Development And Design Of A Transmitting And Echo Receiving System For Minitype Digital Ultrasonic Imaging Equipments

With the rapid development of computer science and electronic technology, foreign advanced ultrasonic diagnostic equipments are developing in the direction of all-digital design. However, the domestic study level of such equipments is still relatively low. On the other hand, recently more and more ultrasonic diagnoses were conducted outside the hospital. Therefore the ultrasonic diagnostic equipments are required to be more small and portable. Compact and cost-effective ultrasonic diagnostic equipments have become popular products in the market.Based on the principles of ultrasonic, using a 3.5MHz convex array probe and a new highly integrated chip AD9271, this project designed and developed a transmitting and echo receiving system, which is controlled by FPGA, for digital ultrasonic imaging equipments. This thesis first introduces the basic principles of ultrasonic imaging, and then presents the hardware circuit design and software control of the whole system. In the section of hardware design, the description of the transmitting and echo receiving circuit will be introduced. Then we discuss the choice of probe element connectivity circuit, the isolation circuit for echo receiving signal transmitting, as well as the circuit for echo receiving signal amplification, filtering and A/D conversion. In the section of software control, we mainly detail the control of FPGA on the pulse of transmitting circuit for ultrasonic imaging equipment, on the probe element strobe, and on AD9271. Experimental results show that this transmitting and receiving system can effectively obtain images of good quality.