Research

Precision microscanning

Tissue microscopy needs precision scanning, which is difficult to achieve in a small, minimally invasive package. We employ micro-actuators and miniaturized designs to realize 2-dimensional laser scanning in side-view or forward-view, compatible with any flying-spot microscopy.

K. Liang*, Z. Wang*, O.O. Ahsen, H.-C. Lee, B.M. Potsaid, V. Jayaraman, A. Cable, H. Mashimo, X. Li, and J.G. Fujimoto, “Cycloid scanning for wide field optical coherence tomography endomicroscopy and angiography in vivo,” Optica 5, 36-43 (2018)
K. Liang, O.O. Ahsen, Z. Wang, H.-C. Lee, W. Liang, B.M. Potsaid, T.-H. Tsai, M.G. Giacomelli, V. Jayaraman, H. Mashimo, X. Li, and J.G. Fujimoto, “Endoscopic forward-viewing optical coherence tomography and angiography with MHz swept source,” Opt. Lett. 42, 3193-3196 (2017)
K. Liang, G. Traverso, H.-C. Lee, O.O. Ahsen, Z. Wang, B. Potsaid, M. Giacomelli, V. Jayaraman, R. Barman, A. Cable, H. Mashimo, R. Langer, and J.G. Fujimoto, “Ultrahigh speed en face OCT capsule for endoscopic imaging,” Biomed. Opt. Express 6, 1146-1163 (2015)

High speed endoscopic microscopy

Endoscopy is complex and requires anesthesia. Diagnosis requires microscopic assessment of the organ surface. Ultrafast Optical Coherence Tomography at millions of axial scans/sec, combined with a micromotor scanning tethered capsule, delivers gigantic fields-of-view in the human esophagus without needing anesthesia.

K. Liang, O.O. Ahsen, A. Murphy, J. Zhang, T.H. Nguyen, B.M. Potsaid, M. Figueiredo, Q. Huang, H. Mashimo, and J.G. Fujimoto, “Tethered capsule en face optical coherence tomography for imaging Barrett’s oesophagus in unsedated patients,” BMJ Open Gastroenterology 7 (2020)
K. Liang, O.O. Ahsen, H.-C. Lee, Z. Wang, B.M. Potsaid, M. Figueiredo, V. Jayaraman, A. Cable, Q. Huang, H. Mashimo, and J.G. Fujimoto, “Volumetric mapping of Barrett’s esophagus and dysplasia with en face Optical Coherence Tomography tethered capsule,” American Journal of Gastroenterology 111 (2016)

Computational imaging with AI

The optical resolution and imaging performance of endoscopic microscopy can be limited by size contraints of optical components. Neural networks can be trained to learn from high resolution images, to computationally enhance low resolution data.

K. Liang, X. Liu, S. Chen, J. Xie, W.Q. Lee, L. Liu, H.K. Lee, “Resolution enhancement and realistic speckle recovery with generative adversarial modeling of micro-optical coherence tomography,” Biomed. Opt. Express accepted (2020)