Optimization of a lensless digital holographic otoscope system for transient measurements of the human tympanic membrane.
Optimization of a lensless digital holographic otoscope system for transient measurements of the human tympanic membrane.
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DOI：
10.1007/s11340-014-9945-4
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发表时间：
2015-02-01
影响因子：
2.4
通讯作者：
Rosowski JJ
中科院分区：
文献类型：
--
作者：
Dobrev I;Furlong C;Cheng JT;Rosowski JJ
在本文中，我们提出了一种多脉冲双曝光（MPDE）采集方法，用于在全视场中量化人类鼓膜（TM或耳膜）瞬态（即> 10 kHz）声学引起的纳米级位移。该方法利用 TM 位移的几何线性和可重复性，能够使用传统相机进行高速测量（即 <20 fps）。 MPDE 在先前开发的数字全息系统 (DHS) 上实施，以最低的成本增强其测量能力，同时避免高速（即 >50 kfps）相机的空间分辨率和尺寸所施加的限制。据我们所知，目前还没有任何现有系统能够为人类 TM 的研究提供此类功能。高时间（即 >50 kHz）和空间（即 >500k 数据点）分辨率的组合可以同时测量 TM 表面上所有点的时间和频率响应。 MPDE 方法的可重复性和准确性通过激光多普勒振动计 (LDV) 在人造膜和离体人类 TM 上进行验证，这些膜通过尖锐的（即 <100 μs 持续时间）点击声学激发。 DHS 的测量能力通过 MPDE 采集方法得到增强，可以量化 TM 的空间相关运动参数，例如模态频率、时间常数，以及推断局部材料属性。
In this paper, we propose a multi-pulsed double exposure (MPDE) acquisition method to quantify in full-field-of-view the transient (i.e., >10 kHz) acoustically induced nanometer scale displacements of the human tympanic membrane (TM or eardrum). The method takes advantage of the geometrical linearity and repeatability of the TM displacements to enable high-speed measurements with a conventional camera (i.e., <20 fps). The MPDE is implemented on a previously developed digital holographic system (DHS) to enhance its measurement capabilities, at a minimum cost, while avoiding constraints imposed by the spatial resolutions and dimensions of high-speed (i.e., >50 kfps) cameras. To our knowledge, there is currently no existing system to provide such capabilities for the study of the human TM. The combination of high temporal (i.e., >50 kHz) and spatial (i.e., >500k data points) resolutions enables measurements of the temporal and frequency response of all points across the surface of the TM simultaneously. The repeatability and accuracy of the MPDE method are verified against a Laser Doppler Vibrometer (LDV) on both artificial membranes and ex-vivo human TMs that are acoustically excited with a sharp (i.e., <100 μs duration) click. The measuring capabilities of the DHS, enhanced by the MPDE acquisition method, allow for quantification of spatially dependent motion parameters of the TM, such as modal frequencies, time constants, as well as inferring local material properties.