In vitro structured tree model of the peripheral vascular network

article in a collection out of WoS and Scopus

en

The peripheral arterial system consists of small arteries and arterioles, further branching into capillaries. This complex system could be faithfully represented by an asymmetrically structured tree. Such an approach has been used solely in computational analyses, for instance, 1D fluid-structure interaction simulations or multiscale modelling (3D/1D). In vitro flow phantom studies incorporate only pure resistance or two-element Windkessel to mimic the periphery. Thus, the flow and pressure waveforms in these in vitro studies do not qualitatively correspond to those measured in vivo and consequently nor do the input impedance of the periphery, which is rarely shown. To consider the frequency-dependent input impedance of the tree close to that observed in vivo, we created an experimental circuit. It comprises a peristaltic pump as a source of a physiological waveform, an asymmetric structured tree model constructed from commonly available silicon tubes, and a measurement technique for obtaining the input impedance. A good agreement between mathematical and experimental data was found despite some inaccuracies and imperfections in the assembled tree. Therefore, the mathematical model can serve as a design tool for individual in vitro structured tree models representing different peripheral sites. Consequently, the in vitro model could be included in phantom studies as a more realistic boundary condition.

The peripheral arterial system consists of small arteries and arterioles, further branching into capillaries. This complex system could be faithfully represented by an asymmetrically structured tree. Such an approach has been used solely in computational analyses, for instance, 1D fluid-structure interaction simulations or multiscale modelling (3D/1D). In vitro flow phantom studies incorporate only pure resistance or two-element Windkessel to mimic the periphery. Thus, the flow and pressure waveforms in these in vitro studies do not qualitatively correspond to those measured in vivo and consequently nor do the input impedance of the periphery, which is rarely shown. To consider the frequency-dependent input impedance of the tree close to that observed in vivo, we created an experimental circuit. It comprises a peristaltic pump as a source of a physiological waveform, an asymmetric structured tree model constructed from commonly available silicon tubes, and a measurement technique for obtaining the input impedance. A good agreement between mathematical and experimental data was found despite some inaccuracies and imperfections in the assembled tree. Therefore, the mathematical model can serve as a design tool for individual in vitro structured tree models representing different peripheral sites. Consequently, the in vitro model could be included in phantom studies as a more realistic boundary condition.

mathematical model; experimental circuit; structured tree model; peripheral vascular network

08.11.2021

University of West Bohemia

Plzeň

978-80-261-1059-0

PROCEEDINGS OF COMPUTATIONAL MECHANICS 2021

118–121

4