Advanced Mobile X-ray Imaging Device

Abstract

Improved mobile X-ray imaging device The mobile device (10) comprises a mobile structure (12) carrying an X-ray source (14), an X-ray detector (22), and a device (24) for controlling the imaging device (10). The mobile structure (12) carries a first positioning system, and - the detector (22) carries a second positioning system. The control device (24) comprises means for processing positioning data supplied by the first and second positioning systems. Figure for abstract: Figure 1

Description

Title of the invention: Improved mobile X-ray imaging device

[0001] The present invention relates to a mobile X-ray imaging device. Such a device is primarily intended for producing images from X-ray-based techniques, such as radiographic or tomosynthesis techniques, on patients.

[0002] A mobile imaging device differs from a fixed imaging device in that it is not permanently installed in a dedicated room, but is transportable to the patient, for example to a hospital room or at home.

[0003] An imaging device typically includes an X-ray source, an X-ray sensitive detector for positioning behind an area of ​​the patient to be X-rayed, and a system control interface for an operator.

[0004] The quality of the image obtained depends on various parameters, in particular the correct alignment between the X-ray source, the patient and the detector.

[0005] In the case of a fixed imaging device, this alignment is easy to ensure, since the positioning of the source and the detector are predefined and do not need to be adjusted each time the device is used.

[0006] On the other hand, in the case of a mobile imaging device, the source and the detector are put in place each time they are used, which makes it very difficult to precisely verify their relative positioning.

[0007] However, in the context of X-ray imaging, it is important to obtain a quality image in order to avoid the need to produce several images on the same patient, in order to limit the exposure of this patient to X-rays.

[0008] The invention aims in particular to optimize the quality of the images produced by the imaging device.

[0009] To this end, the invention relates in particular to a mobile X-ray imaging device, comprising: a mobile structure carrying an X-ray source, an X-ray detector, and a device for controlling the imaging device, characterized in that:

[0010] - the mobile structure carries a first positioning system, and

[0011] - the detector carries a second positioning system,

[0012] - the control device comprises data processing means of positioning provided by the first and second positioning systems.

[0013] According to other advantageous aspects of the invention, the imaging device according to the invention comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

[0014] - The first positioning system comprises a first set of sensors of positioning, and the second positioning system comprises a second set of positioning sensors.

[0015] - The first positioning system comprises a camera carried by the structure mobile, and the control device comprises means for processing images captured by the camera, and for measuring the distance between the X-ray source and a subject to be imaged of which an image is captured by the camera.

[0016] - The control device is configured to display, in augmented reality, the position of the detector on the image captured by the camera.

[0017] - The control device comprises means for calculating the thickness of the subject to image, depending on the positioning between the source and the detector, provided by the positioning systems, and the distance between the source and the subject, provided by the image processing means.

[0018] - The control device comprises means for calculating the intensity of the X-rays emitted by the source, depending on the thickness of the subject.

[0019] - The detector has anti-diffusing side grids.

[0020] - The control device is mobile independently of the mobile structure, by example connected to the source by wireless means.

[0021] The invention also relates to an imaging method, characterized in that it uses an imaging device as defined previously.

[0022] Preferably, the imaging method comprises a step of determining three-dimensional coordinates of edges of the detector, by means of the second positioning system, and of displaying the contour obtained on the image displayed on the control device.

[0023] Preferably, the imaging method comprises a step of calculating the thickness of the subject to be imaged, as a function of the positioning between the source and the detector, provided by the positioning systems, and the distance between the source and the subject, provided by the image processing means.

[0024] Preferably, the imaging method comprises a step of calculating the intensity of the X-rays emitted by the source, as a function of the thickness of the subject.

[0025] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0026] [Fig-1] [Fig.l] is a perspective view of a mobile imaging device according to an exemplary embodiment of the invention, used on a patient;

[0027] [Fig.2] [Fig.2] is a perspective view of a movable structure of the imaging device of [Fig.l].

[0028] [Fig. 1] shows a mobile imaging device 10 according to an exemplary embodiment of the invention.

[0029] It is recalled here that an imaging device is considered mobile when it can be moved to a patient, in particular at home or in a hospital room. A mobile device therefore does not include any element that is permanently fixed in a room, and only includes elements that can be moved by an operator.

[0030] In the example described, the imaging device 10 is used on a subject 11, in particular a patient 11 lying on a bed 13. The bed 13 is for example that of a hospital room, the walls 15 of which are shown schematically.

[0031] The mobile imaging device 10 comprises a mobile structure 12, shown in more detail in [Fig.2], carrying an X-ray source 14.

[0032] In the example described, the mobile structure 12 has a generally parallelepiped shape, formed by an assembly of vertical bars connected to each other by horizontal bars.

[0033] The X-ray source 14 is preferably arranged at the height of the upper ends of the vertical bars.

[0034] The mobile structure 12 is for example carried by a support 16 comprising a vertical foot 18 carrying a preferably horizontal arm 20. The mobile structure 12 is then carried by the arm 20, in order to suspend it above the patient 11. The support 16 preferably comprises a box 21 mounted on casters 23, allowing easy movement of the imaging device 10. The box 21 preferably comprises storage arrangements.

[0035] The mobile imaging device 10 further comprises an X-ray detector 22, intended to be placed behind the patient 11. More particularly, in a conventional manner, the patient 11 is placed between the X-ray source 14 and the detector 22. In the example described, the detector 22 is placed on the bed 13, and the patient 11 is lying on the detector 22, the part of his body to be imaged (in the example shown, the thorax) being above this detector 22.

[0036] The mobile imaging device 10 also comprises a control device 24, for controlling the elements of the imaging device carried by the mobile structure. The control device 24 is preferably mobile independently of the mobile structure 12, so that it can be used by a practitioner 26 outside the room. Indeed, it is preferable to limit as much as possible the exposure of the practitioner 26 to X-rays, since the latter is required to use the imaging device 10 very regularly. The control device 24 must therefore allow remote control of the imaging device 10.

[0037] Advantageously, the storage arrangements of the mobile box 21 allow the control device 24 to be stored when it is not in use.

[0038] Preferably, the control device 24 communicates with the elements carried by the mobile structure 12 by means of wireless technology, for example via Wifi or any other known wireless protocol.

[0039] The control device 24 notably allows the remote activation of the X-ray source 14.

[0040] The imaging device 10 according to the invention comprises a first alignment system 25, carried by the mobile structure 12, and a second alignment system 27, carried by the detector 22. The first and second alignment systems cooperate together to ensure the correct positioning of the X-ray source 14 relative to the detector 22.

[0041] As shown in [Fig.2], the first alignment system 25 comprises a camera 28 carried by the mobile structure 12. For example, the camera 28 is a color camera, in particular an RGB camera.

[0042] The control device 24 enables the activation of the camera 28, and in particular enables the display of the images captured by this camera 28. For this purpose, the control device 24 comprises a screen suitable for displaying these images.

[0043] Preferably, the control device 24 comprises image processing means, in particular image processing software, configured to calculate the distance between the X-ray source 14 and the patient 11 (the position between the source 14 and the camera 28 being fixed).

[0044] The calculation of this distance makes it possible in particular to determine the quantity and intensity of X-rays emitted by the X-ray source 14. This quantity and this intensity depend in fact on this distance, to expose the patient 11 to an optimal quantity and intensity of X-rays, that is to say enough to obtain a good radiological image, but hardly more to limit as much as possible the exposure of the patient 11 to the X-rays.

[0045] It will be noted that the image captured by the camera 28 also allows the practitioner 26 to check the correct position of the patient 11 relative to the source 14 and the detector 22 before activating the X-ray source 14.

[0046] The first alignment system 25 further comprises a first set of at least one first positioning sensor 30, carried by the mobile structure 12. The first set of sensors 30 being carried by the mobile structure 12, the position of the first sensors 30 relative to the source 14 is fixed.

[0047] Each first sensor 30 is preferably arranged at the height of the lower end of each vertical bar, in order to be arranged at a distance from the source 14 and thus limit any possible interference.

[0048] The second alignment system 27 comprises a second set of at least one second positioning sensor 32, carried by the detector 22. The second set of sensors 32 being carried by the detector 22, the position of the second sensors 32 relative to this detector is fixed.

[0049] The control device 24 comprises means for processing positioning data provided by the first 30 and second 32 sets of sensors, and in particular software provided for this purpose. These means for processing positioning data are configured to give, in real time, the relative spatial positioning of the first sensors 30 with respect to the second sensors 32. This makes it possible to place the X-ray source 14 in a desired operating position with respect to the detector 22.

[0050] In particular, by considering a reference frame in the plane of the detector 22, the sensors 30 and 32 make it possible to align the X-ray source 14 in a desired position in this reference frame.

[0051] Furthermore, by considering a direction normal to the plane of the detector 22, the sensors 30 and 32 make it possible to determine the distance between the X-ray source 14 and the detector 12.

[0052] The control device 24 advantageously comprises means for calculating the thickness of the patient 11 at the level of the body part to be radiographed. Indeed, by knowing the distance between the source 14 and the patient 11 (obtained by the image processing means of the camera 28 described previously), and by knowing the distance between the source 14 and the detector 22, it is possible to obtain the thickness of the patient 11 by a simple subtraction, since the patient 11 rests on the detector 22.

[0053] Knowledge of the thickness of the patient 11 also plays a role in calculating the optimal quantity and intensity of X-rays to be emitted. Indeed, these quantities and intensities depend on the corpulence of the patient 11. It should be noted that these quantities and intensities also depend on the imaging protocol chosen, in particular whether it is imaging of the torso, the pelvis, the hand, or another part of the body. The imaging protocol is for example selected from the control device 24.

[0054] The quantity and intensity of the X-rays to be emitted can be calculated automatically by knowing the distance between the X-ray source 14 and the patient 11 and / or by knowing the thickness of the patient 11, for example by means of a predefined conversion table stored in the control device 24.

[0055] The sensor sets 30, 32 also make it possible to determine the angular position of the mobile structure 12, therefore of the source 14, relative to the plane of the detector. 22, around three axes, namely the axes of the aforementioned reference frame, and the axis of the direction normal to the plane of the detector 22. A good angular position is necessary to obtain a good radiological image. These angular positions are displayed by the control device 24.

[0056] Advantageously, the control device 24 is configured to display, in augmented reality, the position of the detector 22 on the image captured by the camera 28, knowing this position of the detector 22 relative to the position of the mobile structure 12. This augmented reality makes it possible to obtain an optimal source 14, patient 11 and detector 22 alignment at each instant.

[0057] The control device 24 is for example formed by a touch tablet or a laptop computer, provided with software allowing the implementation of the functions of the control device 24 described previously.

[0058] Advantageously, the imaging device 10 comprises lateral grids 34 intended to prevent lateral diffusion of the X-rays, carried by the detector 22. These grids 34 are positioned by means of positioning stops.

[0059] A calibration based on a radiopaque target makes it possible to define the transformations between the position sensors 30 of the source 14 and the source 14 itself, as well as that between the position sensors 32 of the detector 22 and the photosensitive zone of the detector 22. With this double knowledge, it is possible to know precisely the position of the source 14 with respect to the sensitive zone of the detector 22 and the focused anti-scattered grid 34. This information obtained in real time makes it possible to help the operator to obtain a fine alignment allowing optimal image quality.

[0060] According to an alternative embodiment, the first set of sensors 30 comprises magnetic sensors, placed on the source 14, on the camera 28 and on the structure 12. This alternative has several advantages. In particular, a placement of the camera 28 with its sensor closest to the axis of the X-ray beam and having a visual field and an angle of incidence direct on the patient to guarantee a direct distance measurement as well as the most optimal real-time vision.

Claims

Claims

1. Mobile X-ray imaging device (10), comprising: a mobile structure (12) carrying an X-ray source (14), an X-ray detector (22), and a device (24) for controlling the imaging device (10), characterized in that: - the mobile structure (12) carries a first positioning system (25), and - the detector (22) carries a second positioning system (27), - the control device (24) comprises means for processing positioning data supplied by the first and second positioning systems.

2. The imaging device (10) of claim 1, wherein the first positioning system (25) comprises a first set of positioning sensors (30), and the second positioning system (27) comprises a second set of positioning sensors (32).

3. Imaging device (10) according to claim 1 or 2, wherein the first positioning system (25) comprises a camera (28) carried by the mobile structure (12), and the control device (24) comprises means for processing images captured by the camera (28), and for measuring the distance between the X-ray source (14) and a subject (11) to be imaged, an image of which is captured by the camera (28).

4. Imaging device (10) according to claim 3, wherein the control device (24) is configured to display, in augmented reality, the position of the detector (22) on the image captured by the camera (28).

5. Imaging device (10) according to claim 3 or 4, wherein the control device (24) comprises means for calculating the thickness of the subject (11) to be imaged, as a function of the positioning between the source (14) and the detector (22), provided by the positioning systems (25; 27), and of the distance between the source (14) and the subject (11), provided by the image processing means.

6. Imaging device (10) according to claim 5, in which the control device (24) comprises means for calculating the intensity of the X-rays emitted by the source (14), as a function of the thickness of the subject (11).

7. An imaging device (10) according to any preceding claim, wherein the detector (22) carries anti-scattering side grids (34).

8. Imaging device (10) according to any one of the preceding claims, wherein the control device (24) is movable independently of the movable structure (12), for example connected to the source (14) by wireless connection means.

9. Imaging method, characterized in that it uses an imaging device (10) according to any one of the preceding claims.

10. Imaging method according to claim 9, using the imaging device (10) according to claim 4, and comprising a step of determining three-dimensional coordinates of edges of the detector (22), by means of the second positioning system (27), and displaying the contour obtained on the image displayed on the control device (24).

11. Imaging method according to claim 9 or 10, using the imaging device (10) according to claim 5, comprising a step of calculating the thickness of the subject (11) to be imaged, as a function of the positioning between the source (14) and the detector (22), provided by the positioning systems (25; 27), and the distance between the source (14) and the subject (11), provided by the image processing means.

12. Imaging method according to claim 11, using the imaging device (10) according to claim 6, comprising a step of calculating the intensity of the X-rays emitted by the source (14), as a function of the thickness of the subject (11).

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