Joseph A. Izatt

Imaging of pediatric pathology in the intensive care nursery using a custom handheld, ultra-compact, swept-source OCT probe (Conference Presentation)

OCT is the gold standard for clinical diagnosis and treatment of many retinal diseases. Most clinical OCT systems are table top systems that can only image seated, compliant patients that can fixate. These systems are incapable of imaging several important patient populations including bedridden patients and infants. In this work we describe the use of a custom, light weight, handheld OCT probe based on a high speed swept source engine for imaging in the intensive care nursery. The probe uses custom optics, optomechanics, and a MEMS mirror to achieve a weight of only 211g. The portability and imaging speed of this probe facilitates repeat, volumetric, bedside imaging in a challenging imaging environment. To date we have imaged over 43 pre-term and full-term infants in the intensive care nursery, with some patients having up to 15 imaging sessions starting at 30 weeks post menstrual age. Volumetric OCT enables visualization of the complex 3D structures associated with retinal pathology that is unavailable to slower, B-scan based probes. Repeat imaging shows the development of both normal and diseased retinal structures. We believe that OCT imaging of these infants will reveal retinal abnormalities, enable further study of pediatric retinal diseases, and allow for better management and prediction of future visual outcomes.

Ultrahigh-resolution robust needle probe for high-speed interstitial OCT imaging at 800 nm (Conference Presentation)

We report an anastigmatic needle probe made with fiber-optic ball lens for high-speed circumferential interstitial OCT imaging. The anastigmatic design affords a high transverse resolution of ~11.9 µm. The improved mechanical design enables a robust circumferential scanning speed up to ~26.8 frames per second. The miniaturized needle probe has an outer diameter of ~620 µm including the encasing metal guard and glass microcapillary. The performance of the anastigmatic OCT needle was demonstrated by imaging rat belly tissues and rat liver ex vivo with a 1300-nm swept-source OCT (SSOCT) system. The preliminary results suggest the potential of the needle probe for minimally invasive interstitial imaging and image-guided biopsy.

Ultrahigh-resolution tethered OCT endoscopic capsule at 800 nm (Conference Presentation)

We present an ultrahigh-resolution, distal-scanning OCT capsule operating at 800 nm targeted towards gastrointestinal tract imaging. Among many others, one significant challenge in the 800-nm OCT capsule technology is the severe chromatic aberration in the imaging optics of the capsule. By combining commercial miniature lenses and customized diffractive lens, the achromatic focal shift was essentially eliminated (i.e. down to ~1 µm) over a 3dB spectral bandwidth of ~150 nm centered around 825 nm. We have achieved an axial resolution ~2.7 µm. Initial proof-of-concept experiments with ex vivo pig esophagus demonstrated the excellent imaging performance of this 800-nm OCT capsule.