Assessment of middle ear structure and function with optical coherence tomography.

Area of Science:

• Biomedical Engineering
• Otolaryngology
• Medical Imaging

Background:

• Current clinical tests for middle ear (ME) injuries and conductive hearing loss (CHL) are time-consuming and expensive.
• Existing methods lack noninvasive, real-time assessment of both ME structure and function.
• Optical Coherence Tomography (OCT) offers structural and functional evaluation but is underutilized in audiology.

Purpose of the Study:

• To adapt a commercial Spectral-Domain OCT (SD-OCT) system for evaluating human ME anatomy.
• To measure sound-evoked vibrations of the tympanic membrane (TM) and ossicles using SD-OCT.
• To assess the potential of SD-OCT for diagnosing ME conditions causing CHL.

Main Methods:

• Utilized a commercial SD-OCT system on fresh human temporal bones.
• Captured high-resolution 3D images of the middle ear.
• Employed phase-sensitive vibrometry, with software adaptations, to measure sound-induced vibrations of the TM and ossicles.

Main Results:

• Generated 3D thickness maps of the tympanic membrane.
• Observed multiple modes of TM vibration, increasing in complexity with frequency.
• Measured vibrations transmitted through the TM to the incus, quantifying sound transmission.
• Successfully quantified middle ear sound transmission, a key metric for CHL assessment.

Conclusions:

• Adapted SD-OCT successfully visualizes human ME anatomy and function.
• SD-OCT demonstrates potential for revolutionizing point-of-care assessment of ME pathologies.
• This technology can identify ME disruptions leading to CHL, which are often missed by otoscopy.