35 results match your criteria: "Oregon Medical Laser Center[Affiliation]"
J Trauma Acute Care Surg
August 2012
From the Oregon Medical Laser Center, Providence Health and Services, Portland, Oregon, USA.
Background: Noncompressible hemorrhage is the leading cause of preventable death caused by hemorrhage on the battlefield. Currently, there are no hemostatic agents with the ability to control noncompressible hemorrhage. A wound stasis dressing based upon rapidly expanding cellulose minisponges (MS) was developed and tested in a lethal noncompressible model in swine, by fully transecting subclavian artery and vein.
View Article and Find Full Text PDFActa Biomater
January 2012
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, OR 97225, USA.
The development of vascular grafts has focused on finding a biomaterial that is non-thrombogenic, minimizes intimal hyperplasia, matches the mechanical properties of native vessels and allows for regeneration of arterial tissue. In this study, the structural and mechanical properties and the vascular cell compatibility of electrospun recombinant human tropoelastin (rTE) were evaluated as a potential vascular graft support matrix. Disuccinimidyl suberate (DSS) was used to cross-link electrospun rTE fibers to produce a polymeric recombinant tropoelastin (prTE) matrix that is stable in aqueous environments.
View Article and Find Full Text PDFJ Biomater Appl
August 2012
Oregon Medical Laser Center, Providence St. Vincent Medical Center, 9205 SW Barnes Road, Portland, Oregon 97225, USA.
An off-the-shelf vascular graft biomaterial for vascular bypass surgeries is an unmet clinical need. The vascular biomaterial must support cell growth, be non-thrombogenic, minimize intimal hyperplasia, match the structural properties of native vessels, and allow for regeneration of arterial tissue. Electrospun recombinant human tropoelastin (rTE) as a medial component of a vascular graft scaffold was investigated in this study by evaluating its structural properties, as well as its ability to support primary smooth muscle cell adhesion and growth.
View Article and Find Full Text PDFJ Biomed Opt
May 2011
Providence St. Vincent Medical Center, Oregon Medical Laser Center, Portland, OR 97225, USA.
We describe the development, design, fabrication, and testing of an optical wire to assist in the surgical removal of small lesions during breast-conserving surgery. We modify a standard localization wire by adding a 200-μm optical fiber alongside it; the resulting optical wire fit through an 18 gauge needle for insertion in the breast. The optical wire is anchored in the lesion by a radiologist under ultrasonic and mammographic guidance.
View Article and Find Full Text PDFJ Gastrointest Surg
November 2010
Oregon Medical Laser Center, Providence St Vincent Medical Center, 9205 SW Barnes Road, Portland, Oregon 97225, USA.
Background: Bleeding from the liver surface is common after hepatic resection. Animal studies have demonstrated superiority of argon beam coagulation (ABC) and 38% human serum albumin when applied together after partial liver resection when compared to ABC alone. There are no data addressing the combination of albumin and argon beam coagulation (ABCA) applied to the bleeding liver after resection in humans.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
July 2009
Oregon Medical Laser Center, Providence St Vincent Medical Center, Portland, OR 97225, USA.
We present a Monte Carlo-derived Green's function for the propagation of partially spatially coherent fields. This Green's function, which is derived by sampling Huygens-Fresnel wavelets, can be used to propagate fields through an optical system and to compute first- and second-order field statistics directly. The concept is illustrated for a cylindrical f/1 imaging system.
View Article and Find Full Text PDFAm J Surg
April 2009
Oregon Medical Laser Center, Providence St Vincent Medical Center, Portland, OR 97225, USA.
Background: Vena caval injury is a rare but serious complication of laparoscopic surgery, and often requires conversion to an open procedure. The current study investigated whether a vena caval injury could be repaired with a chitosan dressing laparoscopically.
Methods: Six domestic swine were studied.
J Endourol
September 2007
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon 97225, USA.
Purpose: Laparoscopic partial nephrectomy (LPN) remains a technically challenging procedure mainly because of the lack of reliable methods of hemostasis. We evaluated the feasibility of using concentrated human albumin with argon-beam coagulation to control hemorrhaging and urinary leakage during LPN.
Materials And Methods: Six domestic swine underwent heparinization, then lower-pole LPN after renal-hilar vascular control had been obtained.
J Biomed Mater Res B Appl Biomater
April 2008
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon, USA.
Objectives: An external chitosan-based hemostatic bandage has been used to control aggressive bleeding from traumatic injuries. This study was to evaluate the feasibility of using an internal chitosan dressing based on the external platform to control hemorrhage and urinary leakage by sealing off the parenchymal wound following Laparoscopic partial nephrectomy (LPN) in a porcine model.
Methods: Nine heparinized domestic swine underwent bilateral laparoscopic partial nephrectomies involving either a polar (N = 13) or wedge resection (N = 5) followed by treatment with the chitosan dressing.
J Biomed Mater Res B Appl Biomater
April 2007
Oregon Medical Laser Center, Providence St. Vincent Medical Center, 9205 SW Barnes Road, Portland, Oregon 97225, USA.
Objectives: To study the feasibility of urethral reconstruction with two urethroplasty techniques using an elastin and collagen heterograft in rabbits.
Materials And Methods: Fifty-two male rabbits were studied. Two types of injury, (1) a 1.
J Biomed Opt
January 2007
Oregon Medical Laser Center, 9205 SW Barnes Road, Portland, Oregon 97225, USA.
We describe a method for the preparation of a polyurethane phantom to simulate the optical properties of biologic tissues at two wavelengths in the visible and near-infrared spectral range. We characterize the addition of added molecular absorbers with relatively narrow absorption bands [full width at half maximum (FWHM) 32 and 76 nm for Epolight 6084 and 4148, respectively] for independent absorption at 690 nm for absorption up to 5 cm(-1), and 830 nm for absorptions up to 3 cm(-1). Absorption by both dyes is linear with concentration in these respective regions and is consistent in polyurethane both before and after curing.
View Article and Find Full Text PDFJ Biomed Opt
March 2005
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon, USA.
Polarized light imaging has been used to detect the borders of skin cancer and facilitate assessment of cancer boundaries. A design for an inexpensive handheld polarized camera is presented and clinical images acquired with this prototype are shown. The camera is built with two universal serial bus (USB) color video cameras, a polarizing beamsplitter cube, and a 4x objective lens.
View Article and Find Full Text PDFLasers Surg Med
February 2005
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon 97225, USA.
Background And Objectives: Laser-assisted end to end vascular anastomosis of an elastin heterograft to native artery may prevent problems associated with currently available vascular synthetic grafts and conventional suture anastomosis.
Study Design/materials And Methods: A total of 21 anastomoses in the carotid arteries of 7 domestic swine were performed with an 800 nm laser and an albumin stent plus solder. There were 5 artery to artery and 16 elastin heterograft to native artery anastomoses.
J Biomed Mater Res B Appl Biomater
October 2004
Oregon Medical Laser Center, Providence St. Vincent Medical Center, 9205 SW Barnes Raod, Portland, Oregon 97225, USA.
Topically applied concentrated albumin with argon beam coagulation (ABCA) has been shown to be more effective at achieving hemostasis than using argon beam coagulation alone (ABC) in a liver injury model. This study investigated the host response to the concentrated albumin after argon beam coagulation. Complete hemostasis was achieved using ABCA (N = 10) or ABC (N = 10) on a nonanatomic liver resection in a heparinized porcine model.
View Article and Find Full Text PDFPhotomed Laser Surg
August 2004
Oregon Medical Laser Center, Providence St. Vincent Medical Center, 9555 SW Barnes Road, Portland, OR 97225, USA.
Background Data: Laser-assisted end-to-end vascular anastomosis of an elastin heterograft to native artery may avoid the problems associated with currently available vascular synthetic grafts and conventional suture anastomosis.
Methods: A total of 21 anastomoses in the carotid arteries of seven domestic pigs were performed with an 800-nm laser and an albumin stent plus solder. There were five artery to artery and 16 elastin heterograft to native artery anastomoses.
J Clin Laser Med Surg
April 2004
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon, USA.
Objective: This investigation was done in order to find optimal indocyanine green (ICG) concentration and energy irradiance in laser vascular welding.
Background Data: Many studies have shown that laser tissue welding with albumin solder/ICG may be an effective technique in surgical reconstruction. However, there are few reports regarding optimal laser settings and concentrations of ICG within the albumin solder in laser-assisted vascular anastomosis.
J Biomed Mater Res A
April 2004
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon 97225, USA.
We have investigated the long-term effect of aluminum chloride (AlCl(3)) treatment on the calcification and inflammatory reaction of a porcine elastin-derived biomaterial (PEB) in a novel subdermal adult mouse model. Untreated PEB disks and PEB treated with AlCl(3) were implanted subdermally in BALB/c mice for 30, 60, and 180 days. The calcification of the elastin disks was examined with histological analysis and atomic absorption analysis of calcium content.
View Article and Find Full Text PDFTissue Eng
August 2003
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon 97225, USA.
A nondestructive, acousto-optical method for characterizing the mechanical loss factor of biological tissues and tissue scaffolds is presented and applied to the characterization of an elastin tissue scaffold derived from bovine nuchal ligament. The method relies on launching guided surface acoustic waves into the tissue scaffold with a small speaker and simultaneously illuminating a small region of the scaffold distant from the speaker with a low-power HeNe laser. The phase lag between the driving acoustic wave and the shift in the backscattered laser speckle pattern is determined as a measure of the mechanical loss factor of the scaffold, tan delta.
View Article and Find Full Text PDFAppl Opt
June 2003
Oregon Medical Laser Center, Providence St. Vincent Hospital, 9205 S.W. Barnes Road, Portland, Oregon 97225, USA.
If a single optical fiber is used for both delivery and collection of light, two major factors affect the measurement of collected light: (1) the light transport in the medium that describes the amount of light that returns to the fiber and (2) the light coupling to the optical fiber that depends on the angular distribution of photons entering the fiber. We focus on the importance of the latter factor and describe how the efficiency of the coupling depends on the optical properties of the medium. For highly scattering tissues, the efficiency is well predicted by the numerical aperture (NA) of the fiber.
View Article and Find Full Text PDFLasers Surg Med
August 2003
Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon 97225, USA.
Background And Objectives: We compared ureteral anastomosis using a laser and intraluminal albumin stent with both conventional suturing and laser soldering techniques.
Study Design/materials And Methods: Twelve pigs underwent bilateral ureteral anastomoses (N = 24) using one of the three anastomotic methods: (1) laser welding with intraluminal albumin stent (N = 11); (2) with albumin solder (N = 8); and (3) conventional suturing (N = 5). Operative parameters, leakage rate, intrapelvic perfusion pressure, urography, and histology of the anastomoses were examined.
J Biomed Mater Res
June 2003
Oregon Medical Laser Center, Oregon Health & Science University, Portland, OR 97225, USA.
Hemostasis in the traumatized liver has been achieved by thermally denaturing topically applied albumin. In this article, the mechanical properties of liver and denatured albumin (solder) were measured, and the failure methods of liver repaired with albumin were identified. The ultimate tensile strength and Young's modulus were measured for healthy liver (N = 20) and thermally damaged liver (N = 20).
View Article and Find Full Text PDFJ Acoust Soc Am
October 2002
Oregon Medical Laser Center and Oregon Graduate Institute, Portland, USA.
Optoacoustic imaging is based on the generation of thermoelastic stress waves by heating an object in an optically heterogeneous medium with a short laser pulse. The stress waves contain information about the distribution of structures with preferential optical absorption. Detection of the waves with an array of broadband ultrasound detectors at the surface of the medium and applying a backprojection algorithm is used to create a map of absorbed energy inside the medium.
View Article and Find Full Text PDFLasers Surg Med
January 2003
Oregon Medical Laser Center, Providence St Vincent Medical Center, 9205 SW Barnes Rd, Portland, Oregon 97225, USA.
Background And Objectives: The success of laser tissue welding or soldering depends on optimal laser settings, solder material, and tissue type and geometry. To develop a practical laser welding technique for ureteral repair, an intraluminal albumin stent was designed to enhance the welding effects on ureteral end to end anastomosis.
Study Design/materials And Methods: In vitro porcine ureters were anastomosed using an albumin stent alone, the albumin stent plus a solder, and the solder alone.
J Thromb Thrombolysis
June 2002
Oregon Medical Laser Center, Portland, OR 97225, USA.
Background/objective: Laser thrombolysis is the selective removal of thrombus from occluded blood vessels using laser energy. A reconstituted clot model with reproducible optical absorption properties was developed to evaluate the effect of various laser parameters on thrombus removal rate.
Study Design/materials And Methods: Reconstituted clots were made with known fibrinogen concentrations and hematocrits.
J Biomed Opt
July 2002
Oregon Health and Science University, Department of Dermatology, Portland, Oregon and Providence St. Vincent Medical Center, Oregon Medical Laser Center, Portland, Oregon, USA.
Linearly polarized light that illuminates skin is backscattered by superficial layers and rapidly depolarized by birefringent collagen fibers. It is possible to distinguish such superficially backscattered light from the total diffusely reflected light that is dominated by light penetrating deeply into the dermis. The method involves acquisition of two images through an analyzing linear polarizer in front of the camera, one image (I(par)) acquired with the analyzer oriented parallel to the polarization of illumination and one image (I(per)) acquired with the analyzer oriented perpendicular to the illumination.
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