scholarly journals Surface Area of Patellar Facets: Inferential Statistics in the Iraqi Population

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Ahmed Al-Imam ◽  
Zaid Al-Zamili ◽  
Rawan Omar
Keyword(s):  
Surface Area ◽  
Three Dimensional ◽  
Statistical Correlation ◽  
Morphometric Parameters ◽  
The Body ◽  
Sesamoid Bone ◽  
Inferential Statistics ◽  
Surface Areas ◽  
Dimensional Complexity ◽  
Image Analyses

Background. The patella is the largest sesamoid bone in the body; its three-dimensional complexity necessitates biomechanical perfection. Numerous pathologies occur at the patellofemoral unit which may end in degenerative changes. This study aims to test the presence of statistical correlation between the surface areas of patellar facets and other patellar morphometric parameters. Materials and Methods. Forty dry human patellae were studied. The morphometry of each patella was measured using a digital Vernier Caliper, electronic balance, and image analyses software known as ImageJ. The patellar facetal surface area was correlated with patellar weight, height, width, and thickness. Results. Inferential statistics proved the existence of linear correlation of total facetal surface area and patellar weight, height, width, and thickness. The correlation was strongest for surface area versus patellar weight. The lateral facetal area was found persistently larger than the medial facetal area, the p value was found to be <0.001 (one-tailed t-test) for right patellae, and another significant p value of < 0.001 (one-tailed t-test) was found for left patellae. Conclusion. These data are vital for the restoration of the normal biomechanics of the patellofemoral unit; these are to be consulted during knee surgeries and implant designs and can be of an indispensable anthropometric, interethnic, and biometric value.

Modelling skin surface areas involved in water transfer in the Palmate Newt (Lissotriton helveticus)

2014 ◽  
Vol 92 (8) ◽  
pp. 707-714 ◽  
Author(s):  
Thomas Wardziak ◽  
Laurent Oxarango ◽  
Sébastien Valette ◽  
Laurent Mahieu-Williame ◽  
Pierre Joly
Keyword(s):  
Surface Area ◽  
Skin Surface ◽  
Water Transfer ◽  
The Body ◽  
Body Volume ◽  
3D Analysis ◽  
Evaporative Water ◽  
Surface Areas ◽  
Lissotriton Helveticus ◽  
Palmate Newt

Magnetic resonance imaging (MRI) based 3D reconstructions were used to derive accurate quantitative data on body volume and functional skin surface areas involved in water transfer in the Palmate Newt (Lissotriton helveticus (Razoumovsky, 1789)). Body surface area can be functionally divided into evaporative surface area that interacts with the atmosphere and controls the transepidermal evaporative water loss (TEWL); ventral surface area in contact with the substratum that controls transepidermal water absorption (TWA); and skin surface area in contact with other skin surfaces when amphibians adopt water-conserving postures. We generated 3D geometries of the newts via volume-rendering by a “segmentation” process carried out using a graph-cuts algorithm and a Web-based interface. The geometries reproduced the two postures adopted by the newts, i.e., an I-shaped posture characterized by a straight body without tail coiling and an S-shaped posture where the body is huddled up with the tail coiling along it. As a guide to the quality of the surface area estimations, we compared measurements of TEWL rates between living newts and their agar replicas (reproducing their two postures) at 20 °C and 60% relative humidity. Whereas the newts did not show any physiological adaptations to restrain evaporation, they expressed an efficient S-shaped posture with a resulting water economy of 22.9%, which is very close to the 23.6% reduction in evaporative surface area measured using 3D analysis.

scholarly journals New Mathematical Model for the Surface Area of the Left Ventricle by the Truncated Prolate Spheroid

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
José Sérgio Domingues ◽  
Marcos de Paula Vale ◽  
Carlos Barreira Martinez
Keyword(s):  
Mathematical Model ◽  
Left Ventricle ◽  
Surface Area ◽  
Age Groups ◽  
Prolate Spheroid ◽  
The Body ◽  
Surface Areas ◽  
Heart Chamber ◽  
Strong Linear Correlation ◽  
Superficial Area

The main aim of this study was the formula application of the superficial area of a truncated prolate spheroid (TPS) in Cartesian coordinates in obtaining a cardiac parameter that is not so much discussed in literature, related to the left ventricle (LV) surface area of the human heart, by age and sex. First we obtain a formula for the area of a TPS. Then a simple mathematical model of association of the axes measures of a TPS with the axes of the LV is built. Finally real values of the average dimensions of the humans LV are used to measure surface areas approximations of this heart chamber. As a result, the average superficial area of LV for normal patients is obtained and it is observed that the percentage differences of areas between men and women and their consecutive age groups are constant. A strong linear correlation between the obtained areas and the ventricular volumes normalized by the body areas was observed. The obtained results indicate that the superficial area of the LV, besides enabling a greater knowledge of the geometrical characteristics of the human LV, may be used as one of the normality cardiac verification criteria and be useful for medical and biological applications.

scholarly journals Quantitative analysis of mechanically retentive ceramic bracket base surfaces with a three-dimensional imaging system

2012 ◽  
Vol 83 (4) ◽  
pp. 705-711 ◽  
Author(s):  
Da-Young Kang ◽  
Sung-Hwan Choi ◽  
Jung-Yul Cha ◽  
Chung-Ju Hwang
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Area ◽  
Three Dimensional ◽  
Micro Ct ◽  
Base Surface ◽  
Surface Areas ◽  
Ceramic Brackets ◽  
Ceramic Bracket ◽  
Bracket Base

ABSTRACT Objective: To investigate the three-dimensional structural features of three types of mechanically retentive ceramic bracket bases. Materials and Methods: One type of stainless steel (MicroArch, Tomy, Tokyo, Japan) and three types of ceramic maxillary right central incisor brackets—Crystaline MB (Tomy), INVU (TP Orthodontics, La Porte, Ind), and Inspire Ice (Ormco, Glendora, Calif)—were tested to compare and quantitatively analyze differences in the surface features of each ceramic bracket base using scanning electron microscopy (SEM), a three-dimensional (3D) optical surface profiler, and microcomputed tomography (micro-CT). One-way analysis of variance was used to find differences in bracket base surface roughness values and surface areas between groups according to base designs. Tukey's honestly significant differences tests were used for post hoc comparisons. Results: SEM revealed that each bracket exhibited a unique surface texture (MicroArch, double mesh; Crystaline MB, irregular; INVU, single mesh; Inspire Ice, bead ball). With a 3D optical surface profiler, the stainless steel bracket showed significantly higher surface roughness values. Crystaline MB had significantly higher surface roughness values than Inspire Ice. Micro-CT demonstrated that stainless steel brackets showed significantly higher whole and unit bracket base surface areas. Among ceramic brackets, INVU showed significantly higher whole bracket base surface area, and Crystaline MB showed a significantly higher unit bracket base surface area than Inspire Ice. Conclusion: Irregular bracket surface features showed the highest surface roughness values and unit bracket base surface area among ceramic brackets, which contributes to increased mechanically retentive bracket bonding strength.

A theoretical morphologic analysis of convergently evolved erect helical colony form in the Bryozoa

Paleobiology ◽  
2000 ◽  
Vol 26 (4) ◽  
pp. 556-577 ◽  
Author(s):  
George R. McGhee ◽  
Frank K. McKinney
Keyword(s):  
Surface Area ◽  
Dimensional Space ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Filter Feeding ◽  
Colony Form ◽  
Surface Areas ◽  
Morphologic Analysis ◽  
Intermediate Surface

Exploration of the theoretical morphospace of erect helical colony form in Bryozoa, created by McKinney and Raup (1982), reveals that only a small volume of the three-dimensional space of hypothetical form is occupied by actual colonies of the Paleozoic fenestrates (Class Stenolaemata) Archimedes and Helicopora, helical species of the cheilostome (Class Gymnolaemata) Bugula, and the cyclostome (Class Stenolaemata) Crisidmonea archimediformis. Actual helical-colony bryozoans are not found in regions of the morphospace characterized by colony geometries that possess the largest surface areas of filtration sheet. Examination of computer-simulated colonies in the theoretical morphospace reveals that, although possessing high surface areas, colonies in the empty region of high-surface-area morphospace possess other aspects of geometry that are unrealistic as filter-feeding geometries: the filtration-sheet whorls are held at small acute angles to the central colony axis and are deeply nested within one another, both of which are disadvantageous conditions for the system of filter feeding used by the extant cheilostome Bugula, and presumably by extinct helical-colony bryozoans as well.Even though actual bryozoans are found only in the low to intermediate surface-area regions of the theoretical morphospace, surface area of filtration sheet is a major determinant of form in these helical colonies, as is evidenced by a negative correlation in values of the parameters BWANG and ELEV exhibited by the colony data. Minimum values of BWANG are even further constrained by the apparent need of the Archimedes colonies to maintain filtration-sheet branching densities within the range of 20 to 50.

scholarly journals Bedsores Management: Efficiency Simulation of a New Mattress Design

Healthcare ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1701
Author(s):  
Abdullatif Alwasel ◽  
Bandar Alossimi ◽  
Maha Alsadun ◽  
Khalid Alhussaini
Keyword(s):  
Surface Area ◽  
Three Dimensional ◽  
The Body ◽  
Absolute Amount ◽  
Body Parts ◽  
Health It ◽  
Original Design ◽  
Element Analysis ◽  
Limited Mobility ◽  
Three Dimensional Models

Bedsores, also known as pressure ulcers, are wounds caused by the applied external force (pressure) on body segments, thereby preventing blood supply from delivering the required elements to the skin tissue. Missing elements hinder the skin’s ability to maintain its health. It poses a significant threat to patients that have limited mobility. A new patented mattress design and alternative suggested designs aimed to reduce pressure are investigated in this paper for their performance in decreasing pressure. A simulation using Ansys finite element analysis (FEA) is carried out for comparison. Three-dimensional models are designed and tested in the simulation for a mattress and human anthropometric segments (Torso and Hip). All designs are carried out in solidworks. Results show that the original design can redistribute the pressure and decrease it up to 17% less than the normal mattress. The original design shows better ability to decrease the absolute amount of pressure on the body. However, increasing the surface area of the movable parts results in less pressure applied to the body parts. Thus, this work suggests changing the surface area of the cubes from 25 to 100 cm2.

scholarly journals Upstroke wing flexion and the inertial cost of bat flight

2012 ◽  
Vol 279 (1740) ◽  
pp. 2945-2950 ◽  
Author(s):  
Daniel K. Riskin ◽  
Attila Bergou ◽  
Kenneth S. Breuer ◽  
Sharon M. Swartz
Keyword(s):  
Surface Area ◽  
Energy Savings ◽  
Three Dimensional ◽  
Flapping Flight ◽  
The Body ◽  
Wing Surface ◽  
Energetic Costs ◽  
Wing Kinematics ◽  
The Cost ◽  
Inertial Energy

Flying vertebrates change the shapes of their wings during the upstroke, thereby decreasing wing surface area and bringing the wings closer to the body than during downstroke. These, and other wing deformations, might reduce the inertial cost of the upstroke compared with what it would be if the wings remained fully extended. However, wing deformations themselves entail energetic costs that could exceed any inertial energy savings. Using a model that incorporates detailed three-dimensional wing kinematics, we estimated the inertial cost of flapping flight for six bat species spanning a 40-fold range of body masses. We estimate that folding and unfolding comprises roughly 44 per cent of the inertial cost, but that the total inertial cost is only approximately 65 per cent of what it would be if the wing remained extended and rigid throughout the wingbeat cycle. Folding and unfolding occurred mostly during the upstroke; hence, our model suggests inertial cost of the upstroke is not less than that of downstroke. The cost of accelerating the metacarpals and phalanges accounted for around 44 per cent of inertial costs, although those elements constitute only 12 per cent of wing weight. This highlights the energetic benefit afforded to bats by the decreased mineralization of the distal wing bones.

scholarly journals The use of planimetric surface area in glacier mass-balance calculations: a potential source of errors

1995 ◽  
Vol 41 (139) ◽  
pp. 441-444 ◽  
Author(s):  
Frank M. Jacobsen ◽  
Wilfred H. Theakstone
Keyword(s):  
Surface Area ◽  
Three Dimensional ◽  
Radiation Energy ◽  
Glacier Mass Balance ◽  
Digital Terrain Models ◽  
Glacier Surface ◽  
Actual Surface ◽  
Surface Areas ◽  
Digital Terrain ◽  
Terrain Models

AbstractLarge errors in the estimation of glacier ablation and accumulation may arise from the uncritical use of planimetric surface areas in volume calculations based on specific point values. Three-dimensional digital terrain models of glacier surfaces show that the actual surface area is likely to be substantially larger than the planimetric area; with high-resolution digital terrain models, approximations of the true surface area may be as much as 20% larger. The errors are sufficient for questions to be raised about some calculations of water storage in glaciers, because incorrect surface-area values may result in ablation being underestimated substantially. Errors may also be introduced into calculations of radiation-energy inputs to a crevassed glacier surface.

scholarly journals Quantification of Contralateral Differences of the Scaphoid: A Comparison of Bone Geometry in Three Dimensions

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Claudio Letta ◽  
Andreas Schweizer ◽  
Philipp Fürnstahl
Keyword(s):  
Surface Area ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Bone Geometry ◽  
Statistical Correlation ◽  
Three Dimensions ◽  
Computed Tomography Images ◽  
Surface Models ◽  
Surface Deviation ◽  
The Right

The purpose of this study was to accurately quantify contralateral differences of the scaphoid in three-dimensional space to evaluate the feasibility of using the healthy contralateral bone as a reconstruction template in the preoperative planning of complex mal- or nonunions. Three-dimensional surface models of the left and right scaphoids were reconstructed from computed tomography images and compared in 26 individuals. Left-right differences were quantified with respect to volume, surface area, length, and surface-to-surface deviation. The average left-right differences in volume, surface area, and length were 95.4 mm3 (SD 66.2 mm3), 32.7 mm2 (SD 22.9 mm32), and 0.28 mm (SD 0.4 mm), respectively. The average surface-to-surface deviation between the sides was 0.26 mm (SD 0.2 mm). High statistical correlation (Pearson) between the left and the right side was found in all evaluated measures.

scholarly journals The use of planimetric surface area in glacier mass-balance calculations: a potential source of errors

1995 ◽  
Vol 41 (139) ◽  
pp. 441-444 ◽  
Author(s):  
Frank M. Jacobsen ◽  
Wilfred H. Theakstone
Keyword(s):  
Surface Area ◽  
Three Dimensional ◽  
Radiation Energy ◽  
Glacier Mass Balance ◽  
Digital Terrain Models ◽  
Glacier Surface ◽  
Actual Surface ◽  
Surface Areas ◽  
Digital Terrain ◽  
Terrain Models

AbstractLarge errors in the estimation of glacier ablation and accumulation may arise from the uncritical use of planimetric surface areas in volume calculations based on specific point values. Three-dimensional digital terrain models of glacier surfaces show that the actual surface area is likely to be substantially larger than the planimetric area; with high-resolution digital terrain models, approximations of the true surface area may be as much as 20% larger. The errors are sufficient for questions to be raised about some calculations of water storage in glaciers, because incorrect surface-area values may result in ablation being underestimated substantially. Errors may also be introduced into calculations of radiation-energy inputs to a crevassed glacier surface.

scholarly journals Physiological determinants of the pulmonary filtration coefficient

2008 ◽  
Vol 295 (2) ◽  
pp. L235-L237 ◽  
Author(s):  
James C. Parker ◽  
Mary I. Townsley
Keyword(s):  
Vascular Permeability ◽  
Surface Area ◽  
The Body ◽  
Filtration Coefficient ◽  
Lung Weight ◽  
Surface Areas ◽  
Fluid Permeability ◽  
Pulmonary Capillary ◽  
Body Weights ◽  
Oxygen Requirements

Current emphasis on translational application of genetic models of lung disease has renewed interest in the measurement of the gravimetric filtration coefficient ( Kf) as a means to assess vascular permeability changes in isolated perfused lungs. The Kf is the product of the hydraulic conductivity and the filtration surface area, and is a sensitive measure of vascular fluid permeability when the pulmonary vessels are fully recruited and perfused. We have observed a remarkable consistency of the normalized baseline Kf values between species with widely varying body weights from mice to sheep. Uniformity of Kf values can be attributed to the thin alveolar capillary barrier required for gas exchange and the conserved matching of lung vascular surface area to the oxygen requirements of the body mass. An allometric correlation between the total lung filtration coefficient ( Kf,t) and body weight in several species ( r2 = 1.00) had a slope that was similar to those reported for alveolar and pulmonary capillary surface areas and pulmonary diffusion coefficients determined by morphometric methods in these species. A consistent Kf is dependent on accurately separating the filtration and vascular volume components of lung weight gain, then Kf is a consistent and repeatable index of lung vascular permeability.

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