Measurement of changes in optical pathlength through human muscle during cuff occlusion on the arm

Duncan, A. R.; Whitlock, TL; Cope, M; Delpy, David T.

doi:10.1016/0030-3992(95)93756-h

Cited by 9 publications

(3 citation statements)

References 26 publications

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“…We observed an increase in the magnitude of ⌬oxyhemoglobin, ⌬deoxyhemoglobin, ⌬total hemoglobin concentrations, and hemoglobin flow values both from the first to the second venous occlusion, which was significant, and from the second to the third, which was only significant for ⌬total hemoglobin concentration. The increasing magnitude in concentration changes over repetitive venous occlusions was also observed by other authors but not discussed (35,51). During the first venous occlusion, blood vessels dilate and capillaries become recruited, which increases the blood volume.…”

Section: Precision and Trvsupporting

confidence: 72%

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Regional Differences of Hemodynamics and Oxygenation in the Human Calf Muscle Detected with Near-Infrared Spectrophotometry

Wolf¹,

Wolf²,

Choi³

et al. 2007

Journal of Vascular and Interventional Radiology

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PURPOSE: Measurements in muscle tissue are often performed at a selected single location over the muscle of interest. The hypothesis is that the values obtained reflect the status within the entire muscle or muscle group. This, however, may not be the case. The study was performed to investigate whether this hypothesis is true for hemodynamics and oxygenation in the healthy human calf muscle at rest. MATERIALS AND METHODS:Hemoglobin flow, blood flow, oxygen consumption, and venous hemoglobin oxygen saturation were mapped at 22 locations in 30 legs of 15 healthy subjects (nine women, six men aged 26 -37 years) simultaneously by using frequency-domain near-infrared spectrophotometry with a specially designed probe during venous occlusion. RESULTS: For all parameters, spatial heterogeneity was found between subjects and within individual legs. All parameters were highly significantly different when comparing proximal and distal regions. Differences were also found between medial and lateral regions. The global mean values (؎standard deviation) over all measurements were as follows: hemoglobin flow, 1.27 mol per 100 mL/min ؎ 0.88; blood flow, 0.56 mL per 100 g/min ؎ 0.38; oxygen consumption, 0.016 mL per 100 g/min ؎ 0.011; and venous oxygen saturation, 77.6% ؎ 5.9. The thickness of the overlying adipose tissue had an influence on the measurements and must be considered. CONCLUSION: Highly significant spatial heterogeneity of hemodynamics and oxygenation was found in the healthy human calf muscle. J Vasc Interv Radiol 2007; 18:1094 -1101Abbreviations: ATT ϭ adipose tissue thickness, DPF ϭ differential pathlength factor, NIRS ϭ near-infrared spectrophotometry, SvO 2 ϭ venous oxygen saturation, TRV ϭ test-retest variability, VO 2 ϭ oxygen consumption NEAR-INFRARED spectrophotometry (NIRS) is a valuable tool for measuring hemodynamics and oxygenation in human tissue. NIRS is noninvasive, provides real-time measurements, is costeffective, is feasible at the bedside, and is easily repeatable and reproducible and, therefore, suitable for use in the clinical setting. Because NIRS provides measurements at the level of arterioles, capillaries, and venules (1) several centimeters deep in the tissue, it is a complementary method to Doppler, which probes larger blood vessels, laser Doppler flowmetry, which measures superficial blood vessels, and imaging techniques such as magnetic resonance (MR) imaging, positron emission tomography (PET), and radiography, which depend on the use of ionizing radiation and/or contrast media. NIRS has been applied to infants and adults to measure hemodynamics and oxygenation in many fields such as the brain, but one particularly promising field is the skeletal muscle (2-5). Studies in the skeletal muscle have included measurements in sports medicine (6,7) and in patients with peripheral vascular disease (8 -17), myopathies (18 -20), and heart failure (21-23).Measurements in muscle tissue are often performed at a selected single location over the muscle of interest. The values obtained are consider...

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Section: Precision and Trvsupporting

confidence: 72%

“…An established method is to take DPF values from the literature although some authors have pointed out the shortcoming of this method (51). From our data, it can be seen that the DPF varies depending on the ATT.…”

Section: Dpfmentioning

confidence: 69%

Regional Differences of Hemodynamics and Oxygenation in the Human Calf Muscle Detected with Near-Infrared Spectrophotometry

Wolf¹,

Wolf²,

Choi³

et al. 2007

Journal of Vascular and Interventional Radiology

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“…The concentration of HbO 2 ͑taken as 70%͒ is higher than ͓Hb͔, and for longer wavelengths, ⑀ HbO 2 is higher, which result in a,m increasing, leading to a decrease in ͗L m ͘ and ͗L ͘ for longer wavelengths. In experimental studies, wavelength dependency has been reported [58][59][60] only for the DPF factor, since it is impossible to measure and isolate ͗L m ͘ from a layered structure. Duncan et al 61 reports DPF values of 4.43Ϯ 0.86 ͑5.78Ϯ 1.05͒ at 690 nm, and 3.94Ϯ 0.78 ͑5.33Ϯ 0.95͒ at 832 nm in the forearm ͑calf͒ for r = 4.5 cm.…”

Section: Discussionmentioning

confidence: 99%

Crosstalk and error analysis of fat layer on continuous wave near-infrared spectroscopy measurements

2008

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Accurate estimation of concentration changes in muscles by continuous wave near-IR spectroscopy for muscle measurements suffers from underestimation and crosstalk problems due to the presence of superficial skin and fat layers. Underestimation error is basically caused by a homogeneous medium assumption in the calculations leading to the partial volume effect. The homogeneous medium assumption and wavelength dependence of mean partial path length in the muscle layer cause the crosstalk. We investigate underestimation errors and crosstalk by Monte Carlo simulations with a three layered (skin-fat-muscle) tissue model for a two-wavelength system where the choice of first wavelength is in the 675- to 775-nm range and the second wavelength is in the 825- to 900-nm range. Means of absolute underestimation errors and crosstalk over the considered wavelength pairs are found to be higher for greater fat thicknesses. Estimation errors of concentration changes for Hb and HbO(2) are calculated to be close for an ischemia type protocol where both Hb and HbO(2) are assumed to have equal magnitude but opposite concentration changes. The minimum estimation errors are found for the 700825- and 725825-nm pairs for this protocol.

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Influence of Repeated Ischaemia/Reperfusion Cycles (Ischaemic Preconditioning) on Human Calf Energy Metabolism by Simultaneous Near Infrared Spectroscopy, 31P-NMR and 23Na-NMR Measurements

Binzoni

Quaresima

Hiltbrand

et al. 1997

Advances in Experimental Medicine and Biology

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Measurement of changes in optical pathlength through human muscle during cuff occlusion on the arm

Cited by 9 publications

References 26 publications

Regional Differences of Hemodynamics and Oxygenation in the Human Calf Muscle Detected with Near-Infrared Spectrophotometry

Regional Differences of Hemodynamics and Oxygenation in the Human Calf Muscle Detected with Near-Infrared Spectrophotometry

Crosstalk and error analysis of fat layer on continuous wave near-infrared spectroscopy measurements

Influence of Repeated Ischaemia/Reperfusion Cycles (Ischaemic Preconditioning) on Human Calf Energy Metabolism by Simultaneous Near Infrared Spectroscopy, 31P-NMR and 23Na-NMR Measurements

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