Positioning device and method for positioning a load

• US 8,702,578 B2
• Filed: 05/30/2008
• Issued: 04/22/2014
• Est. Priority Date: 06/05/2007
• Status: Active Grant

• Current Assignee: Varian Medical Systems Particle Therapy GmbH & Company KG (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Fahrig, Wolfram, Herrmann, Klaus, Lseken, Jochen Miguel
• Primary Examiner(s): Hopkins, Christine
• Assistant Examiner(s): LANNU, JOSHUA DARYL DEANON
• Application Number:
  US12/130,826
• Publication Number:
  US 20080301872A1
• Time in Patent Office: 2,153 Days
• Field of Search: 600/407, 600/1, 700/245, 702/150, 901/2, 901/23
• US Class Current: 600/1
• CPC Class Codes: A61B 6/0487 Motor-assisted positioning
• CPC Class Codes: A61B 6/4092 for producing synchrotron radiation
• CPC Class Codes: A61B 6/5276 involving measuring table sag
• CPC Class Codes: A61G 13/02 Adjustable operating tables; Controls therefor
• CPC Class Codes: A61G 13/04 tiltable around transverse or longitudinal axis
• CPC Class Codes: A61G 13/06 raising or lowering of the whole table surface A61G13/04 takes precedence
• CPC Class Codes: A61N 2005/1057 monitoring flexing of the patient support or the radiation treatment apparatus
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: B25J 9/1638 compensation for arm bending/inertia, pay load weight/inertia
• CPC Class Codes: G05B 2219/35285 Plausibility check for data, within permissible range
• CPC Class Codes: G05B 2219/37285 Load, current taken by motor
• CPC Class Codes: G05B 2219/39176 Compensation deflection arm
• CPC Class Codes: G05B 2219/45117 Medical, radio surgery manipulator
• CPC Class Codes: G05B 2219/49189 Bending of driven table, lag between real and commanded position

Abstract

A positioning device for positioning a load is provided. The positioning device includes a motor, a measuring device, and an evaluation device. The measuring device is associated with the motor, and is operable to ascertain measurement data that characterizes the motor current consumption by the motor in the positioning of the load. The evaluation device evaluates the measurement data that have been ascertained by the measuring device, so that in that way the loading of the positioning device by the load can be ascertained.

Claims

1. A positioning system for positioning a mass, the positioning system comprising:

a robotic arm operable to support the mass, wherein the robotic arm comprises a table system;

a motor operable to move the robotic arm;

a measuring device that is associated with the motor and is configured to determine measurement data representing a motor current consumption by the motor in the positioning of the mass; and

an evaluation device in communication with the measuring device, the evaluation device configured to calculate a location of the mass along the table system of the robotic arm as a function of the measurement data so as to determine a loading of the robotic arm.

2. The positioning system as defined by claim 1, further comprising:

at least one further motor for moving the robotic arm; and

a further measuring device that is associated with the at least one further motor and operable to ascertain further measurement data that characterizes a further motor current consumption by the at least one further motor in the positioning of the mass,

wherein the evaluation device is operable to take the further measurement data into account.

3. The positioning system as defined by claim 1, wherein the robotic arm includes:

a control device that positions the robotic arm such that a deformation of the robotic arm by the mass is compensated for using the determined loading.

4. The positioning system as defined by claim 1, wherein the evaluation device is operable to ascertain the weight of the mass, the position of the center of gravity of the mass, or the weight of the mass and the position of the center of gravity of the mass.

5. The positioning system as defined by claim 1, wherein the robotic arm is a multiaxial robot arm.

6. The positioning system as defined by claim 5, wherein the evaluation device is operable to take into account at least one joint position during the determination of the loading as a function of the measurement data.

7. The positioning system as defined by claim 1, wherein the robotic arm is a patient positioning device for positioning a patient in a medical system.

8. The positioning device as defined by claim 7, wherein the medical system is a particle therapy system.

9. The positioning system as defined by claim 1, wherein the robotic arm comprises a multiaxial robot arm with a plurality of joints, and

wherein the motor is disposed at one joint of the plurality of joints.

10. A method for positioning a mass, the method comprising:

positioning the mass by moving a robotic arm with at least one motor, wherein the robotic arm comprises a table system;

determining measurement data that representing a motor current consumption by the at least one motor in the positioning of the mass;

determining, based on the determined measurement data, a load of the robotic arm, the determining of the load of the robotic arm comprising calculating a location of the mass along the table system of the robotic arm.

11. The method as defined by claim 10, further comprising:

controlling the robotic arm using the determined load of the robotic arm to compensate for a deformation of the robotic arm by the mass.

12. The method as defined by claim 10, further comprising:

performing a plausibility check of the determined load.

13. The method as defined by claim 10, wherein

determining the load includes the weight of the mass, the position of the center of gravity of the mass, or the weight of the mass and the position of the center of gravity of the mass.

14. The method as defined by claim 10, wherein the robotic arm is a multiaxial robot arm with a plurality of joints.

15. The method as defined by claim 14, wherein the determining of the load includes taking into account at least one joint position.

16. The method as defined by claim 10, wherein the at least one motor comprises a plurality of motors,

wherein in each motor of the plurality of motors, measurement data that characterize the respective motor current consumption in the positioning of the mass are ascertained, and

wherein determining the load of the robotic arm by the mass is effected redundantly by evaluating the measurement data ascertained.

17. The method as defined by claim 16, further comprising:

outputting an error signal when a deviation between the determined load and a redundant ascertained load that is outside a tolerance range is determined.

18. A medical diagnosis, treatment, or diagnosis and treatment system comprising:

an examination room or treatment room having a positioning system for a patient, wherein the positioning system comprises;

a robotic arm operable to support a mass, wherein the robotic arm comprises a table system;

a motor operable to move the robotic arm;

a measuring device that is associated with the motor and is configured to determine measurement data representing a motor current consumption by the motor in positioning of the mass; and

an evaluation device in communication with the measuring device, the evaluation device configured to calculate a location of the mass along the table system of the robotic arm as a function of the measurement data, so that a loading of the robotic arm is determined.

19. The medical diagnosis, treatment, or diagnosis and treatment system as defined by claim 18, further comprising:

a radiation therapy device for particle therapy.

20. A particle therapy system comprising:

a particle source operable to generate particles for irradiating a mass; and

a positioning system for positioning the mass, the positioning system comprising;

a robotic arm operable to support the mass, wherein the robotic arm comprises a table system;

a motor operable to move the robotic arm;

a measuring device that is associated with the motor and is configured to determine measurement data representing a motor current consumption by the motor in the positioning of the mass; and

an evaluation device in communication with the measuring device, the evaluation device configured to calculate a location of the mass along the robotic arm as a function of the measurement data so as to determine a loading of the table system of the robotic arm.