TY - GEN
T1 - Investigational detection of pharmacological agents in the eye using photoacoustic spectroscopy
AU - Maswadi, Saher M.
AU - Glickman, Randolph D.
AU - Barsalou, Norman
AU - Elliott, Rowe W.
PY - 2007/4/30
Y1 - 2007/4/30
N2 - This research reports progress in our earlier investigation of detecting specific drug diffusion into eye tissue using photoacoustic spectroscopy (PAS). A key improvement to the technique is using short pulse tunable laser source to stimulate the photoacoustic effect in tissue. An optical parametric oscillator (OPO) laser system was used as a pumping source to generate ultrasonic photoacoustic signals and employed to scan through different wavelengths with 0.1nm wavelength resolution to determine spectra of different drug solutions in an ocular phantom. The short pulse duration (5-10ns) of the OPO laser has significantly increased the photoacoustic efficiency conversion, and the ability to tune its output from 210nm to 1800nm has provided a wide selection range that is useful for optimizing spectroscopic studies. PAS spectra of different solutions of molecules, such as Trypan Blue, Rose Bengal, Indocyanine Green (ICG), and Amphotericin B (AB), at concentrations as low as 1 μg/ml, were constructed and compared to their actual optical absorption spectra. Ultrasonic hydrophone and photothermal deflection technique (PhDT), a noncontact optical method, were both used to record the photoacoustic signals, and compared in terms of sensitivity and applicability to record signals from the ocular tissue-bearing phantom. The results show good agreement between the optical and photoacoustic spectra, which supports moving to an in vivo application of recording the PAS responses from the eye. Future work will be directed at adapting this method for in vivo measurements, as well as improve the data acquisition system for faster PAS signal analysis.
AB - This research reports progress in our earlier investigation of detecting specific drug diffusion into eye tissue using photoacoustic spectroscopy (PAS). A key improvement to the technique is using short pulse tunable laser source to stimulate the photoacoustic effect in tissue. An optical parametric oscillator (OPO) laser system was used as a pumping source to generate ultrasonic photoacoustic signals and employed to scan through different wavelengths with 0.1nm wavelength resolution to determine spectra of different drug solutions in an ocular phantom. The short pulse duration (5-10ns) of the OPO laser has significantly increased the photoacoustic efficiency conversion, and the ability to tune its output from 210nm to 1800nm has provided a wide selection range that is useful for optimizing spectroscopic studies. PAS spectra of different solutions of molecules, such as Trypan Blue, Rose Bengal, Indocyanine Green (ICG), and Amphotericin B (AB), at concentrations as low as 1 μg/ml, were constructed and compared to their actual optical absorption spectra. Ultrasonic hydrophone and photothermal deflection technique (PhDT), a noncontact optical method, were both used to record the photoacoustic signals, and compared in terms of sensitivity and applicability to record signals from the ocular tissue-bearing phantom. The results show good agreement between the optical and photoacoustic spectra, which supports moving to an in vivo application of recording the PAS responses from the eye. Future work will be directed at adapting this method for in vivo measurements, as well as improve the data acquisition system for faster PAS signal analysis.
KW - Biomolecular detection
KW - Hydrophone
KW - Laser
KW - Ocular phantom
KW - Photoacoustic
KW - Photothermal deflection technique
KW - Retina
KW - Spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=34247325233&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34247325233&partnerID=8YFLogxK
U2 - 10.1117/12.699094
DO - 10.1117/12.699094
M3 - Conference contribution
AN - SCOPUS:34247325233
SN - 081946550X
SN - 9780819465504
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Photons Plus Ultrasound
T2 - Photons Plus Ultrasound: Imaging and Sensing 2007: The Eighth Conference on Biomedical Thermoacoustics, Optoacoustics, and Acousto-optics
Y2 - 21 January 2007 through 24 January 2007
ER -