A Multi-Axis Robotic Platform and Testing Protocol for Evaluating In Vitro Biomechanics of the Foot

2011 ◽  
Author(s):  
Denis J. DiAngelo ◽  
Jaymes D. Granata ◽  
Greg C. Berlet ◽  
Rahul Ghotge ◽  
Yuan Li ◽  
...  
Keyword(s):  
External Rotation ◽  
Three Dimensional ◽  
Loading Conditions ◽  
Cadaveric Specimen ◽  
Ankle Complex ◽  
Biomechanics Of The Foot ◽  
3D Loading ◽  
In Vitro Biomechanics ◽  
Cadaveric Model

The purpose of this study was to develop a cadaveric model for evaluating the relative motion across joint segments in the foot under simulated physiologic loading conditions. The specific aims were to 1) Develop a multi-axis testing platform that simulates three-dimensional (3D) loading conditions through the foot and ankle complex (Achilles load, tibial compression, and internal/external rotation) in a sequential or simultaneous manner, and 2) Evaluate and compare the three-dimensional (3D) kinematics between specific bones of interest in the foot for each individual cadaveric specimen.

Development of a Finite Element Lumbar Segment Model for Simulation of Coupled Loading Conditions Validated With In Vitro Experimental Studies

2011 ◽  
Author(s):  
Yuan Li ◽  
Brian P. Kelly ◽  
Denis J. DiAngelo
Keyword(s):  
Finite Element ◽  
Traditional Approach ◽  
Experimental Studies ◽  
Fe Model ◽  
Loading Conditions ◽  
Flexion Extension ◽  
Lumbar Segment ◽  
In Vitro Biomechanics ◽  
Transverse Axial

The traditional approach for evaluating the biomechanics of the spine, both experimentally and computationally, is through a series of planar loading scenarios that are reduced to sagittal (flexion/extension), frontal (lateral bending), and transverse (axial) planes of movement [1]. However, coupled movements occur through daily living activities that place further demands on a spinal device beyond simple planar movements. The objective of this study was to investigate the in vitro biomechanics of the L4-L5 lumbar motion segment unit (MSU) under the coupled loading conditions, and to use the experimental data to validate a high-fidelity non-parametric finite element (FE) model of the L4-L5 lumbar MSU.

Experimental Investigation and Model Predictions of a NiMnGa Alloy’s Response to Three Dimensional Magneto-Mechanical Loading

2015 ◽  
Author(s):  
Jason L. Dikes ◽  
Heidi P. Feigenbaum ◽  
Constantin Ciocanel ◽  
Roger Guiel
Keyword(s):  
Experimental Data ◽  
Mechanical Loading ◽  
Three Dimensional ◽  
Experimental Investigations ◽  
Two Dimensional ◽  
Loading Conditions ◽  
Magnetic Shape Memory ◽  
Model Predictions ◽  
3D Loading ◽  
High Degree

Researchers have attempted to model the magneto-mechanical behavior of magnetic shape memory alloys (MSMAs) for over a decade, but all of the models developed to date have only been validated against experimental data generated under two-dimensional loading conditions. As efforts have been underway to develop models able to predict the most general (i.e. 3D) loading conditions for the material, there is a need for experimental data to support the calibration and validation of these models. This paper presents magneto-mechanical data from experiments where a MSMA specimen whose microstructure accommodates three martensite variants is subjected to three-dimensional magneto-mechanical loading. To the best of our knowledge, all prior experimental investigations on MSMA have been performed on samples accommodating two martensite variants and exposed to two-dimensional magneto-mechanical loads. The experimental results from the 3D loading of the three variant MSMA specimen are used to calibrate and validate a 3D model developed by this group [LaMaster et al. (2014)]. This model assumes that three martensite variants coexist in the material. The LaMaster et al. model captures the general trends seen in the experimental data, but does not predict the data with a high degree of accuracy. Possible reasons for the mismatch between experimental data and model predictions are discussed.

A THREE-DIMENSIONAL MORPOLOGICAL MEASUREMENT AND IN VITRO BIOMECHANICAL STUDY OF METATARSALS

2015 ◽  
Vol 15 (06) ◽  
pp. 1540047
Author(s):  
WENXIN NIU ◽  
LEJUN WANG ◽  
RUI ZHU ◽  
BING LI
Keyword(s):  
Stress Fracture ◽  
Stance Phase ◽  
Testing Machine ◽  
Three Dimensional ◽  
Load Condition ◽  
Morphological Structure ◽  
Biomechanical Study ◽  
Shaft Length ◽  
In Vitro Biomechanics

Stress fracture of the metatarsal (MT) is often reported clinically. This study was aimed to measure and compare the three-dimensional (3D) morphological structure of five MTs, and investigate the in vitro biomechanics of five MTs under simulated stance phase. A total of seven foot-ankle samples of human cadavers were collected for this experiment. All samples were CT-scanned and 3D re-constructed for digital measurements. To simulate the stance phase, each sample was vertically loaded with 700-N through a material testing machine. The 3D-reconstruction-based measurement showed significant differences of the shaft length, vertical height, and inclination angle between the second MT and four others. Experimental strain measurements at dorsal MTs along the principal axis are all compressive. The values are respectively [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] micro-strain from the first to fifth MTs. This study proposed a new load condition of plantar-flexed simply supported beam to describe the MT loading mechanism. The second and third MTs have higher risk of stress fracture due to combined effects of inhomogeneous load distribution, unfavorable geometry and structure, and limited joint motion. This finding would be helpful for design of protective equipment.

In Vitro Kinematics of the Axially Loaded Ankle Complex in Response to Dorsiflexion and Plantarflexion

1995 ◽  
Vol 16 (8) ◽  
pp. 514-518 ◽  
Author(s):  
Beat Hintermann ◽  
Benno M. Nigg
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Axial Loading ◽  
Testing Apparatus ◽  
Ankle Complex ◽  
Axially Loaded

The rotational movements of the tibia and calcaneus that occur with dorsiflexion-plantarflexion and axial loading were studied in cadaver foot-leg specimens using an unconstrained testing apparatus. Independent of the foot flexion position, significant internal rotation of the tibia and eversion of the calcaneus were noted after the ankle complex was axially loaded. Independent of loading, 10° of dorsiflexion resulted in 0.1° of eversion and 2.1° of internal rotation of the tibia. Conversely, 10° of plantarflexion resulted in 1.6° of inversion and 1.3° of external rotation of the tibia. The induced rotational movements of the tibia and the calcaneus differed significantly between the specimens. These results suggest that the foot “axes” did not change by axially loading the ankle complex and they support previous reports that the ankle complex uses different axes for dorsiflexion and plantarflexion.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Hormonal modulation of ishikawa cells during three-dimensional growth in vitro☆

1998 ◽  
Vol 5 (4) ◽  
pp. 217-223 ◽  
Author(s):  
D PINELLI ◽  
J DRAKE ◽  
M WILLIAMS ◽  
D CAVANAGH ◽  
J BECKER
Keyword(s):  
Three Dimensional ◽  
Ishikawa Cells ◽  
Hormonal Modulation ◽  
Dimensional Growth

500 An in vitro steady flow model of mitral regurgitation by three-dimensional Doppler

1999 ◽  
Vol 1 ◽  
pp. S86-S86
Author(s):  
R DESIMONE ◽  
G GLOMBITZA ◽  
C VAHL ◽  
H MEINZER ◽  
S HAGL
Keyword(s):  
Mitral Regurgitation ◽  
Steady Flow ◽  
Flow Model ◽  
Three Dimensional
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