Radiation equipment assembly and method for aligning such an assembly - Patents.com

Abstract

The present invention provides an X-ray tube (11) for generating a beam of X-rays (12) centered in a main emission direction (13); a planar sensor (14) extending in a plane defined by a first direction (D1) and a second direction (D2) substantially perpendicular to the main X-ray emission direction (13), the sensor intended to receive the X-rays (12); A radiological equipment assembly (10) comprising: it is, a first split emitter (15) that is split into two electromagnetic field-emitting parts; a second split emitter (16) that is split into two electromagnetic field-emitting parts; - so-called planar electromagnetic field emitters (24) - electromagnetic field sensors (29, 30, 31, 32) firmly fixed to the planar sensor (14); processing means (17) intended to determine the alignment angle between the main emission direction (13) and the normal (N1) of the planar sensor (14) and to determine the first and second centering errors; - correction means (171) for correcting the alignment angle by applying a first correction movement to the X-ray tube (11) and for correcting the first and second centering errors by applying the first and / or second correction movements to the X-ray tube (11); The present invention is characterized by comprising:

Description

[Technical Field]

[0001] The present invention relates to a radiological equipment assembly, more precisely to the alignment of two elements of a radiological equipment assembly, namely a planar sensor with respect to an X-ray tube. The present invention also relates to a method for aligning such a radiological equipment assembly. The present invention relates to the field of radiological equipment (e.g., medical or veterinary radiological equipment), but is not limited to this field. The present invention also has applicability in the fields of safety and industrial inspection. The present invention may also be applied in other fields where it is necessary to align a point radiation source with respect to a planar sensor, for example in the field of infrared imaging. [Background technology]

[0002] In this patent application, the invention is presented in the context of its application to radiological equipment assemblies, however, the invention may also be applied in other fields where it is necessary to accurately position two elements relative to one another.

[0003] A radiology equipment assembly consists of two elements: an X-ray tube for generating a beam of X-rays and a planar sensor for radiographic imaging. The assembly is primarily intended to create radiographic images of patients in hospitals. The patient whose radiographic image is to be taken is positioned between the X-ray tube and the planar sensor. The two elements must therefore be correctly positioned with respect to each other so that all of the X-rays emitted by the X-ray tube are captured by the planar sensor. These two elements are then said to be precisely aligned. The alignment must be performed before X-rays are emitted from the X-ray tube. The objective is to obtain good image quality while preventing overexposure of the patient by X-rays not captured by the sensor.

[0004] Typically, the X-ray tube is manually aligned by an operator so that it faces the planar sensor. The alignment is performed in translation and rotation. The alignment is typically performed when the patient is positioned in a predetermined position, i.e., between the X-ray tube and the planar sensor. There are many specific cases where the planar sensor is blocked. For example, this can be when the planar sensor is placed under the patient's body for abdominal or pelvic X-ray photography. It can also be when the planar sensor is under a sheet, under a stretcher, or even inside an incubator. Therefore, in these cases, it is very difficult for the operator to align the X-ray tube with respect to the planar sensor.

[0005] Furthermore, the environment of the planar sensor may be of several types, and may in particular be a hospital bed or gurney with a metal frame or an incubator for premature babies, so the sensor environment may pose an additional obstacle to accurately positioning the X-ray tube with respect to the planar sensor.

[0006] The alignment of the first element with respect to the second element involves the correction of several defects: centering defects (the X-ray beam is not centered on the planar sensor), orientation defects (the X-ray beam is not correctly oriented with respect to the plane of the planar sensor), and perpendicularity defects (the X-ray beam is not perpendicular to the planar sensor). The perpendicularity defect is very important if an anti-scatter grid is used for image generation. In this case, the grid is placed on the planar sensor. The X-rays must be perpendicular to the planar sensor and incident on it in order to be detectable by the planar sensor. The angular error with respect to perpendicularity is small (only a few degrees).

[0007] There are two ways to proceed with the alignment of the two elements. First, there can be mentioned optical alignment, where the two elements are aligned by a light beam that measures the relative position of one element with respect to the other. Optical alignment cannot be used in the field of radiography, since the planar sensors are often partially blocked by the bedsheets or the patient himself.

[0008] Alignment can also be achieved with a beam of acoustic waves. However, since alignment is performed in the presence of a patient, the patient's body may block all or part of the planar sensor. In addition, the presence of the patient can locally attenuate the acoustic waves and therefore lead to inaccurate measurements of the distance between the planar sensor and the X-ray tube.

[0009] The alignment of two elements can also be performed based on measuring the propagation time of electromagnetic waves. Measuring the propagation time of the waves makes it possible to measure the distance between the two elements. Trigonometry makes it possible to determine the relative position of the two elements with respect to each other. However, this alignment method does not work well in the case of radiographic applications, because the propagation time of the electromagnetic waves can change depending on the position of the patient between the two elements (X-ray tube and planar sensor). In addition, the environment (bed, stretcher, etc.) can generate multiple echoes, which may have a higher signal level than the main signal.

[0010] According to the same principle, there are alignment techniques based on measuring the distance between two elements based on measuring the attenuation of the electromagnetic signal. For radiographic applications, this alignment technique is unsuitable because the patient's body locally attenuates the electromagnetic waves, which can lead to inaccurate measurements.

[0011] Furthermore, U.S. Pat. No. 10,080,542 describes a method for providing information for aligning an X-ray tube and a detector of a mobile X-ray device using a sensor for detecting the absolute positional orientation of the X-ray tube and the detector. A magnetic field is generated at the X-ray tube along an axis transverse to the X-ray tube and the detector for evaluation by the sensor at the detector. Relative rotational orientation information is calculated from the difference between the absolute orientations of the X-ray tube and the detector. Relative translational positioning is performed by comparing the values ​​of the measured magnetic field components with those registered previously. Because this information is obtained for six degrees of freedom, the use of a single magnetic field appears to be insufficient in terms of robustness in the event of measurement errors in that single magnetic field. Additionally, the use of a single magnetic field involves the use of complex formulas to determine the six degrees of freedom, further complicating the alignment algorithm.

[0012] Finally, dental radiology equipment systems (French Patent No. 2 899 349) use multiple electromagnetic field emitters placed in the same plane or two electromagnetic field receivers capable of receiving the electromagnetic fields emitted by the emitters. The use of two receivers makes it possible to determine the angular orientation of the sensor, but does not provide any indication of the angle of one element relative to the other (with respect to the planar sensor of the X-ray tube). In addition, the positioning of the emitters in the same plane does not provide a very precise indication of the position of the planar sensor relative to the X-ray tube. It will be appreciated that in dental radiography the distance between the X-ray tube and the sensor is relatively short (20-30 cm) compared to the distance between the X-ray tube and the sensor in the field of medical radiography (approximately 1-2 m). [Prior art documents] [Patent documents]

[0013] [Patent Document 1] U.S. Patent No. 10,080,542 [Patent Document 2] French Patent No. 2 899 349 Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention aims to alleviate all or part of the above-mentioned problems by providing a radiological equipment assembly having a plurality of electromagnetic field emitters rigidly fixed to an X-ray tube and positioned in different planes, and a plurality of electromagnetic field sensors positioned on a planar sensor and receiving X-rays. This assembly makes it possible to clearly know the spatial position of the planar sensor and therefore its position relative to the X-ray tube, and therefore to align and position the X-ray tube with respect to the planar sensor. More specifically, the invention is based on vertical alignment of the planar sensor with respect to the X-ray tube, followed by centering about the main direction of X-ray emission. [Means for solving the problem]

[0015] For this reason, one aspect of the present invention is to an X-ray tube for generating a beam of X-rays centered in a main direction of emission; a planar sensor extending in a plane defined by a first direction and a second direction substantially perpendicular to the main X-ray emission direction, the sensor intended to receive X-rays; 1. A radiological equipment assembly comprising: That is, a first split emitter that is split into two electromagnetic field emitting portions and that is arranged to emit a first electromagnetic field in a main direction substantially perpendicular to the main emission direction, each of the two emitting portions of the split emitter being positioned on either side of the beam of X-rays; - divided into two electromagnetic field emission parts, the second electromagnetic field being substantially perpendicular to the main emission direction and parallel to the main direction of the first electromagnetic field; Intersects with a second split emitter arranged to emit in the primary direction, with two portions of the second split emitter positioned on either side of the beam of x-rays; a so-called planar electromagnetic field emitter, which is a coil made of windings and is arranged to emit a third electromagnetic field in a main direction substantially parallel to the main emission direction of the beam of X-rays, the main emission direction passing through the windings; an electromagnetic field sensor, firmly fixed to the planar sensor, capable of detecting first, second and third electromagnetic fields emitted alternately in their main directions by the first emitter, the second emitter and the so-called planar emitter, and generating first, second and third electrical signals in response to the detected electromagnetic fields; - processing means for processing the first, second and third electrical signals intended to determine an alignment angle between the main emission direction and a normal to the planar sensor, to determine a first centering error between the main emission direction of the first electromagnetic field and a first orientation of the planar sensor, and to determine a second centering error between the main emission direction of the second electromagnetic field and a second orientation of the planar sensor; - correction means for correcting the alignment angle by applying a first correction movement to the X-ray tube and for correcting the first and second centering errors by applying the first and / or second correction movements to the X-ray tube; The present invention is characterized by comprising:

[0016] According to one aspect of the invention, the processing means includes means for distinguishing the generated electrical signals.

[0017] According to one aspect of the invention, the processing means for processing the first, second and third electrical signals includes an estimator for estimating an azimuth angle between a principal direction of the first electromagnetic field and a first direction of the planar sensor.

[0018] According to one aspect of the present invention, each of the two emission portions of the first and second split emitters includes at least one winding, and the main emission direction of the X-ray beam is positioned between the at least one winding of the first and second split emitters.

[0019] According to one aspect of the invention, a so-called planar emitter comprises at least one winding through which the main direction of emission of the beam of X-rays passes.

[0020] According to one aspect of the invention, the two emitting portions of the first and second split emitters and so-called planar emitters are planar coils.

[0021] According to one aspect of the invention, the first corrective movement is a rotation of the X-ray tube in one of the main directions and / or a rotation of the X-ray tube in the main emission direction, and the second corrective movement is a translation of the X-ray tube in one of the main directions.

[0022] According to one aspect of the present invention, the planar sensor includes at least one inclinometer.

[0023] According to one aspect of the invention, the processing means and the correction means are mechanically coupled to the planar sensor.

[0024] According to one aspect of the invention, the processing means and the correction means are mechanically coupled to the X-ray tube.

[0025] The present invention also relates to a method for aligning a radiological equipment assembly, comprising: - emitting a first electromagnetic field in a main direction substantially perpendicular to the main emission direction by a first split emitter; - emitting, by a second emitter, a second electromagnetic field in a main direction substantially perpendicular to the main emission direction; - emitting the third electromagnetic field in a main direction substantially parallel to the main emission direction by means of a so-called planar emitter; - detecting, by means of a sensor, the electromagnetic fields emitted alternately by the first emitter, the second emitter and the so-called planar emitter in their main directions; generating first, second, and third electrical signals by the sensor in response to the first, second, and third detected electromagnetic fields; - evaluating the alignment angle between the main emission direction and the normal of the planar sensor; - correcting the alignment angle between the main emission direction and the normal of the planar sensor by applying a first correction movement; - evaluating a first centering error between a main direction of emission of the first electromagnetic field and a first orientation of the planar sensor and a second centering error between a main direction of emission of the second electromagnetic field and a second orientation of the planar sensor; - correcting the first and second centering errors by applying a second corrective movement; - optionally repeating the above steps until the alignment angle is smaller than a predetermined alignment angle threshold and / or until the first and second centering errors are smaller than a predetermined first centering error threshold and smaller than a predetermined second centering error threshold; The present invention is characterized by comprising:

[0026] According to one aspect of the invention, the method includes beforehand a calibration step intended to calibrate the electrical signals as a function of predetermined positions of the X-ray tube and of the planar sensor.

[0027] According to one aspect of the invention, the step of emitting an electromagnetic field by an emitter includes the step of supplying power to the emitter, the emitters being supplied with power at different instants or at different frequencies simultaneously, or out of phase simultaneously, such that the emitted electromagnetic fields are different.

[0028] According to one aspect of the invention, the method includes, after the step of correcting the centering error, a step of evaluating an azimuth angle between a main direction of the first electromagnetic field and a first orientation of the planar sensor, and, after the step of evaluating the azimuth angle, a step of correcting the azimuth angle between the main direction of the first electromagnetic field and the first orientation of the planar sensor.

[0029] The invention will be better understood and other advantages will become apparent from a reading of the detailed description of one embodiment thereof, given by way of example, which description is illustrated by the accompanying drawings, in which: [Brief explanation of the drawings]

[0030] [Figure 1]1 illustrates one embodiment of a radiological equipment assembly according to the present invention. [Figure 2] 1 shows an example of an arrangement of electromagnetic field emitters according to the invention. [Figure 3] 1 shows an example of a holder for an electromagnetic field emitter. [Figure 4] 1 shows a cross-sectional view of a radiological equipment assembly according to the present invention; [Figure 5] 1 shows diagrammatically the steps of an alignment method according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0031] For purposes of clarity, like elements will be designated by like reference numerals in the various drawings.

[0032] FIG. 1 shows an example of a radiological equipment assembly 10 according to the present invention. The radiological equipment assembly 10 includes an X-ray tube 11, which generates a beam of X-rays 12 centered in a main emission direction 13. The radiological equipment assembly 10 also includes a planar sensor 14 extending in a plane defined by a first direction D1 and a second direction D2, which are substantially perpendicular to the main emission direction 13. The planar sensor 14 is intended to receive the X-rays 12. According to the present invention, the radiological equipment assembly also includes a first split emitter 15, which is split into two electromagnetic field emitting portions 20, 21 and is arranged to emit a first electromagnetic field in a main direction 18 substantially perpendicular to the main emission direction 13, each of the two emitting portions 20, 21 of the split emitter 15 being positioned on either side of the beam of X-rays 12. Advantageously, the split emitter 15 is rigidly fixed to the X-ray tube 11 for generating the beam of X-rays 12. In this configuration, the position of the X-ray tube 11 for generating the beam of X-rays 12 can be inferred from the main direction of the electromagnetic field emitted by the split emitter 15 .

[0033] Similarly, the radiation equipment assembly also includes a second split emitter 16, which is split into two electromagnetic field emitting portions 22, 23 and emits the second electromagnetic field substantially perpendicular to the main emission direction 13 and parallel to the main direction of the first electromagnetic field. Intersects withArranged to emit in a main direction, each of the two emitting portions 22 , 23 of the split emitter 16 is positioned on either side of the beam of X-rays 12 .

[0034] In other words, each split emitter (e.g., 15) can be considered to be a pair of emitters 20, 21 whose main surfaces are parallel to one another, with each emitter positioned on one side of the beam of x-rays 12. The pair of emitters 20, 21 (and similarly for 22, 23) is equivalent to a virtual emitter positioned between the two elements 20, 21 in the beam of x-rays 12. When considering a single split emitter (i.e., a pair of emitters), the emitted electromagnetic field is equivalent to the electromagnetic field that would be emitted by an equivalent virtual emitter. This arrangement has the advantage of not blocking x-rays, since the pair of emitters is positioned on each side of the beam of x-rays 12 and is not within the beam. Furthermore, this arrangement of emitters has the advantage of not damaging the emitters. Specifically, an equivalent emitter placed within the beam of x-rays would be damaged by the x-rays during use. In the present invention, the emitter is not irradiated with X-rays and is therefore protected from the viewpoint of material resistance.

[0035] The radiation equipment assembly 10 may further comprise a so-called planar electromagnetic field emitter 24, which is arranged to emit the third electromagnetic field in a main direction 9 substantially parallel to the main emission direction 13. The so-called planar emitter 24 makes it possible to have an electromagnetic field parallel to the main emission direction 13.

[0036] The arrangement of the emitter shown in Figure 1 allows for electromagnetic fields along three different axes, each with a principal direction perpendicular to one another. Since the emitter is rigidly fixed to the X-ray tube 11 for generating the beam of X-rays 12, the three axes of electromagnetic fields allow for specific angular information to be determined that allows for comparison of different positions of the X-ray tube 11 and the planar sensor 14. Note that the three axes are not necessarily perpendicular to one another. The directions 18 and 19 are It is intersecting, can be at any angle (with each other and with the main emission direction 13). The relative position of the X-ray tube 11 with respect to the planar sensor 14 can also be determined.

[0037] There are two constraints on the frequencies of the first, second, and third fields: the relatively small span and power used by the split emitters 15 and 16 and by the planar emitter 14 makes it necessary to use a frequency high enough to extract the signal from the noise while obtaining a wide range of emission for the first, second and third electromagnetic fields; However, if metallic objects are present in the environment of the radiological equipment assembly 100, a lower frequency must be used.

[0038] For example, the frequencies of the first, second, and third electromagnetic fields may be between 10 Hz and 10 kHz.

[0039] Additionally, the first, second, and third electromagnetic fields are emitted sequentially and at different constant orientations to avoid obtaining rotating electromagnetic fields and to avoid any interaction between the first, second, and third electromagnetic fields. Three preferably perpendicular directions are sequentially and individually addressed with electromagnetic fields of constant frequency, orientation, and amplitude over a predetermined period of time.

[0040] The radiological equipment assembly 10 includes four electromagnetic field sensors 29, 30, 31, 32. The four sensors 29, 30, 31, 32 may be integrated into the planar sensor 14. The sensors 29, 30, 31, 32 are intended to detect the electromagnetic fields emitted by the split emitters 15 and 16 and by the so-called planar emitter 24 and to generate electrical signals in response to the detected electromagnetic fields. It should be noted that the radiological equipment assembly may include fewer or more than four electromagnetic field sensors.

[0041] The sensors 29, 30, 31, 32 are integrated into the planar sensor 14. They are mounted in such a way that they do not interfere with the acquisition of the radiation image. They are, for example, installed behind the element for detecting the radiation image, with respect to the plane of incidence of the X-rays. They can have any position on the planar sensor 14. In this case, the correction means must determine the relative position of the X-ray tube 11 with respect to the planar sensor 14. On the other hand, if they were positioned perfectly symmetrically with respect to the center of the planar sensor, the sensors 29, 30, 31, 32 would have perfectly balanced signals, which would result in perfect centering with respect to the X-ray tube 11 for generating the beam of X-rays 12.

[0042] The radiological equipment assembly 10 comprises processing means 17 for processing the first, second and third electrical signals. The processing means 17 further comprises a calculator capable of determining an alignment angle between the main emission direction 13 and the normal N1 of the planar sensor 14. The processing means 17 also comprises a calculator capable of determining a first centering error between the main emission direction 18 of the first electromagnetic field and the first direction D1 of the planar sensor 14, and a second centering error between the main direction 19 of the second electromagnetic field and the second direction D2 of the planar sensor 14. A special feature of the radiological equipment assembly according to the invention is its alignment mode. Instead of considering the absolute position of the planar sensor as is done in the prior art, the invention performs an alignment adjustment between the normal N1 of the planar sensor and the main emission direction 13 of the X-rays, thereby centering the planar sensor around the normal N1 and therefore with the main emission direction 13 of the X-rays.

[0043] The processing means 17 also include an estimator for estimating the azimuth angle between the main direction 18 of the first electromagnetic field and the first direction D1 of the planar sensor 14.

[0044] Furthermore, to ensure robustness of the radiological equipment assembly 10, the processing means 17 includes means for distinguishing between the generated electrical signals. Specifically, each generated electrical signal must be correctly identified as being captured by the sensors 29, 30, 31, 32 of the planar sensor 14 in order to induce corrections.

[0045] The radiation equipment assembly 10 also includes a correction means 171 for correcting the alignment angle and the first and second centering errors. More specifically, upon receiving the alignment angle and the first and second centering errors from the processing means 17, the correction means 171 operates by making a first correction movement on the X-ray tube 11 in the case of correcting the alignment angle, and by making a first correction movement and / or a second correction movement on the X-ray tube 11 in the case of correcting the first and / or second centering errors.

[0046] More specifically, the first corrective movement is a rotation of the X-ray tube 11 in one of the main directions 18 and 19 of the first and second electromagnetic fields or a rotation in the main emission direction 13 of the X-ray tube 11. The second corrective movement is a translation of the X-ray tube 11 in one of the main directions 18 and 19 of the first and second electromagnetic fields. The first corrective movement, like the second corrective movement, may be performed manually or automated in association with the correcting means 171.

[0047] Furthermore, in a similar manner, the correction means 171 can correct the azimuthal angle between the main direction 18 of the first electromagnetic field and the first direction D1 of the planar sensor 14 by applying a first correction movement to the X-ray tube 11.

[0048] However, evaluation and correction of the azimuth angle is still optional with respect to evaluation and correction of the alignment angle and centering error. Specifically, if the X-ray tube 11 for generating the beam of X-rays 12 and the planar sensor 14 are correctly aligned, i.e., if the alignment angle is close to zero degrees, and if the X-ray tube 11 for generating the beam of X-rays 12 and the planar sensor 14 are correctly centered, i.e., if the centering error is close to zero, the azimuth angle will therefore necessarily be close to zero degrees. Therefore, this azimuth angle is a measure that makes it possible to confirm that the X-ray tube 11 for generating the beam of X-rays 12 and the planar sensor 14 are correctly aligned and correctly centered.

[0049] Finally, the processing means 17 and the correction means 171 are in one preferred embodiment mechanically coupled to the planar sensor 14. However, the processing means 17 and the correction means 171 may also be mechanically coupled to the X-ray tube 11.

[0050] When used in a radiological equipment system, a typical operating distance is the distance at which the electromagnetic field measured by the receiver (i.e., the planar sensor 14 in this case) has a moment of

number

[0051] In a Z-axis polar coordinate system whose origin coincides with the center of the emitter block, the magnetic field component B measured at point M in spherical coordinates (ρ, θ, φ) in the reference frame defined by the source (in this case the X-ray tube 11) is γ , B θ , and B φ Therefore,

number

[0052] Therefore, measured at point M,

number

number

[0053] magnetic field

number

number

[0054] The simplifications and approximations possible in the alignment adjustment method therefore make it possible to estimate the alignment deviation, with increasing accuracy the smaller this deviation is. This deviation corresponds to the relative rotational position between the emitter and the detector. This is corrected by a first correction movement by applying a rotation relative to the main emission direction 13 to the detector (planar sensor 14) or a rotation opposite to the main emission direction 13 to the source (in this case the X-ray tube 11). This simplification also has the advantage that the calculations are relatively simple and therefore not very costly in terms of computation time and power.

[0055] There is a first interaction between a translation of the first electromagnetic field in the main direction 18 and a rotation of the second electromagnetic field in the main direction 19, and a similar second interaction between a translation of the second electromagnetic field in the main direction 19 and a rotation of the first electromagnetic field in the main direction 18. The first interaction is described as a translation of the first electromagnetic field between the detector (planar sensor 14) and the source (X-ray tube 11) in the main direction 18 involving a rotation of the magnetic field measured at the detector (planar sensor 14) in the opposite direction, similar to the application of a rotation of the second electromagnetic field in the main direction 19 between the detector (planar sensor 14) and the source (X-ray tube 11).

[0056] This interaction is overcome by using an inclinometer at the detector (planar sensor 14) to assess its alignment with respect to the source (X-ray tube 11). Knowing the alignment angle allows a relative rotation between the detector (planar sensor 14) and the source (X-ray tube 11) to be applied to obtain the alignment between the planar sensor 14 and the X-ray tube 11.

[0057] When the horizontal plane of the detector (the plane formed by the first direction D1 and the second direction D2 of the planar sensor 14) and the horizontal plane of the source (the plane formed by the main directions 18 and 19 of the X-ray tube 11) are aligned, the angle measured in the electromagnetic field results solely from the displacements associated with the first centering error in the main direction 18 and the second centering error in the main direction 19, respectively. Through calculations and estimations similar to those in the previous developments, it is also possible to measure the rotation of the electromagnetic field in the main directions 18 and 19 and deduce therefrom the numerical values ​​of the corrections for the first and second centering errors, which define the position of the radiation detector with respect to the source.

[0058] The distance of the detector (planar sensor 14) relative to the source (X-ray tube 11) in the main emission direction 13 is not a measure that is fixed to an exact value when the two are aligned. This distance must simply be between a minimum and maximum value that is characteristic of the anti-scatter grid. This value can still be estimated from the measure of the module of the electromagnetic field at the center of the detector (planar sensor 14) by taking the average of the values ​​measured by the sensors 29, 30, 31, 32 and correlating it with the calibration of the induction module depending on the distance between the detector (planar sensor 14) and the source (X-ray tube 11).

[0059] All these formulas are very simple when the alignment of the planar sensor 14 and the X-ray tube 11 is close, making it possible to calculate positions and angles with an accuracy that increases the closer the detector (planar sensor 14) is to the target position. These approximations make it possible to obtain a sufficient accuracy locally, whereas if one were to seek this same accuracy for the entire field used, the solution of the inverse problem would become very complex, making it necessary to resort to methods and algorithms such as Kalman filters, which are also costly in terms of calculation time and therefore detrimental to the response time of the system or to the complexity of the computer.

[0060] FIG. 2 shows an example of an arrangement of electromagnetic field emitters 15 and 16 according to the present invention. In FIG. 2, the radiation equipment assembly includes two split emitters 15, 16, which are divided into two electromagnetic field-emitting portions 20, 21 and 22, 23. The first split emitter 15 is divided into two electromagnetic field-emitting portions 20, 21 and is arranged to emit a first electromagnetic field in a main direction 18 that is substantially perpendicular to the main emission direction 13. Each of the two emitting portions 20, 21 of the split emitter 15 is positioned on either side of the beam of x-rays 12. Similarly, the second split emitter 16 is divided into two electromagnetic field-emitting portions 22, 23 and is arranged to emit a second electromagnetic field in a main direction 19 that is substantially perpendicular to the main emission direction 13 and substantially perpendicular to the main direction 18 of the first electromagnetic field. Each of the two emitting portions 22 , 23 of the split emitter 16 is positioned on either side of the X-ray 12 .

[0061] The split emitters 15 and 16 and the so-called planar emitter 24 may be, for example, coils or solenoids. More specifically, each of the two emitting portions 20, 21 of the split emitter 15 and each of the two emitting portions 22, 23 of the split emitter 16 includes at least one winding through which a current can flow. Furthermore, in the same way, the so-called planar emitter 24 includes at least one winding through which a current can flow.

[0062] Considering now the surfaces represented by each winding of each emitting portion 20, 21 and 22, 23, it can be seen that surface 120 of emitting portion 20 is substantially parallel to surface 121 of emitting portion 21. Furthermore, the electromagnetic field emitted by split emitter 15 has a main direction 18 perpendicular to surfaces 120 and 121. By the same principle, surface 122 of emitting portion 22 is substantially parallel to surface 123 of emitting portion 23. Furthermore, the electromagnetic field emitted by split emitter 16 has a main direction 19 perpendicular to surfaces 122 and 123. Advantageously, surfaces 120 and 121 are perpendicular to surfaces 122 and 123. IntersectingIn addition, the main directions 18 and 19 are then substantially perpendicular to one another. This arrangement is particularly advantageous when the X-ray tube 11 for generating the beam of X-rays 12 has a square-shaped emission flux. In this way, the flux of X-rays 12 is emitted in the main emission direction 13 between the surfaces 120, 121, 122, 123 without intersecting (and therefore damaging) or shielding the emitters 15, 16, since they are not in the flux of X-rays 12.

[0063] This configuration of the split emitters 15 and 16 allows the main emission direction 13 of the beam of X-rays 12 to be located between at least one winding of the split emitter 15 and the split emitter 16, and ensures that each pair of emitters 20, 21 and 22, 23, whose respective surfaces 120, 121 and 122, 123 are parallel to one another, is equivalent to a virtual emitter located at the center of the surfaces 120, 121, 122, 123 of the emitters 15, 16 at the same level as the main emission direction 13 of the X-rays, whereas it is not possible to place a single emitter at the center because the X-ray beam passes through the center. Therefore, the emitters can emit an electromagnetic field at an off-center position that is equivalent to the electromagnetic field emitted at the central position, without blocking the X-rays emitted by the X-ray tube 11. In addition, at least one winding of the split emitters 15 and 16 and the so-called planar emitter 24 may be square, rectangular or circular in shape.

[0064] In a similar manner, the surface represented by the windings of the so-called planar emitter 24 can be interpreted as surface 124 of the so-called planar emitter 24. This surface 124 of the so-called planar emitter 24 is substantially perpendicular to surfaces 120, 121, 122, 123. Unlike the segmented emitters 15 and 16, the flux of X-rays 12 can pass through the so-called planar emitter 24 at the windings. The flux of X-rays 12 is not blocked by the so-called planar emitter 24 because it flows therethrough through one or more windings.

[0065] The emitter arrangement shown in Figure 2 makes it possible to have electromagnetic fields on three different axes whose main directions are perpendicular to one another. Since the segmented emitters 15 and 16 and the so-called planar emitter 24 are rigidly fixed to the X-ray tube 11 for generating the beam of X-rays 12, the three axial electromagnetic fields make it possible to determine specific angular information such as the alignment angle, first and second centering errors, or azimuth angle of the X-ray tube 11 for generating the beam of X-rays 12 with respect to the planar sensor 14.

[0066] It will be seen that the three axes are not necessarily mutually perpendicular. Directions 18 and 19 are It is intersecting , and can be at any angle (between themselves and with the main emission direction 13). In a broader sense, the three axial fields allow the position of the X-ray tube 11 relative to the planar sensor 14 to generate the beam of X-rays 12.

[0067] In FIG. 2, there are three emitters (15, 16, 24, i.e., four emitting portions 20, 21, 22, 23 and one emitter 24), positioned to form a rectangular parallelepiped. However, it is entirely conceivable to have more than three emitters, in which case each would be positioned on one face of a polyhedron whose number of faces corresponds to the number of emitting portions and emitters used. Increasing the number of emitters increases the accuracy of the evaluation of the alignment angle, the first and second centering errors, and optionally the azimuth angle of the X-ray tube 11 relative to the planar sensor 14. However, this increase in number increases manufacturing costs and the complexity of the signal processing. Three emitters, as in FIG. 2, provide a very good balance between the accuracy of the evaluation of the angle information and the complexity of the signal processing.

[0068] 3 shows an example of a holder 39 for an electromagnetic field emitter. Corresponding to the configuration of FIG. 2, the holder 39 has faces 40, 41, 42, 43, 44, which are substantially perpendicular to one another. Face 42 has a groove 45 in which the emitting portion 22 can be received. Similarly, face 44 has a groove 46 in which the emitter 24 can be received. The same is true for each of the faces. The holder 39 includes an intermediate element 47, which is substantially perpendicular to faces 40, 41, 42, 43 and substantially parallel to face 44. The intermediate element 47 is a fixing means, by which the holder 39 (and thus the emitters 15, 16, 24) can be firmly fixed to the X-ray tube 11 for generating the beam of X-rays 12.

[0069] When configured with multiple other emitters, the holder 39 may have another three-dimensional geometric shape with flat surfaces, each having a groove arranged to accommodate one emitter. Other arrangements are also possible, particularly when the emitters are fabricated on a printed circuit board. In this case, a planar coil may be fixed to the surface of the collimator, serving as a rigid and movable frame structure for the X-ray tube 11 to generate the beam of X-rays 12. Therefore, the two emission sections 20, 21 and 22, 23 of the first and second split emitters 15 and 16, as well as the so-called planar emitter 24, are planar coils, thereby reducing the overall size of the system.

[0070] It is also conceivable that the planar coil replaces the surface of the collimator or is directly integrated into the collimator.

[0071] 2 and 3, the pairs of mutually parallel surfaces (120 and 121, 122 and 123) and the arrangement of the emitters in the grooves provided for this purpose mean that the left and right windows (on faces 42 and 43) and / or the front and back windings (on faces 40 and 41) have a high degree of symmetry, which makes it possible to have a magnetic field perfectly centered on the center of the geometry and without obstructing the passage of X-rays. There is no need to have multiple windings in the side grooves; the bottom winding, i.e., that of face 44 in groove 46, is sufficient to provide symmetry.

[0072] In other words, each split emitter (15, 16) is divided into two electromagnetic field emitting portions (20, 21 and 22, 23) that are configured to generate an electromagnetic field that is perfectly centered between two planes formed by the emitting portions, each of the two emitting portions having a surface that is parallel to one another.

[0073] 4 shows a cross-sectional view of the radiological equipment assembly 10 according to the invention. As previously described with reference to FIG. 1, the sensors 29, 30, 31, 32 are integrated into the planar sensor 14. They are mounted so that they do not interfere with the acquisition of the radiological image. They are, for example, placed behind the element for detecting the radiological image, with respect to the plane of incidence of the X-rays.

[0074] The electromagnetic field sensors 29, 30, 31, 32 may be, for example, coils, magnetometers, magnetoresistors, anisotropic magnetoresistors, magnetotransistors, magnetodiodes, fluxgates, or Hall effect sensors. Furthermore, the planar sensor 14 and the X-ray tube 11 for generating the X-rays 12 include at least one inclinometer. In particular, the inclinometers installed on the X-ray tube 11 and the planar sensor 14 make it possible to evaluate the gravitational acceleration on the emitting part, i.e., the X-ray tube 11, and on the receiving part, i.e., the planar sensor 14. This acceleration represents an absolute vector, which is usually the same for the emitting and receiving parts, and which must be projected differently depending on observable deviations from the alignment, centering, and orientation of the X-ray tube 11 with respect to the planar sensor.

[0075] If the X-ray tube 11 and the planar sensor 14 are parallel, i.e., if the plane formed by the main directions 15 and 16 of the X-ray tube 11 is parallel to the plane formed by the first direction D1 and the second direction D2 of the planar sensor 14, the absolute vector of the X-ray tube 11 will be collinear with the absolute vector of the planar sensor 14.

[0076] Otherwise, the angle formed between the absolute vector of the X-ray tube 11 and the absolute vector of the planar sensor 14 corresponds to the tilt between the plane formed by the main directions 15 and 16 of the X-ray tube 11 and the plane formed by the first direction D1 and the second direction D2 of the planar sensor 14, and therefore to the misalignment between the X-ray tube 11 and the planar sensor 14.

[0077] Each of the electromagnetic field sensors 29, 30, 31, 32 may include amplification and filtering electronics (not shown) intended to process the electrical signals generated by each of the sensors 29, 30, 31, 32. Each sensor 29, 30, 31, 32 detects an electromagnetic field and generates an electrical signal corresponding to the amplitude of the detected electromagnetic field. The generated electrical signal is processed by the amplification and filtering electronics.

[0078] Depending on the type of sensor used, each sensor 29, 30, 31, 32 may generate one or more pieces of information at any given time. If the sensor is single-axis, it generates one piece of information. If the sensor is Tajik, it generates multiple pieces of information. The use of multi-axis sensors makes it possible to know the amplitude of the electromagnetic field and its direction.

[0079] In the present configuration, if the sensor is a single-axis sensor, 12 pieces of information are generated for a given position of the planar sensor 14. If the sensor is a three-axis sensor, 36 signals are generated.

[0080] The detected signals are digitized and sent to a computer in the processing means 17 shown in Figure 1, which processes angular information such as the tilt angle, the first and second centering errors or the azimuth angle of the planar sensor 14 relative to the X-ray tube 11 for generating the X-rays 12. The information from the sensors 29, 30, 31, 32 is then transferred in digital form and can therefore be transmitted either by wire or wireless link.

[0081] 5 shows diagrammatically the steps of an alignment method according to the invention. The method according to the invention for aligning a radiological equipment assembly 10 comprises the following steps: - a first split emitter 15 emits in a main direction 18 substantially perpendicular to the first main emission direction 13 of the electromagnetic field (step 100); - emitting a second electromagnetic field by a second emitter in a main direction 19 substantially perpendicular to the main emission direction 13 (step 101); - emitting the third electromagnetic field in a main direction 9 substantially parallel to the main emission direction 13 by means of a so-called planar emitter (step 102), - detecting, by means of a sensor, the electromagnetic waves emitted alternately in the respective main directions by the first emitter 15, the second emitter 16 and the so-called planar emitter 24 (step 110); generating, by the sensors 29, 30, 31, 32, first, second and third electrical signals in response to the first, second and third detected electromagnetic fields (step 120); - evaluating the alignment angle between the main emission direction 13 and the normal of the planar sensor 14 (step 130); - correcting the alignment angle between the main emission direction 13 and the normal N1 of the planar sensor 14 by applying a first correction movement (step 131); - evaluating a first centering error between the main direction of emission 18 of the first electromagnetic field and the first direction D1 of the planar sensor 14 and a second centering error between the main direction of emission 19 of the second electromagnetic field and the second direction D2 of the planar sensor 14 (step 140), - Correcting the first and second centering errors by applying a first corrective movement and / or a second corrective movement (step 141).

[0082] Optionally, the above steps are repeated until the alignment angle is less than a predetermined alignment angle threshold and / or until the first and second centering errors are less than a predetermined first and second centering error threshold.

[0083] In particular, if the radiological equipment assembly 10 includes multiple emitters 15, 16, 24, the processing means 17 must include means for distinguishing between the electrical signals generated in response to the detected first, second, and third magnetic fields.

[0084] The step 130 of evaluating the alignment angle between the main emission direction 13 and the normal to the planar sensor 14 is performed by processing the first, second, and third electrical signals, for example by the amplification and filtering electronics described above. The alignment angle can then be evaluated and analyzed by a computer to better understand the alignment difference between the X-ray tube 11 and the planar sensor 14. In particular, the alignment angle makes it possible to determine the degree of parallelism between the plane formed by the main directions 18 and 19 of the first and second electromagnetic fields in the X-ray tube 11 and the plane formed by the first and second directions D1 and D2 of the planar sensor 14.

[0085] Therefore, the step 131 of correcting the alignment angle makes it possible to achieve the above-mentioned parallelism between the plane of the X-ray tube 11 perpendicular to the beam of X-rays 13 and the plane of the planar sensor 14. To do this, a first corrective movement is applied, resulting in a rotation towards one of the main directions 18, 19 of the first or second electromagnetic field. In this way, it is ensured that the beam of X-rays 12 is correctly aligned facing the planar sensor 14 and that irradiation outside the planar sensor 14 is avoided.

[0086] Similarly, a step 140 of evaluating a first centering error between the main emission direction 18 of the first electromagnetic field and the first direction D1 of the planar sensor 14 and a second centering error between the main emission direction 19 of the second electromagnetic field and the second direction D2 of the planar sensor 14 is carried out by processing the first, second and third electrical signals, for example by means of the amplification and filtering electronics described above. The evaluation and analysis of the first and second centering errors makes it possible to reveal a possible lack of centering between the X-ray tube 11 and the planar sensor 14, which would then result in the beam of X-rays 12 being projected outside the area of ​​the planar sensor 14, which is not optimal.

[0087] The step 141 of correcting the first and second centering errors makes it possible to refocus the X-ray tube 11 with respect to the planar sensor 14. To do this, a first corrective movement is applied to rotate the X-ray tube 11 in the main emission direction 13 so that the main direction 18 of the first electromagnetic field of the X-ray tube 11 is parallel to the first direction D1 of the planar sensor 14 and the main direction 19 of the second electromagnetic field is parallel to the second direction D2 of the planar sensor 14. Therefore, the plane formed by the main directions 18 and 19 of the first and second electromagnetic fields of the X-ray tube 11 and the plane formed by the first and second directions D1 and D2 of the planar sensor 14 are collinear.

[0088] Subsequently, a second corrective movement is applied to translate the X-ray tube 11 in the main direction 18 of the first electromagnetic field and / or in the main direction 19 of the second electromagnetic field, so that the projections of the main direction 18 of the first electromagnetic field and the main direction 19 of the second electromagnetic field onto the plane formed by the first direction D1 and the second direction D2 of the planar sensor 14 are respectively in the first direction D1 and the second direction D2 of the planar sensor 14. In this way, the X-ray tube 11 is aligned with the planar sensor 14, thereby optimizing the exposure.

[0089] The alignment method according to the invention may include beforehand a calibration step 150 intended to calibrate the electrical signals according to the predetermined positions of the X-ray tube 11 and the planar sensor 14. During this step, the aforementioned angular information is saved and is then used to determine the correction conditions to be taken into account during the following steps.

[0090] The alignment method according to the invention may comprise, after step 141, a step of evaluating the azimuth angle between the main direction 18 of the first electromagnetic field and the first direction D1 of the planar sensor 14, performed by processing the first, second and third electrical signals, for example by means of the aforementioned amplification and filtering electronics. This step makes it possible to check the correct parallelism between the main direction 18 of the first electromagnetic field and the first direction D1 of the planar sensor 14. In particular, while this parallelism is verified during step 141, the evaluation of the azimuth angle makes it possible to perform a further verification, thereby increasing the accuracy and robustness of the alignment method according to the invention.

[0091] Therefore, the processing means 17 for processing the first, second and third electrical signals of the radiological equipment assembly 10 shown in FIG. 1 may optionally include an estimator for estimating the azimuth angle in addition to estimating the alignment angle with respect to the planar sensor 14 of the first and second centering errors of the X-ray tube 11.

[0092] Additionally, following this step of evaluating the azimuth angle, an additional step of correcting the azimuth angle may be introduced to correct the parallelism between the main direction 18 of the first electromagnetic field and the first direction D1 of the planar sensor 14 by applying a first corrective movement in the main emission direction 13. Therefore, this step of evaluating and correcting the azimuth angle is optional, but it improves the robustness and accuracy of the alignment method.

[0093] Furthermore, the alignment adjustment method may include, following step 131, a step of checking the alignment of the X-ray tube 11 and the planar sensor 14. This step of checking the alignment makes it possible to determine the correct alignment of these two elements. To do this, the alignment angle corrected during step 131 is compared with an alignment angle threshold, which may be, for example, 1° to 2°. In this way, if the alignment check is inconclusive, i.e., if the alignment angle corrected during step 131 is still greater than the alignment angle threshold, a first correction movement may be additionally applied to the alignment angle, thereby newly correcting the alignment angle between the main emission direction 13 and the normal N1 of the planar sensor 14 (step 131).

[0094] Similarly, the alignment method may include a step of checking the X-ray tube 11 and the planar sensor 14 following step 141. This step of checking the centering allows determining the correct centering of the two elements mentioned above. To do this, the first and second centering errors corrected during step 141 are compared with a first and second centering error threshold, respectively, which may be, for example, approximately 2 to 5 centimeters. In this way, if the centering check is inconclusive, i.e., if the first and second centering errors corrected during step 141 remain higher than the first and second centering error thresholds, a new correction of the first and second centering errors may be performed (step 141, additionally by applying the first and / or second corrective movements).

[0095] Therefore, the above steps may be repeated until the alignment angle is less than the alignment angle threshold and / or until the first and second centering errors are less than the first and second centering error thresholds.

[0096] Finally, the emitters 15, 16, 24 may be powered by electrical signals at different times, or simultaneously, at different frequencies, or simultaneously out of phase, causing them to emit different electromagnetic fields.

[0097] In other words, the first split emitter 15 and the second split emitter 16 can be powered at different times, or simultaneously, at different frequencies, or out of phase. Powering the split emitters at different times, or simultaneously, at different frequencies, or out of phase is one means of distinguishing the electrical signals generated.

[0098] Similarly, the so-called planar emitter 24 and the first and second segmented emitters 15, 16 may be powered at different times, or simultaneously, at different frequencies, or out of phase.

[0099] The invention described above has several advantages over existing solutions: -By means of a combination of a low frequency magnetic receiver assembly associated with the source / synchronous detection, e.g. --electromagnetic interference, including the Earth's magnetic field; -- the presence of objects between the source and the receiver that are opaque to high-frequency radiation, including light; This can reduce the sensitivity of the alignment system to external interference such as: The principle of local detection and calculation allows solving magnetic inverse problems in areas where alignment accuracy is required rather than uniform positioning accuracy at all positions, which would be unnecessary and more costly in terms of calculation time and power. Alignment seeking allows operation over long distances between source and receiver. The system may operate inside buildings in environments affected by interference. The invention can be easily implemented by adding an emission system rigidly fixed to the X-ray source and its collimator, and by adding a miniature sensor integrated into the detector electronics. The calculated information can be easily transferred to the radiology equipment system for automatic tube-detector alignment.

[0100] The main innovation is a method that allows the problem of alignment between the source and the receiver to be easily solved in an iterative manner, without resorting to complex calculations, estimations and algorithms.

[0101] This method is - updating the three-axis measurement of the electromagnetic field emitted in three orthogonal directions at a rate slower than the second one, - A simple method for calculating position and orientation that is more accurate the closer the axes are to being aligned, allowing the magnetic inverse problem to be solved through simple calculations that do not require complex algorithms or high computing power; the possibility of combining the initial magnetic information with information provided by inertial sensors to improve the accuracy of the correction; The possibility of using the results of the calculations to facilitate manual alignment or to send control signals to automatic alignment devices. Based on.

[0102] By prioritizing alignment methods over precise positioning at every point in space, the required computation time and power can be reduced. Therefore, delay times can be minimized and measurements can be updated more frequently, resulting in more accurate and smoother displacements.

Claims

1. an X-ray tube (11) for generating a beam of X-rays (12) centered in a main X-ray emission direction (13); a planar sensor (14) extending in a plane defined by a first direction (D1) and a second direction (D2) substantially perpendicular to the main X-ray emission direction (13), the sensor intended to receive the X-rays (12); A radiological equipment assembly (10) comprising: a first split emitter (15) that is split into two electromagnetic field emitting portions (20, 21) and that is arranged to emit a first electromagnetic field in a first electromagnetic field main emission direction (18) that is substantially perpendicular to the main X-ray emission direction (13), each of the two electromagnetic field emitting portions (20, 21) of the first split emitter (15) being positioned on either side of the beam of X-rays (12); a second segmented emitter (16) that is divided into two electromagnetic field emitting portions (22, 23) and that is arranged to emit a second electromagnetic field in a second electromagnetic field main emitting direction (19) that is substantially perpendicular to the main X-ray emitting direction (13) and that intersects with the first electromagnetic field main emitting direction (18), each of the two electromagnetic field emitting portions (22, 23) of the second segmented emitter (16) being positioned on either side of the beam of X-rays (12); an electromagnetic field emitter (24), which is a coil made of windings and is arranged to emit a third electromagnetic field in a main X-ray emission direction (9) substantially parallel to the main X-ray emission direction (13) of the beam of X-rays, the main X-ray emission direction (13) passing through the windings; - electromagnetic field sensors (29, 30, 31, 32) fixed to the planar sensor (14) and capable of detecting the first, second and third electromagnetic fields emitted alternately by the first segmented emitter (15), the second segmented emitter (16) and the electromagnetic field emitter (24) in their main electromagnetic field emission directions, and generating first, second and third electrical signals in response to the detected electromagnetic fields; - processing means (17) for processing the first, second and third electric signals intended to determine an alignment angle between the main X-ray emission direction (13) and a normal (N1) of the planar sensor (14), to determine a first centering error, which is the error between the first electromagnetic field main emission direction (18) and the first direction (D1) of the planar sensor (14), and to determine a second centering error, which is the error between the second electromagnetic field main emission direction (19) and the second direction (D2) of the planar sensor (14), the first direction (D1) and the second direction (D2) being directions of a coordinate system defined relative to the planar sensor (14); - correction means (171) for correcting the alignment angle by applying a first correction movement to the X-ray tube (11) and for correcting first and second centering errors by applying the first and / or second correction movement to the X-ray tube (11); A radiological equipment assembly (10) comprising:

2. A radiological equipment assembly (10) as described in claim 1, wherein the correction means (171) reduces the alignment angle to less than a predetermined alignment angle threshold, and / or reduces the first centering error to less than a first centering error threshold and reduces the second centering error to less than a second centering error threshold.

3. 2. The radiological equipment assembly (10) of claim 1, wherein said processing means (17) includes means for distinguishing said generated electrical signals.

4. 2. The radiological equipment assembly (10) of claim 1, wherein the processing means (17) for processing the first, second, and third electrical signals includes an estimator for estimating an azimuth angle between the first electromagnetic field main emission direction (18) and the first direction (D1) of the planar sensor (14).

5. 5. The radiation equipment assembly (10) according to claim 1, wherein each of the two emission portions (20, 21; 22, 23) of the first and second split emitters (15, 16) comprises at least one winding, and the main X-ray emission direction (13) of the beam of X-rays (12) is located between the at least one winding of the first and second split emitters (15, 16).

6. 6. The radiological equipment assembly (10) according to any one of claims 1 to 5, wherein the two electromagnetic field emitting portions (20, 21; 22, 23) of the first and second split emitters (15, 16) and the electromagnetic field emitter (24) are planar coils.

7. 6. The radiological equipment assembly (10) according to claim 1, wherein the first corrective movement is a rotation of the X-ray tube (11) around one of the main electromagnetic field emission directions (18, 19) and the second corrective movement is a translation of the X-ray tube (11) along one of the main electromagnetic field emission directions (18, 19).

8. The radiological equipment assembly (10) according to any one of claims 1 to 6, wherein the planar sensor (14) comprises at least one inclinometer.

9. Radiation equipment assembly (10) according to any one of claims 1 to 7, wherein said processing means (17) and said correction means (171) are mechanically coupled to said planar sensor (14).

10. The radiological equipment assembly (10) according to any one of the preceding claims, wherein said processing means (17) and said correction means (171) are mechanically coupled to said X-ray tube (11).

11. A method for aligning a radiological equipment assembly (10) according to any one of claims 1 to 10, comprising: - emitting (step 100) by the first segmented emitter (15) the first electromagnetic field in a first electromagnetic field main emission direction (18) substantially perpendicular to the main X-ray emission direction (13); - emitting, by the second segmented emitter, the second electromagnetic field in a second electromagnetic field main emission direction (19) substantially perpendicular to the main X-ray emission direction (13); - emitting by said electromagnetic field emitter a third electromagnetic field in a main X-ray emission direction (9) substantially parallel to said main X-ray emission direction (13); - detecting, by means of the sensor (step 110), the electromagnetic fields emitted alternately by the first split emitter (15, 16), the second split emitter (15, 16) and the electromagnetic field emitter (24) in their main electromagnetic field emission directions; generating (step 120) said first, second and third electrical signals by said sensors (29, 30, 31, 32) in response to said first, second and third detected electromagnetic fields; - evaluating the alignment angle between the main X-ray emission direction (13) and the normal to the planar sensor (14); - correcting the alignment angle between the main X-ray emission direction (13) and the normal to the planar sensor (14) by applying the first corrective movement; - evaluating the first centering error, which is the error between the first main direction of emission (18) of the electromagnetic field and the first orientation (D1) of the planar sensor (14), and the second centering error, which is the error between the second main direction of emission (19) of the electromagnetic field and the second orientation (D2) of the planar sensor (14); - correcting said first and said second centering errors by applying said second corrective movement; An alignment adjustment method comprising:

12. An alignment adjustment method as described in claim 11, further comprising the step of repeating the steps from emitting the first electromagnetic field (100) by the first split emitter (15) to correcting the first and second centering errors until the alignment angle becomes smaller than a predetermined alignment angle threshold and / or until the first centering error and the second centering error become smaller than a predetermined first centering error threshold and a predetermined second centering error threshold.

13. An alignment adjustment method as described in claim 11, comprising a calibration step (150) of calibrating the electrical signal according to predetermined positions of the X-ray tube (11) and the planar sensor (14) before the step (100) of emitting the first electromagnetic field by the first split emitter.

14. 14. The alignment method according to any one of claims 11 to 13, wherein the step of emitting the electromagnetic fields by the emitters comprises the step of supplying power to the emitters (15, 16, 24), the emitters being supplied with power at different moments or at different frequencies simultaneously or out of phase simultaneously such that the emitted electromagnetic fields are different.

15. 15. The alignment adjustment method according to claim 11, further comprising, after the step of correcting the first and second centering errors, a step of evaluating the azimuth angle between the first electromagnetic field main emission direction (18) and the first direction (D1) of the planar sensor (14), and, after the step of evaluating the azimuth angle, a step of correcting the azimuth angle between the first electromagnetic field main emission direction (18) and the first direction (D1) of the planar sensor (14).

Images