Preshaping of excitation signal of ultrasonic transducer by using the inverse filter

Abstract

The quality of a medical ultrasonic image is highly dependent on the axial resolution of the transducer. In many cases of low damped ultrasonic transducer the duration of an ultrasonic pulse is too long to ensure the high axial resolution of the transducer. The duration of the ultrasonic pulse can be reduced if the transducer is excited with a signal, preshaped using inverse filter. However, in many cases, with this method an excitation signal becomes very sophisticated. A method to preshape the excitation signal with sequences of delayed pulses is proposed. The results of theoretical calculations using an excitation of ultrasonic transducer with unit pulse, the inverse WLS filter as well as the delayed pulses are presented.