DE102021204457A1 - Compensating for the deflection of a couch arrangement for a fluoroscopy device - Google Patents

Abstract

The invention relates to avoiding an image offset for a fluoroscopy device with the following steps. Moving a bed arrangement (12), on which an examination object (13) is located, through the X-ray device (10), the bed arrangement (13) being held at a foot end (3) and a bed (4), a cushion (5) and a plate (6). The cushion (5) is arranged between the couch (4) and the plate (6), with the examination subject (13) being located on the plate (6). Determination of an extent of deflection of the plate (6) resulting from the movement of the couch arrangement (12) with the examination subject (13).Filling the cushion (5) with a fluid depending on the deflection.

Description

The present invention relates to a method and a device for avoiding or compensating for the deflection of a couch arrangement for a fluoroscopy device (e.g. an angiography system).

In fluoroscopy devices, such as angiography systems, a patient bed experiences deflection due to the weight of a patient on the patient bed. This deflection is not insignificant, especially in the case of larger patients weighing more than 80 kg. When acquiring an exposure, the offset with a fully extended patient table compared to the middle or minimum extension position can be over 5 cm. (There are e.g. 120 cm between the minimally extended position and the maximally extended position.) This means that the anatomical structures in a fluoroscopic image, which is captured with a completely extended patient bed, are opposite to the same anatomical structures in a fluoroscopic image, which is recorded with a minimal extended position is detected by more than 5 cm, which is also known as "overlay mismatch".

The object of the present invention is therefore to reduce this offset and to avoid it as far as possible.

According to the invention, this object is achieved by a method for avoiding an image offset for a X-ray device according to claim 1, by a corresponding device, by a X-ray device, by a computer program product and by an electronically readable data carrier according to the independent claims. The dependent claims define preferred and advantageous embodiments of the present invention.

• Bewegen einer Liegenanordnung, auf welcher sich ein Untersuchungsobjekt befindet, durch die Durchleuchtungseinrichtung. Dabei wird die Liegenanordnung, welche eine Liege, ein Kissen und eine Platte umfasst, an einem Fußende der Liegenanordnung gehalten. Das Kissen befindet sich zwischen der Liege und der Platte, wobei sich die Platte oberhalb befindet, so dass ein Untersuchungsobjekt in der Regel auf der Platte liegt.

Within the scope of the present invention, a method for avoiding an image offset for a fluoroscopy device is provided. The procedure includes the following steps:

• Moving a bed arrangement, on which an examination object is located, through the X-ray device. In this case, the couch arrangement, which comprises a couch, a cushion and a plate, is held at a foot end of the couch arrangement. The cushion is located between the couch and the panel, with the panel being on top, so that an examination subject usually lies on the panel.

Determination of an extent of deflection of the plate, the deflection resulting from the movement of the couch arrangement and from the weight of the examination object.

Automatic filling of the cushion with a fluid depending on (the amount of) the deflection. The cushion is filled with the fluid using a pump mechanism, for example.

By inflating the cushion with the fluid (e.g., air or foam), the spacing between the bed and the panel (particularly at a head end of the bed assembly, which is opposite the foot end) is increased, increasing the deflection for the panel, and thus for the material thereon existing examination object is virtually undone. In this way, the present invention solves the problem set out above.

According to the invention, the following variants exist for detecting (the extent of) the deflection.

A first image of the examination object located on the bed arrangement can be captured by means of the fluoroscopy device before the bed arrangement is moved (i.e. when the bed arrangement is, for example, in the middle or minimum extended position). In this variant, a second image of the examination object is then recorded with the fluoroscopy device after the couch arrangement with the examination object located on it has been moved into the end position (e.g. maximum extended position). The cushion was not filled with the fluid for the recording of the first image as well as for the recording of the second image, i.e. there is no fluid in the cushion. The first image is superimposed on the second image (or vice versa) in order to determine an offset (of the anatomical structures) of the examination subject between the first image and the second image. Depending on this offset, the extent of the deflection is determined. For example, the amount of deflection can correspond to this offset.

Assuming that the examination object has not moved between the time when the first image was captured and the time when the second image was captured, the extent of the deflection is determined very precisely in this variant.

In a further variant, the weight and/or the size or length of the examination object is/are recorded. Depending on the recorded weight and/or the recorded The extent of the deflection is determined by the size of the examination object.

Quasi as a preparation for this variant, a data set can be generated with the help of phantoms or dummies whose weight and/or size is precisely known, which shows the extent for each weight and/or each size of the phantom (for example with the first or third variant). the associated deflection is determined or measured. With knowledge of the weight and/or the size of the examination object, the associated extent of the deflection can then be determined with this data record.

In a further variant, a distance measuring device is located at the head end of the plate (which corresponds to the head end of the couch arrangement). This measuring device measures either the (minimum) distance to the floor on which the bed arrangement is arranged or to a ceiling above the bed arrangement. If a standard distance (to the floor or to the ceiling) without deflection is known, the extent of the deflection can then be determined based on the measured distance.

In particular, in this variant, the measuring device determines the distance by a transit time measurement with acoustic or electromagnetic waves. In this case, such a wave is emitted by a transmitter of the measuring device, which is reflected at a specific point (of the floor or the ceiling) and then received by a receiver of the measuring device. This variant of distance measurement is also known as ToF (“Time of Flight”). The variant can be implemented with a laser, for example. The transmitter emits a laser beam, for example, which is reflected on the floor or ceiling and received by the receiver. In this variant, the transmitter and receiver are usually located close together in one module.

In a further variant for distance measurement using a measuring device or using measuring means, the measuring device or measuring means comprise two transmitters and two receivers. A first transmitter and a first receiver are located at the top of the disk, while a second transmitter and a second receiver are located either on the floor or on the ceiling (in each case at the exact point at which the distance from the top of the disk is to be determined is). The first transmitter and the first receiver each have a first clock and the second transmitter and the second receiver each have a second clock, which are very precisely coordinated with one another. The first transmitter emits a first acoustic or electromagnetic wave, which is detected by the second receiver. After a known delay after receipt of the first wave by the second receiver, the second transmitter emits a second acoustic or electromagnetic wave which is detected by the first receiver. The distance from the top of the plate to the floor or ceiling can be determined based on the time between the transmission of the first wave and the reception of the second wave.

The advantage of the variant with the measuring device is that the extent of the deflection can be constantly determined and no radiation exposure (as with the first variant) occurs.

In a preferred embodiment, the cushion may be inflated until the amount of deflection is less than a predetermined threshold or limit.

For example, in combination with the measuring device described above, this embodiment could include the following steps, which can be carried out, for example, by means of a controller.

Step 1:

Determining the extent of the deflection, e.g. based on the distance measured using the measuring device.

Step 2:

Inflating the cushion with the fluid if the amount of deflection just determined is greater than the threshold.

Step 3:

Repeat steps 1 and 2 in this order until the amount of deflection is less than the threshold.

Alternatively, a table containing a volume depending on the weight and/or the size of the examination object or the patient could also be created in advance. When the fluid is pumped into the cushion at this volume, the deflection caused by the patient is accommodated.

A device for a fluoroscopy device is also provided within the scope of the present invention. In this case, the device comprises a controller, a holder and a couch arrangement. The holder is designed in such a way that it holds the couch arrangement at a foot end of the couch arrangement and that the couch arrangement can be displaced by means of the holder. The couch arrangement tion consists of a lounger, a cushion and a plate. The pillow is between the lounger and the plate. The bed arrangement is designed to arrange an examination object on the bed arrangement in order to move this examination object on the bed arrangement through the X-ray device. The controller is designed to determine an extent of deflection of the plate (in particular at a head end of the bed arrangement opposite the foot end), the extent of the deflection resulting from the movement of the bed arrangement and from the weight of the examination object. In addition, the controller is configured to fill the cushion with a fluid depending on the degree of deflection, in particular to reduce the degree of deflection.

The advantages of the device according to the invention essentially correspond to the advantages of the method according to the invention, which have been explained in detail above, so that they are not repeated here.

Advantageously, a cross section of the cushion is designed such that a height of the cushion at the head end of the bed arrangement is greater than a height of the cushion in the area of the foot end of the bed arrangement.

Since the distance of the plate from a horizontal straight line, which corresponds to the optimal position of the plate (without deflection), is greater the closer you are to the head end of the bed arrangement, the cushion according to the invention with the cross section described above fits well advantageously, it adapts better to deflection than, for example, a pillow with a rectangular cross-section (where the height at the head end would by definition be equal to a height at the foot end). In addition, it is advantageous if the cushion is designed in such a way that it essentially only expands upwards.

In particular, the cushion is made of plastic and should be radiolucent. In addition, the pillow should be made of a strong and durable material that is difficult to pierce (e.g. even with a scalpel).

According to an embodiment of the invention, the plate is non-slip on its underside. Optionally, it is also designed to be non-slip on its upper side, so that on the one hand the plate is prevented from slipping relative to the cushion and, optionally, the examination subject is prevented from slipping on the plate. Another possibility would be to glue the cushion to the plate to almost completely prevent the plate from slipping relative to the cushion. In addition, the plate (like the pad) should be made of a radiolucent material. This could be carbon fiber for the plate, for example.

Due to the non-slip surface, a patient is (almost) always lying horizontally and neither tilts to the side nor up or down (front or back).

According to one embodiment of the invention, the cushion comprises a valve arrangement which is arranged on an underside of the cushion in the area of the foot end of the couch arrangement. In particular, the fluid can be introduced into the cushion via this valve arrangement, but it can also be discharged from the cushion.

In addition, the device can comprise a measuring device which is arranged at a head end of the plate (which corresponds to the head end of the couch arrangement). The controller is designed to use the measuring device to measure either a distance from a floor on which the bed arrangement is standing or a distance from a ceiling above the bed arrangement. Furthermore, the controller is designed to determine the extent of the deflection based on the measured distance.

The measuring device can be the measuring device or the measuring means that were described above with regard to the method according to the invention.

According to an embodiment of the invention, the device comprises a pumping mechanism. This pumping mechanism is designed to pump the fluid into the cushion (particularly via the valve arrangement) and to pump the fluid out of the cushion (particularly via the valve arrangement).

Within the scope of the present invention, a fluoroscopy device is also provided which comprises a device according to the invention as described above.

The fluoroscopy device can be an X-ray system (e.g. an angiography system) or a magnetic resonance system.

Furthermore, the present invention describes a computer program product, in particular software, which can be loaded into a memory of a programmable control device or a computing unit of a fluoroscopy device. With this computer pro All or various embodiments of the method according to the invention described above can be executed as a program product when the computer program product is executed in the control device. In this case, the computer program product may require program means, for example libraries and auxiliary functions, in order to implement the corresponding embodiments of the method. In other words, the claim directed to the computer program product is intended to protect in particular software with which one of the above-described embodiments of the method according to the invention can be executed or which executes this embodiment. The software can be a source code (e.g. C++) that still needs to be compiled and linked or only interpreted, or it can be an executable software code that only needs to be loaded into the corresponding processing unit or control device for execution.

Finally, the present invention discloses an electronically readable data carrier, e.g. a DVD, a magnetic tape, a hard disk or a USB stick, on which electronically readable control information, in particular software (see above), is stored. If this control information (software) is read from the data carrier and stored in a control device or computing unit of a fluoroscopy device, all of the inventive embodiments of the method described above can be carried out.

The present invention more or less compensates for the effect of the deflection of the couch arrangement by filling the cushion with the fluid in order to avoid the image offset caused by a couch deflection or at least to counteract this image offset.

According to the prior art, the problem of bed deflection is solved by service technicians using image phantoms to create recordings with different weights in order to use these recordings to measure an image offset and to carry out a manual correction of the image overlay. These measured offset values for the weights used are recorded together with the corrections made in a table, which is integrated during the calibration of the system in such a way that the image overlay can be readjusted by the software. As a rule, this measurement procedure leads to a great deal of additional effort, which is incurred again with each corresponding change to an angiography system.

In contrast, according to the invention, the plate and the examination object located on it are automatically raised by means of the cushion, for example via the pump mechanism integrated in the device, whereby the examination object is brought into a horizontal position (if possible) or the image shift is (if possible) avoided. This means that a software-based readjustment to correct the image offset when the bed arrangement is extended is advantageously no longer necessary according to the invention. In addition, the current weight, the current size and also the current position of the patient can advantageously be taken into account exactly, in that the extent of the deflection is directly detected and compensated according to the invention.

• 1 bis 3 stellen das Problem einer Liegenanordnung beim Herausfahren dar.
• 4 stellt eine erfindungsgemäße Liegenanordnung dar.
• In 5 sind bestimmte Merkmale einer erfindungsgemäßen Liegenanordnung im Detail dargestellt.
• 6 stellt schematisch eine erfindungsgemäße Angiografie-Anlage mit einer erfindungsgemäßen Vorrichtung dar.
• 7 stellt schematisch eine erfindungsgemäße Vorrichtung mit einer Liegenanordnung dar.

The present invention is described in detail below using embodiments according to the invention with reference to the figures.

• 1 until 3 represent the problem of a bed arrangement when moving out.
• 4 represents a couch arrangement according to the invention.
• In 5 certain features of a couch arrangement according to the invention are shown in detail.
• 6 shows schematically an angiography system according to the invention with a device according to the invention.
• 7 shows schematically a device according to the invention with a couch arrangement.

In 1 a couch arrangement 12 is shown, which is held by a holder 9 in the area of its foot end 3 . Because of the weight (represented by the force arrow 51) of a patient 13 lying on the bed arrangement 12, the bed arrangement 12 bends.

While 2 represents the table arrangement 12 with a minimum deflection 53 or minimum extended position with a C-arm 60 3 the bed arrangement 12 at maximum deflection 52 or maximum extended position. The extent 54 of the deflection at the head end 2 of the bed arrangement 12 can be seen from the distance of the bed arrangement 12 from a horizontal line 55.

How based on 4 As shown, according to the invention, the amount 54 of deflection is reduced to zero (as far as possible) by inflating a cushion 5 .

In 4 a couch arrangement 12 according to the invention is shown for this purpose, which comprises a couch 4 , a cushion 5 and a plate 6 . In this case, the cushion 5 is arranged on the couch 4, while the Plate 6 is placed on the pad 5. Ie the cushion is located between the bed 4 and the plate 6.

By inflating the cushion 5 with a fluid, the plate 6 can be raised such that the top of the plate is aligned with the horizontal line 55, thereby advantageously compensating for or reversing the deflection. As a result, the patient 13 lying on the bed assembly 12 (more precisely on the plate 6) is located on the same horizontal line 55 regardless of the extended position of the bed assembly 12, so that there is no image offset between images of the same anatomical structures of the patient 13 that are taken at different extended positions ( Extreme case: minimally extended and maximally extended) is detected by means of the C-arm 60.

In 5 1 is a detail of a portion of the bed assembly 12 of the present invention at the head end 2 of the bed assembly 12 with the cushion 5 inflated to accommodate the deflection. It can be seen that the thickness or height of the inflated cushion 5 (in the vertical direction) changes from the head end of the bed arrangement 12 (and thus from the head end of the cushion 5) towards the foot end 3 of the bed arrangement 12 (and thus to the foot end of the cushion 5) scaled down. For this reason, it is advantageous to use a pillow 5 whose dimensions are created accordingly, ie whose height or thickness at the head end is greater than at the foot end.

One recognizes in 5 further that at the head end of the plate 6 there is a measuring device 7 or a sensor. This measuring device 7 measures the (minimum) distance from the head end of the plate 6 to the floor on which the couch arrangement 12 is located. Alternatively, the measuring device 7 can also measure the (minimum) distance to the ceiling below which the couch arrangement 12 is located. This measured distance can then be used to determine the distance of the head end of the plate 6 from the horizontal line 55 or the extent 54 of the deflection.

This measuring device 7 can be used, so to speak, to regulate or monitor the inflation of the cushion 5 . In particular, the cushion 5 is filled with the fluid until the measuring device 7 reports that the distance of the head end of the plate 6 from the horizontal line 55 has fallen below a predetermined limit value (e.g. zero).

In 6 an angiography system 10 according to the invention is shown schematically as a fluoroscopy device. In addition to a C-arm 60, this angiography system 10 includes a storage unit 21, a controller 20 and a device 1 according to the invention 6 a data medium 22 is shown, on which software is located, which can be loaded into the memory unit in order to carry out the method according to the invention in the fluoroscopy device 10 by means of the controller 20 .

The device 1 in 7 is shown schematically comprises, in addition to a couch arrangement 12 with a valve arrangement 30, which is attached to a holder 9, a controller 8, a measuring device 7 and a pump mechanism 40.

If the controllers 8, 20 (i.e. only the controller 8, only the controller 20 or both controllers 8, 20 together) recognize by means of the measuring device 7 that there is a deflection (i.e. an extent of the deflection > 0), it is possible automatically (e.g. under control of controls 8, 20) or with the assistance of an operator, fluid may be pumped via valve assembly 30 into cushion 5 of bed assembly 12 by pumping mechanism 40 to reduce the amount of deflection.

Claims (15)

Method for avoiding an image offset for a fluoroscopy device (10), the method comprising the following steps: Moving a bed arrangement (12), on which an examination object (13) is located, through the X-ray device (10), the bed arrangement (13) being held at a foot end (3) and a bed (4), a cushion (5) and a plate (6), the cushion (5) being arranged between the bed (4) and the plate (6), the examination object (13) being located on the plate (6), Determination of an extent of deflection of the plate (6), which results from the movement of the couch arrangement (12) with the examination object (13), and Filling the cushion (5) with a fluid depending on the deflection. procedure after claim 1 , characterized in that the detection of the deflection comprises: - Capturing a first image of the examination object (13) located on the bed arrangement (12) before the bed arrangement (12) is moved and a second image of the examination object located on the bed arrangement (12) ( 13) by means of the fluoroscopy device (10), without the cushion (5) being filled with fluid, superimposing the first image with the second image, determining an offset of the examination ob ject (13) between the first image and the second image, and determining the amount of deflection dependent on the offset. procedure after claim 1 , characterized in that the weight and/or the size of the examination object (13) is detected, and that the extent of the deflection is determined as a function of the weight and/or the size of the examination object (13). procedure after claim 1 , characterized in that by means of a measuring device (7), which is arranged at a head end (2) of the plate (6), which is opposite the foot end (3) of the couch arrangement (12), a distance to a floor on which the Lying arrangement (12) is, or a distance to a ceiling above the lying arrangement (12) is measured, and that the extent of the deflection is determined based on the distance. Method according to one of the preceding claims, characterized in that the cushion (5) is automatically filled until the degree of deflection is less than a limit value. Device for a fluoroscopic device (10), wherein the device (1) comprises a controller (8), a holder (9) and a bed arrangement (12) that can be displaced by means of the holder (9), wherein the holder (9) holds the bed arrangement (12) at a foot end (3) of the bed arrangement (12) during the displacement, wherein the couch arrangement (12) comprises a couch (4), a cushion (5) and a plate (6), the cushion (5) being arranged between the couch (4) and the plate (6), wherein the couch arrangement (12) is designed to hold an examination object (13) lying on the plate when the examination object (13) moves through the X-ray device (10), the controller (8) being designed to to determine the deflection of the plate (6) of the couch arrangement (12) caused by the examination object (13) and to fill the cushion (5) with a fluid depending on the deflection. device after claim 6 , characterized in that a cross section of the cushion (5) is designed such that a height of the cushion (5) at a head end (2) of the bed arrangement (12) opposite the foot end (3) is greater than a height of the cushion (5) in the area of the foot end (3) of the couch arrangement (12). device after claim 6 or 7 , characterized in that the plate (6) has on its underside a non-slip surface which prevents the plate (6) from slipping relative to the cushion (5). Device according to one of Claims 6 until 8th , characterized in that the cushion (5) comprises a valve assembly (30) which is located on the underside of the cushion (5) near the foot end (3) of the couch assembly (12) to the cushion (5) by means of To fill valve assembly (30) with the fluid. Device according to one of Claims 6 until 9 , characterized in that the device (1) comprises a measuring device (7) which is arranged at a head end (2) of the plate (6) which is opposite the foot end (3) of the couch arrangement (12), the controller (8) is designed to use the measuring device (7) to measure a distance to a floor on which the couch arrangement (12) stands, or a distance to a ceiling above the couch arrangement (12), and to use the distance to measure the extent to determine the deflection. Device according to one of Claims 6 until 10 , characterized in that the device (1) comprises a pumping mechanism (40) which is designed to pump the fluid into the cushion (5) and to pump the fluid out of the cushion (5). Device according to one of Claims 6 until 11 , characterized in that the device (1) for carrying out the method according to one of Claims 1 until 5 is designed. X-ray device with a device (1) according to one of Claims 6 until 12 . Computer program product, which comprises a program and can be loaded directly into a memory (21) of a programmable control device (20) of a fluoroscopy device (10), with program means for carrying out all the steps of the method according to one of Claims 1 - 5 to be carried out when the program is executed in the control device (20) of the fluoroscopy device (10). Electronically readable data carrier with electronically readable control information stored thereon, which are designed in such a way that they Use of the data carrier (22) in a control device (20) of a fluoroscopy device (10), the method according to one of Claims 1 - 5 execute.

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