Measurement of Absolute Cerebral Haemoglobin Concentration in Adults and Neonates

Wolf, Martin; Evans, PD; Bucher, H. U.; Dietz, V.; Keel, M.; Strebel, Ralph; Siebenthal, Kurt von

doi:10.1007/978-1-4615-5399-1_31

Cited by 25 publications

(22 citation statements)

References 17 publications

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“…These results are clearly lower than the 98.8 μmol/l mean tHb obtained in 20 term infants by our group earlier. 21 This is probably due to the quite different algorithms. Whereas the 66% mean StO 2 differs only little from our current results.…”

Section: Discussionmentioning

confidence: 99%

Precision of cerebral oxygenation and hemoglobin concentration measurements in neonates measured by near-infrared spectroscopy

Arri¹,

Muehlemann²,

Biallas³

et al. 2011

J. Biomed. Opt.

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Precision of cerebral oxygenation and hemoglobin concentration measurements in neonates measured by near-infrared spectroscopy Abstract. Background and aim: One source of error with near-infrared spectroscopy (NIRS) is the assumption that the measured tissue is optically homogeneous. This is not always the case. Our aim is to assess the impact of tissue homogeneity (TH) on the precision of NIRS measurements in neonates. Methods: On 36 term and 27 preterm neonates at least five 1-min measurements are performed on each subject using the OxiplexTS. The sensor position is slightly changed before each measurement while assessing TH. The precision for cerebral tissue oxygenation saturation (StO 2 ) and total hemoglobin concentration (tHb) are calculated by repeated measures analysis of variance. Results: The mean StO 2 is not significantly different between term and preterm infants. The mean tHb is significantly lower in preterm infants (p < 0.01). With increasing TH, the precision of StO 2 increase from 5.6 to 4.6% for preterm and from 11.0 to 2.0% for term infants; the precision of tHb increases from 10.1 to 7.5μM for preterm and from 16.4 to 3.5μM for term infants. The precision for StO 2 is higher in term than in preterm infants. The precision for tHb shows no significant difference between the two groups. Conclusions: The precision of NIRS measurements correlates with tissue homogeneity. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

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Section: Discussionmentioning

confidence: 99%

Precision of cerebral oxygenation and hemoglobin concentration measurements in neonates measured by near-infrared spectroscopy

Arri¹,

Muehlemann²,

Biallas³

et al. 2011

J. Biomed. Opt.

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“…regional differences in the DPF (differential pathlength factor). Due to the applicated NIRS algorithm [8], the estimates for the concentration parameters HbO 2 , HbD, and HbT are all proportional to DPF -1 . Because of this relation, variations in regional DPF influence the calculation of HbO 2 , HbD and their sum HbT in a similar direction, while such directional changes cancel out in the calculation of the oxygen saturation parameter rSO 2 (= HbO 2 /HbT).…”

Section: Discussionmentioning

confidence: 99%

“…An additional LED (light emitting diode) between the optodes compensates for differences in sensor light coupling. The principle of operation and the implemented algorithm to convert the light attenuations into estimates for oxygenated hemoglobin (HbO 2 ) and deoxygenated hemoglobin (HbD) concentrations have been described by Wolf et al [8].…”

Section: Nirs Instrument and Algorithmmentioning

confidence: 99%

Reproducibility of Cerebral Near Infrared Spectroscopy in Neonates

Menke¹,

Voss

Möller

et al. 2003

Neonatology

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Near infrared spectroscopy (NIRS) allows to study cerebral hemodynamics and oxygenation in neonates, which may be useful for early detection of cerebral hypoxemia. So far this method is not reliable enough to be used clinically. Reproducibility is one of the prerequisites for reliable quantitative monitoring. The aim of this study was to assess the reproducibility of the NIRS parameters HbO₂ and HbD (oxygenated and deoxygenated hemoglobin concentration) and the derived NIRS parameters HbT (tissue hemoglobin concentration, HbT = HbO₂ + HbD) and rSO₂ (regional cerebral oxygen saturation, rSO₂ = HbO₂/HbT). Two observers repeated a total number of 500 measurements in 25 neonates. Additionally, a baseline measurement was done to assess the physiological variation in every neonate. For all NIRS parameters, the inter-patient variance contributed most to the total variance, while the interobserver variance was the smallest variance component. The cerebral oxygen saturation parameter rSO₂ showed a good reproducibility, with an inter-measurement variance slightly but not significantly higher than the physiological baseline variation. The NIRS concentration parameters HbO₂, HbD, and HbT were less reproducible, with significant variation due to repeated sensor replacement. However, for cerebral oximetry rSO₂ is likely to be more important than the other NIRS parameters, so that NIRS has the potential to become a quantitative cerebral monitoring method.

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“…Edwards et al, 1988;Wyatt et al, 1990) or enhancing the instrumentation (e.g. Matcher et al, 1994Matcher et al, , 1995bWolf et al, 1997). Later time resolved techniques were developed and became available and enabled to determine absolute values.…”

Section: Introductionmentioning

confidence: 99%

A review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology

Scholkmann¹,

Kleiser²,

Metz³

et al. 2014

NeuroImage

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1,394

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This year marks the 20th anniversary of functional near-infrared spectroscopy and imaging (fNIRS/fNIRI). As the vast majority of commercial instruments developed until now are based on continuous wave technology, the aim of this publication is to review the current state of instrumentation and methodology of continuous wave fNIRI. For this purpose we provide an overview of the commercially available instruments and address instrumental aspects such as light sources, detectors and sensor arrangements. Methodological aspects, algorithms to calculate the concentrations of oxy-and deoxyhemoglobin and approaches for data analysis are also reviewed. From the single-location measurements of the early years, instrumentation has progressed to imaging initially in two dimensions (topography) and then three (tomography). The methods of analysis have also changed tremendously, from the simple modified Beer-Lambert law to sophisticated image reconstruction and data analysis methods used today. Due to these advances, fNIRI has become a modality that is widely used in neuroscience research and several manufacturers provide commercial instrumentation. It seems likely that fNIRI will become a clinical tool in the foreseeable future, which will enable diagnosis in single subjects. This year marks the 20th anniversary of functional near-infrared spectroscopy and imaging (fNIRS/fNIRI). As the vast majority of commercial instruments developed until now are based on continuous wave technology, the aim of this publication is to review the current state of instrumentation and methodology of continuous wave fNIRI. For this purpose we provide an overview of the commercially available instruments and address instrumental aspects such as light sources, detectors and sensor arrangements. Methodological aspects, algorithms to calculate the concentrations of oxy-and deoxyhemoglobin and approaches for data analysis are also reviewed. From the single-location measurements of the early years, instrumentation has progressed to imaging initially in two dimensions (topography) and then three (tomography). The methods of analysis have also changed tremendously, from the simple modified Beer-Lambert law to sophisticated image reconstruction and data analysis methods used today. Due to these advances, fNIRI has become a modality that is widely used in neuroscience research and several manufacturers provide commercial instrumentation. It seems likely that fNIRI will become a clinical tool in the foreseeable future, which will enable diagnosis in single subjects. Contents

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Measurement of Absolute Cerebral Haemoglobin Concentration in Adults and Neonates

Cited by 25 publications

References 17 publications

Precision of cerebral oxygenation and hemoglobin concentration measurements in neonates measured by near-infrared spectroscopy

Precision of cerebral oxygenation and hemoglobin concentration measurements in neonates measured by near-infrared spectroscopy

Reproducibility of Cerebral Near Infrared Spectroscopy in Neonates

A review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology

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