In this paper, the possibility of using an electrostatic micromotor for an intravascular echographic system is studied. For this given application, the advantage of a micromotor is the absence of a long cable between motor and minor. This advantage is real only if the micromotor speed can be controlled. In fact electrostatic micromotors are often used with a step-by-step power supply but, for low mean angular speed (2000 rpm), the rotation is not regular with this type of command. So, we propose herein a self-control command based on the rotor-position control carried out by a capacitance measurement. (C) 1997 Elsevier Science S.A.