scholarly journals Polarimetric interferometry to objectively evaluate the optical properties of corneal stroma

2018 ◽  
Vol 2 (2) ◽  
pp. 36-41
Author(s):  
Eugenio Lipari ◽  
Alessandra Sborgia ◽  
Mario Nubile ◽  
Leonardo Mastropasqua ◽  
Giovanni Alessio
Keyword(s):  
Optical Properties ◽  
Early Stage ◽  
Corneal Stroma ◽  
Collagen Fibrils ◽  
New Method ◽  
Strong Impact ◽  
Corneal Disease ◽  
Non Invasive ◽  
Invasive Method ◽  
Corneal Collagen

A new non-invasive method, based on the interferometric analysis of diff ractive and polarizing effects related to the birefringent properties of corneal collagen fibrils, has been developed to objectively evaluate the optical properties of the stroma. The new method shows a relevant impact on corneal surgeries specifically for lamellar transplantation where, due to the polarizing properties of the stroma, the alignment between collagen fibrils of donor corneas with patient collagen fibril orientation has shown an improvement of visual acuity postoperatively. Further studies on the regularity of the corneal isogyre pattern are showing this new method has a strong impact in early-stage diagnosis of corneal disease.

scholarly journals Monitoring the skin NADH changes during ischaemia and reperfusion in humans

2020 ◽  
Vol 89 (1) ◽  
pp. e405
Author(s):  
Jan Nizinski ◽  
Lukasz Kamieniarz ◽  
Piotr Filberek ◽  
Greta Sibrecht ◽  
Przemysław Guzik
Keyword(s):  
Optical Properties ◽  
Nicotinamide Adenine Dinucleotide ◽  
Energy Production ◽  
Reduced Form ◽  
Human Metabolism ◽  
Dynamic Changes ◽  
Non Invasive ◽  
Ischaemia And Reperfusion ◽  
Invasive Method ◽  
Skin Fluorescence

Nicotinamide adenine dinucleotide (NADH/NAD+) is involved in many important biochemical reactions in human metabolism, including participation in energy production by mitochondria. Flow Mediated Skin Fluorescence (FMSF) is a non-invasive method to study dynamic changes in the content of the reduced form of NADH by measuring the optical properties of NADH related to the emission of the autofluorescent light (460 nm) after an earlier excitation by ultraviolet light. This review summarises the available studies using this method to describe its potential and limitations.

‘Small’-proteoglycan: collagen interactions: Keratan sulphate proteoglycan associates with rabbit corneal collagen fibrils at the ‘a’ and ‘c’ bands

1985 ◽  
Vol 5 (9) ◽  
pp. 765-774 ◽  
Author(s):  
J. E. Scott ◽  
M. Haigh
Keyword(s):  
Binding Sites ◽  
Type I Collagen ◽  
Specific Binding ◽  
Corneal Stroma ◽  
Collagen Fibrils ◽  
Type I ◽  
Keratan Sulphate ◽  
Protein Rich ◽  
Small Proteoglycan ◽  
Corneal Collagen

l. Proteoglycans (PGs) in rabbit corneal stroma and mouse sclera have been stained for electron microscopy with Cupromeronic blue in a critical electrolyte concentration (CEC) mode, with and without prior digestion of the tissue by keratanase or chondroitinase ABC to remove the keratan sulphate (KS) or chondroitin-dermatan sulphates (CS or DS) respectively.2. Two classes of PGs, located orthogonally to the corneal collagen fibrils at either the ‘step’ (band ‘a’ or ‘c’) or gap zone (band ‘d’ or ‘e’) are shown to be KS-PGs or DS-PGs respectively. Four separate and specific PG binding sites on Type I collagen fibrils have thus been identified.3. Rabbit corneal KS and DS PGs each contain two kinds of PG (Gregory JD, Coster L & Damle SP (1982) J. Biol. Chem.257, 6965–6970). We propose that each ‘small’ protein-rich PG is associated with a specific binding site on the collagen fibril.

Observations on the Collagen and Proteinpolysaccharide Complex of Rabbit Corneal Stroma

1969 ◽  
Vol 4 (2) ◽  
pp. 421-436
Author(s):  
J. W. SMITH ◽  
J. FRAME
Keyword(s):  
Phosphotungstic Acid ◽  
Corneal Stroma ◽  
Uranyl Acetate ◽  
Collagen Fibrils ◽  
Bismuth Nitrate ◽  
Lead Citrate ◽  
Cross Sectional ◽  
Cross Links ◽  
Beaded Filaments ◽  
Corneal Collagen

The form and interrelationship of the collagen fibrils and proteinpolysaccharide complex of rabbit corneal stroma were studied by electron microscopy. The intact tissue was examined as Araldite sections stained with alkaline lead citrate and uranyl acetate, and the mechanically disintegrated cornea after positive or negative staining with phosphotungstic acid or after treatment with 0.5% bismuth nitrate in 0.1 M nitric acid. The corneal collagen fibrils vary in cross-sectional area from 4.6 to 9.6 x 104 sq. Å and do not exhibit a regular hexagonal distribution. Like tendon fibrils they consist of longitudinal filaments, but their appearance suggests that they lack some of the interfilament cross-links present in tendon. In sections of intact cornea and in negatively stained disintegrated cornea, filaments which are considered to be the protein cores of proteinpolysaccharide macromolecules are evident. They are about 40 Å wide and 2000 Å long. They appear to run an angular course, orthogonal to the collagen fibrils, and to be tangentially attached to several fibrils in the region of the a band. After treatment with bismuth nitrate disintegrated cornea contains coarsely beaded filaments. The filaments are about 2000 Å long and the beads about 70 Å in diameter. It is considered that these are again proteinpolysaccharide macromolecules and that each bead represents one or more polysaccharide chains in coiled configuration.

Vitamin B2 in Corneal Surgery—Riboflavin and Collagen Cross-Linking

2012 ◽  
Vol 05 (02) ◽  
pp. 105
Author(s):  
Spencer Thornton ◽  
Keyword(s):  
Collagen Fibrils ◽  
New Method ◽  
Cross Linking ◽  
Corneal Tissue ◽  
Chemical Bonds ◽  
Vitamin B2 ◽  
Corneal Surgery ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Cross-linking of collagen refers to the ability of collagen fibrils to form strong chemical bonds with adjacent fibrils. Corneal collagen cross-linking (CXL) with vitamin B2 activated by ultraviolet offers a new method for stabilization of unstable or weakened corneal tissue in cases of ectasia, dystrophy and irregular post-surgical healing.

A NOVEL METHOD TO ISCHEMIC HEART DISEASE DETECTION BASED ON NON-INVASIVE ECG IMAGING

2019 ◽  
Vol 19 (03) ◽  
pp. 1950002
Author(s):  
MOHAMMAD KARIMI MORIDANI ◽  
MAJID POULADIAN
Keyword(s):  
Disease Diagnosis ◽  
New Method ◽  
Ischemic Disease ◽  
Ecg Signals ◽  
Advantages And Disadvantages ◽  
Non Invasive ◽  
Invasive Method ◽  
Ischemic Episode ◽  
Time Accuracy ◽  
Sensitivity Specificity

Electrocardiogram (ECG) signals containing very important information about the cardiac are one of the most common tools for physicians in the diagnosis of various types of cardiac diseases. Low accuracy in positioning, limitation of time accuracy, the similarity of signals between some diseases and normal signals and probability of missing some aspect of data are the defect aspects of this method. Importance of cardiac signals and defects of current methods in diagnosis show the need of substituting a new method to show the activity of cardiac. One of the most dangerous defections is ischemia, which corrects and on time diagnose could avoid the latter effect of it. Each of common methods for diagnosis of this illness has their own advantages and disadvantages. In this paper, we consider describing a non-invasive method for ischemic episode detection based on mapping of ECG signals. With this method, we can present the signals with virtual colors and facilitate the diagnosis of ischemic disease. So, a new method of 12-lead cardiac presentation is described that in fact present the 12-lead signals in two images. The result of this paper will present the indicators of sensitivity, specificity and accuracy in the context of disease diagnosis. This paper proposed a novel ECG imaging algorithm for classifying the normal and ischemic signals and 95.35% specificity, 96.79% sensitivity and 95.76% accuracy were achieved which are very much promising compared to the other methods and doctor’s accuracy.

scholarly journals Medicine detection with Low Frequency Electromagnetic Signals

2020 ◽  
Vol 17 ◽  
Keyword(s):  
Low Frequency ◽  
Molecular Structures ◽  
New Method ◽  
Pain Reliever ◽  
Non Invasive ◽  
Reliever Medication ◽  
Invasive Method ◽  
Electromagnetic Signals ◽  
Magnet Resonance

This paper presents a new, non-invasive method to detect molecular structures inside materials . There have been different methods to detect molecular structures such as Chromatography, Spectroscopy and Nuclear Magnet Resonance. A brief description of these methods is presented and how they are used. Then the new method is presented using an apparatus emitting low frequency electromagnetic signals. This paper presents how the frequencies are found, that are used to detect molecular structures. The method was applied for finding the frequencies of four pain-reliever medication. Discussion follows on the results. Conclusions are drawn and further work is proposed

scholarly journals The influence of the optical properties on the determination of capillary diameters

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Moritz Späth ◽  
Maximilian Rohde ◽  
Dongqin Ni ◽  
Ferdinand Knieling ◽  
Florian Stelzle ◽  
...  
Keyword(s):  
Optical Properties ◽  
Absolute Quantification ◽  
The State ◽  
Capillary Diameter ◽  
Non Invasive ◽  
Wide Range ◽  
All Optical ◽  
Invasive Method ◽  
Diffuse Reflectance Imaging

AbstractVarious clinically applicable scores and indices are available to help identify the state of a microcirculatory disorder in a patient. Several of these methods, however, leave room for interpretation and only provide clues for diagnosis. Thus, a measurement method that allows a reliable detection of impending or manifest circulatory malfunctions would be of great value. In this context, the optical and non-invasive method of shifted position-diffuse reflectance imaging (SP-DRI) was developed. It allows to determine the capillary diameter and thus to assess the state of the microcirculation. The aim of the present study is to investigate how the quantification of capillary diameters by SP-DRI behaves in different individuals, i.e. for a wide range of optical properties. For this, within Monte-Carlo simulations all optical properties (seven skin layers, hemoglobin) were randomly varied following a Gaussian distribution. An important finding from the present investigation is that SP-DRI works when the optical properties are chosen randomly. Furthermore, it is shown that appropriate data analysis allows calibration-free absolute quantification of the capillary diameter across individuals using SP-DRI. This underpins the potential of SP-DRI to serve as an early alert system for the onset of microcirculatory associated diseases.

Early Diabetes Discovery From Tongue Images

2020 ◽  
Author(s):  
Safia Naveed ◽  
Geetha G ◽  
Leninisha S
Keyword(s):  
Human Body ◽  
Early Stage ◽  
Texture Features ◽  
The Body ◽  
Body Parts ◽  
Early Diabetes ◽  
Non Invasive ◽  
Internal Structures ◽  
Invasive Method ◽  
Sugar Levels

Abstract Medical imaging shows the internal structures hidden in the skin and bone to diagnose the disease. Diabetes mellitus (DM) is a metabolic disorder that causes high blood sugar levels due to the inadequate secretion of insulin or the body does not respond properly to the secreted insulin. This paper proposes a non-invasive method to detect DM at an early stage based on the physiognomy extracted from tongue images. The tongue extends to identify the disease of a human body. However, unpredictable response of the human body parts such as the stomach, pancreas, liver and intestines revert in the tongue. The changes in the tongue ensure the dereliction of the internal organs of the human being. The changes are difference in the color and surface of the tongue. Processing of tongue image is done by fractional order Darwinian particle swarm optimization (FODPSO) algorithm. The system framework involves obtaining the image, alluring of the image, identifying the texture and color feature and finally classified as normal or diabetic. In this paper, the authors propose to diagnose DM at an early stage from tongue digital image. The tongue image is acquired and processed with FODPSO to extract edge and texture features. Tongue reflects and diagnoses diabetes in a person.

scholarly journals New method of measuring the degree of lumbar spine curvature in pregnant women

1992 ◽  
Vol 48 (4) ◽  
pp. 51-55
Author(s):  
Jeanette Mitchell ◽  
Donnèe Ness ◽  
Sandra Whitelock
Keyword(s):  
Lumbar Spine ◽  
Pregnant Women ◽  
Cost Effective ◽  
Clinical Situation ◽  
New Method ◽  
Non Invasive ◽  
Invasive Method ◽  
Spine Curvature ◽  
English Speaking ◽  
Caucasian Women

There are very few studies which record measurements of the degree of lumbar spine curvature. This study reports a new method of measuring the angle of curvature of the lumbar spine in pregnant women, using photography. It is a simple, cost-effective and non-invasive method which can be used in the laboratory or the clinical situation. The study sample consisted of 13 healthy, middle-class, English-speaking, South African, Caucasian women, aged between 20 and 40 years, in the third trimester of pregnancy. A mean angle of 33,9 ±3,6 (SD) degrees, representing the degree of lumbar spine curvature, was obtained.

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