PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic apparatus which can change a beam width in accordance with an object part to be diagnosed.SOLUTION: The ultrasonic diagnostic apparatus has a diagnostic mode in which a blood flow speed is detected with a fixed focus. The ultrasonic diagnostic apparatus has a reception beam forming control circuit 44 to which signals received by a plurality of ultrasonic vibrators 11 are supplied and which includes a quantization accuracy selecting signal input device 41, a delay quantization amount determining device 42 for determining a delay quantization amount on the basis of the quantization accuracy selecting signal supplied from the input device 41, a signal delay circuit 18 for conferring a predetermined delay amount to the received signal on the basis of an output of the delay quantization amount determining device 42, and a signal synthesis device 20 for synthesizing the received signals delayed by the signal delay circuit 18. With such a configuration, accuracy of reception beam forming can be changed arbitrarily.COPYRIGHT: (C)2010,JPO&INPIT【課題】 診断すべき対象箇所に応じてビーム幅を変化させることが可能な超音波診断装置を提供すること。【解決手段】 固定焦点で血流速度を検出する診断モードを備えた超音波診断装置であって、複数個の超音波振動子11により受信された信号が供給される受信ビームフォーミング制御回路44は、量子化精度選択信号入力装置41と、この入力装置41により供給された量子化精度選択信号に基づいて遅延量子化量を決定する遅延量子化量決定装置42と、この遅延量子化量決定装置42の出力により受信信号に所定の遅延量を付与する信号遅延回路18と、この信号遅延回路18により遅延された前記受信信号を合成する信号合成装置20を備え、受信ビームフォーミングの精度を任意に変更できることを特徴とする超音波診断装置。【選択図】 図5
