نویسندگان

1 دانشجوی کارشناسی ارشد مهندسی پزشکی، بخش مهندسی پزشکی، گروه مهندسی علوم زیستی، دانشکده‌ی علوم و فنون نوین، دانشگاه تهران، تهران

2 دانشیار، بخش مهندسی پزشکی، گروه مهندسی علوم زیستی، دانشکده‌ی علوم و فنون نوین، دانشگاه تهران، تهران

10.22041/ijbme.2018.90499.1381

چکیده

برای بیماران مبتلا به بیماری‌های مزمن ریوی، ریه‌ی مصنوعی (که بطن راست قلب جریان خون را به سمت آن پمپاژ می‌کند)، به عنوان یک مرحله‌ی مقدماتی پیش از پیوند ریه به شمار می‌آید. عمل‌کرد این دستگاه با چندین معیار، از جمله کارآمدی دستگاه در تبادل گاز، عدم آسیب‌رسانی به سلول‌های خونی و امپدانس پایین در مقایسه با ریه‌ی طبیعی، سنجیده می‌شود. در این مطالعه، بررسی عددی جریان خون غیرنیوتنی حول آرایه‌هایی از فیبرهای توخالی، به عنوان مدلی از دسته‌فیبرهای موجود در ریه‌ی مصنوعی، به روش حجم-محدود صورت گرفت. دو نوع آرایش مربعی و قطری برای فیبرها در نظر گرفته شد تا اثر آرایش، اثر سرعت ورودی روی توزیع جریان، تنش برشی و غلظت اکسیژن تبادل‌شده بین سطح فیبرها و جریان خون، بررسی شود. مشاهده شد که سرعت جریان و تنش برشی در آرایش قطری به مراتب بیش‌تر از آرایش مربعی است، به طوری که برای بیشینه‌ی سرعت مورد بررسی (cm/s 87/10)، تنش برشی روی فیبرها در آرایش قطری حدود 5/3 برابر مقدار آن در آرایش مربعی است. هم‌چنین، بین نتایج این تحلیل با نتایج مطالعات دیگری که در آن‌ها از تبادل اکسیژن صرف نظر شده بود، اختلاف قابل توجهی دیده شد، که بیان‌گر اهمیت مدل‌سازی تبادل گاز می‌باشد. میزان دبی جرمی اکسیژن در خروجی دامنه‌ی حل، به عنوان ملاک کارآمدی دستگاه (از دید تبادل گاز) مورد بررسی قرار گرفت. بر این اساس، آرایش قطری در تبادل اکسیژن بسیار کارآمدتر است. اما برای آرایش قطری، افت فشار بیش‌تری در عبور از دسته‌فیبرها، نسبت به آرایش مربعی مشاهده شد. نتایج این شبیه‌سازی می‌تواند نقطه‌ی شروع مناسبی برای طراحی بهینه‌ی ریه‌ی مصنوعی باشد و در طراحی بهینه‌ی آزمایش‌های کلینیکی موثر واقع شود.

کلیدواژه‌ها

عنوان مقاله [English]

Numerical Investigation of Oxygen Transfer and Blood Flow over Arrays of 3D Fibers of Artificial Lung

نویسندگان [English]

  • Zahra Mollahoseini 1
  • Bahman Vahidi 2

1 MSc of Biomedical Engineering-Biomechanics, Faculty of New Sciences and Technologies (FNST), University of Tehran, Tehran, Iran

2 Associate Professor of Biomedical Engineering, Faculty of New Sciences and Technologies (FNST), University of Tehran, Tehran, Iran

چکیده [English]

For patients with chronic pulmonary disease, artificial lungs to which right ventricular pumps blood flow is considered as a bridge to lung transplantation. The performance of this device is measured by several criteria, including the efficiency of the device in gas exchange, non-damage to blood cells and low impedance compared to normal lung. In this study, the non-Newtonian blood flow around arrays of hollow fibers, as a model of fiber bundles in artificial lungs, was numerically investigated by finite volume. Two types of square and diagonal arrangements for fibers were considered to examine the effect of arrangement, besides the inlet velocity effect on the flow distribution, shear stress and the exchanged oxygen concentration between the surface of the fibers and the blood stream. It was observed that the flow velocity and shear stress in the diagonal arrangement were far more than the square arrangement that for the maximum velocity (10/87 cm/s), the shear stress on the fibers in the diagonal arrangement was about 3.5 times that of the square arrangement. Also, there was a significant difference between the results of this analysis and the results of other studies in which oxygen exchange was ignored, which illustrates the importance of gas exchange modeling. As a measure of the efficiency of the device, from the viewpoint of gas exchange, the mass flow rate of oxygen was investigated in the output of the domain. As a result, the diagonal arrangement is much more efficient in oxygen exchange. However, there was a higher pressure drop across the fibers, for a diagonal arrangement, in comparison with the square arrangement. The results of this simulation can be a good starting point for optimal artificial lung design and can be effective in optimizing the design of clinical trials.

کلیدواژه‌ها [English]

  • Artificial Lung
  • Hollow Fiber
  • Fiber Arrangement
  • Computational fluid dynamics
  • Gas Transfer

[1]     J. Potakay, “The promise of microfluidic artificial lungs,” Lab on a chip, vol. 14, no. 21, pp. 4122-4138, Nov., 2014.

[2]     J. Potakay, B. Cmolik, “In vitro evaluation and in vivo demonstration of a biomimetic, hemocompatible, microfluidic artificial lung,” Lab on a chip, vol. 15, no. 5, pp. 1366-1375, Mar., 2015.

[3]     B.A. Zwischenberger, J.B. Clemson, “Artificial lung: progress and prototype,” Expert Rev. Med. Devices, vol. 3, no. 4, pp. 458-497, Jul., 2006.

[4]     A. Comboni, M. Philipp, “First experience with a paracorporeal artificial lung in humans,” ASAIO J., vol. 55, no. 3, pp. 304-306, May-Jun., 2009.

[5]     Y.C. Lin, K.M Khanafer, “An investigation of pulsatile flow past two cylinders as model of blood flow in an artificial lung,” Int. J. Heat Mass Transf., vol. 54, no. 15, pp. 3191-3200, Jul., 2011.

[6]     J. Zhang, T. Nolan, D.C. Zhang,“Characterization of membrane blood oxygenation devices using computational fluid dynamics,” J. Memb. Sci., vol. 288, no. 1, pp. 268-279, Feb., 2007.

[7]     J. Zhang, M. Taskin, A. Zhang,“ Computational design and in vitro characterization of an integrated Maglev pump oxygenator,” Artif. Organs, vol. 33, no. 10, pp. 805-817, Jul., 2009.

[8]     J. Zhang, M. Taskin, A. Zhang,“ Computational study of the blood flow in three types of 3D hollow fiber membrane bundles,” J. Biomech. Eng., vol. 135, no. 12, Dec., 2013.

[9]     K.Y. Chan, H. Fujioka,“ Pulsatile flow and mass transport over an array of cylinders: gas transfer in a cardiac-driven artificial lung,” J. Biomech. Eng., vol. 128, no. 1, pp. 85-96, Feb., 2006.

[10] K.Y. Chan, H. Fujioka,“ Pulsatile blood flow and gas exchange across a cylindrical fiber array,” J. Biomech. Eng., vol. 129, no. 5, pp. 676-687, Oct., 2006.

[11] J.R. Zierenberg, H. Fujioka,“ Pulsatile flow and mass transport past a circular cylinder,” Physics of fluids, vol. 18, no. 1, pp. 102-117, Jan., 2006.

[12] J.R. Zierenberg, H. Fujioka,“ Oxygen and carbon dioxide transport in time-dependent blood flow past fiber rectangular array,” J. Biomech. Eng., vol. 130, no. 3, Jun., 2008.

[13] R.E. Schewe, K.M. Khanafer,“ Thoracic artificial lung impedance studies using computational fluid dynamics and in vitro models,” Ann. Biomed. Eng., vol. 40, no. 3, pp. 628-636, Mar., 2012.

[14] M.J. Gartner, J. Wilhelm, K.L. Farbrizio,“ Modeling flow effects on thrombotic deposition in a membrane oxygenator,” Artif. Organs, vol. 24, no. 1, pp. 29-36, Jan., 2000.

[15] K.L. Gage, M.J. Gartner,“ Predicting membrane oxygenator pressure drop using computational fluid dynamics,” Artif. Organs, vol. 26, no. 7, pp. 600-607, Jul., 2002.

[16] P. W. Dierickx, D.S. Wachter, F. De Somer,“ Mass transfer characteristics of artificial lungs,” ASAIO. J., vol. 47, no. 6, pp. 628-633, Nov., 2001.

[17] A. R. Mazaheri, G. Ahmadi,“ Uniformity of the fluid flow velocities within hollow fiber membranes of blood oxygenation devices,” Artif. Organs, vol. 30, no. 1, pp. 10-15, Jan., 2006.

[18] M.E. Taskin, K.H. Fraser, T. Zhang,“ Micro-scale Modeling of Flow and Oxygen Transfer in Hollow Fiber Membrane Bundle,” J. Memb. Sci., vol. 362, no. 1-2, pp. 172-183, Oct., 2010.

[19] U.P. Fernando, A.J. Tompson, J. Potkay,“ A Membrane Lung Design Based on Circular Blood Flow Paths,” ASAIO J., vol. 63, no. 5, pp. 637-643, Oct., 2017.

[20] C. D’Onofrio, R. van Loon, S. Rolland, R. Johnston,“ Three-dimensional computational model of a blood oxygenator reconstructed from micro-CT scans,” Med. Eng. Phys., vol. 47, pp. 190-197, Sep., 2017.

[21] N. Salehi-Nik, G. Amoabediny, S.P.  Banikarimi, B. Pouran,“ Nanoliposomal growth hormone and sodium nitrite release from silicone fibers reduces thrombus formation under flow,” Ann. Biomed. Eng., vol. 44, no. 8, pp. 2417-2430, Aug., 2016.

[22] M. Pflaum, M. Kuhn-Kauffeldt, S.  Schmeckebier, D. Dipersa,“ Endothelialization and characterization of titanium dioxide-coated gas-exchange membranes for application in the bioartificial lung,” Acta Biomater., pp. 510-521, Mar., 2017.

[23] G.B. Kim, S.J. Kim, C.U.  Hong, T.K. Kwon, “Enhancement of oxygen transfer in hollow fiber membrane by the vibration method,” Korean J Chem Eng., vol. 22, no. 4, pp. 521-527, Jul., 2005.

[24] R.A. Orizondo, G. Gino, G.  Sultzbach, T.K. Kwon, “Effects of hollow fiber membrane oscillation on an artificial lung,” Ann. Biomed. Eng., vol. 46, no. 5, May, 2018.

[25] FLUENT, "User’s guide (release 18.2)," Species Transport Equations”, ANSYS Inc, 2017.

[26]           K.L. Gage, “Development of computational mass and momentum transfer models for extracorporeal hollow fiber membrane oxygenators,”University of Pittsburg, 2007.

[27] L. B. Leverett, J. D. Hellums, C. P. Alfrey, E. C. Lynch,“ Red blood cell damage by shear stress,” Biophys J., vol. 12, no. 3, pp. 257-273, Mar., 1972.

[28] M. Giersiepen, L.J. Wurzinger, R. Optiz, H. Reul,“ Estimation of shear stress-related blood damage in heart valve prostheses--in vitro comparison of 25 aortic valves,” Int. J. Artif Organs., vol. 13, no. 5, May, 1990.

[29] K.H. Fraser, T. Zhang, M.E. Taskin,“ A quantitative comparison of mechanical blood damage parameters in rotary ventricular assist devices: shear stress, exposure time and hemolysis index,” J. Biomech. Eng., vol. 134, no. 8, Aug., 2012.

[30] S.A. Berger, L.D. Jou, “Flows in stenotic vessels,” Annu. Rev. Fluid Mech., vol. 32, no. 1, pp. 347-382, Jan., 2000.

[31] J. Sheriff, J.S. Soares, M. Xenos, J. Jestly, “Evaluation of shear-induced platelet activation models under constant and dynamic shear stress loading conditions relevant to devices,” Ann. Biomed. Eng., vol. 41, no. 6, pp. 1279-1296, Jun., 2013.