An arrangement for manipulating a medical device is inserted into the body of a patient. There is a drive element to be driven by a motor. There is also a control element for controlling at least one motion of the medical device. A transmission arrangement transmits motion from the drive element to the control element, the transmission arrangement having first and second members which are frictionally engaged with one another so that motion may be transmitted from one to the other. There is a manual manipulation control, which may be grasped by a user to move the medical device manually while the first and second members remain in frictional engagement with one another.