The potential of CFD simulations is increasingly being exploited in many modern engineering fields. However, the use of CFD techniques is more restricted to manufacturing domains, to study and optimize the performance of equipments and systems involving fluid flows. Yet, recent advancements in scanning and computing technologies have opened a whole new set of opportunities in biomedical engineering field.
The complexity of human anatomy and human fluid behavior is a reason why CFD techniques took a little more time to be utilized as a research tool in medical domain. Medical researchers, now have the ability to gain knowledge of how body fluids and system components are expected to perform, making possible to improve the bio-fluid physiology studies and design better medical treatments and devices. Some of the recent applications of CFD in biomedical engineering are described here, providing a brief idea on the emerging application of simulation technique.
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Researchers have been applying CFD techniques to predict the blood circulation inside the human body, and are increasingly used to study fluid flow phenomenon inside the vascular system. Predicting the flow circulation in these systems offer several benefits which include: lowering the postoperative complications, developing better surgical procedures and medical equipments such as blood pumps.
One of the example applications of CFD is in predicting coronary artery diseases such as atherosclerosis, which is known to occur due to biomechanical and fluid flow factors such as flow velocity and pressure changes. The CFD analysis can be performed by generating mesh on the coronary artery using three-dimensional medical images converted into a vector format.
Boundary conditions such as velocity and pressure information according to the cardiac cycle can later be applied. Later, selecting appropriate viscosity models to simulate non-Newtonian fluids can be selected to solve fluid flow equations and obtain results. The wall shear stress, velocity and pressure of the fluid flow can be visualized to predict the reasons for atherosclerosis and identify best methods of intervention.
Air Flow in Lungs:
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A CFD based diagnostic system assists physicians in obtaining functional and anatomical data to evaluate patient’s pulmonary status and improve prognostic and therapeutic interventions. There have been extensive studies in simulating the lungs using CFD approach. The process requires obtaining an accurate CAD model using MRI and CT scans and generating mesh model of the geometry. To simulate air flow process, boundary conditions such as pressure and velocity values are a priori.
The walls can be applied with stick physical boundary condition to replicate the effect of mucus layer in trachea and primary bronchi. Thus, the inhalation process can be simulated and critical conditions such as inhaling of pollutant particles during breathing can be visualized. This can help physicians in developing medical devices and treatments required.
Artificial Organ Design:
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The use of CFD is also being used increasingly in evaluating the performance of artificial organs. One of the example applications is to predict the physiological behavior of prosthetic heart valve. Numerical simulations assist in identifying important information about the locations of high shear rates in the flow that damage the blood cells. This requires specifying boundary conditions for the inflow and outflow and a no-slip & no-flux condition for the velocity components on the rigid aorta and the leaflet surfaces. The use of Fluid-structure interaction techniques can also be employed to simulate the valve behavior during cardiac cycle and improve the smoothness of the flow.
The application of CFD is being consistently stretched for several other biomedical applications such as vocal tract analysis, spinal fluid flows, nose and sinus flows, joint lubrication, etc.
Apart from biomedical, the use of computational technique is also employed in developing medical devices that are required during surgical procedures. The decreasing cost of computational power and development of new mathematical models for biomedical applications are further expected to extent the usage of CFD techniques and provide a helping hand in saving human lives.
Mehul Patel specializes in handling CFD projects for Automobile, Aerospace, Oil and Gas and building HVAC sectors.