School of Biomedical and Precision Engineering, Faculty of Medicine, University of Bern, Güterstrasse 24/26, CH-3010, Bern, Switzerland.
Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Biomed Eng Online. 2024 Aug 30;23(1):89. doi: 10.1186/s12938-024-01271-7.
To treat stenosed coronary arteries, percutaneous transluminal coronary angioplasty (PTCA) balloon catheters must combine pushability, trackability, crossability, and rewrap behavior. The existing anatomic track model (ASTM F2394) for catheter testing lacks 3D morphology, vessel tortuosity, and compliance, making evaluating performance characteristics difficult. This study aimed to develop a three-dimensional patient-specific phantom (3DPSP) for device testing and safe training for interventional cardiologists.
A range of silicone materials with different shore hardnesses (00-30-45 A) and wall thicknesses (0.5 mm, 1 mm, 2 mm) were tested to determine compliance for creating coronary vessel phantoms. Compliance was assessed using optical coherence tomography (OCT) and compared to values in the literature. Stenosis was induced using multilayer casting and brushing methods, with gypsum added for calcification. The radial tensile properties of the samples were investigated, and the relationship between Young's modulus and compliance was determined. Various methods have been introduced to approximate the friction between silicone and real coronary vessel walls. Computerized tomography (CT) scans were used to obtain patient-specific anatomy from the femoral artery to the coronary arteries. Artery lumens were segmented from the CT scans to create dissolvable 3D-printed core models.
A 15A shore hardness silicone yielded an experimental compliance of 12.3-22.4 for stenosed tubes and 14.7-57.9 for uniform tubes, aligning closely with the literature data (6.28-40.88 ). The Young's modulus ranged from 43.2 to 75.5 kPa and 56.6-67.9 kPa for the uniform and calcified materials, respectively. The dependency of the compliance on the wall thickness, Young's modulus, and inner diameter could be shown. Introducing a lubricant reduced the silicone friction coefficient from 0.52 to 0.13. The 3DPSP was successfully fabricated, and comparative analyses were conducted among eight commercially available catheters.
This study presents a novel method for crafting 3DPSPs with realistic mechanical and frictional properties. The proposed approach enables the creation of comprehensive and anatomically precise setups spanning the right femoral artery to the coronary arteries, highlighting the importance of such realistic environments for advancing medical device development and fostering safe training conditions.
为了治疗狭窄的冠状动脉，经皮腔内冠状动脉血管成形术（PTCA）球囊导管必须结合可推送性、可跟踪性、可穿越性和重新缠绕性能。现有的导管测试解剖轨迹模型（ASTM F2394）缺乏 3D 形态、血管迂曲和顺应性，使得评估性能特征变得困难。本研究旨在开发一种用于设备测试和介入心脏病学家安全培训的三维患者特定体模（3DPSP）。
测试了一系列具有不同邵氏硬度（00-30-45 A）和壁厚（0.5 毫米、1 毫米、2 毫米）的硅酮材料，以确定创建冠状动脉体模的顺应性。使用光学相干断层扫描（OCT）评估顺应性，并与文献中的值进行比较。通过多层铸造和刷涂方法诱导狭窄，加入石膏以模拟钙化。研究了样品的径向拉伸性能，并确定了杨氏模量与顺应性之间的关系。引入了各种方法来近似硅酮与真实冠状动脉壁之间的摩擦。使用计算机断层扫描（CT）扫描从股动脉到冠状动脉获得患者特定的解剖结构。从 CT 扫描中分割出动脉管腔，以创建可溶解的 3D 打印核心模型。
邵氏硬度为 15A 的硅酮产生的狭窄管实验顺应性为 12.3-22.4 ，均匀管的顺应性为 14.7-57.9 ，与文献数据（6.28-40.88 ）非常吻合。杨氏模量范围分别为 43.2-75.5 kPa 和 56.6-67.9 kPa，用于均匀和钙化材料。可以显示出顺应性对壁厚、杨氏模量和内径的依赖性。引入润滑剂可将硅酮摩擦系数从 0.52 降低至 0.13。成功制作了 3DPSP，并对 8 种市售导管进行了比较分析。
本研究提出了一种新颖的方法，用于制作具有真实机械和摩擦特性的 3DPSP。该方法能够创建全面且解剖精确的设置，涵盖从右股动脉到冠状动脉，突出了这种真实环境对于推进医疗器械开发和培养安全培训条件的重要性。
