Vibration measurement of the tympanic membrane using electronic speckle pattern interferometry

虽然已有一些鼓膜振动测量技术，但其对振动幅值的灵敏度较差，且测量时需要较高的声压级。因此，它们不适合临床应用。因此，本研究利用时间平均电子散斑干涉法、激光注入电流直接调制正弦相位调制技术和数字图像处理技术，尝试开发一套鼓膜小振动测量系统。然后，用该系统测量了豚鼠鼓膜的振动响应。本研究结果表明，即使在较低的刺激水平（如70dB SPL）下，振动幅值也可以在纳米量级上检测到。因此，本小组开发的系统具有临床应用的潜力。

Although some techniques for the measurement of tympanic membrane vibration have alreaby been existed, their sensitivity to vibration amplitude is poor, and they need high SPL for the measurement. As a result, they are not suitable for the clinical application. Therefore, in this study, using the time-averaged electronic speckle pattern interferometry, the sinusoidal phase modulation technique by a direct modulation of laser injection current and the digital image processing technique an attempt is made to develop a system for the measurement of tympanic membrane small vibration. Then, the vibratory responses of guinea pig tympanic membranes are measured by this system. The results of this study indicate that the vibration amplitude is detectable in nanometer order even when the stimulus level is small, e.g. 70dB SPL.Consequently, the system developed by our group has a potential of the clinical application.