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Mohammadi H, Ebrahimian A, Maftoon N. Finite-element modelling of interactions of needle with tympanic membrane and middle ear. Hear Res 2024; 452:109092. [PMID: 39126764 DOI: 10.1016/j.heares.2024.109092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 07/12/2024] [Accepted: 07/24/2024] [Indexed: 08/12/2024]
Abstract
The tympanic membrane (TM) is one of the most common routes to access the middle ear and inner ear for the treatment of hearing and balance pathologies. Since the TM is a soft thin biological tissue with small dimensions, using needles seems to be among the most practical interventional approaches. In this study, we proposed a finite-element (FE) analysis of needle-TM interactions that combines a 3D model of the TM and other main middle-ear structures in gerbil, and a 2D model of needle insertion into the TM based on the cohesive zone method (CZM). The TM was modelled using a 1st-order Ogden hyperelastic material and its properties were obtained by fitting to the experimental force-displacement plots of large deformation in the TM under needle indentation. The cohesive parameters were also acquired by calibrating the puncture force against the experimental data of needle insertion into the TM. These FE models were then used to obtain the deformation behaviour of the TM and other middle-ear structures due to the insertion force applied at different locations on the TM. Moreover, we investigated the effect of the TM thickness, the geometry of the needle (i.e., diameter and tip angle), and needle material on the insertion of needles into the TM. We also studied the penetration success of deformable needles.
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Affiliation(s)
- Hossein Mohammadi
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada; Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada
| | - Arash Ebrahimian
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada; Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada
| | - Nima Maftoon
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada; Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada.
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2
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Nobus O, Parmentier L, Livens P, Muyshondt P, Szewcyk K, Jacobs C, Verdoodt D, Pieters L, Thijssen Q, Van Durme B, Vral A, Dirckx J, Van Rompaey V, Van Vlierberghe S. The importance of mechanical and biological cues of tympanic membrane grafts to ensure optimal regeneration. BIOMATERIALS ADVANCES 2024; 159:213827. [PMID: 38490018 DOI: 10.1016/j.bioadv.2024.213827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 03/05/2024] [Accepted: 03/08/2024] [Indexed: 03/17/2024]
Abstract
Chronic suppurative otitis media (CSOM) is often associated with permanent tympanic membrane (TM) perforation and conductive hearing loss. The current clinical gold standard, using autografts and allografts, suffers from several drawbacks. Artificial replacement materials can help to overcome these drawbacks. Therefore, scaffolds fabricated through digital light processing (DLP) were herein created to support TM regeneration. Various UV-curable printing inks, including gelatin methacryloyl (GelMA), gelatin-norbornene-norbornene (GelNBNB) (crosslinked with thiolated gelatin (GelSH)) and alkene-functionalized poly-ε-caprolactone (E-PCL) (crosslinked with pentaerythritol tetrakis(3-mercaptopropionate) (PETA4SH)) were optimized regarding photo-initiator (PI) and photo-absorber (PA) concentrations through viscosity characterization, photo-rheology and the establishment of working curves for DLP. Our material platform enabled the development of constructs with a range of mechanical properties (plateau storage modulus varying between 15 and 119 kPa). Excellent network connectivity for the GelNBNB and E-PCL constructs was demonstrated (gel fractions >95 %) whereas a post-crosslinking step was required for the GelMA constructs. All samples showed excellent biocompatibility (viability >93 % and metabolic activity >88 %). Finally, in vivo and ex vivo assessments, including histology, vibration and deformation responses measured through laser doppler vibrometry and digital image correlation respectively, were performed to investigate the effects of the scaffolds on the anatomical and physiological regeneration of acute TM perforations in rabbits. The data showed that the most efficient healing with the best functional quality was obtained when both mechanical (obtained with the PCL-based resin) and biological (obtained with the gelatin-based resins) material properties were taken into account.
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Affiliation(s)
- Oriana Nobus
- Polymer Chemistry and Biomaterials Group (PBM), Centre of Macromolecular Chemistry (CMaC), Ghent University, 9000 Ghent, Belgium
| | - Laurens Parmentier
- Polymer Chemistry and Biomaterials Group (PBM), Centre of Macromolecular Chemistry (CMaC), Ghent University, 9000 Ghent, Belgium
| | - Pieter Livens
- Laboratory of Biomedical Physics (BIMEF), University of Antwerp, 2020 Antwerp, Belgium
| | - Pieter Muyshondt
- Laboratory of Biomedical Physics (BIMEF), University of Antwerp, 2020 Antwerp, Belgium
| | - Krystyna Szewcyk
- Department of Translational Neurosciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Christel Jacobs
- Department of Translational Neurosciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Dorien Verdoodt
- Department of Translational Neurosciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Leen Pieters
- Department of Human Structure and Repair, Ghent University, 9000 Ghent, Belgium
| | - Quinten Thijssen
- Polymer Chemistry and Biomaterials Group (PBM), Centre of Macromolecular Chemistry (CMaC), Ghent University, 9000 Ghent, Belgium
| | - Bo Van Durme
- Polymer Chemistry and Biomaterials Group (PBM), Centre of Macromolecular Chemistry (CMaC), Ghent University, 9000 Ghent, Belgium
| | - Anne Vral
- Department of Human Structure and Repair, Ghent University, 9000 Ghent, Belgium
| | - Joris Dirckx
- Laboratory of Biomedical Physics (BIMEF), University of Antwerp, 2020 Antwerp, Belgium
| | - Vincent Van Rompaey
- Department of Translational Neurosciences, University of Antwerp, 2610 Wilrijk, Belgium; Department of Otorhinolaryngology and Head & Neck Surgery, Antwerp University Hospital, 2650 Edegem, Belgium.
| | - Sandra Van Vlierberghe
- Polymer Chemistry and Biomaterials Group (PBM), Centre of Macromolecular Chemistry (CMaC), Ghent University, 9000 Ghent, Belgium.
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Graham AS, Ben-Azu B, Tremblay MÈ, Torre P, Senekal M, Laughton B, van der Kouwe A, Jankiewicz M, Kaba M, Holmes MJ. A review of the auditory-gut-brain axis. Front Neurosci 2023; 17:1183694. [PMID: 37600010 PMCID: PMC10435389 DOI: 10.3389/fnins.2023.1183694] [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: 03/10/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Hearing loss places a substantial burden on medical resources across the world and impacts quality of life for those affected. Further, it can occur peripherally and/or centrally. With many possible causes of hearing loss, there is scope for investigating the underlying mechanisms involved. Various signaling pathways connecting gut microbes and the brain (the gut-brain axis) have been identified and well established in a variety of diseases and disorders. However, the role of these pathways in providing links to other parts of the body has not been explored in much depth. Therefore, the aim of this review is to explore potential underlying mechanisms that connect the auditory system to the gut-brain axis. Using select keywords in PubMed, and additional hand-searching in google scholar, relevant studies were identified. In this review we summarize the key players in the auditory-gut-brain axis under four subheadings: anatomical, extracellular, immune and dietary. Firstly, we identify important anatomical structures in the auditory-gut-brain axis, particularly highlighting a direct connection provided by the vagus nerve. Leading on from this we discuss several extracellular signaling pathways which might connect the ear, gut and brain. A link is established between inflammatory responses in the ear and gut microbiome-altering interventions, highlighting a contribution of the immune system. Finally, we discuss the contribution of diet to the auditory-gut-brain axis. Based on the reviewed literature, we propose numerous possible key players connecting the auditory system to the gut-brain axis. In the future, a more thorough investigation of these key players in animal models and human research may provide insight and assist in developing effective interventions for treating hearing loss.
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Affiliation(s)
- Amy S. Graham
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Benneth Ben-Azu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- Institute for Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada
| | - Peter Torre
- School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA, United States
| | - Marjanne Senekal
- Department of Human Biology, Division of Physiological Sciences, University of Cape Town, Cape Town, South Africa
| | - Barbara Laughton
- Family Clinical Research Unit, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - Andre van der Kouwe
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States
- Department of Radiology, Harvard Medical School, Boston, MA, United States
| | - Marcin Jankiewicz
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Mamadou Kaba
- Department of Pathology, Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Martha J. Holmes
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- ImageTech, Simon Fraser University, Surrey, BC, Canada
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Ebrahimian A, Mohammadi H, Maftoon N. Relative importance and interactions of parameters of finite-element models of human middle ear. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:619-634. [PMID: 37535428 DOI: 10.1121/10.0020273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 07/05/2023] [Indexed: 08/05/2023]
Abstract
In the last decades, finite-element models of the middle ear have been widely used to predict the middle-ear vibration outputs. Even with the simplest linear assumption for material properties of the structures in the middle ear, these models need tens of parameters. Due to the complexities of measurements of material properties of these structures, accurate estimations of the values of most of these parameters are not possible. In this study, we benefited from the stochastic finite-element model of the middle ear we had developed in the past, to perform global sensitivity analysis. For this aim, we implemented Sobol' sensitivity analysis which ranks the importance of all uncertain parameters and interactions among them at different frequencies. To decrease the computational costs, we found Sobol' indices from surrogate models that we created using stochastic finite-element results and the polynomial chaos expansion method. Based on the results, the Young's modulus and thickness of the tympanic membrane, Young's modulus and damping of the stapedial annular ligaments, and the Young's modulus of ossicles are among the parameters with the greatest impacts on vibrations of the umbo and stapes footplate. Furthermore, the most significant interactions happen between the Young's modulus and thickness of the tympanic membrane.
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Affiliation(s)
- Arash Ebrahimian
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Hossein Mohammadi
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Nima Maftoon
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
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Chitin nanofibrils modulate mechanical response in tympanic membrane replacements. Carbohydr Polym 2023; 310:120732. [PMID: 36925264 DOI: 10.1016/j.carbpol.2023.120732] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 02/02/2023] [Accepted: 02/18/2023] [Indexed: 02/25/2023]
Abstract
The tympanic membrane (TM), is a thin tissue lying at the intersection of the outer and the middle ear. TM perforations caused by traumas and infections often result in a conductive hearing loss. Tissue engineering has emerged as a promising approach for reconstructing the damaged TM by replicating the native material characteristics. In this regard, chitin nanofibrils (CN), a polysaccharide-derived nanomaterial, is known to exhibit excellent biocompatibility, immunomodulation and antimicrobial activity, thereby imparting essential qualities for an optimal TM regeneration. This work investigates the application of CN as a nanofiller for poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT) copolymer to manufacture clinically suitable TM scaffolds using electrospinning and fused deposition modelling. The inclusion of CN within the PEOT/PBT matrix showed a three-fold reduction in the corresponding electrospun fiber diameters and demonstrated a significant improvement in the mechanical properties required for TM repair. Furthermore, in vitro biodegradation assay highlighted a favorable influence of CN in accelerating the scaffold degradation over a period of one year. Finally, the oto- and cytocompatibility response of the nanocomposite substrates corroborated their biological relevance for the reconstruction of perforated eardrums.
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Ebrahimian A, Mohammadi H, Rosowski JJ, Cheng JT, Maftoon N. Inaccuracies of deterministic finite-element models of human middle ear revealed by stochastic modelling. Sci Rep 2023; 13:7329. [PMID: 37147426 PMCID: PMC10163043 DOI: 10.1038/s41598-023-34018-w] [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: 11/11/2022] [Accepted: 04/22/2023] [Indexed: 05/07/2023] Open
Abstract
For over 40 years, finite-element models of the mechanics of the middle ear have been mostly deterministic in nature. Deterministic models do not take into account the effects of inter-individual variabilities on middle-ear parameters. We present a stochastic finite-element model of the human middle ear that uses variability in the model parameters to investigate the uncertainty in the model outputs (umbo, stapes, and tympanic-membrane displacements). We demonstrate: (1) uncertainties in the model parameters can be magnified by more than three times in the umbo and stapes footplate responses at frequencies above 2 kHz; (2) middle-ear models are biased and they distort the output distributions; and (3) with increased frequency, the highly-uncertain regions spatially spread out on the tympanic membrane surface. Our results assert that we should be mindful when using deterministic finite-element middle-ear models for critical tasks such as novel device developments and diagnosis.
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Affiliation(s)
- Arash Ebrahimian
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada
| | - Hossein Mohammadi
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada
| | - John J Rosowski
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, 02114, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, 02114, USA
| | - Jeffrey Tao Cheng
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, 02114, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, 02114, USA
| | - Nima Maftoon
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada.
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada.
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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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Techniques for characterizing mechanical properties of soft tissues. J Mech Behav Biomed Mater 2023; 138:105575. [PMID: 36470112 DOI: 10.1016/j.jmbbm.2022.105575] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 08/16/2022] [Accepted: 11/15/2022] [Indexed: 11/21/2022]
Abstract
The characterization of soft tissues remains a vital need for various bioengineering and medical fields. Developing areas such as regenerative medicine, robot-aided surgery, and surgical simulations all require accurate knowledge about the mechanical properties of soft tissues to replicate their mechanics. Mechanical properties can be characterized through several different characterization techniques such as atomic force microscopy, compression testing, and tensile testing. However, many of these methods contain considerable differences in ability to accurately characterize the mechanical properties of soft tissues. As a result of these variations, there are often discrepancies in the reported values for numerous studies. This paper reviews common characterization methods that have been applied to obtain the mechanical properties of soft tissues and highlights their advantages as well as disadvantages. The limitations, accuracies, repeatability, in-vivo testing capability, and types of properties measurable for each method are also discussed.
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Ugarteburu M, Withnell RH, Cardoso L, Carriero A, Richter CP. Mammalian middle ear mechanics: A review. Front Bioeng Biotechnol 2022; 10:983510. [PMID: 36299283 PMCID: PMC9589510 DOI: 10.3389/fbioe.2022.983510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
The middle ear is part of the ear in all terrestrial vertebrates. It provides an interface between two media, air and fluid. How does it work? In mammals, the middle ear is traditionally described as increasing gain due to Helmholtz's hydraulic analogy and the lever action of the malleus-incus complex: in effect, an impedance transformer. The conical shape of the eardrum and a frequency-dependent synovial joint function for the ossicles suggest a greater complexity of function than the traditional view. Here we review acoustico-mechanical measurements of middle ear function and the development of middle ear models based on these measurements. We observe that an impedance-matching mechanism (reducing reflection) rather than an impedance transformer (providing gain) best explains experimental findings. We conclude by considering some outstanding questions about middle ear function, recognizing that we are still learning how the middle ear works.
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Affiliation(s)
- Maialen Ugarteburu
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
| | - Robert H. Withnell
- Department of Speech, Language and Hearing Sciences, Indiana University, Bloomington, IN, United States
| | - Luis Cardoso
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
| | - Alessandra Carriero
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
| | - Claus-Peter Richter
- Department of Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States
- Department of Communication Sciences and Disorders, Northwestern University, Chicago, IL, United States
- The Hugh Knowles Center, Northwestern University, Chicago, IL, United States
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Tang H, Psota P, Rosowski JJ, Furlong C, Cheng JT. Analyses of the Tympanic Membrane Impulse Response Measured with High-Speed Holography. Hear Res 2021; 410:108335. [PMID: 34450569 DOI: 10.1016/j.heares.2021.108335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022]
Abstract
The Tympanic Membrane (TM) transforms acoustic energy to ossicular vibration. The shape and the displacement of the TM play an important role in this process. We developed a High-speed Digital Holography (HDH) system to measure the shape and transient displacements of the TM induced by acoustic clicks. The displacements were further normalized by the measured shape to derive surface normal displacements at over 100,000 points on the TM surface. Frequency and impulse response analyses were performed at each TM point, which enable us to describe 2D surface maps of four new TM mechanical parameters. From frequency domain analyses, we describe the (i) dominant frequencies of the displacement per sound pressure based on Frequency Response Function (FRF) at each surface point. From time domain analyses, we describe the (ii) rising time, (iii) exponential decay time, and the (iv) root-mean-square (rms) displacement of the TM based on Impulse Response Function (IRF) at each surface point. The resultant 2D maps show that a majority of the TM surface has a dominant frequency of around 1.5 kHz. The rising times suggest that much of the TM surface is set into motion within 50 µs of an impulsive stimulus. The maps of the exponential decay time of the IRF illustrate spatial variations in damping, the least known TM mechanical property. The damping ratios at locations with varied dominant frequencies are quantified and compared.
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Affiliation(s)
- H Tang
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester Polytechnic Institute, Worcester, MA United States; Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA United States; Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA United States.
| | - P Psota
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, Czech Republic
| | - J J Rosowski
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA United States; Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - C Furlong
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester Polytechnic Institute, Worcester, MA United States; Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA United States; Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA United States; Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - J T Cheng
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA United States; Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
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11
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Anand S, Stoppe T, Lucena M, Rademakers T, Neudert M, Danti S, Moroni L, Mota C. Mimicking the Human Tympanic Membrane: The Significance of Scaffold Geometry. Adv Healthc Mater 2021; 10:e2002082. [PMID: 33945239 DOI: 10.1002/adhm.202002082] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/27/2021] [Indexed: 12/25/2022]
Abstract
The human tympanic membrane (TM) captures sound waves from the environment and transforms them into mechanical motion. The successful transmission of these acoustic vibrations is attributed to the unique architecture of the TM. However, a limited knowledge is available on the contribution of its discrete anatomical features, which is important for fabricating functional TM replacements. This work synergizes theoretical and experimental approaches toward understanding the significance of geometry in tissue-engineered TM scaffolds. Three test designs along with a plain control are chosen to decouple some of the dominant structural elements, such as the radial and circumferential alignment of the collagen fibrils. In silico models suggest a geometrical dependency of their mechanical and acoustical responses, where the presence of radially aligned fibers is observed to have a more prominent effect compared to their circumferential counterparts. Following which, a hybrid fabrication strategy combining electrospinning and additive manufacturing has been optimized to manufacture biomimetic scaffolds within the dimensions of the native TM. The experimental characterizations conducted using macroindentation and laser Doppler vibrometry corroborate the computational findings. Finally, biological studies with human dermal fibroblasts and human mesenchymal stromal cells reveal a favorable influence of scaffold hierarchy on cellular alignment and subsequent collagen deposition.
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Affiliation(s)
- Shivesh Anand
- Department of Complex Tissue Regeneration MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
| | - Thomas Stoppe
- Ear Research Center Dresden Department of Otorhinolaryngology Head and Neck Surgery Carl Gustav Carus Faculty of Medicine Technische Universität Dresden Dresden 01307 Germany
| | - Mónica Lucena
- Department of Complex Tissue Regeneration MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
| | - Timo Rademakers
- Department of Complex Tissue Regeneration MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
| | - Marcus Neudert
- Ear Research Center Dresden Department of Otorhinolaryngology Head and Neck Surgery Carl Gustav Carus Faculty of Medicine Technische Universität Dresden Dresden 01307 Germany
| | - Serena Danti
- Department of Civil and Industrial Engineering University of Pisa Pisa 56122 Italy
| | - Lorenzo Moroni
- Department of Complex Tissue Regeneration MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
| | - Carlos Mota
- Department of Complex Tissue Regeneration MERLN Institute for Technology‐Inspired Regenerative Medicine Maastricht University Maastricht 6229 ER The Netherlands
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Won J, Porter RG, Novak MA, Youakim J, Sum A, Barkalifa R, Aksamitiene E, Zhang A, Nolan R, Shelton R, Boppart SA. In vivo dynamic characterization of the human tympanic membrane using pneumatic optical coherence tomography. JOURNAL OF BIOPHOTONICS 2021; 14:e202000215. [PMID: 33439538 PMCID: PMC7935452 DOI: 10.1002/jbio.202000215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/14/2020] [Accepted: 07/19/2020] [Indexed: 05/05/2023]
Abstract
Decreased mobility of the human eardrum, the tympanic membrane (TM), is an essential indicator of a prevalent middle ear infection. The current diagnostic method to assess TM mobility is via pneumatic otoscopy, which provides subjective and qualitative information of subtle motion. In this study, a handheld spectral-domain pneumatic optical coherence tomography system was developed to simultaneously measure the displacement of the TM, air pressure inputs applied to a sealed ear canal, and to perform digital pneumatic otoscopy. A novel approach based on quantitative parameters is presented to characterize spatial and temporal variations of the dynamic TM motion. Furthermore, the TM motions of normal middle ears are compared with those of ears with middle ear infections. The capability of noninvasively measuring the rapid motion of the TM is beneficial to understand the complex dynamics of the human TM, and can ultimately lead to improved diagnosis and management of middle ear infections.
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Affiliation(s)
- Jungeun Won
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois
| | - Ryan G. Porter
- Department of Otolaryngology, Carle Foundation Hospital, Urbana, Illinois
| | - Michael A. Novak
- Department of Otolaryngology, Carle Foundation Hospital, Urbana, Illinois
| | - Jon Youakim
- Department of Pediatrics, Carle Foundation Hospital, Urbana, Illinois
| | - Ada Sum
- Department of Pediatrics, Carle Foundation Hospital, Urbana, Illinois
| | - Ronit Barkalifa
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois
| | - Edita Aksamitiene
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois
| | | | | | | | - Stephen A. Boppart
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois
- PhotoniCare, Inc., Champaign, Illinois
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Champaign, Illinois
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13
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Liang J, Engles WG, Smith KD, Dai C, Gan RZ. Mechanical Properties of Baboon Tympanic Membrane from Young to Adult. J Assoc Res Otolaryngol 2020; 21:395-407. [PMID: 32783162 PMCID: PMC7567769 DOI: 10.1007/s10162-020-00765-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 07/24/2020] [Indexed: 11/26/2022] Open
Abstract
Mechanical properties of the tympanic membrane (TM) play an important role in sound transmission through the middle ear. While numerous studies have investigated the mechanical properties of the adult human TM, the effects of age on the TM's properties remain unclear because of the limited published data on the TM of young children. To address this deprivation, we used baboons in this study as an animal model for investigating the effect of age on the mechanical properties of the TM. Temporal bones were harvested from baboons (Papio anubis) of four different age groups: less than 1 year, 1-3 years, 3-5 years, and older than 5 years of age or adult. The TM specimens were harvested from baboon temporal bones and cut into rectangle strips along the inferior-superior direction, mainly capturing the influence of the circumferential direction fibers on the TM's mechanical properties. The elasticity, ultimate tensile strength, and relaxation behavior of the baboon TM were measured in each of the four age groups with a mechanical analyzer. The average effective Young's modulus of adult baboon TM was approximately 3.1 MPa, about two times higher than that of a human TM. The Young's moduli of the TM samples demonstrated a 26 % decrease from newborn to adult (from 4.2 to 3.1 MPa). The average ultimate tensile strength of the TMs for all the age groups was ~ 2.5 MPa. There was no significant change in the ultimate tensile strength and relaxation behavior among age groups. The preliminary results reported in this study provide a first step towards understanding the effect of age on the TM mechanical properties from young to adult.
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Affiliation(s)
- Junfeng Liang
- School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 W. Asp Ave., Norman, OK, 73019, USA
| | - Warren G Engles
- School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 W. Asp Ave., Norman, OK, 73019, USA
| | - Kyle D Smith
- School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 W. Asp Ave., Norman, OK, 73019, USA
| | - Chenkai Dai
- School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 W. Asp Ave., Norman, OK, 73019, USA
| | - Rong Z Gan
- School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 W. Asp Ave., Norman, OK, 73019, USA.
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14
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Psota P, Tang H, Pooladvand K, Furlong C, Rosowski JJ, Cheng JT, Lédl V. Multiple angle digital holography for the shape measurement of the unpainted tympanic membrane. OPTICS EXPRESS 2020; 28:24614-24628. [PMID: 32907000 PMCID: PMC7470675 DOI: 10.1364/oe.398919] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/10/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
The shape of the tympanic membrane (TM) plays an important role in sound transmission through the ear for hearing. Previously we developed a high-speed holographic system employing a tunable wavelength laser for rapid TM shape measurement. However, the tunable laser illumination was not sufficient to measure the shape of the unpainted TM due to the semi-transparency of the TM and short exposure time of the camera. This paper presents a new multiple angle illumination technique that allows us to use a higher power single wavelength laser to perform shape measurements on the unpainted TM. Accuracy of the new method is demonstrated by a measure of a step gauge provided by the National Institute of Standards and Technology. We successfully applied the new shape measurement method on a fresh postmortem human TM without any paint.
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Affiliation(s)
- Pavel Psota
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec 46117, Czech Republic
- TOPTEC, Institute of Plasma Physics of the Czech Academy of Sciences, Turnov 51101, Czech Republic
| | - Haimi Tang
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester, MA 01609, USA
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Koohyar Pooladvand
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester, MA 01609, USA
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Cosme Furlong
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester, MA 01609, USA
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02114, USA
| | - John J. Rosowski
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02114, USA
| | - Jeffrey T. Cheng
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02114, USA
| | - Vít Lédl
- TOPTEC, Institute of Plasma Physics of the Czech Academy of Sciences, Turnov 51101, Czech Republic
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15
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Study of the Dynamic Behaviour of Circular Membranes with Low Tension. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9214716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The dynamic behaviour of membranes has been widely studied by well-known authors for a long time. A clear distinction can be made between the behaviour of membranes without tension (plate case) and membranes subjected to large tension or pre-strain in their plane (membrane case). In classical theories, less attention has been paid to membranes subjected to a low level of tension, which solution is between both extreme cases. Recently, certain fields of research are demanding solutions for this intermediate behaviour. It is the case of membranes present in MEMS and sensor or the response of the tympanic membrane in mammals hearing system. In this paper, the behaviour of plates and circular membranes with boundary conditions clamped in the edges has been studied. The natural frequencies for both cases (plate and membrane) have been calculated using the solutions of the traditional theories and these have been compared with the numerical frequencies calculated by finite element analysis. The dynamic response of membrane with low tension, corresponding to a transition between these extreme behaviours, has also been calculated. A theoretical solution has been used complemented with a wide set of numerical finite elements calculations. The analytical and numerical solutions are very close, being the error made using both methods very low; nevertheless, there are no analytical solutions for the entire transition zone between the plate and membrane behaviour. Therefore, this range has been completed using finite element analysis. Broad ranges of geometric configurations have been studied. The transition behaviour of the membrane has been clearly identified. The main practical consequences of these results have been discussed, in particular focused on the response of the tympanic membrane.
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16
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Tang H, Razavi P, Pooladvand K, Psota P, Maftoon N, Rosowski JJ, Furlong C, Cheng JT. High-Speed Holographic Shape and Full-Field Displacement Measurements of the Tympanic Membrane in Normal and Experimentally Simulated Pathological Ears. APPLIED SCIENCES (BASEL, SWITZERLAND) 2019; 9:2809. [PMID: 32802482 PMCID: PMC7425804 DOI: 10.3390/app9142809] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To improve the understanding of the middle-ear hearing mechanism and assist in the diagnosis of middle-ear diseases, we are developing a high-speed digital holographic (HDH) system to measure the shape and acoustically-induced transient displacements of the tympanic membrane (TM). In this paper, we performed measurements on cadaveric human ears with simulated common middle-ear pathologies. The frequency response function (FRF) of the normalized displacement by the stimulus (sound pressure) at each measured pixel point of the entire TM surface was calculated and the complex modal indicator function (CMIF) of the middle-ear system based on FRFs of the entire TM surface motions was used to differentiate different middle-ear pathologies. We also observed changes in the TM shape and the surface motion pattern before and after various middle-ear manipulations. The observations of distinguishable TM shapes and motion patterns in both time and frequency domains between normal and experimentally simulated pathological ears support the development of a quantitative clinical holography-based apparatus for diagnosing middle-ear pathologies.
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Affiliation(s)
- Haimi Tang
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester, MA 01609, USA
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Payam Razavi
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester, MA 01609, USA
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Koohyar Pooladvand
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester, MA 01609, USA
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Pavel Psota
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester, MA 01609, USA
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec 46117, Czech Republic
| | - Nima Maftoon
- Systems Design Engineering Department, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - John J. Rosowski
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02114, USA
| | - Cosme Furlong
- Center for Holographic Studies and Laser Micro-mechaTronics (CHSLT), Worcester, MA 01609, USA
- Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, USA
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02114, USA
| | - Jeffrey T. Cheng
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02114, USA
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17
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Luo H, Wang F, Cheng C, Nakmali DU, Gan RZ, Lu H. Mapping the Young's modulus distribution of the human tympanic membrane by microindentation. Hear Res 2019; 378:75-91. [DOI: 10.1016/j.heares.2019.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/12/2019] [Accepted: 02/20/2019] [Indexed: 11/30/2022]
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18
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Xie P, Peng Y, Hu J, Yi S. A study on the effect of ligament and tendon detachment on human middle ear sound transfer using mathematic model. Proc Inst Mech Eng H 2019; 233:784-792. [PMID: 31165672 DOI: 10.1177/0954411919853364] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The objective of this study is to investigate the effects of ligament and tendon detachment on human middle ear sound transfer. For this purpose, a geometric human middle ear model was reconstructed based on the computed tomography scanning data of the temporal bones from healthy adult volunteers. For the ear model, pars tensa was assumed to be fit for a 5-parameter Maxwell model and inverse method was used to obtain the necessary coefficients. Furthermore, frequency response method was implemented to investigate the vibration behaviors of tympanic membrane umbo and stapes footplate under an acoustic stimulus of 90 dB within 0.2-8 kHz. Meanwhile, nine patterns of fractured ligaments and tendons, whose effects on the middle ear sound transfer function were simulated by setting free the nodes of the ligaments and tendons of interest. The results indicate that the displacement of tympanic membrane umbo and stapes footplate as well as the velocity transfer function lies within the bounds of the published experimental data. The detachments of ligaments or tendons except for lateral mallear ligament may incur both gains as much as 15 dB and losses of -8 dB in the velocity of stapes footplate at low frequencies (f≤ 1 kHz), while no significant changes were observed at high frequencies (f > 1 kHz). However, detachment of the ligaments or tendons induces tiny changes in the displacement of stapes footplate at the frequencies of 0.2-8 kHz.
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Affiliation(s)
- Pengpeng Xie
- 1 Key Laboratory of Traffic Safety on Track (Central South University), Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, China.,2 Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha, China
| | - Yong Peng
- 1 Key Laboratory of Traffic Safety on Track (Central South University), Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, China.,3 National & Local Joint Engineering Research Center of Safety Technology for Rail Vehicle, Central South University, Changsha, China
| | - Junjiao Hu
- 4 Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Shengen Yi
- 5 Research Laboratory of Hepatobiliary Diseases General Surgical Department, The Second Xiangya Hospital, Central South University, Changsha, China
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19
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Razavi P, Tang H, Rosowski JJ, Furlong C, Cheng JT. Combined high-speed holographic shape and full-field displacement measurements of tympanic membrane. JOURNAL OF BIOMEDICAL OPTICS 2018; 24:1-12. [PMID: 30255670 PMCID: PMC6444583 DOI: 10.1117/1.jbo.24.3.031008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 08/27/2018] [Indexed: 06/08/2023]
Abstract
The conical shape of the tympanic membrane (TM or eardrum) plays an important role in its function, such that variations in shape alter the acoustically induced motions of the TM. We present a method that precisely determines both shape and acoustically induced transient response of the entire TM using the same optics and maintaining the same coordinate system, where the TM transient displacements due to a broadband acoustic click excitation (50-μs impulse) and the shape are consecutively measured within <200 ms. Interferograms gathered with continuous high-speed (>2 kHz) optical phase sampling during a single 100-ms wavelength tuning ramp allow precise and rapid reconstructions of the TM shape at varied resolutions (50 to 200 μm). This rapid acquisition of full-field displacements and shape is immune to slow disturbances introduced by breathing or heartbeat of live subjects. Knowledge of TM shape and displacements enables the estimation of surface normal displacements regardless of the orientation of the TM within the measurement system. The proposed method helps better define TM mechanics and provides TM structure and function information useful for the diagnosis of ear disease.
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Affiliation(s)
- Payam Razavi
- Worcester Polytechnic Institute, Center for Holographic Studies and Laser micromechaTronic, Worcester, Massachusetts, United States
- Worcester Polytechnic Institute, Mechanical Engineering Department, Worcester, Massachusetts, United States
| | - Haimi Tang
- Worcester Polytechnic Institute, Center for Holographic Studies and Laser micromechaTronic, Worcester, Massachusetts, United States
- Worcester Polytechnic Institute, Mechanical Engineering Department, Worcester, Massachusetts, United States
| | - John J. Rosowski
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Eaton–Peabody Laboratory, Department of Otolaryngology, Boston, Massachusetts, United States
- Harvard Medical School, Speech and Hearing Bioscience and Technology Program, Boston, Massachusetts, United States
| | - Cosme Furlong
- Worcester Polytechnic Institute, Center for Holographic Studies and Laser micromechaTronic, Worcester, Massachusetts, United States
- Worcester Polytechnic Institute, Mechanical Engineering Department, Worcester, Massachusetts, United States
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Eaton–Peabody Laboratory, Department of Otolaryngology, Boston, Massachusetts, United States
| | - Jeffrey T. Cheng
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Eaton–Peabody Laboratory, Department of Otolaryngology, Boston, Massachusetts, United States
- Harvard Medical School, Speech and Hearing Bioscience and Technology Program, Boston, Massachusetts, United States
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20
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Analysis of the Mechanical Properties of the Human Tympanic Membrane and Its Influence on the Dynamic Behaviour of the Human Hearing System. Appl Bionics Biomech 2018; 2018:1736957. [PMID: 29853992 PMCID: PMC5966685 DOI: 10.1155/2018/1736957] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/25/2018] [Accepted: 04/29/2018] [Indexed: 11/18/2022] Open
Abstract
The difficulty to estimate the mechanical properties of the tympanic membrane (TM) is a limitation to understand the sound transmission mechanism. In this paper, based on finite element calculations, the sensitivity of the human hearing system to these properties is evaluated. The parameters that define the bending stiffness properties of the membrane have been studied, specifically two key parameters: Young's modulus of the tympanic membrane and the thickness of the eardrum. Additionally, it has been completed with the evaluation of the presence of an initial prestrain inside the TM. Modal analysis is used to study the qualitative characteristics of the TM comparing with vibration patterns obtained by holography. Higher-order modes are shown as a tool to identify these properties. The results show that different combinations of elastic properties and prestrain provide similar responses. The presence of prestrain at the membrane adds more uncertainty, and it is pointed out as a source for the lack of agreement of some previous TM elastic modulus estimations.
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21
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O'Connor KN, Cai H, Puria S. The effects of varying tympanic-membrane material properties on human middle-ear sound transmission in a three-dimensional finite-element model. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:2836. [PMID: 29195482 PMCID: PMC5681352 DOI: 10.1121/1.5008741] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
An anatomically based three-dimensional finite-element human middle-ear (ME) model is used to test the sensitivity of ME sound transmission to tympanic-membrane (TM) material properties. The baseline properties produce responses comparable to published measurements of ear-canal input impedance and power reflectance, stapes velocity normalized by ear-canal pressure (PEC), and middle-ear pressure gain (MEG), i.e., cochlear-vestibule pressure (PV) normalized by PEC. The mass, Young's modulus (ETM), and shear modulus (GTM) of the TM are varied, independently and in combination, over a wide range of values, with soft and bony TM-annulus boundary conditions. MEG is recomputed and plotted for each case, along with summaries of the magnitude and group-delay deviations from the baseline over low (below 0.75 kHz), mid (0.75-5 kHz), and high (above 5 kHz) frequencies. The MEG magnitude varies inversely with increasing TM mass at high frequencies. Increasing ETM boosts high frequencies and attenuates low and mid frequencies, especially with a bony TM annulus and when GTM varies in proportion to ETM, as for an isotropic material. Increasing GTM on its own attenuates low and mid frequencies and boosts high frequencies. The sensitivity of MEG to TM material properties has implications for model development and the interpretation of experimental observations.
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Affiliation(s)
- Kevin N O'Connor
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA
| | - Hongxue Cai
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA
| | - Sunil Puria
- Department of Otology and Laryngology, Harvard Medical School, Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, Massachusetts 02114, USA
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22
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Alper CM, Luntz M, Takahashi H, Ghadiali SN, Swarts JD, Teixeira MS, Csákányi Z, Yehudai N, Kania R, Poe DS. Panel 2: Anatomy (Eustachian Tube, Middle Ear, and Mastoid-Anatomy, Physiology, Pathophysiology, and Pathogenesis). Otolaryngol Head Neck Surg 2017; 156:S22-S40. [PMID: 28372527 DOI: 10.1177/0194599816647959] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Objective In this report, we review the recent literature (ie, past 4 years) to identify advances in our understanding of the middle ear-mastoid-eustachian tube system. We use this review to determine whether the short-term goals elaborated in the last report were achieved, and we propose updated goals to guide future otitis media research. Data Sources PubMed, Web of Science, Medline. Review Methods The panel topic was subdivided, and each contributor performed a literature search within the given time frame. The keywords searched included middle ear, eustachian tube, and mastoid for their intersection with anatomy, physiology, pathophysiology, and pathology. Preliminary reports from each panel member were consolidated and discussed when the panel met on June 11, 2015. At that meeting, the progress was evaluated and new short-term goals proposed. Conclusions Progress was made on 13 of the 20 short-term goals proposed in 2011. Significant advances were made in the characterization of middle ear gas exchange pathways, modeling eustachian tube function, and preliminary testing of treatments for eustachian tube dysfunction. Implications for Practice In the future, imaging technologies should be developed to noninvasively assess middle ear/eustachian tube structure and physiology with respect to their role in otitis media pathogenesis. The new data derived from these structure/function experiments should be integrated into computational models that can then be used to develop specific hypotheses concerning otitis media pathogenesis and persistence. Finally, rigorous studies on medical or surgical treatments for eustachian tube dysfunction should be undertaken.
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Affiliation(s)
- Cuneyt M Alper
- 1 Department of Pediatric Otolaryngology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.,2 Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,3 Clinical and Translational Science Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Michal Luntz
- 4 Department of Otolaryngology Head and Neck Surgery, Bnai Zion Medical Center; Technion-The Ruth and Bruce Rappaport Faculty of Medicine, Haifa, Israel
| | - Haruo Takahashi
- 5 Department of Otolaryngology-Head and Neck Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Samir N Ghadiali
- 6 Department of Biomedical Engineering, Ohio University, Columbus, Ohio, USA.,7 Department of Internal Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Ohio University, Columbus, Ohio, USA
| | - J Douglas Swarts
- 2 Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Miriam S Teixeira
- 2 Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Zsuzsanna Csákányi
- 8 Department of Pediatric Otorhinolaryngology, Heim Pal Children's Hospital, Budapest, Hungary
| | - Noam Yehudai
- 4 Department of Otolaryngology Head and Neck Surgery, Bnai Zion Medical Center; Technion-The Ruth and Bruce Rappaport Faculty of Medicine, Haifa, Israel
| | - Romain Kania
- 9 Department of Otorhinolaryngology-Head and Neck Surgery, Lariboisière Hospital, Diderot University, University Paris Sorbonne, Paris, France
| | - Dennis S Poe
- 10 Department of Otology and Laryngology, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts, USA.,11 Department of Otolaryngology and Communications Enhancement, Boston Children's Hospital, Boston, Massachusetts, USA
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23
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Estimation of the Young's modulus of the human pars tensa using in-situ pressurization and inverse finite-element analysis. Hear Res 2017; 345:69-78. [DOI: 10.1016/j.heares.2017.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 01/03/2017] [Accepted: 01/05/2017] [Indexed: 11/19/2022]
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24
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Motallebzadeh H, Maftoon N, Pitaro J, Funnell WRJ, Daniel SJ. Finite-Element Modelling of the Acoustic Input Admittance of the Newborn Ear Canal and Middle Ear. J Assoc Res Otolaryngol 2017; 18:25-48. [PMID: 27718037 PMCID: PMC5243259 DOI: 10.1007/s10162-016-0587-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/09/2016] [Indexed: 12/25/2022] Open
Abstract
Admittance measurement is a promising tool for evaluating the status of the middle ear in newborns. However, the newborn ear is anatomically very different from the adult one, and the acoustic input admittance is different than in adults. To aid in understanding the differences, a finite-element model of the newborn ear canal and middle ear was developed and its behaviour was studied for frequencies up to 2000 Hz. Material properties were taken from previous measurements and estimates. The simulation results were within the range of clinical admittance measurements made in newborns. Sensitivity analyses of the material properties show that in the canal model, the maximum admittance and the frequency at which that maximum admittance occurs are affected mainly by the stiffness parameter; in the middle-ear model, the damping is as important as the stiffness in influencing the maximum admittance magnitude but its effect on the corresponding frequency is negligible. Scaling up the geometries increases the admittance magnitude and shifts the resonances to lower frequencies. The results suggest that admittance measurements can provide more information about the condition of the middle ear when made at multiple frequencies around its resonance.
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Affiliation(s)
- Hamid Motallebzadeh
- Department of Biomedical Engineering, McGill University, 3775 rue University, Montréal, QC, H3A 2B4, Canada
| | - Nima Maftoon
- Department of Biomedical Engineering, McGill University, 3775 rue University, Montréal, QC, H3A 2B4, Canada
| | - Jacob Pitaro
- Division of Otolaryngology-Head and Neck Surgery, Montréal Children's Hospital, Montréal, Canada
| | - W Robert J Funnell
- Department of Biomedical Engineering, McGill University, 3775 rue University, Montréal, QC, H3A 2B4, Canada.
- Department of Otolaryngology-Head and Neck Surgery, McGill University, Montréal, Canada.
| | - Sam J Daniel
- Department of Otolaryngology-Head and Neck Surgery, McGill University, Montréal, Canada
- Department of Pediatric Surgery, McGill University, Montréal, Canada
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25
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Pressure buffering by the tympanic membrane. In vivo measurements of middle ear pressure fluctuations during elevator motion. Hear Res 2016; 340:113-120. [DOI: 10.1016/j.heares.2015.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 10/25/2015] [Accepted: 12/02/2015] [Indexed: 11/17/2022]
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Biomechanics of the incudo-malleolar-joint – Experimental investigations for quasi-static loads. Hear Res 2016; 340:69-78. [DOI: 10.1016/j.heares.2015.10.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/08/2015] [Accepted: 10/14/2015] [Indexed: 12/29/2022]
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Muyshondt PG, Soons JA, De Greef D, Pires F, Aerts P, Dirckx JJ. A single-ossicle ear: Acoustic response and mechanical properties measured in duck. Hear Res 2016; 340:35-42. [DOI: 10.1016/j.heares.2015.12.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/15/2015] [Accepted: 12/22/2015] [Indexed: 11/28/2022]
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28
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De Greef D, Goyens J, Pintelon I, Bogers JP, Van Rompaey V, Hamans E, Van de Heyning P, Dirckx JJ. On the connection between the tympanic membrane and the malleus. Hear Res 2016; 340:50-59. [DOI: 10.1016/j.heares.2015.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/02/2015] [Accepted: 12/03/2015] [Indexed: 02/08/2023]
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29
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Liang J, Luo H, Yokell Z, Nakmali DU, Gan RZ, Lu H. Characterization of the nonlinear elastic behavior of chinchilla tympanic membrane using micro-fringe projection. Hear Res 2016; 339:1-11. [PMID: 27240479 DOI: 10.1016/j.heares.2016.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 04/01/2016] [Accepted: 05/08/2016] [Indexed: 11/29/2022]
Abstract
The mechanical properties of an intact, full tympanic membrane (TM) inside the bulla of a fresh chinchilla were measured under quasi-static pressure from -1.0 kPa to 1.0 kPa applied on the TM lateral side. Images of the fringes projected onto the TM were acquired by a digital camera connected to a surgical microscope and analyzed using a phase-shift method to reconstruct the surface topography. The relationship between the applied pressure and the resulting volume displacement was determined and analyzed using a finite element model implementing a hyperelastic 2(nd)-order Ogden model. Through an inverse method, the best-fit model parameters for the TM were determined to allow the simulation results to agree with the experimental data. The nonlinear stress-strain relationship for the TM of a chinchilla was determined up to an equibiaxial tensile strain of 31% experienced by the TM in the experiments. The average Young's modulus of the chinchilla TM from ten bullas was determined as approximately 19 MPa.
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Affiliation(s)
- Junfeng Liang
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - Huiyang Luo
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - Zachary Yokell
- School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK 73019, USA
| | - Don U Nakmali
- School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK 73019, USA
| | - Rong Zhu Gan
- School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK 73019, USA
| | - Hongbing Lu
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA.
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30
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Abstract
We present a finite-element model of the gerbil middle ear that, using a set of baseline parameters based primarily on a priori estimates from the literature, generates responses that are comparable with responses we measured in vivo using multi-point vibrometry and with those measured by other groups. We investigated the similarity of numerous features (umbo, pars-flaccida and pars-tensa displacement magnitudes, the resonance frequency and break-up frequency, etc.) in the experimental responses with corresponding ones in the model responses, as opposed to simply computing frequency-by-frequency differences between experimental and model responses. The umbo response of the model is within the range of variability seen in the experimental data in terms of the low-frequency (i.e., well below the middle-ear resonance) magnitude and phase, the main resonance frequency and magnitude, and the roll-off slope and irregularities in the response above the resonance frequency, but is somewhat high for frequencies above the resonance frequency. At low frequencies, the ossicular axis of rotation of the model appears to correspond to the anatomical axis but the behaviour is more complex at high frequencies (i.e., above the pars-tensa break-up). The behaviour of the pars tensa in the model is similar to what is observed experimentally in terms of magnitudes, phases, the break-up frequency of the spatial vibration pattern, and the bandwidths of the high-frequency response features. A sensitivity analysis showed that the parameters that have the strongest effects on the model results are the Young's modulus, thickness and density of the pars tensa; the Young's modulus of the stapedial annular ligament; and the Young's modulus and density of the malleus. Displacements of the tympanic membrane and manubrium and the low-frequency displacement of the stapes did not show large changes when the material properties of the incus, stapes, incudomallear joint, incudostapedial joint, and posterior incudal ligament were changed by ±10 % from their values in the baseline parameter set.
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31
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De Greef D, Buytaert JA, Aerts JR, Van Hoorebeke L, Dierick M, Dirckx J. Details of human middle ear morphology based on micro-CT imaging of phosphotungstic acid stained samples. J Morphol 2015; 276:1025-46. [DOI: 10.1002/jmor.20392] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 03/08/2015] [Accepted: 03/13/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Daniel De Greef
- Laboratory of Biomedical Physics; Department of Physics, University of Antwerp, Groenenborgerlaan 171; 2020 Antwerp Belgium
| | - Jan A.N. Buytaert
- Laboratory of Biomedical Physics; Department of Physics, University of Antwerp, Groenenborgerlaan 171; 2020 Antwerp Belgium
| | - Johan R.M. Aerts
- Laboratory of Biomedical Physics; Department of Physics, University of Antwerp, Groenenborgerlaan 171; 2020 Antwerp Belgium
| | - Luc Van Hoorebeke
- UGCT, Department of Physics and Astronomy; Ghent University, Proeftuinstraat 86; 9000 Ghent Belgium
| | - Manuel Dierick
- UGCT, Department of Physics and Astronomy; Ghent University, Proeftuinstraat 86; 9000 Ghent Belgium
| | - Joris Dirckx
- Laboratory of Biomedical Physics; Department of Physics, University of Antwerp, Groenenborgerlaan 171; 2020 Antwerp Belgium
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32
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De Greef D, Aernouts J, Aerts J, Cheng JT, Horwitz R, Rosowski JJ, Dirckx JJJ. Viscoelastic properties of the human tympanic membrane studied with stroboscopic holography and finite element modeling. Hear Res 2014; 312:69-80. [PMID: 24657621 DOI: 10.1016/j.heares.2014.03.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 02/20/2014] [Accepted: 03/05/2014] [Indexed: 11/30/2022]
Abstract
A new anatomically-accurate Finite Element (FE) model of the tympanic membrane (TM) and malleus was combined with measurements of the sound-induced motion of the TM surface and the bony manubrium, in an isolated TM-malleus preparation. Using the results, we were able to address two issues related to how sound is coupled to the ossicular chain: (i) Estimate the viscous damping within the tympanic membrane itself, the presence of which may help smooth the broadband response of a potentially highly resonant TM, and (ii) Investigate the function of a peculiar feature of human middle-ear anatomy, the thin mucosal epithelial fold that couples the mid part of the human manubrium to the TM. Sound induced motions of the surface of ex vivo human eardrums and mallei were measured with stroboscopic holography, which yields maps of the amplitude and phase of the displacement of the entire membrane surface at selected frequencies. The results of these measurements were similar, but not identical to measurements made in intact ears. The holography measurements were complemented by laser-Doppler vibrometer measurements of sound-induced umbo velocity, which were made with fine-frequency resolution. Comparisons of these measurements to predictions from a new anatomically accurate FE model with varied membrane characteristics suggest the TM contains viscous elements, which provide relatively low damping, and that the epithelial fold that connects the central section of the human manubrium to the TM only loosely couples the TM to the manubrium. The laser-Doppler measurements in two preparations also suggested the presence of significant variation in the complex modulus of the TM between specimens. Some animations illustrating the model results are available at our website (www.uantwerp.be/en/rg/bimef/downloads/tympanic-membrane-motion).
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Affiliation(s)
- Daniel De Greef
- Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
| | - Jef Aernouts
- Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 02114, USA; Department of Otology and Laryngology, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA
| | - Johan Aerts
- Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Jeffrey Tao Cheng
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 02114, USA; Department of Otology and Laryngology, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA
| | - Rachelle Horwitz
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 02114, USA; Speech and Hearing Bioscience and Technology Program, MIT-Harvard Division of Health Sciences and Technology, 260 Longwood Avenue, Boston, MA 02115, USA
| | - John J Rosowski
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 02114, USA; Department of Otology and Laryngology, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA; Speech and Hearing Bioscience and Technology Program, MIT-Harvard Division of Health Sciences and Technology, 260 Longwood Avenue, Boston, MA 02115, USA
| | - Joris J J Dirckx
- Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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Jun HJ, Oh KH, Yoo J, Han WG, Chang J, Jung HH, Choi J. A new patch material for tympanic membrane perforation by trauma: the membrane of a hen egg shell. Acta Otolaryngol 2014; 134:250-4. [PMID: 24320021 DOI: 10.3109/00016489.2013.857784] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSION The egg shell membrane (ESM) patch may promote tympanic membrane (TM) healing in acute traumatic TM perforation. OBJECTIVE To evaluate the use of ESM for treating acute traumatic TM perforation. METHODS We reviewed charts of patients with traumatic TM injury from 2008 to 2011. Treatments were an ESM patch or a perforation edge approximation. We divided patients into two groups according to the treatment used. Each patient was matched by treatment onset and perforation size. We compared healing ratio, healing time, and frequency of otorrhea between the perforation edge approximation group and the ESM patch group. Matched t tests were used for analysis. RESULTS The healing ratio of the TM showed no significant difference between the two groups, but the time to heal was significantly shorter in the ESM patch group than in the perforation edge approximation group.
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Affiliation(s)
- Hyung Jin Jun
- Department of Otolaryngology-Head and Neck Surgery, Korea University College of Medicine , Seoul , Korea
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34
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Malkin R, McDonagh TR, Mhatre N, Scott TS, Robert D. Energy localization and frequency analysis in the locust ear. J R Soc Interface 2014; 11:20130857. [PMID: 24196693 PMCID: PMC3836324 DOI: 10.1098/rsif.2013.0857] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 10/14/2013] [Indexed: 11/12/2022] Open
Abstract
Animal ears are exquisitely adapted to capture sound energy and perform signal analysis. Studying the ear of the locust, we show how frequency signal analysis can be performed solely by using the structural features of the tympanum. Incident sound waves generate mechanical vibrational waves that travel across the tympanum. These waves shoal in a tsunami-like fashion, resulting in energy localization that focuses vibrations onto the mechanosensory neurons in a frequency-dependent manner. Using finite element analysis, we demonstrate that two mechanical properties of the locust tympanum, distributed thickness and tension, are necessary and sufficient to generate frequency-dependent energy localization.
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Affiliation(s)
- Robert Malkin
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
| | | | - Natasha Mhatre
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
| | - Thomas S. Scott
- Interface Analysis Centre, University of Bristol, 121 St Michael's Hill, Bristol BS2 8BS, UK
| | - Daniel Robert
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
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35
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Van der Jeught S, Dirckx JJJ, Aerts JRM, Bradu A, Podoleanu AG, Buytaert JAN. Full-field thickness distribution of human tympanic membrane obtained with optical coherence tomography. J Assoc Res Otolaryngol 2013; 14:483-94. [PMID: 23673509 PMCID: PMC3705083 DOI: 10.1007/s10162-013-0394-z] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 04/24/2013] [Indexed: 11/29/2022] Open
Abstract
The full-field thickness distribution, three-dimensional surface model and general morphological data of six human tympanic membranes are presented. Cross-sectional images were taken perpendicular through the membranes using a high-resolution optical coherence tomography setup. Five normal membranes and one membrane containing a pathological site are included in this study. The thickness varies strongly across each membrane, and a great deal of inter-specimen variability can be seen in the measurement results, though all membranes show similar features in their respective relative thickness distributions. Mean thickness values across the pars tensa ranged between 79 and 97 μm; all membranes were thinnest in the central region between umbo and annular ring (50-70 μm), and thickness increased steeply over a small distance to approximately 100-120 μm when moving from the central region either towards the peripheral rim of the pars tensa or towards the manubrium. Furthermore, a local thickening was noticed in the antero-inferior quadrant of the membranes, and a strong linear correlation was observed between inferior-posterior length and mean thickness of the membrane. These features were combined into a single three-dimensional model to form an averaged representation of the human tympanic membrane. 3D reconstruction of the pathological tympanic membrane shows a structural atrophy with retraction pocket in the inferior portion of the pars tensa. The change of form at the pathological site of the membrane corresponds well with the decreased thickness values that can be measured there.
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Affiliation(s)
- Sam Van der Jeught
- />Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Joris J. J. Dirckx
- />Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Johan R. M. Aerts
- />Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Adrian Bradu
- />Applied Optics Group, School of Physical Sciences, University of Kent, CT2 7NH Canterbury, UK
| | - Adrian Gh Podoleanu
- />Applied Optics Group, School of Physical Sciences, University of Kent, CT2 7NH Canterbury, UK
| | - Jan A. N. Buytaert
- />Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
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36
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Zhang X, Gan RZ. Dynamic properties of human tympanic membrane based on frequency-temperature superposition. Ann Biomed Eng 2013; 41:205-14. [PMID: 22820983 PMCID: PMC3524406 DOI: 10.1007/s10439-012-0624-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Accepted: 07/11/2012] [Indexed: 12/01/2022]
Abstract
The human tympanic membrane (TM) transfers sound in the ear canal into the mechanical vibration of the ossicles in the middle ear. The dynamic properties of TM directly affect the middle ear transfer function. The static or quasi-static mechanical properties of TM were reported in the literature, but the dynamic properties of TM over the auditory frequency range are very limited. In this paper, a new method was developed to measure the dynamic properties of human TM using the Dynamic-Mechanical Analyzer (DMA). The test was conducted at the frequency range of 1-40 Hz at three different temperatures: 5, 25, and 37 °C. The frequency-temperature superposition was applied to extend the testing frequency range to a much higher level (at least 3800 Hz). The generalized linear solid model was employed to describe the constitutive relation of the TM. The storage modulus E' and the loss modulus E″ were obtained from 11 specimens. The mean storage modulus was 15.1 MPa at 1 Hz and 27.6 MPa at 3800 Hz. The mean loss modulus was 0.28 MPa at 1 Hz and 4.1 MPa at 3800 Hz. The results show that the frequency-temperature superposition is a feasible approach to study the dynamic properties of the ear soft tissues. The dynamic properties of human TM obtained in this study provide a better description of the damping behavior of ear tissues. The properties can be transferred into the finite element model of the human ear to replace the Rayleigh type damping. The data reported here contribute to the biomechanics of the middle ear and improve the accuracy of the FE model for the human ear.
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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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37
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Solís SM, Hernández-Montes MDS, Santoyo FM. Tympanic membrane contour measurement with two source positions in digital holographic interferometry. BIOMEDICAL OPTICS EXPRESS 2012; 3:3203-10. [PMID: 23243570 PMCID: PMC3521304 DOI: 10.1364/boe.3.003203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/18/2012] [Accepted: 11/04/2012] [Indexed: 05/03/2023]
Abstract
The data acquisition from the shape of an object is a must to complete its quantitative displacement measurement analysis. Over the past years whole field of view optical non-invasive testing has been widely used in many areas, from industrial ones to, for instance, biomedical research topics. To measure the surface contour from the tympanic membrane (TM) of ex-vivo cats digital holographic interferometry (DHI) is used in combination with a two-illumination positions method: the shape is directly measured from the phase change between two source positions by means of a digital Fourier transform method. The TM shape data in conjunction with its displacement data renders a complete and accurate description of the TM deformation, a feature that no doubt will serve to better comprehend the hearing process. Acquiring knowledge from the tissue shape indicates a mechanical behavior and, indirectly, an alteration in the physiological structure due to middle ear diseases or damages in the tissue that can deteriorate sound transmission. The TM shape contour was successfully measured by using two source positions within DHI showing that the TM has a conical shape. Its maximum depth was found to be 2 mm, considering the umbo as the reference point with respect to the TM annulus plane, where the setup is arranged in such a manner that it is capable of measuring a height of up to 7 mm.
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