Determination of Corneal Biomechanical Properties in-vivo using a Contact Device

2014 ◽  
Author(s):  
Ahmed Elsheikh
Keyword(s):  
Biomechanical Properties ◽  
Contact Device ◽  
Corneal Biomechanical Properties

In Vivo Imaging of Dynamic Shear Modulus of Rodent Mammary Tumors Using Ultrasound

2012 ◽  
Author(s):  
Yue Wang ◽  
Michael Insana
Keyword(s):  
In Vivo Imaging ◽  
Normal Tissue ◽  
Breast Tissue ◽  
Structural Integrity ◽  
Biomechanical Properties ◽  
Dynamic Shear Modulus ◽  
Living Tissue ◽  
Dynamic Shear

Biomechanical properties of living tissue are very important in maintaining normal tissue function, cellular and extracellular structural integrity. Therefore, the quantitative determination of biomechanical properties of breast tissue, especially in vivo, serves an important role in clinical diagnosis.

scholarly journals Corneal Biomechanical Properties Characterization Using Air-jet Indentation Based Optical Coherence Tomography System (AIOCT)

2019 ◽  
Vol 256 ◽  
pp. 01004 ◽  
Author(s):  
Li-ke Wang ◽  
Jia-ying Zhang ◽  
Tian-jie Li ◽  
Xue-yong Zhang ◽  
Lei Tian ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Tensile Test ◽  
Indentation Test ◽  
Biomechanical Properties ◽  
Tomography System ◽  
Air Jet ◽  
Custom Made ◽  
Mechanical Tensile ◽  
Corneal Biomechanical Properties

We proposed a novel method together with system to quantify the corneal biomechanics. The objectives of this study are to develop a method to measure the corneal biomechanical properties in vivo and to evaluate the performance of AIOCT system. A novel AIOCT system was established and a mathematical model was built on the basis of the current air-jet indentation method. Experiments were performed to evaluate the mechanical properties of eleven custom-made silicone corneal mimicking phantoms by the AIOCT system under different intraocular pressures (IOP). The results were then compared with those measured by the standard mechanical tensile test and indentation test. The phantom’s moduli were ranged from 0.08 to 1.03 MPa according to the tensile and indentation test. The elastic moduli of corneal silicone phantoms (Eairjet) were measured using the AIOCT system with the proposed mathematical model at four IOPs (0.6, 15.3, 29.8, and 44.7 mmHg). The Eairjet were agreed well with the corresponding moduli (Etensile) measured by the tensile test (Eairjet = 1.188 Etensile, R2 = 0.925). The preliminary results showed that this technique was capable of measuring corneal biomechanical properties in vivo and it may provide a clinical potential non-invasive and non-contact means to the diagnosis of keratoconus suspects in the future.

scholarly journals Compressional Optical Coherence Elastography of the Cornea

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 111
Author(s):  
Manmohan Singh ◽  
Achuth Nair ◽  
Salavat R. Aglyamov ◽  
Kirill V. Larin
Keyword(s):  
Rabbit Model ◽  
Biomechanical Properties ◽  
Clinical Applications ◽  
Optical Coherence ◽  
Collagen Crosslinking ◽  
Corneal Collagen Crosslinking ◽  
Corneal Biomechanical Properties ◽  
Corneal Collagen

Assessing the biomechanical properties of the cornea is crucial for detecting the onset and progression of eye diseases. In this work, we demonstrate the application of compression-based optical coherence elastography (OCE) to measure the biomechanical properties of the cornea under various conditions, including validation in an in situ rabbit model and a demonstration of feasibility for in vivo measurements. Our results show a stark increase in the stiffness of the corneas as IOP was increased. Moreover, UV-A/riboflavin corneal collagen crosslinking (CXL) also dramatically increased the stiffness of the corneas. The results were consistent across 4 different scenarios (whole CXL in situ, partial CXL in situ, whole CXL in vivo, and partial CXL in vivo), emphasizing the reliability of compression OCE to measure corneal biomechanical properties and its potential for clinical applications.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

Storage of Human Blood Platelets

1974 ◽  
Vol 32 (02/03) ◽  
pp. 405-416 ◽  
Author(s):  
M. R Hardeman ◽  
Carina J L. Heynens
Keyword(s):  
Storage Temperature ◽  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Storage Period ◽  
Serotonin Uptake ◽  
Hypotonic Shock ◽  
Glycolytic Intermediates

SummaryStorage experiments were performed at 4°, 25° and 37° C with platelet-rich plasma under sterile conditions. In some experiments also the effect of storing platelets at 4° C in whole blood was investigated.Before, during and after three days of storage, the platelets were tested at 37° C for their serotonin uptake and response to hypotonic shock. In addition some glycolytic intermediates were determined.A fair correlation was noticed between the serotonin uptake and hypotonic shock experiments. Both parameters were best maintained at 25° C. Also platelet counting, performed after the storage period, indicated 25° C as the best storage temperature. Determination of glycolytic intermediates did not justify any conclusion regarding the optimal storage temperature. Of the various anticoagulants studied, ACD and heparin gave the best results as to the serotonin uptake and hypotonic shock response, either with fresh or stored platelets. The use of EDTA resulted in the lowest activity, especially after storage.The results of these storage experiments in vitro, correspond well with those in vivo reported in the literature.

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