A miniaturized Gyro centrifugal pump has been developed to be incorporated into a totally implantable artificial heart. The Gyro PI (permanently implantable) model is a pivot bearing supported centrifugal pump with a priming volume of 20 ml. With the miniaturized actuator, the pump-actuator package has a height of 53 mm, a diameter of 65 mm, and a displacement volume of 145 ml. To evaluate the hemocompatibility and efficiency of the Gyro PI pump system, a plastic prototype (Gyro PI-601) was implanted into a bovine model as a left or right ventricular assist device (LVAD or RVAD), bypassing from the left ventricular apex to the descending aorta or from the right ventricular infundibulum to the main pulmonary artery. The calves were anticoagulated with heparin to maintain activated clotting times from 150 to 200 s. Four calves were supported for 23, 24, and 50 days in the LVAD studies, and 40 days in the RVAD study. The first calf died due to intrathoracic bleeding associated with sepsis. The second calf was euthanized for a low flow rate less than 2 L/min due to an obstructed inflow with growing pannus. The third and fourth calves were euthanized as scheduled. Renal and hepatic functions remained normal, and plasma free hemoglobin values were less than 8 mg/dL throughout the experiments. The fourth case showed flow rates of 4.83 +/- 0.57 L/min, input power of 6.16 +/- 0.49 W, and the inside temperature of the actuator of 43.5 +/- 0.52 degrees C. The pumps implanted in the fourth calf demonstrated no thrombus formation at the autopsy. These in vivo experiments revealed that the Gyro PI pump can provide adequate flow as an easily implantable, efficient, antithrombogenic, and nonhemolytic centrifugal LVAD or RVAD with miniaturized actuators.
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http://dx.doi.org/10.1046/j.1525-1594.1998.06021.x | DOI Listing |
Comput Methods Biomech Biomed Engin
January 2025
Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, Guangdong Province, China.
Impeller radial gap is one of important parts within a blood pump, which may affect the hemodynamics and hemocompatibility. In this study, computational fluid dynamics method was performed to evaluate the impact of radial gap sizes. The volume of scalar shear stress decreased with radial gap sizes increasing.
View Article and Find Full Text PDFArtif Organs
January 2025
BioCirc Research Laboratory, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA.
Background: Safe and effective pediatric blood pumps continue to lag far behind those developed for adults. To address this growing unmet clinical need, we are developing a hybrid, continuous-flow, magnetically levitated, pediatric total artificial heart (TAH). Our hybrid TAH design, the Dragon Heart (DH), integrates both an axial flow and centrifugal flow blood pump within a single, compact housing.
View Article and Find Full Text PDFJ Artif Organs
January 2025
Department of Artificial Organs, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shinmachi, Suita, Osaka, 5648565, Japan.
This review traces the evolution of centrifugal blood pumps in mechanical circulatory support (MCS) systems. Initially met with concerns over blood damage and thrombus formation, centrifugal pumps have become crucial components in ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO) due to their simplified drive mechanisms and adaptability. This paper outlines three generations of centrifugal pump development: first-generation pumps with sealing components, second-generation pumps utilizing pivot bearings, and third-generation pumps employing contactless bearings.
View Article and Find Full Text PDFInt Heart J
December 2024
Department of Cardiovascular Surgery, The Second Hospital of Jilin University.
This study aimed to summarize our experience using a systematic approach to reduce blood transfusions in acute type A aortic dissection (ATAAD) surgery.From August 2016 to June 2020, 326 patients underwent ATAAD surgery in our center employing a systematic approach, which primarily included the following: Liu's aortic root repair technique, Liu's aortic arch inclusion technique with a frozen elephant trunk, moderate-to-mild hypothermia circulatory arrest, and application of centrifugal pump in cardiopulmonary bypass circuit. Patients were divided into two groups based on whether they had blood product transfusion during their hospital stay: transfusion group and transfusion-free group.
View Article and Find Full Text PDFNutrients
November 2024
Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA.
Background/objectives: Multiple independent variables were analyzed to determine total nutritional intake (caloric and protein), while reviewing vasoactive inotrope scores (VISs).
Methods: Retrospective data were collected for nutritional intake (N = 64), daily VISs, extracorporeal membrane oxygenation (ECMO) complications, delays in nutritional intake (>48 h), reason for delay, and interruptions in nutrition support.
Results: VISs and ECMO characteristics analyzed by box-whisker plots demonstrated that ECMO complications prior to 24 h, cardiac arrest 24 h prior to ECMO, pediatric ECMO patients, venoarterial ECMO type, having a cardiac ECMO indication, and ECMO centrifugal pump had higher VISs.
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