Johari Nasrul Hadi, Osman Kahar, Helmi Nor Harris N, Abdul Kadir Mohammed A Rafiq
a Department of Biomechanics, Faculty of Mechanical Engineering , Universiti Malaysia Pahang , 26600 Pekan , Pahang , Malaysia.
Comput Methods Biomech Biomed Engin. 2015;18(1):48-56. doi: 10.1080/10255842.2013.776548. Epub 2013 Mar 22.
Efforts to model the human upper respiratory system have undergone many phases. Geometrical proximity to the realistic shape has been the subject of many research projects. In this study, three different geometries of the trachea and main bronchus were modelled, which were reconstructed from computed tomography (CT) scan images. The geometrical variations were named realistic, simplified and oversimplified. Realistic refers to the lifelike image taken from digital imaging and communications in medicine format CT scan images, simplified refers to the reconstructed image based on natural images without realistic details pertaining to the rough surfaces, and oversimplified describes the straight wall geometry of the airway. The characteristics of steady state flows with different flow rates were investigated, simulating three varied physical activities and passing through each model. The results agree with previous studies where simplified models are sufficient for providing comparable results for airflow in human airways. This work further suggests that, under most exercise conditions, the idealised oversimplified model is not favourable for simulating either airflow regimes or airflow with particle depositions. However, in terms of immediate analysis for the prediction of abnormalities of various dimensions of human airways, the oversimplified techniques may be used.
对人类上呼吸道系统进行建模的努力经历了多个阶段。与真实形状的几何接近度一直是许多研究项目的主题。在本研究中，对气管和主支气管的三种不同几何形状进行了建模，这些形状是从计算机断层扫描（CT）图像重建而来的。这些几何变化被命名为真实型、简化型和过度简化型。真实型是指从医学数字成像和通信格式的CT扫描图像中获取的逼真图像，简化型是指基于自然图像重建的图像，没有与粗糙表面相关的真实细节，过度简化型描述的是气道的直壁几何形状。研究了不同流速下稳态流动的特征，模拟了三种不同的身体活动并使其通过每个模型。结果与先前的研究一致，即简化模型足以提供人类气道气流的可比结果。这项工作进一步表明，在大多数运动条件下，理想化的过度简化模型不利于模拟气流状态或带有颗粒沉积的气流。然而，就对人类气道各种尺寸异常预测的即时分析而言，可以使用过度简化技术。
