In silico study of the posture-dependent cardiovascular performance during parabolic flights

Arterial wave dynamics preservation upon orthostatic stress: a modelling perspective

“…We describe here the key elements of the CVS model adopted in the present study. Further details, equations, model settings and WA/WIA metrics derivation are given in the electronic supplementary material and in our previous works [26][27][28]33].…”

“…Conversely, the first FCW peak is markedly reduced Table 1. Main haemodynamic parameters variation upon passive head-up tilt from 0 to 90 head-up (refer to Fois et al [26,27]). cMAP and bMAP denote central (aortic) and brachial mean arterial pressure respectively, CVP is central venous pressure, HR is heart rate, SV and CO are stroke volume and cardiac output, respectively, V cp and V lb indicate cardiopulmonary and lower body blood volume, TPR is total peripheral resistance, E ch are cardiac chambers elastances, V v and C v denote venous/venula volume and compliance, whereas R c and C c are cerebral arteriolar resistances and compliance.…”

“…The CVS model accounts for the action of specific extravascular pressures onto given vascular districts: the intramyocardial pressure (IMP [28], figure 1c), the intrathoracic pressure (ITP [27], figure 1e, electronic supplementary material, equation (S8)) and the intracranial pressure (ICP [26], figure 1d). ITP and ICP depend on the body posture [26,27]. royalsocietypublishing.org/journal/rsos R. Soc.…”

“…Modelling tools have never been employed so far to dig into this topic, although multi-scale modelling of blood motion and pulse wave dynamics through large vessels are gathering increasing popularity in the fluid dynamics community [23][24][25] due to their high versatility and usefulness. In our analysis, we adopted a multi-scale and closed-loop model of the entire human circulation developed and validated under different working conditions [26][27][28]. The model is composed of a one-dimensional distributed network of the arterial tree, connected to a zerodimensional lumped parametrization of the peripheral microcirculation, venous return and cardiopulmonary circulation.…”

Linking cerebral hemodynamics and ocular microgravity-induced alterations through an in silico-in vivo head-down tilt framework

“…Figure 5 illustrates in detail only the upper portion of the body (lower body not included for brevity), where the external carotid arteries blood flow goes into the extra-cerebral head circulation, further subdivided into an arterial, a capillary, a venular, and a venous compartment. The blood flow coming from the internal carotids and vertebral arteries is now connected to the novel ocular-cerebrovascular circulation (this is the main modification with respect to the previous version of the model [72]). This novel cerebrovascular circulation combines the lumped-parameter model of the human eye proposed by Nelson et al 2017 [45] and Petersen et al 2022 [28] with the the lumped-parameter model of the cerebral circulation developed by Ursino and Giannessi 2010 [47].…”