Mechanical Bionic Design Of Semicircular Canals And Study On Mechanical Properties Of Meniere’s Disease

The vestibular organ is a receptor that senses the state of motion and spatial position of the human body.The semicircular canal is the organ that senses the state of rotation,and the sensing site is located in the labyrinth of the inner eardrum.The membranous labyrinth is filled with endolymph fluid.The biggest feature of Meniere’s disease is the accumulation of endolymph fluid,which has a huge impact on the rotation of the semicircular canal.Among them,there are theories such as mechanical obstruction of endolymphatic vessels and impaired absorption of endolymph.The semicircular canal is located in the petrous part of the temporal bone of the head,so it is not convenient to detect it directly.In medicine,the phenomenon of nystagmus is usually used to observe and detect the condition of the semicircular canal indirectly,and the internal biomechanical response cannot be detected.In order to explore the internal mechanical movement of the semicircular canal,this subject designed and prepared a one-dimensional bionic semicircular canal model.After confirming that the bionic semicircular canal model is the same as the real semicircular canal internal movement law,on this basis,a bionic model of Meniere’s disease lesion was proposed to study the lesion effects on internal movement.The specific research content is as follows:(1)Based on the human semicircular canal slice tissue data,model the shell of the membranous semicircular canal,establish a second-order overdamped mathematical model for the one-dimensional semicircular canal model,enlarge the design model by four times,and calculate the physical parameters of the endolymph fluid and cupula in accordance with the bionic semicircular canal model.The translucent photosensitive resin was used to prepare the hard shell of semicircular canals.The inner endolymph was replaced by polyvinyl alcohol solution.The cupula was artificially prepared by gelatin/polyvinyl alcohol blend film.The prepared parts are assembled together and initially verified by a long-time constant.(2)Design and build the pulse angular acceleration stimulation experiment platform and the sinusoidal swing stimulation experiment platform with reference to the rotation stimulation method when obtaining electronystagmogram in clinical practice.The pulse angular acceleration experimental platform realizes the application of pulse acceleration or different angular acceleration stimulation to the bionic semicircular canal,and the sinusoidal swing experimental platform realizes the back and forth rotation of different frequencies.The internal motion trajectory of the bionic semicircular canal is recorded by the microscope camera.For the platform that needs continuous rotation,a wireless camera is used,and for the platform that oscillates sinusoidally,a higher-definition USB industrial camera is used to record.Under the stimulation of the two experimental platforms,comparing the clinical nystagmus slowphase curve,it is further confirmed that the bionic semicircular canal can replace the real semicircular canal to reflect the internal movement law.At the same time,different acceleration stimuli were given to verify that the acceleration did not affect the reading of the long-time constant during the rebound process of the cupula.(3)According to the morphological characteristics of Meniere’s disease,design the membrane semicircular canal model after endolymph fluid accumulation,and introduce the increment of the coefficients of the mathematical model after the accumulation of endolymph,and derive the transfer function with the increment coefficient.In order to explore the influence of water swelling in different parts on the law of motion,models of thin tube,ampulla and utricle were prepared separately,and pulse angular acceleration experiments and sinusoidal swing experiments were performed on each model.The results of pulse angular acceleration experiments show that the displacement of the cupula of the swelling model is significantly increased and the long time constant is significantly shortened,and the thin tube part is most seriously affected.In the sinusoidal swing experiment,the gain of the swelling model increases in the whole frequency band,and the phase difference decreases in the high frequency,and the thin tube part has the greatest influence.Therefore,the quantitative expansion of the thin tube part shows that the inner diameter is linearly positively correlated with the maximum displacement of the cupula,and the relationship between the inner diameter and the long-time constant conforms to the theoretical deduction.Considering that the ampulla expands and stretches the cupula,a pre-tightening force is applied to the cupula during assembly,and the results show that the amplitude decreases and the rebound speeds up.Through the establishment of a theoretical model,the internal movement of the semicircular canal in Meniere’s disease was studied.The experimental results showed that the displacement amplitude of the cupula increased and rebounded rapidly after the endolymphatic fluid accumulated,which is similar to the sudden rotational vertigo in patients.This topic studies the difference in biomechanical properties before and after the semicircular canal shape change after suffering from Meniere’s disease,and provides a theoretical reference for the treatment of such diseases.