Monitoring Muscle Oxygenation Research Articles

Impaired muscle oxygenation despite normal pulmonary function in type 2 diabetes without complications.

Long-term hyperglycemia in individuals with type 2 diabetes (T2D) can detrimentally impact pulmonary function and muscle oxygenation. As a result, these factors can impede the body's adaptation to physical exertion. We aimed to evaluate the oxygen pathway during maximal exercise among overweight/obese individuals with type 2 diabetes free from complications, in comparison with a group of matched overweight/obese individuals without diabetes, specifically concentrating on the effects on pulmonary function and muscle oxygenation. Fifteen overweight/obese adults with type 2 diabetes [glycated hemoglobin (HbA1c) = 8.3 ± 1.2%] and 15 matched overweight/obese adults without diabetes underwent pre- and post exercise lung function assessment. A maximal incremental exercise test was conducted, monitoring muscle oxygenation using near-infrared spectroscopy and collecting arterial blood gas samples. Both groups exhibited normal lung volumes at rest and after exercise. Spirometric lung function did not significantly differ pre- and post exercise in either group. During maximal exercise, the type 2 diabetes group showed significantly lower augmentation in total hemoglobin and deoxygenated hemoglobin compared with the control group. Despite comparable usual physical activity levels and comparable heart rates at exhaustion, the type 2 diabetes group had a lower peak oxygen consumption than controls. No significant differences were found in arterial blood gas analyses ([Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text]) between the groups. Individuals with type 2 diabetes free from complications displayed normal pulmonary function at rest and post exercise. However, impaired skeletal muscle oxygenation during exercise, resulting from reduced limb blood volume and altered muscle deoxygenation, may contribute to the lower V̇o2peak observed in this population.NEW & NOTEWORTHY Individuals with type 2 diabetes free from micro- and macrovascular complications have normal resting pulmonary function, but their V̇o2peak is impaired due to poor skeletal muscle oxygenation during exercise. Tailoring exercise regimes for this population should prioritize interventions aimed at enhancing muscle oxygenation and blood flow improvement.

Muscle oxygenation of the paretic and nonparetic legs during and after exercise in chronic stroke: Implications for mobility.

Oxygen delivery and demand are reduced in the paretic leg of individuals after stroke. However, it is unknown how muscle oxygenation, the balance between delivery and utilization of oxygen at the muscle, is altered post-stroke during aerobic exercise and how it relates to mobility. To monitor muscle oxygenation changes between the paretic and nonparetic legs of individuals after stroke during treadmill exercise and the 6-minute walk test and analyze the association with mobility. Cross-sectional study. Cardiac rehabilitation program. Eleven male participants were enrolled in the study. Ten men (30.8 ± 4.1months post-stroke; age 63.9 ± 13.9 years) with hemiparetic gait pattern finished the study. Not applicable. Muscle oxygenation was measured with near-infrared spectroscopy placed on the vastus lateralis of each leg during treadmill exercise at the first ventilatory threshold and during a 6-minute walk test. The desaturation slope during treadmill exercise was significantly steeper (p=.047) in the paretic (-0.7 ± 0.6%/s) compared to the nonparetic leg (-0.3 ± 0.2%/s). There was no other significant difference between legs. The 6-minute walk test distance was not correlated with 6-minute walk test muscle oxygenation in either leg (paretic: r=0.20, p=0.590; nonparetic: r=0.42, p=.232). At the onset of treadmill exercise, the paretic leg was unable to effectively match the oxygen demand and extraction of the nonparetic leg, suggesting the need for an immediate cardiovascular warmup prior to initiating moderate intensity exercise in this population. Because the exercise desaturation rate is thought to indicate increased anaerobic metabolism and lactate production, efforts to delay rapid desaturation could improve the sustainability of activities of daily living and exercise.

Principles, insights, and potential pitfalls of the noninvasive determination of muscle oxidative capacity by near-infrared spectroscopy.

Skeletal muscle oxidative capacity is highly plastic, strongly associated with whole-body aerobic capacity (16, 18) and state of health. Loss of muscle oxidative capacity is associated with physical inactivity, aging and chronic disease (17), and has been implicated in the pathophysiology of obesity and diabetes (21). Evaluating these changes has traditionally been limited to invasive or costly assessments (biopsy or ³¹P MRS). To address this, Hamaoka and colleagues developed an innovative, non-invasive approach using near-infrared spectroscopy (NIRS) to quantitatively measure muscle oxygen consumption (mVO₂; 12) and use this to infer muscle oxidative capacity based on the mVO₂ recovery rate constant (k) (23; later modified 26). This technique has been subsequently used to interpret relative differences in oxidative capacity across a wide range of muscles, ages and disease states (Figure 1C). The purpose of this Viewpoint is to open a discussion on the principles, insights and potential pitfalls of using NIRS to measure k and infer muscle oxidative capacity.

Biophotonic Technique to Study Muscle Tissue Metabolism of Athletes

ABSTRACT.Near-infrared spectroscopy is an affordable technology that can be used in monitoring muscle oxygenation in exercise and sport setting. In this study, we presented a portable, wireless, multichannel near-infrared spectroscopy device for real-time monitoring of muscle activity. Wireless communication was applied to data transmission in order to avoid cumbersome wires, and the whole system is highly integrated. We took special care to eliminate motion artifact when designing the near-infrared spectroscopy sensor for attachment to human skin. In addition, the system is designed with a high sampling rate so as to monitor rapid oxygenation changes during muscle activity. The wireless near-infrared spectroscopy sensor was designed using commercially available electronic components that were mounted onto a 4-layer rigid-flexible printed circuit board. We performed in vivo experiments including arterial occlusion and isometric voluntary forearm muscle contraction among wrestlers and demonstrated that the...

A portable multi-channel wireless NIRS device for muscle activity real-time monitoring.

Near-infrared spectroscopy (NIRS) is a relative new technology in monitoring muscle oxygenation and hemo-dynamics. This paper presents a portable multi-channel wireless NIRS device for real-time monitoring of muscle activity. The NIRS sensor is designed miniaturized and modularized, to make multi-site monitoring convenient. Wireless communication is applied to data transmission avoiding of cumbersome wires and the whole system is highly integrated. Special care is taken to eliminate motion artifact when designing the NIRS sensor and attaching it to human skin. Besides, the system is designed with high sampling rate so as to monitor rapid oxygenation changes during muscle activities. Dark noise and long-term drift tests have been carried out, and the result indicates the device has a good performance of accuracy and stability. In vivo experiments including arterial occlusion and isometric voluntary forearm muscle contraction were performed, demonstrating the system has the ability to monitor muscle oxygenation parameters effectively even in exercise.

Use of NIRS to assess effect of training on peripheral muscle oxygenation changes in elite rugby players performing repeated supramaximal cycling tests.

In most team sports, intermittent high intensity sprint efforts combined with short recovery periods have been identified as a key factor of physical performance; the ability to repeat these efforts at a sustained level is of great importance. Near-infrared spectroscopy (NIRS) has been proposed as a tool to monitor muscle oxygenation changes during such sprint efforts. The purpose of this study was to observe muscle reoxygenation rate (reoxy rate) (% s⁻¹) between sprint efforts in a repeat sprint cycle test. A two wavelength spatially resolved NIR spectrometer (Portamon, Artinis Inc.) was used to assess reoxy rate changes in the vastus lateralis of the dominant leg before and after a training stimulus. Eight UK premiership academy level rugby players were assessed (age 20.6 ± 0.9) years; height 187 ± 0.6 cm; weight 109.5 ± 8.6 kg; quadriceps skin fold 16.6 ± 4.5 mm); the subjects completed ten repeated 10-s cycle sprints interspersed with 40 s recovery, upon a Wattbike Pro cycle. Hemoglobin variables (ΔHHb, ΔtHb, ΔO₂Hb, ΔTSI %) during the sprint and the post-sprint reoxygenation rate (%TSI s⁻¹) were measured. During both cycle tests all subjects experienced a drop in muscle oxygen saturation (Pre-Δ - 12.39 ± 6.01 %), Post-Δ - 14.83 ± 3.88 %). Post-training, there was an increase in the extent of desaturation (drop in TSI %) in the group means, both for the biggest single change and the average of all ten changes. Seven out of eight players showed an increase based on the maximum change and six based on the average of their ten tests. Additionally, seven out of eight players showed a significant increase in ΔHHb (Pre-Δ + 76.80 ± 61.92, Post-Δ + 121.28 ± 69.76) (p < 0.01) (including the one player who did not show a significant effect on the TSI measure). Players who exercised at the highest power tended to decrease their muscle oxygenation to a greater extent. The number of bike training sessions undertaken correlated with improvements in post-exercise recovery of oxygenation (R = 0.63). The simplest explanation for the increase in desaturation following training is an increase in muscle oxygen consumption due to an increase in mitochondrial content. This results in an increased extraction of delivered oxygen as confirmed by the HHb data. In conclusion, NIRS is able to measure positive training effects on muscle oxygen extraction, at the level of the individual elite athlete.

Near-infrared Spectroscopy Monitoring of the Collateral Network Prior to, During, and After Thoracoabdominal Aortic Repair: A Pilot Study

The aim of this study was to evaluate the feasibility of non-invasive monitoring of the paraspinous collateral network (CN) oxygenation prior to, during, and after thoracoabdominal aortic repair in a clinical series. Near-infrared spectroscopy optodes were positioned bilaterally-over the thoracic and lumbar paraspinous vasculature-to transcutaneously monitor muscle oxygenation of the CN in 20 patients (age: 66±10 years; men=11) between September 2010 and April 2012; 15 had open thoracoabdominal aortic repair (Crawford II and III), three had thoracic endovascular aortic repair (TEVAR; Crawford I), and two had a hybrid repair (Crawford II). CN oxygenation was continuously recorded until 48 hours postoperatively. Hospital mortality was 5% (n=1), 15% suffered ischemic spinal cord injury (SCI). Mean thoracic CN oxygenation saturation was 75.5±8% prior to anesthesia (=baseline) without significant variations throughout the procedure (during non-pulsatile cooling on cardiopulmonary bypass and with aortic cross-clamping; range=70.6-79.5%). Lumbar CN oxygenation (LbS) dropped significantly after proximal aortic cross-clamping to a minimum after 11.7±4 minutes (74±13% of baseline), but fully recovered after restoration of pulsatile flow to 98.5% of baseline. During TEVAR, stent-graft deployment did not significantly affect LbS. Three patients developed relevant SCI (paraplegia n=1/paraparesis n=2). In these patients LbS reduction after aortic cross-clamping was significantly lower compared with patients who did not experience SCI (p=.041). Non-invasive monitoring of CN oxygenation prior to, during, and after thoracoabdominal aortic repair is feasible. Lumbar CN oxygenation levels directly respond to compromise of aortic blood circulation.

Ankle position modifies tibialis anterior muscle perfusion and oxygenation in the human leg

Near‐infrared spectroscopy (NIRS) is a noninvasive technique used to monitor muscle oxygenation. Photoplethysmography (PPG) is a noninvasive measure of muscle microvascular blood flow. NIRS and PPG were used in seven tibialis anterior (TA) muscles of five healthy volunteers (3 male, 2 female) aged 31.2±7.8 years (mean, SD) in order to determine whether oxygenation and blood flow of the TA varied with ankle position. Data from the resting ankle position (mean of 11.5º plantarflexion) were compared to following test positions: full passive plantarflexion (PF), passive neutral (Neu) or 0º, and full passive dorsiflexion (DF). Mean oxygenation of the TA muscle yielded significant decreases for PF (p&lt;0.01) and DF (p&lt;0.01), but no significant difference for Neu (p=0.10). Mean perfusion of the TA muscle increased significantly for PF (p=0.027), Neu (p=0.012), and DF (p=0.010). Based on prior research, it was expected that oxygenation levels would decrease across the test ankle positions; however, it was not anticipated that perfusion would increase. Our novel results suggest that local compensatory vasodilation within muscle exists in order to increase microvascular blood flow under conditions of relative tissue hypoxia. These findings are important to the understanding of the local hemodynamic response in the human leg in relation to changes in ankle position from rest.

Ability of Near Infrared Spectroscopy to Measure Oxygenation in Isolated Upper Extremity Muscle Compartments

Near infrared spectroscopy (NIRS), a noninvasive means for monitoring muscle oxygenation, may be useful in the diagnosis of acute compartment syndrome, a condition characterized by poor tissue perfusion. This study used the decrease in muscle oxygenation caused by exercise to investigate the ability of anatomic placement of NIRS sensor pads over compartments of the forearm to isolate perfusion values of a specific compartment. We recruited 63 uninjured volunteers from a private clinic-based setting and placed NIRS sensor pads over the dorsal, volar, and mobile wad compartments of 1 forearm. A total of 49 participants also had the contralateral forearm monitored, which served as an internal control. Participants performed a series of 3 exercises designed to sequentially activate the muscles of each compartment. A washout period separated each exercise to allow perfusion to return to baseline. We compared NIRS values of each compartment recorded during muscle contraction with baseline values. Mean NIRS values decreased significantly from baseline during muscle contraction for all compartments, whereas mean NIRS values of muscle compartments that remained at rest showed little or no change. We observed no changes in NIRS values of the contralateral arm, which remained at rest during the entire data collection period. Although lack of an existing method for quantifying muscle perfusion precludes validation of this technique against a reference standard, this study suggests that NIRS can provide oxygenation values that are both sensitive and specific to muscle compartments of the forearm. Future studies should investigate NIRS among patients with upper extremity injuries. Diagnostic III.

Monitoring muscle oxygenation after eccentric exercise-induced muscle damage using near-infrared spectroscopy

Eccentric exercise (EE), a common type of muscular activity whereby muscles lengthen and contract simultaneously, is associated with higher levels of force but may also evoke muscle damage. We investigated the hypothesis that unaccustomed EE might impair muscle oxygenation and muscle blood flow in healthy adults. Ten healthy males performed a bout of 70 maximal eccentric contractions of the elbow flexors. Before and after EE on day 1 and over the next 6 days, maximum voluntary isometric torque (MVT), serum creatine kinase (CK), and the changes in muscle oxygen saturation, blood flow, and oxygen uptake (using near-infrared spectroscopy) within the biceps brachii were assessed. MVT decreased, whereas muscle soreness and CK increased after EE (p < 0.05). Mean resting oxygen saturation increased by 22% after acute EE, and remained elevated by 5%-9% for the following 6 days. During isometric contractions, significant decreases were observed in oxygen desaturation and re-saturation kinetics after EE and these declines were also significantly prevalent over the following 6 days. Both muscle blood flow and oxygen uptake increased significantly after acute EE, but recovered on the next day. This study revealed some prolonged alterations in muscle oxygenation at rest and during exercise after EE, which might be due to a decrease in muscle oxygen consumption, an increase in oxygen delivery, and (or) a combination of both. However, both oxygen consumption and blood flow recovered within 24 h after the eccentric exercise session, and therefore, the reason(s) for the changes in tissue oxygen saturation remain unknown.

Near-infrared spectroscopy/imaging for monitoring muscle oxygenation and oxidative metabolism in healthy and diseased humans

Near-infrared spectroscopy (NIRS) was initiated in 1977 by Jobsis as a simple, noninvasive method for measuring the presence of oxygen in muscle and other tissues in vivo. This review honoring Jobsis highlights the progress that has been made in developing and adapting NIRS and NIR imaging (NIRI) technologies for evaluating skeletal muscle O(2) dynamics and oxidative energy metabolism. Development of NIRS/NIRI technologies has included novel approaches to quantification of the signal, as well as the addition of multiple source detector pairs for imaging. Adaptation of NIRS technology has focused on the validity and reliability of NIRS measurements. NIRS measurements have been extended to resting, ischemic, localized exercise, and whole body exercise conditions. In addition, NIRS technology has been applied to the study of a number of chronic health conditions, including patients with chronic heart failure, peripheral vascular disease, chronic obstructive pulmonary disease, varying muscle diseases, spinal cord injury, and renal failure. As NIRS technology continues to evolve, the study of skeletal muscle function with NIRS first illuminated by Jobsis continues to be bright.

Muscle Oxygenation Measured by Near-infrared Spectroscopy with Different Loads and Velocities of Resistance Exercise

Near-infrared spectroscopy (NIRS) is a non-invasive optical technique widely used to monitor muscle oxygenation (Mox) during various tasks, particularly during aerobic or isometric exercise, with very few studies related to resistance exercise (RE). Load and velocity of movement are two variables that affect performance in RE, but the physiological reasons for this are not fully understood. NIRS could be a useful technique to investigate fatigue in different RE protocols. PURPOSE: To compare maximum number of repetitions to volitional fatigue (REPS) and Mox variables measured by NIRS (MicroRunman, NIM Inc., PA) during knee extensions with light (L: 60% 1RM) and heavy (H: 80% 1RM) loads, at either slow (S: 25°.s−1) or fast (F: 80°.s−1) movement velocities. METHODS: Informed consent was obtained from 9 healthy volunteers (35.8 ± 10.8 yr; 74.2 ± 16.7 kg; 171.0 ± 10.0 cm). After determining 1RM load for knee extension of the dominant leg, subjects reported to the laboratory on 4 different occasions, separated by at least 48 h, when they randomly performed 1 set of REPS with different combinations of loads and velocities: LS, LF, HS and HF. A repetition was considered valid if range of motion was at least 60°. The NIRS probe was positioned over the vastus lateralis (∼16 cm above knee joint) and Mox was continuously monitored during 2 min rest, REPS and 3 min recovery. In addition to REPS, variables considered for analysis after adjustment for baseline were: minimum during REPS and/or recovery (MIN), and range from MIN to maximum during recovery (RANGE). RESULTS: Paired t-tests showed significant (p <.05) differences in REPS (LS = 8.8 ± 1.3; LF = 16.3 ± 3.9; HS = 5.9 ± 0.9; HF = 9.4 ± 1.9) between speeds (LS × LF and HS × HF) and between loads (LS × HS and LF × HF). However, none of the comparisons for either MIN (OD; LS = −0.218 ± 0.111; LF = −0.177 ± 0.093; HS = −0.217 ± 0.107; HF = −0.204 ± 0.098) or RANGE (OD; LS = 0.241 ± 0.122; LF = 0.230 ± 0.114; HS = 0.266 ± 0.139; HF = 0.253 ± 0.136) were significant. Pearson correlation between REPS and Mox variables was significant only for LF MIN (r = −0,73; p = 0,026). CONCLUSIONS: Mox does not seem to be related to performance during RE to volitional fatigue, suggesting that the level of muscle oxygenation may not be a factor limiting this type of exercise. Further studies using NIRS during RE should be conducted to confirm these findings. Partly supported by CAPES/Ministry of Education, FAPERJ (E-26/170.774/2003), and Righetto Fitness Equipment, Brazil.

Reliability Of Vastus Lateralis Oxygenation Measured By Near Infrared Spectroscopy During Resistance Exercise

Near infrared spectroscopy (NIRS) is a non-invasive optical technique that has been extensively used to monitor muscle oxygenation (Mox) during various tasks in different populations. However, its use during exercise has been restricted to aerobic or isometric activities, with very few attempts to investigate Mox during dynamic resistance exercise. PURPOSE To determine the reliability of vastus lateralis (VL) Mox measured by NIRS during isotonic knee extensions. METHODS Informed consent was obtained from 9 healthy volunteers (37.2 ± 10.2 yr; 74.1 ± 16.7 kg; 170.5 ± 9.6 cm) who randomly completed 4 sessions of 1 set of maximum repetitions (REPS) of the dominant leg on a knee extension machine with 80% 1RM at slow (SS: ∼25°·s−1) and fast (FS: ∼80°·s−1) speeds. A repetition was considered valid if range of motion was at least 60°. Test/ retest measurements were undertaken within a two-week period. The NIRS probe was positioned over VL (∼16 cm above knee joint) and Mox was continuously monitored during 2 min rest, REPS, and 3 min recovery. Variables considered for analysis after adjustment for baseline were: minimum during REPS plus recovery (MIN), range from MIN to maximum during recovery (RANGE), and time for half-recovery after REPS (T1/2). RESULTS Bland-Altman analysis revealed an outlier on FS REPS and one on SS Mox whose data were discarded. Mox data was further discarded for one subject in each speed due to probe displacement. Number of REPS were 6.1 ± 0.8 and 6.3 ± 0.9 for test and retest, respectively, for SS (n = 9; intraclass correlation coefficient, ICC = .674; p = .016); and 9.3 ± 1.9 and 9.9 ± 1.6, respectively, for FS (n = 8; ICC = .560; p = .046). For SS (n = 7), MIN (ICC = .730; p = .014), RANGE (ICC = .795; p = .006) and T1/2 (ICC = .780; p = .007) showed significant reliability, but only MIN (ICC = .854; p = .002) and RANGE (ICC = .973; p = .000) were reliable for FS (n = 7), with ICC = .309 for T1/2 (p = .773). CONCLUSIONS Reproducibility of Mox measurements of VL was moderately high at 80% 1RM during dynamic knee extensions to voluntary fatigue. NIRS is a suitable technique for evaluating Mox changes during resistance exercise. Partly supported by CAPES/Ministry of Education, FAPERJ (E-26/170.774/2003), and Righetto Fitness Equipment, Brazil.

Muscle oxygenation by near infrared spectroscopy and lactate thresholds in endurance trained and recreationally active cyclists.

The development of noninvasive near infrared spectroscopy (NIRS) to monitor tissue oxyghemoglobin/myoglobin saturation provides a means of continuously and noninvasively monitoring muscle oxygenation during exercise (1-3). The lactate threshold has been. used to gauge endurance training (4,5). It would be of interest to determine whether the noninvasive monitoring of muscle oxygenation can be used as a surrogate marker of lactate threshold or as a gauge of conditioning during endurance training. The ability to identify the lactate threshold by a noninvasive, continuous monitor such as NIRS would greatly aid athletes in assessing their level of performance during training and to guide that training.

Near-infrared spectroscopy for monitoring muscle oxygenation.

Near-infrared spectroscopy (NIRS) is a non-invasive method for monitoring oxygen availability and utilization by the tissues. In intact skeletal muscle, NIRS allows semi-quantitative measurements of haemoglobin plus myoglobin oxygenation (tissue O2 stores) and the haemoglobin volume. Specialized algorithms allow assessment of the oxidation-reduction (redox) state of the copper moiety (CuA) of mitochondrial cytochrome c oxidase and, with the use of specific tracers, accurate assessment of regional blood flow. NIRS has demonstrated utility for monitoring changes in muscle oxygenation and blood flow during submaximal and maximal exercise and under pathophysiological conditions including cardiovascular disease and sepsis. During work, the extent to which skeletal muscles deoxygenate varies according to the type of muscle, type of exercise and blood flow response. In some instances, a strong concordance is demonstrated between the fall in O2 stores with incremental work and a decrease in CuA oxidation state. Under some pathological conditions, however, the changes in O2 stores and redox state may diverge substantially.