Table 5.
Summary of the macroscopic mechanisms considered, the adopted cardiovascular changes with respect to the 1G supine condition and details of the corresponding modeling implementation.
| Cardiovascular processes | Adopted changes | Modeling implementation |
|---|---|---|
| Blood volume shift | Legs volume: −235 ml | Total volumes V of the zones within each region were varied proportionally to the 1G supine condition. Unstressed volumes V0 were varied to preserve V0/V as in 1G supine condition |
| Lower abdomen volume: −234 ml | ||
| Head-arms volume: +133 ml | ||
| Cardiac-thoracic volume: +202 ml | ||
| Upper abdomen volume: +134 ml | ||
| Blood volume reduction | −11.5% | Within each region, total volumes V were reduced proportionally to the configuration after blood shift. Unstressed volumes V0 were set to preserve V0/V as in the configuration after blood shift |
| Cardiac function | Amplitude of ventricular elastances: −27% | Cardiac volume reduction was implemented by reducing unstressed volumes V0 of all cardiac chambers by 90% |
| Min ventricular elastances: +3% | ||
| Pulmonary artery compliance: +4% | ||
| Pulmonary vein compliance: +5% | ||
| Cardiac volume: −10% | ||
| Legs venous compliance | +27% | Model parameters are changed of the same percentage |
| Arterial resistances | Vertebral and carotid arteries: +10% | Model parameters are changed of the same percentage |
| Lower body: −10% | ||
| Baroreflex response | Baseline HR: +13% | Model parameters are changed of the same percentage |
| Baseline average aortic-carotid | ||
| sinus pressure: −10% |