Endoscopic optical coherence tomography device for forward imaging with broad field of view

Abstract

One current challenge of studying human tympanic membranes (TM) with optical coherence tomography (OCT) is the implementation of optics that avoid direct contact with the inflamed tissue. At the moment, no commercial device is available. We report an optics design for contactless forward imaging endoscopic optical coherence tomography (EOCT) with a large working distance (WD) and a broad field of view (FOV) by restricting the overall diameter of the probe to be small (3.5 mm), ensuring a sufficient numerical aperture. Our system uses a gradient-index (GRIN) relay lens and a GRIN objective lens, and executes a fan-shaped optical scanning pattern. The WD and FOV can be adjusted by manually changing the distance between the triplet and the GRIN relay lens. The measured lateral resolution is ∼28 μm at a WD of 10 mm with a FOV of 10 mm. Additionally, a camera and an illumination beam path were implemented within the probe for image guidance during investigations of the TM. We demonstrated the performance of the EOCT design by 3-D imaging of a human TM ex vivo and in vivo with a k-linear spectral domain OCT system.

Investigation of the human tympanic membrane oscillation ex vivo by Doppler optical coherence tomography

“…Due to the high-speed measurement principle, no significant problems are expected under in vivo conditions, where motion artifacts caused by a test person will appear with low frequency. Therefore, the presented method is regarded as a promising technique for in vivo investigations, for instance by utilizing an endoscopic setup [25].…”

Improved Imaging of Magnetically Labeled Cells Using Rotational Magnetomotive Optical Coherence Tomography

“…Light microscopy and laser speckle images are detected by a video camera (1.3 megapixel monochrome CMOS, Sumix SMX-M71M, Sumix, Oceanside, CA, USA) mounted on the microscope. The microscope-integrated OCT probe is fiber-coupled to a self-developed spectral domain OCT system operating at 880 nm [10]. This system is equipped with a superluminescent diode (Exalos EXS8810-2411, Exalos AG, Schlieren, Switzerland) with a center wavelength of 876 nm and a spectral bandwidth of 64 nm (FWHM), and a linear-in-wavenumber spectrometer.…”

Miniature probe for dual‐modality photoacoustic microscopy and white‐light microscopy for image guidance: A prototype toward an endoscope

“…In this scheme, WLE can be used for image guidance during operation of other endoscopic imaging modalities as well as providing complementary information. For example, WLE was implemented within a 3.5‐mm optical coherence tomography probe for image guidance during imaging of human tympanic membranes . Besides, integrated WLE and fluorescence endoscopy was utilized to provide complementary information for tumor studies .…”