A device to facilitate moving a curtain with loops along a pole includes at least two sliding elements to be fixed to at least one loop, each element having a face for fixing to the loop which is at least partly covered with an adhesive, the elements being kept a predefined distance apart by detachable andor flexible holding means, at least before they are put on the loop. The seat includes a seating portion, a capacitance sensor, a controller, and a supporting member. The patient’s uterine cervix is held within the interior of the receptacle by the application of a vacuum to the interior of the receptacle through the inner lumen of the shaft while the leading edge of the cervical receptacle press against the patient’s vaginal fornix to occlude the uterine artery. There can be a second section comprising a substantially flat section extending along the longitudinal axis. Control circuitry is configured to receive a first signal based on the input signal and produce a digital control signal, which is used to determine the switch state of the output stage. The tachometer reading unit is configured to obtain the tachometer reading during the stretched pulse in the PWM signal.