title: Handheld, rapidly switchable, anterior/posterior segment swept source optical coherence tomography probe.
abstract: We describe the first handheld, swept source optical coherence tomography (SSOCT) system capable of imaging both the anterior and posterior segments of the eye in rapid succession. A single 2D microelectromechanical systems (MEMS) scanner was utilized for both imaging modes, and the optical paths for each imaging mode were optimized for their respective application using a combination of commercial and custom optics. The system has a working distance of 26.1 mm and a measured axial resolution of 8 μm (in air). In posterior segment mode, the design has a lateral resolution of 9 μm, 7.4 mm imaging depth range (in air), 4.9 mm 6dB fall-off range (in air), and peak sensitivity of 103 dB over a 22° field of view (FOV). In anterior segment mode, the design has a lateral resolution of 24 μm, imaging depth range of 7.4 mm (in air), 6dB fall-off range of 4.5 mm (in air), depth-of-focus of 3.6 mm, and a peak sensitivity of 99 dB over a 17.5 mm FOV. In addition, the probe includes a wide-field iris imaging system to simplify alignment. A fold mirror assembly actuated by a bi-stable rotary solenoid was used to switch between anterior and posterior segment imaging modes, and a miniature motorized translation stage was used to adjust the objective lens position to correct for patient refraction between -12.6 and + 9.9 D. The entire probe weighs less than 630 g with a form factor of 20.3 x 9.5 x 8.8 cm. Healthy volunteers were imaged to illustrate imaging performance.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
authors.forename: Derek
authors.initials: D
authors.lastname: Nankivil
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
authors.forename: Gar
authors.initials: G
authors.lastname: Waterman
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
authors.forename: Francesco
authors.initials: F
authors.lastname: LaRocca
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
authors.forename: Brenton
authors.initials: B
authors.lastname: Keller
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, NC, 27710, USA.
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Kuo
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA ; Department of Ophthalmology, Duke University Medical Center, Durham, NC, 27710, USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Izatt
keywords: (080.3620) Lens system design; (110.4500) Optical coherence tomography; (170.0110) Imaging systems; (170.4460) Ophthalmic optics and devices; (170.4470) Ophthalmology; (170.5755) Retina scanning