Fig 1.
Schematic of the MCL setup with biventricular support.
LA, left atrium; MV, mitral valve; LV, left ventricle; AoV, aortic valve; AoC, aortic compliance chamber; SQ, systemic flow meter; SVR, systemic vascular resistance valve; SVC, systemic venous compliance chamber; RA, right atrium; TV, tricuspid valve; RV, right ventricle; PV, pulmonary valve; PAC, pulmonary arterial compliance chamber; PQ, pulmonary flow meter; PVR, pulmonary vascular resistance valve; PVC, pulmonary venous compliance chamber; LVAD, left ventricular assist device; LVADQ, left ventricular assist device flowmeter; RVAD, right ventricular assist device; RVADQ, right ventricular assist device flowmeter; Ppa, pulmonary arterial pressure sensor; Prv, right ventricular pressure sensor.
Fig 2.
Synchronisation of the (A) pump speed profile with ECG signal, represented by (B) the rectangular pulse in the MCL. ωmax, high pump speed; ωmin, low pump speed; ωmean, the average speed over one cycle; T, wave period; t/T, pulse width; Apulse, pulse amplitude; rpm, rotation per minute.
Table 1.
Variation of pulsing parameters, speed waveforms, phase shift, ventricular contractility and pulmonary arterial compliance.
Fig 3.
The changes in RVAD flow, right ventricular pressure and pulmonary arterial pressure with different pump speed configurations for co- and counter-pulsation modes.
CS: constant speed; C1: Apulse = 13500 rpm and ωmin = 2000 rpm; C2: Apulse = 10000 rpm and ωmin = 3000 rpm; C3: Apulse = 6700 rpm and ωmin = 4000 rpm; RVAD: right ventricular assist device; PRV, right ventricular pressure; Ppa, Pulmonary arterial pressure; black arrow: the beginning of systole.
Table 2.
Effect of varying pump speed configurations on the hemodynamics.
Fig 4.
The PV loops produced through speed modulation with co- and counter-pulsation.
CS: constant speed; C1: Apulse = 13500 rpm and ωmin = 2000 rpm; C2: Apulse = 10000 rpm and ωmin = 3000 rpm; C3: Apulse = 6700 rpm and ωmin = 4000 rpm; PRV, right ventricular pressure; VRV, right ventricular volume.
Fig 5.
Right ventricular PV loops for the mild and severe right heart failure (MRHF and SRHF) scenarios as well as at different pulmonary arterial compliance (PAC) levels.
MRHF, mild right heart failure (ESPVR slope = 0.23 mmHg/mL); SRHF, severe right heart failure (ESPVR slope = 0.1 mmHg/mL); PRV, right ventricular pressure; VRV, right ventricular volume; PAC, pulmonary arterial compliance.
Table 3.
Effect of varying right ventricular contractility on the hemodynamics during speed modulation using pulsing profile C2.
Table 4.
Effect of varying pulmonary arterial compliance on the hemodynamics during speed modulation using pulsing profile C2.