基于耦合模型的人工中耳压电振子设计

Design of Piezoelectric Transducer for Middle Ear Implant Based on Coupling Model

利用中耳与压电振子的耦合力学模型,研究设计人工中耳压电振子。该力学模型基于一无任何听力损伤病史的成年志愿者的左耳,利用CT扫描和逆向成型技术建成模。模型的可靠性通过镫骨底板的位移计算结果与国外文献实验测得数据进行对比加以验证。最终设计的压电振子采取悬浮结构,由绑定装置、压电叠堆及质量块所组成,仅需简单的手术便可直接将其植入在砧骨长突上,且只需要10.5 Vrms的驱动电压便可以对镫骨激起相当于鼓膜处100 dB声压激励的振幅。

To design a simplefloating mass type piezoelectric transducer, consisting of a piezoelectric stack, a metal case and a clamp, for middle ear implant, a biomechanies model coupled by human middle ear and piezoelectric transducer is constructed. This model is built based on a complete set of computerized tomography section images of a healthy volunteer＇s left ear by reverse forming technology. The validity of this model is confirmed by comparing the result of motion of the stapes of this model with the published experimental data on human temporal bones. It is shown that the designed transducer can be implanted on the incus long process by a simple surgical operation, and the stapes footplate displacement by its excitation at 10.5 Vrms is equivalent to that from acoustic stimulation at 100 dB SPL, which is adequate stimulation to the ossicular chain.