eprintid: 1481173
rev_number: 34
eprint_status: archive
userid: 608
dir: disk0/01/48/11/73
datestamp: 2016-04-17 13:48:12
lastmod: 2021-10-04 00:58:24
status_changed: 2016-08-02 14:39:25
type: article
metadata_visibility: show
creators_name: Allen, TJ
creators_name: Beard, PC
title: High power visible light emitting diodes as pulsed excitation sources for biomedical photoacoustics
ispublished: pub
divisions: UCL
divisions: B04
divisions: C05
divisions: F42
keywords: (110.5120) Photoacoustic imaging, (170.3880) Medical and biological imaging
note: Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
abstract: The use of visible light emitting diodes (LEDs) as an alternative to Q-switched lasers conventionally used as photoacoustic excitation sources has been explored. In common with laser diodes, LEDs offer the advantages of compact size, low cost and high efficiency. However, laser diodes suitable for pulsed photoacoustic generation are typically available only at wavelengths greater than 750nm. By contrast, LEDs are readily available at visible wavelengths below 650nm where haemoglobin absorption is significantly higher, offering the prospect of increased SNR for superficial vascular imaging applications. To demonstrate feasibility, a range of low cost commercially available LEDs operating in the 420-620nm spectral range were used to generate photoacoustic signals in physiologically realistic vascular phantoms. Overdriving with 200ns pulses and operating at a low duty cycle enabled pulse energies up to 10µJ to be obtained with a 620nm LED. By operating at a high pulse repetition frequency (PRF) in order to rapidly signal average over many acquisitions, this pulse energy was sufficient to generate detectable signals in a blood filled tube immersed in an Intralipid suspension (µs' = 1mm(-1)) at a depth of 15mm using widefield illumination. In addition, a compact four-wavelength LED (460nm, 530nm, 590nm, 620nm) in conjunction with a coded excitation scheme was used to illustrate rapid multiwavelength signal acquisition for spectroscopic applications. This study demonstrates that LEDs could find application as inexpensive and compact multiwavelength photoacoustic excitation sources for imaging superficial vascular anatomy. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
date: 2016-04-01
date_type: published
official_url: http://dx.doi.org/10.1364/BOE.7.001260
oa_status: green
full_text_type: pub
pmcid: PMC4929638
language: eng
primo: open
primo_central: open_green
article_type_text: Journal Article
verified: verified_manual
elements_id: 1120322
doi: 10.1364/BOE.7.001260
pii: 256512
language_elements: eng
lyricists_name: Allen, Thomas
lyricists_name: Beard, Paul
lyricists_id: TJALL97
lyricists_id: PCBEA63
actors_name: Barczynska, Patrycja
actors_id: PBARC91
actors_role: owner
full_text_status: public
publication: Biomedical Optics Express
volume: 7
number: 4
pagerange: 1260-1270
event_location: United States
issn: 2156-7085
citation:        Allen, TJ;    Beard, PC;      (2016)    High power visible light emitting diodes as pulsed excitation sources for biomedical photoacoustics.                   Biomedical Optics Express , 7  (4)   pp. 1260-1270.    10.1364/BOE.7.001260 <https://doi.org/10.1364/BOE.7.001260>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1481173/1/High%20power%20visible%20light%20emitting%20diodes%20as%20pulsed%20excitation%20sources%20for%20biomedical%20photoacoustics.pdf