Fully Implantable Cochlear Implant Interface Electronics With 51.2-mu W Front-End Circuit

Ulusan, Hasan
Chamanian, Salar
Ilik, Bedirhan
Muhtaroglu, Ali
Külah, Haluk
This paper presents an ultralow power interface circuit for a fully implantable cochlear implant (FICI) system that stimulates the auditory nerves inside cochlea. The input sound is detected with a multifrequency piezoelectric (PZT) sensor array, is signal-processed through a front-end circuit module, and is delivered to the nerves through current stimulation in proportion to the sound level. The front-end unit reduces the power dissipation by combining amplification and compression of the sensor output through an ultralow power logarithmic amplifier. The amplified signal is envelope detected, and fed to a voltage-controlled current source as a reference for stimulation current generation. The single channel performance has been tested with a thin film pulsed-laser deposition (PLD) PZT sensor for sound levels between 60- and 100-dB sound pressure level (SPL). The proposed front-end signal conditioning unit, which can support different back-end stimulators, dissipates only 25.4 and 51.2 mu W based on measurement, for 1- and 8-channel operation, respectively. This represents the lowest in the literature. The interface generates linear stimulation current of 110-430 mu A for the given sound range. The single-channel and eight-channel stimulator consume 105 and 691 mu W, respectively, for 110-mu A biphasic stimulation current.


Neural stimulation interface with ultra-low power signal conditioning circuit for fully-implantable cochlear implants
Ulusan, Hasan; Chamanian, Salar; Zorlu, Ozge; Muhtaroglu, Ali; Külah, Haluk (2018-03-23)
This paper presents an ultra-low power interface circuit to stimulate auditory nerves through fully-implantable cochlear implants (FICIs). The interface circuit senses signals generated from a multi-frequency piezoelectric sensor array, and generates neural stimulation current according to input sound level. Firstly, piezoelectric sensor output is amplified, and compressed with an ultra-low power logarithmic amplifier (LA). This significantly reduces power by eliminating the compression in the next stages. ...
A Pulse-Width Modulated Cochlear Implant Interface Electronics with 513 μW Power Consumption
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The fully implantable cochlear implant (FICI) interface circuit proposed in this work senses sound harmonics from 8 different piezoelectric cantilever sensors, and generates pulse width modulated biphasic current outputs to stimulate the auditory neurons. Signals from the piezoelectric sensors are amplified, rectified, and sampled. The sampled voltage is held and converted to current by a novel logarithmic voltage-to-current converter. The current is then digitized with a current comparator to determine the...
Thin Film PZT Acoustic Sensor for Fully Implantable Cochlear Implants
İlik, Bedirhan; Koyuncuoğlu, Aziz; Uluşan, Hasan; Chamanıan, Salar; Işık Akçakaya, Dilek; Şardan Sukas, Özlem; Külah, Haluk (2017-09-06)
This paper presents design and fabrication of a MEMS-based thin film piezoelectric transducer to be placed on an eardrum for fully-implantable cochlear implant (FICI) applications. Resonating at a specific frequency within the hearing band, the transducer senses eardrum vibration and generates the required voltage output for the stimulating circuitry. Moreover, high sensitivity of the sensor, 391.9 mV/Pa @900 Hz, decreases the required power for neural stimulation. The transducer provides highest voltage ou...
Multi-channel thin film piezoelectric acoustic transducer for cochlear implant applications
YÜKSEL, MUHAMMED BERAT; İlik, Bedirhan; Koyuncuoğlu, Aziz; Külah, Haluk (2019-10-27)
This paper presents a multi-channel piezoelectric acoustic transducer that is working within the audible frequency band (250- 5500 Hz). The transducer consists of eight cantilevers with thin film PLD-PZT piezoelectric layers. The transducer is well suited to be implanted in middle ear cavity with an active volume of 5x5x0.6 mm(3) and mass of 4.8 mg excluding the test frame. Finite Element Method (FEM) is used for modelling cantilever resonance frequencies and piezoelectric outputs. This model and shaker-tab...
Thin-Film PZT based Multi-Channel Acoustic MEMS Transducer for Cochlear Implant Applications
Yüksel, Muhammed Berat; Külah, Haluk (2021-01-01)
AuthorThis paper presents a multi-channel acoustic transducer that works within the audible frequency range (250-5500 Hz) and mimics the operation of the cochlea by filtering incoming sound. The transducer is composed of eight thin film piezoelectric cantilever beams with different resonance frequencies. The transducer is well suited to be implanted in middle ear cavity with an active volume of 5 mm × 5 mm × 0.62 mm and mass of 4.8 mg. Resonance frequencies and piezoelectric outputs of the bea...
Citation Formats
H. Ulusan, S. Chamanian, B. Ilik, A. Muhtaroglu, and H. Külah, “Fully Implantable Cochlear Implant Interface Electronics With 51.2-mu W Front-End Circuit,” IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS, pp. 1504–1512, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46984.