Modeling And Numerical Simulation Of Middle Ear-eustachian Tube System Based On Chinese Digital Visual Human Body

Objective:In this study,a three-dimensional model of the middle ear and eustachian tube was established based on the Chinese digital visual human dataset,and the numerical simulation of changes of middle ear ventilation and pressure after Eustachian tube opening was carried out using computer fluid dynamics tools.On this basis,we further explore the influence of various biomechanical parameters in the process of Eustachian tube opening and its relative importance.Methods:The complete head data set of Chinese Digital Visual Human Body No.1 was used.The images were imported by Amira image processing software,processed and segmented by Geomagic software to form a three-dimensional model of middle ear-eustachian tube system,including eustachian tube,middle ear tympanum,tympanic membrane,auditory ossicles and mastoid air cell system.The 3D model was imported into Hypermesh software for meshing and analysis.The structural mechanics calculation was carried out by using Abaqus nonlinear finite element software,and the gas flow was numerically simulated by Xflow fluid mechanics software.Numerical simulation of tissue deformation and gas flow during eustachian tube opening was carried out by using fluid-solid coupling algorithm combined with fluid mechanics and structural mechanics.Multiple pressure monitoring points were set in the middle ear-eustachian tube model,and the pressure change curve of each monitoring point was recorded.The function verification was carried out by comparing the pressure change of the middle ear after the numerical simulation of the opening process of the eustachian tube.Based on the establishment of the model,by changing the biomechanical parameters of the Eustachian tube,the changes in air flow and viscous flow resistance through the eustachian tube were further calculated.Results:1.In this study,a three-dimensional model of middle ear-eustachian tube including eustachian tube,tympanum,mastoid air cell system,tympanic membrane and ossicles and a numerical simulation model of middle ear ventilation were established,which can simulate the tissue deformation and middle ear pressure changes after the eustachian tube opening.2.The numerical simulation model can verify the sequential opening mechanism of eustachian tube and the pressure buffering effect of mastoid process.3.Influence of biomechanical parameters on active opening of eustachian tube was as follows:? Among the biomechanical parameters of eustachian tube,the muscle strength of tensor veli palatine muscle is the most significant biomechanical parameter affecting the eustachian tube opening,followed by the elastic modulus of eustachian tube mucosa and the elastic modulus of eustachian tube cartilage.?The greater the muscle strength of tensor veli palatine muscle in a certain range,the greater the opening degree of eustachian tube;Beyond a certain range,increasing the muscle strength of tensor veli palatine has no effect on the opening degree of eustachian tube.?The muscle strength of levator veli palatini has little influence on the opening degree of eustachian tube.?The greater the elastic modulus of mucosa around the eustachian tube in a certain range,the smaller the opening degree of the eustachian tube;Exceeding a certain threshold can significantly hinder the eustachian tube opening.?The greater the elastic modulus of eustachian tube cartilage in a certain range,the smaller the opening degree of eustachian tube.? When mucosal adhesion exceeds a certain threshold,it can significantly hinder the Eustachian tube opening function.Conclusion:In this paper,a complete three-dimensional model of the middle ear and Eustachian tube was established based on the Chinese digital visual human dataset,and the structural mechanics and computational fluid dynamics methods were used to numerically simulate the tissue deformation and the change of the middle ear pressure during the opening process of the eustachian tube.The accuracy and reliability of the model were verified by anatomical and functional verification.The model was applied to further study the effect of different biomechanical parameters on the opening degree of the eustachian tube.Modeling and computational simulation can help to improve the understanding of the anatomical and physiological mechanisms of middle ear ventilation,provide an effective target for the treatment of middle ear ventilation dysfunction in the future,or provide a theoretical basis for the selection of treatment methods.