To date, the otoscope and ophthalmoscope represent the main tools that are compact and fast enough to be used in a primary care setting for imaging the ear canal and features of the eye, respectively. Unfortunately, they are limited to visualization of tissue surfaces only and can miss critical health problems deeper within the tissue. Recognizing that optical coherence tomography (OCT) imaging can provide both two-dimensional (2D) and 3D cross-sectional tissue analysis, scientists at the University of Illinois at Urbana-Champaign, the Beckman Institute for Advanced Science and Technology (Urbana, IL), Kyungpook National University (Daegu, Korea), and Blue Highway (Syracuse, NY) have developed a handheld OCT scanner particularly suited for primary care diagnosis.
The four-port fiber-optic Michelson-interferometer-based spectral domain OCT system includes the handheld scanner, 830 nm superluminescent diode light source with 70 nm full width at half maximum for 4 µm axial resolution, and computer/monitor on a 66 × 50 × 94 cm portable cart. Interchangeable lens mounts and galvanometer- or MEMS-mounted mirrors in the scanner head are optimized to image different tissues with a 15 µm transverse resolution and send reflected signals to a custom-designed spectrometer for analysis at a rate of 70,422 axial scans per second (70 frames per second with 1000 axial scans per frame). The less than 12 cm3 handheld OCT scanner successfully imaged the anterior chamber of a rat eye and was able to capture in vivo images of a human retina, cornea, skin, and tympanic membrane, demonstrating its effectiveness in a clinical setting.
Contact Stephen Allen Boppart at [email protected].