HEMOLYSIS ANALYSIS OF AXIAL BLOOD PUMPS WITH VARIOUS STRUCTURE IMPELLERS

2013 ◽  
Vol 13 (04) ◽  
pp. 1350054 ◽  
Author(s):  
ZENGSHENG CHEN ◽  
ZHAOHUI YAO ◽  
LAILAI ZHU ◽  
XIWEN ZHANG
Keyword(s):  
Heart Failure ◽  
Optimization Design ◽  
Blood Pump ◽  
In Vivo Experiments ◽  
Blood Pumps ◽  
Patients With Heart Failure ◽  
Euler Approach ◽  
Hemolytic Property ◽  
Forward Euler

Low hemolysis is an important factor for axial blood pumps that has been used in patients with heart failure. The structure of impellers plays a key role in the hemolytic properties of axial blood pumps. Axial blood pumps with various structure impellers exhibit different hemolytic characteristic. In the present study, we aimed to investigate the type of impellers structures in axial blood pumps that contain the best low hemolytic properties. Also, it is expensive and time-consuming to validate the axial blood pump's hemolytic property by in vivo experiments. Therefore, in the present study, the numerical method was applied to analyze the hemolytic property in a blood pump. Specifically, the hemolysis of the pump was calculated by using a forward Euler approach based on the changes in shear stress and related exposure times along the particle trace lines. The different vane structures and rotational speed that affect hemolysis were analyzed and compared. The results showed that long–short alternant vanes exhibited the best hemolytic property which could be utilized in the optimization design of axial blood pumps.

Computational Fluid Dynamics Analyses of a Micro Pediatric Ventricular Assist Blood Pump

2011 ◽  
Author(s):  
Xiao-chen Yang ◽  
Yan Zhang ◽  
Xing-min Gui ◽  
Sheng-shou Hu
Keyword(s):  
Fluid Dynamics ◽  
Heart Failure ◽  
Computational Fluid Dynamics ◽  
Blood Pump ◽  
Ventricular Assist ◽  
Blood Pumps ◽  
Blade Tip ◽  
Hemolytic Property ◽  
Rotary Blood Pumps ◽  
Dynamics Analyses

The heart failure patients supported by the mechanical rotary blood pumps have been validated and investigated in recent decades. A series of adult blood pumps have been investigated in our research group in the last several years and one of them is currently under clinical trials. This present paper aimed at analyzing a micro pediatric blood pump (MPBP) with Computational fluid dynamics (CFD) tool. MPBP is developed to assist the ventricular according to the practice of pediatric heart failure in Fuwai Hospital of Chinese Academy of Medical Sciences. The blade tip diameter of the MPBP is 10 mm. Some advanced structures proposed in our adult blood pumps were further improved in the MPBP and a cantilevered stator applied in the blood pump is a novel try. The results of the numerical simulation show that the MPBP can generate the flow rates of 0.74–3.21 lpm at the rotational speeds of 9,000–11,000 rpm, producing the pressure rises of 36.9–89.7 mmHg. The structural advantage, hydraulic performance and hemolytic property of the MPBP were analyzed in detail. Overall, the attempt of the cantilevered stator blade improved the performance of the blood pump effectively and the MPBP deserves a promising prospect.

scholarly journals The Design and Evaluation of a Portable Extracorporeal Centrifugal Blood Pump

2021 ◽  
Vol 12 ◽  
Author(s):  
Peng Wu ◽  
Wenjing Xiang ◽  
Chengke Yin ◽  
Shu Li
Keyword(s):  
Heart Failure ◽  
Ring Cavity ◽  
Life Quality ◽  
Blood Pump ◽  
Centrifugal Blood Pump ◽  
Portable Pump ◽  
Blood Pumps ◽  
Patients With Heart Failure ◽  
Clinical Benefits

In recent years, blood pumps have become the bridge to heart transplantation for patients with heart failure. Portability and wearability of blood pumps should be considered to ensure patient satisfaction in everyday life. To date, the focus has been on the development of portable and wearable peripheral components, little attention has been paid to the portable and wearable performance of the blood pump itself. This study reported a novel design of a wearable and portable extracorporeal centrifugal blood pump. Based on an in-house centrifugal maglev blood pump, the wearable and portable blood pump was designed with parallel inlet and outlet pipes to improve the wearable performance. A ring cavity was set at the inlet to convert the circumferential velocity of the inlet pipe to an axial velocity. The hydraulic and hemolytic performance of the baseline and portable blood pumps were analyzed and compared. Compared with the baseline pump, the hydrodynamic and hemolytic performance of the portable pump has been maintained without serious degradation. The results of this study will improve the life quality of patients with heart failure, and enhance the clinical benefits of artificial heart.

HYDRODYNAMIC AND HEMOLYSIS ANALYSIS ON DISTANCE AND CLEARANCE BETWEEN IMPELLER AND DIFFUSER OF AXIAL BLOOD PUMP

2016 ◽  
Vol 16 (02) ◽  
pp. 1650014 ◽  
Author(s):  
JIAJIA YU ◽  
XIWEN ZHANG
Keyword(s):  
Hydraulic Performance ◽  
Blood Pump ◽  
Hydraulic Characteristics ◽  
Empirical Power ◽  
Heartmate Ii ◽  
Blood Damage ◽  
Damage Models ◽  
Blood Pumps ◽  
Patients With Heart Failure ◽  
Hemolytic Property

Low hemolysis and hydraulic performance are important factors for an axial blood pump, which have been transplanted in patients with heart failure (HF). The distance and clearance between impeller and diffuser play a key role in hemolytic properties and hydraulic performances of axial blood pumps that were developed by our group inspired by the design features of HeartMate II. In the present study, we aimed to investigate the appropriate distance and clearance between impellers and diffusers of axial blood pumps, which contains the best low hemolytic property and hydraulic performance using the computational fluid dynamics (CFDs) approach. Specially, the hemolysis of the pump was calculated by using two different empirical power-law hemolytic blood damage models with two sets of parameters. The two hemolytic blood damage models with two sets of parameters were analyzed and compared. Further, the different distances and clearances between impellers and diffusers that affect hemolytic and hydraulic characteristics were also analyzed. The results showed that the pump with distance of 2[Formula: see text]mm and clearance of 0.2[Formula: see text]mm between impeller and diffuser exhibited the best hemolytic property and better hydraulic performance.

STRUCTURAL DESIGN AND NUMERICAL SIMULATION OF THE DIFFUSER FOR MAGLEV AXIAL BLOOD PUMP

2014 ◽  
Vol 14 (03) ◽  
pp. 1450045
Author(s):  
HUACHUN WU ◽  
GAO GONG ◽  
ZHIQIANG WANG ◽  
YEFA HU ◽  
CHUNSHENG SONG
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Leading Edge ◽  
Pressure Head ◽  
Hydraulic Performance ◽  
Blood Pump ◽  
Blade Angle ◽  
Blade Number ◽  
Blade Thickness ◽  
Blood Pumps

Hydraulic performance is an especially important factor for maglev axial blood pumps that have been used in patients with heart disease. Most maglev axial blood pumps basically consist of a straightener, an impeller and a diffuser. The diffuser plays a key role in the performance of the maglev axial blood pump to provide an adequate pressure head and increase the hydraulic efficiency. Maglev axial blood pumps with various structural diffusers exhibit different hydraulic performance. In this study, computational fluid dynamics (CFD) analysis was performed to quantify hydrodynamic in a maglev axial blood pump with a flow rate of 6 L/min against a pressure head of 100 mmHg to optimize the diffuser structure. First, we design the prototype of diffuser structure based on traditional design method, establish blood flow channel models using commercial software ANSYS FLUENT. Specifically, compare the performance of pump with the diffusers of different parameters, such as the leading edge blade angle, blade-thickness and blade-number. The results show that the diffuser structures with the thickening blade by arc airfoil law, blade-number of 6, leading edge blade angle of 24°, and trailing edge blade angle of 90° exhibited the best hydraulic performance which could be utilized in the optimization design of maglev axial blood pumps.

scholarly journals 30 YEARS OF THE MINERALOCORTICOID RECEPTOR: Mineralocorticoid receptor antagonists: 60 years of research and development

2017 ◽  
Vol 234 (1) ◽  
pp. T125-T140 ◽  
Author(s):  
Peter Kolkhof ◽  
Lars Bärfacker
Keyword(s):  
Heart Failure ◽  
Chronic Kidney Disease ◽  
Clinical Trials ◽  
Kidney Disease ◽  
Research And Development ◽  
Mineralocorticoid Receptor ◽  
Clinical Use ◽  
Patients With Heart Failure ◽  
History Of

The cDNA of the mineralocorticoid receptor (MR) was cloned 30 years ago, in 1987. At that time, spirolactone, the first generation of synthetic steroid-based MR antagonists (MRAs), which was identified in preclinical in vivo models, had already been in clinical use for 30 years. Subsequent decades of research and development by Searle & Co., Ciba-Geigy, Roussel Uclaf and Schering AG toward identifying a second generation of much more specific steroidal MRAs were all based on the initial 17-spirolactone construct. The salient example is eplerenone, first described in 1987, coincidentally with the cloning of MR cDNA. Its launch on the market in 2003 paralleled intensive drug discovery programs for a new generation of non-steroidal MRAs. Now, 30 years after the cDNA cloning of MR and 60 years of clinical use of steroidal MRAs, novel non-steroidal MRAs such as apararenone, esaxerenone and finerenone are in late-stage clinical trials in patients with heart failure, chronic kidney disease (CKD), hypertension and liver disease. Finerenone has already been studied in over 2000 patients with heart failure plus chronic kidney disease and/or diabetes, and in patients with diabetic kidney disease, in five phase II clinical trials. Here, we reflect on the history of the various generations of MRAs and review characteristics of the most important steroidal and non-steroidal MRAs.

4966Targeting INaL by a neuronal sodium channel isoform improves survival in a CaMKII-transgenic heart failure mouse model

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
P Bengel ◽  
C Krekeler ◽  
S Ahmad ◽  
P Tirilomis ◽  
K Toischer ◽  
...  
Keyword(s):  
Heart Failure ◽  
Mouse Model ◽  
Sodium Channel ◽  
Sodium Current ◽  
Heart Weight ◽  
Knock Out ◽  
In Vivo Experiments ◽  
Antiarrhythmic Effects

Abstract Background Cardiac pathologies like hypertrophy and heart failure are known to be associated with proarrhythmogenic triggers like early- (EADs) and delayed afterdepolarizations (DADs) that can be partly attributed to an augmentation of late sodium current (INaL). Enhanced INaL is closely connected with increased activity of Ca2+/calmodulin dependent-kinase II (CaMKII) in pathology as it is enhanced by CaMKII on the one hand but can also indirectly increase CaMKII-activity on the other. We recently found neuronal sodium channel NaV1.8 to be involved in INaL-augmentation in heart failure and cardiac hypertrophy. Here, we studied possible antiarrhythmic effects of NaV1.8-inhibition in a transgenic mouse model with enhanced CaMKII-expression by selectively knocking out NaV1.8. Methods/Results To investigate antiarrhythmic effects of NaV1.8-depletion in-vivo and in-vitro we crossbred CaMKII-transgenic mice (CaMKII+/T) with NaV1.8-knock-out mice (SCN10A−/−). Surprisingly, CaMKII+/T-mice lacking NaV1.8 (CaMKII+/T & SCN10A−/−) showed a significantly improved survival compared to CaMKII+/T alone (97.5 vs 72.0 days, p<0.05). Heart weight to tibia length ratio was significantly increased in CaMKII+/T-mice compared to wild-type, without any differences between CaMKII+/T and CaMKII+/T & SCN10A−/−. To investigate the underlying mechanisms out of this observation we isolated single cardiomyocytes and performed patch-clamp experiments as well as confocal microscopy to measure Ca2+-transients and diastolic Ca2+-waves. INaL-integral was significantly smaller in cardiomyocytes from CaMKII+/T & SCN10A−/−-mice compared to CaMKII+/T alone. During action potential recordings, significantly less afterdepolarizations occurred in CaMKII+/T & SCN10A−/− compared to cardiomyocytes from CaMKII+/T -mice (16.7/min vs 34.9/min, p<0.05). There was a trend of less cells exhibiting diastolic Ca2+-waves in Ca2+-measurements from CaMKII+/T & SCN10A−/− compared to CaMKII+/T (15% vs 25%, p=0.09). As some cells showed more than one event, we calculated the frequency of Ca2+-waves and found a significant reduction of Ca2+-waves in CaMKII+/T & SCN10A−/− vs. CaMKII+/T (22.8/min vs 43.0/min, p<0.05). Moreover, the time to the first event was significantly longer in CaMKII+/T & SCN10A−/−. Ca2+-transient amplitude (F/F0) was significantly lower in CaMKII+/T compared to CaMKII+/T & SCN10A−/− (4.6 vs. 5.3, p=0.05). Further, Ca2+-extrusion from the cytosol was significantly faster in CaMKII+/T & SCN10A−/−. Conclusion Our data demonstrates, that inhibition of INaL by targeting NaV1.8 has a potent antiarrhythmic potential as we found a reduction of EADs, DADs and diastolic Ca2+-waves in CaMKII+/T & SCN10A−/−-cardiomyocytes. This antiarrhythmic potential appears to be potent enough to improve survival and to rescue the proarrhythmogenic phenotype of CaMKII-overexpression. However, further in-vivo experiments are necessary to investigate NaV1.8-inhibition for a possible therapeutic approach.

scholarly journals Early activation of the cardiac CX3CL1/CX3CR1 axis delays β-adrenergic-induced heart failure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Flamant ◽  
N. Mougenot ◽  
E. Balse ◽  
L. Le Fèvre ◽  
F. Atassi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Protective Role ◽  
Cardiomyocyte Hypertrophy ◽  
Adrenergic Stimulation ◽  
Intramyocardial Injection ◽  
In Vivo Experiments ◽  
Concentric Hypertrophy

AbstractWe recently highlighted a novel potential protective paracrine role of cardiac myeloid CD11b/c cells improving resistance of adult hypertrophied cardiomyocytes to oxidative stress and potentially delaying evolution towards heart failure (HF) in response to early β-adrenergic stimulation. Here we characterized macrophages (Mφ) in hearts early infused with isoproterenol as compared to control and failing hearts and evaluated the role of upregulated CX3CL1 in cardiac remodeling. Flow cytometry, immunohistology and Mφ-depletion experiments evidenced a transient increase in Mφ number in isoproterenol-infused hearts, proportional to early concentric hypertrophy (ECH) remodeling and limiting HF. Combining transcriptomic and secretomic approaches we characterized Mφ-enriched CD45+ cells from ECH hearts as CX3CL1- and TNFα-secreting cells. In-vivo experiments, using intramyocardial injection in ECH hearts of either Cx3cl1 or Cx3cr1 siRNA, or Cx3cr1−/− knockout mice, identified the CX3CL1/CX3CR1 axis as a protective pathway delaying transition to HF. In-vitro results showed that CX3CL1 not only enhanced ECH Mφ proliferation and expansion but also supported adult cardiomyocyte hypertrophy via a synergistic action with TNFα. Our data underscore the in-vivo transient protective role of the CX3CL1/CX3CR1 axis in ECH remodeling and suggest the participation of CX3CL1-secreting Mφ and their crosstalk with CX3CR1-expressing cardiomyocytes to delay HF.

scholarly journals Methodology for measuring the gap size using a fiber-optic displacement sensor exemplified by a centrifugal blood pump

2020 ◽  
Vol 12 (2) ◽  
pp. 46
Author(s):  
Maciej Gawlikowski ◽  
Przemysław Kurtyka ◽  
Jerzy Zalewski ◽  
Magda Zarwańska-Doffek ◽  
Artur Kapis
Keyword(s):  
Heart Failure ◽  
Ventricular Assist Device ◽  
Fiber Optic ◽  
Displacement Sensor ◽  
Blood Pump ◽  
Rotary Blood Pump ◽  
Assist Device ◽  
Ventricular Assist ◽  
Blood Pumps ◽  
Rotary Blood Pumps

In order to avoid blood clotting, in the second generation of rotary blood pumps the impeller is suspended without mechanical bearing, using balance of magnetic and hydrodynamic forces. Reaching single tens of microns gap between pump housing and impeller is crucial for level of blood traumatization by the pump. In this paper we would like to present the method of physical measurement of this gap on a running pump with the use of commercial fiber-optic proximity sensor on the example of Polish rotary blood pump ReligaHeart ROT. We also discussed technical requirements of the construction of laboratory stand. Full Text: PDF ReferencesS. Westaby, "Rotary blood pumps as definitive treatment for severe heart failure", Future Cardiol. 9, 2 (2013). CrossRef R. Delgado, M. Bergheim, "HeartMate® II left ventricular assist device: a new device for advanced heart failure", Epert Rev. Med. Devices, 2, 5 (2005). CrossRef M. Ozban, T. Yagdi, C. Engin et al, Transplant proc., 44, 6 (2012). CrossRef A.T. Lanfear, M. Hamandi, J. Fan et al., "Trends in HeartMate 3: What we know so far", J. Card. Surg., 35, 1 (2020). CrossRef Ch. Zengsheng, S. Anqiang, W. Hongyu, "Non-physiological shear stress-induced blood damage in ventricular assist device", Medicine in Novel Technology and Devices, 3 (2019). CrossRef A. M. Robertson, A. Sequeira, R. G. Owens, Rheological models of blood In: L. Formaggia, A. Quarteroni, A Veneziani (eds) Cardiovascular Mathematics (Milano, Springer-Verlag 2009) CrossRef M. Gawlikowski et al., "Necessity of telemonitoring in patients treated by means of cardiac assist systems on the example of Polish rotary blood pump ReligaHeart ROT", Advances in Intelligent Systems and Computing, 925 (2019). CrossRef R. Kustosz, et al., "The tin coating utilisation as blood contact surface modification in implantable rotary left ventricle assist device religaheart ROT", Arch. Matall. Mater., 60, 3 (2015). CrossRef S. S. Patil, A. D. Shaligram, "Analytical study of performance variations of fiber optic micro-displacement sensor configurations using mathematical modeling and an experimental test jig", IJSER, 4, 11 (2013). DirectLink Philtec Application Note, 6, 25 (2017) CrossRef

scholarly journals Detrimental proarrhythmogenic interaction of Ca2+/calmodulin-dependent protein kinase II and NaV1.8 in heart failure

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Philipp Bengel ◽  
Nataliya Dybkova ◽  
Petros Tirilomis ◽  
Shakil Ahmad ◽  
Nico Hartmann ◽  
...  
Keyword(s):  
Heart Failure ◽  
Protein Kinase ◽  
Direct Interaction ◽  
Dependent Protein Kinase ◽  
Knock Out ◽  
Downstream Target ◽  
In Vivo Experiments ◽  
Dependent Protein ◽  
Human Ipsc

AbstractAn interplay between Ca2+/calmodulin-dependent protein kinase IIδc (CaMKIIδc) and late Na+ current (INaL) is known to induce arrhythmias in the failing heart. Here, we elucidate the role of the sodium channel isoform NaV1.8 for CaMKIIδc-dependent proarrhythmia. In a CRISPR-Cas9-generated human iPSC-cardiomyocyte homozygous knock-out of NaV1.8, we demonstrate that NaV1.8 contributes to INaL formation. In addition, we reveal a direct interaction between NaV1.8 and CaMKIIδc in cardiomyocytes isolated from patients with heart failure (HF). Using specific blockers of NaV1.8 and CaMKIIδc, we show that NaV1.8-driven INaL is CaMKIIδc-dependent and that NaV1.8-inhibtion reduces diastolic SR-Ca2+ leak in human failing cardiomyocytes. Moreover, increased mortality of CaMKIIδc-overexpressing HF mice is reduced when a NaV1.8 knock-out is introduced. Cellular and in vivo experiments reveal reduced ventricular arrhythmias without changes in HF progression. Our work therefore identifies a proarrhythmic CaMKIIδc downstream target which may constitute a prognostic and antiarrhythmic strategy.

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