Basic Research Of Build The Macro-biomechanical Model Of The Inner Ear

Objective:1. With the rapid development of the diagnosis and treatment of ear disease, the precise anatomy structure and the spatial relations of the inner ear have become increasingly important. To obtain the three-dimensional reconstruction of the geometric model of the inner ear with serial sections, can show the structure and status of the cochlea and the vestibular system, include the bony labyrinth, membranous labyrinth and internal and external lymph, and it can help the clinical doctor deepen understanding with the macro, micro-structure of the inner ear.2. With the three-dimensional reconstruction of the guinea pigs'inner ear, we can preliminary study the subject's macro and micro-structure of the inner ear when they under the normal conditions, then it can laying the basis study for the macro, micro-changes of the human inner ear when we set some abnormal conditions on the subject in the future (such as high noise stimulation, or destroy the balance ability of vestibular system).3. Proficiency in frozen serial sections technology and the computer three-dimensional reconstruction method. the study will also become the effective clinical tools to found the specific lesions of the inner ear and make the measurement and evaluation, it can provided a visual analysis platform for the clinical treatment of inner ear diseases, and accumulate experience for the clinical work in the future.4. This paper has also use the finite element software for three-dimensional reconstruction based on the geometric parameters of the right ear membranous labyrinth which provided by a healthy volunteers, numerical simulation the bio-mechanical response of the vestibular system membranous labyrinth when this volunteer do the sinusoidal rotating chair test. The findings will help us to quantitative understanding the function of how the vestibular system to maintain a balance, and provide a quantitative analysis platform for the clinical treatment of the vestibular system disease.Materials and Methods:One adult healthy guinea pig, decapitated soon after general anesthesia to get the bilateral temporal bone (including the cochlea and vestibular portion) and a fixed, After pruning, decalcification, dehydration, dipping, embedding steps and make the frozen serial sectioning, Each section's interval is 5μm, the fixed section will be dye-coloured and be coverslipping. Use the camera to obtain a set of images which had been enlarged of the guinea pig inner ear tissue, Images are processed by Photoshop and then use the self-compiled MATLAB program to recognized the borders to obtain three-dimensional coordinates of these boundary points, Use the geometrical parameters and finite element software to make the three-dimensional reconstruction, so we can obtain the membrane structure three-dimensional geometric model of guinea pig inner ear (including the cochlea and vestibular portion).We also use the same method to obtain the three-dimensional reconstruction based on the geometric parameters of the right ear membranous labyrinth which provided by a healthy volunteers through finite elemental software, The endolymph was modeled as a compressible pseudo elastic solid, and the cupula partitions, balance receptors located in the ampullae of membranous labyrinth, were represented by linearly elastic solids including large deflection. The biomechanical response of the volunteer during sinusoidal rotation chair test was numerically simulated.Results:1. To obtain a complete set of images which had been enlarged of the guinea pig inner ear tissue.2. According to data provided by continuous tissue sections, we can established the membrane three-dimensional geometric model of the guinea pig inner ear, including cochlea, vestibule and semicircular canals, which can be better response to the details and spatial characteristics of guinea pig inner ear tissue. And to lay the foundation to applied to human studies in future.3. Numerical simulation of three-dimensional geometric model of a right ear membranous labyrinth of vestibular system which provided by a healthy volunteers, the vestibular system within the membranous labyrinth can be deformed part of the ridge tops and within the lymph elastomer will also be subject to the role of centrifugal force and inertia force, relative to the membrane surface deformation sports to form the incoming electrical activity at all levels of the vestibular nerve center, causing a comprehensive response to maintain body balance. In this mechanical and electrical conversion process, membranous labyrinth the vestibular system reflects the biological nature of the instrument angular acceleration, crest displacement characteristics of the node can indirectly reflect the characteristics of ciliary movement, and thus reflect the balance receptors in the human body to maintain a balanced relationship.Conclusion:1. The inner ear has the complex structure, conventional anatomy and histological slices research can not explain very well about the details of their spatial and spatial accuracy of the measurement. But the computer three-dimensional reconstruction with serial sections not only have the sections details, but also reflect its spatial characteristics, is a way to improve the study level of the temporal bone morphology.2. Frozen section is mainly applied to morphological observation, the results is basically the same with the temporal bone celloidin sections, it is a better method to observe the linkages between cochlear duct's inside and outside structures and within the modiolar organizational structure, that's more thin and short production cycle than the cellodin section, which would make sense right for temporal bone anatomy study.3. This experiment will be entirely built the three-dimensional structure of guinea pig's inner ear, it can show out of the structure and state of cochlea and the bony labyrinth, membranous labyrinth of the vestibular system, it can help clinicians to deepen the understanding and create awareness of inner ear's macro and micro-structure.4. For the results of numerical simulation of biomechanical model based on the right ear geometric parameters of healthy volunteers shows that the Lagrangian method applied to the vestibular system, endolymphatic fluid coupled vibration analysis is feasible, experimental results reliable.