【摘要】：隨著人類(lèi)社會(huì)進(jìn)步和醫(yī)療技術(shù)的發(fā)展,醫(yī)學(xué)超聲內(nèi)窺診斷技術(shù)成為人類(lèi)戰(zhàn)勝疾病的利器。醫(yī)學(xué)超聲診斷技術(shù)具有可重復(fù)檢查、無(wú)損、無(wú)痛和無(wú)離子輻射等優(yōu)點(diǎn),因而被廣泛應(yīng)用于臨床醫(yī)學(xué)領(lǐng)域。超聲內(nèi)窺彩色血流成像系統(tǒng)經(jīng)食管導(dǎo)入探頭,對(duì)各臟器內(nèi)流動(dòng)的血液進(jìn)行檢測(cè),得到血流速度、方向等血流動(dòng)力學(xué)參數(shù)信息,在臨床上可用于對(duì)食管和胃底靜脈曲張進(jìn)行檢測(cè),也可輔助血管疾病診斷。 醫(yī)學(xué)超聲內(nèi)窺彩色血流成像系統(tǒng)在超聲內(nèi)窺鏡的基礎(chǔ)上,結(jié)合B型超聲成像和多普勒血流成像,利用多普勒效應(yīng)對(duì)血流中散射子的運(yùn)動(dòng)敏感性對(duì)疾病進(jìn)行診斷。本文在課題組超聲脈沖多普勒系統(tǒng)研究的基礎(chǔ)上,針對(duì)超聲內(nèi)窺彩色血流成像提出了全數(shù)字化的信號(hào)處理與解決方案,設(shè)計(jì)了模擬前端電路和數(shù)字信號(hào)處理電路板,對(duì)超聲換能器接收的回波信號(hào)進(jìn)行處理,利用現(xiàn)場(chǎng)可編程門(mén)陣列(Field Programmable Gate Array, FPGA)進(jìn)行系統(tǒng)時(shí)序控制和信號(hào)處理,搭建基于多普勒效應(yīng)的物理模型實(shí)驗(yàn)裝置,進(jìn)行系統(tǒng)聯(lián)調(diào)實(shí)驗(yàn),通過(guò)系統(tǒng)仿真和模擬血流速度檢測(cè)實(shí)驗(yàn),驗(yàn)證了本系統(tǒng)設(shè)計(jì)的正確性和有效性。 本論文主要的工作包括: (1)確定超聲內(nèi)窺彩色血流成像系統(tǒng)方案。通過(guò)對(duì)超聲彩色血流成像原理以及多普勒信號(hào)特點(diǎn)的詳細(xì)分析,確定基于FPGA的數(shù)字化超聲多普勒回波信號(hào)處理方案,使用正交解調(diào)從載波中解調(diào)出基帶信息,設(shè)計(jì)壁濾波器抑制血管壁信號(hào)的影響,利用自相關(guān)算法估算血流動(dòng)力學(xué)參數(shù)。利用超聲成像仿真軟件Field II進(jìn)行系統(tǒng)旋轉(zhuǎn)掃描成像仿真。 (2)調(diào)試前端模擬電路、設(shè)計(jì)系統(tǒng)數(shù)字電路,獲取超聲多普勒回波信號(hào)。設(shè)計(jì)前置放大電路和抗混疊濾波電路,完成以FPGA為核心的6層數(shù)字電路的PCB設(shè)計(jì)與電路調(diào)試。 (3)完成基于FPGA的系統(tǒng)程序設(shè)計(jì)。在Quartus II軟件環(huán)境下,使用Verilog HDL語(yǔ)言編寫(xiě)程序,實(shí)現(xiàn)FPGA對(duì)系統(tǒng)的時(shí)序控制,并在FPGA中實(shí)現(xiàn)相應(yīng)算法和信號(hào)處理方法,利用FPGA中的IP核和宏功能模塊實(shí)現(xiàn)解調(diào)、濾波、自相關(guān)運(yùn)算等功能。 (4)搭建了由蠕動(dòng)泵、模擬血管、模擬血液等組成的超聲多普勒實(shí)驗(yàn)系統(tǒng),通過(guò)對(duì)多普勒血流模型進(jìn)行實(shí)驗(yàn),驗(yàn)證了系統(tǒng)的正確性和有效性。
[Abstract]:With the progress of human society and the development of medical technology, medical ultrasound endoscope diagnosis technology has become a sharp weapon for human to overcome diseases. Medical ultrasonic diagnostic technology is widely used in clinical medicine because of its advantages of repeatability, nondestructive, painless and ion free radiation. Ultrasound endoscope color blood flow imaging system was introduced into the esophagus to detect the blood flow in various viscera. The hemodynamic parameters such as velocity and direction of blood flow were obtained, which could be used to detect esophageal and gastric varices in clinic. It can also assist in the diagnosis of vascular diseases. The color flow imaging system based on ultrasound endoscope combined with B-mode ultrasound imaging and Doppler flow imaging was used to diagnose the disease by using Doppler effect on the motion sensitivity of scatterers in blood flow. Based on the research of ultrasonic pulse Doppler system, this paper presents a digital signal processing and solution scheme for ultrasonic endoscope color flow imaging, and designs analogue front-end circuit and digital signal processing circuit board. The echo signal received by ultrasonic transducer is processed, the timing control and signal processing are carried out by using field programmable gate array (Field Programmable Gate Array, FPGA), and a physical model experimental device based on Doppler effect is built. The validity and validity of the system design are verified by system simulation and simulated blood flow velocity test. The main work of this thesis is as follows: (1) to determine the scheme of color flow imaging system. By analyzing the principle of ultrasonic color flow imaging and the characteristics of Doppler signal in detail, the digital ultrasonic Doppler echo signal processing scheme based on FPGA is determined, and the baseband information is demodulated from carrier by quadrature demodulation. A wall filter was designed to suppress the influence of vascular wall signal, and the hemodynamic parameters were estimated by autocorrelation algorithm. The system rotation scan imaging is simulated by ultrasonic imaging simulation software Field II. (2) debug the front end analog circuit, design the digital circuit of the system and obtain the ultrasonic Doppler echo signal. The preamplifier circuit and anti-aliasing filter circuit are designed. The PCB design and circuit debugging of the six-layer digital circuit with FPGA as the core are completed. (3) complete the system program design based on FPGA. In the environment of Quartus II software, programming with Verilog HDL language is used to realize the timing control of FPGA to the system, and the corresponding algorithm and signal processing method are realized in FPGA, and the IP core and macro function module in FPGA are used to realize demodulation and filtering. Autocorrelation operation and other functions. (4) an ultrasonic Doppler experimental system consisting of peristaltic pump, simulated blood vessel and simulated blood was built. The validity and validity of the system were verified by the experiment of Doppler blood flow model.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類(lèi)號(hào)】：R310;O426.9

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本文編號(hào)：2327398