Purpose

Fabrication of a suitable flow model or phantom is critical to the study of biomedical fluid dynamics using optical flow visualization and measurement methods. The main difficulties arise from the optical properties of the model material, accuracy of the geometry and ease of fabrication.

Methods

Conventionally an investment casting method has been used, but recently advancements in additive manufacturing techniques such as 3D printing have allowed the flow model to be printed directly with minimal post-processing steps. This study presents results of an investigation into the feasibility of fabrication of such models suitable for particle image velocimetry (PIV) using a common 3D printing Stereolithography process and photopolymer resin.

Results

An idealised geometry of a cerebral aneurysm was printed to demonstrate its applicability for PIV experimentation. The material was shown to have a refractive index of 1.51, which can be refractive matched with a mixture of de-ionised water with ammonium thiocyanate (NH₄SCN). The images were of a quality that after applying common PIV pre-processing techniques and a PIV cross-correlation algorithm, the results produced were consistent within the aneurysm when compared to previous studies.

Conclusions

This study presents an alternative low-cost option for 3D printing of a flow phantom suitable for flow visualization simulations. The use of 3D printed flow phantoms reduces the complexity, time and effort required compared to conventional investment casting methods by removing the necessity of a multi-part process required with investment casting techniques.

中文翻译：

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评估用于脑动脉瘤的PIV测量的台式3D打印的刚性折射率匹配流动体模。

目的

合适的流动模型或模型的制造对于使用光学流动可视化和测量方法研究生物医学流体动力学至关重要。主要困难来自模型材料的光学特性，几何形状的准确性和易于制造。

方法

常规上，已经使用熔模铸造方法，但是近来诸如3D打印之类的增材制造技术的进步已允许以最少的后处理步骤直接打印流模型。这项研究提出了使用常见的3D打印立体光刻工艺和光敏聚合物树脂制造适用于颗粒图像测速（PIV）的模型的可行性的调查结果。

结果

印刷了理想的脑动脉瘤几何形状，以证明其可用于PIV实验。该材料的折射率为1.51，可以与去离子水和硫氰酸铵（NH ₄ SCN）的混合物折射率匹配。这些图像具有以下品质：在应用常见的PIV预处理技术和PIV互相关算法之后，与以前的研究相比，所产生的结果在动脉瘤内是一致的。

结论

这项研究提出了一种适用于流可视化仿真的流模型的3D打印替代低成本方案。与传统的熔模铸造方法相比，使用3D打印的流动模型降低了复杂性，时间和精力，从而消除了熔模铸造技术所需的多部分工艺。