Master's Thesis Defense - Wavelength Effects on In Vivo Confocal Scanning Laser Microscopy
Date: November 9, 2007
Time: 11:00 AM
Location: Bossone Research Enterprise Center, Room: 709
Michael A. Luedtke
Advisor: Elisabeth Papazoglou, Ph.D.
The ability to optically section live biological tissue in vivo with laser light and observe reflections from single scattering events is made possible by in vivo confocal scanning laser microscopy (CSLM). In this thesis the effects of using CSLM at different wavelengths to image in vivo human skin are reported and analyzed. Upon changing the wavelength of incident light, differences are observed while certain features are maintained. This work attempts to deconvolute differences due to wavelength artifacts from differences revealing important skin microstructure. To illustrate the differences due to the optical set up and wavelength changes, in vitro experiments were developed to characterize and model the instrumentation and tissue samples imaged. To further review and illustrate the differences in wavelengths a human test was conducted with 8 subjects to determine qualitative and quantitative differences observed at 405nm, 785nm and 830nm wavelengths from different CSLMs on live human tissue. From these experiments it was found that differences do exist among the selected wavelengths. This was surprising due to the proximity of the near infrared 785nm and 830nm wavelengths.
Future work using 405nm, 785nm, 830nm and lasers on a single CSLM with identical optics in a single experimental setup will enable confirmation of our findings. In conclusion the laser wavelength used in CSLM is important even in reflectance imaging to properly understanding and resolve different biological structures within human skin.
The Bossone Research Enterprise Center is located at the corner of 32nd and Market Streets.