22 research outputs found
Relative root square mean error (rRMSE) between predicted and measured pressures at the proximal and distal tears, for each scenario.
<p><i>TL</i>, True lumen; <i>FL</i>, False lumen</p><p>Relative root square mean error (rRMSE) between predicted and measured pressures at the proximal and distal tears, for each scenario.</p
Changes in intraluminal pressures with changes in Young’s modulus.
<p>Variations in predicted intraluminal true (TL) and false lumen (FL) pressures, close to the proximal tear, with changes in Young’s modulus, for scenarios <i>S<sub>4,4</sub></i> and <i>S<sub>10,10</sub></i>. The value of <i>E = E<sup>ref</sup></i> corresponds to the reference Young’s modulus of the lumen wall, resulting from the calibration of the computational model to the experimental one. Intraluminal pressures did not show substantial differences when the Young’s modulus was increased more than 1e2 <i>E</i>.</p
Changes in flow waveforms across the tears with changes in Young’s modulus.
<p>Variations in predicted flow waveforms across the proximal and distal tears with changes in Young’s modulus, for scenarios <i>S<sub>4,4</sub></i> and <i>S<sub>10,10</sub></i>. Positive flow rate corresponds to flow from the true lumen towards the false lumen. The value of <i>E = E<sup>ref</sup></i> corresponds to the reference Young’s modulus of the lumen wall, resulting from the calibration of the computational model to the experimental one. Flow waveforms did not show substantial differences when the Young’s modulus was increased more than 1e2 <i>E</i>.</p
Proposed experimental representation of a clinical aortic dissection and its equivalent lumped-parameter model.
<p>(a) Clinical appearance of a descending aortic dissection in the longitudinal plane. Transversal plane showing the distinction between TL and FL (Bottom right) (b-c) Proposed anatomic representation of a descending aortic dissection. Longitudinal diagram of the experimental model (b) and cross-sectional plane of the dissected segment (c). (d) Schema of the lumped-parameter model. The dissected region was modelled as two parallel compartments communicated by resistances (rigid tears). Dashed lines enclose the different compartments of the model: Proximal tear (PT), false lumen (FL), true lumen (TL), distal tear (DT) and peripheral (PH) bed.</p
Changes in flow direction across the tears with changes in Young’s modulus.
<p>Index of direction (ID) computed for different values of Young’s modulus for scenarios <i>S<sub>4,4</sub></i> and <i>S<sub>10,10</sub></i>. The ID quantifies the change of direction between the flows across the proximal and distal tears, so that high ID values mean proximal and distal flows simultaneously moving from the true lumen to the false lumen or vice versa. The value of <i>E = E<sup>ref</sup></i> corresponds to the reference Young’s modulus of the lumen wall, resulting from the calibration of the computational model to the experimental one.</p
Intraluminal pressure indexes with changes in Young’s modulus.
<p>Values of predicted true (TL) and false lumen (FL) systolic pressure (SP), diastolic pressure (DP) and pulse pressure (PP), computed for different values of Young’s modulus for scenarios <i>S<sub>4,4</sub></i> and <i>S<sub>10,10</sub></i>. The value of <i>E = E<sup>ref</sup></i> corresponds to the reference Young’s modulus of the lumen wall, resulting from the calibration of the computational model to the experimental one.</p
Estimated parameters’ values of the lumped-parameter model.
<p><i>PT</i>: proximal tear; <i>DT</i>: distal tear; <i>TL</i>: true lumen; <i>FL</i>: false lumen; <i>PH</i>: peripheral</p><p>Estimated parameters’ values of the lumped-parameter model.</p
Experimental versus predicted intraluminal pressures and velocities across the tears.
<p>Comparison at the proximal and distal sites of the model, for scenarios <i>S<sub>4,4</sub></i> and <i>S<sub>10,10</sub></i>. Doppler positive velocities are directed from the TL to the FL and negative velocities the other way around.</p
Pressure gradients across the tears with changes in Young’s modulus.
<p>Variations in predicted false lumen systolic (FPI<sub>systolic</sub>%) and diastolic pressure (FPI<sub>diastolic</sub>%) indexes with changes in Young’s modulus, at the proximal and distal tears for scenarios <i>S<sub>4,4</sub></i> and <i>S<sub>10,10</sub></i>. The value of <i>E = E<sup>ref</sup></i> corresponds to the reference Young’s modulus of the lumen wall, resulting from the calibration of the computational model to the experimental one.</p
Effect of incidence of visceral arteries arising from the FL on intraluminal flows.
<p>Changes in flow patterns with changes in the percentage of abdominal side branches connected to the false lumen (FL). Antegrade flows are positive and retrograde flows are negative. TL, True lumen.</p