scholarly journals Comparative Study of Femur Bone Having Different Boundary Conditions and Bone Structure Using Finite Element Method

2018 ◽  
Vol 12 (1) ◽  
pp. 115-134 ◽  
Author(s):  
K.N. Chethan ◽  
Mohammad Zuber ◽  
Shyamasunder N. Bhat ◽  
Satish B. Shenoy

Background:Femur bone is an important part in human which basically gives stability and support to carry out all day to day activities. It carries loads from upper body to lower abdomen.Objective:In this work, the femur having composite structure with cortical, cancellous and bone marrow cavity is bisected from condyle region with respect to 25%, 50% and 75% of its height. There is considerable difference in the region chosen for fixing all degrees of freedom in the analysis of femur.Methods:The CT scans are taken, and 3D model is developed using MIMICS. The developed model is used for static structural analysis by varying the load from 500N to 3000N.Results:The findings for 25% bisected femur model report difference in directional deformation less than 5% for loads 2000N and less. In the study comparing fully solid bone and the composite bone, the total deformation obtained for a complete solid bone was 3.5 mm which was 18.7% less than that determined for the composite bone.Conclusion:The standardization for fixing the bone is developed. And it is required to fix the distal end always with considering full femur bone.

Author(s):  
Hartiningsih H ◽  
Devita Anggraeni ◽  
Sudarminto S

This study was conducted to assess the effectiveness of a diet contained fresh anchovies and calcitriol supplementation for 6 weeks to prevent osteoporosis in ovariectomized rats. Fifteen Wistar rats aged 8 weeks were divided randomly into 3 groups (normal/K, ovariectomized/Ov, andovariectomized + calcitriol/OVD), 5 mice each. Group K and Ov rats were fed with fresh anchovies, while the OVD group was fed with freshanchovies + calcitriol. At the age of 15 weeks, all mice were done for euthanasia, then left femur was collected for immunohistochemistryexamination of tartrate resistant acid phosphatase5b (TRAP5b). The detection of (TRAP5b) was conducted using a monoclonal ant ibody antiTRAP5b, and detected using a streptavidin-biotin. The results showed that the metaphysis part of distal femur bone of mice group K, Ov, andOVD were positive TRAP5b stained with brown color on trabecular bone in bone marrow cavity and trabecular spiculum surface, but rats ingroup K and Ov had extensive bone marrow cavity and normal trabecular spiculum, whereas OVD group showed bone marrow cavity dilation,accumulation of adipocytes in the bone marrow cavity, and shorter the spiculum of trabeculae. It can be concluded that fresh anchovies diet andcalcitriol supplementation for 6 weeks are not effective in preventing osteoporosis in ovariectomized rats.Key words: calcitriol, femur, ovariohisterectomy


Author(s):  
R. Ramesh Kumar ◽  
D. Rajesh ◽  
S. Kumaran ◽  
S. Ranjieth ◽  
Mohammed Irshad Ali ◽  
...  
Keyword(s):  
3D Model ◽  

2009 ◽  
Vol 06 (02) ◽  
pp. 291-306 ◽  
Author(s):  
JINGZHOU (JAMES) YANG

This paper presents an applicable formula for determining the workspace of digital human lower extremities. The digital human model has over 100 degrees of freedom (DOF): 94 in the upper body, 14 in the lower extremities, 5 in the neck, 4 in the eyes, and 25 for each hand. The Jacobian row rank deficiency criteria are implemented to determine the singular surfaces that finally form the workspace. The use of this digital human model for determining workspace offers several advantages over direct measurement: (1) the workspace can be visualized in real-time based on offline computation, (2) the workspace can be used for the ergonomic design of products in the virtual prototyping stage, and (3) the calculated workspace includes complete information about the envelope and inside characteristics.


2014 ◽  
Vol 98 ◽  
pp. 360-361
Author(s):  
L. Yan-rong ◽  
C. Wang ◽  
X. Du ◽  
S. He ◽  
Y. Chen ◽  
...  

Blood ◽  
2000 ◽  
Vol 95 (11) ◽  
pp. 3363-3370 ◽  
Author(s):  
Hisashi Tagaya ◽  
Takahiro Kunisada ◽  
Hidetoshi Yamazaki ◽  
Toshiyuki Yamane ◽  
Takeshi Tokuhisa ◽  
...  

Adult bone marrow is a major site for hematopoiesis, and reduction of the bone marrow cavity induces hematopoiesis in extramarrow tissues. To investigate the rudimentary intramarrow and the compensatory extramarrow hematopoiesis, particularly B lymphopoiesis, we used 3 osteopetrotic mouse strains [op/op, mi/mi, and Fos(−/−)], which are severely deficient in functional osteoclasts and therefore form inadequate bone marrow cavities. We found that bone marrow in these osteopetrotic mice supports myelopoiesis but not B lymphopoiesis, although cells that have the potential to differentiate into B lineage cells are present in the bone marrow. Although B lymphopoiesis normally occurs both in the spleen and liver of newborn mice, compensatory B lymphopoiesis in adultop/op and mi/mi mice is observed only in the liver, while myelopoiesis is enhanced in both organs. Interestingly, mice lacking the Fos proto-oncogene exhibit B lymphopoiesis in the spleen as well as liver. The amounts of expression of steel factor, Flt3/Flk-2 ligand, and interleukin-7 in the bone marrow, spleen, or liver were not significantly affected in these osteopetrotic mutants. These findings suggest that the volume of the bone marrow cavity regulates B lymphopoiesis without affecting the production of certain hematopoietic growth factors. The splenic microenvironments that support both myelopoiesis and B lymphopoiesis in the neonatal stage are lost in adults and are not reactivated even in the osteopetrotic adults unless the Fos gene is disrupted.


Robotica ◽  
2009 ◽  
Vol 27 (4) ◽  
pp. 607-620 ◽  
Author(s):  
Zan Mi ◽  
Jingzhou (James) Yang ◽  
Karim Abdel-Malek

SUMMARYA general methodology and associated computational algorithm for predicting postures of the digital human upper body is presented. The basic plot for this effort is an optimization-based approach, where we believe that different human performance measures govern different tasks. The underlying problem is characterized by the calculation (or prediction) of the human performance measure in such a way as to accomplish a specified task. In this work, we have not limited the number of degrees of freedom associated with the model. Each task has been defined by a number of human performance measures that are mathematically represented by cost functions that evaluate to a real number. Cost functions are then optimized, i.e., minimized or maximized, subject to a number of constraints, including joint limits. The formulation is demonstrated and validated. We present this computational formulation as a broadly applicable algorithm for predicting postures using one or more human performance measures.


Author(s):  
Monica Bordegoni ◽  
Mario Covarrubias ◽  
Giandomenico Caruso ◽  
Umberto Cugini

This paper presents a novel system that allows product designers to design, experience, and modify new shapes of objects, starting from existing ones. The system allows designers to acquire and reconstruct the 3D model of a real object and to visualize and physically interact with this model. In addition, the system allows designer to modify the shape through physical manipulation of the 3D model and to eventually print it using a 3D printing technology. The system is developed by integrating state-of-the-art technologies in the sectors of reverse engineering, virtual reality, and haptic technology. The 3D model of an object is reconstructed by scanning its shape by means of a 3D scanning device. Then, the 3D model is imported into the virtual reality environment, which is used to render the 3D model of the object through an immersive head mounted display (HMD). The user can physically interact with the 3D model by using the desktop haptic strip for shape design (DHSSD), a 6 degrees of freedom servo-actuated developable metallic strip, which reproduces cross-sectional curves of 3D virtual objects. The DHSSD device is controlled by means of hand gestures recognized by a leap motion sensor.


Author(s):  
Muhammed R. Pac ◽  
Dan O. Popa

Legged robots are more maneuverable, and can negotiate rough terrain much better than conventional locomotion using wheels. However, since the kinematic or dynamic analysis of such robots involves closed chains, it is typically more difficult to investigate the impact of design changes, such as the number, or the design of its legs, to robot performance. Most legged robots consist of 4 legs (quadrupeds) or 6 legs (hexapods). This paper discusses the kinematic analysis of an unconventional, symmetrical 5-legged robot with 2-DOF (Degrees Of Freedom) universal joints in each leg. The analysis was carried out in order to predict the mobility of the upper body platform, and investigate the number of robot actuators needed for mobility. The product of exponentials formulation with respect to the local coordinate frames is used to describe the twists of the joints. The analysis is based on the idea that the robot body platform along with the legs can be considered instantaneously as a parallel robot manipulating the ground. Hence, the analysis can be done using the Jacobian formulation of parallel robots. Simulation results confirm the mobility analysis that the robot can have at most 3-DOF for the body and that these freedoms are coupled rotations and translations in 3D space also with a dependence on the configuration of the robot.


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