一种用于计算耳蜗长度的数学模型的建立

摘要

Objective To compare the cochlear length of the miniature pig calculated by 3-dimensional reconstruction technique and an Archimedean spiral model,and to evaluate the feasibility of determining the length of the cochlea using a mathematical model.Methods The temporal bones of three miniature pigs with normal hearing were selected and scanned by micro-CT.The pictures were input into Mimics software,the 3D structure of the inner ear was reconstructed,and the following parameters were determined through Mimics:cochlear length,diameter of each turn,cochlear height,and apical turn angle.The cochlear length was calculated using the Archimedean spiral model.Results The length of the cochlea was (35.30 ± 0.88)mm based on the three-dimensional reconstruction technique compared to (34.85 ± 0.64) mm based on the Archimedean spiral model.The differences between the two values were not statistically significant.The height of the cochlea is (2.64 ± 0.24) mm.The capsule of the cochlea had 3.67 turns.Conclusions The three-dimensional reconstruction technique provides accurate and reliable results,but the reconstruction process is time-consuming and is unsuitable for clinical application.The Archimedean spiral model method is simple,feasible,reliable,and therefore suitable for clinical applications,in particular to provide references for cochlear implantation surgeries.%目的 比较应用三维重建技术与阿基米德螺线模型测量计算小型猪耳蜗长度的结果,评价数学模型用于耳蜗长度测量的可行性.方法 对3只听力正常小型猪的6个颞骨标本行Micro-CT扫描,将所得图片导入Mimics软件中重建内耳的三维结构,并通过其内置的测量工具包直接测量耳蜗的长度L、各转的直径R、耳蜗的高度h及顶转的角度.同时利用阿基米德螺线模型间接计算出耳蜗的长度L公式,比较两种方法所获耳蜗长度的差异.结果 基于三维重建技术测得小型猪的耳蜗长度为(35.30±0.88)mm,应用阿基米德螺线模型计算出的耳蜗长度为(34.85±0.64) mm,二者差异无统计学意义(t=l.19,P＞0.05).小型猪耳蜗的高度为(2.64±0.24)mm,耳蜗旋转3.67圈.结论 三维重建技术真实地反映了内耳的立体结构并允许直接测量,测量结果准确可靠,但重建过程较为费时,不适合临床上应用.阿基米德螺线模型可作为正常耳蜗长度测量的新方法,简单可行,可为临床人工耳蜗植入提供参考.