Arterial pulsatility improvement in a feedback-controlled continuous flow left ventricular assist device: An ex-vivo experimental study

Bozkurt, Selim; Tuijl, S Sjoerd van; Schampaert, S Stéphanie; Vosse, F.N. van de; Rutten, Mcm Marcel

doi:10.1016/j.medengphy.2014.07.005

Cited by 26 publications

(20 citation statements)

References 37 publications

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“…The balloon pump is placed in the left ventricle, at the same time, the control and drive units are placed in vitro. The inflated volume of the balloon used in this study is 50 cm 3 , and has a smaller implanted volume about 7 cm 3 when it is deflation (likes long cylinder, diameter 1 cm and length 5.6 cm), and thus creates a smaller operation wound. During the systole, the balloon is inflating and pushing the blood into aorta, and meanwhile increasing pressure of the left ventricle.…”

Section: Materials and Methods Ivadmentioning

confidence: 99%

“…These cavities were placed in acrylic chambers. The ventricular sac is a semi-ellipsoid (long axis -180 mm and short axis À 62 mm) and its volume is approximately 181 cm 3 . Ventricular diastole and systole were controlled by two electropneumatic regulators (ITV2030-312BL, SMC Pneumatics, Tokyo, Japan) and two vacuum proportional valves (ITV2090-31N2BN5) and 3/2 way solenoid valves (VT325-025GS, SMC Pneumatics, Tokyo, Japan).…”

Section: Mock Circulatory Systemmentioning

confidence: 99%

“…In most cases, CF-LVADs own much smaller size and lighter and be implanted intracorporeally. Therefore, they have better performance in terms of preventing infection arise from the smaller size [2,3]. However, they still have some significant issues, for example, the decreasing pulsatility and nonphysiologically high levels of shear stress, the patients will suffer long-term complication such as gastrointestinal bleeding and aortic valve insufficiency [4].…”

Section: Introductionmentioning

confidence: 99%

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In vitro testing of an intra-ventricular assist device

Zhu

Luo

Yang

et al. 2019

Computer Assisted Surgery

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A novel pulsatile assist device, intra-ventricular assist device, was proposed to address various disadvantages existing in conventional pulsatile assist device, such as the large size, accessories and reduced pulsatility. The assist device was designed, fabricated and implanted into the sac from left ventricular apex in a home-designed mock circulatory system. In vitro test was carried out and results demonstrated that the response time did not vary with the heart rate, and co-pulsatiled synchronously with native heart by electrocardiograph. The key parameter, stroke volume of proposed device was precisely measured under different afterloads (60, 80, 100, and 120 mmHg), drive pressure (from 90 to 300 mmHg at 30 mmHg intervals), and heart rate (45-150 beats per minute). The measurement results revealed that the output characteristics of device, stroke volume increased with increasing drive pressure but decreased with increasing peripheral resistance, were consistent with the native heart. The proposed pump was then coupled with mock system that was set to a heart failure mode and the circulatory responses were tested. Results showed that the device improved left ventricular pressure from 106 to 158 mmHg, and stroke volume from 25.5 to 44 ml at 90 bpm.

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Section: Materials and Methods Ivadmentioning

confidence: 99%

Section: Mock Circulatory Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

In vitro testing of an intra-ventricular assist device

Zhu

Luo

Yang

et al. 2019

Computer Assisted Surgery

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“…The present study aims to operate a CF-LVAD in co-pulsation support mode, similar to previous studies [ 31 , 32 ], and assess whether the co-pulsation support mode significantly increases arterial pulsatility in a mock circulatory system. Furthermore, a complete control method is presented and applied experimentally by using a physiological model to describe the reference pump flow.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System

2016

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Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.

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“…Several studies have modulated CF-VAD speeds to examine the effects on aortic pulsatility. Bozkurt et al utilized a mock circulatory loop with an ex-vivo porcine heart controlled by a pacemaker to test their novel proportional-integral (PI) controller for device outflow in a MicroMed DeBakey VAD (Bozkurt et al, 2014). The PI controller set the pump flow rate, the control variable, during the first 1/4 th of the cardiac cycle.…”

Section: B Pulsatilitymentioning

confidence: 99%

Rotary pump speed modulation to produce pulsatile flow and ventricular volume unloading.

Smith¹

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Arterial pulsatility improvement in a feedback-controlled continuous flow left ventricular assist device: An ex-vivo experimental study

Cited by 26 publications

References 37 publications

In vitro testing of an intra-ventricular assist device

In vitro testing of an intra-ventricular assist device

Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System

Rotary pump speed modulation to produce pulsatile flow and ventricular volume unloading.

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