Virtual and Experimental Studies about Human Walking - Virtual Lower Leg Environment - Innovative Design of Tibia Nail

2014 ◽  
Vol 657 ◽  
pp. 770-774 ◽  
Author(s):  
Gabriel Buciu ◽  
Danut Nicolae Tarnita ◽  
Dragos Laureţiu Popa ◽  
Mihai Aureliu Lungu ◽  
Cosmin Miritoiu ◽  
...  
Keyword(s):  
Human Subject ◽  
Experimental Studies ◽  
Lower Leg ◽  
Ct Images ◽  
Lower Limbs ◽  
Human Walking ◽  
Kinematic Parameters ◽  
Innovative Design ◽  
New Models ◽  
Complex Models

To re-create a 3D parametrical environment it was used a CAD software which permits to define complex models. First, there were defined the main bone components as femur, tibia and pelvis by using the CT images. The contours of the CT images were transferred to CAD environment where, step by step, and section by section, the virtual bones were defined. The model of the pelvis and of the lower limbs during a virtual walking was recomposed by using kinematic parameters determined by filming the human subject. In this case the entire behavior of each bone component was determined, including that of the tibia. The variations of force and torque which auctioned over the tibia were determined and applied to the fractured tibia with the new models of nails.

Comparison of standardised lymphoscintigraphic function test and high resolution sonography of the lymphoedema of legs

Phlebologie ◽  
2008 ◽  
Vol 37 (05) ◽  
pp. 247-252 ◽  
Author(s):  
V. S. Brauer ◽  
W. J. Brauer
Keyword(s):  
Lower Leg ◽  
Clinical Findings ◽  
Lower Limbs ◽  
Fatty Tissue ◽  
Qualitative And Quantitative ◽  
Function Test ◽  
Unreliable Method ◽  
Negative Conclusion ◽  
Fine Disperse

SummaryPurpose: Comparison of qualitative and quantitative sonography with the lymphoscintigraphic function test and clinical findings in legs. Patients, methods: In 33 patients a lymphoscintigraphic function test of legs combined with measurement of lymph node uptake was performed and subsequently compared with sonography. Sonographic criteria were: Thickness of cutis, thickness of subcutanean fatty tissue and presence of liquid structures or fine disperse tissue structure of lower limbs, foots and toes. Results: In 51 legs uptake values lie in the pathologic area, in four legs in the grey area and in ten legs in the normal area. The cutis thickness in the lower leg shows no significant correlation with the uptake. The determination of the thickness of the subcutanean fatty tissue of the lower leg and of the cutis thickness of the feet turned out to be an unreliable method. In 47% of the medial lower legs and in 57% of the lateral lower legs with clinical lymphoedema sonography is falsely negative. Conclusion: Early lymphoedema is only detectable with the lymphoscintigraphic function test. In the case of clinical lymphoedema clinical examination is more reliable than sonography.

New Algorithm for Modeling of Bronchial Trees

2012 ◽  
Vol 17 (4) ◽  
pp. 179-190
Author(s):  
Kacper Pluta ◽  
Marcin Janaszewski ◽  
Michał Postolski
Keyword(s):  
Quantitative Analysis ◽  
3D Model ◽  
Ct Images ◽  
Basic Algorithm ◽  
New Model ◽  
Comparison Of Results ◽  
Basic Model ◽  
New Models ◽  
Bronchial Tubes

Abstract The article presents new conception of 3D model of human bronchial tubes, which represents bronchial tubes extracted from CT images of the chest. The new algorithm which generates new model is an extension of the algorithm (basic algorithm) proposed by Hiroko Kitaoka, Ryuji Takaki and Bela Suki. The basic model has been extended by geometric deformations of branches and noise which occur in bronchial trees extracted from CT images. The article presents comparison of results obtained with the use of the new algorithm and the basic one. Moreover, the discussion of usefulness of generated new models for testing of algorithms for quantitative analysis of bronchial tubes based on CT images is also included.

scholarly journals Musculoskeletal biomechanics in sit-to-stand and stand-to-sit activities with stroke subjects: a systematic review

2010 ◽  
Vol 23 (1) ◽  
pp. 35-52 ◽  
Author(s):  
Christina Danielli Coelho de Morais Faria ◽  
Viviane Amaral Saliba ◽  
Luci Fuscaldi Teixeira-Salmela
Keyword(s):  
Systematic Review ◽  
Methodological Quality ◽  
Weight Bearing ◽  
Experimental Studies ◽  
Quality Parameters ◽  
Lower Limbs ◽  
Extensive Literature ◽  
Manual Search ◽  
Sit To Stand ◽  
Extensive Literature Search

INTRODUCTION: Sit-to-stand and stand-to-sit are two of the most mechanically demanding activities undertaken in daily life and which are usually impaired in stroke subjects. OBJECTIVES: To determine the distinguishing characteristics in musculoskeletal biomechanical outcomes of the sit-to-stand and stand-to-sit activities with stroke subjects, with an emphasis on the clinical management of stroke disabilities, in a systematic review. MATERIAL AND METHODS: An extensive literature search was performed with the MEDLINE, CINAHL, EMBASE, PEDro, LILACS, and SciELO databases, followed by a manual search, to select studies on musculoskeletal biomechanical outcomes in both activities with stroke subjects, without language restrictions, and published until December/2007. RESULTS: Out of the 432 studies, only 11 reported biomechanical outcomes of both activities and none reached the total score on the selected quality parameters. The majority of the experimental studies which compared groups did not achieve acceptable scores on their methodological quality (PEDRo). The investigated conditions and interventions were also restricted. Only one study compared biomechanical outcomes between the activities, but only evaluated the time spent to perform them. Few musculoskeletal biomechanical outcomes have been investigated, being weight bearing on the lower limbs and duration of the activities the most investigated. CONCLUSION: There is little information regarding musculoskeletal biomechanical outcomes during these activities with stroke subjects and no definite conclusions can be drawn regarding the particularities of these outcomes on their performance with stroke survivors.

THE HEAP PARTS MOVEMENT ON THE SHAREBOARD SURFACE OF THE POTATO HARVESTING MACHINE

2021 ◽  
Vol 14(63) (1) ◽  
pp. 127-140
Author(s):  
Serhii HRUSHETSKYI ◽  
Vitaly YAROPUD ◽  
Ihor KUPCHUK ◽  
Ruslana SEMENYSHENA
Keyword(s):  
Mathematical Model ◽  
Experimental Studies ◽  
Separation Process ◽  
Kinematic Parameters ◽  
Quality Performance ◽  
Machine Operation ◽  
Degree Of Damage ◽  
Total Capacity ◽  
Comparison Of The Results

The article is devoted to the problem of the reduction of tubers mechanical damages while providing qualitative indicators of the potato heap separation process. Theoretical and experimental dependences of the influence of design and kinematic parameters of the machine operation on the quality performance are obtained. Within the field of experimental studies, a field installation was made to investigate the potato harvester as a whole on the efficiency of separation, the degree of damage, the magnitude of losses and the total capacity for aggregation. Comparison of the results of theoretical and experimental studies showed that the developed mathematical model of the process of separation of potato heap is adequate.

scholarly journals An Approach to Human Walking Analysis Based on Balance, Symmetry and Stability Using COG, ZMP and CP

2020 ◽  
Vol 10 (20) ◽  
pp. 7307
Author(s):  
Seonghye Kim ◽  
Toshiyuki Murakami
Keyword(s):  
Personal Characteristic ◽  
Center Of Gravity ◽  
Lower Limbs ◽  
Upper Body ◽  
Human Walking ◽  
Joint Rotation ◽  
Gait Parameters ◽  
Zero Moment ◽  
Crossing Point

The parameters of walking have been studied from the viewpoints of joint rotation and translation of body. The balance and symmetry of walking are indispensable features to understand for healthy walking, while also being a personal characteristic. However, quantification has not been easy to carry out in the case of the conventional gait parameters COG (center of gravity) and ZMP (zero moment point). In this approach, the CP (crossing point) is proposed to quantify the concept of symmetry and balance by comparing it to the COG and ZMP. The CP is estimated based on the intersection between the hip line and the ankle line. While the hip line is fixed on the upper body where the COG is, the ankle line is altered depending on the each footfall, where the ZMP is. Therefore, the values of COG, ZMP, and CP have similar or different tendencies in terms of whether balanced walking results in symmetry or not. The validity of this is verified by carrying out a simulation with robot walking, and an experiment using human walking. Through additional experiments, it was noticed that the CP was able to improve the role of COG and ZMP in terms of not only stability, but also its relationship with the movement range of the lower limbs.

scholarly journals Review of improvements on heat transfer using nanofluids via corrugated facing step

2018 ◽  
Vol 7 (4.13) ◽  
pp. 160 ◽  
Author(s):  
Ali Hilo ◽  
Abd Rahim Abu Talib ◽  
Sadeq R. Nfawa ◽  
Mohamed Thariq Hameed Sultan ◽  
Mohd Faisal Abdul Hamid
Keyword(s):  
Heat Transfer ◽  
Thermal Conduction ◽  
Experimental Studies ◽  
Conductivity Measurement ◽  
Measurement Methods ◽  
Laminar Flows ◽  
Transfer Enhancement ◽  
Innovative Design ◽  
Experimental Findings ◽  
The Ideal

Nanofluids are considered to offer significant advantages as thermodynamic fluids because of their admirable properties on thermal conduction, thermal convection, boiling heat transfer and stability. This paper presents numerous researches focusing on the improvement of heat transfer via facing step and corrugated channels using nanofluids and without it. Exploration on the convective heat transfer was done through numerical modeling. It was reported that experimental studies were carried out in corrugated and facing step channels through the application of nanofluids and conventional fluids for heat transfer enhancement. The turbulent and laminar flows along corrugated and facing step channels have been presented. The numerical and experimental findings in maximizing the heat transfer rate are in accord. Comparisons between thermal conductivity measurement methods were done. Innovative design of corrugated facing step channel is being proposed. The heat transfer enhancements reach 60% by using facing step channel under laminar flow with nanofluid. The dimensions of new channel such as height and width of the baffle, the height of the step, shape and height of corrugated are needed to compare that might to provide the ideal rate of heat transfer.  

scholarly journals Research of a contact impact of a root crop with a screw auger

2020 ◽  
Vol 66 (No. 1) ◽  
pp. 33-42
Author(s):  
Viktor Baranovsky ◽  
Olena Truchanska ◽  
Maria Pankiv ◽  
Valentina Bandura
Keyword(s):  
Process Model ◽  
Empirical Process ◽  
Experimental Studies ◽  
Kinematic Parameters ◽  
Fodder Beet ◽  
Root Crop ◽  
Cleaning System ◽  
Screw Diameter ◽  
Contact Impact ◽  
Further Development

The purpose of this research is the further development of the methodology and methods of optimising the parameters of root pile  combined cleaners of a root crop harvesting machine. We have conducted theoretical and experimental studies of the combined  cleaning system’s functioning process. By executing the analysis, we found the motion of the fodder beet through the working surfaces of the feeding conveyor and the auger installed above it. We have got an analytical and empirical process model for the fodder beet’s oblique sub-hit on the auger turn. It characterises the dependence of the total rate of the sub-hit coefficient of the technological  interaction of the roots and the depth of the root damage, which depend on the main parameters of the combined cleaning system. We found out the rational limits of the basic structural and kinematic parameters of the combined cleaning system by the provided minimum fodder beet damage. It is theoretically justified that the minimum damage to roots of the beet roots will be at a contact angle of zero (γ ≅ 0) or close to it. This condition is protected with the following combinations of parameters: a screw diameter of D = 0.4, 0.6, 0.8 m and a screw speed of n = 99, 72, 50 rpm, respectively.

The Relationship of Transepicondylar Width with the Distal and Posterior Femoral Condyles and Its Clinical Implications: A Three-Dimensional Study

2020 ◽  
Author(s):  
Merrill Lee ◽  
Jade Pei Yuik Ho ◽  
Jerry Yongqiang Chen ◽  
Chung Kia Ng ◽  
Seng Jin Yeo ◽  
...  
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Ct Images ◽  
Revision Total Knee Arthroplasty ◽  
Joint Line ◽  
Lower Limbs ◽  
Anatomical Landmarks ◽  
Medial Condyle ◽  
Lateral Epicondyle ◽  
Femoral Condyles

Abstract Background Restoration of the anatomical joint line, while important for clinical outcomes, is difficult to achieve in revision total knee arthroplasty (rTKA) due to distal femoral bone loss. The objective of this study was to determine a reliable method of restoring the anatomical joint line and posterior condylar offset in the setting of rTKA based on three-dimensional (3D) reconstruction of computed tomography (CT) images of the distal femur. Methods CT scans of 50 lower limbs were analyzed. Key anatomical landmarks such as the medial epicondyle (ME), lateral epicondyle, and transepicondylar width (TEW) were determined on 3D models constructed from the CT images. Best-fit planes placed on the most distal and posterior loci of points on the femoral condyles were used to define the distal and posterior joint lines, respectively. Statistical analysis was performed to determine the relationships between the anatomical landmarks and the distal and posterior joint lines. Results There was a strong correlation between the distance from the ME to the distal joint line of the medial condyle (MEDC) and the distance from the ME to the posterior joint line of the medial condyle (MEPC) (p < 0.001; r = 0.865). The mean ratio of MEPC to MEDC was 1.06 (standard deviation [SD]: 0.07; range: 0.88–1.27) and that of MEPC to TEW was 0.33 (SD: 0.03; range: 0.25–0.38). Conclusions Our findings suggest that the fixed ratios of MEPC to TEW (0.33) and that of MEPC to MEDC (1.06) provide a reliable means for the surgeon to determine the anatomical joint line when used in combination.

Carbon ordering in an aseismic shear zone: implications for crustal weakening and Raman spectroscopy

2020 ◽  
Author(s):  
Lauren Kedar ◽  
Clare Bond ◽  
David Muirhead
Keyword(s):  
Raman Spectroscopy ◽  
Organic Carbon ◽  
Shear Zone ◽  
Experimental Studies ◽  
Carbonaceous Material ◽  
Shear Zones ◽  
Lower Limbs ◽  
Strain Partitioning ◽  
Increasing Temperature ◽  
Two Peaks

&lt;p&gt;Multi-layered stratigraphic sequences present ample opportunity for the study of strain localization and its complexities. By constraining mechanisms of crustal weakening, it is possible to gain a sounder understanding of the dynamic evolution of the Earth&amp;#8217;s crust, especially when applied to realistic, field-based scenarios. One such mechanism is that of strain-related carbon ordering. This is the process whereby the amorphous nanostructure of fossilized organic matter contained within the rock is progressively organized towards a more sheet-like structure, similar to that of graphite. One common method of studying this process is through Raman spectroscopy. This is a non-destructive tool which makes use of the relative positions and intensities of two key spectral peaks, where one peak represents graphitic carbon and the other disordered (or amorphous) carbon. The intensity ratio between these two peaks suggests the degree to which the carbon has progressed from its original kerogen-like structure towards that of graphite. This progression can be due to increasing temperature or increasing strain, and until now, these two contributory factors have been difficult to separate, particularly in field examples.&lt;/p&gt;&lt;p&gt;Previous field-based studies have focused on carbon ordering on fault planes, while experimental studies have monitored the effects of strain-related ordering in organic carbon on both fault surfaces and more distributed shear zones. These studies confirmed the occurrence of strain-related ordering at seismic rates, particularly in the form of graphitization of carbon. However, these experiments showed the effects of strain-related ordering at aseismic rates to be limited when distributed shear zones were considered, in part due to the geological timescales required to emulate true conditions.&lt;/p&gt;&lt;p&gt;In this study, Raman spectroscopy is used to compare the relative nanostructural order of organic carbon within a recumbent isoclinal fold formed of interbedded limestones and marls. The central, overturned fold limb forms a 170m wide, 1km long aseismic shear zone, with evidence of increased strain recorded in calcite grains relative to the upper and lower limbs. Raman spectroscopy intensity ratios (I[d]/I[g]) are compared across the fold, showing a marked 23% decrease in the overturned limb. Such a decrease in I[d]/I[g] suggests increased carbon ordering within the overturned limb, which in combination with evidence for increased strain in calcite, suggests that the carbon ordering here is derived directly from strain-related ordering. This has important implications. We infer, from previous studies, that strain-related carbon ordering encourages further strain partitioning in carbonaceous material, and may enhance zones of weakness in the rock. This ordering in aseismic shear zones has so far been unreported in nature, and so our field-based results are significant in supporting previous experimental evidence for this phenomenon. Our results also have implications for understanding dynamic crustal evolution, and will play an important role in the development of Raman thermobarometry, especially since current methods do not distinguish between strain-related and temperature-related ordering.&lt;/p&gt;

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