دانلود رایگان مقاله طیف سنجی مادون قرمز نزدیک برای ارزیابی عملکرد مویرگ عضلات اسکلتی محلی

Abstract

Abstract Purpose of review: Continuous wave near infrared spectroscopy (CW NIRS) provides non-invasive technology to measure relative changes in oxy- and deoxy-haemoglobin in a dynamic environment. This allows determination of local skeletal muscle O2 saturation, muscle oxygen consumption (VO_ 2) and blood flow. This article provides a brief overview of the use of CW NIRS to measure exercise-limiting factors in skeletal muscle. Recent findings: NIRS parameters that measure O2 delivery and capacity to utilise O2 in the muscle have been developed based on response to physiological interventions and exercise. NIRS has good reproducibility and agreement with gold standard techniques and can be used in clinical populations where muscle oxidative capacity or oxygen delivery (or both) are impaired. CW NIRS has limitations including: the unknown contribution of myoglobin to the overall signals, the impact of adipose tissue thickness, skin perfusion during exercise, and variations in skin pigmentation. These, in the main, can be circumvented through appropriate study design or measurement of absolute tissue saturation. Summary: CW NIRS can assess skeletal muscle O2 delivery and utilisation without the use of expensive or invasive procedures and is useable in large population-based samples, including older adults.

Conclusions

CW NIRS is a non-invasive, portable and relatively cheap way to measure local skeletal muscle O2 utilisation and delivery, which are both important determinants of functional capacity in exercising muscle. This provides the means to investigate pathophysiological mechanisms that limit exercise capacity as well as mechanisms of benefit resulting from exercise intervention. This is of value in a multitude of disease states, but also in the context of age related decline in exercise capacity. Understanding underlying mechanisms of deterioration in capacity would help identify optimal targets for intervention tailored to specific populations. Physiological interventions such as arterial and venous occlusions generate quantitative values and have demonstrated good reproducibility, sensitivity to capacity and agreement with gold standard techniques. Future studies employing NIRS to measure oxygenation and/or muscle VO_ 2 should be designed in light of the advantages and limitations of the technique.