Research Project: Venöz Dönüşe Implant Edilebilen Akıllı Prototip Kan Oksijenaratörünün Tasarımı ve Performansını Etkileyen Faktörlerin Belirlenmesi
Loading...
Contributors
Funders
ID
TB.00419
Authors
Pekkan, Kerem
Faculty Member
Publications
Polymeric hollow fiber membrane oxygenators as artificial lungs: A review
(Elsevier, 2022) Pekkan, Kerem; Teber, Oğuz Orhun; Altınay, Ayşegül Derya; Mehrabani, Seyed Ali Naziri; Taşdemir, Reyhan Şengür; Zeytinci, Bihter; Genceli, Esra Ateş; Dilekgürgen, Ebru; Koyuncu, İsmail; Department of Mechanical Engineering; Yes; College of Engineering
The oxygenator is one of the most important components of respiratory support devices, which began as a heartlung machine for the treatment of heart diseases. Hollow fiber membranes have been widely used in oxygenators due to their outstanding performance in oxygen and carbon dioxide exchange with the blood. In this review, general information on the oxygenator historical evolutions is summarized. Then, the advantages and usage of hollow fiber membranes as oxygenators are explained. Modification strategies to prevent platelet adhesion, plasma leakage have been summarized. There has been some information given on design parameters for hollow fiber membrane oxygenators. In recent years, the rapid development of microchannel structures in oxygenators has been summarized. It is thought that this review will help the reader to find recent studies on the subject.
Tension controlled hollow-fiber winding machine for blood oxygenator prototypes
(Elsevier, 2023) Pekkan, Kerem; Aliabbasi, Easa; Ullah, Azmat; Akseki, Anıl; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; Yes; College of Engineering; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING
Blood oxygenators involve a complex network of hollow fibers for efficient gas exchange with blood. The optimal microstructural arrangement of these fibers is an ongoing research interest. While the fiber systems of commercial oxygenators are manufactured to address mass production, the research oxygenator prototypes demand more flexibility so that different design parameters can be tested. Here a hollow-fiber assembly system is designed and built for winding research grade extracorporeal blood oxygenator mandrels at different layout dimensions so that these different configurations can be evaluated for mass transfer capacity and blood damage. The hardware design and manufacturing details of this system presented together with its impact on the prototype oxygenator device assembly process. This in-house built system can wind thin fibers, having outer diameters ranging from 100 lm to 1 mm, at any specified winding angle continuously. A control system for fiber stress is also incorporated to eliminate fiber damage. Our system consists of three main units: (1) unwinding, (2) accumulator, and (3) winding systems, integrated together via the control software. The unwinding unit has a PID controller to maintain the position of the accumulator motor on the reference point by tuning the velocity of feeding fibers to the accumulator unit. Another PID controller preserves the desired tension value of the fibers by adjusting the position of the accumulator motor. Desired tension value is defined by the user and typically obtained through uniaxial testing of fibers. The control unit employs a "cascaded" PID controller since the PID controller in the accumulator unit maintains the tension and the PID controller in the unwinding unit controls the position of the accumulator motor. Finally, the winding unit utilizes two motors to wind the fibers over the outer diameter of a mandrel at the desired winding angle. The first motor drives the translational movement, and the second one provides mandrel rotation. The desired angles are achieved by tuning the synchronous movement of the winding motors. While the system is designed to produce assembled blood oxygenator mandrel prototypes, this concept is also applicable for producing cylindrical fiber-reinforced composite materials with specified fiber angles and stents winded on jigs.
Estimation of pulsatile energy dissipation in intersecting pipe junctions using inflow pulsatility indices
(American Institute of Physics (AIP) Publishing, 2021) Pekkan, Kerem; Rasooli, Reza; Dur, Onur; Department of Mechanical Engineering; Graduate School of Health Sciences; Yes; College of Engineering; GRADUATE SCHOOL OF HEALTH SCIENCES
This study aims to characterize the effect of inflow pulsatility on the hydrodynamic power loss inside intersecting double-inlet, double-outlet pipe intersection (DIPI) with cross-flow mixing. An extensive set of computational fluid dynamics (CFD) simulations was performed in order to identify the individual effects of flow pulsatility parameters, i.e., amplitude, frequency, and relative phase shift between the inflow waveform oscillations, on power loss. An experimentally validated second order accurate solver is employed in this study. To predict the pulsatile flow performance of any given arbitrary inflow waveforms, we proposed three easy-to-calculate pulsatility indices. The frequency-coupled quasi-steady flow theory is incorporated to identify the functional form of pulsatile power loss as a function of these indices. Our results indicated that the power loss within the inflow branch sections, lumped outflow-junction section, and the whole conduit correlates strongly with the pulsatility of each inflow waveform, the total inflow pulsatility, and inflow frequency content, respectively. The complete CFD simulation matrix provided a unified analytical expression that predicts pulsatile power loss inside a one-degree offset DIPI geometry. The predictive accuracy of this expression is evaluated in comparison to the CFD evaluation of arbitrary multi-harmonic inflow waveforms. These results have important implications on hydrodynamic pipe networks that employ complex junctions as well as in the patient-to-patient comparison of surgically created vascular connections. Coupling the present analytical pulsatile power loss expression with non-dimensional steady power loss formulation provided a valuable predictive tool to estimate the pulsatile energy dissipation for any arbitrary junction geometry with minimum use of the costly CFD computations.
