to the arrangement of the first and the second image channels.

[0013] To further reduce the required installation space and achieve a space-saving arrangement, it is further proposed that at least one spectrally selective beam splitter and / or at least one image sensor of the imaging branches be arranged between two relay optics of different imaging branches. In particular, the at least one spectrally selective beam splitter and / or the at least one image sensor of the imaging branches are arranged between a relay optic of one of the imaging branches and its image plane. Furthermore, preferably at least one image sensor is assigned to the at least one beam splitter of the imaging branch and is optically connected downstream of it. It is conceivable that further optical components, such as lenses, prisms, or the like, can be arranged between the beam splitter and the image sensor assigned to the beam splitter. Advantageously, the image sensor is arranged directly downstream of the beam splitter.In particular, the image sensor could be connected to the beam splitter by force-fit and / or form-fit. "Force-fit and / or form-fit" is understood to mean, in particular, that a holding force between two components is preferably transmitted through a geometric engagement of the components with one another and / or a frictional force between the components. Furthermore, the image sensor and the beam splitter could also be materially bonded to each other. They could also be integrally joined.The term "one-piece" is understood to mean, in particular, at least materially bonded, for example by a welding process, an adhesive bonding process, an injection molding process, and / or another process that would appear appropriate to a person skilled in the art, and / or advantageously formed in one piece, such as by manufacturing from a single casting and / or by manufacturing using a single- or multi-component injection molding process, and advantageously from a single blank. Preferably, the respective spectrally selective beam splitters and / or image sensors of adjacent imaging branches are arranged between two relay optics of the adjacent imaging branches. This is particularly preferred for all beam splitters and / or image sensors of the cascade-arranged imaging branches.

[0014] It is further proposed that at least one of the imaging branches comprise at least one additional optical component whose refractive index and / or material at least substantially matches a refractive index and / or material of a spectrally selective beam splitter of the respective imaging branch, and which is arranged between two relay optics of different imaging branches. This advantageously compensates for or avoids chromatic aberrations that would otherwise reduce the accuracy of both spectral analysis and optical imaging. Furthermore, despite the additional components, the required installation space can be kept to a minimum.The term "at least substantially" with regard to a property, numerical value, or the like shall be understood to mean, in particular, the property, numerical value, or the like, preferably taking into account a deviation of at most 15%, more preferably at most 10%, and most preferably at most 5%. In particular, the at least one further optical component of the imaging branches is arranged between a relay optic of one of the imaging branches and its object plane. The further optical component is preferably designed as a glass cube. Preferably, each of the imaging branches has a corresponding further optical component, which is also arranged accordingly between adjacent imaging branches.

[0015] To avoid imaging errors through a symmetrical arrangement, it is further proposed that the spectrally selective beam splitter and the other optical component be arranged in a mirror-symmetrical manner with respect to the identical image plane and object plane of two, in particular adjacent, relay optics of different imaging branches. Preferably, each spectrally selective beam splitter and each other optical component are arranged in a mirror-symmetrical manner with respect to the identical image plane and object plane of two relay optics of adjacent imaging branches.

[0016] Furthermore, it is proposed that the spectrally selective beam splitter and the other optical component be at least partially integrally connected or formed as a single unit. This advantageously prevents the generation of further imaging aberrations in the boundary regions between these components. Reflections and scattering can also be advantageously avoided.

[0017] It is further proposed that at least one of the spectral ranges of the partial images of the imaging branches comprises shorter wavelengths than at least one other spectral range of the partial images of the imaging branches. A spectral partitioning of the image into the partial images can advantageously be improved. It is particularly preferred that all spectral ranges of the partial images are distinct from one another. In particular, the wavelengths of the spectral ranges of the partial images decrease stepwise. für each of the imaging branches arranged one after the other in a proximal or distal direction.

[0018] Furthermore, it is proposed that at least one image sensor or at least two image sensors of the imaging branches have a sensor plane which is / are arranged at least substantially parallel to a central axis of the shaft. A particularly compact arrangement of the image sensors can advantageously be achieved. A "sensor plane" is understood to mean, in particular, a principal extent plane of the sensor. In the sensor plane, the sensor pixels are arranged in a matrix. Preferably, all sensor planes of all image sensors of the imaging branches are arranged at least substantially parallel to the central axis. Particularly preferably, all image sensors lie in a single plane which is at least substantially parallel to the central axis of the shaft.The term "essentially parallel" here refers in particular to an alignment of a direction relative to a reference direction, especially in a plane, wherein the direction has a deviation from the reference direction of particularly less than 8°, advantageously less than 5° and particularly advantageously less than 2°.

[0019] It is further proposed that the imaging channel comprises at least one printed circuit board (PCB) on which at least one image sensor, or at least two image sensors of the imaging branches, and particularly preferably all of the image sensors of the imaging branches, are arranged. A space-saving and simple arrangement of the image sensors can advantageously be achieved for electrical contact. The PCB defines, in particular, a plane that lies at least substantially parallel to the central axis of the shaft. The PCB could be designed as a flexible printed circuit board (PCB). Preferably, the PCB is designed as a PCB. The PCB is arranged, in particular, within the shaft. Furthermore, it is conceivable that the PCB is integrated into the shaft.

[0020] It is proposed that at least one image sensor or at least two image sensors of the imaging branches have at least one first spectral sensitivity and at least one second spectral sensitivity, and in particular at least one third spectral sensitivity, depending on which of these, a partial image of the imaging branches is captured. Advantageously, the spectral resolution can be further increased. This can be further increased by the number of different spectral sensitivities of the image sensors. Having different spectral sensitivities on one image sensor can be achieved by assigning the sensor pixels to different sensor filters.The image sensor can, for example, be designed as an RGB sensor, which includes a first spectral sensitivity in the blue visible spectrum, a second spectral sensitivity in the green visible spectrum, and a third spectral sensitivity in the red visible spectrum.

[0021] It is conceivable that all image sensors in the imaging branches have the same spectral sensitivities. However, the spectral resolution of the imaging device can be further increased by using a number of different spectral sensitivities for the various image sensors. It is therefore proposed that at least one image sensor in the imaging branches has at least one spectral sensitivity that differs from the spectral sensitivity of another image sensor in the imaging branches. Preferably, the spectral sensitivities of all image sensors are different from each other.

[0022] It is proposed that the imaging channel for capturing at least one of the partial images of the imaging branches comprises at least one camera, which is arranged in a proximal and, in particular, extracorporeal end section of the shaft. Additional image features can advantageously be captured using the separate camera. An "end section" is understood to mean, in particular, a section that extends from one end of a component towards the center of the component. To particularly increase spectral resolution, it is proposed that the camera be configured as a multispectral and / or hyperspectral camera. Preferably, the camera operates according to the spatial scanning principle; however, other imaging principles known to those skilled in the art are also conceivable.

[0023] It is further proposed that the imaging device comprises at least one light source which, in at least one operating state, illuminates a study area to be imaged with at least one illumination spectrum. Since the illumination spectrum is known, it can be included in the evaluation, thereby improving the information content of the evaluation. The light from the light source specifically strikes the study area to be imaged and is at least partially absorbed, transmitted, or reflected there. The absorbed portion of the light from the light source can be re-emitted by the study area, at least partially, in the form of fluorescence and / or phosphorescence. Using the imaging device, at least a reflected portion of the light from the light source and / or fluorescence and / or phosphorescence emitted by the study area can be used to image the study area.It is also conceivable to detect the transmitted portion with the present imaging device. The light source can be a broadband light source, a white light source, a laser light source, or the like. The light source can have at least one and preferably several light elements, such as LEDs, OLEDs, lasers, or the like. The illumination spectrum of the light source could be variable over time, e.g., by switching off and / or adding different light elements. The light source includes at least one light element that generates white light. "White light" is understood to mean, in particular, polychromatic light that corresponds, at least in its essential part, to the daylight spectrum, at least in the visible spectral range. The visible spectral range extends, in particular, between 380 nm and 780 nm.

[0024] It is proposed that the light source emits illumination light with a spectrum broader than at least one spectral range of the partial images of the imaging branches. Advantageously, the entire spectrum relevant for spectral analysis can be covered by a single light source. The light source can, in particular, emit at least two, and preferably more, different illumination lights. These can be distinguished by their spectral emission characteristics. The light source comprises, in particular, at least one light source element. Preferably, the light source comprises at least two, and more preferably, more light source elements. The light source element can be an LED, OLED, laser diode, or the like. The light source elements can be distinguished from one another by the illumination light they provide.

[0025] Alternatively or additionally, it is proposed that the light source emits illumination light which comprises at least one illumination spectrum that lies within at least one spectral range of the partial images of the imaging branches. A particularly sharp spectral resolution can advantageously be achieved.

[0026] It is further proposed that the imaging device comprise at least one additional imaging channel. This can advantageously increase the information content of the spectral imaging, since, in particular, the combination of information from the imaging channel and the additional imaging channel allows for the acquisition of stereoscopic information in addition to the spectral information. The imaging channel and the additional imaging channel differ at least by a portion of an area examined by the endoscopic and / or exoscopic imaging device, as recorded by the respective imaging channel. The imaging channel and the additional imaging channel are arranged offset from each other, preferably at least substantially perpendicular to the central axes of the respective imaging channels.

[0027] Furthermore, the imaging channel and the further imaging path can have different viewing directions; for example, the imaging channels can be arranged in a click-like arrangement relative to each other. Preferably, however, the imaging channel and the further imaging channel are arranged at least substantially parallel to each other. In particular, the imaging device could have a plurality of imaging channels, which could differ from each other by at least one viewing direction and / or be arranged offset from each other.

[0028] Furthermore, it is proposed that the image channels be differentiated from one another at least by the spectral selectivity of at least one spectrally selective beam splitter of their imaging branches and / or by the spectral sensitivity of at least one image sensor of their image branches. Advantageously, the spectral resolution can be further increased. The images and spectral information obtained from the different image channels can be used to generate a stereoscopic and spectrally resolved image. In particular, the spectral information can be matched to the stereoscopic information.

[0029] It is proposed that the imaging channel and the additional imaging channel be arranged in a mirror-symmetrical configuration. This advantageously results in a particularly compact arrangement of the imaging channels. In particular, the image sensors of the imaging channel and the additional imaging channel are arranged on the same circuit board, preferably in a mirror-symmetrical configuration.

[0030] In a further aspect of the invention, which can be considered both alone and in combination with the foregoing, it is proposed that the imaging device comprises at least one further imaging channel, which is free of relay optics. This advantageously provides a stereo imaging device that is also suitable for endoscopes with small shaft diameters. In particular, the further imaging channel comprises at least one further lens and an image sensor arranged upstream of the lens. Furthermore, the further imaging channel can include a mirror and / or a beam splitter, which deflects at least partially, preferably at least a large part, and particularly preferably completely, the light entering through the lens. The beam splitter is, in particular, a spectrally selective beam splitter.

[0031] Furthermore, it is proposed that the shaft be substantially filled, at least in sections, by the imaging channel. Advantageously, the shaft diameter can be reduced, as it only needs to be adapted to the dimensions of the imaging channel and not the rest of the imaging channel. The phrase "several sections of the shaft being substantially filled" means, in particular, that the shaft has at least one section, for example, a middle section, between the distal and proximal end sections, in which the imaging channel fills at least 50%, preferably at least 65%, and particularly preferably at least 80% of its volume.

[0032] In order to be able to use different imaging methods simultaneously, it is further proposed that the imaging channel be set up for multispectral or hyperspectral imaging and the other imaging channel be set up for white light imaging.

[0033] Furthermore, it is proposed that the imaging device include a control unit configured to match at least one multispectral and / or hyperspectral image acquired by the imaging channel with at least one white light image acquired by the other imaging channel. This enables the digital creation of multispectral and / or hyperspectral stereo imaging. Such matching of the white light image and the multispectral or hyperspectral image can be performed using a matching algorithm stored in the control unit. This algorithm can, for example, be based on image stabilization, feature tracking, marker tracking, or similar methods.

[0034] Furthermore, it is proposed that at least one temperature sensor be arranged in a distal end section of the shaft, which is configured for temperature-dependent control of at least the imaging channel. Advantageously, a temperature increase generated by distal electronics can be monitored, and by selectively activating and / or deactivating the electronics, such as the image sensors, the exceeding of a limit temperature, which could lead to injuries to a patient and / or damage to the imaging device, can be avoided. Furthermore, the temperature sensor can be configured as an alternative or additional method for temperature-dependent control of the other imaging channel. For this purpose, the temperature sensor is coupled to the control unit. In particular, the limit temperature to be observed also determines an irradiation time to be observed for the light source.

[0035] It is further proposed that at least one motion sensor be arranged in a distal end section of the shaft, which is configured for motion-dependent control of at least the imaging channel. The motion sensor is designed to register a constant position of the imaging device during image acquisition. In particular, if movement is detected, a message is sent to the control unit and the acquisition is stopped. Furthermore, it is conceivable that movement is recorded by the motion sensor and that the imaging is corrected based on this detected movement.

[0036] Furthermore, an endoscope and / or exoscope with at least one such endoscopic and / or exoscopic imaging device is proposed. This advantageously reduces the installation space required for a multispectral and, in particular, hyperspectral endoscopic and / or exoscopic imaging device.

[0037] The imaging device, the endoscope and / or exoscope, and / or a method for its operation shall not be limited to the application and embodiment described above. In particular, the imaging device, the endoscope and / or exoscope, and / or the method for its operation may, to achieve a functionality described herein, comprise a different number of individual elements, components, units, and process steps than those specified herein. Furthermore, values ​​within the specified limits of the value ranges stated in this disclosure shall also be considered disclosed and freely usable.

[0038] If more than one instance of a particular component exists, only one of them is identified with a reference symbol in the figures and description. The description of this instance can be applied accordingly to the other instances of the component. Drawings

[0039] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0040] They show: Fig. 1 a schematic representation of an imaging device in a perspective view, Fig. 2 a schematic representation of a part of the imaging device in a sectional view, Fig. 3 a schematic representation of the setup of a camera of the imaging device, Fig. 4 a schematic diagram representing the spectral properties of a light source of the imaging device, Fig. 5 a schematic diagram representing exemplary spectral properties of an investigation area to be imaged by means of the imaging device, Fig. 6 a schematic diagram in which optical properties of beam splitters of the imaging device are ideally represented, Fig. 7 a schematic diagram in which further optical properties of beam splitters of the imaging device are ideally represented, Fig.Fig. 8 A schematic diagram showing the detection properties of the image sensors of the imaging device, Fig. 9 A schematic diagram showing the spectral sensitivities of the image sensors, Fig. 10 A schematic diagram showing the spectral sensitivities of the image sensors, Fig. 11 A schematic diagram showing the spectral sensitivities of the image sensors, Fig. 12 A schematic flow chart of an exemplary method for operating the endoscopic imaging device, Fig. 13 A schematic representation of an exoscopic imaging device in a perspective view, Fig. 14 A schematic diagram showing the optical properties of an alternative imaging device, Fig. 15 A schematic diagram showing the optical properties of a further embodiment of another endoscopic and / or exoscopic imaging device.Fig. 16 a schematic representation of an alternative endoscopic and / or exoscopic imaging device in a sectional view, Fig. 17 a schematic representation of an alternative endoscopic and / or exoscopic imaging device in a sectional view, Fig. 18 a schematic representation of another alternative endoscopic and / or exoscopic imaging device in a sectional view, and Fig. 19 a schematic representation of a spectral division of an optical image acquired with the imaging device into partial images. Description of the exemplary implementations

[0041] Fig. 1Figure 1 shows a schematic representation of an endoscopic imaging device 10 in a perspective view. The endoscopic imaging device 10 forms a complete endoscope 12. Alternatively, the endoscopic imaging device could form only a functional component of an endoscope. Alternatively or additionally, the imaging device described herein could also be an exoscopic imaging device. Such an exoscopic imaging device could form a complete exoscope or only a functional component of the exoscope. It is also conceivable that the same device could be suitable for both exoscopic and endoscopic use. In particular, the following description is also applicable to an exoscopic imaging device 10.

[0042] The endoscopic imaging device 10 is configured for spectral imaging. In this case, the endoscopic imaging device 10 is configured at least for multispectral imaging. Furthermore, the endoscopic imaging device 10 can even be configured for hyperspectral imaging. The endoscopic imaging device 10 is configured to image at least one examination area in a single operating state. In this case, the examination area is tissue, for example, of a body part. The examination area can be located inside a body. For this purpose, the endoscopic imaging device 10 is configured to be at least partially positioned in a cavity.

[0043] The imaging device 10 includes a control unit 102. The control unit 102 is configured to control other functional components of the endoscopic imaging device 10. The control unit 102 includes control electronics (not shown). The control electronics comprise a processor. Furthermore, the control electronics have a memory. A program for operating the endoscopic imaging device 10 is stored in the memory. The processor is configured to execute the program for operating the endoscopic imaging device 10. In this case, the control unit 102 is arranged in a common housing with other components of the endoscopic imaging device 10. Alternatively, however, the control unit could be designed as a separate control device.

[0044] The endoscopic imaging device 10 has a shaft 106. The shaft 106 is designed as an elongated component. The shaft 106 has a central axis 108 (see figure). Fig. 2A main extension 110 of the overshaft 106 runs along the central axis 108. A cross-section of the overshaft 106 perpendicular to its central axis 108 has a diameter that is significantly smaller than the main extension 110 of the overshaft 106. The diameter is at least twice as small as the main extension 110. In the present case, the diameter is even at least five times smaller than the main extension 110. The overshaft 106 is tubular in shape. The overshaft 106 is made of metal. For example, the overshaft can be made of steel, titanium, chromium, or the like. The overshaft 106 has a distal end section 112. Furthermore, the overshaft 106 has a proximal end section 114. The Überschafft 106 is designed to be inserted into a cavity in an operational state through a naturally or artificially created opening, such as a body opening.

[0045] Fig. 2Figure 1 shows a schematic representation of a part of the endoscopic imaging device 10 in a sectional view. The endoscopic imaging device 10 has at least one shaft 16. The shaft 16 is arranged within the super-shaft 106. In this case, the shaft 16 is designed as an elongated component. The shaft 16 has a central axis 84. A principal extent 118 of the shaft 16 extends along the central axis 84. A cross-section of the shaft 16 perpendicular to its central axis 84 has a diameter that is significantly smaller than the principal extent 118 of the shaft 16. The diameter is at least twice as small as the principal extent 118. In this case, the diameter is even at least five times smaller than the principal extent 118. The shaft 16 is tubular. The shaft 16 is made of metal.For example, the shaft 16 can be made of steel, titanium, chromium, or the like. The shaft 16 has a distal end section 120. Furthermore, the shaft 16 has a proximal end section 121.

[0046] The endoscopic imaging device 10 has at least one imaging channel 18. The imaging channel 18 is arranged at least partially in the shaft 16. The imaging channel 18 is configured to transmit an optical image 24 of an examination area 138 to be imaged at least partially along the shaft 16.

[0047] The imaging channel 18 has a lens 122. The lens 122 is at least partially arranged in the shaft 16. The lens 122 is located in the distal end section 120 of the shaft 16. The lens 122 is configured to generate an optical image 24 of the area under investigation. The lens 122 has an object plane 124. In an operating state, the area under investigation is located in the object plane 124. The lens 122 also has an image plane 126. The lens 122 projects an optical image 24 of the area under investigation, located in the object plane 124, onto the image plane 126.

[0048] The imaging channel 18 has a first imaging branch 20. The first imaging branch 20 is at least partially arranged in the shaft 16. In the present case, the first imaging branch 20 is completely arranged in the shaft 16. The first imaging branch 20 is located upstream of the lens 122 in terms of light flow.

[0049] The first imaging branch 20 has at least one first spectrally selective beam splitter 22. The first spectrally selective beam splitter 22 divides the optical image 24 of the investigation area into at least one first spectral partial image 26 of a first spectral range 28 and at least one further first spectral partial image 30 of a further first spectral range 32. The partial images 26, 30 and the spectral ranges 28, 32 are in the Figure 6 and 7 The following are shown, which will be described in more detail below. Optical figure 24 and the sub-figures are in Fig. 19The first spectral range 28 is different from the second first spectral range 32. The first spectrally selective beam splitter 22 deflects the first spectral partial image 26, in this case by 90°. The second first spectral partial image 30 passes through the first spectral beam splitter 22 in the same direction. It is conceivable that the spectral ranges could be variable by controlling the beam splitter. For example, the angle of a reflection plane of the beam splitter relative to the incident light beam or to the central axis 84 could be varied to achieve this. In this case, however, the angle of the reflection plane of the first spectral beam splitter 22 is fixed. The angle is 45° to the incident light beam or to the central axis 84 of the shaft 16.

[0050] The first imaging branch 20 has at least one first image sensor 34. The first image sensor 34 is configured to detect the first spectral partial image 26. By deflecting the first spectrally selective beam splitter 22, the first spectral partial image 26 is directed onto the first image sensor 34. The first image sensor 34 lies in an image plane of the first spectral partial image 26. Thus, the first spectral partial image 26 is sharply imaged onto the first image sensor 34. The first image sensor 34 has a sensor plane 82. The sensor plane 82 is arranged at least substantially parallel to the central axis 84 of the shaft 16.

[0051] To transmit the further first partial image 30, the first imaging branch 20 has at least one first relay optic 36. The first relay optic 36 is connected upstream of the first selective beam splitter 22. The first relay optic 36 images the further first partial image 30 from an object plane 128 of the first relay optic into an image plane 54. The objective 122 and the first relay optic 36 are arranged one behind the other, so that the image plane 126 of the objective 122 is identical to the object plane 128 of the first relay optic 36. In this way, the first relay optic 36 transmits the further first partial image 30 true to scale. The first relay optic 36 has a pair of rod lenses 130. Furthermore, the first relay optic 36 has two achromats, apochromats, or the like (not shown). These can be arranged between the pair of rod lenses.These methods can reduce chromatic aberrations, which are further amplified due to the cascade-like arrangement of several imaging branches described below.

[0052] The first spectrally selective beam splitter 22 is arranged between the objective 122 and the first relay optic 36 of the first imaging branch 20. More precisely, the first spectrally selective beam splitter 22 is arranged between the objective 122 and the image plane 126 of the objective 122 or the object plane 128 of the first relay optic 36.

[0053] The first image sensor 34 is arranged between the lens 122 and the first relay optic 36 of the first imaging branch 20. More precisely, the first image sensor 34 is arranged between the lens 122 and the image plane 126 of the lens 122 or the object plane 128 of the first relay optic 36. The first image sensor 34 is connected upstream of the first spectrally selective beam splitter 22. The first spectrally selective beam splitter 22 and the first image sensor 34 are arranged such that an optical path through the first spectrally selective beam splitter 22 to the first image sensor 34 corresponds to an optical path through the first spectrally selective beam splitter 22 to the image plane 126 of the lens 122 or the object plane 128 of the first relay optic 36.

[0054] The first imaging branch 20 has at least one first additional optical component 80. A refractive index and / or a material of the first additional optical component 80 corresponds at least substantially to a refractive index and / or a material of the first spectrally selective beam splitter 22. The first additional optical component 80 is arranged between the objective 122 and the first relay optics 36. More precisely, the first additional optical component 80 is arranged between the first spectrally selective beam splitter 22 and the first relay optics 36. The additional optical component 80 is arranged such that the image plane 126 of the objective 122 or the object plane 128 of the first relay optics 36 lies between the first additional optical component 80 and the first spectrally selective beam splitter 22.The first spectrally selective beam splitter 22 and the first further optical component 80 are arranged in a mirror-symmetrical manner with respect to the identical image plane 126 of the objective 122 and the object plane 128 of the first relay optics 36. In this case, the first further optical component 80 is formed or connected integrally with the first spectrally selective beam splitter 22. For example, the beam splitter and the further optical component could be glued or cemented together. Furthermore, it is conceivable that the beam splitter and the further optical component are at least partially manufactured in one piece from a single blank. Alternatively, the further optical component and the beam splitter could also be formed separately from each other.

[0055] In the present case, imaging channel 18 has several imaging branches 20, 36, 58, specifically, for example, a first imaging branch 20, a second imaging branch 38, and a third imaging branch 58. The imaging branches 20, 38, and 58 are essentially identical in this case, except for their spectral properties. Therefore, the following discussion focuses solely on the specific arrangement of the imaging branches 20, 38, and 58 and their components relative to one another. Unless otherwise stated, a description of the components of imaging branch 20 is applicable to the components of imaging branches 38 and 58. Although the imaging channel 18 in this embodiment has a total of three imaging branches, it is conceivable that the number can be adjusted and, in particular, increased in a manner that is obvious to a person skilled in the art, in order to increase the number of spectral characteristics that can be determined with the imaging branches 20, 38, 58.This could improve the spectral resolution of the device.

[0056] The imaging channel 18 has at least one second imaging branch 38. The second imaging branch 38 is at least partially arranged in the shaft 16. In the present case, the second imaging branch 38 is completely arranged in the shaft 16. Furthermore, the second imaging branch 38 is connected upstream of the first imaging branch 20 in terms of light flow. The first imaging branch 20 is also arranged between the lens 122 and the second imaging branch 38.

[0057] The second imaging branch 38 has at least one second spectrally selective beam splitter 40. The second spectrally selective beam splitter 40 differs in its optical properties from the first spectrally selective beam splitter 22. The second spectrally selective beam splitter 40 spectrally selectively divides the further first partial image 30 into at least one second spectral partial image 42 of a second spectral range 44 and at least one further second spectral partial image 46 of a further second spectral range 48. The second spectral range 44 is different from the further second spectral range 48 (cf. Fig. 3, 4 and 5 The second spectrally selective beam splitter 40 deflects the second spectral partial image 42, in this case by 90°. The further second spectral partial image 46 passes through the second spectrally selective beam splitter 40 in the same direction.

[0058] The second imaging branch 38 has at least one second image sensor 50. The second image sensor 50 is configured to detect the second spectral partial image 42. By deflecting the second spectrally selective beam splitter 40, the second spectral partial image 42 is directed onto the second image sensor 50. The second image sensor 50 lies in an image plane of the first spectral partial image 26. The second image sensor 50 has a sensor plane 82. The sensor plane 82 is arranged at least substantially parallel to the central axis 84 of the shaft 16.

[0059] To transmit the second partial image 46, the second imaging branch 38 has at least one second relay optic 52. The second relay optic 52 is connected upstream of the second selective beam splitter 40. The second relay optic 52 has an object plane 56. Furthermore, the second relay optic 52 has an image plane 74. The first relay optic 36 and the second relay optic 52 are arranged one behind the other, such that the image plane 54 of the first relay optic 36 is identical to the object plane 56 of the second relay optic 52. In this way, the second relay optic 52 transmits the second partial image 30 true to scale.

[0060] The second spectrally selective beam splitter 40 is arranged between the first relay optic 36 and the second relay optic 52 of the second imaging branch 38. More precisely, the second spectrally selective beam splitter 40 is arranged between the first relay optic 36 and the image plane 54 of the first relay optic 36 or the object plane 56 of the second relay optic 52.

[0061] The second image sensor 50 is arranged between the first relay optic 36 and the second relay optic 52 of the second imaging branch 38. More precisely, the second image sensor 50 is arranged between the first relay optic 36 and the image plane 54 of the first relay optic 36 or the object plane 56 of the second relay optic 52. The second image sensor 50 is connected upstream of the second spectrally selective beam splitter 40. The second spectrally selective beam splitter 40 and the second image sensor 50 are arranged such that an optical path through the second spectrally selective beam splitter 40 to the second image sensor 50 corresponds to an optical path through the second spectrally selective beam splitter 40 to the image plane 54 of the first relay optic 36 or the object plane 56 of the second relay optic 52.

[0062] The second imaging branch 38 comprises at least one further optical component 132. A refractive index and / or a material of the second further optical component 132 corresponds at least substantially to a refractive index and / or a material of the second spectrally selective beam splitter 40. The second further optical component 132 is arranged between the first relay optic 36 and the second relay optic 52. More precisely, the second further optical component 132 is arranged between the second beam splitter 40 and the second relay optic 52. The second further optical component 132 is arranged such that the image plane 54 of the first relay optic 36 and the object plane 56 of the second relay optic 52 lie between the second further optical component 132 and the second spectrally selective beam splitter 40.The second spectrally selective beam splitter 40 and the second additional optical component are arranged in a mirror-symmetrical manner with respect to the identical image plane 54 of the first relay optic 36 and object plane 56 of the second relay optic 52. In the present case, the second additional optical component 132 is at least partially formed integrally with or connected to the second beam splitter 40.

[0063] The imaging channel 18 has at least one third imaging branch 58. The third imaging branch 58 is at least partially located in the shaft 16. In this case, the third imaging branch 58 is completely located in the shaft 16. The third imaging branch 58 is located upstream of the second imaging branch 38 in terms of light flow. In other words, the second imaging branch 38 is located between the first imaging branch 20 and the third imaging branch 58.

[0064] The third imaging branch 58 has at least one third spectrally selective beam splitter 60. The third spectrally selective beam splitter 60 differs in its optical properties from the first spectrally selective beam splitter 20. Furthermore, the third spectrally selective beam splitter 60 differs in its optical properties from the second spectrally selective beam splitter 40. The third spectrally selective beam splitter 60 spectrally selectively divides the further second partial image 46 into at least one third spectral partial image 62 of a third spectral range 64 and at least one further third spectral partial image 66 of a further third spectral range 68. The third spectral range 64 is different from the further third spectral range 68.

[0065] The third imaging branch 58 has at least one third image sensor 70. The third image sensor 70 is configured to detect the third spectral partial image 62. By deflecting the second spectrally selective beam splitter 40, the third spectral partial image 62 is directed onto the third image sensor 70. The third image sensor 70 lies in an image plane of the third spectral partial image 62. The third image sensor 70 has a sensor plane 82. The sensor plane 82 is arranged at least substantially parallel to the central axis 84 of the shaft 16.

[0066] To transmit the further third partial image 66, the third imaging branch 58 has at least one third relay optic 72. The third relay optic 72 is connected upstream of the third selective beam splitter 60. The third relay optic 72 has an object plane 76. Furthermore, the third relay optic 72 has an image plane 134. The third relay optic 72 and the second relay optic 52 are arranged one behind the other, such that the image plane 74 of the second relay optic 52 is identical to the object plane 76 of the third relay optic 72. In this way, the third relay optic 72 transmits the further third spectral partial image 66 true to scale. The third relay optic 72 has a pair of rod lenses 130.

[0067] The third spectrally selective beam splitter 60 is arranged between the second relay optic 52 and the third relay optic 72 of the third imaging branch 58. More precisely, the third spectrally selective beam splitter 60 is arranged between the second relay optic 52 and the image plane 74 of the second relay optic 52 or the object plane 76 of the third relay optic 72.

[0068] The third image sensor 70 is arranged between the second relay optic 52 and the third relay optic 72 of the third imaging branch 58. More precisely, the third image sensor 70 is arranged between the second relay optic 52 and the image plane 74 of the second relay optic 52 or the object plane 76 of the third relay optic 72. The third image sensor 70 is connected upstream of the third spectrally selective beam splitter 60. The third spectrally selective beam splitter 60 and the third image sensor 70 are arranged such that an optical path through the third spectrally selective beam splitter 60 to the third image sensor 70 corresponds to an optical path through the third spectrally selective beam splitter 60 to the image plane 74 of the second relay optic 52 or the object plane 76 of the third relay optic 72.

[0069] The third imaging branch 58 comprises at least one further optical component 136. A refractive index and / or a material of the third further optical component 136 corresponds at least substantially to a refractive index and / or a material of the third spectral-selective beam splitter 60. The third further optical component 136 is arranged between the second relay optic 52 and the third relay optic 72. More precisely, the third further optical component 136 is arranged between the third spectral-selective beam splitter 60 and the third relay optic 72. The third further optical component 136 is arranged such that the image plane 74 of the second relay optic 52 and the object plane 76 of the third relay optic 72 lie between the third further optical component 136 and the third spectral-selective beam splitter 60.The third spectrally selective beam splitter 60 and the third additional optical component 136 are arranged in a mirror-symmetrical manner with respect to the identical image plane and object plane of the second relay optic 52 and the third relay optic 72. In the present case, the second additional optical component 132 is at least partially formed integrally with or connected to the second beam splitter 40.

[0070] Imaging channel 18 has at least one printed circuit board 86. At least one of the image sensors 34, 50, 70 is arranged on the printed circuit board 86. In this case, all of the image sensors 34, 50, 70 are arranged on the printed circuit board 86. The printed circuit board 86 is designed as a PCB. Alternatively, such a printed circuit board could also be a flex print or the like.

[0071] The imaging device 10 has at least one light source 98. The light source 98 is controlled by the control unit 102. The light source 98 is arranged in a separate housing of the imaging device 10. The light source 98 emits illumination light in at least one operating state. The light source 98 has at least one luminaire 104. In this case, the luminaire 104 is designed as a white light lamp, in particular a xenon light source, which is, for example, equipped with filters to reduce the light bands known for xenon and to produce a homogeneous white light distribution. In one operating state, the light source 98 illuminates the area to be imaged by the imaging device 10 with the illumination light. The illumination light has an illumination spectrum 100 (see Figure 10). Fig. 4The light source could be, for example, an LED, OLED, laser (especially a diode laser), or similar device. The light source could also have multiple light sources, each with different emission characteristics. By individually controlling or switching such light sources on and / or off, the illumination spectrum could be varied. Alternatively, the light source could be a spectrally tunable light source, such as a tunable laser.

[0072] The imaging device 10 has at least one optical waveguide 116 (see below). Fig. 2In the present case, the imaging device 10 has several optical waveguides 116. For clarity, only one optical waveguide 116 is shown with a reference numeral in the drawings and described in more detail below. The optical waveguide 116 is configured to guide the illumination light provided by the light source 98 along the shaft 16 from a proximal end to a distal end in order to illuminate the area under investigation. The optical waveguide 116 is arranged within the overshaft 106. The optical waveguide 116 is located in an intermediate region between the shaft 16 and the overshaft 106. In this case, the optical waveguide 116 has several optical fibers (not shown). Individual optical fibers could be connected individually to individual lighting elements of the light source.Alternatively, one or more light elements of the light source could be arranged on the distal end section of the shaft, thus eliminating the need for optical fibers.

[0073] The imaging channel 18 has at least one camera 96 ​​for capturing at least one of the partial images 26, 30, 42, 46, 62, 66 of the imaging branches 20, 38, 58. The camera 96 ​​is arranged in a proximal, and in particular extracorporeal, end section 121 of the shaft 16 of the imaging device 10. The camera 96 ​​has a camera housing 168. Further components of the camera 96 ​​are arranged in the camera housing 168. In the present case, the camera 96 ​​is designed as a hyperspectral camera. Alternatively, however, the camera could be designed as a multispectral camera or a white light camera.

[0074] Fig. 3Figure 1 shows a schematic diagram of the camera 96. The camera 96 ​​has at least one input lens 170. The input lens 170 is located in the camera housing 168. The input lens 170 is connected upstream of the imaging branches 20, 38, and 58. The input lens 170 is connected downstream of the third imaging branch 58. The input lens 170 is located behind the third relay optic 72. The input lens 170 is configured to generate a partial image of the area under investigation in an image plane.

[0075] The camera 96 ​​has a spectrometer 172. The spectrometer 172 is connected to the control unit 102 for control purposes. The spectrometer 172 is located in the camera housing 168. The spectrometer 172 is positioned upstream of the input lens 170.

[0076] The spectrometer 172 has at least one aperture 174. The input lens 170 focuses the image onto the aperture 174. The aperture 174 is located in an image plane of the image produced by the input lens 170. The distance between the input lens 170 and the aperture 174 corresponds at least substantially to the image distance of the input lens 170. The aperture 174 lies in the image plane. The aperture 174 is configured to select a region of the image produced by the input lens 170. For this purpose, the aperture 174 has an opening. The opening has the form of a slit. A principal direction of extension of the opening defines a first direction. This first direction is at least substantially parallel to the image plane of the image produced by the input lens 170. The aperture 174 is designed to select a strip of the image which has a width of at least 15 µm and / or at most 30 µm.

[0077] The spectrometer 172 has an internal optic 176. The internal optic 176 is arranged upstream of the aperture 174. The internal optic 176 has at least one internal lens 178. This internal lens 178 is arranged upstream of the aperture 174. The distance between the internal lens 178 and the aperture 174 corresponds to the focal length of the internal lens 178. In this way, the internal lens 178 images the aperture 174 at infinity.

[0078] Furthermore, the spectrometer 172 has at least one dispersive element 180. The dispersive element 180 is arranged upstream of the internal lens 178. The dispersive element 180 is designed to disperse light in a wavelength-dependent manner. In this case, the dispersive element 180 is configured to disperse this light in a second direction. The second direction is at least substantially perpendicular to the main extent of the aperture of the diaphragm 174. For example, the dispersive element 180 could be a prism. In this case, the dispersive element 180 is designed as an optical grating, in particular a blaze grating.

[0079] The internal optics 176 includes at least one further internal lens 182. The further objective lens 182 is arranged upstream of the dispersive element 180. Thus, the dispersive element 180 is positioned between the internal lens 178 and the further internal lens 182. In other words, the dispersive element 180 is located within the internal optics 176. The distance between the further internal lens 182 and the dispersive element 180 corresponds to the focal length of the further internal lens 182. The further internal lens 182 is configured to focus the light dispersed by the dispersive element 180 sharply.

[0080] The spectrometer 172 has a camera image sensor 184. The camera image sensor 184 is connected to the control unit 102. The camera image sensor 184 is located upstream of the additional internal lens 182. In other words, the additional internal lens 182 is located between the dispersive element 180 and the camera image sensor 184. The camera image sensor 184 is a monochrome sensor. Such a monochrome sensor has only a single spectral sensitivity. The camera image sensor 184 is a two-dimensional CMOS camera image sensor. Alternatively, it could be a CCD camera image sensor.

[0081] The camera 96 ​​has an adjustment device 186. The adjustment device 186 is connected to the control unit 102. The adjustment device 186 is arranged in the camera housing 168. The adjustment device 186 is configured to adjust at least the aperture 174 relative to the input lens 170. In this case, the entire spectrometer 172 is adjusted relative to the input lens 170. The adjustment device 186 has at least one bearing. The bearing is configured to provide a movable mounting for the spectrometer 172 relative to the input lens 170. In this case, the bearing is designed as a linear bearing. For example, the bearing can include guide rails extending along the second direction. The adjustment device 186 also has an adjustment actuator for driving it. In this case, the adjustment actuator is designed as a linear actuator.For example, in order to achieve uniform adjustment, the adjustment actuator must be designed as a piezo actuator.

[0082] By adjusting the aperture 174 relative to the input lens 170, spectra can be recorded for different image sections of the area under investigation. By shifting the aperture, the entire area under investigation can be spectrally scanned, thus generating an image including spectral information.

[0083] Camera 96 ​​enables a higher spectral resolution representation of the examination area. However, the frame rate achieved with this technique can be relatively low compared to other methods. Camera 96 ​​is used in a detailed diagnostic procedure, for example, when color images acquired using image sensors in the imaging branches of the imaging channel need to be verified.

[0084] Fig. 4Figure 1 shows a schematic diagram representing the spectral properties of light source 98. The diagram includes an abscissa axis, on which wavelength is plotted. It also includes an ordinate axis, on which intensity is plotted. Furthermore, the diagram shows an illumination characteristic curve. The illumination characteristic curve 140 characterizes the illumination spectrum 100 of light source 98. In this case, the illumination characteristic curve 140 exhibits a shape characteristic of white light.

[0085] Fig. 5 Figure 1 shows a schematic diagram illustrating exemplary spectral properties of the study area. The diagram includes an abscissa axis, on which wavelength is plotted, and an ordinate axis, on which intensity is plotted.

[0086] The diagram shows a first spectral characteristic curve 142. The first spectral characteristic curve 142 characterizes the spectral properties of the area under investigation. In this case, the first spectral characteristic curve 142 shows a profile characteristic of adipose tissue.

[0087] The diagram also shows a second spectral characteristic curve 144. The second spectral characteristic curve 144 characterizes the spectral properties of the investigation area. In this case, the second spectral characteristic curve 144 shows a profile characteristic of aqueous tissue.

[0088] The diagram also shows a third spectral characteristic curve 146. This third spectral characteristic curve 146 characterizes the spectral properties of the area under investigation. In this case, the third spectral characteristic curve 146 exhibits a profile characteristic of deoxygenated tissue.

[0089] The diagram also shows a fourth spectral characteristic curve 148. The fourth spectral characteristic curve 148 characterizes the spectral properties of the study area. In this case, the fourth spectral characteristic curve 148 shows a course characteristic of oxygenated tissue.

[0090] The spectral properties of the tissue vary across the entire study area. Therefore, these properties can be used to infer the tissue type and / or tissue characteristics of the study area. In this case, spectral lines 142, 144, 146, and 148 represent reflection spectra of the study area. Alternatively, transmission spectra, fluorescence spectra, and / or phosphorescence spectra could also be used. This may depend on the operating mode. Depending on the operating mode, the response of the study area to the incident illumination light could be analyzed as reflection, transmission, fluorescence, and / or phosphorescence.

[0091] Fig. 6 Figure 1 shows a schematic diagram in which the optical properties of the beam splitters 22, 40, 60 of the imaging branches 20, 38, 58 of the imaging channel 18 are ideally represented (see Figure 1). Fig. 2 The diagram shows an abscissa axis. Wavelength is plotted on the abscissa axis. The diagram also shows an ordinate axis. Intensity is plotted on the ordinate axis. Transmission intensity is plotted on the ordinate axis. The transmission intensity describes the fraction of the light incident on beam splitters 22, 40, 60 that is transmitted by the beam splitters 22, 40, 60.

[0092] The diagram shows a first transmission characteristic 150. The first transmission characteristic 150 describes the spectral transmission behavior of the first spectrally selective beam splitter 22. The first transmission characteristic 150 characterizes the spectral partitioning of the image of the investigation area into the first spectral sub-image 26 and the further first spectral sub-image 30 by the first spectrally selective beam splitter 22. The first transmission characteristic 150 characterizes the spectral partitioning of an initial spectral response of the investigation area to the illumination light into the first spectral range 28 and the further first spectral range 32 by the first spectrally selective beam splitter 22. In the first spectral range 28, the transmission fraction is at most 25%. In this case, it is even at most 5%. In the further first spectral range 32, the transmission fraction is at least 75%. In this case, at least 95%.The first spectral range 28 and the second first spectral range 32 are separated by a slope in the transmission curve. This slope rises from the first spectral range 28 to the second first spectral range 32. The slope has an inflection point, which lies at approximately 540 nm. However, it is also conceivable that the spectral ranges could be interchanged. Furthermore, the transmission curve could define multiple spectral ranges that might be spectrally offset from one another.

[0093] The diagram shows a second transmission characteristic 152. The second transmission characteristic 152 describes the spectral transmission behavior of the second spectrally selective beam splitter 40. The second transmission characteristic 152 characterizes the spectral partitioning of the further first partial image 30 into the second spectral partial image 42 and the further second spectral partial image 46 by the second spectrally selective beam splitter 40. The second transmission characteristic 152 characterizes the spectral partitioning of the further first spectral range 32 into the second spectral range 44 and the further second spectral range 48 by the second spectrally selective beam splitter 40. In the second spectral range 44, the transmission fraction is at most 25%. In the present case, it is even at most 5%. In the further second spectral range 48, the transmission fraction is at least 75%. In this case, at least 95%.The second spectral range 44 and the further second spectral range 48 are separated by a slope in the transmission curve 152. The slope rises from the second spectral range 44 to the further second spectral range 48. The slope has an inflection point. The inflection point is located at approximately 680 nm. However, it is also conceivable that the spectral ranges could be interchanged. The transmission curve could also define several spectral ranges, which might be spectrally offset from each other.

[0094] The diagram shows a third transmission characteristic 154. The third transmission characteristic 154 describes the spectral transmission behavior of the third spectrally selective beam splitter 60. The third transmission characteristic 154 characterizes the spectral partitioning of the further second partial image 46 into the third spectral partial image 62 and the further third spectral partial image 66 by the third spectrally selective beam splitter 60. The third transmission characteristic 154 characterizes the spectral partitioning of the further second spectral range 48 into the third spectral range 64 and the further third spectral range 68 by the third spectrally selective beam splitter 60. In the third spectral range 64, the transmission fraction is at most 25%. In the present case, it is even at most 5%. In the further third spectral range 68, the transmission fraction is at least 75%. In this case, at least 95%.The third spectral range 64 and the second third spectral range 68 are separated by a slope in the third transmission curve 154. The slope rises from the third spectral range 64 to the second third spectral range 68. The slope has an inflection point. This inflection point is located at approximately 670 nm. However, it is also conceivable that the spectral ranges could be interchanged. Furthermore, the transmission curve could define several spectral ranges, which might be spectrally offset from one another.

[0095] Fig. 7Figure 1 shows a schematic diagram in which further optical properties of the beam splitters 22, 40, 60 of the imaging branches 20, 38, 58 of the imaging channel 18 are idealized. The diagram shows an abscissa axis. Wavelength is plotted on the abscissa axis. The diagram also shows an ordinate axis. Intensity is plotted on the ordinate axis. In the case of Fig. 7 A reflection intensity is plotted on the ordinate axis. The reflection fraction describes the proportion of light incident on beam splitters 22, 40, 60 that is reflected by the beam splitters 22, 40, 60. The reflection behavior of the beam splitters 22, 40, 60 is, with the exception of an absorption fraction which is approximately negligible, essentially complementary to the transmission behavior described above.

[0096] The diagram shows a first reflection characteristic 156. The first reflection characteristic 156 describes the spectral reflection behavior of the first spectrally selective beam splitter 22. The first reflection characteristic 156 characterizes the spectral partitioning of the image of the investigation area into the first spectral sub-image 26 and the further first spectral sub-image 30 by the first spectrally selective beam splitter 22. The first reflection characteristic 156 characterizes the spectral partitioning of an initial spectral response of the investigation area to the illumination light into the first spectral range 28 and the further first spectral range 32 by the first spectrally selective beam splitter 22. In the first spectral range 28, the reflection component is at least 75%. In this case, it is even at least 95%. In the further first spectral range 32, the reflection component is at most 25%. In the present case, it is at most 5%.The first spectral region 28 and the second first spectral region 32 are separated by a slope in the reflection characteristic curve 156. The slope drops from the first spectral region 28 to the second first spectral region 32. The slope has an inflection point. The inflection point is located at approximately 540 nm.

[0097] However, it is also conceivable that the spectral ranges could be interchanged. The transmission characteristic could also define several spectral ranges, which might be spectrally offset from each other.

[0098] The diagram shows a second reflection curve 158. The second reflection curve 158 describes the spectral reflection behavior of the second spectrally selective beam splitter 40. The second reflection curve 158 characterizes the spectral partitioning of the further first partial image 30 into the second spectral partial image 42 and the further second spectral partial image 46 by the second spectrally selective beam splitter 40. The second reflection curve 158 characterizes the spectral partitioning of the further first spectral range 32 into the second spectral range 44 and the further second spectral range 48 by the second spectrally selective beam splitter 40. In the second spectral range 44, the reflection component is at least 75%. In this case, it is even at least 95%. In the further second spectral range 48, the reflection component is at most 25%. In this particular case, at most 5%.The second spectral range 44 and the further second spectral range 48 are separated by a slope of the second reflection characteristic 158. This slope runs from the second spectral range 44 to the further second spectral range 48. The slope has an inflection point. This inflection point is located at approximately 680 nm. However, it is also conceivable that the spectral ranges could be interchanged. Furthermore, the transmission characteristic could define several spectral ranges, which might be spectrally offset from one another.

[0099] The diagram shows a third reflection curve 160. The third reflection curve 160 describes the spectral reflection behavior of the third spectrally selective beam splitter 60. The third reflection curve 160 characterizes the spectral partitioning of the further second partial image 46 into the third spectral partial image 62 and the further third spectral partial image 66 by the third spectrally selective beam splitter 60. The third reflection curve 160 characterizes the spectral partitioning of the further second spectral range 48 into the third spectral range 64 and the further third spectral range 68 by the third spectrally selective beam splitter 60. In the third spectral range 64, the reflection component is at least 75%. In this case, it is even at least 95%. In the further third spectral range 68, the reflection component is at most 25%. In this particular case, at most 5%.The third spectral range 64 and the second third spectral range 68 are separated by a slope in the third transmission curve 154. This slope descends from the third spectral range 64 to the second third spectral range 68. The slope has an inflection point, which lies at approximately 670 nm. However, it is also conceivable that the spectral ranges could be interchanged. Furthermore, the transmission curve could define multiple spectral ranges that might be spectrally offset from one another.

[0100] In this way, the beam splitters 20, 44, 60 divide the light of the image into respective partial images 22, 30, 42, 46, 62, 66 and their respective partial spectral ranges.

[0101] In Fig. 8The detection characteristics of image sensors 34, 50, and 70 are illustrated in a diagram. In this case, image sensors 34, 50, and 70 are essentially identical. Alternatively, the image sensors could be at least partially different and, for example, have different detection characteristics.

[0102] The diagram in Fig. 8 The diagram shows an abscissa axis. A wavelength is plotted on the abscissa axis. Furthermore, the diagram shows an ordinate axis. An intensity is plotted on the ordinate axis. In the case of Fig. 8 The signal intensity is plotted on the ordinate axis. This describes the signal strength with which a sensor detects light of a certain wavelength. The following section describes the properties of image sensors 34, 50, and 70 in more detail, using one of these sensors as an example. This description is applicable to the other image sensors 34, 50, and 70.

[0103] The first image sensor 34 has at least one first spectral sensitivity 88. The diagram shows a first sensitivity curve 162, which characterizes the first spectral sensitivity 88. The first spectral sensitivity 88 corresponds to a blue spectral band of an RGB sensor.

[0104] Furthermore, the first image sensor 34 has at least one second spectral sensitivity 90. The diagram shows a second sensitivity curve 164, which characterizes the second spectral sensitivity 90. The second spectral sensitivity 90 corresponds to a green spectral band of an RGB sensor.

[0105] Furthermore, the first image sensor 34 has at least one third spectral sensitivity 92. The diagram shows a third sensitivity curve 166, which characterizes the third spectral sensitivity 92. The third spectral sensitivity 92 corresponds to a red spectral band of an RGB sensor.

[0106] Alternatively, the spectral sensitivities could also exhibit a different spectral behavior. For example, this could represent the ultraviolet, near-infrared, and infrared spectral bands of a sensor.

[0107] In the Fig. 9, 10 , 11 The spectral sensitivities 88, 90, 92 of the image sensors 34, 50, 70 are shown within the partial spectral ranges assigned to the respective sensors. By comparing the Fig. 4 with the Fig. 9, 10 , 11It is evident that the illumination spectrum 100 encompasses a spectral range that is broader than at least one spectral range of the partial images 22, 30, 42, 46, 62, 66 of the imaging branches 20, 38, 58. In the present case, the illumination spectrum 100 is broader than the first spectral range 28, the second spectral range 44, and the third spectral range 64. During a measurement, the superposition of the spectral response of the investigation area with the spectral ranges 28, 44, 64 yields three reference points within each of the respective partial spectral ranges, which are used to analyze the nature and / or properties of the investigation area.

[0108] Fig. 12 Figure 1 shows a schematic flow chart of an exemplary, but unclaimed, method for operating the endoscopic imaging device 10. This can be directly transferred to the operation of an exoscopic device.

[0109] The procedure comprises at least one process step 200. In process step 200, the endoscopic device is aligned with a field of study. The light source 98 is activated. The light strikes the field of study. The light is at least partially reflected by the field of study. Furthermore, the light is at least partially absorbed and / or transmitted by the field of study. Additionally, the field of study may emit fluorescence or phosphorescence in response to the light. The light reflected or emitted by the field of study is captured by the endoscopic device. The light then enters the imaging channel 18. In the imaging channel, an image of the field of study is generated. This image is divided by the imaging branches 20, 38, 58 into partial images 22, 30, 42, 46, 62, 66 of respective partial spectral ranges.The partial images 22, 30, 42, 46, 62, 66 of the respective partial spectral ranges are acquired by the respective assigned image sensors 34, 50, 70. Image sensors 34, 50, 70 output 88, 90, 92 reference points according to their spectral sensitivities. The signals from image sensors 34, 50, 70 are transmitted to the control unit.

[0110] The procedure includes a further process step 202. In the further process step 202, the control unit 120 compares the support points with comparison values ​​stored in the memory, for example with curve profiles characteristic of different tissue types and / or properties, as in Fig. 5 The control unit 102 then assigns these support points to the different tissue types and / or properties based on the support points. This is done for each pixel or each RGB pixel group of a respective image sensor 34, 50, 70.

[0111] The procedure includes a further process step 204. In process step 204, the control unit 102 stores the assignment in a memory or outputs it by means of a color-coded image. A separate image can be output for each assignment of tissue property and / or type, or they can be displayed together in a single color-coded image. The individual images can be displayed simultaneously, individually, or, in particular, alternately. Furthermore, the acquisition, generation, and / or display of the color images takes place at a frame rate of at least 15 frames per second. Thus, a video is generated which is composed of the color images and advantageously depicts the examination area in real time.

[0112] The procedure comprises at least one further process step 206. In process step 206, the control unit 102 generates a white light image of the examination area by superimposing the partial images 22, 30, 42, 46, 62, 66. This examination area can be displayed separately from the individual image or color-coded image for assigning the tissue property and / or type. Alternatively or additionally, it is conceivable to display these together in a superimposed image. Furthermore, the white light image, individual images, and / or the combined color-coded image could be displayed alternately.

[0113] In the Figures 13 to 16Further embodiments of the invention are shown. The following descriptions and drawings are essentially limited to the differences between the embodiments, whereby, with regard to identically designated components, in particular components with the same reference numerals, reference is also generally made to the drawings and / or the description of the other embodiments, in particular the Figures 1 to 12 Reference is made to the following. To distinguish the embodiments, the letter a is the reference numeral of the embodiment in the Figures 1 to 12 recreated. In the exemplary embodiments of the Figures 13 to 18 is placed after the respective reference numeral to distinguish it from the preceding embodiment of the letters b, c, d, e, f and g.

[0114] Fig. 13Figure 1 shows a schematic representation of an exoscopic imaging device 10b in a perspective view. The present embodiment differs from the previous one primarily in the design of the shaft 16b. In the case of an exoscopic device, this shaft is not designed for insertion into a cavity. The exoscopic imaging device 10b forms a complete exoscope 14b. Alternatively, the exoscopic imaging device could only form a functional component of an exoscope. Using such an exoscopic design, multispectral and / or hyperspectral images can also be acquired from outside a cavity within an examination area of ​​the cavity.

[0115] Fig. 14Figure 10 shows optical properties of an alternative imaging device 10c. The present imaging device 10c differs from the preceding ones essentially by its differently designed image sensors 34c, 50c, 70c.

[0116] The imaging device 10c in this case has at least one imaging channel 18c. The imaging channel 18c comprises at least three imaging channels. In this case, the imaging channels have different image sensors 34c, 50c, 70c. The image sensors 34c, 50c, 70c have different spectral sensitivities 88c, 90c, 92c. Fig. 12 shows a diagram similar to the one of Fig. 7In the present case, however, the image sensors 34c, 50c, and 70c exhibit different spectral sensitivities: 88c, 90c, and 92c. In fact, each sensor has only one spectral sensitivity: 88c, 90c, and 92c. This prevents any overlap of the spectral sensitivities 88c, 90c, and 92c with respect to different sub-spectral ranges. However, it is also conceivable that the image sensors have multiple spectral sensitivities 88c, 90c, and 92c, all of which are different from one another.

[0117] The first image sensor 34c has a spectral sensitivity of at least 88c. The diagram shows a first sensitivity curve 162c, which characterizes the first spectral sensitivity 88c. The first spectral sensitivity 88c corresponds to a blue spectral band of an RGB sensor.

[0118] The second image sensor 50c has a spectral sensitivity of at least 90c. The diagram shows a second sensitivity curve 164c, which characterizes the second spectral sensitivity 90c. The second spectral sensitivity 90c corresponds to a green spectral band of an RGB sensor.

[0119] The third image sensor 70c has at least a spectral sensitivity of 92c. The diagram shows a third sensitivity curve 166c, which characterizes the third spectral sensitivity 92c. The third spectral sensitivity 92c corresponds to a red spectral band of an RGB sensor.

[0120] Fig. 15 Figure 10d shows optical properties of a further embodiment of a further endoscopic and / or exoscopic imaging device. The present embodiment differs from the previous one essentially in the design of the light source 98d.

[0121] The light source 98d emits illumination light which comprises at least one illumination spectrum 100d which lies within at least one spectral range 28d, 32d, 44d, 48d, 64d, 68d of partial images 22d, 30d, 42d, 46d, 62d, 66d of imaging branches 20d, 38d, 58d of an imaging channel 18d of the imaging device 10d (cf. Fig. 5, 6 The 100d illumination spectrum has a width that is smaller than the spectral range 28d, 32d, 44d, 48d, 64d, 68d of the partial image within which it lies. The light source can, for example, comprise one or more LEDs as a single light element, which can be operated individually, together, or alternately.

[0122] Fig. 15Figure 1 shows a schematic diagram representing the spectral properties of light source 98. The diagram includes an abscissa axis, on which wavelength is plotted. It also includes an ordinate axis, on which intensity is plotted. Furthermore, the diagram shows an illumination characteristic curve 140d of light source 98d. This illuminance characteristic curve 140d characterizes the illumination spectrum 100d of light source 98d. In this case, the illumination characteristic curve 140d exhibits a shape characteristic of an LED. The illumination characteristic curve 140d has several principal maxima, which can be used, for example, for the spectral analysis of adipose tissue, water content, oxygenation, deoxygenation, or similar processes.

[0123] Fig. 16Figure 1 shows a schematic representation of an alternative endoscopic and / or exoscopic imaging device 10e in a sectional view. The present imaging device 10e differs from the previous one essentially by the number of imaging channels 18e, 18'e.

[0124] In the present case, the imaging device 10e has at least one imaging channel 18e. Furthermore, the imaging device 10e has at least one additional imaging channel 18'e. In total, the imaging device 10e has two imaging channels 18e, 18'e. The same reference symbols are used for the components of the imaging channels below. To distinguish them, an apostrophe is placed after the reference symbols of the components of the additional imaging channel 18'e. The use of two imaging channels 18e, 18'e enables advantageous stereoscopic multi- and / or hyperspectral imaging. The spectral resolution can also be further increased by using multiple imaging channels. To further improve and / or increase spatial representation and / or spectral resolution, it is conceivable that the imaging device could have additional imaging channels.

[0125] Imaging channel 18e and the further imaging channel 18'e are arranged offset from each other. Imaging channels 18e and 18'e are arranged laterally offset from each other. Imaging channels 18e and 18'e are arranged substantially perpendicular to the central axes of their respective recording shafts. The central axes of imaging channels 18e and 18'e are at least substantially parallel to each other. The viewing directions of imaging channels 18e and 18'e are at least substantially parallel. Alternatively, the central axes of the imaging channels could also be arranged at an angle to each other. The viewing directions of the imaging channels could also be at an angle to each other.

[0126] Imaging channel 18e and further imaging channel 18'e are arranged symmetrically to each other. The imaging device 10e has a shaft 106e. Imaging channels 18e and 18'e are arranged together in a shaft 106e. The shaft 106e comprises a central axis 108e. Imaging channels 18e and 18'e are arranged symmetrically to this central axis 108e.

[0127] Imaging channels 18e and 18'e each have at least one imaging branch 20e, 38e, and 58e. In the present case, each imaging channel has three imaging branches 20e, 38e, and 58e. Imaging channels 18e and 18'e are at least partially different from one another. The imaging channels differ at least by the spectral selectivity of at least one spectral-selective beam splitter 22e, 40e, 60e, 22'e, 40'e, and 60'e of their imaging branches 20e, 38e, 58e, 20'e, 38'e, and 58'e. In the present case, the spectral selectivities of all further spectral-selective beam splitters 22'e, 40'e, 60'e of the further imaging channel 18'e are different from the spectral selectivities of all spectral-selective beam splitters 22e, 40e, 60e, of the imaging channel 18e.Furthermore, the imaging channels differ at least by a spectral sensitivity 88e, 90e, 92e of at least one image sensor 34e, 50e, 70e of their imaging branches 20e, 38e, 58e, 20'e, 38'e, 58'e. In the present case, the spectral sensitivities 88e, 90e, 92e of all further image sensors 34'e, 50'e, 70'e of the further imaging channel 18'e differ from the spectral sensitivities 88e, 90e, 92e of all spectrally selective beam splitters 22e, 40e, 60e of the imaging channel 18e.

[0128] Regarding this method, this design offers the advantage that different tissue properties and / or types can be assigned using the different imaging branches 20e, 38e, 58e, 20'e, 38'e, 58'e. To obtain a uniform representation, the different images can be matched, for example, by feature tracking, thus making the complete information available for a stereo image as well.

[0129] Fig. 17Figure 1 shows a schematic representation of another alternative endoscopic and / or exoscopic imaging device 10f in a sectional view. The present imaging device 10f differs from the previous one essentially in the design of the further imaging channel 18'f of the imaging device.

[0130] Imaging channel 18f is configured for multispectral or hyperspectral imaging. In contrast, the other imaging channel 18'f is configured for white light imaging. Because imaging channels 18f and 18'f are configured differently, for example, by using a different number of beam splitters, images acquired via these channels are coordinated when displayed together. This is achieved, for example, by digital amplification and / or adjustment of brightness and / or contrast.

[0131] The further imaging channel 18'f has a lens 122'f. The lens 122'f is at least partially arranged in the shaft 16'f. The lens 122'f is located in the distal end section 120'f of the shaft 16'f. The lens 122'f is configured to generate an optical image of the area under investigation. The lens 122'f has an object plane 124'f. In an operating state, the area under investigation is located in the object plane 124'f. The lens 122'f also has an image plane. The lens 122'f projects an optical image of the area under investigation, located in the object plane, onto the image plane.

[0132] The further imaging channel 18'f has a first imaging branch 20'f. The further first imaging branch 20'f is at least partially arranged in the shaft 16'. In the present case, the further first imaging branch 20'f is completely arranged in the shaft 16'f. The further first imaging branch 20'f is connected upstream of the lens 122'f in terms of light flow.

[0133] The further first imaging branch 20'f has at least one first spectrally selective beam splitter 22'f. The first spectrally selective beam splitter 22'f divides the optical image of the investigation area into at least one first spectral partial image of a first spectral range and at least one further first spectral partial image of a further first spectral range 32'f. The first spectrally selective beam splitter 22'f deflects the first spectral partial image, in this case by 90°. The further first spectral partial image passes through the first spectral beam splitter 22'f in the same direction. The first spectral partial image extends over a visible spectral range. The further first spectral partial image extends over the near-infrared range.

[0134] The further first imaging branch 20'f has at least one further first image sensor 34'f. The further first image sensor 34'f is configured to capture the first spectral partial image. By deflecting the first spectrally selective beam splitter 22'f, the first spectral partial image is directed onto the first image sensor. The first image sensor 34'f lies in an image plane of the first spectral partial image. Thus, a sharp image of the first spectral partial image is formed on the first image sensor 34'f.

[0135] However, the first imaging branch 20'f does not have a relay optic in this case. Therefore, the further imaging channel 18'f is also free of a relay optic.

[0136] Instead, the imaging channel 18'f has an optical fiber 188'f. The optical fiber 188'f is arranged in the shaft 16'f. To focus the partial image onto the optical fiber 188'f, the further first imaging branch 20'f includes a focusing lens 190'f. The focusing lens 190'f is arranged between the beam splitter 22'f and the optical fiber 188'f.

[0137] Furthermore, the imaging device 10'f includes a spectrometer 172'f. The spectrometer 172'f is configured to record a complete spectrum of the subsequent first partial image. The spectrometer 172'f is connected to the optical fiber.

[0138] The imaging device 10'f includes a control unit. The control unit is configured to match at least one multispectral and / or hyperspectral image acquired by imaging channel 18f with at least one white light image acquired by the other imaging channel 18'f. The control unit uses a matching algorithm for this purpose. In this case, feature tracking is used, but another algorithm can also be employed. Through this matching process, both white light and multispectral or hyperspectral stereo images or stereo videos can be generated, even though only one of the imaging channels 18f, 18'f is configured for white light imaging or multispectral and / or hyperspectral imaging, respectively.

[0139] The imaging device 10'f further comprises at least one temperature sensor 194f. The temperature sensor 194f is arranged in the distal end section 120'f of the shaft 16'f. The temperature sensor 194f is configured for temperature-dependent control of at least the imaging channels 18f, 18'f. By selectively activating and / or deactivating the electronics, such as the camera image sensors, exceeding a limit temperature can be avoided. Furthermore, the limit temperature also regulates the irradiation time to be observed for a light source of the imaging device 10f.

[0140] The imaging device 10'f has at least one motion sensor 196f. The motion sensor is located in a distal end section 120'f of the shaft 16'f. The motion sensor 196f is configured for motion-dependent control of at least the imaging channels 18f, 18'f. The motion sensor 196f is configured to register a constant position of the imaging device 10'f during image acquisition. If movement is detected, a message is sent to the control unit and the acquisition is stopped. Furthermore, movement can be recorded by means of the motion sensor 196f and the imaging can be corrected based on this detected movement.

[0141] The shaft 16'f has a distal end section 120'f, which is wider than a central section 192'f. Both the imaging channel 18'f and the further imaging channel 18'f are located in this distal end section 120'f. However, the central section 192'f is essentially filled by the imaging channel 18'f.

[0142] Fig. 18 Figure 1 shows a schematic representation of an additional alternative endoscopic and / or exoscopic imaging device 10g in a sectional view. The present imaging device 10g differs from the previous one essentially in the design of the further imaging channel 18'g of the imaging device 10'g.

[0143] In the present case, the further imaging channel 18'g has a first imaging branch 21'g instead of a first imaging branch. The imaging branch 21'g is essentially equivalent to one of the previously described imaging branches, except that instead of a beam splitter, it has a mirror which is configured to direct light onto an image sensor of the imaging branch 21'g. The imaging branch 21'f is also free of relay optics. Furthermore, the imaging branch 21'f is free of branches of an optical path. 10 Imaging device 48 Another second spectral range 12 endoscope 50 Second image sensor 14 Exoscope 52 Second relay optics 16 shaft 54 Image plane of the first relay optics 18 Imaging channel 20 Imaging branch 56 Object plane of the second relay optics 21 Imaging strand 58 Third imaging branch 22 Spectral-selective beam splitter 60 Third spectrally selective beam splitter 24 Optical imaging 62 Third spectral 26 First spectral partial image 64 Partial image of the third spectral range 28 First spectral range 66 A further third spectral 30 Further first partial illustration Partial illustration 32 Further first spectral range 68 Further third spectral range 34 First image sensor 70 Third image sensor 36 First relay optics 72 Third relay optics 38 Second imaging branch 74 Image plane of the second relay optics 40 The latter is a spectrally selective beam splitter. 76 Object plane of the third relay optics 42 Second spectral partial image 80 Additional optical component 44 Second spectral range 82 Sensor level 46 Further second spectral partial image 84 central axis of the shaft 86 Circuit board 128 Object plane of the first relay optics 88 Spectral sensitivity 130 Rod lens pair 90 Spectral sensitivity 132 Second additional optical component 92 Spectral sensitivity 96 camera 134 Image plane of the third relay optics 98 light source 136 Third additional optical component 100 Illumination spectrum 102 Control unit 138 Area of ​​investigation to be depicted 104 Lighting element 140 Lighting characteristic curve 106 Overhauled 142 First spectral characteristic curve 108 central axis of the shaft 144 Second spectral characteristic 110 Main extent of the jurisdiction 146 Third spectral characteristic 112 Distal end section of the overshaft 148 Fourth spectral characteristic 150 First transmission characteristic curve 114 Proximal end section of the overshaft 152 second transmission characteristic 116 optical fibers 118 Main extension of the shaft 154 Third transmission characteristic 120 Distal end section of the shaft 156 First reflection characteristic 158 Second reflection characteristic 121 Proximal end section of the shaft 160 Third reflection characteristic 122 lens 162 First sensitivity curve 124 Object plane of the lens 164 Second sensitivity curve 126 Image plane of the lens 166 Third sensitivity curve 186 Adjustment device 168 camera body 188 Light guiding chamfer 170 Entrance lens 190 Focusing lens 172 spectrometer 192 Middle section 174 Aperture 194 temperature sensor 176 Internal optics 196 motion sensor 178 Internal lens 200 Procedure step 180 Dispersive element 202 Procedure step 182 Additional internal lens 204 Procedure step 184 Camera image sensor 206 Procedure step

Claims

1. Endoscopic and / or exoscopic imaging apparatus (10) for spectral, in particular multispectral and / or hyperspectral, imaging for an endoscope (12) and / or an exoscope (14), having at least one shaft (16) and having at least one imaging channel (18) arranged at least partially in the shaft (16), which imaging channel has at least a first imaging branch (20) comprising at least a first spectrally selective beam splitter (22) which spectrally selectively divides an optical image (24) of an original spectral range (28, 32, 44, 48, 64, 68) into at least one first spectral partial image (26) of a first spectral range (28) and at least one further first spectral partial image (30) of a further first spectral range (32), the first spectral range (28) being different from the further first spectral range (32), and the first imaging branch (20) comprising a first image sensor (34) at least for capturing the first spectral partial image (26), and the first imaging branch (20) comprising at least a first relay optic (36) for transmitting the further first partial image (30), which relay optic has a rod lens pair (130), characterized in that the imaging channel (18) has at least a second imaging branch (38) comprising at least a second spectrally selective beam splitter (40) which spectrally selectively divides the further first partial image (30) of the further first spectral range (32) into at least one second spectral partial image (42) of a second spectral range (44) and at least one further second spectral partial image (46) of a further second spectral range (48), the second spectral range (44) being different from the further second spectral range (48), and the second imaging branch (38) comprising at least a second image sensor (50) at least for capturing the second spectral partial image (42), and the second imaging branch (38) comprising at least a second relay optic (52) for transmitting the further second partial image (46), which relay optic has a rod lens pair (130), the first relay optic (36) of the first imaging branch (20) and the second relay optic (52) of the second imaging branch (38) being arranged one behind the other, such that an image plane (54) of the first relay optic (36) is identical to an object plane (56) of the second relay optic (52).

2. Imaging apparatus (10) according to claim 1, characterized in that the imaging channel (18) has at least a third imaging branch (58) comprising at least a third spectrally selective beam splitter (60) which spectrally selectively divides the further second spectral partial image (46) of the further second spectral range into at least one third spectral partial image (62) of a third spectral range (64) and at least one further third spectral partial image (66) of a further third spectral range (68), the third spectral range (64) being different from the further third spectral range (68), and the third imaging branch (58) comprising at least a third image sensor (70) at least for capturing the third spectral partial image (62), and the third imaging branch (58) comprising at least a third relay optic (72) for transmitting the further third spectral partial image (66), the second relay optic (52) of the second imaging branch (38) and the third relay optic (72) of the third imaging branch (58) being arranged one behind the other, such that an image plane (74) of the second relay optic (52) is identical to an object plane (76) of the third relay optic (72).

3. Imaging apparatus (10) according to claim 1 or 2, characterized in that at least one spectrally selective beam splitter (22, 40, 60) and / or at least one image sensor (34, 50, 70) of the imaging branches (20, 38, 58) is arranged between two relay optics (36, 52, 72) of different imaging branches (20, 38, 58).

4. Imaging apparatus (10) according to any of the preceding claims, characterized in that at least one of the imaging branches (20, 38, 58) comprises at least one further optical component (80), the refractive index and / or material of which at least substantially matches a refractive index and / or a material of a spectrally selective beam splitter (22, 40, 60) of the corresponding imaging branch (20, 38, 58), and is arranged between two relay optics (36, 52, 72) of different imaging branches (20, 38, 58).

5. Imaging apparatus (10) according to any of the preceding claims, characterized in that at least one of the spectral ranges (28, 32, 44, 48, 64, 68) of the partial images (26, 30, 42, 46, 62, 66) of the imaging branches (20, 38, 58) encompasses shorter wavelengths than at least one other spectral range (28, 32, 44, 48, 64, 68) of the partial images (26, 30, 42, 46, 62, 66) of the imaging branches (20, 38, 58).

6. Imaging apparatus (10) according to any of the preceding claims, characterized in that at least one image sensor (34, 50, 70) of the imaging branches (20, 38, 58) has at least one spectral sensitivity (88, 90, 92) which is different from a spectral sensitivity (88, 90, 92) of another image sensor (34, 50, 70) of the imaging branches (20, 38, 58).

7. Imaging apparatus (10) according to any of the preceding claims, characterized in that at least one image sensor (34, 50, 70) or at least two image sensors (34, 50, 70) of the imaging branches (20, 38, 58) has / have at least a first spectral sensitivity (88) and at least a second spectral sensitivity (90), and in particular at least a third spectral sensitivity (92), depending on which this image sensor / these image sensors captures a partial image (26, 30, 42, 46, 62, 66) of the imaging branches (20, 38, 58).

8. Imaging apparatus (10) according to any of the preceding claims, characterized in that the imaging channel (18) for capturing at least one of the partial images (26, 30, 42, 46, 62, 66) of the imaging branches (20, 38, 58) has at least one camera (96) which is arranged on a proximal and in particular extracorporeal end portion (121) of the shaft (16) and is preferably in the form of a multispectral and / or hyperspectral camera.

9. Imaging apparatus (10) according to any of the preceding claims, characterized by at least one light source (98) which illuminates a region subject to investigation that is to be imaged with at least one illumination spectrum (100) in at least one operating state.

10. Imaging apparatus (10) according to claim 9, characterized in that the light source (98) emits illuminating light which encompasses an illumination spectrum (100) which is wider than at least one spectral range (28, 32, 44, 48, 64, 68) of the partial images (26, 30, 42, 46, 62, 66) of the imaging branches (20, 38, 58) and / or the light source (98) emits illuminating light which encompasses at least one illumination spectrum (100) which lies within at least one spectral range (28, 32, 44, 48, 64, 68) of the partial images (26, 30, 42, 46, 62, 66) of the imaging branches (20, 38, 58).

11. Imaging apparatus (10) according to any of the preceding claims, characterized by at least one further imaging channel (18'), in particular the imaging channel (18) and the further imaging channel (18') being arranged in a mirror-symmetrical manner relative to each other.

12. Imaging apparatus (10) according to claim 11, characterized in that the image channels (18, 18') differ from each other at least by a spectral selectivity of at least one spectrally selective beam splitter (22, 40, 60) of their imaging branches (20, 38, 58) and / or by a spectral sensitivity 88, 90, 92 of at least one image sensor (34, 50, 70) of their imaging branches (20, 38, 58).

13. Imaging apparatus (10) according to any of claims 1 to 12, characterized by at least one further imaging channel (18') which is free of a relay optic, in particular the imaging channel (18) being configured for multispectral and / or hyperspectral imaging and the further imaging channel (18') being configured for white light imaging.

14. Imaging apparatus (10) according to claim 13, characterized by a control device (102) which is configured to match at least one multispectral and / or hyperspectral image received by the imaging channel (18) with at least one white light image received by the further imaging channel (18').

15. Imaging apparatus (10) according to any of the preceding claims, characterized in that at least one temperature sensor is arranged in a distal end portion (120) of the shaft (16), which temperature sensor is configured for temperature-dependent control of at least the imaging channel (18) and / or at least one motion sensor is arranged in a distal end portion (120) of the shaft (16), which motion sensor is configured for motion-dependent control of at least the imaging channel (18).

16. Endoscope (12) and / or exoscope (14) comprising at least one imaging apparatus (10) according to any of the preceding claims.