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Ebrahimian A, Mohammadi H, Maftoon N. Mechanical Effects of Medical Device Attachment to Human Tympanic Membrane. J Assoc Res Otolaryngol 2024; 25:285-302. [PMID: 38561524 DOI: 10.1007/s10162-024-00942-5] [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: 05/26/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
PURPOSE Several treatment methods for hearing disorders rely on attaching medical devices to the tympanic membrane. This study aims to systematically analyze the effects of the material and geometrical properties and location of the medical devices attached to the tympanic membrane on middle-ear vibrations. METHODS A finite-element model of the human middle ear was employed to simulate the effects of attachment of medical devices. Various types of material and geometrical properties, locations, and modeling scenarios were investigated for the medical device. RESULTS The attachment of the device magnifies the effects of anti-resonances of the middle ear. Additionally, the variations of the material properties of the device significantly alter the middle-ear resonance frequency while changes in the umbo and stapes footplate motions are negligible at frequencies above 5 kHz. Furthermore, modeling the device as a point mass cannot accurately represent the implanted middle-ear behavior. The variations of the diameter and height of the medical device have negligible effects on the middle-ear vibrations at frequencies below 200 Hz but can have considerable impacts at higher frequencies. The effects of changing the device height were negligible at frequencies above 2 kHz. We also discuss the effects of medical device attachment on the vibration patterns of the tympanic membrane as well as the impacts of the variations of the location of the device on the stapes footplate responses. CONCLUSION The findings of our study aid the development and optimization of new therapeutic devices, attached to the tympanic membrane, to have the least adverse effects on middle-ear vibrations.
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Affiliation(s)
- Arash Ebrahimian
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, Ontario, Canada
| | - Hossein Mohammadi
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, Ontario, Canada
| | - Nima Maftoon
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada.
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, Ontario, Canada.
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2
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Zhao Z, Liang J, Yao W. The Impact of the Fluid-Solid Coupling Behavior of Macro and Microstructures in the Spiral Cochlea on Hearing. J Biomech Eng 2024; 146:061001. [PMID: 38470372 DOI: 10.1115/1.4065043] [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] [Accepted: 02/28/2024] [Indexed: 03/13/2024]
Abstract
The cilia of the outer hair cells (OHCs) are the key microstructures involved in cochlear acoustic function, and their interactions with lymph in the cochlea involve complex, highly nonlinear, coupled motion and energy conversions, including macroscopic fluid-solid coupling. Recent optical measurements have shown that the frequency selectivity of the cochlea at high sound levels is entirely mechanical and is determined by the interactions of the hair bundles with the surrounding fluid. In this paper, an analytical mathematical model of the spiral cochlea containing macro- and micromeasurements was developed to investigate how the phonosensitive function of OHCs' motions is influenced by the macrostructural and microstructural fluid-solid coupling in the spiral cochlea. The results showed that the macrostructural and microstructural fluid-solid coupling exerted the radial forces of OHCs through the flow field, deflecting the cilia and generating frequency-selective properties of the microstructures. This finding showed that microstructural frequency selectivity arises from the radial motions of stereocilia hair bundles and enhances the hearing of sound signals at specific frequencies. It also implied that the macrostructural and microstructural fluid-solid couplings influence the OHCs' radial forces and that this is a key factor in the excitation of ion channels that enables their activity in helping the brain to detect sound.
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Affiliation(s)
- Zhengshan Zhao
- School of Mechanics and Engineering Science, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China
| | - Junyi Liang
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44106
| | - Wenjuan Yao
- School of Mechanics and Engineering Science, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China
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3
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Liang J, Wang J, Wang M, Yao W. Pathogenic mechanism analysis of cochlear key structural lesion and phonosensitive hearing loss. Biomech Model Mechanobiol 2024; 23:87-101. [PMID: 37548872 DOI: 10.1007/s10237-023-01760-z] [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: 03/26/2023] [Accepted: 07/26/2023] [Indexed: 08/08/2023]
Abstract
Due to ethical issues and the very fine and complex structure of the cochlea, it is difficult to directly perform experimental measurement on the human cochlea. Therefore, the finite element method has become an effective and replaceable new research means. Accurate numerical analysis on human ear using finite element method can provide better understanding of sound transmission and can be used to assess the influence of diseases on hearing and to treat hearing loss. In this research, a three-dimensional (3D) finite element model (FEM) of the human ear of cochlea was presented to investigate the destruction of basilar membrane (BM), round window (RW) sclerosis and perilymph fistula, the key structures of the cochlea, and analyze the effects of these abnormal pathological states in the cochlea on cochlear hearing, resulting in the changes in cochlear sense structure biomechanical behavior and quantitative prediction of the degree and harm of the disorder to the decline of human hearing. Therefore, this paper can deepen reader's understanding of the cochlear biomechanical mechanism and provide a theoretical foundation for clinical otology.
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Affiliation(s)
- Junyi Liang
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44106, USA
| | - Jiakun Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, 200072, People's Republic of China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, People's Republic of China
| | - Mianzhi Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, 200072, People's Republic of China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, People's Republic of China
| | - Wenjuan Yao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, 200072, People's Republic of China.
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, People's Republic of China.
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4
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Sirithunge C, Wang H, Iida F. Soft touchless sensors and touchless sensing for soft robots. Front Robot AI 2024; 11:1224216. [PMID: 38312746 PMCID: PMC10830750 DOI: 10.3389/frobt.2024.1224216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 01/02/2024] [Indexed: 02/06/2024] Open
Abstract
Soft robots are characterized by their mechanical compliance, making them well-suited for various bio-inspired applications. However, the challenge of preserving their flexibility during deployment has necessitated using soft sensors which can enhance their mobility, energy efficiency, and spatial adaptability. Through emulating the structure, strategies, and working principles of human senses, soft robots can detect stimuli without direct contact with soft touchless sensors and tactile stimuli. This has resulted in noteworthy progress within the field of soft robotics. Nevertheless, soft, touchless sensors offer the advantage of non-invasive sensing and gripping without the drawbacks linked to physical contact. Consequently, the popularity of soft touchless sensors has grown in recent years, as they facilitate intuitive and safe interactions with humans, other robots, and the surrounding environment. This review explores the emerging confluence of touchless sensing and soft robotics, outlining a roadmap for deployable soft robots to achieve human-level dexterity.
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Affiliation(s)
| | - Huijiang Wang
- Bio-Inspired Robotics Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
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5
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Wang J, Liang J, Gao L, Yao W. Study on damage of the macrostructure of the cochlea under the impact load. Proc Inst Mech Eng H 2023; 237:1390-1399. [PMID: 37955248 DOI: 10.1177/09544119231209187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Due to the tiny and delicate structure of the cochlea, the auditory system is the most sensitive to explosion impact damage. After being damaged by the explosion impact wave, it usually causes long-term deafness, tinnitus, and other symptoms. To better understand the influence of impact load on the cochlea and basilar membrane (BM), a three-dimensional (3D) fluid-solid coupling finite element model was developed. This model accurately reflects the actual spatial spiral shape of the human cochlea, as well as the lymph environment and biological materials. Based on verifying the reliability of the model, the curve of impact load-amplitude response was obtained, and damage of impact load on the cochlea and the key macrostructure-BM was analyzed. The results indicate that impact wave at middle frequency has widest influence on the cochlea. Furthermore, impact loading causes tears in the BM and destroys the cochlear frequency selectivity.
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Affiliation(s)
- Jiakun Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai, China
| | - Junyi Liang
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Lei Gao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai, China
| | - Wenjuan Yao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai, China
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6
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Gao L, Wang J, Liang J, Yao W, Zhou L, Huang X. Study of fatigue damage to the cochlea. Comput Methods Biomech Biomed Engin 2023; 26:2047-2056. [PMID: 36629847 DOI: 10.1080/10255842.2022.2164712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/17/2022] [Accepted: 12/28/2022] [Indexed: 01/12/2023]
Abstract
In order to explore the hearing loss resulting from exposure to continuous or intermittent loud noise. A three-dimensional liquid-solid coupling finite element model of spiral cochlea was established. The reliability of the model was verified, and the stress and amplitude of the basilar membrane of the pivotal structure in cochlea were analyzed. The results show that under the action of the same high-pressure sound, the preferential fatigue area of the cochlear high-frequency area mainly causes fatigue in the cochlear. The safer area is a sound pressure level below 70 dB, while one above 90 dB accelerates damage to the ear.
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Affiliation(s)
- Lei Gao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai, China
| | - Jiakun Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai, China
| | - Junyi Liang
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Wenjuan Yao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai, China
| | - Lei Zhou
- Otorhinolaryngology-Head and Neck Surgery, Zhongshan Hospital affiliated to Fudan University, Shanghai, China
| | - Xinsheng Huang
- Otorhinolaryngology-Head and Neck Surgery, Zhongshan Hospital affiliated to Fudan University, Shanghai, China
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Castle N, Liang J, Smith M, Petersen B, Matson C, Eldridge T, Zhang K, Lee CH, Liu Y, Dai C. Finite Element Modeling of Residual Hearing after Cochlear Implant Surgery in Chinchillas. Bioengineering (Basel) 2023; 10:bioengineering10050539. [PMID: 37237608 DOI: 10.3390/bioengineering10050539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/20/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Cochlear implant (CI) surgery is one of the most utilized treatments for severe hearing loss. However, the effects of a successful scala tympani insertion on the mechanics of hearing are not yet fully understood. This paper presents a finite element (FE) model of the chinchilla inner ear for studying the interrelationship between the mechanical function and the insertion angle of a CI electrode. This FE model includes a three-chambered cochlea and full vestibular system, accomplished using µ-MRI and µ-CT scanning technologies. This model's first application found minimal loss of residual hearing due to insertion angle after CI surgery, and this indicates that it is a reliable and helpful tool for future applications in CI design, surgical planning, and stimuli setup.
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Affiliation(s)
- Nicholas Castle
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Junfeng Liang
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Matthew Smith
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Brett Petersen
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Cayman Matson
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Tara Eldridge
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Ke Zhang
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Chung-Hao Lee
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Yingtao Liu
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Chenkai Dai
- Department of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA
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8
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Bradshaw JJ, Brown MA, Jiang S, Gan RZ. 3D Finite Element Model of Human Ear with 3-Chamber Spiral Cochlea for Blast Wave Transmission from the Ear Canal to Cochlea. Ann Biomed Eng 2023; 51:1106-1118. [PMID: 37036617 DOI: 10.1007/s10439-023-03200-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/29/2023] [Indexed: 04/11/2023]
Abstract
Blast-induced auditory trauma is a common injury in military service members and veterans that leads to hearing loss. While the inner ear response to blast exposure is difficult to characterize experimentally, computational models have advanced to predict blast wave transmission from the ear canal to the cochlea; however, published models have either straight or spiral cochlea with fluid-filled two chambers. In this paper, we report the recently developed 3D finite element (FE) model of the human ear mimicking the anatomical structure of the 3-chambered cochlea. The model consists of the ear canal, middle ear, and two and a half turns of the cochlea with three chambers separated by the Reissner's membrane (RM) and the basilar membrane (BM). The blast overpressure measured from human temporal bone experiments was applied at the ear canal entrance and the Fluent/Mechanical coupled fluid-structure interaction analysis was conducted in ANSYS software. The FE model-derived results include the pressure in the canal near the tympanic membrane (TM) and the intracochlear pressure at scala vestibuli, the TM displacement, and the stapes footplate (SFP) displacement, which were compared with experimentally measured data in human temporal bones. The validated model was used to predict the biomechanical response of the ear to blast overpressure: distributions of the maximum strain and stress within the TM, the BM displacement variation from the base to apex, and the energy flux or total energy entering the cochlea. The comparison of intracochlear pressure and BM displacement with those from the FE model of 2-chambered cochlea indicated that the 3-chamber cochlea model with the RM and scala media chamber improved our understanding of cochlea mechanics. This most comprehensive FE model of the human ear has shown its capability to predict the middle ear and cochlea responses to blast overpressure which will advance our understanding of auditory blast injury.
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Affiliation(s)
- John J Bradshaw
- School of Biomedical Engineering, University of Oklahoma, 173 Felgar Street, Room 101, Norman, OK, 73019, USA
| | - Marcus A Brown
- School of Biomedical Engineering, University of Oklahoma, 173 Felgar Street, Room 101, Norman, OK, 73019, USA
| | - Shangyuan Jiang
- School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 Asp Avenue, Room 200, Norman, OK, 73019, USA
| | - Rong Z Gan
- School of Biomedical Engineering, University of Oklahoma, 173 Felgar Street, Room 101, Norman, OK, 73019, USA.
- School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 Asp Avenue, Room 200, Norman, OK, 73019, USA.
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9
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Liang J, Xie W, Yao W, Duan M. Effects of basilar-membrane lesions on dynamic responses of the middle ear. Acta Otolaryngol 2023; 143:255-261. [PMID: 36939118 DOI: 10.1080/00016489.2023.2187451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
BACKGROUND Numerical simulations can reflect the changes in physiological properties caused by various factors in the cochlea. AIMS/OBJECTIVE To analyze the influence of lesions of the basilar membrane (BM) on the dynamic response of the middle ear. METHOD Based on healthy human ear CT scan images, use PATRAN software to build a three-dimensional finite element model of the human ear, then apply NASTRAN software to conduct analysis of solid-fluid coupled frequency response. The influence of lesions in the BM on the dynamic response of the middle ear is simulated through the method of numerical simulation. RESULT Through comparing experimental data and the frequency-response curve of displacement of BM and stapes, the validity of the model in this paper was verified. CONCLUSION Regarding sclerosis in BM, the most obvious decline of displacement and velocity exists in the range of 800-10,000Hz and 800-2000Hz frequency, respectively. The higher degree of sclerosis, the more obvious decline becomes. The maximal decline of hearing can reach from 6.2 dB to 9.1 dB. Regarding added mass in BM, the most obvious decline of displacement exists in the range of 600-1000Hz frequency, and the maximal decline of hearing can reach 4.0 dB. There is no obvious decline in velocity.
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Affiliation(s)
- Junyi Liang
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Wen Xie
- Department of Otolaryngology Head and Neck Surgery, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Wenjuan Yao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, P.R. China.,Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, P.R. China
| | - Maoli Duan
- Division of ENT section, Department of Clinical Science, Intervention and Technology and Department of Otolaryngology Head and Neck & Audiology and Neurotology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
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Garcia-Manrique J, Furlong C, Gonzalez-Herrera A, Cheng JT. Numerical model characterization of the sound transmission mechanism in the tympanic membrane from a high-speed digital holographic experiment in transient regime. Acta Biomater 2023; 159:63-73. [PMID: 36708849 DOI: 10.1016/j.actbio.2023.01.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 01/04/2023] [Accepted: 01/19/2023] [Indexed: 01/27/2023]
Abstract
A methodology for the development of a finite element numerical model of the tympanic membrane (TM) based on experiments carried out in the time domain on a cadaveric human temporal bone is presented. Using a high-speed digital holographic (HDH) system, acoustically-induced transient displacements of the TM surface are obtained. The procedure is capable to generate and validate the finite element model of the TM by numerical and experimental data correlation. Reverse engineering approach is used to identify key material parameters that define the mechanical response of the TM. Finally, modal numerical simulations of the specimen are performed. Results show the feasibility of the methodology to obtain an accurate model of a specific specimen and to help interpret its behaviour with additional numerical simulations. STATEMENT OF SIGNIFICANCE: Improving knowledge of the dynamic behavior of the tympanic membrane is key to understanding the sound transmission system in human hearing and advance in the treatment of its pathologies. Recently we acquired a new tool to carry out experiments in transient regime by means of digital laser holography, capable of providing a large amount of information in a controlled transient test. In this work, these data are used to develop a methodology that generates a numerical model of the tympanic membrane based on numerical-experimental correlations. It is important to be able to develop models that fit specific patients. In this work, additional modal simulations are also presented that, in addition to validating the results, provide more information on the specimen.
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Affiliation(s)
- J Garcia-Manrique
- Department of Civil Engineering, Materials and Manufacturing, School of Engineering, University of Malaga, Spain; Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, MA, USA; Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, USA.
| | - Cosme Furlong
- Center for Holographic Studies and Laser micro-mechaTronics (CHSLT), Worcester, MA, USA; Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA, USA
| | - A Gonzalez-Herrera
- Department of Civil Engineering, Materials and Manufacturing, School of Engineering, University of Malaga, Spain
| | - Jeffrey T Cheng
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, MA, USA; Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, USA
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Shi H, Xiang S, Wang L, Sun Y, Wang J, Liu Z. Characterization of middle ear soft tissue damping and its role in sound transmission. Biomech Model Mechanobiol 2023; 22:1003-1018. [PMID: 36881185 DOI: 10.1007/s10237-023-01696-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 01/22/2023] [Indexed: 03/08/2023]
Abstract
Damping plays an important role in the middle ear (ME) sound transmission system. However, how to mechanically characterize the damping of ME soft tissues and the role of damping in ME sound transmission have not yet reached a consensus. In this paper, a finite element (FE) model of the partial external and ME of the human ear, considering both Rayleigh damping and viscoelastic damping for different soft tissues, is developed to quantitatively investigate the damping in soft tissues effects on the wide-frequency response of the ME sound transmission system. The model-derived results can capture the high-frequency (above 2 kHz) fluctuations and obtain the 0.9 kHz resonant frequency (RF) of the stapes velocity transfer function (SVTF) response. The results show that the damping of pars tensa (PT), stapedial annular ligament (SAL) and incudostapedial joints (ISJ) can help smooth the broadband response of the umbo and stapes footplate (SFP). It is found that, between 1 and 8 kHz, the damping of the PT increases the magnitude and phase delay of the SVTF above 2 kHz while the damping of the ISJ can avoid excessive phase delay of the SVTF, which is important in maintaining the synchronization in high-frequency vibration but has not been revealed before. Below 1 kHz, the damping of the SAL plays a more important role, and it can decrease the magnitude but increases the phase delay of the SVTF. This study has implications for a better understanding of the mechanism of ME sound transmission.
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Affiliation(s)
- Huibin Shi
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Shuyi Xiang
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Liang Wang
- Department of Mechanics and Tianjin Key Laboratory of Nonlinear Dynamics and Control, Tianjin University, Tianjin, 300350, People's Republic of China
| | - Yongtao Sun
- Department of Mechanics and Tianjin Key Laboratory of Nonlinear Dynamics and Control, Tianjin University, Tianjin, 300350, People's Republic of China
| | - Jie Wang
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.,Beijing Engineering Research Center of Audiological Technology, Beijing, 100730, China
| | - Zhanli Liu
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
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Liang J, Wang J, Yao W, Wang M. Development of an Assessment Model for the Effect of the Replacement of Minimal Artificial Ossicles on Hearing in the Inner Ear. MICROMACHINES 2023; 14:483. [PMID: 36838183 PMCID: PMC9962337 DOI: 10.3390/mi14020483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/14/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Due to ethical issues and the nature of the ear, it is difficult to directly perform experimental measurements on living body elements of the human ear. Therefore, a numerical model has been developed to effectively assess the effect of the replacement of artificial ossicles on hearing in the inner ear. A healthy volunteer's right ear was scanned to obtain CT data, which were digitalized through the use of a self-compiling program and coalescent Patran-Nastran software to establish a 3D numerical model of the whole ear, and a frequency response of a healthy human ear was analyzed. The vibration characteristics of the basilar membrane (BM) after total ossicular replacement prosthesis (TORP) implantation were then analyzed. The results show that although the sound conduction function of the middle ear was restored after replacement of the TORP, the sensory sound function of the inner ear was affected. In the low frequency and medium frequency range, hearing loss was 5.2~10.7%. Meanwhile, in the middle-high frequency range, the replacement of a middle ear TORP in response to high sound pressure produced a high acoustic stimulation effect in the inner ear, making the inner ear structures susceptible to fatigue and more prone to fatigue damage compared to the structures in healthy individuals. This developed model is able to assess the effects of surgical operation on the entire hearing system.
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Affiliation(s)
- Junyi Liang
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44106, USA
| | - Jiakun Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, China
| | - Wenjuan Yao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, China
| | - Mianzhi Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, China
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13
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Liang J, Wang J, Yao W, Zhou L, Huang X. Behavioral characteristics in sensing mechanism of the Corti. Comput Struct Biotechnol J 2023; 21:1797-1806. [PMID: 36915377 PMCID: PMC10006463 DOI: 10.1016/j.csbj.2023.02.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 02/16/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Some experiments can't be realized because the cochlea's Corti is the most delicate and complex sensory organ. In this paper, some typical and special behavioral characteristics in the process of sensation were found in medical clinic. Based on the interdisciplinary principles of medicine, physics and biology, a real numerical simulation model of Corti is established. On the basis of verifying the correctness of the model, the mechanism corresponding to these typical and special behavior characteristics in the process of sensation is explored through simulation calculation and analysis. This study provides theoretical and applied basis for people to better understand the sound sensing mechanism, and provides a numerical simulation platform for further analyzing Corti's sensing mechanism and good clinical application.
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Affiliation(s)
- Junyi Liang
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44106, USA
| | - Jiakun Wang
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, PR China
| | - Wenjuan Yao
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, PR China
- Corresponding authors.
| | - Lei Zhou
- Department of Otorhinolaryngology, Zhongshan Hospital, Fudan University, Shanghai 200032, PR China
| | - Xinsheng Huang
- Department of Otorhinolaryngology, Zhongshan Hospital, Fudan University, Shanghai 200032, PR China
- Corresponding authors.
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14
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Zhao Z, Yao W, Wang M, Wang J, Zhang T. Radial Flow Field of Spiral Cochlea and Its Effect On Stereocilia. J Biomech Eng 2022; 144:1143034. [PMID: 35789250 DOI: 10.1115/1.4054930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Indexed: 11/08/2022]
Abstract
The opening of the ion channels ultimately depends on the movement and energy conversion of the microstructural organization. It has not been clear how active sound amplification is generated by the microstructure of the cochlea's characteristic spiral shape. In this paper, an analytical model of the spiral cochlea is developed to investigate the radial flow field generated by the spiral shape of the cochlea and its effect on the outer hair cell stereocilia, and to analyze the effect of the spiral shape on the micromechanics of the cochlea. The results show that the spiral shape of the cochlea exerts a radial shear force on the hair cell stereocilia by generating a radial flow field. This causes the stereocilia to deflect in the radial flow field, with the maximum deflection occurring at the apex of the cochlea. This finding explains the microscopic mechanism that causes the cochlea's spiral shape to enhance low-frequency hearing in humans, and it provides a basis for further studies on the contribution of the movement of stereocilia in the radial flow field of the lymphatic fluid to activate ion channels for auditory production.
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Affiliation(s)
- Zhengshan Zhao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, PRC
| | - Wenjuan Yao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, PRC
| | - Mianzhi Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, PRC
| | - Jiakun Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, PRC
| | - Tianyu Zhang
- ENT Institute, Eye & ENT Hospital of Fudan University, Hearing Medicine Key Laboratory, National Health Commission of China; Department of Facial Plastic Reconstruction Surgery, Eye & ENT Hospital of Fudan University, Shanghai 200031, PRC
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15
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von Benda-Beckmann AM, Ketten DR, Lam FPA, de Jong CAF, Müller RAJ, Kastelein RA. Evaluation of kurtosis-corrected sound exposure level as a metric for predicting onset of hearing threshold shifts in harbor porpoises (Phocoena phocoena). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 152:295. [PMID: 35931542 DOI: 10.1121/10.0012364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Application of a kurtosis correction to frequency-weighted sound exposure level (SEL) improved predictions of risk of hearing damage in humans and terrestrial mammals for sound exposures with different degrees of impulsiveness. To assess whether kurtosis corrections may lead to improved predictions for marine mammals, corrections were applied to temporary threshold shift (TTS) growth measurements for harbor porpoises (Phocoena phocoena) exposed to different sounds. Kurtosis-corrected frequency-weighted SEL predicted accurately the growth of low levels of TTS (TTS1-4 < 10 dB) for intermittent sounds with short (1-13 s) silence intervals but was not consistent with frequency-weighted SEL data for continuous sound exposures.
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Affiliation(s)
| | - D R Ketten
- The Hearing Research Center, Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts 02155, USA
| | - F P A Lam
- TNO Acoustics and Sonar, Oude Waalsdorperweg 63, 2597 AK, The Hague, The Netherlands
| | - C A F de Jong
- TNO Acoustics and Sonar, Oude Waalsdorperweg 63, 2597 AK, The Hague, The Netherlands
| | - R A J Müller
- TNO Acoustics and Sonar, Oude Waalsdorperweg 63, 2597 AK, The Hague, The Netherlands
| | - R A Kastelein
- Sea Mammal Research Company (SEAMARCO), Julianalaan 46, 3843 CC Harderwijk, The Netherlands
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16
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Jain S, Parveen S, Kumar S, Talwar D. Validated Ossicular Measurements on High-Resolution Computed Tomography (CT) in Live and Cadaveric Temporal Bones. Cureus 2022; 14:e22410. [PMID: 35371655 PMCID: PMC8941294 DOI: 10.7759/cureus.22410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2022] [Indexed: 11/05/2022] Open
Abstract
Objective The present study was undertaken to study the utility of high-resolution computed tomography (HRCT) temporal bone in live patients for providing the parameters of ossicular dimensions (OD), using standard assessment protocols, devised by the authors, with regard to the plane of CT scans and axes of measurement of ossicles. Methods This observational study was conducted from January 2021 to February 2022 at Acharya Vinoba Bhave Rural Hospital, Sawanghi, Meghe, Maharashtra, India, in the Department of Otorhinolaryngology and Department of Radiodiagnosis. HRCT scan was performed on temporal bones, 10 in live subjects with no otological complaints and 10 in cadaveric temporal bones. HRCT was also performed for all three ossicles after dissecting them out from the respective cadaveric temporal bones. Measurements of OD were taken using Universalmednet Software and vernier calipers and compared with published anatomic data. Results The measurements taken using HRCT scans of the live subject and cadaveric bone as well as the ossicles taken using calipers fall within the range of published studies. Slight variation is seen in the measurements of stapes and incus, stapes total height is 3.17mm, less than 3.3. Conventional HRCT temporal bone in live patients when performed under set circumstances can be adopted as a standard method for measurement of ossicular sizes for the generation of normative data for different races, ethnicity and sex. Conclusion The results of our study can have implications in terms of translational research as the measurements obtained can help in better understanding of middle ear biomechanics, prosthesis designing, developing ideal tympanoplasty methods in terms of size, shape and placement of autograft.
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Liu Z, Liu H, Wang J, Yang J, Hao J, Yang S. Analysis of design parameters of round-window stimulating type electromagnetic transducer by a nonlinear lumped parameter model of implanted human ear. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2022; 19:2453-2470. [PMID: 35240792 DOI: 10.3934/mbe.2022113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Round-window stimulating transducer is a new solution to treat mixed hearing loss. To uncover the factors affecting the round-window stimulation's performance, we investigated the influence of four main design parameters of round-window stimulating type electromagnetic transducer. Firstly, we constructed a human ear nonlinear lumped parameter model and confirmed its validity by comparing the stapes responses predicted by the model with the experimental data. Following this, an electromagnetic transducer's mechanical model, which simulates the floating mass transducer, was built and coupled to the human ear model; thereby, we established a nonlinear lumped parameter model of implanted human ear under round-window stimulation and verified its reliability. Finally, based on this model, the influences of the four main design parameters, i.e., the excitation voltage, the electromechanical coupling coefficient, the support stiffness, and the preload force, were analyzed. The results show that the change of excitation voltage does not alter the system's natural frequency. Chaotic motion occurs when the electromechanical coupling coefficient is small. Meanwhile, the stapes displacement appears to increase firstly and then decrease with the increase of the electromechanical coupling coefficient. The increase of the support stiffness enlarges the resonance frequency of the stapes displacement and reduces the stapes displacement near the resonance frequency, deteriorating the transducer's hearing compensation at low frequency. The preload force can improve the transducer's hearing compensation performance in mid-high frequency region.
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Affiliation(s)
- Zhaohai Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China
| | - Houguang Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China
| | - Jie Wang
- Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
- Beijing Engineering Research Center of Hearing Technology, Beijing 100730, China
| | - Jianhua Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China
| | - Jingbin Hao
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China
| | - Shanguo Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China
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18
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Zhao Y, Liu H, Yang J, Yang S, Liu W, Huang X. Effects of design and coupling parameters on the performance of electromagnetic transducers in round-window stimulation. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 151:609. [PMID: 35105032 DOI: 10.1121/10.0009313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
Many studies have investigated factors contributing to large variations in the outcomes of round-window (RW) stimulation but most have focused on the floating mass transducer (FMT). To determine whether results for the FMT hold for a fixed-type transducer (FTT), this study constructs two coupled finite element models of the transducer and the human ear that incorporate the cochlear third windows and inner structures of these two electromagnetic transducers. We use these FE models of the human ear and transducers to investigate the influence of four design parameters and coupling conditions for the transducers, i.e., the support's Young's modulus, the coupling layer's cross sectional area and Young's modulus, and the transducer's cross sectional area. The results show that an increase in the support's Young's modulus reduces the output of the FMT but increases that of the FTT. Reducing the cross sectional area and Young's modulus of the coupling layer significantly increases the low-frequency response of the FMT but slightly reduces that of the FTT. Reducing the cross sectional area of the transducer increases the output of the FMT but reduces that of the FTT. This shows that inner structures of electromagnetic transducers should be considered in the optimal design parameters and coupling conditions for RW stimulation.
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Affiliation(s)
- Yu Zhao
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, People's Republic of China
| | - Houguang Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, People's Republic of China
| | - Jianhua Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, People's Republic of China
| | - Shanguo Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, People's Republic of China
| | - Wen Liu
- Department of Otolaryngology, Affiliated Hospital of Xuzhou Medical University, Xuzhou 221006, People's Republic of China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongshan Hospital affiliated to Fudan University, Shanghai, 200032, People's Republic of China
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19
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ZHAO ZHENGSHAN, YAO WENJUAN, WANG JIAKUN, ZHOU LEI, HUANG XINSHENG. MECHANISM OF SENSORINEURAL HEARING LOSS CAUSED BY TYPICAL SCLEROSIS OF COCHLEA. J MECH MED BIOL 2021. [DOI: 10.1142/s0219519422500026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
It is difficult to measure the cochlea directly because of the ethical problems and the complexity of cochlear structure. Therefore, finite element model (FEM) can be used as an effective alternative research method. An accurate FEM of the human ear can not only help people understand the mechanisms of sound transmission, but also effectively assess the effects of otologic diseases and guide research on the treatment of hearing loss. In this paper, a three-dimensional (3D) FEM of the human normal cochlea is proposed to study the changes in the biomechanical behavior of the cochlear sensory structure caused by the anterior fissure sclerosis and bottom-turn and apex-turn ossification of the cochlear window. The degree and harm of hearing loss caused by diseases are quantitatively predicted, which can deepen the understanding of the biomechanical mechanism of cochlea, and provide theoretical basis for clinical medicine.
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Affiliation(s)
- ZHENGSHAN ZHAO
- School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, P. R. China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, P. R. China
| | - WENJUAN YAO
- School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, P. R. China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, P. R. China
| | - JIAKUN WANG
- School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, P. R. China
- Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, P. R. China
| | - LEI ZHOU
- Otorhinolaryngology-Head and Neck Surgery Department, Zhongshan Hospital Affiliated to Fudan University, Shanghai 200032, P. R. China
| | - XINSHENG HUANG
- Otorhinolaryngology-Head and Neck Surgery Department, Zhongshan Hospital Affiliated to Fudan University, Shanghai 200032, P. R. China
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20
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Liang J, Ke Z, Welch PV, Gan RZ, Dai C. A comprehensive finite element model for studying Cochlear-Vestibular interaction. Comput Methods Biomech Biomed Engin 2021; 25:204-214. [PMID: 34641759 DOI: 10.1080/10255842.2021.1946522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We present a 3-D finite element (FE) model of the chinchilla's inner ear consisting of the entire cochlea structure and the vestibular system. The reaction of the basilar membrane to the head rotation and the reaction of ampulla to the stapes movement were investigated. These results demonstrate the existence of hearing-vestibular system interaction. They provide an explanation to the clinical finding on the coexistence between hearing loss and equilibration dysfunction. It is a preliminary, yet critical step toward the development of a comprehensive FE model of an entire ear for mechano-acoustic analysis.
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Affiliation(s)
- Junfeng Liang
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Zhang Ke
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Paige V Welch
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Rong Z Gan
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
| | - Chenkai Dai
- Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA
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21
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Yao W, Zhao Z, Wang J, Duan M. Time-domain analysis of a three-dimensional numerical model of the human spiral cochlea at medium intensity. Comput Biol Med 2021; 136:104756. [PMID: 34388464 DOI: 10.1016/j.compbiomed.2021.104756] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 11/15/2022]
Abstract
For the processing and detection of speech and music, the human cochlea has an exquisite sensitivity and selectivity of frequency and a dynamic range. How the cochlea performs these remarkable functions has fascinated auditory scientists for decades. Because it is not possible to measure sound-induced vibrations within the cochlea in a living human being, mathematical modeling has played an important role in cochlear mechanics. For this study, a three-dimensional human cochlear model with a fluid‒structure coupling was constructed. Time-domain analysis was performed to calculate the displacement, velocity, and stress of the basilar membrane (BM) and osseous spiral lamina (OSL) at different times in response to a pure tone stimulus. The model reproduced the traveling-wave motion of the BM. The model also showed that the cochlea's spiral shape can induce asymmetrical mechanical behavior of the BM and cause cochlear fluid to move in a radial direction; this may contribute to human sound perception. The cochlea's spiral shape not only enhances a low-frequency vibration of the BM but also changes the maximization of the positions of vibration. Therefore, the spiral's characteristics play a key role in the cochlea's frequency selectivity for low-frequency sounds. And this suggests that the OSL can react to sound as quickly as the BM. Furthermore, the basal region of the BM tends to have more stress than its other regions, and this may explain the clinical observation that human sensorineural hearing loss often occurs at high frequencies.
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Affiliation(s)
- Wenjuan Yao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, 200072, PR China; Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, PR China.
| | - Zhengshan Zhao
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, 200072, PR China; Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, PR China
| | - Jiakun Wang
- School of Mechanics and Engineering Science, Shanghai University, Shanghai, 200072, PR China; Shanghai Institute of Applied Mathematics and Mechanics, Shanghai, 200072, PR China
| | - Maoli Duan
- Division of ENT Section, Department of Clinical Science, Intervention and Technology and Department of Otolaryngology Head and Neck, Karolinska University Hospital, Karolinska Institutet, 17176, Stockholm, Sweden.
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22
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Liu H, Xue L, Yang J, Cheng G, Zhou L, Huang X. Effect of ossicular chain deformity on reverse stimulation considering the overflow characteristics of third windows. Comput Methods Biomech Biomed Engin 2021; 25:257-272. [PMID: 34229548 DOI: 10.1080/10255842.2021.1948023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Stimulating the round window membrane via an active actuator of the middle ear implant, named the reverse stimulation, has become an option to help patients with ossicular chain deformity (OCD) to restore hearing. However, there is still no concise description of how OCD affects reverse stimulation considering the overflow characteristics of third windows. In the present study, an impedance model considering the vestibular and cochlear aqueducts was used to investigate the dynamic response of the cochlea to reverse stimulation under OCD. First, a finite-element (FE) model of the middle ear and the ear canal was used to estimate the changes in reverse middle-ear impedance caused by ossicular chain fixation and ossicular chain interruption. Then, the impedance model was used to predict the reverse transfer function, which characterizes the effect of OCD on the dynamic response of the cochlea. The results show that ossicular chain fixation reduces the reverse stimulation's performance. Moreover, the existence of the third windows complicates the effect of ossicular chain fixation on the reverse stimulation and boosts obviously the reverse stimulation's performance at low frequencies. In contrast, regardless of the existence of third windows, ossicular chain interruption enhances the effect of reverse stimulation.
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Affiliation(s)
- Houguang Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, China
| | - Lin Xue
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, China
| | - Jianhua Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, China
| | - Gang Cheng
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, China
| | - Lei Zhou
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital affiliated to Fudan University, Shanghai, China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital affiliated to Fudan University, Shanghai, China
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23
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De Paolis A, Miller BJ, Doube M, Bodey AJ, Rau C, Richter CP, Cardoso L, Carriero A. Increased cochlear otic capsule thickness and intracortical canal porosity in the oim mouse model of osteogenesis imperfecta. J Struct Biol 2021; 213:107708. [PMID: 33581284 DOI: 10.1016/j.jsb.2021.107708] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/30/2021] [Accepted: 02/02/2021] [Indexed: 01/19/2023]
Abstract
Osteogenesis imperfecta (OI or brittle bone disease) is a group of genetic disorders of the connective tissues caused mainly by mutations in the genes encoding collagen type I. Clinical manifestations of OI include skeletal fragility, bone deformities, and severe functional disabilities, such as hearing loss. Progressive hearing loss, usually beginning in childhood, affects approximately 70% of people with OI with more than half of the cases involving the inner ear. There is no cure for OI nor a treatment to ameliorate its corresponding hearing loss, and very little is known about the properties of OI ears. In this study, we investigate the morphology of the otic capsule and the cochlea in the inner ear of the oim mouse model of OI. High-resolution 3D images of 8-week old oim and WT inner ears were acquired using synchrotron microtomography. Volumetric morphometric measurements were conducted for the otic capsule, its intracortical canal network and osteocyte lacunae, and for the cochlear spiral ducts. Our results show that the morphology of the cochlea is preserved in the oim ears at 8 weeks of age but the otic capsule has a greater cortical thickness and altered intracortical bone porosity, with a larger number and volume density of highly branched canals in the oim otic capsule. These results portray a state of compromised bone quality in the otic capsule of the oim mice that may contribute to their hearing loss.
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Affiliation(s)
- Annalisa De Paolis
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | | | - Michael Doube
- Department of Infectious Diseases and Public Health, City University of Hong Kong, HK
| | - Andrew John Bodey
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | - Christoph Rau
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK; Department of Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; University of Manchester, Manchester, UK
| | - Claus-Peter Richter
- Department of Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA; The Hugh Knowles Center, Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, USA
| | - Luis Cardoso
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Alessandra Carriero
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
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24
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Investigating the Geometry and Mechanical Properties of Human Round Window Membranes Using Micro-Fringe Projection. Otol Neurotol 2021; 42:319-326. [PMID: 33278245 DOI: 10.1097/mao.0000000000002911] [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
HYPOTHESIS The geometry and the mechanical property of the round window membrane (RWM) have a fundamental impact on the function of cochlea. BACKGROUND Understanding the mechanical behavior of RWM is important for cochlear surgery and design for the cochlear implant. Although the anatomy of RWM has been widely studied and described in the literature, argument remains regarding the true shape of RWM. The mechanical properties of RWM are also scarcely reported due to the difficulty of the measurement of the small size RWM. METHODS In this paper, micro-fringe projection was used to reconstruct the 3-dimensional geometries of 14 RWMs. Mechanical properties of the RWMs were subsequently measured using finite element (FE) model and an inverse method. The three-dimensional surface topographies and the curvatures of the two major directions reconstructed from the micro-fringe projection both demonstrated wide variations among samples. RESULTS The diameters of the RWMs vary from 1.65 to 2.2 mm and the curvatures vary from -0.97 to 3.76 mm-1. The nonlinear elasticity parameters in the Ogden model for each sample was measured and the average effective Young's modulus is approximately 1.98 MPa. CONCLUSION The geometries and mechanical properties of the human RWM measured in the work could potentially be applied to surgery design and on modeling analysis for the cochlea.
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25
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Aleemardani M, Bagher Z, Farhadi M, Chahsetareh H, Najafi R, Eftekhari B, Seifalian A. Can Tissue Engineering Bring Hope to the Development of Human Tympanic Membrane? TISSUE ENGINEERING PART B-REVIEWS 2021; 27:572-589. [PMID: 33164696 DOI: 10.1089/ten.teb.2020.0176] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The tympanic membrane (TM), more commonly known as the eardrum, consists of a thin layer of tissue in the human ear that receives sound vibrations from outside of the body and transmits them to the auditory ossicles. The TM perforations (TMPs) are a common ontological condition, which in some cases can result in permanent hearing loss. Despite the spontaneous healing capacity of the TM to regenerate in the majority of cases of acute perforation, chronic perforations require surgical interventions. However, the disadvantages of the surgical procedure include infection, anesthetic risks, and high failure of graft patency. The tissue engineering strategy, which includes the applications of a three-dimensional (3D) scaffold, cells, and biomolecules or a combination of them for the closure of chronic perforation, has been considered as an emerging treatment. Using this approach, emerging products are currently under development to regenerate the TM structure and its properties. This research aimed to highlight the problems with the current methods of TMP treatment, and critically evaluate the tissue engineering approaches, which may overcome these drawbacks. The focus of this review is on recent literature to critically discuss the emerging advanced materials used as a 3D scaffold in the development of a TM with cellular engineering, biomolecules, cells, and the fabrications of the TM and its pathway to the clinical application. In this review, we discuss the properties of TM and the advantages and disadvantages of the current clinical products for repair and replacement of the TM. Furthermore, we provide an overview of the in vitro and preclinical studies of emerging products over the past 5 years. The results of recent preclinical studies suggest that the tissue engineering field holds significant promise.
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Affiliation(s)
- Mina Aleemardani
- Biomedical Engineering Department, Amirkabir University of Technology, Tehran, Iran
| | - Zohreh Bagher
- ENT and Head & Neck Research Centre and Department, The Five Senses Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Farhadi
- ENT and Head & Neck Research Centre and Department, The Five Senses Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Hadi Chahsetareh
- Department of Life Science Engineering, Faculty of New Science and Technologies, University of Tehran, Tehran, Iran
| | - Roghayeh Najafi
- Department of Life Science Engineering, Faculty of New Science and Technologies, University of Tehran, Tehran, Iran
| | - Behnaz Eftekhari
- Biomedical Engineering Department, Amirkabir University of Technology, Tehran, Iran
| | - Alexander Seifalian
- Nanotechnology and Regenerative Medicine Commercialisation Centre (NanoRegMed Ltd.), London BioScience Innovation Centre, London, United Kingdom
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26
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Xue L, Liu H, Yang J, Liu S, Zhao Y, Huang X. Research on coupling effects of actuator and round window membrane on reverse stimulation of human cochlea. Proc Inst Mech Eng H 2021; 235:447-458. [PMID: 33427056 DOI: 10.1177/0954411920987960] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An active actuator of a middle-ear implant coupled to the round window membrane (RWM), which transmits vibration to the cochlea, has been used to compensate for hearing loss in patients. However, various factors affect the coupling condition between the actuator and the RWM, resulting in coupling leakage. In this study, a coupling impedance model of the human ear and the actuator was used to investigate the effect of inefficient coupling during reverse stimulation. First, the three-port circuit network model of the actuator was coupled with the acoustic impedance model of human ear reverse sound transmission. Meanwhile, the inefficient coupling impedance was estimated. Then, the effect of the actuator's coupling on reverse stimulation was studied by comparing the reverse pressure transfer function. Furthermore, the inefficient coupling's influence in the ear with middle-ear disorder was also investigated by simulating two typical forms of middle-ear disorder: otosclerosis and ossicular chain disarticulation. The results show that the change of the inefficient coupling impedance plays a significant role during reverse stimulation. Inefficient coupling of the actuator and the RWM deteriorates the cochlear response of reverse stimulation over the entire frequency range. Additionally, the coupling effect of the actuator does not change the influence tendency of middle-ear disorder on reverse stimulation's performance, but changes the response amplitude of the reverse stimulation.
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Affiliation(s)
- Lin Xue
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu Province, China
| | - Houguang Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu Province, China
| | - Jianhua Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu Province, China
| | - Songyong Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu Province, China
| | - Yu Zhao
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu Province, China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital Affiliated to Fudan University, Shanghai, China
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Zhao Y, Liu W, Liu H, Yang J, Zhou L, Huang X. Numerical analysis of the effects of ossicular chain malformations on bone conduction stimulation. Comput Methods Biomech Biomed Engin 2020; 24:817-830. [PMID: 33252263 DOI: 10.1080/10255842.2020.1853107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
To assess the effects of ossicular chain malformations on the performance of bone conduction hearing aids, a human ear finite-element model that includes an ear canal, a middle ear, and a spiral cochlea incorporating the third windows was established. This finite element model was built based on micro-computed tomography scanning and reverse modelling techniques, and the reliability of the finite element model was verified by comparison with reported experimental data. Based on this model, two main types of ossicular chain malformations, i.e., the incudostapedial disconnection and the ossicles fixation, were simulated, and their influences on bone conduction were analyzed by comparing the trans-cochlear-partition differential pressures. The results indicate that the incudostapedial disconnection mainly deteriorates the bone conduction response at mid frequencies. The stapes fixation has the largest effect among the ossicles fixation with the bone conduction stimulation, which also mainly decreases the mid-frequency response of the bone conduction, especially at 2 kHz. As the speech intelligibility has the most important frequency range at the range between 1 kHz and 2.5 kHz, the mid-frequency deterioration caused by ossicular chain malformations should be compensated in optimizing the design of the bone conduction hearing aids. For treating patients with the ossicular chain malformations, especially for the patients who suffer from the stapes fixation, the output of bone conduction hearing aids' actuator in the middle frequency band should be improved.
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Affiliation(s)
- Yu Zhao
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, PR China
| | - Wen Liu
- Department of Otolaryngology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, PR China
| | - Houguang Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, PR China
| | - Jianhua Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, PR China
| | - Lei Zhou
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital affiliated to Fudan University, Shanghai, PR China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital affiliated to Fudan University, Shanghai, PR China
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Ma J, Yao W, Hu B. Simulation of the Multiphysical Coupling Behavior of Active Hearing Mechanism Within Spiral Cochlea. J Biomech Eng 2020; 142:091005. [PMID: 32005999 DOI: 10.1115/1.4046204] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Indexed: 07/25/2024]
Abstract
Nobel Laureate von Békésy first presented traveling wave theory, which explains the vibration mechanism of the basilar membrane (BM) of cochlea in 1960, and thus the mysterious veil of passive phonoreceptive mechanism of human cochlea was unveiled. However, the interpretation of active phonoreceptive mechanism of human cochlea has been a major medical problem for mankind. The active mechanism can be reflected in structures and the perilymph where a series of complex coupling nonlinear motion process is observed in the cochlea. Because the cochlea is small and complex, vibration data of the whole BM are not yet available from existing experiments. To address the problem, first, the motion equations of the organ of Corti (OHC) are established, and the circuit equations of the outer hair cells (OHCs) in the perilymph and the relationship between the motion of the outer hair cells and the electromotile force are derived. Then the active feedback force on the BM is obtained. Finally, an analytical-numerical combination model, where both macrostructures and microstructures of cochlea are included, is established. The model not only vividly depicts the spatial helical body and biological materials of the cochlea but also reflects the fluid-solid coupling nonlinear motion of cochlear structures in the electrical environment. Thus, the active hearing mechanism of cochlea is revealed.
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Affiliation(s)
- J Ma
- Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200444, China
| | - W Yao
- Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200444, China
| | - B Hu
- Department of Civil Engineering, Shanghai University, Shanghai 200072, China
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Liu H, Wang W, Zhao Y, Yang J, Yang S, Huang X, Liu W. Effect of stimulation sites on the performance of electromagnetic middle ear implant: A finite element analysis. Comput Biol Med 2020; 124:103918. [DOI: 10.1016/j.compbiomed.2020.103918] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 12/13/2022]
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Xue L, Liu H, Wang W, Yang J, Zhao Y, Huang X. The role of third windows on human sound transmission of forward and reverse stimulations: A lumped-parameter approach. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:1478. [PMID: 32237813 DOI: 10.1121/10.0000846] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 02/14/2020] [Indexed: 06/11/2023]
Abstract
The vestibular and cochlear aqueducts serve as additional sound transmission paths and produce different degrees of volume velocity shunt flow in cochlear sound transmission. To investigate its effect on forward and reverse stimulations, a lumped-parameter model of the human ear, which incorporates the third windows, was developed. The model combines a transmission-line ear-canal model, a middle-ear model, and an inner-ear model, which were developed previously by different investigators. The model is verified by comparison with experiments. The intracochlear differential-pressure transfer functions, which reflect the input force to the organ of Corti, were calculated. The results show that middle-ear gain for forward sound transmission is greater than the gain for reverse sound transmission. Changes in the cochlear aqueduct impedance have little effect on forward and reverse stimulations. The vestibular aqueduct has little effect on forward stimulation, but increasing its impedance causes deterioration on reverse stimulation below 300 Hz. Decreasing its impedance increases the excitation effect during reverse stimulation over the entire frequency, especially below 1000 Hz. Moreover, compared with the case without the third windows, the presence of the third windows has little effect on forward stimulation. Whereas, it boosts the reverse stimulation's performance below 300 Hz.
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Affiliation(s)
- Lin Xue
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, 221116, China
| | - Houguang Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, 221116, China
| | - Wenbo Wang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, 221116, China
| | - Jianhua Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, 221116, China
| | - Yu Zhao
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, 221116, China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital Affiliated to Fudan University, Shanghai, 200032, China
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Zhang J, Tian J, Ta N, Rao Z. Finite element analysis of round-window stimulation of the cochlea in patients with stapedial otosclerosis. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:4122. [PMID: 31893738 DOI: 10.1121/1.5134770] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 10/30/2019] [Indexed: 06/10/2023]
Abstract
An active actuator coupled to the round window (RW) can transmit mechanical vibrations into the cochlea and has become a therapeutic option of hearing rehabilitation for patients with stapedial otosclerosis. A finite-element model of the human ear that includes sound transmission effects of the vestibular and cochlear aqueducts of the inner ear is adopted in this study for investigating the cochlear response to RW stimulation under stapes fixation. There are two effects due to otosclerosis of the stapes: the fixation of the stapedial annular ligament (SAL) and the increase of the stapes mass. The frequency responses of the middle ear and cochlea with normal and otosclerotic stapes are calculated under sound and RW stimulations. The results show that changes in the material property of the stapes have different effects on the cochlear responses under sound and RW stimulations. Because of the vestibuli aqueduct, the reduction in the low-frequency magnitude of the pressure difference across the cochlear partition due to SAL fixation is much smaller under RW stimulation than under sound stimulation. The results of this study help understand sound transmission during RW stimulation in patients with stapedial otosclerosis.
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Affiliation(s)
- Jing Zhang
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Jiabin Tian
- Wuhan Second Ship Design and Research Institute, Wuhan 403205, People's Republic of China
| | - Na Ta
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Zhushi Rao
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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The Influence of Piezoelectric Transducer Stimulating Sites on the Performance of Implantable Middle Ear Hearing Devices: A Numerical Analysis. MICROMACHINES 2019; 10:mi10110782. [PMID: 31739627 PMCID: PMC6915382 DOI: 10.3390/mi10110782] [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: 10/10/2019] [Revised: 11/08/2019] [Accepted: 11/12/2019] [Indexed: 11/30/2022]
Abstract
To overcome the inherent deficiencies of hearing aids, implantable middle ear hearing devices (IMEHDs) have emerged as a new treatment for hearing loss. However, clinical results show that the IMEHD performance varies with its transducer’s stimulating site. To numerically analyze the influence of the piezoelectric transducer’s stimulating sites on its hearing compensation performance, we constructed a human ear finite element model and confirmed its validity. Based on this finite element model, the displacement stimulation, which simulates the piezoelectric transducer’s stimulation, was applied to the umbo, the incus long process, the incus body, the stapes, and the round window membrane, respectively. Then, the stimulating site’s effect of the piezoelectric transducer was analyzed by comparing the corresponding displacements of the basilar membrane. Besides, the stimulating site’s sensitivity to the direction of excitation was also studied. The result of the finite element analysis shows that stimulating the incus body is least efficient for the piezoelectric transducer. Meanwhile, stimulating the round window membrane or the stapes generates a higher basilar membrane displacement than stimulating the eardrum or the incus long process. However, the performance of these two ideal sites’ stimulation is sensitive to the changes in the excitation’s direction. Thus, the round window membrane and the stapes is the ideal stimulating sites for the piezoelectric transducer regarding the driving efficiency. The direction of the excitation should be guaranteed for these ideal sites.
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Gan RZ, Jiang S. Surface Motion Changes of Tympanic Membrane Damaged by Blast Waves. J Biomech Eng 2019; 141:2736913. [DOI: 10.1115/1.4044052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Indexed: 11/08/2022]
Abstract
Eardrum or tympanic membrane (TM) is a multilayer soft tissue membrane located at the end of the ear canal to receive sound pressure and transport the sound into the middle ear and cochlea. Recent studies reported that the TM microstructure and mechanical properties varied after the ear was exposed to blast overpressure. However, the impact of such biomechanical changes of the TM on its movement for sound transmission has not been investigated. This paper reports the full-field surface motion of the human TM using the scanning laser Doppler vibrometry in human temporal bones under normal and postblast conditions. An increase of the TM displacement after blast exposure was observed in the posterior region of the TM in four temporal bone samples at the frequencies between 3 and 4 kHz. A finite element model of human TM with multilayer microstructure and orthogonal fiber network was created to simulate the TM damaged by blast waves. The consistency between the experimental data and the model-derived TM surface motion suggests that the tissue injuries were resulted from a combination of mechanical property change and regional discontinuity of collagen fibers. This study provides the evidences of surface motion changes of the TM damaged by blast waves and possible fiber damage locations.
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Affiliation(s)
- Rong Z. Gan
- Biomedical Engineering Laboratory, School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 Asp Avenue, Norman, OK 73019 e-mail:
| | - Shangyuan Jiang
- Biomedical Engineering Laboratory, School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 Asp Avenue, Norman, OK 73019
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Liu H, Zhang H, Yang J, Huang X, Liu W, Xue L. Influence of ossicular chain malformation on the performance of round-window stimulation: A finite element approach. Proc Inst Mech Eng H 2019; 233:584-594. [PMID: 30919729 DOI: 10.1177/0954411919839911] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As a novel application of implantable middle ear hearing device, round-window stimulation is widely used to treat hearing loss with middle ear disease, such as ossicular chain malformation. To evaluate the influence of ossicular chain malformations on the efficiency of the round-window stimulation, a human ear finite element model, which incorporates cochlear asymmetric structure, was constructed. Five groups of comparison with experimental data confirmed the model’s validity. Based on this model, we investigated the influence of three categories of ossicular chain malformations, that is, incudostapedial disconnection, incus and malleus fixation, and fixation of the stapes. These malformations’ effects were evaluated by comparing the equivalent sound pressures derived from the basilar membrane displacement. Results show that the studied ossicular chain malformations mainly affected the round-window simulation’s performance at low frequencies. In contrast to the fixation of the ossicles, which mainly deteriorates round-window simulation’s low-frequency performance, incudostapedial disconnection increases this performance, especially in the absence of incus process and stapes superstructure. Among the studied ossicular chain malformations, the stapes fixation has a much more severe impact on the round-window stimulation’s efficiency. Thus, the influence of the patients’ ossicular chain malformations should be considered in the design of the round-window stimulation’s actuator. The low-frequency output of the round-window simulation’s actuator should be enhanced, especially for treating the patients with stapes fixation.
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Affiliation(s)
- Houguang Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
| | - Hu Zhang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
| | - Jianhua Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Wen Liu
- Department of Otolaryngology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, P.R. China
| | - Lin Xue
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
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Abstract
Cochlear implantation (CI) surgery is a very successful technique, performed on more than 300,000 people worldwide. However, since the challenge resides in obtaining an accurate surgical planning, computational models are considered to provide such accurate tools. They allow us to plan and simulate beforehand surgical procedures in order to maximally optimize surgery outcomes, and consequently provide valuable information to guide pre-operative decisions. The aim of this work is to develop and validate computational tools to completely assess the patient-specific functional outcome of the CI surgery. A complete automatic framework was developed to create and assess computationally CI models, focusing on the neural response of the auditory nerve fibers (ANF) induced by the electrical stimulation of the implant. The framework was applied to evaluate the effects of ANF degeneration and electrode intra-cochlear position on nerve activation. Results indicate that the intra-cochlear positioning of the electrode has a strong effect on the global performance of the CI. Lateral insertion provides better neural responses in case of peripheral process degeneration, and it is recommended, together with optimized intensity levels, in order to preserve the internal structures. Overall, the developed automatic framework provides an insight into the global performance of the implant in a patient-specific way. This enables to further optimize the functional performance and helps to select the best CI configuration and treatment strategy for a given patient.
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Analytical and numerical modeling of the hearing system: Advances towards the assessment of hearing damage. Hear Res 2017; 349:111-128. [PMID: 28161584 DOI: 10.1016/j.heares.2017.01.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 01/20/2017] [Accepted: 01/25/2017] [Indexed: 12/16/2022]
Abstract
Hearing is an extremely complex phenomenon, involving a large number of interrelated variables that are difficult to measure in vivo. In order to investigate such process under simplified and well-controlled conditions, models of sound transmission have been developed through many decades of research. The value of modeling the hearing system is not only to explain the normal function of the hearing system and account for experimental and clinical observations, but to simulate a variety of pathological conditions that lead to hearing damage and hearing loss, as well as for development of auditory implants, effective ear protections and auditory hazard countermeasures. In this paper, we provide a review of the strategies used to model the auditory function of the external, middle, inner ear, and the micromechanics of the organ of Corti, along with some of the key results obtained from such modeling efforts. Recent analytical and numerical approaches have incorporated the nonlinear behavior of some parameters and structures into their models. Few models of the integrated hearing system exist; in particular, we describe the evolution of the Auditory Hazard Assessment Algorithm for Human (AHAAH) model, used for prediction of hearing damage due to high intensity sound pressure. Unlike the AHAAH model, 3D finite element models of the entire hearing system are not able yet to predict auditory risk and threshold shifts. It is expected that both AHAAH and FE models will evolve towards a more accurate assessment of threshold shifts and hearing loss under a variety of stimuli conditions and pathologies.
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De Greef D, Pires F, Dirckx JJ. Effects of model definitions and parameter values in finite element modeling of human middle ear mechanics. Hear Res 2017; 344:195-206. [DOI: 10.1016/j.heares.2016.11.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/03/2016] [Accepted: 11/22/2016] [Indexed: 11/26/2022]
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Hitt BM, Wang X, Gan RZ. Dynamic property changes in stapedial annular ligament associated with acute otitis media in the chinchilla. Med Eng Phys 2017; 40:65-74. [PMID: 27989383 PMCID: PMC5292076 DOI: 10.1016/j.medengphy.2016.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/26/2016] [Accepted: 12/05/2016] [Indexed: 10/20/2022]
Abstract
Located at the end of the ossicular chain, the stapedial annular ligament (SAL) serves as a closed yet mobile boundary between the cochlear fluid and stapes footplate. It is unclear how SAL properties change with acute otitis media (AOM). This paper reports the measurements of SAL dynamic properties in chinchilla AOM model using dynamic mechanical analyzer (DMA) and frequency-temperature superposition (FTS) principle. AOM was analyzed in two infection groups: 4 days (4D) and 8 days (8D) post induction. SAL specimens were measured using DMA at three temperatures: 5, 25, and 37°C. To extend the testing frequencies to higher levels, FTS principle was employed. Then generalized Maxwell model was utilized to define the constitutive equations of the SAL. The complex shear moduli were obtained from seven samples of control, 4D, and 8D groups. Results show that the storage and loss shear moduli of SALs decreased due to AOM. The storage moduli for 4D and 8D ears were similar below 100Hz, and the loss modulus for 4D was significantly larger than 8D across the entire frequency range. This study reports data that contributes to ear biomechanics and improves understanding on the effects of AOM in middle ear tissues.
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Affiliation(s)
- Brooke M Hitt
- School of Aerospace and Mechanical Engineering and Biomedical Engineering Center, University of Oklahoma, Norman, OK 73019, United States
| | - Xuelin Wang
- School of Aerospace and Mechanical Engineering and Biomedical Engineering Center, University of Oklahoma, Norman, OK 73019, United States
| | - Rong Z Gan
- School of Aerospace and Mechanical Engineering and Biomedical Engineering Center, University of Oklahoma, Norman, OK 73019, United States.
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Xu D, Liu H, Zhou L, Cheng G, Yang J, Huang X, Liu X. The effect of actuator and its coupling conditions on eardrum-stimulated middle ear implants: A numerical analysis. Proc Inst Mech Eng H 2016. [DOI: 10.1177/0954411916675381] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Consisting of the actuator and coupling layer, a finite element model of the human middle ear was used to analyze the effect of the actuator and its coupling conditions on the performance of the eardrum-stimulated middle ear implants. This model which was based on the right ear of a healthy adult was built via microcomputed tomography imaging and the technique of reverse engineering. Based on this finite element model, the linear viscoelasticity of the human middle ear soft tissues and three-layer structure of the eardrum pars tensa which was orthotropic were considered. The validity of the model was verified by comparing the model calculated results with experimental data. After that, the influence of the three main design parameters of the actuator and two aspects of the coupling layer were investigated by the finite element model. The results show that (1) the manubrium tip is the optimal position for the actuator to stimulate; (2) the increased cross-section of the actuator would worsen its hearing compensation performance, especially in the low frequencies; (3) both the patients’ residual hearing and the actuator’s hearing compensation performance at high frequencies will be deteriorated with the increase in the actuator’s mass; and (4) a coupling layer with a small Young’s modulus and an area approximating 80% of the eardrum would reduce the stress of the eardrum effectively.
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Affiliation(s)
- Dan Xu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
| | - Houguang Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
| | - Lei Zhou
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Gang Cheng
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
| | - Jianhua Yang
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Xiaole Liu
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, P.R. China
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40
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Zhang J, Tian J, Ta N, Huang X, Rao Z. Numerical evaluation of implantable hearing devices using a finite element model of human ear considering viscoelastic properties. Proc Inst Mech Eng H 2016; 230:784-94. [PMID: 27276992 DOI: 10.1177/0954411916652923] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 05/10/2016] [Indexed: 11/17/2022]
Abstract
Finite element method was employed in this study to analyze the change in performance of implantable hearing devices due to the consideration of soft tissues' viscoelasticity. An integrated finite element model of human ear including the external ear, middle ear and inner ear was first developed via reverse engineering and analyzed by acoustic-structure-fluid coupling. Viscoelastic properties of soft tissues in the middle ear were taken into consideration in this model. The model-derived dynamic responses including middle ear and cochlea functions showed a better agreement with experimental data at high frequencies above 3000 Hz than the Rayleigh-type damping. On this basis, a coupled finite element model consisting of the human ear and a piezoelectric actuator attached to the long process of incus was further constructed. Based on the electromechanical coupling analysis, equivalent sound pressure and power consumption of the actuator corresponding to viscoelasticity and Rayleigh damping were calculated using this model. The analytical results showed that the implant performance of the actuator evaluated using a finite element model considering viscoelastic properties gives a lower output above about 3 kHz than does Rayleigh damping model. Finite element model considering viscoelastic properties was more accurate to numerically evaluate implantable hearing devices.
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Affiliation(s)
- Jing Zhang
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China
| | - Jiabin Tian
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China
| | - Na Ta
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital Affiliated to Fudan University, Shanghai, China
| | - Zhushi Rao
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China
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Evaluation of Round Window Stimulation Performance in Otosclerosis Using Finite Element Modeling. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2016; 2016:3603207. [PMID: 27034709 PMCID: PMC4789402 DOI: 10.1155/2016/3603207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 01/17/2016] [Accepted: 01/27/2016] [Indexed: 11/17/2022]
Abstract
Round window (RW) stimulation is a new type of middle ear implant's application for treating patients with middle ear disease, such as otosclerosis. However, clinical outcomes show a substantial degree of variability. One source of variability is the variation in the material properties of the ear components caused by the disease. To investigate the influence of the otosclerosis on the performance of the RW stimulation, a human ear finite element model including middle ear and cochlea was established based on a set of microcomputerized tomography section images of a human temporal bone. Three characteristic changes of the otosclerosis in the auditory system were simulated in the FE model: stapedial annular ligament stiffness enlargement, stapedial abnormal bone growth, and partial fixation of the malleus. The FE model was verified by comparing the model-predicted results with published experimental measurements. The equivalent sound pressure (ESP) of RW stimulation was calculated via comparing the differential intracochlear pressure produced by the RW stimulation and the normal eardrum sound stimulation. The results show that the increase of stapedial annular ligament and partial fixation of the malleus decreases RW stimulation's ESP prominently at lower frequencies. In contrast, the stapedial abnormal bone growth deteriorates RW stimulation's ESP severely at higher frequencies.
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42
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Wang X, Keefe DH, Gan RZ. Predictions of middle-ear and passive cochlear mechanics using a finite element model of the pediatric ear. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 139:1735. [PMID: 27106321 PMCID: PMC4833734 DOI: 10.1121/1.4944949] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 02/10/2016] [Accepted: 03/16/2016] [Indexed: 06/05/2023]
Abstract
A finite element (FE) model was developed based on histological sections of a temporal bone of a 4-year-old child to simulate middle-ear and cochlear function in ears with normal hearing and otitis media. This pediatric model of the normal ear, consisting of an ear canal, middle ear, and spiral cochlea, was first validated with published energy absorbance (EA) measurements in young children with normal ears. The model was used to simulate EA in an ear with middle-ear effusion, whose results were compared to clinical EA measurements. The spiral cochlea component of the model was constructed under the assumption that the mechanics were passive. The FE model predicted middle-ear transfer functions between the ear canal and cochlea. Effects of ear structure and mechanical properties of soft tissues were compared in model predictions for the pediatric and adult ears. EA responses are predicted to differ between adult and pediatric ears due to differences in the stiffness and damping of soft tissues within the ear, and any residual geometrical differences between the adult ear and pediatric ear at age 4 years. The results have significance for predicting effects of otitis media in children.
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Affiliation(s)
- Xuelin Wang
- School of Aerospace and Mechanical Engineering and Biomedical Engineering Center, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Douglas H Keefe
- Boys Town National Research Hospital, Omaha, Nebraska 68131, USA
| | - Rong Z Gan
- School of Aerospace and Mechanical Engineering and Biomedical Engineering Center, University of Oklahoma, Norman, Oklahoma 73019, USA
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Hanekom T, Hanekom JJ. Three-dimensional models of cochlear implants: A review of their development and how they could support management and maintenance of cochlear implant performance. NETWORK (BRISTOL, ENGLAND) 2016; 27:67-106. [PMID: 27136100 DOI: 10.3109/0954898x.2016.1171411] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Three-dimensional (3D) computational modeling of the auditory periphery forms an integral part of modern-day research in cochlear implants (CIs). These models consist of a volume conduction description of implanted stimulation electrodes and the current distribution around these, coupled with auditory nerve fiber models. Cochlear neural activation patterns can then be predicted for a given input stimulus. The objective of this article is to present the context of 3D modeling within the field of CIs, the different models, and approaches to models that have been developed over the years, as well as the applications and potential applications of these models. The process of development of 3D models is discussed, and the article places specific emphasis on the complementary roles of generic models and user-specific models, as the latter is important for translation of these models into clinical application.
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Affiliation(s)
- Tania Hanekom
- a Bioengineering, Department of Electrical, Electronic and Computer Engineering , University of Pretoria , Pretoria , South Africa
| | - Johan J Hanekom
- a Bioengineering, Department of Electrical, Electronic and Computer Engineering , University of Pretoria , Pretoria , South Africa
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Kim N, Steele CR, Puria S. The importance of the hook region of the cochlea for bone-conduction hearing. Biophys J 2015; 107:233-41. [PMID: 24988357 DOI: 10.1016/j.bpj.2014.04.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 04/18/2014] [Accepted: 04/29/2014] [Indexed: 11/25/2022] Open
Abstract
For the most part, the coiled shape of the cochlea has been shown to have only minor importance for air-conducted hearing. It is hypothesized, however, that this coiled shape may play a more significant role for the bone-conducted (BC) route of hearing, through inertial forces exerted by the middle ear and cochlear fluid, and that this can be tested by comparing the results of applying BC stimuli in a variety of different directions. A three-dimensional finite element model of a human middle ear coupled to the inner ear was formulated. BC excitations were simulated by applying rigid-body vibrations normal to the surface of the basilar membrane (BM) at 0.8 (d(1)), 5.8 (d(2)), 15.6 (d(3)), and 33.1 (d(4)) mm from the base of the cochlea, such that relative motions of the fluid within the cochlea produced excitations of the BM. The vibrational direction normal to the BM surface at the base of the cochlea (d(1)) produced the highest BM velocity response across all tested frequencies-higher than an excitation direction normal to the BM surface at the nonbasal locations (d(2)-d(4)), even when the stimulus frequency matched the best frequency for each location. The basal part of the human cochlea features a well-developed hook region, colocated with the cochlear vestibule, that features the largest difference in fluid volume between the scala vestibuli (SV) and scala tympani (ST) found in the cochlea. The proximity of the hook region to the oval and round windows, combined with it having the biggest fluid-volume difference between the SV and ST, is thought to result in a maximization of the pressure difference between the SV and ST for BC stimuli normal to the BM in this region, and consequently a maximization of the resulting BM velocity.
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Affiliation(s)
- Namkeun Kim
- Department of Mechanical Engineering, Stanford University, Stanford, California
| | - Charles R Steele
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California
| | - Sunil Puria
- Department of Mechanical Engineering, Stanford University, Stanford, California; Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California.
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TIAN JIABIN, HUANG XINSHENG, RAO ZHUSHI, TA NA, XU LIFU. FINITE ELEMENT ANALYSIS OF THE EFFECT OF ACTUATOR COUPLING CONDITIONS ON ROUND WINDOW STIMULATION. J MECH MED BIOL 2015. [DOI: 10.1142/s0219519415500487] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The finite element (FE) method was used to analyze the effect of coupling conditions between the actuator and the round window membrane (RWM) on the performance of round window (RW) stimulation. A FE model of the human ear consisting of the external ear canal, middle ear and cochlea was firstly developed, and then validation of this model was accomplished through comparison between analytical results and experimental data in the literature. Intracochlear pressure were derived from the model under normal forward sound stimulation and reverse RW stimulation. The equivalent sound pressure of RW stimulation was then calculated via comparing the differential intracochlear pressure produced by the actuator and normal ear canal sound stimulus. The actuator was simulated as a floating mass and placed onto the middle ear cavity side of RWM. Two aspects about the actuator coupling conditions were considered in this study: (1) the cross-section area of the actuator relative to the RWM; (2) the coupling layer between the actuator and the RWM. The results show that smaller actuator size can improve the implant performance of RW stimulation, and size requirements of the actuator can also be reduced by introducing a coupling layer between the actuator and RWM, which will benefit the manufacture of the actuator.
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Affiliation(s)
- JIABIN TIAN
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - XINSHENG HUANG
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Zhongshan Hospital Affiliated to Fudan University, Shanghai 200032, P. R. China
| | - ZHUSHI RAO
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - NA TA
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - LIFU XU
- Institute of Vibration, Shock and Noise, State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
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Keefe DH. Human middle-ear model with compound eardrum and airway branching in mastoid air cells. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:2698-2725. [PMID: 25994701 PMCID: PMC4570511 DOI: 10.1121/1.4916592] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 03/02/2015] [Accepted: 03/09/2015] [Indexed: 06/01/2023]
Abstract
An acoustical/mechanical model of normal adult human middle-ear function is described for forward and reverse transmission. The eardrum model included one component bound along the manubrium and another bound by the tympanic cleft. Eardrum components were coupled by a time-delayed impedance. The acoustics of the middle-ear cleft was represented by an acoustical transmission-line model for the tympanic cavity, aditus, antrum, and mastoid air cell system with variable amounts of excess viscothermal loss. Model parameters were fitted to published measurements of energy reflectance (0.25-13 kHz), equivalent input impedance at the eardrum (0.25-11 kHz), temporal-bone pressure in scala vestibuli and scala tympani (0.1-11 kHz), and reverse middle-ear impedance (0.25-8 kHz). Inner-ear fluid motion included cochlear and physiological third-window pathways. The two-component eardrum with time delay helped fit intracochlear pressure responses. A multi-modal representation of the eardrum and high-frequency modeling of the middle-ear cleft helped fit ear-canal responses. Input reactance at the eardrum was small at high frequencies due to multiple modal resonances. The model predicted the middle-ear efficiency between ear canal and cochlea, and the cochlear pressures at threshold.
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Affiliation(s)
- Douglas H Keefe
- Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131
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Zhang X, Gan RZ. Dynamic properties of human stapedial annular ligament measured with frequency-temperature superposition. J Biomech Eng 2015; 136:1873140. [PMID: 24828880 DOI: 10.1115/1.4027668] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 05/14/2014] [Indexed: 11/08/2022]
Abstract
Stapedial annular ligament (SAL) is located at the end of human ear ossicular chain and provides a sealed but mobile boundary between the stapes footplate and cochlear fluid. Mechanical properties of the SAL directly affect the acoustic-mechanical transmission of the middle ear and the changes of SAL mechanical properties in diseases (e.g., otosclerosis) may cause severe conductive hearing loss. However, the mechanical properties of SAL have only been reported once in the literature, which were obtained under quasi-static condition (Gan, R. Z., Yang, F., Zhang, X., and Nakmali, D., 2011, "Mechanical Properties of Stapedial Annular Ligament," Med. Eng. Phys., 33, pp. 330-339). Recently, the dynamic properties of human SAL were measured in our lab using dynamic-mechanical analyzer (DMA). The test was conducted at the frequency range from 1 to 40 Hz at three different temperatures: 5 °C, 25 °C, and 37 °C. The frequency-temperature superposition (FTS) principle was applied to extend the testing frequency range to a much higher level. The generalized Maxwell model was employed to describe the constitutive relation of the SAL. The storage shear modulus G' and the loss shear modulus G" were obtained from seven specimens. The mean storage shear modulus was 31.7 kPa at 1 Hz and 61.9 kPa at 3760 Hz. The mean loss shear modulus was 1.1 kPa at 1 Hz and 6.5 kPa at 3760 Hz. The dynamic properties of human SAL obtained in this study provide a better description of the damping behavior of soft tissues than the classic Rayleigh type damping, which was widely used in the published ear models. The data reported in this study contribute to ear biomechanics and will improve the accuracy of finite element (FE) model of the human ear.
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A clinically oriented introduction and review on finite element models of the human cochlea. BIOMED RESEARCH INTERNATIONAL 2014; 2014:975070. [PMID: 25530973 PMCID: PMC4235757 DOI: 10.1155/2014/975070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/29/2014] [Accepted: 09/03/2014] [Indexed: 12/30/2022]
Abstract
Due to the inaccessibility of the inner ear, direct in vivo information on cochlear mechanics is difficult to obtain. Mathematical modelling is a promising way to provide insight into the physiology and pathology of the cochlea. Finite element method (FEM) is one of the most popular discrete mathematical modelling techniques, mainly used in engineering that has been increasingly used to model the cochlea and its elements. The aim of this overview is to provide a brief introduction to the use of FEM in modelling and predicting the behavior of the cochlea in normal and pathological conditions. It will focus on methodological issues, modelling assumptions, simulation of clinical scenarios, and pathologies.
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Abstract
Implantable hearing aids are gaining importance for the treatment of sensorineural hearing loss and also for mixed hearing loss. The various hearing aid systems, combined with different middle ear situations, give rise to a wide range of different reconstructions. This article attempts to summarize the current knowledge concerning the mechanical interaction between active middle ear implants (AMEIs) and the normal or reconstructed middle ear. Some basic characteristics of the different AMEIs are provided in conjunction with the middle ear mechanics. The interaction of AMEIs and middle ear and the influence of various boundary conditions are discussed in more detail.
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Zhang X, Guan X, Nakmali D, Palan V, Pineda M, Gan RZ. Experimental and modeling study of human tympanic membrane motion in the presence of middle ear liquid. J Assoc Res Otolaryngol 2014; 15:867-81. [PMID: 25106467 DOI: 10.1007/s10162-014-0482-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 07/18/2014] [Indexed: 10/24/2022] Open
Abstract
Vibration of the tympanic membrane (TM) has been measured at the umbo using laser Doppler vibrometry and analyzed with finite element (FE) models of the human ear. Recently, full-field TM surface motion has been reported using scanning laser Doppler vibrometry, holographic interferometry, and optical coherence tomography. Technologies for imaging human TM motion have the potential to lead to using a dedicated clinical diagnosis tool for identification of middle ear diseases. However, the effect of middle ear fluid (liquid) on TM surface motion is still not clear. In this study, a scanning laser Doppler vibrometer was used to measure the full-field surface motion of the TM from four human temporal bones. TM displacements were measured under normal and disease-mimicking conditions with different middle ear liquid levels over frequencies ranging from 0.2 to 8 kHz. An FE model of the human ear, including the ear canal, middle ear, and spiral cochlea was used to simulate the motion of the TM in normal and disease-mimicking conditions. The results from both experiments and FE model show that a simple deflection shape with one or two major displacement peak regions of the TM in normal ear was observed at low frequencies (1 kHz and below) while complicated ring-like pattern of the deflection shapes appeared at higher frequencies (4 kHz and above). The liquid in middle ear mainly affected TM deflection shapes at the frequencies higher than 1 kHz.
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Affiliation(s)
- Xiangming Zhang
- School of Aerospace and Mechanical Engineering and Bioengineering Center, University of Oklahoma, 865 Asp Avenue, Room 200, Norman, OK, 73019, USA,
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