Methods and systems for generating three-dimensional images of at least a partial segment of a row of teeth, computer program products, and mirror elements.

Abstract

The present invention relates to a method and system for generating three-dimensional images (A, A2) of at least a partial segment of a row of teeth (Z) using a stereo camera system (1) with a surgical microscope (2), and a computer program product wherein the stereo camera system (1) includes a first image capturing device (5a) and another image capturing device (5b), wherein a. corresponding image mirrors (S5a, S5b) are detected in the image (I5a) generated by the first image capturing device (5a) and the image (I5b) generated by the other image capturing device (5b), the image mirrors being provided by mirror elements (3) arranged in the capture area (4) of the stereo camera system (1), such that image mirrors of at least a partial segment of a row of teeth (Z) can be imaged by the first image capturing device (5a) and the other image capturing device (5b), b. the orientation (P) of the mirror elements (3) is determined, and c. three-dimensional images (A, A2) are determined based on the at least image mirrors (S5a, S5b) and the orientation (P) of the mirror elements (3).

Description

Technical Field

[0001] The present invention relates to a method and system for generating a three-dimensional image of at least a partial segment of a row of teeth using a stereo camera system of a surgical microscope, and to a computer program product and mirror element for generating the three-dimensional image. Background Technology

[0002] In dentistry, among other things, dental impressions are required, particularly in cases of restorative treatment with implants or orthodontic treatment. These are used, for example, to determine occlusal position and / or jaw status, especially for documentation at different stages of treatment. Dental impressions are also important as the basis for the planning and fabrication of implants and braces / splint.

[0003] As is well known, a malleable material is pressed onto a row of teeth to create a dental impression. After a typical waiting period of several minutes, the dried material is then removed from the teeth, providing a negative model of the teeth. This negative model can then be used to create a model of the teeth, such as a plaster model, which can be used for the aforementioned applications. In fact, when the material is removed from the teeth, minor alterations can occur to the negative model, leading to a deterioration in the accuracy of the resulting model, which is problematic. In some cases, this deterioration may necessitate repeated printing. Similarly, the time required to create the impression, particularly the previously explained waiting time, and material consumption are generally undesirable aspects.

[0004] So-called intraoral scanners are also known, serving as an alternative to the graphical representation of impressions made using malleable materials. These intraoral scanners use various measurement methods to generate a reconstruction of the surface of a row of teeth, as well as a digital model, which can then be used as the basis for the described applications. For example, it is conceivable that the model serves as the basis for producing dental impressions via additive manufacturing methods (especially 3D printing). Implants can also be produced in this way, which can then be implanted in a timely manner.

[0005] Typically, intraoral scanners generate signals based on corresponding physical measurement principles using sensors, and then process these signals to reconstruct or create a model. Known measurement principles for intraoral scanners include confocal laser scanning, triangulation, and tactile measurement. To create the most complete and accurate model possible, all sides of a row of teeth or a single tooth must be captured using (multiple) corresponding sensors. A known disadvantage of intraoral scanners is that, during use, a sensor carrier with one or more sensors used in each case needs to be inserted into the mouth to specifically capture the back surfaces of a row of teeth, i.e., the side facing inwards. This insertion can be very uncomfortable for the patient, as it can lead to unpleasant contact with the lips or other areas of the oral cavity. The patient may also feel discomfort from deep insertion into the oral cavity (which may be necessary). Another disadvantage is that the sensor carrier, or the portion of the sensor carrier introduced into the mouth, must be cleaned after use, undesirably delaying reuse.

[0006] For those taking dental impressions, such as dentists or orthodontists, this type of intraoral scanner in the treatment room represents an additional piece of equipment that, due to its size, disadvantageously reduces the available space in the treatment room. Furthermore, it may be difficult to integrate such an additional device into established procedures (such as those used for taking dental impressions).

[0007] Surgical microscopes are also known. These microscopes are used by the user during treatment to provide images, particularly magnified images, of the treated area (especially the site). So-called stereoscopic surgical microscopes typically include two separate optical channels for beam guidance and can provide the user with a depth impression of the area being examined. For this purpose, the beams guided in the two channels can be captured by the user's eye via eyepieces. As an alternative or complement, digital surgical microscopes include two image-capturing devices, each capturing the beam in one of the optical channels to generate an image, which is then used to provide the user with a three-dimensional image, hereinafter also referred to as corresponding images, based on the two images via a suitable display device. Furthermore, other surgical microscopes capable of optically capturing depth information and providing three-dimensional images of the treated area are also known. For this purpose, optical detection systems, particularly as alternatives to stereoscopic vision systems, can be used, for example in surgical microscopes, to provide depth information based on interferometry, triangulation, time-of-flight (TOF), or microlens arrays.

[0008] Accurate calibration of the stereo camera system is required to ensure correct depiction, where known calibration methods are used to determine intrinsic and extrinsic camera parameters, which are subsequently used by the image processing process to ensure correct depiction. Intrinsic camera parameters describe parameters related to the respective camera / image capturing device itself, such as its distortion. Extrinsic camera parameters describe the relationships between the image capturing devices, particularly spatial relationships, and thus the relationships between camera images. Such intrinsic and extrinsic camera parameters are known to those skilled in the art.

[0009] Known prior art includes DE 10 2020 133 627A1, which discloses a method and intraoral scanner for detecting the surface morphology of translucent objects (particularly dental objects).

[0010] DE 10 2019 008 510A1 is also known; it also discloses an intraoral scanner, particularly for three-dimensional scanning of the maxilla or mandible with or without teeth and jaw components in the context of implant prostheses.

[0011] DE 10 2016 121 687A1 is also known; it also discloses an intraoral scanner for digital dental impressions in the dental field and a method for generating digital dental impressions by means of an intraoral scanner.

[0012] EP 3 689 295A1 is also known; it discloses dental observation equipment, in which a so-called dental microscope is used.

[0013] The technical problem arising in this context is the development of methods and systems for generating three-dimensional images of at least a partial segment of a row of teeth, as well as computer program products and mirror elements for generating such three-dimensional images, which allow for rapid, accurate, and patient-friendly generation of the images in time. Furthermore, it should be possible to integrate improvements into existing application processes and treatment rooms, which in turn reduces the costs associated with providing such a system. Summary of the Invention

[0014] Based on the subject matter characterized by the independent claims, the solution to the technical problem is obvious. Other advantageous configurations of the invention are apparent according to the dependent claims.

[0015] A method is proposed for generating three-dimensional images of at least a partial segment of a row of teeth using a stereo camera system of a surgical microscope. Surgical microscopes can be used for magnified depiction of objects or regions, especially in medical applications. Therefore, in particular, partial areas of the mouth or areas within the mouth can be depicted.

[0016] The surgical microscope includes a stereo camera system having a first image capturing device and a second image capturing device. These can each be designed to generate a two-dimensional image. In this case, an image with a predetermined number of image elements and therefore a predetermined resolution can be generated. For example, the image sensor of the image capturing device can be a CMOS sensor or a CCD sensor. Needless to say, other sensor types can also be used. As mentioned above, the surgical microscope can include two optically independent beam paths, wherein the first image capturing device is arranged and / or designed such that an image can be generated based on a beam guided in the first beam path. The other image capturing device can be arranged and / or designed such that another image can be generated based on a beam guided in the other beam path. In particular, images can be generated simultaneously. Furthermore, the image generated by the first image capturing device and the other image capturing device and subsequently used to generate a three-dimensional image can be referred to as a corresponding image. This description also extends to a surgical microscope that, in addition to or in an alternative to the stereo camera system, uses another optical capturing system to generate a three-dimensional image, particularly to provide depth information. Such an optical capturing system has already been described in the above introduction.

[0017] Furthermore, the surgical microscope may include at least one optical element for beam guiding and / or beam shaping, particularly in the form of a lens element, wherein at least one optical element may be used, for example, to generate a magnified image. The optical properties of the surgical microscope (e.g., magnification, focus, zoom, exposure time, and capture area size) may be adjustable.

[0018] The stereo camera system can be a calibrated stereo camera system. In particular, the aforementioned intrinsic and extrinsic parameters of the stereo camera system can therefore be predetermined, especially through calibration methods known to those skilled in the art. Preferably, the aforementioned parameters are determined for all or predetermined operating states of the surgical microscope, wherein the operating states are characterized by the setting (adjustable) parameters of the surgical microscope (e.g., zoom, focus, capture area).

[0019] The surgical microscope may additionally include at least one eyepiece through which a user can gaze or look into in order to visually capture an image generated by the surgical microscope. In particular, the user can also capture the area to be examined in three dimensions through the eyepiece. The surgical microscope may include at least one objective lens or objective lens system, wherein the latter includes at least one optical element for beam guiding and / or beam shaping. The eyepiece may be optically connected to the objective lens or is already optically connected to the objective lens.

[0020] A surgical microscope can be part of a microscope system, which may include not only the surgical microscope but also a support for holding it. In this context, the support can be designed to allow the surgical microscope to move in space, particularly having at least one degree of freedom, preferably six degrees of freedom, where the degrees of freedom can be translational or rotational. The degrees of freedom in this context can relate to a reference coordinate system. The vertical axis (z-axis) of this reference coordinate system can be parallel to gravity and oriented opposite to it. In this context, the longitudinal axis (x-axis) and transverse axis (y-axis) of the reference coordinate system can span a plane oriented perpendicular to the vertical axis. Furthermore, the longitudinal and transverse axes can also be orthogonal to each other. Additionally, the support can include at least one drive mechanism, such as a servo motor, for moving the surgical microscope. The support can also include means for transmitting force / torque, such as gears and / or coupling units. Therefore, the surgical microscope can be mounted or held in a movable manner. Furthermore, this allows the user to modify the posture, i.e., position and / or orientation, of the surgical microscope, for example, to modify the viewing angle over the examination area or to view other examination areas.

[0021] Surgical microscopes, especially dental surgical microscopes, are designed to generate images in dental applications.

[0022] A segment of a row of teeth may in particular include at least one tooth or a portion of a tooth. "Teeth" may also refer to dentures as understood in this invention.

[0023] According to the present invention, the proposed method includes the following steps:

[0024] In the first step, corresponding image mirrors are detected in the image generated by the first image capturing device of the stereo camera system and in the image generated by the other image capturing device of the stereo camera system. These image mirrors are provided by mirror elements arranged in the capture area of ​​the stereo camera system.

[0025] Therefore, specifically, before detecting the imaged mirror, the aforementioned mirror element can be arranged in the capture area of ​​the stereo camera system, whereby the image of at least one segment of the row of teeth can be imaged by a first image capture device and another image capture device. Furthermore, prior to detection, images, particularly corresponding images, can be generated by the image capture devices, and these images are subsequently used to determine the three-dimensional image. This will be explained in detail below.

[0026] Specifically, the mirror element can be a dental mirror or a portion thereof. Specifically, the mirror element can include or take the form of a mirror surface that reflects radiation. An image of the mirror surface, i.e., an imaged mirror, generated by an image capturing device is generated by capturing this reflected radiation. The image generated / provided by the mirror element is thus perceived by means of capturing the reflected radiation. The capture performed by the image capturing device results in the generation of the imaged mirror. However, in addition to the imaged mirror, the image generated by the image capturing device may also include other areas that are not imaged by the mirror. In other words, the mirror may be imaged in a partial area of ​​the image generated by the image capturing device. In the imaged mirror, at least a partial segment of the row of teeth is imaged. The mirror element may also include a frame segment surrounding the mirror surface. The mirror element may also include a handle segment allowing the user to position the mirror element in space. The mirror element is preferably a mirror element having a non-curved mirror surface. Preferably, the mirror surface is a circular surface. However, the use of a polygonal mirror surface is also contemplated.

[0027] In the second step, the orientation of the mirror element, particularly the orientation of the mirror surface, is determined. Orientation can include translational and rotational components. For example, the position of a reference point of the mirror element (e.g., the center of the mirror surface) and the orientation of the mirror element (e.g., the orientation of the mirror surface normal) can be determined as the orientation of the mirror element. It goes without saying that the positions of multiple reference points of the mirror element or the orientation of multiple segments can also be determined as the orientation, especially in the case of a curved mirror surface. Exemplary methods for determining the orientation are explained in detail below. The orientation can be determined in a reference coordinate system. For example, this could be the reference coordinate system of a stereo camera system or a surgical microscope, or a reference coordinate system as previously explained.

[0028] In the third step, a 3D image is determined based on at least the image of the mirror and the pose of the mirror element, the image of which is detected in (corresponding) images generated by two image capture devices. For example, a stereo reconstruction method can be used for this purpose, in which the image of the mirror forms the input image for the method. Such methods are known to those skilled in the art. In particular, corresponding image elements can be determined in the two input images in such a method. For example, a feature matching method can be used to determine such corresponding pixels or groups of pixels. The corresponding methods and features are known to those skilled in the art. An exemplary feature is a so-called SIFT feature, i.e., a feature of scale-invariant feature transform. However, it is self-evident that other methods can also be used for this determination, such as variational methods or AI-based methods. The 3D coordinates of the object point or object segment imaged in the corresponding image element or group of image elements can then be determined in the reference coordinate system previously explained. This can also be referred to as reconstruction, in which a corresponding reconstruction method is performed based on the pose of the mirror element. In particular, at least one method step of the reconstruction method can be performed based on the pose. In particular, the pose can be represented by at least one parameter, in which at least one method step is performed based on the parameter, or the parameter is considered during implementation. Preferably, a stereo triangulation reconstruction method is performed to determine the three-dimensional image. Stereo triangulation reconstruction methods are known to those skilled in the art. In this case, the projection matrix used during reconstruction, which describes the perspective transformation from the coordinates of the three-dimensional object in the reference coordinate system to the coordinates of the two-dimensional image, can be determined based on the orientation of the mirror elements and the (known) laws of reflection. In other words, the orientation of the mirror elements affects the projection matrices of both image capturing devices, and therefore also affects the stereo triangulation reconstruction performed based on or dependent on these projection matrices. For example, so-called homogeneous solution methods or so-called non-homogeneous solution methods can be applied to the determination of the three-dimensional coordinates. In particular, correction methods for compensating for or eliminating nonlinear distortions in the image can be performed before determining the three-dimensional image.

[0029] The proposed method advantageously allows for the simple, accurate, and patient-friendly generation of three-dimensional images, particularly intraoral scans, because, compared to previously explained existing methods, it typically only requires the placement of a small-sized mirror element in the mouth to capture a partial segment of a row of teeth and image it in three dimensions.

[0030] The proposed method is specifically used to generate three-dimensional images of the back surfaces and / or the occlusal or masticatory surfaces of a row of teeth. The back surfaces of the teeth can specifically refer to the side of the teeth facing inwards into the mouth. Three-dimensional images of the front surfaces of a row of teeth or a partial segment of the teeth can be determined without the aforementioned first and second steps. In particular, the three-dimensional images can therefore be determined based on corresponding images already generated by an image capture device, wherein known methods for stereoscopic reconstruction can be used. The image capture device used to generate the images can be arranged outside the oral cavity, i.e., extraoral. Therefore, the method can also be referred to as extraoral scanning.

[0031] For example, 3D images can be generated in the form of CAD datasets, such as in STL format. Such 3D images can then be visualized, for example, through the output of a display device. 3D images can also be used in further processes, such as CAD / CAM processes, for example, to generate dental impressions.

[0032] In another embodiment, the three-dimensional image is further determined based on at least one optical property of the mirror element. In this context, the at least one optical property may be predetermined. Alternatively, the at least one optical property may also be determined in another step of the proposed method, particularly in an image-based manner, i.e., by evaluating at least one image of the mirror element. In particular, the optical property of the mirror element may be a magnification or reduction property. It goes without saying that other optical properties of the mirror element that affect mirror imaging can also be considered. For example, optical properties may be represented by the interpreted projection matrix. This advantageously leads to high accuracy of the generated three-dimensional image.

[0033] Alternatively or cumulatively, the three-dimensional image is further determined based on at least one imaging property of the surgical microscope. Specifically, the imaging property can be a set magnification (zoom), a set focus, or any other imaging property that affects the image. This imaging property can also be represented by an interpreted projection matrix. This also advantageously leads to the possibility of generating high-precision three-dimensional images.

[0034] In another embodiment, the (corresponding) image of the virtual image capturing device is determined at least based on the orientation of the mirror element, wherein at least one corresponding segment of a row of teeth reflected in the catadioptric system is imaged in the image of such a virtual image capturing device. Furthermore, a three-dimensional image is determined based on the image of the virtual image capturing device (particularly the corresponding segment in the corresponding image).

[0035] A catadioptric system refers to a relay optical system that includes at least a mirror element and an optical element, such as an objective lens, of an image capturing device. Specifically, a catadioptric system may include the optical element of an objective lens of a surgical microscope. The beam path through the catadioptric system can be determined based on the optical properties of the optical elements in the system (which are known or determinable in advance) and based on the orientation of the mirror element and known optical laws.

[0036] A virtual image capture device is a model of an image capture device, which is mathematical or physical, and in particular, can be evaluated with computer assistance. Based on the model, virtual images generated or computed by the virtual image capture device can be produced or calculated, particularly through computer-implemented computation of image elements. This virtual image depends in particular on the parameters and orientation of the (modeled) image capture device. These parameters of the virtual image capture device, particularly extrinsic and / or intrinsic parameters, can depend on the optical properties of the mirror elements. If the mirror surface is, for example, not curved and has no magnification properties, the intrinsic parameters of the virtual image capture device can be equal to the intrinsic parameters of the modeled image capture device.

[0037] Specifically, the orientation of the virtual image capturing device can be determined based on the orientation of the mirror element, such that the virtual image captured by the virtual image capturing device in that orientation images the non-reflective segment of the dental arch, which is reflected by the catadioptric system and therefore also by the mirror element. The latter represents the corresponding segment. In addition to the orientation of the mirror element, the generation of this virtual image also depends on (further) properties of the catadioptric system, such as the objective lens's zoom setting.

[0038] The three-dimensional image can then be determined based on the virtual image (particularly a virtual image of the corresponding segment) using methods known to those skilled in the art. An exemplary method has been explained above. In this method, in particular, the properties of the catadioptric system can be considered, and therefore the properties of the mirror element's orientation can also be considered. In other words, the reflected image can be transformed into a non-reflective image, and then the three-dimensional image can be generated based on the non-reflective image. This advantageously leads to an accurate and computationally readily achievable determination of the three-dimensional image, which can be generated with particularly high precision.

[0039] In another embodiment, the pose is determined by evaluating at least one property of the imaged mirror or the imaged mirror element (or a segment thereof). The at least one property can be determined in an image-based manner, particularly by evaluating an image generated by a corresponding image capture device. Specifically, the imaged mirror surface or the imaged mirror element can be identified in such an image, for example, by object recognition methods known to those skilled in the art. For example, the object recognition method could be a segmentation method. Thus, for example, the imaged mirror surface, the imaged frame segment, or the imaged handle segment can be identified in an image-based manner. For example, the segment of the mirror element (e.g., the frame segment) can be formed from a material having predetermined optical properties (e.g., a matte material), particularly to allow for reliable detection of this segment in the image. Alternatively, detection can also be achieved by means of a user selecting an image region, for example, via a suitable input device, in which the imaged mirror or segment to be detected is imaged.

[0040] The properties of the image mirror or the mirror element of the image can be geometric properties of the image mirror, such as dimensional properties, like dimension variables. Dimension variables can be width, height, diameter, or any other dimensional variable. Alternatively, the property can be a shape property, such as a geometric shape, such as a circular shape, an elliptical shape, a rectangular shape, or any other geometric shape. In particular, a shape factor representing the relationship between the shape of the image and the actual shape can be determined, where the pose is determined based on the shape factor.

[0041] As mentioned above, the orientation of a mirror element can affect the imaging of an image capture device. Therefore, the orientation can also affect how the actual properties of the mirror image or mirror element are mapped to the properties of the imaged mirror image or mirror element. If the relationship between the actual properties and the properties of the imaged mirror can be described by a transformation matrix that depends on the orientation, then the orientation can be determined based on the actual properties and the properties of the imaged mirror or the imaged mirror element. The actual properties can be known, for example, from a model of the mirror element (especially a CAD model), or they can be determined.

[0042] If the mirror element or a portion thereof (especially the mirror surface) is circular and the imaged mirror is elliptical, the pose can be determined based on the properties of the ellipse (e.g., the orientation and length of the elliptical axis) and the pre-known properties of the circular mirror element, such that the pre-known properties are transformed into the properties of the imaged mirror. If a polygonal mirror element, especially an equilateral polygonal mirror element, is used, at least a portion of the pose can be determined by the ratio of the edge lengths in the image and the relative positions of the edges to each other in the image.

[0043] Additionally, attributes can be the image mirror or the orientation of the image mirror element or a portion thereof in the image coordinate system. For example, position can be determined as the location of a reference point (e.g., the geometric center). For example, the orientation of the axis of the reference segment can be determined as the orientation. For example, if the mirror element includes a handle segment, the handle segment can be identified in the image, and its position and / or orientation can be determined. For example, the orientation of the longitudinal axis of the handle segment can be determined.

[0044] If the pose is determined by evaluating at least one property of the image or the mirror element of the image, this advantageously results in a simple determination of the pose, since the image generated in any case can be evaluated for the purpose of determining the pose.

[0045] Alternatively, the orientation can be determined based on markings. For this purpose, the mirror element may include or take the form of at least one marking element for determining the orientation of the mirror element. It goes without saying that the mirror element may also include or take the form of multiple markings, wherein the orientation of the mirror element can be determined based on the relative positions and / or dimensions of these markings that are known in advance.

[0046] The marking element can be an active marking element or preferably a passive marking element. It can be designed to be captured by a capturing device. In particular, the capturing device can be an image capturing device. Therefore, in this case, the marking element can be an optically captureable marking element. For example, it is conceivable that an optically captureable mark includes a predetermined pattern that allows the orientation of the mark to be determined and thus the orientation of the mirror element. For example, such an optically captureable pattern can take the form of a QR code. Alternatively, such an optically captureable mark can be a reflective marking element, wherein these are, for example, designed to reflect radiation from a predetermined wavelength range (e.g., the infrared wavelength range). The image capturing device for optically capturing the marking element can be the image capturing device of a stereo camera system or a different image capturing device. If the mirror element comprises multiple marking elements, the orientation of the mirror element can also be determined based on the relative positions of the marking elements imaged in the image. Furthermore, the orientation of the mirror element can be determined at least in part by stereoscopic determination of the orientation of at least the marking elements.

[0047] Image capture devices and marker elements can be used to perform, in particular, so-called single-field-of-view pose determination. In this case, the pose can be determined by evaluating a two-dimensional image, specifically exactly one two-dimensional image captured by an image capture device. Specifically, the intensity values ​​of the pixels in the two-dimensional image can be evaluated to determine the position. This method of image-based position detection using exactly one image capture device and / or based on exactly one two-dimensional image is known to those skilled in the art. However, if a stereo camera system is used, the pose can also be determined by evaluating the corresponding image captured by the image capture device.

[0048] In particular, the pose can therefore be determined by optical tracking methods, specifically using an image capture device to determine the pose. This optical tracking can be marker-based tracking, in which specific visually or optically captureable marker elements, such as QR codes or optical patterns of different designs, are used to determine the pose.

[0049] Alternatively, particularly when determining the pose by evaluating at least one property of the image or the mirror element of the image, unmarked tracking methods can also be applied, in which features are captured and used to determine the pose in these methods.

[0050] However, as an alternative to optically captureable tagging elements, the orientation of the mirror element can also be determined using tagging elements that can be captured by other devices, such as tagging elements that can be captured magnetically, capacitively, inductively, or in a radio-based manner. For example, the tagging element can be designed as an RFID tag.

[0051] The mirror element may also include an attitude sensor, such as an initialization sensor or a GNSS sensor, wherein the attitude is determined based on the output signal of such a sensor. In this embodiment, the surgical microscope may include, or may be connected to, a receiver device for the output signal generated by the attitude sensor.

[0052] Needless to say, a hybrid approach can also be used to determine attitude, which combines at least two of the attitude determination methods explained above.

[0053] In the case of marker-based pose determination, there is an advantage to very accurate pose determination, which in turn leads to the generation of accurate 3D images.

[0054] The marking element can also be identifiable, particularly bidirectionally identifiable. For example, the pattern of an optically identifiable mark can encode the mark's identity. Therefore, a marking element or mirror element can be identified by capturing the marking element. Thus, a determinable identity can be assigned to the attributes of the mirror element, particularly the optical attributes explained above. This assignment, along with the identity and attributes, can be stored in a retrieveable or readable manner, for example, in a memory device. This advantageously leads to the simple determination of the optical attributes of the mirror element.

[0055] For the purpose of marker-based attitude determination, in another embodiment, at least the marker element is imaged by at least one image capturing device of a stereo camera system or by another image capturing device. At least one marker element is arranged on or formed by a mirror element. The attitude is then determined based on at least one property of the imaged marker element. This has already been explained above. The other image capturing device can, in particular, be a tracking camera or an environmental camera of a microscope system, taking a different form from the image capturing device of the stereo camera system. This tracking or environmental camera can be used specifically for marker-based tracking of another instrument. In both cases, this advantageously produces the simplest possible integration for optical attitude determination when using a surgical microscope or a microscope system with a surgical microscope.

[0056] In a further embodiment, the focal position of the surgical microscope is set based on the orientation of the mirror element. Specifically, this allows the focal position to be set at a point on the mirror surface or at a point spaced no more than a predetermined distance from the mirror surface. In particular, the predetermined distance can depend on the depth of field of the surgical microscope, especially if it is smaller than the depth of field range. In this case, the depth of field is known in advance or can be determined. Therefore, this allows the mirror to achieve high imaging quality, which in turn advantageously increases the accuracy of the generated three-dimensional image.

[0057] In particular, this also allows for easier and more reliable detection of the image in the image captured by the image capture device.

[0058] In another embodiment, the radiation captured to generate images for a stereo camera system is filtered. In a preferred embodiment, the filtering is polarization filtering. However, it goes without saying that other radiation filters may also be used. Advantageously, this can suppress unwanted reflections from the tooth surfaces in the image, thereby improving the accuracy of the generated 3D image. In this case, polarization filtering makes it possible to suppress reflections to the greatest extent or completely.

[0059] In another embodiment, filter elements are arranged in the illumination beam path and / or imaging beam path of the surgical microscope. Specifically, the corresponding filter elements can be arranged in each imaging beam path. Both cases result in good structural integration of the filter elements within the surgical microscope or microscope system, which allows for the generation of very accurate three-dimensional images.

[0060] In another alternative, or cumulatively, filter elements are arranged on the mirror element. For example, the filter elements can be arranged on the mirror surface of the mirror element. Advantageously, since the mirror element provides the required filter properties, there is no need to integrate additional filter elements into the surgical microscope or microscope system to generate high-precision three-dimensional images.

[0061] In another embodiment, at least a portion of a row of teeth is irradiated by radiation having predetermined radiation properties. For example, such radiation properties may be predetermined wavelengths, predetermined intensities, or, in a preferred embodiment, predetermined polarization properties or other properties of the radiation for illumination purposes. Advantageously, this can also reduce reflections from the tooth surface, which in turn has a beneficial effect on the accuracy of the generated three-dimensional image.

[0062] In another embodiment, the image generated by the stereo camera system is filtered, wherein the 3D image is determined based at least on the filtered image. Specifically, filtering can be performed to reduce unwanted reflections in the image. However, filtering can also generally be used to improve image quality, thereby advantageously improving the accuracy of the 3D image. An exemplary method for filtering to suppress reflections is the so-called tone mapping method.

[0063] For example, teeth can be temporarily stained during image capture. Then, color filtering can be performed, whereby, for example, color components in the image that are different from the color of the stain can be reduced.

[0064] In another embodiment, at least one quality metric of the 3D image is determined. Furthermore, if the quality metric is less than a predetermined threshold, user information is generated. In this case, the quality metric is thus selected such that it is proportional to the quality of the 3D image. The user information can be output to the user via an output device, such as an optical or acoustic output device. This can be part of a surgical microscope or microscope system.

[0065] For example, it can be determined whether the point density in a predetermined segment of the generated 3D image is less than a predetermined threshold. If this is the case, user information can be generated because it may be desirable to perform a more accurate reconstruction with a higher density, at least in that region. In particular, the determined quality metric (e.g., point density) can be generated as part of the user information.

[0066] Furthermore, if the quality measurement is determined in a manner specific to a particular region, information about that region, particularly its orientation, can be generated as part of the user information.

[0067] This advantageously leads to ensuring high accuracy of the generated 3D images, since user information is generated in the event of potentially undesirable low quality, and the method can be performed again, for example, particularly for regions where unacceptable low quality metrics have been identified.

[0068] A system for generating a three-dimensional image of at least a partial segment of a row of teeth is also proposed, wherein the system includes a stereo camera system and at least one evaluation device. The stereo camera system includes a first image capture device and a second image capture device. The system is configured to perform a method according to one of the embodiments described in this disclosure, particularly the following steps:

[0069] a) Detecting mirror images of images generated by a first image capture device and images generated by another image capture device, wherein the mirror image is provided by a mirror element arranged in the capture area of ​​the stereo camera system and reflecting at least one segment of a row of teeth.

[0070] b) Determine the orientation of the mirror element.

[0071] c) Determine the three-dimensional image based at least on the image being imaged and the orientation of the mirror element.

[0072] The evaluation apparatus may take the form of a computing device or include a computing device. The computing device may further include or take the form of a microcontroller or integrated circuit. In this case, the evaluation apparatus may perform at least one of steps a), b), and c), but preferably all of these steps.

[0073] This system can be a component of a surgical microscope or microscope system, wherein the surgical microscope or microscope system may include a stereo camera system and an evaluation device. Furthermore, the system may include a capture device for capturing marker elements. Additionally, the system may include a filter element for filtering radiation used to generate an image from the stereo camera system. Furthermore, the system may include an illumination device for illuminating a portion of the area with predetermined radiation properties. Finally, the system may include an output device for user information.

[0074] This system advantageously enables the implementation of the method according to one of the embodiments described in this disclosure, as well as the advantages also described.

[0075] In another embodiment, the system includes a mirror element that will be arranged in the capture area of ​​the stereo camera system.

[0076] A computer program product having a computer program is also proposed, wherein the computer program includes a software device for performing one, several, or all steps of a method according to one of the embodiments described in this disclosure, particularly steps from a set including a first step, a second step, and a third step, when the computer program is executed by a computer or an automated system, or is executed in a computer or an automated system. In other words, the method can be a computer-implemented method.

[0077] A mirror element for generating a three-dimensional image of at least a partial segment of a row of teeth is also proposed. According to the invention, the mirror element includes or forms at least one marking element for determining the orientation of the mirror element. Alternatively or cumulatively, the mirror element includes or forms at least one filter element for filtering reflected radiation. This advantage and corresponding advantages have been explained above. Attached Figure Description

[0078] The invention will be explained in detail based on exemplary embodiments. In the accompanying drawings:

[0079] Figure 1 A schematic flowchart of the method according to the present invention is shown.

[0080] Figure 2 A schematic flowchart of the method according to the invention in another embodiment is shown.

[0081] Figure 3 A schematic block diagram of the system according to the present invention is shown.

[0082] Figure 4a The mirror element is shown in its first orientation.

[0083] Figure 4b It shows a different posture Figure 4a The mirror element depicted in the text,

[0084] Figure 4c It shows a different posture Figure 4a The mirror element depicted in the text,

[0085] Figure 4d It shows a different posture Figure 4a The mirror element depicted in the text,

[0086] Figure 5 A schematic diagram of a mirror element according to the present invention is shown.

[0087] Figure 6 A schematic block diagram of a virtual image capture device is shown.

[0088] Figure 7a A schematic diagram of a stereoscopic capture of a row of teeth without a mirror element is shown, and

[0089] Figure 7b A schematic diagram of a three-dimensional capture of a row of teeth with a mirror element is shown.

[0090] The same reference numerals in the following figures denote elements having the same or similar technical features. Detailed Implementation

[0091] Figure 1A schematic flowchart of a method according to the present invention is shown, which is used to generate a row of teeth Z using a stereo camera system 1 of a surgical microscope 2 (see...). Figure 3 A three-dimensional image A of at least a portion of a row of teeth Z. Prior to the first step S1 of the method, a mirror element 3 is arranged in the capture area 4 of the stereo camera system 1 such that a mirror image of at least a portion of a row of teeth Z can be imaged by a first image capture device 5a and another image capture device 5b of the stereo camera system 1 (arrangement step SA). Following this arrangement, the first image capture device 5a and the other image capture device 5b each generate corresponding images I5a, I5b, which can be referred to as corresponding images (image generation step SB). These are generated from different locations and / or with different orientations. Furthermore, these can be generated simultaneously or with a predetermined maximum time offset. In the first step S1 of the method, the image I5a is then detected in the image I5a generated by the first image capture device 5a, for example, using an object recognition method. In addition to the portion of the image image provided by the mirror element 3, in this case, the image I5a generated by the first image capture device 5a may include another portion of the image, which, for example, images other portions of the row of teeth Z, particularly those portions not reflected by the mirror element 3. The image mirror S5b is also detected accordingly in the image I5b generated by another image capture device 5b. The detected image mirrors S5a and S5b form input variables for determining the three-dimensional image A. In the second step S2 of the method, the orientation P, i.e., position and / or orientation, of the mirror element 3 is determined in a reference coordinate system. The reference coordinate system can be the coordinate system of the surgical microscope 2 used as a reference or the coordinate system of the stereo camera system 1 used as a reference. It goes without saying that other reference coordinate systems are also conceivable. In addition to the image mirrors S5a and S5b, the orientation P forms another input variable for determining the three-dimensional image A.

[0092] In the third step S3, the three-dimensional image A is then determined based on at least the imaged mirrors S5a and S5b and the pose P of the mirror element 3, for example, by or using stereo reconstruction. This has already been explained above.

[0093] In this context, it should be mentioned that, Figure 1 The order of the first step S1 and the second step S2 described in the diagram is not mandatory. In particular, the pose P can be determined simultaneously with or before the detection of the imaged mirrors S5a and S5b.

[0094] It is also possible to additionally determine the three-dimensional image A based on at least one optical property of the mirror element 3. This optical property then forms another input variable for the third step S3. In this context, the optical property can be predetermined. In particular, a mirror element can be identified, wherein at least one optical property can be assigned a preferred dual unique identity to the mirror element 3. Depending on this assignment, the optical property can then be determined using, for example, the identified identity of the mirror element 3 retrieved from a database, which can be stored in a storage device and represents the assignment of the identity of at least one optical property. Figure 1 This identification step, not shown, can be performed before the third step S3. Preferably, there can be image-based identification of the mirror element, for which at least one of the generated images I5a and I5b of the image formed by the mirror element 3 is evaluated. For example, without being mandatory, identification can be performed simultaneously with the determination of the pose in the second step S2. Identification can be achieved by evaluating at least one attribute of the imaged mirror element or in a marker-based manner. This will still be explained in detail below in conjunction with the determination of the pose P.

[0095] Alternatively or cumulatively, prior to the third step S3, the imaging properties of the surgical microscope 2, such as the currently set zoom, can also be determined. This imaging property of the surgical microscope 2 can then form another input variable for the third step S3. Therefore, the three-dimensional image A can be determined additionally based on at least one optical property of the mirror element 3 and / or based on at least one imaging property of the surgical microscope 2.

[0096] The determination of the orientation P of the mirror element 3 in the second step S2 can be achieved in an image-based manner, specifically by evaluating at least one attribute of the imaged mirrors S5a and S5b or the imaged mirror element 3. The attribute can be a dimensional attribute. The attribute can also be a shape attribute. These have been explained above. In particular, the attributes in images S5a and S5b can be determined and compared with the image or mirror element 3 at a reference position (see, for example...). Figure 4a The image is compared with a pre-known property of the mirror element 3, particularly with a mathematically determinable image of the mirror or mirror element 3 at that reference position. The orientation P of the mirror element 3 can then be determined based on the deviation between the actual properties in the image and the pre-known properties determined therefrom. For example, a transformation can be determined to transform the image of the mirror or mirror element at the reference position into the actual image, the transformation containing information about the current orientation P of the mirror element 3.

[0097] Alternatively, the determination of pose P can be achieved in a label-based manner. For this purpose, it is possible to capture... Figure 5In the exemplary embodiments described herein, a tag element is depicted as an optically trappable tag element 6. Such a tag element 6 may be an active tag element, i.e., a tag element that generates a trappable signal with energy consumption, or a passive tag element that can be trapped without consuming energy. Figure 5 The optically captureable tag element 6 depicted, employing a barcode or optical pattern, is an example of a passive tag element. However, it is equally self-evident that an optically captureable tag can also be an active tag, which, for example, generates an optically captureable signal with energy consumption. However, in an alternative to the optically captureable tag element 6, a tag element captureable in another form, such as a magnetically captureable tag element, can also be used. In this case, the tag element can be arranged in or on the mirror element 3, where the orientation P of the mirror element can then be determined based on the captured tag element.

[0098] If at least one marking element is an optically captureable marking element 6, for example Figure 5 The passive optically captureable marker element 6 shown can be imaged by at least one image capture device 5a, 5b of the stereo camera system 1 or by another image capture device (not shown) to determine the pose P. The pose P can then be determined based on at least one attribute of the imaged marker element. In this case, the pose P can only be determined after capturing the corresponding images 5a, 5b.

[0099] Another approach is to set the focal position of the surgical microscope 2 based on the orientation P of the mirror element 3. In this case, images I5a and I5b, which are evaluated to determine the three-dimensional image A, can be generated after the orientation P is determined. If the orientation P is determined in an image-based manner, an image for determining the orientation P can be generated before determining the orientation P, wherein the focal position is then set based on the orientation P, and subsequently, images I5a and I5b, which are mirror images S5a and S5b, are generated for detecting the imaging.

[0100] Figure 2 A schematic flowchart of the method according to the invention in another embodiment is shown. Figure 1 In contrast to the illustrated embodiment, in another image generation step SBV, images I5a and I5b (i.e., corresponding images) of the frontal view 7 from a row of teeth Z are additionally generated. In the reconstruction step SRV, a three-dimensional partial image A1 of the frontal view is generated based on these images I5a and I5b. Subsequently, the following steps are performed: Figure 1The method shown involves generating an image A that is a partial image A2 of the back surface 8 of a row of teeth Z and the chewing surface 9 of the teeth in the row of teeth Z. In the fusion step FS, the partial images A1 and A2 are fused / merged to form a composite image A of the row of teeth Z. For this purpose, corresponding points in the three-dimensional partial images A1 and A2 can be detected to facilitate fusion. For this purpose, it may be necessary to scale the structure imaged in at least one of the partial images A1 and A2, particularly the structure in the partial image A2 of the back surface 8. This scaling can be achieved based on the distance between the mirror element 13 and the reflective segment of the row of teeth Z. This distance can be determinable, particularly based on the pose P of the mirror element 13. The distance can also be determined based on different focal positions of the stereo camera system 1, which will be explained in detail below. The partial images A1 and A2 and the composite image A can preferably be provided in STL data format, which advantageously allows for their use in further processes, particularly in CAD / CAM processes. The composite three-dimensional image A or the partial images A1 and A2 can also be displayed to a user via a suitable display device. Information, such as color information, can be overlaid on the displayed image.

[0101] Figure 3 A schematic block diagram of a system according to the invention for generating a three-dimensional image A of at least a partial segment of a row of teeth Z is shown, wherein the system includes a stereo camera system 1 and at least one evaluation device 10. The system is configured to at least perform... Figure 1 and Figure 2 The steps S1, S2, and S3 are described in the text. It goes without saying that the system can also be configured to execute... Figure 2 The steps SBV, SRV, and FS are described in the text. In this case, the steps, or at least a portion thereof, can be performed by the evaluation device 10.

[0102] Figure 3 The capture areas EB of the image capture devices 5a and 5b and the optically separated beam paths 11a and 11b of the surgical microscope 2 are schematically depicted. The illumination device of the surgical microscope 2 capable of illuminating a row of teeth Z is not depicted. In this case, the illumination device can generate radiation with predetermined radiation properties (particularly predetermined polarization properties). The radiation reflected by the row of teeth Z reaches the image sensors of the image capture devices 5a and 5b via beam paths 11a and 11b, thereby generating images I5a and I5b of the row of teeth Z. This can be evaluated by the evaluation device 10. A mirror element 3 is also depicted, which similarly reflects the beam from the row of teeth Z, particularly the beam from its back surface 8, wherein the reflected radiation also reaches the image sensor via beam paths 11a and 11b and is imaged there as a mirror image. This image can then be detected by the evaluation device 10 as an imaged mirror image.

[0103] The radiation captured to generate images I5a and I5b of the stereo camera system 1 can be filtered. This can be achieved, for example, by a filter element arranged in the beam paths 11a and 11b in each case. Alternatively, the filter element can be arranged in the illumination beam path of the illumination device (not depicted) of the surgical microscope 1. Additionally, the filter element can be arranged on / at the mirror element 3. In particular, such a filter element can be a polarizing filter element. It is also possible that the evaluation device 10 filters the images I5a and I5b generated by the image capture devices 5a and 5b, for example, to suppress reflections.

[0104] Figure 4a An image of mirror element 3 in a reference orientation is shown. Mirror element 3 includes a handle section 12 and a circular mirror section 13, which in turn includes a mirror surface 14. For example, the center of this mirror surface 14 is a reference point P3 of mirror element 3. A coordinate system stationary relative to the mirror is depicted, having a longitudinal axis x3, a transverse axis y3, and a vertical axis z3 (see [reference]). Figure 4b ).

[0105] Figure 4b The image shows the mirror element 3 in posture P, which is when the mirror element 3 is in the position P. Figure 4a The reference position shown is formed when rotated about the longitudinal axis x3a. Clearly, in this case, Figure 4a The circular mirror surface 14 depicted is imaged as an ellipse. Depending on the orientation and length of the major and minor axes of this ellipse (which can be detected, for example, by an object recognition method), the rotation angle of the mirror element 3 about the longitudinal axis x3a can then be determined, whereby it can then be further determined... Figure 4b The current orientation P of the imaging mirror element 3 shown.

[0106] In a similar way, Figure 4c and Figure 4d It shows the relationship with Figure 4a The reference position shown is compared to the position around the transverse axis y3 ( Figure 4c ) or around the vertical axis z3 ( Figure 4d ) The mirror element 3 for rotating imaging. For example, it can be based on the longitudinal axis x3 ( Figure 4d The orientation of the elliptical image of the mirror surface 14 and / or the orientation and length of the axis of the elliptical image of the mirror surface 14 are used to determine the corresponding rotation angle.

[0107] from Figures 4a to 4d It can be seen that the orientation P of the mirror element 3 can be determined based on shape, wherein the shape properties of the imaging mirror element 3 can be determined, and the orientation P can then be determined based on these properties.

[0108] It is also evident that the center of mirror surface 14 is detectable. If, in addition to the point of reflection on mirror surface 14 (e.g., the center), the focus is also directed towards the non-reflective edge of mirror surface 14, the distance between mirror surface 14 (especially the reflection point) and a row of teeth Z can be determined by the difference in the focal point position.

[0109] Specifically, the difference between the focal position when the stereo camera system 1 or surgical microscope 2 is focused on a point on a non-reflective edge (e.g., a point on frame segment 13) and the focal position when focused on a point on the object reflected at mirror surface 14 (e.g., a point reflected at the center of mirror surface 14) can be determined. This difference in focal position can represent the distance between mirror element 13 and the object (in this case, a point on a row of teeth Z), which can therefore be determined based on this difference. Additionally, the distance can also be determined based on the orientation P of mirror element 13. This distance information can be used for scaling within the described stereo reconstruction, particularly to match the magnification when reconstructing reflective segments (e.g., the back side 8 of a row of teeth Z) with the magnification when reconstructing non-reflective segments (e.g., the front side 7 of a row of teeth Z), i.e., to perform scaling.

[0110] Figure 5 A schematic diagram of a mirror element 3 according to the invention is shown. The latter includes or forms a marking element 6 on the handle section 12, the marking element 6 being in the form of an optically captureable barcode. The mirror element 3 also includes another optically captureable marking element 6 on the frame section 13 of the mirror surface 14, which is in the form of a barcode. These marking elements can be captured in an image of the mirror element 3, wherein these marking elements specifically enable the identification of the mirror element 3 and the determination of the orientation P of the mirror element 3. Specifically, it is possible to... Figure 5 In the case of the mirror element 3 depicted in the image, each marker element 6 is detected, and the pose P can then be determined by the relative arrangement of the marker elements in the image.

[0111] Figure 6 A stereo camera system 1 is shown (see Figure 3 A schematic diagram of the image capturing device 5 and the mirror element 3 is shown, with the mirror element 3 arranged in the capturing area EB of the image capturing device 5. The object point OP to be imaged is also depicted, such as a point on the surface of a row of teeth Z (see [reference]). Figure 3 The normal n of the mirror surface 14 of the mirror element 3 is also depicted.

[0112] A virtual image capture device 15 is also depicted. The (virtual) image of this virtual image capture device 15 can be determined by evaluating a mathematical or physical model. Specifically, the model is determined in a manner that generates a virtual image that images a segment of a row of teeth Z in a non-reflective manner; that is, specifically, the object point OP corresponding to the segment reflected in the catadioptric system is imaged, however, taking into account the properties of the catadioptric system. A three-dimensional image A can then be determined based on the virtual image using methods known to those skilled in the art, such as by means of or using stereo reconstruction. This has already been explained above.

[0113] Figure 7a A schematic diagram illustrates stereoscopic capture of a row of teeth Z using two image capture devices 5a and 5b of a stereo camera system 1 without a mirror element 3. The capture of the frontal view 7 of the row of teeth Z is depicted, for example, in another image generation step SBV for reconstructing the three-dimensional image A of the frontal view 7 (see [link to image 1]). Figure 2 Implemented in ).

[0114] Figure 7b A schematic diagram shows stereoscopic capture of a row of teeth Z using two image capture devices 5a and 5b of a stereo camera system 1 with a mirror element 3. The mirror element 3 is shown, which is arranged inside the mouth and provides the back surface 8 of the row of teeth Z (see [reference]). Figure 3 The mirror image of the back side 8 is then captured by image capture devices 5a and 5b. A three-dimensional image A of the back side 8 is then reconstructed based on the corresponding mirror images S5a and S5b.

[0115] In addition, preoperative data can also be used with images generated by image capture devices 5a and 5b to generate a three-dimensional image A.

[0116] In an alternative approach, and similar to stereoscopic detection of the treatment area, depth information can also be optically captured by another capture system used in the surgical microscope to generate a three-dimensional image of at least a partial segment of a row of teeth. For this purpose, this other detection system can be used to generate an alternative image, replacing the image generated by the first image capture device and the image generated by the other image capture device, and in this alternative image, the mirror image provided by a mirror element arranged in the capture area of ​​the surgical microscope and, in particular, in the capture area of ​​the capture system, can be detected. Then, as explained, the orientation of the mirror element and the three-dimensional image can be determined at least based on the image and the orientation of the mirror element. Therefore, in particular, the optical depth information of a partial segment of a row of teeth can be captured by the surgical microscope and, in particular, by the capture system, and can be embedded in a suitable coordinate system.

[0117] List of reference numerals

[0118] 1. Stereo camera system

[0119] 2. Surgical microscope

[0120] 3-mirror element

[0121] 4 capture areas

[0122] 5. Image capture devices, 5a, 5b

[0123] 6 Optical Capture Marking Elements

[0124] 7 front

[0125] 8 Back

[0126] 9. Chewing surface

[0127] 10 Evaluation Devices

[0128] 11a, 11b beam paths

[0129] 12 handle sections

[0130] 13 Frame Sections

[0131] 14 mirror surfaces

[0132] 15 Virtual Image Capture Device

[0133] SA Layout Steps

[0134] SB image generation steps

[0135] S1 First Step

[0136] S2 Second Step

[0137] S3 Third Step

[0138] SBV image generation steps

[0139] SRV Reconstruction Steps

[0140] EB capture area

[0141] I5a and I5b images

[0142] Mirror images of S5a and S5b

[0143] P posture

[0144] Images A1, A2, and A

[0145] OP object point

Claims

1. A method for generating three-dimensional images (A, A2) of at least a partial segment of a row of teeth (Z) using a stereo camera system (1) of a surgical microscope (2), wherein the stereo camera system (1) comprises a first image capturing device (5a) and another image capturing device (5b), wherein, a. Detect corresponding image mirrors (S5a, S5b) in the image (I5a) generated by the first image capturing device (5a) and the image (I5b) generated by the other image capturing device (5b), the image mirrors being provided by mirror elements (3) arranged in the capture area (4) of the stereo camera system (1), such that the image mirrors of at least one partial segment of the row of teeth (Z) can be imaged by the first image capturing device (5a) and the other image capturing device (5b). b. Determine the orientation (P) of the mirror element (3). c. Determine the three-dimensional image (A, A2) based on at least the imaged mirrors (S5a, S5b) and the pose (P) of the mirror element (3).

2. The method of claim 1, wherein, The three-dimensional image (A, A2) is also determined based on at least one optical property of the mirror element (3) and / or at least one imaging property of the surgical microscope (2).

3. The method according to any of the preceding claims, characterized in that, The image of the virtual image capturing device is determined at least based on the pose (P) of the mirror element (3), wherein at least one corresponding segment of the row of teeth (Z) reflected in the catadioptric system is imaged in the image of the virtual image capturing device, wherein the three-dimensional image (A, A2) is determined at least based on the image of the virtual image capturing device.

4. The method according to claim 1 or 2, characterized in that, The pose (P) is determined by evaluating at least one property of the image or the mirror element (3) of the image or by using a marker-based method.

5. The method according to claim 4, characterized in that, For the purpose of determining the pose (P) based on the marker, at least one marker element (6) is imaged by at least one image capturing device (5a, 5b) of the stereo camera system (1) or by another image capturing device, wherein the at least one marker element (6) is arranged on or formed by the mirror element (3), and wherein the pose (P) is determined based on at least one attribute of the imaged marker element (6).

6. The method according to claim 1 or 2, characterized in that, The focal position of the surgical microscope (2) is set based on the orientation (P) of the mirror element (3).

7. The method according to claim 1 or 2, characterized in that, The radiation captured in order to generate the images (I5a, I5b) of the stereo camera system (1) is filtered.

8. The method according to claim 7, characterized in that, The filtering method is polarization filtering.

9. The method according to claim 1 or 2, characterized in that, The filter element is arranged in the illumination beam path and / or the imaging beam path (11a, 11b) and / or on the mirror element (3).

10. The method according to claim 1 or 2, characterized in that, At least one section of the row of teeth (Z) is irradiated by radiation having a predetermined radiation property.

11. The method according to claim 10, characterized in that, Generate radiation with predetermined polarization properties.

12. The method according to claim 7, characterized in that, The images (I5a, I5b) generated by the stereo camera system are filtered, wherein the three-dimensional images (A, A2) are determined based at least on the filtered images.

13. The method according to claim 1 or 2, characterized in that, Determine at least one quality metric for the three-dimensional image (A, A2), wherein if the quality metric is less than a predetermined threshold, user information is generated.

14. The method according to claim 1 or 2, characterized in that, The image of the virtual image capturing device is determined at least based on the pose (P) of the mirror element (3), wherein at least one corresponding segment of the row of teeth (Z) reflected in the catadioptric system is imaged in the image of the virtual image capturing device, wherein the three-dimensional image (A, A2) is determined at least based on the image of the virtual image capturing device; and The pose (P) is determined by evaluating at least one property of the image or the mirror element (3) of the image or by using a marker-based method.

15. The method according to claim 1 or 2, characterized in that, The pose (P) is determined by evaluating at least one property of the image or the mirror element (3) of the image, or in a marker-based manner; and The focal position of the surgical microscope (2) is set based on the orientation (P) of the mirror element (3).

16. The method according to claim 1 or 2, characterized in that, The radiation captured for generating the images (I5a, I5b) of the stereo camera system (1) is filtered; and In this process, at least a portion of the row of teeth (Z) is irradiated by radiation having a predetermined radiation property.

17. A system for generating three-dimensional images (A, A2) of at least one partial segment of a row of teeth (Z), comprising a stereo camera system (1) and at least one evaluation device (10), the stereo camera system (1) comprising a first image capture device (5a) and at least one other image capture device (5b). Its features are, The system is configured to perform the following steps: a. Detect mirror images (S5a, S5b) formed in the image (I5a) generated by the first image capture device (5a) and the image (I5b) generated by the other image capture device (5b), wherein the mirror images are generated by a mirror element (3) arranged in the capture area (4) of the stereo camera system (1) and reflect at least one portion of the row of teeth (Z). b. Determine the orientation (P) of the mirror element (3). c. The three-dimensional image (A, A2) is determined based at least on the image mirrors (S5a, S5b) and the orientation (P) of the mirror element (3).

18. The system according to claim 17, characterized in that, The system includes a mirror element (3).

19. A computer program, wherein, The computer program includes a software device configured to perform all of steps a to c of the method according to any one of claims 1 to 16 when the computer program is executed by or in the computer or automation system.

Images