MEMS micromirror integrated endoscopic probe for optical coherence tomography bioimaging

A prototype of an optical coherence tomography (OCT) bioimaging endoscopic probe utilizing a MEMS micromirror as the light beam manipulator has been developed. The MEMS micromirror and the silicon optical bench (SiOB) assembly are enclosed within a biocompatible, transparent and waterproof polycarbonate tube equipped with toroidal-lens for in vivo diagnostic applications. The effects of the curvatures of the mirror platform and the housing on the optical behavior of the OCT probe have been discussed. The toroidal-lens embedded catheter design is proposed to reduce the cylindrical lens effect induced by the cylindrical shape tube. The two-axis scanning micromirror is driven by four independent electrothermal bimorph actuators at a driving voltage of less than 2 V to produce a tilt angle of 11°. High resolution OCT images of the skin tissue from the hind leg of a mouse can be obtained by integrating the MEMS micromirror probe with a commercially available OCT system.