Comparing friction of additively manufactured materials with animal blood vessels

The replication of blood vessels for training and research purposes is possible with the help of additively manufactured (AM) models. However, a meaningful evaluation of the quality of the haptics, here concentrating on friction characteristics, of additively manufactured blood vessel models compared to human vessels is difficult and often only based on subjective assessments. To enable an objective comparison of friction of different AM materials, tests were performed in which a braided stent was pulled through straight test tubes. The force required to do so was measured. The same test setup was used to examine animal blood vessels so that these results could be compared with the findings of the AM materials. In addition, physicians were asked for their assessment of the haptics concerning friction of different materials. Summarizing the results, for the tested Formlabs materials Flexible 80A and Elastic 50A, it can be stated that Flexible 80A is strongly recommended for the replication of blood vessels - even though it is comparatively smooth. The Elastic 50A should only be used for training with increased difficulty since the models are stickier and a flipping of instruments is possible. Coating the materials only involve effort that is not reflected in the benefits.