Light emitting diodes as an excitation source for biomedical photoacoustics

T. J. Allen; P. C. Beard

doi:10.1117/12.2004471

4 March 2013 Light emitting diodes as an excitation source for biomedical photoacoustics

T. J. Allen, P. C. Beard

Proceedings Volume 8581, Photons Plus Ultrasound: Imaging and Sensing 2013; 85811F (2013) https://doi.org/10.1117/12.2004471
Event: SPIE BiOS, 2013, San Francisco, California, United States

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.

Citation Download Citation

T. J. Allen and P. C. Beard "Light emitting diodes as an excitation source for biomedical photoacoustics", Proc. SPIE 8581, Photons Plus Ultrasound: Imaging and Sensing 2013, 85811F (4 March 2013); https://doi.org/10.1117/12.2004471

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available