Time Domain Near Infrared Spectroscopy Device for Monitoring Muscle Oxidative Metabolism: Custom Probe and In Vivo Applications

Abstract

Measurement of muscle oxidative metabolism is of interest for monitoring the training status in athletes and the rehabilitation process in patients. Time domain near infrared spectroscopy (TD NIRS) is an optical technique that allows the non-invasive measurement of the hemodynamic parameters in muscular tissue: concentrations of oxy- and deoxy-hemoglobin, total hemoglobin content, and tissue oxygen saturation. In this paper, we present a novel TD NIRS medical device for muscle oxidative metabolism. A custom-printed 3D probe, able to host optical elements for signal acquisition from muscle, was develop for TD NIRS in vivo measurements. The system was widely characterized on solid phantoms and during in vivo protocols on healthy subjects. In particular, we tested the in vivo repeatability of the measurements to quantify the error that we can have by repositioning the probe. Furthermore, we considered a series of acquisitions on different muscles that were not yet previously performed with this custom probe: a venous-arterial cuff occlusion of the arm muscle, a cycling exercise, and an isometric contraction of the vastus lateralis.

Dual wavelength spread-spectrum time-resolved diffuse optical instrument for the measurement of human brain functional responses

“…Whilst the spread-spectrum method fundamentally leads to a higher noise floor and reduced dynamic range compared to traditional pulsed excitation systems, we have previously shown that the recorded time-of-flight information is of sufficient quality to enable its use in forming quantitative measures of haemodynamic changes in typical experimental paradigms. The stability and pertinent aspects of the temporal performance, such as jitter, was shown to be comparable with traditional pulsed systems demonstrated in the literature [ 4 , 19 – 21 ].…”

NIRS-EMG for Clinical Applications: A Systematic Review

“…A high-power version, the TRS-20SD, has been used by Koga et al [64] to probe deep into quadricep muscles. Moreover, a research-oriented TD-NIRS device dedicated to muscle metabolism monitoring has been recently developed by Re et al [65].…”

Instrument response function acquisition in reflectance geometry for time-resolved diffuse optical measurements

“…A 3D custom-printed IRF acquisition system in "reflectance" geometry, shown in Figure 1(c), has been developed for an in-house built TR fNIRS device that is dedicated to muscle oxidative metabolism monitoring 4 . The probe used for measurements can host one injection and two detection 90° bended optical fibers at two different interfiber distances (ρ 1 = 1.5 cm; ρ 2 = 3 cm).…”