Laser speckle contrast imaging with principal component and entropy analysis: a novel approach for depth-independent blood flow assessment.

Current study presents an advanced method for improving the visualization of subsurface blood vessels using laser speckle contrast imaging (LSCI), enhanced through principal component analysis (PCA) filtering. By combining LSCI and laser speckle entropy imaging with PCA filtering, the method effectively separates static and dynamic components of the speckle signal, significantly improving the accuracy of blood flow assessments, even in the presence of static scattering layers located above and below the vessel. Experiments conducted on optical phantoms, with the vessel depths ranging from 0.

Optical Clearing of Ex Vivo Adipose Tissue.

Objectives: The paper focuses on the development of technology of adipose tissue optical clearing using different complex hyperosmotic optical clearing agents and tissue permeability enhancers.

Methods: To quantify optical clearing efficiency, reduced scattering coefficient was estimated from the ex vivo spatially resolved backreflectance measurements using a multi-distant fiber optical device. Tissue morphology modification was monitored with the help of histological studies.

Light in evaluation of molecular diffusion in tissues: Discrimination of pathologies.

The evaluation of the diffusion properties of different molecules in tissues is a subject of great interest in various fields, such as dermatology/cosmetology, clinical medicine, implantology and food preservation. In this review, a discussion of recent studies that used kinetic spectroscopy measurements to evaluate such diffusion properties in various tissues is made. By immersing ex vivo tissues in agents or by topical application of those agents in vivo, their diffusion properties can be evaluated by kinetic collimated transmittance or diffuse reflectance spectroscopy.

Influence of optical clearing agents on the scattering properties of human nail bed and blood microrheological properties: In vivo and in vitro study.

Optical clearing agents (OCAs) are substances that temporarily modify tissue's optical properties, enabling better imaging and light penetration. This study aimed to assess the impact of OCAs on the nail bed and blood using in vivo and in vitro optical methods. In the in vivo part, OCAs were applied to the nail bed, and optical coherence tomography and optical digital capillaroscopy were used to evaluate their effects on optical clearing and capillary blood flow, respectively.