部分人工听骨植入位置对中耳传声影响--有限元模型研究

Effect of the position of PORP on the middle ear transferfunction——a finite element model

目的研究部分人工听骨(partial ossicular replacement prosthesis,PORP)植入位置对中耳传声的影响。方法在去除砧骨的中耳有限元模型上,建立钛金属柱状结构连接锤骨与镫骨的有限元模型,模拟PORP功能。计算锤骨柄不同位置放置PORP,以及软骨片置入PORP和移植筋膜之间对中耳传声的影响。结果 PORP分别置于锤骨颈部、锤骨柄中部和锤骨头去除后的3种情况下,鼓膜脐部振幅于200~8000 Hz均减低,于200~3200 Hz减低大于3200~8000 Hz减低幅度。同样上述3种情况下,镫骨振幅于200~8000 Hz增加,PORP放置于锤骨柄和锤骨颈部基本一致;锤骨头去除后,1000~8000 Hz镫骨振幅较前二者有轻度增高,约2~3 d B。当PORP与鼓膜间置入软骨片时,镫骨底板振动均轻度增强,但不同材料的软骨片差别不大。结论 PORP材料属性和放置位置对实现中耳传声至关重要。

OBJECTIVE To study the effect of partial ossicular replacement prothesis （PORP） on the middle ear transfer function. METHODS On a incus removed finite element model, a titanium columnar structure which link the malleus and the stapes was used to simulate the function of PORP to transmit acoustic pressure. The effect of placement of PORP on different positions of the manubrium, as well as the insertion of the cartilage between the artificial bone and the fascia on the middle ear transfer function were calculated. RESULTS When the PORP is placed on the neck of manubrium, mid-manubrium and head of malleus removed, the vibration amplitude of the umbo of the tympanic membrane is reduced in 200-8000 Hz, and the reduction range in 200-3200 Hz is more than that of 3200- 8000 Hz. While the vibration amplitude of the stapes in the 200-8000 Hz amplitude increased. The vibration amplitude is basically the same when placed on the neck of manubrium and mid-manubrium, while it slightly increased about 2-3 dB than the former two when the head of malleus removed. In 1000-8000 Hz. When putting the cartilage between the PORP and transplanted fascia, the vibration amplitude of the stapes footplate was slightly increased, but there was a slight difference with different cartilages. CONCLUSION The placement and material property of PORP play an important role in the middle ear transfer function.