Authors:
N. Williams
;
H. T. Tran
and
M. S. Olufsen
Affiliation:
NC State University, United States
Keyword(s):
Cardiovascular Dynamics Modeling, Head-up Tilt, Pulsatile vs. Non-pulsatile Modeling, Parameter Estimation.
Abstract:
This study compares a pulsatile and a non-pulsatile model for prediction of head-up tilt dynamics for healthy young adults. Many people suffering from dizziness or light-headedness are often exposed to the head-up tilt test to explore potential deficits within the autonomic control system, which is supposed to maintain the cardiovascular system at homeostasis. However, this system is complex and difficult to study in vivo. This study shows how mathematical modeling can be used to extract features of the system that cannot be measured experimentally. More specifically, we show that it is possible to develop a mathematical model that can predict changes in cardiac contractility and vascular resistance, quantities that cannot be measured directly, but which can be useful to assess the state of the system. The cardiovascular system is pulsatile, yet predicting control in response to head-up tilt for the complete system is computationally challenging, and limits the applicability of the m
odel. In this study we show how to develop a simpler non- pulsatile model that can be interchanged with the pulsatile model, which is significantly easier to compute, yet it still is able to predict internal variables. The models are validated using head-up tilt data from healthy young adults.
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