Sensor-based moving system for a gantry of a computer-tomography device, and computer-tomography device

Abstract

The invention relates to an apparatus (1) for linearly moving a gantry of a computer-tomography device. The apparatus comprises a carriage (2) having a first part (4) of a measuring system and a guide rail (5) accommodated in a recess (11) in the floor (12). The guide rail (5) comprises a second part (8) of a measuring system in a cutout (7), with the cutout (7) being covered with a cover plate (9). The carriage (2) comprises a friction roller (3) which rolls on a guide shaft (10), which is accommodated in a groove in the guide rail and projects out of the floor (12), to enable linear movement.

Description

[0001] Title of the invention

[0002] Sensorized traversing system for a gantry of a computed tomography device and computed tomography device

[0003] Field of the invention

[0004] The invention relates to a device for moving a gantry and a computer tomography device having such a gantry.

[0005] Background of the invention

[0006] Computed tomography (CT) scanners or magnetic resonance imaging (MRI) scanners are often used for medical imaging procedures. A CT scanner consists of a scanning unit, also referred to as a gantry. The gantry rotates around a table on which a patient is positioned. For imaging, the gantry and table must be moved relative to each other.

[0007] DE 10 2012 201 527 B4 comprises a device for linearly adjusting a gantry of a computed tomography device with a linear guide. The linear guide comprises a rack and a running axis arranged parallel to the rack. The rack is arranged in a first groove in a rail of the linear guide. The running axis is arranged in a second groove of the rail, parallel to the first groove, such that its upper side does not protrude beyond the second groove.

[0008] DE 102014 213204 A1 discloses a device for linearly adjusting a gantry of a computed tomography device, as well as a computed tomography system. The device comprises a linear guide with a rack that engages a guide rail. The guide rail is covered by a cover strip outside the linear guide. The cover strip is guided around the rack within the linear guide by means of a roller system. Object of the invention

[0009] The invention is based on the object of providing an improved device for moving a gantry.

[0010] Description of the invention

[0011] According to the invention, this object is achieved by a device for linearly moving a gantry of a computer tomography device, comprising

[0012] - at least one carriage having a friction roller and a first part of a measuring system,

[0013] - at least one elongated guide rail with a longitudinal groove and a recess in which a second part of the measuring system is accommodated, the recess being covered by a cover plate,

[0014] - a guide shaft received by the guide rail in the groove, on which the friction roller of the carriage rolls, wherein the guide rail is inserted into a recess in the floor at a location of the device in such a way that an upper side of the guide rail having the groove is flush with the floor at least on one side of the groove, wherein the guide shaft protrudes from the floor to contact the friction roller.

[0015] One challenge with movable gantries is ensuring they move accurately during a patient scan. The precise position of a gantry must be known at all times. Furthermore, the guidance system must be protected from the ingress of dirt and other particles. In addition, there are requirements regarding the practical integration of the gantries into examination rooms. Currently, gantries are often driven by rack and pinion drives and guided via a shaft guide or profile rail guide. The guidance system is covered by a cover strip. The cover strip is raised and lowered by a carriage. This protects the guide from external influences, apart from the current position of the carriage. However, such solutions are complex because the cover strip is subject to wear.During the wear process, particles detach from the cover strip and penetrate the guide system, which subsequently wears out as well. Furthermore, the frequent movement over such cover strips negatively impacts their service life. To address this, the cover strips must be replaced at regular intervals, which leads to increased effort and costs.

[0016] The invention is based on the finding that a device for the linear movement of a gantry must meet the aforementioned challenges in order to be able to operate safely, accurately, and in a resource-efficient manner. The device is used for the linear movement of a gantry of a computed tomography device and has a guide rail and a carriage. The guide rail is a body that is long in relation to its width, runs in a longitudinal direction, and specifies the direction of the linear travel path. The guide rail has an elongated groove on its upper side in the longitudinal direction. The upper side of the guide rail is the side of the guide rail that is visible before the guide rail is installed and faces away from the floor. A guide shaft is accommodated in the groove. Together with a friction roller accommodated in the carriage, the guide shaft implements a linear movement of the carriage on the guide rail.The guide shaft is an elongated, cylindrical body. The friction roller is a body with a high coefficient of friction on its surface. The friction roller is preferably made of stainless steel, in particular X90. The coefficient of friction is preferably increased by a coating. The friction roller is preferably profiled. The carriage is a body that can be moved linearly on the guide shaft. The friction roller of the carriage moves along the guide shaft in a rolling motion. The carriage preferably has a drive shaft as an interface for motors, couplings or gears. The carriage has at least one support surface for a gantry or for a crossbeam of a gantry of a CT scanner. The carriage can also have contact surfaces for the crossbeam or the gantry.

[0017] To ensure accurate positioning of the carriage relative to the guide rail, the device is equipped with sensors and a measuring system. The first part of the measuring system is located in or on the carriage, while the second part of the measuring system is located in the guide rail. To protect the measuring system, the second part of the measuring system is located in a recess on the top side of the guide rail. The recess extends lengthwise across the guide rail. The top side of the recess is also completely covered by a cover plate to protect the measuring system from dirt particles, scratches, and other disruptive influences. The guide rail at the device location is recessed into a hollow space, i.e. a pit, in the floor that is open at the top. The guide rail is located largely below floor level, while the carriage is above floor level.The guide rail is flush with the floor level on one side of the groove. Since the cover plate is preferably designed to be very low in comparison to the guide rail, the guide rail is preferably flush with the floor level on both sides of the groove. The height of the cover plate is preferably less than 1 mm, in particular 0.9 mm. With such a design, any overhang of the cover plate is neither noticeable nor safety-relevant for objects such as hospital beds that roll over the cover plate, or for staff or patients who move around the room on foot. In a further embodiment, the guide rail is designed to be lower on one side of the groove than on the other side of the groove, so that on one side of the groove the guide rail itself reaches the floor level, while on the other side the part of the guide rail covered by the cover plate reaches the floor level.Since the cover plate is preferably very narrow compared to its length, in this embodiment a section of the guide rail that is flush with the floor level preferably adjoins it. Only a section of the guide shaft protrudes from the floor. This is necessary so that the friction roller can make contact with the guide shaft and thus move the carriage linearly. Here too, however, the protrusion is so small that driveability and safety are guaranteed. Gaps formed between the guide shaft and the groove are preferably sealed to prevent the ingress of dirt or other disruptive particles or substances. Epoxy resin or adhesive are particularly suitable for sealing. When setting up the device, the guide rail can be permanently fixed in place after it has been finally positioned in the pit in the floor.For this purpose, the guide rail is preferably cast in.

[0018] By means of the described features, a self-contained device for the linear movement of a gantry and a computed tomography device is provided, which is safe, low-maintenance and, due to the small number of required and low-wear components, also economical.

[0019] Preferably, the first part of the measuring system consists of a measuring head attached to the carriage, and the second part of the measuring system consists of a measuring tape housed in the recess of the guide rail. The measuring system is preferably designed such that a measuring tape is located in the guide rail. Information provided by the measuring tape is recorded by a measuring head using non-contact measurement. In this embodiment, the measuring head is attached to the outside of the carriage. Preferably, the measuring tape is designed as a magnetic tape. Preferably, a magnetic tape is integrated into the guide rail. The measuring head detects changes in the magnetic field and uses this to determine the exact position of the carriage.

[0020] Preferably, the cover plate has projections facing the guide rail, and the guide rail has further recesses facing the cover plate for receiving the projections. Preferably, a plurality of webs extend from the cover plate and into openings provided for this purpose on the guide rail. The openings and the webs face one another. The webs enter the openings. In this way, the positioning of the cover plate on the guide rail is implemented. Depending on the design of the webs and openings, a loose, force-fitting, or positive connection is possible. The connection can be reversible or irreversible as required. Preferably, the projections engage with the further recesses and fix the cover plate in place. Preferably, the webs and openings are designed so that they form undercuts or snap into one another.In this way, the cover plate can be attached to the guide rail and slipping of the cover plate with potential damage to the sensors is prevented.

[0021] Preferably, in addition to the carriage, a support is arranged on the guide shaft. Preferably, the guide rail, apart from the carriage, also has another movable component, also referred to as a support. The support moves actively or passively. The support has a support surface for a gantry or a crossbeam of a gantry of a computed tomography device. In one embodiment, the support is designed analogously to the carriage and moves actively on the guide rail. In another embodiment, the support is moved along by the carriage. In this embodiment, the support can also be based on a movement mechanism different from the carriage and without a friction roller.

[0022] The guide rail is preferably designed to be height-adjustable. The guide rail can preferably be adjusted in height at several positions. In this way, the guide rail can be positioned in the pit in the floor during installation so that unevenness can be compensated for and the desired flushness with the floor level can be achieved. Support elements are preferably attached to both sides of or in the guide rail along the guide rail, which can be individually adjusted in height. Height adjustment is preferably implemented using a thread. Once the height of the guide rail has been adjusted, the set position can be permanently maintained, preferably by casting the guide rail into place.

[0023] The guide rail is preferably designed as an extruded profile. The guide rail is preferably manufactured using the extrusion process and has corresponding visible features. This is a cost-effective process that also allows for the integration of cavities to reduce weight while maintaining high strength, as required here. The outer shape of the extruded profile is preferably designed so that it is held in place in all directions when cast into the floor.

[0024] The device is preferably a component of a linear system for the linear movement of a gantry of a computed tomography device, comprising two devices arranged parallel to one another according to one of claims 1 to 8, wherein a further carriage, which is designed without a measuring system, is arranged on each guide rail. Preferably, the device, in duplicate together with two further carriages, forms a linear system for the linear movement of a gantry of a computed tomography device. The two devices are arranged next to one another in parallel in the longitudinal direction. In addition to the carriage, each guide rail has a further carriage. Unlike the carriage of the device, the further carriage is designed without a measuring system. Analogous to the carriage of the device, the further carriage has a support surface for a gantry or a crossbeam of a gantry of a computed tomography device.This means that the carriage and the other carriage move the gantry components together along the respective guide rails. However, on each guide rail, only the carriage detects its position via a measuring system and transmits this information to other control systems, while the other carriage does not have a measuring system.

[0025] Preferably, the device according to one of claims 1 to 8 is a component of a computed tomography device with a gantry. The device is preferably a component of a computed tomography device having a gantry. Using the device, the computed tomography device can be moved linearly in space with high precision to perform an imaging procedure, with the guide rail being walkable and drivable on the floor.

[0026] Short description of the drawings

[0027] The invention is explained below using exemplary embodiments with reference to the drawings. The drawings are schematic representations and show:

[0028] Figure 1 shows part of a device for linear movement of a gantry in a cross-sectional view,

[0029] Figure 2 is a schematic representation of a device for linear movement of a gantry,

[0030] Figure 3 is a partial view of a linear system having two devices for linearly moving a gantry.

[0031] Detailed description of the drawings

[0032] Figure 1 shows a cross-sectional view of part of a device 1 for the linear movement of a gantry. A guide rail 5 having several cavities 21 is supported on the floor by means of support elements 20. The support elements 20 are arranged on both sides in a transverse direction. The guide rail 5 has an upper side 13. The upper side 13 has a groove 6 in which a guide shaft 10 is arranged. The guide shaft 10 is not completely accommodated in the groove 6, but protrudes from the height level of the guide rail 5. In addition to the groove 6, the guide rail 5 has a recess 7 in which a second part 8 of a measuring system is accommodated. A first part 4 of the measuring system is located in or on a carriage 2 (not shown in Figure 1). The second part 8 of the measuring system is covered by a cover plate 9.The cover plate 9 has two projections 16 which point away from the top side 13 of the guide rail 5. For the purpose of local positioning, the guide rail 5 has two further recesses 17 on the top side 13, into which the projections 16 of the cover plate 9 are received. The further recesses 17 differ in their shape and design from the recess 7 for receiving the second part 8 of the measuring system. A surface of a further recess 17 is complementary to the facing surface of a projection 16 which the respective further recess 17 receives. The surface of a further recess 17 is concave, i.e. has a recess in cross-section. The complementary surface of a projection 16 is convex compared to the surface of a further recess 17, i.e. has a bulge.The bulge on a projection 16 of the cover plate 9 engages with another recess in the guide rail 5. Due to the complementary surfaces, the projections 16 of the cover plate 9 are hooked into the other recesses 17. Thus, the cover plate 9 is positively secured to the guide rail 5.

[0033] Figure 2 shows a schematic representation of a device 1 for the linear movement of a gantry. A guide rail 5 installed in the floor 12 is shown in a cross-section, while a carriage 2 arranged above the guide rail 5 is shown in a plan view. The carriage 2 moves linearly on the guide rail 5. The guide rail 5 has a groove 6 in which a guide shaft 10 is inserted. On one side, the guide rail 5 has a recess 7 in which a measuring tape 15 is inserted. The measuring tape 15 is a second part 8 of a measuring system and is covered by a cover plate 9, which is attached to the guide rail 5 by means of a locking mechanism. The carriage 2 has a friction roller 3, which can move linearly on the guide shaft 10.To prevent the ingress of dirt and other particles, the carriage 2 is equipped with wiper brushes 22 in the area of ​​the friction roller 3. As a counterpart to the measuring tape 15 in the guide rail 5 as the second part 8 of the measuring system, a measuring head 14 is arranged on the carriage 2 as the first part 4 of the measuring system. Furthermore, the carriage 2 has a drive shaft 24 as an interface for the coupling, gear, and motor, as well as a support surface 23 on the upper side of the carriage 2 for a gantry or a crossbeam of a gantry of a computed tomography device.

[0034] Figure 3 shows a partial view of a linear system 18 having two devices 1 for the linear movement of a gantry. The linear system 18 runs along a longitudinal direction I and consists of two guide rails 5. Each guide rail 5 has a plurality of support elements 20 along the longitudinal direction I. A measuring tape 15 is integrated into each guide rail 5 and is covered by a cover plate 9. Each guide rail 5 guides a carriage 2, on which a measuring head 14 is arranged, which serves for the contactless recording of the position data on the measuring tape 15. In addition, a further carriage 19 is arranged on each guide rail 5, which together with the carriage 2 on the respective guide rail forms the support surfaces for a gantry or the crossbeams of a gantry of a computed tomography device.

[0035] List of reference symbols

[0036] 1 device

[0037] 2 carriages

[0038] 3 friction roller

[0039] 4 first part of the measuring system

[0040] 5 Guide rail

[0041] 6 grooves

[0042] 7 Recess

[0043] 8 second part of the measuring system

[0044] 9 Cover plate

[0045] 10 Guide shaft

[0046] 11 Recess in the floor

[0047] 12 Floor

[0048] 13 Top of the guide rail

[0049] 14 Measuring head

[0050] 15 measuring tape

[0051] 16 projections on the cover plate

[0052] 17 additional recesses

[0053] 18 Linear system

[0054] 19 additional carriages

[0055] 20 height-adjustable supports

[0056] 21 cavities in the guide rail

[0057] 22 scraper brushes

[0058] 23 Support surface for a gantry or cross beams of a gantry

[0059] 24 Drive shaft

[0060] I Longitudinal direction

Claims

Patent claims 1. Device (1 ) for linearly moving a gantry of a computer tomography device, comprising - at least one carriage (2) having a friction roller (3) and a first part (4) of a measuring system, - at least one elongated guide rail (5) with a groove (6) extending in the longitudinal direction (I) and a recess (7) in which a second part (8) of the measuring system is accommodated, the recess (7) being covered by a cover plate (9), - a guide shaft (10) which is received in the groove (6) by the guide rail (5) and on which the friction roller (3) of the carriage (2) rolls, the guide rail (5) being inserted into a recess (11) in the floor (12) at a location of the device (1) in such a way that an upper side (13) of the guide rail (5) which has the groove (6) is flush with the floor (12) at least on one side of the groove (6), the guide shaft (10) protruding from the floor (12) to make contact with the friction roller (3).

2. Device (1) according to claim 1, characterized in that the first part (4) of the measuring system consists of a measuring head (14) attached to the carriage (2) and the second part (8) of the measuring system consists of a measuring tape (15) received in the recess (7) of the guide rail (5).

3. Device (1) according to claim 2, characterized in that the measuring tape (15) is designed as a magnetic tape.

4. Device (1) according to claim 1, characterized in that the cover plate (9) has projections (16) facing the guide rail (5) and the guide rail (5) has further recesses (17) facing the cover plate (9) for receiving the projections (16).

5. Device (1) according to claim 4, characterized in that the projections (16) engage with the further recesses (17) and fix the cover plate (9).

6. Device (1) according to claim 1, characterized in that in addition to the carriage (2) a support is arranged on the guide shaft (10).

7. Device (1) according to claim 1, characterized in that the guide rail (5) is designed to be height adjustable.

8. Device (1) according to claim 1, characterized in that the guide rail (5) is designed as an extruded profile.

9. Linear system (18) with two devices (1) arranged parallel to one another according to one of claims 1 to 8, wherein a further carriage (19) is arranged on each guide rail (5), which is designed without a measuring system.

10. Computed tomography apparatus with a gantry and a device (1) according to one of claims 1 to 8.

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