초록 ▼

A patient support device of a radiation therapy treatment system includes an electromechanical motor and control system for raising and lowering the support device in the Z direction. The control system utilizes regenerative braking concepts, converting the motor into a generator as the support devi

A patient support device of a radiation therapy treatment system includes an electromechanical motor and control system for raising and lowering the support device in the Z direction. The control system utilizes regenerative braking concepts, converting the motor into a generator as the support device is lowered such that no matter the load, the support device will be lowered at a constant speed. The control system also allows for lowering of the support device in the powered off situation (i.e., when there is no power to the support device).

대표청구항 ▼

What is claimed is: 1. A patient support device comprising: a base; a table assembly supported by the base and configured to support a patient; an actuator assembly electrically coupled to and operable to control motion of the table assembly, the actuator assembly including a motor and a brake; a c

What is claimed is: 1. A patient support device comprising: a base; a table assembly supported by the base and configured to support a patient; an actuator assembly electrically coupled to and operable to control motion of the table assembly, the actuator assembly including a motor and a brake; a controller electrically coupled to the actuator assembly, the controller operable to generate a signal to activate the brake when power to the actuator assembly is interrupted; and an dynamic brake assembly electrically coupled to the actuator assembly and the controller, the dynamic brake assembly operable upon deactivation of the brake, the dynamic brake assembly including a passive dynamic load module electrically coupled to the motor to increase speed of the motor, a rectification module electrically coupled to the motor and operable to convert AC voltage to DC voltage when the AC voltage reaches a predetermined value, a controlled dynamic load module electrically coupled to the passive dynamic load module, and a switch operable to deactivate the brake and electrically couple the controlled dynamic load module and the actuator assembly to control a braking operation of the motor. 2. The patient support device of claim 1 wherein the motor is operable to control a substantially vertical motion of the table assembly. 3. The patient support device of claim 1 wherein the passive dynamic load module includes a capacitive dynamic load module and a resistive dynamic load module. 4. The patient support device of claim 3 wherein the passive dynamic load module further includes a voltage sensor dynamic load module. 5. The patient support device of claim 4 wherein the voltage sensor dynamic load module is operable to receive the DC voltage on the motor from the rectification module. 6. The patient support device of claim 1 wherein the controlled dynamic load module includes a current sensor dynamic load and a controlled dynamic load. 7. A radiation therapy treatment system comprising: a patient support device including a table assembly configured to support a patient, an actuator assembly electrically connected to the table assembly and operable to control movement of the table assembly, the actuator assembly including a motor and a brake; and a control system electrically connected to the actuator assembly the control system including a dynamic brake assembly operable upon release of the brake and operable to control a speed of the motor and provide linear motion of the table assembly when power to the actuator assembly is interrupted. 8. A radiation therapy treatment system of claim 7 wherein the dynamic brake assembly includes a passive dynamic load module electrically coupled to the motor to increase speed of the motor, a rectification module electrically coupled to the motor and operable to convert AC voltage to DC voltage when the AC voltage reaches a predetermined value, a controlled dynamic load module electrically coupled to the passive dynamic load module, and a switch operable to release the brake and electrically couple the controlled dynamic load module and the actuator assembly to control a braking operation of the motor. 9. The radiation therapy treatment system of claim 8 wherein the controlled dynamic load module includes a current sensor dynamic load and a controlled dynamic load. 10. The radiation therapy treatment system of claim 9 wherein the current sensor dynamic load is connected to the motor when a voltage on the current sensor dynamic load is equal to or greater than a reference voltage.