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1.
Journal of Medical Biomechanics ; (6): E431-E436, 2016.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-804053

RESUMO

Objective To study effects from sand therapy of Uyghur medicine on hemodynamics in femoral artery branch and stress, so as to further discuss the functions and mechanisms of Uyghur sand therapy for treatment of femoral artery thrombosis formation. Methods Uyghur sand therapy was conducted on the subjects by indoor Uyghur sand therapy system. The peak values of blood flow velocity, inner diameter and resistance index (RI) of femoral artery before and after receiving Uyghur sand therapy were measured by the ultra-portable Doppler Diagnostic Ultrasound System for statistic analysis. Three-dimensional fluid-solid coupling model of femoral artery branch was reconstructed, and blood flow velocity, pressure, wall shear stress in the flow field as well as the equivalent stress, strain, total displacement on femoral artery wall were simulated and analyzed by the ANSYS Workbench. Results After receiving Uyghur sand therapy, the mean peak values of blood flow velocity and inner diameter of femoral artery increased by 32.43% and 2.68%, while the mean values of RI decreased by 4.88%, which showed it had the statistical difference(P0.05).Besides, the maximum values of blood flow velocity, pressure and wall shear stress increased by 29.91%,68.51%,46.54%,respectively, while the maximum values of equivalent stress, equivalent strain, total displacement on femoral artery wall increased by 65.85%,45.45%,44%, respectively, after receiving Uyghur sand therapy. Conclusions Uyghur sand therapy can increase blood flow velocity and decrease RI obviously,and help to expand the inner diameter of femoral artery to make blood circulation inside improved. With Uyghur sand therapy, the shear stress, blood flow velocity, pressure as well as the stress, strain, total displacement on femoral artery walls also increase, meanwhile,high pressure area on femoral artery branch reduces to some extent, which shows it plays a certain positive role in reducing atherosclerosis and thrombus formation inside femoral artery.

2.
Ultrasound Med Biol ; 41(1): 99-113, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25438850

RESUMO

Despite the availability of multiple ultrasound approaches to left ventricular (LV) flow characterization in two dimensions, this technique remains in its childhood and further developments seem warranted. This article describes a new methodology for tracking the 2-D LV flow field based on ultrasound data. Hereto, a standard speckle tracking algorithm was modified by using a dynamic kernel embedding Navier-Stokes-based regularization in an iterative manner. The performance of the proposed approach was first quantified in synthetic ultrasound data based on a computational fluid dynamics model of LV flow. Next, an experimental flow phantom setup mimicking the normal human heart was used for experimental validation by employing simultaneous optical particle image velocimetry as a standard reference technique. Finally, the applicability of the approach was tested in a clinical setting. On the basis of the simulated data, pointwise evaluation of the estimated velocity vectors correlated well (mean r = 0.84) with the computational fluid dynamics measurement. During the filling period of the left ventricle, the properties of the main vortex obtained from the proposed method were also measured, and their correlations with the reference measurement were also calculated (radius, r = 0.96; circulation, r = 0.85; weighted center, r = 0.81). In vitro results at 60 bpm during one cardiac cycle confirmed that the algorithm properly measures typical characteristics of the vortex (radius, r = 0.60; circulation, r = 0.81; weighted center, r = 0.92). Preliminary qualitative results on clinical data revealed physiologic flow fields.


Assuntos
Algoritmos , Velocidade do Fluxo Sanguíneo/fisiologia , Ecocardiografia Doppler/métodos , Ventrículos do Coração/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Modelos Cardiovasculares , Função Ventricular Esquerda/fisiologia , Simulação por Computador , Ecocardiografia Doppler/instrumentação , Humanos , Aumento da Imagem/métodos , Imagens de Fantasmas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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