Design And Implementation Of Ultrasonic Detection System Based On FPGA

The main research work of this dissertation is to design and develop a portable ultrasonic detection system which has three advantages:easy to carry, low energy consumption, and easy to connect with other equipment. Based on this idea, we choose the Supertex’s MD1211and TC6320as the core components to build the pulse transmitting circuit, choose the ADI’s AD8331and AD9215to build the signal receiving circuit, and utilize the Altera’s FPGA chip EP3C10E144as the control and arithmetic processor. After the completion of the design, we use this system to measure:(1) standard test block,(2) ultrasonic phantoms and (3) adipose tissue of pigs. The results of experiment show that, this ultrasonic detection system can obtain accurate measurement result and the system’s power consumption is relatively low. The system is very suitable for mobile treatment, especially for the detection of subcutaneous adipose tissue.The main work of this paper includes:(1) Introduce the development and current situation of the ultrasonic detection instrument. Put forward the concept of portable ultrasonic diagnostic instrument, analyses its advantages, indicates meaning and purpose of this research.(2) The basic principles of ultrasonic detection and the current detection technology are introduced. Introduce the acoustic parameters (including sound pressure, sound power, and sound impedance) and related formula of this parameters; Introduce the ultrasonic propagation rule, including reflection, refraction, absorption and attenuation. The basic principle of the ultrasonic pulse echo is also briefly described.(3) Introduce the hardware circuit of ultrasonic detection system, focus on the analog front end, receiving system and logic control module.(4) Introduce the post processing of echo signal. Firstly, analysis the noise signal’s characteristics. The noise could be divided into three types:electrical noise, scattering noise and structure noise. Each kind of noise’s characteristics has been analyzed, and then proposed the corresponding solution. At last a FIR filter has been designed to remove the echo signal clutter.(5) Design experiments to test the ultrasonic detection device. In these experiments we use the device to measure the standard test block, ultrasound phantoms and adipose tissue samples of pigs. Compare the measurement results of these experiments to other means.