Dr. Kenton W. Gregory Profile

Dr. Kenton W. Gregory

at Oregon Health & Science Univ

SPIE Involvement:

Conference Program Committee | Editor | Author

Publications (24)

SPIE Journal Paper | 1 March 2006 Open Access

Special Section Guest Editorial: Cardiovascular Photonics

Laura Marcu, Guillermo Tearney, Kenton Gregory

JBO, Vol. 11, Issue 02, 021001, (March 2006) https://doi.org/10.1117/12.10.1117/1.2191508

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Proceedings Article | 12 September 2003 Paper

Optimal dye concentration and power density for laser-assisted vascular anatomosis (LAVA)

Zhen Ren, Anthony Furnary, Hua Xie, Kathryn Lagerquist, Allen Burke, Scott Prahl, Kenton Gregory

Proceedings Volume 4949, (2003) https://doi.org/10.1117/12.479374

KEYWORDS: Laser welding, Laser tissue interaction, Injuries, Semiconductor lasers, Tissues, Arteries, Control systems, Laser vision correction, Laser therapeutics, Indocyanine green

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Proceedings Article | 17 June 2002 Paper

Hemostasis after partial hepatectomy using argon beam coagulation and a concentrated albumin

Hua Xie, Ron Wolf, John Petty, Allen Burke, Jeffery Teach, Kenton Gregory, Scott Prahl

Proceedings Volume 4609, (2002) https://doi.org/10.1117/12.438971

KEYWORDS: Liver, Argon, Surgery, Tissues, Injuries, Natural surfaces, Blood, Laser welding, Laser therapeutics, Inflammation

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Proceedings Article | 17 June 2002 Paper

Effects of in-vitro target compression modulus on laser thrombolytic ablation rate

Abram Janis, Sean Kirkpatrick, Kenton Gregory, Scott Prahl

Proceedings Volume 4609, (2002) https://doi.org/10.1117/12.441250

KEYWORDS: Laser ablation, In vitro testing, Absorbance, Laser therapeutics, Blood, Calibration, Proteins, Laser energy, In vivo imaging, Pulsed laser operation

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Proceedings Article | 17 June 2002 Paper

Vascular anastomosis using a pulsed diode laser

Douglas Deford, Adam Higgins, Kenton Gregory

Proceedings Volume 4609, (2002) https://doi.org/10.1117/12.444382

KEYWORDS: Arteries, Laser welding, Liquids, Semiconductor lasers, Blood vessels, Laser tissue interaction, Mercury, Blood, Solids, Laser therapeutics

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The objective of this research is to provide a novel approach to the problem of vascular anastomosis. The work subscribes to the idea that if we use a human protein that has adhesive properties, denatures by heat in an irreversible way and forms a semi-hard but flexible matter. Also belongs to the circulatory system, is liquid in its native state , and after denaturing it is not soluble inwater, blood plasma or any other related fluids anymore. Therefore, a pulsed diode laser beam can be used on this protein in order to have a strong welding for vascular anastomosis. It was established in the Oregon Medical Laser Center that the best proteins to be used , as a welding biomaterial, is human albumin. Indocyanine Green was added to provide a compound that absorbs light and transforms it in heat to the denaturing and welding process. Tests with liquid albumin were performed, the results obtained were unreliable due to the following facts: the variation in the liquid film thickness produced pockets of native (non-denatured albumin) underneath the denatured welded crust and bubbles produced by water evaporation. This phenomenon led to a weak welding. After testing different options, it was decided that the manufacturing of asolid thin film of albumin/ICG with a content of water between 37-40% was the best option. It reduces the number of bubbles, and provides a constant thickness between 200-250 ?m. This thin film can be used alone on the vascular surface to be welded , or in combination with an elastin strip to increase strength. To avoid collapsing of the blood vessel while welding, and also keep both edges of the vessel together, an albumin/ICG stent was designed so the configuration of the stent does not allow the vessel to slip away or collapse. The stent is made out of native human albumin with water content between 37-40%. When the weld is completed and the forceps are released, it is expected that the natural flow of blood will dissolve the stent in less than 12 minutes (according with experiments already performed with lukewarm water).

Proceedings Article | 21 May 2001 Paper

Thermal damage control of dye-assisted laser tissue welding: effect of dye concentration

Hua Xie, Lisa Buckley, Scott Prahl, Brian Shaffer, Kenton Gregory

Proceedings Volume 4244, (2001) https://doi.org/10.1117/12.427789

KEYWORDS: Solids, Tissues, Laser welding, Laser tissue interaction, Injuries, Indocyanine green, Semiconductor lasers, Beam controllers, In vitro testing, Absorption

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Proceedings Article | 21 May 2001 Paper

Characterization of an in-vitro laser thrombolysis model

Abram Janis, Abby Nyara, Kenton Gregory, Lisa Buckley

Proceedings Volume 4244, (2001) https://doi.org/10.1117/12.427833

KEYWORDS: Laser ablation, In vitro testing, Laser therapeutics, Scanning electron microscopy, Absorbance, Blood, Laser systems engineering, In vivo imaging, Laser energy, Laser safety

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Proceedings Article | 9 April 2001 Paper

Evaluating clinical outcomes of PDT

Teresa Goodell, Steven Jacques, Kenton Gregory

Proceedings Volume 4248, (2001) https://doi.org/10.1117/12.424432

KEYWORDS: Photodynamic therapy, Cancer, Safety, Picosecond phenomena, Clinical trials, Data centers, Oncology, Clinical research, Lung cancer, Solids

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Proceedings Article | 17 May 2000 Paper

Liver repair and hemorrhage control using laser soldering of liquid albumin in a porcine model

Yasmin Wadia, Hua Xie, Michio Kajitani, Kenton Gregory, Scott Prahl

Proceedings Volume 3907, (2000) https://doi.org/10.1117/12.386239

KEYWORDS: Liver, Laser welding, Injuries, Blood, Liquids, Surgery, Pulsed laser operation, Laser irradiation, Laser tissue interaction, Laser vision correction

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Proceedings Article | 17 May 2000 Paper

OCT-guided TMR

John Viator, Kenton Gregory

Proceedings Volume 3907, (2000) https://doi.org/10.1117/12.386296

KEYWORDS: Optical coherence tomography, Heart, Laser ablation, Excimer lasers, Signal detection, Laser therapeutics, Arteries, Optical fibers, Natural surfaces, Tissues

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Proceedings Article | 17 May 2000 Paper

Laser welding with an albumin stent: experimental ureteral end-to-end anastomosis

Hua Xie, Brian Shaffer, Scott Prahl, Kenton Gregory

Proceedings Volume 3907, (2000) https://doi.org/10.1117/12.386258

KEYWORDS: Laser welding, Laser tissue interaction, Semiconductor lasers, Liquids, Continuous wave operation, Tissues, Pulsed laser operation, Laser energy, Injuries, Laser therapeutics

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Proceedings Article | 17 May 2000 Paper

Laser thrombolysis in an in-vitro model

Abram Janis, Lisa Buckley, Kenton Gregory

Proceedings Volume 3907, (2000) https://doi.org/10.1117/12.386303

KEYWORDS: Laser ablation, In vitro testing, Laser energy, Absorbance, Therapeutics, Energy efficiency, Absorption, Laser therapeutics, Blood, Calibration

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Proceedings Article | 17 September 1999 Paper

Sutureless end-to-end ureteral anastomosis using a new albumin stent and diode laser

Hua Xie, Brian Shaffer, Scott Prahl, Kenton Gregory

Proceedings Volume 3863, (1999) https://doi.org/10.1117/12.364420

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Proceedings Article | 22 June 1999 Paper

Effects of transmyocardial laser revascularization using a prototype pulsed CO2 laser on contractility and perfusion of chronically ischemic myocardium in a porcine model

Yasmin Wadia, Ali Khaki, Michio Kajitani, Yoshiki Mori, Timothy Irvine, David Sahn, Michael Yessik, Deborah Bahlman, Anthony Furnary, Kenton Gregory

Proceedings Volume 3590, (1999) https://doi.org/10.1117/12.350975

KEYWORDS: Echocardiography, Carbon dioxide lasers, Ischemia, Arteries, Pulsed laser operation, Angiography, Prototyping, Blood, Heart, Tissues

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Proceedings Article | 13 May 1998 Paper

Pressure effects on soft tissues monitored by changes in tissue optical properties

HanQun Shangguan, Scott Prahl, Steven Jacques, Lee Casperson, Kenton Gregory

Proceedings Volume 3254, (1998) https://doi.org/10.1117/12.308187

KEYWORDS: Tissues, Optical properties, Absorption, Scattering, Transmittance, Reflectivity, Diffuse reflectance spectroscopy, Light scattering, Water, Optical testing

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Proceedings Article | 16 June 1997 Paper

Laser welding of biomaterials stained with indocyanine green to tissues

Steven Jacques, Andrew Barofsky, HanQun Shangguan, Scott Prahl, Kenton Gregory

Proceedings Volume 2975, (1997) https://doi.org/10.1117/12.275511

KEYWORDS: Tissues, Natural surfaces, Pulsed laser operation, Laser welding, Laser energy, Arteries, Absorption, Indocyanine green, Semiconductor lasers, Interfaces

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This paper considers some issues pertinent to laser welding of elastin-based biomaterials to tissues using a pulsed diode laser (lO-is pulse) and indocyanine green (ICG) as an absorbing chromophore to localize laser heating to the "weld surface", the elastin/tissue interface where welding occurs. Experiments involved laser welding of elastin heterographs to the intimal surface of the carotid artery (in vitro, porcine) as a '-4x5 spotweld, then determining the breaking strength when the two tissues were pulled in a direction parallel to the plane of the spot weld while submerged in water. The questions answered are: . WHAT IS THE PEAK TEMPERATURE REQUIRED FOR WELDING ELASTIN HETEROGRAPH TO THE INTIMAL SURFACE OF CAROTID ARTERY? ANSWER: 3OO °C threshold, -6OO °C for maximum strength. This estimate is based on optical measurements of dye accumulation in stain layer and measurements of thickness of stain layer via fluorescence microscope examination. . WHATIS THE DEPENDENCE OF WELD STRENGTH ON THE LASER EXPOSURE? ANSWER: Breaking force (g) = Max*(1 exp(-(E Eth)/U67)), where Max is the maximum strength achievable by laser welding, expressed as the breaking force in g when elastin heterograph and tissue are pulled. E is the laser pulse energy. Eth is the apparent threshold laser pulse energy that will break the weld. Uth is the laser energy above threshold which achieves 67% of Max. Max was about 15 g for the -2O --2weld area of our experiments. Eth was 0.8 J. U67 was 1 .44 J. . DOES WELD STRENGTH DEPEND ON HYDRATION CONDITIONS? ANSWER: Not on the amount of excess unbound water. There was no significant difference in weld strength between welding dripping wet tissues vs well blotted tissues. S WHAT DIFFERENCE IS THERE BETWEEN IRRADIATING THE WELD SURFACE THROUGH THE BIOMATERIAL VS THROUGH THE TISSUE, WHEN THE BIOMATERIAL IS PARTIALLY STAINED WITH ICG? ANSWER: There is a difference if the stain layer is heavily stained. Irradiation through the tissue allows direct irradiation on the weld surface which achieves the highest peak temperatures for the least laser pulse energy. Irradiation through the elastin heterograph causes direct irradiation of the rear surface of the stain layer, within the biomaterial and away from the weld surface, and thermal diffusion must bring the heat to the weld surface. This difference occurs only when the absorption by the stain layer is sufficiently high that little laser energy directly reaches the weld surface.

Proceedings Article | 22 May 1997 Paper

Penetration of fluorescent particles in gelatin during laser thrombolysis

HanQun Shangguan, Lee Casperson, Kenton Gregory, Scott Prahl

Proceedings Volume 2970, (1997) https://doi.org/10.1117/12.275030

KEYWORDS: Laser energy, Optical spheres, Laser ablation, Particles, Arteries, Absorption, Cavitation, Pulsed laser operation, Laser therapeutics, Visualization

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Proceedings Article | 17 May 1996 Paper

Photochemotherapy of intimal hyperplasia using Psoralen activated by uv light in porcine model

Lisa Buckley, Kenton Gregory, Deborah Bahlman, HanQun Shangguan, Henner Fahrenbach, Eli Rosenthal, Peter Block

Proceedings Volume 2671, (1996) https://doi.org/10.1117/12.239996

KEYWORDS: Injuries, Arteries, Animal model studies, Ultraviolet radiation, Blood, Heart, Statistical analysis, LASIK, Skin, Surgery

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Proceedings Article | 22 May 1995 Paper

Photoacoustic drug delivery: the effect of laser parameters on the spatial distribution of delivered drug

HanQun Shangguan, Lee Casperson, Alan Shearin, Kenton Gregory, Scott Prahl

Proceedings Volume 2391, (1995) https://doi.org/10.1117/12.209907

KEYWORDS: Absorption, Laser energy, Cavitation, Pulsed laser operation, Acoustics, Laser ablation, Photoacoustic spectroscopy, Laser tissue interaction, Fiber lasers, Dye lasers

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Proceedings Article | 12 May 1995 Paper

Welding artificial biomaterial with a pulsed diode laser and indocyanine green dye

Elaine La Joie, Andrew Barofsky, Kenton Gregory, Scott Prahl

Proceedings Volume 2395, (1995) https://doi.org/10.1117/12.209139

KEYWORDS: Semiconductor lasers, Indocyanine green, Laser tissue interaction, Tissues, Absorption, Laser welding, Glasses, Pulsed laser operation, Chromophores, Magnesium

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Proceedings Article | 12 July 1994 Paper

Quantifying psoralen in tissues by fluorescence: dosimetry for psoralen administration followed by ultraviolet A irradiation (PUVA) to block restenosis

Steven Jacques, Lisa Buckley, Scott Prahl, Kenton Gregory

Proceedings Volume 2130, (1994) https://doi.org/10.1117/12.179911

KEYWORDS: Luminescence, Tissues, In vitro testing, Optical fibers, Calibration, Ultraviolet radiation, Cell death, In vivo imaging, Magnesium, Blood

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Proceedings Article | 23 June 1993 Paper

Novel cylindrical illuminator tip for ultraviolet light delivery

HanQun Shangguan, Thomas Haw, Kenton Gregory, Lee Casperson

Proceedings Volume 1878, (1993) https://doi.org/10.1117/12.146582

KEYWORDS: Scattering, Light scattering, Epoxies, Fiber optic illuminators, Ultraviolet radiation, Optical fibers, Fabrication, Etching, Cladding, Laser energy

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Proceedings Article | 1 May 1991 Paper

Intraluminal laser atherectomy with ultrasound and electromagnetic guidance

Kenton Gregory, H. Thomas Aretz, Michael Martinelli, Earl LeDet, G. Hatch, Richard Gregg, Tomas Sedlacek, Wayne Haase

Proceedings Volume 1425, (1991) https://doi.org/10.1117/12.44040

KEYWORDS: Ultrasonography, Arteries, Electromagnetism, Sensors, Imaging systems, Image processing, Transducers, Navigation systems, Laser ablation, Diagnostics and therapeutics

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Proceedings Article | 1 July 1990 Paper

Fluid-core optical transmission for laser angioplasty

Kenton Gregory, R. Rox Anderson

Proceedings Volume 1201, (1990) https://doi.org/10.1117/12.17531

KEYWORDS: Laser energy, Laser therapeutics, Transmittance, Optical fibers, Cladding, Blood, Refraction, Microfluidics, Tissue optics, Tissues

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Showing 5 of 24 publications

Proceedings Volume Editor (28)

SPIE Conference Volume | 11 March 2020

Diagnostic and Therapeutic Applications of Light in Cardiology 2020

SPIE Conference Volume | 7 June 2019

Diagnostic and Therapeutic Applications of Light in Cardiology 2019

SPIE Conference Volume | 14 June 2018

Diagnostic and Therapeutic Applications of Light in Cardiology 2018

SPIE Conference Volume | 25 April 2017

Diagnostic and Therapeutic Applications of Light in Cardiology

SPIE Conference Volume | 18 May 2016

Photonic Therapeutics and Diagnostics XII

Showing 5 of 28 publications

Conference Committee Involvement (34)

Light in Cardiology 2025

25 January 2025 | San Francisco, California, United States

Diagnostic and Therapeutic Applications of Light in Cardiology 2024

27 January 2024 | San Francisco, California, United States

Diagnostic and Therapeutic Applications of Light in Cardiology 2023

28 January 2023 | San Francisco, California, United States

Diagnostic and Therapeutic Applications of Light in Cardiology 2022

22 January 2022 | San Francisco, California, United States

Diagnostic and Therapeutic Applications of Light in Cardiology 2021

6 March 2021 | Online Only, California, United States

Diagnostic and Therapeutic Applications of Light in Cardiology 2020

1 February 2020 | San Francisco, California, United States

Diagnostic and Therapeutic Applications of Light in Cardiology 2019

2 February 2019 | San Francisco, California, United States

Diagnostic and Therapeutic Applications of Light in Cardiology 2018

27 January 2018 | San Francisco, California, United States