Speed modulation methods have been studied and even used clinically to create extra pulsation in the blood circulatory system with the assistance of a continuous flow rotary blood pump. However, fast speed variations may also increase the hemolysis potential inside the pump. This study investigates the hemolysis performance of a ventricular assist rotary blood pump under sinusoidal, square, and triangular wave speed modulation profiles using the computational fluid dynamics (CFD) method. The CFD boundary pressure conditions of the blood pump were obtained by combining simulations with the pump's mathematical model and a complete cardiovascular lumped parameter model. The hemolysis performance of the blood pump was quantified by the hemolysis index (HI) calculated from a Eulerian scalar transport equation. The HI results were obtained and compared with a constant speed condition when the blood pump was run under three speed profiles. The speed modulations were revealed to slightly affect the pump hemolysis, and the hemolysis differences between the different speed modulation profiles were insignificant. This study suggests that speed modulations could be a feasible way to improve the flow pulsatility of rotary blood pumps while not increasing the hemolysis performance.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9931726 | PMC |
http://dx.doi.org/10.3389/fphys.2023.1116266 | DOI Listing |
J Cardiothorac Surg
January 2025
Department of Cardiothoracic Surgery, Aalborg University Hospital, Hobrovej 18-22, Aalborg, 9000, Denmark.
Background: The outcome of coronary artery bypass grafting (CABG) depends on several factors, including the quality of the distal anastomoses to the coronary arteries. Early graft failure may be caused by, e.g.
View Article and Find Full Text PDFJ Vasc Surg Cases Innov Tech
February 2025
Department of Health and Kinesiology, Purdue University, West Lafayette, IN.
Artif Organs
January 2025
Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Background: Predicting hemolysis numerically based on the power-law model using idealized coefficients obtained from simplified devices yields a large variability in hemolysis index predictions. A computational fluid dynamics (CFD)-based Kriging surrogate modeling approach, developed by Craven et al. at the US Food & Drug Administration (FDA), was applied to a Fontan cavopulmonary assist device (CPAD) to generate device-specific hemolysis power-law coefficients.
View Article and Find Full Text PDFCurr Drug Metab
December 2024
Nutrition and Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
The well-established calcineurin inhibitor, tacrolimus, as an immunosuppressive agent, is widely prescribed after organ transplantation. Cytochrome P450 (CYP 450) isoforms are responsible for the metabolism of many features associated with food parameters like phytochemicals, juices, and fruits. This review article summarizes the findings of previous studies to help predict the efficacy or side effects of tacrolimus in the presence of food variables.
View Article and Find Full Text PDFJ Cardiothorac Surg
January 2025
Department of Anesthesiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College and Chinese Academy of Medical Sciences, No. 167, Beilishi Road, Xicheng District, China.
Background: Heparin, an anticoagulant used in cardiac surgery, can result in heparin rebound (HR), where it returns postoperatively despite being neutralized with protamine. This study was designed to investigate the prevalence of HR in patients undergoing off-pump coronary artery bypass grafting (OPCAB) and evaluate the impact of HR on their short-term outcomes.
Methods: HR was defined by a 10% increase in activated coagulation time (ACT) following two hours of heparin neutralization with protamine, bleeding over 200 mL/h, and abnormal laboratory coagulation examination results.
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