| 摘要 |
An ultrasonic apparatus has a pulse transmission and reception unit (2,4), an envelope curve detection unit (25), a time difference detection unit (27), and an attenuation characteristic obtaining unit (29). The pulse transmission and reception unit transmits a first transmitted pulse that a frequency increases with time and a second transmitted pulse that the frequency decreases with time, further receives a first received pulse corresponding to the first transmitted pulse and a second received pulse corresponding to the second transmitted pulse. The envelope curve detection unit detects a first envelope curve based on the first received signal and a second envelope curve based on the second received signal, respectively. The time difference detection unit detects a time difference between the first envelope curve and the second envelope curve. The attenuation characteristic obtaining unit obtains a frequency dependent ultrasound attenuation characteristic based on the time difference. |
