Because conventional light endoscopies only look at the exterior of tissue, scientists at the University of Florida have developed an infrared laser powered endoscope that can scan stratified epithelium below the surface. The system uses a mirror hat can pivot at 200 Hz while capturing 3D imagery of potential tumors forming within tissue.
Technology Review reports:
Instead of a tiny camera at the tip, Xie’s [Huikai Xie, associate professor of electrical and computer engineering and director of the UF Biophotonics and Microsystems Laboratory] endoscope is equipped with an infrared scanner and a tiny mirror, which scans tissue layer by layer to provide a three-dimensional image with microscopic resolution. The technique is based on a method called optical coherence tomography (OCT) – as a laser beams through the arm of an OCT scope, it hits tissue, and reflects some light back, while the rest scatters. Different tissues, such as cancer versus normal tissue, reflect light differently. An interferometer measures the reflected light and subtracts the scattered light. Altering the length of the arm alters the depth at which light is directly reflected back, producing images of different layers, which together form a three-dimensional image. The method is similar to ultrasound technology, and is often called “optical ultrasound.”
Xie’s prototype uses a MEMS-based (microelectromechanical system) approach, centered on a tiny, one-by-one-millimeter mirror. Xie and his students designed the mirror with tiny actuators, or mechanical supports, which pivot the mirror. As infrared light beams down the endoscope, the mirror steers the light back and forth, illuminating a slice of tissue. The reflected light bounces back up the endoscope, and is analyzed and depicted on a screen in real time.
More at Technology Review…
Link: University of Florida Biophotonics & Microsystems Laboratory…