scholarly journals Interpretation of Near-Infrared Spectroscopy (NIRS) Signals in Skeletal Muscle

2019 ◽  
Vol 4 (2) ◽  
pp. 28
Author(s):  
Adeola A. Sanni ◽  
Kevin K. McCully
Keyword(s):  
Skeletal Muscle ◽  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Blood Volume ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Continuous Wave ◽  
Saturation Index ◽  
Muscle Oxygen ◽  
Significant Difference

Near-infrared spectroscopy (NIRS) uses the relative absorption of light at 850 and 760 nm to determine skeletal muscle oxygen saturation. Previous studies have used the ratio of both signals to report muscle oxygen saturation. Purpose: The purpose of this pilot study is to assess the different approaches used to represent muscle oxygen saturation and to evaluate the pulsations of oxygenated hemoglobin/myoglobin (O2heme) and deoxygenated hemoglobin/myoglobin (Heme) signals. Method: Twelve participants, aged 20–29 years, were tested on the forearm flexor muscles using continuous-wave NIRS at rest. Measurements were taken during 2–3 min rest, physiological calibration (5 min ischemia), and reperfusion. Ten participants were included in the study analysis. Results: There was a significant difference in pulse size between O2heme and Heme signals at the three locations (p < 0.05). Resting oxygen saturation was 58.8% + 9.2%, 69.6% + 3.9%, and 89.2% + 6.9% when calibrated using O2heme, the tissue oxygenation/saturation index (TSI), and Heme, respectively. Conclusion: The difference in magnitude of O2heme and Heme pulses with each heartbeat might suggest different anatomical locations of these signals, for which calibrating with just one of the signals instead of the ratio of both is proposed. Calculations of physiological calibration must account for increased blood volume in the tissue because of the changes in blood volume, which appear to be primarily from the O2heme signal. Resting oxygen levels calibrated with Heme agree with theoretical oxygen saturation.

scholarly journals Interpretation of Near-Infrared Spectroscopy (NIRS) Signals in Skeletal Muscle

2019 ◽  
Author(s):  
Adeola A. Sanni ◽  
Kevin K. McCully
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Saturation ◽  
Blood Volume ◽  
Near Infrared ◽  
Continuous Wave ◽  
Muscle Oxygen ◽  
Significant Difference ◽  
Forearm Flexor Muscles ◽  
The Difference ◽  
Forearm Flexor

NIRS uses the relative absorption of light at 850nm and 760nm, to determine skeletal muscle oxygen saturation. Previous studies have used the ratio of both signals to report muscle oxygen saturation. Purpose: To evaluate the different approaches used to represent muscle oxygen saturation, and to evaluate the pulsations of the O2heme and Heme signal. Method: Twelve participants, ages 20-29years were tested on the forearm flexor muscles using continuous wave NIRS at rest. Measurements were taken during 2-3mins rest, during physiological calibration (5-minuts Ischemia) and during reperfusion.&nbsp; Results: There was a significant difference in pulse size between O2heme and Heme signal at the three locations (p &lt; 0.05). Resting oxygen saturation was 58.8+9.2%, 69.6+3.9%, and 89.2+6.9% when calibrated using O2heme, TSI, and Heme, respectively.&nbsp; Conclusion: The difference in magnitude of O2heme and Heme pulse with each heartbeat might suggest different anatomical locations of these signals, which propose calibrating with just one of the signals instead of the ratio of both. Calculations of physiological calibration must account for increased blood volume in the tissue, because of the changes in blood volume which appear to be primarily from the O2heme signal. Resting oxygen levels calibrated with Heme agrees with theoretical oxygen saturation.

scholarly journals Quantitative measurement of muscle oxygen saturation without influence from skin and fat using continuous-wave near infrared spectroscopy

2007 ◽  
Vol 15 (21) ◽  
pp. 13715 ◽  
Author(s):  
Ye Yang ◽  
Olusola Soyemi ◽  
Peter J. Scott ◽  
Michelle R. Landry ◽  
Stuart M. Lee ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Near Infrared Spectroscopy ◽  
Quantitative Measurement ◽  
Near Infrared ◽  
Continuous Wave ◽  
Muscle Oxygen

A comparison of exercise type and intensity on the noninvasive assessment of skeletal muscle mitochondrial function using near-infrared spectroscopy

2013 ◽  
Vol 114 (2) ◽  
pp. 230-237 ◽  
Author(s):  
Terence E. Ryan ◽  
Jared T. Brizendine ◽  
Kevin K. McCully
Keyword(s):  
Skeletal Muscle ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Mitochondrial Function ◽  
Rate Constants ◽  
Near Infrared ◽  
Clinical Settings ◽  
Muscle Oxygen ◽  
Muscle Oxygen Consumption ◽  
Intensity Of Exercise

Near-infrared spectroscopy (NIRS) can be used to measure muscle oxygen consumption (mVO2) using arterial occlusions. The recovery rate of mVO2after exercise can provide an index of skeletal muscle mitochondrial function. The purpose of this study was to test the influence of exercise modality and intensity on NIRS measurements of mitochondrial function. Three experiments were performed. Thirty subjects (age: 18–27 yr) were tested. NIRS signals were corrected for blood volume changes. The recovery of mVO2after exercise was fit to a monoexponential curve, and a rate constant was calculated (directly related to mitochondrial function). No differences were found in NIRS rate constants for VOL and ES exercises (2.04 ± 0.57 vs. 2.01 ± 0.59 min−1for VOL and ES, respectively; P = 0.317). NIRS rate constants were independent of the contraction frequency for both VOL and ES (VOL: P = 0.166 and ES: P = 0.780). ES current intensity resulted in significant changes to the normalized time-tension integral (54 ± 11, 82 ± 7, and 100 ± 0% for low, medium, and high currents, respectively; P < 0.001) but did not influence NIRS rate constants (2.02 ± 0.54, 1.95 ± 0.44, 2.02 ± 0.46 min−1for low, medium, and high currents, respectively; P = 0.771). In summary, NIRS measurements of skeletal muscle mitochondrial function can be compared between VOL and ES exercises and were independent of the intensity of exercise. NIRS represents an important new technique that is practical for testing in research and clinical settings.

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