Development of a high performance reduced cost OCT Otoscope

The method physicians use to examine the tympanic membrane (TM) and middle ear (ME) in clinical settings
has remained largely unchanged for the past 150 years. Typically, a speculum is inserted into the ear canal, with
the physician using a lens for magnified viewing and a light source for illumination through the speculum's
opening. The most widely used speculum today was designed by A. Hartmann in Berlin in 1881. Since then,
advancements have been made in lighting and optics, but the basic technique has seen little innovation, except
for the addition of a digital camera for video otoscopy. Routine otoscopic imaging provides information about
the TM's surface, but it lacks depth perception because only a monocular view is possible. If the membrane is
transparent, the underlying ossicles may be visible and used to estimate the TM's depth. However, obtaining a
quantitative three-dimensional image is not possible, and in many pathological cases, the TM is opaque,
obstructing the view of the ossicular chain. The subjective nature of the interpretation, which varies with the
physician's experience, can lead to misdiagnoses or delayed diagnoses. While modern imaging techniques like
MRI and CT are available, they are rarely used because of their high cost, the need for a follow-up appointment,
and their relatively poor resolution of the TM and ear.
We have developed a handheld OCT otoscope with a wide field of view, capable of imaging the TM and ME,
extending down to the cochlear promontory. Our latest device features an improved form factor, an even wider
field of view covering almost the entire TM, and faster line rates, making it less susceptible to motion artifact and
highly suitable for clinical use.
In this recent study, we presented cases where our device provided important diagnostic information that could
not be obtained with traditional imaging techniques. Additionally, we have demonstrated that TM thickness can
be utilized to characterize and differentiate various pathologies. We also developed an algorithm to assess
symmetry between the right and left ears of healthy volunteers, revealing a high degree of symmetry. This finding
suggests that symmetry could serve as a metric for identifying early signs of TM and ME pathology. These results
further validate the potential of OCT as a valuable clinical tool, offering clinicians enhanced capabilities for the
early detection and management of various TM and ME pathologies.
In this phase 1 proposal we will redevelop the OCT otoscope as a prototype commercial device, making
improvements in the design while incorporating cost saving measures that reduces the overall materials cost by
44%. The new device will then be validated against our most recent research device to verify similar or better
performance in healthy volunteers and patients with TM and/or ME pathology.

Grant Number: 1R41DC022812-01
NIH Institute/Center: NIH
Principal Investigator: Brian Applegate