Publication

Noninvasive determination of the optical properties of two-layered turbid media from time-resolved reflectance measurements

Hubert van den Bergh, Georges Wagnières
1999
Conference Papers

Abstract

The influence of the adipose tissue thickness on near-infrared spectroscopy to monitor the haemodynamics in muscles is investigated. It is shown by calculation of the mean optical pathlength of two-layered turbid media that the validity of the modified Beer-Lambert law is reduced with increasing thickness of the first layer (fat), because the assumption, that the mean optical pathlength is constant, is not fulfilled. In order to avoid these problems we demonstrate that it is possible to derive the optical properties of both layers from time-resolved reflectance measurements using a solution of the two-layered diffusion equation if the thickness of the first layer is known.

Official source

https://infoscience.epfl.ch/entities/publication/eebf8289-edc4-499d-a9d4-c21f36c95e60

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Hubert van den Bergh, Georges Wagnières
1999
Conference Papers

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/eebf8289-edc4-499d-a9d4-c21f36c95e60

About this result

Related concepts (22)

Near-infrared spectroscopy

Near-infrared spectroscopy (NIRS) is a spectroscopic method that uses the near-infrared region of the electromagnetic spectrum (from 780 nm to 2500 nm). Typical applications include medical and physiological diagnostics and research including blood sugar, pulse oximetry, functional neuroimaging, sports medicine, elite sports training, ergonomics, rehabilitation, neonatal research, brain computer interface, urology (bladder contraction), and neurology (neurovascular coupling).

Infrared spectroscopy

Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or functional groups in solid, liquid, or gaseous forms. It can be used to characterize new materials or identify and verify known and unknown samples. The method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer (or spectrophotometer) which produces an infrared spectrum.

Fourier-transform infrared spectroscopy

Fourier-transform infrared spectroscopy (FTIR) is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas. An FTIR spectrometer simultaneously collects high-resolution spectral data over a wide spectral range. This confers a significant advantage over a dispersive spectrometer, which measures intensity over a narrow range of wavelengths at a time. The term Fourier-transform infrared spectroscopy originates from the fact that a Fourier transform (a mathematical process) is required to convert the raw data into the actual spectrum.

Related publications (1)

Noninvasive determination of the optical properties of two-layered turbid media from time-resolved reflectance measurements

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