Measurement of Vibrating Tympanic Membrane in an In Vivo Mouse Model Using Doppler Optical Coherence Tomography.

Jeon Jeon,Kim Kim

doi:10.3390/jimaging5090074

Abstract

Optical coherence tomography (OCT) has a micro-resolution with a penetration depth of about 2 mm and field of view of about 10 mm. This makes OCT well suited for analyzing the anatomical and internal structural assessment of the middle ear. To study the vibratory motion of the tympanic membrane (TM) and its internal structure, we developed a phase-resolved Doppler OCT system using Kasai’s autocorrelation algorithm. Doppler optical coherence tomography is a powerful imaging tool which can offer the micro-vibratory measurement of the tympanic membrane and obtain the micrometer-resolved cross-sectional images of the sample in real-time. To observe the relative vibratory motion of individual sections (malleus, thick regions, and the thin regions of the tympanic membrane) of the tympanic membrane in respect to auditory signals, we designed an experimental study for measuring the difference in Doppler phase shift for frequencies varying from 1 to 8 kHz which were given as external stimuli to the middle ear of a small animal model. Malleus is the very first interconnecting region between the TM and cochlea. In our proposed study, we observed that the maximum change in Doppler phase shift was seen for the 4 kHz acoustic stimulus in the malleus, the thick regions, and in the thin regions of the tympanic membrane. In particular, the vibration signals were higher in the malleus in comparison to the tympanic membrane.

Highlights

In the field of otolaryngology, some of the most widely known diseases are effusion of otitis media, noise induced hearing loss, acute and chronic suppurative otitis media, Meniere’s disease, and perforated eardrum [1,2]
The Doppler optical coherence tomography (DOCT) images are shown for the measurements made in the absence of sound and at 1, 2, 4, and 8 kHz
The malleus and the thick and thin sections of the tympanic membrane (TM) were confirmed by the Optical coherence tomography (OCT) image, and the end of the cochlea under the TM was confirmed

Summary

Introduction

In the field of otolaryngology, some of the most widely known diseases are effusion of otitis media, noise induced hearing loss, acute and chronic suppurative otitis media, Meniere’s disease, and perforated eardrum [1,2]. The LDV method has a low signal-to-noise ratio, and cannot provide high-resolution depth profile information due to the long coherence length of the laser. To overcome these shortcomings, we proposed a Doppler optical coherence tomography (DOCT). We have proposed aaDOCT autocorrelation method to to measure the vibration tendency of TM in accordance with pure tone audio signals. [31,32]

Materials

Schematic

Results

Conclusion