Papers by Arkady Voloshin
International journal of biomedical engineering and science, Jan 30, 2016
Live cells respond to the changes of their physiological environment as well as to the mechanical... more Live cells respond to the changes of their physiological environment as well as to the mechanical stimuli occurring in and out of the cell body. It is known that cell directional motion is influenced by the substrate stiffness. A finite element modelling based on the tensegrity approach is used here to describe the biomechanical behavior of cells. The effects of substrate stiffness and prestress on strain energy of a cell are investigated by defining several substrate stiffness values and prestress values. Numerical simulations reveal that the internal elastic strain energy of the cell decreases as the substrate stiffness increases. As prestress of cell increases, the strain energy increases as well. The change of prestress value does not change behavior pattern of the strain energy: strain energy of a cell will decrease when substrate stiffness increases. These findings indicate that both cell prestress and substrate stiffness influence the cell directional movement.
Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2003
In-plane Strain Measurement by Digital Image Correlation This paper presents a "fast and simple" ... more In-plane Strain Measurement by Digital Image Correlation This paper presents a "fast and simple" (FAS) detection algorithm based on the digital image correlation for measurement of the surface deformation of planar objects. The proposed algorithm uses only fine search at the pixel level resolution and surface fitting for sub-pixel level. Two different specimens are investigated to explore the feasibility of this proposed algorithm. The displacements calculated by the FAS algorithm are compared with the ones obtained from Newton-Raphson method (N-R) and Enhanced Sequential Similarity Detection Algorithm (ESSDA). The results show that the experimental data are in good agreement with the theoretical solution. The proposed algorithm is found to be much faster than Newton-Raphson method with inferior, yet reasonable, accuracy for displacement and strain evaluation in the cases of uniaxial tension and disk under diametrical compression tests.
Experimental Mechanics, 1993
Surface topography can be conveniently investigated by a well-known shadow-moir technique. It is ... more Surface topography can be conveniently investigated by a well-known shadow-moir technique. It is relatively free from stringent requirements on stability of instrumentation and quality of the light source. The main unresolved problem of the shadow moir is its relatively low resolution. The digital-image-analysis enhanced shadow-moir technique described here is based on the marriage of two well-known and developed methods: classical
Computer Methods in Biomechanics and Biomedical Engineering, Jan 21, 2022
The application of microelectromechanical systems (MEMS) in biomedical devices has expanded vastl... more The application of microelectromechanical systems (MEMS) in biomedical devices has expanded vastly over the last few decades, with MEMS devices being developed to measure different characteristics of cells. The study of cell mechanics offers valuable understanding of cell viability and functionality. Cell biomechanics approaches also facilitate the characterization of important cell and tissue behaviors. In particular, understanding of the biological response of cells to their biomechanical environment would enhance the knowledge of how cellular responses correlate to tissue level characteristics and how some diseases, such as cancer, grow in the body. This study focuses on viscoelastic modeling of the behavior of a single suspended human mesenchymal stem cell (hMSC). Mechanical properties of hMSC cells are particularly important in tissue engineering and research for the treatment of cardiovascular diseases. We evaluated the elastic and viscoelastic properties of hMSC cells using a miniaturized custom-made BioMEMS device. Our results were compared to the elastic and viscoelastic properties measured by other methods such as atomic force microscopy (AFM) and micropipette aspiration. Different approaches were applied to model the experimentally obtained force data, including elastic and Standard Linear Solid (SLS) constitutive models, and the corresponding constants were derived. These values were compared to the ones in literature that were based on micropipette aspiration and AFM methods. We then utilized a tensegrity approach to model major parts of the internal structure of the cell and treat the cell as a network of viscoelastic microtubules and microfilaments, as opposed to a simple spherical blob. The results predicted from the tensegrity model were similar to the recorded experimental data.
Proceedings of SPIE, Oct 25, 2004
Effect of thermal loading on the deformations of the optoelectronic package: a moire interferomet... more Effect of thermal loading on the deformations of the optoelectronic package: a moire interferometry approach. [Proceedings of SPIE 5595, 428 (2004)]. Arkady S. Voloshin. Abstract. Advance optoelectronic packaging is dependent ...
Proceedings of SPIE, Jun 14, 2000
ABSTRACT A whole-field polarimetric method through digital image processing has been developed fo... more ABSTRACT A whole-field polarimetric method through digital image processing has been developed for mapping the three optical parameters, which determine normalized Jones matrix of an elliptic retarder. The suggested technique conveys measurement data sufficient to describe optical anisotropy in the media exhibiting rotation of birefringence axes along the light path. Particularly, homogeneous or inhomogeneous birefringent gyrotropic objects and initially isotropic transparent samples bearing stress-induced anisotropy can be investigated by use of this technique. Operational principle of the method implies incremental rotation of polarizer and analyzer with the ratio 1:3 over the revolution of the polarizer and collection of 9 intensity images between successive rotation steps. Then thus obtained intensity patterns are digitally processed by use of Fourier analysis. Specifically in this paper we address issues concerning the accuracy of mapping all the three parameters at different values of those. Some ad hoc experiments with test crystalline quartz phase plates are reported. Computer simulations and measurement results are presented and discussed.
Applied sciences, Nov 10, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Engineering Fracture Mechanics, 1991
A least-squares approach for evaluating stress intensity factors from mixed-mode caustics is pres... more A least-squares approach for evaluating stress intensity factors from mixed-mode caustics is presented. The motivation for this work is first explained by illwtrating the limitations of the commonly used method of principal diameters. It is then shown that the least-squares approach can be used successfully for different test cases including numerically and experimentally generated caustics.
Journal of dance medicine & science : official publication of the International Association for Dance Medicine & Science, Dec 1, 2008
There is no consensus on a valid and reliable method of measuring turnout. However, there is a bu... more There is no consensus on a valid and reliable method of measuring turnout. However, there is a building awareness that such measures need to exist. Total turnout is the sum of hip rotation, tibial torsion, and contributions from the foot. To our knowledge, there has been no research that directly measures and then sums each individual component of turnout to verify a total turnout value. Furthermore, the tibial torsion component has not previously been confirmed by an imaging study. The purpose of this study was to test the validity and reliability of a single total passive turnout (TPT) test taken with a goniometer by comparing it with the sum of the individual components. Fourteen female dancers were recruited as participants. Measurements of the subjects' right and left legs were gathered for the components of turnout. Tibial torsion was measured using Magnetic Resonance Imaging (MRI). Retro-reflective marker assisted measurements were used to calculate the static components of TPT. Hip external rotation, TPT, and total active turnout (TAT) were measured by goniometer. Additional standing turnout values were collected on rotational disks. Tibial torsion and hip rotation were summed and compared with three whole-leg turnout values using Two-Tailed T-Tests and Pearson product-moment correlation coefficients. Tibial torsion measurements in dancers were found to demonstrate substantial variation between subjects and between legs in the same subject. The range on the right leg was 16 degrees to 60 degrees, and the range on the left leg was 16 degrees to 52 degrees. Retro-reflective markers and biomechanical theory demonstrated that when the knee is extended and locked, "screwed home," it will not factor into a whole-leg turnout value. TAT and turnout on the disks were not statistically significant when compared with the summed total. Statistical significance was achieved in four of the eight measurement series comparing TPT with the summed value of tibial torsion and hip rotation. The advantages of a standard, valid, and reliable method of measuring turnout are many, and the risks are few. Some advantages include improved training techniques, mastery of the use of turnout at an earlier age, better dancer and teacher compliance with suggested turnout rates, understanding the use of parallel position, understanding the etiology of many dance-related injuries, and possible development of preventative measures.
Taylor & Francis eBooks, Dec 1, 2003
Journal of Thermal Stresses, Apr 1, 1993
Page 1. TRANSIENT STRESS INTENSITY FACTORS FOR THERMALLY LOADED EDGE-CRACKED PLATES Ravi Mahqjan ... more Page 1. TRANSIENT STRESS INTENSITY FACTORS FOR THERMALLY LOADED EDGE-CRACKED PLATES Ravi Mahqjan and Arkady S. Voloshin Department of Mechanical Engineering and Mechanics Lehigh Uniuersi& Bethlehem, Pennsylvania 18015 ...
Cmes-computer Modeling in Engineering & Sciences, Mar 1, 2014
ABSTRACT Mechanical behavior of cells plays a crucial role in response to external stimuli and en... more ABSTRACT Mechanical behavior of cells plays a crucial role in response to external stimuli and environment. It is very important to elucidate the mechanisms of cellular activities like spreading and alignment as it would shed light on further biological concepts. In this study, a multi-scale computational approach is adopted by modeling the cytoskeleton of cell as a tensegrity structure. The model is based on the complementary force balance between the tension and compression elements, resembling the internal structure of cell cytoskeleton composed of microtubules and actin filaments. The effect of surface topology on strain energy of a spread cell is investigated by defining strain energy of the structure as the main criterion in the simulation process of the cell spreading. Spreading as a way to decrease internal energy toward a minimum energy state is the main hypothesis that is investigated. The cell model is placed at different positions along the wavy surface and the spreading and alignment behavior is observed. The implementation of the model illustrates the effect of topological factors on spreading and alignment of the cell. Experiments were conducted by seeding Bovine Aortic Endothelial Cells (BAECs) on poly (dimethylsiloxane) (PDMS) wavy surface to serve as a verification for the proposed model in the context of cellular behavior. Experimental observations are in general agreement with the computational results, which points out that the model can be explanatory in terms of understanding mechanical characteristics of cells.
Journal of Biomechanics, 1987
Research & development in materials science, Oct 23, 2017
Pore size regulates mesenchymal stem cell response to Bioglass-loaded composite scaffolds. J Mate... more Pore size regulates mesenchymal stem cell response to Bioglass-loaded composite scaffolds. J Mater Chem B 3(44): 8650-8658. 4. Matsiko A, Gleeson JP, O'Brien FJ (2015) Scaffold mean pore size influences mesenchymal stem cell chondrogenic differentiation and matrix deposition. Tissue Eng Part A 21(3-4): 486-497. 5. Datta N, Pham QP, Sharma U, Sikavitsas VI, Jansen JA, et al. (2006) In vitro generated extracellular matrix and fluid shear stress synergistically enhance 3D osteoblastic differentiation.
Strain, Jan 8, 2010
This paper presents the application of a Stereo-Digital Image Correlation (Stereo-DIC) based appr... more This paper presents the application of a Stereo-Digital Image Correlation (Stereo-DIC) based approach for full-field deformation measurements on a porcine intervertebral disc (IVD) under in-vitro loading. Full-field capabilities of Stereo-DIC provide useful information on the IVD structure-function relationship needed for designing novel disc replacement devices on the basis of biomimetic concepts. In this work, the use of a multi-view Stereo-DIC system allows full-field measurement over more than 180°of the IVD surface. This is achieved by sequentially moving a single camera through seven fixed positions in order to cover the desired angle of vision. Ad hoc data processing and merging procedures are calibrated for a cylindrical sample. Strain maps are determined for a rubber cylinder subjected to rigid-body motions and then to uniform compression. These preliminary procedures serve to evaluate strain-mapping errors as well as to assess repeatability and accuracy of camera re-positioning. Once the entire procedure is verified and calibrated, a fresh porcine functional spine unit is loaded under anterior, posterior and lateral compression. From displacement maps obtained with the multi-view setup , it is possible to gather information on both IVD bulging and surface strains. Results are consistent with the IVD global behaviour under standard testing protocols reported in the recent literature. Furthermore, detailed information on local variations in structural response and stiffness properties occurring when load is applied in different regions of the IVD are obtained. The present approach allows to correlate structural response with the entire 3-D deformation and strain field and not just with a single displacement/strain component and thus it could be effectively used for explaining in-homogeneity observed in human discs degenerative patterns.
Journal of Micromechanics and Microengineering, Jun 9, 2008
Page 1. A polymer V-shaped electrothermal actuator array for biological applications This article... more Page 1. A polymer V-shaped electrothermal actuator array for biological applications This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2008 J. Micromech. Microeng. 18 075020 (http://iopscience.iop.org/0960-1317/18/7/075020) ...
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Papers by Arkady Voloshin