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Sakthivelpathi V, Li T, Qian Z, Lee C, Taylor Z, Chung JH. Advancements and Applications of Micro and Nanostructured Capacitive Sensors: A Review. SENSORS AND ACTUATORS. A, PHYSICAL 2024; 377:115701. [PMID: 39129941 PMCID: PMC11308742 DOI: 10.1016/j.sna.2024.115701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Capacitors are essential components in modern electrical systems, functioning primarily to store electrical charges and regulate current flow. Capacitive sensors, developed in the 20th century, have become crucial in various applications, including touchscreens and smart devices, due to their ability to detect both metallic and non-metallic objects with high sensitivity and low energy consumption. The advancement of microelectromechanical systems (MEMS) and nanotechnology has significantly enhanced the capabilities of capacitive sensors, leading to unprecedented sensitivity, dynamic range, and cost-effectiveness. These sensors are integral to modern devices, enabling precise measurements of proximity, pressure, strain, and other parameters. This review provides a comprehensive overview of the development, fabrication, and integration of micro and nanostructured capacitive sensors. In terms of an electric field, the working and detection principles are discussed with analytical equations and our numerical results. The focus extends to novel fabrication methods using advanced materials to enhance sensitivities for various parameters, such as proximity, force, pressure, strain, temperature, humidity, and liquid sensing. Their applications are demonstrated in wearable devices, human-machine interfaces, biomedical sensing, health monitoring, robotics control, industrial monitoring, and molecular detection. By consolidating existing research, this review offers insights into the advancements and future directions of capacitive sensor technology.
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Affiliation(s)
| | - Tianyi Li
- Mechanical Engineering, University of Washington, Seattle, WA, USA 98195
| | - Zhongjie Qian
- Mechanical Engineering, University of Washington, Seattle, WA, USA 98195
| | - Changwoo Lee
- Mechanical Engineering, University of Washington, Seattle, WA, USA 98195
| | - Zachary Taylor
- Mechanical Engineering, University of Washington, Seattle, WA, USA 98195
| | - Jae-Hyun Chung
- Mechanical Engineering, University of Washington, Seattle, WA, USA 98195
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Uluşan H, Yüksel MB, Topçu Ö, Yiğit HA, Yılmaz AM, Doğan M, Gülhan Yasar N, Kuyumcu İ, Batu A, Göksu N, Uğur MB, Külah H. A full-custom fully implantable cochlear implant system validated in vivo with an animal model. COMMUNICATIONS ENGINEERING 2024; 3:132. [PMID: 39277675 PMCID: PMC11401833 DOI: 10.1038/s44172-024-00275-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 08/27/2024] [Indexed: 09/17/2024]
Abstract
Realizations of fully implantable cochlear implants (FICIs) for providing adequate solution to esthetic concerns and frequent battery replacement have lacked of addressing system level criteria as a complete device. Here, we present a full-custom FICI that considers design of both an implantable sensor for wide range sound sensing and a signal conditioning circuit for electrical stimulation of the auditory nerve. The microelectromechanical system (MEMS)-based acoustic sensor utilizes multiple cantilever beam structures to sense and filter the mechanical vibrations on the ossicular chain. The area optimized bilayer design of the piezoelectric sensor met with the volume limitation in the middle ear while achieving high signal-to-noise-ratio. The sensor outputs are processed by a current mode low-power signal conditioning circuit that stimulates the auditory neurons through intracochlear electrodes. The FICI is validated with an in vivo model where the electrical auditory brainstem response (eABR) of the animal was observed while applying sound excitation. The eABR results demonstrate that the system is able to evoke responses in the auditory nerves of a guinea pig for sound range of 45-100 dB SPL within the selected frequency bands.
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Affiliation(s)
- Hasan Uluşan
- Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey
- METU-MEMS Research and Applications Center, Ankara, Turkey
| | - M Berat Yüksel
- Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey
- METU-MEMS Research and Applications Center, Ankara, Turkey
| | - Özlem Topçu
- Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey
- METU-MEMS Research and Applications Center, Ankara, Turkey
| | - H Andaç Yiğit
- Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey
| | - Akın M Yılmaz
- Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey
- METU-MEMS Research and Applications Center, Ankara, Turkey
| | - Mert Doğan
- Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey
| | - Nagihan Gülhan Yasar
- Department of Otorhinolaryngology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - İbrahim Kuyumcu
- Department of Otorhinolaryngology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Aykan Batu
- METU-MEMS Research and Applications Center, Ankara, Turkey
| | - Nebil Göksu
- Department of Otorhinolaryngology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - M Birol Uğur
- Department of Otorhinolaryngology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Haluk Külah
- Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey.
- METU-MEMS Research and Applications Center, Ankara, Turkey.
- Micro-Nano Technologies Graduate Program, Middle East Technical University, Ankara, Turkey.
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Yüksel MB, Atik AC, Külah H. Piezoelectric Multi-Channel Bilayer Transducer for Sensing and Filtering Ossicular Vibration. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308277. [PMID: 38380504 DOI: 10.1002/advs.202308277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/10/2024] [Indexed: 02/22/2024]
Abstract
This paper presents an acoustic transducer for fully implantable cochlear implants (FICIs), which can be implanted on the hearing chain to detect and filter the ambient sound in eight frequency bands between 250 and 6000 Hz. The transducer dimensions are conventional surgery compatible. The structure is formed with 3 × 3 × 0.36 mm active space for each layer and 5.2 mg total active mass excluding packaging. Characterization of the transducer is carried on an artificial membrane whose vibration characteristic is similar to the umbo vibration. On the artificial membrane, piezoelectric transducer generates up to 320.3 mVpp under 100 dB sound pressure level (SPL) excitation and covers the audible acoustic frequency. The measured signal-to-noise-ratio (SNR) of the channels is up to 84.2 dB. Sound quality of the transducer for fully implantable cochlear implant application is graded with an objective qualification method (PESQ) for the first time in the literature to the best of the knowledge, and scored 3.42/4.5.
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Affiliation(s)
- Muhammed Berat Yüksel
- Department of Electrical and Electronics Engineering, Middle East Technical University (METU), Universiteler Mah. Dumlipinar Blv. No:1, Ankara, 06800, Turkey
- METU MEMS Center, Mustafa Kemal Mah, Dumlupınar Bulvarı No: 280, Ankara, 06350, Turkey
| | - Ali Can Atik
- Department of Electrical and Electronics Engineering, Middle East Technical University (METU), Universiteler Mah. Dumlipinar Blv. No:1, Ankara, 06800, Turkey
- METU MEMS Center, Mustafa Kemal Mah, Dumlupınar Bulvarı No: 280, Ankara, 06350, Turkey
| | - Haluk Külah
- Department of Electrical and Electronics Engineering, Middle East Technical University (METU), Universiteler Mah. Dumlipinar Blv. No:1, Ankara, 06800, Turkey
- METU MEMS Center, Mustafa Kemal Mah, Dumlupınar Bulvarı No: 280, Ankara, 06350, Turkey
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Hake AE, Kitsopoulos P, Grosh K. Design of Piezoelectric Dual-Bandwidth Accelerometers for Completely Implantable Auditory Prostheses. IEEE SENSORS JOURNAL 2023; 23:13957-13965. [PMID: 38766647 PMCID: PMC11101158 DOI: 10.1109/jsen.2023.3276271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
For the last 20 years, researchers have developed accelerometers to function as ossicular vibration sensors in order to eliminate the external components of hearing aid and cochlear implant systems. To date, no accelerometer has met all of the stringent performance requirements necessary to function in this capacity. In this work, we present an accelerometer design with an equivalent noise floor less than 20 phon equal-loudness-level over a 0.1-8 kHz bandwidth in a package small enough to be implanted in the middle ear. Our approach uses a dual-bandwidth (two sensing elements) microelectromechanical systems piezoelectric accelerometer, sized using an area-minimization process based on an experimentally-validated analytical model of the sensor. The resulting bandwidth of the low-frequency sensing element is 0.1-1.25 kHz and that of the high-frequency sensing element is 1.25-8 kHz. These sensing elements fit within a silicon frame that is 795 μm × 778 μm, which can reasonably be housed along with a required integrated circuit in a 2.2 mm × 2.7 mm × 1 mm package. The estimated total mass of the packaged system is approximately 14 mg. This dual-bandwidth MEMS sensor fills a technological gap in current completely implantable auditory prosthesis research and development by enabling a device capable of meeting physical and performance specifications needed for use in the middle ear.
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Affiliation(s)
- Alison E Hake
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA, and is now with the Mechanical Engineering and Materials Science Department at the University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Panagiota Kitsopoulos
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Karl Grosh
- Department of Mechanical Engineering and the Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
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Mallegni N, Molinari G, Ricci C, Lazzeri A, La Rosa D, Crivello A, Milazzo M. Sensing Devices for Detecting and Processing Acoustic Signals in Healthcare. BIOSENSORS 2022; 12:835. [PMID: 36290973 PMCID: PMC9599683 DOI: 10.3390/bios12100835] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/27/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Acoustic signals are important markers to monitor physiological and pathological conditions, e.g., heart and respiratory sounds. The employment of traditional devices, such as stethoscopes, has been progressively superseded by new miniaturized devices, usually identified as microelectromechanical systems (MEMS). These tools are able to better detect the vibrational content of acoustic signals in order to provide a more reliable description of their features (e.g., amplitude, frequency bandwidth). Starting from the description of the structure and working principles of MEMS, we provide a review of their emerging applications in the healthcare field, discussing the advantages and limitations of each framework. Finally, we deliver a discussion on the lessons learned from the literature, and the open questions and challenges in the field that the scientific community must address in the near future.
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Affiliation(s)
- Norma Mallegni
- Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy
| | - Giovanna Molinari
- Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy
| | - Claudio Ricci
- Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy
| | - Andrea Lazzeri
- Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy
| | - Davide La Rosa
- ISTI-CNR, Institute of Information Science and Technologies, 56124 Pisa, Italy
| | - Antonino Crivello
- ISTI-CNR, Institute of Information Science and Technologies, 56124 Pisa, Italy
| | - Mario Milazzo
- Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy
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The remaining obstacles for a totally implantable cochlear implant. Curr Opin Otolaryngol Head Neck Surg 2022; 30:298-302. [PMID: 36004785 DOI: 10.1097/moo.0000000000000840] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF THE REVIEW For years, the development of a totally implantable cochlear implant (TICI) has faced several technical challenges hindering any prototypes from reaching full commercialization. This article aims to review the necessary specifications for a viable TICI. An overview of the remaining challenges when designing TICIs will be provided, focusing on energy supply and implantable microphones. RECENT FINDINGS The literature review highlights how research efforts to generate sufficient power to supply a fully implantable CI could take advantage of microelectromechanical systems (MEMS)-based energy harvesters incorporating piezoelectric materials. Using one of the various energy sources in the vicinity of the temporal bone would allow the development of a self-sufficient implant, overcoming the limitations of electrochemical batteries. Middle ear implantable microphones could also use similar fabrication techniques and transduction mechanisms to meet the sensor requirements for a TICI. SUMMARY Recent breakthroughs in power supply using MEMS-based energy harvesting technologies and piezoelectric implantable microphones may make TICIs become a more practical reality in the foreseeable future. Once available, TICIs will have major impact on our patients' quality of life and may help to make hearing rehabilitation a more appealing option to a greater proportion of those who fulfill our candidacy criteria.
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Hake AE, Zhao C, Sung WK, Grosh K. Design and Experimental Assessment of Low-Noise Piezoelectric Microelectromechanical Systems Vibration Sensors. IEEE SENSORS JOURNAL 2021; 21:17703-17711. [PMID: 35177956 PMCID: PMC8846575 DOI: 10.1109/jsen.2021.3085825] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The ubiquity of vibration sensors and accelerometers, as well as advances in microfabrication technologies, have led to the development of implantable devices for biomedical applications. This work describes a piezoelectric microelectromechanical systems accelerometer designed for potential use in auditory prostheses. The design includes an aluminum nitride bimorph beam with a silicon proof mass. Analytic models of the device sensitivity and noise are presented. These lead to a minimum detectable acceleration cost function for the sensor that can be used to optimize sensor designs more effectively than typical sensitivity maximizing or electrical noise minimizing approaches. A fabricated device with a 1 μm thick, 100 μm long, and 700 μm wide beam and a 400 μm thick, 63 μm long, and 740 μm wide proof mass is tested experimentally. Results indicate accurate modeling of the system sensitivity up to the first resonant frequency (1420 Hz). The low-frequency sensitivity of the device is 1.3 mV/g, and the input referred noise is 36.3 nV / Hz at 100 Hz and 11.8 nV / Hz at 1 kHz. The resulting minimum detectable acceleration at 100 Hz and 1 kHz is 28 μg / Hz and 9.1 μg / Hz , respectively. A brief explanation of the use of the validated cost function for sensor design is provided, as well as an example comparing the piezoelectric sensor design to another from the literature. It is concluded that a traditional single-resonance design cannot compete with the performance of acoustic sensors; therefore, novel device designs must be considered for implantable auditory prosthesis applications.
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Affiliation(s)
- Alison E Hake
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
| | - Chuming Zhao
- University of Michigan, Ann Arbor, MI 48109 USA. He is now with Facebook Reality Lab, Redmond, WA 98052 USA
| | - Wang-Kyung Sung
- Vesper Technologies, Inc., Boston, MA 02110 USA. He is now with TDK-Invensense, San Jose, CA 95110 USA
| | - Karl Grosh
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
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Latif R, Noor MM, Yunas J, Hamzah AA. Mechanical Energy Sensing and Harvesting in Micromachined Polymer-Based Piezoelectric Transducers for Fully Implanted Hearing Systems: A Review. Polymers (Basel) 2021; 13:polym13142276. [PMID: 34301034 PMCID: PMC8309449 DOI: 10.3390/polym13142276] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 01/12/2023] Open
Abstract
The paper presents a comprehensive review of mechanical energy harvesters and microphone sensors for totally implanted hearing systems. The studies on hearing mechanisms, hearing losses and hearing solutions are first introduced to bring to light the necessity of creating and integrating the in vivo energy harvester and implantable microphone into a single chip. The in vivo energy harvester can continuously harness energy from the biomechanical motion of the internal organs. The implantable microphone executes mechanoelectrical transduction, and an array of such structures can filter sound frequency directly without an analogue-to-digital converter. The revision of the available transduction mechanisms, device configuration structures and piezoelectric material characteristics reveals the advantage of adopting the polymer-based piezoelectric transducers. A dual function of sensing the sound signal and simultaneously harvesting vibration energy to power up its system can be attained from a single transducer. Advanced process technology incorporates polymers into piezoelectric materials, initiating the invention of a self-powered and flexible transducer that is compatible with the human body, magnetic resonance imaging system (MRI) and the standard complementary metal-oxide-semiconductor (CMOS) processes. The polymer-based piezoelectric is a promising material that satisfies many of the requirements for obtaining high performance implantable microphones and in vivo piezoelectric energy harvesters.
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Dwivedi A, Khanna G. A microelectromechanical system (MEMS) capacitive accelerometer-based microphone with enhanced sensitivity for fully implantable hearing aid: a novel analytical approach. BIOMED ENG-BIOMED TE 2020; 65:/j/bmte.ahead-of-print/bmt-2017-0183/bmt-2017-0183.xml. [PMID: 32621727 DOI: 10.1515/bmt-2017-0183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 04/21/2020] [Indexed: 11/15/2022]
Abstract
The present work proposes a novel, compact, intuitively simple and efficient structure to improve the sensitivity of a microelectromechanical system (MEMS) capacitive accelerometer using an arrangement of microlever as a displacement amplifier. The accelerometer is proposed to serve as a microphone in the fully implantable cochlear prosthetic system which can be surgically implanted at the middle ear bone structure. Therefore, the design parameters such as size, weight and resonant frequency require deliberation. The paper presents a novel analytical model considering the impact of the mechanical amplification along with the width of the microlever and the capacitive fringe effects on the performance of the sensor. The design is simulated and verified using COMSOL MULTIPHYSICS 4.2. The accelerometer is designed within a sensing area of 1 mm2 and accomplishes a nominal capacitance of 4.85 pF and an excellent sensitivity of 5.91 fF/g.
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Affiliation(s)
- Apoorva Dwivedi
- Electronics and Communications Engineering Department, NIT Hamirpur, Hamirpur, Himachal Pradesh, India
| | - Gargi Khanna
- Electronics and Communications Engineering Department, NIT Hamirpur, Hamirpur, Himachal Pradesh, India
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Gao L, Chen F, Yao Y, Xu D. High-Precision Acceleration Measurement System Based on Tunnel Magneto-Resistance Effect. SENSORS 2020; 20:s20041117. [PMID: 32085651 PMCID: PMC7070936 DOI: 10.3390/s20041117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 12/03/2022]
Abstract
A high-precision acceleration measurement system based on an ultra-sensitive tunnel magneto-resistance (TMR) sensor is presented in this paper. A “force–magnetic–electric” coupling structure that converts an input acceleration into a change in magnetic field around the TMR sensor is designed. In such a structure, a micro-cantilever is integrated with a magnetic field source on its tip. Under an acceleration, the mechanical displacement of the cantilever causes a change in the spatial magnetic field sensed by the TMR sensor. The TMR sensor is constructed with a Wheatstone bridge structure to achieve an enhanced sensitivity. Meanwhile, a low-noise differential circuit is developed for the proposed system to further improve the precision of the measured acceleration. The experimental results show that the micro-system achieves a measurement resolution of 19 μg/√Hz at 1 Hz, a scale factor of 191 mV/g within a range of ± 2 g, and a bias instability of 38 μg (Allan variance). The noise sources of the proposed system are thoroughly investigated, which shows that low-frequency 1/f noise is the dominant noise source. We propose to use a high-frequency modulation technique to suppress the 1/f noise effectively. Measurement results show that the 1/f noise is suppressed about 8.6-fold at 1 Hz and the proposed system resolution can be improved to 2.2 μg/√Hz theoretically with this high-frequency modulation technique.
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Affiliation(s)
- Lu Gao
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.G.); (Y.Y.)
| | - Fang Chen
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China;
| | - Yingfei Yao
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.G.); (Y.Y.)
| | - Dacheng Xu
- School of Electronic and Information Engineering, Soochow University, Suzhou 215006, China; (L.G.); (Y.Y.)
- Correspondence:
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Dwivedi A, Khanna G. Sensitivity enhancement of a folded beam MEMS capacitive accelerometer-based microphone for fully implantable hearing application. BIOMED ENG-BIOMED TE 2018; 63:699-708. [PMID: 29087950 DOI: 10.1515/bmt-2016-0181] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 08/17/2017] [Indexed: 11/15/2022]
Abstract
The present work attempts to enhance the sensitivity of a folded beam microelectromechanical systems (MEMS) capacitive accelerometer by optimising the device geometry. The accelerometer is intended to serve as a microphone in the fully implantable hearing application which can be surgically implanted in the middle ear bone structure. For the efficient design of the accelerometer as a fully implantable biomedical device, the design parameters such as size, weight and resonant frequency have been considered. The geometrical parameters are varied to obtain the optimum sensitivity considering the design constraints and the stability of the structure. The optimised design is simulated and verified using COMSOL MULTIPHYSICS 4.2. The stability of the device is ensured using eigenfrequency analysis. Optimised results of the device geometry are presented and discussed. The accelerometer has a sensing area of 1 mm2 and attains a nominal capacitance of 5.3 pF and an optimum sensitivity of 6.89 fF.
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Affiliation(s)
- Apoorva Dwivedi
- Electronics and Communications Engineering Department, NIT Hamirpur, Hamirpur 177005, Himachal Pradesh, India, Phone: +91-7831059900, Fax: 01972-223834
| | - Gargi Khanna
- Electronics and Communications Engineering Department, NIT Hamirpur, Hamirpur 177005, Himachal Pradesh, India
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Dong W, Wang Y, Zhou Y, Bai Y, Ju Z, Guo J, Gu G, Bai K, Ouyang G, Chen S, Zhang Q, Huang Y. Soft human–machine interfaces: design, sensing and stimulation. INTERNATIONAL JOURNAL OF INTELLIGENT ROBOTICS AND APPLICATIONS 2018. [DOI: 10.1007/s41315-018-0060-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Calero D, Paul S, Gesing A, Alves F, Cordioli JA. A technical review and evaluation of implantable sensors for hearing devices. Biomed Eng Online 2018; 17:23. [PMID: 29433516 PMCID: PMC5810055 DOI: 10.1186/s12938-018-0454-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/07/2018] [Indexed: 11/10/2022] Open
Abstract
Most commercially available cochlear implants and hearing aids use microphones as sensors for capturing the external sound field. These microphones are in general located in an external element, which is also responsible for processing the sound signal. However, the presence of the external element is the cause of several problems such as discomfort, impossibility of being used during physical activities and sleeping, and social stigma. These limitations have driven studies with the goal of developing totally implantable hearing devices, and the design of an implantable sensor has been one of the main challenges to be overcome. Different designs of implantable sensors can be found in the literature and in some commercial implantable hearing aids, including different transduction mechanisms (capacitive, piezoelectric, electromagnetic, etc), configurations microphones, accelerometers, force sensor, etc) and locations (subcutaneous or middle ear). In this work, a detailed technical review of such designs is presented and a general classification is proposed. The technical characteristics of each sensors are presented and discussed in view of the main requirements for an implantable sensor for hearing devices, including sensitivity, internal noise, frequency bandwidth and energy consumption. The feasibility of implantation of each sensor is also evaluated and compared.
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Affiliation(s)
- Diego Calero
- Laboratory of Vibration and Acoustics, Florianópolis, Brazil
| | - Stephan Paul
- Laboratory of Vibration and Acoustics, Florianópolis, Brazil
| | - André Gesing
- Laboratory of Vibration and Acoustics, Florianópolis, Brazil
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Jang J, Jang JH, Choi H. Biomimetic Artificial Basilar Membranes for Next-Generation Cochlear Implants. Adv Healthc Mater 2017; 6. [PMID: 28892270 DOI: 10.1002/adhm.201700674] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/13/2017] [Indexed: 01/27/2023]
Abstract
Patients with sensorineural hearing loss can recover their hearing using a cochlear implant (CI). However, there is a need to develop next-generation CIs to overcome the limitations of conventional CIs caused by extracorporeal devices. Recently, artificial basilar membranes (ABMs) are actively studied for next-generation CIs. The ABM is an acoustic transducer that mimics the mechanical frequency selectivity of the BM and acoustic-to-electrical energy conversion of hair cells. This paper presents recent progress in biomimetic ABMs. First, the characteristics of frequency selectivity of the ABMs by the trapezoidal membrane and beam array are addressed. Second, to reflect the latest research of energy conversion technologies, ABMs using various piezoelectric materials and triboelectric-based ABMs are discussed. Third, in vivo evaluations of the ABMs in animal models are discussed according to the target position for implantation. Finally, future perspectives of ABM studies for the development of practical hearing devices are discussed.
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Affiliation(s)
- Jongmoon Jang
- Department of Robotics Engineering; DGIST-ETH Microrobot Research Center; Daegu Gyeongbuk Institute of Science and Technology (DGIST); 333, Techno jungang-daero, Hyeonpung-Myeon Dalseong-Gun Daegu 42988 Republic of Korea
| | - Jeong Hun Jang
- Department of Otorhinolaryngology-Head and Neck Surgery; Ajou University College of Medicine; 164, World cup-ro Yeongtong-gu Suwon 16499 Republic of Korea
| | - Hongsoo Choi
- Department of Robotics Engineering; DGIST-ETH Microrobot Research Center; Daegu Gyeongbuk Institute of Science and Technology (DGIST); 333, Techno jungang-daero, Hyeonpung-Myeon Dalseong-Gun Daegu 42988 Republic of Korea
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Mitchell-Innes A, Morse R, Irving R, Begg P. Implantable microphones as an alternative to external microphones for cochlear implants. Cochlear Implants Int 2017; 18:304-313. [PMID: 28889786 DOI: 10.1080/14670100.2017.1371974] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Totally implantable cochlear implants may be able to address many of the problems cochlear implant users have around cosmetic appearances, discomfort, and restriction of activities. The major technological challenges that need to be solved to develop a totally implantable device relate to implanted microphone performance. Previous attempts at implanting microphones for cochlear implants have not performed as well as conventional cochlear implant microphones, and in addition have struggled with extraneous body or surface contact noise. Microphones can be implanted under the skin or act as sensors in the middle ear; however, evidence from middle ear implants suggest body and contact noise can be overcome by converting ossicular chain movements into digital signals. This article reviews implantable microphone systems and discusses the technology behind them.
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Affiliation(s)
- Alistair Mitchell-Innes
- a University Hospital Birmingham NHS Foundation Trust , Mindelsohn Way, Edgbaston, Birmingham B15 2TH , UK
| | - Robert Morse
- b School of Engineering, University of Warwick , Library Road, Coventry , CV4 7AL , UK
| | - Richard Irving
- a University Hospital Birmingham NHS Foundation Trust , Mindelsohn Way, Edgbaston, Birmingham B15 2TH , UK
| | - Philip Begg
- a University Hospital Birmingham NHS Foundation Trust , Mindelsohn Way, Edgbaston, Birmingham B15 2TH , UK
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Anabtawi N, Freeman S, Ferzli R. An Auditory Nerve Stimulation Chip with Integrated AFE, Sound Processing, and Power Management for Fully Implantable Cochlear Implants. ... IEEE-EMBS INTERNATIONAL CONFERENCE ON BIOMEDICAL AND HEALTH INFORMATICS. IEEE-EMBS INTERNATIONAL CONFERENCE ON BIOMEDICAL AND HEALTH INFORMATICS 2016; 2016:616-619. [PMID: 28702513 DOI: 10.1109/bhi.2016.7455974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This paper presents a system on chip for a fully implantable cochlear implant. It includes acoustic sensor front-end, 4-channel digital sound processing and auditory nerve stimulation circuitry. It also features a digital, switched mode, single inductor dual output power supply that generates two regulated voltages; 0.4 V used to supply on-chip digital blocks and 0.9 V to supply analog blocks and charge the battery when an external RF source is detected. All passives are integrated on-chip including the inductor. The system was implemented in 14nm CMOS and validated with post layout simulations.
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Affiliation(s)
- Nijad Anabtawi
- Intel Corporation, Chandler, AZ and the Department of Electrical Engineering, Arizona State University, Tempe, AZ
| | - Sabrina Freeman
- Department of Biomedical Engineering, Arizona State University, Tempe, AZ
| | - Rony Ferzli
- Department of Electrical Engineering, Arizona State University, Tempe, AZ
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17
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Dadlani V, Levine JA, McCrady-Spitzer SK, Dassau E, Kudva YC. Physical Activity Capture Technology With Potential for Incorporation Into Closed-Loop Control for Type 1 Diabetes. J Diabetes Sci Technol 2015; 9:1208-16. [PMID: 26481641 PMCID: PMC4667300 DOI: 10.1177/1932296815609949] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Physical activity is an important determinant of glucose variability in type 1 diabetes (T1D). It has been incorporated as a nonglucose input into closed-loop control (CLC) protocols for T1D during the last 4 years mainly by 3 research groups in single center based controlled clinical trials involving a maximum of 18 subjects in any 1 study. Although physical activity data capture may have clinical benefit in patients with T1D by impacting cardiovascular fitness and optimal body weight achievement and maintenance, limited number of such studies have been conducted to date. Clinical trial registries provide information about a single small sample size 2 center prospective study incorporating physical activity data input to modulate closed-loop control in T1D that are seeking to build on prior studies. We expect an increase in such studies especially since the NIH has expanded support of this type of research with additional grants starting in the second half of 2015. Studies (1) involving patients with other disorders that have lasted 12 weeks or longer and tracked physical activity and (2) including both aerobic and resistance activity may offer insights about the user experience and device optimization even as single input CLC heads into real-world clinical trials over the next few years and nonglucose input is introduced as the next advance.
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Affiliation(s)
- Vikash Dadlani
- Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA
| | - James A Levine
- Mayo Clinic, Scottsdale, AZ, USA Obesity Solutions, Mayo Clinic Arizona and Arizona State University, Tempe, AZ, USA
| | | | - Eyal Dassau
- Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, USA
| | - Yogish C Kudva
- Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA
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Woo ST, Shin DH, Lim HG, Seong KW, Gottlieb P, Puria S, Lee KY, Cho JH. A New Trans-Tympanic Microphone Approach for Fully Implantable Hearing Devices. SENSORS 2015; 15:22798-810. [PMID: 26371007 PMCID: PMC4610505 DOI: 10.3390/s150922798] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/28/2015] [Accepted: 08/31/2015] [Indexed: 11/16/2022]
Abstract
Fully implantable hearing devices (FIHDs) have been developed as a new technology to overcome the disadvantages of conventional acoustic hearing aids. The implantable microphones currently used in FIHDs, however, have difficulty achieving high sensitivity to environmental sounds, low sensitivity to body noise, and ease of implantation. In general, implantable microphones may be placed under the skin in the temporal bone region of the skull. In this situation, body noise picked up during mastication and touching can be significant, and the layer of skin and hair can both attenuate and distort sounds. The new approach presently proposed is a microphone implanted at the tympanic membrane. This method increases the microphone’s sensitivity by utilizing the pinna’s directionally dependent sound collection capabilities and the natural resonances of the ear canal. The sensitivity and insertion loss of this microphone were measured in human cadaveric specimens in the 0.1 to 16 kHz frequency range. In addition, the maximum stable gain due to feedback between the trans-tympanic microphone and a round-window-drive transducer, was measured. The results confirmed in situ high-performance capabilities of the proposed trans-tympanic microphone.
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Affiliation(s)
- Seong Tak Woo
- Graduate School of Electronic Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, 41566 Daegu, Korea.
| | - Dong Ho Shin
- Graduate School of Electronic Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, 41566 Daegu, Korea.
| | - Hyung-Gyu Lim
- Graduate School of Electronic Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, 41566 Daegu, Korea.
| | - Ki-Woong Seong
- Department of Biomedical Engineering, Kyungpook National University Hospital, 130 Dongdeok-ro, Jung-gu, 41944 Daegu, Korea.
| | - Peter Gottlieb
- Department of Mechanical Engineering, Stanford University, 496 Lomita Mall, 94305 CA, USA.
| | - Sunil Puria
- Department of Mechanical Engineering, Stanford University, 496 Lomita Mall, 94305 CA, USA.
| | - Kyu-Yup Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, 41944 Daegu, Korea.
| | - Jin-Ho Cho
- Graduate School of Electronic Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, 41566 Daegu, Korea.
- School of Electronics Engineering, College of IT Engineering, Kyungpook National University, 80 Daehakro, Buk-gu, 41566 Daegu, Korea.
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Use of inertial sensors as devices for upper limb motor monitoring exercises for motor rehabilitation. HEALTH AND TECHNOLOGY 2015. [DOI: 10.1007/s12553-015-0110-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Yip M, Jin R, Nakajima HH, Stankovic KM, Chandrakasan AP. A Fully-Implantable Cochlear Implant SoC with Piezoelectric Middle-Ear Sensor and Arbitrary Waveform Neural Stimulation. IEEE JOURNAL OF SOLID-STATE CIRCUITS 2015; 50:214-229. [PMID: 26251552 PMCID: PMC4523309 DOI: 10.1109/jssc.2014.2355822] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A system-on-chip for an invisible, fully-implantable cochlear implant is presented. Implantable acoustic sensing is achieved by interfacing the SoC to a piezoelectric sensor that detects the sound-induced motion of the middle ear. Measurements from human cadaveric ears demonstrate that the sensor can detect sounds between 40 and 90 dB SPL over the speech bandwidth. A highly-reconfigurable digital sound processor enables system power scalability by reconfiguring the number of channels, and provides programmable features to enable a patient-specific fit. A mixed-signal arbitrary waveform neural stimulator enables energy-optimal stimulation pulses to be delivered to the auditory nerve. The energy-optimal waveform is validated with in-vivo measurements from four human subjects which show a 15% to 35% energy saving over the conventional rectangular waveform. Prototyped in a 0.18 μm high-voltage CMOS technology, the SoC in 8-channel mode consumes 572 μW of power including stimulation. The SoC integrates implantable acoustic sensing, sound processing, and neural stimulation on one chip to minimize the implant size, and proof-of-concept is demonstrated with measurements from a human cadaver ear.
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Affiliation(s)
- Marcus Yip
- Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Rui Jin
- Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Hideko Heidi Nakajima
- Harvard Medical School, Boston, MA 02115 USA, and Massachusetts Eye and Ear Infimary, Boston, MA 02114 USA
| | - Konstantina M. Stankovic
- Harvard Medical School, Boston, MA 02115 USA, and Massachusetts Eye and Ear Infimary, Boston, MA 02114 USA
| | - Anantha P. Chandrakasan
- Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
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