Enhanced diagnostic of skin conditions by polarized laser speckles:Phantom studies and computer modeling

The incidence of the skin melanoma, the most commonly fatal form of skin cancer, is increasing faster than any other potentially preventable cancer. Clinical practice is currently hampered by the lack of the ability to rapidly screen the functional and morphological properties of tissues. In our previous study we show that the quantification of scattered laser light polarization provides a useful metrics for diagnostics of the malignant melanoma. In this study we exploit whether the image speckle could improve skin cancer diagnostic in comparison with the previously used free-space speckle. The study includes skin phantom measurements and computer modeling. To characterize the depolarization of light we measure the spatial distribution of speckle patterns and analyse their depolarization ratio taken into account radial symmetry. We examine the dependences of depolarization ratio vs. roughness for phantoms which optical properties are of the order of skin lesions. We demonstrate that the variation in bulk optical properties initiates the assessable changes in the depolarization ratio. We show that image speckle differentiates phantoms significantly better than free-space speckle. The results of experimental measurements are compared with the results of Monte Carlo simulation

Skin Roughness Assessment

Non

Real-Time Raman Spectroscopy for Noninvasive in vivo Skin Analysis and Diagnosis

Non

Remimazolam in pediatric anesthesia: a systematic review for clinical decision-making

BackgroundRemimazolam's role in pediatric anesthesia is evolving. We systematically reviewed 2024–2025 evidence to establish a clinical decision-making framework for its use.MethodsFollowing PRISMA guidelines, a systematic search identified 23 studies (15 RCTs) involving 2,847 pediatric patients for narrative synthesis.ResultsRemimazolam demonstrated superior hemodynamic stability vs. propofol (cardiovascular complications: RR 0.30, 95% CI 0.20–0.46) and reduced emergence delirium by 61% (RR 0.39, 95% CI 0.21–0.70). The CES1 G143E polymorphism was identified as a genetic basis for prolonged sedation, reducing drug clearance >90%. Critical limitations include a 15% re-sedation rate post-flumazenil, a complete lack of data in infants <1 year, and unknown long-term neurodevelopmental safety.ConclusionRemimazolam represents a valuable anesthetic tool with specific advantages in pediatric anesthesia. While it demonstrates superior hemodynamic stability and reduced emergence delirium compared to standard agents, it is not a universal replacement for established anesthetics. Current evidence supports its use in specific clinical scenarios, particularly for preventing post-sevoflurane emergence delirium and in hemodynamically unstable patients. However, the absence of infant and long-term neurodevelopmental safety data necessitates continued research before widespread adoption.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD420251058023, PROSPERO CRD420251058023

Human skin optical properties and autofluorescence decay dynamics

Human skin is an optical organ which constantly interacts with light. Its optical properties are fundamental to understanding various effects of light-tissue interaction inhuman skin and to laser applications in medicine and biology. The aim of this thesis was to test two hypotheses: (1) that skin optical properties can be quantitatively modeled, and (2)that in vivo spectroscopic measurements can be used to derive information about skin structures. Both theoretical and experimental procedures were used to test these hypotheses. Experimental studies were completed in terms of macroscopic, in vivo diffuse reflectance spectroscopy, autofluorescence spectroscopy, and temporal behavior of the autofluorescence signal during continuous laser exposure, as well as microscopic in vitro fluorophore distribution and spectral differences. Several interesting physical phenomena were discovered. Three new methods were developed for deriving information of different skin layers from in vivo and in vitro measurements. The most interesting finding was that, under continuous laser exposure, skin autofluorescence decays following a double exponential function and that the autofluorescence recovery takes about six days. A seven layer skin optical model was developed based on(1) the structural anatomy of skin, (2) published optical properties of different skin layers and blood, and (3) measured skin fluorophore micro-distribution. Monte Carlo simulation was used to solve the Boltzmann equation of radiative transfer for the new skin model. The solutions provided a detailed knowledge of light propagation in skin tissue. The theoretical modeling unified the microscopic properties with the macroscopic in vivo skin measurements. The physical meaning of the auto fluorescence double exponential decay dynamics was also elucidated. It was shown that the coefficients of the double decay can be used to estimate the fractional contributions of different skin layers to the observed in vivo auto fluorescence signal. Using this approach, it was determined that the fractional contribution of the stratum corneum was - 14%, while the calculated value for the Monte Carlo skin model was - 15%, providing a close agreement between experimental and theoretical values. The dermis contributed the remaining 85% of the observed in vivo signal. We therefore, believe that the thesis hypotheses have been substantially proven. Although the skin has complicated inhomogeneous structures, its optical properties can now be quantitatively modeled and various modalities of in vivo skin spectroscopy can be used to derive information on skin structures.Science, Faculty ofPhysics and Astronomy, Department ofGraduat