| 摘要 |
A hearing aid (10) includes an implantable microphone (28), signal-processing amplifier (30), battery, and microactuator (32). The amplifier (30) amplifies and processes a signal from the microphone (28) for application to the microactuator (32). The microactuator (32) is implanted to mechanically create vibrations in perilymph fluid (20a) within a subject's inner ear (17). A transducer (45) of the microactuator (32) is preferably a circular disk, 2 to 8 mils thick, of stress-biased PLZT. Such disks can be mounted as drumheads, preferably in conjunction with a flexible diaphragm (53, 56, 57), to a threaded metal tube (46), e.g. 1.4 mm in diameter and 2.0 mm long. The tube (46) is implanted into a fenestration in the promontory (18) of a subject's inner ear (17). Securing the disk-shaped transducer (45) to a tube (46) having a diameter larger than the fenestration and filling the tube (46) with fluid (58) provides hydraulic amplification for the transducer's displacement. The microphone (28) is preferably fabricated from a thin sheet of PVDF overcoated with inert metal electrodes (42a, 42b). |
