Endoscopic functional fourier domain common-path optical coherence tomography for microsurgery

A single-arm interferometer-based optical coherence tomography (OCT) system known as common-path OCT (CP-OCT) is rapidly progressing towards practical application. Due in part to the simplicity and robustness of its design, Fourier domain CP-OCT (FD-CP-OCT) offers advantages in many endoscopic sensing and imaging applications. FD-CP-OCT uses simple, interchangeable fiber optic probes that are easily integrated into small and delicate surgical tools. The system is capable of providing not only high-resolution imaging but also optical sensing. Here, we report progress towards practical application of FD-CP-OCT in the setting of delicate microsurgical procedures such as intraocular retinal surgery. To meet the challenges presented by the microsurgical requirements of these procedures, we have developed and initiated the validation of applicable fiber optic probes. By integrating these probes into our developing imaging system, we have obtained high-resolution OCT images and have also completed a demonstration of their potential sensing capabilities. Specifically, we utilize multiple superluminescent diodes to demonstrate sub-3-μm axial resolution in water; we propose a technique to quantitatively evaluate the spatial distribution of oxygen saturation levels in tissue; and we present evidence supportive of the technology's surface sensing and tool guidance potential by demonstrating topological and motion compensation capabilities.