A medical apparatus having first and second relatively movable parts, a drive means for causing relative movement therebetween, and control means for controlling the operation of drive means, the control means including a sensor for detecting the relative position of the first and second parts, the control means including at least one of an acceleration control system and a deceleration control system, the acceleration control system having a first acceleration control for operating the drive means in a first acceleration phase in which the relative position is periodically detected and power fed to the drive means is increased using a preset power increase protocol until relative motion between the first and second parts is detected by the sensor, and a second acceleration control for operating the drive means in a second acceleration phase, after the first acceleration phase, in which the relative speed between the first and second parts is accelerated up to a set speed value at a set acceleration rate, and the deceleration control system includes a deceleration control for operating the respective drive means in a deceleration phase in which power fed to the drive means is decreased using a preset power decrease protocol.