Experimental study for quantification of traveling mucosal wave of the vocal fold

声带振动实质上是声带下表面产生的粘膜行波的传播。粘膜行波速度（TWV）可定量评价粘膜波。在第一年，我们研究了发音过程中TWV与垂直声带运动速度（Vvt）的关系。VVT的测量与激光多普勒测振仪（LDV）的帮助下，而TWV的同时通过测量的持续时间的行波之间的时间移动放置在声带上的一个已知的距离的两个标记获得。TWV与VVT有显著的相关性（相关系数为0.90 ~ 0.98），提示VVT和TWV都是粘膜行波的有用指标。第二年，我们在三种情况下同时记录声带的垂直和水平运动。垂直运动用LDV获得，水平运动用photoglottography（PGG）测量。将这两种运动结合起来，绘制发声过程中声带的Lissajous轨迹。当气流增加时，两个方向上的振幅增加。在犬喉中，甲杓肌收缩在喉开放初期引起喉的垂直方向增大，在喉开放后期引起喉的水平方向增大。另一方面，在人类喉，垂直扩大是突出的，而水平振幅变得更小。这种差异可能是由于人喉固有层较薄，声带肌较厚所致。

Vocal fold vibration is essentially propagation of mucosal traveling wave arising from the lower surface of the vocal fold. Velocity of the mucosal traveling wave (TWV) could quatitatively assess the mucosal wave. In the first year, We examined relationship between TWV and velocity of vertical vocal fold movement (Vvt) during phonation. Vvt was measured with the aid of laser doopler vibrometer (LDV) while TWV was simultaneously obtained by measuring the duration of time the traveling wave moved between two markers placed on the vocal fold with a known distance. TWV and Vvt had a significantly high correlation (correlation coefficient : 0.90 to 0.98), which suggested that Vvt as well as TWV is an useful index of mucosal traveling wave. In the second year, we recorded vertical and horizontal movements of thc vocal fold simultaneously under three conditions. Vertical movement was obtained using LDV and horizontal movement was measured with the aid of photoglottography (PGG). The two movements were combined to draw Lissajous trajectories of the vocal fold during phonation. Amplitude in the two direction increased when airflow was increased. In the canine larynx, thyroarytenoid contraction caused vertical enlargement during initial stage of thc opening phase and caused horizontal enlargement during late stage of the opening phase. On the other hand, in the human larynx, vertical enlargement was prominent while horizontal amplitude became even smaller. The difference may be ascribed to relatively thin lamina propria and thick vocalis muscle in thc human larynx.