In a first scenario, a third switch 42 is opened by a command from a main body controller 44, when a first switch 32 is opened in order to turn off the power supply provided to a device main body and a second switch 33 is short-circuited. In other words, the third switch 42 comprising a make contact relay is opened as a result of the power supply provided to the main body controller 44 being stopped. In a second scenario, the third switch 42 is opened when the device main body is in a running state, in a state in which the first switch 32 is short-circuited and the second switch 33 is short-circuited, when, e.g., a trolley is moved between hospital rooms. Whether or not the device main body is in a running state is recognized as a result of a lock unit 18 sending a signal to the main body controller 44, said signal indicating that the lower surface of an arm 13 has come in contact with the lock unit 18 and the arm is arranged at a fixed position where the arm should be arranged when moving the trolley.
