Low Optical Coherence Interferometry for the Cochlea

本课题的主要目标是研制一种测量活体豚鼠Corti器官振动的仪器。该仪器将利用光学相干地形图（OCT）和低光学相干干涉仪的原理来可视化基底膜和器官的内部结构，并分别测量它们在耳声刺激下引起的振动位移。OCT干涉仪将利用来自两个不同的超发光二极管的光耦合到一个共同的光纤中，允许同时测量基底膜和Corti器官网状层成分的振动位移。该提案的前两个目标是：1)开发一种双源（双通道）OCT干涉仪，用于测量器官中的单个位置；2)开发一种扫描OCT干涉仪，用于测量器官的三维Corti运动。OCT干涉仪的优点是不需要在耳组织上放置任何反射物体（如镜子或珠子），并且具有高光学空间分辨率（特别是在沿光轴的“z”方向），允许对Corti组织振动器官进行精确的幅度和相位测量。第三个目的是利用OCT仪器测量豚鼠基底膜和网状板的三维振动模式。这些数据将为Corti器官的微观机械运动和耳蜗放大过程的机制提供重要的新见解，其中外毛细胞被认为是积极增强Corti器官运动的。

The major goal in this proposal is to develop and instrument to measure the vibration of the organ of Corti in the living guinea pig. The instrument will use the principles of optical coherence topography (OCT) and low optical coherence interferometer to visualize the basilar membrane and the internal structures of the organ and to measure their vibratory displacements induced by sound stimulation of the ear, respectively. The OCT interferometer will utilize light from two different super luminescent diodes coupled into a common optical fiber, allowing simultaneous measurement of the vibratory displacement of the basilar membrane and the reticular lamina components of the organ of Corti. The first two aims of the proposal are 1) to develop a dual source (two channels) OCT interferometer for measurements at a single location in the organ and 2) to develop a scanning OCT interferometer to measure organ of Corti motion in three dimensions. OCT interferometer will have the advantage of not requiring any reflective objects (such as mirrors or beads) to be placed on the ear tissues and will have high optical spatial resolution (particularly in the 'z' direction along the optical axis) allowing accurate magnitude and phase measurements of organ of Corti tissue vibration. The third aim is to use the OCT instrument to measure the three-dimensional vibration pattern of the basilar membrane and reticular lamina in the guinea pig. The data will give critical new insight into the micro mechanical motion of the organ of Corti and on the mechanism of the cochlear amplification process whereby outer hair cells are thought to be actively enhancing organ of Corti motion.