相控阵超声内镜发射及信号采集系统研究

发布时间：2018-11-14 16:41

【摘要】：在现代医学胃肠道检测,尤其是早期胃癌的检测手段中,超声内镜成像技术因自身无损、无电离辐射、无痛的特点,被认为是诊断的最佳方法之一,在临床医学应用中有巨大的价值。目前我国各大医院中使用的内镜产品均来自进口,其昂贵的价格限制了超声内镜检测的普及。为改变进口产品的垄断地位,促进国产医用超声内镜设备的产品化,课题组开展了一系列超声内镜成像技术的研究。本文在课题组环扫超声内镜成像研究的基础之上,设计了以FPGA为控制核心的相控阵超声内镜系统方案,并完成了系统中多通道发射电路的设计和系统回波数据采集控制程序编写,实现了声束偏转扫描成像。以上工作的完成,为进一步开展相控阵成像高分辨率算法研究奠定了基础。本论文的主要工作有:1.制定相控阵超声内镜成像系统方案。以FPGA作为系统控制核心,设计了16路并行发射、1路串行接收的发射采集电路,完成阵列探头的激励及超声回波的接收处理。2.设计了系统中多通道发射电路,包括FPGA及其周边电路、精细延时、相控发射、电源转换、高压产生及监控等模块,实现16通路并行相控发射。发射超声波的激励脉冲幅值在0-200V可调,各个通路间相对延时精度达0.5ns。3.设计并编写了FPGA控制程序,实现各模块逻辑控制、回波数据缓存、USB2.0数据传输等功能,完成了对超声回波数据的采集。4.搭建超声成像实验平台,以水槽中的多根铁丝为目标进行成像实验。使用MATLAB中Field II工具对获得的超声回波数据进行处理并生成B-Mode图像,验证了系统设计的可行性与正确性。
[Abstract]:In modern medical gastrointestinal detection, especially in early gastric cancer, endoscopic ultrasound imaging is considered to be one of the best methods for diagnosis because of its nondestructive, non-ionizing radiation and painless characteristics. It has great value in clinical application. At present, the endoscopic products used in major hospitals in China are imported, which limits the popularity of endoscopic ultrasonography. In order to change the monopoly position of imported products and promote the production of domestic medical ultrasound endoscopy equipment, a series of research on endoscopic ultrasound imaging technology was carried out. In this paper, based on the research of EUS, a phased array EUS system with FPGA as the control core is designed. The design of the multi-channel transmission circuit and the programming of the echo data acquisition control program in the system are completed, and the acoustic beam deflection scanning imaging is realized. The above work lays a foundation for further research on high resolution algorithm of phased array imaging. The main work of this paper is as follows: 1. A phased array ultrasonic endoscopic imaging system was developed. Taking FPGA as the control core of the system, 16 parallel transmitting circuits and one serial receiving transmitter acquisition circuit are designed to complete the excitation of the array probe and the receiving and processing of ultrasonic echo. 2. The multi-channel transmission circuit is designed, including FPGA and its peripheral circuit, fine delay, phase-controlled transmission, power conversion, high-voltage generation and monitoring module. The 16-channel parallel phase-controlled transmission is realized. The amplitude of excitation pulse of ultrasonic wave can be adjusted from 0 to 200 V, and the relative delay precision of each channel is 0.5ns.3. The FPGA control program is designed and written to realize the functions of logic control of each module, echo data cache, USB2.0 data transmission and so on. Finally, the acquisition of ultrasonic echo data is completed. 4. The ultrasonic imaging experiment platform was set up, and the imaging experiment was carried out with multiple wire in the water tank as the target. The Field II tool in MATLAB is used to process the ultrasonic echo data and generate the B-Mode image, which verifies the feasibility and correctness of the system design.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R445.1;TP274.2

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