Browsing by Author "Liu, Chien-Hao"

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A Bone-Guided Cochlear Implant CMOS Microsystem Preserving Acoustic Hearing
(2017-01-01)
Qian, Xin-Hong
;
Wu, Yi-Chung
;
Yang, Tzu-Yi
;
Cheng, Cheng-Hsiang
;
Chu, Hsing-Chien
In this paper, a bone-guided cochlear implant (BGCI) SOC microsystem is proposed and designed. The BGCI microsystem uses four or more electrodes placed on the bone surface of the cochlea and one on the round window to preserve partially the acoustic hearing. The external SOC of the BGCI processes the acoustic signals and generates stimulation patterns and command that are transmitted to the implanted chip through the 13.56MHz wireless power and bidirectional data telemetry. The implanted chip with 4-channel high-voltage-tolerant stimulator generates biphasic stimulation currents up to 800 mu A and sends back the power indication and electrode impedance error signals to the external SOC. Electrical tests on the fabricated BGCI has been performed. The in-vivo animal tests on guinea pigs has shown the evoked Wave III of EABR waveforms. The proposed BGCI can be applied to patients with high-frequency hearing loss, tinnitus, and dizziness.
Design and In Vivo Verification of a CMOS Bone-Guided Cochlear Implant Microsystem
(2019-11-01)
Qian, Xin-Hong
;
Wu, Yi-Chung
;
Yang, Tzu-Yi
;
Cheng, Cheng-Hsiang
;
Chu, Hsing-Chien
Objective: To develop and verify a CMOS bone-guided cochlear implant (BGCI) microsystem with electrodes placed on the bone surface of the cochlea and the outside of round window for treating high-frequency hearing loss. Methods: The BGCI microsystem consists of an external unit and an implanted unit. The external system-on-chip is designed to process acoustic signals through an acquisition circuit and an acoustic DSP processor to generate stimulation patterns and commands that are transmitted to the implanted unit through a 13.56 MHz wireless power and bidirectional data telemetry. In the wireless power telemetry, a voltage doubler/tripler (2X/3X) active rectifier is used to enhance the power conversion efficiency and generate 2 and 3 V output voltages. In the wireless data telemetry, phase-locked loop based binary phase-shift keying and load-shift keying modulators/demodulators are adopted for the downlink and uplink data through high-Q coils, respectively. The implanted chip with four-channel high-voltage-tolerant stimulator generates biphasic stimulation currents up to 800 mu A. Results: Electrical tests on the fabricated BGCI microsystem have been performed to verify the chip functions. The in vivo animal tests in guinea pigs have shown the evoked third wave of electrically evoked auditory brainstem response waveforms. It is verified that auditory nerves can be successfully stimulated and acoustic hearing can be partially preserved. Conclusion and Significance: Different from traditional cochlear implants, the proposed BGCI microsystem is less invasive, preserves partially acoustic hearing, and provides an effective alternative for treating high-frequency hearing loss.