B Choi

Summary

Affiliation: University of California
Country: USA

Publications

  1. ncbi request reprint Laser speckle imaging for monitoring blood flow dynamics in the in vivo rodent dorsal skin fold model
    Bernard Choi
    Beckman Laser Institute, University of California, Irvine, 92612, USA
    Microvasc Res 68:143-6. 2004
  2. ncbi request reprint Computational model to evaluate port wine stain depth profiling using pulsed photothermal radiometry
    Bernard Choi
    University of California, Beckman Laser Institute, Irvine, California 92612, USA
    J Biomed Opt 9:299-307. 2004
  3. ncbi request reprint Infrared imaging of 2-D temperature distribution during cryogen spray cooling
    Bernard Choi
    Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
    J Biomech Eng 124:669-75. 2002
  4. ncbi request reprint Determination of chemical agent optical clearing potential using in vitro human skin
    Bernard Choi
    Beckman Laser Institute, University of California, Irvine, California 92612, USA
    Lasers Surg Med 36:72-5. 2005
  5. ncbi request reprint Dynamic impedance measurements during radio-frequency heating of cornea
    Bernard Choi
    Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
    IEEE Trans Biomed Eng 49:1610-6. 2002
  6. ncbi request reprint Analysis of thermal relaxation during laser irradiation of tissue
    B Choi
    Biomedical Engineering Laser Laboratory, The University of Texas at Austin, Austin, TX 78712, USA
    Lasers Surg Med 29:351-9. 2001
  7. ncbi request reprint Use of optical coherence tomography to monitor biological tissue freezing during cryosurgery
    Bernard Choi
    Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
    J Biomed Opt 9:282-6. 2004
  8. ncbi request reprint A library based fitting method for visual reflectance spectroscopy of human skin
    Wim Verkruysse
    Beckman Laser Institute, University of California, Irvine, CA 92612, USA
    Phys Med Biol 50:57-70. 2005
  9. ncbi request reprint Effect of ambient humidity on light transmittance through skin phantoms during cryogen spray cooling
    Julio C Ramirez-San-Juan
    Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, USA
    Phys Med Biol 51:113-20. 2006
  10. ncbi request reprint Hand-held pulsed photothermal radiometry system to estimate epidermal temperature rise during laser therapy
    Byungjo Jung
    Beckman Laser Institute, Irvine, CA, USA
    Skin Res Technol 12:292-7. 2006

Collaborators

Detail Information

Publications46

  1. ncbi request reprint Laser speckle imaging for monitoring blood flow dynamics in the in vivo rodent dorsal skin fold model
    Bernard Choi
    Beckman Laser Institute, University of California, Irvine, 92612, USA
    Microvasc Res 68:143-6. 2004
  2. ncbi request reprint Computational model to evaluate port wine stain depth profiling using pulsed photothermal radiometry
    Bernard Choi
    University of California, Beckman Laser Institute, Irvine, California 92612, USA
    J Biomed Opt 9:299-307. 2004
    ..Comparison of the actual and reconstructed profiles from PPTR data revealed a good match for all four PWS skin characteristics. Results of this study indicate that PPTR is a viable approach for depth profiling of PWS skin...
  3. ncbi request reprint Infrared imaging of 2-D temperature distribution during cryogen spray cooling
    Bernard Choi
    Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
    J Biomech Eng 124:669-75. 2002
    ..5 mm. These results suggest that it is necessary to consider radial temperature gradients during cryogen spray cooling of tissue...
  4. ncbi request reprint Determination of chemical agent optical clearing potential using in vitro human skin
    Bernard Choi
    Beckman Laser Institute, University of California, Irvine, California 92612, USA
    Lasers Surg Med 36:72-5. 2005
    ..Optical clearing is a method that temporarily reduces the optical scattering of biological tissues...
  5. ncbi request reprint Dynamic impedance measurements during radio-frequency heating of cornea
    Bernard Choi
    Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
    IEEE Trans Biomed Eng 49:1610-6. 2002
    ..Preliminary impedance data obtained for in vivo porcine eyes were similar in magnitude to the in vitro values...
  6. ncbi request reprint Analysis of thermal relaxation during laser irradiation of tissue
    B Choi
    Biomedical Engineering Laser Laboratory, The University of Texas at Austin, Austin, TX 78712, USA
    Lasers Surg Med 29:351-9. 2001
    ..The objectives of this study were (1) to analyze tissue thermal relaxation following laser-induced heating, and (2) to calculate the time required for a laser-induced temperature rise to decrease to near-baseline values...
  7. ncbi request reprint Use of optical coherence tomography to monitor biological tissue freezing during cryosurgery
    Bernard Choi
    Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
    J Biomed Opt 9:282-6. 2004
    ..OCT can be used as a feedback tool during cryosurgical procedures to monitor progression of the freezing front...
  8. ncbi request reprint A library based fitting method for visual reflectance spectroscopy of human skin
    Wim Verkruysse
    Beckman Laser Institute, University of California, Irvine, CA 92612, USA
    Phys Med Biol 50:57-70. 2005
    ..The method is demonstrated using both simulated and measured reflectance spectra. An additional advantage of the method is that the fitting procedure is very fast...
  9. ncbi request reprint Effect of ambient humidity on light transmittance through skin phantoms during cryogen spray cooling
    Julio C Ramirez-San-Juan
    Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, USA
    Phys Med Biol 51:113-20. 2006
    ..The reduced light transmittance immediately after spurt termination was most likely because of scattering of light caused by condensation of water vapour due to aggressive cooling of ambient air in the wake of the cryogen spurt...
  10. ncbi request reprint Hand-held pulsed photothermal radiometry system to estimate epidermal temperature rise during laser therapy
    Byungjo Jung
    Beckman Laser Institute, Irvine, CA, USA
    Skin Res Technol 12:292-7. 2006
    ..In order to measure DeltaT(epi) on a specific PWS skin site, we developed an AC-coupled hand-held pulsed photothermal radiometry (PPTR) system, which overcomes the in vivo measurement limitations of bench-top systems...
  11. pmc Noninvasive blood flow imaging for real-time feedback during laser therapy of port wine stain birthmarks
    Yu Chih Huang
    Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92612, USA
    Lasers Surg Med 40:167-73. 2008
    ..To address this need, we propose use of laser speckle imaging (LSI) to provide real-time, quantitative feedback during laser surgery. Herein, we present in vitro and in vivo data collected with a clinic-based LSI instrument...
  12. ncbi request reprint Use of erythema index imaging for systematic analysis of port wine stain skin response to laser therapy
    Byungjo Jung
    Beckman Laser Institute, University of California, Irvine, CA, USA
    Lasers Surg Med 37:186-91. 2005
    ....
  13. ncbi request reprint Description and analysis of treatments for port-wine stain birthmarks
    Kristen M Kelly
    Beckman Laser Institute, Irvine, CA 92612, USA
    Arch Facial Plast Surg 7:287-94. 2005
    ....
  14. ncbi request reprint Microvascular blood flow dynamics associated with photodynamic therapy, pulsed dye laser irradiation and combined regimens
    Tia K Smith
    Beckman Laser Institute, University of California, Irvine, California 92612, USA
    Lasers Surg Med 38:532-9. 2006
    ..We further evaluate vascular effects of PDT alone, PDL alone and PDT/PDL in an in vivo rodent dorsal skinfold model...
  15. pmc Methods to enhance laser speckle imaging of high-flow and low-flow vasculature
    Bernard Choi
    Department of Biomedical Engineering, Beckman Laser Institute, University of California, Irvine, CA 92612, USA
    Conf Proc IEEE Eng Med Biol Soc 2009:4073-6. 2009
    ..01 ms, the linear response range extended to 10 and 280 mm/s, respectively. With application of an AC magnetic field to a solution of stagnant SPIO particles, an apparent increase of approximately 3x in speckle flow index was induced...
  16. ncbi request reprint Thermal responses of ex vivo human skin during multiple cryogen spurts and 1,450 nm laser pulses
    Rong Zhang
    Beckman Laser Institute, University of California, Irvine, 92612, USA
    Lasers Surg Med 38:137-41. 2006
    ..The objective of this study is to measure temperature variations at the epidermal-dermal junction in ex vivo human skin during three clinically relevant multiple cryogen spurt-laser pulse sequences (MCS-LPS)...
  17. ncbi request reprint Linear response range characterization and in vivo application of laser speckle imaging of blood flow dynamics
    Bernard Choi
    University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, USA
    J Biomed Opt 11:041129. 2006
    ..These findings imply that LSI can provide accurate wide-field maps of microvascular blood flow rate dynamics and highlight heterogeneities in flow response to the application of exogenous agents...
  18. ncbi request reprint Treatment of cutaneous vascular lesions using multiple-intermittent cryogen spurts and two-wavelength laser pulses: numerical and animal studies
    Wangcun Jia
    Beckman Laser Institute, University of California, Irvine, California 92612 1475, USA
    Lasers Surg Med 39:494-503. 2007
    ..In this study, the feasibility of applying multiple cryogen spurts intermittently with multiple two-wavelength laser pulses (MCS-MTWLP) was studied using numerical and animal models...
  19. pmc Thermal depth profiling of vascular lesions: automated regularization of reconstruction algorithms
    Wim Verkruysse
    Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, USA
    Phys Med Biol 53:1463-74. 2008
    ..Similar, or better, accuracy reconstructions can be achieved with an automated regularization procedure which enhances prospects for user friendly implementation of PPTR to optimize laser therapy on an individual patient basis...
  20. pmc Long-term blood vessel removal with combined laser and topical rapamycin antiangiogenic therapy: implications for effective port wine stain treatment
    Wangcun Jia
    Beckman Laser Institute, University of California, Irvine, California 92617 3010, USA
    Lasers Surg Med 42:105-12. 2010
    ..Our objectives were to (1) investigate whether topical RPM can inhibit reperfusion of photocoagulated blood vessels in an animal model and (2) determine the effective RPM concentration required to achieve this objective...
  21. ncbi request reprint Determination of human skin optical properties from spectrophotometric measurements based on optimization by genetic algorithms
    Rong Zhang
    University of California, Beckman Laser Institute, 1002 Health Sciences Road East, Irvine, California 92612, USA
    J Biomed Opt 10:024030. 2005
    ..Furthermore, the GA approach can lead to a reasonable understanding of the blood volume fraction and other skin properties, provided that the applicability of the diffusion approximation is satisfied...
  22. ncbi request reprint Determination of optimal view angles for quantitative facial image analysis
    Byungjo Jung
    Yonsei University, Department of Biomedical Engineering, Korea, 220 710
    J Biomed Opt 10:024002. 2005
    ..From these results, we propose that optimal view angles can be identified using the mannequin head model to image specific regions of interest on the face of human subjects...
  23. ncbi request reprint Influence of laser wavelength and pulse duration on gas bubble formation in blood filled glass capillaries
    Sol Kimel
    Beckman Laser Institute, University of California, Irvine, California 92612, USA
    Lasers Surg Med 36:281-8. 2005
    ..However, recent studies suggest that this assumption may not always be true. Our objective was to quantify thermally induced changes in blood that occur during irradiation using standard laser parameters...
  24. ncbi request reprint Characterization of port wine stain skin erythema and melanin content using cross-polarized diffuse reflectance imaging
    Byungjo Jung
    Beckman Laser Institute, Irvine, California 92612 1475, USA
    Lasers Surg Med 34:174-81. 2004
    ..To address these issues, a cross-polarized diffuse reflectance imaging system and color image analysis method has been developed to evaluate quantitatively erythema and melanin content in PWS skin...
  25. ncbi request reprint Measurements of laser light attenuation following cryogen spray cooling spurt termination
    Ahmad Edris
    College of Medicine, University of California, Irvine, California 92697, USA
    Lasers Surg Med 32:143-7. 2003
    ..However, while CSC can protect the epidermis from non-specific thermal damage, the cryogen film on the skin surface may pose a potential problem of laser light attenuation due to optical scattering...
  26. ncbi request reprint Spectra from 2.5-15 microm of tissue phantom materials, optical clearing agents and ex vivo human skin: implications for depth profiling of human skin
    John A Viator
    Beckman Laser Institute, University of California, 1002 Health Sciences Road East, Irvine, CA 92612, USA
    Phys Med Biol 48:N15-24. 2003
    ..In such cases, overestimating mu(ir) will underestimate chromophore depth and vice versa, although the effect is dependent on actual chromophore depth...
  27. ncbi request reprint In vivo port-wine stain depth determination with a photoacoustic probe
    John A Viator
    Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, Calfornia 92612, USA
    Appl Opt 42:3215-24. 2003
    ..In vivo measurements of PWS skin with different epidermal melanin concentrations correlated with the phantoms. Thus the photoacoustic probe can be used to determine PWS depth for most patients receiving laser therapy...
  28. ncbi request reprint Reversible dissociation of collagen in tissues
    Alvin T Yeh
    Laser Microbeam and Medical Program, Beckman Laser Institute, University of California, Irvine, California, USA
    J Invest Dermatol 121:1332-5. 2003
    ..These results reveal the assembly process of high-order collagen structures and propose a molecular mechanism for the increase in tissue transparency observed after glycerol application...
  29. ncbi request reprint Compensation of polarization-dependent loss in transmission fiber gratings by use of a Sagnac loop interferometer
    Chang Seok Kim
    Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
    Opt Lett 30:20-2. 2005
    ..The result is verified experimentally for a fiber acousto-optic tunable filter and cascaded long-period fiber gratings with either intrinsic or process-induced polarization-dependent filtering characteristics...
  30. ncbi request reprint Free electron laser lithotripsy: threshold radiant exposures
    K F Chan
    Department of Electrical and Computer Engineering, The University of Texas at Austin, 78712, USA
    J Endourol 14:161-7. 2000
    ....
  31. ncbi request reprint Determination of an optimized conversion matrix for device independent skin color image analysis
    Chang Seok Kim
    Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA 92612, USA
    Lasers Surg Med 37:138-43. 2005
    ..To obtain calibrated Commission International de l'Eclairage (CIE) color space images from RGB (red, green, and blue) images, it was necessary to derive an optimized conversion matrix specific to our imaging system...
  32. pmc Blood flow dynamics after laser therapy of port wine stain birthmarks
    Yu Chih Huang
    Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92612, USA
    Lasers Surg Med 41:563-71. 2009
    ..The objective of this study was to use objective feedback to assess the acute vascular response to laser therapy...
  33. ncbi request reprint Correlation between collagen solubility and skin optical clearing using sugars
    Jason Hirshburg
    Department of Biomedical Engineering, Texas A and M University, 337 Zachry Engineering Center, 3120 TAMU, College Station, Texas 77843, USA
    Lasers Surg Med 39:140-4. 2007
    ..This study examines the correlation between collagen solubility and the optical clearing potential (OCP) of sugars and sugar-alcohols using in vitro rodent skin...
  34. ncbi request reprint Investigation of the transduction mechanism of infrared detection in Melanophila acuminata: photo-thermal-mechanical hypothesis
    D X Hammer
    Department of Electrical Engineering, University of Texas, Austin, TX 78712, USA
    Comp Biochem Physiol A Mol Integr Physiol 132:381-92. 2002
    ..The results of this paper are discussed in relation to the photo-thermal-mechanical transduction hypothesis. This is the first experimental examination of the transduction mechanism in Melanophila acuminata...
  35. ncbi request reprint Dependence of calculus retropulsion dynamics on fiber size and radiant exposure during Ho:YAG lithotripsy
    Ho Lee
    Dept of Mechanical Engineering, The University of Texas at Austin, Texas Longhorns, Austin, TX 78712, USA
    J Biomech Eng 126:506-15. 2004
    ..The re-entrance flow of water induced by the bubble collapse is considered to be the cause of the rocking of the phantom...
  36. pmc Vascular effects of photodynamic and pulsed dye laser therapy protocols
    Jennifer Channual
    Beckman Laser Institute, University of California, Irvine, California 92612, USA
    Lasers Surg Med 40:644-50. 2008
    ..Here, we evaluate PDT alone, PDL alone, and PDT+PDL protocols using an optimized in vivo rodent dorsal window chamber model...
  37. pmc Combined benzoporphyrin derivative monoacid ring photodynamic therapy and pulsed dye laser for port wine stain birthmarks
    Joshua A Tournas
    Beckman Laser Institute, University of California, Irvine, CA 92612, USA
    Photodiagnosis Photodyn Ther 6:195-9. 2009
    ..We propose an alternative treatment option, combined PDT+PDL and performed a proof-of-concept preliminary clinical trial...
  38. pmc Following dimethyl sulfoxide skin optical clearing dynamics with quantitative nonlinear multimodal microscopy
    Maxwell Zimmerley
    Department of Chemistry, University of California, Irvine, California 92697, USA
    Appl Opt 48:D79-87. 2009
    ..Evidence is provided for a role of DMSO in compromising the structure of collagen fibers, associated with a reduction of the tissue's scattering properties...
  39. pmc Revisiting optical clearing with dimethyl sulfoxide (DMSO)
    Albert K Bui
    School of Biological Sciences, University of California, Irvine, California 92697, USA
    Lasers Surg Med 41:142-8. 2009
    ..Collectively, our data demonstrate the potential of DMSO alone to mitigate effects of scattering, which we expect will improve molecular imaging studies...
  40. pmc Impact of velocity distribution assumption on simplified laser speckle imaging equation
    Julio C Ramirez-San-Juan
    Optics Department, Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro No 1, Puebla, 72840, Mexico
    Opt Express 16:3197-203. 2008
    ..6) and predict different flow velocity range for high contrast. Our derived equations form the basis for simplified calculations of SFI values...
  41. ncbi request reprint A comparative study of photoacoustic and reflectance methods for determination of epidermal melanin content
    John A Viator
    Department of Dermatology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Invest Dermatol 122:1432-9. 2004
    ..We present preliminary modeling for photoacoustic probe design and analysis necessary for depth profiling of epidermal melanin...
  42. pmc The importance of long-term monitoring to evaluate the microvascular response to light-based therapies
    Bernard Choi
    J Invest Dermatol 128:485-8. 2008
  43. ncbi request reprint Collagen solubility correlates with skin optical clearing
    Jason Hirshburg
    J Biomed Opt 11:040501. 2006
    ..Herein we show that a chemical agent's tissue optical clearing potential is directly related to its collagen solubility, providing a rational design basis for effective, percutaneous formulations...
  44. pmc Enhancement of optical skin clearing efficacy using a microneedle roller
    Jinhee Yoon
    Yonsei University, Department of Biomedical Engineering, Wonju, Korea
    J Biomed Opt 13:021103. 2008
    ..In conclusion, our data suggest that the microneedle roller can be a good physical method to enhance transdermal delivery of optical clearing agents, and hence their optical clearing potential over large regions of skin...
  45. ncbi request reprint Can topically applied optical clearing agents increase the epidermal damage threshold and enhance therapeutic efficacy?
    Misbah H Khan
    Lasers Surg Med 35:93-5. 2004
  46. ncbi request reprint Optical clearing of in vivo human skin: implications for light-based diagnostic imaging and therapeutics
    Misbah H Khan
    Lasers Surg Med 34:83-5. 2004