scholarly journals An improved analytic function for predicting light fluence rate in circular fields on a semi-infinite geometry

2016 ◽  
Author(s):  
Timothy C. Zhu ◽  
Amy Lu ◽  
Yi-Hong Ong
Keyword(s):  
Analytic Function ◽  
Fluence Rate ◽  
Light Fluence

Photodynamic Therapy at Low-Light Fluence Rate: in vitro Assays on Colon Cancer Cells

2019 ◽  
Vol 25 (1) ◽  
pp. 1-6 ◽  
Author(s):  
J. A. Rodrigues ◽  
R. Amorim ◽  
M. F. Silva ◽  
F. Baltazar ◽  
R. F. Wolffenbuttel ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Photodynamic Therapy ◽  
Cancer Cells ◽  
Fluence Rate ◽  
Colon Cancer Cells ◽  
Low Light ◽  
Light Fluence

The Effect of Light Fluence Rate in Photodynamic Therapy of Normal Rat Brain

1992 ◽  
Vol 132 (1) ◽  
pp. 120 ◽  
Author(s):  
Q. Chen ◽  
M. Chopp ◽  
M. O. Dereski ◽  
B. C. Wilson ◽  
M. S. Patterson ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Rat Brain ◽  
Fluence Rate ◽  
Light Fluence ◽  
Normal Rat ◽  
Effect Of Light

scholarly journals Principle study on the signal connection at transabdominal fetal pulse oximetry

2016 ◽  
Vol 2 (1) ◽  
pp. 659-663 ◽  
Author(s):  
Marcel Böttrich ◽  
Daniel Laqua ◽  
Peter Husar
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Element Model ◽  
Maternal Blood ◽  
Measured Signal ◽  
Fluence Rate ◽  
Frequency Spectra ◽  
Additional Signal ◽  
Light Fluence ◽  
Fetal Pulse Oximetry

AbstractTransabdominal fetal pulse oximetry is an approach to measure oxygen saturation of the unborn child non-invasively. The principle of pulse oximetry is applied to the abdomen of a pregnant woman, such that the measured signal includes both, the maternal and the fetal pulse curve. One of the major challenges is to extract the shape of the fetal pulse curve from the mixed signal for computation of the oxygen saturation. In this paper we analyze the principle kind of connection of the fetal and maternal pulse curves in the measured signal. A time varying finite element model is used to rebuild the basic measurement environment, including a bulk tissue and two independently pulsing arteries to model the fetal and maternal blood circuit. The distribution of the light fluence rate in the model is computed by applying diffusion equation. From the detectors we extracted the time dependent fluence rate and analyzed the signal regarding its components. The frequency spectra of the signals show peaks at the fetal and maternal basic frequencies. Additional signal components are visible in the spectra, indicating multiplicative coupling of the fetal and maternal pulse curves. We conclude that the underlying signal model of algorithms for robust extraction of the shape of the fetal pulse curve, have to consider additive and multiplicative signal coupling.

scholarly journals Measurement of Cyanine Dye Photobleaching in Photosensitizer Cyanine Dye Conjugates Could Help in Optimizing Light Dosimetry for Improved Photodynamic Therapy of Cancer

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1842 ◽  
Author(s):  
Nadine James ◽  
Ravindra Cheruku ◽  
Joseph Missert ◽  
Ulas Sunar ◽  
Ravindra Pandey
Keyword(s):  
Photodynamic Therapy ◽  
Fluorescence Imaging ◽  
Tumor Response ◽  
Cyanine Dye ◽  
Fluence Rate ◽  
Low Light ◽  
Light Dosimetry ◽  
Light Fluence ◽  
Photodynamic Therapy Of Cancer

Photodynamic therapy (PDT) of cancer is dependent on three primary components: photosensitizer (PS), light and oxygen. Because these components are interdependent and vary during the dynamic process of PDT, assessing PDT efficacy may not be trivial. Therefore, it has become necessary to develop pre-treatment planning, on-line monitoring and dosimetry strategies during PDT, which become more critical for two or more chromophore systems, for example, PS-CD (Photosensitizer-Cyanine dye) conjugates developed in our laboratory for fluorescence-imaging and PDT of cancer. In this study, we observed a significant impact of variable light dosimetry; (i) high light fluence and fluence rate (light dose: 135 J/cm2, fluence rate: 75 mW/cm2) and (ii) low light fluence and fluence rate (128 J/cm2 and 14 mW/cm2 and 128 J/cm2 and 7 mW/cm2) in photobleaching of the individual chromophores of PS-CD conjugates and their long-term tumor response. The fluorescence at the near-infrared (NIR) region of the PS-NIR fluorophore conjugate was assessed intermittently via fluorescence imaging. The loss of fluorescence, photobleaching, caused by singlet oxygen from the PS was mapped continuously during PDT. The tumor responses (BALB/c mice bearing Colon26 tumors) were assessed after PDT by measuring tumor sizes daily. Our results showed distinctive photobleaching kinetics rates between the PS and CD. Interestingly, compared to higher light fluence, the tumors exposed at low light fluence showed reduced photobleaching and enhanced long-term PDT efficacy. The presence of NIR fluorophore in PS-CD conjugates provides an opportunity of fluorescence imaging and monitoring the photobleaching rate of the CD moiety for large and deeply seated tumors and assessing PDT tumor response in real-time.

A study of light fluence rate distribution for PDT using MC simulation

2011 ◽  
Author(s):  
Julia L. Sandell ◽  
Timothy C. Zhu ◽  
Jarod C. Finlay
Keyword(s):  
Fluence Rate ◽  
Rate Distribution ◽  
Light Fluence ◽  
Mc Simulation
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