USC applies OCT to ear disease diagnosis

27 Aug 2024

Incorporating OCT into traditional otoscope improves views of eardrum and middle ear.

Diagnosis of ear disease has traditionally involved use of an otoscope, a straightforward device incorporating magnifying optics and a light source to allow clinicians to examine the ear canal and ear drum, or tympanic membrane (TM).

But otoscopes give only limited views, not always providing the clear and detailed imaging of the TM that would allow rigorous diagnosis of disease.

A project at the University of Southern California (USC) has now developed a new device that could improve the situation, by incorporating OCT into a traditional otoscope. The work was published in Journal of Biomedical Optics.

"Traditional otoscopes only allow for a superficial examination of the TM, often missing deeper pathologies," commented USC.

"In contrast, the OCT otoscope combines the familiar otoscopic view with high-resolution imaging of the inner structures of the TM and middle ear (ME), offering a clearer and more comprehensive view, which can help in diagnosing conditions that were previously missed."

Putting OCT into otoscopes has been an attractive prospect for some time, with Illinois-based PhotoniCare winning the 2018 SPIE Startup Challenge for a similar project. In 2020 that company announced a total of $7 million in Series A financing and NIH support for its OtoSight Middle Ear Scope, which is moving towards commercialization.

The USC team, under Brian Applegate at the university's Applegate Research Lab, said that it wanted its system to have a significantly smaller physical footprint than existing platforms, to allow for portable hand-held imaging that is intuitive for clinicians to use in a manner similar to an otoscope.

A design incorporating a dual-axes MEMS mirror and a high-pass dichroic mirror achieved a small device footprint, and the device optics were designed to allow a large field of view, 7.4 millimeters at the focal plane through the limited aperture of the middle ear according to the team's paper. Lateral and axial resolutions of 38 and 33.4 microns were ultimately achieved.

Transforming the way ear health is assessed

During a clinical study at USC Keck Hospital, the researchers tested the OCT otoscope on over 100 patients presenting a number of different pathologies.

The new imaging system identified several critical conditions that were not apparent through existing methods, according to USC, and was used for monitoring myringitis, tympanic membrane perforation healing, retraction pockets, and subsurface scarring or air pockets.

"The improved imaging speed and field of view have aided in the collection of images that provide information not readily available from a traditional otoscope examination," noted the team.

Since the OCT otoscope's design allows for easy integration into existing clinical workflows, with a user interface controlled by a foot pedal for image acquisition, USC anticipates that the device should be readily adopted by clinicians, providing them with a powerful new tool for diagnosing and managing TM and ME disorders.

"This advance marks a significant step forward in otolaryngology, enhancing the precision of ear examinations and potentially leading to better outcomes for patients suffering from hearing loss due to ear pathologies," said USC. "As this technology becomes more widely available, it promises to transform the way ear health is assessed and treated, offering hope for more accurate diagnoses and improved patient care."