Time-dependent blood flow and oxygenation in human skeletal muscles measured with noninvasive near-infrared diffuse optical spectroscopies

Abstract

We have employed near-infrared optical methods to measure noninvasively the dynamics of muscle blood flow and oxygen saturation (StO2) during cuff occlusion and plantar flexion exercise. Relative muscle oxygen consumption (rVO2) was also computed from these data. Diffuse correlation spectroscopy provides information about blood flow, and diffuse reflectance spectroscopy provides information about blood oxygenation. Ten healthy subjects and one patient with peripheral arterial disease (PAD) were studied during 3-min arterial cuff occlusion of arm and leg, and during 1-min plantar flexion exercise. Signals from different layers (cutaneous tissues and muscles) during cuff occlusion were differentiated, revealing strong hemodynamic responses from muscle layers. During exercise in healthy legs, the observed approximately 4.7 fold increase in relative blood flow (rBF) was significantly lower than the corresponding increase in rVO2 (approximately 7 fold). The magnitudes of rBF and rVO2 during exercise in the PAD patient were approximately 1/2 of the healthy controls, and the StO2 recovery time was twice that of the controls. The hybrid instrument improves upon current technologies for measuring muscle responses by simultaneously measuring rBF and StO2. The instrument thus provides a method for evaluation of microcirculation and muscle metabolism in patients with vascular diseases.

Fiber-based multispeckle detection for time-resolved diffusing-wave spectroscopy: characterization and application to blood flow detection in deep tissue

“…Data from skin [11], tumors [12][13][14][15], skeletal muscle [16,17], and the human brain cortex [18 -20] suggest a strong coupling of the DWS signal to blood flow. While the driven erythrocyte motion, which is thought to be the origin of the DWS signal, is not Brownian in living tissue, experimental field autocorrelation functions are generally better described with diffusion than with (random) flow [19,21,22].…”

Oximetric angiosome imaging in diabetic feet

“…This is consistent with results reported using near-infrared spectroscopy techniques to measure OEF in the skin and adipose tissue of lower extremities of healthy subjects, where increased muscle oxygen consumption during exercise was met with both increases in OEF and skin blood flow. 24,25 However, there was no report of the same isometric toe-flexion exercise, as in this study, for the assessment of skin or skeletal muscle oxygenation. The relatively small increase in SMOEF during the toeflexion exercise may be caused by the variations of toe-flexion strength controlled by the subjects.…”

Optical Spectroscopic Analysis of Muscle Spasticity for Low-Level Laser Therapy (LLLT)

“…The laser source is connected with an optical fiber at the center of the designed probe and the fibers for the light source and spectroscopic detection were connected at the sides of the probe. Because the thickness of the skin and adipose tissue layer in humans is approximately 3 mm the source-detector separation used in this study was 2 cm, which allowed for sufficient light penetration into the muscle [32]. The incident light source was generated by a tungsten-halogen lamp (HL-2000, Ocean Optics, Dunedin, FL, USA) and the acquired signal reflected from tissue was transmitted to the spectrometer with the spectral range from 300-1000 nm.…”