血管内超声成像系统的机械控制装置及数字扫描变换技术的研究

发布时间：2018-04-14 00:12

本文选题：IVUS + 成像系统　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：随着医学影像技术的飞速发展，心血管病变的成像诊断技术不断成熟。其主要的诊断方式为X射线冠状动脉造影和血管内超声(IVUS)。冠状动脉造影只能够检查管腔而血管内超声还能提供粥样斑块的组织信息，便于医生对血管病变做出全面和准确的评价。本文重点研究了IVUS成像系统的机械控制装置和数字扫描变换技术，主要工作如下： (1)设计了血管内超声成像系统的机械控制装置的结构，分析了装置的组成和意义。通过硬件对装置传递的超声回波信号进行噪声评估，并利用FPGA控制装置中的编码器进行旋转位置检测。 (2)重点研究了数字扫描变换技术中动态滤波和坐标转换的原理、设计和实现。首先，利用MATLAB获取滤波器参数，在此基础上，利用分布式算法实现了基于FPGA的FIR带通滤波器。然后，介绍了坐标转换的必要性，重点分析了CORDIC算法和查找表法原理，基于CORDIC算法利用FPGA芯片进行仿真，完成了整个坐标转换的硬件逻辑设计，利用圆插补法进行漏点插补，，实现了从一维回波信号到二维数字圆形扫描图像的成像过程仿真。 (3)介绍了IVUS成像系统的实验平台，搭建了以FPGA为核心的硬件控制系统并进行实验得到实时的血管壁图像数据。实验结果表明：最终采集图像的分辨率为1000×1024、帧频1Hz，图像从输入到输出仅1s的延时，能在保证图像质量的基础上满足系统实时性的要求，验证了设计的可行性和正确性。
[Abstract]:With the rapid development of medical imaging technology, the imaging diagnosis of cardiovascular disease has been matured.The main diagnostic methods were X-ray coronary angiography and intravascular ultrasound.Coronary angiography can only examine the lumen and intravascular ultrasound can provide tissue information of atherosclerotic plaques and facilitate doctors to make a comprehensive and accurate evaluation of vascular lesions.This paper focuses on the mechanical control device and digital scanning conversion technology of IVUS imaging system. The main work is as follows:1) the structure of mechanical control device of intravascular ultrasound imaging system is designed, and the composition and significance of the device are analyzed.The ultrasonic echo signal transmitted by the device is evaluated by hardware, and the rotary position is detected by the encoder in the FPGA control device.The principle, design and implementation of dynamic filtering and coordinate transformation in digital scanning transform technology are studied.Firstly, the filter parameters are obtained by MATLAB, and then the FIR bandpass filter based on FPGA is implemented by distributed algorithm.Then, the necessity of coordinate transformation is introduced, and the principle of CORDIC algorithm and lookup table method is analyzed. Based on CORDIC algorithm, the hardware logic design of coordinate transformation is completed by using FPGA chip, and the interpolation of leak point is carried out by circle interpolation method.The imaging process from one-dimensional echo signal to two-dimensional digital circular scanning image is simulated.The experimental platform of IVUS imaging system is introduced. The hardware control system based on FPGA is built and the real time image data of vascular wall are obtained by experiments.The experimental results show that the resolution of the acquired image is 1000 脳 1024, the frame rate is 1Hz, and the delay of the image from input to output is only 1s, which can meet the real-time requirements of the system on the basis of guaranteeing the image quality, and verifies the feasibility and correctness of the design.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP391.41;R445.1

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