Development of diagnostic method of velopharyngeal closing function by speech using Chaos analysis

为了建立腭裂语音诊断方法，我们对唇部运动分析方法和语音混沌分析方法进行了研究。嘴唇运动分析方法采用3台红外摄像机、1台彩色摄像机、1台红外模式投影仪、4台数字视频平台和1台同步器捕捉面部运动。应用多基线立体图像算法，成功地生成了人脸的距离图像。采用高精度作动器和已知目标对测距图像的精度进行了研究。因此，从距离图像计算的距离与已知值在纵向和横向上的差异分别为0.53-0.73mm和0.14-0.44mm。在临床应用中，认为距离图像的精度是足够的。随后，我们开发了以下程序来分析嘴唇运动：1)将嘴唇划分为几个区域，2)应用uv坐标系，3)计算速度和特征值。现在分析发音中的嘴唇运动。语音的混沌分析利用“ki- tsuu -ki- tsuu -ki- tsuu - zu -ku”和“u-e-o-o-o-u”两个句子，计算李雅普诺夫指数。同时，还记录了鼻平衡。研究对象为16例健康成人和9例腭裂患者，其中2例有明显的腭咽功能不全（VPI）。结果表明：1)健康组鼻平衡评分非常稀疏，2)鼻平衡评分与Lyapunov指数无相关性，3)VPI患者鼻平衡评分和Lyapunov指数均较高。提示有可能提高腭咽闭合功能的诊断精度。

To establish a diagnostic method of cleft palate speech, we study on analyzing method of lip movement and chaos analyzing of speech.1. Analyzing method of lip movementA motion of the face was captured using 3 IR cameras, one color camera, a projector of infrared pattern, 4 digital video decks and a synchronizer. We succeeded in production of range images for a face by applying the algorithm of ~a multiple-baseline stereo. Accuracy of the range image was investigated using an actuator with high accuracy and a known object. Consequently, the differences between the distances calculated from the range images and the known values were ranging from 0.53-0.73mm and 0.14-0.44mm in longitudinal and lateral directions, respectively. It was considered that the accuracy of the range images was enough in clinical usage. Subsequently, we developed the following programs to analyze a lip motion : 1) the lip was divided into several areas, 2) uv coordinate system was applied, and 3) the speed and eigenvalue were calculated. Now lip motion in articulation is analyzed.2. Chaos analysis of speechUsing sentences of "ki-tsu-tsu-ki-tsu-tsu-ku" and "u-e-o-o-o-u", Lyapunov exponents were calculated. Simultaneously, nasalance was recorded. The subjects were 16 healthy adults and 9 cleft palate patients, including the two patients who displayed obvious velopharyngeal incompetence (VPI). As a result, the following findings were indicated : 1) nasalance scores in the healthy group were very sparse, 2) there was no correlation between nasalance scores and Lyapunov exponents, 3) both nasalance scores and Lyapunov exponents were high in the patients with VPI. This indicated the possibility to raise the precision of diagnosis for velopharyngeal closing function.