Apparatus, computer program and method for assisting in positioning at least one body part of a patient for x-ray acquisition - Patents.com

Abstract

The present invention relates to an apparatus, method, and X-ray system having such an apparatus for assisting in positioning a patient's body part for X-ray acquisition by an X-ray system, the apparatus comprising: a display for displaying the body part to a user; a first camera on a first side of the display for monitoring the body part from an observation viewpoint of the apparatus; and a processing unit. The processing unit estimates actual bone positions of the body part based on one or more images acquired by the first camera, determines target bone positions, and calculates a difference between the estimated actual bone positions and the target bone positions. The apparatus displays at least one of the target bone positions, the estimated actual bone positions, and the calculated difference between the estimated actual bone positions and the target bone positions overlaid on an image of the body part. The apparatus adapts the display of at least one of the target bone positions, the estimated actual bone positions, and the difference between the estimated actual bone positions and the target bone positions in response to changes in the observation viewpoint of the apparatus.

Description

[Technical Field]

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

[0002] In practice, accurate patient positioning, i.e., the precise location of the patient's body parts relative to the musculoskeletal x-ray acquisition, is crucial to the diagnostic quality of the x-ray image. Recently, methods have been developed to image the patient positioned for the x-ray acquisition, estimate the actual positions of the bones from the image, and align the actual positions with the expected ideal posture to be assumed for the x-ray acquisition. During the acquisition, the technologist must manage and position the examination table, the x-ray system, e.g., the x-ray tube head, and the patient's body parts while attending to the patient.

[0003] Typically, a camera for viewing the patient is attached to the X-ray tube head. This camera is part of the X-ray system. The display of the viewed scene is on a display in the tube head, a console display, or a separate display on the side wall of the examination room. The user, i.e., 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 parts while attending to the patient and positioning the patient for X-ray acquisition.

[0004] If the patient position or the position of the patient's body part is not appropriate or correct, a retake of the image is required, and in this retake the technician must take into account the patient position, the position of the X-ray system, and at least the display on the wall (or tube head) of the examination room. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, there is a need to present the body part to be positioned to the user / technician in a more natural and less complicated manner, and to guide the user more easily and intuitively when positioning the patient's body part.

[0006] The question arises as to how patient placement information can best be presented to operators, medical staff, and radio technicians in a manner that does not constrain their workflow. [Means for solving the problem]

[0007] There is a need for easier and more natural assistance for a user in positioning at least a patient's body part for X-ray acquisition. In particular, there is a need for easier guidance and assistance for a user to position a patient's body part, and for easier indication of the position of the body part to be positioned, so that an examiner can perform fewer administrative steps for positioning the patient on the examination table and can more easily indicate the position of the body part to be positioned.

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

[0009] It is an object of the present invention to improve the positioning of at least a body part of a patient for an X-ray acquisition, in particular to improve assistance in the positioning of at least a body part of a patient for an X-ray acquisition, in particular to provide an improved representation of the positioning of the body part and improved guidance to the user for the positioning of the patient's body part.

[0010] According to one aspect of the present invention, an apparatus for assisting in positioning at least a body part of a patient for X-ray acquisition by an X-ray system is described, the apparatus including: a display for displaying the body part to be positioned to a user operating the apparatus; a first camera on a first side of the display, the first camera positioned and configured to monitor the body part of the patient to be positioned, the body part being monitored from an observation viewpoint of the apparatus; and a processing unit. The processing unit is configured to estimate actual bone positions of the body part based on one or more images acquired by the first camera, determine target bone positions, and calculate a difference between the estimated actual bone positions and the target bone positions. The apparatus is configured to display, via the display, at least one of the target bone positions, the estimated actual bone positions, and the calculated difference between the estimated actual bone positions and the target bone positions, superimposed on at least one image of the body part. Furthermore, the apparatus is configured to adapt the display of at least one of the target bone positions, the estimated actual bone positions, and the difference between the estimated actual bone positions and the target bone positions in response to changes in the observation viewpoint of the apparatus.

[0011] In the context of the present invention, the term "X-ray acquisition" is understood to describe obtaining information about at least a patient's body part 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 the patient's body part, must be positioned in a suitable manner so that the information received by the X-ray acquisition is good enough for analysis by medical personnel.

[0012] In the context of the present invention, the term "positioning assistance" is understood to describe that the device can be used to help the user of the device, who may be a medical professional, prepare a patient for X-ray acquisition. The assistance can be to guide the user to correctly and accurately position the patient's body part so that an accurate X-ray image can be created of the body part after patient positioning. Thus, the device can be used as instructions to guide the user to position the patient / patient's body part, or the device can show instructions to the user for correct positioning.

[0013] In the context of the present invention, the term "observation viewpoint" shall be understood as describing a viewpoint from a first viewpoint to a second viewpoint, where the observation direction extends from the first viewpoint to the second viewpoint. In the described embodiments, the observation viewpoint extends between the body part and the device and / or the user of the device, where the user of the device holds the device and points it in the direction of the body part to be positioned, and therefore may indirectly be the first viewpoint. In the embodiments described herein, the second viewpoint may be the body part to be positioned, and therefore the observation viewpoint is directed toward the body part. Thus, the observation viewpoint of the device is the viewpoint of the device and indirectly the observation viewpoint of the user who positions the device from any spatial angle toward the direction of the body part, which may be appropriate for the best observation for each desired posture, i.e., position, of the body part.

[0014] In the context of the present invention, the term "target bone position" is understood to describe a bone position of a body part that is suitable for X-ray acquisition; once the target bone position is reached by the patient, no resetting or repositioning of the body part is necessary. Thus, the positioning procedure during an X-ray examination can be simplified. In other words, the target bone position can be understood as the desired posture of the body part for the respective diagnostic image. The use of an optimal target bone position results in optimal X-ray images, and different target bone positions exist depending on the body part being X-rayed and the specific diagnostic requirements.

[0015] In the context of the present invention, the term "actual bone positions" is understood to describe the positions of the body parts assumed at the moment. In other words, the actual posture assumed by the patient, the actual positions of the body parts actually assumed by the patient. On the one hand, depending on the patient's positioning, the actual bone positions may be incorrect body part positions. Therefore, the body part must be repositioned in that position. On the other hand, if the body part has already been repositioned, the actual bone positions may correspond to the desired target bone positions.

[0016] In this embodiment, the device is proposed to monitor the patient's position, particularly the position of the patient's body part, and estimate the bone position in the device's reference coordinate system in real time. An ideal target bone for acquisition may be defined and transferred to the device's reference coordinate system. The difference between the two adjustments is calculated and augments the image displayed on the device. The display may include images and / or videos, i.e., a display of a sequence of images. This device, which can be held in front of the patient's body part to be positioned, provides very natural hints on how to adjust the position of this body part from any viewpoint and easily fits into the positioning workflow. In this embodiment, the device may be capable of simultaneously displaying the target bone position, the estimated actual bone position, and the calculated difference between the estimated actual bone position and the target bone position via a display. Thus, the display may not only display at least one of the different positions (actual bone position, target bone position, and the difference between these two positions), but may also display two or all of them, or only one of them, superimposed on the display to the user. In particular, the processing unit may be configured to reconstruct the scene from the device's (or the user's) observation viewpoint with the aid of the first camera. The display position can be changed depending on the observation viewpoint of the device. This means that when a user changes the viewpoint of the device aimed at a body part, and therefore the viewpoint from which the user views the body part, the device is configured to adapt the change directly and in real time so that the information on the display adapts accordingly. After comparing the target bone position with the actual bone position, the difference, i.e., deviation, can be calculated. The simultaneous display of at least one posture and the image of the patient's body part can be performed in live mode, meaning real time. Thus, the patient's live position can be monitored, analyzed, and directly repositioned. The appropriate combination of the target bone position, the actual bone position, and the change between them should be displayed on the device's display from the device's viewpoint, aligned with the live image.Therefore, this device allows the user to view the body part to be positioned in a more natural way, eliminating the need to simultaneously observe the examination table, the tube head display, or the wall display. This makes it easier to monitor the positioning of the body part. Furthermore, this device allows the user to guide and assist the user to position the body part in a more intuitive manner, and the step of analyzing the examination table and the body part positioned thereon, the tube head (display), and the wall display may be omitted. The patient's body part is displayed from a natural perspective for the user of the device, which facilitates the step of positioning the body part. The user can approach the body part from any side and fine-tune its position from there. To do this, augmented reality overlays may be displayed on top of the live image of the body part from the display. They are aligned with the image on the display and appear from the perspective of the display (and therefore the user), making them very intuitive to follow.

[0017] The use of this device may be convenient for the user. Generally, the device can be used anywhere and at any time as long as the user is in the acquisition room. At least one hand is required for positioning the body part, and the other hand may hold the device to ensure closed-loop feedback on fine positioning until the desired position is reached. Feedback is given during positioning by visual or tactile means directly. The above-described device allows the user to easily adapt to work from a desired position different from the position of the tube, which may be more decisive for positioning and at the same time more convenient for the user and the patient.

[0018] The desired position (target bone position) is reached when the target bone position and the estimated actual bone position coincide, and therefore both positions are similar, and therefore there is no or little difference between these two determined positions. After reaching the target bone position with assisted positioning of the body part, X-ray acquisition may be performed in a satisfactory manner.

[0019] It should be noted that any feature, function and / or element described above and / or below with reference to an apparatus applies equally to the system and / or method, and vice versa. Thus, any feature, function, step and / or element described below with reference to one aspect of the present disclosure applies equally to any other aspect of the present disclosure.

[0020] According to an exemplary embodiment of the present invention, the observation viewpoint of the device may have a spatial perspective between the observation direction of the first camera toward the body part. Thus, when the viewpoint of the device is changed, for example by a user's movement, the spatial perspective across the optical axis between the first camera and the body part changes, and the body part is observed from a different perspective. In this case, the device can again estimate, calculate, monitor, etc., the position of each of the bones of the body part in real time and display this 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 on a second side of the display positioned and configured to monitor a user's viewpoint, where the user's viewing viewpoint includes a spatial perspective between the user's observation direction and the device relative to the direction of the body part. The second camera and the first camera may be positioned on opposite sides of the display such that the first camera has a field of view toward the body part and the second camera has a field of view toward the user. Thus, the first camera acquires at least one image of the body part and the second camera acquires at least one image of the user. The first camera may be configured to monitor the patient's body part from the user's viewpoint, where the first camera is positioned on an imaginary line that, during use, forms a viewing viewpoint from the user to the body part.

[0022] Both cameras may allow zooming in and out, for example, when moving the device along the optical axis of observation between the body part and the device. The second camera may be aligned with the display and the user, giving the display a very natural impression as a continuous part of the operator's field of view. A more detailed explanation may be given using FIG.

[0023] According to an exemplary embodiment of the present invention, a first camera may generate one or more images, and a processing unit is configured to estimate actual bone positions of a body part based on one or more images from the first camera. In particular, the images generated by the camera may be used to display at least one image, or an image sequence, or a video to a user via a display, or the user may select which ones to display. Preferably, the generated images are a sequence of images, a video, or a live video of the body part to be positioned for X-ray acquisition, which is displayed to the user via a display. The processing unit may be configured to estimate actual bone positions based on one or more RGB images and / or RGBd images (images with depth information). The RGBd images from the first camera may be used to estimate, for example, the pose and position of joints and parts thereof. Furthermore, the images may be any images that can be used to extract depth information for generating bone positions. In particular, a time-of-flight camera may be used for the first and / or second cameras of the device, as it may provide suitable depth information in the images. For example, the actual bone positions may be estimated from the 3D surface of the body part, which surface is analyzed from images acquired by a first camera of the device.

[0024] According to an exemplary embodiment of the present invention, the second camera may generate one or more images, and the processing unit may be configured to estimate the user's gaze direction, gaze origin, and / or eyes based on the one or more images of the second camera. The estimation of the first and second cameras may be performed with reference to a device coordinate system, whereby the device itself may serve as a common reference. The estimated actual bone positions may then be superimposed on a live image of the body part.

[0025] According to an exemplary embodiment of the present invention, to determine the target bone position, the processing unit may be further configured to determine the position of the X-ray source and the position of the X-ray detector of the X-ray system used for the X-ray acquisition, the positions being determined with reference to an X-ray coordinate system. The target bone position determination may be performed by the processing unit itself, or alternatively, the determination may be cloud-based, such that the processing unit has access to data related to known target bone positions typically used for each body part (knee, ankle, joint, foot, hand, etc.) during the X-ray acquisition. Thus, the processing unit may use external data to determine the target bone position. In the context of the present invention, reference to an X-ray coordinate system may be understood to describe that all parts of the X-ray system are positioned relative to each other and that these parts are spatially positioned relative to each other in their respective coordinate systems, which are the X-ray coordinate system. Thus, parts of the X-ray system may be configured and positioned relative to each other in the X-ray system. The position of the X-ray source and the position of the X-ray detector may be determined in the X-ray reference coordinate system either by pre-calibration via external markers and / or by using built-in gyroscope tracking of the device position. The reconstructed scene may be analyzed and determined in this X-ray reference coordinate system, where a reference position, i.e., target bone position, is available based on guidelines and / or training data. In determining the target bone position with reference to the X-ray coordinate system, it can be ensured that the target bone position is the correct position of the body part and is the optimal position for X-ray acquisition.

[0026] According to an example embodiment of the present invention, the processing unit may be configured to determine at least one of the position and / or orientation of the display with reference to an X-ray coordinate system, so as to be able to determine the position of the display relative to the X-ray system. In other words, the position and orientation of the device, in particular the position and orientation of the display, are localized relative to the X-ray coordinate system, in particular the X-ray source and / or the X-ray detector, or vice versa. Localizing the device or parts thereof in the X-ray coordinate system allows the device to be referenced relative to the X-ray system, linking the respective viewpoint of the device to the viewpoint of the X-ray system (the viewpoint of the X-ray system relative to the body part), and defining 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 estimated actual bone positions of the body part into an X-ray coordinate system and to compare the estimated actual bone positions in the X-ray coordinates with target bone positions. Furthermore, the processing unit may be configured to transform the estimated actual bone positions in the X-ray coordinate system and the target bone positions in the X-ray coordinate system into a device coordinate system, so that the positions can be displayed from the device's observation viewpoint via a display. In other words, the processing unit may be configured to transform one or more bone positions in the X-ray coordinate system, while transforming one or more bone positions into the device coordinate system, or vice versa, and both transformations may be performed independently of each other, simultaneously, or separately, one after the other. The estimated actual bone positions may be transformed into X-ray coordinates, and the positions may be compared with the target bone positions; the target bone positions may already be transformed into X-ray coordinates, or the device may transform the target bone positions into X-ray coordinates. After the comparison, the device may indicate whether the estimated actual bone positions correspond to the target bone positions. If the actual bone position is not the same as the target bone position, the difference between them may be calculated, and the difference between these positions is determined with reference to the X-ray coordinate system. The three bone positions, i.e., the actual bone position, the target bone position, and the difference between them, are then transformed into the device coordinate system so that they are superimposed and aligned on a live image of the body part on the display. Transforming the bone positions into the X-ray coordinate system allows for comparison with the target bone positions, which are already in X-ray coordinate format. Transforming into the device coordinate system allows for the creation of a reference to the device's perspective, and therefore the user's perspective, so that adaptation to a changed device perspective (changed user perspective) can be enabled.

[0028] According to an exemplary embodiment of the present invention, the processing unit may be further configured to generate geometric primitives representing joint models or joint pose parameters of the anatomical structures of the imaged body part. The device may be configured to show the estimated actual bone positions via a display using at least one of the joint models or the geometric primitives representing the joint pose parameters of the anatomical structures of the imaged body part. For example, the display of the actual bone positions may be performed by using a joint model of the imaged anatomical structures that simultaneously shows the bone model overlaid on the image of the body part. Additionally or separately, geometric primitives representing joint properties may be determined and displayed overlaid on the image of the body part, in particular on a 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 a target bone position and the difference between the actual bone position and the target bone position for positioning the patient's body part. The feedback may be, for example, tactile feedback via vibration indicating whether the target bone has been reached, i.e., whether the actual bone position matches the target bone position. This feedback may be provided to the user in real time. This tactile feedback may depend on the match between the scene shown on the live image and the desired configuration and is intended to guide the user / operator to the desired configuration to help obtain optimal placement of the body part relative to the anatomical model. This feedback may also be visual feedback. For example, the feedback may indicate the difference between the actual bone position and the target bone position, indicated by an arrow indicating the direction in which the user must adjust the position of the body part or the ankle to the optimal position of the body part. This difference may be adapted in real time when the device and / or the user's viewpoint changes and when the body part is repositioned.

[0030] According to an exemplary embodiment of the present invention, the second camera may be positioned and configured to track the eyes of a user operating the device to determine the user's observation point. In particular, the second camera may track the user's eyes to render the image of the first camera to represent a natural continuation of the user's field of view. In this way, bringing the device closer to the eyes is a very natural way to zoom out, and vice versa.

[0031] According to an exemplary embodiment of the present invention, the first camera may be positioned opposite the center of the display so that the parallax between the display and the first camera is reduced. In other words, the first camera and the center of the display are positioned 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 so that the parallax between these three points is reduced. In particular, the first camera and the second camera may be positioned opposite each other on either side of the display. The positions of both cameras relative to each other may be fixed or at least sufficiently determined to achieve a correct augmented reality impression, which is displayed to the user in a superimposed manner via the display.

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

[0033] According to a second aspect of the present invention, a computer program product for assisting in positioning at least one body part of a patient for X-ray acquisition is described. When executed by a processor of an apparatus for positioning at least one body part of a patient presented herein, the computer program element is configured to: monitor the body part via a first camera of the apparatus, where the body part is monitored from the visual perspective of the apparatus; estimate actual bone positions of the body part based on one or more images acquired by the first camera; determine a target bone position; calculate a 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 difference between the estimated actual bone position and the target bone position superimposed on at least one image of the body part on a display; and adapt the display of 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 response to changes in the field of view of the apparatus. The processor of this embodiment may be similar or equivalent to the processing units described in other embodiments.

[0034] In this embodiment, the computer program product may estimate actual bone positions based on the RGB and / or RGBd images as described in the above embodiments. When executed by a processor of an apparatus for positioning at least a body part of a patient presented herein, the computer program element may be further configured to: determine a position and orientation of a display of the apparatus with reference to an X-ray coordinate system; transform the estimated actual bone positions into X-ray coordinates; compare the estimated actual bone positions with target bone positions; and transfer at least one of the estimated actual bone positions, the target bone positions, and a difference between the estimated actual bone positions and the target bone positions to 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, an X-ray detector for generating an X-ray image of at least a body part of a patient, and an apparatus for positioning the body part of the patient for X-ray acquisition according to any one of the embodiments described herein. The apparatus 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 comprise such an apparatus according to one or more embodiments described herein, such that the apparatus 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 comprising the steps of: operating an apparatus for positioning at least one body part of a patient for X-ray acquisition; monitoring the body part to be positioned via a first camera, the body part being monitored from an observation viewpoint of the apparatus; estimating actual bone positions of the body part based on one or more images acquired by the first camera; determining a target bone position; calculating a difference between the estimated actual bone position and the target bone position; displaying 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 on a display superimposed on at least one image of the body part; and adapting the display of 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 to changes in the observation viewpoint of the apparatus. The list of steps does not impose a set order on the steps, and therefore the steps may be performed in a different order from that mentioned above. Furthermore, some or all of the steps may be performed simultaneously or independently of each other. This also applies to other and / or further 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 comprise at least one of the following steps: determining positions of an X-ray detector and an X-ray source of an X-ray system used for X-ray acquisition, each of the positions being determined with reference to an X-ray coordinate system; transforming estimated actual bone positions of the body part into the X-ray coordinate system and comparing the estimated actual bone positions with target positions in the X-ray coordinate system; and transforming the estimated actual bone positions in the X-ray coordinate system and the target bone positions in the X-ray coordinate system into an apparatus coordinate system so that they can be displayed via a display from an observation viewpoint of the apparatus.

[0038] It should be noted that embodiments of the present invention are described with reference to different subject matters. In particular, some embodiments are described with reference to apparatus-type claims, while other embodiments are described with reference to method-type claims. However, those skilled in the art will infer from the above and following descriptions that, unless otherwise notified, any combination of features belonging to one type of subject matter, as well as any combination between features relating to different subject matters, in particular, a combination between a feature of an apparatus-type claim and a feature of a method-type claim, is also considered to be disclosed in the present application.

[0039] The above-mentioned and further aspects of the invention will be apparent from and elucidated with reference to the example embodiments described hereinafter. The invention is explained in more detail below with reference to example embodiments, but the invention is not limited thereto. [Brief explanation of the drawings]

[0040] [Figure 1] 1 is an illustration of an apparatus according to one embodiment of the present invention; [Figure 2] FIG. 2 is an illustration of a user's perspective according to one embodiment of the present invention. [Figure 3] 1 is an illustration of an apparatus according to one embodiment of the present invention; [Figure 4] FIG. 10 is an illustration of displayed bone positions according to one embodiment of the present invention. [Figure 5]FIG. 10 is an illustration of additional bone positions displayed according to one embodiment of the present invention. [Figure 6] FIG. 10 is an illustration of additional bone positions displayed according to one embodiment of the present invention. [Figure 7] FIG. 1 is an illustration of a target bone location according to one embodiment of the present invention. [Figure 8] FIG. 1 is an illustration of a method according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0041] The figures in the drawings are schematic. It should be noted that in different figures, similar or identical elements are provided with the same reference signs.

[0042] FIG. 1 illustrates an apparatus 100 according to an embodiment of the present invention. The apparatus 100 for assisting in positioning at least one body part 104 of a patient for X-ray acquisition by an X-ray system comprises a display 101 for displaying the body part 104 to a user 105 operating the apparatus 100. The apparatus 100 further comprises a first camera 103 on a first side of the display 101, in particular on a first side of the apparatus 100. The first camera 103 is positioned and configured to monitor the patient's body part 104 being positioned, where the body part 104 is monitored from an observation viewpoint of the apparatus 100 (indicated in the figure by an arrow pointing from the apparatus 100 to the body part 104). As can be seen from FIG. 1 , the viewpoint of the apparatus 100 may indirectly be a user's viewpoint 106, indicated in FIG. 1 by a dotted line 106. The device 100 further comprises a processing unit (not shown) configured to estimate actual bone positions of the body part 104 based on one or more images acquired by the first camera 103, determine target bone positions, and calculate a difference between the estimated actual bone positions and the target bone positions. The device 100 is configured to display, via the display 101, at least one of the target bone positions, the estimated actual bone positions, and the calculated difference between the estimated actual bone positions and the target bone positions superimposed on at least one image of the body part 104. Furthermore, the device 100 is configured to adapt the display of at least one of the target bone positions, the estimated actual bone positions, and the difference between the estimated actual bone positions and the target bone positions in response to a change in the observation viewpoint 106 of the device.

[0043] Additionally, device 100 may have a second camera 102 on a second side of display 101, the second camera 102 positioned and configured to monitor the observation viewpoint of user 105, at least the origin of the observation line of user 105, which is indicated by an arrow pointing from second camera 102 to user 105. Second camera 102 may be configured to track the eyes of user 105. User's observation viewpoint 106 comprises a spatial perspective between device 100 and the observation direction of user 105 in the direction of body part 104.

[0044] 2 illustrates the placement of a body part 104 in an X-ray system 220 from an apparatus perspective 106 and / or a user's 105 perspective according to one embodiment of the present invention. In particular, in this illustration, the patient's feet are shown positioned on the X-ray system examination table 220. The perspective in this illustration may be considered to be a perspective appropriate for natural placement from the user, which may or may not be the perspective of the X-ray system.

[0045] 3 is an illustration of device 100 according to one embodiment of the present invention, showing a portion of a user 105, their arm and hand. The device is attached to the hand 307 or wrist of user 105, for example by a wristband (not shown). Display 101 of device 100 displays a live image of the body part 104 to be positioned, in this illustration the patient's ankle. As can be seen, the patient is positioned on the examination table of X-ray system 220, and device 100 displays a live image of body part 104.

[0046] 4 is an illustration of displayed bone positions 408 according to one embodiment of the present invention. The display 101 shows the user 105 the estimated actual bone positions 408 overlaid on an actual image of the body part 104. In particular, the device 100 displays the estimated actual bone positions 408 via the display 101 using a bone diagram that is an articulated model of the imaged anatomical structure. The image of the body part is acquired by a first camera 103, which cannot be seen in this diagram. A second camera 102 is mounted on the side of the display 101 facing the user 105 so that the second camera 102 can track the user's 105 viewpoint and / or the user's 105 eyes.

[0047] 5 is an illustration of displayed additional bone positions 509 according to one embodiment of the present invention. In this illustration, estimated actual bone positions are shown on the display 101 of the device 100 using geometric primitives indicated by joint position parameters. These geometric primitives are intersecting lines indicating the angles of the joints of the body part 104. These geometric primitives 509 are displayed simultaneously with a live image or video of the body part 104 via the display 101. As the user 105 moves or moves the device 100, the observation viewpoint changes and the depicted bone positions 509 change accordingly, allowing for positioning of the body part 104 from any viewpoint in real time.

[0048] FIG. 6 illustrates additional bone positions 610, 611 displayed on the display 101 of the device 100 according to an embodiment of the present invention. In this illustration, three bone positions are displayed to the user 105 on the display 101. The target bone position 610 is indicated by a geometric line 610, and the estimated actual bone position is indicated by another geometric line on the left, to which an arrow 611 points. Furthermore, the difference between the actual bone position and the target bone position is indicated by the arrow 611. This simultaneous display of all bone positions may enable the user 105 to adapt the position of the body part 104 while viewing the estimated actual bone position 611, the target bone position 610, and the difference between them live during patient positioning on the display 101. If there is no difference between the target bone position 610 and the estimated actual bone position 611, there will be no difference (arrows) displayed, and the lines for the target bone position and the estimated actual bone position may overlap each other, or only one line may be displayed.

[0049] 7 shows examples of bone locations, specifically target bone locations. In the example of angular joint acquisition, as shown in other figures, there are standard ankle anteroposterior (AP) or ankle mortise locations, represented with known ranges of position parameters that result in slightly different optimal views in the x-ray images. These target locations can be used for comparison with estimated actual bone locations of body part 104.

[0050] FIG. 8 is an illustration of method steps according to one embodiment of the present invention. The method illustrated in this figure may also be performed by the apparatus 100 and by computer program products described in other embodiments of the present invention. This method is for assisting in the positioning of at least one body part of a patient for X-ray acquisition. The method includes the following steps S1 to S7. In FIG. 8, each element or unit that may be used in or that performs a step is associated with a respective rectangle in the figure. The steps may be performed in the order shown in FIG. 8, but it may be possible to change the order of the steps or exchange one or more steps for other steps. Furthermore, some or all of the steps may be performed simultaneously. This also applies to other and / or further method steps mentioned in other embodiments of the present invention. Therefore, the present invention is not limited to the respective order of the steps illustrated in FIG. 8 and described below. The first step S1 includes operating the apparatus 100 to position at least one body part 104 of a patient for X-ray acquisition. A next step S2 comprises monitoring the body part 104 to be positioned via the first camera 103, where the body part 104 is monitored from the observation viewpoint of the device 100. This step S2 may also comprise monitoring the user 105 via the second camera 102. Alternatively, monitoring the user 105 may be performed as a separate step of the method. A next step S3 comprises estimating an actual bone position 408 of the body part 105 based on one or more images acquired by the first camera 103. In a next step S4, a target bone position 610 is determined. After steps S3 and S4, in step S5, a difference between the estimated actual bone position and the target bone position is calculated. A step S6 comprises displaying, on the display 101, at least one of the target bone position 610, the estimated actual bone position 408, and a calculated difference 611 between the estimated actual bone position 408 and the target bone position 610, superimposed on at least one image of the body part 104.In step S6, the different bone positions (target bone position 610, actual bone position 408) or their difference 611 may be displayed simultaneously, or each of them may be displayed separately one after the other. Nevertheless, all of them or at least one or several of them are displayed simultaneously via the display 101 together with a real-time image and / or video of the body part 104. Step 7 comprises adapting the display of at least one of 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 610 in response to a change in the observation point of view of the device 100. When step S7 is performed, it is determined whether the point of view has changed and whether the actual bone position 408 has to be estimated again, so that the method can resume again from step S2. It may also be possible to start with any other suitable step, for example the estimation of the actual bone position 408 in step S3.

[0051] According to an exemplary embodiment of the present invention, the method may further comprise at least one of the following steps, which may be integrated into one of steps S1 to S7 described above: determining the position of the X-ray detector and the position of the X-ray source of the X-ray system used for X-ray acquisition, each position being determined with reference to an X-ray coordinate system; transforming the estimated actual bone positions 408 of the body part into the X-ray coordinate system, which may be performed in step S3, or S3 may comprise further transformation steps; another step may be comparing the transformed estimated actual bone positions 408 with the target positions 610 in the X-ray coordinate system, which may be a separate step of the method shown in FIG. 8 or may be part of step S4; a further step may be transforming the estimated actual bone positions 408 in the X-ray coordinate system and the target bone positions 610 in the X-ray coordinate system into the device coordinate system, so that the position(s) can be displayed via the display 101 from the observation viewpoint of the device 100. This transformation to the display coordinate system may be part of step S4, or may be a step performed after step S4 and before step S5.

[0052] It should be noted that the term "comprises" does not exclude other elements or steps, and that "a" or "an" does not exclude a plurality. Also, elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims shall not be construed as limiting the scope of the claims. [Explanation of symbols]

[0053] 100: Equipment 101: Display 102: First camera 103: Second Camera 104: Body parts 105:User 106: Observation viewpoint 220: X-ray system 307: User's hand 408: Actual bone position 509: Actual bone position 610:Target bone position 611: Difference between positions

Claims

1. 1. An apparatus for assisting in positioning at least one body part of a patient for x-ray acquisition by an x-ray system, said apparatus comprising: a display for displaying the body part to be positioned to a user operating the device; a first camera on a first side of the display, the first camera being positioned and configured to monitor the body part of the patient to be positioned, the body part being monitored from a visual perspective of the device; a processing unit; and The processing unit estimating actual bone positions of the body part based on one or more images acquired by the first camera; Determine the target bone position, calculating a difference between the estimated actual bone position and the target bone position; It is configured as follows: the device is configured to display, by the 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; the device is configured to adapt a display of 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 response to a change in a viewing point of the device. Device.

2. the observation viewpoint of the device has a spatial perspective between the observation directions of the first camera toward the body part; 10. The apparatus of claim 1.

3. a second camera on a second side of the display positioned and configured to monitor the user's viewpoint; and the observation viewpoint of the user comprises a spatial perspective between the device and the observation direction of the user in the direction of the body part; 3. The device according to claim 1 or 2.

4. the first camera generates one or more images; the processing unit is configured to estimate the actual bone arrangement of the body part based on the one or more images of the first camera.

4. An apparatus according to any one of claims 1 to 3.

5. In order to determine the target bone position, the processing unit is further configured to determine a position of an X-ray source and a position of an X-ray detector of an X-ray system used for the X-ray acquisition, the target bone position being determined with reference to an X-ray coordinate system.

5. An apparatus according to any one of claims 1 to 4.

6. the processing unit is configured to determine, with reference to the X-ray coordinate system, at least one of a position of the display and an orientation of the display, such that a position of the display relative to the X-ray system can be determined.

6. The apparatus of claim 5.

7. the processing unit is configured to transform the estimated actual bone positions of the body part into the X-ray coordinate system; configured to compare the estimated actual bone position with the target bone position in the X-ray coordinate system.

7. Apparatus according to any one of claims 5 or 6.

8. the processing unit is further configured to generate geometric primitives indicative of joint models or joint pose parameters of an anatomical structure of the imaged body part; the device is configured to show the estimated actual bone positions via the display using at least one of a joint model or geometric primitives representing joint pose parameters of an anatomical structure of the imaged body part.

8. An apparatus according to any one of claims 1 to 7.

9. the device is configured to provide feedback to a 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.

9. An apparatus according to any one of claims 1 to 8.

10. the second camera is positioned and configured to track the eyes of the user operating the device to determine the observation point of the user.

10. Apparatus according to any one of claims 3 to 9.

11. the first camera is positioned opposite a center of the display such that parallax between the display and the first camera is reduced; 11. Apparatus according to any one of claims 1 to 10.

12. 1. A computer program for assisting in positioning at least one body part of a patient for an X-ray acquisition, comprising: The computer program, when executed by a processor of a device for positioning at least one body part of a patient as presented herein, causes the device to: monitoring the body part via a first camera of the device, the body part being monitored from a viewing vantage point of the device; estimating actual bone positions of the body part based on one or more images acquired by the first camera; Determine the target bone location, calculating a difference between the estimated actual bone position and the target bone position; causing the display to display, superimposed on at least one image of the body part, 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; adapting a display of at least one of the target bone position, the estimated real bone position, and the difference between the estimated real bone position and the target bone position in response to changes in the viewing viewpoint of the device. It is configured as follows: Computer program.

13. an X-ray source; an x-ray detector for producing an x-ray image of at least a body portion of a patient; A device for positioning a body part of a patient for X-ray acquisition according to any one of claims 1 to 11, In an X-ray system having the device is configured to determine a position of the X-ray detector and a position of the X-ray source; X-ray system.

14. 1. A method for assisting in positioning at least one body part of a patient for an X-ray acquisition, comprising: operating a device to position the at least one body part of the patient for the x-ray acquisition; monitoring the body part to be positioned via a first camera, the body part being monitored from a viewing vantage point of the device; estimating actual bone positions of the body part based on one or more images acquired by the first camera; determining a target bone location; calculating a difference between the estimated actual bone position and the target bone position; displaying, by the 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; adapting a display of 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 response to a change in the observation viewpoint of the device; A method comprising:

15. determining a position of an X-ray detector and a position of an X-ray source of an X-ray system used to acquire the X-rays, each position being determined with reference to an X-ray coordinate system; transforming the estimated actual bone positions of the body part into the X-ray coordinate system; comparing the estimated actual bone position with the target position in the X-ray coordinate system; transforming the estimated actual bone position in the X-ray coordinate system and the target bone position in the X-ray coordinate system into a device coordinate system such that the positions are viewable via the display from the observation viewpoint of the device; The method of claim 14 , further comprising at least one of:

Images