Artefact subspace reconstruction for both EEG and fNIRS co-registred signals.

Combining electroencephalography (EEG) to functional near-infrared spectroscopy (fNIRS) is a promising technique that has gained momentum thanks to their complementarity. While EEG measures the electrical activity of the brain, fNIRS records the variations in cerebral blood flow and related hemoglobin concentrations. However, both modalities are typically contaminated with artefacts.

Chromophore reconstruction at depth in bilayered media: a method for quantification.

We report a method for deriving the absolute value of absorption coefficients at depth in bilayered media. The method was simplified from that of time-resolved diffuse optical tomography (TR-DOT) into one dimension to validate and set up the main parameters with the help of simulations, and to test it in an easy preclinical model. The method was applied to buried flaps as used in reconstructive surgery, and absolute chromophore concentrations in the flap and in the upper (skin and fat) layer were derived.

Noninvasive Monitoring of Deep Tissue Oxygenation in Buried Flaps by Time-Resolved Near-Infrared Spectroscopy in Pigs.

Background: Flap monitoring in reconstructive surgery is particularly important because flap failure is a dramatic event for the patient and for the medical team. Noninvasive deep tissue oxygenation monitoring is a challenge. The aim of this experimental study was to assess the performance of time-resolved near-infrared spectroscopy compared with continuous-wave near-infrared spectroscopy and with invasive oxygen partial pressure measurement in pigs.

Distinction between arterial and venous occlusion with tissue oxygen pressure in a porcine fascio-cutaneous flap model.

Background: In recent years, many devices have been developed to monitor free flaps. The Licox probe, which measures tissue oxygen pressure (PtO ), is one of the available devices. Our aim was to demonstrate that PtO could distinguish arterial from venous occlusion in a porcine fascio-cutaneous flap model.

Validation of optical properties quantification with a dual-step technique for biological tissue analysis.

To approach wide-field optical properties quantification in real heterogeneous biological tissue, we developed a Dual-Step setup that couples a punctual diffuse reflectance spectroscopy (DRS) technique with multispectral imaging (MSI). The setup achieves wide-field optical properties assessment through an initial estimation of scattering with DRS, which is used to estimate absorption with MSI. The absolute quantification of optical properties is based on the ACA-Pro algorithm that has been adapted both for DRS and for MSI.