A modular NIRS system for clinical measurement of impaired skeletal muscle oxygenation

2000 ◽  
Vol 88 (1) ◽  
pp. 315-325 ◽  
Author(s):  
Ramesh Wariar ◽  
John N. Gaffke ◽  
Ronald G. Haller ◽  
Loren A. Bertocci

Near-infrared spectrometry (NIRS) is a well-known method used to measure in vivo tissue oxygenation and hemodynamics. This method is used to derive relative measures of hemoglobin (Hb) + myoglobin (Mb) oxygenation and total Hb (tHb) accumulation from measurements of optical attenuation at discrete wavelengths. We present the design and validation of a new NIRS oxygenation analyzer for the measurement of muscle oxygenation kinetics. This design optimizes optical sensitivity and detector wavelength flexibility while minimizing component and construction costs. Using in vitro validations, we demonstrate 1) general optical linearity, 2) system stability, and 3) measurement accuracy for isolated Hb. Using in vivo validations, we demonstrate 1) expected oxygenation changes during ischemia and reactive hyperemia, 2) expected oxygenation changes during muscle exercise, 3) a close correlation between changes in oxyhemoglobin and oxymyoglobin and changes in deoxyhemoglobin and deoxymyoglobin and limb volume by venous occlusion plethysmography, and 4) a minimal contribution from movement artifact on the detected signals. We also demonstrate the ability of this system to detect abnormal patterns of tissue oxygenation in a well-characterized patient with a deficiency of skeletal muscle coenzyme Q10. We conclude that this is a valid system design for the precise, accurate, and sensitive detection of changes in bulk skeletal muscle oxygenation, can be constructed economically, and can be used diagnostically in patients with disorders of skeletal muscle energy metabolism.

2017 ◽  
Vol 14 (127) ◽  
pp. 20160992 ◽  
Author(s):  
B. Zeller-Plumhoff ◽  
T. Roose ◽  
G. F. Clough ◽  
P. Schneider

The supply of oxygen in sufficient quantity is vital for the correct functioning of all organs in the human body, in particular for skeletal muscle during exercise. Disease is often associated with both an inhibition of the microvascular supply capability and is thought to relate to changes in the structure of blood vessel networks. Different methods exist to investigate the influence of the microvascular structure on tissue oxygenation, varying over a range of application areas, i.e. biological in vivo and in vitro experiments, imaging and mathematical modelling. Ideally, all of these methods should be combined within the same framework in order to fully understand the processes involved. This review discusses the mathematical models of skeletal muscle oxygenation currently available that are based upon images taken of the muscle microvasculature in vivo and ex vivo . Imaging systems suitable for capturing the blood vessel networks are discussed and respective contrasting methods presented. The review further informs the association between anatomical characteristics in health and disease. With this review we give the reader a tool to understand and establish the workflow of developing an image-based model of skeletal muscle oxygenation. Finally, we give an outlook for improvements needed for measurements and imaging techniques to adequately investigate the microvascular capability for oxygen exchange.


2009 ◽  
Vol 23 (5-6) ◽  
pp. 233-241 ◽  
Author(s):  
Babak Shadgan ◽  
W. Darlene Reid ◽  
Reza Gharakhanlou ◽  
Lynn Stpublisher-ids ◽  
Andrew John Macnab

The majority ofin vivoapplications of near-infrared spectroscopic (NIRS) monitoring use continuous wave instruments that require a fiberoptic cable connection between the subject and the instrument during monitoring. In studies of muscle physiology where subjects are exercising, and particularly in those who are engaged in sports activity, a wireless instrument with telemetric capacity provides obvious advantages. Having access to reliable telemetric NIRS technology will also increase the practicality and scope of this biomedical monitoring technique in clinical settings.We report the feasibility of using a wireless continuous wave NIRS instrument with light emitting diodes, spatially resolved configuration, and Bluetooth®capability to study skeletal muscle oxygenation and hemodynamics during isometric contraction and ischemia induction.In ten healthy subjects comparable patterns of change in chromophore concentration (oxygenated and deoxygenated hemoglobin), total hemoglobin and muscle oxygen saturation were observed during 3 sets of isometric voluntary forearm muscle contraction at 10, 30 and 50% of maximum voluntary capacity (MVC), and a period of ischemia generated subsequently.This small series indicates that data with good intra- and inter-subject reproducibility that is free of movement artifact can be obtained with the wireless NIRS instrument described. The validity of these muscle studies demonstrate a basis for applying wireless NIRS monitoring to publisher-id biomedical applications.


2015 ◽  
Vol 308 (2) ◽  
pp. R105-R111 ◽  
Author(s):  
Wladimir M. Medeiros ◽  
Mari C. T. Fernandes ◽  
Diogo P. Azevedo ◽  
Flavia F. M. de Freitas ◽  
Beatriz C. Amorim ◽  
...  

Central cardiorespiratory and gas exchange limitations imposed by chronic obstructive pulmonary disease (COPD) impair ambulatory skeletal muscle oxygenation during whole body exercise. This investigation tested the hypothesis that peripheral factors per se contribute to impaired contracting lower limb muscle oxygenation in COPD patients. Submaximal neuromuscular electrical stimulation (NMES; 30, 40, and 50 mA at 50 Hz) of the quadriceps femoris was employed to evaluate contracting skeletal muscle oxygenation while minimizing the influence of COPD-related central cardiorespiratory constraints. Fractional O2 extraction was estimated by near-infrared spectroscopy (deoxyhemoglobin/myoglobin concentration; deoxy-[Hb/Mb]), and torque output was measured by isokinetic dynamometry in 15 nonhypoxemic patients with moderate-to-severe COPD (SpO2 = 94 ± 2%; FEV1 = 46.4 ± 10.1%; GOLD II and III) and in 10 age- and gender-matched sedentary controls. COPD patients had lower leg muscle mass than controls (LMM = 8.0 ± 0.7 kg vs. 8.9 ± 1.0 kg, respectively; P < 0.05) and produced relatively lower absolute and LMM-normalized torque across the range of NMES intensities ( P < 0.05 for all). Despite producing less torque, COPD patients had similar deoxy-[Hb/Mb] amplitudes at 30 and 40 mA ( P > 0.05 for both) and higher deoxy-[Hb/Mb] amplitude at 50 mA ( P < 0.05). Further analysis indicated that COPD patients required greater fractional O2 extraction to produce torque (i.e., ↑Δdeoxy-[Hb/Mb]/torque) relative to controls ( P < 0.05 for 40 and 50 mA) and as a function of NMES intensity ( P < 0.05 for all). The present data obtained during submaximal NMES of small muscle mass indicate that peripheral abnormalities contribute mechanistically to impaired contracting skeletal muscle oxygenation in nonhypoxemic, moderate-to-severe COPD patients.


Critical Care ◽  
2009 ◽  
Vol 13 (Suppl 5) ◽  
pp. S7 ◽  
Author(s):  
Daniel S Martin ◽  
Denny ZH Levett ◽  
Michael Mythen ◽  
Mike PW Grocott ◽  

2002 ◽  
Vol 16 (2) ◽  
pp. 127-130 ◽  
Author(s):  
Masayasu Nakayama ◽  
Soushi Iwasaki ◽  
Hiromichi Ichinose ◽  
Shuji Yamamoto ◽  
Noriaki Kanaya ◽  
...  

2012 ◽  
Vol 113 (7) ◽  
pp. 1101-1109 ◽  
Author(s):  
Simone Porcelli ◽  
Mauro Marzorati ◽  
Lorenzo Pugliese ◽  
Saverio Adamo ◽  
Julien Gondin ◽  
...  

A recent study has demonstrated that neuromuscular electrical stimulation (NMES) determines, in vitro, a fast-to-slow shift in the metabolic profile of muscle fibers. The aim of the present study was to evaluate if, in the same subjects, these changes would translate, in vivo, into an enhanced skeletal muscle oxidative metabolism. Seven young men were tested (cycle ergometer) during incremental exercises up to voluntary exhaustion and moderate and heavy constant-load exercises (CLE). Measurements were carried out before and after an 8-wk training program by isometric bilateral NMES (quadriceps muscles), which induced an ∼25% increase in maximal isometric force. Breath-by-breath pulmonary O2 uptake (V̇o2) and vastus lateralis oxygenation indexes (by near-infrared spectroscopy) were determined. Skeletal muscle fractional O2 extraction was estimated by near-infrared spectroscopy on the basis of changes in concentration of deoxygenated hemoglobin + myoglobin. Values obtained at exhaustion were considered “peak” values. The following functional evaluation variables were unaffected by NMES: peak V̇o2; gas exchange threshold; the V̇o2 vs. work rate relationship (O2 cost of cycling); changes in concentration of deoxygenated hemoglobin + myoglobin vs. work rate relationship (related to the matching between O2 delivery and V̇o2); peak fractional O2 extraction; V̇o2 kinetics (during moderate and heavy CLE) and the amplitude of its slow component (during heavy CLE). Thus NMES did not affect several variables of functional evaluation of skeletal muscle oxidative metabolism. Muscle hypertrophy induced by NMES could impair peripheral O2 diffusion, possibly counterbalancing, in vivo, the fast-to-slow phenotypic changes that were observed in vitro, in a previous work, in the same subjects of the present study.


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