【作者】 佟成国；

【导师】 史冬岩；

【作者基本信息】 哈尔滨工程大学 ， 机械设计及理论， 2011， 硕士

【摘要】 光学相干层析(OCT)是90年代发展起来的一种新型光学成像手段。基于微型化光纤扫描探头的光学相干层析系统,能与内窥镜、导管或针管有机结合,使得针对人体内腔表面以下或深层组织内部数毫米深度的高分辨在体成像成为可能,因此,开展光学相干层析小型快速扫描探头研制具有重要意义。本文设计了一种新的基于PZT的应用于OCT成像的内窥式二维光纤扫描探头。即利用两片压电陶瓷片和一片薄导电基片驱动光纤构成了光纤二维扫描探头。建立了压电陶瓷扫描探头机电耦合的有限元模型,采用有限元分析方法对压电陶瓷扫描探头进行了模态分析,得到了加载后模型的形变,同时分析了不同尺寸及电压对振动模态的影响。该探头利用光纤悬臂的共振特性,通过对压电陶瓷施加接近于光纤共振频率的混频信号,能同时激发光纤悬臂两正交方向上的振动,实现了光纤悬臂的二维扫描。驱动方法利用了光纤的谐振特性形成行扫描,增加了光纤的行扫描范围,同时场扫描采用了非谐振的方案,因此扫描过程不存在盲点。制作了探头的实际模型,并且利用该探头获得了扫描图像。更多还原

【Abstract】 Optical coherence tomography (OCT) is a new optical imaging technology developed in the 90’s. The optical coherence tomography system based on miniaturized optical fiber scanning probe can integrate with an endoscope, catheter or needle, which allows for high-resolution in vivo imaging with millimeters penetration depth. Therefore, it has important significance to develop a small-sized fast scanning probe for OCT technology.An endoscope 2D fiber scanning probe based on PZT is designed for optical coherence tomography (OCT) imaging. The fiber in the 2D scanning probe is driven by two piezoelectric ceramic and a thin conductive substrate.A finite element model on the electromechanical coupling of the piezoelectric scanning probe is established. By using the finite element analysis software ANSYS11.0, the model analysis on the PZT scanning probe is carried out and the deformation of the model is obtained. The effects of different size and voltage on vibration mode are also analyzed.In consideration with resonance characteristics of the optical fiber probe cantilever, two orthogonal vibrations of the fiber cantilever can be excited by imposing mixing signals with frequency close to optical fiber’s resonant frequency on the piezoelectric ceramic, which accomplishes two-dimensional scanning of the fiber cantilever. The resonance characteristics are used to achieve line scanning in the driving method, which can improve the scanning range. In addition, nonresonant program is employed for filed scanning, which ensure that there is not blind spot during scanning. At last, a fiber probe is fabricated and the scanning images are obtained by using the fiber probe.更多还原