A Study On The Design,Fabrication And Sensing Characteristics Of Artificial Crista Ampullaris

The semicircular canal system is a part of the inner ear of human body,which is composed of three semicircular canals.They are approximately orthogonal to each other.Each semicircular canal has a transverse sickle bulge in its enlarged ampulla,which is called crista ampullaris.The semicircular canal is full of lymph inside and outside.When the human body is rotating,the crest of ampulla crista is deformed because of the inertia of lymph.And thus the spatial movement of the human head is sensed.Due to physiological factors,we lack the deep understanding of the perception mechanism of crista ampullarisBased on the previous work,this paper takes a semi-electrode piezoelectric fiber with metal core as sensing element.And a solid model of human ampulla crista was designed and fabricated according to the ratio of 1:1,in order to study its angular acceleration sensing characteristics and explore the perception mechanism of human crista ampullaris.The main contents of this paper are as follows1.The biomimetic hair sensor of SMPF(Symmetric Metal core PVDF Fiber)was designed and fabricated,and the relationship between the electric charge generated by SMPF and the excitation was deduced.The experimental results show that SMPF can sense the type,frequency and amplitude of the excitation signal,and the amplitude of the sensing signal has a linear relationship with the excitation amplitude.2.Using SMPF to replace the sensory hair of crista ampullaris and silicone rubber to replace the crest of crista ampullaris,and imitating the structure of human crista ampullaris,an artificial straight ampulla crest was fabricated.On the basis of One,the relationship between the deformation of silicone rubber and the output charge of SMPF is deduced,and the experimental demonstration is carried out.The experimental results show that SMPF can sense the frequency and amplitude of silicone rubber deformation,and the amount of deformation has a linear relationship with the charge.3.On the basis of Two,a one-dimensional solid model of human crista ampullaris was designed and fabricated with the proportion of 1:1 by imitating the structure of human semicircular canal.The relationships between the output charge of SMPF and gravity,as well as angular acceleration were analyzed through the theoretical model,and the experimental verification was carried out.The theoretical and experimental results show that the crista ampullaris is affected by the gravity during the sensing process.And the output charge is linearly related to the angular acceleration when the gravity effect is constant.4.On the basis of Three,a solid model of human 3D crista ampullaris was designed.A theoretical model is established to study the relationship between the output signals of three semicircular canals when the solid model is affected by the spatial angular acceleration.The experimental results verify the theoretical model,and show that no matter which semicircular canal is in the position of responsible semicircular canal,revealing that the other two semicircular canals have the role of auxiliary perception no matter which semicircular canal is in the position of responsible semicircular canal.Through the analysis of theoretical model and experimental verification,it shows that the concave convex deformation of human can reflect the angular acceleration of the head.The deformation of crista ampullaris in one-dimensional semicircular canal is linear to the angular acceleration on this plane,and is also affected by the direction of gravity.According to the output signal of the three-dimensional semicircular tube,the direction and magnitude of the space angular acceleration on the head can be calculated.The results of this study verify and modify some traditional theories of human inner ear biomechanics,which can provide some references for the examination and treatment of related diseases in vestibular research field.