Dr. Thomas H. Meier Profile

Dr. Thomas H. Meier

at Univ Ulm

SPIE Involvement:

Author

Publications (19)

Proceedings Article | 16 October 2003 Paper

Thermal effects in IR-laser-irradiated living cells

Thomas Meier, Angelika Rueck, Claudia Scalfi-Happ, Hubert Hug, Marion Schneider

Proceedings Volume 5142, (2003) https://doi.org/10.1117/12.501158

KEYWORDS: Liquid crystals, Temperature metrology, Fused deposition modeling, Thermal effects, Cell death, Infrared lasers, Absorption, Finite difference methods, Crystals, Tumors

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SPIE Journal Paper | 1 January 2003 Open Access

Time-resolved microspectrofluorometry and fluorescence lifetime imaging of photosensitizers using picosecond pulsed diode lasers in laser scanning microscopes

Matthias Kress, Thomas Meier, Rudolf Steiner, Frank Dolp, Rainer Erdmann, Uwe Ortmann, Angelika Rueck

JBO, Vol. 8, Issue 01, (January 2003) https://doi.org/10.1117/12.10.1117/1.1528595

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This work describes the time-resolved fluorescence characteristics of two different photosensitizers in single cells, in detail mTHPC and 5-ALA induced PPIX, which are currently clinically used in photodynamic therapy. The fluorescence lifetime of the drugs was determined in the cells from time-gated spectra as well as single photon counting, using a picosecond pulsed diode laser for fluorescence excitation. The diode laser, which emits pulses at 398 nm with 70 ps full width at half maximum duration, was coupled to a confocal laser scanning microscope. For time-resolved spectroscopy a setup consisting of a Czerny Turner spectrometer and a MCP-gated and -intensified CCD camera was used. Time-gated spectra within the cells were acquired by placing the laser beam in ‘‘spot scan’’ mode. In addition, a time-correlated single photon counting module was used to determine the fluorescence lifetime from single spots and to record lifetime images. The fluorescence lifetime of mTHPC decreased from 7.5 to 5.5 ns during incubation from 1 to 6 h. This decrease was probably attributed to enhanced formation of aggregates during incubation. Fluorescence lifetime imaging showed that longer lifetimes were correlated with accumulation in the cytoplasm in the neighborhood of the cell nucleus, whereas shorter lifetimes were found in the outer cytoplasm. For cells that were incubated with 5-ALA, a fluorescence lifetime of 7.4 ns was found for PPIX; a shorter lifetime at 3.6 ns was probably attributed to photoproducts and aggregates of PPIX. In contrast from fluorescence intensity images alone, different fluorescence species could not be distinguished. However, in the lifetime image a structured fluorescence distribution in the cytoplasm was correlated with the longer lifetime and probably coincides with mitochondria. In conclusion, picosecond diode lasers coupled to a laser scanning microscope equipped with appropriate detection units allows time-resolved spectroscopy and lifetime imaging with high spatial resolution and provides numerous possibilities in cellular and pharmaceutical research.

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Proceedings Article | 2 November 2001 Paper

Short-pulsed diode lasers as an excitation source for time-resolved fluorescence applications and confocal laser scanning microscopy in PDT

Matthias Kress, Thomas Meier, Tarek El-Tayeb, Ralf Kemkemer, Rudolf Steiner, Angelika Rueck

Proceedings Volume 4431, (2001) https://doi.org/10.1117/12.447408

KEYWORDS: Luminescence, Semiconductor lasers, Time resolved spectroscopy, Laser scanners, Fluorescence spectroscopy, Spectroscopy, Microscopy, Photodynamic therapy, Argon ion lasers, Sensors

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Proceedings Article | 26 October 2001 Paper

Laser-induced temperature distribution in cell layers

Martin Edelmann, Thomas Meier, Markus Rupp, Kathia Vilpoux

Proceedings Volume 4433, (2001) https://doi.org/10.1117/12.446512

KEYWORDS: Laser development, Infrared lasers, Continuous wave operation, Sapphire, Laser systems engineering, Laser cutting, Fused deposition modeling, Microscopes, Temperature metrology, Semiconductor lasers

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Proceedings Article | 1 January 1998 Paper

Fast OCT assembly using wide-area detection

Razvan Lazar, Herman Brunner, Ralf Seschek, Thomas Meier, Rudolf Steiner

Proceedings Volume 3194, (1998) https://doi.org/10.1117/12.301070

KEYWORDS: Optical coherence tomography, Sensors, Tomography, CCD cameras, Data acquisition, In vivo imaging, Head, Detector arrays, Detector development, Analog electronics

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Proceedings Article | 1 January 1998 Paper

OCT images of human skin

Herman Brunner, Razvan Lazar, Ralf Seschek, Thomas Meier, Rudolf Steiner

Proceedings Volume 3194, (1998) https://doi.org/10.1117/12.301058

KEYWORDS: Optical coherence tomography, Skin, Tissue optics, Melanoma, Photomultipliers, Scattering media, Detector development, CCD cameras, Interferometry, Scattering

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Proceedings Article | 5 December 1996 Paper

Recommendations and guidelines for safe medical laser application

Thomas Meier

Proceedings Volume 2923, (1996) https://doi.org/10.1117/12.260743

KEYWORDS: Laser dentistry, Laser safety, Laser therapeutics, Laser applications, Laser tissue interaction, LASIK, Laser cutting, Carbon dioxide lasers, Safety, Er:YAG lasers

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Proceedings Article | 10 January 1996 Paper

Determination of polycyclic aromatic hydrocarbons (PAH) originating from laser-treated porcine tissue

Martin Spleiss, Lothar Weber, Thomas Meier

Proceedings Volume 2624, (1996) https://doi.org/10.1117/12.229558

KEYWORDS: Aerosols, Laser tissue interaction, Liver, Calibration, Particles, Glasses, Combustion, Chromatography, Optical filters, Tissues

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Proceedings Article | 10 January 1996 Paper

Concepts of risk assesment of complex chemical mixtures in laser pyrolysis fumes

Lothar Weber, Thomas Meier

Proceedings Volume 2624, (1996) https://doi.org/10.1117/12.229560

KEYWORDS: Tissues, Lung, Chemical lasers, Aerosols, Particles, Laser tissue interaction, Animal model studies, Data modeling, Chemical analysis, Tumors

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Proceedings Article | 10 January 1996 Paper

Genotoxity of pyrolysis products originating from laser-treated porcine tissues

Bernd Stocker, Ulla Plappert, Lothar Weber, Theodor Fliedner, Bernd Treffler, Thomas Meier

Proceedings Volume 2624, (1996) https://doi.org/10.1117/12.229567

KEYWORDS: Tissues, Blood, Comets, Aerosols, Glasses, Optical filters, Carbon dioxide lasers, Microscopes, Control systems, Liver

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Proceedings Article | 10 January 1996 Paper

Investigations of pulsed laser tissue ablation by short-time exposure video recording and image processing

Bernd Treffler, Thomas Meier, Marc Sauter, Lothar Weber

Proceedings Volume 2624, (1996) https://doi.org/10.1117/12.229559

KEYWORDS: Particles, Atmospheric particles, Video, Tissues, Laser ablation, Liver, Image processing, Pulsed laser operation, Continuous wave operation, Er:YAG lasers

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Proceedings Article | 18 January 1995 Paper

Identification and quantification of selected chemicals in laser pyrolysis products of mammalian tissues

Martin Spleiss, Lothar Weber, Thomas Meier, Bernd Treffler

Proceedings Volume 2323, (1995) https://doi.org/10.1117/12.199236

KEYWORDS: Tissues, Chemical lasers, Particles, Humidity, Silica, Optical filters, Liver, Spectroscopy, Aerosols, Atmospheric particles

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Proceedings Article | 18 January 1995 Paper

Spatial distribution of plume and particulate debris during laser tissue ablation

Thomas Meier, Bernd Treffler, Lothar Weber

Proceedings Volume 2323, (1995) https://doi.org/10.1117/12.199244

KEYWORDS: Particles, Laser ablation, Tissues, Laser tissue interaction, Skin, Visualization, Pulsed laser operation, Laser therapeutics, Safety, Video

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SPIE Journal Paper | 1 September 1994

Photodynamic tumor therapy and on-line fluorescence spectroscopy after ALA administration using 633-nm light as therapeutic and fluorescence excitation radiation

Karsten Koenig, Alwin Kienle, Wolf-Henning Boehncke, Roland Kaufmann, Angelika Rueck, Thomas Meier, Rudolf Steiner

OE, Vol. 33, Issue 09, (September 1994) https://doi.org/10.1117/12.10.1117/12.177511

KEYWORDS: Luminescence, Tumors, Skin, Photodynamic therapy, Fluorescence spectroscopy, Monte Carlo methods, Tissues, Photon transport, Laser therapeutics, Phototherapy

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Proceedings Article | 1 March 1994 Paper

Photodynamic tumor therapy and on-line fluorescence spectroscopy after aminolevulinic acid administration using 633-nm light as therapeutic and fluorescence excitation radiation

Karsten Koenig, Alwin Kienle, Wolf-Henning Boehncke, Roland Kaufmann, Angelika Rueck, Thomas Meier, Rudolf Steiner

Proceedings Volume 2078, (1994) https://doi.org/10.1117/12.168686

KEYWORDS: Luminescence, Skin, Photodynamic therapy, Monte Carlo methods, Photon transport, Tissues, Tumors, Fluorescence spectroscopy, Absorption, In vivo imaging

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Proceedings Article | 1 February 1994 Paper

Influence of laser parameters on by-products during laser treatment of biological tissues

Thomas Meier, Martin Spleiss, Bernd Treffler, Lothar Weber

Proceedings Volume 2077, (1994) https://doi.org/10.1117/12.168040

KEYWORDS: Tissues, Excimer lasers, Medium wave, Statistical analysis, Particles, Liver, Chemical analysis, Laser therapeutics, Laser applications, Skin

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Proceedings Article | 1 February 1994 Paper

Review on toxicology of aerosols produced during medical laser treatment or electrosurgery

Lothar Weber, Thomas Meier

Proceedings Volume 2077, (1994) https://doi.org/10.1117/12.168046

KEYWORDS: Laser tissue interaction, Aerosols, Laser therapeutics, LASIK, Tissues, Skin, Particles, Laser applications, Carbon dioxide lasers, Tumors

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Proceedings Article | 1 February 1994 Paper

Visualization of flow distribution at the evacuator nozzle

J. Gruenvogel, Thomas Meier, Bernd Treffler, Lothar Weber

Proceedings Volume 2077, (1994) https://doi.org/10.1117/12.168048

KEYWORDS: Visualization, Particles, Video, Image processing, Medicine, Laser optics, Laser applications, Helium neon lasers, Cameras, Prototyping

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Proceedings Article | 1 July 1991 Paper

Dual wavelengths (750/375 nm) laser lithotripsy

Rudolf Steiner, Thomas Meier

Proceedings Volume 1421, (1991) https://doi.org/10.1117/12.43918

KEYWORDS: Alexandrite lasers, Absorption, Pulsed laser operation, Laser therapeutics, Gallbladder, Laparoscopy, Fiber coupled lasers, Laser lithotripsy, Crystals, Ultraviolet radiation

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