Influence of hypoxia on wavelength dependence of differential pathlength and near-infrared quantification.

Continuous wave near-infrared spectroscopy (NIRS) measurements of cardiac correlated changes in attenuation in the adult human head were computed using a Fourier analysis technique that eliminates the positive error bias associated with the magnitude of the Fourier coefficient. These attenuation changes were used to determine wavelength dependence of differential pathlength, DP(lambda), at four stages during progressive hypoxia (21, 17, 13 and 9% FIO2) in normal volunteers. The effects of incorporating DP(lambda) into NIRS algorithms to compute relative concentration changes and absolute concentration of oxyhaemoglobin and deoxyhaemoglobin are discussed. Because variations in DP(lambda) are restricted to wavelengths below 780 nm, absolute concentration calculations are influenced by hypoxia-induced changes while relative concentrations are unaffected. However, even accounting for changes in DP(lambda) did not allow computation of physiologically reasonable absolute concentrations of the haemoglobin species.

[1]  E. P. Vovenko,et al.  Distribution of oxygen tension on the surface of arterioles, capillaries and venules of brain cortex and in tissue in normoxia: an experimental study on rats , 1999, Pflügers Archiv.

[2]  C. Cooper,et al.  Absolute quantification of deoxyhaemoglobin concentration in tissue near infrared spectroscopy. , 1994, Physics in medicine and biology.

[3]  A. Villringer,et al.  Determining changes in NIR absorption using a layered model of the human head , 2001, Physics in medicine and biology.

[4]  S. Arridge,et al.  A Monte Carlo investigation of optical pathlength in inhomogeneous tissue and its application to near-infrared spectroscopy. , 1993, Physics in medicine and biology.

[5]  S R Arridge,et al.  Quantitation of pathlength in optical spectroscopy. , 1989, Advances in experimental medicine and biology.

[6]  N. Draper,et al.  Applied Regression Analysis , 1966 .

[7]  Susan Wray,et al.  QUANTIFICATION OF CEREBRAL OXYGENATION AND HAEMODYNAMICS IN SICK NEWBORN INFANTS BY NEAR INFRARED SPECTROPHOTOMETRY , 1986, The Lancet.

[8]  D. R. White,et al.  The composition of body tissues. , 1986, The British journal of radiology.

[9]  F. Jöbsis.  Noninvasive, infrared monitoring of cerebral and myocardial oxygen sufficiency and circulatory parameters. , 1977, Science.

[10]  S. Arridge,et al.  Estimation of optical pathlength through tissue from direct time of flight measurement , 1988 .

[11]  D. Delpy,et al.  Use of the water absorption spectrum to quantify tissue chromophore concentration changes in near-infrared spectroscopy. , 1994, Physics in medicine and biology.

[12]  S. Arridge,et al.  Experimentally measured optical pathlengths for the adult head, calf and forearm and the head of the newborn infant as a function of inter optode spacing. , 1992, Advances in experimental medicine and biology.

[13]  R. Ordidge,et al.  MRI measurements of cerebral deoxyhaemoglobin concentration [dHb]—correlation with near infrared spectroscopy (NIRS) , 1998, NMR in biomedicine.

[14]  D T Delpy,et al.  The Noninvasive Measurement of Absolute Cerebral Deoxyhemoglobin Concentration and Mean Optical Path Length in the Neonatal Brain by Second Derivative Near Infrared Spectroscopy , 1996, Pediatric Research.

[15]  D. Delpy,et al.  Quantification of adult cerebral hemodynamics by near-infrared spectroscopy. , 1994, Journal of applied physiology.

[16]  M. Ferrari,et al.  Cerebral blood volume and hemoglobin oxygen saturation monitoring in neonatal brain by near IR spectroscopy. , 1986, Advances in experimental medicine and biology.

[17]  A. Villringer,et al.  Determination of the wavelength dependence of the differential pathlength factor from near-infrared pulse signals , 1998, Physics in medicine and biology.

[18]  S R Arridge,et al.  The theoretical basis for the determination of optical pathlengths in tissue: temporal and frequency analysis. , 1992, Physics in medicine and biology.

[19]  M. Ferrari,et al.  Noninvasive measurement of cerebral hemoglobin oxygen saturation using two near infrared spectroscopy approaches. , 2000, Journal of biomedical optics.

[20]  Willis W. Harman,et al.  Principles of the Statistical Theory of Communication , 1963 .

[21]  D. Delpy,et al.  Optical pathlength measurements on adult head, calf and forearm and the head of the newborn infant using phase resolved optical spectroscopy. , 1995, Physics in medicine and biology.

[22]  William H. Press,et al.  Numerical recipes in C. The art of scientific computing , 1987 .

[23]  D. Delpy,et al.  Oxygen dependency and precision of cytochrome oxidase signal from full spectral NIRS of the piglet brain. , 2000, American journal of physiology. Heart and circulatory physiology.

[24]  Hellmuth Obrig,et al.  Linear Aspects of Changes in Deoxygenated Hemoglobin Concentration and Cytochrome Oxidase Oxidation during Brain Activation , 2001, NeuroImage.

[25]  H. Gudbjartsson,et al.  The rician distribution of noisy mri data , 1995, Magnetic resonance in medicine.

[26]  R J Ordidge,et al.  Correlation between absolute deoxyhaemoglobin [dHb] measured by near infrared spectroscopy (NIRS) and absolute R2' as determined by magnetic resonance imaging (MRI). , 1997, Advances in experimental medicine and biology.

[27]  D. Delpy,et al.  Performance comparison of several published tissue near-infrared spectroscopy algorithms. , 1995, Analytical biochemistry.