1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Mohammadi H, Ebrahimian A, Maftoon N. Experimental Study of Needle Insertion into Gerbil Tympanic Membrane. J Assoc Res Otolaryngol 2024:10.1007/s10162-024-00953-2. [PMID: 38992318 DOI: 10.1007/s10162-024-00953-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 06/12/2024] [Indexed: 07/13/2024] Open
Abstract
The perforation characteristics and fracture-related mechanical properties of the tympanic membrane (TM) greatly affect surgical procedures like myringotomy and tympanostomy performed on the middle ear. We analyzed the most important features of the gerbil TM perforation using an experimental approach that was based on force measurement during a 2-cycle needle insertion/extraction process. Fracture energy, friction energy, strain energy, and hysteresis loss were taken into consideration for the analysis of the different stages of needle insertion and extraction. The results demonstrated that (1) although the TM shows viscoelastic behavior, the contribution of hysteresis loss was negligible compared to other irreversible dissipated energy components (i.e., fracture energy and friction energy). (2) The TM puncture force did not substantially change during the first hours after animal death, but interestingly, it increased after 1 week due to the drying effects of soft tissue. (3) The needle geometry affected the crack length and the most important features of the force-displacement plot for the needle insertion process (puncture force, puncture displacement, and jump-in force) increased with increasing needle diameter, whereas the insertion velocity only changed the puncture and jump-in forces (both increased with increasing insertion velocity) and did not have a noticeable effect on the puncture displacement. (4) The fracture toughness of the gerbil TM was almost independent of the needle geometry and was found to be around 0.33 ± 0.10 kJ/m2.
Collapse
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.
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Thompson CW, Rohani SA, Dirckx JJ, Ladak HM, Agrawal SK. Finite element modelling of the human middle ear using synchrotron-radiation phase-contrast imaging. Comput Biol Med 2023; 157:106747. [PMID: 36907036 DOI: 10.1016/j.compbiomed.2023.106747] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 02/18/2023] [Accepted: 03/04/2023] [Indexed: 03/08/2023]
Abstract
Finite element (FE) models of the middle ear often lack accurate geometry of soft tissue structures, such as the suspensory ligaments, as they can be difficult to discern using conventional imaging modalities, such as computed tomography. Synchrotron-radiation phase-contrast imaging (SR-PCI) is a non-destructive imaging modality that has been shown to produce excellent visualization of soft tissue structures without the need for extensive sample preparation. The objectives of the investigation were to firstly use SR-PCI to create and evaluate a biomechanical FE model of the human middle ear that includes all soft tissue structures, and secondly, to investigate how modelling assumptions and simplifications of ligament representations affect the simulated biomechanical response of the FE model. The FE model included the suspensory ligaments, ossicular chain, tympanic membrane, the incudostapedial and incudomalleal joints, and the ear canal. Frequency responses obtained from the SR-PCI-based FE model agreed well with published laser doppler vibrometer measurements on cadaveric samples. Revised models with exclusion of the superior malleal ligament (SML), simplification of the SML, and modification of the stapedial annular ligament were studied, as these revised models represented modelling assumptions that have been made in literature.
Collapse
Affiliation(s)
- Caleb W Thompson
- Department of Electrical and Computer Engineering, Western University, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada.
| | - Seyed A Rohani
- Department of Otolaryngology - Head and Neck Surgery, Western University, London, Ontario, Canada
| | - Joris J Dirckx
- Laboratory of Biomedical Physics, University of Antwerp, Antwerp, Belgium
| | - Hanif M Ladak
- Department of Electrical and Computer Engineering, Western University, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; Department of Otolaryngology - Head and Neck Surgery, Western University, London, Ontario, Canada
| | - Sumit K Agrawal
- Department of Otolaryngology - Head and Neck Surgery, Western University, London, Ontario, Canada
| |
Collapse
|
5
|
Hussain Z, Pei R. Necessities, opportunities, and challenges for tympanic membrane perforation scaffolding-based bioengineering. Biomed Mater 2021; 16. [PMID: 33260166 DOI: 10.1088/1748-605x/abcf5d] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 12/01/2020] [Indexed: 02/08/2023]
Abstract
Tympanic membrane (TM) perforation is a global clinical dilemma. It occurs as a consequence of object penetration, blast trauma, barotrauma, and middle ear diseases. TM perforation may lead to otitis media, retraction pockets, cholesteatoma, and conductive deafness. Molecular therapies may not be suitable to treat perforation because there is no underlying tissue matrix to support epithelium bridging. Chronic perforations are usually reconstructed with autologous grafts via surgical myringoplasty. Surgical treatment is uncomfortable for the patients. The grafting materials are not perfect because they produce an opaque membrane, fail in up to 20% of cases, and are suboptimal to restore acoustic function. Millions of patients from developing parts of the world have not got access to surgical grafting due to operational complexities, lack of surgical resources, and high cost. These shortcomings emphasize bioengineering to improve placement options, healing rate, hearing outcomes, and minimize surgical procedures. This review highlights cellular, structural, pathophysiological, and perforation specific determinants that affect healing, acoustic and surgical outcomes; and integrates necessities relevant to bioengineered scaffolds. This study further summarizes scaffolding components, progress in scaffolding strategies and design, and engenders limitations and challenges for optimal bioengineering of chronic perforation.
Collapse
Affiliation(s)
- Zahid Hussain
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, People's Republic of China
- CAS Key Laboratory for Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, People's Republic of China
| | - Renjun Pei
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, People's Republic of China
- CAS Key Laboratory for Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, People's Republic of China
| |
Collapse
|
6
|
Vibration Measurements of the Gerbil Eardrum Under Quasi-static Pressure Steps. J Assoc Res Otolaryngol 2020; 21:287-302. [PMID: 32783164 DOI: 10.1007/s10162-020-00763-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 07/22/2020] [Indexed: 10/23/2022] Open
Abstract
Tympanometry is a relatively simple non-invasive test of the status of the middle ear. An important step towards understanding the mechanics of the middle ear during tympanometry is to make vibration measurements on the eardrum under tympanometric pressures. In this study, we measured in vivo vibration responses in 11 gerbils while varying the middle-ear pressure quasi-statically, with the ear canal at ambient pressure. Vibrations were recorded using a single-point laser Doppler vibrometer with five glass-coated reflective beads (diameter ~ 40 μm) as targets. The locations were the umbo, mid-manubrium, posterior pars tensa, anterior pars tensa and pars flaccida. As described in earlier studies, the unpressurized vibration magnitude was flat at low frequencies, increased until a resonance frequency at around 1.8-2.5 kHz, and became complex at higher frequencies. At both the umbo and mid-manubrium points, when the static pressure was decreased to the most negative middle-ear pressure (- 2500 Pa), the low-frequency vibration magnitude (measured at 1.0 kHz) showed a monotonic decrease, except for an unexpected dip at around - 500 to - 1000 Pa. This dip was not present for the pars-tensa and pars-flaccida points. The resonance frequency shifted to higher frequencies, to around 7-8 kHz at - 2500 Pa. For positive middle-ear pressures, the low-frequency vibration magnitude decreased monotonically, with no dip, and the resonance frequency shifted to around 5-6 kHz at + 2500 Pa. There was more inter-specimen variability on the positive-pressure side than on the negative-pressure side. The low-frequency vibration magnitudes on the negative-pressure side were higher for the pars-tensa points than for the umbo and mid-manubrium points, while the magnitudes were similar at all four locations on the positive-pressure side. Most gerbils showed repeatability within less than 10 dB for consecutive cycles. The results of this study provide insight into the mechanics of the gerbil middle ear under tympanometric pressures.
Collapse
|
7
|
Eldaebes MMAS, Landry TG, Bance ML. Repair of subtotal tympanic membrane perforations: A temporal bone study of several tympanoplasty materials. PLoS One 2019; 14:e0222728. [PMID: 31536572 PMCID: PMC6752791 DOI: 10.1371/journal.pone.0222728] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/05/2019] [Indexed: 11/18/2022] Open
Abstract
The aim of this project was to investigate the effects of different types of graft material, and different remaining segments of the native TM on its motion. In twelve human temporal bones, controlled TM perforations were made to simulate three different conditions. (1) Central perforation leaving both annular and umbo rims of native TM. (2) Central perforation leaving only a malleal rim of native TM. (3) Central perforation leaving only an annular rim of native TM. Five different graft materials (1) perichondrium (2) silastic (3) thin cartilage (4) thick cartilage (5) Lotriderm® cream were used to reconstruct each perforation condition. Umbo and stapes vibrations to acoustic stimuli from 250 to 6349 Hz were measured using a scanning laser Doppler vibrometer. Results showed that at low frequencies: in the Two Rims condition, all grafting materials except thick cartilage and Lotriderm cream showed no significant difference in umbo velocity from the Normal TM, while only Lotriderm cream showed a significant decrease in stapes velocity; in the Malleal Rim condition, all materials showed a significant decrease in both umbo and stapes velocities; in the Annular Rim condition, all grafting materials except Lotriderm and perichondrium showed no significant difference from the Normal TM in stapes velocity. Umbo data might not be reliable in some conditions because of coverage by the graft. At middle and high frequencies: all materials showed a significant difference from the Normal TM in both umbo and stapes velocities for all perforation conditions except in the Annular Rim condition, in which silastic and perichondrium showed no significant difference from the Normal TM at umbo velocity in the middle frequencies. In the low frequencies, the choice of repair material does not seem to have a large effect on sound transfer. Our data also suggests that the annular rim could be important for low frequency sound transfer.
Collapse
Affiliation(s)
- Mostafa M. A. S. Eldaebes
- Department of Surgery, Division of Otolaryngology, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
| | - Thomas G. Landry
- Department of Surgery, Division of Otolaryngology, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
| | - Manohar L. Bance
- Department of Surgery, Division of Otolaryngology, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
- * E-mail:
| |
Collapse
|
8
|
Ng C, Liang W, Gan CW, Lim HY, Tan KK. Novel Design and Validation of a Micro Instrument in an Ear Grommet Insertion Device. J Med Device 2018. [DOI: 10.1115/1.4040185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
An automated surgical device, the ventilator tube applicator (VTA), enables a grommet insertion surgery for patients with otitis media with effusion (OME) to be completed in a short time automatically and precisely, eliminating the use of general anesthesia (GA) typically required in such procedure. However, its current design limits the usefulness of the device as it is restricted by the properties of the tympanic membrane (TM), such as angle, thickness, and strength. Therefore, a novel design was conceptualized and the insertion control algorithm was improved to overcome the current challenges of the VTA. This innovative cover-cutter instrument design allows three-dimensional (3D) motion on an oblique surface using a single axis actuator. Experimental results on mock membranes showed great improvements in terms of robustness and success rate. The new design allowed the procedure to be performed on wider range of TM angles and hence increased the effectiveness of VTA. Grommet insertion force was reduced by an average of 66%, and the overall peak force reduced by an average of 14%. Finite element (FE) analysis on a cadaveric TM model further validated the usefulness of the cover-cutter instrument, and showed some interesting insights in the grommet insertion process.
Collapse
Affiliation(s)
- Cailin Ng
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 119077 e-mail:
| | - Wenyu Liang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119077 e-mail:
| | - Chee Wee Gan
- Department of Otolaryngology, National University of Singapore, Singapore 119077 e-mail:
| | - Hsueh Yee Lim
- Department of Otolaryngology, National University of Singapore, Singapore 119077 e-mail:
| | - Kok Kiong Tan
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119077 e-mail:
| |
Collapse
|
9
|
Eldaebes MMAS, Landry TG, Bance ML. Effects of Cartilage Overlay on the Tympanic Membrane: Lessons From a Temporal Bone Study for Cartilage Tympanoplasty. Otol Neurotol 2018; 39:995-1004. [PMID: 29957671 DOI: 10.1097/mao.0000000000001888] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
HYPOTHESIS Placing cartilage grafts on different tympanic membrane (TM) locations will affect sound transfer function, and the effects will differ according to the part of the TM modified. BACKGROUND Cartilage tympanoplasty is increasingly popular because of lower reperforation rates, and better long-term stability. In this temporal bone study, we investigated the effect of placing cartilage grafts over different parts of the normal TM on sound transmission. METHODS In 10 human fresh frozen temporal bones, umbo and stapes vibrations to acoustic stimuli from 250 to 8000 Hz were measured at multiple points using a scanning laser vibrometer. Four different cartilage arrangements were measured in each temporal bone. 1) Overlay condition leaving an umbo rim of normal TM (Umbo Rim). 2) Overlay condition leaving annular rim of normal TM (Annular Rim). 3) Overlay condition leaving both rims of normal TM (Two Rims). 4) Overlay condition leaving no normal TM exposed (No Rims). RESULTS At low frequencies, there was a statistically significant decrease in velocity from baseline for the No Rims (umbo mean -4 dB; stapes -6 dB) and Umbo Rim (umbo -4 dB; stapes -3.7 dB) conditions. All conditions showed significant decreases for middle frequencies (umbo -4.0, -5.9, -7.4 and -6.3 dB; stapes -10.8, -6.6, -6.3 and -7.7 dB) and high frequencies (umbo -13.2, -3.0, -3.1 and -5.5 dB; stapes -4.6, -2.4, -2.6 and -3.5 dB). Results are in order for No Rims, Umbo Rim, Two Rims, and Annular Rim conditions. CONCLUSION In the low frequencies, it seems to matter where the cartilage is placed, and in particular the annular rim of the TM seems to be important for the low-frequency acoustic transfer function. In the higher frequencies, all graft placements caused some drop at all frequencies. In all frequencies, effects were modest by clinical standards.
Collapse
Affiliation(s)
| | - Thomas G Landry
- Division of Otolaryngology, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
| | - Manohar L Bance
- Division of Otolaryngology, Department of Surgery, Dalhousie University.,Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Liang J, Yokell ZA, Nakmaili DU, Gan RZ, Lu H. The effect of blast overpressure on the mechanical properties of a chinchilla tympanic membrane. Hear Res 2017; 354:48-55. [DOI: 10.1016/j.heares.2017.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 07/30/2017] [Accepted: 08/15/2017] [Indexed: 10/19/2022]
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
3D displacement of the middle ear ossicles in the quasi-static pressure regime using new X-ray stereoscopy technique. Hear Res 2016; 340:60-68. [DOI: 10.1016/j.heares.2015.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/13/2015] [Accepted: 12/01/2015] [Indexed: 11/17/2022]
|
14
|
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]
|
15
|
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.
Collapse
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.
| |
Collapse
|
16
|
Lossi L, D’Angelo L, De Girolamo P, Merighi A. Anatomical features for an adequate choice of experimental animal model in biomedicine: II. Small laboratory rodents, rabbit, and pig. Ann Anat 2016; 204:11-28. [DOI: 10.1016/j.aanat.2015.10.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/01/2015] [Accepted: 10/05/2015] [Indexed: 01/24/2023]
|
17
|
Razavi P, Ravicz ME, Dobrev I, Cheng JT, Furlong C, Rosowski JJ. Response of the human tympanic membrane to transient acoustic and mechanical stimuli: Preliminary results. Hear Res 2016; 340:15-24. [PMID: 26880098 DOI: 10.1016/j.heares.2016.01.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/21/2015] [Accepted: 01/31/2016] [Indexed: 11/18/2022]
Abstract
The response of the tympanic membrane (TM) to transient environmental sounds and the contributions of different parts of the TM to middle-ear sound transmission were investigated by measuring the TM response to global transients (acoustic clicks) and to local transients (mechanical impulses) applied to the umbo and various locations on the TM. A lightly-fixed human temporal bone was prepared by removing the ear canal, inner ear, and stapes, leaving the incus, malleus, and TM intact. Motion of nearly the entire TM was measured by a digital holography system with a high speed camera at a rate of 42 000 frames per second, giving a temporal resolution of <24 μs for the duration of the TM response. The entire TM responded nearly instantaneously to acoustic transient stimuli, though the peak displacement and decay time constant varied with location. With local mechanical transients, the TM responded first locally at the site of stimulation, and the response spread approximately symmetrically and circumferentially around the umbo and manubrium. Acoustic and mechanical transients provide distinct and complementary stimuli for the study of TM response. Spatial variations in decay and rate of spread of response imply local variations in TM stiffness, mass, and damping.
Collapse
Affiliation(s)
- Payam Razavi
- Center for Holographic Studies and Laser micro-mechaTronics, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Michael E Ravicz
- Eaton-Peabody Laboratory of Auditory Physiology, Massachusetts Eye & Ear Infirmary, Boston, MA, USA; Harvard/MIT Division of Health Sciences and Technology, Cambridge, MA, USA.
| | - Ivo Dobrev
- Center for Holographic Studies and Laser micro-mechaTronics, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Jeffrey Tao Cheng
- Eaton-Peabody Laboratory of Auditory Physiology, Massachusetts Eye & Ear Infirmary, Boston, MA, USA; Harvard/MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Cosme Furlong
- Center for Holographic Studies and Laser micro-mechaTronics, Worcester Polytechnic Institute, Worcester, MA, USA; Harvard/MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - John J Rosowski
- Eaton-Peabody Laboratory of Auditory Physiology, Massachusetts Eye & Ear Infirmary, Boston, MA, USA; Harvard/MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| |
Collapse
|
18
|
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.
Collapse
|
19
|
Kazmitcheff G, Miroir M, Nguyen Y, Ferrary E, Sterkers O, Cotin S, Duriez C, Grayeli AB. Validation Method of a Middle Ear Mechanical Model to Develop a Surgical Simulator. ACTA ACUST UNITED AC 2014; 19:73-84. [DOI: 10.1159/000356301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 10/08/2013] [Indexed: 11/19/2022]
|
20
|
Abstract
HYPOTHESIS The sound-induced motion of the tympanic membrane has features that are most consistent with modal responses to a uniform stimulus. BACKGROUND Conceptual models of the coupling of tympanic membrane motion to the ossicular chain can be classified as either modal responses to a uniform stimulation of the entire membrane or traveling wave models in which sound energy is captured at the membrane's rim and travels along the surface to the umbo. The stroboscopic holography technique we use can separate strongly modal or traveling wave-dominated motions of the tympanic membrane surface. METHODS We use computer-aided optoelectronic holography with stroboscopic illumination to measure the magnitude and phase of the sound-induced motion of more than 40,000 points on the surface of the tympanic membrane in cadaveric human temporal bones. Our techniques are sensitive to motions of the membrane as small as 0.01 µm and allow determinations of membrane displacement at frequencies as large as 20 kHz. RESULTS We report clear signs of both modal tympanic membrane responses and traveling waves on the human tympanic membrane. Modal responses are seen throughout the frequency range, whereas the traveling waves are most apparent between 2 and 8 kHz. In general, the magnitudes of the traveling waves are small compared with the modal magnitudes. CONCLUSION Much of the motion of the tympanic membrane is well approximated by modal motions of the tympanic membrane surface. This conclusion has implications for eardrum pathology and its treatment.
Collapse
|
21
|
Huang S, Dong W, Olson ES. Subharmonic distortion in ear canal pressure and intracochlear pressure and motion. J Assoc Res Otolaryngol 2012; 13:461-71. [PMID: 22526734 DOI: 10.1007/s10162-012-0326-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 03/25/2012] [Indexed: 10/28/2022] Open
Abstract
When driven at sound pressure levels greater than ~110 dB stimulus pressure level, the mammalian middle ear is known to produce subharmonic distortion. In this study, we simultaneously measured subharmonics in the ear canal pressure, intracochlear pressure, and basilar membrane or round window membrane velocity, in gerbil. Our primary objective was to quantify the relationship between the subharmonics measured in the ear canal and their intracochlear counterparts. We had two primary findings: (1) The subharmonics emerged suddenly, with a substantial amplitude in the ear canal and the cochlea; (2) at the stimulus level for which subharmonics emerged, the pressure in scala vestibuli/pressure in the ear canal amplitude relationship was similar for the subharmonic and fundamental components. These findings are important for experiments and clinical conditions in which high sound pressure level stimuli are used and could lead to confounding subharmonic stimulation.
Collapse
Affiliation(s)
- Stanley Huang
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | | | | |
Collapse
|
22
|
The effect of static ear canal pressure on human spontaneous otoacoustic emissions: spectral width as a measure of the intra-cochlear oscillation amplitude. J Assoc Res Otolaryngol 2011; 12:13-28. [PMID: 21061039 PMCID: PMC3015033 DOI: 10.1007/s10162-010-0241-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 09/30/2010] [Indexed: 11/23/2022] Open
Abstract
Spontaneous otoacoustic emissions can be detected as peaks in the Fourier spectrum of a microphone signal recorded from the ear canal. The height, center frequency, and spectral width of SOAE peaks changed when a static pressure was applied to the ear canal. Most commonly, with either increasing or decreasing static pressure, the frequency increased, the amplitude decreased, and the width increased. These changes are believed to result from changes in the middle ear properties. Specifically, reduced middle ear transmission is assumed to attenuate the amplitude of emissions. We reconsidered this explanation by investigating the relation between peak height and width. We showed that the spectral width of SOAE peaks is approximately proportional to \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ 1/\sqrt {{{\hbox{peak}}\;{\hbox{height}}}} $$\end{document}. This is consistent with a (Rayleigh) oscillator model in which broadening of the SOAE peak is caused by broadband intra-cochlear noise, which is assumed to be independent of static ear canal pressure. The relation between emission peak height and width implicates that the intra-cochlear oscillation amplitude attentuates relative to the intra-cochlear noise level when a static ear canal pressure is applied. Apparently, ear canal static pressure directly affects the active mechanics in the inner ear.
Collapse
|
23
|
Aernouts J, Dirckx JJJ. Elastic characterization of the gerbil pars flaccida from in situ inflation experiments. Biomech Model Mechanobiol 2010; 10:727-41. [DOI: 10.1007/s10237-010-0269-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
|