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Motion Capture

E Auvinet, F Multon, V Manning, J Meunier, J P Cobb
Gait asymmetry information is a key point in disease screening and follow-up. Constant Relative Phase (CRP) has been used to quantify within-stride asymmetry index, which requires noise-free and accurate motion capture, which is difficult to obtain in clinical settings. This study explores a new index, the Longitudinal Asymmetry Index (ILong) which is derived using data from a low-cost depth camera (Kinect). ILong is based on depth images averaged over several gait cycles, rather than derived joint positions or angles...
August 24, 2016: Gait & Posture
Ryoichi Nakashima, Yuya Komori, Eriko Maeda, Takeharu Yoshikawa, Kazuhiko Yokosawa
Although viewing multiple stacks of medical images presented on a display is a relatively new but useful medical task, little is known about this task. Particularly, it is unclear how radiologists search for lesions in this type of image reading. When viewing cluttered and dynamic displays, continuous motion itself does not capture attention. Thus, it is effective for the target detection that observers' attention is captured by the onset signal of a suddenly appearing target among the continuously moving distractors (i...
2016: Frontiers in Psychology
Marcel M Rossi, Jacqueline Alderson, Amar El-Sallam, James Dowling, Jeffrey Reinbolt, Cyril J Donnelly
The aims of this study were to: (i) establish a new criterion method to validate inertia tensor estimates by setting the experimental angular velocity data of an airborne objects as ground truth against simulations run with the estimated tensors, and (ii) test the sensitivity of the simulations to changes in the inertia tensor components. A rigid steel cylinder was covered with reflective kinematic markers and projected through a calibrated motion capture volume. Simulations of the airborne motion were run with two models, using inertia tensor estimated with geometric formula or the compound pendulum technique...
October 15, 2016: Journal of Biomechanics
Jesse V Jacobs, Carrie L Roy, Juvena R Hitt, Roman E Popov, Sharon M Henry
This study sought to determine the effects of chronic low back pain (LBP) on the cortical evoked potentials, muscle activation, and kinematics of postural responses to perturbations of standing balance. Thirteen subjects with chronic, recurrent, non-specific LBP and 13 subjects without LBP participated. The subjects responded to unpredictably timed postural perturbations while standing on a platform that randomly rotated either "toes up" or "toes down". Electroencephalography (EEG) was used to calculate the negative peak (N1) and subsequent positive peak (P2) amplitudes of the perturbation evoked cortical potentials...
October 19, 2016: Neuroscience
Devis Peressutti, Matthew Sinclair, Wenjia Bai, Thomas Jackson, Jacobus Ruijsink, David Nordsletten, Liya Asner, Myrianthi Hadjicharalambous, Christopher A Rinaldi, Daniel Rueckert, Andrew P King
We present a framework for combining a cardiac motion atlas with non-motion data. The atlas represents cardiac cycle motion across a number of subjects in a common space based on rich motion descriptors capturing 3D displacement, velocity, strain and strain rate. The non-motion data are derived from a variety of sources such as imaging, electrocardiogram (ECG) and clinical reports. Once in the atlas space, we apply a novel supervised learning approach based on random projections and ensemble learning to learn the relationship between the atlas data and some desired clinical output...
October 11, 2016: Medical Image Analysis
Yanfeng Shen, Carlos E S Cesnik
This article presents a parallel algorithm to model the nonlinear dynamic interactions between ultrasonic guided waves and fatigue cracks. The Local Interaction Simulation Approach (LISA) is further developed to capture the contact-impact clapping phenomena during the wave crack interactions based on the penalty method. Initial opening and closure distributions are considered to approximate the 3-D rough crack microscopic features. A Coulomb friction model is integrated to capture the stick-slip contact motions between the crack surfaces...
October 6, 2016: Ultrasonics
Nabia S Ikram, Judy Yee, Stefanie Weinstein, Benjamin M Yeh, Carlos U Corvera, Alexander Monto, Thomas A Hope
PURPOSE: To establish if triple-phase arterial imaging improves the detection of arterial phase hyperintense lesions based on arterial phase capture, motion artifact degradation, and lesion enhancement when compared to single-phase imaging. MATERIALS AND METHODS: Patients at risk for hepatocellular carcinoma were imaged at 3.0T. Seventy-three consecutive patients with a standard single-phase MRI and eighty-five consecutive patients were imaged using extracellular contrast with triple arterial phase MRI using three sequential accelerated acquisitions of 8 s...
October 21, 2016: Abdominal Radiology
Na Jin Seo, Mojtaba F Fathi, Pilwon Hur, Vincent Crocher
STUDY DESIGN: Repeated measures. INTRODUCTION: The Kinect (Microsoft, Redmond, WA) is widely used for telerehabilitation applications including rehabilitation games and assessment. PURPOSE OF THE STUDY: To determine effects of the Kinect location relative to a person on measurement accuracy of upper limb joint angles. METHODS: Kinect error was computed as difference in the upper limb joint range of motion (ROM) during target reaching motion, from the Kinect vs 3D Investigator Motion Capture System (NDI, Waterloo, Ontario, Canada), and compared across 9 Kinect locations...
October 18, 2016: Journal of Hand Therapy: Official Journal of the American Society of Hand Therapists
Rita R Patel, Karen Forrest, Drew Hedges
OBJECTIVE: This study aimed to investigate the relationship between (1) onset of the acoustic signal (X1a) and prephonatory phases associated with oscillatory onset and (2) offset of the acoustic signal (X2a) with the postphonatory events associated with oscillatory offset across vocally healthy adults. SUBJECTS AND METHODS: High-speed videoendoscopy was captured simultaneously with the acoustic signal during repeated production of /hi.hi.hi/ at typical pitch and loudness from 56 vocally healthy adults (aged 20-42 years; 21 men, 35 women)...
October 18, 2016: Journal of Voice: Official Journal of the Voice Foundation
Arin M Ellingson, Joseph D Mozingo, Dixon J Magnuson, Mark W Pagnano, Kristin D Zhao
Fluoroscopic imaging has become increasingly popular to investigate total knee arthroplasty kinematics non-invasively - 3D implant models are aligned with 2D image projections, and optimized via an edge-contour alignment technique. Previous studies have quantified the accuracy of this approach, however they do not always adequately address the impact of image collection parameters. A particularly sensitive parameter is the pulse width, or exposure time per frame. At longer pulse widths, more motion is captured in a single frame; this can lead to image blur and subsequent degradation to image edge quality...
October 11, 2016: Journal of Biomechanics
R Stannarius, K Harth
Disclinations in liquid crystals bear striking analogies to defect structures in a wide variety of physical systems, and their straightforward optical observability makes them excellent models to study fundamental properties of defect interactions. We employ freely suspended smectic-C films, which behave as quasi-two-dimensional polar nematics. A procedure to capture high-strength disclinations in localized spots is introduced. These disclinations are released in a controlled way, and the motion of the mutually repelling topological charges with strength +1 is studied quantitatively...
October 7, 2016: Physical Review Letters
Philipp Leinen, Matthew F B Green, Taner Esat, Christian Wagner, F Stefan Tautz, Ruslan Temirov
Considering organic molecules as the functional building blocks of future nanoscale technology, the question of how to arrange and assemble such building blocks in a bottom-up approach is still open. The scanning probe microscope (SPM) could be a tool of choice; however, SPM-based manipulation was until recently limited to two dimensions (2D). Binding the SPM tip to a molecule at a well-defined position opens an opportunity of controlled manipulation in 3D space. Unfortunately, 3D manipulation is largely incompatible with the typical 2D-paradigm of viewing and generating SPM data on a computer...
October 2, 2016: Journal of Visualized Experiments: JoVE
Janna M Gottwald, Sheila Achermann, Carin Marciszko, Marcus Lindskog, Gustaf Gredebäck
The importance of executive functioning for later life outcomes, along with its potential to be positively affected by intervention programs, motivates the need to find early markers of executive functioning. In this study, 18-month-olds performed three executive-function tasks-involving simple inhibition, working memory, and more complex inhibition-and a motion-capture task assessing prospective motor control during reaching. We demonstrated that prospective motor control, as measured by the peak velocity of the first movement unit, is related to infants' performance on simple-inhibition and working memory tasks...
October 7, 2016: Psychological Science
Tsuyoshi Goto, Toshinori Sakai, Tetsuya Enishi, Nori Sato, Koji Komatsu, Koichi Sairyo, Shinsuke Katoh
Neurogenic intermittent claudication is a main symptom in lumbar spinal stenosis (LSS), and postural change is often observed during walking. This study aimed to identify the changes in posture and muscle activity in the trunk and legs during walking in patients with LSS by examining 6 patients who had undergone decompression surgery. None of them had significant paralysis. Gait analysis using Vicon motion capture system(®) with electromyographic recordings of the paravertebral muscles (PVM) and vastus lateralis muscle (VL) was performed preoperatively and 2 weeks postoperatively...
October 6, 2016: Gait & Posture
Mitsuhiro Nishida, Takeo Nagura, Nobuyuki Fujita, Naobumi Hosogane, Takashi Tsuji, Masaya Nakamura, Morio Matsumoto, Kota Watanabe
BACKGROUND AND PURPOSE: Adolescent idiopathic scoliosis (AIS) is a structural, lateral curvature with rotation of the spine that develops around puberty. The influence of this spinal deformity on three-dimensional trunk movements during gait has not yet been elucidated. The aim of this study was to determine the influence of spinal curve pattern (single thoracic curve vs. single lumbar curve) on trunk kinematics during gait. METHODS: Twenty-two patients with a single thoracic curve (Lenke type 1) and 17 patients with a single lumbar curve (Lenke type 5) were included in this study...
October 11, 2016: Gait & Posture
Felix M Duerr, Alexandra Pauls, Chris Kawcak, Kevin Haussler, Gina Bertocci, Valerie Moorman, Melissa King
OBJECTIVE: To evaluate the use of inertial measurement units (IMU) for quantification of canine limb kinematics. METHODS: Sixteen clinically healthy, medium-sized dogs were enrolled. Baseline kinematic data were acquired using an optical motion capture system. Following this baseline data acquisition, a harness system was used for attachment of IMU to the animals. Optical kinematic data of dogs with and without the harness were compared to evaluate the influence of the harness on gait parameters...
October 20, 2016: Veterinary and Comparative Orthopaedics and Traumatology: V.C.O.T
Jamie M Schiffer, Victoria A Feher, Robert D Malmstrom, Roxana Sida, Rommie E Amaro
Proteins commonly sample a number of conformational states to carry out their biological function, often requiring transitions from the ground state to higher-energy states. Characterizing the mechanisms that guide these transitions at the atomic level promises to impact our understanding of functional protein dynamics and energy landscapes. The leucine-99-to-alanine (L99A) mutant of T4 lysozyme is a model system that has an experimentally well characterized excited sparsely populated state as well as a ground state...
October 18, 2016: Biophysical Journal
V Komisar, A C Novak, B Haycock
Synchronization of multiple data collection systems is necessary for accurate temporal alignment of data, and is particularly important when considering rapid movements which occur in less than one second. This paper describes a novel method for synchronizing multiple data collection instruments including load cells and a motion capture system, using a common analog signal. An application of the synchronization method is demonstrated using biomechanical data collected during a rapid reach-to-grasp reaction, where data from motion capture and load cells are collected...
October 4, 2016: Gait & Posture
Mark W Creaby, Conor Honeywill, Melinda M Franettovich Smith, Anthony G Schache, Kay M Crossley
PURPOSE: Achilles tendinopathy (AT) is a prevalent injury in running sports. Understanding the biomechanical factors associated with AT will assist in its management and prevention. The purpose of this study was to compare hip and ankle kinematics and kinetics in runners with and without AT. METHODS: Fourteen male runners with AT and eleven healthy male runners (CTRL) ran over-ground whilst lower-limb joint motion and ground reaction force data were synchronously captured...
October 17, 2016: Medicine and Science in Sports and Exercise
Zhen Li, Zhiqiang Wei, Lei Huang, Shugang Zhang, Jie Nie
Human activity recognition is important for healthcare and lifestyle evaluation. In this paper, a novel method for activity recognition by jointly considering motion sensor data recorded by wearable smart watches and image data captured by RGB-Depth (RGB-D) cameras is presented. A normalized cross correlation based mapping method is implemented to establish association between motion sensor data with corresponding image data from the same person in multi-person situations. Further, to improve the performance and accuracy of recognition, a hierarchical structure embedded with an automatic group selection method is proposed...
October 15, 2016: Sensors
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