• GWU Department of Mechanical and Aerospace Engineering

Professor Rajat Mittal (PI),  Xudong Zheng (PhD Candidate), Qian Xue(phD Student), S.A. Mohsen Karimian(Post-doc)

• GWU Medical Center:

Professor Steven A. Bielamowicz, M.D., Professor Raymond J. Walsh

• GWU Department of Computer Science

Professor James Hahn,  Ge Jin (Post-doc)

It is estimated that in the United States about 2.5 million people suffer from vocal fold paresis or paralysis. Medialization laryngoplasty is the treatment of choice for this type of voice disorder where a uniquely configured structural support is implanted into the paretic vocal fold to facilitate the voice production. However, the failure rate of this procedure is as high as 24% even for experienced surgeons. One primary factor for the failure is that the surgeons have no means of predicting and adjusting for the effects of the implant on the vibratory characteristics of the paralyzed vocal fold.

Vocal fold vibration and phonation result from a complex biomechanical interaction between glottal aerodynamics and the vocal fold tissues, and variations in the laryngeal anatomy of individual patients make phonation a more complex problem to address. A realistic computer based biophysics model, which is based on phonatory vocal fold functions and glottal flow, and incorporates patient-specific anatomical characteristics, could be used to predetermine the implant shape and location, and potentially reduce the revision rate for the surgery.

In this multidisciplinary project, we attempt to develop a high-fidelity model of the vocal fold vibration and phonatory aerodynamics.  To guarantee model accuracy, several new key factors are being incorporated into our approach: 

1.  Realistic CT based laryngeal anatomy

2.  High-accuracy modeling of aerodynamics with direct numerical simulation (DNS) and large-eddy simulation (LES)

3.  Continuum model of vocal fold dynamics

The computer model will be used to simulate the fluid dynamics and vocal fold vibration during voice production for normal, diseased, and surgically altered larynges; to identify patient-specific phonatory characteristics by understanding physics of phonation, and ultimately to guide the surgeon in determining the optimal location and size/shape of the implant.

1. Flow Induced Vibration (AVI Movie file, size 3.8 MB)  

Figure1. Vorticity contours in a 2D flow-induced vocal fold vibration simulation where

 the larynx is simplified as a straight channel with a pair of multi-tissued vocal folds.  

2. Aerodynamic force on the vocal fold (AVI Movie file, size 2.7 MB)  

 Figure2. aerodynamic force on the vocal fold during sustained vibration.

3.  3D_Flow Induced Vibration   

Figure3. 2D/3D flow-induced vocal fold vibration. The left picture shows positive eigen value of velocity gredient during a vibration cycle. The right picture shows the intruduced-vibration of a vocal folds pair during a vibration cycle      

4.  Computer Reconstruction of 3D Real Shape of Vocal Folds

Ø        “Xudong.Zheng, Steve Bielamowicz, Haoxiang Luo and Rajat Mittal, "Computational Study of the Effect of False Vocal Folds on Glottal Flow and Vocal Fold Vibration During Phonation," Annals of Biomedical Engineering, Vol. 37, No. 3 pp. 625-642 March 2009,   

Ø        “A Method for Computational Modeling of Fluid-Structure Interaction in Surgically Altered Vocal Folds” Q. Xue, X, Zheng  and R.Mittal   XVIth International Conference on Mechanics in Medicine and Biology, Pittsburg PA, 2008,   

Ø        “High Fidelity Computational Method for Flow-Tissue Interaction in Biological Flows”  X. Zheng and R.Mittal  AIAA 2008-3954, AIAA paper 2008,     

Ø        “A Hierarchical Nest Grid Approach for Local Refinement Coupled with an Immersed Boundary Method”,  X. Zheng, R.Mittal and Y. Peng  ICCFD -0513, proceedings of International Conference on Computational Fluid Dynamics,2008       

Ø        “High Fidelity Modeling of the Biophysics of Phonation Using a Coupled IBM-FEM Method”  X. Zheng , H Luo and R.Mittal the APS Division of Fluid Dynamics 60th Annual Meeting, Nov 19-21 2007 Salt Lake City ,Utha       

Ø        “An immersed-boundary method for fluid-structure interaction in Biological Flow with application to Phonation ” H. Luo, R.Mittal. X Zheng and S. Bielamowicz  J. Comput. Physic.  2008        

Ø        “An immersed-boundary method for fluid-structure interaction in the human larynx” H. Luo, X. Zheng and R.Mittal the APS Division of Fluid Dynamics 59th Annual Meeting, Nov 19-21 2006 Tampa Bay, FL       

Ø “Computational Analysis of Glottal Aerodynamics and vocal Fold Vibrations During Phonation” X.Zheng, H. Luo and R.Mittal  the APS Division of Fluid Dynamics 59th Annual Meeting, Nov 19-21 2006 Tampa Bay, FL

Ø        “Computational Fluid Dynamics(CFD) based tools for planning phonosurgery. GWU Symposium on High-Performance Computing and Applications H. Luo, X.Zheng and R. Mittal Oct 18 2006. Washington D.C.

Ø        “Numerical Analysis of Glottal Dynamics Using an Immersed Boundary Method” H. Luo, X zheng  R. Mittal et al The American Society of Biomechanics Annual Meeting September 6-9 2006 BlcakBurg, VA

Ø“ Development of High-Fidelity Biophysical Model of Vocal Fold Vibration and Glottal Flow Aerodynamics”, R.Mittal, H.Luo, X.Zheng et al  5th International Conference On Voice  Physiology and Biomechanics  July 12-14 2006 Tokyo Japan       

Ø“Toward a High Fidelity Biophysical Model of Vocal Fold Vibration and Glottal Flow Aerodynamics”, X.Zheng, H.Luo,     R.Mittal, et al. Summer Bioengineering Conference( BIO2006-157432 2006)  June 21-25 2006 Amelia Island  FL.

  National Institute of Health (NIH)

Last modified on 02/10/2009