The use of muscle near-infrared spectroscopy in sport, health and medical sciences: recent developments

Abstract

Near-infrared spectroscopy (NIRS) has been shown to be one of the tools that can measure oxygenation in muscle and other tissues in vivo. This review paper highlights the progress, specifically in this decade, that has been made for evaluating skeletal muscle oxygenation and oxidative energy metabolism in sport, health and clinical sciences. Development of NIRS technologies has focused on improving quantification of the signal using multiple wavelengths to solve for absorption and scattering coefficients, multiple pathlengths to correct for the influence of superficial skin and fat, and time-resolved and phase-modulated light sources to determine optical pathlengths. In addition, advances in optical imaging with multiple source and detector pairs as well as portability using small wireless detectors have expanded the usefulness of the devices. NIRS measurements have provided information on oxidative metabolism in various athletes during localized exercise and whole-body exercise, as well as training-induced adaptations. Furthermore, NIRS technology has been used in the study of a number of chronic health conditions. Future developments of NIRS technology will include enhancing signal quantification. In addition, advances in NIRS imaging and portability promise to transform how measurements of oxygen utilization are obtained in the future.

Modified Beer-Lambert law for blood flow

“…The Modified Beer-Lambert approach has been employed extensively in the biomedical optics community [2,7,[67][68][69][70], in large part because of its simplicity. With this approach, researchers have monitored temporal changes in blood oxygenation and blood volume with CW light, using only one source-detector separation.…”

“…Diffuse optical techniques, such as near-infrared or diffuse optical spectroscopy (DOS, NIRS) and diffuse correlation spectroscopy (DCS), have been employed with remarkable success over the last two decades to probe hemodynamic processes in highly scattering tissues such as human brain, muscle and breast [1][2][3][4][5][6][7][8][9][10][11]. In total, this research has discovered new indicators of tissue function and health that are proving to be clinically relevant [6][7][8][9][10][11][12][13][14].…”

“…In total, this research has discovered new indicators of tissue function and health that are proving to be clinically relevant [6][7][8][9][10][11][12][13][14]. The most basic DOS/NIRS instrument measures diffuse reflectance from tissue as a function of input wavelength, and thereby derives the concentration of tissue chromophores and contrast agents, including oxyand deoxy-hemoglobin (HbO 2 , Hb), and changes thereof.…”

Using the Placebo Effect to Isolate Control Mechanisms of Athletic Performance: A Research Protocol

“…The role of NIRS in exercise physiology is increasing (nearly, 2004) and the results of several studies suggest that NIRS is a powerful tool for being applied successfully in sports medicine, 67 as NIRS can objectively evaluate muscle oxidative metabolism and its modifications following interventions. 68,69 The development of light wireless NIRS devices, operating on Bluetooth basis allow the application on freely moving subjects and enable the use during exercise protocols. Several studies have shown that these wireless NIRS devices produce nearly artifact free and reproducible data.…”

Textile integrated sensors and actuators for near-infrared spectroscopy

“…NIRS and NIRI are applied in many clinical applications, using different types of instruments to track oxygenation and blood flow in tissue [14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Many of these applications could profit from textile integrated optic devices, as described in [22].…”