Device, computer program product and method for assistant positioning of at least one body part of a patient for x-

Abstract

The present invention relates to a device, a method and an X-ray system comprising such a device for assisting in positioning at least one body part of a patient for X-ray acquisition by an X-ray system, comprising: a display for displaying said body part to a user, a first camera arranged on a first side of the display and configured to monitor said body part, and a second camera arranged on a second side of the display and configured to monitor said body part, wherein the body part is monitored from a viewing perspective of the device; and a processing unit. The processing unit is configured to estimate an actual bone position of the body part based on the one or more images captured by the first camera, determine a target bone position, and calculate a difference between the estimated actual bone position and the target bone position. The device is configured to display at least one of the target bone position, an estimated actual bone position, and a calculated difference between the estimated actual bone position and the target bone position superimposed on at least one image of the body part through a display, the device is configured to adjust at least one of the target bone position, the estimated actual bone position, and a difference between the estimated actual bone position and the target bone position when a viewing angle of view of the device changes.

Description

Technical Field

[0001] The present invention relates to the field of X-ray acquisition, and more particularly to the field of positioning a patient for X-ray acquisition. More specifically, the present invention relates to an apparatus for assisting in positioning a body part of a patient to be imaged by an X-ray system, an X-ray system including such an apparatus, a computer program product, and a method for assisting in positioning at least one body part of a patient for X-ray acquisition. Background Art

[0002] In practice, for musculoskeletal X-ray acquisition, accurate patient positioning (i.e., the accurate position of the patient's body part) is crucial for the diagnostic quality of the X-ray image. Recently, some methods have been developed to image a patient positioned for X-ray acquisition, estimate the actual position of the skeleton from the image, and align the actual position with the desired ideal pose to be taken for X-ray acquisition. During the acquisition, the technician must manage and position the examination table, the X-ray system (such as the X-ray tube head), and the patient's body part while taking care of the patient.

[0003] Generally, a camera for viewing the patient is attached to the tube head of the X-ray tube. The camera is part of the X-ray system. The display of the observed scene is on a display at the tube head, on a display of the console, or on a separate display on the examination room wall. The user, i.e., the technician, medical staff, must manage, monitor, and position the examination table, the external display on the wall, the tube head, and the patient's body part when taking care of the patient and arranging the patient for X-ray acquisition.

[0004] If the position of the patient or the position of the patient's body part is inappropriate or incorrect, the image needs to be retaken. For this retake, the technician must consider the position of the patient, the position of the X-ray system, and at least the display on the wall (or the tube head) of the examination room.

[0005] Therefore, it is necessary to show the body part to be positioned to the user (technician) in a more natural and simpler way and guide the user to position the patient's body part in an easier and more intuitive way.

[0006] The problem is how to best display the information for positioning the patient to the operator, medical staff, radiology technician so that the person is not restricted by the workflow. Summary of the Invention

[0007] There is a need for a simpler and more natural positioning support for at least a body part of a patient for a user to perform X-ray acquisition. Specifically, there is a need to provide the user with more convenient guidance and assistance to position the body part of the patient, such that the examiner can perform fewer administrative steps to position the patient on the examination table and it is easier to display the positioning of the body part to be positioned.

[0008] The object of the present invention is solved by the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims.

[0009] One object of the present invention is to improve the positioning of at least one body part of a patient for X-ray acquisition, in particular to improve the assistance for the positioning of at least one body part of a patient for X-ray acquisition. Specifically, to improve the guidance for the user to improve the display of the positioning of the body part and the positioning of the body part of the patient.

[0010] According to a first aspect of the present invention, there is described a device for assisting in positioning at least one body part of a patient for X-ray acquisition by an X-ray system, comprising: a display for displaying to a user operating the device the body part to be positioned; a first camera on a first side of the display, which is arranged and configured to monitor the body part of the patient to be positioned, wherein the body part is monitored from a viewing perspective of the device; and a processing unit. The processing unit is configured to: estimate an actual bone position of the body part based on one or more images captured by the first camera, determine a target bone position, and calculate a difference between the estimated actual bone position and the target bone position. The device is configured to superimpose and display on at least one image of the body part via the display at least one of the following: the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position, and the device is further configured to adjust at least one of the following when the viewing perspective of the device changes: the target bone position, the estimated actual bone position, and the difference between the estimated actual bone position and the target bone position.

[0011] In the context of the present invention, the term "X-ray acquisition" should be understood to describe obtaining information about a patient, at least about a body part of the patient, during X-ray imaging. In other words, receiving X-ray data, preferably X-ray image data of the patient. For this X-ray acquisition, the patient, or more precisely a body part of the patient, must be positioned in the correct way such that the information received by the X-ray acquisition is sufficient for medical staff to analyze.

[0012] In the context of the present invention, the term "auxiliary positioning" should be understood as describing that the device can be used to assist the user of the device (who may be a medical staff member) in preparing the patient for X-ray acquisition. The assistance can be guiding the user to position the body part of the patient in a correct and appropriate manner so that an accurate X-ray image of the body part can be taken after the patient is positioned. Thus, the device can serve as an instruction for guiding the user to position the patient / body part, or the device can show the user the instructions for correct positioning.

[0013] In the context of the present invention, the term "viewing perspective" should be understood as describing the perspective from a first viewing point to a second viewing point, where the viewing direction extends from the first viewing point to the second viewing point. In the described embodiment, the viewing perspective extends between the body part and the device and / or the user of the device, where the user of the device may be indirectly the first viewing point since the user holds the device and points the device in the direction of the body part to be positioned. In the embodiments described herein, the second viewing point can be the body part that should be positioned, so the viewing perspective points to the body part. Thus, the viewing perspective of the device is the perspective of the device, which is indirectly the viewing perspective of the user who is arranging the device, in the direction towards the body part from any spatial angle, which may be suitable for optimal viewing for the corresponding desired pose (i.e., the position of the body part).

[0014] In the context of the present invention, the term "target bone position" should be understood as describing the position of the bone of the body part suitable for X-ray acquisition, where when the patient reaches the target bone position, there is no need to reset or re-arrange the body part. Thus, the arrangement process during X-ray examination can be simplified. In other words, the target bone position can be understood as the desired pose of the body part for the corresponding diagnostic image. The best X-ray image can be obtained using the optimal target bone position, where depending on the body part for which the X-ray examination is to be performed and the specific diagnostic request, there are different target bone positions.

[0015] In the context of the present invention, the term "actual bone position" should be understood as describing the position of the body part taken at the current moment. In other words, the actual pose taken by the patient, i.e., the actual position of the body part actually taken by the patient. On the one hand, depending on the arrangement of the patient, the actual bone position may be an incorrect position of the body part. Thus, the position of the body part must be re-arranged. On the other hand, when the body part has been re-positioned, the actual bone position may correspond to the desired target bone position.

[0016] In this embodiment, the device is proposed to monitor the position of a patient, in particular the position of a body part of the patient, and to estimate the bone position in the device reference system in real time. An ideal target bone position for acquisition can be defined and transferred into the reference system of the device. The difference between the two adjustments to be made is calculated and the image displayed on the device is enhanced. The display can include displaying an image and / or a video, i.e., a sequence of images. The device can be held in front of the body part of the patient to be positioned, can very naturally suggest how to adjust the position of this body part from any perspective, and can be easily integrated into the positioning workflow. In this embodiment, the device can also simultaneously display, in a superimposed manner via a display, the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position. Thus, the display can display not only at least one of the different positions (the actual bone position, the target bone position, and the difference between these two positions), but also two or all of them, and display them to the user on the display in a superimposed manner or display only one of them. Specifically, the processing unit can be configured to reconstruct the scene of the viewing perspective of the device (or the user) with the assistance of a first camera. The displayed positions can be changed according to the viewing perspective of the device. This means that if the user changes the perspective of the device to point to the body part, and thus if the user changes the perspective from which he views the body part, the device will be configured to directly and real-time adjust to the change in perspective such that the information displayed on the display screen is adjusted accordingly when the perspective changes. After comparing the target bone position with the actual bone position, the difference, i.e., the deviation, can be calculated. At least one pose and an image of the patient's body part can be displayed simultaneously in a live mode (which means in real time). Thus, the real-time position of the patient can be monitored and analyzed, and can be directly repositioned. The appropriate combination of the target bone position, the actual bone position, and the change between the two will be displayed on the display screen of the device from the perspective of the device and aligned with the (one or more) live images. Thus, with this device, the user can view the body part to be positioned in a more natural way such that there is no need to simultaneously observe the examination table, the tube head display, or the wall display. With this, the monitoring of the positioning of the body part becomes easier. In addition, the device allows the user to be guided and assisted in positioning the body part in a more intuitive way, where the steps of analyzing the examination table and the body part placed thereon, as well as the tube head (display) and the wall display, can also be omitted. The body part of the patient is displayed to the device user in a natural perspective, which simplifies the positioning steps of the body part. The user can approach the body part from either side and fine-tune its position from there. To do this, an augmented reality overlay can be displayed on top of the live image of the body part on the display. Since they are aligned with the image on the display and also appear at the perspective of the display (and thus also at the user's perspective), they are very intuitive to follow.

[0017] The use of this device can bring convenience to users. Generally speaking, users can use this device anywhere and at any time in the acquisition room. At least one hand is required to position the body part, and the other hand can hold the device, which can ensure the closed-loop feedback of fine positioning until the desired position is reached. Feedback can be given directly visually or tactilely during positioning. With the described device, the user can easily adjust himself to work from a desired position different from the tube position, which may be more definite for positioning and at the same time more convenient for both the user and the patient.

[0018] If the target bone position matches the estimated actual bone position, then these two positions are similar, so there is no or almost no difference between the determined two positions, and the desired position (target bone position) is reached. After assisting in positioning the body part to the target bone position, X-ray acquisition can be performed in a sufficient manner.

[0019] It should be noted that any feature, function, and / or element described above and / or below with reference to this device is equally applicable to this system and / or method, and vice versa. Therefore, any feature, function, step, and / or element described below with reference to one aspect of this disclosure is equally applicable to any other aspect of this disclosure.

[0020] According to an exemplary embodiment of the present invention, the viewing angle of the device may include the spatial angle between the viewing direction of the first camera and the direction of the body part. Therefore, when the viewing angle of the device changes (e.g., through the operation of the user), the spatial angle across the optical axis between the first camera and the body part changes, and the body part is viewed from another angle. When this occurs, the device can estimate, calculate, monitor, etc., the corresponding position of the bones of the body part again and display it to the user for correct positioning of the body part.

[0021] According to an exemplary embodiment of the present invention, the device may further include a second camera located on the second side of the display, which is arranged and configured to monitor the viewing angle of the user, wherein the viewing angle of the user includes the spatial angle between the viewing directions of the user and the device to the direction of the body part. The second camera and the first camera can be arranged on opposite sides of the display, such that the first camera includes a view towards the direction of the body part, and the second camera includes a view towards the direction of the user. Therefore, the first camera captures at least one image of the body part, and the second camera captures at least one image of the user. The first camera can be configured to monitor the body part of the patient from the perspective of the user, wherein the first camera is arranged on an imaginary line during use to form a viewing angle from the user to the body part.

[0022] Both cameras can be zoomed in and out. For example, when the device is moved along the optical axis of the viewing perspective between the body part and the device. The second camera can be aligned with the display and the user such that the display gives a very natural impression as a continuation of the operator's view. A more detailed description can be combined with Figure 1 to describe.

[0023] According to an exemplary embodiment of the present invention, the first camera can generate one or more images, wherein the processing unit is configured to estimate the actual bone position of the body part based on one or more images of the first camera. Specifically, the images generated by the camera can be used to show at least one image, or an image sequence, or a video to the user via the display, or the user can select what to display. Preferably, the generated images are a sequence of images, a video, which are displayed to the user via the display and are a live video of the body part that should be positioned for X-ray acquisition. The processing unit can be configured to estimate the actual bone position based on one or more RGB images and / or RGBd images (images containing depth information). The (one or more) RGBd images from the first camera can be used to estimate, for example, the pose and position of joints and their parts. In addition, the images can be any images that can be used to extract depth information to generate the bone position. Specifically, a time-of-flight camera can be used as the first and / or second camera of the device because they can provide appropriate depth information in the image. For example, the actual bone position can be estimated based on the 3D surface of the body part, wherein the surface of the body part is analyzed according to the images taken by the first camera of the device.

[0024] According to an exemplary embodiment of the present invention, the second camera can generate one or more images, wherein the processing unit can be configured to estimate the viewing direction, viewing origin, and / or eyes of the user based on one or more images of the second camera. The estimations of the first and second cameras can be made with reference to the device coordinate system such that the device itself can serve as a common reference. Then, the estimated actual bone position can be superimposed on the live image of the body part.

[0025] According to an exemplary embodiment of the present invention, in order to determine the target bone position, the processing unit may also be configured to determine the position of the X-ray source of the X-ray system for X-ray acquisition and the position of the X-ray detector, wherein the position is determined with reference to the X-ray coordinate system. The determination of the target bone position can be performed by the processing unit itself. On the other hand, the determination can be performed in a cloud-based manner, enabling the processing unit to access data related to known target bone positions, which are typically used during X-ray acquisition, depending on the corresponding body part (knee, limb, joint, foot, hand, etc.). Therefore, the processing unit can use external data to determine the target bone position. In the context of the present invention, the reference to the X-ray coordinate system can be understood as describing the arrangement of all parts of the X-ray system relative to each other, wherein these parts are spatially arranged relative to each other in their respective coordinate systems, which is the X-ray coordinate system. Thus, the components of the X-ray system can be arranged and positioned relative to each other in the X-ray system. The determination of the X-ray source position and the X-ray detector position can be determined in the X-ray reference system by pre-calibration via external markers and / or by using a built-in gyroscope to track the device position. The reconstructed scene can also be analyzed and judged in this X-ray reference system, for which the reference position, i.e., the target bone position, is available based on guidelines and / or training data. When the target bone position is determined in the reference X-ray coordinate system, it can be ensured that the target bone position is the correct position of the body part, which is the optimal position for X-ray acquisition.

[0026] According to an exemplary embodiment of the present invention, the processing unit may be configured to determine at least one of the position of the display and the orientation of the display with reference to the X-ray coordinate system, such that the position of the display relative to the X-ray system can be determined. In other words, the position and orientation of the device (especially the display) are positioned relative to the X-ray coordinate system (especially relative to the X-ray source and / or the X-ray detector), or vice versa. Positioning the device or components thereof in the X-ray coordinate system allows the device to define a reference relative to the X-ray system and link the corresponding viewing angle of the device to the viewing angle of the X-ray system (the viewing angle of the X-ray system is linked to the body part), and whether the position of the body part is sufficient for the X-ray system to perform a good X-ray acquisition.

[0027] According to an exemplary embodiment of the present invention, the processing unit may be configured to transform the estimated actual bone position of the body part into the X-ray coordinate system and to compare the estimated actual bone position with the target bone position in the X-ray coordinate system. In addition, the processing unit may be configured to transform the estimated actual bone position in the X-ray coordinate system and the target bone position in the X-ray coordinate system into the device coordinate system so that these positions can be displayed from the viewing perspective of the device via the display. In other words, the processing unit may be configured to transform one or more bone positions in the X-ray coordinate system and, on the other hand, may be configured to transform one or more bone positions into the device coordinate system or vice versa, where the two transformations may be performed independently of each other, simultaneously or successively separately. The (one or more) estimated actual bone positions are transformed into the X-ray coordinates and their positions are compared with the target bone position, where the target bone position may already have been transformed into the X-ray coordinates or the device may also transform the target bone position into the X-ray coordinates. After the comparison, the device may indicate whether the estimated actual bone position corresponds to the target bone position. If the actual bone position is different from the target bone position, the difference between the two positions may be calculated, where the difference between these positions is also determined with reference to the X-ray coordinate system. Subsequently, all three bone positions, namely the actual bone position, the target bone position and the difference between the two, are transformed back into the device coordinates in order to be displayed and aligned in a superimposed manner on the live image of the body part on the display. Transforming the bone position into the X-ray coordinate system allows comparison with the target bone position, which is already in X-ray coordinate format. Transforming into the device coordinate system allows a reference to the viewing perspective of the device and thus a corresponding reference to the user's viewing perspective so that modifications can be made on the changed device perspective (changed user perspective).

[0028] According to an exemplary embodiment of the present invention, the processing unit may also be configured to generate an articulated model of the anatomical structure of the imaged body part or of geometric primitives indicating joint pose parameters. The device may be configured to indicate the estimated actual bone position via the display using at least one of the anatomical structure of the imaged body part or the articulated model of geometric primitives indicating joint pose parameters. For example, an articulated model of the imaged anatomy may be used to display the actual bone position, which simultaneously shows a bone model superimposed on the body part image. Additionally or alternatively, some geometric primitives indicating joint attributes may be determined and displayed in a superimposed manner on the image of the body part, in particular on the live image of the body part. These geometric primitives may be one or more axes representing bones or limbs.

[0029] According to an exemplary embodiment of the present invention, the device may be configured to provide feedback to the user regarding the target bone position and the difference between the actual bone position and the target bone position for positioning a body part of the patient. The feedback may be haptic feedback, for example, by vibration to determine whether the target bone position is reached, i.e., whether the actual bone position matches the target bone position. The feedback may be provided to the user in real time. The haptic feedback may depend on the consistency between the scene shown on the live image and the desired configuration and is intended to guide the user (operator) towards the desired configuration to support them in obtaining an optimal positioning of the body part relative to the anatomical model. The feedback may also be visual feedback. For example, the feedback may be an indicated difference between the actual bone position and the target bone position, and an arrow may indicate to the user that they must adjust the position of the body part or the orientation of the ankle to obtain an optimal position of the body part. This difference may be adjusted in real time when the perspective of the device and / or the user changes and when the body part is repositioned.

[0030] According to an exemplary embodiment of the present invention, the second camera may be arranged and configured to track the eyes of the user operating the device to determine the viewing perspective of the user. Specifically, the second camera may track the eyes of the user so as to present the image of the first camera in a manner that represents the natural continuation of the user's field of view. In this way, bringing the device closer to the eyes is a very natural way of zooming in, and vice versa.

[0031] According to an exemplary embodiment of the present invention, the first camera may be positioned opposite to the center of the display such that the parallax between the display and the first camera is reduced. That is, the first camera and the center of the display are arranged on the same optical axis. In addition, the first camera, the second camera, and the center of the display may be positioned on the same optical axis such that the parallax between these three points is reduced. Specifically, the first camera and the second camera may be arranged on both sides of the display relative to each other. To achieve a correct augmented reality impression, the positions between the two cameras may be fixed or at least well determined and displayed to the user via the display in a superimposed manner.

[0032] According to an exemplary embodiment of the present invention, the device may further include a wristband, wherein the display may be arranged on the wristband and wherein the first camera may be arranged on the wristband. When the device is arranged on the wristband, this allows the user to freely perform X-ray acquisitions with both hands, and only one hand can be used for positioning during the positioning of the body part.

[0033] According to a second aspect of the present invention, a computer program product is described for assisting in positioning at least one body part of a patient for X-ray acquisition. The computer program unit, when run by a processor of the device for positioning at least one body part of a patient presented herein, is adapted to cause the device to monitor the body part via a first camera of the device, wherein the body part is monitored from the viewing perspective of the device, estimate the actual bone position of the body part based on one or more images captured by the first camera, determine a target bone position, calculate the difference between the estimated actual bone position and the target bone position, display at least one of the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position superimposed on at least one image of the body part by a display, and adjust at least one of the target bone position, the estimated actual bone position, and the difference between the estimated actual bone position and the target bone position when the viewing perspective of the device changes. The processor of this embodiment may be similar or equivalent to the processing unit described in other embodiments.

[0034] In this embodiment, the computer program product may estimate the actual bone position based on RGB and / or RGBd images, as described in the above embodiments. The computer program unit, when run by a processor of the device for positioning at least the body part of a patient presented herein, may also be adapted to determine the position and orientation of the display of the device relative to the X-ray coordinate system, transform the estimated actual bone position into X-ray coordinates, compare the estimated actual bone position with the target bone position, and transfer at least one of the estimated actual bone position, the target bone position, and the difference between the estimated actual bone position and the target bone position into the device coordinate system.

[0035] According to a third aspect of the present invention, an X-ray system is described, comprising: an X-ray source for generating an X-ray image of at least one body part of a patient; an X-ray detector; and a device for positioning the body part of a patient for X-ray acquisition according to any one of the above-described embodiments. The device may be configured to determine the position of the X-ray detector and the position of the X-ray source. In this embodiment, the X-ray system may be equipped with a device according to one or more of the above-described embodiments such that the device can assist in positioning the patient for X-ray acquisition.

[0036] According to a fourth aspect of the present invention, a method for assisting in positioning at least one body part of a patient for X-ray acquisition is described. The method includes the following steps. Operate a device for positioning at least one body part of a patient for X-ray acquisition. Monitor the body part to be positioned via a first camera, wherein the body part is monitored from the viewing perspective of the device. Based on one or more images captured by the first camera, estimate the actual bone position of the body part. Determine a target bone position. Calculate the difference between the estimated actual bone position and the target bone position. Display at least one of the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position overlaid on at least one image of the body part via a display. When the viewing perspective of the device changes, adjust at least one of the target bone position, the estimated actual bone position, and the difference between the estimated actual bone position and the target bone position. In this list of steps, the order of the steps is not fixed, so the steps can be performed in an order different from the above. In addition, some or all of the steps can be performed simultaneously or independently of each other. This also applies to other and / or other method steps mentioned in one or more embodiments of the present invention.

[0037] According to an exemplary embodiment of the present invention, the method may further include at least one of the following steps. Determine the position of the X-ray detector of the X-ray system for X-ray acquisition and the position of the X-ray source, wherein each position is determined with reference to the X-ray coordinate system. Transform the estimated actual bone position of the body part into the X-ray coordinate system and compare the estimated actual bone position with the target position in the X-ray coordinate system. Transform the estimated actual bone position in the X-ray coordinate system and the target bone position in the X-ray coordinate system into the device coordinate system so that the positions can be displayed via the display of the viewing perspective of the device.

[0038] It must be noted that embodiments of the present invention have been described with reference to different subjects. Specifically, some embodiments have been described with reference to apparatus-type claims, while other embodiments have been described with reference to method-type claims. However, those skilled in the art will appreciate from the above and the following description that, unless otherwise stated, any combination between the features of different objects, in particular any combination between the features of apparatus-type claims and the features of method-type claims, is also considered to be disclosed in this application, in addition to any combination of features belonging to one type of object. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and other aspects of the present invention will become apparent from the following examples of embodiments to be described and will be explained with reference to the examples of embodiments. The present invention will be described in more detail below with reference to embodiments, but the present invention is not limited to the embodiments.

[0040] Figure 1 It is a schematic diagram of the device according to the embodiment.

[0041] Figure 2 It is a diagram from the perspective of the user according to the embodiment.

[0042] Figure 3 It is a schematic diagram of the device according to the embodiment.

[0043] Figure 4 It is a diagram showing the bone position according to the embodiment.

[0044] Figure 5 It is a diagram showing another bone position according to the embodiment.

[0045] Figure 6 It is a diagram showing another bone position according to the embodiment.

[0046] Figure 7 It is a diagram of the target bone position according to the embodiment.

[0047] Figure 8 It is a diagram of the method according to the embodiment of the present invention.

[0048] List of reference numerals

[0049] 100 Device

[0050] 101 Display

[0051] 102 First camera

[0052] 103 Second camera

[0053] 104 Body part

[0054] 105 User

[0055] 106 Viewing perspective

[0056] 220 X-ray system

[0057] 307 User's hand

[0058] 408 Actual bone position

[0059] 509 Actual bone position

[0060] 610 Target bone position

[0061] 611 Difference between positions Detailed description

[0062] The illustrations in the drawings are schematic. It should be noted that in different figures, similar or identical elements have the same reference numerals.

[0063] Figure 1 Device 100 according to an embodiment of the present invention is illustrated. Device 100 for assisting in positioning at least one body part 104 of a patient for X-ray acquisition by an X-ray system includes a display 101 for displaying the body part 104 to a user 105 operating the device 100. Device 100 further includes a first camera 103 located on a first side of the display 101 (specifically, on a first side of the device 100). The first camera 103 is arranged and configured to monitor the body part 104 of the patient to be positioned, wherein the body part 104 is monitored from a viewing perspective of the device 100 (represented by an arrow in the figure pointing from the device 100 to the body part 104). As Figure 1 can be seen, the viewing perspective of the device 100 can indirectly be the viewing perspective of the user 106, which is indicated by a dashed line 106 in Figure 1 Device 100 further includes a processing unit (not shown) configured to: estimate an actual bone position of the body part 104 based on one or more images captured by the first camera 103, determine a target bone position, and calculate a difference between the estimated actual bone position and the target bone position. Device 100 is configured to superimpose on the body part 104 displayed by the display 101 at least one of the following: the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position on at least one image. In addition, device 100 is configured to adjust at least one of the following when the viewing perspective of the device changes: the target bone position, the estimated actual bone position, and the difference between the estimated actual bone position and the target bone position.

[0064] In addition, device 100 may include a second camera 102 located on a second side of the display 101, which is arranged and configured to monitor the viewing perspective of the user 105 at least at the origin of the viewing perspective of the user 105, which is indicated by an arrow from the second camera 102 to the user 105. The second camera 102 may be configured to track the eyes of the user 105. The viewing perspective of the user 106 includes the spatial perspective between the viewing directions of the user 105 and the device 100 to the body part 104.

[0065] Figure 2 Illustrated is the positioning of the body part 104 in the X-ray system 220 from the perspective of the device 106 and / or from the perspective of the user 105 according to an embodiment. Specifically, in this figure, the foot of the patient is positioned on the examination table 220 of the X-ray system. The viewing perspective in the figure can be regarded as a viewing perspective suitable for natural positioning from the user side, where this viewing perspective may or may not also be the viewing perspective of the X-ray system.

[0066] Figure 3FIG. 0 is an illustration of device 100 according to an embodiment of the present invention, where a portion of user 105, namely their arm and hand, is illustrated. The device is attached to hand 307 or the wrist of user 105, for example, via a wristband (not shown). Display 101 of device 100 displays a live image of body part 104, in which it should be positioned at the patient's ankle. It can be seen that the patient is positioned on the examination table of X-ray system 220, and device 100 displays a live image of body part 104.

[0067] Figure 4 FIG. 4 is an illustration of the displayed bone position 408 according to an embodiment of the present invention. Display 101 shows the estimated actual bone position 408 to user 105, superimposed on the actual image of body part 104. Specifically, device 100 uses a graphical representation of the skeleton and an articulated model of the imaged anatomy via display 101 to show the estimated actual bone position. The image of the body part is captured by first camera 103, which is not visible in this figure. Second camera 102 is attached to the side of display 101 facing user 105, such that the camera can track the perspective of user 105 and / or the eyes of user 105.

[0068] Figure 5 FIG. 8 is an illustration of another displayed bone position 509 according to an embodiment of the present invention. In this figure, the estimated actual bone position is indicated on display 101 of device 100 using geometric primitives indicated by joint position parameters. These geometric primitives are crosshairs, representing the angles of the joints of body part 104. These geometric primitives 509 are displayed simultaneously with the live image or video of body part 104 via display 101. When user 105 moves or when user 105 moves device 100, the perspective of the view changes, and thus the illustrated bone position 509 also changes, so that body part 104 can be positioned in real time from any angle. 4

[0069] Figure 6It is an illustration of another bone position 610, 611 displayed on the display 101 of the device 100 according to an embodiment of the present invention. In this figure, three bone positions are displayed to the user 105 on the display 101. The target bone position 610 is represented by the geometric line 610, and the estimated actual bone position is represented by another geometric line on the left, and the arrow 611 points to this geometric line. In addition, the difference between the actual bone position and the target bone position is represented by the arrow 611. By simultaneously displaying all these bone positions, during the positioning of the patient, the estimated actual bone position 611, the target bone position 610, and the difference between the two are checked live on the display 101, and the user 105 can adjust the position of the body part 104. When there is no difference between the target bone position 610 and the estimated actual bone position 611, the difference is not displayed (no arrow), and the lines of the target bone position and the estimated actual bone position overlap each other, or only one line is displayed.

[0070] Figure 7 Examples of bone positions are shown, particularly examples of target bone positions. For an example of ankle acquisition as shown in other figures, there are standard ankle anteroposterior (AP) or ankle positions indicated by a known range of position parameters, which result in slightly different optimal views in the X-ray image. These target positions can be used for comparison with the estimated actual bone position of the body part 104.

[0071] Figure 8 It is an illustration of the method steps according to an embodiment of the present invention. The method described in this figure can be executed by the device 100 or by a computer program product described in other embodiments of the present invention. The method is a method for assisting in positioning at least one body part of a patient for X-ray acquisition. The method includes the following steps S1 to S7. In Figure 8 it, the corresponding elements or units available for or executing this step are associated with the corresponding rectangles in the figure. These steps can be executed in the order shown in Figure 8 but the order of these steps can also be changed or one or more steps can be exchanged with other steps. In addition, some or all of the steps can be executed simultaneously. This also applies to other and / or additional method steps mentioned in other embodiments of the present invention. Therefore, the present invention is not limited to Figure 8The corresponding sequence of steps shown and elucidated below. The first step S1 includes operating the device 100 to position at least one body part 104 of the patient for X-ray acquisition. The next step S2 includes monitoring the body part 104 to be positioned via the first camera 103, wherein the body part 104 is monitored from the viewing perspective of the device 100. This step S2 may also include monitoring the user 105 via the second camera 102. Alternatively, the monitoring of the user 105 may be performed as a separate step of the method. The next step S3 includes estimating the actual bone position 408 of the body part 105 based on one or more images captured by the first camera 103. Next, the target bone position 610 is determined in step S4. After steps S3 and S4, the difference between the estimated actual bone position and the target bone position is calculated in step S5. Step S6 includes displaying, via the display 101 and superimposed on at least one image of the body part 104, at least one of the following: the target bone position 610, the estimated actual bone position 408, and the calculated difference 611 between the estimated actual bone position 408 and the target bone position 610. In step S6, different bone positions (target bone position 610, actual bone position 408) or their differences 611 may also be displayed simultaneously, or each of them may be displayed individually one after another. Nevertheless, all or at least one or some of them are displayed via the display 101 simultaneously with the live image and / or video of the body part 104. Step 7 includes adjusting the display of at least one of the following when the viewing perspective of at least one of the devices changes: the target bone position 610, the estimated actual bone position 408, and the difference 611 between the estimated actual bone position 408 and the target bone position of the device. When step S7 is executed, it is determined whether the viewing perspective has changed and whether the actual bone position 408 must be estimated again, such that the method may restart from step S2 again. It may also start from any other suitable step, such as estimating the actual bone position 408 in step S3.

[0072] According to an exemplary embodiment of the present invention, the method may further include at least one of the following steps. The following steps may also be integrated into one of steps S1 to S7 described above. Determining the position of the X-ray detector of the X-ray X-ray system for X-ray acquisition and the position of the X-ray source, wherein each position is determined with reference to the X-ray coordinate system. Transforming the estimated actual bone position 408 of the body part into the X-ray coordinate system, which may be performed in step S3, or wherein S3 may further include a transformation step. Another step may be comparing the transformed estimated actual bone position 408 with the target position 610 in the X-ray coordinate system. This may be Figure 8Individual steps of the method shown may also be part of step S4. Further steps may be to transform the actual bone position 408 estimated in the X-ray coordinate system and the target bone position 610 in the X-ray coordinate system into the device coordinate system so that the (one or more) positions can be displayed from the viewing perspective of the device 100 via the display 101. This transformation to the display coordinate system may also be part of step S4, or may be a step performed after step 4 and before step 5.

[0073] It should be noted that the word "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. In addition, elements described in connection with different embodiments may be combined. It should also be noted that the reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. An apparatus for assisting in positioning at least one body part of a patient for X-ray acquisition by an X-ray system, comprising: A display for displaying to a user operating the apparatus the body part to be positioned, A first camera on a first side of the display, the first camera being arranged and configured to monitor the body part of the patient to be positioned, wherein the body part is monitored from a viewing perspective of the apparatus, A processing unit; Wherein the processing unit is configured to: Estimate an actual bone position of the body part based on one or more images captured by the first camera, Determine a target bone position, Calculate a difference between the estimated actual bone position and the target bone position, Wherein the apparatus is configured to display, via the display, at least one of the following on at least one image of the body part: the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position, Wherein the apparatus is configured to adjust the display of at least one of the following when the viewing perspective of the apparatus changes: the target bone position, the estimated actual bone position, and the difference between the estimated actual bone position and the target bone position.

2. The apparatus according to claim 1, Among them, The viewing perspective of the apparatus includes a spatial perspective between the viewing direction of the first camera and the direction to the body part.

3. The apparatus according to claim 1 or 2, further comprising: A second camera on a second side of the display, the second camera being arranged and configured to monitor the viewing perspective of the user, Wherein the viewing perspective of the user includes a spatial perspective between the user and the viewing direction of the apparatus and the direction to the body part.

4. The apparatus according to any one of the preceding claims, Among them, The first camera generates one or more images, Wherein the processing unit is configured to estimate the actual bone position of the body part based on the one or more images of the first camera.

5. The apparatus according to any one of the preceding claims, Among them, In order to determine the target bone position, the processing unit is further configured to determine the position of an X-ray source and the position of an X-ray detector of the X-ray system for the X-ray acquisition, wherein the target bone position is determined with reference to an X-ray coordinate system.

6. The apparatus according to claim 5, Among them, The processing unit is configured to determine at least one of the position of the display and the orientation of the display with reference to the X-ray coordinate system such that the position of the display relative to the X-ray system can be determined.

7. The apparatus according to claim 5 or 6 of the preceding claims, Among them, The processing unit is configured to transform the estimated actual bone position of the body part into the X-ray coordinate system and is configured to compare the estimated actual bone position with the target bone position in the X-ray coordinate system, Wherein, the processing unit is configured to transform the estimated actual bone position in the X-ray coordinate system and the target bone position in the X-ray coordinate system into the coordinate system of the device, such that the positions can be displayed from the viewing perspective of the device via the display.

8. The device according to any one of the preceding claims, Among them, the processing unit is further configured to generate an articulated model of the anatomical structure of the imaged body part or geometric primitives indicating joint pose parameters, wherein the device is configured to indicate the estimated actual bone position via the display using at least one of the anatomical structure of the imaged body part or the articulated model of geometric primitives indicating joint pose parameters.

9. The device according to any one of the preceding claims, Among them, the device is configured to provide feedback to the user regarding the target bone position and the difference between the actual bone position and the target bone position for positioning the body part of the patient.

10. The device according to any one of claims 3 to 9, Among them, the second camera is arranged and configured to track the eyes of the user operating the device to determine the viewing perspective of the user.

11. The device according to any one of the preceding claims, Among them, the first camera is positioned opposite the center of the display such that the parallax between the display and the first camera is reduced.

12. A computer program product for assisting in positioning at least one body part of a patient for X-ray acquisition, Among them, the computer program unit, when run by a processor of a device for positioning at least one body part of a patient as proposed herein, is adapted to cause the device to: monitor the body part via a first camera of the device, wherein the body part is monitored from the viewing perspective of the device, estimate the actual bone position of the body part based on one or more images captured by the first camera, determine a target bone position, calculate the difference between the estimated actual bone position and the target bone position, display, via a display, at least one of the following superimposed on at least one image of the body part: the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position, when the viewing perspective of the device changes, adjust the display of at least one of the following: the target bone position, the estimated actual bone position, and the difference between the estimated actual bone position and the target bone position.

13. An X-ray system, comprising: an X-ray source, an X-ray detector for generating an X-ray image of at least a body part of a patient, the device for positioning the body part of the patient for X-ray acquisition according to claims 1 to 11, wherein the device is configured to determine the position of the X-ray detector and the position of the X-ray source.

14. A method for assisting in positioning at least one body part of a patient for X-ray acquisition, the method comprising the steps of: Operate a device for positioning the at least one body part of the patient for the X-ray acquisition, Monitor the body part to be positioned via a first camera, wherein the body part is monitored from a viewing perspective of the device, Estimate an actual bone position of the body part based on one or more images captured by the first camera, Determine a target bone position, Calculate a difference between the estimated actual bone position and the target bone position, Overlay and display on at least one image of the body part via a display at least one of the following: the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position, When the viewing perspective of the device changes, adjust the display of at least one of the following: the target bone position, the estimated actual bone position, and the difference between the estimated actual bone position and the target bone position.

15. The method according to claim 14, further comprising at least one of the following steps: Determine the position of the X-ray detector and the position of the X-ray source of the X-ray system for the X-ray acquisition, wherein, Each position is determined with reference to an X-ray coordinate system, Transform the estimated actual bone position of the body part into the X-ray coordinate system, Compare the estimated actual bone position with the target bone position in the X-ray coordinate system, Transform the estimated actual bone position in the X-ray coordinate system and the target bone position in the X-ray coordinate system into the coordinate system of the device such that the positions can be displayed from the viewing perspective of the device via the display.

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