Forward-imaging needle-type optical coherence tomography probe with Doppler OCT capability

A forward-imaging needle-type optical coherence tomography  (OCT) probe with Doppler OCT (DOCT) capability has the potential to  solve critical challenges in interventional procedures. A case in point is  stereotactic neurosurgery where probes are advanced into the brain based on predetermined coordinates. In order to address this challenge, we developed a forward-imaging OCT probe (740 μm O.D.) using a gradient-index (GRIN) rod lens that can provide real-time imaging feedback for avoiding at-risk vessels (8 frames/s with 1024 Ascans per frame for OCT/DOCT dual imaging) and guiding the instrument  to specific targets  with  12 μm axial resolution (100 frames/s with 160 Ascans per frame for OCT imaging only). 

Conventional optical imaging of functional activation in the brain is limited to surface structures such as the cerebral cortex. To access subcortical structures and image sensory-evoked neural activity, we designed a needle-based optical system using gradient-index (GRIN) rod lens. We performed voltage-sensitive dye imaging (VSDi) with GRIN rod lens to visualize neural activity evoked in the thalamic barreloids by deflection of whiskers in vivo. 

C.P. Liang, J. Wierwille, T. Moreira, G. Schwartzbauer, M.S. Jafri, C.M. Tang, Y. Chen*, "A Forward-Imaging Needle-Type OCT Probe for Image Guided Stereotactic Procedures," Optics Express, 19, 26283-26294 (2011).
Yu Chen, Fischell Department of Bioengineering