Numerical evaluation of implantable hearing devices using a finite element model of human ear considering viscoelastic properties.
Finite element method was employed in this study to analyze the change in performance of implantable hearing devices due to the consideration of soft tissues' viscoelasticity. An integrated finite element model of human ear including the external ear, middle ear and inner ear was first developed via reverse engineering and analyzed by acoustic-structure-fluid coupling. Viscoelastic properties of soft tissues in the middle ear were taken into consideration in this model. The model-derived dynamic responses including middle ear and cochlea functions showed a better agreement with experimental data at high frequencies above 3000 Hz than the Rayleigh-type damping. On this basis, a coupled finite element model consisting of the human ear and a piezoelectric actuator attached to the long process of incus was further constructed. Based on the electromechanical coupling analysis, equivalent sound pressure and power consumption of the actuator corresponding to viscoelasticity and Rayleigh damping were calculated using this model. The analytical results showed that the implant performance of the actuator evaluated using a finite element model considering viscoelastic properties gives a lower output above about 3 kHz than does Rayleigh damping model. Finite element model considering viscoelastic properties was more accurate to numerically evaluate implantable hearing devices.
Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China.
Jing
J
Zhang
Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China.
Jiabin
J
Tian
Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China.
Na
N
Ta
Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital Affiliated to Fudan University, Shanghai, China.
Xinsheng
X
Huang
Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China zsrao@sjtu.edu.cn.
Zhushi
Z
Rao
D001696:Biomechanical Phenomena; D003054:Cochlear Implants; D003198:Computer Simulation; D004423:Ear / Q000033:anatomy & histology* / Q000502:physiology*; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D014783:Viscosity
Viscoelasticity; finite element method; human ear; implantable hearing device; piezoelectric actuator