In vivocharacterization of the optical and hemodynamic properties of the human sternocleidomastoid muscle through ultrasound-guided hybrid near-infrared spectroscopies

Abstract

The non-invasive monitoring of the hemodynamics and metabolism of the sternocleidomastoid muscle (SCM) during respiration became a topic of increased interest partially due to the increased use of mechanical ventilation during the COVID-19 pandemic. Near-infrared diffuse optical spectroscopies were proposed as potential practical monitors of increased recruitment of SCM during respiratory distress. They can provide clinically relevant information on the degree of the patient's respiratory effort that is needed to maintain an optimal minute ventilation, with potential clinical application ranging from evaluating chronic pulmonary diseases to more acute settings, such as acute respiratory failure, or to determine the readiness to wean from invasive mechanical ventilation. In this paper, we present a detailed characterization of the optical properties (wavelength dependent absorption and reduced scattering coefficients) and hemodynamic properties (oxy-, deoxy- and total hemoglobin concentrations, blood flow, blood oxygen saturation and metabolic rate of oxygen extraction) of the human SCM, obtained by measuring sixty-five subjects through ultrasound-guided near-infrared time-resolved and diffuse correlation spectroscopies. We provide detailed tables of the results related to SCM baseline (i.e. muscle at rest) properties, and reveal significant differences on the measured parameters due to variables such as side of the neck, sex, age, body mass index and thickness of the overlaying tissues, allowing future clinical studies to take into account such dependencies.

Combined frequency domain near-infrared spectroscopy and diffuse correlation spectroscopy system for comprehensive metabolic monitoring of inspiratory muscles during loading

“…This is consistent with previous work that has shown differences in respiratory system mechanics during activation between the sexes 37 . Baseline values in oxy [Hb+Mb] and total [Hb+Mb] were different between the sexes, with males having higher concentrations on average, which has also been reported by other groups 15 , 19 , 38 . This may be attributable to the known hemoglobin content difference between sexes 39 .…”

“…In this work, we describe how we combined a custom frequency-domain NIRS (FD-NIRS) system with a custom diffuse correlation spectroscopy (DCS) system, which can measure blood flow, to evaluate metabolic changes of the SCM during a dynamic inspiratory loading protocol. Although there have been prior works combining NIRS and DCS systems to measure a range of tissues, 17 – 20 this is the first to our knowledge to investigate dynamic changes in inspiratory muscles. It is also the first to characterize the unique alterations in oxygenation, blood flow, and oxygen extraction that occur during inspiratory muscle loading.…”

In vivo characterization of the optical and hemodynamic properties of the human sternocleidomastoid muscle through ultrasound-guided hybrid near-infrared spectroscopies

“…The data that support the findings of this study are openly available at the following URL/DOI:https://doi.org/ 10.5281/zenodo.7741369 (Cortese et al 2023).…”