This paper presents a novel mock circulation for the evaluation of ventricular assist devices (VADs), which is based on hardware-in-the-loop concept. A numerical model human blood runs in real time and computes instantaneous pressure, volume, flow rate values. The VAD to be tested connected numerical-hydraulic interface, allows interaction between circulation. interface consists two pressure-controlled reservoirs, apply computed pressure values from VAD, probe feed resulting back model....

Evidence has been gathered that biomechanical factors have a significant impact on cell differentiation and behavior in vitro cultures. The aim of this bioreactor is to create physiological environment which tissue engineered (TE) aortic valves seeded with human cells can be cultivated during period several days. consists 2 major parts: the left ventricle (LV) afterload consisting compliance, representing elastic function large arteries, series resistance, mimicking arterioles capillaries....

Abstract The current article presents a novel physiological control algorithm for ventricular assist devices ( VAD s), which is inspired by the preload recruitable stroke work. This controller adapts hydraulic power output of to end‐diastolic volume left ventricle. We tested this on hybrid mock circulation where LVV ) known, i.e., problem measuring not addressed in article. Experiments were conducted compare response with and pathological circulation, without support. A sensitivity analysis...

Rotary blood pumps (RBPs) running at a constant speed are routinely used for the mechanical support of heart in various clinical applications, from short-term use heart-lung machines to long-term failing heart. Their operating range is delineated by suction and regurgitation events, leaving limited control on cardiac workload. This study investigates whether different ratios systolic/diastolic advantageous over constant-speed operation. In order effectively load heart, this aimed developing...

A lumped parameter model of the cardiovascular system has been developed and optimized using experimental data obtained from 13 healthy subjects during graded head-up tilt (HUT) supine position to . The includes descriptions left right heart, direct ventricular interaction through septum pericardium, systemic pulmonary circulations, nonlinear pressure volume relationship lower body compartment, arterial cardiopulmonary baroreceptors, as well autoregulatory mechanisms. number important...

The time-varying elastance theory of Suga et al. is widely used to simulate left ventricular function in mathematical models and contemporary vitro models. We investigated the validity this presence a assist device. Left pressure volume data are presented that demonstrate heart-device interaction for positive-displacement pump (Novacor) rotary blood (Medos). Novacor was implanted calf fixed-rate mode (85 BPM), whereas Medos at several flow levels (0–3 l/min) seven healthy sheep. display high...

Pulsatile operation of rotary blood pumps (RBPs) has received interest due to potential concern with nonphysiological hemodynamics. This study aimed gain insight the effects various RBP modes on heart-device interaction. A Deltastream diagonal pump (Medos Medizintechnik GmbH) was inserted in a cardiovascular simulator apical-to-ascending aorta cannulation. The run continuous mode incrementally increasing rotating speed (0–5000 rpm). repeated for three heart rates (50-100-150 bpm) and levels...

Lumped parameter models have been employed for decades to simulate important hemodynamic couplings between a left ventricular assist device (LVAD) and the native circulation. However, these studies seldom consider pathological descending limb of Frank-Starling response overloaded ventricle. This study introduces dilated heart failure model featuring unimodal end systolic pressure-volume relationship (ESPVR) address this critical shortcoming. The resulting mechanical circulatory support are...

Due to the increased appeal of rotary blood pumps for long-term cardiac assist, we conducted a study their capacity unload left ventricle (LV). We used validated mathematical model cardiovascular system and implemented pump characteristics an investigational microdiagonal (Medos). The influence on systemic hemodynamics, LV energetic parameters, wall stress was evaluated in continuous synchronous pulsatile modes operation. For mode simulations, heart rate, contractility, speed assessed...

The clinical importance of pulsatility is a recurring topic debate in mechanical circulatory support. Lack has been identified as possible factor responsible for adverse events and also demonstrated role myocardial perfusion cardiac recovery. A commonly used method restoring with rotodynamic blood pumps (RBPs) to modulate the speed profile, synchronized cycle. This introduces additional parameters that influence (un)loading heart, including timing (phase shift) between native cycle pump...

The PediaFlow pediatric ventricular assist device is a miniature magnetically levitated mixed flow pump under development for circulatory support of newborns and infants (3-15 kg) with targeted range 0.3-1.5 L/min. first generation design the (PF1) was manufactured weight approximately 100 g, priming volume less than 2 mL, length 51 mm, outer diameter 28 5-mm blood ports. PF1 evaluated in an vitro loop 6 h implanted ovines three chronic experiments 6, 17, 10 days. In test, normalized index...

Abstract The characteristic depressed hemodynamic state and gradually declining circulatory function in Fontan patients necessitates alternative postoperative management strategies incorporating a system level approach. In this study, the single‐ventricle circulation is modeled by constructing practical vitro bench‐top pulsatile pediatric flow loop which demonstrates ability to simulate wide range of clinical scenarios. aim study illustrate utility novel mechanical cardiac assist aid...

The current paper presents a methodology for the derivation of optimal operating strategies turbo dynamic ventricular assist devices (tVADs). In clinical practice, tVADs are typically operated at constant rotational speed, resulting in blood flow with low pulsatility. Recent research field has aimed optimizing interaction between tVAD and cardiovascular system by using predefined periodic speed profiles. paper, we avoid limitation profiles formulating an optimal-control problem based on...

Ventricular assist devices (VADs) are blood pumps that offer an option to support the circulation of patients with severe heart failure. Since a failing has remaining pump function, its interaction VAD influences hemodynamics. Ideally, heart's action is taken into account for actuating device such synchronized natural cardiac cycle. To realize this in practice, reliable real-time algorithm automatic synchronization rate required. This paper defines tasks needs fulfill: detection irregular...

Abstract In this study, the effect of time derivatives flow rate and rotational speed was investigated on mathematical modeling a rotary blood pump (RBP). The basic model estimates pressure head as dependent variable using measured predictive variables. Performance evaluated by adding derivative terms for speed. First, to create realistic working condition, Levitronix CentriMag RBP implanted in sheep. All parameters from were physically digitally acquired over wide range conditions,...

There is no established technique for managing large thrombus burden (LTB) in patients with acute coronary syndrome (ACS).The aim of this study was to assess the safety and efficacy NeVa (Vesalio) mechanical thrombectomy device (MTD) ACS LTB.Consecutive LTB were treated MTD as primary vessel recanalisation removal modality, followed by conventional intervention. We further developed a bench model applied subset patients, vacuum-assisted aspiration technique, exploiting 6 Fr-compatible...

Abstract Fluid dynamic analysis of turbodynamic blood pumps (TBPs) is often conducted under steady flow conditions. However, the preponderance clinical applications for ventricular assistance involves unsteady, pulsatile flow—due to residual contractility native heart. This study was undertaken demonstrate importance pulsatility and associated time derivative rate (dQ/dt) on hemodynamics within a clinical‐scale TBP. accomplished by performing visualization studies transparent model...

To investigate a pressure-controlled intermittent coronary sinus occlusion (PICSO) system in an ischaemia/reperfusion model.We randomly assigned 18 pigs subjected to 60 minutes ischaemia by left anterior descending (LAD) artery balloon PICSO (n=12, groups A and B) or controls (n=6, group C). started 10 before (group A), after reperfusion was maintained for 180 minutes. continuous drop of distal LAD pressure observed C. At reperfusion, diastolic significantly lower C compared B (p=0.02). mean...