Characterization of an intraluminal differential frequency-domain photoacoustics system
| Autor: | Robin F. Castelino, Bahman Lashkari, F. Stuart Foster, Andreas Mandelis, Jungik Son, Simon Liang, Brian K. Courtney |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
medicine.diagnostic_test Dynamic range business.industry 01 natural sciences 010309 optics Photoacoustic Doppler effect Wavelength Optics Optical coherence tomography 0103 physical sciences Intravascular ultrasound Angiography medicine Spectroscopy business 010301 acoustics Photoacoustic spectroscopy Biomedical engineering |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| Popis: | Cardiovascular related diseases are ranked as the second highest cause of death in Canada. Among the most important cardiovascular diseases is atherosclerosis. Current methods of diagnosis of atherosclerosis consist of angiography, intravascular ultrasound (IVUS) and optical coherence tomography (OCT). None of these methods possesses adequate sensitivity, as the ideal technique should be capable of both depth profiling, as well as functional imaging. An alternative technique is photoacoustics (PA) which can perform deep imaging and spectroscopy. The presented study explores the application of wavelength-modulated differential photoacoustic radar (WM-DPAR) for characterizing arterial vessels. The wavelength-modulated differential photoacoustic technique was shown to be able to substantially increase the dynamic range and sensitivity of hemoglobin oxygenation level detection. In this work the differential PA technique was used with a very high frequency modulation range. To perform spectroscopic PA imaging, at least two wavelengths are required. The selected wavelengths for this work are 1210 nm and 980 nm. 1210 nm corresponds to the maximum optical absorption coefficient of cholesterol and cholesteryl esters which are the main constituents of plaques. Since water, elastin and collagen also have high absorption coefficients at 1210 nm, this wavelength alone cannot provide very high sensitivity and specificity. The additional wavelength, 980 nm corresponds to high absorption coefficient of those constituents of healthy artery tissue. The simultaneous application of the abovementioned wavelengths can provide higher sensitivity and improved specificity in detecting lipids in the arterial vessels. |
| Databáze: | OpenAIRE |
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