"Development of Digital and Physical Equivalents of Human Arteries"
Development of Digital and Physical Equivalents of Human Arteries
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Worldwide, most deaths are caused by cardiovascular diseases, one tenth of these by strokes, which are caused, for example, by burst cerebral arteries. To prevent this, early detection and surgery is necessary. However, the categorization of dangerousness and possibly accelerated recognition could be promoted by investigating the development. For this, a mathematical description of the behaviour of the vessels is necessary. This work is therefore concerned with determining and describing the behaviour of this tissue, as well as creating digital and physical copies of them. In addition, methods previously used only for isotropic materials were investigated for their applicability to anisotropic materials.
Since these tissues are very soft, a new testing machine has been developed which sensitively measures the low forces and also allows biaxial loading. In this work, the main focus is on the software that controls the testing process and allows a brief analysis of the recorded data, providing an overview of the measurement without the need for external software.
Two different approaches to creating the artificial blood vessels were tested: One produced specimens with randomly distributed fibres in 3D, which were printed from photopolymer in one process step due to the required resolution; the other, which allows almost arbitrarily large test specimens thanks to hybrid fabrication, produced specimens with defined fibre angle in 2.5D.
The first method unfortunately resulted only in visually appealing models, without realistic mechanical properties. In contrast, the hybrid fabrication method produced promising results. In the future, this may help to generate more and increasingly accurate measurement data without the need for human tissue.
In parallel to the experiments, simulations of the artificial replicas were carried out to describe their real behaviour with sufficient accuracy. The results of the biological tests, however, are to be viewed mainly as a learning experience in the handling of these test specimens.