Development of Single Axis Controlled Attraction Type Magnetic Bearing and its Application in Ventricular Assist Device

Aiming the development of an implantable Ventricular Assist Device – VAD, or an artificial heart, a joint project was started in 2007, involving the Escola Politécnica of São Paulo University (EPUSP) and the Dante Pazzanese of Cardiology (IDPC). One of objectives of the project is the development of a VAD with a rotor levitated by a magnetic bearing. Here, a magnetic bearing proposed by authors, called as EPUSP bearing, is elected mainly because of its simplicity. This work presents the entire development work. One of most important work is related with the mitigation of a topology of the EPUSP bearing that enables a robust levitation, enough for supporting the rotor of a VAD. Moreover some complementary studies are developed so as to execute the Zero Power control in the EPUSP bearing, identify the best way of driving the rotor supported by the EPUSP bearing and finally, use the Hall sensor in the measurement of the rotor position in the EPUSP bearing.