| 摘要 |
PROBLEM TO BE SOLVED: To improve S/N of ultrasonic images by correcting the distortion of ultrasonic transmission/reception sensitivity generated in a vibration element. SOLUTION: The ultrasonic diagnostic apparatus is provided with an ultrasonic probe 10, a transmission circuit 12, a reception circuit 14, an image processing means 16 and a monitor 18. For the ultrasonic probe 10, the plurality of vibration elements 22 for mutually converting ultrasonic waves and electric signals are arrayed, and each vibration element 22 has an insulation film 22c and a gap 22d between opposing electrode 22a and electrode 22b. The ultrasonic transmission/reception sensitivity is changed corresponding to the size of bias impressed between the electrodes, and a bias polarity changing means 26 for inverting the polarity of the bias impressed between the electrodes of the vibration element 22 by a predetermined trigger is provided. COPYRIGHT: (C)2008,JPO&INPIT
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