scholarly journals The Optical Properties of Indocyanine Green suspended in Solution as Observed under Near Infrared LED and LASER Light Conditions

2021 ◽  
Vol 10 (5) ◽  
pp. 080-089
Author(s):  
Angharad Curtis ◽  
Kang Li ◽  
Mohammed Ali ◽  
Nigel Copner
Keyword(s):  
Optical Properties ◽  
Indocyanine Green ◽  
Near Infrared ◽  
Laser Light ◽  
Optical Power ◽  
Excitation Power ◽  
Light Conditions ◽  
Cmos Camera ◽  
Fluorescent Marker ◽  
Optimal Imaging

The use of Indocyanine Green (ICG) as a fluorescent marker at Near Infrared (NIR) excitation wavelengths is well established in clinical imaging. Typical systems comprise multiple LED sources for optimal imaging which can result in unnecessary energy transfer to patients and contribute to tissue damage. An experimental setup comprising a 780 nm excitation channel generating up to 10 mW of optical power is used in order to determine if there is potential to exploit the optical properties of ICG, in order to reduce the total excitation power through pulsing. We demonstrate in this work that a single 1.6 Megapixel CMOS camera with quantum efficiency of less than 30% is appropriate to capture both fluorescent and non-fluorescent landmarks at NIR wavelengths. Experimental results verify that all ICG solutions tested yielded detectable fluorescence and that degradation of fluorescence intensity over time is multifaceted.

scholarly journals Interférométrie et réflectométrie haute résolution en lumière incohérente : modélisation d'interférogrammes

2000 ◽  
Vol 77 (9) ◽  
pp. 685-692
Author(s):  
C Lupi ◽  
E Tanguy ◽  
C Boisrobert ◽  
F de Fornel
Keyword(s):  
Optical Properties ◽  
Spatial Resolution ◽  
White Light ◽  
Near Infrared ◽  
Michelson Interferometer ◽  
Optical Power ◽  
Source Spectrum ◽  
Optical Fibres ◽  
Low Coherence ◽  
Haute Résolution

We report on low-coherence, near-infrared reflectometry applied to optical fibres, waveguides, and coupling devices to detect the echoes due to reflective propagation defects and measure their optical properties — losses or attenuation, dispersion. This technique, based on interferometry, leads to the highest spatial resolution and the lowest detectable reflected optical power. We scan the reference arm of our Michelson interferometer around the ``white light fringe'' position and obtain interferograms whose envelopes and fringes contain information on the light source spectrum and the reflectivity of the test arm. Theoretical and experimental results are compared. Examples are given and show that numerical simulations are needed to understand the signatures of the reflectors and get to their physical structures.

Optimal imaging windows of indocyanine green‐assisted near‐infrared dental imaging with rat model and its comparison to X‐ray imaging

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Zhongqiang Li ◽  
Thomas Hartzler ◽  
Alexandra Ramos ◽  
Michelle L. Osborn ◽  
Yanping Li ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Rat Model ◽  
Near Infrared ◽  
X Ray ◽  
Dental Imaging ◽  
X Ray Imaging ◽  
Optimal Imaging

scholarly journals Frond Optical Properties of the Fern Phyllitis scolopendrium Depend on Light Conditions in the Habitat

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1254
Author(s):  
Mateja Grašič ◽  
Tjaša Sovdat ◽  
Alenka Gaberščik
Keyword(s):  
Optical Properties ◽  
Phenotypic Plasticity ◽  
Near Infrared ◽  
Morphological Plasticity ◽  
Biochemical Properties ◽  
Tree Canopy ◽  
Light Conditions ◽  
Radiation Level ◽  
Sampling Times ◽  
Insight Into

Ferns display an elevated degree of phenotypic plasticity to changes in irradiance levels; however, only a few reports deal with their response to different light conditions. To get an insight into the extent of phenotypic plasticity of the fern Phyllitis scolopendrium, thriving in a forested area along a radiation gradient at the entrance of a cave, we examined selected biochemical, morphological, and physiological frond traits of the ferns from three different habitats. Sampling was performed two times during the vegetation season, in April and June. We also measured frond optical properties to point out the differences in leaf/light interactions between different plant samples. According to frond size, the middle habitat, receiving 125 µmol m−2s−1 of photosynthetically active radiation at both sampling times, appeared to be the most favourable. The production of UV-absorbing substances was highest in the habitat with the lowest radiation level. At the beginning of the season, the level of photosynthetic pigments in this habitat was the same as in the other habitats, while it was significantly lower in June when the tree canopy was closed. Frond reflectance was similar when comparing habitats and different sampling times. The most significant differences were obtained in the UV-A and near-infrared regions. The reflectance spectra depended mainly on frond biochemical properties, which altogether explained 54% (p ≤ 0.05) of the spectra variability. Frond transmittance depended on both, morphological parameters, explaining 51% (p ≤ 0.05), and frond biochemistry, explaining 73% (p ≤ 0.05) of the spectra variability. P. scolopendrium was revealed to be highly plastic regarding light conditions. The shapes of the frond reflectance and transmittance optical curves were similar to those typical of leaves of seed plants. The fronds exhibited high morphological plasticity when comparing different habitats. However, their biochemical and optical traits differed more between the two sampling times than between the habitats.

Reversible photo- and thermal-effects on luminescence of gold nanoclusters: implications for nanothermometry

2021 ◽  
Author(s):  
Jan Valenta ◽  
Michael Greben ◽  
Goutam Pramanik ◽  
Klaudia Kvakova ◽  
Petr Cigler
Keyword(s):  
Optical Properties ◽  
Thermal Effects ◽  
Near Infrared ◽  
Variable Temperature ◽  
Gold Nanoclusters ◽  
Excitation Power ◽  
Optical Transitions ◽  
Excitation Spectra

Optical properties of colloidal near infrared (NIR) emitting gold nanoclusters (AuNCs) are thoroughly investigated at variable temperature and excitation power. Both absorption and photoluminescence (PL) excitation spectra reveal optical transitions...

scholarly journals A novel indocyanine green-based fluorescent marker for guiding surgical tumor resection

2021 ◽  
pp. 2150013
Author(s):  
Jiawei Ge ◽  
Justin D. Opfermann ◽  
Hamed Saeidi ◽  
Katherine A. Huenerberg ◽  
Christopher D. Badger ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Feasibility Study ◽  
Near Infrared ◽  
Ex Vivo ◽  
Tumor Resection ◽  
Fluorescent Marker ◽  
India Ink ◽  
Long Term Treatment ◽  
Mouse Study

Surgical tumor resection is a common approach to cancer treatment. India Ink tattoos are widely used to aid tumor resection by localizing and mapping the tumor edge at the surface. However, India Ink tattoos are easily obscured during electrosurgical resection, and fade in intensity over time. In this work, a novel near-infrared (NIR) fluorescent marker is introduced as an alternative. The NIR marker was made by mixing indocyanine green (ICG), biocompatible cyanoacrylate, and acetone. The marking strategy was evaluated in a chronic ex vivo feasibility study using porcine tissues, followed by a chronic in vivo mouse study while compared with India Ink. In both studies, signal-to-noise (SNR) ratios and dimensions of the NIR markers and/or India Ink over the study period were calculated and reported. Electrocautery was performed on the last day of the mouse study after mice were euthanized, and SNR ratios and dimensions were quantified and compared. Biopsy was performed at all injection sites and slides were examined by a pathologist. The proposed NIR marker achieved (i) consistent visibility in the 26-day feasibility study and (ii) improved durability, visibility, and biocompatibility when compared to traditional India Ink over the six-week period in an in vivo mouse model. These effects persist after electrocautery whereas the India Ink markers were obscured. The use of a NIR fluorescent presurgical marking strategy has the potential for intraoperative tracking during long-term treatment protocols.

Antibacterial photodynamic treatment of periodontopathogenic bacteria with indocyanine green and near-infrared laser light enhanced by TroloxTM

2015 ◽  
Vol 47 (4) ◽  
pp. 350-360 ◽  
Author(s):  
Stefan Kranz ◽  
Marie Huebsch ◽  
Andre Guellmar ◽  
Andrea Voelpel ◽  
Silke Tonndorf-Martini ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Near Infrared ◽  
Laser Light ◽  
Infrared Laser ◽  
Photodynamic Treatment ◽  
Periodontopathogenic Bacteria

scholarly journals Near infrared light fluorescence imaging-guided biomimetic nanoparticles of extracellular vesicles deliver indocyanine green and paclitaxel for hyperthermia combined with chemotherapy against glioma

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Meng Wang ◽  
Chen-Yan Lv ◽  
Shu-Ang Li ◽  
Jun-Kuan Wang ◽  
Wen-Zheng Luo ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Indocyanine Green ◽  
Extracellular Vesicles ◽  
Near Infrared ◽  
Laser Light ◽  
Cell Counting ◽  
Infrared Light ◽  
Acetoxymethyl Ester ◽  
Nude Mouse Model ◽  
U251 Cells

Abstract Background We investigated the therapeutic effect of targeting extracellular vesicles (EVs) loaded with indocyanine green (ICG) and paclitaxel (PTX) on glioma. Methods Raw264.7 cells were harvested to extract EVs for the preparation of ICG/PTX@RGE-EV by electroporation and click chemistry. We evaluated the success of modifying Neuropilin-1 targeting peptide (RGE) on the EV membrane of ICG/PTX@RGE-EV using super-resolution fluorescence microscopy and flow cytometry. Spectrophotometry and high performance liquid chromatography (HPLC) were implemented for qualitative and quantitative analysis of the ICG and PTX loaded in EVs. Photothermal properties of the vesicles were evaluated by exposing to 808-nm laser light. Western blot analysis, cell counting kit 8 (CCK-8), Calcein Acetoxymethyl Ester/propidium iodide (Calcein-AM/PI) staining, and flow cytometry were utilized for assessing effects of vesicle treatment on cellular behaviors. A nude mouse model bearing glioma was established to test the targeting ability and anti-tumor action of ICG/PTX@RGE-EV in vivo. Results Under exposure to 808-nm laser light, ICG/PTX@RGE-EV showed good photothermal properties and promotion of PTX release from EVs. ICG/PTX@RGE-EV effectively targeted U251 cells, with activation of the Caspase-3 pathway and elevated apoptosis in U251 cells through chemotherapy combined with hyperthermia. The anti-tumor function of ICG/PTX@RGE-EV was confirmed in the glioma mice via increased accumulation of PTX in the ICG/PTX@RGE-EV group and an increased median survival of 48 days in the ICG/PTX@RGE-EV group as compared to 25 days in the PBS group. Conclusion ICG/PTX@RGE-EV might actively target glioma to repress tumor growth by accelerating glioma cell apoptosis through combined chemotherapy-hyperthermia. Graphic Abstract

scholarly journals Non-Invasive Measurement Of Tissue Chromophore Concentrations And Cerebral Blood Flow Using Broad-Band Continuous Wave Near Infrared Spectroscopy

2021 ◽  
Author(s):  
Hadi Zabihi-Yeganeh
Keyword(s):  
Blood Flow ◽  
Optical Properties ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Continuous Wave ◽  
Broad Band ◽  
Optical Properties Of Tissue

We present a broad-band, continuous wave spectral approach to quantify the baseline optical properties of tissue, in particular the absolute absorption and scattering properties and changes in the concentrations of chromophores, which can assist to quantify the regional blood flow from dynamic contrast-enhanced near-infrared spectroscopy data. Experiments were conducted on phantoms and piglets. The baseline optical properties of tissue were determined by performing a multi-parameter wavelength-dependent differential data fit of the near infrared reflectance spectrum between 680 nm and 970 nm of a photon diffusion equation solution for a semi-infinite homogeneous medium. These baseline optical properties of the piglet head tissue were used to quantify the temporal dynamics of the concentration of the intravenously administered contrast agent Indocyanine Green in the piglet brain. The temporal traces of the Indocyanine Green concentration measured by our method were used to estimate the cerebral blood flow using a bolus tracking technique.

scholarly journals Non-Invasive Measurement Of Tissue Chromophore Concentrations And Cerebral Blood Flow Using Broad-Band Continuous Wave Near Infrared Spectroscopy

2021 ◽  
Author(s):  
Hadi Zabihi-Yeganeh
Keyword(s):  
Blood Flow ◽  
Optical Properties ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Continuous Wave ◽  
Broad Band ◽  
Optical Properties Of Tissue

We present a broad-band, continuous wave spectral approach to quantify the baseline optical properties of tissue, in particular the absolute absorption and scattering properties and changes in the concentrations of chromophores, which can assist to quantify the regional blood flow from dynamic contrast-enhanced near-infrared spectroscopy data. Experiments were conducted on phantoms and piglets. The baseline optical properties of tissue were determined by performing a multi-parameter wavelength-dependent differential data fit of the near infrared reflectance spectrum between 680 nm and 970 nm of a photon diffusion equation solution for a semi-infinite homogeneous medium. These baseline optical properties of the piglet head tissue were used to quantify the temporal dynamics of the concentration of the intravenously administered contrast agent Indocyanine Green in the piglet brain. The temporal traces of the Indocyanine Green concentration measured by our method were used to estimate the cerebral blood flow using a bolus tracking technique.

Sign in / Sign up

Export Citation Format

Share Document