Optical target, optical test and / or calibration system and medical system

Abstract

Optical target (20, 20', 20'', 20''') for testing and / or calibrating a medical imaging device (30), comprising: a target body (40, 40', 40'', 40''') that is additively manufactured; and a dispersion element (55) which is incorporated into the target body (40, 40', 40'', 40''').

Description

[0001] The present application relates to an optical target, an optical test and / or calibration system and a medical system.

[0002] In medical imaging, endoscopes and exoscopes are state-of-the-art tools that can generate magnified images of an area under examination. Furthermore, medical imaging with endoscopes and / or exoscopes allows for the visualization of different layers, such as organs, blood vessels, and / or other tissue, at varying depths beneath the skin and / or beneath the organs into which the endoscope is inserted.

[0003] Furthermore, endoscopes and / or exoscopes, particularly for use in robot-assisted surgeries, are employed in combination with other imaging techniques, especially optical coherence tomography (OCT), computed tomography (CT), and / or magnetic resonance imaging (MRI). Therefore, it is crucial to be able to realistically test and / or calibrate these endoscopes and / or exoscopes, as well as the other imaging techniques, and to verify their interaction with these techniques. The calibration requirements for endoscopes and / or exoscopes, as well as for OCT, CT, and / or MRI, can vary. Nevertheless, it is essential to be able to test and / or calibrate them using simple, user-friendly methods.

[0004] Fluorescence imaging techniques are used to better identify and visualize the depth and size of the different layers. For this purpose, the patient is administered a medication containing fluorescence and / or fluorescent dyes, which are deposited in one of the different layers. This means that one of the layers can exhibit additional fluorescence properties during medical imaging, which can be identified by the endoscope and / or exoscope. This allows for a more precise determination, using medical imaging, of the depth and size of the fluorescent layer beneath the skin and / or organs into which the endoscope is inserted. Furthermore, multimodal medical imaging techniques can also be employed.For this purpose, the patient is administered several medications with different fluorescences, each marking different layers with different fluorescences.

[0005] In summary, medical imaging provides surgeons with highly precise information about the depth to which they need to cut in order to reach and remove the desired tissue layers. This allows them to more intuitively assess and / or monitor their actions on a screen. In particular, multimodal medical imaging techniques can visualize not only the tissue layers that need to be removed, but also additional layers that must not be damaged under any circumstances.

[0006] To test and evaluate the confocal imaging properties of endoscopes and / or exoscopes, or to test and evaluate whether the endoscopes and / or exoscopes can correctly identify fluorescences at sufficient penetration depth and / or distance from the endoscope and / or exoscope, a silicone tube filled with a specific concentration of fluorescent dye is inserted into a scattering test medium in known test setups. However, a problem arises because the concentration of the fluorescent dye decreases over time due to photobleaching. This means that the fluorescence properties of the silicone tube vary considerably depending on the storage time.The above test setup is so sensitive that even small errors in mixing the fluorescent dye for the silicone tube, and subsequent storage on the day of the experiment due to photobleaching, already lead to highly inaccurate test conditions.

[0007] Furthermore, the above arrangement does not allow for the simulation of more complex test setups. However, more complex test setups are urgently needed to evaluate multimodal medical imaging procedures in order to test whether different fluorescences at different penetration depths can be realistically reproduced by the medical imaging procedure.

[0008] Documents FR 3 069 691 A1, DE 10 2020 201 806 A1 and DE 10 2022 102 547 A1 are also known from the prior art.

[0009] Based on the prior art, the invention is based, in particular but not limited to, the objective of easily verifying an image acquisition unit. In particular, the invention is based on the objective of easily verifying several different image acquisition units.

[0010] This problem is solved according to the invention by an optical target, an optical calibration system and a medical system as described herein and defined in the claims.

[0011] The present invention provides an optical target for testing and / or calibrating a medical imaging device. The optical target comprises a target body. Furthermore, at least the target body is additively manufactured. The optical target also includes a scattering element which is incorporated into the target body.

[0012] The optical target can be used to evaluate several imaging techniques. In particular, it can be used to evaluate the spatial mapping of image information and the ability to overlay image data from an endoscope and / or exoscope with image data from an OCT and / or CT and / or MRI scanner. The optical target can also be used for stereoscopic calibration of the medical imaging device and / or for calibrating the fluorescence imaging techniques of the medical imaging device. Specifically, the optical target can be used to calibrate the stereo zero plane of the stereoscopic imaging capabilities of the medical imaging device.

[0013] The medical imaging device can be, in particular, an exoscope. Alternatively or additionally, the imaging device can be, for example, an endoscope. Furthermore, the imaging device can be a CT, OCT, and / or MRI scanner. Several imaging devices can also be calibrated using the optical target. The medical imaging device can be configured to acquire images of an examination area. In some embodiments, the imaging device can be configured to generate magnified images of the examination area. The image can be observed during a medical procedure and / or during a diagnostic procedure. The medical imaging device can be mobile and / or movable and / or stationary. It can be provided that the imaging device and / or at least one of several image processing devices is movable, for example, in an operating room.

[0014] For example, if a user requires imaging support, the imaging device can be movable to the point of use, such as a patient. The imaging device itself can also be movable. For instance, the imaging device can include a movable support arm and / or the imaging device can be mounted on the movable support arm.

[0015] The target body defines, in particular, at least one outer surface of the optical target. Light can be coupled or introduced into the optical target through the target body from at least one spatial direction. Preferably, light can be coupled or introduced into the optical target through the target body from all spatial directions. For example, during a test and / or during a calibration, light is coupled or introduced into the optical target through at least one outer surface of the target body, preferably from all outer surfaces of the target body.

[0016] Additive manufacturing describes, in particular, a process by which an object is built up layer by layer, for example, a 3D printing process. Starting materials for additive manufacturing are, in particular, molding sands, polymer gypsum, acrylic resins, plastics, metals, and / or acrylic glass. Preferably, acrylic glass is used for additive manufacturing in the present invention.

[0017] According to the invention, daylight and / or an external light source, which is also provided for illuminating the room, can be sufficient to adequately illuminate the optical target for calibrating the medical imaging device.

[0018] In particular, the features according to the invention can provide an optical target that exhibits comparable properties over an extended period, is user-friendly and cannot be negatively affected by user errors.

[0019] Additionally, the optical target can also include at least one conversion structure formed in and / or on the target body, which is designed to convert incoming light with a first wavelength at least partially into outgoing light with a second wavelength different from the first wavelength.

[0020] In a particularly simple and cost-effective design of the optical target, the conversion structure can fill a cavity of the target body at least substantially completely and, in particular, entirely.

[0021] Furthermore, the target body can be manufactured entirely in the form of a conversion structure. In this case, for example, an additional conversion structure can be omitted.

[0022] The conversion structure, designed to convert light with a first wavelength at least partially into light with a second wavelength different from the first, is used in particular for evaluating the confocal imaging properties of the endoscope and / or exoscope. The scattering element enhances the extraction of light from the optical target. This allows the optical target to be used for verifying and / or calibrating the fluorescence imaging techniques of the medical imaging device, especially an endoscope and / or exoscope. Daylight and / or an external light source, also intended for room illumination, may be sufficient to adequately illuminate the optical target for calibrating the fluorescence imaging techniques of the medical imaging device.Furthermore, the scattering element can be used, in particular, for verifying and / or calibrating MRI imaging. The different properties, especially the varying light scattering of the scattering element and the target body and / or conversion element, can be used to evaluate CT or OCT imaging techniques.

[0023] Furthermore, the conversion structure can be partially transparent to light of the first wavelength. For example, the conversion structure can be configured to convert 10% to 100%, in particular 30% to 80%, preferably 40% to 60% of the amount of light and / or the luminous flux of the light of the first wavelength into light of the second wavelength. The conversion structure can also be configured to convert light into narrow spectral bands. Narrow can mean that the converted spectral band is, for example, up to 200 nm, in particular 100 nm, preferably 50 nm, and particularly preferably 20 nm wide. The conversion structure can, in particular, be configured to emit light of the second wavelength. The emitted light can be used to illuminate the optical target. Alternatively or additionally, light of the first wavelength can be used to illuminate the optical target.For example, the conversion structure can be configured to alternately convert and transmit light. For this purpose, the conversion structure can be surrounded by, and / or formed from, a switchable film, particularly a PDLC film. The switchable film can have a multilayer structure. In particular, the switchable film comprises a liquid crystal layer, for example, a PDLC layer, sandwiched between two conductive layers, especially made of PET and / or ITP. In the de-energized state, the crystals of the liquid crystal layer can be disordered, resulting in the switchable film being opaque. However, when an electric current is applied to the two conductive layers, the crystals of the liquid crystal layer can align themselves in a way that allows light to pass through.In other words, a transparent surface can be created by arranging the crystals.

[0024] The conversion structure can include filters configured for light conversion. In particular, the conversion structure can be configured to absorb light of the first wavelength and emit light of the second wavelength. Furthermore, in some embodiments, the wavelength of the light of the first wavelength can alternatively or additionally be halved by means of the conversion, for example, by frequency doubling (second harmonic generation, SHG) and / or frequency multiplication using non-linear optical processes. For example, the second wavelength can be a wavelength from the ultraviolet range. Furthermore, quantum dots can be provided for light conversion, or the conversion area can include quantum dots.

[0025] In particular, the conversion structure and / or the target body can be designed as a hollow structure, especially as a closed hollow structure, in order to accommodate the scattering element simply and cost-effectively, for example.

[0026] For easy, demand-oriented filling of the conversion structure and / or the target body, the conversion structure and / or the target body can have a valve through which the scattering element can be filled into the conversion structure and / or the target body.

[0027] To replicate complex, realistic structures, the target body can include at least one additional scattering element embedded within it. For example, the scattering elements can scatter light differently. In particular, the scattering element can be a diffusely scattering test medium. For example, the scattering element and / or the additional scattering element can be a fluid, especially water, and / or a solid, especially sand. Furthermore, the scattering element and / or the additional scattering element can be formed by a sandblasted surface, and / or the scattering properties of the scattering element and / or the additional scattering element can be further enhanced by a sandblasted surface. The fluid, especially water, enables, for example, the simple verification and / or calibration of imaging using MRI.The solid material, particularly sand, can be optimized to scatter light. For the evaluation and / or calibration of MRI imaging, the scattering element can be T1-, T2-, and / or proton-weighted. With T1 weighting, the scattering element and / or any additional scattering element can simulate fatty and / or fat-rich tissue, particularly bone marrow, and / or may itself be fatty and / or fat-rich tissue. Furthermore, the scattering element can be enriched with a contrast agent, particularly gadolinium. With T2 weighting, the scattering element and / or any additional scattering element can simulate structures, particularly cerebrospinal fluid spaces, filled with fluid. T2 weighting is suitable, for example, for simulating effusions and edema, as well as for differentiating cysts from solid tumors.Using proton weighting, the scattering element and / or the further scattering element can particularly replicate cartilage.

[0028] Furthermore, the target body can be manufactured additively together with the conversion structure and / or the further conversion structure. For this purpose, the target body can, for example, be printed simultaneously with the conversion structure and / or the further conversion structure by switching appropriately between two materials during the 3D printing process.

[0029] To ensure even more realistic test conditions, the scattering element and / or the target body can mimic the scattering of human tissue and / or human cells, especially fluorescent cell nuclei and / or fluorescent cell walls.

[0030] Furthermore, the target body and / or the conversion structure can comprise acrylic gas and preferably be formed from it, so that light can be easily introduced into the optical target.

[0031] To create more complex, realistic structures, the optical target can further comprise a conversion structure and / or another conversion structure. Furthermore, the first and / or second wavelengths of the conversion structure and the other conversion structure can differ. For example, the conversion structure can be configured to convert light with a first wavelength, at least partially, into light with a second wavelength different from the first. The other conversion structure can be configured to convert light with a third wavelength, at least partially, into light with a fourth wavelength different from the third. In this case, the first wavelength can differ from the third wavelength. Alternatively or additionally, the second wavelength can differ from the fourth wavelength.

[0032] For example, at least one conversion structure and / or further conversion structures have a rectangular and / or round shape and / or the shape of an anatomical vessel, such as a blood vessel. The shape of the conversion structure and / or further conversion structures can be modeled on a blood vessel. For example, the conversion structure and / or further conversion structures can be cylindrical and / or tubular. This allows the use of optical targets during the calibration of the medical imaging device that replicate realistic structures or, if necessary, simplified but realistic structures that are recorded by the optical target during surgery, for example.

[0033] In particular, the optical target comprises acrylic gas and is preferably made of acrylic glass.

[0034] Furthermore, the scattering elements incorporated into the conversion structure and / or subsequent conversion structures can differ. In particular, the scattering elements can scatter light differently, especially in different spatial directions and / or to different degrees. For example, the scattering elements may include elements with different properties; in particular, a scattering element may comprise a fluid. Moreover, the fluid may be enriched with elements that further enhance light scattering. Because the scattering elements scatter light differently, CT or OCT imaging can be improved and verified.

[0035] To ensure that the medical imaging device has the desired penetration depth, for example, the penetration depth required for surgery, the optical target can have several conversion structures, in particular the conversion structure and the further conversion structure, which are arranged one above the other and / or next to each other. Specifically, the conversion structure and / or the further conversion structure are arranged one above the other and / or next to each other.

[0036] To achieve a more realistic calibration of the medical imaging device, the conversion structure and / or subsequent conversion structures can at least partially replicate a blood vessel and / or organ and / or body part. Furthermore, to simulate an organ and / or to replicate different markers / fluorescence solutions dissolved in different parts / layers of the organs or vessels, the optical target can have multiple conversion structures and / or the conversion structure and / or subsequent conversion structures with different wavelength conversion properties.

[0037] To improve the identification of the optical target by the medical imaging device, particularly without the use of additional external light sources, and / or to create a realistic calibration environment, especially to simulate the scattering of light from skin, the surface of the target body can scatter light. For example, the surface of the target body, the surface of the conversion structure, the surface of any further conversion structure, the surfaces of multiple conversion structures, and / or the scattering element can scatter light. The scattering of light on the surface of the target body, the scattering of light on the surface of the conversion structure, and / or the scattering of light by the scattering element can differ. In particular, the surface of the target body scatters light differently than the scattering element.Due to the different scattering of light, imaging using CT or OCT can be improved and verified.

[0038] For cost-effective manufacturing, in particular the surface of the target body and / or the surface of the conversion structure and / or the surface of the further conversion structure and / or the surface of the multiple conversion structures can be roughened and / or sandblasted.

[0039] To make the optical target more visible to the medical imaging device, especially without the use of additional external light sources, and / or to create a realistic calibration environment, the target body can be further embedded, in particular, in a scattering element.

[0040] In particular, the scattering element and / or the further scattering element and / or the target body, in order to create a realistic calibration environment, replicates the scattering of human tissue.

[0041] Furthermore, an optical calibration system can be provided. The optical calibration system comprises a target according to the invention and a holder designed to couple the optical target to the stereoscopic medical imaging device under test. The holder enables reproducible verification of the geometric calibration. Moreover, the holder makes the calibration system easy to operate, particularly by allowing efficient, lightweight, and / or simple alignment with the imaging device.

[0042] The mount may also include a spacer that sets and / or defines a specific distance between the medical imaging device under test and the target. This distance may, for example, correspond approximately to the distance that the imaging device, in particular an imaging unit and / or the input optics of the imaging unit, would typically have in an operational setting relative to an object under examination. Furthermore, the distance may be specifically adjustable with the optical target and / or with the imaging device. The distance may correspond at least substantially to the focal length of a first image acquisition unit and / or a focal length of a second image acquisition unit of the medical imaging device. In some embodiments, the distance may be at least 5 cm, at least 10 cm, or at least 20 cm and / or at most 100 cm, at most 80 cm, or at most 50 cm.The reproducibility of the inspection can be increased. Furthermore, the inspection can be standardized.

[0043] Furthermore, the mounting can be designed to support the weight of the calibration system when coupled to the medical imaging device being calibrated. This means that the calibration system can be coupled to the imaging device in such a way that it does not rest on the floor. In other words, the calibration system does not need to include a stand or similar support. This allows for a more dynamically efficient coupling of the system, particularly between the calibration system and the imaging device. Advantageously, fewer vibrations and / or less vibrational energy can be transmitted to the calibration system via the floor. This can improve the accuracy of the verification. Additionally, the calibration system can be designed more compactly.

[0044] The mount may also have openings through which ambient light can reach the target body, or to ensure that the ambient light falls on the target body. For example, additional mirrors may be attached to the mount to increase the proportion of ambient light that falls on the target body.

[0045] The mount can also include a coupling section for connecting to the medical imaging device under test, wherein the coupling section includes a projection configured to hold the calibration system by engaging behind it. The imaging device can also include a holding section to which the mount can be coupled. For example, the projection can engage behind the holding section, at least partially. Furthermore, the projection can be configured to hold the calibration system during coupling by engaging behind it, in particular at least partially behind the holding section. The calibration system can be rotated about the projection during coupling, particularly while the projection is partially engaging behind the holding section. The projection can be rotatably mounted in the holding section.The calibration system, in particular the coupling section and / or the projection, and the imaging device, in particular the holding section, can jointly form a connection. The connection can, for example, include a dovetail joint. This can result in a compact and / or efficient calibration system.

[0046] The coupling section can further comprise a movable retaining element designed to selectively fix the holder to or detach it from the medical imaging device under test. For example, the retaining element can clamp the holder to the imaging device. Alternatively or additionally, the movable retaining element can be designed to engage the imaging device, particularly the holding section, section by section. The movable retaining element can include, for example, a tensionable retaining element, in particular a clamping spring, a spring adjuster, and / or the like, a screw, and / or a locking lug. This allows the calibration system to be easily and selectively fixed to and / or detached from the imaging device. Coupling can be performed quickly and / or flexibly.

[0047] The invention further comprises a medical system with a medical imaging device and an optical target for verifying the stereoscopic calibration of the medical imaging device. The medical imaging device to be tested may further comprise a fluorescence channel and / or a white light channel. The medical system may also include at least one further imaging device, in particular an OCT, CT, and / or MRI scanner, which can also be verified using the optical target and / or whose images can be used for additional verification of the medical imaging device.

[0048] The present invention is described below by way of example with reference to the accompanying figures. The drawing, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and use them meaningfully in combination within the scope of the claims.

[0049] If more than one instance of a particular object exists, only one of them may be identified with a reference symbol in the figures and description. The description of this instance can then be applied to the other instances of the object. If objects are named using numerical terms, such as first, second, third object, etc., these serve to identify and / or classify objects. Thus, for example, a first object and a third object, but not a second object, may be included. However, numerical terms could also indicate a number and / or sequence of objects.

[0050] They show: Fig. 1 an exemplary embodiment of an optical target according to the invention; Fig. 2 another exemplary embodiment of an optical target according to the invention; Fig. 3 another exemplary embodiment of an optical target according to the invention; Fig. 4 an exemplary embodiment of a medical system according to the invention comprising a medical imaging device and an optical target according to the invention for verifying a stereoscopic calibration of the medical imaging device.

[0051] Fig. Figure 1 shows an exemplary embodiment of an optical target 20 with a target body 40. The target body 40 can, for example, comprise glass and / or acrylic glass and / or be formed from glass and / or acrylic glass. For example, the target body 40 is manufactured using an additive manufacturing process, in particular a 3D printing process. The entire target body 40 can form a conversion structure. A scattering element (not shown) can be incorporated into the target body. The scattering element can, in particular, be a fluid, for example, water. Furthermore, the target body can have a valve (not shown) through which the scattering element can be filled into the target body.

[0052] Fig. Figure 2 shows another exemplary embodiment of a further optical target 20' with a target body 40'. At least one conversion structure 50', 52', and / or 54'' is incorporated into the target body 40'. As shown, several conversion structures 50', 52', and / or 54'' can be incorporated into the target body 40'. For example, as shown, the conversion structures 50' and 52'' can be arranged side by side, and the conversion structure 54' can be arranged below and, if necessary, between the conversion structures 50' and 52''. However, many shapes, arrangements, and / or numbers of conversion structures are possible, particularly to ensure a realistic calibration environment for the medical imaging devices. The conversion structures 50', 52', and / or 54'' can be connected to one another by a connecting element 60.In particular, the conversion structures 50', 52' and / or 54'' and the connecting elements 60 can be manufactured by an additive manufacturing process, especially a 3D printing process. Subsequently, for example, the target body 40' can be cast around the conversion structures 50', 52' and / or 54'' and / or the connecting element 60 with the target body 40'. Furthermore, in the exemplary embodiment, a scattering element (not shown) is incorporated into the conversion structures 50', 52' and / or 54'. The scattering element can, in particular, comprise or be a fluid, for example, water. The properties of the scattering element can correspond to the properties of human tissue. Furthermore, the conversion structure and / or the target body can have a valve (not shown) through which the scattering element can be filled into the conversion structure and / or the target body.

[0053] Fig. Figure 3 shows a further exemplary embodiment of another optical target 20'', comprising a target body 40'', conversion structures 50'', 52'' and 54'' and a connecting element 60''. In principle, the conversion structures 50'', 52'' and 54'' and the connecting element 60'' are arranged in a manner comparable to the exemplary embodiment shown in Figure 3. Fig. Figure 2 illustrates this. However, many shapes, arrangements, and / or numbers of conversion structures are possible, particularly to ensure a realistic calibration environment for medical imaging devices. The target body 40'' can, for example, be a prefabricated body that is hollow and open on at least one side. The target body 40'' can be made of glass and / or acrylic glass. The conversion structures 50'', 52'', and / or 54'' and / or the connecting element 60'' are incorporated into the target body 40''. Furthermore, the conversion structures 50'', 52'', and / or 54'' and / or the connecting element 60'' can be surrounded within the target body 40'' by a scattering element 55''.The scattering element 55'' can, for example, be cast around the conversion structures 50'', 52'' and / or 54'' and / or the connecting element 60'' and / or be additively manufactured together with the conversion structures 50'', 52'' and / or 54'' and / or the connecting element 60'' and / or the target body 40''. The scattering element 55 can, in particular, be a fluid, for example, water. In this case, the target body 40'' forms a closed cavity to prevent the fluid from escaping from the target body 40''. Furthermore, the conversion structure and / or the target body can have a valve (not shown) through which the scattering element can be filled into the conversion structure and / or the target body.

[0054] Fig.Figure 4 shows a schematic representation of a medical system 10 with a medical imaging device 30 and an optical target 20'''. The optical target 20''' comprises a target body 40''' and a conversion structure 50''', which is shown as a round shape. The optical target 20''' is part of an optical calibration system 12. The optical target 20''' also includes a holder 70 into which the target body 40''' can be inserted. In this case, the holder 70 has a receptacle 72 for the optical target 20'''. One end of a spacer 80 is attached to the receptacle 72. The medical imaging device 30 is attached to the opposite end of the spacer 80, which is connected to the receptacle 72. The spacer 80 allows a distance 90° to be established between the target body 40''' and the medical imaging device 30.The spacer bracket 80 has further holes 85 to allow more ambient light to hit the target body 40''' or to prevent shadows from being cast on the target body 40''.

[0055] The medical imaging device 30 can comprise a first image acquisition unit and a second image acquisition unit, each of which is light-sensitive in a first spectral range. Furthermore, the medical imaging device 30 can comprise a third image acquisition unit and a fourth image acquisition unit, each of which is light-sensitive in a further spectral range. For example, stereo imaging in the first spectral range can be performed using the first and second image acquisition units. Stereo imaging in the further spectral range can be performed using the third and fourth image acquisition units. In particular, the further spectral range lies in the near-infrared range.This makes it possible to perform fluorescence stereo image acquisition using the second image acquisition device and the fourth image acquisition device.

[0056] To enable fluorescence imaging, the image acquisition devices can include further image sensors that are light-sensitive in different spectral ranges. The first and second image acquisition devices can each include a first image sensor that is light-sensitive, at least predominantly, in the first spectral range, which is primarily associated with visible light. This means that image acquisition in the wavelength range of visible light is possible using the first image sensor. This corresponds approximately to a spectral range of white light. The third and fourth image acquisition devices can each include a second image sensor that is light-sensitive, at least predominantly, in the further spectral range, which is primarily associated with the near-infrared range. This means that image acquisition in the near-infrared wavelength range is possible using the second image sensor.Furthermore, or alternatively, the second image sensor can be light-insensitive at least predominantly in the first spectral range, particularly in the wavelength range of visible light. For the calibration of such a medical imaging device 30, the optical target 20''' can, for example, provide light in both spectral ranges by means of several, in particular two, conversion structures in order to verify the geometric calibration of the medical imaging device 30. To verify the geometric calibration, the medical imaging device 30 captures the target 20''' or the at least one conversion structure 50'''. In particular, each of the image acquisition devices captures at least one image of the target body 40''' with at least one conversion structure 50'''.For example, the user can check the geometric calibration of the imaging device 30 using the images of at least one conversion structure 50''' of the optical target 20'''.

[0057] Furthermore, the medical system 10 can include at least one additional medical imaging device (not shown). The additional medical imaging device can be an OCT, CT, and / or an MRI. The imaging of the additional medical imaging device can also be verified by the optical target. Furthermore, the imaging of the additional medical imaging device can be used to improve the verification of the imaging of the medical imaging device 30. Reference symbol list 10 medical system 20, 20', 20'', 20'' optical target 30 medical imaging devices 40, 40', 40'', 40''' Target body 50, 50', 50'', 50''' conversion structure 52', 52'' conversion structure 54', 54'' conversion structure 55 Dispersion element 60 connecting element 70 bracket 72 recording 80 spacers 90 distance

Claims

[1] Optical target (20, 20', 20'', 20''') for testing and / or calibrating a medical imaging device (30), comprising: a target body (40, 40', 40'', 40''') that is additively manufactured; and a dispersion element (55) which is incorporated into the target body (40, 40', 40'', 40'''). [2] Optical target according to claim 1, further comprising: at least one conversion structure (50'', 50''', 52'', 54'') formed in and / or on the target body (40'', 40''') and configured to convert incoming light with a first wavelength at least partially into outgoing light with a second wavelength different from the first wavelength. [3] Optical target according to claim 2, wherein the conversion structure (50'', 50''', 52'', 54'') fills a cavity of the target body (40'', 40''') at least substantially completely and in particular completely and / or wherein the scattering element (55) forms the target body (40, 40', 40'', 40'''). [4] Optical target according to claim 2 or 3, wherein the dispersion element (55) surrounds the conversion structure (50'', 50''', 52'', 54''); and / or where the dispersion element (55) is included in the conversion structure (50'', 50''', 52'', 54''). [5] Optical target (20, 20', 20'', 20''') according to any one of claims 2 to 4, wherein the conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') and / or the target body (40, 40', 40'', 40''') is designed as a hollow structure, in particular as a closed hollow structure. [6] Optical target (20, 20', 20'', 20''') according to any one of claims 2 to 5, wherein the conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') and / or the target body (40, 40', 40'', 40''') has a valve through which the scattering element (55) can be inserted into the conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') and / or the target body (40, 40', 40'', 40'''). [7] Optical target according to any one of claims 2 to 6 wherein the target body (40, 40', 40'', 40''') is cast around the conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54''); and / or wherein the target body (40, 40', 40'', 40''') is manufactured additively together with the conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54''). [8] Optical target (20, 20', 20'', 20''') according to any one of claims 2 to 7, wherein the at least one conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') has a rectangular and / or round shape or the shape of an anatomical vessel. [9] Optical target (20, 20', 20'', 20''') according to any one of claims 2 to 8, further comprising: at least one further conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') designed to convert light with a first wavelength at least partially into light with a second wavelength different from the first wavelength; where the first and / or second wavelengths of the conversion structures (50, 50', 50'', 50''', 52', 52'', 54', 54'') are different. [10] Optical target (20, 20', 20'', 20''') according to any one of claims 2 to 9, wherein a dispersion element (55) is included in each of the conversion structure and / or the further conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54''), wherein the scattering elements (55) scatter light differently. [11] Optical target (20, 20', 20'', 20''') according to any one of claims 2 to 10, wherein the conversion structure and / or the further conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') are arranged one above the other and / or next to each other. [12] Optical target (20, 20', 20'', 20''') according to any one of claims 2 to 11, wherein the conversion structure and / or the further conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') at least partially replicates the shape of an anatomical vessel and / or organ and / or body part. [13] Optical target (20, 20', 20'', 20''') according to any of the preceding claims, wherein a surface of the target body (40, 40', 40'', 40''') and / or a surface of the conversion structure and / or a surface of the further conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') and / or the scattering element and / or a surface of the scattering element scatters light. [14] Optical target (20, 20', 20'', 20''') according to any one of the preceding claims, further comprising: at least one further scattering element (55) which is incorporated into the target body, wherein the scattering elements (55) preferentially scatter light differently. [15] Optical target (20'', 20''') according to one of the preceding claims, wherein the scattering element (55) and / or the further scattering element (55) comprises a fluid, in particular water. [16] Optical target (20, 20', 20'', 20''') according to any of the preceding claims, wherein the scattering element (55) and / or the further scattering element (55) and / or the target body (40, 40', 40'', 40''') replicates the scattering of human tissue and / or human cells, in particular of fluorescent cell nuclei and / or fluorescent cell walls. [17] Optical target (20, 20', 20'', 20''') according to any of the preceding claims, wherein the optical target comprises acrylic gas and is preferably made of acrylic glass. [18] Optical target (20, 20', 20'', 20''') according to claim 17, wherein the scattering of light on the surface of the target body (40, 40', 40'', 40''') and / or the scattering of light on the surface of the conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') and / or the scattering of light of the scattering element (55) and / or the scattering of light of the further scattering element (55) are different. [19] Optical target (20, 20', 20'', 20''') according to any of the preceding claims, wherein the surface of the target body (40, 40', 40'', 40''') and / or the surface of the conversion structure (50, 50', 50'', 50''', 52', 52'', 54', 54'') is roughened and / or sandblasted. [20] Optical test and / or calibration system (12), comprising: an optical target (20, 20', 20'', 20''') according to any one of the preceding claims; and a holder (70) designed to couple the optical target (20, 20', 20'', 20'') to the medical imaging device (30) under test. [21] Optical test and / or calibration system (12) according to claim 20, wherein the holder (70) comprises a spacer (80) which establishes a defined distance (90) between the medical imaging device (30) to be tested and the optical target (20, 20', 20'', 20'''). [22] Medical system (10), comprising: a medical imaging device (30), in particular an endoscope and / or exoscope; an optical target (20, 20', 20'', 20''') for verifying a stereoscopic calibration of the medical imaging device (30) according to one of claims 1 to 19 and / or an optical calibration system (12) according to claim 20 or 21. [23] Medical system (10) according to claim 22, wherein the medical imaging device (30) to be tested has a fluorescence channel and / or a white light channel. [24] Medical system according to claim 22 or 23, further comprising: at least one additional imaging device, in particular an OCT, CT and / or MRI.

Images