How does vestibular fold removal affect the air stream during inspiration? – A computational study

Introduction:

Investigations of fluid dynamics associated with phonation and speech may play an important role in improving the treatment of voice disorders. Both experimental and virtual methods have contributed to the understanding of the underlying mechanisms. One of the key advantages is that various treatment strategies can be applied virtually without any risk for the patients. This method is used in the current study in order to address virtual removal of vestibular folds, and its effect on the air stream during inspiration.

Methods:

Anatomy segmentation is based on a CT data set. The region of interest covers the respiratory tract from the trachea to the nostrils, with open vocal folds. Computational modeling is used to remove the vestibular folds, leading to four different configurations: initial state, surgical removal of the left, right, and both vestibular folds. For each configuration the inspiration process is numerically modeled, capturing fluctuations of high frequencies and small-scale eddies.

Results:

Velocities inside the glottis region reach up to 10 m/s when normal human breathing is considered. The glottis represents the narrowest section within the upper airways; thus large fluctuations of the flow field are present. Furthermore, virtual removal of the vestibular folds comes with altered air flow patterns above and below the glottis, which causes local differences in the shear stress distribution on the surrounding structures.

Conclusions:

Further research is needed to investigate a possible relationship between changes in air flow and mucosal damage, and its effect on clinical outcomes.

Publication History

Publication Date:
23 April 2019 (online)