心導管之設計與臨床性質評估

心導管技術於二十世紀初開始發展，至今已成熟地廣泛應用於多項心血管疾病的介入性診斷以及治療手術中，此外心導管的製造也成為利潤豐厚的業務之一。傳統上，驗證導心管設計方法為製造出許多不同的心導管的原型後，藉由不同的血管網絡模型進行各項機械性質的測量以進行驗證比較。然而，目前對於心導管的測試並沒有標準的測試準則，所以不同的心導管所得出的結果僅在同一測試狀況下擁有相對的比較性質，除此之外亦需耗費相當多的時間與成本。因此本研究透過整理現有不同的實驗方法，並以有限元素分析法建立出一心導管機械性質評量的標準模型，提供更有效評估心導管在傳遞性上的表現。在本研究中所進行的傳遞性測試中，包含追蹤性與傳矩性兩個面向性質的分析，分別探討心導管沿著導線在血管中前進時的容易性以及傳遞力矩的能力。本研究中所建立的模型主要分成三個部分－心導管、導線與血管模型，而主要測試的心導管為RX 系統（Rapid Exchange System）氣球導管的前端部分，比較不同的長度和設計以及摩擦力在傳遞性上的表現。研究的結果中顯示，長度對於追蹤性並沒有顯著的影響，但長度越長其傳矩性的表現越差；在不同的設計上，結構有特別弱的地方會影響追蹤性，且造成力值的明顯變動，因此需盡量避免。此外，摩擦力對於整個模型具有顯著的影響，故心導管的設計中改善心導管與導線間的摩擦力，將可大幅提升心導管的傳遞性。

關鍵字

心導管； RX 系統；傳遞性；追蹤性；傳矩性；有限元素分析法

並列摘要

Cardiac catheterization technology was first developed in the early twentieth century, it has been widely used in interventional diagnosis and treatment of cardiovascular diseases. In the recent years, catheter manufacturing has become one of the more lucrative business in the manufacturing industry. Traditionally, verification of different catheter designs was done by manufacturing a number of different prototypes, and then testing them with different network of blood vessel models to compare various mechanical properties between these designs. However, there is currently no standardized testing guidelines for catheters, resulting in different designs cannot be compared unless done under the same testing conditions. In addition, considerable time and cost are spent in the testing process. Therefore, in this study, integrated procedures from existing experimental methods were arranged, and a standard model based on the finite element analysis for evaluating mechanical properties of catheter designs was established, in order provide a more effective valuation method for deliverability performance of cardiac catheters. The deliverability test in this study includes trackability test and torqueability test, which represent the ease of a catheter advancing along a guidewire in a blood vessel and the ability of torque transmission of a catheter respectively. In this study, the standard model is divided into three parts – a cardiac catheter, a guidewire, and a vascular model. The main test body of the catheter is focused on the distal part of a rapid exchange system balloon catheter. The effect of lengths, designs, and frictions on deliverability performance of catheter design was also analyzed in this research. From the results of this study, there is no significant impact between different lengths on trackability, but it is shown that longer length may cause worse performance on torqueability. When considering different designs, areas that are structurally weak will affect the performance of trackability, leading to clear changes on track forces, and therefore needs to be avoided. Furthermore, friction is found to have significant influence on the entire model, so design with improved friction between the catheter and the guidewire would greatly improve the deliverability performance of cardiac catheter.