Patient positioning device and medical workstation

Abstract

Patient positioning device comprising: - a patient couch (2) which has a lying surface (2a) for one person, - a robot arm (3) with eight links and seven joints, which are arranged serially and alternately in a kinematic chain of the robot arm (3), - wherein the first link (4.1) in the kinematic chain of the robot arm (3) forms a base frame for attaching the robot arm (3) to a base (6), and the eighth link (4.8) in the kinematic chain of the robot arm (3) forms a mounting flange of a robot hand (7) of the robot arm (3) to which the patient bed (2) is attached, - the second link (4.2) is rotatably mounted on the first link (4.1) by means of the first joint (5.1) about a first, vertical axis of rotation (D1), - the third link (4.3) is rotatably mounted on the second link (4.2) by means of the second joint (5.2) about a second, vertical axis of rotation (D2), - the fourth link (4.4) is rotatably mounted on the third link (4.3) by means of the third joint (5.3) about a third, vertical axis of rotation (D3), - the fifth link (4.5) is rotatably mounted on the fourth link (4.4) by means of the fourth joint (5.4) about a fourth, horizontal axis of rotation (D4), - and the robot hand (7) of the robot arm (3) is attached to the fifth segment (4.5), which robot hand (7) includes the sixth segment (4.6), the seventh segment (4.7) and the eighth segment (4.8), as well as the fifth joint (5.5), the sixth joint (5.6) and the seventh joint (5.7) of the robot arm (3).

Description

[0001] The invention relates to a patient positioning device comprising a patient bed having a lying surface for one person, a robot arm with eight links and seven joints arranged serially in a kinematic chain of the robot arm, wherein the first link in the kinematic chain of the robot arm forms a base frame for attaching the robot arm to a standing surface, and the eighth link in the kinematic chain of the robot arm forms a mounting flange of a robot hand of the robot arm to which the patient bed is attached.

[0002] DE 10 2010 043 421 B4 discloses a medical workstation comprising a device for generating ionizing, high-energy radiation for irradiating an area of ​​a living being, a storage device for holding a living being, and a robotic arm. The robotic arm is part of a robot and includes a mounting device to which the storage device is attached.

[0003] EP 2 944 259 A1 describes a patient positioning device with a motion device for moving a patient receptacle, wherein the motion device enables translational movements of the patient receptacle in all three spatial directions and rotational movements about all three spatial axes. The patient receptacle is connected to the motion device via a pivoting mechanism, which enables a pivoting movement of the patient receptacle relative to the motion device about a horizontal pivoting axis.

[0004] WO 2009 / 036169 A1 describes a patient positioning system comprising a robot arm providing five rotational degrees of freedom and one linear degree of freedom in the vertical direction, with a first robot arm segment, a second robot arm segment movably attached at a first end of the second robot arm segment to the second end of the first robot arm segment, the second robot arm segment being attached to the first arm segment to extend parallel to it so that the second arm segment is rotatable, a robot wrist assembly being attached to the second end of the second arm segment, generally extending upwards from it so as not to interfere with the rotation of the second arm segment relative to the first arm segment, and a patient table attached to the wrist assembly.

[0005] One object of the invention is to provide a patient positioning device with an improved robot arm.

[0006] Another object of the invention is to specify a medical workplace with such a patient positioning device.

[0007] The object of the invention is solved by a patient positioning device according to claim 1 and a medical workstation according to claim 14.

[0008] Each joint of the robot arm can be assigned a motor configured to drive and adjust that joint, thereby allowing the link immediately following the respective joint in the kinematic chain to be adjusted relative to the link immediately preceding it. Such adjustment can be automatic, for example, via a robot program stored on a robot controller, with the motors being controlled and moved by the robot controller. However, the joints of the robot arm can also be adjusted manually, in particular by manually manipulating one or more links of the robot arm, detecting the external forces introduced into the robot arm by grasping it, and then controlling the robot arm's motors accordingly via the robot controller based on these external forces.

[0009] The second member can be beam-shaped and have a first beam end section at which the first joint is located and a second beam end section opposite the first beam end section at which the second joint is located; the third member can also be beam-shaped and have a first beam end section at which the second joint is located and a second beam end section opposite the first beam end section at which the third joint is located; and furthermore, the fourth member can be beam-shaped and have a first beam end section at which the third joint is located and a second beam end section opposite the first beam end section at which the fourth joint is located.

[0010] The beam-shaped second, third, and fourth members can each be arranged horizontally aligned with their longitudinal extension sections leading from the first beam end section to the second beam end section, in different horizontal planes such that both the third member is rotatably mounted relative to the second member by means of the second joint by at least 360 degrees, and the fourth member is rotatably mounted relative to the third member by means of the third joint by at least 360 degrees.

[0011] By mounting the second link rotatably around a first vertical axis of rotation to the first link via the first joint, and the third link rotatably around a second vertical axis of rotation to the second link via the second joint, and the fourth link rotatably around a third vertical axis of rotation to the third link via the third joint, and furthermore, by mounting each of the beam-shaped second, third, and fourth links rotatably around a minimum of 360 degrees, a very large reach for positioning the patient table can be achieved, while simultaneously creating a robot arm that can be folded into a very compact, i.e., small, basic form. A very compact, i.e., small, basic form means both a space-saving arrangement for the patient positioning device and a very rigid basic structure in this basic configuration of the robot arm.

[0012] The second, third, and fourth links can have different beam lengths, in particular such that the first axial distance of the vertical axis of rotation of the first joint from the vertical axis of rotation of the second joint is greater than the second axial distance of the vertical axis of rotation of the third joint from the vertical axis of rotation of the second joint. The patient table can be connected to the mounting flange of the robot arm, particularly with its upper surface, i.e., the side on which the patient rests. The fifth link, in particular, can be moved past the other links, especially the third and second links, without collision during its rotation through the fourth joint.

[0013] The fifth link, which is rotatably mounted on the fourth link about the fourth horizontal axis of rotation by means of the fourth joint, can preferably be mounted on the fourth link such that the fourth axis of rotation is always horizontally oriented, but optionally aligned either along the longitudinal extent of the fourth link or transversely to the longitudinal extent of the fourth link. The axis of rotation of the fifth joint is preferably always arranged parallel to and offset from the axis of rotation of the fourth joint. Accordingly, depending on the orientation of the axis of rotation of the fourth joint, the axis of rotation of the fifth joint can also be aligned along the longitudinal extent of the fourth link or transversely to the longitudinal extent of the fourth link. The axis of rotation of the sixth joint and the axis of rotation of the seventh joint need not always be aligned parallel to the axis of rotation of the fourth joint and the fifth joint, respectively.The axis of rotation of the sixth joint and the axis of rotation of the seventh joint can preferably be arranged at right angles to each other. The axes of rotation of the fifth, sixth, and seventh joints can intersect at a common point. The fifth, sixth, and seventh joints can be combined in the form of a so-called central hand.

[0014] The sixth link can be coupled to the fourth link by means of a gear mechanism in such a way that, despite a rotation of the fifth link by means of the fourth joint, the sixth link retains its original orientation.

[0015] Thus, regardless of the control of the other joints by the control device, it is ensured that the patient bed always remains aligned in a horizontal plane, even if the fourth joint rotates. The drive unit can have a first pulley connected to the sixth link and a second pulley connected to the fourth link. A belt runs on both the first and second pulleys, coupling them. The effective diameters of the two pulleys are the same, resulting in a direct 1:1 transmission for the drive unit.

[0016] The gearbox can include a spring mechanism designed to hold the sixth link in its orientation relative to the fourth link with spring tension. The gearbox can, in particular, serve to provide drive assistance and / or to achieve torque reduction. By specifically controlling the drive motors of the fourth and fifth joints, tilting movements of the patient bed by small angles can be achieved. If the two drive motors of the fourth and fifth joints move at the same angular velocities in opposite directions, the patient bed remains in its original horizontal position. If a positional or angular difference is applied to the two drive motors of the fourth and fifth joints, a slight tilting of the patient bed occurs, corresponding to the positional or angular difference.

[0017] The second pulley can have an internal stop contour against which at least one spring element is supported in each direction of rotation. Each spring element is supported at its respective end, opposite the stop contour, by a driver attached to a central shaft. The shaft is rigidly connected to the fourth link. The spring elements allow the second pulley to rotate by a small angle in each direction relative to the central shaft when a force or torque is applied to the spring elements. Such a force or torque can be generated by a first motor and a second motor of the robot arm.

[0018] The robot arm can have a first motor configured to rotate the fifth link relative to the fourth link about the fourth axis of rotation, and a second motor configured to rotate the sixth link relative to the fifth link about the fifth axis of rotation, and the two motors are configured to drive in order to generate a force or a torque by means of a position difference or an angular difference at the two motors, thereby assisting a drive motor of the fifth joint.

[0019] The sixth, seventh and eighth segments, as well as the fifth, sixth and seventh joints of the robot arm, can be designed and arranged on the robot hand in such a way that the axes of rotation of the fifth, sixth and seventh joints always intersect.

[0020] The mounting flange of the robot arm can be attached to the underside of the patient bed opposite the lying surface, at a point offset from the center of the underside of the patient bed.

[0021] In all embodiments, the fifth joint can be designed to rotate a fifth axis of rotation, which is horizontally oriented and arranged parallel to the fourth, horizontal axis of rotation at a fixed distance. This allows the robot hand to be raised and / or lowered by synchronously rotating the fourth and fifth axes of rotation in opposite directions relative to the fourth joint, while the patient table remains in a horizontal position.

[0022] A support device can be associated with the sixth joint, which elastically couples the seventh joint to the sixth joint in such a way that torques induced at the sixth joint by gravitational forces, particularly those acting on the patient bed, are at least partially or completely compensated by a spring force of the support device. The support device can, for example, have a lever arm attached to the seventh joint, with its free end projecting outwards. Two springs can be mounted at the free end of the lever arm, elastically coupling it to the sixth joint. The springs can thus be arranged between the sixth and seventh joints and can therefore relieve the load on the drive, i.e., the motor, of the sixth joint.

[0023] The support device may have at least one stop designed to mechanically limit a rotation of the sixth joint caused by the effects of gravity to a maximum angle of rotation.

[0024] The patient positioning device may include a robot comprising the robot arm and a control device configured to control movement of the robot arm.

[0025] The medical workplace according to the invention comprises a medical device and a patient positioning device as described according to the invention.

[0026] The medical workstation according to the invention is particularly intended for radiotherapy. The medical device is therefore preferably a device for generating ionizing, high-energy radiation, such as gamma radiation, X-rays, or accelerated electrons, neutrons, protons, or heavy ions. The device for generating ionizing, high-energy radiation comprises, for example, a radiation source that generates the ionizing, high-energy radiation.

[0027] The robot arm can be part of a robot that, in addition to the robot arm, includes an electronic control device for controlling the movement of the robot arm. According to one embodiment of the patient positioning device according to the invention, this device includes this robot.

[0028] The robot arm can include motors, especially electric motors, which, at least indirectly controlled by the electronic control device, enable movement of the robot arm.

[0029] It is also possible for the robot arm to be manually movable. For this purpose, an input device connected to the electronic control unit can be provided, allowing a person to make inputs that the electronic control unit then uses to move the robot arm accordingly. This aligns the position and orientation of the mounting device, and thus the patient table, within the room.

[0030] The medical device may have its own electronic control unit, which controls the intended operation of the medical device. The electronic control unit of the medical device and the electronic control unit of the robot may be configured to communicate with each other.

[0031] It may also be provided that the medical workplace has a common electronic control device that not only controls the robot arm or is set up to control the robot arm, but also controls the intended operation of the medical device or is set up to control the intended operation of the medical device.

[0032] For example, in tumor treatment using radiation therapy, a specially focused and prepared proton beam is directed at the tumor of the living being, especially the patient, from all sides. For this, the patient lies on a treatment table and is moved around a stationary radiation center according to the treatment procedure. The medical device directs and shapes the beam and, if necessary, also allows for rotation of the beam direction to align it around a horizontal axis towards the radiation center. In this process, the radiation-generating part of the medical device is swiveled around the treatment table on which the patient lies, so that radiation from the side and below is also possible. To ensure that the tumor is treated evenly from all sides, further movements, such as rotating and shifting the treatment table, are usually necessary.The patient table is moved by the robotic arm of the patient positioning device. The robotic arm has several automatically movable joints and links and a serial kinematic structure, which is connected to the patient table at its distal end. For procedural reasons, only the patient table and the patient may be near the radiation center; metallic objects, such as components of the robotic arm, must not be present.

[0033] New treatment strategies require even greater mobility, higher positioning accuracy, and a larger working area, all while maintaining minimal installation space and setup requirements. For example, the patient should be able to be positioned significantly below the radiation focus, pivoting around any vertical axis through the patient's body should be possible, and / or additional tilting movements around any horizontal axis should be superimposed. Furthermore, the patient should be able to be moved to a separate location up to three meters away from the radiation focus and positioned there.

[0034] However, during the phases of patient loading in the treatment room, i.e. at the medical workstation, and setup in the radiation center, the patient positioning device should be compact, take up little space, offer sufficient distance to the walls of the treatment room and allow good access to both sides of the patient bed.

[0035] The patient positioning device according to the invention solves these problems and, depending on the specific embodiment, fulfills one or more of the aforementioned requirements. The patient positioning device has a serial structure with three proximally arranged vertical parallel axes of rotation and a subsequent horizontal fourth axis of rotation, oriented particularly in the direction of the limb. This basic axis structure is followed by a wrist assembly, particularly spherical, consisting of three individual axes of rotation, which can be designed, in particular, as a robotic central hand. The patient table can be attached to the device, particularly in the posterior third from below, resulting in a small load distance and reducing hand strain.

[0036] To avoid collisions even during extreme movements and to avoid having to reduce the installation space for the main bearing in the first joint, a greater distance of the first axis of rotation of, for example, at least 2000 millimeters, in particular 2500 millimeters, to the radiation center can be chosen.

[0037] Due to the at least seven, in particular exactly seven, degrees of freedom, i.e. joints of the robot arm of the patient positioning device according to the invention, unfavorable joint positions can be specifically compensated for or avoided, so that the entire working space can be completely free of singularities and no rapid or sudden movements of the structure of the robot arm occur.

[0038] The kinematic dimensions, or the size of the structural components (i.e., the links), can be selected so that the structure can fold in a single plane. This means that the second, third, and fourth links can be positioned directly on top of each other, sharing a common, identical footprint. Furthermore, the second, third, and fourth links can each rotate 360 ​​degrees or more around the link preceding them in the kinematic chain without any possibility of collision. This allows for a shallow lowering of the patient table, which can be advantageous for a low entry height when loading the table. In this way, a very slim and compact resting position can be achieved, for example, when loading or parking the patient positioning device.

[0039] The kinematic structure of the patient positioning device according to the invention enables a very drive-efficient design. The first three vertical axes of rotation move with neutral potential and are therefore not subject to gravity loads. Only potentially high tilting moments that may act on the bearings need to be considered. The fourth axis of rotation is subjected to the highest load but also offers the largest installation space for a motor-gearbox unit. The fifth link can be kept very short, for example, 400 millimeters in length, and serves only to cover the necessary working height. This significantly reduces the drive torque. High loads are only to be expected during infrequent and short-term movements, such as when the patient table is perpendicular to the fourth link, for example, just before the kick end positions. In these cases, in addition to the crank length, the distance between the wrist and the center of load also has an effect.The same applies to the fifth axis, which is completely unloaded when the patient table is in the 0° position relative to the fifth link at the associated drive. Only the seventh axis is almost always unloaded, with very few exceptions.

[0040] A key advantage of the presented robot arm structure lies in its ability to compensate for or support the more heavily loaded axes. The fourth joint has a large range of motion of 180 degrees or + / -180 degrees. Spring compensation or spring support systems can be implemented here. If, despite ample installation space for a powerful drive, additional support is still required, a counterweight at the fourth joint can also be beneficial for weight compensation.

[0041] The patient table is generally held preferably horizontally. Minor compensatory movements, such as tilting rolls or pitches of the table, of a few degrees, for example + / - 15 degrees, may be possible. In other words, the fifth joint performs a large relative rotation between the fifth segment and the robot hand (sixth to eighth segments). However, the orientation between the robot hand and the fourth segment is almost constant, except for minor compensatory movements, which are possible in a specific design variant. In such a variant, the robot hand and the fourth segment can be kinematically coupled. This can be achieved, in particular, with the aid of a special drive system, such as a traction drive. The traction drive can, in particular, have a belt drive with a gear ratio of 1:1.Both identical pulleys are mounted centrally in the fourth and fifth joints, respectively, and connected to the fourth link and the robot arm. There is no connection to the fifth link. The connection between the pulley and the fourth joint is not rigid, but rather rotatably elastic over the range in which compensatory movement of the patient table is required, for example, + / - 5 degrees to + / - 15 degrees. The system is pre-tensioned with high force in the neutral position and has a compliance with a flat spring characteristic, so that the supporting force or torque remains constant or changes only slightly over the range of motion. The pre-tension and the characteristic curves determine the extent to which the drive for the fifth joint is relieved and the torque is transferred directly to the fourth link via the springs and the support.The drive train and the torque relief are connected in parallel, meaning that the spring support and its compliance do not affect the stiffness of the drive. The drive motor for the fifth joint is then located not in the fourth link, but in the fifth link.

[0042] The moment acting on the sixth joint is very high under maximum load with the patient facing forward. The sixth joint connects the two remaining wrist segments (seventh and eighth), which, due to the structural kinematics close to the patient's position on the table, only move very little relative to each other. An additional elastic connection between the two segments, in the form of a pre-tensioned spring positioned away from the center of the wrist, can be deflected in such a way as to positively influence the drive load. For example, the spring, with its flat characteristic curve and high preload, could be dimensioned for half the maximum load. Under maximum load, the drive then only needs to withstand half the actual moment. The flat characteristic curve prevents significant deviations in the moment support from the ideal values ​​during small movements.

[0043] In addition to the compensating options, the chosen structural design is also suitable for convenient end stops at the fifth and sixth joints, which can prevent the patient from tipping over in the event of a malfunction, such as brake failure. Only the gravity-loaded fourth joint would need to be equipped with a safety brake. However, sufficient space is available for this.

[0044] Based on the aforementioned options for moment relief on the wrist, the following alternative is also possible. This involves attaching the patient table from above and placing the attachment point flat behind the table. This is not possible with other structures, such as a classic articulated arm kinematics, as the wrist would be overloaded due to the lack of support. Since the wrist no longer restricts the range of motion under the table, the first joint can be moved further forward without reducing the working space.

[0045] The patient positioning device according to the invention opens up new avenues in radiation therapy for tumor treatment. Its foldable structure also offers numerous possibilities for implementing an aesthetically pleasing and elegant design. The robot's positioning during loading and setup provides optimal accessibility and walking distances, and never restricts personnel. Furthermore, no extensive construction work or modifications to the medical setup in the treatment room are necessary. Its kinematics and additional joint supports minimize drive torques and significantly increase safety.

[0046] Several embodiments of the invention are illustrated by way of example in the accompanying schematic drawings. Specific features of these embodiments, regardless of the specific context in which they are mentioned, may also, if considered individually or in combinations other than those shown, represent general features of the invention.

[0047] They show: Fig. 1 a schematic perspective representation of an exemplary first embodiment of a patient positioning device, Fig. 2 a schematic perspective representation of an exemplary medical workplace with a medical device and the patient positioning device according to Fig. 1, Fig. 3 a schematic perspective representation of the patient positioning device according to Fig. 1 with superimposed third and fourth term, Fig. 4 a schematic perspective representation of the patient positioning device according to Fig. 1 with superimposed second, third and fourth members, Fig. 5 a schematic perspective representation of an exemplary second embodiment of a patient positioning device with second, third and fourth links with different link lengths, Fig. 6 a schematic perspective representation of a gear coupling the fourth link to the sixth link, Fig. 7 a schematic representation of the gearbox in a basic position of the patient bed, Fig. 8 a schematic representation of the gearbox in a position in which the patient bed is raised, Fig. 9 a schematic representation of the gearbox with a patient bed inclined to the left, Fig. 10 a schematic representation of the gearbox with a patient bed inclined to the right, Fig. 11 a schematic representation of a first variant of a spring device on the gearbox, Fig. 12 a schematic representation of a second variant of a spring device on the gearbox, Fig. 13 a schematic representation of a third variant of a spring device on the gearbox, and Fig. 14 a perspective view of the robot hand according to Fig. 6 with an optional spring-loaded support device for the sixth joint.

[0048] The Fig. 1 to Fig. Figure 4 shows an exemplary first embodiment of a patient positioning device 1 and the Fig. Figure 5 shows a second modified embodiment of a patient positioning device 1, both of which have the following features.

[0049] The patient positioning device 1 includes a patient bed 2, which has a lying surface 2a for one person. The patient positioning device 1 also includes a robot arm 3.

[0050] The robot arm 3 has exactly one first link 4.1, one second link 4.2, one third link 4.3, one fourth link 4.4, one fifth link 4.5, one sixth link 4.6, one seventh link 4.7, and one eighth link 4.8. The robot arm 3 has exactly one first joint 5.1, one second joint 5.2, one third joint 5.3, one fourth joint 5.4, one fifth joint 5.5, one sixth joint 5.6, and one seventh joint 5.7. The eight links 4.1 to 4.8 and the seven joints 5.1 to 5.7 are arranged serially in a kinematic chain of the robot arm 3.

[0051] The first link 4.1 in the kinematic chain of the robot arm 3 forms a base frame for attaching the robot arm 3 to a base 6. The eighth link 4.8 in the kinematic chain of the robot arm 3 forms a mounting flange for a robot hand 7 of the robot arm 3, to which the patient bed 2 is attached.

[0052] The second link 4.2 is rotatably mounted on the first link 4.1 about a first vertical axis of rotation D1 by means of the first joint 5.1. The third link 4.3 is rotatably mounted on the second link 4.2 about a second vertical axis of rotation D2 by means of the second joint 5.2. The fourth link 4.4 is rotatably mounted on the third link 4.3 about a third vertical axis of rotation D3 by means of the third joint 5.3. The fifth link 4.5 is rotatably mounted on the fourth link 4.4 about a fourth horizontal axis of rotation D4 by means of the fourth joint 5.4. The robot hand 7 of the robot arm 3 is attached to the fifth link 4.5. The robot hand 7 includes the sixth segment 4.6, the seventh segment 4.7 and the eighth segment 4.8, as well as the fifth joint 5.5, the sixth joint 5.6 and the seventh joint 5.7 of the robot arm 3.

[0053] The medical workplace 8 according to Fig. 2 comprises the patient positioning device 1 and a medical device 9. In the present embodiment, the medical device 9 is a device known in principle to those skilled in the art for generating ionizing, high-energy radiation, such as gamma radiation, X-rays, or accelerated electrons, neutrons, protons, or heavy ions. The device for generating ionizing, high-energy radiation comprises, for example, a radiation source that generates the ionizing, high-energy radiation.

[0054] The patient positioning device 1 comprises a robot 10, which has the robot arm 3 and a control device 11, which is configured to control a movement of the robot arm 3 automatically controlled by a robot program or in a manual operation, in particular to move it.

[0055] As in the Fig. 1 to Fig. As shown in Figure 5, the second member 4.2 is beam-shaped and has a first beam end section where the first hinge 5.1 is located and a second beam end section opposite the first beam end section where the second hinge 5.2 is located. The third member 4.3 is beam-shaped and has a first beam end section where the second hinge 5.2 is located and a second beam end section opposite the first beam end section where the third hinge 5.3 is located. The fourth member 4.4 is also beam-shaped and has a first beam end section where the third hinge 5.3 is located and a second beam end section opposite the first beam end section where the fourth hinge 5.4 is located.

[0056] The beam-shaped second member 4.2, third member 4.3 and fourth member 4.4 are each arranged horizontally with their longitudinal extension sections leading from the first beam end section to the second beam end section in different horizontal planes such that both the third member 4.3 is rotatably mounted relative to the second member 4.2 by means of the second joint 5.2 by at least 360 degrees, and the fourth member 4.4 is rotatably mounted relative to the third member 4.3 by means of the third joint 5.3 by at least 360 degrees.

[0057] In the second embodiment according to Fig. In this embodiment, the second member 4.2, the third member 4.3, and the fourth member 4.4 have different beam lengths, such that the first axial distance A1 of the vertical axis of rotation D1 of the first joint 5.1 from the vertical axis of rotation D2 of the second joint 5.2 is greater than the second axial distance A2 of the vertical axis of rotation D3 of the third joint 5.3 from the vertical axis of rotation D2 of the second joint 5.2. Furthermore, the arm length A3 of the fourth member 4.4 is shorter than the second axial distance A2 of the third joint 5.3 from the second joint 5.2. In addition, in this embodiment, in a modification to Fig. 1 to Fig. 4 the eighth link 4.8, i.e. the mounting flange of the robot arm 3, is attached to a top of the patient bed.

[0058] As in Fig. As can be seen in a transparent representation in Figure 6, in all embodiments the sixth link 4.6 can be coupled to the fourth link 4.4 by means of a gear 12 such that, despite a rotation of the fifth link 4.5 by means of the fourth joint 5.4, the sixth link 4.6 retains its original orientation. Thus, regardless of the control of the other joints by means of the control device 11, it is ensured that, despite a rotation of the fourth joint 5.4, the patient bed 2 always remains aligned in a horizontal plane, as is particularly important in the Fig. 7 and Fig. As indicated in Figure 8, the gearbox 12 can have a first pulley 12.1 connected to the sixth link 4.6 and a second pulley 12.2 connected to the fourth link 4.4. A belt 12.3 runs on the first pulley 12.1 and the second pulley 12.2, coupling these two pulleys 12.1 and 12.2. The effective diameters of the two pulleys 12.1 and 12.2 are the same, resulting in a direct 1:1 transmission ratio for the gearbox 12.

[0059] The gearbox 12 can, as in the Fig. 6 to Fig. Figure 10 shows a spring device 13 designed to hold the sixth link 4.6 in its orientation relative to the fourth link 4.4 with spring elastic tension. This tension can include preload, meaning a greater than zero moment is required to deflect the sixth link from its neutral position relative to the fourth link. An eccentric neutral position, i.e., an equilibrium position outside the operating point, can lead to a negative drive load when unloaded, for example, when the patient stretcher is handled without a patient on it. With a load, i.e., when a patient is lying on the stretcher, the load is then positive, but significantly lower than without a compensating system. For this purpose, the second pulley 12.2 can have an internal stop contour 14 against which at least one spring element 15 is supported in each of the two directions of rotation.Each spring element 15 is supported at its respective end opposite the stop contour 14 on a driver 16, which is attached to a central shaft 17. The shaft 17 is rigidly connected to the fourth link 4.4. The spring elements 15 allow the second pulley 12.2 to rotate by a slight angle in both directions relative to the central shaft 17 when a force or moment is applied to the spring elements 15, as shown in the figure. Fig. 9 and in the Fig. Figure 10 shows that such a force or moment can be generated by a first motor and a second motor of the robot arm 3.

[0060] How in particular the Fig. 1 and the Fig. As shown in Figure 6, the sixth link 4.6, the seventh link 4.7 and the eighth link 4.8, as well as the fifth joint 5.5, the sixth joint 5.6 and the seventh joint 5.7 of the robot arm 3 on the robot hand 7 can be designed and arranged such that the axes of rotation D5, D6, D7 of the fifth joint 5.5, the sixth joint 5.6 and the seventh joint 5.7 always intersect at a point S.

[0061] The mounting flange of the robot arm 3 is, in the case of the design variant according to Fig. 1 to Fig. 4 on one of the undersides opposite the lying surface 2a ( Fig. 6) attached to the patient bed 2 at a point offset from the center of the underside of the patient bed 2.

[0062] The Fig. 11 to Fig. Figure 13 shows three different variants of spring devices 13, which are variations of the embodiment according to Fig. 7 to Fig. 9 are trained.

[0063] The first spring device variant according to Fig. 11 has a first elastic element 13.1 which supports the second pulley 12.2 in a torsionally elastic manner on the fourth link 4.4. The first motor 18.1 is supported on the fourth link 4.4 and its motor shaft is coupled to the fifth link 4.5. Furthermore, the second motor 18.2 is supported on the fifth link 4.5 and its motor shaft is coupled to the sixth link 4.6.

[0064] The second spring device variant according to Fig. 12 has a second elastic element 13.2 by which the first pulley 12.1 is torsionally spring-loaded on the sixth link 4.6. The first motor 18.1 is mounted on the fourth link 4.4 and its motor shaft is coupled to the fifth link 4.5. The motor shaft of the second motor 18.2 is also coupled to the sixth link 4.6.

[0065] The third spring device variant according to Fig. 13 features a pair of third elastic elements 13.3a and 13.3b, formed by inherent elasticities of the belt 12.3. The first motor 18.1 is mounted on the fourth link 4.4, and its motor shaft is coupled to the fifth link 4.5. The second motor 18.2 is also mounted on the fifth link 4.5, and its motor shaft is coupled to the sixth link 4.6.

[0066] In all these variants, a preload can be set such that a neutral position, in which the forces are in equilibrium, is set centrally. Alternatively, in all these variants, a preload can be set such that a neutral position, in which the forces are in equilibrium, is set off-center. The fourth joint 5.4, the fifth joint 5.5, and the sixth joint 5.6 can each be driven independently by a separate motor. Alternatively, the respective motor can be assisted, in particular by a mass in the case of the fourth joint 5.4, by the gearbox 12 in the case of the fifth joint 5.5, which acts in particular parallel to the drive, i.e., the motor, and / or by the spring assembly 13, 13.1, 13.2, 13.3 in the case of the sixth joint 5.6, which can act in particular parallel to the drive, i.e., the motor.

[0067] The Fig. Figure 14 shows an optional, spring-loaded support device 19 for the sixth joint 5.6. The support device 19 can, for example, be configured as shown in Fig. Figure 14 shows a lever arm 20 that is attached to the seventh link 4.7 and projects from there with its free end. Two springs 21.1, 21.2 can, for example, be mounted on the free end of the lever arm 20, which elastically couple the free end of the lever arm 20 to the sixth link 4.6. The springs 21.1, 21.2 are thus arranged between the sixth link 4.6 and the seventh link 4.7 and therefore relieve the drive, i.e., the motor of the sixth joint 5.6.

[0068] Each type of spring assembly 13 (elastic elements 13.1, 13.2, 13.3a, 13.3b, and / or springs 21.1, 21.2) can have stops in both directions of rotation of the respective associated joint, which can mechanically limit the respective maximum spring-elastic swivel angle. This can, for example, prevent or limit uncontrolled lowering due to gravity, especially in the event of a failure of the drives or the joint brakes.

Claims

[1] Patient positioning device comprising: - a patient couch (2) which has a lying surface (2a) for one person, - a robot arm (3) with eight links and seven joints, which are arranged serially and alternately in a kinematic chain of the robot arm (3), - wherein the first link (4.1) in the kinematic chain of the robot arm (3) forms a base frame for attaching the robot arm (3) to a base (6), and the eighth link (4.8) in the kinematic chain of the robot arm (3) forms a mounting flange of a robot hand (7) of the robot arm (3) to which the patient bed (2) is attached, - the second link (4.2) is rotatably mounted on the first link (4.1) by means of the first joint (5.1) about a first, vertical axis of rotation (D1), - the third link (4.3) is rotatably mounted on the second link (4.2) by means of the second joint (5.2) about a second, vertical axis of rotation (D2), - the fourth link (4.4) is rotatably mounted on the third link (4.3) by means of the third joint (5.3) about a third, vertical axis of rotation (D3), - the fifth link (4.5) is rotatably mounted on the fourth link (4.4) by means of the fourth joint (5.4) about a fourth, horizontal axis of rotation (D4), - and the robot hand (7) of the robot arm (3) is attached to the fifth segment (4.5), which robot hand (7) includes the sixth segment (4.6), the seventh segment (4.7) and the eighth segment (4.8), as well as the fifth joint (5.5), the sixth joint (5.6) and the seventh joint (5.7) of the robot arm (3). [2] Patient positioning device according to claim 1, characterized by, that the second member (4.2) is beam-shaped and has a first beam end section on which the first hinge (5.1) is arranged and a second beam end section opposite the first beam end section on which the second hinge (5.2) is arranged, the third member (4.3) is beam-shaped and has a first beam end section on which the second hinge (5.2) is arranged and a second beam end section opposite the first beam end section on which the third hinge (5.3) is arranged, and the fourth member (4.4) is beam-shaped and has a first beam end section on which the third hinge (5.3) is arranged and a second beam end section opposite the first beam end section on which the fourth hinge (5.4) is arranged. [3] Patient positioning device according to claim 2, characterized by, that the respective beam-shaped second member (4.2), third member (4.3) and fourth member (4.4) are each arranged horizontally with their longitudinal extension sections leading from the first beam end section to the second beam end section in different horizontal planes such that both the third member (4.3) is rotatably mounted relative to the second member (4.2) by means of the second joint (5.2) by at least 360 degrees, and the fourth member (4.4) is rotatably mounted relative to the third member (4.3) by means of the third joint (5.3) by at least 360 degrees. [4] Patient positioning device according to claim 2 or 3, characterized by, that the second member (4.2), the third member (4.3) and the fourth member (4.4) have different beam lengths, such that a first axial distance of the vertical axis of rotation (D1) of the first joint (5.1) from the vertical axis of rotation (D2) of the second joint (5.2) is greater than a second axial distance of the vertical axis of rotation (D3) of the third joint (5.3) from the vertical axis of rotation (D2) of the second joint (5.2). [5] Patient positioning device according to any one of claims 1 to 4, characterized by , that the sixth link (4.6) is coupled to the fourth link (4.4) by means of a gear (12) such that, despite a rotation of the fifth link (4.5) by means of the fourth joint (5.4), the sixth link (4.6) retains its original orientation. [6] Patient positioning device according to claim 5, characterized by, that the transmission (12) has a spring device (13) which is designed to hold the sixth link (4.6) in its orientation in a spring-elastic manner relative to the fourth link (4.4). [7] Patient positioning device according to claim 6, characterized by , that the robot arm has a first motor configured to rotate the fifth link (4.5) relative to the fourth link (4.4) about the fourth axis of rotation (D4) and a second motor configured to rotate the sixth link (4.6) relative to the fifth link (4.5) about the fifth axis of rotation (D5), and the two motors are configured to drive in order to generate a force by means of a position difference or an angular difference at the two motors, thereby assisting a drive motor of the fifth joint. [8] Patient positioning device according to any one of claims 1 to 7, characterized by, that the sixth link (4.6), the seventh link (4.7) and the eighth link (4.8), as well as the fifth joint (5.5), the sixth joint (5.6) and the seventh joint (5.7) of the robot arm (3) on the robot hand (7) are designed and arranged such that the axes of rotation (D5, D6, D7) of the fifth joint (5.5), the sixth joint (5.6) and the seventh joint (5.7) always intersect at a point of intersection (S). [9] Patient positioning device according to any one of claims 1 to 8, characterized by , that the mounting flange of the robot arm (3) is attached to an underside of the patient bed (2) opposite the lying surface (2a), specifically at a point offset from the center of the underside (U) of the patient bed (2). [10] Patient positioning device according to any one of claims 1 to 9, characterized by, that the fifth joint (5.5) is designed to be rotatable to a fifth axis of rotation (D5) which is horizontally oriented and arranged parallel to the fourth, horizontal axis of rotation (D4) at a fixed distance. [11] Patient positioning device according to any one of claims 1 to 10, characterized by , that the sixth joint (5.6) is associated with a support device (19) which spring-elastically couples the seventh link (4.7) to the sixth link (4.6) in such a way that torques induced at the sixth joint (5.6) by gravitational influences, in particular by the gravitational influences acting on the patient bed (2), are at least partially or completely compensated by means of a spring force of the support device (19). [12] Patient positioning device according to claim 11, characterized by, that the support device (19) has at least one stop designed to mechanically limit a rotation of the sixth joint (5.6) caused by the effects of gravity to a maximum angle of rotation. [13] Patient positioning device according to any one of claims 1 to 12, characterized by a robot (10) comprising the robot arm (3) and a control device (11) configured to control a movement of the robot arm (3). [14] Medical workstation comprising a medical device (9) and a patient positioning device (1) according to any one of claims 1 to 13.

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