| 摘要 |
<p>An ultrasonic imaging method including the step of transmitting ultrasonic energy to a subject under examination, which energy is generated by a plurality of electroacoustic transducers (110,110') actuated with predetermined delays according to a predetermined focusing rule; receiving the reflected ultrasonic energy by an array of electroacoustic transducers (110,110'), the received signals detected thereby being read with predetermined delays according to a focusing rule; turning the focused received signals into image data for reconstructing a displayable image; the transmitting transducers (110,110') being actuated with such delays as to generate a homogeneous acoustic field over all or at least a portion of the region of the subject under examination; two subgroups of transmitting electroacoustic transducers being provided being actuated for transmission of ultrasonic energy with a predetermined waveform, which are inverted one with respect to the other and which have a half-period increase.
According to the invention, the received signal of each transducer is sampled by analog-to-digital conversion (19) and stored in a memory (21) by using, as a storage address, the subject penetration depth, i.e. the instant or interval in which the corresponding part of the signal is received.</p> |
