Fig 1.
Labelled diagram of a generic central aortic waveform.
Fig 2.
Operating schematic of the current EVHP system.
Fig 3.
Mock aorta 2D drawings and 3D isometric view.
Fig 4.
A schematic of the experimental setup used to mimic the left flow loop of the EVHP system.
Fig 5.
Vector field images with a background color map of streamwise velocity component obtained from processing Camera 2 images, (a) at the beginning of systole, (b) during systole, (c) end of diastole phase.
Fig 6.
Plot of central aortic pressure waveforms for rigid (ωAl pump = 1235 RPM) and compliant mock aorta (ωAl pump = 1235 RPM, Pch = 103 mmHg) cases over three normalized pump cycles.
Ps and Pd locations are shown for rigid and compliant cases with the same colour codes.
Fig 7.
Plot of mock aorta pulse pressure tube distension (circles) and afterload tube distension (dashed horizontal line) over one and three normalized pump cycles.
Fig 8.
Plot of centerline velocities (vCL) for rigid (ωAl pump = 1235 RPM) and compliant mock aorta (ωAl pump = 1235 RPM, Pch = 103 mmHg) cases over one normalized pump cycle.
Fig 9.
Normalized plot of central aortic waveform (P/Pmax) and downstream centerline velocity (vCL/vCL,max) for the rigid case with ωAl pump = 1235 RPM.
Fig 10.
(a) Plot of normalized central aortic pressure waveform (P/Pmax), normalized downstream centerline velocity (vCL/vCL,max) and normalized tube distension (ΔD/D × 100) and (b) plot of flow rate and the pressure for the compliant case with Pch = 103 mmHg and ωAl pump = 1235 RPM. Points (a), (b) and (c) on Fig 10(a) are the time stamp of the 3 phases for which the velocity vector fields are plotted in Fig 5(a).
Fig 11.
Plot representing the peak positive downstream centerline velocity, peak negative centerline velocity and peak velocities ratio (peak negative to peak positive) as function of the afterload pump speed for the rigid case.
Fig 12.
Plot representing the peak positive downstream centerline velocity, peak negative centerline velocity and peak velocities ratio (peak negative to peak positive) as function of mock aorta distensibility for the compliant case where Pch = 103 mmHg.
Table 1.
Summary of determined pump energy results.
Fig 13.
Plot representing the impact of mock aorta distensibility (d) on the energy expenditure of the VAD per minute (EVAD) for each tested setting of ωAl pump.