Methodology for Assessment of Structural Vibrations by Spectral Domain Optical Coherence Tomography

摘要

Clinical diagnosis of cochlear dysfunction typically remains incomplete due to a lack of proper diagnostic methods. Medical imaging modalities can only detect gross changes in the cochlea, and non-invasive in vivo cochlear measurements are scarce. As a result, extensive efforts have been made to adapt optical coherence tomography (OCT) techniques to analyze and study the cochlea. Herein, we detail the methods for measuring vibration using OCT. We used spectral domain OCT with ～950 nm as the center wavelength and a bandwidth of ～80 nm. The custom spectrometer used was based on a high speed line scan camera which is capable of line rates up to 28 kHz. The signal-to-noise ratio of the system was ～90 dB. The data collection and processing software was written in Lab VIEW and MATLAB. We tested whether streaming directly from the camera, writing the data to multiple hard drives in the RAID-0 configuration, and processing using the GPU shortened experiment times. We then analyzed the A-line phase noise over several hundred milliseconds and growth curves from a piezoelectric element. We believe this is the first step towards a diagnostic device which generates vibration information of cochlear structures.