Near infrared spectroscopy as a tool for in vivo analysis of human muscles
Recent advances in materials and fabrication techniques provided portable, performant, sensing optical spectrometers readily operated by user-friendly cabled or wireless systems. Such systems allow rapid, non-invasive and not destructive quantitative analysis of human tissues. In this proof-of-principle investigation, we will test whether infrared spectroscopy techniques, currently utilized in areas as primary/secondary raw materials sector, cultural heritage, agricultural/food/pharmaceutical industry, environmental remote and proximal sensing, could be applied in living humans to categorize muscles. Using an ASD FieldSpec 4 Standard-Res Spectroradiometer with a spectral sampling capability of 1.4 nm at 350-1000 nm and 1.1 nm at 1001-2500 nm, we will acquire muscles reflectance spectra in the visible short-wave infra-red regions (350-2500 nm), from the upper limb muscles (flexors and extensors) in healthy subjects. Spectra off-line analysis will include preliminary pre-processing for signal scattering reduction, Principal Component Analysis aimed to spectral grouping, and Partial Least-Squares Discriminant Analysis for implementing discrimination/prediction models.