Abstract

Confocal microscopy has been shown to be useful in imaging skin slightly below the junction of the dermis and epidermis. However, the depth of imaging is a significant limitation. We present a novel concept designed both to improve the depth of penetration and to increase the information content of images obtained with a reflectance confocal microscope. Using an approach similar to optoacoustics, we plan to explore the use of laser heating to generate tissue expansion, which will be measured by the microscope. The microscope will incorporate a pulsed heating laser along the same optical path as the imaging laser in order to generate localized heating. This will result in periodic thermal expansion and contraction at the focus. Optical quadrature detection is used to measure the phase of the scattered light, and Doppler techniques will be employed to quantify the thermal expansion. For the purposes of imaging, two lasers of different wavelengths will be needed to resolve phase ambiguities in the expansion measurement. The motion resulting from thermal expansion will provide additional discrimination against multiply scattered light. It will also provide a measurement of a mechanical parameter, the coefficient of thermal expansion, which may aid in the characterization of different types of tissue.

Notes

Poster presented at the 2006 Validating TestBED and Research Posters on Real World Problems for I-PLUS Development Conference

Keywords

Laser, epidermis, optoacoustics, Doppler

Subject Categories

Confocal microscopy, Imaging systems, Epidermis - Imaging

Disciplines

Bioimaging and biomedical optics

Publisher

Bernard M. Gordon Center for Subsurface Sensing and Imaging Systems (Gordon-CenSSIS)

Publication Date

10-2006

Rights Holder

Bernard M. Gordon Center for Subsurface Sensing and Imaging Systems (Gordon-CenSSIS)


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