Simulation of Human Phonation with Vocal Nodules

• 作者: Shinji Deguchi Yuki Kawahara
• 来源期刊: 美国计算数学期刊(英文)
• 学科: 医学
• 关键词: Aerodynamics Flow–Structure Interaction Self-Excited Oscillation PHONATION VOCAL Fold LARYNX VOCAL Tract Speech PRODUCTION VOICE PRODUCTION VOCAL Nodules VOCAL Cord POLYP VOICE Disorder
• 年，卷（期）: 2011,（3）
• 页码范围: 189-201
• 页数: 13页
• 分类号: R73

摘要

The geometric and biomechanical properties of the larynx strongly influence voice quality and efficiency. A physical understanding of phonation natures in pathological conditions is important for predictions of how voice disorders can be treated using therapy and rehabilitation. Here, we present a continuum-based numerical model of phonation that considers complex fluid-structure interactions occurring in the airway. This model considers a three-dimensional geometry of vocal folds, muscle contractions, and viscoelastic properties to provide a realistic framework of phonation. The vocal fold motion is coupled to an unsteady compressible respiratory flow, allowing numerical simulations of normal and diseased phonations to derive clear relationships between actual laryngeal structures and model parameters such as muscle activity. As a pilot analysis of diseased phonation, we model vocal nodules, the mass lesions that can appear bilaterally on both sides of the vocal folds. Comparison of simulations with and without the nodules demonstrates how the lesions affect vocal fold motion, consequently restricting voice quality. Furthermore, we found that the minimum lung pressure required for voice production increases as nodules move closer to the center of the vocal fold. Thus, simulations using the developed model may provide essential insight into complex phonation phenomena and further elucidate the etiologic mechanisms of voice disorders.