Eddy current technology is used to detect displacement between rotor and stator in maglev artificial heart. However

traditional eddy current sensor configuration is inapplicable in such application because the rotor and stator of a maglev artificial heart are covered by titanium alloy shells. The characteristic of sensor coils is significantly altered by the shell on the coil surface. Furthermore

the sign of the sensitivity is changed. Present influence of titanium alloy shells on the characteristic of sensor coils

and deficiency of the common eddy current sensor configuration is discussed. A new optimization method is proposed through proper selection of driving frequency.