ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

3. METHODS
One healthy adult man aged 33 years was participated in this study and he gave written
informed consent to protocols approved by the Human Research Committee of Shahid
Rajayee hospital of Tehran. The normal results of physical examination and
echocardiography were observed. Echocardiographic test was performed using a
commercially ultrasonograph (MAYLAB). We recorded a four-chamber view at rest
and during each stage of exercise, increase of 10 heart beats. Maylab-desk software was
used to measure the required geometrical data for the model. Using the data, the 2D
model was generated by Solidworks
software which is illustrated in Figure 1.
Figure 1. The generated geometry for flexible aortic valve.
The blood behaves as a non Newtonian fluid , however it can be considered as
Newtonian fluid in large arteries and heart. Therefore, we have assumed blood as a
Newtonian fluid with constant viscosity of 0.005 kg/m.s. The density of blood was
3
considered 1060 kg/m . The aortic valve leaf lets were assumed to behave as a
3
incompressible linier elastic material. The density is 1000 kg/m , the Young module:
2
1800000 N/m , and Poisson’s ratio: 0.495.
Figure 2 illustrates the interpolated curves of central, ventricular, and Brachial
systolic/diastolic pressures from rest position and during exercise with respect to
variation of heart beats. Regarding the boundary conditions, the central diastolic
pressure was considered as the pressure outlet and the maximum systolic left ventricle
pressure was considered as the inlet pressure.
Figure 2. The curves of systolic/diastolic pressures for central, ventricular, and
Brachial.