Investigating the effect of limited spectral information on NIRS-derived changes in hemoglobin and cytochrome-c-oxidase concentration with a diffusion-based model.

This paper investigates the theoretical capability of near-infrared spectroscopy (NIRS) systems to accurately measure changes in the oxidation state of cerebral cytochrome-c-oxidase (CCO) alongside the hemoglobins, for a deeper understanding of NIRS limitations. Concentration changes of oxy and deoxyhemoglobin (HbO and HbR) indicate the oxygen status of blood vessels and correlate with several other physiological parameters across different pathologies. The oxidation state of CCO indicates cellular energy usage efficiency through oxidative metabolism, potentially serving as a biomarker for brain and other tissue disorders.

Using spectral derivatives to remove the influence of hair on optical images of the static absorbing properties of tissue-like turbid media.

Significance: Although measurements of near-infrared light diffusely reflected from the head and other biological tissues are commonly used to generate images revealing changes in the concentrations of oxy- and deoxy-hemoglobin, static imaging of absolute concentrations has been inhibited by the unknown and variable coupling between the optical probe and the skin, to which hair is often a significant contributor. Measurements of spectral derivatives provide a means of overcoming this shortcoming.

Aim: The aim is to demonstrate experimentally that measurements of the derivative of the attenuation of the detected signal with respect to wavelength can be used to achieve images that are immune to the spatial variation of hair on the surface.

Disinfection of central venous access device needleless connectors: A human factors analysis.

Objective: Evidence-based central-line-associated bloodstream infection (CLABSI) prevention guidelines recommend the use of an antiseptic scrub to disinfect needleless connectors before device access. Guideline noncompliance may render disinfection ineffective. The goal of this study was to observe needleless-connector disinfection practices and to identify perceived facilitators and barriers to best practices of needleless-connector access.