DESIGN AND DEVELOPMENT OF MINIATURE SLOTTED IMPELLER FOR SAI SPANDAN TOTAL ARTIFICIAL HEART FOR DESTINATION THERAPY

2021 ◽  
pp. 37-39
Author(s):  
Pradeep Kumar Radhakrishnan ◽  
Sujatha Mohanty ◽  
Pulivarthi Nageshwar Rao ◽  
Sivakrishna Rao G V ◽  
Nagesh Kumar ◽  
...  
Keyword(s):  
Total Artificial Heart ◽  
Circulatory Support ◽  
Blood Component ◽  
Centrifugal Pumps ◽  
Ventricular Assist ◽  
Circulatory Assist Devices ◽  
Blood Pumps ◽  
Pump Housing ◽  
Evaluation Metric ◽  
Rotary Blood Pumps

In recent years, the use of rotary blood pumps (RBPs) as continuous ow VADs has surged ahead, and virtually eliminated the use of pulsatile-ow or volume-displacement pumps for implantable, chronic mechanical circulatory support (MCS). Circuit Design modications like that in Saispandan has imparted pulsatility into RBP.Impeller designs are a signicant factor when designing centrifugal pumps as mechanical circulatory assist devices as smaller diameter impellers with higher rotational speeds to achieve target outputs would cause more blood component trauma compared to larger diameter impellers.Hydraulic performance and hemolysis tests in the same pump housing with different prototypes is needed. Ventricular assist parameters for efcient circulatory support would include an output of 5 L/min against 100 mmHg at speeds of 2500-3500 rpm. Vein height does not contribute signicantly to evaluation metric in most studies.

Cardiac transplantation and mechanical circulatory support

2020 ◽  
pp. 3428-3435
Author(s):  
Jayan Parameshwar ◽  
Steven Tsui
Keyword(s):  
Side Effects ◽  
Cardiac Transplantation ◽  
First Generation ◽  
Immunosuppressive Agents ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Blood Pumps ◽  
Rotary Blood Pumps

Cardiac transplantation is the treatment of choice for selected patients with advanced heart failure: median survival approaches 12 years and recipients enjoy an excellent quality of life, but availability is severely limited by shortage of donor organs. The need for lifelong immunosuppression is associated with side effects, including an increased incidence of malignancy. Newer immunosuppressive agents reduce nephrotoxicity and delay the onset of cardiac allograft vasculopathy, but may produce other side effects. Ventricular assist devices are mechanical blood pumps that work in parallel or series with the native ventricles. First-generation volume-displacement pulsatile ventricular assist devices have been superseded by rotary blood pumps that generate continuous flow. Significant complications include bleeding, thromboembolism, device failure due to pump thrombosis, and infection.

Abstract WMP66: Cerebrovascular Hemodynamics of Mechanical Circulatory Support Device Patients

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Kara R Melmed ◽  
Konrad H Shlick ◽  
Brenda Rinsky ◽  
Shlee S Song ◽  
Patrick D Lyden
Keyword(s):  
Continuous Flow ◽  
Mechanical Circulatory Support ◽  
Left Ventricular ◽  
Total Artificial Heart ◽  
Circulatory Support ◽  
Normative Values ◽  
Mean Flow ◽  
Mean Velocity ◽  
Ventricular Assist ◽  
Cerebrovascular Hemodynamics

Background: Multiple types of mechanical circulatory support (MCS) devices are commonly used in heart failure patients. These devices carry risk for neurologic complications, specifically cardioembolic stroke. Alterations in blood flow play a role in the pathophysiology, however there is limited data regarding cerebrovascular hemodynamics in MCS patients. We used transcranial Doppler (TCD) to define hemodynamics of commonly used MCS devices. Methods: We retrospectively examined charts from 2/2013 through 6/2016 for patients with MCS who underwent TCD, and obtained the following: peak systolic,end-diastolic velocities, mean flow velocities, pulsatility indices (PI) and number of high-intensity transient signals (HITS). Waveform morphologies were compared between devices. Results: Of 1,796 TCDs studies screened, 62 TCD studies were from 32 MCS patients. Of these, 21 were on extracorporeal membrane oxygenation (ECMO), 15 had a left ventricular assist device (LVAD), 18 had total artificial heart (TAH), and 2 had intra-aortic balloon pumps (IABP). Waveforms in patients supported by ECMO demonstrated continuous flow without clear systolic peaks. The averaged mean MCA velocity was 57.57 (SD= 21.00) cm/sec and mean PI is 0.35 (0.17). LVAD averaged mean MCA velocity was 57.57 (14.38) cm/sec and mean PI of 0.45 (0.28). PIs were low in patients with continuous-flow LVADs. Impella patients had morphologically distinct pulsatile waveforms compared to other types of VADs. IABP had averaged mean velocity of 56.21 (14.78) cm/sec and mean PI of 0.77 (0.15). These waveforms demonstrated pronounced diastolic upstrokes not present in other devices. In TAH patients, mean MCA velocity was 73.69 (33.00) cm/sec and PI of 0.86 (0.40). Emboli detection was performed in 46 studies, and HITS were detected in 29 (63%). Of these 15 (51%) were administered 100% oxygen which suppressed >50% HITS in 10 (67%) patients. Conclusion: Patients supported by MCS devices produce unique and characteristic waveforms on TCD studies. Further studies will describe normative values in this special population. HITS were not universally present and intermittently suppressible by oxygen, suggesting some may be gaseous in nature. Risk of stroke in patients with MCS and HITS is under study.

scholarly journals Haemolysis induced by mechanical circulatory support devices: unsolved problems

Perfusion ◽  
2020 ◽  
Vol 35 (6) ◽  
pp. 474-483
Author(s):  
Inge Köhne
Keyword(s):  
Shear Stress ◽  
Continuous Flow ◽  
Mechanical Circulatory Support ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Ventricular Assist ◽  
Theoretical Approaches ◽  
Blood Pumps ◽  
Mechanical Circulatory Support Devices ◽  
Support Devices

Since the use of continuous flow blood pumps as ventricular assist devices is standard, the problems with haemolysis have increased. It is mainly induced by shear stress affecting the erythrocyte membrane. There are many investigations about haemolysis in laminar and turbulent blood flow. The results defined as threshold levels for the damage of erythrocytes depend on the exposure time of the shear stress, but they are very different, depending on the used experimental methods or the calculation strategy. Here, the results are resumed and shown in curves. Different models for the calculation of the strengths of erythrocytes are discussed. There are few results reported about tests of haemolysis in blood pumps, but some theoretical approaches for the design of continuous flow blood pumps according to low haemolysis have been investigated within the last years.

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.

Design Optimization of Rotary Blood Pumps: Alternatives to Anticoagulation Therapy

2011 ◽  
Author(s):  
Gaurav Girdhar ◽  
Michalis Xenos ◽  
Wei-Che Chiu ◽  
Yared Alemu ◽  
Bryan Lynch ◽  
...  
Keyword(s):  
Heart Valves ◽  
Anticoagulation Therapy ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Shear Stresses ◽  
Ventricular Assist ◽  
Bridge To Transplant ◽  
Life Saving ◽  
Optimization Methodology ◽  
Rotary Blood Pumps

Mechanical circulatory support (MCS) devices such as the ventricular assist devices (VADs) provide life saving short-term bridge-to-transplant solutions (1) to a large proportion of patients who suffer from chronic heart failure. Although hemodynamically efficient, such devices are burdened with high incidence of thromboembolic events due to non-physiological flow past constricted geometries where platelets (the principal cellular clotting elements in blood) are exposed to elevated shear stresses and exposure times (2) — requiring mandatory anticoagulation. We recently developed an optimization methodology — Device Thrombogenicity Emulator (DTE)(3) — that integrates device specific hemodynamic stresses (from numerical simulations) with experimental measurements of platelet activation. The DTE was successfully applied by our group to measure / optimize the thromboresistance of mechanical heart valves (MHV) (3, 4).

510 Preliminary study on total artificial heart using rotary blood pumps

2009 ◽  
Vol 2009.45 (0) ◽  
pp. 147-148
Author(s):  
Hidekazu MIURA ◽  
Yasuyuki SHIRAISHI ◽  
Shota YABE ◽  
Telma Keiko SUGAI ◽  
Hong Jian LIU ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Total Artificial Heart ◽  
Blood Pumps ◽  
Preliminary Study ◽  
Rotary Blood Pumps

Mechanical Bridge to Transplantation with the Vienna Heart in TAH and LVAD Configuration

1992 ◽  
Vol 15 (3) ◽  
pp. 147-167 ◽  
Author(s):  
A. Moritz ◽  
A. Rokitansky ◽  
H. Schima ◽  
A. Prodinger ◽  
G. Laufer ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Clinical Problem ◽  
Left Ventricular ◽  
Total Artificial Heart ◽  
Circulatory Support ◽  
Ventricular Assist ◽  
Septic Focus ◽  
Left Ventricular Assist ◽  
Liver And Kidney ◽  
Kidney Insufficiency

The Vienna heart uses a vacuum formed, pellethane pulsatile ventricle and is available in left ventricular assist (LVAD) and total artificial heart (TAH) configurations. This device was used as mechanical support of the failing heart in nine patients intended for heart transplantation. In two patients with cardiomyopathy an orthotopic TAH was implanted; one survived despite severe preoperative ischemic liver damage, and the other died of sepsis. In seven patients an atrio-aortic LVAD was implanted; six had suffered an acute myocardial infarction with cardiogenic shock, and one could not be weaned off bypass. Three patients survived. These included one 65-year-old with incipient ARDS at operation, and a 40-year-old with preoperative liver and kidney insufficiency who was transplanted in septicemia. In this patient the septic focus, natural and artificial heart, were removed at transplantation. Four patients died. In one we were unable to establish satisfactory circulation, one died after failure of the transplanted heart, one suffered a lethal cerebral embolism and one developed multi-organ failure after repeated attacks of ventricular fibrillation. With the Vienna heart sufficient circulatory support could be established with cardiac outputs between 6 and 8 l/min for the TAH and 3.5 to 4.5 I/min for the LVAD. With this type of support an overall survival rate of 44% could be achieved. Mechanical hemolysis was not a clinical problem and no device failure occurred.

From Rotary Blood Pumps to Mechanical Circulatory Support Systems

2016 ◽  
Vol 40 (9) ◽  
pp. 821-822 ◽  
Author(s):  
Francesco Moscato ◽  
Ulrich Steinseifer
Keyword(s):  
Mechanical Circulatory Support ◽  
Support Systems ◽  
Circulatory Support ◽  
Blood Pumps ◽  
Rotary Blood Pumps

Design Optimization of a Novel Polymeric Prosthetic Heart Valve and a Ventricular Assist Device via Device Thrombogenicity Emulation

2013 ◽  
Author(s):  
Thomas E. Claiborne ◽  
Wei-Che Chiu ◽  
Marvin J. Slepian ◽  
Danny Bluestein
Keyword(s):  
Heart Valves ◽  
Anticoagulation Therapy ◽  
Prosthetic Heart Valve ◽  
Total Artificial Heart ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Prosthetic Heart Valves ◽  
Ventricular Assist ◽  
Mechanical Circulatory Support Devices ◽  
Optimization Methodology

Thrombotic complications, such as hemorrhage or embolism, remain a major concern of blood contacting medical devices [1], including prosthetic heart valves (PHV) and mechanical circulatory support devices, e.g. ventricular assist devices (VAD) or the Total Artificial Heart (TAH) [2]. In most cases device recipients require life-long anticoagulation therapy, which increases the risk of hemorrhagic stroke and other bleeding disorders. In order to obviate the need for anticoagulants and reduce stroke risks, our group developed a unique optimization methodology, Device Thrombogenicity Emulation (DTE) [2–5]. With the DTE, the thrombogenic potential of a device is evaluated using extensive numerical modeling and calculating multiple platelet trajectories flowing through the device. The platelet stress-time waveforms are then emulated in our Hemodynamic Shearing Device (HSD) and their activation level is measured with our Platelet Activation State (PAS) assay. This provides a proxy validation of the simulation. We identify high shear stress producing regions within the device and modify its design to reduce or eliminate those potentially thrombogenic ‘hot-spots.’ Through an iterative process, we can optimize the device design prior to prototyping.

Physiology of Continuous-Flow Pumps

2012 ◽  
Vol 23 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Dawn M. Christensen
Keyword(s):  
Continuous Flow ◽  
Blood Pump ◽  
Circulatory Support ◽  
Cardiovascular Physiology ◽  
Rotary Blood Pump ◽  
Monitoring Methods ◽  
Failing Heart ◽  
Blood Pumps ◽  
Rotary Blood Pumps

The use of mechanical pumps for circulatory support started in the mid-1950s. The evolution of these devices has led to the present-day use of continuous-flow pumps to take over the function of a patient’s failing heart. The physiology associated with rotary blood pump use is quite different from normal cardiovascular physiology. Clinicians caring for patients who are supported by rotary blood pumps must have an understanding of the differences in physiology, monitoring methods, and unique complications associated with the use of these pumps.

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