Abstract
Numerical method is employed to simulate the muscle material characteristics of obstructive sleep apnea (OSA) patients. A set of averaged muscle material characteristics for the range of body mass index (BMI) examined is concluded to predict the expansion of the patient’s upper airway after surgery for the clinic reference before the surgery. Firstly, the mandibular bone, chin, neck and upper airway models of three patients, whose BMI are similar, are reconstructed based on the computed tomography (CT) images before and after surgery. Then, the model structures before and after “virtual surgery” are simulated by computational solid mechanics (CSM) with the assumptions of elasticity, anisotropy and homogeneous muscle material characteristics. Iterations are subsequently performed through comparing the model outlines obtained by “virtual surgery” simulation and the clinical surgery to acquire the appropriate muscle material characteristics of patients. A set of proper muscle material characteristics of patients is thus attained for 21<BMI<23. On the other hand, the flow structures and pressure lose of upper airway both before and after clinical surgery as well as after “virtual surgery” are investigated and compared using computational fluid dynamics (CFD) with k-ωSST model at a flow rate 5×〖10〗^(-4) m^3/s of healthy persons. The results of CSM “virtual surgery” and CFD simulations show that the average differences of upper airway narrow rate and total inhaling pressure drop are 2.1% and 4.1% respectively. It suggests that the new proposed CSM “virtual surgery”-CFD together with the “working procedure” is able to provide useful clinical reference for the condition of upper airway after surgery.