| 摘要 |
The combined modality device comprises an ultrasound transducer (10) which is suitable for transmission as well as reception and which is connected to a transmitter stage (20) as well as to a receiver stage (30). The transducer (10) has a bandwidth which at least equals approximately one octave. The transmitter stage (20) comprises a generator for generating activation signals for the transducer (10) with a frequency fo near the lower limit of said bandwidth, the spectrum of these activation signals excluding the frequency f1=2fo. The receiver stage (30) comprises a B-scan channel and also a B/A processing channel (200) which itself includes a bandpass filter (210) which is centered around said frequency f1, an envelope detector (220, 230), a comparison circuit (240), a differentiation circuit (250) and a display device (260) whereby measured results in both modalities may be displayed.
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