scholarly journals A Three-Dimensional Ankle Kinetostatic Model to Simulate Loaded and Unloaded Joint Motion

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Margherita Forlani ◽  
Nicola Sancisi ◽  
Vincenzo Parenti-Castelli
Keyword(s):  
Kinematic Model ◽  
Three Dimensional ◽  
Rigid Bodies ◽  
Published Data ◽  
Calcaneofibular Ligament ◽  
Ankle Motion ◽  
Starting Point ◽  
Kinetostatic Model ◽  
Definition Of ◽  
External Loads

A kinetostatic model able to replicate both the natural unloaded motion of the tibiotalar (or ankle) joint and the joint behavior under external loads is presented. The model is developed as the second step of a sequential procedure, which allows the definition of a kinetostatic model as a generalization of a kinematic model of the joint defined at the first step. Specifically, this kinematic model taken as the starting point of the definition procedure is a parallel spatial mechanism which replicates the ankle unloaded motion. It features two rigid bodies (representing the tibia–fibula and the talus–calcaneus complexes) interconnected by five rigid binary links, that mimic three articular contacts and two nearly isometric fibers (IFs) of the tibiocalcaneal ligament (TiCaL) and calcaneofibular ligament (CaFiL). In the kinetostatic model, the five links are considered as compliant; moreover, further elastic structures are added to represent all the main ankle passive structures of the joint. Thanks to this definition procedure, the kinetostatic model still replicates the ankle unloaded motion with the same accuracy as the kinematic model. In addition, the model can replicate the behavior of the joint when external loads are applied. Finally, the structures that guide these motions are consistent with the anatomical evidence. The parameters of the model are identified for two specimens from both subject-specific and published data. Loads are then applied to the model in order to simulate two common clinical tests. The model-predicted ankle motion shows good agreement with results from the literature.

Radula-centric and odontophore-centric kinematic models of swallowing inAplysia californica

2002 ◽  
Vol 205 (14) ◽  
pp. 2029-2051 ◽  
Author(s):  
Richard F. Drushel ◽  
Greg P. Sutton ◽  
David M. Neustadter ◽  
Elizabeth V. Mangan ◽  
Benjamin W. Adams ◽  
...  
Keyword(s):  
Kinematic Model ◽  
Three Dimensional ◽  
Rigid Bodies ◽  
High Temporal Resolution ◽  
Buccal Mass ◽  
Kinematic Models ◽  
Dimensional Shape ◽  
Position Parameter ◽  
Three Dimensional Shape

SUMMARYTwo kinematic models of the radula/odontophore of the marine mollusc Aplysia californica were created to characterize the movement of structures inside the buccal mass during the feeding cycle in vivo. Both models produce a continuous range of three-dimensional shape changes in the radula/odontophore, but they are fundamentally different in construction. The radulacentric model treats the radular halves as rigid bodies that can pitch, yaw and roll relative to a fixed radular stalk, thus creating a three-dimensional shape. The odontophore-centric model creates a globally convex solid representation of the radula/odontophore directly, which then constrains the positions and shapes of internal structures. Both radula/odontophore models are placed into a pre-existing kinematic model of the I1/I3 and I2 muscles to generate three-dimensional representations of the entire buccal mass. High-temporal-resolution, mid-sagittal magnetic resonance(MR) images of swallowing adults in vivo are used to provide non-invasive, artifact-free shape and position parameter inputs for the models. These images allow structures inside the buccal mass to be visualized directly, including the radula, radular stalk and lumen of the I1/I3 cavity. Both radula-centric and odontophore-centric models were able to reproduce two-dimensional, mid-sagittal radula/odontophore and buccal mass kinematics,but the odontophore-centric model's predictions of I1/I3, I2 and I7 muscle dimensions more accurately matched data from MR-imaged adults and transilluminated juveniles.

scholarly journals On Rotor calculus, I

1966 ◽  
Vol 6 (4) ◽  
pp. 402-423 ◽  
Author(s):  
H. A. Buchdahl
Keyword(s):  
Vector Space ◽  
Lorentz Transformation ◽  
Real World ◽  
Three Dimensional ◽  
Linear Vector ◽  
Complex Rotation ◽  
Starting Point ◽  
Complex Linear ◽  
Definition Of ◽  
Linear Vector Space

SummaryIt is known that to every proper homogeneous Lorentz transformation there corresponds a unique proper complex rotation in a three-dimensional complex linear vector space, the elements of which are here called “rotors”. Equivalently one has a one-one correspondence between rotors and self- dual bi-vectors in space-time (w-space). Rotor calculus fully exploits this correspondence, just as spinor calculus exploits the correspondence between real world vectors and hermitian spinors; and its formal starting point is the definition of certain covariant connecting quantities τAkl which transform as vectors under transformations in rotor space (r-space) and as tensors of valence 2 under transformations in w-space.

scholarly journals HBIM TO VR. SEMANTIC AWARENESS AND DATA ENRICHMENT INTEROPERABILITY FOR PARAMETRIC LIBRARIES OF HISTORICAL ARCHITECTURE

2018 ◽  
Vol XLII-2 ◽  
pp. 937-943 ◽  
Author(s):  
R. Quattrini ◽  
C. Battini ◽  
R. Mammoli
Keyword(s):  
Three Dimensional ◽  
Data Migration ◽  
Architectural Heritage ◽  
Data Enrichment ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Starting Point ◽  
Historical Architecture ◽  
Definition Of ◽  
Semantic Awareness

Recently we assist to an increasing availability of HBIM models rich in geometric and informative terms. Instead, there is still a lack of researches implementing dedicated libraries, based on parametric intelligence and semantically aware, related to the architectural heritage. Additional challenges became from their portability in non-desktop environment (such as VR). The research article demonstrates the validity of a workflow applied to the architectural heritage, which starting from the semantic modeling reaches the visualization in a virtual reality environment, passing through the necessary phases of export, data migration and management. The three-dimensional modeling of the classical Doric order takes place in the BIM work environment and is configured as a necessary starting point for the implementation of data, parametric intelligences and definition of ontologies that exclusively qualify the model. The study also enables an effective method for data migration from the BIM model to databases integrated into VR technologies for AH. Furthermore, the process intends to propose a methodology, applicable in a return path, suited to the achievement of an appropriate data enrichment of each model and to the possibility of interaction in VR environment with the model.

Fast Kinematic Model of a Seven-Bar Linkage With a Single Compliant Link

2014 ◽  
Author(s):  
Alberto Borboni ◽  
Francesco Aggogeri ◽  
Rodolfo Faglia
Keyword(s):  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Small Deformation ◽  
Rigid Bodies ◽  
Fast Method ◽  
Closed Loops ◽  
Torsion Effect ◽  
Kinematical Model ◽  
Kinetostatic Model ◽  
The Ideal

This work deals on a kinematical model of a parallel mechanism for biomedical applications. The mechanism is a linkage composed by three closed loops. It is composed by seven bars (one of them is the frame) constrained each other by ideal constraints (prismatic, rotary or lock joints). The ideal joints introduce 21 degrees of constraint, while the bars produce eighteen degrees of freedom when considered rigid. Six bars are really rigid, while one of them is compliant with respect to the others and allows the mobility of the mechanism. The kinematic of this seven-bar linkage is analyzed with the aim of Hermite’s polynomials. The proposed approach is based on the knowledge of kinematical constraints at the ends of the compliant beam, in terms of position and curvature. This knowledge is based on the fact that the rest of the structure is composed by rigid bodies and ideal concentrated constraints. The compliance affects the beam only with bending effects, furthermore, in this work, we consider only a planar linkage, thus the torsion effect is not considered, and the beam is constrained in ways that compression instability is negligible. Although the beam is subjected to important deformations, it is divided in parts, such that each part is subjected to a small deformation. In this way, we propose the Hermite’s polynomials to describe the shape of the beam. We tested this fast method to describe the kinematical behavior of the system with a kinetostatic model of a mechanical device, finding that it is reliable for the proposed application.

Defining Best 3D Practices in Archaeology

2014 ◽  
Vol 2 (4) ◽  
pp. 353-365 ◽  
Author(s):  
Fabrizio Galeazzi ◽  
Holley Moyes ◽  
Mark Aldenderfer
Keyword(s):  
Data Acquisition ◽  
Stereo Matching ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Heritage Sites ◽  
Dense Stereo Matching ◽  
Starting Point ◽  
3D Documentation ◽  
Definition Of ◽  
Data Acquisition And Processing

AbstractThis research aims to investigate the potential use of three-dimensional (3D) technologies for the analysis and interpretation of heritage sites. This article uses different 3D survey technologies to find the most appropriate methods to document archaeological stratigraphy, based on diverse environmental conditions, light exposures, and varied surfaces. The use of 3D laser scanners and dense stereo matching (DSM) techniques is now well established in archaeology. However, no convincing comparisons between those techniques have been presented. This research fills this gap to provide an accurate data assessment for the Las Cuevas site (Belize) and represents a starting point for the definition of a sharable methodology. Tests in Las Cuevas were conducted to compare both accuracy and density reliability in cave environments using two different techniques: triangulation light laser scanner and DSM. This study finds that DSM is the most economical, portable, and flexible approach for the 3D documentation of archaeological sites today. In fact, DSM allows the 3D documentation process to be done more efficiently, reducing both data acquisition and processing time. Nonetheless, the quantitative comparison presented in this paper underscores the need to integrate this technique with other technologies when the data acquisition of micro-stratigraphy is required.

Application of high-resolution field-emission LVSEM, backscatter imaging, immunogold staining to definition of the spatial distributions of two human neutrophil adherence receptors

1993 ◽  
Vol 51 ◽  
pp. 36-37
Author(s):  
Robert D. Nelson ◽  
Sharon R. Hasslen ◽  
Stanley L. Erlandsen
Keyword(s):  
Cell Surface ◽  
Surface Membrane ◽  
Three Dimensional ◽  
Human Neutrophils ◽  
Spatial Distributions ◽  
Immunogold Staining ◽  
Functional Control ◽  
Neutrophil Adherence ◽  
Definition Of ◽  
Mode Of Attachment

Receptors are commonly defined in terms of number per cell, affinity for ligand, chemical structure, mode of attachment to the cell surface, and mechanism of signal transduction. We propose to show that knowledge of spatial distribution of receptors on the cell surface can provide additional clues to their function and components of functional control.L-selectin and Mac-1 denote two receptor populations on the neutrophil surface that mediate neutrophil-endothelial cell adherence interactions and provide for targeting of neutrophil recruitment to sites of inflammation. We have studied the spatial distributions of these receptors using LVSEM and backscatter imaging of isolated human neutrophils stained with mouse anti-receptor (primary) antibody and goat anti-mouse (secondary) antibody conjugated to 12 nm colloidal gold. This combination of techniques provides for three-dimensional analysis of the expression of these receptors on different surface membrane domains of the neutrophil: the ruffles and microvilli that project from the cell surface, and the cell body between these projecting structures.

Holism, Chinese Medicine and Systems Ideologies: Rewriting the Past to Imagine the Future

2018 ◽  
Author(s):  
Volker Scheid
Keyword(s):  
Eighteenth Century ◽  
Chinese Medicine ◽  
Medical Humanities ◽  
Science And Technology Studies ◽  
Human Beings ◽  
The Past ◽  
Starting Point ◽  
The Us ◽  
Shared Objective ◽  
Definition Of

This chapter explores the articulations that have emerged over the last half century between various types of holism, Chinese medicine and systems biology. Given the discipline’s historical attachments to a definition of ‘medicine’ that rather narrowly refers to biomedicine as developed in Europe and the US from the eighteenth century onwards, the medical humanities are not the most obvious starting point for such an inquiry. At the same time, they do offer one advantage over neighbouring disciplines like medical history, anthropology or science and technology studies for someone like myself, a clinician as well as a historian and anthropologist: their strong commitment to the objective of facilitating better medical practice. This promise furthermore links to the wider project of critique, which, in Max Horkheimer’s definition of the term, aims at change and emancipation in order ‘to liberate human beings from the circumstances that enslave them’. If we take the critical medical humanities as explicitly affirming this shared objective and responsibility, extending the discipline’s traditional gaze is not a burden but becomes, in fact, an obligation.

scholarly journals Second sacral sacralalar‐iliac (S2AI) screw placement in adult degenerative scoliosis (ADS) patients: an imaging study

BMC Surgery ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bing Wu ◽  
Kai Song ◽  
Junyao Cheng ◽  
Pengfei Chi ◽  
Zhaohan Wang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Imaging Study ◽  
Outer Diameter ◽  
Degenerative Scoliosis ◽  
Female Patients ◽  
Lateral Angle ◽  
Adult Degenerative Scoliosis ◽  
Imaging Characteristics ◽  
Starting Point ◽  
Trajectory Length

Abstract Background The imaging characteristics of sacral sacralalar-iliac (S2AI) screw trajectory in adult degenerative scoliosis (ADS) patients will be determined. Methods S2AI screw trajectories were mapped on three-dimensional computed tomography (3DCT) reconstructions of 40 ADS patients. The starting point, placement plane, screw template, and a circle centered at the lowest point of the ilium inner cortex were set on these images. A tangent line from the starting point to the outer diameter of the circle was selected as the axis of the screw trajectory. The related parameters in different populations were analyzed and compared. Results The trajectory length of S2AI screws in ADS patients was 12.00 ± 0.99 cm, the lateral angle was 41.24 ± 3.92°, the caudal angle was 27.73 ± 6.45°, the distance from the axis of the screw trajectory to the iliosciatic notch was 1.05 ± 0.81 cm, the distance from the axis of the screw trajectory to the upper edge of the acetabulum was 1.85 ± 0.33 cm, and the iliac width was 2.12 ± 1.65 cm. Compared with females, the lateral angle of male ADS patients was decreased, but the trajectory length was increased (P < 0.05). Compared to patients without ADS in previous studies, the lateral angle of male patients was larger, the lateral angle of female patients was increased, and the caudal angle was decreased (P < 0.05). Conclusions There is an ideal trajectory of S2AI screws in ADS patients. A different direction should be noticed in the placement of S2AI screws, especially in female patients.

scholarly journals Colourful Poincaré symmetry, gravity and particle actions

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Joaquim Gomis ◽  
Euihun Joung ◽  
Axel Kleinschmidt ◽  
Karapet Mkrtchyan
Keyword(s):  
Field Theory ◽  
Free Particle ◽  
Three Dimensional ◽  
Background Field ◽  
Quantum Field ◽  
Symmetry Factor ◽  
Starting Point ◽  
Poincaré Algebra ◽  
Poincaré Symmetry ◽  
Three Space

Abstract We construct a generalisation of the three-dimensional Poincaré algebra that also includes a colour symmetry factor. This algebra can be used to define coloured Poincaré gravity in three space-time dimensions as well as to study generalisations of massive and massless free particle models. We present various such generalised particle models that differ in which orbits of the coloured Poincaré symmetry are described. Our approach can be seen as a stepping stone towards the description of particles interacting with a non-abelian background field or as a starting point for a worldline formulation of an associated quantum field theory.

scholarly journals Proposing 3D Thermal Technology for Heritage Building Energy Monitoring

2021 ◽  
Vol 13 (8) ◽  
pp. 1537
Author(s):  
Antonio Adán ◽  
Víctor Pérez ◽  
José-Luis Vivancos ◽  
Carolina Aparicio-Fernández ◽  
Samuel A. Prieto
Keyword(s):  
Computer Vision ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Building Energy ◽  
Energy Monitoring ◽  
3D Computer Vision ◽  
Building Monitoring ◽  
Heritage Buildings ◽  
Heritage Building ◽  
Definition Of

The energy monitoring of heritage buildings has, to date, been governed by methodologies and standards that have been defined in terms of sensors that record scalar magnitudes and that are placed in specific positions in the scene, thus recording only some of the values sampled in that space. In this paper, however, we present an alternative to the aforementioned technologies in the form of new sensors based on 3D computer vision that are able to record dense thermal information in a three-dimensional space. These thermal computer vision-based technologies (3D-TCV) entail a revision and updating of the current building energy monitoring methodologies. This paper provides a detailed definition of the most significant aspects of this new extended methodology and presents a case study showing the potential of 3D-TCV techniques and how they may complement current techniques. The results obtained lead us to believe that 3D computer vision can provide the field of building monitoring with a decisive boost, particularly in the case of heritage buildings.

Sign in / Sign up

Export Citation Format

Share Document