Medical imaging device, endoscope device, endoscope, and method for manufacturing medical imaging

Abstract

The invention relates to a medical imaging device (10) having a spectral camera (12) which is configured to capture a hyperspectral image. The spectral camera (12) comprises optics (14) configured to spectrally separate incident light by diffraction with respect to a spatial axis (16), and image acquisition sensing means (18) defining a light sensitive area (20) and arranged with respect to the optics (14), the light-sensitive region (20) extends along the spatial axis (16) and the spectrally separated light falls on the light-sensitive region (20). The image acquisition sensor (18) comprises a first image sensor (22) which is photosensitive in a first spectral range (24) and covers a first detection region (26) of the photosensitive region (20), and a second image sensor (28) which covers a second detection region (26) of the photosensitive region (20) in a second spectral range (24). The second image sensor is photosensitive in a second spectral range (30) different from the first spectral range (24) and covers a second detection region (32) of the photosensitive region (20) different from the first detection region (26), wherein the second image sensor (28) is arranged next to the first image sensor (22) with respect to the spatial axis (16). The first spectral range (24) and the second spectral range (30) together define an at least substantially continuous total spectral range (34) extending from the first wavelength (36) to the second wavelength (38), wherein the first wavelength (36) is located in the first spectral range (24). The invention further relates to an endoscopic device (74) having the imaging device (10), to an endoscope (76) having the endoscopic device (74), and to a method for producing a medical imaging device (10).

Description

Technical Field

[0001] The present invention relates to a medical imaging device, an endoscopic device, an endoscope and a method for manufacturing a medical imaging device. Background Art

[0002] Imaging devices that generate multispectral or hyperspectral images are known from the prior art, such as endoscopes, exoscopes, or microscopes. In addition to the two spatial dimensions (e.g., the spatial dimensions of a conventional camera image), multispectral or hyperspectral images also have a spectral dimension. The spectral dimension includes multiple spectral bands (wavelength bands). Multispectral and hyperspectral images differ primarily in the number and width of their spectral bands. Such systems are, in principle, also suitable for performing fluorescence imaging.

[0003] In particular, in the context of medical applications, some imaging devices are known for generating such multispectral or hyperspectral images. For example, DE 20 2014 010 558 U1 describes a device for capturing hyperspectral images of an examination area of ​​a body. Arranged in this device are an input objective for generating an image in an image plane and a slit-shaped aperture for shielding a slit-shaped area of ​​the image in the image plane. The light passing through the aperture is spread out by means of a dispersive element and captured by means of a camera sensor. This allows the camera sensor to capture a large number of spectra along the longitudinal direction of the slit-shaped aperture, each with correspondingly associated spatial coordinates. The device described is further configured to capture additional spectra along the longitudinal direction of the slit-shaped aperture in a direction different from the longitudinal direction of the slit-shaped aperture. The method for generating multispectral or hyperspectral images on which this disclosure is based is also known as a so-called push-scan method.

[0004] As described in DE 10 2020 105 458 A1, multispectral and hyperspectral imaging devices are particularly suitable as endoscopic imaging devices. In this context, multispectral and / or hyperspectral imaging is a fundamental application area, for example, for diagnosis and for assessing the success or quality of interventions.

[0005] The described apparatus and method utilize an image sensor that is sensitive in a specific spectral range, typically the visible and near-infrared range. Suitable dispersive elements direct the incident light to different locations on the image sensor, and thus to different pixels, depending on their wavelength. The wavelength of the light can then be derived from the pixel's location. The image sensor is typically arranged so that one direction of dispersion separation extends parallel to one of the image sensor's two image axes. One or more adjacent image rows or one or more adjacent image columns can then be interpreted as the spectrum of a pixel.

[0006] In hyperspectral cameras, optical gratings are often used as dispersive elements. The angle at which light of a specific wavelength is emitted is given by the known grating equation,

[0007]

[0008] where n is the order of the main maximum, λ is the wavelength, g is the grating constant, and φ_n is the deflection angle of the main maximum.

[0009] Based on the grating equation, higher-order maxima for short wavelengths coincide with lower-order maxima for longer wavelengths. For example, the first principal maximum for a given wavelength (e.g., 1000 nm) coincides with the second principal maximum at half the wavelength (e.g., 500 nm). Therefore, if a correspondingly large spectral range is observed, the actual wavelength cannot be reliably deduced based solely on the deflection angle or observation position. In practice, the spectral range captured by a hyperspectral camera is therefore correspondingly limited, for example, to the range from 500 nm to 1000 nm, so that no higher-order diffraction maxima occur. Summary of the Invention

[0010] Based on the prior art, the object of the present invention is to make hyperspectral imaging widely available.

[0011] According to the invention, this object is achieved by a medical imaging device, an endoscopic device, an endoscope and a method as described herein and defined in the claims.

[0012] A medical imaging device may be provided that includes a spectral camera configured to capture hyperspectral images. The spectral camera includes an optical system configured to spectrally separate incident light relative to a spatial axis by diffraction, and an image acquisition sensor system that defines a photosensitive region and is arranged relative to the optical system such that the photosensitive region extends along the spatial axis and the spectrally separated light falls on the photosensitive region. The image acquisition sensor system may include a first image sensor that is photosensitive in a first spectral range and covers a first detection area of ​​the photosensitive region. The image acquisition sensor system may also include a second image sensor that is photosensitive in a second spectral range that is different from the first spectral range and covers a second detection area of ​​the photosensitive region that is different from the first detection area, wherein the second image sensor is arranged adjacent to the first image sensor relative to the spatial axis. The first spectral range and the second spectral range may together define an at least substantially continuous total spectral range that extends from a first wavelength to a second wavelength, wherein the first wavelength is within the first spectral range.

[0013] Furthermore, an endoscopic device having an imaging device of this type may be provided.

[0014] Furthermore, an endoscope having such an endoscopic device may be provided.

[0015] Furthermore, a method for manufacturing a medical imaging device may be provided, wherein the imaging device may be an imaging device according to the present invention. The method includes providing an optical assembly configured to spectrally separate incident light and image the spectrally separated light onto a spatial axis. Furthermore, the method may include providing a first image sensor that is photosensitive in a first spectral range. Furthermore, the method may include providing a second image sensor that is photosensitive in a second spectral range that is different from the first spectral range, wherein the first spectral range and the second spectral range together define an at least substantially continuous total spectral range extending from a first wavelength to a second wavelength, wherein the first wavelength is within the first spectral range, wherein the second wavelength is within the second spectral range, and wherein the second wavelength is at least twice the size of the first wavelength. Furthermore, the method may include arranging the first image sensor and the second image sensor such that the second image sensor is located adjacent to the first image sensor relative to the spatial axis, and such that the first image sensor covers a first detection region of the photosensitive image area, and the second image sensor covers a second detection region of the photosensitive image area that is different from the first detection region.

[0016] Furthermore, a medical imaging device may be provided. The imaging device includes a spectral camera configured to capture hyperspectral images. The spectral camera includes an optical device and an image acquisition sensor mechanism. The optical device is configured to spectrally separate incident light relative to a spatial axis by diffraction. The image acquisition sensor mechanism defines a photosensitive region and is arranged relative to the optical device such that the photosensitive region extends along the spatial axis and the spectrally separated light falls on the photosensitive region, with different diffraction orders superimposed in subregions of the photosensitive region. The image acquisition sensor mechanism may be configured to acquire spatially resolved intensity information for at least two different color channels, which differ from each other in their wavelength-dependent sensitivity, such that at least second-order diffracted light can be detected with different intensities in the color channels. The imaging device may further include a processing unit configured to obtain spectral information based on the spatially resolved intensity information of the color channels, the spectral information describing a spectrum corrected for at least second-order diffracted light.

[0017] Furthermore, an endoscopic device having an imaging device of this type may be provided.

[0018] Furthermore, an endoscope having such an endoscopic device may be provided.

[0019] A method for imaging, in particular a method for imaging with the aid of a medical imaging device according to the present invention, may also be provided. The method comprises spectrally separating incident light relative to a spatial axis by diffraction. Furthermore, the method may comprise imaging the spectrally separated light onto an image acquisition sensor mechanism, the image acquisition sensor mechanism defining a photosensitive region and being arranged such that the photosensitive region extends along the spatial axis and the spectrally separated light falls on the photosensitive region, wherein different diffraction orders are superimposed in sub-regions of the photosensitive region. Furthermore, the method may comprise acquiring spatially resolved intensity information for at least two different color channels with the aid of the image acquisition sensor mechanism, which differ from one another in their wavelength-dependent sensitivity, such that at least second-order diffracted light can be detected with different intensities in the color channels. Furthermore, the method may comprise acquiring spectral information based on the spatially resolved intensity information of the color channels, the spectral information describing a correction spectrum corrected for at least second-order diffracted light over a spectral range.

[0020] The features of the present invention allow for widespread use of hyperspectral imaging. In particular, a large spectral range can be achieved that can be used for hyperspectral imaging. Despite the large available spectral range, the image acquisition sensor system used can also be constructed in a simple and / or inexpensive manner. The inventors have recognized that spectral ranges below 500 nm and / or above 1000 nm are also important for medical applications of hyperspectral imaging, and these additional spectral ranges should advantageously be available simultaneously. In particular, the inventors have determined that important tissue information related to tissue perfusion is available in the wavelength range between approximately 400 nm and 500 nm, provided that image data is acquired in this region in a suitable manner. The features of the present invention make it possible to distinguish between different orders of diffracted light, thereby allowing the spectrally separated object light to be comprehensively analyzed and used for hyperspectral imaging. This thus makes available spectral ranges that would otherwise require multiple different hyperspectral cameras. Accordingly, a compact design, low complexity, and high cost-effectiveness can be achieved.

[0021] Imaging devices can be configured for medical imaging. "Medical imaging" should be understood in particular as imaging that allows conclusions to be drawn about the physiological properties of the examination region, such as tissue type and / or tissue properties, such as fat content, water content, oxygenation, the presence of dyes, etc. Preferably, imaging uses spectral analysis to determine these physiological properties. The examination region is, in particular, a region comprising physiological components, such as tissue, blood, etc. The examination region is, for example, located within a natural or artificially created cavity. Examples of such cavities are the abdominal cavity, intestines, bladder, kidneys, etc. However, open tissue can also be used as the examination region. In some embodiments, the imaging device is configured to be introduced into a cavity for evaluation and / or observation, such as an artificial and / or natural cavity, such as the interior of the body, into a body organ, into tissue, etc. The imaging device can also be configured to be introduced into a housing, cannula, shaft, tube, or other (especially artificial) structure for evaluation and / or observation.

[0022] The recording process can be performed using an imaging device, in particular a spectral camera. A "recording process" is to be understood as a process for recording that includes at least one or more method steps. In a medical imaging recording process, a spectral image of the examination region or a subsection of a spectral image is recorded using a spectral camera.

[0023] The spectral camera can be a hyperspectral camera, in particular a push-broom spectral camera, or one that operates according to the push-broom principle. Spatial scanning or spatial scanning techniques are preferably used for capturing hyperspectral images. In particular, for capturing spectral images, the examination region is generated from individual subsegments in a plurality of recording steps, in particular by scanning the examination region in a temporally staggered, row-by-row manner. These subsegments can then be spectrally unfolded to provide information about the spatial and spectral dimensions. A spectral image can then be formed from these subsegments, which are then brought together along the other spatial dimensions for image construction. The spectral image is formed, in particular, from a data cube that includes the spatial dimension, other spatial dimensions, and the spectral dimension. In other words, the spectral camera, and in particular the image acquisition sensor, is configured to generate and / or capture image data that includes spatially and spectrally resolved information. The spatial and spectral information in the image data can make it possible to obtain associated spectra for a plurality of spatial pixels. The spectral camera can be spatially resolving in that it provides a resolution of at least 100 pixels, preferably at least 200 pixels, preferably at least 300 pixels and advantageously at least 400 pixels in each of at least two different spatial directions.

[0024] The spectral camera, and in particular the optical device and / or the image acquisition sensor system, can be configured for hyperspectral imaging, in particular for acquiring and / or generating hyperspectral image data. Hyperspectral imaging or hyperspectral image data may particularly refer to imaging in which at least 10, at least 20, at least 50, or even at least 100 spectral bands are acquired and / or can be acquired independently of one another. The spectral camera can operate according to the push-broom principle, the sweep principle, the staring principle, and / or the snapshot principle.

[0025] In some embodiments, the imaging device can additionally implement a stereoscopic imaging function, which can be used to capture additional three-dimensional spatial information. In this case, a hyperspectral image is formed using a four-dimensional hypercube, which includes the spatial dimension, other spatial dimensions, the spectral dimension, and the additional spatial dimension. This can be achieved, for example, by combining two spectral cameras that are offset relative to each other in their viewing direction.

[0026] The spectroscopic camera may be an endoscopic spectroscopic camera. An “endoscopic spectroscopic camera” is to be understood in particular as a spectroscopic camera that cooperates with, is connected or can be connected to, or is preferably formed integrally with an endoscope. Alternatively or additionally, the spectroscopic camera may be an exoscopic spectroscopic camera. An “exoscopic spectroscopic camera” is to be understood in particular as a spectroscopic camera that cooperates with, is connected or can be connected to, or is preferably formed integrally with an exoscopic camera. An “exoscopic” may also be understood in particular as a surgical microscope. However, an exoscopic is preferably to be understood as a surgical imaging device, in particular a surgical microscope, which does not have an eyepiece but preferably includes a camera device, which preferably has at least one white light camera.

[0027] In general, the imaging device can be a microscopic imaging device, a macroscopic imaging device, and / or an exoscopic imaging device. The imaging device can be configured as a microscope, a macroscope, and / or an exoscope and / or include such a microscope, a macroscope, and / or an exoscope. In some embodiments, the imaging device can be an endoscopic imaging device. The imaging device can be an endoscopic device. It can include an endoscope and / or an endoscopic system and / or be configured as such an endoscope and / or an endoscopic system and / or constitute at least a part and preferably at least a major part and / or a major component of such an endoscope and / or endoscopic system. "At least a major part" can mean at least 55%, preferably at least 65%, preferably at least 75%, particularly preferably at least 85%, and quite particularly preferably at least 95%, in particular with reference to the volume and / or mass of the object.

[0028] In some embodiments, the image acquisition unit is configured to generate continuously updated image data. For example, the image acquisition unit can be configured to generate image data substantially in real time, which can include, for example, generating updated image data every at least 30 seconds, in some cases every at least 20 seconds, and in some cases even at least every 10 seconds or at least every 5 seconds.

[0029] The imaging device may include and / or be connected to the lighting device, in particular in a detachable manner, the lighting device including at least one light-emitting element, which is configured to illuminate and / or illuminate the object to be imaged in at least one operating state. The light-emitting element may include a white light source, in particular a tunable monochromatic light source, a laser, a white light laser, at least one light-emitting diode and / or light-emitting diode array, at least one laser diode and / or laser diode array, etc. The lighting device may include a plurality of different light-emitting elements, which can be selectively activated. In particular, in different lighting modes, the illumination light can be provided by appropriately mixing and / or activating and / or deactivating one or more light-emitting elements.

[0030] The imaging device may include a control unit. The control unit may include suitable control electronics and / or a computer. In some embodiments, the control unit includes at least one processor, a computer-readable memory, an operating system, and / or suitable input and output units. The control unit may include at least one control program. In particular, its functions may be implemented by the control program or be part of the control program. The imaging device and in particular the control unit may accordingly include at least one processor and / or associated memory with program code that implements the described functions and steps, and / or associated working memory and / or associated ports and / or data interfaces and / or electronic circuits in order to implement the functional units mentioned herein and / or perform the method steps mentioned herein. One or more processors, memories, working memories, ports, data interfaces, and / or circuits may also be associated with one or more functional units and / or implement one or more method steps.

[0031] The imaging device may include an output unit configured to output to a user an output based on the hyperspectral image and / or a user output generated based on the output. The output unit may be configured to output a visual output and / or an audio output and / or a tactile output and / or any other output perceptible to the user. To this end, the output unit may include suitable components, such as one or more lights, lighting elements, speakers, a screen, a vibrator, etc. The output unit may include a computer and / or a processor and / or a memory and / or a working memory and / or a port and / or a data interface for receiving, processing, and outputting unprocessed, pre-processed, and / or processed output data. The output generation unit may be connected to the output unit via an interface. The generated output may be processed and / or output by the output unit.

[0032] The imaging device may include a display unit configured to display images, in particular moving images, to a user. The display unit may be part of and / or constitute an output unit. The displayed images may be based on image data. The display unit may include a screen and / or control electronics. The display unit may include a computer and / or a processor and / or a memory and / or a working memory and / or a port and / or a data interface for receiving, processing, and outputting unprocessed, pre-processed, and / or processed image data and / or display data. An output generation unit may be connected to the display unit via an interface. The generated output may be processed and / or output by the display unit.

[0033] A medical imaging device may include a shaft having at least a proximal section, a distal section, and / or an intermediate section. Alternatively or additionally, the imaging device may be configured to be coupled to such a shaft. The spectral camera may be optically coupled and / or attachable to the proximal end of the shaft. The distal section is particularly configured to be introduced into and / or positioned within a cavity to be examined in an operational state, for example, during diagnostic and / or therapeutic procedures. The proximal section is particularly configured to be positioned outside the cavity to be examined in an operational state, for example, during diagnostic and / or therapeutic procedures. "Distal" should be understood to mean, in particular, close to the patient and / or away from the user during use. "Proximal" should be understood to mean, in particular, away from the patient and / or close to the user during use. In particular, proximal is the opposite side of distal. The shaft may be an elongated object. Furthermore, the shaft may at least partially, and preferably at least largely, constitute the distal section.

[0034] The optical system can include at least one dispersive element, in particular at least one optical grating. The optical system can also include an observation gap. Image light can pass through the observation gap and reach the optical grating, so that the image light band defined by the observation gap can be spectrally separated. The spatial axis along which the incident light is separated extends, in particular, at least substantially perpendicular to the observation gap. The spectral camera can include input optics, in particular an input objective. The spectral camera can include a scanning device that is configured to move at least the observation gap and in particular the optical system and / or the image acquisition sensor, for example, relative to the input optics. This movement of the observation gap can be used to scan the object to be imaged in bands and / or rows and / or columns.

[0035] The image acquisition sensor system may include at least one image sensor. The at least one image sensor may define a photosensitive area. The photosensitive area may typically extend from a first, particularly smaller, wavelength to a second, particularly larger wavelength. The image sensor, and in particular the first image sensor mentioned, may be a silicon sensor, such as a CCD sensor or a CMOS sensor. The image sensor and / or the first image sensor and / or the second image sensor may have a two-dimensional pixel pattern. Generally speaking, the image acquisition sensor system may define pixels arranged in the photosensitive area and, in particular, covering the photosensitive area according to a pixel pattern. The photosensitive area may be an image acquisition sensor area defined by one or more image sensors. In some embodiments, the photosensitive area is rectangular, wherein a first side of the photosensitive area may be oriented parallel to a spatial axis along which spectral separation occurs, and wherein a second side may be oriented perpendicular to the first side. Image strips extending parallel to the second side may thus correspond to spatial image strips of monochrome or narrowband imaging. In particular, they are defined by an observation gap. Image strips extending parallel to the first side may correspond to the spectrum of a specific image point. The first side may be longer than the second side. The term "image sensor" may refer to a complete electronic assembly. Therefore, within the meaning of the present disclosure, an image sensor may accordingly include, in addition to the semiconductor chip, associated contacts, conductor tracks, frames and / or structural elements.

[0036] The first detection area and the second detection area may not intersect each other. The first detection surface may define the first detection area. The second detection surface may define the second detection area.

[0037] The first spectral range and the second spectral range can together form a total spectral range. The total spectral range can be at least substantially continuous in such a way that the maximum spectral width of the uncovered spectral range between the first wavelength and the second wavelength is at most 100 nm, preferably at most 50 nm, particularly preferably at most 20 nm, and preferably at most 10 nm wide. The first spectral range and the second spectral range can overlap. In other embodiments, the first spectral range and the second spectral range can directly adjoin each other or be spaced apart from each other. The spectral interval can be selected so that, despite the spectral interval, the resulting total spectral range is at least substantially continuous.

[0038] The photosensitive region can be flat and / or planar at least in sections, and in particular, entirely. The photosensitive region can be oriented parallel to the spatial axis at least in sections, and in particular, entirely. In some embodiments, the photosensitive region can also be tilted relative to the spatial axis at least in sections, and in particular, entirely. The expression "the photosensitive region extends along the spatial axis" should be understood to mean, in particular, that the projection of the photosensitive region onto the spatial axis extends over a length corresponding to at least 50%, at least 60%, at least 70%, or even at least 80% of the length of the photosensitive region.

[0039] The first image sensor and the second image sensor can be arranged in a plane. In particular, the first image sensor defines a first detection surface, and the second image sensor defines a second detection surface. The first detection surface and the second detection surface can be arranged parallel to each other. Furthermore, the first detection surface and the second detection surface can be arranged in a common plane. A plane parallel to the first detection surface and the second detection surface can be present, which is spaced at most 5 mm, preferably at most 2 mm, particularly preferably at most 1 mm, and preferably at most 0.5 mm from the first detection surface and the second detection surface.

[0040] In some embodiments, the first and second image sensors can be arranged adjacent to each other so that the two adjacent edges of the image sensors extend parallel to each other, but the image sensors are tilted relative to each other. This allows each image sensor to achieve its own optimal orientation relative to the optical device, and in particular, the dispersive element of the optical device. This allows for different dispersions per unit distance for the image sensors. The photosensitive area can be configured to be curved and / or bent accordingly. In this case, the photosensitive area as a whole can extend along a spatial axis. In this case, one of the detection surfaces can be oriented parallel to the spatial axis. Alternatively, both the first and second detection surfaces can be tilted relative to the spatial axis. The first and second image sensors can be arranged directly adjacent to each other. In particular, the image sensors can touch each other. In some embodiments, the image sensors can be spaced apart from each other. The distance between the image sensors is in particular at most 5 mm, preferably at most 2 mm, particularly preferably at most 1 mm, and preferably at most 0.5 mm. The distance between the image sensors is, in particular, at most 20%, preferably at most 10%, particularly preferably at most 5%, and preferably at most 2% of the extension of the largest of the image sensors in a direction parallel to the spacing direction.

[0041] Within the scope of the present disclosure, the expression "minimum wavelength and / or maximum wavelength of a spectral width and / or spectral range" may be understood to mean a wavelength or wavelength range, respectively, at which the intensity is at most 10%, at most 5%, at most 2%, or even at most 1% of the maximum intensity of the relevant reference spectral range. For example, the spectral width of the emission spectrum of a light-emitting element may represent the distance between a first wavelength and a second wavelength, between which there is an emission maximum, and at which the emission intensity at the first wavelength and the second wavelength is at most 10%, at most 5%, at most 2%, or even at most 1% of the emission intensity at the emission maximum. Within the scope of the present disclosure, the expression "minimum and / or maximum wavelength of a spectral width and / or spectral range" may be understood in the same way, which is related to the transmission and / or reflection properties and / or other wavelength-dependent optical properties of an object.

[0042] The spatially resolved intensity information can be at least two-dimensional, point-resolved intensity information. In other words, the spatially resolved intensity information can relate to a matrix of pixels. The color channels mentioned can each contain two-dimensional, point-resolved intensity information. The color channels can include a first color channel and a second color channel. Furthermore, the color channels can include a third color channel. The first color channel can be a red channel for visible light. The second color channel can be a green channel for visible light. The third color channel can be a blue channel for visible light. The image sensor can be a color-sensitive image sensor, in particular a three-color image sensor, such as an RGB image sensor. The color channels can each be sensitive in a subrange of the visible spectral range and, in addition, in at least a subrange of the near-infrared range.

[0043] In particular, in embodiments with two image sensors, a processing unit may be provided that is configured to obtain combined spectral information describing a spectrum over the entire spectral range from the sensor signal of the first image sensor and the sensor signal of the second image sensor. In this case, as described above, the processing unit is not necessarily configured to obtain a corrected spectrum.

[0044] The processing unit may include a processor and / or a working memory and / or a machine-readable medium. The machine-readable medium may contain program codes that implement the functions of the processing unit.

[0045] The corrected spectrum differs from the intensity distribution of the reference spatial axis for the light separated relative to the spatial axis in that the intensity of at least the second-order diffracted light is reduced, in particular by at least 50%, preferably by at least 80%, particularly preferably by at least 90%, and preferably by at least 95%. Due to diffraction by the dispersive element, at least the second-order diffracted light of a first wavelength reaches a location on the photosensitive area where first-order diffracted light of a second wavelength greater than the first wavelength falls. For example, at a specific location on the photosensitive area, first-order light of wavelength X nm overlaps with second-order light of wavelength X / 2, where X is a positive real number. The light intensity at this location is greater than the intensity of the first-order light because the second-order light at this location also contributes to the light intensity. Given the position-wavelength dependency, this results in an erroneous spectrum because the intensity at wavelength X is overestimated. The processing unit is configured to reduce or eliminate this overestimation by acquiring the corrected spectrum.

[0046] In a method for manufacturing a medical imaging device, a first image sensor and a second image sensor may be arranged so that they are positioned as described. The image sensors may be arranged on a common substrate and / or board. In particular, the image sensors may be bonded to each other and / or to the substrate and / or board.

[0047] In some embodiments, the photosensitive region and / or the image acquisition sensor mechanism can be movable relative to the optical device and, in particular, relative to the dispersive element. This allows for the wavelength ranges that fall within the photosensitive region and / or the positions of the image acquisition sensor mechanism to be changed. For example, if the first image sensor is spatially separated from the second image sensor and, as a result, there are spectral gaps in the overall spectral range, the spectral gaps can be changed. Thus, by ensuring that each wavelength range between the first and second wavelengths in at least one of the hyperspectral images falls within the photosensitive region and / or the detection surface of at least one image sensor, the spectral gaps can be closed by capturing multiple hyperspectral images at different locations. In the case of continuous photosensitive regions and / or a single image sensor, the spectral range to be imaged can also be changed by changing the position.

[0048] In the context of the present disclosure, visible light and / or the visible spectral range may refer to light having a wavelength of at least 500 nm, at least 450 nm or at least 400 nm and at most 780 nm, at most 750 nm or at most 700 nm. In the context of the present disclosure, near-infrared light and / or the near-infrared spectral range and / or the expression "near-infrared" may refer to light having a wavelength of at least 750 nm, at least 780 nm or at least 800 nm and at most 3000 nm, at most 2000 nm or at most 1500 nm.

[0049] In some embodiments, the second wavelength is located in a second spectral range, wherein the second wavelength is greater than twice, preferably at least 2.1 times, particularly preferably at least 2.5 times, and preferably at least 3 times, the first wavelength. This allows for a large spectral range for imaging. Furthermore, the limitation that only the spectral range between the low cutoff wavelength and twice the low cutoff wavelength can be used due to interfering higher diffraction orders can be overcome.

[0050] The first wavelength may be at most 450 nm, and preferably at most 400 nm. Alternatively or additionally, the second wavelength may be at least 1000 nm, and preferably at least 1200 nm. In particular, for embodiments having a first image sensor and a second image sensor, the second wavelength may be at least 1400 nm, preferably at least 1500 nm, particularly preferably at least 1600 nm, and preferably at least 1700 nm.

[0051] In particular, if the first spectral range includes at least one wavelength range from 500 nm, preferably from 450 nm to 800 nm, preferably to 900 nm, inexpensive and reliable sensor technology can be used for detecting wavelengths in the visible range and just beyond the visible range into the near-infrared range. In particular, a silicon image sensor can be used as the first image sensor.

[0052] In particular, if the second spectral range includes at least one wavelength range from 1000 nm, preferably from 900 nm to 1500 nm, preferably to 1700 nm, widely available sensor technology for detecting visible light can be advantageously supplemented, and a large spectral range useful for medical applications can be achieved. The first and second spectral ranges can overlap. Depending on the design and arrangement of the dispersive element, it can be provided that the respective spectral ranges of the first image sensor and / or the second image sensor are not fully utilized for capturing hyperspectral images.

[0053] The first image sensor can be a monochrome image sensor, in particular a monochrome silicon image sensor. Alternatively or additionally, the second image sensor can be a SWIR sensor (shortwave infrared sensor), in particular an InGaAs sensor. This allows readily available sensor elements to be inexpensively and easily combined to expand the usable spectral range for hyperspectral medical imaging.

[0054] In particular, a high degree of information density over a large spectral range can be achieved in a structurally simple and cost-effective manner if the first and second image sensors are arranged directly adjacent to one another and the photosensitive region is defined as a substantially continuous region. The photosensitive region can be defined solely by the first and second image sensors, and in particular by their detection areas.

[0055] According to some embodiments, the optical device is configured to spectrally separate incident light such that, for light having a wavelength in a first spectral range, nth-order diffracted light reaches a first detection region and is detectable by the first image sensor due to its photosensitivity in the first spectral range, while (n+1)th-order diffracted light reaches a second detection region but is not detectable by the second image sensor due to its insufficient photosensitivity in the first spectral range, where n is a positive integer and is particularly 1. This insufficient photosensitivity can be achieved by a filter element positioned upstream of the second image sensor and / or can be inherent in the material of the second image sensor. In this regard, the second image sensor itself can be adapted to detect the (n+1)th-order diffracted light, but can be integrated, adapted, and / or arranged in the image acquisition sensor arrangement in such a way that the (n+1)th-order diffracted light is not detected by the second image sensor. This description can apply to multiple values ​​of n. For example, the described situation can apply to first-order diffracted light on the first image sensor and second-order diffracted light on the second image sensor, as well as second-order diffracted light on the first image sensor and third-order diffracted light on the second image sensor. Furthermore, higher-order light, such as the (n+2)th order, the (n+3)th order, etc., may not be detected by the second image sensor. Generally speaking, the first image sensor and the second image sensor may be constructed, arranged, and / or provided with filters in such a way that the image acquisition sensor arrangement can distinguish between different diffraction orders or can be calibrated to a single diffraction order.

[0056] A high degree of reliability in shielding higher diffraction orders can be achieved, in particular, when the imaging device, and in particular the image acquisition sensor arrangement, further comprises at least one optical edge filter that is transparent to light with wavelengths above a cutoff wavelength and opaque to light with wavelengths below the cutoff wavelength, wherein the cutoff wavelength is less than twice the first wavelength, and wherein the optical edge filter is arranged at least partially upstream of the second image sensor. In general, for higher diffraction orders, the cutoff wavelength can also be selected so that it is greater than the first wavelength by a factor of (n+1) / n, where n is a positive integer. Furthermore, a plurality of different edge filters can be provided, which progressively sensitize the photosensitive region to different spectral ranges or which progressively shield different diffracted light of higher orders. The aforementioned edge filters can be arranged at least partially or completely upstream of the second image sensor. This prevents short-wavelength light of higher diffraction orders from reaching the second image sensor.

[0057] Alternatively or in addition to an edge filter positioned upstream of the second image sensor, the imaging device, and in particular the image acquisition sensor arrangement, can include at least one optical edge filter that is transparent to light with wavelengths below a cutoff wavelength and opaque to light with wavelengths above the cutoff wavelength, wherein the cutoff wavelength is less than twice the first wavelength, and wherein the optical edge filter is positioned at least partially upstream of the first image sensor. Typically, for higher diffraction orders, the cutoff wavelength can also be selected so that it is smaller than the first wavelength by a factor of (n+1) / n, where n is a positive integer. Furthermore, a plurality of different edge filters can be provided, which progressively sensitize the photosensitive region to different spectral ranges or which progressively shield different diffracted light of higher orders. The aforementioned edge filters can be positioned at least partially or completely upstream of the second image sensor. This prevents short-wavelength light of higher diffraction orders from reaching the second image sensor.

[0058] The aforementioned edge filters, namely the edge filter at least partially positioned before the first image sensor and / or the edge filter at least partially positioned before the second image sensor, can each be positioned at least partially before both image sensors. The position can be selected so that the physical edge of the edge filter overlaps the spatial location of the photosensitive region, where higher-order wavelengths, particularly second-order wavelengths, and lower-order wavelengths to be imaged, particularly first-order wavelengths, reach. The edge filters can then ensure that higher-order diffracted light is not detected. For example, the first image sensor may be sensitive to wavelengths up to at least 950 nm, at least 1000 nm, or at least 1100 nm. If the first wavelength is, for example, at most 450 nm, then wavelengths starting at 900 nm should already be blocked. The edge filter can be positioned partially before the first image sensor. It is also conceivable that the second image sensor is sensitive to a spectral range up to wavelengths less than, for example, twice the first wavelength. If necessary, light from higher diffraction orders falls only on a subregion of the second image sensor. The edge filter can then be positioned so that it covers only this subregion.

[0059] In particular, if the optical device is configured to spectrally separate the incident light in such a manner that, for light having a wavelength in a first spectral range, nth-order diffracted light reaches the first detection region and can be detected by the first image sensor due to its light sensitivity in the first spectral range, and (n+1)th-order diffracted light reaches and is blocked by the optical edge filter, where n is a positive integer and in particular 1, then the shielding of higher diffraction orders can effectively result in a wide usable spectral range. Alternatively or in addition to the selective light intensity of different image sensors, edge filters can therefore be used to shield higher diffraction orders.

[0060] The spectral information may relate to visible light and near-infrared light. In particular, if the processing unit is configured to acquire spectral information related to near-infrared light according to different color channels in a wavelength-dependent manner, an inexpensive and / or readily available image sensor can be used as part of the image acquisition sensor mechanism. For example, the processing unit may be configured to access different color channels and / or different combinations of color channels for different sub-ranges in the near-infrared range. The processing unit may include a lookup table in which it is recorded which color channel and / or color channels should be considered for different wavelengths. Additionally, the processing unit may be configured to acquire spectral information related to visible light according to different color channels in a wavelength-dependent manner.

[0061] The image acquisition sensor system can be configured to provide spatially resolved intensity information for at least three different color channels. Furthermore, the processing unit can be configured to acquire spectral information for at least one first spectral range from a single color channel and spectral information for a second spectral range from a combination of exactly two color channels. This facilitates the use of RGB image sensors or other multi-color image sensors. Multiple spectral ranges can be provided, in which the processing unit acquires spectral information from corresponding single color channels. For example, in the visible range, this could be the case for the red spectral range, the green spectral range, and / or the blue spectral range. Furthermore, multiple spectral ranges can be provided, in which the processing unit uses a combination of exactly two color channels. For example, two, three, four, or even more spectral ranges of this type can be provided. For example, the number of distinguishable spectral ranges can thus exceed the number of color channels. The total spectral range that can be acquired using the image acquisition sensor system can be divided into a first number of sub-spectral ranges, each of which is associated with a specific rule, i.e., which color channel and / or channels the processing unit is to use to acquire spectral information in that sub-spectral range. Accordingly, a first number of acquisition rules can be provided. A second number of color channels can also be provided. In some embodiments, the first number may be greater than the second number.

[0062] In particular, if the processing unit is configured to obtain spectral information for at least one third spectral range from a combination of exactly three color channels, the available spectral information can be effectively utilized using simple electronic components. For example, the processing unit can combine the R channel, the G channel, and the B channel for this purpose.

[0063] In some embodiments, the image acquisition sensor mechanism includes a filter pattern that defines color channels. The filter pattern can in particular be a pixel pattern. The image sensor can include a filter pattern. The filter pattern can include, for example, a Bayer matrix. The image sensor can be a Bayer sensor. Other filter patterns, such as an XTrans matrix, are also conceivable according to the present invention. In addition, there can be more than three color channels, such as RGEB color channels, where e stands for "emerald" (smaragdgrün). In addition to the color channels, there can also be a broadband white light channel. The filter pattern can, for example, define white pixels and / or filter-free pixels in addition to colored pixels.

[0064] Typically, according to the present invention, the image acquisition sensor system can be configured to provide spatially resolved intensity information for at least three different color channels, wherein the color channels include a red color channel, a green color channel, and a blue color channel. The color representation can relate to the visible spectral range, i.e., the color channels can also be sensitive in the near-infrared range, in particular in different sub-ranges of the near-infrared range.

[0065] It should be understood that the described targeted evaluation of different color channels can also be used in the described imaging device having two image sensors. For example, the first image sensor can include multiple color channels in the described manner and can be combined with a second image sensor that is sensitive in a different spectral range. Alternatively or additionally, the second image sensor can provide multiple color channels in the described manner.

[0066] Furthermore, it is understood that according to the present invention, three or four or even more different image sensors can also be provided, which are arranged adjacent to one another or whose detection surfaces and / or detection areas jointly define a light-sensitive area.

[0067] The present invention may generally comprise a method of performing imaging by means of an imaging device according to the present invention.Furthermore, a method for operating an imaging device according to the present invention may be provided.

[0068] The devices and systems according to the present invention and the methods according to the present invention are not limited to the above-described applications and embodiments. In particular, in order to achieve the functions described herein, they may have a number of individual elements, components and units, as well as method steps, which may differ from the numbers mentioned herein. Furthermore, for ranges of values ​​given in this disclosure, the values ​​within the limits mentioned are also to be considered disclosed and may be applied in any manner.

[0069] In particular, it is pointed out that all features and characteristics described with respect to the device and the method methods can reasonably be transferred to the method and applied within the meaning of the present invention and are considered to be disclosed together. Vice versa. This means that structural features mentioned with respect to the method, i.e., features of the device, can be considered and claimed within the scope of the device claims and are also considered to be part of the present disclosure.

[0070] The present invention will be described illustratively below with reference to the accompanying drawings. The drawings, the description, and the claims contain many features in combination. A person skilled in the art will also readily examine each feature individually and use them in appropriate combinations within the scope of the claims.

[0071] If there are more than one example of a particular object, only one of them may be assigned a reference number in the drawings and description, if necessary. The description of the example can be transferred accordingly to the other examples of the object. If the objects are named, in particular, using ordinal numbers, such as first, second, third, etc., these are used to name and / or associate the objects. Thus, for example, the first and third objects may be included, but the second object may not be included. However, the number and / or order of the objects can also be derived from the ordinal numbers. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In the figure:

[0073] Figure 1 A schematic diagram of a system having a medical imaging device is shown;

[0074] Figure 2 A schematic diagram of a spectral camera of an imaging device is shown;

[0075] Figure 3 A schematic diagram of an image acquisition sensor mechanism of an imaging device is shown;

[0076] Figure 4 Schematic diagram showing different spectral ranges;

[0077] Figure 5 A schematic diagram illustrating an image acquisition sensing mechanism of an alternative imaging device;

[0078] Figure 6 shows the transmission spectra of different color filters of the image acquisition sensor mechanism;

[0079] Figure 7 A schematic diagram showing the sensitivity of different color channels of an image acquisition sensor mechanism;

[0080] Figure 8 A schematic diagram showing a method for selecting a spectral range from a color channel of an image acquisition sensing mechanism is shown;

[0081] Figure 9 Schematic spectra are shown for illustrating the correction spectra;

[0082] Figure 10 A schematic flow chart illustrating a method for manufacturing an imaging device; and

[0083] Figure 11 A schematic flow chart of a method for imaging is shown. DETAILED DESCRIPTION

[0084] Figure 1 A schematic diagram of a system 78 is shown having a medical imaging device 10. The imaging device 10 comprises a spectral camera 12, which in the present case is a hyperspectral camera that performs hyperspectral imaging. The imaging device 10 also comprises a processing unit 44 configured to process the image data acquired by the spectral camera 12.

[0085] The imaging device 10 may be part of an endoscopic device 74. The endoscopic device 74 may be part of an endoscope 76.

[0086] System 78 includes endoscope 76. As shown in the figure, system 78 may include a supply unit 80, to which endoscope 76 can optionally be connected. Supply unit 80 can be configured to control endoscope 76 and / or receive image data and / or other data from endoscope 76. Supply unit 80 can be connected and / or connectable to a display 82 of system 78, on which captured images can be displayed to a user. Supply unit 80 can also provide illumination light for endoscope 76 and / or endoscopic device 74. In the illustrated embodiment, an illumination device 82 is provided that provides illumination light for imaging. Endoscope 76 can be connected and / or connectable to illumination device 82 via an optical conductor cable 84. Endoscope 76 can also be connected and / or connectable to supply unit 80 via an electrical cable 86. Electrical cable 86 can be configured to transmit electrical energy and / or data.

[0087] In other embodiments, a separate lighting device and / or illumination light source may be provided.Furthermore, the endoscope 76 may alternatively or additionally comprise an integrated light emitting element for providing illumination light.

[0088] In other embodiments, the processing unit 44 can be part of a supply unit 82 to which the endoscope 76 can be attached. Thus, the endoscopic device 74 can include, for example, the imaging device 10 and the endoscope 76. In some embodiments, the endoscopic device 74 can include the supply unit 82 and / or the lighting device and / or the display 84.

[0089] Figure 2A schematic diagram of a spectral camera 12 of an imaging device 10 is shown. In the present case, the spectral camera 12 operates according to the push-broom principle. The spectral camera 12 is designed as a spectral scanning hyperspectral camera. The spectral camera 12 includes an input optical system 94. The spectral camera 12 also includes an observation gap 96. The spectral camera 12 also includes an image acquisition sensor 18. The spectral camera 12 also includes an optical system 14, which is configured to spectrally separate the incident light relative to a spatial axis 16 by diffraction. The optical system 14 can include optical elements 98, 100, such as lenses. The optical system 14 can also include a dispersive element 102. In the present case, the dispersive element 102 is designed as a light-transmitting grating.

[0090] The spectral camera 12 includes a camera unit 104 that can be moved by means of a scanning device 106. The camera unit 104 can include a carrier 108. Furthermore, the camera unit 104 includes at least an observation gap 96, a dispersive element 102, and an image acquisition sensor system 18. The scanning device 106 is designed to move at least the observation gap 96 and, in particular, the optical system 14 and / or the image acquisition sensor system 18. In the present case, this movement occurs relative to the input optical system 94. This movement serves to scan the object to be imaged in strips and / or rows and / or columns. Thus, for each scanning position, an image can be acquired by means of the image acquisition sensor system 18, an axis of which, in particular, an axis perpendicular to the spatial direction 16, corresponds to the spatial axis, and another axis of which, in particular, an axis parallel to the spatial direction 16, corresponds to the spectral axis. Each acquired image is therefore a spectrally resolved image strip. The multiple scanned images can be combined in a generally known manner to obtain a hyperspectral image. The spectral camera 12 may also include a housing 110 that houses the camera unit 104 and the scanning device 106. The stem of the endoscope 76 may be coupled to the housing.

[0091] Figure 3A schematic diagram of an image acquisition sensor mechanism 18 of an imaging device 10 is shown. The image acquisition sensor mechanism 18 includes a first image sensor 22, which defines a first detection area 26. In the present case, the first image sensor 22 is a monochrome silicon image sensor. The image acquisition sensor mechanism 18 also includes a second image sensor 28, which defines a second detection area 32. In the present case, the second image sensor 28 is configured as a SWIR sensor. The resolution of the first image sensor 22 can be at least 0.5 megapixels, at least 1 megapixel, at least 2 megapixels, at least 5 megapixels or at least 10 megapixels, where larger or smaller values ​​are also possible. The resolution of the second image sensor 28 can be at least 0.5 megapixels, at least 1 megapixel, at least 2 megapixels, at least 5 megapixels or at least 10 megapixels, where larger or smaller values ​​are also possible.

[0092] First image sensor 22 and second image sensor 28 are arranged directly adjacent to each other. For example, image sensors 22 and 28 are mounted on a common board and touch each other along their edges. Detection areas 26 and 32 can be spaced apart from each other due to their structural design, as the corresponding detection areas of image sensors 22 and 28 do not extend to their outermost edges.

[0093] The two detection regions 26, 32 together form the photosensitive region 20 of the image acquisition sensor system 18. The photosensitive region 20 extends along the spatial axis 16, in the present case, for example, parallel to the spatial axis 16. The two detection regions 26, 32 lie in a common plane. The photosensitive region 20 is therefore a planar region extending parallel to the spatial axis 16. The light spectrally separated by the optical device 14 falls on different positions along the spatial axis 16, correspondingly depending on the wavelength. A monochromatic or narrow / single-color image band of the object to be imaged is projected and / or focused onto the photosensitive region 20 in a direction perpendicular to the spatial axis 16, the spatial dimensions of which are predetermined by the observation gap 96.

[0094] Figure 4 Schematic diagram showing different spectral ranges associated with image acquisition sensing mechanisms. Figure 3 and Figure 4Due to its characteristics, the first image sensor 22 is photosensitive in a first spectral range 24, which extends, for example, from 450 nm to at least 900 nm, in the present case, approximately from 400 nm to 1000 nm. Due to its characteristics, the second image sensor 26 is photosensitive in a second spectral range 30, which extends, for example, from 900 nm to at least 1500 nm, in the present case, to at least 1700 nm. The relative spatial arrangement of the optical device 14 and the photosensitive region 20 results in light from a total spectral range 30 falling on the photosensitive region 20, which is defined by the two spectral ranges 24 and 30. The total spectral range 30 extends, for example, from a first wavelength 36 to a second wavelength 38. The first wavelength is, for example, 420 nm or 450 nm, and the second wavelength is, for example, 1500 nm or 1600 nm.

[0095] like Figure 4 As shown, total spectral range 34 may have at least one spectral gap 112 caused by the spacing between two detection regions 26, 32. In this region, spectrally separated light does not reach the photosensitive portion of image acquisition sensor system 18, but rather reaches, for example, frame elements of image sensors 22, 28, and therefore cannot be detected. However, due to the adjacent arrangement of image sensors 22, 28, total spectral range 34 is at least substantially continuous.

[0096] Due to the large spectral width of the total spectral range 24, it includes diffracted light which can originate from different diffraction orders. For example, if the first wavelength 36 is 420 nm, the second diffraction order appears from twice this value, i.e. from a wavelength of 840 nm, and the third diffraction order additionally appears from a wavelength of 1260 nm. Due to the different spectral sensitivities of the image sensors 22, 28, at least some of these higher diffraction orders are not detected by the second image sensor 28. In addition, an edge filter 40 is provided, which is located upstream of the second image sensor 28. In the exemplary embodiment shown, this edge filter 40 also covers a part of the first image sensor 22. The spectral edge of the edge filter 40 is at the cut-off wavelength The cut-off wavelength 42 is selected so that higher diffraction orders are blocked. In this example, the cut-off wavelength 42 is located at twice the first wavelength 36, namely 840 nm. Therefore, higher diffraction orders of light with wavelengths between the first wavelength 36 and the cut-off wavelength 42 are blocked by the covered portion of the first image sensor 22 and the second image sensor 28. The second order of the cut-off wavelength 42, which occurs at 1680 nm, is already outside the total spectral range 34. Therefore, the current arrangement ensures that only light of the first diffraction order is imaged.

[0097] It will be appreciated that a plurality of different edge filters can be used. This allows operation with higher diffraction orders for which the critical wavelengths involved are closer together. Furthermore, an even larger total spectral range can be used.

[0098] In some embodiments, the image sensors 22, 28 can also be selected or provided with their own filters in such a way that the transition between the two image sensors 22, 28 overlaps with the second order of the first wavelength 36. The higher diffraction orders then fall only on the second image sensor 28 and can therefore be easily shielded.

[0099] The processing unit 44 is configured to acquire a common image and thus combined spectral information from the sensor signals of the two image sensors 22 , 28 , which then describes the spectrum over the total spectral range 34 .

[0100] If the optical device 14 is appropriately rotated relative to the image acquisition sensor mechanism 18, the spectral position of the gap 112 can be shifted. If necessary, multiple scans can be performed in sequence to also obtain spectral information for the gap 112. In some embodiments, the gap 112 can also be simply accepted by giving up spectral resolution in the narrow spectral range involved.

[0101] It should be noted that the edge filter 40 does not necessarily have to cover the entire second image sensor 28. In some embodiments, for example when the spectral sensitivity of the second image sensor 28 does not detect any undesired higher-order diffracted light, the edge filter 40 may be provided only in front of a sub-region of the first image sensor.

[0102] Figure 5 A schematic diagram of an image acquisition sensor mechanism 18' of an alternative imaging device is shown. For the sake of clarity, the figure numerals of this embodiment are provided with single quotes. With regard to the structure and function of the alternative imaging device, reference is basically made to the above description of the imaging device 10. This applies similarly to the alternative imaging device 10. In this embodiment, some or all of the components of the above-mentioned system may also be present. In this respect, the embodiment described below also relates to a system having this structure.

[0103] The image acquisition sensor mechanism 18' includes an image sensor 54', which defines a photosensitive area 20'. The image sensor 54' is, for example, a silicon-based color sensor, such as an RGB-CCD sensor. It is used in spectral cameras, such as those in Figure 2 As shown in .

[0104] Image sensor 54' defines a photosensitive region 20' extending along spatial axis 16'. As described above, incident light is spectrally separated along spatial axis 16' by the optics of the spectral camera. Image sensor 54' is photosensitive in a spectral range in which light of different diffraction orders can occur. In the present case, image sensor 54' is photosensitive, for example, in the spectral range between 400 nm and 1300 nm. In subregion 46' of photosensitive region 20', light of the first and second diffraction orders thus overlap. For example, subregion 46' extends from 800 nm (i.e., twice the minimum detectable wavelength) to 1300 nm (i.e., the maximum detectable wavelength).

[0105] Additional reference is made below Figure 6 and Figure 7 . Figure 6 The transmission spectra of different color filters of the image acquisition sensor system 18 ′ are shown. Figure 7 A schematic diagram illustrating the sensitivity of different color channels of the image acquisition sensing mechanism 18' is shown. In the present example, the image sensor 54' detects light in a first color channel 48', a second color channel 50', and a third color channel 52'.

[0106] The three color channels 48, 50, 52 may be, for example, a red channel, a green channel, and a blue channel for visible light. The image sensor 54' includes, for example, a filter pattern 72', which may include, for example, Figure 5 The filter pattern 72' comprises a plurality of pixel filters, for illustration purposes, in Figure 5 The pixel filters in FIG. 5 have excess dimensions and are shown in smaller numbers. The pixel filters are labeled R for red, G for green, and B for blue. The resolution of image sensor 54 ′ may be at least 0.5 megapixels, at least 1 megapixel, at least 2 megapixels, at least 5 megapixels, or at least 10 megapixels, with larger or smaller values ​​also possible.

[0107] The filters used define three different spectral sensitivities 88', 90', 92' according to the three different transmission spectra 162, 164, 166. Figure 7, transmission spectra 162, 164, 166 are shown for a wavelength range extending from approximately 450 nm to 1000 nm. Transmission spectrum 166' belongs to a red filter or red pixel filter, transmission spectrum 164' belongs to a green filter or green pixel filter, and transmission spectrum 162' belongs to a blue filter or blue pixel filter. Transmission spectrum 166' belongs to first color channel 48', transmission spectrum 164' belongs to second color channel 50', and transmission spectrum 162' belongs to third color channel 52'. In other words, color channels 48', 50', 52' relate to light that can be detected by the corresponding color pixels of image sensor 54' based on the associated spectral sensitivities 88', 90', 92', respectively.

[0108] As can be seen, transmission spectra 162', 164', and 166' each define a specific color sensitivity in the visible range, which is why they are associated with three color channels 48', 50', and 52'. Spectral sensitivity varies depending on wavelength. In particular, it does not disappear outside the visible range. Instead, each of color channels 48', 50', and 52' also exhibits a specific spectral sensitivity in the near-infrared. The spectral sensitivity is different for the three color channels 48', 50', and 52'.

[0109] exist Figure 7 For illustrative purposes, spectral sensitivity is divided into three categories. High spectral sensitivity within a specific spectral range is indicated by a white filled box. Medium spectral sensitivity is indicated by a light gray filled box. Low spectral sensitivity is indicated by a dark gray filled box. Due to diffraction through optical device 14, the spatial axis 16' shown in the transverse direction corresponds to the spectral position. Therefore, the relevant wavelength can be inferred from the position on image sensor 54' relative to the spatial axis.

[0110] If imaging is to be performed over the entire available spectral range, this also includes a subregion 46' in which light from different diffraction orders overlaps. To be able to differentiate between the diffraction orders, the respective spectral sensitivities 88, 90, 92 of the color channels 48', 50', 52' are taken into account. To this end, the alternative imaging device includes a processing unit 44' that is configured to obtain spectral information describing a corrected spectrum based on the spatially resolved intensity information of the color channels 48', 50', 52', which is corrected for at least the second diffracted light order.

[0111] refer to Figure 8 Describe the corresponding method, Figure 8A schematic diagram of the spectral ranges selected from the color channels 48', 50', 52' is shown. The rectangles marked with thick frame lines mark the position ranges on the image sensor 56' corresponding thereto or the spectral ranges selected therein. For detection in the corresponding ranges, the following color channels 48', 50', 52' are selected, which are appropriately spectrally sensitive and have transmission characteristics that allow shielding of light of higher diffraction orders. For example, in order to detect light in the range of twice the wavelength of blue light, the use of the blue color channel 56' is abandoned, since its filter passes short-wave light, and therefore, for example for wavelengths between 800 and 900 nm, the corresponding secondary light with a wavelength from 400 to 450 nm falls on the pixels of the color channel 56'. However, this light is blocked by the filters of the red channel 48' and the green channel 50', as shown from Figure 6 It can be seen in.

[0112] In the present case, the following selection is made by way of example. For blue, green, and red light, spectral ranges 56', 58, 60' are observed in exactly one of the color channels 48', 50', 52'. In spectral range 66', which is immediately adjacent to the visible range, all three color channels 48', 50', 52' are combined. In spectral range 68', which is immediately adjacent to it, two color channels 48', 50' are combined, but the third color channel 52' is excluded. In the further red spectral range 62', only the first color channel 48' is observed.

[0113] For example, the two color channels 48', 52' are further combined in the red in the spectral range 70', and finally only the third color channel 52' is present in the spectral range 64'. Here, the first color channel 48' and the second color channel 50' will each contribute second-order diffracted light, which, however, is blocked due to the spectral sensitivity of the third color channel 52' (see Figure 6 ).

[0114] By combining the light detected in the color channels 48', 50', 52' as described, the processing unit 44' can perform a spectral correction. As described, the processing unit 44' obtains spectral information from a single color channel of the color channels 48', 50', 52' in spectral ranges 56', 58', 60', 62', 64', obtains spectral information from two color channels of the color channels 48', 50', 52' in spectral ranges 66', 68', and obtains spectral information from all three color channels 48', 50', 52' in spectral range 70'.

[0115] Figure 9A schematic spectrum is shown to illustrate the correction achieved thereby. The solid line shows the corrected spectrum obtained by the processing unit 44 ′, which is free of higher diffraction orders. However, if light of higher diffraction orders is also detected, a distorted spectrum 116 is obtained. This will, for example, contain second-order magnitudes, shown as spectrum 118. By selecting appropriate color channels 48 ′, 50 ′, 52 ′, higher orders can be reliably masked while using existing filter patterns.

[0116] It will be appreciated that the image sensor 56′ having the filter pattern can also be used as the first image sensor 22 in the imaging device 10′ described above having two image sensors 22, 28. The color channel-based correction described can then be performed within the spectral range covered by this image sensor. Additionally, if desired, the different spectral sensitivity of the second image sensor 28′ can be utilized and / or additional edge filters can be used.

[0117] Figure 10 A schematic flow chart of a method for manufacturing an imaging device 10, as described above, having two image sensors 22 and 28 arranged adjacent to each other, is shown. The method flow can also be derived from the above description. Step S11 includes providing an optical device 14 configured to spectrally separate incident light and image it in spectrally separated form onto a spatial axis 16. Step S12 includes providing a first image sensor 22 that is photosensitive in a first spectral range 24. Step S13 includes providing a second image sensor 28 that is photosensitive in a second spectral range 30 that is different from the first spectral range 24. The first spectral range 24 and the second spectral range 30 together define a substantially continuous total spectral range 34 extending from a first wavelength 36 to a second wavelength 38. The first wavelength 36 is located in the first spectral range 24, the second wavelength 38 is located in the second spectral range 30, and the second wavelength 38 is at least twice as large as the first wavelength 36. Step S14 includes arranging the first image sensor 22 and the second image sensor 28 so that the second image sensor 28 is located next to the first image sensor 22 relative to the spatial axis 16, and so that the first image sensor 22 covers a first detection area 26 of the photosensitive image area 20, and the second image sensor 28 covers a second detection area 32 of the photosensitive image area 20 that is different from the first detection area 26.

[0118] Optional step S15 includes installing at least one edge filter 40 on at least a portion of the first image sensor 22 and / or on at least a portion of the second image sensor 28 .

[0119] Figure 11A schematic flow chart is shown for a method for imaging using an imaging device, which, as described, includes an image sensor having a plurality of different color channels 48', 50', 52'. The method flow can also be derived from the above description. Step S21 includes spectrally separating incident light relative to a spatial axis 16' by diffraction. Step S22 includes imaging the spectrally separated light onto an image acquisition sensor arrangement 18', which defines a photosensitive region 20' and is arranged such that the photosensitive region 20' extends along the spatial axis 16' and the spectrally separated light falls on the photosensitive region 20', with different diffraction orders superimposed in a subregion 46' of the photosensitive region 20'. Step S23 includes acquiring spatially resolved intensity information for at least two different color channels 48', 50', 52' using the image acquisition sensor arrangement 18', which differ from one another in terms of wavelength-dependent sensitivity, such that at least second-order diffracted light can be detected with different intensities in the color channels 48', 50', 52'. Step S24 comprises acquiring spectral information based on the spatially resolved intensity information of the color channels 48 ′, 50 ′, 52 ′, which spectral information describes a spectrum corrected for at least second-order diffracted light over a spectral range.

[0120] Description of Reference Numerals

[0121] 10 Imaging equipment

[0122] 12 Spectral Camera

[0123] 14 Optical devices

[0124] 16 Space Axis

[0125] 18 Image acquisition sensor mechanism

[0126] 20 Photosensitive areas

[0127] 22 Image Sensor

[0128] 24 spectral range

[0129] 26 Detection Area

[0130] 28 Image Sensor

[0131] 30 spectral range

[0132] 32 detection areas

[0133] 34 total spectral range

[0134] 36 wavelength

[0135] 38 wavelength

[0136] 40 Edge Filter

[0137] 42 Cut-off wavelength

[0138] 44 processing units

[0139] 46 sub-areas

[0140] 48 color channels

[0141] 50 color channels

[0142] 52 color channels

[0143] 54 Image Sensor

[0144] 56 spectral range

[0145] 58 spectral range

[0146] 60 spectral range

[0147] 62 spectral range

[0148] 64 spectral range

[0149] 66 spectral range

[0150] 68 spectral range

[0151] 70 spectral range

[0152] 72 filter patterns

[0153] 74 Endoscopic equipment

[0154] 76 Endoscope

[0155] 78 System

[0156] 80 supply units

[0157] 82 Display

[0158] 84 Optical conductor cable

[0159] 86 Cable

[0160] 88 spectral sensitivity

[0161] 90 spectral sensitivity

[0162] 92 Spectral sensitivity

[0163] 94 Input Optics

[0164] 96 Observation Gap

[0165] 98 optical elements

[0166] 100 optical components

[0167] 102 dispersion elements

[0168] 104 Camera Unit

[0169] 106 Scanning Device

[0170] 108 bearings

[0171] 110 housing

[0172] 112 Gap

[0173] 114 Spectrum

[0174] 116 Spectrum

[0175] 118 Spectrum

[0176] 162 Transmission Spectrum

[0177] 164 Transmission Spectra

[0178] 166 Transmission Spectrum

Claims

1. A medical imaging device (10) having a spectral camera (12) configured to capture hyperspectral images, wherein the spectral camera (12) comprises: an optical device (14) configured to spectrally separate incident light by diffraction about a spatial axis (16); and An image acquisition sensor mechanism (18) defines a photosensitive area (20) and is arranged relative to the optical device (14) such that the photosensitive area (20) extends along the spatial axis (16) and the spectrally separated light falls on the photosensitive area (20), wherein the image acquisition sensor mechanism (18) comprises: a first image sensor (22) which is photosensitive in a first spectral range (24) and covers a first detection area (26) of the photosensitive area (20); as well as a second image sensor (28) which is light-sensitive in a second spectral range (30) different from the first spectral range (24) and covers a second detection area (32) of the light-sensitive area (20) different from the first detection area (26), wherein the second image sensor (28) is arranged next to the first image sensor (22) relative to the spatial axis (16), The first spectral range (24) and the second spectral range (30) together define an at least substantially continuous overall spectral range (34) extending from a first wavelength (36) to a second wavelength (38), wherein the first wavelength (36) is located in the first spectral range (24).

2. The medical imaging device (10) according to claim 1, The second wavelength (38) is located in the second spectral range, and the second wavelength (38) is greater than twice the first wavelength (36).

3. The medical imaging device (10) according to claim 1 or 2, The first spectral range (24) comprises at least one wavelength range from 500 nm, preferably from 450 nm to 800 nm, preferably to 900 nm.

4. The medical imaging device (10) according to any one of the preceding claims, The second spectral range (30) comprises at least one wavelength range from 1000 nm, preferably from 900 nm to 1500 nm, preferably to 1700 nm.

5. The medical imaging device (10) according to any one of the preceding claims, The first image sensor (22) is a monochrome image sensor, and the second image sensor (28) is a SWIR sensor, in particular an InGaAs sensor.

6. The medical imaging device (10) according to any one of the preceding claims, The first image sensor (22) and the second image sensor (28) are arranged directly adjacent to each other and define the light-sensitive area (20) as a substantially continuous area.

7. The medical imaging device (10) according to any one of the preceding claims, The optical device is configured to separate the incident light spectrum so that, for light having a wavelength in the first spectral range (24), n-th order diffracted light reaches the first detection region (26) and can be detected by the first image sensor (22) due to the photosensitivity of the first image sensor in the first spectral range (24), and (n+1)-th order diffracted light reaches the second detection region (32) but cannot be detected by the second image sensor (28) due to the insufficient photosensitivity of the second image sensor in the first spectral range (24), wherein n is a positive integer and in particular 1.

8. The medical imaging device (10) according to any one of the preceding claims, Also included is at least one optical edge filter (40) that is transparent to light having a wavelength above a cut-off wavelength (42) and is not transparent to light having a wavelength below the cut-off wavelength (42), wherein the cut-off wavelength (42) is less than twice the first wavelength (36), and The optical edge filter (40) is at least partially arranged before the second image sensor (28).

9. The medical imaging device (10) according to any one of the preceding claims, Also included is at least one optical edge filter (40) that is transparent to light having a wavelength below a cut-off wavelength (42) and is not transparent to light having a wavelength above the cut-off wavelength (42), wherein the cut-off wavelength (42) is less than twice the first wavelength, and The optical edge filter (40) is at least partially arranged before the first image sensor.

10. The medical imaging device (10) according to claim 8 or 9, The optical device (14) is configured to separate the incident light spectrum so that, for light having a wavelength in the first spectral range (24), n-th order diffracted light reaches the first detection region (26) and can be detected by the first image sensor (22) due to the light sensitivity of the first image sensor in the first spectral range, and (n+1)-th order diffracted light reaches the optical edge filter (40) and is blocked thereby, wherein n is a positive integer and in particular 1.

11. The medical imaging device (10) according to any one of the preceding claims, The spectral camera (12) operates according to the push-broom principle.

12. The medical imaging device (10) according to any one of the preceding claims, The invention also comprises a processing unit (44) configured to obtain combined spectral information based on the sensor signal of the first image sensor (22) and the sensor signal of the second image sensor (28), wherein the spectral information describes the spectrum over the total spectral range (34).

13. Endoscopic device (74) having an imaging device (10) according to any one of the preceding claims.

14. Endoscope (76) having an endoscope device (74) according to claim 13.

15. Method for producing a medical imaging device (10), in particular according to any one of claims 1 to 12, comprising the following steps: Providing an optical device (14) configured to spectrally separate incident light and image it onto a spatial axis (16) in spectrally separated form; providing a first image sensor (22) that is photosensitive in a first spectral range (24); providing a second image sensor (28) that is photosensitive in a second spectral range (30) different from the first spectral range (24), wherein the first spectral range (24) and the second spectral range (30) together define a substantially continuous total spectral range (34) extending from a first wavelength (36) to a second wavelength (38), wherein the first wavelength (36) is located in the first spectral range (24), wherein the second wavelength (38) is located in the second spectral range (30), and wherein the second wavelength (38) is at least twice as large as the first wavelength (36); and The first image sensor (22) and the second image sensor (28) are arranged such that the second image sensor (28) is located next to the first image sensor (22) relative to the spatial axis (16), and such that the first image sensor (22) covers a first detection area (26) of the light-sensitive image area (20), and the second image sensor (28) covers a second detection area (32) of the light-sensitive image area (20) that is different from the first detection area (26).

Images