Design Study of a Round Window Piezoelectric Transducer for Active Middle Ear Implants

Abstract

This report describes the design of a new piezoelectric transducer for round window (RW)-driven middle ear implants. The transducer consists of a piezoelectric element, gold-coated copper bellows, silicone elastomer (polydimethylsiloxane, PDMS), metal cylinder (tungsten), and titanium housing. The piezoelectric element is fixed to the titanium housing and mechanical resonance is generated by the interaction of the bellows, PDMS, and tungsten cylinder. The dimensions of PDMS and the tungsten cylinder with output characteristics suitable for compensation of sensorineural hearing loss were derived by mechanical vibrational analysis (equivalent mechanical model and finite element analysis (FEA)). Based on the results of FEA, the RW piezoelectric transducer was implemented, and bench tests were performed under no-load conditions to confirm the output characteristics. The transducer generates an average displacement of 219.6 nm in the flat band (0.1–1 kHz); the resonance frequency is 2.3 kHz. To evaluate the output characteristics, the response was compared to that of an earlier transducer. When driven by the same voltage (6 Vp), the flat band displacement averaged 30 nm larger than that of the other transducer, and no anti-resonance was noted. Therefore, we expect that the new transducer can serve as an output device for hearing aids, and that it will improve speech recognition and treat high-frequency sensorineural hearing loss more effectively.

Novel low-carbon energy solutions for powering emerging wearables, smart textiles, and medical devices

“…As a result, the novel transducer acted as a cochlear hearing aid, boosting speech perception and treating high-frequency deafness relatively in a better way. 343 Peripheral parts are a key drawback of today's cochlear hearing devices since they cause soreness and annoyance. To overcome such limitations, completely implanted cochlear implants have been explored recently; however, creating internal sensing elements has remained tricky.…”

“…Photo-biomodulation Fig. 18 (a) Piezoelectric transducer with an implantable middle ear hearing device, 342 (b) diagram of a piezoelectric transducer installed in the round window, 343 and (c and d) prototype of the annular accelerometer and MEMS sensor implanted at the umbo of the ear 344 (reproduced with permission 342 Copyright 2017, MDPI) (reproduced with permission 343 Copyright 2021, MDPI) (reproduced with permission 344 Copyright 2018, Springer Nature).…”

“…As a result, the novel transducer acted as a cochlear hearing aid, boosting speech perception and treating high-frequency deafness relatively in a better way. 343…”