Development of an intracoronary Raman spectroscopy

Atherosclerosis is a leading cause of death in the United States, with 1 in 5 deaths (500,000 annually) attributable to coronary artery disease alone. While the disease processes are not completely understood, it is believed that patient risk depends on a variety of factors including lesion structure, biomechanical behavior, and morphological and chemical composition. Raman spectroscopy, based on spectral analysis of inelastically scattered photons, is a nondestructive technique that yields detailed information about the chemical composition of the sample being interrogated. Intracoronary Raman spectroscopy can be performed via the use of a flexible, small diameter (< 2 mm) optical fiber probe to guide light to and from the arterial wall in situ. The fact that Raman scattering has inherently low signal intensity, combined with the need for a small diameter probe, makes it difficult to develop a probe with sufficient signal-to-noise for robust plaque diagnosis. This thesis addresses two approaches for increasing SNR: increasing Raman signal intensity and optimizing probe design. While most biological applications of Raman spectroscopy have been performed in the "fingerprint" region (Raman shifts between 400 and 1800 cm-1), the high wavenumber region (2700 - 3100 cm-1) offers distinct technical advantages, including increased Raman signal relative to the fluorescent background and potentially less fiber background. However, the high wavenumber region may yield different molecular information and thus have different diagnostic capability. In this thesis, we develop a benchtop Raman system capable of acquiring Raman spectra in both wavenumber regions.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2009

Author dc:creator

• Chau, Alexandra H. (Alexandra Hung), 1980-

Advisor dc:contributor.advisor

• Guillermo J. Tearney and Peter T. So.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/49757

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/49757