IRONLESS ELECTRIC MOTOR FOR MRI COMPATIBILITY

An electric motor (20) usable in proximity to a magnetic resonance imaging (MRI) device (4) includes a stator (30) comprising electrical windings (32), and a rotor (40, 50, 60) magnetically coupled with the stator. The electric motor does not include ferromagnetic material, and the electric motor does not include any permanent magnet. The rotor may include an outer rotor cylinder (50, 60) surrounding the stator, and may further include an inner rotor cylinder (40) disposed inside the stator and connected to rotate with the outer rotor cylinder. The rotor may comprise a cylindrical sheet rotor (40, 50). Alternatively, the rotor (60) may comprise one or more conductive loops (62A, 62B, 62C) each shaped such that the induced voltage in one loop portion (HL1) cancels the effect of the induced voltage in another loop portion (HL2), and a coupled split stator (301, 302). In another disclosed aspect, an infusion pump (10) includes the electric motor.