Method for balancing the load-bearing capacity of a medical imaging device

Abstract

Method (1) for compensating the load-bearing capacity of a medical imaging device (10), in particular a gantry of a computed tomography scanner, wherein the medical imaging device (10) has a plurality of leveling feet (12), comprising the steps: - covering (2) a substrate (14) with at least one leveling plate (16), - positioning (4) at least one leveling foot (12) on the at least one leveling plate (16), - aligning (6) the medical imaging device (10) relative to the substrate (14) by adjusting the height of at least one of the leveling feet (12), wherein the height adjustment is effected by rotating the at least one leveling foot (12), and - adjusting (8) the at least one leveling foot (12) on the at least one leveling plate (16) by applying a predetermined torque, wherein the predetermined torque is such that a predetermined load-bearing capacity is achieved on the at least one leveling foot (12) during the adjustment (8).wherein the predetermined torque was determined taking into account the known friction behavior of a thread pairing and / or the friction behavior between a bottom surface of the at least one adjusting foot (12) and the compensating plate (16) located below it.

Description

[0001] The invention relates to a method for balancing loads of a medical imaging device. The invention further relates to a system for supporting a medical imaging device.

[0002] Regardless of the grammatical gender of a particular term, it includes persons with male, female or other gender identities.

[0003] A medical imaging device, such as a CT scanner with a gantry, is usually positioned upright on a surface. Since the surface is usually not optimally level or flat, local high and / or low points of the surface must be compensated for using adaptive leveling feet. By adjusting the height of the individual leveling feet, correct alignment of the gantry relative to reference surfaces can be achieved. The fact that the gantry has a slight residual imbalance and a large mass that rotates at high speeds can lead to undesirable natural vibration behavior of the medical imaging device. The more evenly the distribution of the adjustment force is among the leveling feet used for support, the less pronounced the vibrations will be.Especially in the case of statically overdetermined storage, it is important to distribute the load evenly, as otherwise the device may tip over.

[0004] To ensure an even distribution of the positioning force across the feet, the positioning force would have to be measured during the imaging device's setup. However, this is technically complex and difficult to perform without changing the setup, and is therefore generally not done.

[0005] The invention is based on the object of providing a method for mounting a medical imaging device, in particular a computer tomography device with a gantry, so that the vibration behavior of the device is improved during operation.

[0006] The invention relates to a method for compensating loads of a medical imaging device, in particular a gantry of a computed tomography scanner, wherein the medical imaging device has a plurality of adjustable feet. The method comprises the following steps: covering a base with at least one compensation plate, positioning at least one adjustable foot on the at least one compensation plate, adjusting the height of at least one of the adjustable feet in order to align, in particular level, the medical imaging device relative to the base, and adjusting the at least one adjustable foot on the at least one compensation plate by applying a predetermined torque, wherein the predetermined torque is sufficiently large that a predetermined load on the at least one adjustable foot is achieved during the adjustment.

[0007] In this way, locally varying roughness values ​​and locally varying unevenness of the substrate can be equalized by the at least one compensation plate. The leveling feet have, for example, a riser thread with which they are screwed into the medical imaging device, so that the height of the medical imaging device can be adjusted. Due to the roughness equalization of the substrate, a known and consistent friction behavior results between the at least one leveling foot and the compensation plate located underneath. Thus, the load-bearing capacity of this leveling foot can be determined from the torque applied to the leveling foot. Consequently, a balanced load-bearing capacity of the at least one leveling foot can be adjusted by means of a predetermined tightening torque of the leveling foot.

[0008] In particular, adjusting a (single) leveling foot is sufficient to balance the load distribution of the other leveling feet and thus of the entire medical imaging device. In particular, if the geometry or mass distribution of the medical device is known, the leveling force on the other leveling feet can be calculated from the leveling force (also called load) on one leveling foot. This makes it easy to distribute the load evenly or in a defined manner across the leveling feet when setting up the medical imaging device, thus reducing the vibration excitation of the medical imaging device caused by the mass-bearing, rotating gantry.

[0009] The compensation plate creates a base with a defined roughness under at least one adjustable foot. It is also conceivable for the compensation plate(s) to be arranged under several adjustable feet, in particular under all of the plurality of adjustable feet. This allows several adjustable feet of the medical imaging device to be adjusted to different positions. The compensation plate is preferably non-deformable. This makes it possible to provide a surface that is as rigid as possible with constant friction values. It is also conceivable for the compensation plate to be two-part. In other words, the compensation plate can have a bottom side and a top side, with the two sides being different from one another. The bottom side can have increased adaptability and / or softness compared to the surface, while the top side can have increased rigidity.This allows for the provision of a leveling plate that is both adaptable and particularly flat.

[0010] At least one of the two sides of the compensating plate, in particular the upper side of the compensating plate, can have a constant roughness value at least in a partial area. In other words, at least one side can have a uniform coefficient of friction, preferably in the center of the surface. This allows equal frictional forces, defined as the product of the normal force on the side and the coefficient of friction, to arise, preferably in the center of the surface of the compensating plate.

[0011] Furthermore, the underside can be designed to be non-slip. This allows the underside to adhere to the surface. The compensating plate can also be designed in one piece, in particular having the same properties on both sides. This allows the compensating plate to be manufactured inexpensively, in particular as an injection-molded part. The compensating plate can be designed as a flat plate. In other words, the extent of the compensating plate in two spatial directions can be significantly greater than in a third spatial direction orthogonal to it. The compensating plate can, for example, have dimensions of between 5 cm and 30 cm, preferably 8 cm to 15 cm side length and a thickness of 0.3 to 10 mm, preferably 1 mm to 2 mm.

[0012] The leveling feet of the medical imaging device are height-adjustable so that the alignment of the device can be adjusted. For this purpose, there is preferably a thread pairing between each leveling foot and the medical imaging device, in particular by means of a rising thread. By using a plurality (e.g. 3 to 6, in particular 4 or 5) of leveling feet, the load of the device can be distributed across several leveling feet. The device is positioned with at least one leveling foot on the at least one compensation plate. This can expediently be the leveling foot subjected to the least load. When adjusting the leveling foot, friction arises both within the thread pairing and between the underside of the leveling foot and the underlying surface or the compensation plate. The thread friction, in particular the frictional force, between the leveling foot and the medical imaging device is known, e.g. determined through tests.The frictional force between the underside of the leveling foot and the top of the leveling plate is also known, e.g., determined through testing. A defined torque can then be applied using a torque wrench. This torque, minus the frictional forces, produces a resulting, predetermined adjustment force on the adjusted leveling foot. This allows a defined adjustment force distribution and, consequently, a low-vibration setup of the gantry to be achieved.

[0013] Because the frictional forces occurring during adjustment, particularly resistance forces, are known and reproducible, a consistent relationship results between a torque during adjustment of the leveling foot on the compensating plate and an alignment force on this leveling foot. This torque can be determined experimentally before adjustment. In particular, a relationship between torque and alignment force can be defined, whereby this relationship assumes constant friction conditions. Consequently, the leveling plate can fulfill the task of maintaining a constant frictional behavior of the at least one leveling foot on its base, the compensating plate.

[0014] According to one embodiment, the at least one compensating plate can be attached to the substrate in a rotationally secure manner, in particular glued and / or screwed to the substrate. The compensating plate can also have an adhesive surface on the underside. Furthermore, the compensating plate can have holes for receiving mounting means, in particular screws, for anchoring. The compensating plate can additionally or alternatively be attached to the substrate in another way and / or can be attached to the substrate by a combination of several fastening options. As a result, the compensating plate cannot be moved or shifted after installation on the substrate, in particular can be stationary. Furthermore, the compensating plate can be subjected to loads, in particular a torque, orthogonal to a surface normal of the substrate, without slipping, buckling or splitting.The compensation plate can be made of metal or plastic, for example. It can have a coating with defined friction properties, such as a paint finish.

[0015] According to an alternative embodiment, the leveling plate can be designed as a coating, in particular a curing liquid coating, on the substrate. The coating can be poured onto the floor as a leveling layer, evenly distributed, and allowed to cure. Epoxy resins are particularly suitable for this purpose, as they can provide a uniformly smooth surface after curing. Curing rubber coatings are also conceivable. The coating can provide the advantage that large areas of the substrate can be leveled particularly efficiently and provided with a substantially uniform roughness.

[0016] According to one embodiment, the leveling plate can reduce, in particular completely compensate for, unevenness in the subsurface. At least the underside of the leveling plate can be designed as an adaptable surface. This allows local unevenness to be compensated by the leveling plate.

[0017] According to one embodiment, the medical imaging device can be statically overdetermined by means of the plurality of adjustable feet. The floor of the device can be approximately considered a plane, which requires three support elements for complete static determination in space. The medical imaging device can comprise four or more adjustable feet, so that the medical imaging device is statically overdetermined. This allows the total load of the medical imaging device to be distributed particularly evenly into the ground.

[0018] According to one embodiment, the at least one adjustable foot can have at least one plunger, wherein the plunger can comprise a rising thread and wherein the height adjustment of the adjustable foot can be achieved by rotating the rising thread of the plunger in a complementary internal thread of the medical imaging device. The rising thread of the plunger can have a metric thread, in particular also another thread type. The rising thread is arranged at one end distal to the adjustable foot plate. The plunger can be designed to be screwed to the internal thread of the medical imaging device. Because the internal thread of the medical imaging device can be designed to be complementary to the rising thread of the plunger, both complementary right-hand and left-hand threads can be provided.

[0019] Preferably, a load acting on an adjustable foot is at least substantially proportional to a torque required to rotate the adjustable foot. In other words, the proportion of the adjustable foot's load to the total device load increases with the increase in the torque under which the height-adjustable adjustable foot is rotated further out of the base of the medical imaging device. Thus, the load applied to the adjustable foot can be varied by rotating the adjustable foot. Furthermore, adjusting an adjustable foot can lead to a redistribution of the respective loads of other adjustable feet of the device. Consequently, an even load distribution can be achieved.

[0020] Preferably, the friction behavior of the thread pairing between the lead thread and the complementary internal thread is known. The coefficient of friction of the thread pairing can be determined by means of experimental tests. This makes it possible to determine a relationship between the load-bearing capacity of the support element, which acts along a direction of displacement of the thread partners, relative to a torque with which the thread pairing is twisted into one another. This relationship can be linear. Because the friction values ​​can be constant, a consistent relationship can be expected when the thread pairing is repeatedly brought together. Preferably, the friction behavior between an underside of the leveling foot and the compensating plate located underneath is known. The underside of the leveling foot can be formed at least partially by the leveling foot plate.The load to be applied when adjusting at least one leveling foot depends on the torque with which the at least one leveling foot is rotated relative to the support plate. In order to achieve experimentally determined torque values, the friction behavior between the underside of the leveling foot and the leveling foot below it must be consistent.

[0021] Preferably, the predetermined torque can be determined taking into account the known friction behavior of the thread pair and / or the friction behavior between the underside of the leveling foot and the compensating plate located below it. This can provide the advantage that experimentally determined torques for rotating at least one leveling foot always produce consistent corresponding loads.

[0022] Preferably, the leveling foot plate and the plunger of the leveling foot can be connected to one another in a rotationally fixed manner. This prevents any relative movements, in particular rotations, between the two components of the leveling foot. Consequently, the accuracy of the method can be increased because no friction coefficients between the aforementioned components need to be taken into account. Furthermore, the plunger can be made of a metallic material, in particular steel, preferably tool steel. The plunger and the leveling foot plate can be formed as a single piece, in particular from the same material.

[0023] The adjustable foot can preferably be designed in several parts, in particular have an at least partial coating, and / or be formed at least partially from a second material. The second material can comprise an elastomer, preferably rubber. Furthermore, the second material can be designed to be a particularly low-friction friction partner to the at least one compensating plate. This allows adjustment to be carried out with reduced expenditure of force, in particular reduced torque. In particular, the adjustable foot plate of the adjustable foot is formed from the second material. It is also conceivable for the adjustable foot plate to have a coating formed from the second material. Furthermore, the adjustable foot plate can be formed integrally with the plunger and have an insert made of the second material, which insert is inserted into the adjustable foot plate, in particular glued or otherwise fastened.Furthermore, the second material can be designed to be particularly vibration-absorbing, in particular flexible. This allows the adjustable foot plate to dampen a periodic movement of the medical imaging device, in particular to absorb vibration.

[0024] Preferably, the coefficient of friction between the riser thread and the internal thread can be reduced with a lubricant, in particular oil. By reducing the friction within the thread pair of the plurality of adjustable feet, the torque required to adjust at least one adjustable foot can be reduced.

[0025] Preferably, the adjustable foot can have a hole, which runs particularly centrally along the tappet. The hole can be designed to accommodate a fastening means. This allows the adjustable foot to be anchored to the substrate. Consequently, the device's tolerance to vibrations can be increased.

[0026] The adjustable foot can preferably have an actuating surface, in particular an actuating region, in order to be rotatable with a rotating tool, in particular a torque wrench. The actuating surface can be arranged at a distal end of the plunger. By rotating the adjustable foot at the actuating region, the adjustable foot is rotated relative to the base, in particular the compensating plate, and is forcibly displaced relative to it along a longitudinal direction, in particular rotated out of the internal thread of the medical imaging device. The actuating surface can be designed as an outer peripheral polygon and / or Allen key, in particular a hexagon, so that a corresponding tool can engage with it. The actuating region can be located within the medical imaging device and be accessible. Additionally or alternatively, the actuating surface can be arranged on the outer circumference of the adjustable foot plate.This allows the operating area to be accessible outside the medical imaging device.

[0027] The invention further relates to a system for supporting a medical imaging device, in particular a gantry of a computed tomography scanner. The system can comprise a plurality of adjustable feet, which are designed to be screwed into the medical imaging device, and at least one compensating plate, which is attachable and / or mounted on a base, wherein at least one of the adjustable feet can be arranged and / or is arranged on the at least one compensating plate, wherein the at least one adjustable foot can be subjected to a specific torque relative to the medical imaging device in such a way that a uniform load distribution of the medical imaging device across the plurality of adjustable feet results.

[0028] The system can in particular comprise three, four or five, or possibly more, leveling feet. This allows the medical imaging device to be mounted in a statically overdetermined manner. The leveling feet can be screwed into the medical imaging device in a height-adjustable manner using a complementary thread pairing for each leveling foot. A compensating plate can be positioned beneath at least one leveling foot. This allows the friction partner between the at least one leveling foot and its base, the compensating plate, to be defined. In other words, there is a constant or repeatable friction behavior between the at least one leveling foot and the compensating plate. The at least one leveling foot can be subjected to a specific torque relative to the two friction partners a) thread pairing and b) friction between the leveling foot and the compensating plate, whereby a load-bearing component of the at least one leveling foot can be varied, in particular increased.This inevitably also varies the load share of the other adjustable feet so that a balanced load distribution can be achieved across the majority of adjustable feet of the medical imaging device.

[0029] The invention further relates to a medical imaging device with a system according to the invention. Thus, a load distribution for the medical imaging device can be achieved in a manner according to the invention. The invention further relates to a medical imaging device configured to be set up using a method according to the invention.

[0030] Individual embodiments and individual features can be combined with other embodiments and other features to form new embodiments. Embodiments and advantages of the embodiments and features also apply analogously to the new embodiments. Furthermore, embodiments and advantages mentioned in connection with the medical imaging device also apply analogously to the method, and vice versa.

[0031] The invention is explained below using exemplary embodiments with reference to the accompanying figures. The representation in the figures is schematic, highly simplified, and not necessarily to scale. They show: Fig. 1: a flowchart of a method for balancing loads of a medical imaging device, Fig. 2: a section of a system for supporting the medical imaging device, and Fig. 3: a top view of a system for supporting the medical imaging device.

[0032] In the figures, identical features are identified by the same reference numerals.

[0033] Fig. 1 shows the sequence of method 1 in the sequence of individual steps. In a first step, a base 14 is covered 2 with a compensating plate 16. By means of the compensating plate 16, a flat surface with constant friction values ​​is thereby provided over at least part of the, in particular the entire, surface of the compensating plate 16. In a second step, a positioning 4 of an adjustable foot 12 of the medical imaging device 10 is carried out on the compensating plate 16. The medical imaging device 10 comprises a plurality of adjustable feet 12, in particular 3, 4 or 5 adjustable feet 12. Subsequently, an alignment 6 of the medical imaging device 10 relative to the base 14 can take place by adjusting the height of at least one of the adjustable feet 12.

[0034] The leveling feet 12 are designed to move into or out of the medical device when the leveling feet 12 are rotated relative to the medical imaging device 10. This allows the distance of a leveling foot plate 20 of a leveling foot 12 to the medical imaging device to be varied. Consequently, unevenness of the base 14 can be compensated for by means of the height-adjustable leveling feet 12. The alignment 6 can be checked and adjusted in space against various reference surfaces on a gantry (e.g., stationary frame, drum). After alignment 6, the distribution of adjustment forces on the individual leveling feet 12 may be uneven due to the position of the center of mass relative to the respective leveling feet 12. When the mass-bearing gantry rotates, this can lead to vibration excitations of the medical imaging device.

[0035] Therefore, an adjustment 8 of the at least one adjustable foot on the at least one compensating plate is carried out. In particular, it is sufficient to adjust only one of the plurality of adjustable feet 12 so that the load distribution of the entire medical imaging device 10 can be balanced across all loaded adjustable feet 12. In this case, the adjustable foot 12 is subjected to a predetermined torque. In other words, the adjustable foot 12 is rotated with the predetermined torque against the medical imaging device 10, in particular out of the medical imaging device 10 against the compensating plate 16. Due to a known friction behavior between the one adjustable foot 12 and the compensating plate 16 and additionally a known friction behavior of a thread pairing of a lead thread 19 of the adjustable foot 12 and the internal thread 22 of the medical imaging device 10, the load of the one adjustable foot 12 can be adjusted with the predetermined torque.This allows a predetermined load-bearing capacity of one adjustable foot 12 to be set. Furthermore, this compensates, in particular, the distribution of other adjustable feet 12, so that the vibration behavior of the medical imaging device 10 is optimized.

[0036] Fig. 2 shows a section of the system for supporting the medical imaging device 10. A compensating plate 16 is arranged on a base 14. The compensating plate 16 can be glued and / or screwed and / or attached to the base 14 in some other way such that it cannot slip, be compressed, or split relative to the base 14. An adjustable foot 12 is positioned above the compensating plate 16 in an assembled state. The adjustable foot comprises a plunger 18, on which an adjustable foot plate 20 is arranged such that the adjustable foot plate 20 contacts the compensating plate 16. The plunger 18 can comprise a metallic tool steel and be formed integrally, in particular in one piece, with the adjustable foot plate 20. The adjustable foot plate 20 can comprise an elastic material, preferably rubber, in particular a second material. The adjustable foot plate 20 is in particular coated with the second material.It is also conceivable that the leveling foot plate 20 is formed from the second material, wherein the second material differs from the material of the leveling foot 12. This can result in increased damping behavior and, at the same time, increased strength of the leveling foot 12. At an opposite, distal end, the leveling foot 12 has an actuating surface 24, in particular an actuating region, which is designed to engage with a complementary tool, in particular a torque wrench. This then advantageously rotates the leveling foot 12 relative to the medical imaging device 10. The medical imaging device 10 comprises an internal thread for each leveling foot 12, which is designed to be complementary to a rising thread 19 formed on the outer circumference of the plunger 18. Consequently, the leveling foot 12 can be screwed into the internal thread 22 of the medical imaging device 10.Furthermore, the plunger 18 can have a central hole extending along a longitudinal axis of the plunger. This allows the entire adjustable foot 12 to be anchored to the base 14 by means of a fastening means.

[0037] Fig. 3 shows a top view of a system for supporting the medical imaging device 10. A Fig.The underside of the medical imaging device 10 shown in Figure 3 has four adjustable feet 12. This means that the system is statically overdetermined. Consequently, tilting can occur if the individual adjustable feet 12 have different load-bearing capacities, particularly across the two diagonals shown. A compensating plate 16 is arranged between the base 14 and one of the adjustable feet. The adjustable foot 12 positioned thereon can be rotated with a predetermined torque such that its load-bearing capacity reaches a predetermined value. If the torque to be applied does not result in the adjustable foot 12 being able to be rotated on the compensating plate 16, the adjustable foot 12 must first be screwed into the medical imaging device 10 and then screwed out using the torque.

Claims

Method (1) for compensating loads of a medical imaging device (10), in particular a gantry of a computer tomography scanner, wherein the medical imaging device (10) has a plurality of adjustable feet (12), comprising the steps of: - covering (2) a base (14) with at least one compensating plate (16), - positioning (4) at least one adjustable foot (12) on the at least one compensating plate (16), - aligning (6) the medical imaging device (10) relative to the base (14) by adjusting the height of at least one of the adjustable feet (12), wherein the height adjustment is carried out by rotating the adjustable foot (12), and - adjusting (8) the at least one adjustable foot (12) on the at least one compensating plate (16) by applying a predetermined torque, wherein the predetermined torque is so great that a predetermined load on the at least one adjustable foot (12) is achieved during the adjustment (8). Method according to claim 1, wherein the compensating plate (16) is attached to the substrate (14) in a rotationally secure manner, in particular is glued and / or screwed to the substrate (14). Method according to one of the preceding claims, wherein the compensating plate (16) is designed as a coating, in particular a hardening liquid coating, on the substrate (14). Method according to one of the preceding claims, wherein the at least one adjustable foot (12) has at least one plunger (18), wherein the plunger (18) comprises a rising thread (19), and wherein the height adjustment of the adjustable foot (12) is effected by a rotation of the rising thread (19) of the plunger (18) in a complementary internal thread (22) of the medical imaging device (10). Method according to one of the preceding claims, wherein a load acting on an adjusting foot (12) is at least substantially proportional to a torque necessary for the rotation of the adjusting foot (12). Method according to one of the preceding claims, wherein the friction behavior between an underside of the adjusting foot (12) and the compensating plate (16) located thereunder is known. Method according to one of the preceding claims, wherein the predetermined torque was determined taking into account the known friction behavior of a thread pairing and / or the friction behavior between an underside of the adjusting foot (12) and the compensating plate (16) located thereunder. Method according to one of the preceding claims, wherein an adjustable foot plate (20) and the plunger (18) of the adjustable foot (12) are connected to one another in a rotationally fixed manner. Method according to one of the preceding claims, wherein the adjustable foot (12) is designed in several parts, in particular has an at least partial coating, and / or is at least partially formed from a second material. Method according to one of the preceding claims, wherein the coefficient of friction of the thread pairing is reduced with a lubricant, in particular oil. Method according to one of the preceding claims, wherein the adjusting foot has a hole which runs in particular centrally along the plunger. Method according to one of the preceding claims, wherein the adjusting foot (12) has an actuating surface (24), in particular an actuating region, in order to be rotatable with a turning tool, in particular a torque wrench. A system for supporting a medical imaging device (10), in particular a gantry of a computer tomography scanner, comprising a plurality of adjustable feet (12) which are designed to be screwed into the medical imaging device (10), and at least one compensating plate (16) which is attachable and / or mounted on a base (14), wherein at least one of the adjustable feet (12) is attachable and / or mounted on the at least one compensating plate (16), wherein the at least one adjustable foot (12) can be subjected to a specific torque relative to the medical imaging device (10) in such a way that a uniform load distribution of the medical imaging device (10) over the plurality of adjustable feet (12) results. Medical imaging device (10) comprising a system according to claim 13. A medical imaging device (10) configured to be set up using a method (1) according to any one of claims 1 to 12.

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