| 摘要 |
A system for dynamically focusing ultrasonic waves consisting of a housing filled with a liquid media, an ultrasonic transducer, a reflector, and a control device. The ultrasonic transducer, located within the housing, emits ultrasonic waves and detects echoes of the ultrasonic waves as they return from the object being scanned. The reflector is also located within the housing and is positioned so as to intercept and redirect the ultrasonic waves and the resulting echoes. The reflector consists of a flexible reflective membrane which is stretched across an air filled enclosure. The control device is located adjacent the housing and consists of a member adapted to variably compress the liquid media contained in the housing so as to provide pressure variations to the reflective membrane. These pressure variations periodically deform the reflective membrane so that the ultrasonic waves from the transducer are reflected to converge at a point a preselected distance beyond the reflector and the echoes returning from a preselected range within the scanned object are in focus approximately at the ultrasonic transducer surface.
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