Ultrasonic processes and circuits for performing them

Claim 1

An ultrasonic process for imaging and, optionally, for evaluation of a Doppler spectrum, of an object having limited resistance to sonic energy, in an inspection zone, which comprises: introducing into the inspection zone, the object to be imaged and an ultrasonic contrast medium that contains microbubbles as scattering bodies or that produces microbubbles upon exposure to ultrasonic waves, such that the contrast agent provides nonlinear vibrations of the microbubbles when irradiated in the inspection zone by irradiated ultrasonic waves, applying an HF burst of excitation frequency, f o , to electrically excite a wide-band, acoustically highly damped, electrically matched ultrasonic transducer having a transducer element or having several transducer elements, controllable individually or in groups, and thereby exposing the inspection zone to ultrasonic waves, f o , of 1 MHz to 22 MHz, and receiving by the ultrasonic transducer, the ultrasonic signal reflected from the inspection zone and scattered back from that zone, and processing the received ultrasonic signal for further evaluation, evaluating from the reflected and backscattered ultrasonic signal at least one of the harmonics, the subharmonics and the ultraharmonics of the excitation frequency, f o , and, optionally, the excitation frequency f o .