Understanding how blood interacts with deformable tissue

Modeling fluid-structure interactions (FSIs) — namely, with blood as the fluid — is key for cardiovascular bioengineering. However, current methods are limited in their ability to efficiently couple pulsatile fluid with highly deformable tissues. To address this limitation, Monteleone et al. developed a method for simulating FSIs that overcomes previous computational bottlenecks and proposed a new experimental technique for benchmarking computations.

The researchers’ approach focuses on treating both the blood and its surrounding tissue as particles that, in the solid domain, are connected to their neighbors via springs. This spring-like link allows the overall structure to evolve in a physically realistic way, including stretching, bending, and deforming. Because the fluid and the structure are treated alike, this method avoids the fixed grids that are typically needed for such simulations, which become complicated when fluid boundaries move and distort the structure.

“In many cases, FSI codes are ‘validated’ by comparing their results with those of other numerical codes on benchmark cases that are physically difficult to implement experimentally,” said author Gaetano Burriesci.

In contrast, the group’s experimental validation relies on imaging pulsed fluid flow through a deformable curved chamber, a straightforward test that can provide a practical reference point for cardiovascular computations.

Using this technique, they confirmed their FSI simulation’s accuracy in predicting blood velocity fields and overall structural deformations.

The group plans to extend the method to investigate the effects of blood clots and uncover the limits of current bioprosthetic valves.

“Our experimentally validated FSI approach could be applied to several cardiovascular problems characterized by complex, patient-specific geometries and large structural deformations,” said Burriesci. “Ultimately, this type of modeling could contribute to a better understanding of cardiovascular pathologies and support the development of improved treatment strategies.”

Source: “An advanced immersed fluid-structure interaction particle method for cardiovascular applications experimentally validated versus a new benchmark case,” by Alessandra Monteleone, Sofia Di Leonardo, Marco Correnti, Enrico Napoli, Giorgio Micale, and Gaetano Burriesci, Physics of Fluids (2026). The article can be accessed at https://doi.org/10.1063/5.0315544 .