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Yu A, Zhu M, Chen C, Li Y, Cui H, Liu S, Zhao Q. Implantable Flexible Sensors for Health Monitoring. Adv Healthc Mater 2024; 13:e2302460. [PMID: 37816513 DOI: 10.1002/adhm.202302460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/05/2023] [Indexed: 10/12/2023]
Abstract
Flexible sensors, as a significant component of flexible electronics, have attracted great interest the realms of human-computer interaction and health monitoring due to their high conformability, adjustable sensitivity, and excellent durability. In comparison to wearable sensor-based in vitro health monitoring, the use of implantable flexible sensors (IFSs) for in vivo health monitoring offers more accurate and reliable vital sign information due to their ability to adapt and directly integrate with human tissue. IFSs show tremendous promise in the field of health monitoring, with unique advantages such as robust signal reading capabilities, lightweight design, flexibility, and biocompatibility. Herein, a review of IFSs for vital signs monitoring is detailly provided, highlighting the essential conditions for in vivo applications. As the prerequisites of IFSs, the stretchability and wireless self-powered properties of the sensor are discussed, with a special attention paid to the sensing materials which can maintain prominent biosafety (i.e., biocompatibility, biodegradability, bioresorbability). Furthermore, the applications of IFSs monitoring various parts of the body are described in detail, with a summary in brain monitoring, eye monitoring, and blood monitoring. Finally, the challenges as well as opportunities in the development of next-generation IFSs are presented.
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Affiliation(s)
- Aoxi Yu
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
| | - Mingye Zhu
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Congkai Chen
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Yang Li
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
| | - Haixia Cui
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Shujuan Liu
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Qiang Zhao
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
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Zhang Z, Liu G, Li Z, Zhang W, Meng Q. Flexible tactile sensors with biomimetic microstructures: Mechanisms, fabrication, and applications. Adv Colloid Interface Sci 2023; 320:102988. [PMID: 37690330 DOI: 10.1016/j.cis.2023.102988] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/07/2023] [Accepted: 08/26/2023] [Indexed: 09/12/2023]
Abstract
In recent years, flexible devices have gained rapid development with great potential in daily life. As the core component of wearable devices, flexible tactile sensors are prized for their excellent properties such as lightweight, stretchable and foldable. Consequently, numerous high-performance sensors have been developed, along with an array of innovative fabrication processes. It has been recognized that the improvement of the single performance index for flexible tactile sensors is not enough for practical sensing applications. Therefore, balancing and optimization of overall performance of the sensor are extensively anticipated. Furthermore, new functional characteristics are required for practical applications, such as freeze resistance, corrosion resistance, self-cleaning, and degradability. From a bionic perspective, the overall performance of a sensor can be optimized by constructing bionic microstructures which can deliver additional functional features. This review briefly summarizes the latest developments in bionic microstructures for different types of tactile sensors and critically analyzes the sensing performance of fabricated flexible tactile sensors. Based on this, the application prospects of bionic microstructure-based tactile sensors in human detection and human-machine interaction devices are introduced.
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Affiliation(s)
- Zhuoqing Zhang
- College of Bioresources Chemical and Materials Engineering, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China; Key Laboratory of Functional Printing and Transport Packaging of China National Light Industry, Key Laboratory of Paper-based Functional Materials of China National Light Industry, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China
| | - Guodong Liu
- College of Bioresources Chemical and Materials Engineering, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China; Key Laboratory of Functional Printing and Transport Packaging of China National Light Industry, Key Laboratory of Paper-based Functional Materials of China National Light Industry, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China.
| | - Zhijian Li
- College of Bioresources Chemical and Materials Engineering, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China; Key Laboratory of Functional Printing and Transport Packaging of China National Light Industry, Key Laboratory of Paper-based Functional Materials of China National Light Industry, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China
| | - Wenliang Zhang
- College of Bioresources Chemical and Materials Engineering, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China; Key Laboratory of Functional Printing and Transport Packaging of China National Light Industry, Key Laboratory of Paper-based Functional Materials of China National Light Industry, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China
| | - Qingjun Meng
- College of Bioresources Chemical and Materials Engineering, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China; Key Laboratory of Functional Printing and Transport Packaging of China National Light Industry, Key Laboratory of Paper-based Functional Materials of China National Light Industry, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China
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Yogev D, Goldberg T, Arami A, Tejman-Yarden S, Winkler TE, Maoz BM. Current state of the art and future directions for implantable sensors in medical technology: Clinical needs and engineering challenges. APL Bioeng 2023; 7:031506. [PMID: 37781727 PMCID: PMC10539032 DOI: 10.1063/5.0152290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 08/28/2023] [Indexed: 10/03/2023] Open
Abstract
Implantable sensors have revolutionized the way we monitor biophysical and biochemical parameters by enabling real-time closed-loop intervention or therapy. These technologies align with the new era of healthcare known as healthcare 5.0, which encompasses smart disease control and detection, virtual care, intelligent health management, smart monitoring, and decision-making. This review explores the diverse biomedical applications of implantable temperature, mechanical, electrophysiological, optical, and electrochemical sensors. We delve into the engineering principles that serve as the foundation for their development. We also address the challenges faced by researchers and designers in bridging the gap between implantable sensor research and their clinical adoption by emphasizing the importance of careful consideration of clinical requirements and engineering challenges. We highlight the need for future research to explore issues such as long-term performance, biocompatibility, and power sources, as well as the potential for implantable sensors to transform healthcare across multiple disciplines. It is evident that implantable sensors have immense potential in the field of medical technology. However, the gap between research and clinical adoption remains wide, and there are still major obstacles to overcome before they can become a widely adopted part of medical practice.
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Affiliation(s)
| | | | | | | | | | - Ben M. Maoz
- Authors to whom correspondence should be addressed: and
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Putzeys T, Borgers C, Fierens G, Walraevens J, Van Wieringen A, Verhaert N. Intracochlear pressure as an objective measure for perceived loudness with bone conduction implants. Hear Res 2022; 422:108550. [PMID: 35689853 DOI: 10.1016/j.heares.2022.108550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 05/25/2022] [Accepted: 05/28/2022] [Indexed: 01/18/2023]
Abstract
BACKGROUND The generally accepted method to assess the functionality of novel bone conduction implants in a preclinical stage is to experimentally measure the vibratory response of the cochlear promontory. Yet, bone conduction of sound is a complex propagation phenomenon, depending on both frequency and amplitude, involving different conduction pathways. OBJECTIVES The aim of this study is to validate the use of intracochlear sound pressure (ICP) as an objective indicator for perceived loudness for bone conduction stimulation. It is investigated whether a correlation exists between intracochlear sound pressure measurements in cadaveric temporal bones and clinically obtained results using the outcome of a loudness balancing experiment. METHODS Ten normal hearing subjects were asked to balance the perceived loudness between air conducted (AC) sound and bone conducted (BC) sound by changing the AC stimulus. Mean balanced thresholds were calculated and used as stimulation levels in a cadaver trial (N = 4) where intracochlear sound pressure was measured during AC and BC stimulation to assess the correlation with the measured clinical data. The intracochlear pressure was measured at the relatively low stimulation amplitude of 80 dBHL using a lock-in amplification technique. RESULTS Applying AC and BC stimulation at equal perceived loudness on cadaveric heads yield a similar differential intracochlear pressure, with differences between AC and BC falling within the range of variability of normal hearing test subjects. CONCLUSION Comparing the perceived loudness at 80 dB HL for both AC and BC validates intracochlear pressure as an objective indicator of the cochlear drive. The measurement setup is more time-intensive than measuring the vibratory response of the cochlear promontory, yet it provides direct information on the level of the cochlear scalae.
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Affiliation(s)
- Tristan Putzeys
- KU Leuven - University of Leuven, Department of Neurosciences, ExpORL, B-3000 Leuven, Belgium; KU Leuven - University of Leuven, Department of Physics and Astronomy, Laboratory for Soft Matter and Biophysics, Heverlee, Belgium.
| | - Charlotte Borgers
- KU Leuven - University of Leuven, Department of Neurosciences, ExpORL, B-3000 Leuven, Belgium
| | - Guy Fierens
- KU Leuven - University of Leuven, Department of Neurosciences, ExpORL, B-3000 Leuven, Belgium; KU Leuven - University of Leuven, Department of Physics and Astronomy, Laboratory for Soft Matter and Biophysics, Heverlee, Belgium; Cochlear Technology Centre, Mechelen, Belgium
| | | | - Astrid Van Wieringen
- KU Leuven - University of Leuven, Department of Neurosciences, ExpORL, B-3000 Leuven, Belgium
| | - Nicolas Verhaert
- KU Leuven - University of Leuven, Department of Neurosciences, ExpORL, B-3000 Leuven, Belgium; University Hospitals Leuven, Department of Otorhinolaryngology, Head and Neck Surgery, Leuven, Belgium
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Toward Personalized Diagnosis and Therapy for Hearing Loss: Insights From Cochlear Implants. Otol Neurotol 2022; 43:e903-e909. [PMID: 35970169 DOI: 10.1097/mao.0000000000003624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
ABSTRACT Sensorineural hearing loss (SNHL) is the most common sensory deficit, disabling nearly half a billion people worldwide. The cochlear implant (CI) has transformed the treatment of patients with SNHL, having restored hearing to more than 800,000 people. The success of CIs has inspired multidisciplinary efforts to address the unmet need for personalized, cellular-level diagnosis, and treatment of patients with SNHL. Current limitations include an inability to safely and accurately image at high resolution and biopsy the inner ear, precluding the use of key structural and molecular information during diagnostic and treatment decisions. Furthermore, there remains a lack of pharmacological therapies for hearing loss, which can partially be attributed to challenges associated with new drug development. We highlight advances in diagnostic and therapeutic strategies for SNHL that will help accelerate the push toward precision medicine. In addition, we discuss technological improvements for the CI that will further enhance its functionality for future patients. This report highlights work that was originally presented by Dr. Stankovic as part of the Dr. John Niparko Memorial Lecture during the 2021 American Cochlear Implant Alliance annual meeting.
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Recent Advances in Cochlear Implant Electrode Array Design Parameters. MICROMACHINES 2022; 13:mi13071081. [PMID: 35888898 PMCID: PMC9323156 DOI: 10.3390/mi13071081] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 02/04/2023]
Abstract
Cochlear implants are neural implant devices that aim to restore hearing in patients with severe sensorineural hearing impairment. Here, the main goal is to successfully place the electrode array in the cochlea to stimulate the auditory nerves through bypassing damaged hair cells. Several electrode and electrode array parameters affect the success of this technique, but, undoubtedly, the most important one is related to electrodes, which are used for nerve stimulation. In this paper, we provide a comprehensive resource on the electrodes currently being used in cochlear implant devices. Electrode materials, shape, and the effect of spacing between electrodes on the stimulation, stiffness, and flexibility of electrode-carrying arrays are discussed. The use of sensors and the electrical, mechanical, and electrochemical properties of electrode arrays are examined. A large library of preferred electrodes is reviewed, and recent progress in electrode design parameters is analyzed. Finally, the limitations and challenges of the current technology are discussed along with a proposal of future directions in the field.
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Ding AS, Lu A, Li Z, Galaiya D, Ishii M, Siewerdsen JH, Taylor RH, Creighton FX. Statistical Shape Model of the Temporal Bone Using Segmentation Propagation. Otol Neurotol 2022; 43:e679-e687. [PMID: 35761465 PMCID: PMC10072910 DOI: 10.1097/mao.0000000000003554] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS Automated image registration techniques can successfully determine anatomical variation in human temporal bones with statistical shape modeling. BACKGROUND There is a lack of knowledge about inter-patient anatomical variation in the temporal bone. Statistical shape models (SSMs) provide a powerful method for quantifying variation of anatomical structures in medical images but are time-intensive to manually develop. This study presents SSMs of temporal bone anatomy using automated image-registration techniques. METHODS Fifty-three cone-beam temporal bone CTs were included for SSM generation. The malleus, incus, stapes, bony labyrinth, and facial nerve were automatically segmented using 3D Slicer and a template-based segmentation propagation technique. Segmentations were then used to construct SSMs using MATLAB. The first three principal components of each SSM were analyzed to describe shape variation. RESULTS Principal component analysis of middle and inner ear structures revealed novel modes of anatomical variation. The first three principal components for the malleus represented variability in manubrium length (mean: 4.47 mm; ±2-SDs: 4.03-5.03 mm) and rotation about its long axis (±2-SDs: -1.6° to 1.8° posteriorly). The facial nerve exhibits variability in first and second genu angles. The bony labyrinth varies in the angle between the posterior and superior canals (mean: 88.9°; ±2-SDs: 83.7°-95.7°) and cochlear orientation (±2-SDs: -4.0° to 3.0° anterolaterally). CONCLUSIONS SSMs of temporal bone anatomy can inform surgeons on clinically relevant inter-patient variability. Anatomical variation elucidated by these models can provide novel insight into function and pathophysiology. These models also allow further investigation of anatomical variation based on age, BMI, sex, and geographical location.
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Affiliation(s)
- Andy S. Ding
- Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Biomedical Engineering, Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland
| | - Alexander Lu
- Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Biomedical Engineering, Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland
| | - Zhaoshuo Li
- Department of Computer Science, Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland
| | - Deepa Galaiya
- Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Masaru Ishii
- Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jeffrey H. Siewerdsen
- Department of Biomedical Engineering, Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland
- Department of Computer Science, Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland
| | - Russell H. Taylor
- Department of Computer Science, Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland
| | - Francis X. Creighton
- Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
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The Impact of Location and Device Coupling on the Performance of the Osia System Actuator. BIOMED RESEARCH INTERNATIONAL 2022; 2022:9079903. [PMID: 35411307 PMCID: PMC8994691 DOI: 10.1155/2022/9079903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 02/11/2022] [Accepted: 02/26/2022] [Indexed: 11/18/2022]
Abstract
Active transcutaneous bone conduction (BC) devices offer the benefit of improved power output compared to passive transcutaneous devices and remove the risk of skin infections that are more common in traditional percutaneous BC devices. Despite these advantages, more research is needed on implant location, device coupling, and their influence on device performance. This study is aimed at quantifying the extent to which certain parameters affect device output when using the Osia® system actuator. Parameters under study are (1) implant location, (2) comparison with the actuator of a state-of-the-art BC device, (3) bone undergrowth simulation, and (4) skull fixation. Five human cadaveric heads were implanted with the actuator at three different implant locations: (1) recommended, (2) posterior Osia® positions, and (3) standard Baha® position. At each location, the cochlear promontory velocity and the intracochlear pressure difference were measured. A percutaneous bone conduction actuator was used as a reference for the obtained measurements. Stimulation levels corresponded to a hearing level of 60 dB HL for frequencies between 250 and 6000 Hz. In addition, bone cement was used as a simulation for reactive bone growth. Results obtained in four heads indicate an improved power transmission of the transcutaneous actuator when implanted at the recommended position compared to the actuator of the percutaneous device on its respective recommended location when stimulating at an identical force level. A correlation was found between the promontory vibration and the actuator position, indicating that the same level of stimulation leads to higher promontory vibrations when the device is implanted closer to the ear canal. This is mainly reflected at frequencies higher than 1 kHz, where an increase was observed in both measurement modalities. At lower frequencies (<1 kHz), the power transmission is less influenced by the implant position and differences between the acquired responses are limited. In addition, when no rigid coupling to the skull is provided, power transfer losses of up to 30 dB can be expected.
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Cary BG, Zhang JZ, McHugh CI, Kymissis I, Olson ES, Nakajima HH, Lang JH. An Implantable Umbo Microphone For Fully-Implantable Assistive Hearing Devices. IEEE SENSORS JOURNAL 2021; 2021:10.1109/sensors47087.2021.9639746. [PMID: 37786543 PMCID: PMC10544841 DOI: 10.1109/sensors47087.2021.9639746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
This paper presents an implantable microphone for sensing the displacement of the umbo, the end of the malleus where it attaches to the center tip of the cone-shaped tympanic membrane. The sensor comprises a piezoelectric polyvinylidene fluoride (PVDF) film with copper-nickel electrodes suspended across a brass cylinder. The cylinder is oriented so that the umbo pushes on the film center, causing a static and acoustically-driven dynamic film displacement. An amplifier filters the resulting piezoelectric charge to produce an output signal. The sensor enables the full implantation of assistive hearing devices, which can restore hearing without inhibiting the user's lifestyle, while enabling better sound localization in noisy environments.
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Voltage readout from a piezoelectric intracochlear acoustic transducer implanted in a living guinea pig. Sci Rep 2019; 9:3711. [PMID: 30842456 PMCID: PMC6403321 DOI: 10.1038/s41598-019-39303-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 01/14/2019] [Indexed: 12/04/2022] Open
Abstract
The ability to measure the voltage readout from a sensor implanted inside the living cochlea enables continuous monitoring of intracochlear acoustic pressure locally, which could improve cochlear implants. We developed a piezoelectric intracochlear acoustic transducer (PIAT) designed to sense the acoustic pressure while fully implanted inside a living guinea pig cochlea. The PIAT, fabricated using micro-electro-mechanical systems (MEMS) techniques, consisted of an array of four piezoelectric cantilevers with varying lengths to enhance sensitivity across a wide frequency bandwidth. Prior to implantation, benchtop tests were conducted to characterize the device performance in air and in water. When implanted in the cochlea of an anesthetized guinea pig, the in vivo voltage response from the PIAT was measured in response to 80–95 dB sound pressure level 1–14 kHz sinusoidal acoustic excitation at the entrance of the guinea pig’s ear canal. All sensed signals were above the noise floor and unaffected by crosstalk from the cochlear microphonic or external electrical interference. These results demonstrate that external acoustic stimulus can be sensed via the piezoelectric voltage response of the implanted MEMS transducer inside the living cochlea, providing key steps towards developing intracochlear acoustic sensors to replace external or subcutaneous microphones for auditory prosthetics.
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A Vibro-Acoustic Hybrid Implantable Microphone for Middle Ear Hearing Aids and Cochlear Implants. SENSORS 2019; 19:s19051117. [PMID: 30841613 PMCID: PMC6427140 DOI: 10.3390/s19051117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 02/15/2019] [Accepted: 02/19/2019] [Indexed: 12/03/2022]
Abstract
To develop totally implantable middle ear and cochlear implants, a miniature microphone that is surgically easy to implant and has a high sensitivity in a sufficient range of audio frequencies is needed. Of the various implantable acoustic sensors under development, only micro electro-mechanical system-type acoustic sensors, which attach to the umbo of the tympanic membrane, meet these requirements. We describe a new vibro-acoustic hybrid implantable microphone (VAHIM) that combines acceleration and sound pressure sensors. Each sensor can collect the vibration of the umbo and sound pressure of the middle ear cavity. The fabricated sensor was implanted into a human temporal bone and the noise level and sensitivity were measured. From the experimental results, it is shown that the proposed method is able to provide a wider-frequency band than conventional implantable acoustic sensors.
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Park S, Guan X, Kim Y, Creighton F(PX, Wei E, Kymissis I, Nakajima HH, Olson ES. PVDF-Based Piezoelectric Microphone for Sound Detection Inside the Cochlea: Toward Totally Implantable Cochlear Implants. Trends Hear 2018; 22:2331216518774450. [PMID: 29732950 PMCID: PMC5987900 DOI: 10.1177/2331216518774450] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 04/07/2018] [Accepted: 04/09/2018] [Indexed: 01/31/2023] Open
Abstract
We report the fabrication and characterization of a prototype polyvinylidene fluoride polymer-based implantable microphone for detecting sound inside gerbil and human cochleae. With the current configuration and amplification, the signal-to-noise ratios were sufficiently high for normally occurring sound pressures and frequencies (ear canal pressures >50-60 dB SPL and 0.1-10 kHz), though 10 to 20 dB poorer than for some hearing aid microphones. These results demonstrate the feasibility of the prototype devices as implantable microphones for the development of totally implantable cochlear implants. For patients, this will improve sound reception by utilizing the outer ear and will improve the use of cochlear implants.
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Affiliation(s)
- Steve Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Xiying Guan
- Department of Otolaryngology, Harvard Medical School, Massachusetts Eye and Ear, Boston, MA, USA
| | - Youngwan Kim
- Department of Electrical Engineering, Columbia University, New York City, NY, USA
| | | | - Eric Wei
- Department of Otolaryngology Head and Neck Surgery, Columbia University Medical Center, New York City, NY, USA
| | | | - Hideko Heidi Nakajima
- Department of Otolaryngology, Harvard Medical School, Massachusetts Eye and Ear, Boston, MA, USA
| | - Elizabeth S. Olson
- Department of Otolaryngology Head and Neck Surgery, Columbia University Medical Center, New York City, NY, USA
- Department of Biomedical Engineering, Columbia University, New York City, NY, USA
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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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