scholarly journals 5-ALA Mediated Fluorescence Detection of Gastrointestinal Tumors

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Ekaterina Borisova ◽  
Borislav Vladimirov ◽  
Latchezar Avramov
Keyword(s):  
Light Guide ◽  
Aminolevulinic Acid ◽  
Light Emitting Diode ◽  
Protoporphyrin Ix ◽  
Normal Mucosa ◽  
Effective Algorithm ◽  
Mechanical Device ◽  
Light Emitting ◽  
Clinical Applicability ◽  
Dimensionless Ratio

Delta-aminolevulinic acid/protoporphyrin IX is applied for fluorescent tumor detection in the upper part of gastrointestinal tract. The 5-ALA is administered per os six hours before measurements at dose 20 mg/kg weight. High-power light-emitting diode at 405 nm is used as an excitation source. Special opto-mechanical device is built to use the light guide of standard video-endoscopic system. Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer. In such way, 1D detection and 2D visualization of the lesions' fluorescence are received, and both advantages and limitations of these methodologies are discussed in relation to their clinical applicability. Comparison of the spectra received from normal mucosa, inflammatory, and tumor areas is applied to evaluate the feasibility for development of simple but effective algorithm based on dimensionless ratio of the fluorescence signals at 560 and 635 nm, for differentiation of normal/abnormal gastrointestinal tissues.

scholarly journals Some Measures for COVID-19 Including Deep Ultraviolet Light-Emitting Diode (DUV-LED), Gc protein-derived Macrophage-Activating Factor (Gcmaf), and 5-Aminolevulinic Acid (5-ALA)

2021 ◽  
Vol 4 (2) ◽  
pp. 110-113
Author(s):  
Hiroshi Bando
Keyword(s):  
Influenza A ◽  
Aminolevulinic Acid ◽  
Light Emitting Diode ◽  
Protoporphyrin Ix ◽  
Chronic Fatigue ◽  
Influenza A Viruses ◽  
Light Emitting ◽  
Duv Led ◽  
Deep Ultraviolet ◽  
Gc Protein

Several trials for the COVID-19 pandemic are found. Prof. Shunji Nakamura, Tokushima University was awarded the 2014 Nobel prize in Physics for light-emitting diodes (LEDs). Deep ultraviolet LED (DUV-LED) causes SARS-CoV-2 inactivation as 99.9% by 265 nm. Gc protein-derived macrophage-activating factor (GcMAF)-based immunotherapy has a wider application for serious infection, chronic fatigue syndrome, and cancers. Covid center in Naples submitted a phase II report concerning GcMAF and COVID-19 in Feb 2021. 5-aminolevulinic acid (5-ALA) and its metabolite protoporphyrin IX (PpIX) show anti-inflammatory and antiviral effects for Zika, Dengue, influenza A viruses, and SARS-CoV-2. These results hopefully contribute to the research development for COVID-19.

scholarly journals Development and validation of a triple-LED surgical loupe device for fluorescence-guided resections with 5-ALA

2021 ◽  
pp. 1-9
Keyword(s):  
Predictive Value ◽  
Aminolevulinic Acid ◽  
Light Emitting Diode ◽  
Malignant Gliomas ◽  
Protoporphyrin Ix ◽  
Emission Spectra ◽  
White Led ◽  
Light Emitting ◽  
Blinded Study ◽  
Development And Validation

OBJECTIVE Fluorescence-guided resections performed using 5-aminolevulinic acid (5-ALA) have been studied extensively using the BLUE400 system. The authors introduce a triple–light-emitting diode (LED) headlight/loupe device for visualizing fluorescence, and compare this to the BLUE400 gold standard in order to assure similar and not more or less sensitive protoporphyrin-IX visualization. METHODS The authors defined the spectral requirements for a triple-LED headlight/loupe device for reproducing the xenon-based BLUE400 module. The system consisted of a white LED (normal surgery), a 409-nm LED for excitation, a 450-nm LED for background illumination, and appropriate observation filters. The prototype’s excitation and emission spectra, illumination and detection intensities, and spot homogeneity were determined. The authors further performed a prospectively randomized and blinded study for fluorescence assessments of fresh, marginal, fluorescing and nonfluorescing tumor samples comparing the LED/loupe device with BLUE400 in patients with malignant glioma treated with 20 mg/kg body weight 5-ALA. Tumor samples were immediately assessed in turn, both with a Kinevo and with a novel triple-LED/loupe device by different surgeons. RESULTS Seven triple-LED/loupe devices were analyzed. Illumination intensities in the 409- and 450-nm range were comparable to BLUE400, with high spot homogeneity. Fluorescence intensities measured distally to microscope oculars/loupes were 9.9-fold higher with the loupe device. For validation 26 patients with malignant gliomas with 240 biopsies were analyzed. With BLUE400 results as the reference, sensitivity for reproducing fluorescence findings was 100%, specificity was 95%, positive predictive value was 98%, negative predictive value was 100%, and accuracy was 95%. This study reached its primary aim, with agreement in 226 of 240 (94.2%, 95% CI 0.904–0.968). CONCLUSIONS The authors observed only minor differences regarding spectra and illumination intensities during evaluation. Fluorescence intensities available to surgeons were 9.9-fold higher with the loupe device. Importantly, the independent perception of fluorescence achieved using the new system and BLUE400 was statistically equivalent. The authors believe the triple-LED/loupe device to be a useful and safe option for surgeons who prefer loupes to the microscope for resections in appropriate patients.

A Highly Directional Light Emitting Diode Light Guide Bar Based on Concave V-Grooves

2012 ◽  
Vol 605-607 ◽  
pp. 2019-2022
Author(s):  
Chi Feng Chen ◽  
Bo Han Lin ◽  
Shin Hong Kuo
Keyword(s):  
Light Guide ◽  
Light Emitting Diode ◽  
Simulation Software ◽  
Optical Simulation ◽  
Structure Parameters ◽  
Light Emitting ◽  
Led Light

A light emitting diode (LED) light guide bar based on concave V-grooves is investigated by using optical simulation software to control the distribution of illumination angle. The structure parameters of V-groove and the distribution of micro-prism are considered. It is found that the illumination angle of LED light guide bar is most concentrated within ±35 degrees.

Fabrication of High Performance Light Guide Plate and New Design for High Luminance

2010 ◽  
Author(s):  
Takaya Fujimoto ◽  
Kenji Yamashita ◽  
Satoshi Nishida ◽  
Daiji Noda ◽  
Tadashi Hattori
Keyword(s):  
High Performance ◽  
Light Guide ◽  
Liquid Crystal Display ◽  
Light Emitting Diode ◽  
High Luminance ◽  
Light Emitting ◽  
Light Guide Plate ◽  
Guide Plate ◽  
Average Luminance ◽  
Point Light

Recently, LED (Light Emitting Diode) is paid to attention as a new source of light. However, it doesn’t turn to shine on a wide area efficiently because LED is a point light. Then, the method of the light guide plate technology used for the liquid crystal display etc, and use as the LED lighting is examined. A minute reflection dots exists bottom of the light guide plate, system is such that light comes out from the surface because the light that hits the dots break a total reflection condition. In our laboratory, the function of the diffusion seat and the condensing prism seat that is complete parts of the lighting panel was involved by optimizing shape and the arrangement of the dots, and it works on the research of the light guide plate where uniform luminescence is enabled. In the process of study, it has been understood that luminance increases by increasing the number of dots, too. Therefore, an accumulating method of piling up two or more light guide plates was proposed as a method of achieving high luminance for highly effective lighting usage, and the device was analyzed with an optical simulator. As a result of optimization, the average luminance has improved by 15%. We are starting to fabricate this high luminance light guide plate by accumulating method. If this piled light guide plate is completed and luminance is improved in accordance with the simulation, it will be possible to convert it to a higher luminance light guide plate.

scholarly journals A Light Guide Plate That Uses Asymmetric Intensity Distribution of Mini-LEDs for the Planar Illuminator

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 141 ◽  
Author(s):  
Zhi-Ting Ye ◽  
Yung-Min Pai ◽  
Cheng-Huan Chen ◽  
Hao-Chung Kuo ◽  
Lung-Chien Chen
Keyword(s):  
Intensity Distribution ◽  
Light Guide ◽  
Light Emitting Diode ◽  
Bottom Surface ◽  
Total Efficiency ◽  
Considerable Time ◽  
Light Emitting ◽  
Light Guide Plate ◽  
Guide Plate ◽  
Diffusion Reflection

Traditional backlights are designed with new dot patterns, and then injection molding, laser beam fabrication, or UV (Ultraviolet) roll-to-plate imprinting is used to apply dot patterns to a light guide plate—the process consumes considerable time and resources. Therefore, we propose a novel light guide design that does not use a dot pattern. We designed an asymmetric intensity distribution of mini-LEDs (Light Emitting Diode) and a light guide plate with a fully printed diffusion reflection on the bottom surface for a planar illuminator. The design rules for the proposed architecture are described in this paper. The archetype design with a 152.4 mm circular down-light has a diameter of 143 mm for the planar light source module. The experiment achieved a total efficiency of 85% and uniformity of 92.6%.

Influence of Multiple Peak Light-emitting-diode Curing Unit Beam Homogenization Tips on Microhardness of Resin Composites

2020 ◽  
Vol 45 (3) ◽  
pp. 327-338 ◽  
Author(s):  
J Soto-Montero ◽  
G Nima ◽  
FA Rueggeberg ◽  
CTS Dias ◽  
M Giannini
Keyword(s):  
Light Guide ◽  
Profile Analysis ◽  
Light Emitting Diode ◽  
Beam Profile ◽  
Composite Resins ◽  
Bottom Surface ◽  
Light Emitting ◽  
Blue Led ◽  
Significant Difference ◽  
Light Guides

SUMMARY This study evaluated the effect of light curing unit (LCU) guide type (regular or homogenizing) on top and bottom microhardness of conventional and bulk-fill resin-based composites (RBCs). A polywave light-emitting-diode (LED) LCU (Bluephase Style, Ivoclar Vivadent AG) was used with two different light guides: a regular tip (RT, 935 mW/cm2 emittance) and a homogenizer tip (HT, 851 mW/cm2 emittance). Two conventional RBCs (Herculite Ultra [HER], Kerr Corp; Tetric EvoCeram [TEC], Ivoclar Vivadent AG) and two bulk-fill RBCs (SonicFill [SOF], Kerr Corp; Tetric EvoCeram Bulk Fill [TBF], Ivoclar Vivadent AG) were tested. Disc-shaped samples (10 mm Ø), 2-mm thick for conventional composites and 4-mm thick for bulk-fill composites were prepared. Samples were light cured according to manufacturer-recommended times. Knoop microhardness values (KHN) were obtained on the top and bottom surfaces of each specimen at locations correlated with the output of the three LED chips emitting blue (456 nm) or violet light (409 nm). Beam profile analysis using both light guides was also performed. Microhardness of each composite was analyzed using three-way analysis of variance and Tukey honestly significant difference post hoc test (α=0.05). Beam profile images showed better light distribution across the surface of the HT light guide. Use of the HT decreased KHN of HER at the locations of the blue LED chips at bottom of the sample but had no effect on the top surface. For TEC, use of HT increased KHN of all three LED locations at the top surface. Use of the HT increased KHN of SOF at locations corresponding to one of the blue and the violet LED chips at the bottom surface. For TBF, HT increased KHN at all top surface locations. All RBCs showed higher mean KHN at the top compared with the bottom surfaces. In general, all composites presented a higher KHN at the blue LED areas regardless of the surface or the tip used. Results suggest that the homogenizer light guide resulted in significantly increased microhardness at the top, in composite resins containing alternative photoinitiators; however, that effect was not observed at the bottom surfaces.

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