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Young CA, O'Bannon M, Thomson SL. Three-Dimensional Printing of Ultrasoft Silicone with a Functional Stiffness Gradient. 3D PRINTING AND ADDITIVE MANUFACTURING 2024; 11:435-445. [PMID: 38689918 PMCID: PMC11057526 DOI: 10.1089/3dp.2022.0218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
A methodology for three-dimensionally printing ultrasoft silicone with a functional stiffness gradient is presented. Ultraviolet-cure silicone was deposited via two independently controlled extruders into a thixotropic, gel-like, silicone oil-based support matrix. Each extruder contained a different liquid silicone formulation. The extrusion rates were independently varied during printing such that the combined selectively deposited material contained different ratios of the two silicones, resulting in localized control of material stiffness. Tests to validate the process are reported, including tensile testing of homogeneous cubic specimens to quantify the range of material stiffness that could be printed, indentation testing of cuboid specimens to characterize printed stiffness gradients, and vibratory testing of synthetic multilayer vocal fold (VF) models to demonstrate that the method may be applied to the fabrication of biomechanical models for voice production research. The cubic specimens exhibited linear stress-strain data with tensile elasticity modulus values between 1.11 and 27.1 kPa, more than a factor of 20 in stiffness variation. The cuboid specimens exhibited material variations that were visually recognizable and quantifiable via indentation testing. The VF models withstood rigorous phonatory flow-induced vibration and exhibited vibratory characteristics comparable to those of previous models. Overall, while process refinements are needed, the results of these tests demonstrate the ability to print ultrasoft silicone with stiffness gradients.
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Affiliation(s)
- Clayton A. Young
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah, USA
| | - MeiLi O'Bannon
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah, USA
| | - Scott L. Thomson
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah, USA
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Cruz DRD, Zheng A, Debele T, Larson P, Dion GR, Park YC. Drug delivery systems for wound healing treatment of upper airway injury. Expert Opin Drug Deliv 2024; 21:573-591. [PMID: 38588553 PMCID: PMC11208077 DOI: 10.1080/17425247.2024.2340653] [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: 10/27/2023] [Accepted: 04/04/2024] [Indexed: 04/10/2024]
Abstract
INTRODUCTION Endotracheal intubation is a common procedure to maintain an open airway with risks for traumatic injury. Pathological changes resulting from intubation can cause upper airway complications, including vocal fold scarring, laryngotracheal stenosis, and granulomas and present with symptoms such as dysphonia, dysphagia, and dyspnea. Current intubation-related laryngotracheal injury treatment approaches lack standardized guidelines, relying on individual clinician experience, and surgical and medical interventions have limitations and carry risks. AREAS COVERED The clinical and preclinical therapeutics for wound healing in the upper airway are described. This review discusses the current developments on local drug delivery systems in the upper airway utilizing particle-based delivery systems, including nanoparticles and microparticles, and bulk-based delivery systems, encompassing hydrogels and polymer-based approaches. EXPERT OPINION Complex laryngotracheal diseases pose challenges for effective treatment, struggling due to the intricate anatomy, limited access, and recurrence. Symptomatic management often requires invasive surgical procedures or medications that are unable to achieve lasting effects. Recent advances in nanotechnology and biocompatible materials provide potential solutions, enabling precise drug delivery, personalization, and extended treatment efficacy. Combining these technologies could lead to groundbreaking treatments for upper airways diseases, significantly improving patients' quality of life. Research and innovation in this field are crucial for further advancements.
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Affiliation(s)
- Denzel Ryan D. Cruz
- Medical Scientist Training Program, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Avery Zheng
- Chemical Engineering Program, College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Tilahun Debele
- Chemical Engineering Program, College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Peter Larson
- Department of Otolaryngology – Head and Neck Surgery, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Gregory R. Dion
- Department of Otolaryngology – Head and Neck Surgery, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Yoonjee C. Park
- Chemical Engineering Program, College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH, USA
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Luizard P, Bailly L, Yousefi-Mashouf H, Girault R, Orgéas L, Henrich Bernardoni N. Flow-induced oscillations of vocal-fold replicas with tuned extensibility and material properties. Sci Rep 2023; 13:22658. [PMID: 38114547 PMCID: PMC10730560 DOI: 10.1038/s41598-023-48080-x] [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: 09/01/2023] [Accepted: 11/22/2023] [Indexed: 12/21/2023] Open
Abstract
Human vocal folds are highly deformable non-linear oscillators. During phonation, they stretch up to 50% under the complex action of laryngeal muscles. Exploring the fluid/structure/acoustic interactions on a human-scale replica to study the role of the laryngeal muscles remains a challenge. For that purpose, we designed a novel in vitro testbed to control vocal-folds pre-phonatory deformation. The testbed was used to study the vibration and the sound production of vocal-fold replicas made of (i) silicone elastomers commonly used in voice research and (ii) a gelatin-based hydrogel we recently optimized to approximate the mechanics of vocal folds during finite strains under tension, compression and shear loadings. The geometrical and mechanical parameters measured during the experiments emphasized the effect of the vocal-fold material and pre-stretch on the vibration patterns and sounds. In particular, increasing the material stiffness increases glottal flow resistance, subglottal pressure required to sustain oscillations and vibratory fundamental frequency. In addition, although the hydrogel vocal folds only oscillate at low frequencies (close to 60 Hz), the subglottal pressure they require for that purpose is realistic (within the range 0.5-2 kPa), as well as their glottal opening and contact during a vibration cycle. The results also evidence the effect of adhesion forces on vibration and sound production.
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Affiliation(s)
- Paul Luizard
- Univ. Grenoble Alpes, CNRS, Grenoble INP, GIPSA-lab, Grenoble, 38000, France
- CNRS, Centrale Marseille, Aix Marseille Univ, LMA UMR 7031, Marseille, France
- Audio Communication Group, Technische Universität Berlin, Einsteinufer 17c, Berlin, 10587, Germany
| | - Lucie Bailly
- Univ. Grenoble Alpes, CNRS, Grenoble INP, 3SR, Grenoble, 38000, France
| | - Hamid Yousefi-Mashouf
- Univ. Grenoble Alpes, CNRS, Grenoble INP, GIPSA-lab, Grenoble, 38000, France
- Univ. Grenoble Alpes, CNRS, Grenoble INP, 3SR, Grenoble, 38000, France
| | - Raphaël Girault
- Univ. Grenoble Alpes, CNRS, Grenoble INP, GIPSA-lab, Grenoble, 38000, France
| | - Laurent Orgéas
- Univ. Grenoble Alpes, CNRS, Grenoble INP, 3SR, Grenoble, 38000, France
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Döllinger M, Jakubaß B, Cheng H, Carter SJ, Kniesburges S, Aidoo B, Lee CH, Milstein C, Patel RR. Computational fluid dynamics of upper airway aerodynamics for exercise-induced laryngeal obstruction: A feasibility study. Laryngoscope Investig Otolaryngol 2023; 8:1294-1303. [PMID: 37899858 PMCID: PMC10601582 DOI: 10.1002/lio2.1140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 07/31/2023] [Indexed: 10/31/2023] Open
Abstract
Objective Use of computational fluid dynamic (CFD) simulations to measure the changes in upper airway geometry and aerodynamics during (a) an episode of Exercise-Induced Laryngeal Obstruction (EILO) and (b) speech therapy exercises commonly employed for patients with EILO. Methods Magnetic resonance imaging stills of the upper airway including the nasal and oral cavities from an adult female were used to re-construct three-dimensional geometries of the upper airway. The CFD simulations were used to compute the maximum volume flow rate (l/s), pressure (Pa), airflow velocity (m/s) and area of cross-section opening in eight planes along the vocal tract, separately for inhalation and exhalation. Results Numerical predictions from three-dimensional geometrical modeling of the upper airway suggest that the technique of nose breathing for inhalation and pursed lip breathing for exhalation show most promising pressure conditions and cross-sectional diameters for rescue breathing exercises. Also, if EILO is due to the constriction at the vocal fold level, then a quick sniff may also be a proper rescue inhalation exercise. EILO affects both the inspiratory and the expiratory phases of breathing. Conclusions A prior knowledge of the supraglottal aerodynamics and the corresponding upper airway geometry from CFD analysis has the potential to assist the clinician in choosing the most effective rescue breathing technique for optimal functional outcome of speech therapy intervention in patients with EILO and in understanding the pathophysiology of EILO on a case-by-case basis with future studies. Level of Evidence 4.
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Affiliation(s)
- Michael Döllinger
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology Head & Neck SurgeryUniversity Hospital Erlangen, Friedrich‐Alexander‐Universität Erlangen‐NürnbergErlangenGermany
| | - Bernhard Jakubaß
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology Head & Neck SurgeryUniversity Hospital Erlangen, Friedrich‐Alexander‐Universität Erlangen‐NürnbergErlangenGermany
| | - Hu Cheng
- Department of Psychological and Brain Sciences, Program of NeuroscienceIndiana UniversityBloomingtonIndianaUSA
| | - Stephen J. Carter
- Department of KinesiologySchool of Public Health, Indiana UniversityBloomingtonIndianaUSA
| | - Stefan Kniesburges
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology Head & Neck SurgeryUniversity Hospital Erlangen, Friedrich‐Alexander‐Universität Erlangen‐NürnbergErlangenGermany
| | - Bea Aidoo
- Department of MedicineIndiana University School of MedicineBloomingtonIndianaUSA
| | - Chi Hwan Lee
- Department of Biomedical Engineering & Mechanical EngineeringPurdue UniversityWest LafayetteIndianaUSA
| | - Claudio Milstein
- Department of Otolaryngology‐Head & Neck Surgery, Cleveland Clinic Lerner and Case Western Reserve University Schools of MedicineHead and Neck Institute, Cleveland ClinicClevelandOhioUSA
| | - Rita R. Patel
- Department of Speech, Language, and Hearing Sciences and Department of Otolaryngology Head and Neck SurgeryIndiana UniversityBloomington/IndianapolisIndianaUSA
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Tur B, Gühring L, Wendler O, Schlicht S, Drummer D, Kniesburges S. Effect of Ligament Fibers on Dynamics of Synthetic, Self-Oscillating Vocal Folds in a Biomimetic Larynx Model. Bioengineering (Basel) 2023; 10:1130. [PMID: 37892860 PMCID: PMC10604794 DOI: 10.3390/bioengineering10101130] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/13/2023] [Accepted: 09/25/2023] [Indexed: 10/29/2023] Open
Abstract
Synthetic silicone larynx models are essential for understanding the biomechanics of physiological and pathological vocal fold vibrations. The aim of this study is to investigate the effects of artificial ligament fibers on vocal fold vibrations in a synthetic larynx model, which is capable of replicating physiological laryngeal functions such as elongation, abduction, and adduction. A multi-layer silicone model with different mechanical properties for the musculus vocalis and the lamina propria consisting of ligament and mucosa was used. Ligament fibers of various diameters and break resistances were cast into the vocal folds and tested at different tension levels. An electromechanical setup was developed to mimic laryngeal physiology. The measurements included high-speed video recordings of vocal fold vibrations, subglottal pressure and acoustic. For the evaluation of the vibration characteristics, all measured values were evaluated and compared with parameters from ex and in vivo studies. The fundamental frequency of the synthetic larynx model was found to be approximately 200-520 Hz depending on integrated fiber types and tension levels. This range of the fundamental frequency corresponds to the reproduction of a female normal and singing voice range. The investigated voice parameters from vocal fold vibration, acoustics, and subglottal pressure were within normal value ranges from ex and in vivo studies. The integration of ligament fibers leads to an increase in the fundamental frequency with increasing airflow, while the tensioning of the ligament fibers remains constant. In addition, a tension increase in the fibers also generates a rise in the fundamental frequency delivering the physiological expectation of the dynamic behavior of vocal folds.
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Affiliation(s)
- Bogac Tur
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
| | - Lucia Gühring
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
| | - Olaf Wendler
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
| | - Samuel Schlicht
- Institute of Polymer Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Am Weichselgarten 10, 91058 Erlangen, Germany
| | - Dietmar Drummer
- Institute of Polymer Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Am Weichselgarten 10, 91058 Erlangen, Germany
| | - Stefan Kniesburges
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
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Lasota M, Šidlof P, Maurerlehner P, Kaltenbacher M, Schoder S. Anisotropic minimum dissipation subgrid-scale model in hybrid aeroacoustic simulations of human phonation. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:1052. [PMID: 36859151 DOI: 10.1121/10.0017202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
This article deals with large-eddy simulations of three-dimensional incompressible laryngeal flow followed by acoustic simulations of human phonation of five cardinal English vowels, /ɑ, æ, i, o, u/. The flow and aeroacoustic simulations were performed in OpenFOAM and in-house code openCFS, respectively. Given the large variety of scales in the flow and acoustics, the simulation is separated into two steps: (1) computing the flow in the larynx using the finite volume method on a fine moving grid with 2.2 million elements, followed by (2) computing the sound sources separately and wave propagation to the radiation zone around the mouth using the finite element method on a coarse static grid with 33 000 elements. The numerical results showed that the anisotropic minimum dissipation model, which is not well known since it is not available in common CFD software, predicted stronger sound pressure levels at higher harmonics, and especially at first two formants, than the wall-adapting local eddy-viscosity model. The model on turbulent flow in the larynx was employed and a positive impact on the quality of simulated vowels was found.
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Affiliation(s)
- Martin Lasota
- Institute of New Technologies and Applied Informatics, Technical University of Liberec, Studentská 2, 460 01 Liberec, Czechia
| | - Petr Šidlof
- Institute of Thermomechanics, Czech Academy of Sciences, Dolejškova 5, 182 00 Prague, Czechia
| | - Paul Maurerlehner
- Institute of Fundamentals and Theory in Electrical Engineering, Graz University of Technology, Inffeldgasse 18, 8010 Graz, Austria
| | - Manfred Kaltenbacher
- Institute of Fundamentals and Theory in Electrical Engineering, Graz University of Technology, Inffeldgasse 18, 8010 Graz, Austria
| | - Stefan Schoder
- Institute of Fundamentals and Theory in Electrical Engineering, Graz University of Technology, Inffeldgasse 18, 8010 Graz, Austria
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Hilton BA, Thomson SL. Aerodynamic-induced Effects of Artificial Subglottic Stenosis on Vocal Fold Model Phonatory Response. J Voice 2022:S0892-1997(22)00374-5. [PMID: 36496305 PMCID: PMC10244482 DOI: 10.1016/j.jvoice.2022.11.024] [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: 06/14/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Subglottic stenosis (SGS) is characterized by a narrowing of the trachea near the cricotracheal junction and impairs breathing. SGS may also adversely affect voice quality, but for reasons that are not fully understood. The purpose of this study is to provide experiment-based data concerning the effects on phonation of airway obstruction due to SGS. STUDY DESIGN Basic science METHODS: A device simulating a SGS of adjustable severity ranging from 36% to 99.8% obstruction was created. Self-oscillating synthetic VF models were mounted downstream of the device and data were acquired to evaluate the effects of the obstruction on phonatory response. RESULTS Onset pressures were relatively insensitive to obstructions of up to approximately 80% to 90% reductions in subglottic airway area and sharply increased thereafter. Flow rate (under conditions of constant pressure), flow resistance, and fundamental frequency all exhibited similar degrees of sensitivity to SGS obstruction as onset pressure. High-frequency noise became significant by 80% obstruction. Glottal area appeared to be less sensitive, not being affected until approximately 90% obstruction. CONCLUSIONS Consistent with previous computational studies, this study found that aerodynamic, acoustic, and vibratory responses of self-oscillating VF models were largely unaffected by SGS until approximately 80% to 90% obstruction, and significantly affected at higher obstructions. This suggests that Grades I and II stenoses are unlikely to introduce subglottic airway aerodynamic disturbances that are sufficient in and of themselves to significantly alter phonatory output. The SGS model introduces a framework for future benchtop studies involving subglottic and supraglottic airway constrictions.
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Affiliation(s)
- Benjamin A Hilton
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah
| | - Scott L Thomson
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah.
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Schlegel P, Berry DA, Chhetri DK. Analysis of vibratory mode changes in symmetric and asymmetric activation of the canine larynx. PLoS One 2022; 17:e0266910. [PMID: 35421159 PMCID: PMC9009716 DOI: 10.1371/journal.pone.0266910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 03/29/2022] [Indexed: 12/02/2022] Open
Abstract
Investigations of neuromuscular control of voice production have primarily focused on the roles of muscle activation levels, posture, and stiffness at phonation onset. However, little work has been done investigating the stability of the phonation process in regards to spontaneous changes in vibratory mode of vocal fold oscillation as a function of neuromuscular activation. We evaluated 320 phonatory conditions representing combinations of superior and recurrent laryngeal nerve (SLN and RLN) activations in an in vivo canine model of phonation. At each combination of neuromuscular input, airflow was increased linearly to reach phonation onset and beyond from 300 to 1400 mL/s. High-speed video and acoustic data were recorded during phonation, and spectrograms and glottal-area-based parameters were calculated. Vibratory mode changes were detected based on sudden increases or drops of local fundamental frequency. Mode changes occurred only when SLNs were concurrently stimulated and were more frequent for higher, less asymmetric RLN stimulation. A slight increase in amplitude and cycle length perturbation usually preceded the changes in the vibratory mode. However, no inherent differences between signals with mode changes and signals without were found.
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Affiliation(s)
- Patrick Schlegel
- Department of Head & Neck Surgery, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, United States of America
- * E-mail:
| | - David A. Berry
- Department of Head & Neck Surgery, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, United States of America
| | - Dinesh K. Chhetri
- Department of Head & Neck Surgery, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, United States of America
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Lodermeyer A, Bagheri E, Kniesburges S, Näger C, Probst J, Döllinger M, Becker S. The mechanisms of harmonic sound generation during phonation: A multi-modal measurement-based approach. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2021; 150:3485. [PMID: 34852620 DOI: 10.1121/10.0006974] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
Sound generation during voiced speech remains an open research topic because the underlying process within the human larynx is hardly accessible for direct measurements. In the present study, harmonic sound generation during phonation was investigated with a model that replicates the fully coupled fluid-structure-acoustic interaction (FSAI). The FSAI was captured using a multi-modal approach by measuring the flow and acoustic source fields based on particle image velocimetry, as well as the surface velocity of the vocal folds based on laser vibrometry and high-speed imaging. Strong harmonic sources were localized near the glottis, as well as further downstream, during the presence of the supraglottal jet. The strongest harmonic content of the vocal fold surface motion was verified for the area near the glottis, which directly interacts with the glottal jet flow. Also, the acoustic back-coupling of the formant frequencies onto the harmonic oscillation of the vocal folds was verified. These findings verify that harmonic sound generation is the result of a strong interrelation between the vocal fold motion, modulated flow field, and vocal tract geometry.
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Affiliation(s)
- Alexander Lodermeyer
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, 91058, Germany
| | - Eman Bagheri
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, 91058, Germany
| | - Stefan Kniesburges
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, 91054, Germany
| | - Christoph Näger
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, 91058, Germany
| | - Judith Probst
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, 91058, Germany
| | - Michael Döllinger
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, 91054, Germany
| | - Stefan Becker
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, 91058, Germany
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Greenwood TE, Thomson SL. Embedded 3D printing of multi-layer, self-oscillating vocal fold models. J Biomech 2021; 121:110388. [PMID: 33873116 DOI: 10.1016/j.jbiomech.2021.110388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 02/05/2021] [Accepted: 03/15/2021] [Indexed: 01/19/2023]
Abstract
The biomechanics of human voice production are commonly studied using benchtop silicone vocal fold models that mimic the vibration of their in vivo counterparts. These models often have multiple layers of differing stiffness that represent human vocal fold tissue layers and are fabricated using a multi-step casting process. The purpose of the present study is to introduce and demonstrate a process for fabricating functional multi-layer vocal fold models using an alternative approach, termed embedded 3D printing, that is a hybrid of casting and 3D printing. In this paper the fabrication process is described. Analysis of the resulting geometric and stiffness characteristics of the layers, including layer elastic modulus values ranging from less than 1 kPa to approximately 40 kPa, is presented. The results of tests demonstrating that the models are capable of sustained phonomimetic vibration are given. Capabilities and limitations of the embedded 3D printing process are discussed. It is concluded that the process has the potential to contribute to voice biomechanics research by facilitating prospective improvements in the fabrication, design, and functionality of multi-layer vocal fold models.
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Affiliation(s)
- Taylor E Greenwood
- Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Scott L Thomson
- Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602, USA.
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Falk S, Kniesburges S, Schoder S, Jakubaß B, Maurerlehner P, Echternach M, Kaltenbacher M, Döllinger M. 3D-FV-FE Aeroacoustic Larynx Model for Investigation of Functional Based Voice Disorders. Front Physiol 2021; 12:616985. [PMID: 33762964 PMCID: PMC7982522 DOI: 10.3389/fphys.2021.616985] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 02/09/2021] [Indexed: 12/02/2022] Open
Abstract
For the clinical analysis of underlying mechanisms of voice disorders, we developed a numerical aeroacoustic larynx model, called simVoice, that mimics commonly observed functional laryngeal disorders as glottal insufficiency and vibrational left-right asymmetries. The model is a combination of the Finite Volume (FV) CFD solver Star-CCM+ and the Finite Element (FE) aeroacoustic solver CFS++. simVoice models turbulence using Large Eddy Simulations (LES) and the acoustic wave propagation with the perturbed convective wave equation (PCWE). Its geometry corresponds to a simplified larynx and a vocal tract model representing the vowel /a/. The oscillations of the vocal folds are externally driven. In total, 10 configurations with different degrees of functional-based disorders were simulated and analyzed. The energy transfer between the glottal airflow and the vocal folds decreases with an increasing glottal insufficiency and potentially reflects the higher effort during speech for patients being concerned. This loss of energy transfer may also have an essential influence on the quality of the sound signal as expressed by decreasing sound pressure level (SPL), Cepstral Peak Prominence (CPP), and Vocal Efficiency (VE). Asymmetry in the vocal fold oscillations also reduces the quality of the sound signal. However, simVoice confirmed previous clinical and experimental observations that a high level of glottal insufficiency worsens the acoustic signal quality more than oscillatory left-right asymmetry. Both symptoms in combination will further reduce the quality of the sound signal. In summary, simVoice allows for detailed analysis of the origins of disordered voice production and hence fosters the further understanding of laryngeal physiology, including occurring dependencies. A current walltime of 10 h/cycle is, with a prospective increase in computing power, auspicious for a future clinical use of simVoice.
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Affiliation(s)
- Sebastian Falk
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head & Neck Surgery, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Stefan Kniesburges
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head & Neck Surgery, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Stefan Schoder
- Institute of Fundamentals and Theory in Electrical Engineering, Division Vibro- and Aeroacoustics, Graz University of Technology, Graz, Austria
| | - Bernhard Jakubaß
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head & Neck Surgery, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Paul Maurerlehner
- Institute of Fundamentals and Theory in Electrical Engineering, Division Vibro- and Aeroacoustics, Graz University of Technology, Graz, Austria
| | - Matthias Echternach
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Munich University Hospital (LMU), Munich, Germany
| | - Manfred Kaltenbacher
- Institute of Fundamentals and Theory in Electrical Engineering, Division Vibro- and Aeroacoustics, Graz University of Technology, Graz, Austria
| | - Michael Döllinger
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head & Neck Surgery, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
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Calvache C, Solaque L, Velasco A, Peñuela L. Biomechanical Models to Represent Vocal Physiology: A Systematic Review. J Voice 2021; 37:465.e1-465.e18. [PMID: 33678534 DOI: 10.1016/j.jvoice.2021.02.014] [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: 12/03/2020] [Revised: 01/26/2021] [Accepted: 02/02/2021] [Indexed: 11/24/2022]
Abstract
Biomechanical modeling allows obtaining information on physical phenomena that cannot be directly observed. This study aims to review models that represent voice production. A systematic review of the literature was conducted using PubMed/Medline, SCOPUS, and IEEE Xplore databases. To select the papers, we used the protocol PRISMA Statement. A total of 53 publications were included in this review. This article considers a taxonomic classification of models found in the literature. We propose four categories in the taxonomy: (1) Models representing the Source (Vocal folds); (2) Models representing the Filter (Vocal Tract); (3) Models representing the Source - Filter Interaction; and (4) Models representing the Airflow - Source Interaction. We include a bibliographic analysis with the evolution of the publications per category. We provide an analysis of the number as well of publications in journals per year. Moreover, we present an analysis of the term occurrence and its frequency of usage, as found in the literature. In each category, different types of vocal production models are mentioned and analyzed. The models account for the analysis of evidence about aerodynamic, biomechanical, and acoustic phenomena and their correlation with the physiological processes involved in the production of the human voice. This review gives an insight into the state of the art related to the mathematical modeling of voice production, analyzed from the viewpoint of vocal physiology.
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Affiliation(s)
- Carlos Calvache
- Vocology Center, Bogotá, Colombia; Department of Mechatronics Engineering, Universidad Militar Nueva Granada, Bogotá, Colombia.
| | - Leonardo Solaque
- Department of Mechatronics Engineering, Universidad Militar Nueva Granada, Bogotá, Colombia
| | - Alexandra Velasco
- Department of Mechatronics Engineering, Universidad Militar Nueva Granada, Bogotá, Colombia
| | - Lina Peñuela
- Department of Mechatronics Engineering, Universidad Militar Nueva Granada, Bogotá, Colombia
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Kniesburges S, Lodermeyer A, Semmler M, Schulz YK, Schützenberger A, Becker S. Analysis of the tonal sound generation during phonation with and without glottis closure. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:3285. [PMID: 32486803 DOI: 10.1121/10.0001184] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The human phonation is characterized by periodical oscillations of the vocal folds with a complete glottis closure. In contrast, a glottal insufficiency (GI) represents an oscillation without glottis closure resulting in a breathy and weak voice. In this study, flow-induced oscillations of silicone vocal folds were modeled with and without glottis closure. The measurements comprised the flow pressure in the model, the generated sound, and the high-speed footage of the vocal fold motion. The analysis revealed that the sound signal for vocal fold oscillations without closure exhibits a lower number of harmonic tones with smaller amplitudes compared to the case with complete closure. The time series of the pressure signals showed small and periodical oscillations occurring less frequently and with smaller amplitude for the GI case. Accordingly, the pressure spectra include fewer harmonics similar to the sound. The analysis of the high-speed videos indicates that the strength of the pressure oscillations correlates with the divergence angle of the glottal duct during the closing motion. Physiologically, large divergence angles typically occur for a pronounced mucosal wave motion with glottis closure. Thus, the results indicate a correlation between the intensity of the mucosal wave and the development of harmonic tones.
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Affiliation(s)
- Stefan Kniesburges
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
| | - Alexander Lodermeyer
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 7, 91058 Erlangen, Germany
| | - Marion Semmler
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
| | - Yvonne Katrin Schulz
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
| | - Anne Schützenberger
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
| | - Stefan Becker
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 7, 91058 Erlangen, Germany
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Romero RGT, Colton MB, Thomson SL. 3D-Printed Synthetic Vocal Fold Models. J Voice 2020; 35:685-694. [PMID: 32312610 DOI: 10.1016/j.jvoice.2020.01.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Synthetic vocal fold (VF) models used for studying the physics of voice production are comprised of silicone and fabricated using traditional casting processes. The purpose of this study was to develop and demonstrate a new method of creating synthetic VF models through 3D printing in order to reduce model fabrication time, increase yield, and lay the foundation for future models with more life-like geometric, material, and vibratory properties. STUDY DESIGN Basic science. METHODS A 3D printing technique based on embedding a UV-curable liquid silicone into a gel-like medium was selected and refined. Cubes were printed and subjected to tensile testing to characterize their material properties. Self-oscillating VF models were then printed, coated with a thin layer of silicone representing the epithelium, and used in phonation tests to gather onset pressure, frequency, and amplitude data. RESULTS The cubes were found to be anisotropic, exhibiting different modulus values depending on the orientation of the printed layers. The VF models self-oscillated and withstood the strains induced by phonation. Print parameters were found to affect model vibration frequency and onset pressure. Primarily due to the design of the VF models, their onset pressures were higher than what is found in human VFs. However, their frequencies were within a comparable range. CONCLUSION The results demonstrate the ability to 3D print synthetic, self-oscillating VF models. It is anticipated that this method will be further refined and used in future studies exploring flow-induced vibratory characteristics of phonation.
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Affiliation(s)
- Ryan G T Romero
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah
| | - Mark B Colton
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah
| | - Scott L Thomson
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah.
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Computational Models of Laryngeal Aerodynamics: Potentials and Numerical Costs. J Voice 2018; 33:385-400. [PMID: 29428274 DOI: 10.1016/j.jvoice.2018.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/04/2018] [Indexed: 11/23/2022]
Abstract
Human phonation is based on the interaction between tracheal airflow and laryngeal dynamics. This fluid-structure interaction is based on the energy exchange between airflow and vocal folds. Major challenges in analyzing the phonatory process in-vivo are the small dimensions and the poor accessibility of the region of interest. For improved analysis of the phonatory process, numerical simulations of the airflow and the vocal fold dynamics have been suggested. Even though most of the models reproduced the phonatory process fairly well, development of comprehensive larynx models is still a subject of research. In the context of clinical application, physiological accuracy and computational model efficiency are of great interest. In this study, a simple numerical larynx model is introduced that incorporates the laryngeal fluid flow. It is based on a synthetic experimental model with silicone vocal folds. The degree of realism was successively increased in separate computational models and each model was simulated for 10 oscillation cycles. Results show that relevant features of the laryngeal flow field, such as glottal jet deflection, develop even when applying rather simple static models with oscillating flow rates. Including further phonatory components such as vocal fold motion, mucosal wave propagation, and ventricular folds, the simulations show phonatory key features like intraglottal flow separation and increased flow rate in presence of ventricular folds. The simulation time on 100 CPU cores ranged between 25 and 290 hours, currently restricting clinical application of these models. Nevertheless, results show high potential of numerical simulations for better understanding of phonatory process.
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Kniesburges S, Birk V, Lodermeyer A, Schützenberger A, Bohr C, Becker S. Effect of the ventricular folds in a synthetic larynx model. J Biomech 2017; 55:128-133. [PMID: 28285747 DOI: 10.1016/j.jbiomech.2017.02.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/25/2017] [Accepted: 02/16/2017] [Indexed: 10/20/2022]
Abstract
Within the human larynx, the ventricular folds serve primarily as a protecting valve during swallowing. They are located directly above the sound-generating vocal folds. During normal phonation, the ventricular folds are passive structures that are not excited to periodical oscillations. However, the impact of the ventricular folds on the phonation process has not yet been finally clarified. An experimental synthetic human larynx model was used to investigate the effect of the ventricular folds on the phonation process. The model includes self-oscillating vocal fold models and allows the comparison of the pressure distribution at multiple locations in the larynx for configurations with and without ventricular folds. The results indicate that the ventricular folds increase the efficiency of the phonation process by reducing the phonation threshold level of the pressure below the vocal folds. Two effects caused by the ventricular folds could be identified as reasons: (1) a decrease in the mean pressure level in the region between vocal and ventricular folds (ventricles) and (2) an increase in the glottal flow resistance. The reason for the first effect is a reduction of the pressure level in the ventricles due to the jet entrainment and the low static pressure in the glottal jet. The second effect results from an increase in the glottal flow resistance that enhances the aerodynamic energy transfer into the vocal folds. This effect reduces the onset threshold of the pressure difference across the glottis.
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Affiliation(s)
- Stefan Kniesburges
- Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Germany.
| | - Veronika Birk
- Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Alexander Lodermeyer
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Germany; Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander Unversity Erlangen-Nürnberg, Germany
| | - Anne Schützenberger
- Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Christopher Bohr
- Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Stefan Becker
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Germany
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Kniesburges S, Lodermeyer A, Becker S, Traxdorf M, Döllinger M. The mechanisms of subharmonic tone generation in a synthetic larynx model. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 139:3182. [PMID: 27369142 DOI: 10.1121/1.4954264] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The sound spectra obtained in a synthetic larynx exhibited subharmonic tones that are characteristic for diplophonia. Although the generation of subharmonics is commonly associated with asymmetrically oscillating vocal folds, the synthetic elastic vocal folds showed symmetrical oscillations. The amplitudes of the subharmonics decreased with an increasing lateral diameter of the supraglottal channel, which indicates a strong dependence of the supraglottal boundary conditions. Investigations of the supraglottal flow field revealed small cycle-to-cycle variations of the static pressure in the region of the pulsatile glottal jet as the origin of the first subharmonic tone. It is located at half the fundamental frequency of the vocal fold oscillation. A principle component analysis of the supraglottal flow field with the fully developed glottal jet revealed a large recirculation area in the second spatial eigenvector which deflected the glottal jet slightly in a perpendicular direction of the jet axis. The rotation direction of the recirculation area changed with different oscillation cycles between clockwise and counterclockwise. As both directions were uniformly distributed across all acquired oscillation cycles, a cycle-wise change can be assumed. It is concluded that acoustic subharmonics are generated by small fluctuations of the glottal jet location favored by small lateral diameters of the supraglottal channel.
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Affiliation(s)
- Stefan Kniesburges
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Bohlenplatz 21, 91054 Erlangen, Germany
| | - Alexander Lodermeyer
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 7, 91058 Erlangen, Germany
| | - Stefan Becker
- Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 7, 91058 Erlangen, Germany
| | - Maximilian Traxdorf
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Waldstrasse 1, 91054 Erlangen, Germany
| | - Michael Döllinger
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Bohlenplatz 21, 91054 Erlangen, Germany
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Döllinger M, Berry DA, Kniesburges S. Dynamic vocal fold parameters with changing adduction in ex-vivo hemilarynx experiments. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 139:2372. [PMID: 27250133 PMCID: PMC4859834 DOI: 10.1121/1.4947044] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 03/22/2016] [Accepted: 04/05/2016] [Indexed: 05/25/2023]
Abstract
Ex-vivo hemilarynx experiments allow the visualization and quantification of three-dimensional dynamics of the medial vocal fold surface. For three excised human male larynges, the vibrational output, the glottal flow resistance, and the sound pressure during sustained phonation were analyzed as a function of vocal fold adduction for varying subglottal pressure. Empirical eigenfunctions, displacements, and velocities were investigated along the vocal fold surface. For two larynges, an increase of adduction level resulted in an increase of the glottal flow resistance at equal subglottal pressures. This caused an increase of lateral and vertical oscillation amplitudes and velocity indicating an improved energy transfer from the airflow to the vocal folds. In contrast, the third larynx exhibited an amplitude decrease for rising adduction accompanying reduction of the flow resistance. By evaluating the empirical eigenfunctions, this reduced flow resistance was assigned to an unbalanced oscillation pattern with predominantly lateral amplitudes. The results suggest that adduction facilitates the phonatory process by increasing the glottal flow resistance and enhancing the vibrational amplitudes. However, this interrelation only holds for a maintained balanced ratio between vertical and lateral displacements. Indeed, a balanced vertical-lateral oscillation pattern may be more beneficial to phonation than strong periodicity with predominantly lateral vibrations.
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Affiliation(s)
- Michael Döllinger
- Division of Phoniatrics and Pediatric Audiology-Computational Medicine, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander-Universität Erlangen-Nürnberg, Bohlenplatz 21, 91054 Erlangen, Germany
| | - David A Berry
- The Laryngeal Dynamics Laboratory, Division of Head and Neck Surgery, David Geffen School of Medicine at UCLA, 31-24 Rehab Center, 1000 Veteran Avenue, Los Angeles, California 90095-1794, USA
| | - Stefan Kniesburges
- Division of Phoniatrics and Pediatric Audiology-Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Medical School at Friedrich-Alexander-Universität Erlangen-Nürnberg, Bohlenplatz 21, 91054 Erlangen, Germany
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Dion GR, Jeswani S, Roof S, Fritz M, Coelho PG, Sobieraj M, Amin MR, Branski RC. Functional assessment of the ex vivo vocal folds through biomechanical testing: A review. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 64:444-453. [PMID: 27127075 DOI: 10.1016/j.msec.2016.04.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 03/21/2016] [Accepted: 04/06/2016] [Indexed: 11/25/2022]
Abstract
The human vocal folds are complex structures made up of distinct layers that vary in cellular and extracellular composition. The mechanical properties of vocal fold tissue are fundamental to the study of both the acoustics and biomechanics of voice production. To date, quantitative methods have been applied to characterize the vocal fold tissue in both normal and pathologic conditions. This review describes, summarizes, and discusses the most commonly employed methods for vocal fold biomechanical testing. Force-elongation, torsional parallel plate rheometry, simple-shear parallel plate rheometry, linear skin rheometry, and indentation are the most frequently employed biomechanical tests for vocal fold tissues and each provide material properties data that can be used to compare native tissue to diseased or treated tissue. Force-elongation testing is clinically useful, as it allows for functional unit testing, while rheometry provides physiologically relevant shear data, and nanoindentation permits micrometer scale testing across different areas of the vocal fold as well as whole organ testing. Thoughtful selection of the testing technique during experimental design to evaluate a hypothesis is critical to optimize biomechanical testing of vocal fold tissues.
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Affiliation(s)
- Gregory R Dion
- NYU Voice Center, Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, NY, United States
| | - Seema Jeswani
- NYU Voice Center, Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, NY, United States
| | - Scott Roof
- NYU Voice Center, Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, NY, United States
| | - Mark Fritz
- NYU Voice Center, Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, NY, United States
| | - Paulo G Coelho
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY, United States
| | - Michael Sobieraj
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY, United States
| | - Milan R Amin
- NYU Voice Center, Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, NY, United States
| | - Ryan C Branski
- NYU Voice Center, Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, NY, United States.
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Bohr C, Döllinger M, Kniesburges S, Traxdorf M. [3D visualization and analysis of vocal fold dynamics]. HNO 2016; 64:254-61. [PMID: 26842549 DOI: 10.1007/s00106-016-0122-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Visual investigation methods of the larynx mainly allow for the two-dimensional presentation of the three-dimensional structures of the vocal fold dynamics. The vertical component of the vocal fold dynamics is often neglected, yielding a loss of information. The latest studies show that the vertical dynamic components are in the range of the medio-lateral dynamics and play a significant role within the phonation process. OBJECTIVES This work presents a method for future 3D reconstruction and visualization of endoscopically recorded vocal fold dynamics. MATERIALS AND METHODS The setup contains a high-speed camera (HSC) and a laser projection system (LPS). The LPS projects a regular grid on the vocal fold surfaces and in combination with the HSC allows a three-dimensional reconstruction of the vocal fold surface. Hence, quantitative information on displacements and velocities can be provided. The applicability of the method is presented for one ex-vivo human larynx, one ex-vivo porcine larynx and one synthetic silicone larynx. RESULTS The setup introduced allows the reconstruction of the entire visible vocal fold surfaces for each oscillation status. This enables a detailed analysis of the three dimensional dynamics (i. e. displacements, velocities, accelerations) of the vocal folds. CONCLUSIONS The next goal is the miniaturization of the LPS to allow clinical in-vivo analysis in humans. We anticipate new insight on dependencies between 3D dynamic behavior and the quality of the acoustic outcome for healthy and disordered phonation.
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Affiliation(s)
- C Bohr
- Abteilung für Phoniatrie und Pädaudiologie an der Hals-Nasen-Ohren-Klinik, Kopf- und Halschirurgie, Universitätsklinikum Erlangen, Bohlenplatz 21, 91054, Erlangen, Deutschland.
| | - M Döllinger
- Abteilung für Phoniatrie und Pädaudiologie an der Hals-Nasen-Ohren-Klinik, Kopf- und Halschirurgie, Universitätsklinikum Erlangen, Bohlenplatz 21, 91054, Erlangen, Deutschland
| | - S Kniesburges
- Abteilung für Phoniatrie und Pädaudiologie an der Hals-Nasen-Ohren-Klinik, Kopf- und Halschirurgie, Universitätsklinikum Erlangen, Bohlenplatz 21, 91054, Erlangen, Deutschland
| | - M Traxdorf
- Hals-Nasen-Ohren-Klinik, Kopf- und Halschirurgie, Universitätsklinikum Erlangen, Erlangen, Deutschland
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Manti M, Cianchetti M, Nacci A, Ursino F, Laschi C. A biorobotic model of the human larynx. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:3623-6. [PMID: 26737077 DOI: 10.1109/embc.2015.7319177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This work focuses on a physical model of the human larynx that replicates its main components and functions. The prototype reproduces the multilayer vocal folds and the ab/adduction movements. In particular, the vocal folds prototype is made with soft materials whose mechanical properties have been obtained to be similar to the natural tissue in terms of viscoelasticity. A computational model was used to study fluid-structure interaction between vocal folds and the airflow. This tool allowed us to make a comparison between theoretical and experimental results. Measurements were performed with this prototype in an experimental platform comprising a controlled air flow, pressure sensors and a high-speed camera for measuring vocal fold vibrations. Data included oscillation frequency at the onset pressure and glottal width. Results show that the combination between vocal fold geometry, mechanical properties and dimensions exhibits an oscillation frequency close to that of the human vocal fold. Moreover, computational results show a high correlation with the experimental one.
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Erdoğan S, Sağsöz H, Paulsen F. Functional Anatomy of the Syrinx of the Chukar Partridge (Galliformes:Alectoris chukar) as a Model for Phonation Research. Anat Rec (Hoboken) 2014; 298:602-17. [DOI: 10.1002/ar.23044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/04/2014] [Accepted: 07/30/2014] [Indexed: 01/16/2023]
Affiliation(s)
- Serkan Erdoğan
- Department of Anatomy, Faculty of Veterinary Medicine; Dicle University; Diyarbakir Turkey
| | - Hakan Sağsöz
- Department of Histology and Embryology, Faculty of Veterinary Medicine; Dicle University; Diyarbakir Turkey
| | - Friedrich Paulsen
- Department of Anatomy II; Friedrich Alexander University of Erlangen-Nuremberg; Erlangen Germany
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Affiliation(s)
- G.J. Verkerke
- Department of Rehabilitation Medicine, University of Groningen, University Medical Center Groningen, 9700 AD Groningen, The Netherlands;
- Department of Biomechanical Engineering, University of Twente, 7500 AE Enschede, The Netherlands
| | - S.L. Thomson
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah 84602;
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Xuan Y, Zhang Z. Influence of embedded fibers and an epithelium layer on the glottal closure pattern in a physical vocal fold model. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2014; 57:416-25. [PMID: 24167236 PMCID: PMC4002672 DOI: 10.1044/2013_jslhr-s-13-0068] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
PURPOSE The purpose of this study was to explore the possible structural and material property features that may facilitate complete glottal closure in an otherwise isotropic physical vocal fold model. METHOD Seven vocal fold models with different structural features were used in this study. An isotropic model was used as the baseline model, and other models were modified from the baseline model by either embedding fibers aligned along the anterior-posterior direction in the body or cover layer, adding a stiffer outer layer simulating the epithelium layer, or a combination of the 2 features. Phonation tests were performed with both aerodynamic and acoustic measurements and high-speed imaging of vocal fold vibration. RESULTS Compared with the isotropic one-layer model, the presence of a stiffer epithelium layer led to complete glottal closure along the anterior-posterior direction and strong excitation of high-order harmonics in the resulting acoustic spectra. Similar improvements were observed with fibers embedded in the cover layer, but to a lesser degree. The presence of fibers in the body layer did not yield noticeable improvements in glottal closure or harmonic excitation. CONCLUSION This study shows that the presence of collagen and elastin fibers and the epithelium layer may play a critical role in achieving complete glottal closure.
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Murray PR, Thomson SL, Smith ME. A synthetic, self-oscillating vocal fold model platform for studying augmentation injection. J Voice 2014; 28:133-43. [PMID: 24476985 DOI: 10.1016/j.jvoice.2013.10.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 10/21/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To design and evaluate a platform for studying the mechanical effects of augmentation injections using synthetic, self-oscillating vocal fold models. STUDY DESIGN Basic science. METHODS Life-sized, synthetic, multilayer, self-oscillating vocal fold models were created that simulated bowing via volumetric reduction of the body layer relative to that of a normal, unbowed model. Material properties of the layers were unchanged. Models with varying degrees of bowing were created and paired with normal models. Following initial acquisition of data (onset pressure, vibration frequency, flow rate, and high-speed image sequences), bowed models were injected with silicone that had material properties similar to those used in augmentation procedures. Three different silicone injection quantities were tested: sufficient to close the glottal gap, insufficient to close the glottal gap, and excess silicone to create convex bowing of the bowed model. The above-mentioned metrics were again taken and compared. Pre- and post-injection high-speed image sequences were acquired using a hemilarynx setup, from which medial surface dynamics were quantified. RESULTS The models vibrated with mucosal wave-like motion and at onset pressures and frequencies typical of human phonation. The models successfully exhibited various degrees of bowing which were then mitigated by injecting filler material. The models showed general pre- to post-injection decreases in onset pressure, flow rate, and open quotient and a corresponding increase in vibration frequency. CONCLUSION The model may be useful in further explorations of the mechanical consequences of augmentation injections.
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Affiliation(s)
- Preston R Murray
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah
| | - Scott L Thomson
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah.
| | - Marshall E Smith
- Division of Otolaryngology-Head Neck Surgery, University of Utah, Salt Lake City, Utah
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Schmidt B, Leugering G, Stingl M, Hüttner B, Agaimy A, Döllinger M. Material and shape optimization for multi-layered vocal fold models using transient loadings. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2013; 134:1261-1270. [PMID: 23927124 DOI: 10.1121/1.4812253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Commonly applied models to study vocal fold vibrations in combination with air flow distributions are self-sustained physical models of the larynx consisting of artificial silicone vocal folds. Choosing appropriate mechanical parameters and layer geometries for these vocal fold models while considering simplifications due to manufacturing restrictions is difficult but crucial for achieving realistic behavior. In earlier work by Schmidt et al. [J. Acoust. Soc. Am. 129, 2168-2180 (2011)], the authors presented an approach in which material parameters of a static numerical vocal fold model were optimized to achieve an agreement of the displacement field with data retrieved from hemilarynx experiments. This method is now generalized to a fully transient setting. Moreover in addition to the material parameters, the extended approach is capable of finding optimized layer geometries. Depending on chosen material restriction, significant modifications of the reference geometry are predicted. The additional flexibility in the design space leads to a significantly more realistic deformation behavior. At the same time, the predicted biomechanical and geometrical results are still feasible for manufacturing physical vocal fold models consisting of several silicone layers. As a consequence, the proposed combined experimental and numerical method is suited to guide the construction of physical vocal fold models.
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Affiliation(s)
- Bastian Schmidt
- Department Mathematics, Applied Mathematics II, University of Erlangen, Cauerstrasse 11, 91058 Erlangen, Germany.
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Kniesburges S, Hesselmann C, Becker S, Schlücker E, Döllinger M. Influence of vortical flow structures on the glottal jet location in the supraglottal region. J Voice 2013; 27:531-44. [PMID: 23911009 DOI: 10.1016/j.jvoice.2013.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 04/15/2013] [Indexed: 10/26/2022]
Abstract
Within the fully coupled multiphysics phonation process, the fluid flow plays an important role for sound production. This study addresses phenomena in the flow downstream of synthetic self-oscillating vocal folds. An experimental setup consisting of devices for producing and conditioning the flow including the main test channel was applied. The supraglottal channel was designed to prevent an acoustic coupling to the vocal folds. Hence, the oscillations were aerodynamically driven. The cross-section of the supraglottal channel was systematically varied by increasing the distance between the lateral channel walls. The vocal folds consisted of silicone rubber of homogenous material distribution generating self-sustained oscillations. The airflow was visualized in the immediate supraglottal region using a laser-sheet technique and a digital high-speed camera. Furthermore, the flow was studied by measuring the static pressure distributions on both lateral supraglottal channel walls. The results clearly showed different flow characteristics depending on the supraglottal configuration. In all cases with supraglottal channel, the jet was located asymmetrical and bent in medial-lateral direction. Furthermore, the side to which the jet was deflected changed in between the consecutive cycles showing a bifurcational behavior. Previously, this phenomenon was explained by the Coanda effect. However, the present data suggest that the deflection of the jet was mainly caused by large air vortices in the supraglottal channel produced by the flow field of previous oscillations. In contrast, for the case without supraglottal channel, the air jet was found totally symmetrical stabilized by the constant pressure in the ambient region. The emitted sound signal showed additional subharmonic tonal peaks for the asymmetric flow cases, which are characteristics for diplophonia.
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Affiliation(s)
- Stefan Kniesburges
- Institute of Process Machinery and Systems Engineering, University of Erlangen-Nuremberg, Erlangen, Germany.
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Murray PR, Thomson SL. Vibratory responses of synthetic, self-oscillating vocal fold models. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2012; 132:3428-38. [PMID: 23145623 PMCID: PMC3505215 DOI: 10.1121/1.4754551] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The flow-induced responses of four self-oscillating synthetic vocal fold models are compared. All models were life-sized and fabricated using flexible silicone compounds with material properties comparable to those of human vocal fold tissue. Three of the models had two layers of different stiffness to represent the body-cover grouping of vocal fold tissue. Two of the two-layer models were based on the "M5" geometry [Scherer et al., J. Acoust. Soc. Am. 109, 1616-1630 (2001)], while the third was based on magnetic resonance imaging data. The fourth model included several layers, including a thin epithelial layer, an exceedingly flexible superficial lamina propria layer, a ligament layer that included an anteriorly-posteriorly oriented fiber to restrict vertical motion, and a body layer. Measurements were performed with these models in full larynx and hemilarynx configurations. Data included onset pressure, vibration frequency, glottal flow rate, maximum glottal width, and medial surface motion, the latter two of which were acquired using high-speed imaging techniques. The fourth, multi-layer model exhibited onset pressure, frequency, and medial surface motion traits that are comparable to published human vocal fold data. Importantly, the model featured an alternating convergent-divergent glottal profile and mucosal wave-like motion, characteristics which are important markers of human vocal fold vibration.
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Affiliation(s)
- Preston R Murray
- Department of Mechanical Engineering, Brigham Young University, Provo, Utah 84602, USA
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Shaw SM, Thomson SL, Dromey C, Smith S. Frequency response of synthetic vocal fold models with linear and nonlinear material properties. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2012; 55:1395-406. [PMID: 22271874 PMCID: PMC4028721 DOI: 10.1044/1092-4388(2012/11-0153)] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
PURPOSE The purpose of this study was to create synthetic vocal fold models with nonlinear stress-strain properties and to investigate the effect of linear versus nonlinear material properties on fundamental frequency (F0) during anterior-posterior stretching. METHOD Three materially linear and 3 materially nonlinear models were created and stretched up to 10 mm in 1-mm increments. Phonation onset pressure (Pon) and F0 at Pon were recorded for each length. Measurements were repeated as the models were relaxed in 1-mm increments back to their resting lengths, and tensile tests were conducted to determine the stress-strain responses of linear versus nonlinear models. RESULTS Nonlinear models demonstrated a more substantial frequency response than did linear models and a more predictable pattern of F0 increase with respect to increasing length (although range was inconsistent across models). Pon generally increased with increasing vocal fold length for nonlinear models, whereas for linear models, Pon decreased with increasing length. CONCLUSION Nonlinear synthetic models appear to more accurately represent the human vocal folds than do linear models, especially with respect to F0 response.
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Abstract
Sound for the human voice is produced via flow-induced vocal fold vibration. The vocal folds consist of several layers of tissue, each with differing material properties. Normal voice production relies on healthy tissue and vocal folds, and occurs as a result of complex coupling between aerodynamic, structural dynamic, and acoustic physical phenomena. Voice disorders affect up to 7.5 million annually in the United States alone and often result in significant financial, social, and other quality-of-life difficulties. Understanding the physics of voice production has the potential to significantly benefit voice care, including clinical prevention, diagnosis, and treatment of voice disorders. Existing methods for studying voice production include in vivo experimentation using human and animal subjects, in vitro experimentation using excised larynges and synthetic models, and computational modeling. Owing to hazardous and difficult instrument access, in vivo experiments are severely limited in scope. Excised larynx experiments have the benefit of anatomical and some physiological realism, but parametric studies involving geometric and material property variables are limited. Further, they are typically only able to be vibrated for relatively short periods of time (typically on the order of minutes). Overcoming some of the limitations of excised larynx experiments, synthetic vocal fold models are emerging as a complementary tool for studying voice production. Synthetic models can be fabricated with systematic changes to geometry and material properties, allowing for the study of healthy and unhealthy human phonatory aerodynamics, structural dynamics, and acoustics. For example, they have been used to study left-right vocal fold asymmetry, clinical instrument development, laryngeal aerodynamics, vocal fold contact pressure, and subglottal acoustics (a more comprehensive list can be found in Kniesburges et al.) Existing synthetic vocal fold models, however, have either been homogenous (one-layer models) or have been fabricated using two materials of differing stiffness (two-layer models). This approach does not allow for representation of the actual multi-layer structure of the human vocal folds that plays a central role in governing vocal fold flow-induced vibratory response. Consequently, one- and two-layer synthetic vocal fold models have exhibited disadvantages such as higher onset pressures than what are typical for human phonation (onset pressure is the minimum lung pressure required to initiate vibration), unnaturally large inferior-superior motion, and lack of a "mucosal wave" (a vertically-traveling wave that is characteristic of healthy human vocal fold vibration). In this paper, fabrication of a model with multiple layers of differing material properties is described. The model layers simulate the multi-layer structure of the human vocal folds, including epithelium, superficial lamina propria (SLP), intermediate and deep lamina propria (i.e., ligament; a fiber is included for anterior-posterior stiffness), and muscle (i.e., body) layers. Results are included that show that the model exhibits improved vibratory characteristics over prior one- and two-layer synthetic models, including onset pressure closer to human onset pressure, reduced inferior-superior motion, and evidence of a mucosal wave.
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Affiliation(s)
- Preston R Murray
- Department of Mechanical Engineering, Brigham Young University, USA
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