3D marker element, medical product, tracking system and position detection method for spatial tracking

Abstract

The invention relates to a surgical 3D marker element (1) with a surface (2), on or in which a two-dimensional optical pattern (4) is permanently incorporated or applied, for spatial position detection of a medical product (100), wherein the optical pattern (4) is in the form of a matrix (6) with M rows and N columns with corresponding pattern elements (8) as pattern fields (8), and the optical pattern (4) has at least four pattern elements (10), of which at least two pattern elements (10) are designed differently in order to provide an optical reference for position detection of the 3D marker element (1) via an optical tracking system (500). The invention also relates to a medical product (100), a tracking system (500), a position detection method, a computer-readable storage medium and a computer program according to the associated claims.

Description

[0001] 3D marker element, medical device, tracking system and position detection method for spatial tracking

[0002] Description

[0003] Technical area

[0004] The present disclosure relates to a surgical (optical) 3D marker element having a surface, in particular a sterilizable or sterilized surface for use in surgery, with a two-dimensional optical pattern that can be used for spatial position detection of a medical product. Furthermore, the present disclosure relates to a medical product, a tracking system, a position detection method, and a computer-readable storage medium and computer program according to the preambles of the independent claims.

[0005] Background of the present disclosure

[0006] Spatial tracking and estimation of the position of a (medical) object, such as an instrument or a device (e.g., a handpiece), based on a 2D image requires a precise appearance model of the object. Typically, central, characteristic points or key points of the object are identified and compared with a (stored) basic model or template. Knowledge of a 2D-to-3D correspondence or a 3D-to-3D correspondence enables the calculation or estimation of the object's position, i.e., its position and orientation. Estimating the Euclidean position of an object based on its image also requires that the image be captured by a calibrated camera.

[0007] Currently, there are different classic solutions for the spatial tracking of surgical instruments, which are based on the following tracking methods or systems: - infrared markers are attached around a handle of the instrument, which are captured by a camera, in particular at least four infrared markers are attached in the form of spheres (rigid body),

[0008] - planar, optically visible markers or optical patterns, such as a QR code, are applied to or around the handle of an instrument, which are captured by a camera,

[0009] - colored or elongated markers are attached to one tip of the instrument, which are used for tracking.

[0010] However, surgical instruments typically lack sufficient distinguishing features on their surface, making it impossible for traditional computer vision algorithms to estimate their position. Their appearance also presents a challenge. For example, metallic surfaces are often reflective and smooth, making it difficult to extract any or only a few visual features from an image (insufficient contrast, etc.).

[0011] Therefore, a precise determination of the position of an instrument without additional geometric objects such as rigid bodies or similar objects attached to the instrument often cannot be ensured, which endangers the safety of a patient during an operation. In addition, instruments currently require complex expansion and

[0012] Summary of the present disclosure

[0013] It is therefore the object of the present disclosure to avoid or at least mitigate the disadvantages of the prior art and, in particular, to provide a surgical 3D marker element, a medical product, a tracking system, a position detection method, a computer-readable storage medium, and a computer program with which precise and effective spatial position detection can be achieved by means of optical detection. A further sub-objective can be seen, in particular, in the cost-effective production and adaptation of medical products and tracking systems. Furthermore, a further sub-objective can be seen, in particular, in the provision of additional data optically (encrypted) in addition to position detection.

[0014] The object is achieved according to the invention with regard to a surgical 3D marker element by the features of claim 1, with regard to a medical product by the features of claim 8, with regard to a tracking system by the features of claim 12, with regard to a position detection method by the features of claim 15 and with regard to a computer-readable storage medium by the features of claim 16.

[0015] One basic idea is to integrate a special optical pattern directly onto or into a surface, which is specifically adapted and optically detectable. Based on a 2D or 3D image of the 3D marker element with the defined optical pattern, position detection can then be achieved using a tracking system, particularly a navigation system with a camera.

[0016] In other words, such a marker design or 3D marker element is proposed that can be printed or engraved on or into surfaces, in particular on medical products such as surgical instruments. This defined 3D marker element then enables the calculation of the position (if appropriate, also that of an instrument) with six degrees of freedom (6-DOF). The 3D marker element can be provided on sections or parts of a medical product, in particular printed or engraved, in particular lasered, onto sections of an instrument, for example, on a distal section of a suction cannula or a navigation pointer.In this way, a position detection element can be created simply and effectively, as well as in a way that is optimized in terms of installation space (no further elements need to be added), and can be attached to a medical product, in particular directly integrated into it, for example by laser engraving it into a surface. Specifically, a surgical 3D marker element with a surface, in particular a sterilizable surface, is proposed, wherein a two-dimensional optical pattern is permanently applied or introduced on or in this surface, in particular printed or engraved (for example by laser engraving), for spatial position detection of a medical product. A position detection reference is therefore provided by the optical 3D marker element on or in a visible (external) surface. According to the disclosure, the optical pattern (on orin the surface) in the form of a matrix with M rows and N columns (i.e. a matrix M times N similar to a table) with corresponding (individual) pattern elements / modules as pattern fields of the matrix, and the optical pattern has at least four pattern elements (as pattern fields), of which at least two pattern elements are designed differently from one another in order to provide (as a minimum requirement) an optical reference for position detection (position and orientation, i.e. six degrees of freedom - 6D0F) of the 3D marker element by means of an (external) optical tracking system.

[0017] What is described here is, in a sense, a design guideline for the production of such a (visual) 3D marker element, which can be used in particular for tracking surgical instruments. These, in particular rectilinear, 3D marker elements are, for example, mapped onto a cylindrical or flat surface, i.e., applied or incorporated onto this surface. The optical pattern of the 3D marker element is divided into M by N (in particular equally sized) cells or pattern fields. The visual appearance of each pattern element is created in particular from a predefined dictionary of pattern element types. The recognition of the optical pattern and the visible pattern elements (i.e., the cells or the pattern fields filled by the pattern elements) can be carried out using conventional image processing algorithms based on machine learning or deep learning.

[0018] Especially for optical patterns larger than four elements, it is advantageous that not all elements need to be visible for position determination. A minimum of four keypoints must be visible to determine a 6D position of the marker (3D position and 3D orientation). This optical pattern therefore does not need to be completely visible to be recognized, identified, and spatially tracked.

[0019] In other words, one could also say that for the 3D marker element, a special, particularly linear, marker design is applied to or incorporated into a surface, particularly on or in a cylindrical part of an instrument or a flat surface, in particular printed or engraved. The marker design is prepared in such a way that visual cell characteristics or the visual differences between the pattern elements are used to uniquely identify each cell or pattern field.

[0020] In particular, the optical patterns of two different 3D marker elements can be designed differently for different instrument models to ensure differentiation of the instrument type. Thus, a specific instrument model can be identified by the design of the optical pattern of the 3D marker element.

[0021] The term "position" refers to a geometric position in three-dimensional space, which is specified in particular using coordinates of a Cartesian coordinate system. In particular, the position can be specified by the three coordinates X, Y, and Z.

[0022] The term "orientation," in turn, indicates an alignment (e.g., position) in space. One could also say that orientation indicates an orientation with a direction or rotation specification in three-dimensional space. In particular, orientation can be specified using three angles.

[0023] The term "attitude" encompasses both position and orientation. In particular, attitude can be specified using six coordinates: three position coordinates X, Y, and Z, and three angular coordinates for orientation.

[0024] Advantageous embodiments are claimed in the subclaims and are explained in particular below. According to one embodiment, the surface can be curved, preferably a section of a cylindrical surface. This means that the surface is not, or does not have to be, a planar / flat surface.

[0025] According to one embodiment, the optical pattern can be designed in the form of a rectangular matrix with correspondingly rectangular pattern fields, each with the same outline, in particular with at least eight rows and / or at least five columns. Such a standardized optical pattern can be implemented simply and efficiently and represents standardized geometric relationships. The pattern elements, which can be taken from a dictionary, are then inserted into the individual pattern fields of the matrix. In particular, such a design can be easily applied to or incorporated into a surface and enables reliable spatial tracking.

[0026] In particular, the surface (with the optical pattern) can be planar (i.e. flat) or curved, for example a section of a cylindrical surface.

[0027] According to one embodiment, the matrix can be non-square. This means that the matrix cannot be a QR code.

[0028] According to one embodiment, the different pattern elements can be arranged irregularly across a section of the optical pattern, across a large portion of the optical pattern, or across the entire optical pattern, in particular not in rows or columns with exclusively identical pattern elements. This means that the matrix, in particular, cannot be a barcode.

[0029] According to one embodiment, the matrix can have a greater number of rows than columns. Preferably, the matrix can have at least 1.2 times, 1.5 times, or 2 times as many and / or a maximum of 5 times, 4 times, or 3 times as many rows as columns. Such a configuration is particularly advantageous for attachment to rather elongated, particularly circular-cylindrical shaft instruments.

[0030] In particular, the optical pattern can have exactly two or more than two, preferably exactly three or exactly four or exactly five, different pattern elements (as a pattern dictionary), which differ from one another in at least one color or color perception (e.g., through different contrasts), and further preferably by a circle, ellipse, or dot in the center of the pattern field, or a rectangle or rectangular outline in the center of the pattern field, in particular each in a further color. The term "color" in this case refers to black and white. If a single 3D marker element is created, the first step is to determine how many pattern elements it should have.If, for example, only binary pattern elements are used, differentiation can be made easily and reliably. Of course, for the "encoding" of additional data such as an instrument type, the optical pattern must be made larger in terms of rows and columns. Two high-contrast colors are particularly suitable for differentiation. For engraving into a surface, there are two "cases": one pattern field has not been engraved and thus forms a first pattern element, whereas a second pattern field has been engraved and accordingly forms a second pattern field with a different color (or color perception) (e.g., because it is matte and therefore appears different from the smooth surface, or because the light is only partially reflected and therefore appears darker).The number of pattern elements can be expanded using additional geometric elements such as a circle or dot (e.g. in the case of laser engraving), so that the optical pattern can still be created in the surface in a simple and cost-effective manner.

[0031] According to a further embodiment, the optical pattern can have exactly two different pattern elements as binary pattern elements (one can also say that they form an entry in the dictionary of a binary pattern group), with the following preferred embodiments: a first pattern element of a first color, in particular a white pattern field (in particular not engraved) and a second pattern element of a second color, in particular a black (in particular engraved) pattern field (it is crucial that the pattern fields differ in particular in terms of contrast in order to be distinguished by a camera image); or a first pattern element as a light, in particular white, pattern field with a central dark, in particular black, dot or ellipse and a second pattern element as a dark, in particular black, pattern field with a central light, in particular white, dot ellipse;or a first pattern element as a light, in particular white, pattern field with a central dark, in particular black, rectangle, in particular square, and a second pattern element as a dark, in particular black, pattern field. In this case, a binary cell type or pattern element type is formed from two different visual appearances, which form the pattern elements of the optical pattern.

[0032] Alternatively, the optical pattern can preferably have exactly three different pattern elements as ternary pattern elements, with the following preferred embodiments: a first pattern element as a light, in particular white, pattern field, a second pattern element as a dark, in particular black, pattern field and a third pattern element in a further (different) color, in particular red; or a first pattern element as a light, in particular white, pattern field with a central dark, in particular black, dot or ellipse, a second pattern element as a dark, in particular black, pattern field with a central light, in particular white, dot or ellipse and a third pattern element as a light, in particular white, pattern field; or a first pattern element as a light, in particular white, pattern field with a central dark, in particular black, rectangle, in particular square, a second pattern element as a dark, in particular black,A pattern field with a central light, particularly white, rectangle, particularly square, and a third pattern element as a light, particularly white, pattern field with a central dark, particularly black, rectangular outline. A ternary cell type or pattern element type is formed from three different visual appearances, so that even more information can be integrated into a matrix of the same size compared to the binary pattern elements (or binary dictionary entry). Alternatively, the optical pattern can preferably have exactly four different pattern elements as quaternary pattern elements, with in particular: a first pattern element as a white pattern field, a second pattern element as a black pattern field, a third pattern element in a further first color, particularly red, and a fourth pattern element in a further, second color, particularly green.or a first pattern element as a white pattern field with a central black dot, a second pattern element as a black pattern field with a central white dot, a third pattern element as a white pattern field, and a fourth pattern element as a black pattern field. A quaternary cell type is formed from four different visual appearances.

[0033] According to one embodiment, the optical pattern can have at least three rows by three columns (3x3), so that a central pattern element is adjacent (surrounded) by eight pattern elements, which together form a pattern word and can be uniquely identified. The marker is obtained by assigning each cell to a type of the predefined dictionary. A pattern element or cell on a grid, especially a rectilinear one, has eight direct neighbors. The concatenation of the cell type and the eight directly neighboring cell types forms the so-called cell word / pattern word. In particular, each cell of the matrix is ​​associated with a different word. This special property makes it possible to develop efficient image processing algorithms that can identify each cell of a marker using only local image information.In particular, each cell / pattern element of a marker can be uniquely identified by analyzing the neighboring cell types / pattern element types.

[0034] Preferably, different pattern elements can be distinguished by color and / or circle centers and / or corners and / or contours. Thus, in a sense, different dictionaries or a dictionary with different groups of entries with visual features can be used to create a 3D marker element. Different 3D marker elements can also be created from the same dictionary (or group of entries, e.g., entry group of binary pattern elements), for example, with binary pattern elements. This property makes it possible to associate different 3D marker elements with different medical products, in particular instruments. It should be noted that for the problem of pose determination, all visual features present in the dictionary can be used, which can be one or a combination of the following features: circle centers, corners, edges, contours.

[0035] According to one embodiment, a first section of the optical pattern can be offset and / or inclined relative to a second section of the optical pattern such that the first section and the second section are not visible simultaneously. Such a configuration arises particularly when the surface is not flat / planar / level.

[0036] According to one embodiment, the optical pattern may not contain any coded information. This means that the optical pattern primarily serves for purely optical detection of the position and / or, in particular, is not a barcode and / or a QR code.

[0037] With regard to a medical product, in particular a medical instrument or a medical device, with or for optical position detection during an intervention on a patient, the object is achieved in that the medical product has the surgical 3D marker element according to the present disclosure, in particular on a distal section of the medical product, wherein preferably the 3D marker element is directly integrated into the medical product and the optical pattern is printed on a surface of the medical product or incorporated into it, for example engraved, in particular laser engraved.

[0038] In one embodiment, the medical product can be a surgical instrument with a distal instrument tip, in particular a scalpel or a trocar or a navigation timer, and the 3D marker element can be arranged in an area less than 50%, in particular less than 30%, particularly preferably less than 10% of a total length of a longitudinal axis from the distal tip, in particular directly in the area of ​​the instrument tip, in order to provide spatial position detection of the instrument tip, in particular in the case of a surgical scalpel as an instrument which has the 3D marker element on a flat surface of the cutting edge.If the optical marker element is positioned at a distal section, such as a pointer, its position can be detected when it enters the field of view of a digital surgical microscope used for tracking and navigation, and this position can be incorporated into the digital data accordingly. The special design allows for simple and reliable tracking.

[0039] According to a further embodiment, the medical product can have a cylindrical contour with a corresponding cylindrical surface at a distal portion, and the 3D marker element can be arranged, in particular engraved, over part of the circumference, in particular over the entire circumference. The medical product is preferably a medical suction device with a distal suction tube / suction cannula, wherein the 3D marker element with the optical pattern is provided on the suction tube, in particular the optical pattern is printed on the surface of the suction tube or engraved into it. In particular, such a suction tube can be used as a pointer, for example to define characteristic points. This form of the 3D marker element thus expands the functional possibilities of medical products.

[0040] In particular, the medical product can be a medical instrument with a special, in particular conical, geometry of a distal section, and an optical template pattern in the form of a rectangular matrix can be adapted / deformed (distorted) to the special geometry, in particular the conical geometry, using a linear transformation matrix, and can be present as an optical pattern on or in the surface in an adapted / deformed (distorted) manner. One could also say that the design of the template can be deformed or cut out in order to be mapped onto any surface as an optical pattern. For example, if a digital template of the optical pattern is available as a rectangular matrix with corresponding pattern elements, this template can be adapted to a target surface and applied to or incorporated into it using appropriate matrix transformation (linear algebra).Similar to the analogy of an elastic rubber surface (known from a balloon), on which a homogeneously stretched rectangular matrix with pattern elements is initially printed, this can then be applied to an object and the optical pattern distorts accordingly, but its structure remains recognizable. In particular, special instrument geometries such as tweezers or conical instruments require special optical patterns that are not rectilinear. Such a design can be achieved in particular by masking or mapping a rectilinear marker design template onto the geometry of the surface, in particular that of the instrument to be tracked. Alternatively, a rectilinear marker design template can be deformed onto the instrument surface as an optical pattern by deforming the rectilinear cell lattice.The marker can be applied to or embedded in any type of surface, particularly by deforming and / or cutting out a linear marker design.

[0041] With regard to a surgical tracking system, in particular a navigation system, for a surgical procedure on a patient, the objects are achieved in that this surgical tracking system has the following system components: a surgical 3D marker element or a medical product according to the present disclosure (with the corresponding optical pattern), and a tracking unit / tracking device with at least one camera, preferably at least two cameras such as a stereo camera for a 3D recording, which is adapted to optically detect the 3D marker element with the optical pattern and to determine a position (with respect to the tracking unit) on the basis of the detected optical pattern and in particular to include it in a navigation system and to visually output a position by means of a display device.The tracking system is specially adapted to use the optical pattern for position detection, in particular by providing the tracking system with definitions and relations to optical patterns, which it can process accordingly.

[0042] In particular, the surgical tracking system may further comprise a storage unit in which a dictionary of (groups of) pattern elements is stored, in particular binary pattern elements and / or ternary pattern elements and / or quaternary pattern elements, and a control unit may be adapted to read out the optical pattern on the basis of the dictionary and to determine a position accordingly, wherein preferably a part of the optical pattern is already sufficient to determine the position.

[0043] According to one embodiment, any section of the optical pattern with at least four pattern elements can be used for position determination. This means that not the entire pattern, but only a section with at least four pattern elements, needs to be visible to determine the position.

[0044] According to one embodiment, the optical pattern can preferably be used purely optically for position determination, in particular without the use of information encoded in the optical pattern. This means that no additional information stored encoded in the optical pattern is required for unambiguous position determination.

[0045] Preferably, a data set associated with the optical pattern can be stored in a storage unit, in particular with a transformation from the position of the optical pattern to a working point of a medical product, such as an instrument tip (e.g. a vector or an indication in the form of 1 cm in the orientation direction (such as the longitudinal axis), 3 mm offset from the longitudinal axis center (such as an angle) in order to detect the position of the working point and an orientation of the distal section, and a control unit can be adapted to determine the working point and orientation of the distal section based on the position detection of the optical pattern and the stored transformation, and to visually output it in a view by the display device. This provides the surgeon with important information for his procedure.

[0046] With regard to a position detection method for detecting the position of a 3D marker element with an optical pattern or of a medical product according to the present disclosure, the object is achieved by the steps: creating a 2D image by a camera of a tracking unit or a 3D image by at least two cameras of a tracking unit and capturing each visible pattern element of the optical pattern; identifying each pattern element by a control unit based on a dictionary with different pattern elements, in particular binary pattern elements or ternary pattern elements or quaternary pattern elements;Determining a correspondence between a 2D position in the 2D image and a position of the template of the 3D marker element with the optical pattern, or a correspondence between a 3D position in the 3D image and a position of the template of the 3D marker element with the optical pattern; performing an n-point perspective position determination (estimation) on the 2D image for a position determination or a 3D-to-3D point determination for a position determination of the optical pattern. In other words, the determination / calculation or at least estimation of the position of such a marker comprises the following: detecting each cell / pattern element visible in an image; identifying each cell that results in a correspondence between a 2D position in the image and a position on the theoretical 3D marker design;Use of perspective n-point position estimation based on the calculated correspondences. The position-Z-pose estimation can be extended to a 3D camera or stereo camera: detection of each visible cell in the two stereo images; identification of each cell that results in a correspondence between a 2D position on the images and a position on the theoretical 3D marker design. The two positions on the stereo images can be triangulated, resulting in a 3D cell position; use of 3D-to-3D point matching to estimate the position of the 3D marker element.

[0047] With regard to a computer-readable storage medium or a computer program, the objects are achieved in that it comprises instructions which, when executed by a computer, cause the computer to carry out the steps of the position detection method according to the present disclosure.

[0048] Any disclosure in connection with the 3D marker element according to the present disclosure also applies to the medical product, the tracking system and the position detection method according to the present disclosure, just as any disclosure in connection with the medical product or the tracking system or the position detection method applies to the 3D marker element or the respective other generic terms.

[0049] Short description of the characters

[0050] The present disclosure is explained in more detail below using preferred embodiments with the aid of figures. They show:

[0051] Fig. 1 is a schematic front view of a surgical tracking system with a medical product with a 3D marker element, each according to a first preferred embodiment,

[0052] Fig. 2 a sketch of an unfilled rectangular matrix with rectangular pattern fields for an optical pattern,

[0053] Fig. 3 shows an exemplary 3D marker element with an optical pattern, in which a partial area is shown enlarged for illustration purposes with a central pattern element and eight adjacent pattern elements,

[0054] Fig. 4a to 4c each show examples of binary pattern elements, where the hatching represents a different color perception,

[0055] Fig. 5a to 5c each show examples of ternary pattern elements,

[0056] Fig. 6a and 6b each show examples of quaternary pattern elements,

[0057] Fig. 7 is a schematic illustration of an image of a template of a binary type optical pattern on a surface of a medical product, Fig. 8 is a schematic illustration of an image of a template of a quaternary type optical pattern on a surface of a medical product, and

[0058] Fig. 9 is a flowchart of a position detection method according to a preferred embodiment.

[0059] The figures are schematic in nature and are intended only to aid understanding of the invention. Like elements are designated by the same reference numerals. The features of the various embodiments may be interchanged.

[0060] Detailed description of preferred embodiments

[0061] Fig. 1 shows a schematic front view of a surgical tracking system 500 in the form of a navigation system for tracking a surgical instrument, in particular during a surgical procedure on a patient (not shown) according to a preferred embodiment.

[0062] This tracking system 500 has a tracking unit 502 with a camera 504 in the form of a surgical microscope for spatial tracking. Furthermore, the tracking system 500 has a medical product 100 of a preferred embodiment in the form of a medical device 104 of a suction device with a distal suction tube 110, which is to be spatially tracked with respect to a location, i.e., a position and an orientation, using the camera 504. This suction tube 110 has a surgical 3D marker element 1 according to a preferred embodiment on its distal section 108. For example, a statement about the position and / or orientation of the medical product 100 with respect to the surgical microscope is sufficient to adjust the position of the surgical microscope.Optionally, the surgical tracking system 500 comprises an additional external navigation system with a marker on the surgical microscope, in particular on the microscope head, and an external camera (not shown), in particular in the form of a stereo camera, which detects and evaluates the position of the marker on the surgical microscope. This enables additional tracking of the position of the surgical microscope relative to the patient.

[0063] This surgical 3D marker element 1 has a sterilizable surface 2, in which a two-dimensional optical pattern 4 is permanently incorporated, in particular printed or engraved, for spatial position detection of a medical product 100. Specifically, the optical pattern 4 is designed in the form of a matrix 6 with M=10 rows and N=5 columns with corresponding pattern elements 8 (10x5=50) as pattern fields 8.

[0064] The optical pattern 4 comprises over four pattern elements 10, two of which are configured differently to provide an optical reference for detecting the position of the 3D marker element 1 by the optical tracking system 500. In particular, the optical pattern is incorporated at least partially around the circumference of the suction tube 110, so that the camera 504 can capture at least a portion of the optical pattern 4 from every side or in every position of the suction tube. The position can still be determined based on this portion of the optical pattern 4.

[0065] The tracking system 500 is specifically adapted to optically detect the 3D marker element 1 with the optical pattern 4 and, based on the detected optical pattern 4, to determine a position and incorporate it into its navigation system or its navigation function. A display device 506 can visually output a current position to the surgeon in conjunction with preoperative image data such as a CT scan and an MRI scan. Thus, on the one hand, the suction tube 110 can be displayed in the microscope image, and, in a further view, the exact position of the suction tube 110 can also be displayed in a section of the MRI data to ensure reliable and effective navigation. In particular, landmarks can also be set using this method, and the suction tube 110 can also be used as a pointer.The suction tube 110 does not require any complex adaptation; in this embodiment, it is sufficient to use a commercially available suction tube, engrave the optical pattern directly into the surface 2 of the distal section using a laser, and then optically detect this pattern. The 3D marker elements thus provide an efficient and cost-effective way of adapting already approved medical products, preparing them for position detection, and upgrading them. This allows them to be upgraded to the next functional level without the need for complex additional components, which would typically result in a lengthy and cost-intensive approval process. In particular, the optical pattern enables very precise position detection, as it can be positioned in close proximity to a working point of the medical product and, if necessary,can even extend over a wide area, so that even if an instrument tip or a tip of the suction tube 110 is covered, position detection can still be carried out and position detection can even be carried out reliably from different directions (even if part of the optical pattern 4 is covered).

[0066] Fig. 2 shows an exemplary embodiment of a matrix with M by N cells or pattern fields into which pattern elements can be inserted (see Fig. 3). In Fig. 2, the matrix is ​​rectangular in shape with square pattern fields 8, all of which have the same outline, i.e., are of identical design.

[0067] Turning now to Fig. 3, these pattern fields 8 are populated with pattern elements 10, wherein in Fig. 3, binary pattern elements 10 are configured with a first light (here white) pattern element 10 and a second dark (here black) pattern element 10 (the hatching is intended to represent a dark, particularly black, color). This ultimately results in an optical pattern 4 of first and second pattern elements 10, which were arranged according to a definition rule and, so to speak, make the information optically encrypted or (computer-technically) detectable.

[0068] In Fig. 3, in the optical pattern 4 (left part), a cell group of 3x3 pattern elements is shown outlined in a central area for an overview and shown individually in a right part of Fig. 3 for explanation. A central pattern element 10 (dark) is surrounded by eight other neighboring pattern elements. These nine pattern elements 10 form a pattern word. In particular, the tracking system 500 can determine, based on the pattern word, that binary pattern elements 10 are being used.

[0069] Figs. 4a to 4c each show different (pairs) of binary pattern elements 10. Fig. 4a shows a light (approximately white) pattern field 8 as the pattern element and a dark (approximately black - hatching is intended to represent dark or black) pattern field as the pattern element 10. In Fig. 4b, a solid circle (can also be called a dot) in the center of the pattern field is provided, each in the opposite color. Alternatively, as shown in Fig. 4c, a rectangle in the shape of a square can be used instead of a circle.

[0070] Fig. 5a to 5c show further embodiments of (triples) ternary pattern elements 10. These are constructed similarly to the binary ones from Fig. 4a to 4c, with the difference that another pattern field 8 is added with another, different pattern element 10.

[0071] Fig. 6a and 6b show alternative ternary (quadruples) on quaternary pattern elements 10

[0072] All of these groups of pairs, triples, quadruples can each be stored as group entries in a pattern dictionary, so that the tracking system 500 knows the respective pairs or triples or quadruples and the tracking system can then determine the various pattern elements 10 and subsequently at least one position on the basis of this pattern dictionary.

[0073] Fig. 7 shows an example of a template for an optical pattern (left part) as well as a corresponding introduction of the optical pattern 4 into the surface 2 of the suction tube 110. The pattern is, so to speak, unrolled or wound over the cylindrical surface of the suction tube and forms the 3D marker element 1 integrated into the medical device. In particular, the optical pattern 4 can have further information about the device / instrument type (encoded) and can be combined with data associated with the device or instrument. Fig. 8 shows a further embodiment of a template for a 3D marker element with the optical pattern (left part), which is then introduced onto a distal section 108 of the suction tube 110. In this embodiment, a quadruple is used as quaternary pattern elements 10, which have ellipses as well as nested ellipses. With only two “colors” orFor contrasts, four different elements can be created using the different designs of the pattern elements 10 and can be provided accordingly for at least one position detection on an instrument or device. Above the suction tube 110 on the right-hand side of Fig. 8, the group of pattern elements 10 is shown again for illustration purposes (as a kind of character set of pattern elements).

[0074] Fig. 9 shows a flowchart of a position detection method for detecting the position of a 3D marker element 1 with an optical pattern 4, in particular for the tracking system 500 as described above. This method comprises the following steps.

[0075] In a first step S1, a 2D image is created by the camera 504 of a tracking unit 502 or a 3D image is created by at least two cameras of a tracking unit 502 and each visible pattern element 10 of the optical pattern 4 is captured.

[0076] In a subsequent step S2, each pattern element 10 is identified by a control unit 510 on the basis of a dictionary with different pattern elements 10, in particular binary pattern elements (10).

[0077] Subsequently, in step S3, a correspondence is determined between a 2D position in the 2D image and a position of the template of the 3D marker element 1 with the optical pattern 4 or a correspondence between a 3D position in the 3D image and a position of the template of the 3D marker element 1 with the optical pattern 4. Finally, in step S4, an n-point perspective position determination is carried out in the 2D image for a position determination or a 3D-to-3D point determination is carried out for a position determination of the optical pattern 4.

[0078] The position and orientation of the 3D marker element 1 with the optical pattern 4 are then determined and can be integrated into a navigation accordingly.

[0079] In particular, precise and unambiguous position detection can be carried out using only one (conventional) 2D recording (i.e. a two-dimensional image) using the defined optical pattern 4.

[0080] List of reference symbols

[0081] 1 3D marker element

[0082] 2 Surface

[0083] 4 optical pattern

[0084] 6 Matrix

[0085] 8 Pattern field / cell field

[0086] 10 pattern elements /

[0087] 100 Medical Device

[0088] 102 instruments

[0089] 104 Medical Device

[0090] 106 Instrument tip

[0091] 108 Distal section

[0092] 110 Suction pipe

[0093] 500 tracking system

[0094] 502 tracking unit

[0095] 504 Camera

[0096] 506 Display device

[0097] 508 storage unit

[0098] 510 control unit

[0099] S1 Step Creating a Recording

[0100] S2 Step Identification of Pattern Elements

[0101] S3 Step Determine Correspondence

[0102] S4 Step Carry out position determination

Claims

Claims 1. Surgical 3D marker element (1) with a surface (2), in particular a sterilizable surface (2), on or in which a two-dimensional optical pattern (4) is permanently applied or incorporated, in particular printed or engraved, for spatial position detection of a medical product (100), wherein the optical pattern (4) is designed in the form of a matrix (6) with M rows and N columns with corresponding pattern elements (8) as pattern fields (8), and wherein the optical pattern (4) has at least four pattern elements (10), of which at least two pattern elements (10) are designed differently in order to provide an optical reference for position detection of the 3D marker element (1) by an optical tracking system (500).

2. Surgical 3D marker element (1) according to claim 1, characterized in that the surface (2) is curved, preferably a section of a cylindrical outer surface.

3. Surgical 3D marker element (1) according to claim 1 or 2, characterized in that the optical pattern (4) is designed in the form of a rectangular matrix (6) with correspondingly rectangular pattern fields (8) each having the same outline shape, in particular with at least eight rows and / or at least five columns.

4. Surgical 3D marker element (1) according to one of claims 1 to 3, characterized in that the matrix (6) is non-square.

5. Surgical 3D marker element (1) according to one of claims 1 to 4, characterized in that the different pattern elements (10) are arranged irregularly over a section of the optical pattern (4), over a large part of the optical pattern (4) or over the entire optical pattern (4), in particular not in rows or columns with exclusively identical pattern elements.

6. Surgical 3D marker element (1) according to one of claims 1 to 5, characterized in that the matrix has a larger number of rows than columns, preferably at least 1.2 times or 1.5 times or 2 times as many and / or at most 5 times or 4 times or 3 times as many rows as columns.

7. Surgical 3D marker element (1) according to one of claims 1 to 6, characterized in that the optical pattern (4) has exactly two or more than two different pattern elements (10), preferably exactly three or exactly four or exactly five different pattern elements (10), which differ from one another at least in one color or color perception, and further preferably by a circle or ellipse or point in the center of the pattern field (8) or a rectangle or rectangular outline in the center of the pattern field, in particular each in a further color.

8. Surgical 3D marker element (1) according to one of claims 1 to 7, characterized in that the optical pattern (4) has exactly two different pattern elements (10) as binary pattern elements (10), with: a first pattern element (10) as a light, in particular white, pattern field (8) and a second pattern element as a dark, in particular black, pattern field (8), or a first pattern element (10) as a light, in particular white, pattern field (8) with a central dark, in particular black dot or a black ellipse and a second pattern element (10) as a dark, in particular black, pattern field (8) with a central white dot or white ellipse, or a first pattern element as a light, in particular white, pattern field (8) with a central black rectangle, in particular square, and a second pattern element (10) as a black pattern field (8).

9. Surgical 3D marker element (1) according to one of claims 1 to 8, characterized in that the optical pattern (4) has exactly three different pattern elements (10) as ternary pattern elements (10), with: a first pattern element (10) as a white pattern field (8), a second pattern element (10) as a black pattern field (8) and a third pattern element (10) in a further color, in particular red, or a first pattern element (10) as a white pattern field (8) with a central black dot or ellipse, a second pattern element (10) as a black pattern field (8) with a central white dot or ellipse and a third pattern element (10) as a white pattern field (8), or a first pattern element (10) as a white pattern field (10) with a central black rectangle, in particular a square, a second pattern element (10) as a black pattern field (8) with a central white rectangle, in particular a square, and a third pattern element (10) as a white pattern field (8) with a central black rectangular outline.

10. Surgical 3D marker element (1) according to one of claims 1 to 9, characterized in that the optical pattern has exactly four different pattern elements (10) as quaternary pattern elements (10), with in particular a first pattern element (10) as a white pattern field (8), a second pattern element (10) as a black pattern field (8), a third pattern element (10) in a further first color, in particular red, and a fourth pattern element (109) in a further, second color, in particular green, or a first pattern element (10) as a white pattern field (8) with a central black dot, a second pattern element (10) as a black pattern field (8) with a central white dot, a third pattern element (109) as a white pattern field (8) and a fourth pattern element (10) as a black pattern field (8).

11. Surgical 3D marker element (1) according to one of the preceding claims, characterized in that the optical pattern (4) has at least three rows by three columns, so that a central pattern element (10) is adjacent to eight pattern elements (10) which together form a pattern word and can be uniquely identified.

12. Surgical 3D marker element (1) according to one of the preceding claims, characterized in that different pattern elements (10) differentiated by color and / or circle centers and / or corners and / or contours.

13. Surgical 3D marker element (1) according to one of the preceding claims, characterized in that a first section of the optical pattern (4) is offset and / or inclined relative to a second section of the optical pattern (4) such that the first section and the second section are not visible at the same time.

14. Surgical 3D marker element (1) according to one of the preceding claims, characterized in that the surface (2) is not a planar surface.

15. Surgical 3D marker element (1) according to one of the preceding claims, characterized in that the optical pattern (4) does not contain any coded information.

16. Surgical 3D marker element (1) according to one of the preceding claims, characterized in that the optical pattern (4) is not a barcode and / or a QR code.

17. A medical product (100), in particular a medical instrument (102) or a medical device (104), with optical position detection during an intervention on a patient, characterized in that the medical product (100) has the surgical 3D marker element (1) according to one of claims 1 to 16, in particular on a distal section of the medical product (100), wherein preferably the 3D marker element (1) is directly integrated into the medical product (100) and the optical pattern (4) is applied or introduced, in particular printed or engraved, preferably laser engraved, on or into a surface of the medical product.

18. Medical product (100) according to claim 17, characterized in that the medical product (100) is a surgical instrument (102) with a distal instrument tip (106), in particular a scalpel or a trocar, and in an area less than 50%, in particular less than 30%, of a total length of a distal instrument tip (106), in particular directly in the area of ​​the instrument tip (106), the 3D marker element (1) is arranged in order to provide spatial position detection of the instrument tip (106), in particular in a surgical scalpel as an instrument which has the 3D marker element on a flat surface of the cutting edge.

19. Medical product (100) according to claim 17 or 18, characterized in that the medical product (100) has a cylindrical contour with a corresponding cylindrical surface (2) on a distal section (108), and the 3D marker element (1) is arranged, in particular engraved, over part of the circumference, in particular over the entire circumference, wherein the medical product (100) is preferably a medical suction device (104) with a distal suction tube (110), wherein the 3D marker element (1) with the optical pattern (4) is provided on the suction tube (110), in particular the optical pattern (4) is printed on the surface (2) of the suction tube (110) or engraved therein.

20. Medical product (100) according to one of claims 17 to 19, characterized in that the medical product (100) is a medical instrument (104) with a special, in particular conical, geometry of a distal section (108) and an optical template pattern in the form of a rectangular matrix is ​​imaged by means of a linear transformation matrix adapted to the special geometry, in particular the conical geometry, and is present as an optical pattern (4) on or in the surface (2).

21. Surgical tracking system (500), in particular a navigation system, for a surgical intervention on a patient, characterized by: a surgical 3D marker element (1) according to one of claims 1 to 16 or a medical product (100) according to one of claims 17 to 20, and a tracking unit (502) with at least one camera (504), preferably a stereo camera, which is adapted to optically detect the 3D marker element (1) with the optical pattern (4) and on the basis of the detected optical Pattern (4) to determine a position and in particular to include it in a navigation system and to visually output a position by means of a display device (506).

22. Surgical tracking system (500) according to claim 21, characterized in that the surgical tracking system (500) further comprises a storage unit (508) in which a dictionary of pattern elements is stored, in particular binary pattern elements and / or ternary pattern elements and / or quaternary pattern elements, and a control unit (510) is adapted to read the optical pattern (4) on the basis of the dictionary and to determine a position, 23. Surgical tracking system (500) according to claim 22, characterized in that a part of the optical pattern (4) is sufficient to determine the position.

24. Surgical tracking system (500) according to one of claims 21 to 23, characterized in that any section of the optical pattern (4) with at least four pattern elements (10) can be used for position determination.

25. Surgical tracking system (500) according to one of claims 21 to 23, characterized in that the optical pattern (4) can preferably be used purely optically for position determination, in particular without using information encoded in the optical pattern (4).

26. Surgical tracking system (500) according to one of claims 21 to 25, characterized in that a data set associated with the optical pattern (504) is stored in a storage unit (508), with in particular a transformation from the position of the optical pattern (4) to a working point of a medical product (100) in order to detect the position of the working point and an orientation of the distal section (108), and a control unit (510) is adapted to determine the working point and orientation of the distal section (108) on the basis of the position detection of the optical pattern (4) and the stored transformation. Section (108) and to visually display it in a view by the display device (506).

27. Position detection method for position detection of a 3D marker element (1) with an optical pattern (4), in particular according to one of claims 1 to 16, or of a medical product (100), in particular according to one of claims 17 to 20, characterized by the steps: Creating (S1) a 2D image by a camera (504) of a tracking unit (502) or a 3D image by at least two cameras of a tracking unit (502) and capturing each visible pattern element (10) of the optical pattern (4), Identification (S2) of each pattern element (10) by a control unit (510) on the basis of a dictionary with different pattern elements (10), in particular binary pattern elements (10) or ternary pattern elements (10) or quaternary pattern elements (10), Determining (S3) a correspondence between a 2D position in the 2D image and a position of the template of the 3D marker element (1) with the optical pattern (4) or a correspondence between a 3D position in the 3D image and a position of the template of the 3D marker element (1) with the optical pattern (4), Performing (S4) an n-point perspective position determination during the 2D recording for a position determination or a 3D-to-3D point determination for a position determination of the optical pattern (4).

28. A computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to perform the steps of the position detection method according to claim 27.

Images