Dep. of Otorhinolaryngology, Div. of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
Dep. of Communication Sciences and Disorders, Louisiana State University, Baton Rouge, LA, United States of America.
PLoS One. 2019 Apr 22;14(4):e0215168. doi: 10.1371/journal.pone.0215168. eCollection 2019.
In laryngeal high-speed videoendoscopy (HSV) the area between the vibrating vocal folds during phonation is of interest, being referred to as glottal area waveform (GAW). Varying camera resolution may influence parameters computed on the GAW and hence hinder the comparability between examinations. This study investigates the influence of spatial camera resolution on quantitative vocal fold vibratory function parameters obtained from the GAW. In total 40 HSV recordings during sustained phonation (20 healthy males and 20 healthy females) were investigated. A clinically used Photron Fastcam MC2 camera with a frame rate of 4000 fps and a spatial resolution of 512×256 pixels was applied. This initial resolution was reduced by pixel averaging to (1) a resolution of 256×128 and (2) to a resolution of 128×64 pixels, yielding three sets of recordings. The GAW was extracted and in total 50 vocal fold vibratory parameters representing different features of the GAW were computed. Statistical analyses using SPSS Statistics, version 21, was performed. 15 Parameters showing strong mathematical dependencies with other parameters were excluded from the main analysis but are given in the Supporting Information. Data analysis revealed clear influence of spatial resolution on GAW parameters. Fundamental period measures and period perturbation measures were the least affected. Amplitude perturbation measures and mechanical measures were most strongly influenced. Most glottal dynamic characteristics and symmetry measures deviated significantly. Most energy perturbation measures changed significantly in males but were mostly unaffected in females. In females 18 of 35 remaining parameters (51%) and in males 22 parameters (63%) changed significantly between spatial resolutions. This work represents the first step in studying the impact of video resolution on quantitative HSV parameters. Clear influences of spatial camera resolution on computed parameters were found. The study results suggest avoiding the use of the most strongly affected parameters. Further, the use of cameras with high resolution is recommended to analyze GAW measures in HSV data.
在喉高速视频内窥镜（HSV）中，声带振动期间的区域是感兴趣的，被称为声门区波形（GAW）。不同的摄像机分辨率可能会影响 GAW 上计算的参数，从而阻碍检查之间的可比性。本研究调查了空间摄像机分辨率对从 GAW 获得的定量声带振动功能参数的影响。总共对 40 个持续发音的 HSV 记录（20 名健康男性和 20 名健康女性）进行了研究。使用临床使用的 Photron Fastcam MC2 摄像机，帧率为 4000 fps，空间分辨率为 512×256 像素。此初始分辨率通过像素平均减少到（1）分辨率为 256×128 和（2）分辨率为 128×64 像素，得到三组记录。提取 GAW，并总共计算了 50 个代表 GAW 不同特征的声带振动参数。使用 SPSS Statistics，版本 21 进行统计分析。15 个参数与其他参数具有很强的数学依赖性，从主要分析中排除，但在支持信息中给出。数据分析显示空间分辨率对 GAW 参数有明显影响。基频测量和周期微扰测量受影响最小。幅度微扰测量和力学测量受影响最大。大多数声门动力学特性和对称性测量明显偏差。大多数能量微扰测量在男性中显著变化，但在女性中大多不受影响。在女性中，35 个剩余参数中的 18 个（51%）和男性中的 22 个参数（63%）在空间分辨率之间发生显著变化。这项工作代表了研究视频分辨率对定量 HSV 参数影响的第一步。发现空间摄像机分辨率对计算参数有明显影响。研究结果表明避免使用受影响最大的参数。此外，建议使用高分辨率的摄像机来分析 HSV 数据中的 GAW 测量值。
