fiber

Determining the optical scattering and absorption properties of tissue for diagnostic and therapeutic applications is of interest in medicine. Most reflectance techniques rely on light distribution information over a large area (>1cm2) and use separate illumination and collection fibers with a separation distance of several millimeters or have mixed fiber bundles with source and emission fibers randomly arranged from 0.1-1 mm from each other.

At least two studies on devices with separate source and detector fibers have shown that the mean photon penetration depth increases as the square root of the separation between source and detector fibers either spatially or temporally. Source-detector fiber devices sample relatively large volumes, because of the separation between the fibers. Though effort has been made to minimize the sampling volume using small source-detector separations, little work has been done on photon penetration depths when the source fiber is also used to collect backscattered photons. Since large sampling volumes are less likely to be homogenous, we are developing a device that acquires information from small volumes of tissue (<1 1mm3) by using the same fiber for both source and detector.

We are applying this technique to oral and skin cancer detection. We are particularly interested in make fiber-based needle sensors and incorporating recent work on differential path-length spectroscopy by Amelink et al.

2006

T. Moffitt, Y.-C. Chen, S. A. Prahl, "Preparation and characterization of polyurethane optical phantoms," Journal of Biomedical Optics, 11, 041103 (2006).

2005

T. P. Moffitt, "Light Transport in Polymers for Optical Sensing and Photopolymerization", Oregon Health & Science University, (2005).

T. P. Moffitt, S. A. Prahl, "The Influence of Optical Scattering upon Differential Reflection Measurements with Side-By-Side Optical Fibers," Proceedings of the Oregon Academy of Science, 41, 69 (2005 abstract only).

T. P. Moffitt, S. A. Prahl, "Implementation of a Real-time Differential Pathlength Spectrometer System," SPIE Saratov Fall Meeting 2004: Optical Technologies in Biophysics & Medicine VI, 5771, 267-275 (2005).

2004

T. P. Moffitt, S. A. Prahl, "Sensitivity of a Reflection Mode Optical Fiber System to the Orientation of Tissue Fiber within In Vitro Tissues," Proceedings of the Oregon Academy of Science, 40, 52 (2004 abstract only).

2003

T. P. Moffitt, S. A. Prahl, "A Dual Sized-Fiber Reflection Probe for Decreased Measurement Variability," Proceedings of the Oregon Academy of Science, 39, 40 (2003 abstract only).

T. P. Moffitt, S. A. Prahl, "The Specular Reflection Problem with a Single Fiber for Emission and Collection," SPIE Saratov Fall Meeting 2002: Optical Technologies in Biophysics and Medicine IV, 5068, (2003).

2002

T. P. Moffitt, S. A. Prahl, "Determining the Reduced Scattering of Skin in Vivo Using Sized-Fiber Reflectometry," SPIE Proceedings on Optical Biopsy IV, 4613, 254-263 (2002).

T. P. Moffitt, D. A. Baker, S. J. Kirkpatrick, S. A. Prahl, "Mechanical Properties of Repaired Liver Using an Argon Beam Coagulator with Albumin," SPIE Proceedings on Lasers in Surgery: Advanced Characterization, Therapeutics, and Systems XII, 4609, 178-185 (2002).

T. P. Moffitt, D. Baker, S. J. Kirkpatrick, S. A. Prahl, "Mechanical Properties of Coagulated Albumin and Failure Mechanisms of Liver Repaired Using an Argon Beam Coagulator with Albumin," J. Biomedical Materials Research (Applied Biomaterials), 63, 722-728 (2002).

T. P. Moffitt, S. A. Prahl, "In Vivo Optical Properties of Skin Using Sized-Fiber Reflectometry," Proceedings of the Oregon Academy of Science, 38, 47 (2002 abstract only).

T. P. Moffitt, S. A. Prahl, "In Vivo Determination of Optical Properties of Skin in the UV Using Sized-Fiber Reflectometry," Laser Med. Surg., S14, 3 (2002 abstract only).

2001

T. P. Moffitt, S. A. Prahl, "Sized-Fiber Reflectometry for Measuring Local Optical Properties," IEEE JSTQE, 7, 952-958 (2001).

T. Moffitt, S. Prahl, "Sampling Depths of the Sized-Fiber Technique," Proceedings of the Oregon Academy of Science, 37, 65 (2001 abstract only).

2000

T. P. Moffitt, S. A. Prahl, "In-Vivo Sized-Fiber Spectroscopy," SPIE Proceedings on Optical Biopsy III, 3917, 225-231 (2000).

T. P. Moffitt, S. A. Prahl, "Sized-Fiber Spectroscopy," Proceedings of the Oregon Academy of Science, 36, 54 (2000 abstract only).