ABSTRACT
For cochlear implant training and robotic cochlear implant experiments, the design method of scalable scala tympani model was proposed. The mathematical model of the cochlea was used as the central curve of scala tympani channel. Referring to the clinical anatomy data, the contour of the scala tympani cross-section was approximated as an ellipse. The profile was placed along the central curve, and the angle was adjusted to determine the position and orientation of the profile in three dimensions such that the central curve passes through its center. The data was imported into Matlab to generate a three-dimensional mathematical model of scala tympani, which can be expanded by setting different scale factors. The virtual scala tympani model was generated in SolidWorks, and the 2:1 fully transparent scala tympani model were fabricated by 3D printing to replace the specimen for experiment.
Subject(s)
Cochlea/surgery , Cochlear Implantation , Cochlear Implants , Robotics , Scala Tympani/surgeryABSTRACT
Objective To inject PPTA into the cochlea of guinea pigs through scala tympani fenestration ,to study the protective effect of PPTA injection on the cochlear damage induced by gentamicin and mechanism of oxy-gen free radical .Methods Randomly divided were the guinea pigs with normal hearing into three groups :the con-trol group ,GM group and PPTA group .We injected the artificial perilymph 10μl /d into cochlea through scala tym-pani fenestration on control group for 3 days ,injected GM 160 mg · kg -1 · d-1 on GM group for 3 days ,injected the PPTA 10 μl /d into the cochlea through scala tympani fenestration and injected GM 160 mg · kg -1 · d-1 at the same time on PPTA group for 3 days .We tested ABR and analyzed the hearing changes .We tested the OFR level reacted by SOD and GSH of the cochlea tissue .SEM and TEM were performed to observe the change of cell mor-phology .Results For ABR ,the control group was 12 .75 ± 3 .796 ,GM group 28 .230 ± 4 .953 ,PPTA group23 .47 ±9 .211 dB SPL(P<0 .05) .For SOD ,the normal group was 50 .241 ± 9 .080 ,GM group 28 .230 ± 4 .953 ,PPTA group 43 .089 ± 4 .587 U/mgprot(P<0 .05) .For GSH ,the normal group was 3 .03 ± 0 .33 ,GM group 1 .51 ± 0 .13 ,PP-TA group 2 .50 ± 0 .16 Ggsh/L(P<0 .05) .The changes of hair cells of PPTA group were obviously less severe than that of GM group .For TEM ,the changes of spiral ganglion and stria vascularis of PPTA group were obviously less severe than that of GM group .Conclusion Injecting PPTA through scala tympani fenestration can protect cochlea by generating the excess of OFR when confronting against GM .
ABSTRACT
Objective To provide anatomic data for operation of inserting the electron cochlear in young children. Methods Fourteen heads,28 sides specimens of young children of 1to-5-year old were dissected,through posterior tympanum approach,via mastoidectomy,posterior tympanoto to enter posterior tympanum.The related anatomy structures of the location of the electron cochlear inserted into the proper sites were observed and measured under surgical microscope. Results The round window was seated in superior part of the round window niche.The pyramidal eminence,tendo musculi stapedius,incudostapedial joint,base of stapes,cochleariform process,round window niche and promontorium tympani were all visible from different directions.The posterior arch of stapes was situated in the prozone of scala.Scala was situated in the posteroinferior scala vestibuli.The distance from the middle point of the anterior border of the round window niche to the inferior wall was(1.49?0.42)mm,to the posterior wall of the Scala tympani(0.90?0.31)mm,to the basal tissue(1.49?0.41)mm,to the pyramidal eminence(3.28?0.55)mm,to the lateral semicircular canal(7.41?0.90)mm,to the inferior margin of the base of stapes(3.09?0.53)mm.Conclusion It is considered that the location of the insertion should be at the middle point of anterior border of the round window niche anterior from 0.90mm to 1.49mm,deorsum from 0mm to 1.49mm.When the round window niche is not found,the location of the insertion has to be at the middle point of the inferior margin of the base of stapes deorsum 3mm.