Analysis of sensitivity and optical path-length in non-invasive measurement of glucose with near infrared spectroscopy

2005 ◽  
Author(s):  
Yunhan Luo ◽  
Rong Liu ◽  
Wenliang Chen ◽  
Houxin Cui ◽  
Kexin Xu
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Path Length ◽  
Near Infrared ◽  
Optical Path Length ◽  
Optical Path ◽  
Non Invasive ◽  
Invasive Measurement

Measurement of Optical Path Length for Cerebral Near-Infrared Spectroscopy in Newborn Infants

1990 ◽  
Vol 12 (2) ◽  
pp. 140-144 ◽  
Author(s):  
J.S. Wyatt ◽  
M. Cope ◽  
D.T. Delpy ◽  
P. van der Zee ◽  
S. Arridge ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Path Length ◽  
Near Infrared ◽  
Newborn Infants ◽  
Optical Path Length ◽  
Optical Path

Estimation of partial optical path length in the brain in subject-specific head models for near-infrared spectroscopy

2016 ◽  
Vol 23 (2) ◽  
pp. 316-322 ◽  
Author(s):  
Kotaro Nakamura ◽  
Kazuki Kurihara ◽  
Hiroshi Kawaguchi ◽  
Takayuki Obata ◽  
Hiroshi Ito ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Path Length ◽  
Near Infrared ◽  
Optical Path Length ◽  
Optical Path ◽  
Subject Specific ◽  
The Brain

scholarly journals Measurement of Cranial Optical Path Length as a Function of Age Using Phase Resolved Near Infrared Spectroscopy

1996 ◽  
Vol 39 (5) ◽  
pp. 889-894 ◽  
Author(s):  
Arlene Duncan ◽  
Judith H Meek ◽  
Matthew Clemence ◽  
Clare E Elwell ◽  
Penny Fallon ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Path Length ◽  
Near Infrared ◽  
Optical Path Length ◽  
Optical Path

scholarly journals Quantification in tissue near–infrared spectroscopy

1997 ◽  
Vol 352 (1354) ◽  
pp. 649-659 ◽  
Author(s):  
D. T. Delpy ◽  
M. Cope
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Path Length ◽  
Near Infrared ◽  
Modulation Depth ◽  
Light Attenuation ◽  
Complex Function ◽  
Optical Path Length ◽  
Optical Path ◽  
Light Transport

In near–infrared spectroscopy (NIRS) of tissue, light attenuation is due to: (i) absorption from chromophores of fixed concentration, (ii) absorption from chromophores of variable concentration, and (iii) light scatter. NIRS is usually concerned with trying to quantify the concentrations of chromophores in category (ii), in particular oxy– and deoxyhaemoglobin (HbO 2 and Hb) and cytochrome oxidase. In the absence of scatter the total light absorption in the medium is a linear sum of that due to each chromophore. In a scattering medium like tissue, this linear summation is distorted because the optical path length at each wavelength may differ. This distorted spectrum is then superimposed upon a further wavelength–dependent attenuation arising from light loss due to scatter, which is a complex function of the tissue absorption and scattering coefficients ( μ a and μ s ), scattering phase function, and tissue and measurement geometry. Consequently, quantification of NIRS data is difficult. Over the past 20 years many differing approaches to quantification have been tried. The development of methods for measuring optical path length in tissue initially enabled changes in concentration to be quantified, and subsequently methods for absolute quantification of HbO 2 and Hb were developed by correlating NIRS changes with an independent measurement of arterial haemoglobin saturation. Absolute determination of tissue optical properties, however, requires additional information over and above the detected intensity at the tissue surface, which must then be combined with a model of light transport to derive μ a and μ s . The additional data can take many forms, e.g. the change in intensity with distance, the temporal dispersion of light from an ultrashort input light pulse, or phase, and modulation depth changes of intensity–modulated light. All these approaches are now being actively pursued with considerable success. However, all the approaches are limited by the accuracy of the light transport models, especially in inhomogeneous media.

scholarly journals Non-invasive measurement of right atrial pressure by near-infrared spectroscopy: preliminary experience. A report from the SICA-HF study

2017 ◽  
Vol 19 (7) ◽  
pp. 883-892 ◽  
Author(s):  
Pierpaolo Pellicori ◽  
Andrew L. Clark ◽  
Anna Kallvikbacka-Bennett ◽  
Jufen Zhang ◽  
Alessia Urbinati ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Non Invasive ◽  
Invasive Measurement
Sign in / Sign up

Export Citation Format

Share Document