Patent Number: 
Section: claims

1. A positioning device for positioning a patient in a medical device, comprising:a patient receiving device on which the patient is placed;a robot arm having a plurality of movement axes that changes a position of the patient receiving device; anda switchover device that switches the positioning device from a normal operating mode for automatically changing the position of the patient receiving device into a manual operating mode for manually changing the position of the patient receiving device. 2. The positioning device as claimed in claim 1, wherein the manual operating mode comprises a rotation of the patient receiving device about a vertical axis of the rotation. 3. The positioning device as claimed in claim 1, wherein at least one of the movement axes is unlocked in the manual operating mode so that the robot arm is moved manually about the at least one of the movement axes. 4. The positioning device as claimed in claim 1, wherein the manual operating mode is activated automatically if a fault condition occurs during the normal operation mode. 5. The positioning device as claimed in claim 1, wherein the switchover device is manually actuatable. 6. The positioning device as claimed in claim 1, wherein the switchover device is disposed on one of the movement axes of the robot arm for mechanically unlocking the one of the movement axes. 7. The positioning device as claimed in claim 1, wherein the patient receiving device comprises a device for manually holding and moving the patient receiving device. 8. An irradiation device, comprising:a particle source that generates particles;an accelerator that accelerates the particles and provides a high-energy particle beam;an irradiation room where a patient to be irradiated to the high-energy particle beam is exposed; anda positioning device that comprises:a patient receiving device on which the patient is placed,a robot arm having a plurality of movement axes that changes a position of the patient receiving device, anda switchover device that switches the positioning device from a normal operating mode for automatically changing the position of the patient receiving device into a manual operating mode for manually changing the position of the patient receiving device. 9. The irradiation device as claimed in claim 8, wherein the irradiation room comprises:a movable gantry for directing the high-energy particle beam from different selectable directions onto the patient, anda removable floor. 10. A method for operating a positioning device of a medical device comprising a patient receiving device and a robot arm having a plurality of movement axes, comprising:providing a normal operating mode of the positioning device in which the patient receiving device is positioned automatically at a position;providing a manual operating mode of the positioning device in which the position of the patient receiving device is changed manually; andswitching from the normal operating mode into the manual operating mode if a switchover condition is present. 11. The method as claimed in claim 10, wherein the manual operating mode comprises a rotation of the patient receiving device about a vertical axis of the rotation. 12. The method as claimed in claim 10, wherein the switchover condition is automatically present if a fault condition is detected in the normal operating mode. 13. The method as claimed in claim 10, wherein the switchover condition is present following a manual actuation of a switchover device that switches the positioning device from the normal operating mode into the manual operating mode. 14. The method as claimed in claim 13, wherein the actuation of the switchover device comprises a mechanical unlocking of one of the movement axes of the robot arm.