College of Engineering, Peking University, Beijing 100871, China.
Sci China Life Sci. 2013 Apr;56(4):366-72. doi: 10.1007/s11427-013-4448-6. Epub 2013 Mar 12.
Obstructive sleep apnea syndrome (OSAS) is characterized by recurrent collapses of the upper airway, which lead to repetitive transient hypoxia, arousals and finally sleep fragmentation. Both anatomical and neuromuscular factors may play key roles in the pathophysiology of OSAS. The purpose of this paper was to study the control mechanism of OSAS from the mechanical point of view. A three-dimensional finite element model was developed, which not only reconstructed the realistic anatomical structure of the human upper airway, but also included surrounding structures such as the skull, neck, hyoid, cartilage and soft tissues. The respiration process during the normal and apnea states was simulated with the fluid-structure interaction method (FSI) and the computational fluid dynamics method (CFD). The airflow and deformation of the upper airway obtained from the FSI and the CFD method were compared and the results obtained under large negative pressure during an apnea episode were analyzed. The simulation results show that the FSI method is more feasible and effective than the CFD method. The concave configuration of the upper airway may accelerate the collapse of the upper airway in a positive feedback mechanism, which supplies meaningful information for clinical treatment and further research of OSAS.
阻塞性睡眠呼吸暂停综合征（OSAS）的特征是上气道反复塌陷，导致反复短暂缺氧、觉醒，最终导致睡眠碎片化。解剖和神经肌肉因素都可能在上气道睡眠呼吸暂停综合征的病理生理学中起关键作用。本文旨在从力学角度研究 OSAS 的控制机制。建立了一个三维有限元模型，不仅重建了人体上气道的真实解剖结构，还包括了颅骨、颈部、舌骨、软骨和软组织等周围结构。采用流固耦合（FSI）和计算流体动力学（CFD）方法模拟了正常和呼吸暂停状态下的呼吸过程。比较了 FSI 和 CFD 方法得到的上气道气流和变形，并分析了呼吸暂停期间大负压下的结果。模拟结果表明，FSI 方法比 CFD 方法更可行、更有效。上气道的凹形结构可能在正反馈机制中加速上气道的塌陷，为临床治疗和进一步研究 OSAS 提供了有意义的信息。
