Bias voltage modulation methods and its optimization for nonlinear contrast imaging

Abstract : The main difficulty in applying ultrasound contrast imaging techniques with cMUT probe comes from the intrinsic nonlinearity of the transducer itself. An approach has been developed in order to adapt the amplitude modulation techniques (AM) to cMUTs. Bias Voltage Modulation (BVM)[1] allows a complete cancellation of the echoes from linear reflectors and thus an enhancement of the contrast agent detection. The main limit is that it can only be applied with low bias voltage, far from the maximum of the probe sensitivity (i.e. at the collapse). Here is proposed an optimization of the BVM sequence allowing a good compensation of cMUT intrinsic nonlinearity even at high bias voltages.