Research And Application On Coded Excitation And Pulse Compression Used In Ultrasonic Imaging System

As an important modern medical imaging technology, medical ultrasonic imaging gets more and more attention for its safe, fast imaging, portable and so on. With a fast development of electronic technology, there is a great innovation in the medical ultrasonic imaging system, which makes it more popularity. Accompanied with its extensive exposure to various users, the weaknesses of the traditional medical ultrasonic imaging system appear. A weakness is the contradiction between two important parameters of the imaging quality: vertical resolution and penetration depth. Coded excitation and pulse compression can increase the penetration depth, but at the same time keep the resolution. Currently coded excitation and pulse compression are limited to the theoretical simulation, and there are few literatures on hardware design. The application of coded excitation technology in medical ultrasonic imaging system shall improve the image quality, increase the diagnostic depth, and advance the sensitivity of signal. This paper bases on such theories to build a coded excitation and pulse compression ultrasonic transmitting and receiving platform.In this dissertation, I accomplish the following work: do investigations on the medical ultrasonic imaging system, coded excitation and pulse compression technology; deduce and analysis two types of coded excitation of frequency modulation signal and phase modulation signal; compare the advantages and disadvantages of several coded excitation signal, and choose the coded excitation signal which use in this paper; detailed analysis of the pulse compression techniques; introduce detailed the principles and functions of each part of the hardware experimental system platform of this design; collected the transmitted signal and echo signal data by the hardware platform, and prove the advantage of coded excitation and pulse compression technology compared to tradition ultrasonic imaging technique by simulation and analysis; finally, give a summary of this paper, and put forward the lack of this design and possible improving methods.The main results of this dissertation are: give a detailed analysis and simulation of coded excitation and pulse compression technology. And then build the hardware platform. By the data acquisition and simulation, achieve this technology used in ultrasound imaging system preliminary. And lay a solid foundation for the commercialization of coded excitation and pulse compression technology used in the ultrasound imaging system.