基于压电叠堆的砧骨激励式人工中耳低功耗结构设计

Low power consumption structure design of an incus-stimulating middle ear implant based on piezoelectric stack

目的设计一种具有位移放大结构的压电振子改进方案,用于降低现有砧骨激励式人工中耳压电叠堆振子的功耗。方法首先,基于人耳解剖结构,设计带有位移放大结构和仅仅由压电叠堆构成的两种压电振子,并建立相应压电振子与中耳的耦合力学模型。通过对比该两种耦合力学模型的计算结果,分析引入位移放大结构前后的人工中耳听力补偿性能及功耗。结果引入位移放大结构后,压电振子在10.5 V有效电压驱动下,在1 kHz频率处的等效声压级由之前的100 dB增大至113 dB。此外,由压电叠堆直接激振时,振子在1、2和4 kHz处的功耗分别为6.42、1.56和0.28 mW;引入位移放大结构后,压电振子对应上述3个频率点的功耗分别降低至0.39、0.09和0.01 mW。结论所设计的带有位移放大结构的压电振子能够提高砧骨激励式人工中耳的听力补偿能力,有效降低压电振子的功耗。研究结果将有助于人工中耳结构设计的进一步完善,从而达到更好的听力补偿效果。

Objective To design an improvement plan of piezoelectric actuator with displacement magnification structure, so as to reduce power consumption of the existing incus-stimulating piezoelectric actuator for middle ear implant. Methods First, based on anatomical structure of human ear, the piezoelectric actuator with displacement magnification structure and the one just composed of piezoelectric stack were designed, respectively, and the corresponding coupled mechanical models of the middle ear and the piezoelectric actuator were established. By comparing the calculation results from the two types of coupling mechanical models, the hearing compensation property and power consumption of the actuator before and after the implantation of displacement magnification structure were analyzed. Results After adding the displacement magnification structure, the sound pressure level （SPL） at 1 kHz frequency was increased from 100 dB to 113 dB, when the piezoelectric actuator was stimulated by 10.5 V effective voltage. In addition, when the actuator was stimulated by the piezoelectric stack, its power consumption at the frequency of 1, 2 and 4 kHz were 6.42, 1.56 and 0.28 mW, respectviely; after introducing the displacement magnification structure, power consumption at the above-mentioned 3 frequencies decreased to 0.39, 0.09 and 0.01 mW, resepectively. Conclusions Piezoelectric actuator with displacement magnification structure in this study can improve hearing compensation ability of the incus-stimulating middle ear implant and effectively reducing the power consumption. The research findings will help to further improve the structure design of middle ear implant, thus achieving better hearing compensation effect.