Lumped Parameter Model of the Systemic Circulation and a Rotary Blood Pump Interaction

A method which can personalize the lumped parameter model of coronary artery and cardiovascular system based on the non-invasive physiological parameters has been developed. The parameters of system were determined by different physiological parameters. The heart module was determined by aortic pressure and heart rate; the systemic circulation module was determined by cardiac output, height and cardio-ankle vascular index (CAVI), while the CAVI was determined by age and aortic pressure; the coronary module was determined by the target waveforms of coronary flow rate predicted from cardiac output. The considerable results proved that this method could be applied to each patient.

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STUDY OF UNCERTAINTIES ON A 0D MODEL OF THE SYSTEMIC CIRCULATION

Revista Mundi Engenharia Tecnologia e Gestão (ISSN 2525-4782) ◽

10.21575/25254782rmetg2020vol5n21152 ◽

2020 ◽

Vol 5 (2) ◽

Author(s):

Gilmar Ferreira Da Silva Filho ◽

Rafael Alves Bonfim De Queiroz ◽

Luis Paulo Da Silva Barra ◽

Bernardo Martins Rocha

Keyword(s):

Sensitivity Analysis ◽

Computational Models ◽

Clinical Decision Making ◽

Systemic Circulation ◽

Lumped Parameter Model ◽

Patient Specific ◽

Accurate Estimation ◽

Clinical Patient ◽

Lumped Parameter ◽

Input Parameters

Cardiovascular system is intensely researched to understand the intricate nature of the heart and blood circulation. Nowadays we have well evolved computational models which are useful in many ways for the understanding and analysis of physiological and pathophysiological conditions of the heart. However, the practical use of these models and their results for clinical decision making in specific patients is not straightforward. In this context, models predictions must be accurate and reliable, which can be assessed by quantification of uncertainties in the predictions and sensitivity analysis of the input parameters. Lumped parameter models for the cardiovascular physiology can provide useful data for clinical patient-specific applications. However, the accurate estimation of all parameters of these models is a difficult task, and therefore the determination of the most sensitive parameters is an important step towards the calibration of these models. We perform uncertainty quantification and sensitivity analysis based on generalised polynomial chaos expansion in a lumped parameter model for the systemic circulation. The objective of this work is to verify the effect of uncertainties from input parameters on the predictions of the models and to identify parameters that contribute significantly to relevant quantities of interest. Numerical experiments are performed and results indicate a set of the most relevant parameters in the context of these models.

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Influence of Impeller Speed Patterns on Hemodynamic Characteristics and Hemolysis of the Blood Pump

Applied Sciences ◽

10.3390/app9214689 ◽

2019 ◽

Vol 9 (21) ◽

pp. 4689 ◽

Cited By ~ 2

Author(s):

Yiwen Wang ◽

Peng Shen ◽

Minli Zheng ◽

Pengqiang Fu ◽

Lijia Liu ◽

...

Keyword(s):

Pulsating Flow ◽

Constant Speed ◽

Lumped Parameter Model ◽

Blood Pump ◽

Impeller Speed ◽

Hydrodynamic Characteristics ◽

Rotary Blood Pump ◽

Arterial Blood ◽

Speed Modulation ◽

Hemodynamic Characteristics

A continuous-flow output mode of a rotary blood pump reduces the fluctuation range of arterial blood pressure and easily causes complications. For a centrifugal rotary blood pump, sinusoidal and pulsatile speed patterns are designed using the impeller speed modulation. This study aimed to analyze the hemodynamic characteristics and hemolysis of different speed patterns of a blood pump in patients with heart failure using computational fluid dynamics (CFD) and the lumped parameter model (LPM). The results showed that the impeller with three speed patterns (including the constant speed pattern) met the normal blood demand of the human body. The pulsating flow generated by the impeller speed modulation effectively increased the maximum pulse pressure (PP) to 12.7 mm Hg, but the hemolysis index (HI) in the sinusoidal and pulsatile speed patterns was higher than that in the constant speed pattern, which was about 2.1 × 10−5. The flow path of the pulsating flow field in the spiral groove of the hydrodynamic suspension bearing was uniform, but the alternating high shear stress (0~157 Pa) was caused by the impeller speed modulation, causing blood damage. Therefore, the rational modulation of the impeller speed and the structural optimization of a blood pump are important for improving hydrodynamic characteristics and hemolysis.

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Optimal measurement locations for diagnosis of aortic abnormalities in a lumped-parameter model of the systemic circulation using sensitivity analysis

International Journal of Biomathematics ◽

10.1142/s1793524517501169 ◽

2017 ◽

Vol 10 (08) ◽

pp. 1750116 ◽

Cited By ~ 2

Author(s):

R. Gul ◽

S. Bernhard

Keyword(s):

Sensitivity Analysis ◽

Systemic Circulation ◽

The Body ◽

Lumped Parameter Model ◽

Aorta Ascendens ◽

Optimal Measurement ◽

Linear Elastic ◽

Lumped Parameter ◽

Basic Theme ◽

Cardiovascular Simulator

The basic theme of this work is to identify the optimal measurement locations for pressure and flow in the systemic circulation to detect aortic stenoses and aneurysms in early stages of a disease. For this purpose, a linear elastic lumped parameter model of the fluid dynamical simulator, major arterial cardiovascular simulator (MACSim), is considered and global sensitivity analysis is applied to identify the better measurement locations for pressure and flow in the systemic circulation. The obtained results of sensitivity analysis provide insight that enable the experimentalists to optimize their experimental setups for detecting aortic stenoses and aneurysms using parameter estimation process. From the results, it is observed that the stenosis in the thoracic aorta can be identified from both pressure and flow at the location itself, nearby nodes, aorta ascendens, arcus aorta, arteria subclavia and arteria axillaris. On the other hand, the preferable measurement locations for abdominal aneurysms are locations themselves, nearby nodes and left/right leg of the body.

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