scholarly journals Small separation frequency-domain near-infrared spectroscopy for the recovery of tissue optical properties at millimeter depths

2019 ◽  
Vol 10 (10) ◽  
pp. 5362
Author(s):  
Seung Yup Lee ◽  
Corey Zheng ◽  
Rowan Brothers ◽  
Erin M. Buckley
Keyword(s):  
Optical Properties ◽  
Infrared Spectroscopy ◽  
Frequency Domain ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Tissue Optical Properties ◽  
Small Separation

scholarly journals A scalable, multi-wavelength, broad bandwidth frequency-domain near-infrared spectroscopy platform for real-time quantitative tissue optical imaging

2021 ◽  
Author(s):  
Roy A. Stillwell ◽  
Vincent J. Kitsmiller ◽  
Alicia Y. Wei ◽  
Alyssa Chong ◽  
Lyla Senn ◽  
...  
Keyword(s):  
Optical Properties ◽  
Infrared Spectroscopy ◽  
Frequency Domain ◽  
Real Time ◽  
Near Infrared Spectroscopy ◽  
High Speed ◽  
Near Infrared ◽  
Single Channel ◽  
Lookup Table ◽  
K Nearest Neighbor

Frequency-domain near-infrared spectroscopy (FD-NIRS) provides quantitative noninvasive measurements of tissue optical absorption and scattering, and provides a safe and accurate method for characterizing tissue composition and metabolism. However, the poor scalability and high complexity of most FD-NIRS systems assembled to date have contributed to its limited clinical impact. To address these shortcomings, we present a scalable, digital-based FD-NIRS platform capable of measuring optical properties and tissue chromophore concentrations in real-time. The system provides single-channel FD-NIRS amplitude/phase, optical property, and chromophore data at a maximum display rate of 36.6 kHz, 17.9 kHz, and 10.2 kHz, respectively, and can be scaled to multiple channels as well as integrated into a handheld format. The entire system is enabled by several innovations including an ultra-high-speed k-nearest neighbor lookup table method (maximum of 250,000 inversions/s for large 2500x700 table of absorption and reduced scattering coefficients), embedded FPGA and CPU high-speed co-processing, and high-speed data transfer (due to on-board processing). We show that our 6-wavelength, broad modulation bandwidth (1-400 MHz) system can be used to perform 2D high-density spatial mapping of optical properties.

In vivo determination of the optical properties of infant brain using frequency-domain near-infrared spectroscopy

2005 ◽  
Vol 10 (2) ◽  
pp. 024028 ◽  
Author(s):  
Jun Zhao ◽  
Hai Shu Ding ◽  
Xin Lin Hou ◽  
Cong Le Zhou ◽  
Britton Chance
Keyword(s):  
Optical Properties ◽  
Infrared Spectroscopy ◽  
Frequency Domain ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Infant Brain

Influence of Blood Glucose Level on the Scattering Coefficient of the Skin in Near-Infrared Spectroscopy

2011 ◽  
Author(s):  
Sachiko Kessoku ◽  
Katsuhiko Maruo ◽  
Shinpei Okawa ◽  
Kazuto Masamoto ◽  
Yukio Yamada
Keyword(s):  
Optical Properties ◽  
Infrared Spectroscopy ◽  
Blood Glucose ◽  
Blood Glucose Level ◽  
Glucose Level ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Monitoring Methods ◽  
Absorbance Spectra

Various non-invasive glucose monitoring methods using near-infrared spectroscopy have been investigated although no method has been successful so far. Our previous study has proposed a new promising method utilizing numerically generated absorbance spectra instead of the experimentally acquired absorbance spectra. The method suggests that the correct estimation of the optical properties is very important for numerically generating the absorbance spectra. The purpose of this study is to measure the change in the optical properties of the skin with the change in the blood glucose level in vivo. By measuring the reflectances of light incident on the skin surface at two distances from the incident point, the optical properties of the skin can be estimated. The estimation is a kind of the inverse problem based on the simulation of light propagation in the skin. Phantom experiments have verified the method and in vivo experiments are to be performed.

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