| 摘要 |
<p>In the illustrated embodiment, ultrasonic transmitter/receiver elements are arranged along a curved formation within a housing containing a coupling medium which is a good conductor of ultrasonic energy (for example a water medium) and are successively excited to direct ultrasonic beam energy via the coupling medium to an ultrasonic window of the housing. The transducer elements are mounted at different angular orientations such that their beam paths converge external to the ultrasonic window. The curvature of a carrier for the transducer elements may be controlled to adjust the distance of the point of convergence beyond the window without changing the length of the acoustic path in the coupling medium, or the transducer elements and/or ultrasonic window may be bodily shifted to simultaneously change the length of the acoustic path and the distance of the convergence point beyond the window. Internal body regions accessible through narrow acoustic apertures at varying depths dependent on individual body characteristics may thus be reached for scanning by appropriate adjustment of the depth of the convergence point of the ultrasonic beam paths, the diverging beam paths beyond such depth providing for a sector scanning configuration within the desired body region.</p> |
