Dr. Theodore G. Papazoglou Profile

Dr. Theodore G. Papazoglou

at FORTH

SPIE Involvement:

Author

Publications (27)

Proceedings Article | 8 April 2005 Paper

Production and laser-induced fluorescence spectroscopy (L.I.F.S.) of different Hypericum perforatum L. extracts

Dimitris Skalkos, George Filippidis, Dimitris Kapsokalyvas, Heiko Meyer, Theodore Papazoglou, Eleni Karentzou, Heleni Dimitriou, M. Kalmanti

Proceedings Volume 5689, (2005) https://doi.org/10.1117/12.587484

KEYWORDS: Luminescence, Photodynamic therapy, Fluorescence spectroscopy, Bioalcohols, Laser induced fluorescence, Spectroscopy, Tumors, Bladder, Environmental sensing, Laser spectroscopy

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SPIE Journal Paper | 1 March 2005 Open Access

Imaging of Caenorhabditis elegans neurons by second-harmonic generation and two-photon excitation fluorescence

Giorgos Filippidis, C. Kouloumentas, G. Voglis, F. Zacharopoulou, Theodore Papazoglou, N. Tavernarakis

JBO, Vol. 10, Issue 02, 024015, (March 2005) https://doi.org/10.1117/12.10.1117/1.1886729

KEYWORDS: Second-harmonic generation, Neurons, Signal detection, Green fluorescent protein, Molecules, Luminescence, Microscopy, Proteins, Monochromators, Absorption

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Proceedings Article | 13 October 2003 Paper

Spectroscopic fluorescence measurements of lamb and human heart tissue in vitro

George Filippidis, Giannis Zacharakis, G. Kochiadakis, S. Chrysostomakis, P. Vardas, Costas Fotakis, Theodore Papazoglou

Proceedings Volume 5068, (2003) https://doi.org/10.1117/12.518767

KEYWORDS: Heart, Luminescence, Tissues, Tissue optics, Fluorescence spectroscopy, Spectroscopy, Laser tissue interaction, Laser induced fluorescence, In vitro testing, Absorption

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Proceedings Article | 8 October 2003 Paper

Laser transmission measurements toward the detection of abnormal muscle denervation

Despoina Stambouli, George Filippidis, Theodore Papazoglou, Eleftherios Stamboulis, Alexandros Siafakas, Constantinos Fotakis

Proceedings Volume 5141, (2003) https://doi.org/10.1117/12.500291

KEYWORDS: Modulation, Photons, Laser scattering, Semiconductor lasers, Light scattering, Scattering, Dynamic light scattering, Electromyography, Diagnostics, Doppler effect

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Proceedings Article | 8 October 2003 Paper

Optical characterization of small biopsy samples

Anikitos Garofalakis, Giannis Zacharakis, George Filippidis, Elias Sanidas, Dimitris Tsiftsis, Eleftherios Stathopoulos, Maria Kafousi, Theodore Papazoglou, Jorge Ripoll

Proceedings Volume 5141, (2003) https://doi.org/10.1117/12.500546

KEYWORDS: Tissues, Scattering, Diffusion, Biopsy, Tumors, Breast, Optical properties, Absorption, Tissue optics, Light scattering

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Proceedings Article | 22 September 2003 Paper

LIF after excitation with ultrafast laser irradiation: the response of a single cell and the effect of its scattering environment

Theodore Papazoglou, Giannis Zacharakis

Proceedings Volume 5149, (2003) https://doi.org/10.1117/12.518633

KEYWORDS: Laser scattering, Scattering, Light scattering, Photons, Random lasers, Luminescence, Polymers, Picosecond phenomena, Photodynamic therapy, Skin

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New and fascinating field of highly scattering gain media, random lasers and the study of the behavior of such materials of biological significance is presented. Especially the study of the behavior of various fluorophores embedded in highly scattering matrices. The observed fluorescence signal of the fluorophore quenches in both temporal and spectral domains due to the intense scattering that the photons undergo. This happens when the excitation energy reaches and exceeds a threshold value. Above that value the narrowed fluorescence exhibits the same features as the excitation laser pulse. Lifetime in the order of 50 psec and spectral FWHM in the order of few nanometers are observed. For energies below the threshold value the amplification is negligible and the samples behave exactly as those without scatterers. As the excitation energy increases the laser action requirements are fulfilled and the sudden narrowing takes place. Similar studies are underway when various fluorophores are embedded in biological tissues. The final goal is to take advantage of this effect towards a more spatially and spectrally confined agent in Photodynamic Therapy of target tissue lesions on skin or other types of superficial lesions. Very promising in the field of skin PDT would be thin polymer sheets with various dyes, which could be applied directly on the lesion and allow the selection of different irradiation wavelengths using the same laser as excitation source. Thus, improving by far the efficiency of the destruction of different types of cancerous cells. In the biomedical arena, the materials high conversion efficiency per unit volume (≥ 50 percent in a 250 μm thickness) allows for wavelength-shifted catheters and laser creams, potentially useful for the removal of tattoos and other skin discolorations. In addition, random lasers can be used for wavelength shifting the installed base of lasers for other applications such as photodynamic therapy where narrow-band excitations are required for drugs such as benzoporphyrin derivatives (BPD). As far as detection is concerned random lasers could be implemented in various applications such as medical imaging. The combined use of these materials with chromophores that are selectively absorbed by malignant tumors and the narrowband emission along with the high-emitted intensity could boost the detection efficiency.

Proceedings Article | 16 July 2002 Paper

Single and double photon excitation of dyes in highly scattering media of biological significance

Giannis Zacharakis, Theodore Papazoglou

Proceedings Volume 4707, (2002) https://doi.org/10.1117/12.475626

KEYWORDS: Luminescence, Scattering, Laser scattering, Random lasers, Picosecond phenomena, Scattering media, Photon counting, Streak cameras, Temporal coherence, Light scattering

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Proceedings Article | 2 November 2001 Paper

Second harmonic generation and random lasing after two-photon excitation

Giannis Zacharakis, Dmitrios Anglos, Theodore Papazoglou

Proceedings Volume 4431, (2001) https://doi.org/10.1117/12.447429

KEYWORDS: Random lasers, Luminescence, Second-harmonic generation, Harmonic generation, Photons, Absorption, Scattering, Laser scattering, Tissue optics, Tumors

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SPIE Journal Paper | 1 October 2001 Open Access

In vitro optical characterization and discrimination of female breast tissue during near infrared FSEC laser pulsed propagation

Giannis Zacharakis, A. Zolindaki, V. Sakkalis, George Filippidis, Theodore Papazoglou, D. Tsiftsis, Eugenios Koumantakis

JBO, Vol. 6, Issue 04, (October 2001) https://doi.org/10.1117/12.10.1117/1.1412223

KEYWORDS: Tissues, Tissue optics, Scattering, Breast, Near infrared, Absorption, Photons, In vitro testing, Laser tissue interaction, Diffusion

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Proceedings Article | 19 January 2001 Paper

Artificial neural networks analysis of laser-induced fluorescence spectra for characterization of peripheral vascular tissue

George Filippidis, Giannis Zacharakis, A. Katsamouris, G. Rovithakis, M. Maniadakis, M. Zervakis, Theodore Papazoglou

Proceedings Volume 4158, (2001) https://doi.org/10.1117/12.413797

KEYWORDS: Tissues, Neural networks, Artificial neural networks, Luminescence, Feature extraction, Laser induced fluorescence, Laser tissue interaction, Nonlinear filtering, In vitro testing, Arteries

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Proceedings Article | 3 November 2000 Paper

Photon statistics of the laserlike emission from polymeric scattering gain media with tissuelike optical properties

Giannis Zacharakis, Nektarios Papadogiannis, George Filippidis, Theodore Papazoglou

Proceedings Volume 4162, (2000) https://doi.org/10.1117/12.405942

KEYWORDS: Laser scattering, Scattering, Picosecond phenomena, Polymers, Luminescence, Optical properties, Laser tissue interaction, Streak cameras, Laser applications, Random lasers

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Proceedings Article | 6 April 2000 Paper

Interactions of ultrafast laser pulses with biologic tissues

Theodore Papazoglou

Proceedings Volume 4001, (2000) https://doi.org/10.1117/12.381479

KEYWORDS: Tissues, Scattering, Photons, Diffraction, Streak cameras, Laser scattering, Tissue optics, Breast, Laser tissue interaction, Absorption

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Proceedings Article | 29 December 1997 Paper

Effect of liquid nitrogen and formalin-based conservation in the in-vitro measurement of laser-induced fluorescence of peripheral vascular tissue

George Filippidis, Giannis Zacharakis, A. Katsamouris, M. Kouktzela, Sune Montan, Stefan Andersson-Engels, Theodore Papazoglou

Proceedings Volume 3197, (1997) https://doi.org/10.1117/12.297984

KEYWORDS: Tissues, Liquids, Nitrogen, Luminescence, Laser induced fluorescence, Laser tissue interaction, Arteries, In vitro testing, Algorithm development, Mirrors

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Proceedings Article | 29 December 1997 Paper

Use of the polarization vector in modeling tissue fluorescence: theoretical and experimental comparison

Ourania Panou-Diamanti, Nikolaos Uzunoglou, A. Vasiliou, Giannis Zacharakis, George Filippidis, Theodore Papazoglou, Dimitrios Koutsouris

Proceedings Volume 3197, (1997) https://doi.org/10.1117/12.297953

KEYWORDS: Tissues, Luminescence, Mathematical modeling, Scattering, Electromagnetic scattering, Dielectrics, Data modeling, Polarization, Collagen, Dielectric polarization

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Proceedings Article | 31 January 1995 Paper

Influence of cw laser beam diffraction on the imaging of hidden discontinuities in turbid media of biological significance

Theodore Papazoglou, W. Liu, Athanassios Manolopoulos

Proceedings Volume 2326, (1995) https://doi.org/10.1117/12.200820

KEYWORDS: Diffraction, Polymethylmethacrylate, Sensors, Diodes, Continuous wave operation, Light scattering, Laser scattering, Laser tissue interaction, Tissues, Scattering

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Proceedings Article | 4 January 1995 Paper

Influence of medium's optical properties on laser-induced fluorescence measurements: experimental study on solutions and a gel model of biological significance

Theodore Papazoglou, W. Liu, Athanassios Manolopoulos

Proceedings Volume 2324, (1995) https://doi.org/10.1117/12.198725

KEYWORDS: Optical properties, Laser induced fluorescence, Luminescence, Rhodamine B, Laser therapeutics, Polymethylmethacrylate, Laser tissue interaction, Solids, Helium neon lasers, Tissue optics

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Proceedings Article | 1 March 1994 Paper

Biodistribution detection of Photofrin porfimer sodium and benzoporphyrin derivative using a fiber optic sensor and ratio fluorometry

Sandor Vari, Theodore Papazoglou, Thanassis Papaioannou, Marigo Stavridi, Vani Pergadia, Michael Fishbein, Maurits van der Veen, Reem Thomas, Warren Grundfest

Proceedings Volume 2078, (1994) https://doi.org/10.1117/12.168656

KEYWORDS: Tissues, Luminescence, Tumors, Sodium, Laser induced fluorescence, Skin, Lymphatic system, Fluorescence spectroscopy, Liver, Spectroscopy

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Proceedings Article | 15 February 1994 Paper

Differentiation of artery wall lesions using porphyrins and fiberoptic sensor in rabbits

Sandor Vari, Maurits van der Veen, Theodore Papazoglou, Michael Fishbein, Marigo Stavridi, Thanassis Papaioannou, Warren Grundfest

Proceedings Volume 2086, (1994) https://doi.org/10.1117/12.169112

KEYWORDS: Laser induced fluorescence, Luminescence, Fluorescence spectroscopy, Spectroscopy, Arteries, Laser applications, Laser spectroscopy, Tissues, Control systems, Medical laser equipment

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Proceedings Article | 15 January 1994 Paper

Blood perfusion and pH monitoring in organs by laser-induced fluorescence spectroscopy

Sandor Vari, Theodore Papazoglou, Vani Pergadia, Marigo Stavridi, Wendy Snyder, Thanassis Papaioannou, J. Duffy, Andrew Weiss, Reem Thomas, Warren Grundfest

Proceedings Volume 2081, (1994) https://doi.org/10.1117/12.166817

KEYWORDS: Blood, Kidney, Laser induced fluorescence, Fluorescence spectroscopy, Spectroscopy, Laser spectroscopy, Biopsy, Luminescence, Fiber optics sensors, Blood circulation

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Proceedings Article | 7 July 1993 Paper

Fluorescence-based tissue biopsy needle: in vivo optical diagnosis in rat model with low cost, arc-lamp-based system

Karlheinz Strobl, Sandor Vari, Theodore Papazoglou, Warren Grundfest, Doug Brenner

Proceedings Volume 1892, (1993) https://doi.org/10.1117/12.147494

KEYWORDS: Lymphatic system, Tissue optics, Tissues, Luminescence, Biopsy, Tumors, Light, Diagnostics, Fiber optics, LASIK

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Proceedings Article | 23 June 1993 Paper

Laser-induced fluorescence detection of cardiovascular calcified deposits via tetracarboxylate ion dye probing

Theodore Papazoglou, E. Katerinopoulos, Costas Fotakis, Helene Iatridou, Evangelia Foukaraki

Proceedings Volume 1878, (1993) https://doi.org/10.1117/12.146591

KEYWORDS: Luminescence, Ions, Tissues, Laser induced fluorescence, Argon ion lasers, Fluorescence spectroscopy, Laser tissue interaction, Spectrographs, Laser applications, Algorithm development

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Proceedings Article | 18 June 1993 Paper

Biodistribution of benzoporphyrin derivative in tumor-bearing rats by laser-induced fluorescence spectroscopy

Sandor Vari, Marigo Stavridi, Thanassis Papaioannou, Theodore Papazoglou, Vani Pergadia, Michael Fishbein, David Wolfson, Warren Grundfest

Proceedings Volume 1881, (1993) https://doi.org/10.1117/12.146311

KEYWORDS: Tissues, Lymphatic system, Tumors, Luminescence, Laser induced fluorescence, Fluorescence spectroscopy, Skin, Laser spectroscopy, Spectroscopy, Animal model studies

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Proceedings Article | 1 July 1991 Paper

Laser-induced fluorescence spectroscopy of pathologically enlarged prostate gland in vitro

Mudjianto Chandra, Alex Gershman, Theodore Papazoglou, Leon Bender, Dudley Danoff, Thanassis Papaioannou, Sandor Vari, Gregory Coons, Warren Grundfest

Proceedings Volume 1421, (1991) https://doi.org/10.1117/12.43909

KEYWORDS: Prostate, Laser induced fluorescence, Spectroscopy, Tissues, Fluorescence spectroscopy, Laser spectroscopy, Luminescence, In vitro testing, Laser therapeutics, Surgery

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Proceedings Article | 1 July 1991 Paper

Practical considerations for effective microendoscopy

Thanassis Papaioannou, Theodore Papazoglou, Leon Daykhovsky, Alex Gershman, Jacob Segalowitz, G. Reznik, Clain Beeder, Mudjianto Chandra, Warren Grundfest

Proceedings Volume 1420, (1991) https://doi.org/10.1117/12.43884

KEYWORDS: Endoscopes, Endoscopy, Light sources, Cameras, Video, Optical fibers, Medicine, Ranging, Light, Fiber optics

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Proceedings Article | 1 June 1991 Paper

Intraoperative metastases detection by laser-induced fluorescence spectroscopy

Sandor Vari, Theodore Papazoglou, Maurits van der Veen, Michael Fishbein, J. Young, Mudjianto Chandra, Thanassis Papaioannou, Clain Beeder, Wei-Qiang Shi, Warren Grundfest

Proceedings Volume 1426, (1991) https://doi.org/10.1117/12.44051

KEYWORDS: Laser induced fluorescence, Fluorescence spectroscopy, Tissue optics, Spectroscopy, Lymphatic system, Tumors, Tissues, Luminescence, Laser spectroscopy, Laser tissue interaction

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Proceedings Article | 1 June 1991 Paper

Detection of atheroma using Photofrin II and laser-induced fluorescence spectroscopy

Sandor Vari, Theodore Papazoglou, Maurits van der Veen, Thanassis Papaioannou, Michael Fishbein, Mudjianto Chandra, Clain Beeder, Wei-Qiang Shi, Warren Grundfest

Proceedings Volume 1426, (1991) https://doi.org/10.1117/12.44081

KEYWORDS: Laser induced fluorescence, Luminescence, Arteries, Tissue optics, Fluorescence spectroscopy, Spectroscopy, Laser spectroscopy, Angiography, Tissues, Fiber lasers

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Proceedings Article | 1 July 1990 Paper

Laser-induced tissue autofluorescence versus exogenous chemical probe induced fluorescence as an arterial layer detection method: a comparative study

Theodore Papazoglou, Koh Arakawa, Warren Grundfest, Thanassis Papaioannou, Michael Fishbein, Frank Litvack

Proceedings Volume 1201, (1990) https://doi.org/10.1117/12.17511

KEYWORDS: Luminescence, Tissues, Laser induced fluorescence, Laser ablation, Excimer lasers, Optical fibers, Natural surfaces, Medicine, Pulsed laser operation, Tissue optics

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