Towards a Fast Dynamic Model of the Human Circulatory System
NAVAL RESEARCH LAB WASHINGTON DC
Pagination or Media Count:
We describe a model for blood transport in the human circulatory system that is based on a set of equations for an unsteady elastic pipe-flow circuit. The Navier-Stokes equations are collapsed from three spatial dimensions and time to one spatial dimension and time by assuming axisymmetric vessel geometry and a parabolic velocity profile across the cylindrical vessels. Contractions of a beating heart that drive the fluid are modeled as prescribed area changes of the elastic vessels. When the effects of fluid acceleration are also included in the model equations, peak pressure increases and additional oscillations are introduced in local pressure and velocity. The model response to variations in the physical parameters and actuation are consistent with the human physiological response. Increasing the rigidity of the vasculature is found to increase peak arterial pressures on the order of 10, and including a distributed vascular contraction to model distributed skeletal muscle contractions monotonically increases time-averaged blood flow in the veins. The computational model simulates the circulatory system on the order of one hundred times faster than real-time that is, we compute thousands of heartbeats per minute, and time-resolved distributions of pressure, velocity, and area compare well with reference data.
- Anatomy and Physiology
- Medicine and Medical Research