Optical Technologies for Medicine and Biology(From Optical Bench to Bedside)
  • Beop-Min Kim Ph.D
  • SLS Colloquia / May 31th 04:00 pm / BLDG110 ROOM N104
Abstract

Optical imaging uses light for visualization of molecules, cells, and tissues in living organism. Scientists have investigated ways to overcome the intrinsic limitations of optical imaging such as shallow light penetration and spatial resolution. As a result, various optical imaging techniques have been introduced both in biological laboratory and clinical settings. At the KU-Biomedical Optics Laboratory, we build various optical imaging technologies that are useful for monitoring cell-level activities and structural or functional imaging of biological tissues and organs such as brain.

Starting from the technology for the smallest object imaging, we constructed a 3D label free traction microscope based on second harmonic generation (SHG) and two photon fluorescence (TPF) which can quantify the strains caused by a human mesenchymal stem cells in collagen-based extra cellular matrix (ECM).

Optical coherence tomography (OCT) has been commercialized in the field of ophthalmology and cardiology. It is currently being tested for feasibility in cancer detection, dermatology and image-guided therapy. We have employed an ultrafast optical switch along with several new techniques to fully expand the OCT imaging range in ophthalmology including entire anterior part and the retina, which we call a whole eye imaging. Also, a new angiographic imaging technique for the retinal and choroidal layer is discussed.

Near Infra-red spectroscopy (NIRS) is a neuroimaging technique which uses near-infrared light source in the 700-1000 nm range and enables to detect hemodynamic changes (i.e., oxygenated hemoglobin, deoxygenated hemoglobin, blood volume) as a response to various brain processes. In this study, we developed a new, portable, prefrontal fNIRS system which has 12 light sources, 15 detectors and 108 channels with a sampling rate of 5 Hz. It has been widely used in various applications involving brain hemodynamics changes. Examples include characterizing sleep stages, clinical diagnosis of orthostatic intolerance and neurofeedback. We also show that the NIRS can be applied to monitoring brain hemodynamics of freely moving mice.

Intraoperative near infrared fluorescence imaging system has been developed for minimal resection lung cancer surgery. The system of both thoracotomy and thoracoscopic versions provides merged color and NIR fluorescence images simultaneously. The system overcomes poor sensitivity to NIR fluorescence signals aided by custom software in real-time. We successfully conducted sentinel lymph node diagnosis, segmentectomy and cancer margin detection using indocyanine green (ICG) in various porcine organs.