| 摘要 |
PURPOSE:To prevent the frame rate from falling at the time of applying a focus of a multistage at the time of transmission by transmitting simultaneously each ultrasonic wave of different kinds of frequencies by a transmitting means, and changing the focus at every frequency thereof. CONSTITUTION:A transmitting means 2 consists of combination of oscillators 4A, 4B and a transmitting pulser circuit 5, transmits simultaneously each ultrasonic wave of different kinds of frequencies from an ultrasonic probe 1, and changes a focus at every frequency thereof. A receiving means 3 consists of combination of band pass filters 6A, 6B and phasing addition delay lines 7A, 7B, and receives a reflected wave from each sound field of a living body (not shown in the figure) focused by the transmitting means 2 as a receiving signal at every frequency through the ultrasonic probe 1. That is, the focus is applied to plural stages by simultaneous transmission of different kinds of frequencies, and an ultrasonic image is synthesized, based on the receiving signal of every frequency, therefore, even if the focus stage increases, the frame rate does not fall. |
