Reza Sahebi Kuzeh Kanan; Hanieh Niroomand-Oscuii; Kohyar Yazdanpanah-Ardakani
Volume 13, Issue 4 , December 2019, , Pages 315-326
Abstract
Nowadays, patients crowd suffering from heart disease are increasing along with the development of technology and mechanized life. On the other hand, donor hearts ready for transplantation is limited in the world. Therefore, exploiting blood pumps is a suitable alternative for helping the patient during ...
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Nowadays, patients crowd suffering from heart disease are increasing along with the development of technology and mechanized life. On the other hand, donor hearts ready for transplantation is limited in the world. Therefore, exploiting blood pumps is a suitable alternative for helping the patient during the waiting time and even until the end of life. The blood pumps should be able to satisfy the biological needs, including proper output pressure and flow rate, in an acceptable margin of safety in terms of blood injuries. Reduction of pump size, blood exposure time and blood damages such as hemolysis are mentioned as the important challenges in the design of blood pumps. 30% of the patients who are using a left ventricle blood pump, required right ventricle blood pump due to right ventricle failure. Fulfilling the physiological requirement of right ventricle a RVAD must generate pressure in the range of 15-25 mmHg and flow rate equal to 5 L/min. generation of pressure over 25 mmHg will lead to pulmonary hypertension and its consequent problems. In this research, a centrifugal blood pump is designed for the right ventricle with an emphasis on impeller geometry. This pump is simulated for rotational speeds of 1500, 2000 rpm and flow rates of 4-6 L/min by using the computational fluid dynamics. The designed pump produces a flow rate of 5 L/min at 1500 rpm and a pressure of 23 mmHg. The amount of the hemolysis index calculated by the Lagrangian method is 0.00413.
Cell Biomechanics / Cell Mechanics / Mechanobiology
Farhad Tabatabaei Ghomshe; Ahmad Reza Arshi; Masoud Mahmoudian; Mahyar Janahmadi
Volume -1, Issue 1 , June 2004, , Pages 77-92
Abstract
Effective pharmacological analysis encompassing both the pharmacodynamics and the pharmacokinetics of the heart, dictates the necessity for responses made by the main channel receptors, to be appropriately modelled. This approach is of critical value when the pharmacological responses of the organ during ...
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Effective pharmacological analysis encompassing both the pharmacodynamics and the pharmacokinetics of the heart, dictates the necessity for responses made by the main channel receptors, to be appropriately modelled. This approach is of critical value when the pharmacological responses of the organ during pathological states are under investigation. To this effect, the electrochemical phenomenon in the heart was simulated using a specifically simplified three dimensional model based on the cellular physiological concepts. Various advanced models for different types of heart cells were combined to produce a three dimensional model capable of describing the electrophysiological, electrochemical and geometric characteristics of a heart in a non-pathological state. Various cell type models such as central and peripheral SA node, AV node, atrial myocyte, ventricular myocyte, and specialized cells for rapid conductance like purkinje fibres were included in the 3D model. The cellular architecture in the model follows the non-heterogeneity of the heart structure accompanied by gap junctions representing cellular interconnections. Here the transport of Na+, Ca++, K+ and CL- was primarily governed by such factors as electrical and chemical potential gradients along with other energetic mechanisms. The simplified heart geometry is introduced through 18 layers with 25 cells in each layer. Model equations were solved to simulate a one second using a 2.6 GHz Pentium IV PC. The simulation was performed utilizing MA TLAB programming language which provides effective visualization capabilities. The CEP model could be adopted as a preliminary basis towards individualizations in pharmacology and electrophysiology.
