Surgical machine and method for controlling and/or regulating a surgical machine

Surgical machine, comprising:

• a sensorless electric motor comprising a rotor and at least two motor windings, and
• a motor controller for at least one of controlling and regulating the electric motor,
• wherein:
• a space vector pulse width modulation (SVPWM) method (A) for said at least one of controlling and regulating the electric motor, in which all motor windings are able to be simultaneously supplied with electric current, is performable with the motor controller;
• a rotor position of the electric motor is determinable for said at least one of controlling and regulating the supplying of the at least two motor windings with electric current;
• and
• to determine the rotor position of the electric motor at least one of the at least two motor windings is separable from a power supply of the machine for a time interval tinterrupt, a CEMF (counterelectromotive force) of the at least one of the at least two motor windings is measurable during the time interval tinterrupt, and the position of the rotor is calculatable from the measured CEMF (counterelectromotive force).