TY  - EJOU
AU  - Chen, Wenyuan 
AU  - Zhang, Tao 
AU  - Yang, Yantao 

TI  - An Explicit and Non-Iterative Moving-Least-Squares Immersed-Boundary Method and Its Applications in the Aorta Hemodynamics with Type B  Intramural Hematoma
T2  - The International Conference on Computational \& Experimental Engineering and Sciences

PY  - 2023
VL  - 27
IS  - 3
SN  - 1933-2815

AB  - Based on the moving-least-squares immersed boundary method, we proposed a new technique to improve 
the calculation of the volume force representing the body boundary. For boundary with simple geometry, 
we theoretically analyze the error between the desired volume force at boundary and the actual force 
applied by the original method. The ratio between the two forces is very close to a constant and exhibits a 
very narrow distribution. A spatially uniform coefficient is then introduced to correct the force and can be 
fixed by the least-square method over all boundary markers. Such method is explicit and non-iterative, and 
is easy to implement into the existing scheme. We apply the new method to analyze the aorta hemodynamics 
with type B intramural hematoma for a group of 20 patients (The Ethical Review Board of Peking University 
People’s Hospital approved the study protocols, and informed consent about data collection and figure 
presentation in this paper was obtained from all patients). Based on the wall-shear-stress field, the mean 
oscillatory shear index (OSI) over the hematoma section are calculated. We also calculate the blood pressure 
difference Pd between the inlet and outlet and study the duration Td of high pressure in one cardiac cycle for 
different patients, which we think is important for the periodic loading process. By combining two criteria, 
namely the duration T<sub>d</sub> > 0.05s and the mean oscillatory shear index OSI > 0.125, we can distinguish the 
patients with tear from those without for a confidence pvalue of .023. We then propose a new parameter 
|∇<sub>
KW  - Immersed boundary method; moving least squares; aorta hemodynamics; type B intramural hematoma

DO  - 10.32604/icces.2023.09754