血管內超音波探頭製程研究

Abstract

血管內超音波系統(Intravascular Ultrasound)因能對血管內腔組織深層進行成像、提供血管硬化病灶長度資訊、且在即時成像等優勢，在臨床應用中有助於正確地評估病情。血管內超音波系統需透過高速旋轉超音波探頭與線性移動機構來實現血管影像，因此需要搭配超音波探頭微小化、旋轉與線性馬達、以及電路旋轉連接器等元件。本論文提出微小化超音波探頭的製程，並嘗試透過結合自製的旋轉移動機構來完成血管內超音波影像系統之原型。本研究使用聚偏二氟乙烯、鈮酸鋰、鈮鎂酸鉛-鈦酸鉛作為壓電材料，並將其固定於軟性電路板載板上。所製作出來的超音波探頭原型尺寸為0.5mm2。在自發自收量測以及頻譜分析中，三種材料的探頭其中心頻率分別落在50、45、34MHz、而相對應的頻寬分別為25、15、17MHz頻寬。最後我們整合超音波探頭、超音波系統與自製之旋轉移動機構，並實際對鎢線仿體進行成像。

Intravascular ultrasound (IVUS) system, which can provide real-time information of vascular tissue, vascular sclerosis and lesion length, is a reliable image modality in clinical assessment. Generally, IVUS consists of a specified ultrasound transducer, rotational/linear motion motors, and the corresponding connector. We proposed a prototype of IVUS system which integrated a specified transducer fabrication for IVUS and a motor drive unit. Three materials, 1) Polyvinylidene Difluoride, 2) Lithium Niobate, and 3) Lead magnesium niobate-lead titanate, were used to fabricate the transducers. The size of the transducers are less than 0.5 mm2, and each transducer were mounted on a flexible printed circuit, and the final size of transducer. The central frequencies/bandwidths of our transducer are 50(25), 45(15), and 34(17)MHz respectively. Finally, the image of tungsten wire was successfully obtained by the prototype of our IVUS system.