
Proceedings Paper
Light emitting diodes as an excitation source for biomedical photoacousticsFormat | Member Price | Non-Member Price |
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Paper Abstract
Semiconductor light sources, such as laser diodes or light emitting diodes (LEDs) could provide an inexpensive
and compact alternative to traditional Q-switched lasers for photoacoustic imaging. So far, only laser diodes 1-3
operating in the 750 to 905nm wavelength range have been investigated for this purpose. However, operating in
the visible wavelength range (400nm to 650nm) where blood is strongly absorbent (<10cm-1) and water
absorption is weak (<0.01cm-1) could allow for high contrast photoacoustic images of the superficial vasculature to be achieved. High power laser diodes (<10Watt peak power) are however not available in this wavelength
range. High power LEDs could be a potential alternative as they are widely available in the visible wavelength
range (400nm to 632nm) and relatively cheap. High power LEDs are generally operated in continuous wave
mode and provide average powers of several Watts. The possibility of over driving them by tens of times their
rated current when driven at a low duty cycle (<1%), offers the prospect of achieving similar pulse energies
(tens of μJ) to that provided by high peak power pulsed laser diodes. To demonstrate the possibility of using
high power LEDs as an excitation source for biomedical applications, single point measurements were
implemented in a realistic blood vessel phantom. A four colour device was also used to demonstrate the
possibility of using LEDs for making spectroscopic measurements. It was shown that when driving all four
wavelengths at once, the generated photoacoustic signal could be used to design a filter in order to improve the
SNR of the photoacoustic signals generated at each individual wavelength. The possibility of acquiring
multiwavelength data sets simultaneously when using Golay excitation methods was also demonstrated. This
preliminary study demonstrated the potential for using high power LEDs as an inexpensive and compact
excitation source for biomedical photoacoustics.
Paper Details
Date Published: 4 March 2013
PDF: 9 pages
Proc. SPIE 8581, Photons Plus Ultrasound: Imaging and Sensing 2013, 85811F (4 March 2013); doi: 10.1117/12.2004471
Published in SPIE Proceedings Vol. 8581:
Photons Plus Ultrasound: Imaging and Sensing 2013
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)
PDF: 9 pages
Proc. SPIE 8581, Photons Plus Ultrasound: Imaging and Sensing 2013, 85811F (4 March 2013); doi: 10.1117/12.2004471
Show Author Affiliations
T. J. Allen, Univ. College London (United Kingdom)
P. C. Beard, Univ. College London (United Kingdom)
Published in SPIE Proceedings Vol. 8581:
Photons Plus Ultrasound: Imaging and Sensing 2013
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)
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