WorldWideScience

Sample records for vicon motion capture

  1. Comparative abilities of Microsoft Kinect and Vicon 3D motion capture for gait analysis.

    Science.gov (United States)

    Pfister, Alexandra; West, Alexandre M; Bronner, Shaw; Noah, Jack Adam

    2014-07-01

    Biomechanical analysis is a powerful tool in the evaluation of movement dysfunction in orthopaedic and neurologic populations. Three-dimensional (3D) motion capture systems are widely used, accurate systems, but are costly and not available in many clinical settings. The Microsoft Kinect™ has the potential to be used as an alternative low-cost motion analysis tool. The purpose of this study was to assess concurrent validity of the Kinect™ with Brekel Kinect software in comparison to Vicon Nexus during sagittal plane gait kinematics. Twenty healthy adults (nine male, 11 female) were tracked while walking and jogging at three velocities on a treadmill. Concurrent hip and knee peak flexion and extension and stride timing measurements were compared between Vicon and Kinect™. Although Kinect measurements were representative of normal gait, the Kinect™ generally under-estimated joint flexion and over-estimated extension. Kinect™ and Vicon hip angular displacement correlation was very low and error was large. Kinect™ knee measurements were somewhat better than hip, but were not consistent enough for clinical assessment. Correlation between Kinect™ and Vicon stride timing was high and error was fairly small. Variability in Kinect™ measurements was smallest at the slowest velocity. The Kinect™ has basic motion capture capabilities and with some minor adjustments will be an acceptable tool to measure stride timing, but sophisticated advances in software and hardware are necessary to improve Kinect™ sensitivity before it can be implemented for clinical use.

  2. Normal human gait patterns in Peruvian individuals: an exploratory assessment using VICON motion capture system

    Science.gov (United States)

    Dongo, R.; Moscoso, M.; Callupe, R.; Pajaya, J.; Elías, D.

    2017-11-01

    Gait analysis is of clinical relevance for clinicians. However, normal gait patterns used in foreign literature could be different from local individuals. The aim of this study was to determine the normal gait patterns and parameters of Peruvian individuals in order to have a local referent for clinical assessments and making diagnosis and treatment Peruvian people with lower motor neuron injuries. A descriptive study with 34 subjects was conducted to assess their gait cycle. VICON® cameras were used to capture body movements. For the analyses, we calculated spatiotemporal gait parameters and average angles of displacement of the hip, knee, and ankle joints with their respective 95% confidence intervals. The results showed gait speed was 0.58m/s, cadence was 102.1steps/min, and the angular displacement of the hip, knee and ankle joints were all lower than those described in the literature. In the graphs, gait cycles were close to those reported in previous studies, but the parameters of speed, cadence and angles of displacements are lower than the ones shown in the literature. These results could be used as a better reference pattern in the clinical setting.

  3. A study on validating KinectV2 in comparison of Vicon system as a motion capture system for using in Health Engineering in industry

    Science.gov (United States)

    Jebeli, Mahvash; Bilesan, Alireza; Arshi, Ahmadreza

    2017-06-01

    The currently available commercial motion capture systems are constrained by space requirement and thus pose difficulties when used in developing kinematic description of human movements within the existing manufacturing and production cells. The Kinect sensor does not share similar limitations but it is not as accurate. The proposition made in this article is to adopt the Kinect sensor in to facilitate implementation of Health Engineering concepts to industrial environments. This article is an evaluation of the Kinect sensor accuracy when providing three dimensional kinematic data. The sensor is thus utilized to assist in modeling and simulation of worker performance within an industrial cell. For this purpose, Kinect 3D data was compared to that of Vicon motion capture system in a gait analysis laboratory. Results indicated that the Kinect sensor exhibited a coefficient of determination of 0.9996 on the depth axis and 0.9849 along the horizontal axis and 0.2767 on vertical axis. The results prove the competency of the Kinect sensor to be used in the industrial environments.

  4. Clinically acceptable agreement between the ViMove wireless motion sensor system and the Vicon motion capture system when measuring lumbar region inclination motion in the sagittal and coronal planes.

    Science.gov (United States)

    Mjøsund, Hanne Leirbekk; Boyle, Eleanor; Kjaer, Per; Mieritz, Rune Mygind; Skallgård, Tue; Kent, Peter

    2017-03-21

    Wireless, wearable, inertial motion sensor technology introduces new possibilities for monitoring spinal motion and pain in people during their daily activities of work, rest and play. There are many types of these wireless devices currently available but the precision in measurement and the magnitude of measurement error from such devices is often unknown. This study investigated the concurrent validity of one inertial motion sensor system (ViMove) for its ability to measure lumbar inclination motion, compared with the Vicon motion capture system. To mimic the variability of movement patterns in a clinical population, a sample of 34 people were included - 18 with low back pain and 16 without low back pain. ViMove sensors were attached to each participant's skin at spinal levels T12 and S2, and Vicon surface markers were attached to the ViMove sensors. Three repetitions of end-range flexion inclination, extension inclination and lateral flexion inclination to both sides while standing were measured by both systems concurrently with short rest periods in between. Measurement agreement through the whole movement range was analysed using a multilevel mixed-effects regression model to calculate the root mean squared errors and the limits of agreement were calculated using the Bland Altman method. We calculated root mean squared errors (standard deviation) of 1.82° (±1.00°) in flexion inclination, 0.71° (±0.34°) in extension inclination, 0.77° (±0.24°) in right lateral flexion inclination and 0.98° (±0.69°) in left lateral flexion inclination. 95% limits of agreement ranged between -3.86° and 4.69° in flexion inclination, -2.15° and 1.91° in extension inclination, -2.37° and 2.05° in right lateral flexion inclination and -3.11° and 2.96° in left lateral flexion inclination. We found a clinically acceptable level of agreement between these two methods for measuring standing lumbar inclination motion in these two cardinal movement planes. Further

  5. Clinically acceptable agreement between the ViMove wireless motion sensor system and the Vicon motion capture system when measuring lumbar region inclination motion in the sagittal and coronal planes

    DEFF Research Database (Denmark)

    Mjøsund, Hanne Leirbekk; Boyle, Eleanor; Kjær, Per

    2017-01-01

    BACKGROUND: Wireless, wearable, inertial motion sensor technology introduces new possibilities for monitoring spinal motion and pain in people during their daily activities of work, rest and play. There are many types of these wireless devices currently available but the precision in measurement...

  6. An improved kinematic model of the spine for three-dimensional motion analysis in the Vicon system.

    Science.gov (United States)

    Długosz, Mirosława M; Panek, Daria; Maciejasz, Paweł; Chwała, Wiesław; Alda, Witold

    2012-01-01

    The mechanism of creation and pathomechanics of lateral spinal deformation is still not fully explained. Modern medical imaging techniques give scientists possibility to understand some aspects, but vast majority of those techniques is based on static trials. A motion capture system belongs to techniques which enable visualization of a spine during dynamic trials; however, due to lack of appropriate computational model, it is unsuitable for scoliosis imaging. A few years ago our group has proposed a kinematic model of the spine to be used with Vicon Motion Capture System, which was based on Bézier curves. That model allowed for much more precise investigation of spinal kinematics during dynamic trials as compared with other computational models. However, it did not allowed to restrict only selected movements for particular segments of the spine (e.g. axial rotation for lumbar spine). The aim of the current work is to improve the proposed model in order to be able to restrict selected movements according to the knowledge concerning spinal anatomy and spinal range of motion. The new kinematic model of the spine was written in BodyBuilder for Biomechanics Language. For the purpose of visualization also an accurate graphical representation of each vertebra (polygon mesh) was computed and adapted to be compatible with the kinematic model. Using a new version of the model it is possible to perform precise analysis of movement of all vertebrae during such dynamic activities as e.g. gait and forward or lateral bending, as well as to present the results not only on the charts, but also as a 3D animation of movements of a realistically looking spine. The paper describes the new kinematic model and the process of creating graphical representation of the vertebrae. Also sample results obtained using that model are presented.

  7. A Study of Vicon System Positioning Performance

    Directory of Open Access Journals (Sweden)

    Pierre Merriaux

    2017-07-01

    Full Text Available Motion capture setups are used in numerous fields. Studies based on motion capture data can be found in biomechanical, sport or animal science. Clinical science studies include gait analysis as well as balance, posture and motor control. Robotic applications encompass object tracking. Today’s life applications includes entertainment or augmented reality. Still, few studies investigate the positioning performance of motion capture setups. In this paper, we study the positioning performance of one player in the optoelectronic motion capture based on markers: Vicon system. Our protocol includes evaluations of static and dynamic performances. Mean error as well as positioning variabilities are studied with calibrated ground truth setups that are not based on other motion capture modalities. We introduce a new setup that enables directly estimating the absolute positioning accuracy for dynamic experiments contrary to state-of-the art works that rely on inter-marker distances. The system performs well on static experiments with a mean absolute error of 0.15 mm and a variability lower than 0.025 mm. Our dynamic experiments were carried out at speeds found in real applications. Our work suggests that the system error is less than 2 mm. We also found that marker size and Vicon sampling rate must be carefully chosen with respect to the speed encountered in the application in order to reach optimal positioning performance that can go to 0.3 mm for our dynamic study.

  8. Validation of enhanced kinect sensor based motion capturing for gait assessment.

    Science.gov (United States)

    Müller, Björn; Ilg, Winfried; Giese, Martin A; Ludolph, Nicolas

    2017-01-01

    Optical motion capturing systems are expensive and require substantial dedicated space to be set up. On the other hand, they provide unsurpassed accuracy and reliability. In many situations however flexibility is required and the motion capturing system can only temporarily be placed. The Microsoft Kinect v2 sensor is comparatively cheap and with respect to gait analysis promising results have been published. We here present a motion capturing system that is easy to set up, flexible with respect to the sensor locations and delivers high accuracy in gait parameters comparable to a gold standard motion capturing system (VICON). Further, we demonstrate that sensor setups which track the person only from one-side are less accurate and should be replaced by two-sided setups. With respect to commonly analyzed gait parameters, especially step width, our system shows higher agreement with the VICON system than previous reports.

  9. Measuring Behavior using Motion Capture

    NARCIS (Netherlands)

    Fikkert, F.W.; van der Kooij, Herman; Ruttkay, Z.M.; van Welbergen, H.; Spink, A.J.; Ballintijn, M.R.; Bogers, N.D.; Grieco, F; Loijens, L.W.S.; Noldus, L.P.J.J.; Smit, G; Zimmerman, P.H.

    2008-01-01

    Motion capture systems, using optical, magnetic or mechanical sensors are now widely used to record human motion. Motion capture provides us with precise measurements of human motion at a very high recording frequency and accuracy, resulting in a massive amount of movement data on several joints of

  10. Auditory motion capturing ambiguous visual motion

    Directory of Open Access Journals (Sweden)

    Arjen eAlink

    2012-01-01

    Full Text Available In this study, it is demonstrated that moving sounds have an effect on the direction in which one sees visual stimuli move. During the main experiment sounds were presented consecutively at four speaker locations inducing left- or rightwards auditory apparent motion. On the path of auditory apparent motion, visual apparent motion stimuli were presented with a high degree of directional ambiguity. The main outcome of this experiment is that our participants perceived visual apparent motion stimuli that were ambiguous (equally likely to be perceived as moving left- or rightwards more often as moving in the same direction than in the opposite direction of auditory apparent motion. During the control experiment we replicated this finding and found no effect of sound motion direction on eye movements. This indicates that auditory motion can capture our visual motion percept when visual motion direction is insufficiently determinate without affecting eye movements.

  11. MOTION CAPTURE AS A MODERN TECHNOLOGY FOR ANALYSING ERGOMETER ROWING

    Directory of Open Access Journals (Sweden)

    Maria Skublewska-Paszkowska

    2016-03-01

    Full Text Available The paper presents a purpose-built laboratory stand consisting of a Vicon motion capture system with reference video cameras, wireless EMG system, Concept 2 Indoor Rower ergometer, wireless heart rate monitor and the Nexus software. A pilot study of people who exercise on the ergometer helped to create a proper configuration of all the components of the laboratory. Moreover, a procedure for carrying out research was developed, which consists of several steps divided into 4 stages: preparation of the motion acquisition system; preparation of the participant; familiarising participants with the technique of rowing, recording their movements and acquiring other measurement signals. Preliminary analysis of the results obtained from heterogeneous signals from various devices showed that all the components of the research stand are mutually compatible and the received signals do not interfere with one another.

  12. Motion capture in educational robotics

    Science.gov (United States)

    Gajniyarov, Igor; Obabkov, Ilya; Khlebnikov, Nikolai

    2017-09-01

    The learning of a basic task is based on traditional classroom instruction with qualitative assessment and observation. Introduction of individualized tutorials with integrated behavioral-based evaluation techniques could significantly accelerate skill acquisition. The main idea is to provide correct behavior feedback during the process of skill acquisition but isn't by the result only. It is possible by special motion capture suit.

  13. Understanding Motion Capture for Computer Animation

    CERN Document Server

    Menache, Alberto

    2010-01-01

    The power of today's motion capture technology has taken animated characters and special effects to amazing new levels of reality. And with the release of blockbusters like Avatar and Tin-Tin, audiences continually expect more from each new release. To live up to these expectations, film and game makers, particularly technical animators and directors, need to be at the forefront of motion capture technology. In this extensively updated edition of Understanding Motion Capture for Computer Animation and Video Games, an industry insider explains the latest research developments in digital design

  14. Multimodal human motion capture and synthesis

    OpenAIRE

    Gowing, Marc; Monaghan, David; O'Connor, Noel E.

    2014-01-01

    Human motion capture (HMC) involves the sensing, recording and mapping of human motion to a digital model. It is useful for many commercial applications and fields of study, including digital animation, virtual reality/gaming, biomechanical/clinical studies and sports performance analysis. What follows is an overview of the current research being carried out in Insight.

  15. AMUC: Associated Motion capture User Categories.

    Science.gov (United States)

    Norman, Sally Jane; Lawson, Sian E M; Olivier, Patrick; Watson, Paul; Chan, Anita M-A; Dade-Robertson, Martyn; Dunphy, Paul; Green, Dave; Hiden, Hugo; Hook, Jonathan; Jackson, Daniel G

    2009-07-13

    The AMUC (Associated Motion capture User Categories) project consisted of building a prototype sketch retrieval client for exploring motion capture archives. High-dimensional datasets reflect the dynamic process of motion capture and comprise high-rate sampled data of a performer's joint angles; in response to multiple query criteria, these data can potentially yield different kinds of information. The AMUC prototype harnesses graphic input via an electronic tablet as a query mechanism, time and position signals obtained from the sketch being mapped to the properties of data streams stored in the motion capture repository. As well as proposing a pragmatic solution for exploring motion capture datasets, the project demonstrates the conceptual value of iterative prototyping in innovative interdisciplinary design. The AMUC team was composed of live performance practitioners and theorists conversant with a variety of movement techniques, bioengineers who recorded and processed motion data for integration into the retrieval tool, and computer scientists who designed and implemented the retrieval system and server architecture, scoped for Grid-based applications. Creative input on information system design and navigation, and digital image processing, underpinned implementation of the prototype, which has undergone preliminary trials with diverse users, allowing identification of rich potential development areas.

  16. Mobile Motion Capture--MiMiC.

    Science.gov (United States)

    Harbert, Simeon D; Jaiswal, Tushar; Harley, Linda R; Vaughn, Tyler W; Baranak, Andrew S

    2013-01-01

    The low cost, simple, robust, mobile, and easy to use Mobile Motion Capture (MiMiC) system is presented and the constraints which guided the design of MiMiC are discussed. The MiMiC Android application allows motion data to be captured from kinematic modules such as Shimmer 2r sensors over Bluetooth. MiMiC is cost effective and can be used for an entire day in a person's daily routine without being intrusive. MiMiC is a flexible motion capture system which can be used for many applications including fall detection, detection of fatigue in industry workers, and analysis of individuals' work patterns in various environments.

  17. Comparison of lower limb and trunk kinematics between markerless and marker-based motion capture systems.

    Science.gov (United States)

    Perrott, Margaret A; Pizzari, Tania; Cook, Jill; McClelland, Jodie A

    2017-02-01

    Three dimensional (3-D) motion capture systems are used by researchers and clinicians to analyze the kinematics of human movement. Traditional marker based systems are time consuming and limit the size of studies. Markerless 3-D systems are quicker to use but the differences between data captured in each system is unclear. To examine the relationship of kinematic data captured by marker based and markerless motion capture systems. Movement was assessed in two tests: a simple knee flexion test and single leg squat with a marker based protocol (Vicon) and a markerless protocol (Organic Motion). There was no significant difference between protocols in knee flexion angle (p=0.33). In single leg squat there was no significant difference in 9 of 13 clinically relevant joint angles in the change in angle from the start to the peak of squat. There were significant differences in the angle at the peak of the squat for 9 of 13 joint angles. This study provides evidence that a marker-based and a markerless protocol report similar ranges of change in angle from the start of a squat to peak squat in the pelvis and lower limb in single leg squat. Specific joint angles should not be compared between protocols. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Virtual Dance and Motion-Capture

    Directory of Open Access Journals (Sweden)

    Marc Boucher

    2011-01-01

    Full Text Available A general view of various ways in which virtual dance can be understood is presented in the first part of this article. It then appraises the uses of the term “virtual” in previous studies of digital dance. A more in-depth view of virtual dance as it relates to motion-capture is offered, and key issues are discussed regarding computer animation, digital imaging, motion signature, virtual reality and interactivity. The paper proposes that some forms of virtual dance be defined in relation to both digital technologies and contemporary theories of virtuality.

  19. Virtual Dance and Motion-Capture

    OpenAIRE

    Marc Boucher

    2011-01-01

    A general view of various ways in which virtual dance can be understood is presented in the first part of this article. It then appraises the uses of the term “virtual” in previous studies of digital dance. A more in-depth view of virtual dance as it relates to motion-capture is offered, and key issues are discussed regarding computer animation, digital imaging, motion signature, virtual reality and interactivity. The paper proposes that some forms of virtual dance be defined in relation to...

  20. Inertial Motion Capture Costume Design Study.

    Science.gov (United States)

    Szczęsna, Agnieszka; Skurowski, Przemysław; Lach, Ewa; Pruszowski, Przemysław; Pęszor, Damian; Paszkuta, Marcin; Słupik, Janusz; Lebek, Kamil; Janiak, Mateusz; Polański, Andrzej; Wojciechowski, Konrad

    2017-03-17

    The paper describes a scalable, wearable multi-sensor system for motion capture based on inertial measurement units (IMUs). Such a unit is composed of accelerometer, gyroscope and magnetometer. The final quality of an obtained motion arises from all the individual parts of the described system. The proposed system is a sequence of the following stages: sensor data acquisition, sensor orientation estimation, system calibration, pose estimation and data visualisation. The construction of the system's architecture with the dataflow programming paradigm makes it easy to add, remove and replace the data processing steps. The modular architecture of the system allows an effortless introduction of a new sensor orientation estimation algorithms. The original contribution of the paper is the design study of the individual components used in the motion capture system. The two key steps of the system design are explored in this paper: the evaluation of sensors and algorithms for the orientation estimation. The three chosen algorithms have been implemented and investigated as part of the experiment. Due to the fact that the selection of the sensor has a significant impact on the final result, the sensor evaluation process is also explained and tested. The experimental results confirmed that the choice of sensor and orientation estimation algorithm affect the quality of the final results.

  1. Inertial Motion Capture Costume Design Study

    Directory of Open Access Journals (Sweden)

    Agnieszka Szczęsna

    2017-03-01

    Full Text Available The paper describes a scalable, wearable multi-sensor system for motion capture based on inertial measurement units (IMUs. Such a unit is composed of accelerometer, gyroscope and magnetometer. The final quality of an obtained motion arises from all the individual parts of the described system. The proposed system is a sequence of the following stages: sensor data acquisition, sensor orientation estimation, system calibration, pose estimation and data visualisation. The construction of the system’s architecture with the dataflow programming paradigm makes it easy to add, remove and replace the data processing steps. The modular architecture of the system allows an effortless introduction of a new sensor orientation estimation algorithms. The original contribution of the paper is the design study of the individual components used in the motion capture system. The two key steps of the system design are explored in this paper: the evaluation of sensors and algorithms for the orientation estimation. The three chosen algorithms have been implemented and investigated as part of the experiment. Due to the fact that the selection of the sensor has a significant impact on the final result, the sensor evaluation process is also explained and tested. The experimental results confirmed that the choice of sensor and orientation estimation algorithm affect the quality of the final results.

  2. A multi scale motion saliency method for keyframe extraction from motion capture sequences

    OpenAIRE

    Halit, Cihan

    2010-01-01

    Ankara : The Department of Computer Engineering and the Institute of Engineering and Science of Bilkent University, 2010. Thesis (Master's) -- Bilkent University, 2010. Includes bibliographical references leaves 47-50. Motion capture is an increasingly popular animation technique; however data acquired by motion capture can become substantial. This makes it di cult to use motion capture data in a number of applications, such as motion editing, motion understanding, automati...

  3. Motion onset does not capture attention when subsequent motion is "smooth".

    Science.gov (United States)

    Sunny, Meera Mary; von Mühlenen, Adrian

    2011-12-01

    Previous research on the attentional effects of moving objects has shown that motion per se does not capture attention. However, in later studies it was argued that the onset of motion does capture attention. Here, we show that this motion-onset effect critically depends on motion jerkiness--that is, the rate at which the moving stimulus is refreshed. Experiment 1 used search displays with a static, a motion-onset, and an abrupt-onset stimulus, while systematically varying the refresh rate of the moving stimulus. The results showed that motion onset only captures attention when subsequent motion is jerky (8 and 17 Hz), not when it is smooth (33 and 100 Hz). Experiment 2 replaced motion onset with continuous motion, showing that motion jerkiness does not affect how continuous motion is processed. These findings do not support accounts that assume a special role for motion onset, but they are in line with the more general unique-event account.

  4. Motion Capture Depends Upon the Common Fate Factor Among Elements.

    Science.gov (United States)

    Ichikawa, Makoto; Masakura, Yuko

    2017-12-01

    When observers move the head backwards and forwards while fixating on the center of the concentric circles that consist of oblique lines, they see illusory rotation of those circles. If several dots are superimposed on the proximity to the inner concentric circles, observers see the illusory rotation not only for the circles but also for the superimposed dots. This illusory rotation of the dots is based on motion capture. In this study, in order to understand the basis of the motion capture, we examined how motion signal with different directions (rotation, expansion/contraction, and horizontal translation) in terms of motion on a display, as well as illusory motion signal from the oblique components, affects the motion capture. If the stimulus presented rotation with expansion/contraction, or rotation with horizontal translation for the entire stimulus, then observers tended to perceive motion capture for the superimposed dots. However, if the stimulus presented only rotation of the circles, then observers tended to perceive induced motion for the superimposed dots. These results suggest that the existences of the common fate factor for the entire stimulus determine the means of allocating and integrating the motion signal in each element in the stimulus to generate motion capture.

  5. Motion capture measures variability in laryngoscopic movement during endotracheal intubation: a preliminary report.

    Science.gov (United States)

    Carlson, Jestin N; Das, Samarjit; De la Torre, Fernando; Callaway, Clifton W; Phrampus, Paul E; Hodgins, Jessica

    2012-08-01

    Success rates with emergent endotracheal intubation (ETI) improve with increasing provider experience. Few objective metrics exist to quantify differences in ETI technique between providers of various skill levels. We tested the feasibility of using motion capture videography to quantify variability in the motions of the left hand and the laryngoscope in providers with various experience. Three providers with varying levels of experience [attending physician (experienced), emergency medicine resident (intermediate), and postdoctoral student with no previous ETI experience (novice)] each performed ETI 4 times on a mannequin. Vicon, a 16-camera system, tracked the 3-dimensional orientation and movement of markers on the providers, handle of the laryngoscope, and mannequin. Attempt duration, path length of the left hand, and the inclination of the plane of the laryngoscope handle (mean square angular deviation from vertical) were calculated for each laryngoscopy attempt. We compared interattempt and interprovider variability of each measure. All ETI attempts were successful. Mean (SD) duration of laryngoscopy attempts differed between experienced [5.50 (0.68) seconds], intermediate [6.32 (1.13) seconds], and novice [12.38 (1.06) seconds] providers (P = 0.021). Mean path length of the left hand did not differ between providers (P = 0.37). Variability of the plane of the laryngoscope differed between providers: 8.3 (experienced), 28.7 (intermediate), and 54.5 (novice) degrees squared. Motion analysis can detect interprovider differences in hand and laryngoscope movements during ETI, which may be related to provider experience. This technology has potential to objectively measure training and skill in ETI.

  6. Attentional capture by motion onsets is modulated by perceptual load.

    Science.gov (United States)

    Cosman, Joshua D; Vecera, Shaun P

    2010-11-01

    The onset of motion captures attention during visual search even if the motion is not task relevant, which suggests that motion onsets capture attention in a stimulus-driven manner. However, we have recently shown that stimulus-driven attentional capture by abruptly appearing objects is attenuated under conditions of high perceptual load. In the present study, we examined the influence of perceptual load on attentional capture by another type of dynamic stimulus: the onset of motion. Participants searched for a target letter through briefly presented low- and high-load displays. On each trial, two irrelevant flankers also appeared, one with a motion onset and one that was static. Flankers defined by a motion onset captured attention in the low-load but not in the high-load displays. This modulation of capture in high-load displays was not the result of overall lengthening of reaction times (RTs) in this condition, since search for a single low-contrast target lengthened RTs but did not influence capture. These results, together with those of previous studies, suggest that perceptual load can modulate attentional capture by dynamic stimuli.

  7. Capturing Motion and Depth Before Cinematography.

    Science.gov (United States)

    Wade, Nicholas J

    2016-01-01

    Visual representations of biological states have traditionally faced two problems: they lacked motion and depth. Attempts were made to supply these wants over many centuries, but the major advances were made in the early-nineteenth century. Motion was synthesized by sequences of slightly different images presented in rapid succession and depth was added by presenting slightly different images to each eye. Apparent motion and depth were combined some years later, but they tended to be applied separately. The major figures in this early period were Wheatstone, Plateau, Horner, Duboscq, Claudet, and Purkinje. Others later in the century, like Marey and Muybridge, were stimulated to extend the uses to which apparent motion and photography could be applied to examining body movements. These developments occurred before the birth of cinematography, and significant insights were derived from attempts to combine motion and depth.

  8. Motion Capture: Drawing and the Moving Image Exhibition, Letterkenny, Donegal.

    OpenAIRE

    Fay, Brian

    2013-01-01

    Motion Capture Drawing & the Moving Image A GLUCKSMAN exhibition, touring to Regional Cultural Centre, Letterkenny, Co. Donegal, 22 January – 9 March 2013 Supported by a Touring and Dissemination award from the Arts Council of Ireland/An Chomhairle Ealaíon. Motion Capture is an exhibition that explores the relationship of movement in two artistic media: drawing and the moving image. Featuring artworks from the mid-twentieth century through to the present day, the exhibition emphasises the ...

  9. Quantifying spinal gait kinematics using an enhanced optical motion capture approach in adolescent idiopathic scoliosis.

    Science.gov (United States)

    Schmid, Stefan; Studer, Daniel; Hasler, Carol-Claudius; Romkes, Jacqueline; Taylor, William R; Lorenzetti, Silvio; Brunner, Reinald

    2016-02-01

    The pathogenesis of adolescent idiopathic scoliosis (AIS) remains poorly understood. Previous research has indicated possible relationships between kinematics of the spine, pelvis and lower extremities during gait and the progression of AIS, but adequate evidence on spinal kinematics is lacking. The aim of this study was to provide a detailed assessment of spinal gait kinematics in AIS patients compared to asymptomatic controls. Fourteen AIS patients and 15 asymptomatic controls were included. Through introducing a previously validated enhanced trunk marker set, sagittal and frontal spinal curvature angles as well as general trunk kinematics were measured during gait using a 12-camera Vicon motion capture system. Group comparisons were conducted using T-tests and relationships between kinematic parameters and severity of scoliosis (Cobb angle) were investigated using regression analyses. The sagittal thoracic curvature angle in AIS patients showed on average 10.7° (4.2°, 17.3°) less kyphosis but 4.9° (2.3°, 7.6°) more range of motion (Cobb angle-dependent (R(2)=0.503)). In the frontal plane, thoracic and thoracolumbar/lumbar curvature angles indicated average lateral deviations in AIS patients. General trunk kinematics and spatio-temporal gait parameters, however, did not show any clinically relevant differences between the groups. This demonstrates that the dynamic functionality of the scoliotic spine can be assessed using advanced non-invasive optical approaches and that these should become standard in clinical gait analysis. Furthermore, curvature angle data might be used to drive sophisticated computer simulation models in order to gain an insight into the dynamic loading behavior of the scoliotic spine during gait. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Marker-Free Human Motion Capture

    DEFF Research Database (Denmark)

    Grest, Daniel

    are compared with respect to their efficiency. A new contribution is the inclusion of second order motion derivatives within the pose estimation. The pose estimation step requires correspondences between known model of the person and observed data. Computer Vision techniques are used to combine multiple types...... of correspondences, which are used simultaneously in the estimation without making approximations to the motion or optimization function, namely 3D-3D correspondences from stereo algorithms and 3D-2D correspondences from image silhouettes and 2D point tracking....

  11. Auditory capture of visual motion: effects on perception and discrimination.

    Science.gov (United States)

    McCourt, Mark E; Leone, Lynnette M

    2016-09-28

    We asked whether the perceived direction of visual motion and contrast thresholds for motion discrimination are influenced by the concurrent motion of an auditory sound source. Visual motion stimuli were counterphasing Gabor patches, whose net motion energy was manipulated by adjusting the contrast of the leftward-moving and rightward-moving components. The presentation of these visual stimuli was paired with the simultaneous presentation of auditory stimuli, whose apparent motion in 3D auditory space (rightward, leftward, static, no sound) was manipulated using interaural time and intensity differences, and Doppler cues. In experiment 1, observers judged whether the Gabor visual stimulus appeared to move rightward or leftward. In experiment 2, contrast discrimination thresholds for detecting the interval containing unequal (rightward or leftward) visual motion energy were obtained under the same auditory conditions. Experiment 1 showed that the perceived direction of ambiguous visual motion is powerfully influenced by concurrent auditory motion, such that auditory motion 'captured' ambiguous visual motion. Experiment 2 showed that this interaction occurs at a sensory stage of processing as visual contrast discrimination thresholds (a criterion-free measure of sensitivity) were significantly elevated when paired with congruent auditory motion. These results suggest that auditory and visual motion signals are integrated and combined into a supramodal (audiovisual) representation of motion.

  12. Wearable Sensor Networks for Motion Capture

    Directory of Open Access Journals (Sweden)

    Dennis Arsenault

    2015-08-01

    Full Text Available This work presents the development of a full body sensor-based motion tracking system that functions through wearable inertial sensors. The system is comprised of a total of ten wearable sensors and maps the player's motions to an on-screen character in real-time. A hierarchical skeletal model was implemented that allows players to navigate and interact with the virtual world without the need of a hand-held controller. To demonstrate the capabilities of the system, a simple virtual reality game was created. As a wearable system, the ability for the users to engage in activities while not being tied to a camera system, or being forced indoors presents a significant opportunity for mobile entertainment, augmented reality and interactive systems that use the body as a significant form of input. This paper outlines the key developments necessary to implement such a system.

  13. Human Motion Capture System and its Sensor Analysis

    Directory of Open Access Journals (Sweden)

    Guangtian Shi

    2014-06-01

    Full Text Available The approach taken in the paper is to compare the features and limitations of motion trackers in common use. Results from the author’s experimentation with an inertial motion capture system are discussed. The system mainly involves inertia sensing technology, Bluetooth, sensor network and software development of human body motion capture model. The sensor network of the system is used to collect motion data of the body key joints, and the data are delivered to workstation through Bluetooth, then the software on workstation uses analytical inverse kinematics algorithm to analyze the motion data. The system has advantages of lower cost and high precision. The resulting model tends to handle uncertainty well and is suitable for incrementally updating models. There is value in regularly surveying the research areas considered in this paper due to the rapid progress in sensors and especially data modeling.

  14. Scalable Photogrammetric Motion Capture System "mosca": Development and Application

    Science.gov (United States)

    Knyaz, V. A.

    2015-05-01

    Wide variety of applications (from industrial to entertainment) has a need for reliable and accurate 3D information about motion of an object and its parts. Very often the process of movement is rather fast as in cases of vehicle movement, sport biomechanics, animation of cartoon characters. Motion capture systems based on different physical principles are used for these purposes. The great potential for obtaining high accuracy and high degree of automation has vision-based system due to progress in image processing and analysis. Scalable inexpensive motion capture system is developed as a convenient and flexible tool for solving various tasks requiring 3D motion analysis. It is based on photogrammetric techniques of 3D measurements and provides high speed image acquisition, high accuracy of 3D measurements and highly automated processing of captured data. Depending on the application the system can be easily modified for different working areas from 100 mm to 10 m. The developed motion capture system uses from 2 to 4 technical vision cameras for video sequences of object motion acquisition. All cameras work in synchronization mode at frame rate up to 100 frames per second under the control of personal computer providing the possibility for accurate calculation of 3D coordinates of interest points. The system was used for a set of different applications fields and demonstrated high accuracy and high level of automation.

  15. Markerless motion capture using appearance and inertial data.

    Science.gov (United States)

    Wong, Charence; Zhang, Zhiqiang; Lo, Benny; Yang, Guang-Zhong

    2014-01-01

    Current monitoring techniques for biomechanical analysis typically capture a snapshot of the state of the subject due to challenges associated with long-term monitoring. Continuous long-term capture of biomechanics can be used to assess performance in the workplace and rehabilitation at home. Noninvasive motion capture using small low-power wearable sensors and camera systems have been explored, however, drift and occlusions have limited their ability to reliably capture motion over long durations. In this paper, we propose to combine 3D pose estimation from inertial motion capture with 2D pose estimation from vision to obtain more robust posture tracking. To handle the changing appearance of the human body due to pose variations and illumination changes, our implementation is based upon Least Soft-Threshold Squares Tracking. Constraints on the variation of the appearance model and estimated pose from an inertial motion capture system are used to correct 2D and 3D estimates simultaneously. We evaluate the performance of our method with three state-of-the-art trackers, Incremental Visual Tracking, Multiple Instance Learning, and Least Soft-Threshold Squares Tracking. In our experiments, we track the movement of the upper limbs. While the results indicate an improvement in tracking accuracy at some joint locations, they also show that the result can be further improved. Conclusions and further work required to improve our results are discussed.

  16. Remo Dance Motion Estimation with Markerless Motion Capture Using The Optical Flow Method

    Directory of Open Access Journals (Sweden)

    Neny Kurniati

    2016-03-01

    Full Text Available Motion capture has been developed and applied in various fields, one of them is dancing. Remo dance is a dance from East Java that tells the struggle of a prince who fought on the battlefield. Remo dancer does not use body-tight costume. He wears a few costume pieces and accessories, so required a motion detection method that can detect limb motion which does not damage the beauty of the costumes and does not interfere motion of the dancer. The method is Markerless Motion Capture. Limbs motions are partial behavior. This means that all limbs do not move simultaneously, but alternately. It required motion tracking to detect parts of the body moving and where the direction of motion. Optical flow is a method that is suitable for the above conditions. Moving body parts will be detected by the bounding box. A bounding box differential value between frames can determine the direction of the motion and how far the object is moving. The optical flow method is simple and does not require a monochrome background. This method does not use complex feature extraction process so it can be applied to real-time motion capture. Performance of motion detection with optical flow method is determined by the value of the ratio between the area of the blob and the area of the bounding box. Estimate coordinates are not necessarily like original coordinates, but if the chart of estimate motion similar to the chart of the original motion, it means motion estimation it can be said to have the same motion with the original. Keywords: Motion Capture, Markerless, Remo Dance, Optical Flow

  17. Motion Analysis System for Instruction of Nihon Buyo using Motion Capture

    Science.gov (United States)

    Shinoda, Yukitaka; Murakami, Shingo; Watanabe, Yuta; Mito, Yuki; Watanuma, Reishi; Marumo, Mieko

    The passing on and preserving of advanced technical skills has become an important issue in a variety of fields, and motion analysis using motion capture has recently become popular in the research of advanced physical skills. This research aims to construct a system having a high on-site instructional effect on dancers learning Nihon Buyo, a traditional dance in Japan, and to classify Nihon Buyo dancing according to style, school, and dancer's proficiency by motion analysis. We have been able to study motion analysis systems for teaching Nihon Buyo now that body-motion data can be digitized and stored by motion capture systems using high-performance computers. Thus, with the aim of developing a user-friendly instruction-support system, we have constructed a motion analysis system that displays a dancer's time series of body motions and center of gravity for instructional purposes. In this paper, we outline this instructional motion analysis system based on three-dimensional position data obtained by motion capture. We also describe motion analysis that we performed based on center-of-gravity data obtained by this system and motion analysis focusing on school and age group using this system.

  18. Scattered Data Processing Approach Based on Optical Facial Motion Capture

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    2013-01-01

    Full Text Available In recent years, animation reconstruction of facial expressions has become a popular research field in computer science and motion capture-based facial expression reconstruction is now emerging in this field. Based on the facial motion data obtained using a passive optical motion capture system, we propose a scattered data processing approach, which aims to solve the common problems of missing data and noise. To recover missing data, given the nonlinear relationships among neighbors with the current missing marker, we propose an improved version of a previous method, where we use the motion of three muscles rather than one to recover the missing data. To reduce the noise, we initially apply preprocessing to eliminate impulsive noise, before our proposed three-order quasi-uniform B-spline-based fitting method is used to reduce the remaining noise. Our experiments showed that the principles that underlie this method are simple and straightforward, and it delivered acceptable precision during reconstruction.

  19. Transitional modes of motion and capture regions of vibroshock systems

    Science.gov (United States)

    Ragulskene, V. L.

    1973-01-01

    A numerical analysis of the transitional modes of motion for a vibroshock system was conducted. The capture regions of the system are emphasized. The three initial parameters for a nonautonomous vibroshock system with one degree of freedom are identified as: (1) coordinates, (2) velocity, and (3) time. Mathematical models are developed to show the relationship of the parameters. Graphs are included to show the nature of the capture regions and to portray the trajectory of motion of mass with time, by solution of differential equations during increase and decrease in time.

  20. Mobile platform for motion capture of locomotion over long distances.

    Science.gov (United States)

    Ojeda, Lauro; Rebula, John R; Adamczyk, Peter G; Kuo, Arthur D

    2013-09-03

    Motion capture is usually performed on only a few steps of over-ground locomotion, limited by the finite sensing volume of most capture systems. This makes it difficult to evaluate walking over longer distances, or in a natural environment outside the laboratory. Here we show that motion capture may be performed relative to a mobile platform, such as a wheeled cart that is moved with the walking subject. To determine the person's absolute displacement in space, the cart's own motion must be localized. We present three localization methods and evaluate their performance. The first detects cart motion solely from the relative motion of the subject's feet during walking. The others use sensed motion of the cart's wheels to perform odometry, with and without an additional gyroscope to enhance sensitivity to turning about the vertical axis. We show that such methods are practical to implement, and with present-day sensors can yield accuracy of better than 1% over arbitrary distances. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Augmenting traditional instruments with a motion capture system

    DEFF Research Database (Denmark)

    Götzen, Amalia De; Vidolin, Alvise; Bernardini, Nicola

    2013-01-01

    This paper describes some composition works where the real instruments have been augmented through a motion capture system (Phasespace). While playing his instrument in the traditional way, the player is also controlling some other sound effects by moving his hands: the instrument becomes totally...

  2. Monocular omnidirectional head motion capture in the visible light spectrum

    NARCIS (Netherlands)

    Lichtenauer, Jeroen; Pantic, Maja

    2011-01-01

    Conventional marker-based optical motion capture methods rely on scene attenuation (e.g. by infrared-pass filtering). This renders the images useless for development and testing of machine vision methods under natural conditions. Unfortunately, combining, calibrating and synchronising a system for

  3. Predicting kinetics using musculoskeletal modeling and inertial motion capture

    NARCIS (Netherlands)

    Karatsidis, Angelos; Jung, Moonki; Schepers, H. Martin; Bellusci, Giovanni; de Zee, Mark; Veltink, Peter H.; Andersen, Michael Skipper

    2018-01-01

    Inverse dynamic analysis using musculoskeletal modeling is a powerful tool, which is utilized in a range of applications to estimate forces in ligaments, muscles, and joints, non-invasively. To date, the conventional input used in this analysis is derived from optical motion capture (OMC) and force

  4. A Virtual Reality Dance Training System Using Motion Capture Technology

    Science.gov (United States)

    Chan, J. C. P.; Leung, H.; Tang, J. K. T.; Komura, T.

    2011-01-01

    In this paper, a new dance training system based on the motion capture and virtual reality (VR) technologies is proposed. Our system is inspired by the traditional way to learn new movements-imitating the teacher's movements and listening to the teacher's feedback. A prototype of our proposed system is implemented, in which a student can imitate…

  5. Outdoor Markerless Motion Capture With Sparse Handheld Video Cameras.

    Science.gov (United States)

    Wang, Yangang; Liu, Yebin; Tong, Xin; Dai, Qionghai; Tan, Ping

    2017-04-12

    We present a method for outdoor markerless motion capture with sparse handheld video cameras. In the simplest setting, it only involves two mobile phone cameras following the character. This setup can maximize the flexibilities of data capture and broaden the applications of motion capture. To solve the character pose under such challenge settings, we exploit the generative motion capture methods and propose a novel model-view consistency that considers both foreground and background in the tracking stage. The background is modeled as a deformable 2D grid, which allows us to compute the background-view consistency for sparse moving cameras. The 3D character pose is tracked with a global-local optimization through minimizing our consistency cost. A novel L1 motion regularizer is also proposed in the optimization to constrain the solution pose space. The whole process of the proposed method is simple as frame by frame video segmentation is not required. Our method outperforms several alternative methods on various examples demonstrated in the paper.

  6. MotionExplorer: exploratory search in human motion capture data based on hierarchical aggregation.

    Science.gov (United States)

    Bernard, Jürgen; Wilhelm, Nils; Krüger, Björn; May, Thorsten; Schreck, Tobias; Kohlhammer, Jörn

    2013-12-01

    We present MotionExplorer, an exploratory search and analysis system for sequences of human motion in large motion capture data collections. This special type of multivariate time series data is relevant in many research fields including medicine, sports and animation. Key tasks in working with motion data include analysis of motion states and transitions, and synthesis of motion vectors by interpolation and combination. In the practice of research and application of human motion data, challenges exist in providing visual summaries and drill-down functionality for handling large motion data collections. We find that this domain can benefit from appropriate visual retrieval and analysis support to handle these tasks in presence of large motion data. To address this need, we developed MotionExplorer together with domain experts as an exploratory search system based on interactive aggregation and visualization of motion states as a basis for data navigation, exploration, and search. Based on an overview-first type visualization, users are able to search for interesting sub-sequences of motion based on a query-by-example metaphor, and explore search results by details on demand. We developed MotionExplorer in close collaboration with the targeted users who are researchers working on human motion synthesis and analysis, including a summative field study. Additionally, we conducted a laboratory design study to substantially improve MotionExplorer towards an intuitive, usable and robust design. MotionExplorer enables the search in human motion capture data with only a few mouse clicks. The researchers unanimously confirm that the system can efficiently support their work.

  7. Reference equations of motion for automatic rendezvous and capture

    Science.gov (United States)

    Henderson, David M.

    1992-01-01

    The analysis presented in this paper defines the reference coordinate frames, equations of motion, and control parameters necessary to model the relative motion and attitude of spacecraft in close proximity with another space system during the Automatic Rendezvous and Capture phase of an on-orbit operation. The relative docking port target position vector and the attitude control matrix are defined based upon an arbitrary spacecraft design. These translation and rotation control parameters could be used to drive the error signal input to the vehicle flight control system. Measurements for these control parameters would become the bases for an autopilot or feedback control system (FCS) design for a specific spacecraft.

  8. Feasibility of Using Low-Cost Motion Capture for Automated Screening of Shoulder Motion Limitation after Breast Cancer Surgery.

    Science.gov (United States)

    Gritsenko, Valeriya; Dailey, Eric; Kyle, Nicholas; Taylor, Matt; Whittacre, Sean; Swisher, Anne K

    2015-01-01

    To determine if a low-cost, automated motion analysis system using Microsoft Kinect could accurately measure shoulder motion and detect motion impairments in women following breast cancer surgery. Descriptive study of motion measured via 2 methods. Academic cancer center oncology clinic. 20 women (mean age = 60 yrs) were assessed for active and passive shoulder motions during a routine post-operative clinic visit (mean = 18 days after surgery) following mastectomy (n = 4) or lumpectomy (n = 16) for breast cancer. Participants performed 3 repetitions of active and passive shoulder motions on the side of the breast surgery. Arm motion was recorded using motion capture by Kinect for Windows sensor and on video. Goniometric values were determined from video recordings, while motion capture data were transformed to joint angles using 2 methods (body angle and projection angle). Correlation of motion capture with goniometry and detection of motion limitation. Active shoulder motion measured with low-cost motion capture agreed well with goniometry (r = 0.70-0.80), while passive shoulder motion measurements did not correlate well. Using motion capture, it was possible to reliably identify participants whose range of shoulder motion was reduced by 40% or more. Low-cost, automated motion analysis may be acceptable to screen for moderate to severe motion impairments in active shoulder motion. Automatic detection of motion limitation may allow quick screening to be performed in an oncologist's office and trigger timely referrals for rehabilitation.

  9. Feasibility of Using Low-Cost Motion Capture for Automated Screening of Shoulder Motion Limitation after Breast Cancer Surgery.

    Directory of Open Access Journals (Sweden)

    Valeriya Gritsenko

    Full Text Available To determine if a low-cost, automated motion analysis system using Microsoft Kinect could accurately measure shoulder motion and detect motion impairments in women following breast cancer surgery.Descriptive study of motion measured via 2 methods.Academic cancer center oncology clinic.20 women (mean age = 60 yrs were assessed for active and passive shoulder motions during a routine post-operative clinic visit (mean = 18 days after surgery following mastectomy (n = 4 or lumpectomy (n = 16 for breast cancer.Participants performed 3 repetitions of active and passive shoulder motions on the side of the breast surgery. Arm motion was recorded using motion capture by Kinect for Windows sensor and on video. Goniometric values were determined from video recordings, while motion capture data were transformed to joint angles using 2 methods (body angle and projection angle.Correlation of motion capture with goniometry and detection of motion limitation.Active shoulder motion measured with low-cost motion capture agreed well with goniometry (r = 0.70-0.80, while passive shoulder motion measurements did not correlate well. Using motion capture, it was possible to reliably identify participants whose range of shoulder motion was reduced by 40% or more.Low-cost, automated motion analysis may be acceptable to screen for moderate to severe motion impairments in active shoulder motion. Automatic detection of motion limitation may allow quick screening to be performed in an oncologist's office and trigger timely referrals for rehabilitation.

  10. Feasibility of Using Low-Cost Motion Capture for Automated Screening of Shoulder Motion Limitation after Breast Cancer Surgery

    Science.gov (United States)

    Gritsenko, Valeriya; Dailey, Eric; Kyle, Nicholas; Taylor, Matt; Whittacre, Sean; Swisher, Anne K.

    2015-01-01

    Objective To determine if a low-cost, automated motion analysis system using Microsoft Kinect could accurately measure shoulder motion and detect motion impairments in women following breast cancer surgery. Design Descriptive study of motion measured via 2 methods. Setting Academic cancer center oncology clinic. Participants 20 women (mean age = 60 yrs) were assessed for active and passive shoulder motions during a routine post-operative clinic visit (mean = 18 days after surgery) following mastectomy (n = 4) or lumpectomy (n = 16) for breast cancer. Interventions Participants performed 3 repetitions of active and passive shoulder motions on the side of the breast surgery. Arm motion was recorded using motion capture by Kinect for Windows sensor and on video. Goniometric values were determined from video recordings, while motion capture data were transformed to joint angles using 2 methods (body angle and projection angle). Main Outcome Measure Correlation of motion capture with goniometry and detection of motion limitation. Results Active shoulder motion measured with low-cost motion capture agreed well with goniometry (r = 0.70–0.80), while passive shoulder motion measurements did not correlate well. Using motion capture, it was possible to reliably identify participants whose range of shoulder motion was reduced by 40% or more. Conclusions Low-cost, automated motion analysis may be acceptable to screen for moderate to severe motion impairments in active shoulder motion. Automatic detection of motion limitation may allow quick screening to be performed in an oncologist's office and trigger timely referrals for rehabilitation. PMID:26076031

  11. Wearable sensor system for human localization and motion capture

    OpenAIRE

    Zihajehzadeh, Shaghayegh

    2017-01-01

    Recent advances in MEMS wearable inertial/magnetic sensors and mobile computing have fostered a dramatic growth of interest for ambulatory human motion capture (MoCap). Compared to traditional optical MoCap systems such as the optical systems, inertial (i.e. accelerometer and gyroscope) and magnetic sensors do not require external fixtures such as cameras. Hence, they do not have in-the-lab measurement limitations and thus are ideal for ambulatory applications. However, due to the manufacturi...

  12. A biological motion toolbox for reading, displaying, and manipulating motion capture data in research settings.

    Science.gov (United States)

    van Boxtel, Jeroen J A; Lu, Hongjing

    2013-10-15

    Biological motion research is an increasingly active field, with a great potential to contribute to a wide range of applications, such as behavioral monitoring/motion detection in surveillance situations, intention inference in social interactions, and diagnostic tools in autism research. In recent years, a large amount of motion capture data has become freely available online, potentially providing rich stimulus sets for biological motion research. However, there currently does not exist an easy-to-use tool to extract, present and manipulate motion capture data in the MATLAB environment, which many researchers use to program their experiments. We have developed the Biomotion Toolbox, which allows researchers to import motion capture data in a variety of formats, to display actions using Psychtoolbox 3, and to manipulate action displays in specific ways (e.g., inversion, three-dimensional rotation, spatial scrambling, phase-scrambling, and limited lifetime). The toolbox was designed to allow researchers with a minimal level of MATLAB programming skills to code experiments using biological motion stimuli.

  13. Validity of time series kinematical data as measured by a markerless motion capture system on a flatland for gait assessment.

    Science.gov (United States)

    Tanaka, Ryo; Takimoto, Haruka; Yamasaki, Takahiro; Higashi, Ariaki

    2018-02-08

    As a cost-effective, clinician-friendly gait assessment tool, the Kinect v2 sensor may be effective for assessing lower extremity joint kinematics. This study aims to examine the validity of time series kinematical data as measured by the Kinect v2 on a flatland for gait assessment. In this study, 51 healthy subjects walked on a flatland while kinematic data were extracted concurrently using the Kinect and Vicon systems. The kinematic outcomes comprised the hip and knee joint angles. Parallel translation of Kinect data obtained throughout the gait cycle was performed to minimize the differences between the Kinect and Vicon data. The ensemble curves of the hip and knee joint angles were compared to investigate whether the Kinect sensor can consistently and accurately assess lower extremity joint motion throughout the gait cycle. Relative consistency was assessed using Pearson correlation coefficients. Joint angles measured by the Kinect v2 followed the trend of the trajectories made by the Vicon data in both the hip and knee joints in the sagittal plane. The trajectories of the hip and knee joint angles in the frontal plane differed between the Kinect and Vicon data. We observed moderate to high correlation coefficients of 20%-60% of the gait cycle, and the largest difference between Kinect and Vicon data was 4.2°. Kinect v2 time series kinematical data obtained on the flatland are validated if the appropriate correction procedures are performed. Future studies are warranted to examine the reproducibility and systematic bias of the Kinect v2. Copyright © 2018. Published by Elsevier Ltd.

  14. Applications of markerless motion capture in gait recognition.

    Science.gov (United States)

    Sandau, Martin

    2016-03-01

    This thesis is based on four manuscripts where two of them were accepted and two were submitted to peer-reviewed journals. The experimental work behind the thesis was conducted at the Institute of Neuroscience and Pharmacology, University of Copenhagen. The purpose of the studies was to explore the variability of human gait and to conduct new methods for precise estimation of the kinematic parameters applied in forensic gait analysis. The gait studies were conducted in a custom built gait laboratory designed to obtain optimal conditions for markerless motion analysis. The set-up consisted of eight synchronised cameras located in the corners of the laboratory, which were connected to a single computer. The captured images were processed with stereovision-based algorithms to provide accurate 3D reconstructions of the participants. The 3D reconstructions of the participants were obtained during normal walking and the kinematics were extracted with manual and automatic methods. The kinematic results from the automatic approach were compared to marker-based motion capture to validate the precision. The results showed that the proposed markerless motion capture method had a precision comparable to marker-based methods in the frontal plane and the sagittal plane. Similar markerless motion capture methods could therefore provide the basis for reliable gait recognition based on kinematic parameters. The manual annotations were compared to the actual anthropometric measurements obtained from MRI scans and the intra- and inter-observer variability was also quantified to observe the associated effect on recognition. The results showed not only that the kinematics in the lower extremities were important but also that the kinematics in the shoulders had a high discriminatory power. Likewise, the shank length was also highly discriminatory, which has not been previously reported. However, it is important that the same expert performs all annotations, as the inter

  15. Satellite attitude motion models for capture and retrieval investigations

    Science.gov (United States)

    Cochran, John E., Jr.; Lahr, Brian S.

    1986-01-01

    The primary purpose of this research is to provide mathematical models which may be used in the investigation of various aspects of the remote capture and retrieval of uncontrolled satellites. Emphasis has been placed on analytical models; however, to verify analytical solutions, numerical integration must be used. Also, for satellites of certain types, numerical integration may be the only practical or perhaps the only possible method of solution. First, to provide a basis for analytical and numerical work, uncontrolled satellites were categorized using criteria based on: (1) orbital motions, (2) external angular momenta, (3) internal angular momenta, (4) physical characteristics, and (5) the stability of their equilibrium states. Several analytical solutions for the attitude motions of satellite models were compiled, checked, corrected in some minor respects and their short-term prediction capabilities were investigated. Single-rigid-body, dual-spin and multi-rotor configurations are treated. To verify the analytical models and to see how the true motion of a satellite which is acted upon by environmental torques differs from its corresponding torque-free motion, a numerical simulation code was developed. This code contains a relatively general satellite model and models for gravity-gradient and aerodynamic torques. The spacecraft physical model for the code and the equations of motion are given. The two environmental torque models are described.

  16. A New Motion Capture System For Automated Gait Analysis Based On Multi Video Sequence Analysis

    DEFF Research Database (Denmark)

    Jensen, Karsten; Juhl, Jens

    There is an increasing demand for assessing foot mal positions and an interest in monitoring the effect of treatment. In the last decades several different motion capture systems has been used. This abstract describes a new low cost motion capture system.......There is an increasing demand for assessing foot mal positions and an interest in monitoring the effect of treatment. In the last decades several different motion capture systems has been used. This abstract describes a new low cost motion capture system....

  17. Finger motion capture from wrist-electrode contact resistance.

    Science.gov (United States)

    Yoshimoto, Shunsuke; Kawaguchi, Junki; Imura, Masataka; Oshiro, Osamu

    2015-01-01

    Hand motion capture is an important yet challenging topic for biomechanics and human computer interaction. We proposed a novel electrical sensing technology for capturing the finger angles from the variation of the wrist shape. The proposed device detects the signal related to the wrist-electrode contact resistances, which change according to the variation of the wrist shape accompanying finger movements. The developed sensing device consists of a wrist band, sixteen electrodes and a sensing circuit of contact resistances. We investigated the relationships between the finger angles and the system outputs by using a glove-type joint angle sensor. As a result, we confirmed high correlations of the system outputs with the finger angles for several electrodes. Therefore, we conclude that the proposed system can be used for the estimation of the finger joint angles.

  18. Basis for motion capture in terms of illusory motion signal obtained from oblique lines.

    Science.gov (United States)

    Ichikawa, Makoto; Masakura, Yuko

    2014-01-01

    As in the Pinna illusion, when an observer moves their head backwards and forwards while fixating on the center of concentric circles that consist of oblique lines, the observer sees illusory rotation of those circles. When several dots are superimposed on the concentric circles, an observer sees the illusory rotation not only for the circles, but also for those dots (Ichikawa, Masakura, & Munechika, 2006, Perception, 35, 933-946). This illusory rotation of the dots, which have no means of generating illusory motion themselves, is based on motion capture. We examined how the number of dots affects the illusory rotation for such circles and superimposed dots. Results showed that the illusory rotation for the inner circle was most salient when the superimposed dots were extremely numerous or few, although the illusory motion for the dots increased with the increment of the dots. These results suggest that motion capture depends upon a locally obtained motion signal from the oblique lines, and upon the accumulation of the motion signal within the groups of superimposed dots.

  19. Visual Confirmation (VICON) of Takeoff Clearance Signal System Impact Study.

    Science.gov (United States)

    1980-11-01

    Throughput, THOG THI IEAYTtAI 1SICAI Simulation, Sampling Techniques wMPORMAION 5SsIlVIC. SPAMO.euLD. P9. Ammoty C,hLuMO..EA..s-W . "awfoc .1aeis.ea W"" FE2...solution to airport surface traffic problems . VICON consists of a cluster of three green lights located on the left side of the runway at each...overall solution to airport surface traffic problems . VICON consists of a cluster of three green lights located on the left side of the runway at each

  20. Validation of the Leap Motion Controller using markered motion capture technology.

    Science.gov (United States)

    Smeragliuolo, Anna H; Hill, N Jeremy; Disla, Luis; Putrino, David

    2016-06-14

    The Leap Motion Controller (LMC) is a low-cost, markerless motion capture device that tracks hand, wrist and forearm position. Integration of this technology into healthcare applications has begun to occur rapidly, making validation of the LMC׳s data output an important research goal. Here, we perform a detailed evaluation of the kinematic data output from the LMC, and validate this output against gold-standard, markered motion capture technology. We instructed subjects to perform three clinically-relevant wrist (flexion/extension, radial/ulnar deviation) and forearm (pronation/supination) movements. The movements were simultaneously tracked using both the LMC and a marker-based motion capture system from Motion Analysis Corporation (MAC). Adjusting for known inconsistencies in the LMC sampling frequency, we compared simultaneously acquired LMC and MAC data by performing Pearson׳s correlation (r) and root mean square error (RMSE). Wrist flexion/extension and radial/ulnar deviation showed good overall agreement (r=0.95; RMSE=11.6°, and r=0.92; RMSE=12.4°, respectively) with the MAC system. However, when tracking forearm pronation/supination, there were serious inconsistencies in reported joint angles (r=0.79; RMSE=38.4°). Hand posture significantly influenced the quality of wrist deviation (P<0.005) and forearm supination/pronation (P<0.001), but not wrist flexion/extension (P=0.29). We conclude that the LMC is capable of providing data that are clinically meaningful for wrist flexion/extension, and perhaps wrist deviation. It cannot yet return clinically meaningful data for measuring forearm pronation/supination. Future studies should continue to validate the LMC as updated versions of their software are developed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Exploiting Motion Capture to Enhance Avoidance Behaviour in Games

    Science.gov (United States)

    van Basten, Ben J. H.; Jansen, Sander E. M.; Karamouzas, Ioannis

    Realistic simulation of interacting virtual characters is essential in computer games, training and simulation applications. The problem is very challenging since people are accustomed to real-world situations and thus, they can easily detect inconsistencies and artifacts in the simulations. Over the past twenty years several models have been proposed for simulating individuals, groups and crowds of characters. However, little effort has been made to actually understand how humans solve interactions and avoid inter-collisions in real-life. In this paper, we exploit motion capture data to gain more insights into human-human interactions. We propose four measures to describe the collision-avoidance behavior. Based on these measures, we extract simple rules that can be applied on top of existing agent and force based approaches, increasing the realism of the resulting simulations.

  2. Octopus: A Design Methodology for Motion Capture Wearables

    Science.gov (United States)

    2017-01-01

    Human motion capture (MoCap) is widely recognised for its usefulness and application in different fields, such as health, sports, and leisure; therefore, its inclusion in current wearables (MoCap-wearables) is increasing, and it may be very useful in a context of intelligent objects interconnected with each other and to the cloud in the Internet of Things (IoT). However, capturing human movement adequately requires addressing difficult-to-satisfy requirements, which means that the applications that are possible with this technology are held back by a series of accessibility barriers, some technological and some regarding usability. To overcome these barriers and generate products with greater wearability that are more efficient and accessible, factors are compiled through a review of publications and market research. The result of this analysis is a design methodology called Octopus, which ranks these factors and schematises them. Octopus provides a tool that can help define design requirements for multidisciplinary teams, generating a common framework and offering a new method of communication between them. PMID:28809786

  3. Octopus: A Design Methodology for Motion Capture Wearables.

    Science.gov (United States)

    Marin, Javier; Blanco, Teresa; Marin, Jose J

    2017-08-15

    Human motion capture (MoCap) is widely recognised for its usefulness and application in different fields, such as health, sports, and leisure; therefore, its inclusion in current wearables (MoCap-wearables) is increasing, and it may be very useful in a context of intelligent objects interconnected with each other and to the cloud in the Internet of Things (IoT). However, capturing human movement adequately requires addressing difficult-to-satisfy requirements, which means that the applications that are possible with this technology are held back by a series of accessibility barriers, some technological and some regarding usability. To overcome these barriers and generate products with greater wearability that are more efficient and accessible, factors are compiled through a review of publications and market research. The result of this analysis is a design methodology called Octopus, which ranks these factors and schematises them. Octopus provides a tool that can help define design requirements for multidisciplinary teams, generating a common framework and offering a new method of communication between them.

  4. Integration of a Motion Capture System into a Spacecraft Simulator for Real-Time Attitude Control

    Science.gov (United States)

    2016-08-16

    DISTRIBUTION A. Approved for public release: distribution unlimited. Integration of a Motion Capture System into a Spacecraft Simulator for Real-Time...integrated with a Phase- Space Impulse X2 motion capture system. This system calculates the testbed’s inertial attitude, which can be used to simulate various...generate measurements via another source. To that end, a PhaseSpace Impulse X2 motion capture system has been integrated with the ACSPG and a wireless

  5. The Role of Motion Extrapolation in Amphibian Prey Capture.

    Science.gov (United States)

    Borghuis, Bart G; Leonardo, Anthony

    2015-11-18

    Sensorimotor delays decouple behaviors from the events that drive them. The brain compensates for these delays with predictive mechanisms, but the efficacy and timescale over which these mechanisms operate remain poorly understood. Here, we assess how prediction is used to compensate for prey movement that occurs during visuomotor processing. We obtained high-speed video records of freely moving, tongue-projecting salamanders catching walking prey, emulating natural foraging conditions. We found that tongue projections were preceded by a rapid head turn lasting ∼ 130 ms. This motor lag, combined with the ∼ 100 ms phototransduction delay at photopic light levels, gave a ∼ 230 ms visuomotor response delay during which prey typically moved approximately one body length. Tongue projections, however, did not significantly lag prey position but were highly accurate instead. Angular errors in tongue projection accuracy were consistent with a linear extrapolation model that predicted prey position at the time of tongue contact using the average prey motion during a ∼ 175 ms period one visual latency before the head movement. The model explained successful strikes where the tongue hit the fly, and unsuccessful strikes where the fly turned and the tongue hit a phantom location consistent with the fly's earlier trajectory. The model parameters, obtained from the data, agree with the temporal integration and latency of retinal responses proposed to contribute to motion extrapolation. These results show that the salamander predicts future prey position and that prediction significantly improves prey capture success over a broad range of prey speeds and light levels. Neural processing delays cause actions to lag behind the events that elicit them. To cope with these delays, the brain predicts what will happen in the future. While neural circuits in the retina and beyond have been suggested to participate in such predictions, few behaviors have been explored sufficiently

  6. Click-on-and-play human motion capture using wearable sensors

    NARCIS (Netherlands)

    Weenk, D.

    2015-01-01

    Human motion capture is often used in rehabilitation clinics for diagnostics and monitoring the effects of treatment. Traditionally, camera based systems are used. However, with these systems the measurements are restricted to a lab with expensive cameras. Motion capture outside a lab, using

  7. Markerless motion capture systems for tracking of persons in forensic biomechanics

    DEFF Research Database (Denmark)

    Yang, Sylvia; Christiansen, Martin S.; Larsen, Peter Kastmand

    2014-01-01

    Markerless motion capture is a pronounced topic in computer vision. In forensic science, markerless motion capture can be an important tool for identification through gait analysis. Recent studies of gait analysis in forensic science have shown that individuals can be identified when analysing th...

  8. Development of Human Motion Capture System Based on Inertial Sensors 2125

    Directory of Open Access Journals (Sweden)

    Guangtian Shi

    2014-06-01

    Full Text Available Motion capture systems play an important role in health-care, sport-training systems and cartoon animation. This paper develops a motion capture system with inertial motion trackers for three-dimensional animation production. The system mainly involves inertia sensing technology, Bluetooth, sensor network and software development of human body motion capture model. The sensor network is used to collect motion data of the body key joints, and the data are delivered to workstation through Bluetooth, then the software on workstation uses analytical inverse kinematics algorithm to analyze the motion data. Human body motion capture system mainly involves the design of human body model and development of real-time reconstruction software. A human body is abstracted into 17 key joints affecting human movement for model, and inertial sensors are put on each joint point to measure the motion data of the node, so a 17 nodes sensor network is built. The experiment shows that the model tends to handle uncertainty well and the software and hardware of motion capture system have advantages of good consistency of virtual character and performer athletic stance and farther effective communication distance, and it is very easy to further expand the research of this subject, such as the design of multiplayer real-time motion capture system.

  9. A Survey of Advances in Vision-Based Human Motion Capture and Analysis

    DEFF Research Database (Denmark)

    Moeslund, Thomas B.; Hilton, Adrian; Krüger, Volker

    2006-01-01

    This survey reviews advances in human motion capture and analysis from 2000 to 2006, following a previous survey of papers up to 2000 Human motion capture continues to be an increasingly active research area in computer vision with over 350 publications over this period. A number of significant...... actions and behavior. This survey reviews recent trends in video based human capture and analysis, as well as discussing open problems for future research to achieve automatic visual analysis of human movement....

  10. Projectile Motion on an Inclined Misty Surface: I. Capturing and Analysing the Trajectory

    Science.gov (United States)

    Ho, S. Y.; Foong, S. K.; Lim, C. H.; Lim, C. C.; Lin, K.; Kuppan, L.

    2009-01-01

    Projectile motion is usually the first non-uniform two-dimensional motion that students will encounter in a pre-university physics course. In this article, we introduce a novel technique for capturing the trajectory of projectile motion on an inclined Perspex plane. This is achieved by coating the Perspex with a thin layer of fine water droplets…

  11. Performance of Dual Depth Camera Motion Capture System for Athletes’ Biomechanics Analysis

    Directory of Open Access Journals (Sweden)

    An Wee Chang

    2017-01-01

    Full Text Available Motion capture system has recently being brought to light and drawn much attention in many fields of research, especially in biomechanics. Marker-based motion capture systems have been used as the main tool in capturing motion for years. Marker-based motion capture systems are very pricey, lab-based and beyond reach of many researchers, hence it cannot be applied to ubiquitous applications. The game however has changed with the introduction of depth camera technology, a markerless yet affordable motion capture system. By means of this system, motion capture has been promoted as more portable application and does not require substantial time in setting up the system. Limitation in terms of nodal coverage of single depth camera has widely accepted but the performance of dual depth camera system is still doubtful since it is expected to improve the coverage issue but at the same time has bigger issues on data merging and accuracy. This work appraises the accuracy performance of dual depth camera motion capture system specifically for athletes’ running biomechanics analysis. Kinect sensors were selected to capture motions of an athlete simultaneously in three-dimension, and fused the recorded data into an analysable data. Running was chosen as the biomechanics motion and interpreted in the form of angle-time, angleangle and continuous relative phase plot. The linear and angular kinematics were analysed and represented graphically. Quantitative interpretations of the result allowed the deep insight of the movement and joint coordination of the athlete. The result showed that the root-mean-square error of the Kinect sensor measurement to exact measurement data and rigid transformation were 0.0045 and 0.0077291 respectively. The velocity and acceleration of the subject were determined to be 3.3479 ms-1 and –4.1444 ms-2. The result showed that the dual Kinect camera motion capture system was feasible to perform athletes' biomechanics analysis.

  12. Real-Time Human Motion Capture Driven by a Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Peng-zhan Chen

    2015-01-01

    Full Text Available The motion of a real object model is reconstructed through measurements of the position, direction, and angle of moving objects in 3D space in a process called “motion capture.” With the development of inertial sensing technology, motion capture systems that are based on inertial sensing have become a research hot spot. However, the solution of motion attitude remains a challenge that restricts the rapid development of motion capture systems. In this study, a human motion capture system based on inertial sensors is developed, and the real-time movement of a human model controlled by real people’s movement is achieved. According to the features of the system of human motion capture and reappearance, a hierarchical modeling approach based on a 3D human body model is proposed. The method collects articular movement data on the basis of rigid body dynamics through a miniature sensor network, controls the human skeleton model, and reproduces human posture according to the features of human articular movement. Finally, the feasibility of the system is validated by testing of system properties via capture of continuous dynamic movement. Experiment results show that the scheme utilizes a real-time sensor network-driven human skeleton model to achieve the accurate reproduction of human motion state. The system also has good application value.

  13. Filling gaps in visual motion for target capture.

    Science.gov (United States)

    Bosco, Gianfranco; Monache, Sergio Delle; Gravano, Silvio; Indovina, Iole; La Scaleia, Barbara; Maffei, Vincenzo; Zago, Myrka; Lacquaniti, Francesco

    2015-01-01

    A remarkable challenge our brain must face constantly when interacting with the environment is represented by ambiguous and, at times, even missing sensory information. This is particularly compelling for visual information, being the main sensory system we rely upon to gather cues about the external world. It is not uncommon, for example, that objects catching our attention may disappear temporarily from view, occluded by visual obstacles in the foreground. Nevertheless, we are often able to keep our gaze on them throughout the occlusion or even catch them on the fly in the face of the transient lack of visual motion information. This implies that the brain can fill the gaps of missing sensory information by extrapolating the object motion through the occlusion. In recent years, much experimental evidence has been accumulated that both perceptual and motor processes exploit visual motion extrapolation mechanisms. Moreover, neurophysiological and neuroimaging studies have identified brain regions potentially involved in the predictive representation of the occluded target motion. Within this framework, ocular pursuit and manual interceptive behavior have proven to be useful experimental models for investigating visual extrapolation mechanisms. Studies in these fields have pointed out that visual motion extrapolation processes depend on manifold information related to short-term memory representations of the target motion before the occlusion, as well as to longer term representations derived from previous experience with the environment. We will review recent oculomotor and manual interception literature to provide up-to-date views on the neurophysiological underpinnings of visual motion extrapolation.

  14. Filling gaps in visual motion for target capture

    Directory of Open Access Journals (Sweden)

    Gianfranco eBosco

    2015-02-01

    Full Text Available A remarkable challenge our brain must face constantly when interacting with the environment is represented by ambiguous and, at times, even missing sensory information. This is particularly compelling for visual information, being the main sensory system we rely upon to gather cues about the external world. It is not uncommon, for example, that objects catching our attention may disappear temporarily from view, occluded by visual obstacles in the foreground. Nevertheless, we are often able to keep our gaze on them throughout the occlusion or even catch them on the fly in the face of the transient lack of visual motion information. This implies that the brain can fill the gaps of missing sensory information by extrapolating the object motion through the occlusion. In recent years, much experimental evidence has been accumulated that both perceptual and motor processes exploit visual motion extrapolation mechanisms. Moreover, neurophysiological and neuroimaging studies have identified brain regions potentially involved in the predictive representation of the occluded target motion. Within this framework, ocular pursuit and manual interceptive behavior have proven to be useful experimental models for investigating visual extrapolation mechanisms. Studies in these fields have pointed out that visual motion extrapolation processes depend on manifold information related to short-term memory representations of the target motion before the occlusion, as well as to longer term representations derived from previous experience with the environment. We will review recent oculomotor and manual interception literature to provide up-to-date views on the neurophysiological underpinnings of visual motion extrapolation.

  15. Low-cost human motion capture system for postural analysis onboard ships

    Science.gov (United States)

    Nocerino, Erica; Ackermann, Sebastiano; Del Pizzo, Silvio; Menna, Fabio; Troisi, Salvatore

    2011-07-01

    The study of human equilibrium, also known as postural stability, concerns different research sectors (medicine, kinesiology, biomechanics, robotics, sport) and is usually performed employing motion analysis techniques for recording human movements and posture. A wide range of techniques and methodologies has been developed, but the choice of instrumentations and sensors depends on the requirement of the specific application. Postural stability is a topic of great interest for the maritime community, since ship motions can make demanding and difficult the maintenance of the upright stance with hazardous consequences for the safety of people onboard. The need of capturing the motion of an individual standing on a ship during its daily service does not permit to employ optical systems commonly used for human motion analysis. These sensors are not designed for operating in disadvantageous environmental conditions (water, wetness, saltiness) and with not optimal lighting. The solution proposed in this study consists in a motion acquisition system that could be easily usable onboard ships. It makes use of two different methodologies: (I) motion capture with videogrammetry and (II) motion measurement with Inertial Measurement Unit (IMU). The developed image-based motion capture system, made up of three low-cost, light and compact video cameras, was validated against a commercial optical system and then used for testing the reliability of the inertial sensors. In this paper, the whole process of planning, designing, calibrating, and assessing the accuracy of the motion capture system is reported and discussed. Results from the laboratory tests and preliminary campaigns in the field are presented.

  16. Accuracy of Base of Support Using an Inertial Sensor Based Motion Capture System

    National Research Council Canada - National Science Library

    Liangjie Guo; Shuping Xiong

    2017-01-01

    .... This study aims to evaluate the accuracy of Xsens MVN BIOMECH, a commercial widely used inertial sensor-based motion capture system, for measuring static BOS and examine the effect of different task...

  17. Capture of attention by new motion in young and older adults.

    Science.gov (United States)

    Christ, Shawn E; Castel, Alan D; Abrams, Richard A

    2008-03-01

    Recent research has shown that newly introduced motion in a scene captures attention in young adults. Prior research has been mixed in terms of possible age-related differences in the allocation of visual attention, and it remains unclear whether new motion has a similar influence on visual attention in older adults. In the present study, we directly compared the capture of attention by new motion in young and older adults. The results suggest that new motion has a similar influence on visual attention in older adults as compared with young adults and that the mechanisms underlying attentional capture by motion are preserved with adult aging. We discuss the findings within the context of our present understanding of visual attention and aging.

  18. Using motion capture to assess colonoscopy experience level

    DEFF Research Database (Denmark)

    Svendsen, Morten Bo Søndergaard; Preisler, Louise; Hillingsø, Jens Georg

    2014-01-01

    AIM: To study technical skills of colonoscopists using a Microsoft Kinect™ for motion analysis to develop a tool to guide colonoscopy education. RESULTS: Ten experienced endoscopists (gastroenterologists, n = 2; colorectal surgeons, n = 8) and 11 novices participated in the study. A Microsoft......, specifically the “Kagaku Colonoscope Training Model” (Kyoto Kagaku Co. Ltd, Kyoto, Japan). After the introduction to the scope and colonoscopy model, the test was performed. Seven metrics were analyzed to find discriminative motion patterns between the novice and experienced endoscopists: hand distance from...

  19. The role of flicker and abrupt displacement in attention capture by motion onsets.

    Science.gov (United States)

    Sunny, Meera Mary; von Mühlenen, Adrian

    2014-02-01

    Sunny and von Mühlenen (Psychonomic Bulletin & Review, 18, 1050-1056, 2011) showed that an onset of motion captured attention only when the motion was jerky (refreshed at 8 or 17 Hz), but not when it was smooth (33 or 100 Hz). However, it remained unclear why the onset of jerky motion captures attention. In the present study, we systematically tested the role of different aspects of jerky motion in capturing attention. Simple flicker without motion did not capture attention in the same way as jerky motion (Exp. 1). An abrupt displacement between 0.26° and 1.05° captured attention, irrespective of whether the stimulus subsequently continued to move smoothly (Exp. 2) or whether it remained stationary (Exps. 3 and 4). A displaced stimulus that was preceded briefly at the new location by a figure-8 placeholder did not capture attention (Exp. 5). These results are explained within a masking account, according to which abrupt onsets and abrupt displacements receive a processing advantage because they escape forward masking by the preceding figure-8 placeholders.

  20. A common framework for the analysis of complex motion? Standstill and capture illusions.

    Science.gov (United States)

    Dürsteler, Max R

    2014-01-01

    A series of illusions was created by presenting stimuli, which consisted of two overlapping surfaces each defined by textures of independent visual features (i.e., modulation of luminance, color, depth, etc.). When presented concurrently with a stationary 2-D luminance texture, observers often fail to perceive the motion of an overlapping stereoscopically defined depth-texture. This illusory motion standstill arises due to a failure to represent two independent surfaces (one for luminance and one for depth textures) and motion transparency (the ability to perceive motion of both surfaces simultaneously). Instead the stimulus is represented as a single non-transparent surface taking on the stationary nature of the luminance-defined texture. By contrast, if it is the 2D-luminance defined texture that is in motion, observers often perceive the stationary depth texture as also moving. In this latter case, the failure to represent the motion transparency of the two textures gives rise to illusionary motion capture. Our past work demonstrated that the illusions of motion standstill and motion capture can occur for depth-textures that are rotating, or expanding / contracting, or else spiraling. Here I extend these findings to include stereo-shearing. More importantly, it is the motion (or lack thereof) of the luminance texture that determines how the motion of the depth will be perceived. This observation is strongly in favor of a single pathway for complex motion that operates on luminance-defines texture motion signals only. In addition, these complex motion illusions arise with chromatically-defined textures with smooth transitions between their colors. This suggests that in respect to color motion perception the complex motions' pathway is only able to accurately process signals from isoluminant colored textures with sharp transitions between colors, and/or moving at high speeds, which is conceivable if it relies on inputs from a hypothetical dual opponent color

  1. A Common Framework for the Analysis of Complex Motion? Standstill and Capture Illusions

    Directory of Open Access Journals (Sweden)

    Max Reinhard Dürsteler

    2014-12-01

    Full Text Available A series of illusions was created by presenting stimuli, which consisted of two overlapping surfaces each defined by textures of independent visual features (i.e. modulation of luminance, color, depth, etc.. When presented concurrently with a stationary 2-D luminance texture, observers often fail to perceive the motion of an overlapping stereoscopically defined depth-texture. This illusory motion standstill arises due to a failure to represent two independent surfaces (one for luminance and one for depth textures and motion transparency (the ability to perceive motion of both surfaces simultaneously. Instead the stimulus is represented as a single non-transparent surface taking on the stationary nature of the luminance-defined texture. By contrast, if it is the 2D-luminance defined texture that is in motion, observers often perceive the stationary depth texture as also moving. In this latter case, the failure to represent the motion transparency of the two textures gives rise to illusionary motion capture. Our past work demonstrated that the illusions of motion standstill and motion capture can occur for depth-textures that are rotating, or expanding / contracting, or else spiraling. Here I extend these findings to include stereo-shearing. More importantly, it is the motion (or lack thereof of the luminance texture that determines how the motion of the depth will be perceived. This observation is strongly in favor of a single pathway for complex motion that operates on luminance-defines texture motion signals only. In addition, these complex motion illusions arise with chromatically-defined textures with smooth, transitions between their colors. This suggests that in respect to color motion perception the complex motions’ pathway is only able to accurately process signals from isoluminant colored textures with sharp transitions between colors, and/or moving at high speeds, which is conceivable if it relies on inputs from a hypothetical dual

  2. Adding Image Constraints to Inverse Kinematics for Human Motion Capture

    Science.gov (United States)

    Jaume-i-Capó, Antoni; Varona, Javier; González-Hidalgo, Manuel; Perales, Francisco J.

    2009-12-01

    In order to study human motion in biomechanical applications, a critical component is to accurately obtain the 3D joint positions of the user's body. Computer vision and inverse kinematics are used to achieve this objective without markers or special devices attached to the body. The problem of these systems is that the inverse kinematics is "blinded" with respect to the projection of body segments into the images used by the computer vision algorithms. In this paper, we present how to add image constraints to inverse kinematics in order to estimate human motion. Specifically, we explain how to define a criterion to use images in order to guide the posture reconstruction of the articulated chain. Tests with synthetic images show how the scheme performs well in an ideal situation. In order to test its potential in real situations, more experiments with task specific image sequences are also presented. By means of a quantitative study of different sequences, the results obtained show how this approach improves the performance of inverse kinematics in this application.

  3. Flexible CNT-array double helices Strain Sensor with high stretchability for Motion Capture.

    Science.gov (United States)

    Li, Cheng; Cui, Ya-Long; Tian, Gui-Li; Shu, Yi; Wang, Xue-Feng; Tian, He; Yang, Yi; Wei, Fei; Ren, Tian-Ling

    2015-11-04

    Motion capture is attracting more and more attention due to its potential wide applications in various fields. However, traditional methods for motion capture still have weakness such as high cost and space consuming. Based on these considerations, a flexible, highly stretchable strain sensor with high gauge factor for motion capture is fabricated with carbon nanotube (CNT) array double helices as the main building block. Ascribed to the unique flexible double helical CNT-array matrix, the strain sensor is able to measure strain up to 410%, with low hysteresis. Moreover, a demonstration of using this strain sensor for capture hand motion and to control a mechanical hand in real time is also achieved. A model based on finite difference method is also made to help understand the mechanism of the strain sensors. Our work demonstrates that strain sensors can measure very large strain while maintaining high sensitivity, and the motion capture based on this strain sensor is expected to be less expensive, more convenient and accessible.

  4. Samba: a real-time motion capture system using wireless camera sensor networks.

    Science.gov (United States)

    Oh, Hyeongseok; Cha, Geonho; Oh, Songhwai

    2014-03-20

    There is a growing interest in 3D content following the recent developments in 3D movies, 3D TVs and 3D smartphones. However, 3D content creation is still dominated by professionals, due to the high cost of 3D motion capture instruments. The availability of a low-cost motion capture system will promote 3D content generation by general users and accelerate the growth of the 3D market. In this paper, we describe the design and implementation of a real-time motion capture system based on a portable low-cost wireless camera sensor network. The proposed system performs motion capture based on the data-driven 3D human pose reconstruction method to reduce the computation time and to improve the 3D reconstruction accuracy. The system can reconstruct accurate 3D full-body poses at 16 frames per second using only eight markers on the subject's body. The performance of the motion capture system is evaluated extensively in experiments.

  5. Attentional capture by the onset and offset of motion signals outside the spatial focus of attention.

    Science.gov (United States)

    Kawahara, Jun; Yanase, Kaori; Kitazaki, Michiteru

    2012-11-16

    The present study examined whether participants were able to ignore a task-irrelevant commencement or cessation of optic flow while they were engaging in a letter-identification task, as claimed by adherents of the view that attentional set determines deployment of attention, or whether irrelevant events would capture attention regardless of observers' attentional set, as claimed by adherents of a broad range of views emphasizing the behavioral urgency of stimulus motion. Observers identified a green letter in a central rapid stream of heterogeneously colored nontargets. A completely task-irrelevant optic flow occurred in the periphery. If attentional deployment were governed by a top-down attentional set, the letter identification would be unaffected by the temporal change in the optic flow. The results reflected attentional capture by commencement or cessation of optic flow, which is inconsistent with the top-down view. When the peripheral dots expanded at various speeds before onset of the target, identification was impaired relative to when no motion occurred. Mere commencement or cessation of motion was sufficient to produce the capture effect. Qualitative (commencement or cessation) rather than quantitative changes (acceleration or deceleration) of the motion display were critical for the occurrence of attentional capture. We conclude that salient discontinuities in optic flow induce attentional capture when observers search for a feature in a different stimulus domain, an idea implying a unique role for of expanding global motion in the deployment of visual attention.

  6. Samba: A Real-Time Motion Capture System Using Wireless Camera Sensor Networks

    Directory of Open Access Journals (Sweden)

    Hyeongseok Oh

    2014-03-01

    Full Text Available There is a growing interest in 3D content following the recent developments in 3D movies, 3D TVs and 3D smartphones. However, 3D content creation is still dominated by professionals, due to the high cost of 3D motion capture instruments. The availability of a low-cost motion capture system will promote 3D content generation by general users and accelerate the growth of the 3D market. In this paper, we describe the design and implementation of a real-time motion capture system based on a portable low-cost wireless camera sensor network. The proposed system performs motion capture based on the data-driven 3D human pose reconstruction method to reduce the computation time and to improve the 3D reconstruction accuracy. The system can reconstruct accurate 3D full-body poses at 16 frames per second using only eight markers on the subject’s body. The performance of the motion capture system is evaluated extensively in experiments.

  7. SCALABLE PHOTOGRAMMETRIC MOTION CAPTURE SYSTEM “MOSCA”: DEVELOPMENT AND APPLICATION

    Directory of Open Access Journals (Sweden)

    V. A. Knyaz

    2015-05-01

    Full Text Available Wide variety of applications (from industrial to entertainment has a need for reliable and accurate 3D information about motion of an object and its parts. Very often the process of movement is rather fast as in cases of vehicle movement, sport biomechanics, animation of cartoon characters. Motion capture systems based on different physical principles are used for these purposes. The great potential for obtaining high accuracy and high degree of automation has vision-based system due to progress in image processing and analysis. Scalable inexpensive motion capture system is developed as a convenient and flexible tool for solving various tasks requiring 3D motion analysis. It is based on photogrammetric techniques of 3D measurements and provides high speed image acquisition, high accuracy of 3D measurements and highly automated processing of captured data. Depending on the application the system can be easily modified for different working areas from 100 mm to 10 m. The developed motion capture system uses from 2 to 4 technical vision cameras for video sequences of object motion acquisition. All cameras work in synchronization mode at frame rate up to 100 frames per second under the control of personal computer providing the possibility for accurate calculation of 3D coordinates of interest points. The system was used for a set of different applications fields and demonstrated high accuracy and high level of automation.

  8. FlyCap: Markerless Motion Capture Using Multiple Autonomous Flying Cameras.

    Science.gov (United States)

    Xu, Lan; Liu, Yebin; Cheng, Wei; Guo, Kaiwen; Zhou, Guyue; Dai, Qionghai; Fang, Lu

    2017-07-18

    Aiming at automatic, convenient and non-instrusive motion capture, this paper presents a new generation markerless motion capture technique, the FlyCap system, to capture surface motions of moving characters using multiple autonomous flying cameras (autonomous unmanned aerial vehicles(UAVs) each integrated with an RGBD video camera). During data capture, three cooperative flying cameras automatically track and follow the moving target who performs large-scale motions in a wide space. We propose a novel non-rigid surface registration method to track and fuse the depth of the three flying cameras for surface motion tracking of the moving target, and simultaneously calculate the pose of each flying camera. We leverage the using of visual-odometry information provided by the UAV platform, and formulate the surface tracking problem in a non-linear objective function that can be linearized and effectively minimized through a Gaussian-Newton method. Quantitative and qualitative experimental results demonstrate the plausible surface and motion reconstruction results.

  9. Capturing Revolute Motion and Revolute Joint Parameters with Optical Tracking

    Science.gov (United States)

    Antonya, C.

    2017-12-01

    Optical tracking of users and various technical systems are becoming more and more popular. It consists of analysing sequence of recorded images using video capturing devices and image processing algorithms. The returned data contains mainly point-clouds, coordinates of markers or coordinates of point of interest. These data can be used for retrieving information related to the geometry of the objects, but also to extract parameters for the analytical model of the system useful in a variety of computer aided engineering simulations. The parameter identification of joints deals with extraction of physical parameters (mainly geometric parameters) for the purpose of constructing accurate kinematic and dynamic models. The input data are the time-series of the marker’s position. The least square method was used for fitting the data into different geometrical shapes (ellipse, circle, plane) and for obtaining the position and orientation of revolute joins.

  10. Kinematic differences between optical motion capture and biplanar videoradiography during a jump-cut maneuver.

    Science.gov (United States)

    Miranda, Daniel L; Rainbow, Michael J; Crisco, Joseph J; Fleming, Braden C

    2013-02-01

    Jumping and cutting activities are investigated in many laboratories attempting to better understand the biomechanics associated with non-contact ACL injury. Optical motion capture is widely used; however, it is subject to soft tissue artifact (STA). Biplanar videoradiography offers a unique approach to collecting skeletal motion without STA. The goal of this study was to compare how STA affects the six-degrees-of-freedom motion of the femur and tibia during a jump-cut maneuver associated with non-contact ACL injury. Ten volunteers performed a jump-cut maneuver while their landing leg was imaged using optical motion capture (OMC) and biplanar videoradiography. The within-bone motion differences were compared using anatomical coordinate systems for the femur and tibia, respectively. The knee joint kinematic measurements were compared during two periods: before and after ground contact. Over the entire activity, the within-bone motion differences between the two motion capture techniques were significantly lower for the tibia than the femur for two of the rotational axes (flexion/extension, internal/external) and the origin. The OMC and biplanar videoradiography knee joint kinematics were in best agreement before landing. Kinematic deviations between the two techniques increased significantly after contact. This study provides information on the kinematic discrepancies between OMC and biplanar videoradiography that can be used to optimize methods employing both technologies for studying dynamic in vivo knee kinematics and kinetics during a jump-cut maneuver. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Generic Content-Based Retrieval of Marker-Based Motion Capture Data.

    Science.gov (United States)

    Lv, Na; Jiang, Zifei; Huang, Yan; Meng, Xiangxu; M, Gopi; Peng, Jingliang

    2017-05-09

    In this work, we propose an original scheme for generic content-based retrieval of marker-based motion capture data. It works on motion capture data of arbitrary subject types and arbitrary marker attachment and labelling conventions. Specifically, we propose a novel motion signature to statistically describe both the high-level and the low-level morphological and kinematic characteristics of a motion capture sequence, and conduct the content-based retrieval by computing and ordering the motion signature distance between the query and every item in the database. The distance between two motion signatures is computed by a weighted sum of differences in separate features contained in them. For maximum retrieval performance, we propose a method to pre-learn an optimal set of weights for each type of motion in the database through biased discriminant analysis, and adaptively choose a good set of weights for any given query at the run time. Excellence of the proposed scheme is experimentally demonstrated on various data sets and performance metrics.

  12. Motion dazzle and the effects of target patterning on capture success.

    Science.gov (United States)

    Hughes, Anna E; Troscianko, Jolyon; Stevens, Martin

    2014-09-13

    Stripes and other high contrast patterns found on animals have been hypothesised to cause "motion dazzle", a type of defensive coloration that operates when in motion, causing predators to misjudge the speed and direction of object movement. Several recent studies have found some support for this idea, but little is currently understood about the mechanisms underlying this effect. Using humans as model 'predators' in a touch screen experiment we investigated further the effectiveness of striped targets in preventing capture, and considered how stripes compare to other types of patterning in order to understand what aspects of target patterning are important in making a target difficult to capture. We find that striped targets are among the most difficult to capture, but that other patterning types are also highly effective at preventing capture in this task. Several target types, including background sampled targets and targets with a 'spot' on were significantly easier to capture than striped targets. We also show differences in capture attempt rates between different target types, but we find no differences in learning rates between target types. We conclude that striped targets are effective in preventing capture, but are not uniquely difficult to catch, with luminance matched grey targets also showing a similar capture rate. We show that key factors in making capture easier are a lack of average background luminance matching and having trackable 'features' on the target body. We also find that striped patterns are attempted relatively quickly, despite being difficult to catch. We discuss these findings in relation to the motion dazzle hypothesis and how capture rates may be affected more generally by pattern type.

  13. Mirror neuron activation of musicians and non-musicians in response to motion captured piano performances

    DEFF Research Database (Denmark)

    Hou, Jiancheng; Rajmohan, Ravi; Fang, Dan

    2017-01-01

    Mirror neurons (MNs) activate when performing an action and when an observer witnesses the same action performed by another individual. Functional magnetic resonance imaging (fMRI) and presentation of motion captured piano performances were used to identify differences in MN activation for musici......Mirror neurons (MNs) activate when performing an action and when an observer witnesses the same action performed by another individual. Functional magnetic resonance imaging (fMRI) and presentation of motion captured piano performances were used to identify differences in MN activation...

  14. Accuracy and repeatability of joint angles measured using a single camera markerless motion capture system.

    Science.gov (United States)

    Schmitz, Anne; Ye, Mao; Shapiro, Robert; Yang, Ruigang; Noehren, Brian

    2014-01-22

    Markerless motion capture systems have developed in an effort to evaluate human movement in a natural setting. However, the accuracy and reliability of these systems remain understudied. Therefore, the goals of this study were to quantify the accuracy and repeatability of joint angles using a single camera markerless motion capture system and to compare the markerless system performance with that of a marker-based system. A jig was placed in multiple static postures with marker trajectories collected using a ten camera motion analysis system. Depth and color image data were simultaneously collected from a single Microsoft Kinect camera, which was subsequently used to calculate virtual marker trajectories. A digital inclinometer provided a measure of ground-truth for sagittal and frontal plane joint angles. Joint angles were calculated with marker data from both motion capture systems using successive body-fixed rotations. The sagittal and frontal plane joint angles calculated from the marker-based and markerless system agreed with inclinometer measurements by motion capture system to accurately measure lower extremity kinematics and provide a first step in using this technology to discern clinically relevant differences in the joint kinematics of patient populations. © 2013 Published by Elsevier Ltd.

  15. [In vivo study on the body motion during the Shi's cervical reduction technique with 3D motion capture].

    Science.gov (United States)

    Wang, Hui-hao; Zhang, Min; Niu, Wen-xin; Shen, Xu-zhe; Zhan, Hong-sheng

    2015-10-01

    The clinical effect of the Shi's cervical reduction technique for cervical spondylosis and related disorders has confirmed, however, there were few studies on the body motion during manipulation in vivo study. This study is to summary the law of motion and the motion characteristics of the right operation shoulder, elbow, knee and ankle joints by data acquisition and analysis with the 3D motion capture system. The markers were pasted on the head, trunk, left and right acromion, elbow joint, wrist joint inner side and the outer side of the inner and the outer side and the lateral upper arm, forearm lateral, anterior superior iliac spine, posterior superior iliac spine, trochanter, femoral and tibial tubercle, inner and outer side of knee, ankle, fibular head, medial and lateral in first, 2,5 metatarsal head, heel and dual lateral thigh the calf, lateral tibia of one manipulation practioner, and the subject accepted a complete cycle of cervical "Jin Chu Cao and Gu Cuo Feng" manipulation which was repeated five times. The movement trajectory of the practioner's four markers of operation joints were captured, recorded, calculated and analyzed. The movement trajectories of four joints were consistent, while the elbow joint had the biggest discrete degree. The 3D activities of the shoulder and elbow were more obvious than other two joints, but the degree of flexion and extension in the knee was significantly greater than the rotation and lateral bending. The flexibility of upper limb joint and stability of lower limb joint are the important guarantees for the Shi's cervical reduction technique, and the right knee facilitated the exerting force of upper limb by the flexion and extension activities. The 3D model built by the motion capture system would provide a new idea for manipulation teaching and further basic biomechanical research.

  16. Multi-Sensor Methods for Mobile Radar Motion Capture and Compensation

    Science.gov (United States)

    Nakata, Robert

    Remote sensing has many applications, including surveying and mapping, geophysics exploration, military surveillance, search and rescue and counter-terrorism operations. Remote sensor systems typically use visible image, infrared or radar sensors. Camera based image sensors can provide high spatial resolution but are limited to line-of-sight capture during daylight. Infrared sensors have lower resolution but can operate during darkness. Radar sensors can provide high resolution motion measurements, even when obscured by weather, clouds and smoke and can penetrate walls and collapsed structures constructed with non-metallic materials up to 1 m to 2 m in depth depending on the wavelength and transmitter power level. However, any platform motion will degrade the target signal of interest. In this dissertation, we investigate alternative methodologies to capture platform motion, including a Body Area Network (BAN) that doesn't require external fixed location sensors, allowing full mobility of the user. We also investigated platform stabilization and motion compensation techniques to reduce and remove the signal distortion introduced by the platform motion. We evaluated secondary ultrasonic and radar sensors to stabilize the platform resulting in an average 5 dB of Signal to Interference Ratio (SIR) improvement. We also implemented a Digital Signal Processing (DSP) motion compensation algorithm that improved the SIR by 18 dB on average. These techniques could be deployed on a quadcopter platform and enable the detection of respiratory motion using an onboard radar sensor.

  17. Accuracy map of an optical motion capture system with 42 or 21 cameras in a large measurement volume.

    Science.gov (United States)

    Aurand, Alexander M; Dufour, Jonathan S; Marras, William S

    2017-06-14

    Optical motion capture is commonly used in biomechanics to measure human kinematics. However, no studies have yet examined the accuracy of optical motion capture in a large capture volume (>100m 3 ), or how accuracy varies from the center to the extreme edges of the capture volume. This study measured the dynamic 3D errors of an optical motion capture system composed of 42 OptiTrack Prime 41 cameras (capture volume of 135m 3 ) by comparing the motion of a single marker to the motion reported by a ThorLabs linear motion stage. After spline interpolating the data, it was found that 97% of the capture area had error below 200μm. When the same analysis was performed using only half (21) of the cameras, 91% of the capture area was below 200μm of error. The only locations that exceeded this threshold were at the extreme edges of the capture area, and no location had a mean error exceeding 1mm. When measuring human kinematics with skin-mounted markers, uncertainty of marker placement relative to underlying skeletal features and soft tissue artifact produce errors that are orders of magnitude larger than the errors attributed to the camera system itself. Therefore, the accuracy of this OptiTrack optical motion capture system was found to be more than sufficient for measuring full-body human kinematics with skin-mounted markers in a large capture volume (>100m 3 ). Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A Novel Method to Compute Breathing Volumes via Motion Capture Systems: Design and Experimental Trials.

    Science.gov (United States)

    Massaroni, Carlo; Cassetta, Eugenio; Silvestri, Sergio

    2017-10-01

    Respiratory assessment can be carried out by using motion capture systems. A geometrical model is mandatory in order to compute the breathing volume as a function of time from the markers' trajectories. This study describes a novel model to compute volume changes and calculate respiratory parameters by using a motion capture system. The novel method, ie, prism-based method, computes the volume enclosed within the chest by defining 82 prisms from the 89 markers attached to the subject chest. Volumes computed with this method are compared to spirometry volumes and to volumes computed by a conventional method based on the tetrahedron's decomposition of the chest wall and integrated in a commercial motion capture system. Eight healthy volunteers were enrolled and 30 seconds of quiet breathing data collected from each of them. Results show a better agreement between volumes computed by the prism-based method and the spirometry (discrepancy of 2.23%, R 2  = .94) compared to the agreement between volumes computed by the conventional method and the spirometry (discrepancy of 3.56%, R 2  = .92). The proposed method also showed better performances in the calculation of respiratory parameters. Our findings open up prospects for the further use of the new method in the breathing assessment via motion capture systems.

  19. Markerless motion capture can provide reliable 3D gait kinematics in the sagittal and frontal plane

    DEFF Research Database (Denmark)

    Sandau, Martin; Koblauch, Henrik; Moeslund, Thomas B.

    2014-01-01

    Estimating 3D joint rotations in the lower extremities accurately and reliably remains unresolved in markerless motion capture, despite extensive studies in the past decades. The main problems have been ascribed to the limited accuracy of the 3D reconstructions. Accordingly, the purpose of the pr...

  20. Auditory motion in depth is preferentially 'captured' by visual looming signals.

    Science.gov (United States)

    Harrison, Neil

    2012-01-01

    The phenomenon of crossmodal dynamic visual capture occurs when the direction of motion of a visual cue causes a weakening or reversal of the perceived direction of motion of a concurrently presented auditory stimulus. It is known that there is a perceptual bias towards looming compared to receding stimuli, and faster bimodal reaction times have recently been observed for looming cues compared to receding cues (Cappe et al., 2009). The current studies aimed to test whether visual looming cues are associated with greater dynamic capture of auditory motion in depth compared to receding signals. Participants judged the direction of an auditory motion cue presented with a visual looming cue (expanding disk), a visual receding cue (contracting disk), or visual stationary cue (static disk). Visual cues were presented either simultaneously with the auditory cue, or after 500 ms. We found increased levels of interference with looming visual cues compared to receding visual cues, compared to asynchronous presentation or stationary visual cues. The results could not be explained by the weaker subjective strength of the receding auditory stimulus, as in Experiment 2 the looming and receding auditory cues were matched for perceived strength. These results show that dynamic visual capture of auditory motion in the depth plane is modulated by an adaptive bias for looming compared to receding visual cues.

  1. Leveraging Two Kinect Sensors for Accurate Full-Body Motion Capture.

    Science.gov (United States)

    Gao, Zhiquan; Yu, Yao; Zhou, Yu; Du, Sidan

    2015-09-22

    Accurate motion capture plays an important role in sports analysis, the medical field and virtual reality. Current methods for motion capture often suffer from occlusions, which limits the accuracy of their pose estimation. In this paper, we propose a complete system to measure the pose parameters of the human body accurately. Different from previous monocular depth camera systems, we leverage two Kinect sensors to acquire more information about human movements, which ensures that we can still get an accurate estimation even when significant occlusion occurs. Because human motion is temporally constant, we adopt a learning analysis to mine the temporal information across the posture variations. Using this information, we estimate human pose parameters accurately, regardless of rapid movement. Our experimental results show that our system can perform an accurate pose estimation of the human body with the constraint of information from the temporal domain.

  2. Quaternion-Based Gesture Recognition Using Wireless Wearable Motion Capture Sensors

    Directory of Open Access Journals (Sweden)

    Shamir Alavi

    2016-04-01

    Full Text Available This work presents the development and implementation of a unified multi-sensor human motion capture and gesture recognition system that can distinguish between and classify six different gestures. Data was collected from eleven participants using a subset of five wireless motion sensors (inertial measurement units attached to their arms and upper body from a complete motion capture system. We compare Support Vector Machines and Artificial Neural Networks on the same dataset under two different scenarios and evaluate the results. Our study indicates that near perfect classification accuracies are achievable for small gestures and that the speed of classification is sufficient to allow interactivity. However, such accuracies are more difficult to obtain when a participant does not participate in training, indicating that more work needs to be done in this area to create a system that can be used by the general population.

  3. Quaternion-Based Gesture Recognition Using Wireless Wearable Motion Capture Sensors.

    Science.gov (United States)

    Alavi, Shamir; Arsenault, Dennis; Whitehead, Anthony

    2016-04-28

    This work presents the development and implementation of a unified multi-sensor human motion capture and gesture recognition system that can distinguish between and classify six different gestures. Data was collected from eleven participants using a subset of five wireless motion sensors (inertial measurement units) attached to their arms and upper body from a complete motion capture system. We compare Support Vector Machines and Artificial Neural Networks on the same dataset under two different scenarios and evaluate the results. Our study indicates that near perfect classification accuracies are achievable for small gestures and that the speed of classification is sufficient to allow interactivity. However, such accuracies are more difficult to obtain when a participant does not participate in training, indicating that more work needs to be done in this area to create a system that can be used by the general population.

  4. Shoulder motion during tennis serve: dynamic and radiological evaluation based on motion capture and magnetic resonance imaging.

    Science.gov (United States)

    Charbonnier, Caecilia; Chagué, Sylvain; Kolo, Frank C; Lädermann, Alexandre

    2015-08-01

    Rotator cuff and labral lesions in tennis players could be related to posterosuperior internal impingement or subacromial impingement during tennis serve. However, it is unknown which of these impingements are responsible for the lesions found in the tennis player's shoulder. Moreover, there is a lack of validated noninvasive methods and dynamic studies to ascertain impingement during motion. Ten intermediate or ex-professional tennis players were motion captured with an optical tracking system while performing tennis serves. The resulting computed motions were applied to patient-specific shoulder joints' 3D models based on magnetic resonance imaging (MRI) data. During motion simulation, impingements were detected and located using computer-assisted techniques. An MRI examination was also performed to evaluate the prevalence of shoulder lesions and to determine their relevance with the simulation findings. Simulation showed that internal impingement was frequently observed compared to subacromial impingement when serving. The computed zones of internal impingement were mainly located in the posterosuperior or superior region of the glenoid. These findings were relevant with respect to radiologically diagnosed damaged zones in the rotator cuff and glenoid labrum. Tennis players presented frequent radiographic signs of structural lesions that seem to be mainly related to posterosuperior internal impingement due to repetitive abnormal motion contacts. The present study indicates that the practice of tennis serve could lead with time to cartilage/tendon hyper compression, which could be damageable for the glenohumeral joint.

  5. Interaction of perceptual grouping and crossmodal temporal capture in tactile apparent-motion.

    Directory of Open Access Journals (Sweden)

    Lihan Chen

    Full Text Available Previous studies have shown that in tasks requiring participants to report the direction of apparent motion, task-irrelevant mono-beeps can "capture" visual motion perception when the beeps occur temporally close to the visual stimuli. However, the contributions of the relative timing of multimodal events and the event structure, modulating uni- and/or crossmodal perceptual grouping, remain unclear. To examine this question and extend the investigation to the tactile modality, the current experiments presented tactile two-tap apparent-motion streams, with an SOA of 400 ms between successive, left-/right-hand middle-finger taps, accompanied by task-irrelevant, non-spatial auditory stimuli. The streams were shown for 90 seconds, and participants' task was to continuously report the perceived (left- or rightward direction of tactile motion. In Experiment 1, each tactile stimulus was paired with an auditory beep, though odd-numbered taps were paired with an asynchronous beep, with audiotactile SOAs ranging from -75 ms to 75 ms. Perceived direction of tactile motion varied systematically with audiotactile SOA, indicative of a temporal-capture effect. In Experiment 2, two audiotactile SOAs--one short (75 ms, one long (325 ms--were compared. The long-SOA condition preserved the crossmodal event structure (so the temporal-capture dynamics should have been similar to that in Experiment 1, but both beeps now occurred temporally close to the taps on one side (even-numbered taps. The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping. In Experiment 3, only odd-numbered, but not even-numbered, taps were paired with auditory beeps. This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation. These findings suggest that asymmetric crossmodal grouping leads

  6. Interaction of perceptual grouping and crossmodal temporal capture in tactile apparent-motion.

    Science.gov (United States)

    Chen, Lihan; Shi, Zhuanghua; Müller, Hermann J

    2011-02-23

    Previous studies have shown that in tasks requiring participants to report the direction of apparent motion, task-irrelevant mono-beeps can "capture" visual motion perception when the beeps occur temporally close to the visual stimuli. However, the contributions of the relative timing of multimodal events and the event structure, modulating uni- and/or crossmodal perceptual grouping, remain unclear. To examine this question and extend the investigation to the tactile modality, the current experiments presented tactile two-tap apparent-motion streams, with an SOA of 400 ms between successive, left-/right-hand middle-finger taps, accompanied by task-irrelevant, non-spatial auditory stimuli. The streams were shown for 90 seconds, and participants' task was to continuously report the perceived (left- or rightward) direction of tactile motion. In Experiment 1, each tactile stimulus was paired with an auditory beep, though odd-numbered taps were paired with an asynchronous beep, with audiotactile SOAs ranging from -75 ms to 75 ms. Perceived direction of tactile motion varied systematically with audiotactile SOA, indicative of a temporal-capture effect. In Experiment 2, two audiotactile SOAs--one short (75 ms), one long (325 ms)--were compared. The long-SOA condition preserved the crossmodal event structure (so the temporal-capture dynamics should have been similar to that in Experiment 1), but both beeps now occurred temporally close to the taps on one side (even-numbered taps). The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping. In Experiment 3, only odd-numbered, but not even-numbered, taps were paired with auditory beeps. This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation. These findings suggest that asymmetric crossmodal grouping leads to an

  7. A markerless motion capture system to study musculoskeletal biomechanics: visual hull and simulated annealing approach.

    Science.gov (United States)

    Corazza, S; Mündermann, L; Chaudhari, A M; Demattio, T; Cobelli, C; Andriacchi, T P

    2006-06-01

    Human motion capture is frequently used to study musculoskeletal biomechanics and clinical problems, as well as to provide realistic animation for the entertainment industry. The most popular technique for human motion capture uses markers placed on the skin, despite some important drawbacks including the impediment to the motion by the presence of skin markers and relative movement between the skin where the markers are placed and the underlying bone. The latter makes it difficult to estimate the motion of the underlying bone, which is the variable of interest for biomechanical and clinical applications. A model-based markerless motion capture system is presented in this study, which does not require the placement of any markers on the subject's body. The described method is based on visual hull reconstruction and an a priori model of the subject. A custom version of adapted fast simulated annealing has been developed to match the model to the visual hull. The tracking capability and a quantitative validation of the method were evaluated in a virtual environment for a complete gait cycle. The obtained mean errors, for an entire gait cycle, for knee and hip flexion are respectively 1.5 degrees (+/-3.9 degrees ) and 2.0 degrees (+/-3.0 degrees ), while for knee and hip adduction they are respectively 2.0 degrees (+/-2.3 degrees ) and 1.1 degrees (+/-1.7 degrees ). Results for the ankle and shoulder joints are also presented. Experimental results captured in a gait laboratory with a real subject are also shown to demonstrate the effectiveness and potential of the presented method in a clinical environment.

  8. Automated Quantification of the Landing Error Scoring System With a Markerless Motion-Capture System.

    Science.gov (United States)

    Mauntel, Timothy C; Padua, Darin A; Stanley, Laura E; Frank, Barnett S; DiStefano, Lindsay J; Peck, Karen Y; Cameron, Kenneth L; Marshall, Stephen W

    2017-11-01

      The Landing Error Scoring System (LESS) can be used to identify individuals with an elevated risk of lower extremity injury. The limitation of the LESS is that raters identify movement errors from video replay, which is time-consuming and, therefore, may limit its use by clinicians. A markerless motion-capture system may be capable of automating LESS scoring, thereby removing this obstacle.   To determine the reliability of an automated markerless motion-capture system for scoring the LESS.   Cross-sectional study.   United States Military Academy.   A total of 57 healthy, physically active individuals (47 men, 10 women; age = 18.6 ± 0.6 years, height = 174.5 ± 6.7 cm, mass = 75.9 ± 9.2 kg).   Participants completed 3 jump-landing trials that were recorded by standard video cameras and a depth camera. Their movement quality was evaluated by expert LESS raters (standard video recording) using the LESS rubric and by software that automates LESS scoring (depth-camera data). We recorded an error for a LESS item if it was present on at least 2 of 3 jump-landing trials. We calculated κ statistics, prevalence- and bias-adjusted κ (PABAK) statistics, and percentage agreement for each LESS item. Interrater reliability was evaluated between the 2 expert rater scores and between a consensus expert score and the markerless motion-capture system score.   We observed reliability between the 2 expert LESS raters (average κ = 0.45 ± 0.35, average PABAK = 0.67 ± 0.34; percentage agreement = 0.83 ± 0.17). The markerless motion-capture system had similar reliability with consensus expert scores (average κ = 0.48 ± 0.40, average PABAK = 0.71 ± 0.27; percentage agreement = 0.85 ± 0.14). However, reliability was poor for 5 LESS items in both LESS score comparisons.   A markerless motion-capture system had the same level of reliability as expert LESS raters, suggesting that an automated system can accurately assess movement. Therefore, clinicians can use

  9. Normative data for modified Box and Blocks test measuring upper-limb function via motion capture.

    Science.gov (United States)

    Hebert, Jacqueline S; Lewicke, Justin; Williams, Thomas R; Vette, Albert H

    2014-01-01

    Motion analysis is an important tool for examining upper-limb function. Based on previous work demonstrating a modified Box and Blocks (BB) test with motion capture to assess prosthetic performance, we collected data in 16 nondisabled participants to establish normative kinematics for this test. Four motions of the modified BB test were analyzed to establish kinematic data for upper-limb and trunk motion. The test was repeated for right and left arms in standing and seated positions. Data were compared using a nonparametric Friedman test. No differences were found between right- and left-hand performance other than for task completion time. Small but significant differences were found for standing and seated performance, with slightly greater ranges in standing for axial trunk rotation, medial-lateral sternum displacement, and anterior-posterior hand displacement. The kinematic trajectories, however, were very consistent. The consistency in our nondisabled data suggests that normative kinematic trajectories can be defined for this task. This motion capture procedure may add to the understanding of movement in upper-limb impairment and may be useful for measuring the effect of interventions to improve upper-limb function.

  10. Interaction of Perceptual Grouping and Crossmodal Temporal Capture in Tactile Apparent-Motion

    Science.gov (United States)

    Chen, Lihan; Shi, Zhuanghua; Müller, Hermann J.

    2011-01-01

    Previous studies have shown that in tasks requiring participants to report the direction of apparent motion, task-irrelevant mono-beeps can “capture” visual motion perception when the beeps occur temporally close to the visual stimuli. However, the contributions of the relative timing of multimodal events and the event structure, modulating uni- and/or crossmodal perceptual grouping, remain unclear. To examine this question and extend the investigation to the tactile modality, the current experiments presented tactile two-tap apparent-motion streams, with an SOA of 400 ms between successive, left-/right-hand middle-finger taps, accompanied by task-irrelevant, non-spatial auditory stimuli. The streams were shown for 90 seconds, and participants' task was to continuously report the perceived (left- or rightward) direction of tactile motion. In Experiment 1, each tactile stimulus was paired with an auditory beep, though odd-numbered taps were paired with an asynchronous beep, with audiotactile SOAs ranging from −75 ms to 75 ms. Perceived direction of tactile motion varied systematically with audiotactile SOA, indicative of a temporal-capture effect. In Experiment 2, two audiotactile SOAs—one short (75 ms), one long (325 ms)—were compared. The long-SOA condition preserved the crossmodal event structure (so the temporal-capture dynamics should have been similar to that in Experiment 1), but both beeps now occurred temporally close to the taps on one side (even-numbered taps). The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping. In Experiment 3, only odd-numbered, but not even-numbered, taps were paired with auditory beeps. This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation. These findings suggest that asymmetric crossmodal grouping leads to an

  11. Measuring Aksak Rhythm and Synchronization in Transylvanian Village Music by Using Motion Capture

    Directory of Open Access Journals (Sweden)

    Filippo Bonini-Baraldi

    2016-01-01

    Full Text Available Techniques based on motion capture can be useful in analyzing a wide range of musical styles and practices: in this case, Transylvanian village music. We focused on a repertoire known as ‘Gypsy songs of sorrow’, played by professional Gypsy musicians during parties and celebrations of their own community. Two parameters were the object of study: rhythmic duration, and synchronization between musicians (a violinist and a viola player. Results show that rhythm is a local variant of aksak and is based on two duration units (S=short, L=long which respect the formula 2:3 < S:L < 3:4. Performances are characterized by large variations of the S:L ratio from period to period, which have an expressive function. Tracking the bow’s movements with motion capture techniques allowed to show that these variations are related to a swinging interpretation, which also involves a voluntary asynchrony between the two musicians.

  12. MARCOnI-ConvNet-Based MARker-Less Motion Capture in Outdoor and Indoor Scenes.

    Science.gov (United States)

    Elhayek, A; de Aguiar, E; Jain, A; Thompson, J; Pishchulin, L; Andriluka, M; Bregler, C; Schiele, B; Theobalt, C

    2017-03-01

    Marker-less motion capture has seen great progress, but most state-of-the-art approaches fail to reliably track articulated human body motion with a very low number of cameras, let alone when applied in outdoor scenes with general background. In this paper, we propose a method for accurate marker-less capture of articulated skeleton motion of several subjects in general scenes, indoors and outdoors, even from input filmed with as few as two cameras. The new algorithm combines the strengths of a discriminative image-based joint detection method with a model-based generative motion tracking algorithm through an unified pose optimization energy. The discriminative part-based pose detection method is implemented using Convolutional Networks (ConvNet) and estimates unary potentials for each joint of a kinematic skeleton model. These unary potentials serve as the basis of a probabilistic extraction of pose constraints for tracking by using weighted sampling from a pose posterior that is guided by the model. In the final energy, we combine these constraints with an appearance-based model-to-image similarity term. Poses can be computed very efficiently using iterative local optimization, since joint detection with a trained ConvNet is fast, and since our formulation yields a combined pose estimation energy with analytic derivatives. In combination, this enables to track full articulated joint angles at state-of-the-art accuracy and temporal stability with a very low number of cameras. Our method is efficient and lends itself to implementation on parallel computing hardware, such as GPUs. We test our method extensively and show its advantages over related work on many indoor and outdoor data sets captured by ourselves, as well as data sets made available to the community by other research labs. The availability of good evaluation data sets is paramount for scientific progress, and many existing test data sets focus on controlled indoor settings, do not feature much variety

  13. Evaluation of a Gait Assessment Module Using 3D Motion Capture Technology.

    Science.gov (United States)

    Baskwill, Amanda J; Belli, Patricia; Kelleher, Leila

    2017-03-01

    Gait analysis is the study of human locomotion. In massage therapy, this observation is part of an assessment process that informs treatment planning. Massage therapy students must apply the theory of gait assessment to simulated patients. At Humber College, the gait assessment module traditionally consists of a textbook reading and a three-hour, in-class session in which students perform gait assessment on each other. In 2015, Humber College acquired a three-dimensional motion capture system. The purpose was to evaluate the use of 3D motion capture in a gait assessment module compared to the traditional gait assessment module. Semester 2 massage therapy students who were enrolled in Massage Theory 2 (n = 38). Quasi-experimental, wait-list comparison study. The intervention group participated in an in-class session with a Qualisys motion capture system. The outcomes included knowledge and application of gait assessment theory as measured by quizzes, and students' satisfaction as measured through a questionnaire. There were no statistically significant differences in baseline and post-module knowledge between both groups (pre-module: p = .46; post-module: p = .63). There was also no difference between groups on the final application question ( p = .13). The intervention group enjoyed the in-class session because they could visualize the content, whereas the comparison group enjoyed the interactivity of the session. The intervention group recommended adding the assessment of gait on their classmates to their experience. Both groups noted more time was needed for the gait assessment module. Based on the results of this study, it is recommended that the gait assessment module combine both the traditional in-class session and the 3D motion capture system.

  14. Analysis of the posture pattern during robotic simulator tasks using an optical motion capture system.

    Science.gov (United States)

    Takayasu, Kenta; Yoshida, Kenji; Mishima, Takao; Watanabe, Masato; Matsuda, Tadashi; Kinoshita, Hidefumi

    2018-01-01

    Surgeons are sometimes forced to maintain uncomfortable joint positions during robotic surgery despite the high degree of instrument maneuverability. This study aimed to use an optical motion capture system to analyze the differences in posture patterns during robotic simulator tasks between surgeons at two skill levels. Ten experienced and ten novice surgeons performed two tasks in a da Vinci Skills Simulator: Suture Sponge 1 (SP) and Tubes (TU). The participants' upper body motion during each task was captured, including the joint angles (axilla, elbow, and wrist), the percentage of time when the wrist height was lower than the elbow height (PTW), and the height of the elbow and wrist relative to the armrest. The novice group showed significantly more excess extension in both elbow angles and extension (>50°) in both wrist angles than did the experienced group. The novice group had significantly lower PTW than the experienced group on the right side in both tasks (both p motion capture system can detect the differences in posture patterns in the positional relationship between the elbow and wrist and the joint angles of the upper limb between two groups of surgeons at different skill levels during robotic simulator tasks.

  15. Designing for physically disabled users: benefits from human motion capture - a case study.

    Science.gov (United States)

    Thomann, Guillaume; Magnier, Cécile; Villeneuve, François; Palluel-Germain, Richard

    2016-11-01

    The present study aimed to improve the design of an interface that may help disabled children to play a musical instrument. The main point is to integrate human motion capture in the design process. The participant performed 20 pointing movements toward four selected locations. A three one-way analysis of variance (ANOVA) was performed in order to determine the most efficient input location. For each button position, we compared (1) the reaction time (RT), (2) the movement time (MT), and (3) the spatial variability of the movements. According to the results obtained for RT and MT, one position was the most efficient button location in order to produce efficient movements. As the case study showed, combining the 3D motion capture system and the statistical analysis led to help the designers their design methodology and crucial choices. Implications for Rehabilitation The paper point out the possibility for designers to use motion capture science to improve the efficiency of the personal interface manipulation to play musical instrument. This experiment with the disabled user allows researcher not only to propose standard procedure to characterize an interface but also to take into account the complete behaviour of the user: from the decision of the movement to the execution of the action. The discussion and the experiment with the disabled user help him to better understand its own difficulties. This kind of experimental procedure helps a lot the user in his future rehabilitation choices and decisions.

  16. A novel method for synchronizing motion capture with other data sources for millisecond-level precision.

    Science.gov (United States)

    Komisar, V; Novak, A C; Haycock, B

    2017-01-01

    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. Results are provided to validate and demonstrate the accuracy of the synchronization of motion capture with other data collection systems. During the reach-to-grasp trials, delays between the data collection systems ranged from 4ms to 235ms. The large range and variability in delay times between trials highlights the need for synchronization on a continual basis, rather than application of an average or constant value to correct for time delays between systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Biomechanics Analysis of Combat Sport (Silat) By Using Motion Capture System

    Science.gov (United States)

    Zulhilmi Kaharuddin, Muhammad; Badriah Khairu Razak, Siti; Ikram Kushairi, Muhammad; Syawal Abd. Rahman, Mohamed; An, Wee Chang; Ngali, Z.; Siswanto, W. A.; Salleh, S. M.; Yusup, E. M.

    2017-01-01

    ‘Silat’ is a Malay traditional martial art that is practiced in both amateur and in professional levels. The intensity of the motion spurs the scientific research in biomechanics. The main purpose of this abstract is to present the biomechanics method used in the study of ‘silat’. By using the 3D Depth Camera motion capture system, two subjects are to perform ‘Jurus Satu’ in three repetitions each. One subject is set as the benchmark for the research. The videos are captured and its data is processed using the 3D Depth Camera server system in the form of 16 3D body joint coordinates which then will be transformed into displacement, velocity and acceleration components by using Microsoft excel for data calculation and Matlab software for simulation of the body. The translated data obtained serves as an input to differentiate both subjects’ execution of the ‘Jurus Satu’. Nine primary movements with the addition of five secondary movements are observed visually frame by frame from the simulation obtained to get the exact frame that the movement takes place. Further analysis involves the differentiation of both subjects’ execution by referring to the average mean and standard deviation of joints for each parameter stated. The findings provide useful data for joints kinematic parameters as well as to improve the execution of ‘Jurus Satu’ and to exhibit the process of learning a movement that is relatively unknown by the use of a motion capture system.

  18. Comprehensive molecular motion capture for sphingomyelin by site-specific deuterium labeling.

    Science.gov (United States)

    Matsumori, Nobuaki; Yasuda, Tomokazu; Okazaki, Hiroki; Suzuki, Takashi; Yamaguchi, Toshiyuki; Tsuchikawa, Hiroshi; Doi, Mototsugu; Oishi, Tohru; Murata, Michio

    2012-10-23

    Lipid rafts have attracted much attention because of their significant functional roles in membrane-associated processes. It is thought that sphingomyelin and cholesterol are essential for forming lipid rafts; however, their motion characteristics are not fully understood despite numerous studies. Here we show accurate local motions encompassing an entire sphingomyelin molecule, which were captured by measuring quadrupole splittings for 19 kinds of site-specifically deuterated sphingomyelins (that is, molecular motion capture of sphingomyelin). The quadrupole splitting profiles, which are distinct from those reported from perdeuterated sphingomyelins or simulation studies, reveal that cholesterol enhances the order in the middle parts of the alkyl chains more efficaciously than at the shallow positions. Comparison with dimyristoylphosphocholine bilayers suggests that cholesterol is deeper in sphingomyelin bilayers, which likely explains the so-called umbrella effect. The experiments also demonstrate that (i) the C2'-C3' bond predominantly takes the gauche conformation, (ii) the net ordering effect of cholesterol in sphingomyelin bilayers is not larger than that in phosphatidylcholine bilayers, (iii) cholesterol has no specific preference for the acyl or sphingosine chain, (iv) the acyl and sphingosine chains seem mismatched by about two methylene lengths, and (v) the motion of the upper regions of sphingomyelin chains is less temperature dependent than that of lower regions probably due to intermolecular hydrogen bond formation among SM molecules. These insights into the atomic-level dynamics of sphingomyelin provide critical clues to understanding the mechanism of raft formation.

  19. Estimation of Ground Reaction Forces and Moments During Gait Using Only Inertial Motion Capture

    Directory of Open Access Journals (Sweden)

    Angelos Karatsidis

    2016-12-01

    Full Text Available Ground reaction forces and moments (GRF&M are important measures used as input in biomechanical analysis to estimate joint kinetics, which often are used to infer information for many musculoskeletal diseases. Their assessment is conventionally achieved using laboratory-based equipment that cannot be applied in daily life monitoring. In this study, we propose a method to predict GRF&M during walking, using exclusively kinematic information from fully-ambulatory inertial motion capture (IMC. From the equations of motion, we derive the total external forces and moments. Then, we solve the indeterminacy problem during double stance using a distribution algorithm based on a smooth transition assumption. The agreement between the IMC-predicted and reference GRF&M was categorized over normal walking speed as excellent for the vertical (ρ = 0.992, rRMSE = 5.3%, anterior (ρ = 0.965, rRMSE = 9.4% and sagittal (ρ = 0.933, rRMSE = 12.4% GRF&M components and as strong for the lateral (ρ = 0.862, rRMSE = 13.1%, frontal (ρ = 0.710, rRMSE = 29.6%, and transverse GRF&M (ρ = 0.826, rRMSE = 18.2%. Sensitivity analysis was performed on the effect of the cut-off frequency used in the filtering of the input kinematics, as well as the threshold velocities for the gait event detection algorithm. This study was the first to use only inertial motion capture to estimate 3D GRF&M during gait, providing comparable accuracy with optical motion capture prediction. This approach enables applications that require estimation of the kinetics during walking outside the gait laboratory.

  20. Estimation of Ground Reaction Forces and Moments During Gait Using Only Inertial Motion Capture.

    Science.gov (United States)

    Karatsidis, Angelos; Bellusci, Giovanni; Schepers, H Martin; de Zee, Mark; Andersen, Michael S; Veltink, Peter H

    2016-12-31

    Ground reaction forces and moments (GRF&M) are important measures used as input in biomechanical analysis to estimate joint kinetics, which often are used to infer information for many musculoskeletal diseases. Their assessment is conventionally achieved using laboratory-based equipment that cannot be applied in daily life monitoring. In this study, we propose a method to predict GRF&M during walking, using exclusively kinematic information from fully-ambulatory inertial motion capture (IMC). From the equations of motion, we derive the total external forces and moments. Then, we solve the indeterminacy problem during double stance using a distribution algorithm based on a smooth transition assumption. The agreement between the IMC-predicted and reference GRF&M was categorized over normal walking speed as excellent for the vertical ( ρ = 0.992, rRMSE = 5.3%), anterior ( ρ = 0.965, rRMSE = 9.4%) and sagittal ( ρ = 0.933, rRMSE = 12.4%) GRF&M components and as strong for the lateral ( ρ = 0.862, rRMSE = 13.1%), frontal ( ρ = 0.710, rRMSE = 29.6%), and transverse GRF&M ( ρ = 0.826, rRMSE = 18.2%). Sensitivity analysis was performed on the effect of the cut-off frequency used in the filtering of the input kinematics, as well as the threshold velocities for the gait event detection algorithm. This study was the first to use only inertial motion capture to estimate 3D GRF&M during gait, providing comparable accuracy with optical motion capture prediction. This approach enables applications that require estimation of the kinetics during walking outside the gait laboratory.

  1. Case report of modified Box and Blocks test with motion capture to measure prosthetic function.

    Science.gov (United States)

    Hebert, Jacqueline S; Lewicke, Justin

    2012-01-01

    This case study report demonstrates the use of motion analysis with a modification of the Box and Blocks test. The goal was to quantify observed improvements in compensatory movements and simultaneous control in a subject using different prostheses before and after targeted muscle reinnervation (TMR) surgery. This is a single case study with data collection using a body-powered prosthesis pre-TMR surgery and 6 mo postfitting with a TMR myoelectric prosthesis. The Box and Blocks test was modified for cyclical motion within a motion capture laboratory. With the TMR myoelectric prosthesis, the subject was able to simultaneously activate the hand and elbow. Task performance was slower, but there was improved elbow flexion and less trunk compensatory motion than with the body-powered prosthesis. There are several limitations to the case study because there is no direct comparison of myoelectric performance before and after TMR surgery; however, the current report presents a potential method to quantify quality of motion and compensatory movements of prosthetic users. With further study, this test procedure has the potential to be a useful outcome measure for future standardized assessments of upper-limb prosthetic function.

  2. Static versus dynamic kinematics in cyclists: A comparison of goniometer, inclinometer and 3D motion capture.

    Science.gov (United States)

    Holliday, W; Fisher, J; Theo, R; Swart, J

    2017-10-01

    Kinematic measurements conducted during bike set-ups utilise either static or dynamic measures. There is currently limited data on reliability of static and dynamic measures nor consensus on which is the optimal method. The aim of the study was to assess the difference between static and dynamic measures of the ankle, knee, hip, shoulder and elbow. Nineteen subjects performed three separate trials for a 10-min duration at a fixed workload (70% of peak power output). Static measures were taken with a standard goniometer (GM), an inclinometer (IM) and dynamic three-dimensional motion capture (3DMC) using an eight camera motion capture system. Static and dynamic joint angles were compared over the three trials to assess repeatability of the measurements and differences between static and dynamic values. There was a positive correlation between GM and IM measures for all joints. Only the knee, shoulder and elbow were positively correlated between GM and 3DMC, and IM and 3DMC. Although all three instruments were reliable, 3D motion analysis utilised different landmarks for most joints and produced different means. Changes in knee flexion angle from static to dynamic are attributable to changes in the positioning of the foot. Controlling for this factor, the differences are negated. It was demonstrated that 3DMC is not interchangeable with GM and IM, and it is recommended that 3DMC develop independent reference values for bicycle configuration.

  3. An evaluation method on seat comfort based on optical motion capture

    Directory of Open Access Journals (Sweden)

    Qing TAO

    2015-10-01

    Full Text Available To research the sitting posture comfort evaluation method, through the example of comfort evaluation of the ergonomic seat and standard office seat, a methodology is introduced to evaluate the sitting posture comfort combining ergonomics theory. The proposed method is based on optical motion capture system, pressure sensor and JACK software, and TRC file is acquired by using EVART real-time capture software for identifying the spatial motion trail of human body. Then MATLAB software is used to analyze the human body motion data, and the sitting posture angle difference data for human body in different seats is acquired. TRC file is loaded into JACK software, and with the TAT REPORTER of JACK software, muscle force, moment of force and fatigue data, etc. are output, which are compared with the actual measured data from experiments, and ergonomics method is used for the evaluation. The result shows that the method of considering joint angles combining JACK software for data output is effective for evaluating sitting comfort.

  4. Wearable motion capturing with the flexing and turning based on a hetero-core fiber optic stretching sensor

    Science.gov (United States)

    Koyama, Y.; Nishiyama, M.; Watanabe, K.

    2011-05-01

    In recent years, motion capturing technologies have been applied to the service of the rehabilitation for the physically challenged people and practicing sports in human daily life. In these application fields, it is important that a measurement system does not prevent human from doing natural activity for unrestricted motion capture in daily-life. The hetero-core optic fiber sensor that we developed is suited for the unconstrained motion capturing because of optical intensity-based measurement with excellent stability and repeatability using single-mode transmission fibers and needless of any compensation. In this paper, we propose the development of wearable sensor enables unconstrained motion capture systems using the hetero-core fiber optic stretching sensor in real time, which satisfy user's requirements of comfort and ubiquitous. The experiments of motion capturing were demonstrated by setting the hetero-core fiber optic stretching sensor on the elbow, the back of the body and the waist. As a result, the hetero-core fiber optic stretching sensor was able to detect the displacement of expansion and contraction in the optical loss by flexion motion of the arm and the trunk motion. The optical loss performance of the hetero-core fiber optic stretching sensor reveals monotonic characteristics with the displacement. The optical loss changes at the full scale of motion were 1.45dB for the motion of anteflexion and 1.99 dB for the motion of turn. The real-time motion capturing was demonstrated by means of the proposed hetero-core fiber optic stretching sensor without restricting natural human behavior.

  5. Four-dimensional quantitative analysis of the gait of mutant mice using coarse-grained motion capture.

    Science.gov (United States)

    Oota, S; Mekada, K; Fujita, Y; Humphries, J; Fukami-Kobayashi, K; Obata, Y; Rowe, T; Yoshiki, A

    2009-01-01

    To analyze an abnormal gait pattern in mutant mice (Hugger), we conducted coarse-grained motion capture. Using a simple retroreflective marker-based approach, we could detect high-resolution mutant-specific gait patterns. The phenotypic gait patterns are caused by extreme vertical motion of limbs, revealing inefficient motor functions. To elucidate the inefficiency, we developed a musculoskeletal computer model of the mouse hindlimb based on X-ray CT data. By integrating motion data with the model, we determined mutant-specific musculotendon lengths, suggesting that three major muscles were involved in the abnormal gait. This approach worked well on laboratory mice, which were putatively too small to be motion capture subjects. Motion capture technology was originally developed for human study, and our approach may help fill neuroscience gaps between mouse and human behavioral phenotypes.

  6. Human Actions Analysis: Templates Generation, Matching and Visualization Applied to Motion Capture of Highly-Skilled Karate Athletes

    OpenAIRE

    Hachaj, Tomasz; Piekarczyk, Marcin; Ogiela, Marek R.

    2017-01-01

    The aim of this paper is to propose and evaluate the novel method of template generation, matching, comparing and visualization applied to motion capture (kinematic) analysis. To evaluate our approach, we have used motion capture recordings (MoCap) of two highly-skilled black belt karate athletes consisting of 560 recordings of various karate techniques acquired with wearable sensors. We have evaluated the quality of generated templates; we have validated the matching algorithm that calculate...

  7. [An attempt to evaluate postural control with a magnetic motion capture system].

    Science.gov (United States)

    Kudo, Koji; Mitobe, Kazutaka; Honda, Kohei; Ishikawa, Kazuo

    2013-10-01

    Measurement of the body sway can be useful in the assessment of the ability to maintain posture. It is, however, difficult to quantitatively evaluate the chronological changes in the equilibrium function in the elderly. Although it is considered that not only sway movement of body center of gravity but also head movement should be measured for essential assessment of postural control, few methods are suitable for a clinical test. In this study, we investigated the head and trunk movement in elderly subjects standing upright, using a magnetic motion capture system to substantiate its usefulness. Seven subjects aged 66 to 83 years old were instructed to stand with their feet close together on the stabilometer with eyes open and then eyes closed for periods of 30 seconds each, while the movement of the head, cervix and lumbar region (MH, MC and ML) were monitored three-dimensionally with the magnetic motion capture system. The obtained data were compared with the movement of the body's center of gravity (MCG). The results were as follows: The MH was the largest, followed by MC and ML, and the ML trace was similar to that of the MCG. MH, MC, ML and the ratio of the MH to ML increased with age, and they were considered to be a valid index for assessment of postural control. A magnetic motion capture system, which can record the movements of the head, cervix and lumbar region accurately and conveniently, is seen as potentially and clinically useful apparatus for evaluation of postural control in dizzy patients, especially the elderly.

  8. Accuracy and precision of gait events derived from motion capture in horses during walk and trot.

    Science.gov (United States)

    Boye, Jenny Katrine; Thomsen, Maj Halling; Pfau, Thilo; Olsen, Emil

    2014-03-21

    This study aimed to create an evidence base for detection of stance-phase timings from motion capture in horses. The objective was to compare the accuracy (bias) and precision (SD) for five published algorithms for the detection of hoof-on and hoof-off using force plates as the reference standard. Six horses were walked and trotted over eight force plates surrounded by a synchronised 12-camera infrared motion capture system. The five algorithms (A-E) were based on: (A) horizontal velocity of the hoof; (B) Fetlock angle and horizontal hoof velocity; (C) horizontal displacement of the hoof relative to the centre of mass; (D) horizontal velocity of the hoof relative to the Centre of Mass and; (E) vertical acceleration of the hoof. A total of 240 stance phases in walk and 240 stance phases in trot were included in the assessment. Method D provided the most accurate and precise results in walk for stance phase duration with a bias of 4.1% for front limbs and 4.8% for hind limbs. For trot we derived a combination of method A for hoof-on and method E for hoof-off resulting in a bias of -6.2% of stance in the front limbs and method B for the hind limbs with a bias of 3.8% of stance phase duration. We conclude that motion capture yields accurate and precise detection of gait events for horses walking and trotting over ground and the results emphasise a need for different algorithms for front limbs versus hind limbs in trot. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Model-Based Reinforcement of Kinect Depth Data for Human Motion Capture Applications

    Directory of Open Access Journals (Sweden)

    Andreas Skiadopoulos

    2013-07-01

    Full Text Available Motion capture systems have recently experienced a strong evolution. New cheap depth sensors and open source frameworks, such as OpenNI, allow for perceiving human motion on-line without using invasive systems. However, these proposals do not evaluate the validity of the obtained poses. This paper addresses this issue using a model-based pose generator to complement the OpenNI human tracker. The proposed system enforces kinematics constraints, eliminates odd poses and filters sensor noise, while learning the real dimensions of the performer’s body. The system is composed by a PrimeSense sensor, an OpenNI tracker and a kinematics-based filter and has been extensively tested. Experiments show that the proposed system improves pure OpenNI results at a very low computational cost.

  10. Quantitative measurement of motor symptoms in Parkinson's disease: a study with full-body motion capture data.

    Science.gov (United States)

    Das, Samarjit; Trutoiu, Laura; Murai, Akihiko; Alcindor, Dunbar; Oh, Michael; De la Torre, Fernando; Hodgins, Jessica

    2011-01-01

    Recent advancements in the portability and affordability of optical motion capture systems have opened the doors to various clinical applications. In this paper, we look into the potential use of motion capture data for the quantitative analysis of motor symptoms in Parkinson's Disease (PD). The standard of care, human observer-based assessments of the motor symptoms, can be very subjective and are often inadequate for tracking mild symptoms. Motion capture systems, on the other hand, can potentially provide more objective and quantitative assessments. In this pilot study, we perform full-body motion capture of Parkinson's patients with deep brain stimulator off-drugs and with stimulators on and off. Our experimental results indicate that the quantitative measure on spatio-temporal statistics learnt from the motion capture data reveal distinctive differences between mild and severe symptoms. We used a Support Vector Machine (SVM) classifier for discriminating mild vs. severe symptoms with an average accuracy of approximately 90%. Finally, we conclude that motion capture technology could potentially be an accurate, reliable and effective tool for statistical data mining on motor symptoms related to PD. This would enable us to devise more effective ways to track the progression of neurodegenerative movement disorders.

  11. Relationships of a Circular Singer Arm Gesture to Acoustical and Perceptual Measures of Singing: A Motion Capture Study

    Science.gov (United States)

    Brunkan, Melissa C.

    2016-01-01

    The purpose of this study was to validate previous research that suggests using movement in conjunction with singing tasks can affect intonation and perception of the task. Singers (N = 49) were video and audio recorded, using a motion capture system, while singing a phrase from a familiar song, first with no motion, and then while doing a low,…

  12. Kinematics differences between the flat, kick, and slice serves measured using a markerless motion capture method.

    Science.gov (United States)

    Sheets, Alison L; Abrams, Geoffrey D; Corazza, Stefano; Safran, Marc R; Andriacchi, Thomas P

    2011-12-01

    Tennis injuries have been associated with serving mechanics, but quantitative kinematic measurements in realistic environments are limited by current motion capture technologies. This study tested for kinematic differences at the lower back, shoulder, elbow, wrist, and racquet between the flat, kick, and slice serves using a markerless motion capture (MMC) system. Seven male NCAA Division 1 players were tested on an outdoor court in daylight conditions. Peak racquet and joint center speeds occurred sequentially and increased from proximal (back) to distal (racquet). Racquet speeds at ball impact were not significantly different between serve types. However, there were significant differences in the direction of the racquet velocity vector between serves: the kick serve had the largest lateral and smallest forward racquet velocity components, while the flat serve had the smallest vertical component (p < 0.01). The slice serve had lateral velocity, like the kick, and large forward velocity, like the flat. Additionally, the racquet in the kick serve was positioned 8.7 cm more posterior and 21.1 cm more medial than the shoulder compared with the flat, which could suggest an increased risk of shoulder and back injury associated with the kick serve. This study demonstrated the potential for MMC for testing sports performance under natural conditions.

  13. A New Position Measurement System Using a Motion-Capture Camera for Wind Tunnel Tests

    Directory of Open Access Journals (Sweden)

    Yousok Kim

    2013-09-01

    Full Text Available Considering the characteristics of wind tunnel tests, a position measurement system that can minimize the effects on the flow of simulated wind must be established. In this study, a motion-capture camera was used to measure the displacement responses of structures in a wind tunnel test, and the applicability of the system was tested. A motion-capture system (MCS could output 3D coordinates using two-dimensional image coordinates obtained from the camera. Furthermore, this remote sensing system had some flexibility regarding lab installation because of its ability to measure at relatively long distances from the target structures. In this study, we performed wind tunnel tests on a pylon specimen and compared the measured responses of the MCS with the displacements measured with a laser displacement sensor (LDS. The results of the comparison revealed that the time-history displacement measurements from the MCS slightly exceeded those of the LDS. In addition, we confirmed the measuring reliability of the MCS by identifying the dynamic properties (natural frequency, damping ratio, and mode shape of the test specimen using system identification methods (frequency domain decomposition, FDD. By comparing the mode shape obtained using the aforementioned methods with that obtained using the LDS, we also confirmed that the MCS could construct a more accurate mode shape (bending-deflection mode shape with the 3D measurements.

  14. Understanding and Visualizing Multitasking and Task Switching Activities: A Time Motion Study to Capture Nursing Workflow.

    Science.gov (United States)

    Yen, Po-Yin; Kelley, Marjorie; Lopetegui, Marcelo; Rosado, Amber L; Migliore, Elaina M; Chipps, Esther M; Buck, Jacalyn

    2016-01-01

    A fundamental understanding of multitasking within nursing workflow is important in today's dynamic and complex healthcare environment. We conducted a time motion study to understand nursing workflow, specifically multitasking and task switching activities. We used TimeCaT, a comprehensive electronic time capture tool, to capture observational data. We established inter-observer reliability prior to data collection. We completed 56 hours of observation of 10 registered nurses. We found, on average, nurses had 124 communications and 208 hands-on tasks per 4-hour block of time. They multitasked (having communication and hands-on tasks simultaneously) 131 times, representing 39.48% of all times; the total multitasking duration ranges from 14.6 minutes to 109 minutes, 44.98 minutes (18.63%) on average. We also reviewed workflow visualization to uncover the multitasking events. Our study design and methods provide a practical and reliable approach to conducting and analyzing time motion studies from both quantitative and qualitative perspectives.

  15. A new position measurement system using a motion-capture camera for wind tunnel tests.

    Science.gov (United States)

    Park, Hyo Seon; Kim, Ji Young; Kim, Jin Gi; Choi, Se Woon; Kim, Yousok

    2013-09-13

    Considering the characteristics of wind tunnel tests, a position measurement system that can minimize the effects on the flow of simulated wind must be established. In this study, a motion-capture camera was used to measure the displacement responses of structures in a wind tunnel test, and the applicability of the system was tested. A motion-capture system (MCS) could output 3D coordinates using two-dimensional image coordinates obtained from the camera. Furthermore, this remote sensing system had some flexibility regarding lab installation because of its ability to measure at relatively long distances from the target structures. In this study, we performed wind tunnel tests on a pylon specimen and compared the measured responses of the MCS with the displacements measured with a laser displacement sensor (LDS). The results of the comparison revealed that the time-history displacement measurements from the MCS slightly exceeded those of the LDS. In addition, we confirmed the measuring reliability of the MCS by identifying the dynamic properties (natural frequency, damping ratio, and mode shape) of the test specimen using system identification methods (frequency domain decomposition, FDD). By comparing the mode shape obtained using the aforementioned methods with that obtained using the LDS, we also confirmed that the MCS could construct a more accurate mode shape (bending-deflection mode shape) with the 3D measurements.

  16. Musculoskeletal Simulation Model Generation from MRI Data Sets and Motion Capture Data

    Science.gov (United States)

    Schmid, Jérôme; Sandholm, Anders; Chung, François; Thalmann, Daniel; Delingette, Hervé; Magnenat-Thalmann, Nadia

    Today computer models and computer simulations of the musculoskeletal system are widely used to study the mechanisms behind human gait and its disorders. The common way of creating musculoskeletal models is to use a generic musculoskeletal model based on data derived from anatomical and biomechanical studies of cadaverous specimens. To adapt this generic model to a specific subject, the usual approach is to scale it. This scaling has been reported to introduce several errors because it does not always account for subject-specific anatomical differences. As a result, a novel semi-automatic workflow is proposed that creates subject-specific musculoskeletal models from magnetic resonance imaging (MRI) data sets and motion capture data. Based on subject-specific medical data and a model-based automatic segmentation approach, an accurate modeling of the anatomy can be produced while avoiding the scaling operation. This anatomical model coupled with motion capture data, joint kinematics information, and muscle-tendon actuators is finally used to create a subject-specific musculoskeletal model.

  17. Volumetric definition of shoulder range of motion and its correlation with clinical signs of shoulder hyperlaxity. A motion capture study.

    Science.gov (United States)

    Ropars, Mickaël; Cretual, Armel; Thomazeau, Hervé; Kaila, Rajiv; Bonan, Isabelle

    2015-02-01

    Shoulder hyperlaxity (SHL) is assessed with clinical signs. Quantification of SHL remains difficult, however, because no quantitative definition has yet been described. With use of a motion capture system (MCS), the aim of this study was to categorize SHL through a volumetric MCS-based definition and to compare this volume with clinical signs used for SHL diagnosis. Twenty-three subjects were examined with passive and active measurement of their shoulder range of motion (SROM) and then with an MCS protocol, allowing computation of the shoulder configuration space volume (SCSV). Clinical data of SHL were assessed by the sulcus sign, external rotation with the arm at the side (ER1) >85° in a standing position, external rotation >90° in a lying position, and Beighton score for general joint laxity. Active and passive ER1, EIR2 (sum of external and internal rotation at 90° of abduction), flexion-extension, and abduction were also measured and correlated to SCSV. Except for the sulcus sign, SCSV was significantly correlated with all clinical signs used for SHL. Passive examination of the different SROMs was better correlated to SCSV than active examination. In passive examination, the worst SROM was ER1 (R = 0.36; P = .09), whereas EIR2, flexion, and abduction were highly correlated to SCSV (P 85° in a standing position appear less discriminating and should be replaced by EIR2 measurement for SHL diagnosis. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  18. Reaction null-space filter: extracting reactionless synergies for optimal postural balance from motion capture data.

    Science.gov (United States)

    Nenchev, D N; Miyamoto, Y; Iribe, H; Takeuchi, K; Sato, D

    2016-01-01

    This paper introduces the notion of a reactionless synergy: a postural variation for a specific motion pattern/strategy, whereby the movements of the segments do not alter the force/moment balance at the feet. Given an optimal initial posture in terms of stability, a reactionless synergy can ensure optimality throughout the entire movement. Reactionless synergies are derived via a dynamical model wherein the feet are regarded to be unfixed. Though in contrast with the conventional fixed-feet models, this approach has the advantage of exhibiting the reactions at the feet explicitly. The dynamical model also facilitates a joint-space decomposition scheme yielding two motion components: the reactionless synergy and an orthogonal complement responsible for the dynamical coupling between the feet and the support. Since the reactionless synergy provides the basis (a feedforward control component) for optimal balance control, it may play an important role when evaluating balance abnormalities or when assessing optimality in balance control. We show how to apply the proposed method for analysis of motion capture data obtained from three voluntary movement patterns in the sagittal plane: squat, sway, and forward bend.

  19. Virtual Character Animation Based on Affordable Motion Capture and Reconfigurable Tangible Interfaces.

    Science.gov (United States)

    Lamberti, Fabrizio; Paravati, Gianluca; Gatteschi, Valentina; Cannavo, Alberto; Montuschi, Paolo

    2017-04-03

    Software for computer animation is generally characterized by a steep learning curve, due to the entanglement of both sophisticated techniques and interaction methods required to control 3D geometries. This paper proposes a tool designed to support computer animation production processes by leveraging the affordances offered by articulated tangible user interfaces and motion capture retargeting solutions. To this aim, orientations of an instrumented prop are recorded together with animator's motion in the 3D space and used to quickly pose characters in the virtual environment. High-level functionalities of the animation software are made accessible via a speech interface, thus letting the user control the animation pipeline via voice commands while focusing on his or her hands and body motion. The proposed solution exploits both off-the-shelf hardware components (like the Lego Mindstorms EV3 bricks and the Microsoft Kinect, used for building the tangible device and tracking animator's skeleton) and free open-source software (like the Blender animation tool), thus representing an interesting solution also for beginners approaching the world of digital animation for the first time. Experimental results in different usage scenarios show the benefits offered by the designed interaction strategy with respect to a mouse & keyboard-based interface both for expert and non-expert users.

  20. An effective attentional set for a specific colour does not prevent capture by infrequently presented motion distractors.

    Science.gov (United States)

    Retell, James D; Becker, Stefanie I; Remington, Roger W

    2016-01-01

    An organism's survival depends on the ability to rapidly orient attention to unanticipated events in the world. Yet, the conditions needed to elicit such involuntary capture remain in doubt. Especially puzzling are spatial cueing experiments, which have consistently shown that involuntary shifts of attention to highly salient distractors are not determined by stimulus properties, but instead are contingent on attentional control settings induced by task demands. Do we always need to be set for an event to be captured by it, or is there a class of events that draw attention involuntarily even when unconnected to task goals? Recent results suggest that a task-irrelevant event will capture attention on first presentation, suggesting that salient stimuli that violate contextual expectations might automatically capture attention. Here, we investigated the role of contextual expectation by examining whether an irrelevant motion cue that was presented only rarely (∼3-6% of trials) would capture attention when observers had an active set for a specific target colour. The motion cue had no effect when presented frequently, but when rare produced a pattern of interference consistent with attentional capture. The critical dependence on the frequency with which the irrelevant motion singleton was presented is consistent with early theories of involuntary orienting to novel stimuli. We suggest that attention will be captured by salient stimuli that violate expectations, whereas top-down goals appear to modulate capture by stimuli that broadly conform to contextual expectations.

  1. Electromyographic and Motion Capture Analysis of the Elbow and Forearm in the Overhead Football Throw

    Science.gov (United States)

    Smith, Jarrod; Winnier, Scott; Douglas, Lonnie; Ostrander, Roger V.; Anz, Adam William; Andrews, James R.

    2017-01-01

    Objectives: Muscle activation patterns and the kinetics of overhead throwing have been well described in the baseball athlete but not in the football athlete. Injury patterns vary between these two populations. The purpose of this controlled laboratory study was to describe the muscle activation patterns of the elbow and forearm during the overhead football throw. A better understanding of muscle activation patterns and kinetics will help clinicians understand the difference in injury between these two populations, with an objective of preventing injury in both groups. The hypothesis was that the unique grip and obligatory pronation upon ball release will cause the elbow and forearm muscles to have a unique activation pattern during the overhead football throw. Methods: IRB approval was obtained. Electromyographic (EMG) and motion capture data was collected on eight male quarterbacks. An EMG direct transmission system measuring at 1200 Hz with 9 surface electrodes was used to collect EMG data, with signals normalized to maximal voluntary contraction values for each subject. EMG sensors were placed on the biceps, triceps, brachialis, brachioradialis, anconeus, extensor digitorum communis, flexor digitorum superficialis, pronator teres, and pronator quadratus. A 13 camera motion capture system measuring at 240 Hz with a full body marker set of 39 retro-reflective 9mm markers was used to capture motion data. The throwing motion was divided into four event segments: early cocking, late cocking, acceleration, and follow through. Results: All athletes had NCAA experience and were aged 18-30 years old. The anconeus (26.9%, 36.3%, 57.6%, and 105.8% MVCs), extensor digitorum communis (22.7%, 28.0%, 31.0%, and 42.8% MVCs), and flexor digitorum superficialis (19.4%, 39.3%, 22.3%, and 104.7% MVCs) had high levels of activity throughout all phases of the football throw. The brachioradialis (56.8%MVC) and anconeus (57.6%MVC) were the most active muscles during the acceleration

  2. Extraction of bowing parameters from violin performance combining motion capture and sensors.

    Science.gov (United States)

    Schoonderwaldt, E; Demoucron, M

    2009-11-01

    A method is described for measurement of a complete set of bowing parameters in violin performance. Optical motion capture was combined with sensors for accurate measurement of the main bowing parameters (bow position, bow velocity, bow acceleration, bow-bridge distance, and bow force) as well as secondary control parameters (skewness, inclination, and tilt of the bow). In addition, other performance features (moments of on/off in bow-string contact, string played, and bowing direction) were extracted. Detailed descriptions of the calculations of the bowing parameters, features, and calibrations are given. The described system is capable of measuring all bowing parameters without disturbing the player, allowing for detailed studies of musically relevant aspects of bow control and coordination of bowing parameters in bowed-string instrument performance.

  3. Estimation of Joint types and Joint Limits from Motion capture data

    DEFF Research Database (Denmark)

    Engell-Nørregård, Morten Pol; Erleben, Kenny

    2009-01-01

    It is time-consuming for an animator to explicitly model joint types and joint limits of articulated figures. In this paper we describe a simple and fast approach to automated joint estimation from motion capture data of articulated figures. Our method will make the joint modeling more efficient...... and less time consuming for the animator by providing a good starting estimate that can be fine-tuned or extended by the animator if she wishes, without restricting her artistic freedom. Our method is simple, easy to implement and specific for the types of articulated figures used in interactive animation...... such as computer games. Other work for joint limit modeling consider more complex and general purpose models. However, these are not immediately suitable for inverse kinematics skeletons used in interactive applications....

  4. Motion-Capture-Enabled Software for Gestural Control of 3D Models

    Science.gov (United States)

    Norris, Jeffrey S.; Luo, Victor; Crockett, Thomas M.; Shams, Khawaja S.; Powell, Mark W.; Valderrama, Anthony

    2012-01-01

    Current state-of-the-art systems use general-purpose input devices such as a keyboard, mouse, or joystick that map to tasks in unintuitive ways. This software enables a person to control intuitively the position, size, and orientation of synthetic objects in a 3D virtual environment. It makes possible the simultaneous control of the 3D position, scale, and orientation of 3D objects using natural gestures. Enabling the control of 3D objects using a commercial motion-capture system allows for natural mapping of the many degrees of freedom of the human body to the manipulation of the 3D objects. It reduces training time for this kind of task, and eliminates the need to create an expensive, special-purpose controller.

  5. Pengembangan Game Simulasi Tari Kreasi Khas Semarangan dengan Memanfaatkan Sensor Gerak (Motion Capture

    Directory of Open Access Journals (Sweden)

    Rahina Nugrahani

    2017-09-01

    Full Text Available Pengembangangan game simulasi tari kreasi khas Semarangan ini dilatarbelakangi oleh semakin menurunnya minat dan pengetahuan remaja mengenai kesenian tradisional seperti tari, namun di sisi lain animo remaja pada produk aplikasi game tari (dance game seperti Pump It Up, Dance Dance Revolution dan Danz Base yang dikembangkan oleh game developer Asing semakin tinggi. Penelitian dilaksanakan dengan mengadaptasi pendekatan Research and Development (R & D. Kegiatan penelitian dimulai dengan memetakan kebutuhan dari aspek teknologi dan aspek visual. Aspek teknologi mencakup teknologi motion capture (sensor gerak yang dijadikan sebagai dasar untuk mengembangkan game simulasi tari khas Semarangan, sedangkan aspek visual adalah hal-hal yang terkait dengan pengembangan elemen visual dan estetis yang sesuai dengan karakter remaja. Target dari penelitian ini adalah sebuah aplikasi simulasi tari khas Semarangan yang menggunakan teknologi sensor gerak. Dari simulasi tersebut diharapkan mampu meningkatkan pengetahuan dan minat remaja mengenai tari khas Semarangan sebagai salah satu produk kesenian tradisional.

  6. A Single Camera Motion Capture System for Human-Computer Interaction

    Science.gov (United States)

    Okada, Ryuzo; Stenger, Björn

    This paper presents a method for markerless human motion capture using a single camera. It uses tree-based filtering to efficiently propagate a probability distribution over poses of a 3D body model. The pose vectors and associated shapes are arranged in a tree, which is constructed by hierarchical pairwise clustering, in order to efficiently evaluate the likelihood in each frame. Anew likelihood function based on silhouette matching is proposed that improves the pose estimation of thinner body parts, i. e. the limbs. The dynamic model takes self-occlusion into account by increasing the variance of occluded body-parts, thus allowing for recovery when the body part reappears. We present two applications of our method that work in real-time on a Cell Broadband Engine™: a computer game and a virtual clothing application.

  7. A specialized motion capture system for real-time analysis of mandibular movements using infrared cameras.

    Science.gov (United States)

    Furtado, Daniel Antônio; Pereira, Adriano Alves; Andrade, Adriano de Oliveira; Bellomo, Douglas Peres; da Silva, Marlete Ribeiro

    2013-02-22

    In the last years, several methods and devices have been proposed to record the human mandibular movements, since they provide quantitative parameters that support the diagnosis and treatment of temporomandibular disorders. The techniques currently employed suffer from a number of drawbacks including high price, unnatural to use, lack of support for real-time analysis and mandibular movements recording as a pure rotation. In this paper, we propose a specialized optical motion capture system, which causes a minimum obstruction and can support 3D mandibular movement analysis in real-time. We used three infrared cameras together with nine reflective markers that were placed at key points of the face. Some classical techniques are suggested to conduct the camera calibration and three-dimensional reconstruction and we propose some specialized algorithms to automatically recognize our set of markers and track them along a motion capture session. To test the system, we developed a prototype software and performed a clinical experiment in a group of 22 subjects. They were instructed to execute several movements for the functional evaluation of the mandible while the system was employed to record them. The acquired parameters and the reconstructed trajectories were used to confirm the typical function of temporomandibular joint in some subjects and to highlight its abnormal behavior in others. The proposed system is an alternative to the existing optical, mechanical, electromagnetic and ultrasonic-based methods, and intends to address some drawbacks of currently available solutions. Its main goal is to assist specialists in diagnostic and treatment of temporomandibular disorders, since simple visual inspection may not be sufficient for a precise assessment of temporomandibular joint and associated muscles.

  8. CAPTURE: Consistently Acquired Projections for Tuned and Robust Estimation: A Self-Navigated Respiratory Motion Correction Approach.

    Science.gov (United States)

    Eldeniz, Cihat; Fraum, Tyler; Salter, Amber; Chen, Yasheng; Gach, H Michael; Parikh, Parag J; Fowler, Kathryn J; An, Hongyu

    2018-01-08

    In this study, we present a fully automated and robust self-navigated approach to obtain 4-dimensional (4-D) motion-resolved images during free breathing. The proposed method, Consistently Acquired Projections for Tuned and Robust Estimation (CAPTURE), is a variant of the stack-of-stars gradient-echo sequence. A 1-D navigator was consistently acquired at a fixed azimuthal angle for all stacks of spokes to reduce nonphysiological signal contamination due to system imperfections. The resulting projections were then "tuned" using complex phase rotation to adapt to scan-to-scan variations, followed by the detection of the respiratory curve. Four-dimensional motion-corrected and uncorrected images were then reconstructed via respiratory and temporal binning, respectively.This Health Insurance Portability and Accountability Act-compliant study was performed with Institutional Review Board approval. A phantom experiment was performed using a custom-made deformable motion phantom with an adjustable frequency and amplitude. For in vivo experiments, 10 healthy participants and 12 liver tumor patients provided informed consent and were imaged with the CAPTURE sequence.Two radiologists, blinded to which images were motion-corrected and which were not, independently reviewed the images and scored the image quality using a 5-point Likert scale. In the respiratory motion phantom experiment, CAPTURE reversed the effects of motion blurring and restored edge sharpness from 36% to 78% of that observed in the images from the static scan.Despite large intra- and intersubject variability in respiration patterns, CAPTURE successfully detected the respiratory motion signal in all participants and significantly improved the image quality according to the subjective radiological assessments of 2 raters (P motion blurring were more clearly depicted on the CAPTURE images. CAPTURE provides a robust and fully automated solution for obtaining 4-D motion-resolved images in a free

  9. Accuracy of Base of Support Using an Inertial Sensor Based Motion Capture System.

    Science.gov (United States)

    Guo, Liangjie; Xiong, Shuping

    2017-09-12

    The potential of miniature inertial sensors for human balance and gait analysis appears promising. Base of support (BOS), together with its interaction with center of mass, is a critical indicator in above mentioned research fields. This study aims to evaluate the accuracy of Xsens MVN BIOMECH, a commercial widely used inertial sensor-based motion capture system, for measuring static BOS and examine the effect of different task complexity on the accuracy. Eleven young males participated in this study and went through eleven different experimental tasks. Results showed there were considerable errors in estimating BOS area (error ranged from -12.6% to +64.6%) from Xsens MVN and a large error in foot separation distance when there was knee flexion. The estimated BOS area from MVN was smaller than the ground truth from footprint when there was no knee flexion, and larger when there was knee flexion, and it increased monotonically along with the knee flexion angles. Wrongly estimated foot separations, mainly caused by knee flexion, and the initial system estimation error on BOS, were two major reasons for error and instability of BOS estimation. The findings suggested that caution should be taken when using Xsens MVN BIOMECH to estimate BOS and foot position-related measurements, especially for postures/motions with knee flexion.

  10. Markerless motion capture can provide reliable 3D gait kinematics in the sagittal and frontal plane.

    Science.gov (United States)

    Sandau, Martin; Koblauch, Henrik; Moeslund, Thomas B; Aanæs, Henrik; Alkjær, Tine; Simonsen, Erik B

    2014-09-01

    Estimating 3D joint rotations in the lower extremities accurately and reliably remains unresolved in markerless motion capture, despite extensive studies in the past decades. The main problems have been ascribed to the limited accuracy of the 3D reconstructions. Accordingly, the purpose of the present study was to develop a new approach based on highly detailed 3D reconstructions in combination with a translational and rotational unconstrained articulated model. The highly detailed 3D reconstructions were synthesized from an eight camera setup using a stereo vision approach. The subject specific articulated model was generated with three rotational and three translational degrees of freedom for each limb segment and without any constraints to the range of motion. This approach was tested on 3D gait analysis and compared to a marker based method. The experiment included ten healthy subjects in whom hip, knee and ankle joint were analysed. Flexion/extension angles as well as hip abduction/adduction closely resembled those obtained from the marker based system. However, the internal/external rotations, knee abduction/adduction and ankle inversion/eversion were less reliable. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  11. Objective assessment of exploratory behaviour in schizophrenia using wireless motion capture.

    Science.gov (United States)

    Siddiqui, Ishraq; Remington, Gary; Fletcher, Paul J; Voineskos, Aristotle N; Fong, Jason W; Saperia, Sarah; Fervaha, Gagan; Da Silva, Susana; Zakzanis, Konstantine K; Foussias, George

    2017-09-24

    Motivation deficits are a prominent feature of schizophrenia and have substantial consequences for functional outcome. The impact of amotivation on exploratory behaviour has not been extensively assessed by entirely objective means. This study evaluated deficits in exploratory behaviour in an open-field setting using wireless motion capture. Twenty-one stable adult outpatients with schizophrenia and twenty matched healthy controls completed the Novelty Exploration Task, in which participants explored a novel environment containing familiar and uncommon objects. Objective motion data were used to index participants' locomotor activity and tendency for visual and tactile object exploration. Clinical assessments of positive and negative symptoms, apathy, cognition, depression, medication side-effects, and community functioning were also administered. Relationships between task performance and clinical measures were evaluated using Spearman correlations, and group differences were evaluated using multivariate analysis of covariance tests. Although locomotor activity and tactile exploration were similar between the schizophrenia and healthy control groups, schizophrenia participants exhibited reduced visual object exploration (F(2,35)=3.40, p=0.045). Further, schizophrenia participants' geometric pattern of locomotion, visual exploration, and tactile exploration were correlated with overall negative symptoms (|ρ|=0.46-0.64, pcaptured through standard clinical instruments and human observer ratings. Findings from this initial study suggest that locomotor activity and object interaction tendencies are impacted by motivation, and reveal deficits specifically in visual exploration in schizophrenia. Copyright © 2017. Published by Elsevier B.V.

  12. MOCA: A Low-Power, Low-Cost Motion Capture System Based on Integrated Accelerometers

    Directory of Open Access Journals (Sweden)

    Elisabetta Farella

    2007-01-01

    Full Text Available Human-computer interaction (HCI and virtual reality applications pose the challenge of enabling real-time interfaces for natural interaction. Gesture recognition based on body-mounted accelerometers has been proposed as a viable solution to translate patterns of movements that are associated with user commands, thus substituting point-and-click methods or other cumbersome input devices. On the other hand, cost and power constraints make the implementation of a natural and efficient interface suitable for consumer applications a critical task. Even though several gesture recognition solutions exist, their use in HCI context has been poorly characterized. For this reason, in this paper, we consider a low-cost/low-power wearable motion tracking system based on integrated accelerometers called motion capture with accelerometers (MOCA that we evaluated for navigation in virtual spaces. Recognition is based on a geometric algorithm that enables efficient and robust detection of rotational movements. Our objective is to demonstrate that such a low-cost and a low-power implementation is suitable for HCI applications. To this purpose, we characterized the system from both a quantitative point of view and a qualitative point of view. First, we performed static and dynamic assessment of movement recognition accuracy. Second, we evaluated the effectiveness of user experience using a 3D game application as a test bed.

  13. Accuracy of Base of Support Using an Inertial Sensor Based Motion Capture System

    Science.gov (United States)

    Guo, Liangjie; Xiong, Shuping

    2017-01-01

    The potential of miniature inertial sensors for human balance and gait analysis appears promising. Base of support (BOS), together with its interaction with center of mass, is a critical indicator in above mentioned research fields. This study aims to evaluate the accuracy of Xsens MVN BIOMECH, a commercial widely used inertial sensor-based motion capture system, for measuring static BOS and examine the effect of different task complexity on the accuracy. Eleven young males participated in this study and went through eleven different experimental tasks. Results showed there were considerable errors in estimating BOS area (error ranged from −12.6% to +64.6%) from Xsens MVN and a large error in foot separation distance when there was knee flexion. The estimated BOS area from MVN was smaller than the ground truth from footprint when there was no knee flexion, and larger when there was knee flexion, and it increased monotonically along with the knee flexion angles. Wrongly estimated foot separations, mainly caused by knee flexion, and the initial system estimation error on BOS, were two major reasons for error and instability of BOS estimation. The findings suggested that caution should be taken when using Xsens MVN BIOMECH to estimate BOS and foot position-related measurements, especially for postures/motions with knee flexion. PMID:28895897

  14. Exercise Sensing and Pose Recovery Inference Tool (ESPRIT) - A Compact Stereo-based Motion Capture Solution For Exercise Monitoring

    Science.gov (United States)

    Lee, Mun Wai

    2015-01-01

    Crew exercise is important during long-duration space flight not only for maintaining health and fitness but also for preventing adverse health problems, such as losses in muscle strength and bone density. Monitoring crew exercise via motion capture and kinematic analysis aids understanding of the effects of microgravity on exercise and helps ensure that exercise prescriptions are effective. Intelligent Automation, Inc., has developed ESPRIT to monitor exercise activities, detect body markers, extract image features, and recover three-dimensional (3D) kinematic body poses. The system relies on prior knowledge and modeling of the human body and on advanced statistical inference techniques to achieve robust and accurate motion capture. In Phase I, the company demonstrated motion capture of several exercises, including walking, curling, and dead lifting. Phase II efforts focused on enhancing algorithms and delivering an ESPRIT prototype for testing and demonstration.

  15. Automatic human body modeling for vision-based motion capture system using B-spline parameterization of the silhouette

    Science.gov (United States)

    Jaume-i-Capó, Antoni; Varona, Javier; González-Hidalgo, Manuel; Mas, Ramon; Perales, Francisco J.

    2012-02-01

    Human motion capture has a wide variety of applications, and in vision-based motion capture systems a major issue is the human body model and its initialization. We present a computer vision algorithm for building a human body model skeleton in an automatic way. The algorithm is based on the analysis of the human shape. We decompose the body into its main parts by computing the curvature of a B-spline parameterization of the human contour. This algorithm has been applied in a context where the user is standing in front of a camera stereo pair. The process is completed after the user assumes a predefined initial posture so as to identify the main joints and construct the human model. Using this model, the initialization problem of a vision-based markerless motion capture system of the human body is solved.

  16. Using a Motion Capture System for Spatial Localization of EEG Electrodes.

    Directory of Open Access Journals (Sweden)

    Pedro eReis

    2015-04-01

    Full Text Available Electroencephalography (EEG is often used in source analysis studies, in which the locations of cortex regions responsible for a signal are determined. For this to be possible, accurate positions of the electrodes at the scalp surface must be determined, otherwise errors in the source estimation will occur. Today, several methods for acquiring these positions exist but they are often not satisfyingly accurate or take a long time to perform. Therefore, in this paper we describe a method capable of determining the positions accurately and fast.This method uses an infrared light motion capture system (IR-MOCAP with 8 cameras arranged around a human participant. It acquires 3D coordinates of each electrode and automatically labels them. Each electrode has a small reflector on top of it thus allowing its detection by the cameras. We tested the accuracy of the presented method by acquiring the electrodes positions on a rigid sphere model and comparing these with measurements from computer tomography (CT. The average Euclidean distance between the sphere model CT measurements and the presented method was 1.23 mm with an average standard deviation of 0.51 mm. We also tested the method with a human participant. The measurement was quickly performed and all positions were captured.These results tell that, with this method, it is possible to acquire electrode positions with minimal error and little time effort for the study participants and investigators.

  17. [An Introduction to A Newly-developed "Acupuncture Needle Manipulation Training-evaluation System" Based on Optical Motion Capture Technique].

    Science.gov (United States)

    Zhang, Ao; Yan, Xing-Ke; Liu, An-Guo

    2016-12-25

    In the present paper, the authors introduce a newly-developed "Acupuncture Needle Manipulation Training-evaluation System" based on optical motion capture technique. It is composed of two parts, sensor and software, and overcomes some shortages of mechanical motion capture technique. This device is able to analyze the data of operations of the pressing-hand and needle-insertion hand during acupuncture performance and its software contains personal computer (PC) version, Android version, and Internetwork Operating System (IOS) Apple version. It is competent in recording and analyzing information of any ope-rator's needling manipulations, and is quite helpful for teachers in teaching, training and examining students in clinical practice.

  18. A new calibration methodology for thorax and upper limbs motion capture in children using magneto and inertial sensors.

    Science.gov (United States)

    Ricci, Luca; Formica, Domenico; Sparaci, Laura; Lasorsa, Francesca Romana; Taffoni, Fabrizio; Tamilia, Eleonora; Guglielmelli, Eugenio

    2014-01-09

    Recent advances in wearable sensor technologies for motion capture have produced devices, mainly based on magneto and inertial measurement units (M-IMU), that are now suitable for out-of-the-lab use with children. In fact, the reduced size, weight and the wireless connectivity meet the requirement of minimum obtrusivity and give scientists the possibility to analyze children's motion in daily life contexts. Typical use of magneto and inertial measurement units (M-IMU) motion capture systems is based on attaching a sensing unit to each body segment of interest. The correct use of this setup requires a specific calibration methodology that allows mapping measurements from the sensors' frames of reference into useful kinematic information in the human limbs' frames of reference. The present work addresses this specific issue, presenting a calibration protocol to capture the kinematics of the upper limbs and thorax in typically developing (TD) children. The proposed method allows the construction, on each body segment, of a meaningful system of coordinates that are representative of real physiological motions and that are referred to as functional frames (FFs). We will also present a novel cost function for the Levenberg-Marquardt algorithm, to retrieve the rotation matrices between each sensor frame (SF) and the corresponding FF. Reported results on a group of 40 children suggest that the method is repeatable and reliable, opening the way to the extensive use of this technology for out-of-the-lab motion capture in children.

  19. A New Calibration Methodology for Thorax and Upper Limbs Motion Capture in Children Using Magneto and Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Luca Ricci

    2014-01-01

    Full Text Available Recent advances in wearable sensor technologies for motion capture have produced devices, mainly based on magneto and inertial measurement units (M-IMU, that are now suitable for out-of-the-lab use with children. In fact, the reduced size, weight and the wireless connectivity meet the requirement of minimum obtrusivity and give scientists the possibility to analyze children’s motion in daily life contexts. Typical use of magneto and inertial measurement units (M-IMU motion capture systems is based on attaching a sensing unit to each body segment of interest. The correct use of this setup requires a specific calibration methodology that allows mapping measurements from the sensors’ frames of reference into useful kinematic information in the human limbs’ frames of reference. The present work addresses this specific issue, presenting a calibration protocol to capture the kinematics of the upper limbs and thorax in typically developing (TD children. The proposed method allows the construction, on each body segment, of a meaningful system of coordinates that are representative of real physiological motions and that are referred to as functional frames (FFs. We will also present a novel cost function for the Levenberg–Marquardt algorithm, to retrieve the rotation matrices between each sensor frame (SF and the corresponding FF. Reported results on a group of 40 children suggest that the method is repeatable and reliable, opening the way to the extensive use of this technology for out-of-the-lab motion capture in children.

  20. Evaluation of a portable markerless finger position capture device: accuracy of the Leap Motion controller in healthy adults.

    Science.gov (United States)

    Tung, James Y; Lulic, Tea; Gonzalez, Dave A; Tran, Johnathan; Dickerson, Clark R; Roy, Eric A

    2015-05-01

    Although motion analysis is frequently employed in upper limb motor assessment (e.g. visually-guided reaching), they are resource-intensive and limited to laboratory settings. This study evaluated the reliability and accuracy of a new markerless motion capture device, the Leap Motion controller, to measure finger position. Testing conditions that influence reliability and agreement between the Leap and a research-grade motion capture system were examined. Nine healthy young adults pointed to 15 targets on a computer screen under two conditions: (1) touching the target (touch) and (2) 4 cm away from the target (no-touch). Leap data was compared to an Optotrak marker attached to the index finger. Across all trials, root mean square (RMS) error of the Leap system was 17.30  ±  9.56 mm (mean ± SD), sampled at 65.47  ±  21.53 Hz. The % viable trials and mean sampling rate were significantly lower in the touch condition (44% versus 64%, p motion capture systems, the Leap Motion controller is sufficiently reliable for measuring motor performance in pointing tasks that do not require high positional accuracy (e.g. reaction time, Fitt's, trails, bimanual coordination).

  1. 4D computed tomography scans for conformal thoracic treatment planning: is a single scan sufficient to capture thoracic tumor motion?

    Science.gov (United States)

    Tseng, Yolanda D.; Wootton, Landon; Nyflot, Matthew; Apisarnthanarax, Smith; Rengan, Ramesh; Bloch, Charles; Sandison, George; St. James, Sara

    2018-01-01

    Four dimensional computed tomography (4DCT) scans are routinely used in radiation therapy to determine the internal treatment volume for targets that are moving (e.g. lung tumors). The use of these studies has allowed clinicians to create target volumes based upon the motion of the tumor during the imaging study. The purpose of this work is to determine if a target volume based on a single 4DCT scan at simulation is sufficient to capture thoracic motion. Phantom studies were performed to determine expected differences between volumes contoured on 4DCT scans and those on the evaluation CT scans (slow scans). Evaluation CT scans acquired during treatment of 11 patients were compared to the 4DCT scans used for treatment planning. The images were assessed to determine if the target remained within the target volume determined during the first 4DCT scan. A total of 55 slow scans were compared to the 11 planning 4DCT scans. Small differences were observed in phantom between the 4DCT volumes and the slow scan volumes, with a maximum of 2.9%, that can be attributed to minor differences in contouring and the ability of the 4DCT scan to adequately capture motion at the apex and base of the motion trajectory. Larger differences were observed in the patients studied, up to a maximum volume difference of 33.4%. These results demonstrate that a single 4DCT scan is not adequate to capture all thoracic motion throughout treatment.

  2. Validation of Attitude and Heading Reference System and Microsoft Kinect for Continuous Measurement of Cervical Range of Motion Compared to the Optical Motion Capture System.

    Science.gov (United States)

    Song, Young Seop; Yang, Kyung Yong; Youn, Kibum; Yoon, Chiyul; Yeom, Jiwoon; Hwang, Hyeoncheol; Lee, Jehee; Kim, Keewon

    2016-08-01

    To compare optical motion capture system (MoCap), attitude and heading reference system (AHRS) sensor, and Microsoft Kinect for the continuous measurement of cervical range of motion (ROM). Fifteen healthy adult subjects were asked to sit in front of the Kinect camera with optical markers and AHRS sensors attached to the body in a room equipped with optical motion capture camera. Subjects were instructed to independently perform axial rotation followed by flexion/extension and lateral bending. Each movement was repeated 5 times while being measured simultaneously with 3 devices. Using the MoCap system as the gold standard, the validity of AHRS and Kinect for measurement of cervical ROM was assessed by calculating correlation coefficient and Bland-Altman plot with 95% limits of agreement (LoA). MoCap and ARHS showed fair agreement (95% LoA10°) for measuring ROM in all directions. Intraclass correlation coefficient (ICC) values between MoCap and AHRS in -40° to 40° range were excellent for flexion/extension and lateral bending (ICC>0.9). ICC values were also fair for axial rotation (ICC>0.8). ICC values between MoCap and Kinect system in -40° to 40° range were fair for all motions. Our study showed feasibility of using AHRS to measure cervical ROM during continuous motion with an acceptable range of error. AHRS and Kinect system can also be used for continuous monitoring of flexion/extension and lateral bending in ordinary range.

  3. Development of real-time motion capture system for 3D on-line games linked with virtual character

    Science.gov (United States)

    Kim, Jong Hyeong; Ryu, Young Kee; Cho, Hyung Suck

    2004-10-01

    Motion tracking method is being issued as essential part of the entertainment, medical, sports, education and industry with the development of 3-D virtual reality. Virtual human character in the digital animation and game application has been controlled by interfacing devices; mouse, joysticks, midi-slider, and so on. Those devices could not enable virtual human character to move smoothly and naturally. Furthermore, high-end human motion capture systems in commercial market are expensive and complicated. In this paper, we proposed a practical and fast motion capturing system consisting of optic sensors, and linked the data with 3-D game character with real time. The prototype experiment setup is successfully applied to a boxing game which requires very fast movement of human character.

  4. Analysis of anticipation by 3D motion capturing - a new method presented in karate kumite.

    Science.gov (United States)

    Petri, Katharina; Lichtenstein, Marvin; Bandow, Nicole; Campe, Sebastian; Wechselberger, Marcus; Sprenger, Dominik; Kaczmarek, Felix; Emmermacher, Peter; Witte, Kerstin

    2017-01-01

    Anticipation is an important performance factor in karate kumite. A new approach analysing anticipation in realistic combat situations by motion capturing with a high temporal resolution is presented. The advantage of this approach is that both karate athletes interacting sports specific can be recorded synchronously; thus, the presented method has the potential to analyse visual information pickup due to coordination pattern of interaction between real athletes. The aim is to demonstrate the usability of the current method for anticipation research and to investigate if the distance between two athletes and their attacking technique play a role in the reaction of the defending athlete. Furthermore, relevant cues lying within each attacking technique and little individual differences are shown. Four male karate athletes took part in this study. Logistic regression indicated that both factors (distance × attacking technique) play a significant role in reaction. However, a correlation between these factors shows that only the attacking technique is a good predictor for reaction. Results show that the attacking technique jabbing punch (jap. Kizami-Zuki) was easier to anticipate than the attacking techniques reverse punch (jap. Gyaku-Zuki) and the round kick (jap. Mawashi-Geri).

  5. Greater trochanter location measurement using a three-dimensional motion capture system during prone hip extension.

    Science.gov (United States)

    Yu, Ji-Su; Oh, Jae-Seop

    2017-02-01

    [Purpose] The greater trochanter (GT) is an important structure in biomedical research, but the measurement methods require development. This study presents data from a new measurement method that does not use GT-marker-based measurement (No GT-m) in comparison with GT-marker based measurement (GT-m). [Subjects and Methods] We recruited 20 healthy subjects, who were asked to perform and maintain a prone position and then move to the prone hip extension. A motion capture system collected the kinematic data and the location of the GT was calculated by two measurements. [Results] GT migration distance differed significantly between the two measurements and the coefficient of the variation value was lower for the No GT-m method. Thigh lengths of the No GT-m method were comparable to the original lengths. There were significant differences between the GT-m and the other methods. [Conclusions] These data suggest that the GT-m method yielded a lower precision with a smaller GT migration distance. In the comparison of thigh length, the No GT-m method was in close agreement with the original length. We suggest that determining the location of the GT using the No GT-m has greater accuracy than the GT-m method.

  6. DNA motion capture reveals the mechanical properties of DNA at the mesoscale.

    Science.gov (United States)

    Price, Allen C; Pilkiewicz, Kevin R; Graham, Thomas G W; Song, Dan; Eaves, Joel D; Loparo, Joseph J

    2015-05-19

    Single-molecule studies probing the end-to-end extension of long DNAs have established that the mechanical properties of DNA are well described by a wormlike chain force law, a polymer model where persistence length is the only adjustable parameter. We present a DNA motion-capture technique in which DNA molecules are labeled with fluorescent quantum dots at specific sites along the DNA contour and their positions are imaged. Tracking these positions in time allows us to characterize how segments within a long DNA are extended by flow and how fluctuations within the molecule are correlated. Utilizing a linear response theory of small fluctuations, we extract elastic forces for the different, ∼2-μm-long segments along the DNA backbone. We find that the average force-extension behavior of the segments can be well described by a wormlike chain force law with an anomalously small persistence length. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  7. Combining EEG, MIDI, and motion capture techniques for investigating musical performance.

    Science.gov (United States)

    Maidhof, Clemens; Kästner, Torsten; Makkonen, Tommi

    2014-03-01

    This article describes a setup for the simultaneous recording of electrophysiological data (EEG), musical data (MIDI), and three-dimensional movement data. Previously, each of these three different kinds of measurements, conducted sequentially, has been proven to provide important information about different aspects of music performance as an example of a demanding multisensory motor skill. With the method described here, it is possible to record brain-related activity and movement data simultaneously, with accurate timing resolution and at relatively low costs. EEG and MIDI data were synchronized with a modified version of the FTAP software, sending synchronization signals to the EEG recording device simultaneously with keypress events. Similarly, a motion capture system sent synchronization signals simultaneously with each recorded frame. The setup can be used for studies investigating cognitive and motor processes during music performance and music-like tasks--for example, in the domains of motor control, learning, music therapy, or musical emotions. Thus, this setup offers a promising possibility of a more behaviorally driven analysis of brain activity.

  8. Mirror neuron activation of musicians and non-musicians in response to motion captured piano performances.

    Science.gov (United States)

    Hou, Jiancheng; Rajmohan, Ravi; Fang, Dan; Kashfi, Karl; Al-Khalil, Kareem; Yang, James; Westney, William; Grund, Cynthia M; O'Boyle, Michael W

    2017-07-01

    Mirror neurons (MNs) activate when performing an action and when an observer witnesses the same action performed by another individual. Functional magnetic resonance imaging (fMRI) and presentation of motion captured piano performances were used to identify differences in MN activation for musicians/non-musicians when viewing piano pieces played in a "Correct" mode (i.e., emphasis on technical correctness) or an "Enjoyment" mode (i.e., simply told to "enjoy" playing the piece). Results showed greater MN activation in a variety of brain regions for musicians, with these differences more pronounced in the "Enjoyment" mode. Our findings suggest that activation of MNs is not only initiated by the imagined action of an observed movement, but such activation is modulated by the level of musical expertise and knowledge of associated motor movements that the observer brings to the viewing situation. Enhanced MN activation in musicians may stem from imagining themselves actually playing the observed piece. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Power estimation of martial arts movement using 3D motion capture camera

    Science.gov (United States)

    Azraai, Nur Zaidi; Awang Soh, Ahmad Afiq Sabqi; Mat Jafri, Mohd Zubir

    2017-06-01

    Motion capture camera (MOCAP) has been widely used in many areas such as biomechanics, physiology, animation, arts, etc. This project is done by approaching physics mechanics and the extended of MOCAP application through sports. Most researchers will use a force plate, but this will only can measure the force of impact, but for us, we are keen to observe the kinematics of the movement. Martial arts is one of the sports that uses more than one part of the human body. For this project, martial art `Silat' was chosen because of its wide practice in Malaysia. 2 performers have been selected, one of them has an experienced in `Silat' practice and another one have no experience at all so that we can compare the energy and force generated by the performers. Every performer will generate a punching with same posture which in this project, two types of punching move were selected. Before the measuring start, a calibration has been done so the software knows the area covered by the camera and reduce the error when analyze by using the T stick that have been pasted with a marker. A punching bag with mass 60 kg was hung on an iron bar as a target. The use of this punching bag is to determine the impact force of a performer when they punch. This punching bag also will be stuck with the optical marker so we can observe the movement after impact. 8 cameras have been used and placed with 2 cameras at every side of the wall with different angle in a rectangular room 270 ft2 and the camera covered approximately 50 ft2. We covered only a small area so less noise will be detected and make the measurement more accurate. A Marker has been pasted on the limb of the entire hand that we want to observe and measure. A passive marker used in this project has a characteristic to reflect the infrared that being generated by the camera. The infrared will reflected to the camera sensor so the marker position can be detected and show in software. The used of many cameras is to increase the

  10. Power estimation of martial arts movement with different physical, mood, and behavior using motion capture camera

    Science.gov (United States)

    Awang Soh, Ahmad Afiq Sabqi; Mat Jafri, Mohd Zubir; Azraai, Nur Zaidi

    2017-07-01

    In Malay world, there is a spirit traditional ritual where they use it as healing practices or for normal life. Malay martial arts (silat) also is not exceptional where some branch of silat have spirit traditional ritual where they said can help them in combat. In this paper, we will not use any ritual, instead we will use some medicinal and environment change when they are performing. There will be 2 performers (fighter) selected, one of them have an experience in martial arts training and another performer does not have experience. Motion Capture (MOCAP) camera will help observe and analyze this move. 8 cameras have been placed in the MOCAP room 2 on each side of the wall facing toward the center of the room from every angle. This will help prevent the loss detection of a marker that been stamped on the limb of a performer. Passive marker has been used where it will reflect the infrared to the camera sensor. Infrared is generated by the source around the camera lens. A 60 kg punching bag was hung on the iron bar function as the target for the performer when throws a punch. Markers also have been stamped on the punching bag so we can detect the movement how far can it swing when hit by the performer. 2 performers will perform 2 moves each with the same position and posture. For every 2 moves, we have made the environment change without the performer notice about it. The first 2 punch with normal environment, second part we have played a positive music to change the performer's mood and third part we have put a medicine (cream/oil) on the skin of the performer. This medicine will make the skin feel a little bit hot. This process repeated to another performer with no experience. The position of this marker analyzed by the Cortex Motion Analysis software where from this data, we can estimate the kinetics and kinematics of the performer. It shows that the increase of kinetics for every part because of the change in the environment, and different result for the 2

  11. Cross-Modal Dynamic Capture: Congruency Effects in the Perception of Motion Across Sensory Modalities

    Science.gov (United States)

    Soto-Faraco, Salvador; Spence, Charles; Kingstone, Alan

    2004-01-01

    This study investigated multisensory interactions in the perception of auditory and visual motion. When auditory and visual apparent motion streams are presented concurrently in opposite directions, participants often fail to discriminate the direction of motion of the auditory stream, whereas perception of the visual stream is unaffected by the…

  12. Substantiating Appropriate Motion Capture Techniques for the Assessment of Nordic Walking Gait and Posture in Older Adults.

    Science.gov (United States)

    Dalton, Christopher M; Nantel, Julie

    2016-05-12

    Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques have been employed, each with positives and negatives. The aim was to determine the effect of NW on older adult gait and posture and to determine optimal use of different data collection systems in both short and long duration analysis. Gait and posture during NW and normal walking were assessed in 17 healthy older adults (age: 69 ± 7.3). Participants performed two trials of 6 Minute Walk Tests (6MWT) (1 with poles (WP) and 1 without poles (NP)) and 6 trials of a 5m walk (3 WP and 3 NP). Motion was recorded using two systems, a 6-sensor accelerometry system and an 8-camera 3-dimensional motion capture system, in order to quantify spatial-temporal, kinematic, and kinetic parameters. With both systems, participants demonstrated increased stride length and double support and decreased gait speed and cadence WP compared to NP (p motion capture, larger single support time was found WP (p capture, smaller hip power generation and moments of force were found at heel contact and pre-swing as well as smaller knee power absorption at heel contact, pre-swing, and terminal swing WP compared to NP, when assessed over one cycle (p motion capture should primarily be used during short duration gait analysis (i.e. single gait cycle), while accelerometry systems should be primarily employed in instances requiring longer duration analysis such as during the 6MWT.

  13. Agreement of spatio-temporal gait parameters between a vertical ground reaction force decomposition algorithm and a motion capture system.

    Science.gov (United States)

    Veilleux, Louis-Nicolas; Raison, Maxime; Rauch, Frank; Robert, Maxime; Ballaz, Laurent

    2016-01-01

    A ground reaction force decomposition algorithm based on large force platform measurements has recently been developed to analyze ground reaction forces under each foot during the double support phase of gait. However, its accuracy for the measurement of the spatiotemporal gait parameters remains to be established. The aim of the present study was to establish the agreement between the spatiotemporal gait parameters obtained using (1) a walkway (composed of six large force platforms) and the newly developed algorithm, and (2) an optoelectronic motion capture system. Twenty healthy children and adolescents (age range: 6-17 years) and 19 healthy adults (age range: 19-51 years) participated in this study. They were asked to walk at their preferred speed and at a speed that was faster than the preferred one. Each participant performed three blocks of three trials in each of the two walking speed conditions. The spatiotemporal gait parameters measured with the algorithm did not differ by more than 2.5% from those obtained with the motion capture system. The limits of agreement represented between 3% and 8% of the average spatiotemporal gait parameters. Repeatability of the algorithm was slightly higher than that of the motion capture system as the coefficient of variations ranged from 2.5% to 6%, and from 1.5% to 3.5% for the algorithm and the motion capture system, respectively. The proposed algorithm provides valid and repeatable spatiotemporal gait parameter measurements and offers a promising tool for clinical gait analysis. Further studies are warranted to test the algorithm in people with impaired gait. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. A novel tool and procedure for in-situ volumetric calibration of motion capture systems for breathing analysis.

    Science.gov (United States)

    Massaroni, C; Schena, E; Saccomandi, P; Silvestri, S

    2016-08-01

    Optical motion capture systems are widely used in biomechanics although have not been significantly explored for measuring volumes and volume variations yet. The aim of this study was to propose and test a completely novel procedure for the calibration of motion capture systems for the breathing analysis in terms of volume measurements, by the use of a tool consisting in an ad-hoc designed in-situ calibration device (CD) and two algorithms for calibration. Both the calibration tool and the calibration procedure performed in the range 0-2780mL on an Optoelectronic Plethysmography (OEP) system are presented. The CD delivered known volume (ΔVCD) variations to the OEP; the two algorithms performed the calibration by the comparison between ΔVCD and OEP recorded volume (ΔVOEP), in both static and dynamic conditions. Discrimination threshold, accuracy, precision and repeatability for the volume variation measurements have been evaluated, as well as the calibration curve of the OEP. OEP volume threshold of ±8.92mL was assessed; the volume measurement accuracy was always better than 6.0% of measured volume, and a volume repeatability of ±2.7mL was found. Lastly, the calibration curve was assessed to be ΔVOEP= 0.962·ΔVCD. Results demonstrate that the proposed calibration procedure can be useful to provide an in-situ accurate calibration of motion capture systems in the volume analysis, to optimize the hardware and the software of the available system for volume measurement as well as to establish the motion capture system appropriateness, in terms of technical suitability and data quality.

  15. Finite helical axis for the analysis of joint kinematics: comparison of an electromagnetic and an optical motion capture system.

    Science.gov (United States)

    Cescon, Corrado; Tettamanti, Andrea; Barbero, Marco; Gatti, Roberto

    2015-01-01

    The analysis of joints kinematics is important in clinical practice and in research. Nowadays it is possible to evaluate the mobility of joints in vivo with different motion capture techniques available in the market. Optical systems use infrared cameras and reflective markers to evaluate body movements, while other systems use electromagnetic fields to detect position and orientation of sensors. The aim of this study was the evaluation of two motion capture systems based on different technologies (optical and electromagnetic) by comparing the distribution of finite helical axis (FHA) of rotation during controlled rotations of an object in different positions. The distribution of position and angle errors of the FHA were extracted by optical and electromagnetic system recordings during a controlled rotation of a low friction stool in different positions in a controlled environment. The optical motion capture system showed lower angle and position errors in the distribution of FHA while the electromagnetic system had higher errors that increased with increasing distance from the antenna. The optical system showed lower errors in the estimation of FHA that could make it preferable with respect to electromagnetic systems during joint kinematics.

  16. Temporal-spatial reach parameters derived from inertial sensors: Comparison to 3D marker-based motion capture.

    Science.gov (United States)

    Cahill-Rowley, Katelyn; Rose, Jessica

    2017-02-08

    Reaching is a well-practiced functional task crucial to daily living activities, and temporal-spatial measures of reaching reflect function for both adult and pediatric populations with upper-extremity motor impairments. Inertial sensors offer a mobile and inexpensive tool for clinical assessment of movement. This research outlines a method for measuring temporal-spatial reach parameters using inertial sensors, and validates these measures with traditional marker-based motion capture. 140 reaches from 10 adults, and 30 reaches from nine children aged 18-20 months, were recorded and analyzed using both inertial-sensor and motion-capture methods. Inertial sensors contained three-axis accelerometers, gyroscopes, and magnetometers. Gravitational offset of accelerometer data was measured when the sensor was at rest, and removed using sensor orientation measured at rest and throughout the reach. Velocity was calculated by numeric integration of acceleration, using a null-velocity assumption at reach start. Sensor drift was neglected given the 1-2s required for a reach. Temporal-spatial reach parameters were calculated independently for each data acquisition method. Reach path length and distance, peak velocity magnitude and timing, and acceleration at contact demonstrated consistent agreement between sensor- and motion-capture-based methods, for both adult and toddler reaches, as evaluated by intraclass correlation coefficients from 0.61 to 1.00. Taken together with actual difference between method measures, results indicate that these functional reach parameters may be reliably measured with inertial sensors. Copyright © 2016. Published by Elsevier Ltd.

  17. Using motion capture technology to measure the effects of magnification loupes on dental operator posture: A pilot study.

    Science.gov (United States)

    Branson, B G; Abnos, R M; Simmer-Beck, M L; King, G W; Siddicky, S F

    2018-01-01

    Motion analysis has great potential for quantitatively evaluating dental operator posture and the impact of interventions such as magnification loupes on posture and subsequent development of musculoskeletal disorders. This study sought to determine the feasibility of motion capture technology for measurement of dental operator posture and examine the impact that different styles of magnification loupes had on dental operator posture. Forward and lateral head flexion were measured for two different operators while completing a periodontal probing procedure. Each was measured while wearing magnification loupes (flip up-FL and through the lens-TTL) and basic safety lenses. Operators both exhibited reduced forward flexion range of motion (ROM) when using loupes (TTL or FL) compared to a baseline lens (BL). In contrast to forward flexion, no consistent trends were observed for lateral flexion between subjects. The researchers can report that it is possible to measure dental operator posture using motion capture technology. More study is needed to determine which type of magnification loupes (FL or TTL) are superior in improving dental operator posture. Some evidence was found supporting that the quality of operator posture may more likely be related to the use of magnification loupes, rather than the specific type of lenses worn.

  18. Comparison of markerless and marker-based motion capture technologies through simultaneous data collection during gait: proof of concept.

    Science.gov (United States)

    Ceseracciu, Elena; Sawacha, Zimi; Cobelli, Claudio

    2014-01-01

    During the last decade markerless motion capture techniques have gained an increasing interest in the biomechanics community. In the clinical field, however, the application of markerless techniques is still debated. This is mainly due to a limited number of papers dedicated to the comparison with the state of the art of marker based motion capture, in term of repeatability of the three dimensional joints' kinematics. In the present work the application of markerless technique to data acquired with a marker-based system was investigated. All videos and external data were recorded with the same motion capture system and included the possibility to use markerless and marker-based methods simultaneously. Three dimensional markerless joint kinematics was estimated and compared with the one determined with traditional marker based systems, through the evaluation of root mean square distance between joint rotations. In order to compare the performance of markerless and marker-based systems in terms of clinically relevant joint angles estimation, the same anatomical frames of reference were defined for both systems. Differences in calibration and synchronization of the cameras were excluded by applying the same wand calibration and lens distortion correction to both techniques. Best results were achieved for knee flexion-extension angle, with an average root mean square distance of 11.75 deg, corresponding to 18.35% of the range of motion. Sagittal plane kinematics was estimated better than on the other planes also for hip and ankle (root mean square distance of 17.62 deg e.g. 44.66%, and 7.17 deg e.g. 33.12%), meanwhile estimates for hip joint were the most incorrect. This technique enables users of markerless technology to compare differences with marker-based in order to define the degree of applicability of markerless technique.

  19. Comparison of markerless and marker-based motion capture technologies through simultaneous data collection during gait: proof of concept.

    Directory of Open Access Journals (Sweden)

    Elena Ceseracciu

    Full Text Available During the last decade markerless motion capture techniques have gained an increasing interest in the biomechanics community. In the clinical field, however, the application of markerless techniques is still debated. This is mainly due to a limited number of papers dedicated to the comparison with the state of the art of marker based motion capture, in term of repeatability of the three dimensional joints' kinematics. In the present work the application of markerless technique to data acquired with a marker-based system was investigated. All videos and external data were recorded with the same motion capture system and included the possibility to use markerless and marker-based methods simultaneously. Three dimensional markerless joint kinematics was estimated and compared with the one determined with traditional marker based systems, through the evaluation of root mean square distance between joint rotations. In order to compare the performance of markerless and marker-based systems in terms of clinically relevant joint angles estimation, the same anatomical frames of reference were defined for both systems. Differences in calibration and synchronization of the cameras were excluded by applying the same wand calibration and lens distortion correction to both techniques. Best results were achieved for knee flexion-extension angle, with an average root mean square distance of 11.75 deg, corresponding to 18.35% of the range of motion. Sagittal plane kinematics was estimated better than on the other planes also for hip and ankle (root mean square distance of 17.62 deg e.g. 44.66%, and 7.17 deg e.g. 33.12%, meanwhile estimates for hip joint were the most incorrect. This technique enables users of markerless technology to compare differences with marker-based in order to define the degree of applicability of markerless technique.

  20. ALGORITHMS FOR TENNIS RACKET ANALYSIS BASED ON MOTION DATA

    Directory of Open Access Journals (Sweden)

    Maria Skublewska-Paszkowska

    2016-09-01

    Full Text Available Modern technologies, such as motion capture systems (both optical and markerless, are more and more frequently used for athlete performance analysis due to their great precision. Optical systems based on the retro-reflective markers allow for tracking motion of multiple objects of various types. These systems compute human kinetic and kinematic parameters based on biomechanical models. Tracking additional objects like a tennis racket is also a very important aspect for analysing the player’s technique and precision. The motion data gathered by motion capture systems may be used for analysing various aspects that may not be recognised by the human eye or a video camera. This paper presents algorithms for analysis of a tennis racket motion during two of the most important tennis strokes: forehand and backhand. An optical Vicon system was used for obtaining the motion data which was the input for the algorithms. They indicate: the velocity of a tennis racket’s head and the racket’s handle based on the trajectories of attached markers as well as the racket’s orientation. The algorithms were implemented and tested on the data obtained from a professional trainer who participated in the research and performed a series of ten strikes, separately for: 1 forehand without a ball, 2 backhand without a ball, 3 forehand with a ball and 4 backhand with a ball. The computed parameters are gathered in tables and visualised in a graph.

  1. TWO-DIMENSIONAL VIDEO ANALYSIS IS COMPARABLE TO 3D MOTION CAPTURE IN LOWER EXTREMITY MOVEMENT ASSESSMENT.

    Science.gov (United States)

    Schurr, Stacy A; Marshall, Ashley N; Resch, Jacob E; Saliba, Susan A

    2017-04-01

    Although 3D motion capture is considered the "gold standard" for recording and analyzing kinematics, 2D video analysis may be a more reasonable, inexpensive, and portable option for kinematic assessment during pre-participation screenings. Few studies have compared quantitative measurements of lower extremity functional tasks between 2D and 3D. To compare kinematic measurements of the trunk and lower extremity in the frontal and sagittal planes between 2D video camera and 3D motion capture analyses obtained concurrently during a SLS. Descriptive laboratory study. Twenty-six healthy, recreationally active adults volunteered to participate. Participants performed three trials of the single leg squat on each limb, which were recorded simultaneously by three 2D video cameras and a 3D motion capture system. Dependent variables analyzed were joint displacement at the trunk, hip, knee, and ankle in the frontal and sagittal planes during the task compared to single leg quiet standing. Dependent variables exhibited moderate to strong correlations between the two measures in the sagittal plane ( r  = 0.51-.093), and a poor correlation at the knee in the frontal plane ( r  = 0.308) at ( p  ≤ 0.05) All other dependent variables revealed non-significant results between the two measures. Bland-Altman plots revealed strong agreement in the average mean difference in the amount of joint displacement between 2D and 3D in the sagittal plane (trunk = 1.68 º, hip = 2.60 º, knee = 0.74 º, and ankle = 3.12 º). Agreement in the frontal plane was good (trunk = 7.92 °, hip = -8.72 º, knee = -6.62 º, and ankle = 3.03 °). Moderate to strong relationships were observed between 2D video camera and 3D motion capture analyses at all joints in the sagittal plane, and the average mean difference was comparable to the standard error of measure with goniometry. The results suggest that despite the lack of precision and ability to

  2. A MAC protocol with high scalability for motion capture based on frequency division multiple and time division multiple access.

    Science.gov (United States)

    Wang Yongfeng; Jie Li; Shengyun Liang; Yingnan Ma; Xing Gao; Shuncheng Fan; Yunkun Ning; Cuiju Xiong; Lei Wang; Guoru Zhao

    2017-07-01

    A good performance of motion capture, which belongs to body sensor network, depends on a reasonable design of MAC protocol. The purpose of this study is to design a reliable and highly extensible protocol for applying in motion capture. The proposed MAC protocol can easily be actualized by the timer in the chip. With this MAC protocol, the network would be built quickly. One or more nodes could be added easily in the net or deleted randomly from the net. In order to verify the superiority of this protocol, a series of experiments were designed. The results showed that the mean of simulation receive frames for node1-node7 from each stage were very close to the original frames. In addition, the final Pocket Loss Rates for node1-node7 were 0.081%, 0.175%, 0.143%, 0.249%, 0.248%, 0.044% and 1.897%, which could be in the error-allowed range. Thus, this protocol is stable and reliable, which can be widely used to capture human movement signal.

  3. Estimating 3D L5/S1 moments and ground reaction forces during trunk bending using a full-body ambulatory inertial motion capture system

    NARCIS (Netherlands)

    Faber, G.S.; Chang, C.C.; Kingma, I.; Dennerlein, J.T.; van Dieen, J.H.

    2016-01-01

    Inertial motion capture (IMC) systems have become increasingly popular for ambulatory movement analysis. However, few studies have attempted to use these measurement techniques to estimate kinetic variables, such as joint moments and ground reaction forces (GRFs). Therefore, we investigated the

  4. Utilizing Commercial Hardware and Open Source Computer Vision Software to Perform Motion Capture for Reduced Gravity Flight

    Science.gov (United States)

    Humphreys, Brad; Bellisario, Brian; Gallo, Christopher; Thompson, William K.; Lewandowski, Beth

    2016-01-01

    Long duration space travel to Mars or to an asteroid will expose astronauts to extended periods of reduced gravity. Since gravity is not present to aid loading, astronauts will use resistive and aerobic exercise regimes for the duration of the space flight to minimize the loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the area available for an exercise device in the next generation of spacecraft is limited. Therefore, compact resistance exercise device prototypes are being developed. The NASA Digital Astronaut Project (DAP) is supporting the Advanced Exercise Concepts (AEC) Project, Exercise Physiology and Countermeasures (ExPC) project and the National Space Biomedical Research Institute (NSBRI) funded researchers by developing computational models of exercising with these new advanced exercise device concepts. To perform validation of these models and to support the Advanced Exercise Concepts Project, several candidate devices have been flown onboard NASAs Reduced Gravity Aircraft. In terrestrial laboratories, researchers typically have available to them motion capture systems for the measurement of subject kinematics. Onboard the parabolic flight aircraft it is not practical to utilize the traditional motion capture systems due to the large working volume they require and their relatively high replacement cost if damaged. To support measuring kinematics on board parabolic aircraft, a motion capture system is being developed utilizing open source computer vision code with commercial off the shelf (COTS) video camera hardware. While the systems accuracy is lower than lab setups, it provides a means to produce quantitative comparison motion capture kinematic data. Additionally, data such as required exercise volume for small spaces such as the Orion capsule can be determined. METHODS: OpenCV is an open source computer vision library that provides the

  5. Computer Animation Complete All-in-One; Learn Motion Capture, Characteristic, Point-Based, and Maya Winning Techniques

    CERN Document Server

    Parent, Rick

    2009-01-01

    A compilation of key chapters from the top MK computer animation books available today - in the areas of motion capture, facial features, solid spaces, fluids, gases, biology, point-based graphics, and Maya. The chapters provide CG Animators with an excellent sampling of essential techniques that every 3D artist needs to create stunning and versatile images. Animators will be able to master myriad modeling, rendering, and texturing procedures with advice from MK's best and brightest authors. Learn hundreds of tips, tricks, shortcuts and more - all within the covers of one complete, inspiring r

  6. Motion statistics at the saccade landing point: attentional capture by spatiotemporal features in a gaze-contingent reference

    Science.gov (United States)

    Belardinelli, Anna; Carbone, Andrea

    2012-06-01

    Motion is known to play a fundamental role in attentional capture, still it is not always included in computational models of visual attention. A wealth of literature in the past years has investigated natural image statistics at the centre of gaze to assess static low-level features accounting for fixation capture on images. A motion counterpart describing which features trigger saccades on dynamic scenes has been less looked into, whereas it would provide significant insight on the visuomotor behaviour when attending to events instead of less realistic still images. Such knowledge would be paramount to devise active vision systems that can spot interesting or malicious activities and disregard less relevant patterns. In this paper, we present an analysis of spatiotemporal features at the future centre of gaze to extract possible regularities in the fixation distribution to contrast with the feature distribution of non-fixated points. A substantial novelty in the methodology is the evaluation of the features in a gaze-contingent reference. Each video sequence fragment is indeed foveated with respect to the current fixation, while features are collected at the next saccade landing point. This allows us to estimate covertly selected motion cues in a retinotopic fashion. We consider video sequences and eye-tracking data from a recent state-of-the art dataset and test a bottom-up motion saliency measure against human performance. Obtained results can be used to further tune saliency computational models and to learn to predict human fixations on video sequences or generate meaningful shifts of active sensors in real world scenarios.

  7. Benchmarking Close-range Structure from Motion 3D Reconstruction Software under Varying Capturing Conditions

    DEFF Research Database (Denmark)

    Nikolov, Ivan Adriyanov; Madsen, Claus B.

    2016-01-01

    Structure from Motion 3D reconstruction has become widely used in recent years in a number of fields such as industrial surface in- inspection, archeology, cultural heritage preservation and geomapping. A number of software solutions have been released using variations of this technique. In this ......Structure from Motion 3D reconstruction has become widely used in recent years in a number of fields such as industrial surface in- inspection, archeology, cultural heritage preservation and geomapping. A number of software solutions have been released using variations of this technique...

  8. Assessment of congruence and impingement of the hip joint in professional ballet dancers: a motion capture study.

    Science.gov (United States)

    Charbonnier, Caecilia; Kolo, Frank C; Duthon, Victoria B; Magnenat-Thalmann, Nadia; Becker, Christoph D; Hoffmeyer, Pierre; Menetrey, Jacques

    2011-03-01

    Early hip osteoarthritis in dancers could be explained by femoroacetabular impingements. However, there is a lack of validated noninvasive methods and dynamic studies to ascertain impingement during motion. Moreover, it is unknown whether the femoral head and acetabulum are congruent in typical dancing positions. The practice of some dancing movements could cause a loss of hip joint congruence and recurrent impingements, which could lead to early osteoarthritis. Descriptive laboratory study. Eleven pairs of female dancer's hips were motion captured with an optical tracking system while performing 6 different dancing movements. The resulting computed motions were applied to patient-specific hip joint 3-dimensional models based on magnetic resonance images. While visualizing the dancer's hip in motion, the authors detected impingements using computer-assisted techniques. The range of motion and congruence of the hip joint were also quantified in those 6 recorded dancing movements. The frequency of impingement and subluxation varied with the type of movement. Four dancing movements (développé à la seconde, grand écart facial, grand écart latéral, and grand plié) seem to induce significant stress in the hip joint, according to the observed high frequency of impingement and amount of subluxation. The femoroacetabular translations were high (range, 0.93 to 6.35 mm). For almost all movements, the computed zones of impingement were mainly located in the superior or posterosuperior quadrant of the acetabulum, which was relevant with respect to radiologically diagnosed damaged zones in the labrum. All dancers' hips were morphologically normal. Impingements and subluxations are frequently observed in typical ballet movements, causing cartilage hypercompression. These movements should be limited in frequency. The present study indicates that some dancing movements could damage the hip joint, which could lead to early osteoarthritis.

  9. Improved Machine Tool Linear Axis Calibration Through Continuous Motion Data Capture

    OpenAIRE

    Miller, J. E.; Longstaff, A.P.; Parkinson, S.; Fletcher, S

    2017-01-01

    Machine tool calibration is becoming recognised as an important part of the manufacturing process. The current international standards for machine tool linear axes calibration support the use of quasi-static calibration techniques. These techniques can be time consuming but more importantly a compromise in quality due to the practical restriction on the spatial resolution of target positions on the axis under test. Continuous motion calibration techniques have the potential to dramatically in...

  10. Human Actions Analysis: Templates Generation, Matching and Visualization Applied to Motion Capture of Highly-Skilled Karate Athletes

    Directory of Open Access Journals (Sweden)

    Tomasz Hachaj

    2017-11-01

    Full Text Available The aim of this paper is to propose and evaluate the novel method of template generation, matching, comparing and visualization applied to motion capture (kinematic analysis. To evaluate our approach, we have used motion capture recordings (MoCap of two highly-skilled black belt karate athletes consisting of 560 recordings of various karate techniques acquired with wearable sensors. We have evaluated the quality of generated templates; we have validated the matching algorithm that calculates similarities and differences between various MoCap data; and we have examined visualizations of important differences and similarities between MoCap data. We have concluded that our algorithms works the best when we are dealing with relatively short (2–4 s actions that might be averaged and aligned with the dynamic time warping framework. In practice, the methodology is designed to optimize the performance of some full body techniques performed in various sport disciplines, for example combat sports and martial arts. We can also use this approach to generate templates or to compare the correct performance of techniques between various top sportsmen in order to generate a knowledge base of reference MoCap videos. The motion template generated by our method can be used for action recognition purposes. We have used the DTW classifier with angle-based features to classify various karate kicks. We have performed leave-one-out action recognition for the Shorin-ryu and Oyama karate master separately. In this case, 100 % actions were correctly classified. In another experiment, we used templates generated from Oyama master recordings to classify Shorin-ryu master recordings and vice versa. In this experiment, the overall recognition rate was 94.2 % , which is a very good result for this type of complex action.

  11. Human Actions Analysis: Templates Generation, Matching and Visualization Applied to Motion Capture of Highly-Skilled Karate Athletes.

    Science.gov (United States)

    Hachaj, Tomasz; Piekarczyk, Marcin; Ogiela, Marek R

    2017-11-10

    The aim of this paper is to propose and evaluate the novel method of template generation, matching, comparing and visualization applied to motion capture (kinematic) analysis. To evaluate our approach, we have used motion capture recordings (MoCap) of two highly-skilled black belt karate athletes consisting of 560 recordings of various karate techniques acquired with wearable sensors. We have evaluated the quality of generated templates; we have validated the matching algorithm that calculates similarities and differences between various MoCap data; and we have examined visualizations of important differences and similarities between MoCap data. We have concluded that our algorithms works the best when we are dealing with relatively short (2-4 s) actions that might be averaged and aligned with the dynamic time warping framework. In practice, the methodology is designed to optimize the performance of some full body techniques performed in various sport disciplines, for example combat sports and martial arts. We can also use this approach to generate templates or to compare the correct performance of techniques between various top sportsmen in order to generate a knowledge base of reference MoCap videos. The motion template generated by our method can be used for action recognition purposes. We have used the DTW classifier with angle-based features to classify various karate kicks. We have performed leave-one-out action recognition for the Shorin-ryu and Oyama karate master separately. In this case, 100 % actions were correctly classified. In another experiment, we used templates generated from Oyama master recordings to classify Shorin-ryu master recordings and vice versa. In this experiment, the overall recognition rate was 94.2 % , which is a very good result for this type of complex action.

  12. Human Actions Analysis: Templates Generation, Matching and Visualization Applied to Motion Capture of Highly-Skilled Karate Athletes

    Science.gov (United States)

    Piekarczyk, Marcin; Ogiela, Marek R.

    2017-01-01

    The aim of this paper is to propose and evaluate the novel method of template generation, matching, comparing and visualization applied to motion capture (kinematic) analysis. To evaluate our approach, we have used motion capture recordings (MoCap) of two highly-skilled black belt karate athletes consisting of 560 recordings of various karate techniques acquired with wearable sensors. We have evaluated the quality of generated templates; we have validated the matching algorithm that calculates similarities and differences between various MoCap data; and we have examined visualizations of important differences and similarities between MoCap data. We have concluded that our algorithms works the best when we are dealing with relatively short (2–4 s) actions that might be averaged and aligned with the dynamic time warping framework. In practice, the methodology is designed to optimize the performance of some full body techniques performed in various sport disciplines, for example combat sports and martial arts. We can also use this approach to generate templates or to compare the correct performance of techniques between various top sportsmen in order to generate a knowledge base of reference MoCap videos. The motion template generated by our method can be used for action recognition purposes. We have used the DTW classifier with angle-based features to classify various karate kicks. We have performed leave-one-out action recognition for the Shorin-ryu and Oyama karate master separately. In this case, 100% actions were correctly classified. In another experiment, we used templates generated from Oyama master recordings to classify Shorin-ryu master recordings and vice versa. In this experiment, the overall recognition rate was 94.2%, which is a very good result for this type of complex action. PMID:29125560

  13. Study of human body: Kinematics and kinetics of a martial arts (Silat) performers using 3D-motion capture

    Science.gov (United States)

    Soh, Ahmad Afiq Sabqi Awang; Jafri, Mohd Zubir Mat; Azraai, Nur Zaidi

    2015-04-01

    The Interest in this studies of human kinematics goes back very far in human history drove by curiosity or need for the understanding the complexity of human body motion. To find new and accurate information about the human movement as the advance computing technology became available for human movement that can perform. Martial arts (silat) were chose and multiple type of movement was studied. This project has done by using cutting-edge technology which is 3D motion capture to characterize and to measure the motion done by the performers of martial arts (silat). The camera will detect the markers (infrared reflection by the marker) around the performer body (total of 24 markers) and will show as dot in the computer software. The markers detected were analyzing using kinematic kinetic approach and time as reference. A graph of velocity, acceleration and position at time,t (seconds) of each marker was plot. Then from the information obtain, more parameters were determined such as work done, momentum, center of mass of a body using mathematical approach. This data can be used for development of the effectiveness movement in martial arts which is contributed to the people in arts. More future works can be implemented from this project such as analysis of a martial arts competition.

  14. 3D measurements of alpine skiing with an inertial sensor motion capture suit and GNSS RTK system.

    Science.gov (United States)

    Supej, Matej

    2010-05-01

    To date, camcorders have been the device of choice for 3D kinematic measurement in human locomotion, in spite of their limitations. This study examines a novel system involving a GNSS RTK that returns a reference trajectory through the use of a suit, imbedded with inertial sensors, to reveal subject segment motion. The aims were: (1) to validate the system's precision and (2) to measure an entire alpine ski race and retrieve the results shortly after measuring. For that purpose, four separate experiments were performed: (1) forced pendulum, (2) walking, (3) gate positions, and (4) skiing experiments. Segment movement validity was found to be dependent on the frequency of motion, with high accuracy (0.8 degrees , s = 0.6 degrees ) for 10 s, which equals approximately 10 slalom turns, while accuracy decreased slightly (2.1 degrees , 3.3 degrees , and 4.2 degrees for 0.5, 1, and 2 Hz oscillations, respectively) during 35 s of data collection. The motion capture suit's orientation inaccuracy was mostly due to geomagnetic secular variation. The system exhibited high validity regarding the reference trajectory (0.008 m, s = 0.0044) throughout an entire ski race. The system is capable of measuring an entire ski course with less manpower and therefore lower cost compared with camcorder-based techniques.

  15. A Novel Technology for Motion Capture Using Passive UHF RFID Tags

    DEFF Research Database (Denmark)

    Krigslund, Rasmus; Popovski, Petar; Pedersen, Gert Frølund

    2013-01-01

    ) tags placed on the body segments whose kinematics is to be captured. Dual polarized antennas are used to estimate the inclination of each tag based on the polarization of the tag responses. The method has been validated experimentally for the shank and thigh in the sagittal plane during treadmill...... walking. The reference joint angles for the validation were obtained by an optoelectronic system. Although the method is in its initial phase of development, the results of the validation are promising and show that the movement information can be extracted from the RFID response signals....

  16. The measurement of in vivo joint angles during a squat using a single camera markerless motion capture system as compared to a marker based system.

    Science.gov (United States)

    Schmitz, Anne; Ye, Mao; Boggess, Grant; Shapiro, Robert; Yang, Ruigang; Noehren, Brian

    2015-02-01

    Markerless motion capture may have the potential to make motion capture technology widely clinically practical. However, the ability of a single markerless camera system to quantify clinically relevant, lower extremity joint angles has not been studied in vivo. Therefore, the goal of this study was to compare in vivo joint angles calculated using a marker-based motion capture system and a Microsoft Kinect during a squat. Fifteen individuals participated in the study: 8 male, 7 female, height 1.702±0.089m, mass 67.9±10.4kg, age 24±4 years, BMI 23.4±2.2kg/m(2). Marker trajectories and Kinect depth map data of the leg were collected while each subject performed a slow squat motion. Custom code was used to export virtual marker trajectories for the Kinect data. Each set of marker trajectories was utilized to calculate Cardan knee and hip angles. The patterns of motion were similar between systems with average absolute differences of 0.9 for both systems. The peak angles calculated by the marker-based and Kinect systems were largely correlated (r>0.55). These results suggest the data from the Kinect can be post processed in way that it may be a feasible markerless motion capture system that can be used in the clinic. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Development of a Wearable Device for Motion Capturing Based on Magnetic and Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Bin Fang

    2017-01-01

    Full Text Available This paper presents a novel wearable device for gesture capturing based on inertial and magnetic measurement units that are made up of micromachined gyroscopes, accelerometers, and magnetometers. The low-cost inertial and magnetic measurement unit is compact and small enough to wear and there are altogether thirty-six units integrated in the device. The device is composed of two symmetric parts, and either the right part or the left one contains eighteen units covering all the segments of the arm, palm, and fingers. The offline calibration and online calibration are proposed to improve the accuracy of sensors. Multiple quaternion-based extended Kalman filters are designed to estimate the absolute orientations, and kinematic models of the arm-hand are considered to determine the relative orientations. Furthermore, position algorithm is deduced to compute the positions of corresponding joint. Finally, several experiments are implemented to verify the effectiveness of the proposed wearable device.

  18. The 3D Human Motion Control Through Refined Video Gesture Annotation

    Science.gov (United States)

    Jin, Yohan; Suk, Myunghoon; Prabhakaran, B.

    In the beginning of computer and video game industry, simple game controllers consisting of buttons and joysticks were employed, but recently game consoles are replacing joystick buttons with novel interfaces such as the remote controllers with motion sensing technology on the Nintendo Wii [1] Especially video-based human computer interaction (HCI) technique has been applied to games, and the representative game is 'Eyetoy' on the Sony PlayStation 2. Video-based HCI technique has great benefit to release players from the intractable game controller. Moreover, in order to communicate between humans and computers, video-based HCI is very crucial since it is intuitive, easy to get, and inexpensive. On the one hand, extracting semantic low-level features from video human motion data is still a major challenge. The level of accuracy is really dependent on each subject's characteristic and environmental noises. Of late, people have been using 3D motion-capture data for visualizing real human motions in 3D space (e.g, 'Tiger Woods' in EA Sports, 'Angelina Jolie' in Bear-Wolf movie) and analyzing motions for specific performance (e.g, 'golf swing' and 'walking'). 3D motion-capture system ('VICON') generates a matrix for each motion clip. Here, a column is corresponding to a human's sub-body part and row represents time frames of data capture. Thus, we can extract sub-body part's motion only by selecting specific columns. Different from low-level feature values of video human motion, 3D human motion-capture data matrix are not pixel values, but is closer to human level of semantics.

  19. Continuous ambulatory hand force monitoring during manual materials handling using instrumented force shoes and an inertial motion capture suit.

    Science.gov (United States)

    Faber, G S; Koopman, A S; Kingma, I; Chang, C C; Dennerlein, J T; van Dieën, J H

    2017-10-25

    Hand forces (HFs) are commonly measured during biomechanical assessment of manual materials handling; however, it is often a challenge to directly measure HFs in field studies. Therefore, in a previous study we proposed a HF estimation method based on ground reaction forces (GRFs) and body segment accelerations and tested it with laboratory equipment: GFRs were measured with force plates (FPs) and segment accelerations were measured using optical motion capture (OMC). In the current study, we evaluated the HF estimation method based on an ambulatory measurement system, consisting of inertial motion capture (IMC) and instrumented force shoes (FSs). Sixteen participants lifted and carried a 10-kg crate from ground level while 3D full-body kinematics were measured using OMC and IMC, and 3D GRFs were measured using FPs and FSs. We estimated 3D hand force vectors based on: (1) FP+OMC, (2) FP+IMC and (3) FS+IMC. We calculated the root-mean-square differences (RMSDs) between the estimated HFs to reference HFs calculated based on crate kinematics and the GRFs of a FP that the crate was lifted from. Averaged over subjects and across 3D force directions, the HF RMSD ranged between 10-15N when using the laboratory equipment (FP + OMC), 11-18N when using the IMC instead of OMC data (FP+IMC), and 17-21N when using the FSs in combination with IMC (FS + IMC). This error is regarded acceptable for the assessment of spinal loading during manual lifting, as it would results in less than 5% error in peak moment estimates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Definition of anatomical zero positions for assessing shoulder pose with 3D motion capture during bilateral abduction of the arms.

    Science.gov (United States)

    Rettig, Oliver; Krautwurst, Britta; Maier, Michael W; Wolf, Sebastian I

    2015-12-09

    Surgical interventions at the shoulder may alter function of the shoulder complex. Clinically, the outcome can be assessed by universal goniometry. Marker-based motion capture may not resemble these results due to differing angle definitions. The clinical inspection of bilateral arm abduction for assessing shoulder dysfunction is performed with a marker based 3D optical measurement method. An anatomical zero position of shoulder pose is proposed to determine absolute angles according to the Neutral-0-Method as used in orthopedic context. Static shoulder positions are documented simultaneously by 3D marker tracking and universal goniometry in 8 young and healthy volunteers. Repetitive bilateral arm abduction movements of at least 150° range of motion are monitored. Similarly a subject with gleno-humeral osteoarthritis is monitored for demonstrating the feasibility of the method and to illustrate possible shoulder dysfunction effects. With mean differences of less than 2°, the proposed anatomical zero position results in good agreement between shoulder elevation/depression angles determined by 3D marker tracking and by universal goniometry in static positions. Lesser agreement is found for shoulder pro-/retraction with systematic deviations of up to 6°. In the bilateral arm abduction movements the volunteers perform a common and specific pattern in clavicula-thoracic and gleno-humeral motion with maximum shoulder angles of 32° elevation, 5° depression and 45° protraction, respectively, whereas retraction is hardly reached. Further, they all show relevant out of (frontal) plane motion with anteversion angles of 30° in overhead position (maximum abduction). With increasing arm anteversion the shoulder is increasingly retroverted, with a maximum of 20° retroversion. The subject with gleno-humeral osteoarthritis shows overall less shoulder abduction range of motion but with increased out-of-plane movement during abduction. The proposed anatomical zero definition

  1. Dealing with Magnetic Disturbances in Human Motion Capture: A Survey of Techniques

    Directory of Open Access Journals (Sweden)

    Gabriele Ligorio

    2016-03-01

    Full Text Available Magnetic-Inertial Measurement Units (MIMUs based on microelectromechanical (MEMS technologies are widespread in contexts such as human motion tracking. Although they present several advantages (lightweight, size, cost, their orientation estimation accuracy might be poor. Indoor magnetic disturbances represent one of the limiting factors for their accuracy, and, therefore, a variety of work was done to characterize and compensate them. In this paper, the main compensation strategies included within Kalman-based orientation estimators are surveyed and classified according to which degrees of freedom are affected by the magnetic data and to the magnetic disturbance rejection methods implemented. By selecting a representative method from each category, four algorithms were obtained and compared in two different magnetic environments: (1 small workspace with an active magnetic source; (2 large workspace without active magnetic sources. A wrist-worn MIMU was used to acquire data from a healthy subject, whereas a stereophotogrammetric system was adopted to obtain ground-truth data. The results suggested that the model-based approaches represent the best compromise between the two testbeds. This is particularly true when the magnetic data are prevented to affect the estimation of the angles with respect to the vertical direction.

  2. Motion capture and manipulation of a single synthetic molecular rotor by optical microscopy.

    Science.gov (United States)

    Ikeda, Tomohiro; Tsukahara, Takahiro; Iino, Ryota; Takeuchi, Masayuki; Noji, Hiroyuki

    2014-09-15

    Single-molecule imaging and manipulation with optical microscopy have become essential methods for studying biomolecular machines; however, only few efforts have been directed towards synthetic molecular machines. Single-molecule optical microscopy was now applied to a synthetic molecular rotor, a double-decker porphyrin (DD). By attaching a magnetic bead (ca. 200 nm) to the DD, its rotational dynamics were captured with a time resolution of 0.5 ms. DD showed rotational diffusion with 90° steps, which is consistent with its four-fold structural symmetry. Kinetic analysis revealed the first-order kinetics of the 90° step with a rate constant of 2.8 s(-1). The barrier height of the rotational potential was estimated to be greater than 7.4 kJ mol(-1) at 298 K. The DD was also forcibly rotated with magnetic tweezers, and again, four stable pausing angles that are separated by 90° were observed. These results demonstrate the potency of single-molecule optical microscopy for the elucidation of elementary properties of synthetic molecular machines. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Effect of Load Change on Foot Arch in Different Positions-Assessment of Foot Arch Using a Motion Analysis System and a Caliper-Goniometer System

    National Research Council Canada - National Science Library

    Maeda, Yusuke; Tanaka, Toshiaki; Miyasaka, Tomoya; Takayanagi, Kiyomi; Tsuruga, Takeshi

    2012-01-01

    [Purpose] The purpose of this study was to analyze the effect of load change on the foot arch in different foot positions using a Vicon motion analysis system and clinical assessment using a goniometer and calipers...

  4. Predictive error detection in pianists: A combined ERP and motion capture study

    Directory of Open Access Journals (Sweden)

    Clemens eMaidhof

    2013-09-01

    Full Text Available Performing a piece of music involves the interplay of several cognitive and motor processes and requires extensive training to achieve a high skill level. However, even professional musicians commit errors occasionally. Previous event-related potential (ERP studies have investigated the neurophysiological correlates of pitch errors during piano performance, and reported pre-error negativity already occurring approximately 70-100 ms before the error had been committed and audible. It was assumed that this pre-error negativity reflects predictive control processes that compare predicted consequences with actual consequences of one’s own actions. However, in previous investigations, correct and incorrect pitch events were confounded by their different tempi. In addition, no data about the underlying movements were available. In the present study, we exploratively recorded the ERPs and 3D movement data of pianists’ fingers simultaneously while they performed fingering exercises from memory. Results showed a pre-error negativity for incorrect keystrokes when both correct and incorrect keystrokes were performed with comparable tempi. Interestingly, even correct notes immediately preceding erroneous keystrokes elicited a very similar negativity. In addition, we explored the possibility of computing ERPs time-locked to a kinematic landmark in the finger motion trajectories defined by when a finger makes initial contact with the key surface, that is, at the onset of tactile feedback. Results suggest that incorrect notes elicited a small difference after the onset of tactile feedback, whereas correct notes preceding incorrect ones elicited negativity before the onset of tactile feedback. The results tentatively suggest that tactile feedback plays an important role in error-monitoring during piano performance, because the comparison between predicted and actual sensory (tactile feedback may provide the information necessary for the detection of an

  5. Smartphone viewing distance and sleep: an experimental study utilizing motion capture technology.

    Science.gov (United States)

    Yoshimura, Michitaka; Kitazawa, Momoko; Maeda, Yasuhiro; Mimura, Masaru; Tsubota, Kazuo; Kishimoto, Taishiro

    2017-01-01

    There are studies reporting the negative impact of smartphone utilization on sleep. It is considered that reduction of melatonin secretion under the blue light exposure from smart-phone displays is one of the causes. The viewing distance may cause sleep disturbance, because the viewing distance determines the screen illuminance and/or asthenopia. However, to date, there has been no study closely investigating the impact of viewing distance on sleep; therefore, we sought to determine the relationship between smartphone viewing distance and subjective sleep status. Twenty-three nursing students (mean age ± standard deviation of 19.7±3.1 years) participated in the study. Subjective sleep status was assessed using the Pittsburgh Sleep Quality Index, morningness-eveningness questionnaire, and the Epworth sleepiness scale. We used the distance between the head and the hand while holding a smartphone to measure the viewing distance while using smartphones in sitting and lying positions. The distance was calculated using the three-dimensional coordinates obtained by a noncontact motion-sensing device. The viewing distance of smartphones in the sitting position ranged from 13.3 to 32.9 cm among participants. In the lying position, it ranged from 9.9 to 21.3cm. The viewing distance was longer in the sitting position than in the lying position (mean ± standard deviation: 20.3±4.7 vs 16.4±2.7, respectively, Psleep state (R(2)=0.27, Psleep efficiency (R(2)=0.35, Psleep latency (R(2)=0.38, Psleep status. Therefore, when recommending ideal smartphone use in lying position, one should take into account the viewing distances.

  6. A comparison of accuracy and precision of 5 gait-event detection algorithms from motion capture in horses during over ground walk

    DEFF Research Database (Denmark)

    Olsen, Emil; Boye, Jenny Katrine; Pfau, Thilo

    2012-01-01

    Motion capture is frequently used over ground in equine locomotion science to study kinematics. Determination of gait events (hoof-on/off and stance) without force plates is essential to cut the data into strides. The lack of comparative evidence emphasise the need to compare existing algorithms...... surrounded by a 12-camera infrared motion capture system. The algorithms were based on horizontal or vertical velocity displacement and velocity of the hoof relative to the centre of mass movement or fetlock angle and velocity or displacement of the hoof. Horizontal hoof velocity relative to the centre...

  7. Smartphone viewing distance and sleep: an experimental study utilizing motion capture technology

    Directory of Open Access Journals (Sweden)

    Yoshimura M

    2017-03-01

    Full Text Available Michitaka Yoshimura,1,* Momoko Kitazawa,1–3,* Yasuhiro Maeda,2 Masaru Mimura,4 Kazuo Tsubota,1 Taishiro Kishimoto,4,5 1Department of Ophthalmology, Keio University School of Medicine, Tokyo, 2RIKEN Center for Advanced Photonics, Wako, Saitama, 3Department of Nursing, Aino University Junior College, 4Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan; 5Department of Psychiatry, Hofstra Northwell School of Medicine, NY, USA *These authors contributed equally to this work Abstract: There are studies reporting the negative impact of smartphone utilization on sleep. It is considered that reduction of melatonin secretion under the blue light exposure from smartphone displays is one of the causes. The viewing distance may cause sleep disturbance, because the viewing distance determines the screen illuminance and/or asthenopia. However, to date, there has been no study closely investigating the impact of viewing distance on sleep; therefore, we sought to determine the relationship between smartphone viewing distance and subjective sleep status. Twenty-three nursing students (mean age ± standard deviation of 19.7±3.1 years participated in the study. Subjective sleep status was assessed using the Pittsburgh Sleep Quality Index, morningness–eveningness questionnaire, and the Epworth sleepiness scale. We used the distance between the head and the hand while holding a smartphone to measure the viewing distance while using smartphones in sitting and lying positions. The distance was calculated using the three-dimensional coordinates obtained by a noncontact motion-sensing device. The viewing distance of smartphones in the sitting position ranged from 13.3 to 32.9 cm among participants. In the lying position, it ranged from 9.9 to 21.3cm. The viewing distance was longer in the sitting position than in the lying position (mean ± standard deviation: 20.3±4.7 vs 16.4±2.7, respectively, P<0.01. We found that the short viewing

  8. Motion

    CERN Document Server

    Graybill, George

    2007-01-01

    Take the mystery out of motion. Our resource gives you everything you need to teach young scientists about motion. Students will learn about linear, accelerating, rotating and oscillating motion, and how these relate to everyday life - and even the solar system. Measuring and graphing motion is easy, and the concepts of speed, velocity and acceleration are clearly explained. Reading passages, comprehension questions, color mini posters and lots of hands-on activities all help teach and reinforce key concepts. Vocabulary and language are simplified in our resource to make them accessible to str

  9. Using an Empirical Model of Human Turning Motion to Aid Heading Estimation in a Personal Navigation System

    Science.gov (United States)

    Jakel, Thomas

    With the adoption of Global Navigation Satellite Systems in smart phones, soldier equipment, and emergency responder navigation systems users have realized the usefulness of low cost Personal Navigation Systems. The state-of-the-art Personal Navigation System is a unit that fuses information based on external references with a low cost IMU. Due to the size, weight, power, and cost constraints imposed on a pedestrian navigation systems as well as current IMU performance limitations, the gyroscopes used to determine heading exhibit significant drift limiting the performance of the navigation system. In this thesis biomechanical signals are used to predict the onset of pedestrian turning motion. Experimental data from eight subjects captured in a gait laboratory using a Vicon motion tracking unit is used for validation. The analysis of experimental data shows the heading computed by turn prediction augmented integration is more accurate than open loop gyro integration alone.

  10. Neck range of motion measurements using a new three-dimensional motion analysis system: validity and repeatability.

    Science.gov (United States)

    Inokuchi, Haruhi; Tojima, Michio; Mano, Hiroshi; Ishikawa, Yuki; Ogata, Naoshi; Haga, Nobuhiko

    2015-12-01

    Neck movement is important for many activities of daily living (ADL). Neck disorders, such as cervical spondylosis and whiplash can limit neck movement and ADL. The cervical range of motion (CROM) device has been recently used to measure neck range of motion (ROM); however, this measurement includes trunk motion, and therefore does not represent a pure neck ROM measurement. The authors aimed to develop a new method to establish pure neck ROM measurements during flexion, extension, lateral bending, and rotation using a three-dimensional motion analysis system, VICON. Twelve healthy participants were recruited and neck ROMs during flexion, extension, lateral bending, and rotation were measured using VICON and the CROM device. Test-retest repeatability was assessed using interclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimal detectable change (MDC). Validity between two measurements was evaluated using a determination coefficient and Pearson's correlation coefficient. ICCs of neck ROM measured using VICON and the CROM device were all at substantial or almost perfect levels [VICON: ICC(1,2) = 0.786-0.962, the CROM device: ICC(1,2) = 0.736-0.950]. Both SEMs and MDCs were low in all measurement directions (VICON: SEM = 1.3°-4.5°, MDC = 3.6°-12.5°; the CROM device: SEM = 2.2°-3.9°, MDC = 6.1°-10.7°). Determination coefficients (R(2)s) and Pearson's correlation coefficients (rs) between the two measurement methods were high (R(2) = 0.607-0.745, r = 0.779-0.863). VICON is a useful system to measure neck ROMs and evaluate the efficacy of interventions, such as surgery or physiotherapeutic exercise.

  11. Predicted knee kinematics and kinetics during functional activities using motion capture and musculoskeletal modelling in healthy older people.

    Science.gov (United States)

    Worsley, Peter; Stokes, Maria; Taylor, Mark

    2011-02-01

    Knowledge of joint forces and moments is essential for comparisons between healthy people and those with pathological conditions, with observed changes at joints providing basis for a particular intervention. Currently the literature analysing both kinematics and kinetics at the knee has been limited to small samples, typically of young subjects or those who have undergone joint arthroplasty. In this study, we examined tibiofemoral joint (TFJ) kinematics and kinetics during gait, sit-stand-sit, and step-descent in 20 healthy older subjects (aged 53-79 years) using motion capture data and inverse dynamic musculoskeletal models. Mean peak distal-proximal force in the TFJ were 3.1, 1.6, and 3.5 times body weight (N/BW) for gait, sit-stand, and step-descent respectively. There were also significant posterior-anterior forces, with sit-stand activity peaking at 1.6 N/BW. Moments about the TFJ peaked at a mean of 0.07 Nm/BW during the sit-stand activity. One of the most important findings of this study was variability found across the subjects, who spanned a wide age range, showing large standard deviations in all of the activities for both kinematics and kinetics. These data have provided an initial prediction for assessing kinematics and kinetics in the older population. Larger studies are needed to refine the database, in particular to reduce the variability in the results by studying sub-populations, to enable more robust comparisons between healthy and pathological TFJ kinematics and kinetics. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Estimating 3D L5/S1 moments and ground reaction forces during trunk bending using a full-body ambulatory inertial motion capture system

    OpenAIRE

    Faber, G S; Chang, C. C.; Kingma, I.; Dennerlein, J.T.; van Dieen, J.H.

    2016-01-01

    Inertial motion capture (IMC) systems have become increasingly popular for ambulatory movement analysis. However, few studies have attempted to use these measurement techniques to estimate kinetic variables, such as joint moments and ground reaction forces (GRFs). Therefore, we investigated the performance of a full-body ambulatory IMC system in estimating 3D L5/S1 moments and GRFs during symmetric, asymmetric and fast trunk bending, performed by nine male participants. Using an ambulatory IM...

  13. Using Xbox kinect motion capture technology to improve clinical rehabilitation outcomes for balance and cardiovascular health in an individual with chronic TBI.

    Science.gov (United States)

    Chanpimol, Shane; Seamon, Bryant; Hernandez, Haniel; Harris-Love, Michael; Blackman, Marc R

    2017-01-01

    Motion capture virtual reality-based rehabilitation has become more common. However, therapists face challenges to the implementation of virtual reality (VR) in clinical settings. Use of motion capture technology such as the Xbox Kinect may provide a useful rehabilitation tool for the treatment of postural instability and cardiovascular deconditioning in individuals with chronic severe traumatic brain injury (TBI). The primary purpose of this study was to evaluate the effects of a Kinect-based VR intervention using commercially available motion capture games on balance outcomes for an individual with chronic TBI. The secondary purpose was to assess the feasibility of this intervention for eliciting cardiovascular adaptations. A single system experimental design ( n = 1) was utilized, which included baseline, intervention, and retention phases. Repeated measures were used to evaluate the effects of an 8-week supervised exercise intervention using two Xbox One Kinect games. Balance was characterized using the dynamic gait index (DGI), functional reach test (FRT), and Limits of Stability (LOS) test on the NeuroCom Balance Master. The LOS assesses end-point excursion (EPE), maximal excursion (MXE), and directional control (DCL) during weight-shifting tasks. Cardiovascular and activity measures were characterized by heart rate at the end of exercise (HRe), total gameplay time (TAT), and time spent in a therapeutic heart rate (TTR) during the Kinect intervention. Chi-square and ANOVA testing were used to analyze the data. Dynamic balance, characterized by the DGI, increased during the intervention phase χ 2 (1, N = 12) = 12, p = .001. Static balance, characterized by the FRT showed no significant changes. The EPE increased during the intervention phase in the backward direction χ 2 (1, N = 12) = 5.6, p = .02, and notable improvements of DCL were demonstrated in all directions. HRe ( F (2,174) = 29.65, p = motion capture gaming. Further studies appear warranted to

  14. Three-dimensional finite element analysis of unilateral mastication in malocclusion cases using cone-beam computed tomography and a motion capture system

    Science.gov (United States)

    2016-01-01

    Purpose Stress distribution and mandible distortion during lateral movements are known to be closely linked to bruxism, dental implant placement, and temporomandibular joint disorder. The present study was performed to determine stress distribution and distortion patterns of the mandible during lateral movements in Class I, II, and III relationships. Methods Five Korean volunteers (one normal, two Class II, and two Class III occlusion cases) were selected. Finite element (FE) modeling was performed using information from cone-beam computed tomographic (CBCT) scans of the subjects’ skulls, scanned images of dental casts, and incisor movement captured by an optical motion-capture system. Results In the Class I and II cases, maximum stress load occurred at the condyle of the balancing side, but, in the Class III cases, the maximum stress was loaded on the condyle of the working side. Maximum distortion was observed on the menton at the midline in every case, regardless of loading force. The distortion was greatest in Class III cases and smallest in Class II cases. Conclusions The stress distribution along and accompanying distortion of a mandible seems to be affected by the anteroposterior position of the mandible. Additionally, 3-D modeling of the craniofacial skeleton using CBCT and an optical laser scanner and reproduction of mandibular movement by way of the optical motion-capture technique used in this study are reliable techniques for investigating the masticatory system. PMID:27127690

  15. The efficacy of interactive, motion capture-based rehabilitation on functional outcomes in an inpatient stroke population: a randomized controlled trial.

    Science.gov (United States)

    Cannell, John; Jovic, Emelyn; Rathjen, Amy; Lane, Kylie; Tyson, Anna M; Callisaya, Michele L; Smith, Stuart T; Ahuja, Kiran Dk; Bird, Marie-Louise

    2018-02-01

    To compare the efficacy of novel interactive, motion capture-rehabilitation software to usual care stroke rehabilitation on physical function. Randomized controlled clinical trial. Two subacute hospital rehabilitation units in Australia. In all, 73 people less than six months after stroke with reduced mobility and clinician determined capacity to improve. Both groups received functional retraining and individualized programs for up to an hour, on weekdays for 8-40 sessions (dose matched). For the intervention group, this individualized program used motivating virtual reality rehabilitation and novel gesture controlled interactive motion capture software. For usual care, the individualized program was delivered in a group class on one unit and by rehabilitation assistant 1:1 on the other. Primary outcome was standing balance (functional reach). Secondary outcomes were lateral reach, step test, sitting balance, arm function, and walking. Participants (mean 22 days post-stroke) attended mean 14 sessions. Both groups improved (mean (95% confidence interval)) on primary outcome functional reach (usual care 3.3 (0.6 to 5.9), intervention 4.1 (-3.0 to 5.0) cm) with no difference between groups ( P = 0.69) on this or any secondary measures. No differences between the rehabilitation units were seen except in lateral reach (less affected side) ( P = 0.04). No adverse events were recorded during therapy. Interactive, motion capture rehabilitation for inpatients post stroke produced functional improvements that were similar to those achieved by usual care stroke rehabilitation, safely delivered by either a physical therapist or a rehabilitation assistant.

  16. Markerless motion capture systems as training device in neurological rehabilitation: a systematic review of their use, application, target population and efficacy.

    Science.gov (United States)

    Knippenberg, Els; Verbrugghe, Jonas; Lamers, Ilse; Palmaers, Steven; Timmermans, Annick; Spooren, Annemie

    2017-06-24

    Client-centred task-oriented training is important in neurological rehabilitation but is time consuming and costly in clinical practice. The use of technology, especially motion capture systems (MCS) which are low cost and easy to apply in clinical practice, may be used to support this kind of training, but knowledge and evidence of their use for training is scarce. The present review aims to investigate 1) which motion capture systems are used as training devices in neurological rehabilitation, 2) how they are applied, 3) in which target population, 4) what the content of the training and 5) efficacy of training with MCS is. A computerised systematic literature review was conducted in four databases (PubMed, Cinahl, Cochrane Database and IEEE). The following MeSH terms and key words were used: Motion, Movement, Detection, Capture, Kinect, Rehabilitation, Nervous System Diseases, Multiple Sclerosis, Stroke, Spinal Cord, Parkinson Disease, Cerebral Palsy and Traumatic Brain Injury. The Van Tulder's Quality assessment was used to score the methodological quality of the selected studies. The descriptive analysis is reported by MCS, target population, training parameters and training efficacy. Eighteen studies were selected (mean Van Tulder score = 8.06 ± 3.67). Based on methodological quality, six studies were selected for analysis of training efficacy. Most commonly used MCS was Microsoft Kinect, training was mostly conducted in upper limb stroke rehabilitation. Training programs varied in intensity, frequency and content. None of the studies reported an individualised training program based on client-centred approach. Motion capture systems are training devices with potential in neurological rehabilitation to increase the motivation during training and may assist improvement on one or more International Classification of Functioning, Disability and Health (ICF) levels. Although client-centred task-oriented training is important in neurological rehabilitation

  17. Stress-In-Motion (SIM) system for capturing tri-axial tyre-road interaction in the contact patch

    CSIR Research Space (South Africa)

    De Beer, Morris

    2013-08-01

    Full Text Available in order to represent a typical ‘‘textured’’ road surface. The system is referred to as the Stress-In-Motion (SIM) system. A single SIM measuring pad testing area comprises a total of 1020 supporting pins and a transverse array of 21 sensing elements...

  18. Three dimensional motion capture applied to violin playing: A study on feasibility and characterization of the motor strategy.

    Science.gov (United States)

    Ancillao, Andrea; Savastano, Bernardo; Galli, Manuela; Albertini, Giorgio

    2017-10-01

    Playing string instruments requires advanced motor skills and a long training that is often spent in uncomfortable postures that may lead to injuries or musculoskeletal disorders. Thus, it is interesting to objectively characterize the motor strategy adopted by the players. In this work, we implemented a method for the quantitative analysis of the motor performance of a violin player. The proposed protocol takes advantage of an optoelectronic system and some infra-red reflecting markers in order to track player's motion. The method was tested on a professional violin player performing a legato bowing task. The biomechanical strategy of the upper limb and bow positioning were described by means of quantitative parameters and motion profiles. Measured quantities were: bow trajectory, angles, tracks, velocity, acceleration and jerk. A good repeatability of the bowing motion (CV < 2%) and high smoothness (jerk < 5 m/s 3 ) were observed. Motion profiles of shoulder, elbow and wrist were repeatable (CV < 7%) and comparable to the curves observed in other studies. Jerk and acceleration profiles demonstrated high smoothness in the ascending and descending phases of bowing. High variability was instead observed for the neck angle (CV ∼56%). "Quantitative" measurements, instead of "qualitative" observation, can support the diagnosis of motor disorders and the accurate evaluation of musicians' skills. The proposed protocol is a powerful tool for the description of musician's performance, that may be useful to document improvements in playing abilities and to adjust training strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Capturing Invisible Motions in the Transition from Ground to Rare Excited States of T4 Lysozyme L99A.

    Science.gov (United States)

    Schiffer, Jamie M; Feher, Victoria A; Malmstrom, Robert D; Sida, Roxana; Amaro, Rommie E

    2016-10-18

    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. Despite the exhaustive study of L99A protein dynamics, the conformational changes that permit transitioning to the experimentally detected excited state (∼3%, ΔG ∼2 kcal/mol) remain unclear. Here, we describe the transitions from the ground state to this sparsely populated excited state of L99A as observed through a single molecular dynamics (MD) trajectory on the Anton supercomputer. Aside from detailing the ground-to-excited-state transition, the trajectory samples multiple metastates and an intermediate state en route to the excited state. Dynamic motions between these states enable cavity surface openings large enough to admit benzene on timescales congruent with known rates for benzene binding. Thus, these fluctuations between rare protein states provide an atomic description of the concerted motions that illuminate potential path(s) for ligand binding. These results reveal, to our knowledge, a new level of complexity in the dynamics of buried cavities and their role in creating mobile defects that affect protein dynamics and ligand binding. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  20. 4DCapture/4DPlayer: evolving software packages for capturing, analyzing and displaying two- and three-dimensional motion data

    Science.gov (United States)

    Walton, James S.; Hodgson, Peter N.; Hallamasek, Karen G.

    2007-01-01

    In September 2002, during the 25 th Congress on High Speed Photography and Photonics, 4DVideo described a general purpose software application for the PC platform. This software (4DCapture TM) is designed to capture, analyze and display multiple video sequences. The application extracts trajectories and other kinematic information from (highspeed) video streams. Since 4DCapture TM was originally described, it has matured, and a second application (4DPlayer TM) has been introduced to support the distribution and viewing of video streams and kinematic data acquired by 4DCapture TM. 4DPlayer TM is "freeware". It may be redistributed to third parties, but it may not be modified. 4DCapture TM provides a structured environment for experimental data. Cameras are treated as transducers-that is, a source of technical data. The application provides an interface to the cameras for previewing the object-space, calibrating the images, and testing. This application can automatically track multiple landmarks seen from two or more views in two or three dimensions. Trajectories can be processed within the main application or they can be exported to a spreadsheet where they can be processed or passed along to a more sophisticated, data analysis application. 4DCapture TM also incorporates a simple animation capability and a friendly (FlowStack TM) user interface that assists the end-user to capture and treat image sequences in a natural progression. 4DCapture TM employs the AVI 2.0 standard and DirectX technology. 4DPlayer TM can be used to view multiple video sequences simultaneously and perform simple measurements of displacements and angles that vary over time. This application can detect and display the coordinates of landmarks previously identified by 4DCapture TM that have been embedded in the video streams.

  1. Comparison of base of support size during gait initiation using force-plate and motion-capture system: A Bland and Altman analysis.

    Science.gov (United States)

    Yiou, E; Teyssèdre, C; Artico, R; Fourcade, P

    2016-12-08

    This study aimed to estimate the error made by investigators when force-plate data are used to approximate base of support size during gait initiation. Step length and step width obtained with a method based on motion capture system (Kinematics method, considered the "gold standard") and with a method based on the centre of pressure traces obtained from a force-plate (Force-plate method) were purposely compared using descriptive statistics and the Bland and Altman (BA) method. Participants (N=19) performed series of gait initiation in Spontaneous and Maximal Velocity Conditions (SVC and MVC, respectively). BA analysis showed that 1) step length and width biases, corresponding to the difference between the two methods, were very small (plate method is sufficiently accurate to compare step parameters across conditions. However, researchers should be aware that non-negligible errors might occur when considering individual data. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Estimating 3D L5/S1 moments and ground reaction forces during trunk bending using a full-body ambulatory inertial motion capture system.

    Science.gov (United States)

    Faber, G S; Chang, C C; Kingma, I; Dennerlein, J T; van Dieën, J H

    2016-04-11

    Inertial motion capture (IMC) systems have become increasingly popular for ambulatory movement analysis. However, few studies have attempted to use these measurement techniques to estimate kinetic variables, such as joint moments and ground reaction forces (GRFs). Therefore, we investigated the performance of a full-body ambulatory IMC system in estimating 3D L5/S1 moments and GRFs during symmetric, asymmetric and fast trunk bending, performed by nine male participants. Using an ambulatory IMC system (Xsens/MVN), L5/S1 moments were estimated based on the upper-body segment kinematics using a top-down inverse dynamics analysis, and GRFs were estimated based on full-body segment accelerations. As a reference, a laboratory measurement system was utilized: GRFs were measured with Kistler force plates (FPs), and L5/S1 moments were calculated using a bottom-up inverse dynamics model based on FP data and lower-body kinematics measured with an optical motion capture system (OMC). Correspondence between the OMC+FP and IMC systems was quantified by calculating root-mean-square errors (RMSerrors) of moment/force time series and the interclass correlation (ICC) of the absolute peak moments/forces. Averaged over subjects, L5/S1 moment RMSerrors remained below 10Nm (about 5% of the peak extension moment) and 3D GRF RMSerrors remained below 20N (about 2% of the peak vertical force). ICCs were high for the peak L5/S1 extension moment (0.971) and vertical GRF (0.998). Due to lower amplitudes, smaller ICCs were found for the peak asymmetric L5/S1 moments (0.690-0.781) and horizontal GRFs (0.559-0.948). In conclusion, close correspondence was found between the ambulatory IMC-based and laboratory-based estimates of back load. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. The validity and intra-tester reliability of markerless motion capture to analyse kinematics of the BMX Supercross gate start.

    Science.gov (United States)

    Grigg, Josephine; Haakonssen, Eric; Rathbone, Evelyne; Orr, Robin; Keogh, Justin W L

    2017-11-13

    The aim of this study was to quantify the validity and intra-tester reliability of a novel method of kinematic measurement. The measurement target was the joint angles of an athlete performing a BMX Supercross (SX) gate start action through the first 1.2 s of movement in situ on a BMX SX ramp using a standard gate start procedure. The method employed GoPro® Hero 4 Silver (GoPro Inc., USA) cameras capturing data at 120 fps 720 p on a 'normal' lens setting. Kinovea 0.8.15 (Kinovea.org, France) was used for analysis. Tracking data was exported and angles computed in Matlab (Mathworks®, USA). The gold standard 3D method for joint angle measurement could not safely be employed in this environment, so a rigid angle was used. Validity was measured to be within 2°. Intra-tester reliability was measured by the same tester performing the analysis twice with an average of 55 days between analyses. Intra-tester reliability was high, with an absolute error <6° and <9 frames (0.075 s) across all angles and time points for key positions, respectively. The methodology is valid within 2° and reliable within 6° for the calculation of joint angles in the first ~1.25 s.

  4. Motion-capture-based walking simulation of digital human adapted to laser-scanned 3D as-is environments for accessibility evaluation

    Directory of Open Access Journals (Sweden)

    Tsubasa Maruyama

    2016-07-01

    Full Text Available Owing to our rapidly aging society, accessibility evaluation to enhance the ease and safety of access to indoor and outdoor environments for the elderly and disabled is increasing in importance. Accessibility must be assessed not only from the general standard aspect but also in terms of physical and cognitive friendliness for users of different ages, genders, and abilities. Meanwhile, human behavior simulation has been progressing in the areas of crowd behavior analysis and emergency evacuation planning. However, in human behavior simulation, environment models represent only “as-planned” situations. In addition, a pedestrian model cannot generate the detailed articulated movements of various people of different ages and genders in the simulation. Therefore, the final goal of this research was to develop a virtual accessibility evaluation by combining realistic human behavior simulation using a digital human model (DHM with “as-is” environment models. To achieve this goal, we developed an algorithm for generating human-like DHM walking motions, adapting its strides, turning angles, and footprints to laser-scanned 3D as-is environments including slopes and stairs. The DHM motion was generated based only on a motion-capture (MoCap data for flat walking. Our implementation constructed as-is 3D environment models from laser-scanned point clouds of real environments and enabled a DHM to walk autonomously in various environment models. The difference in joint angles between the DHM and MoCap data was evaluated. Demonstrations of our environment modeling and walking simulation in indoor and outdoor environments including corridors, slopes, and stairs are illustrated in this study.

  5. Survey of Motion Tracking Methods Based on Inertial Sensors: A Focus on Upper Limb Human Motion

    Science.gov (United States)

    Filippeschi, Alessandro; Schmitz, Norbert; Miezal, Markus; Bleser, Gabriele; Ruffaldi, Emanuele; Stricker, Didier

    2017-01-01

    Motion tracking based on commercial inertial measurements units (IMUs) has been widely studied in the latter years as it is a cost-effective enabling technology for those applications in which motion tracking based on optical technologies is unsuitable. This measurement method has a high impact in human performance assessment and human-robot interaction. IMU motion tracking systems are indeed self-contained and wearable, allowing for long-lasting tracking of the user motion in situated environments. After a survey on IMU-based human tracking, five techniques for motion reconstruction were selected and compared to reconstruct a human arm motion. IMU based estimation was matched against motion tracking based on the Vicon marker-based motion tracking system considered as ground truth. Results show that all but one of the selected models perform similarly (about 35 mm average position estimation error). PMID:28587178

  6. Real-Time Motion Capture Toolbox (RTMocap): an open-source code for recording 3-D motion kinematics to study action-effect anticipations during motor and social interactions.

    Science.gov (United States)

    Lewkowicz, Daniel; Delevoye-Turrell, Yvonne

    2016-03-01

    We present here a toolbox for the real-time motion capture of biological movements that runs in the cross-platform MATLAB environment (The MathWorks, Inc., Natick, MA). It provides instantaneous processing of the 3-D movement coordinates of up to 20 markers at a single instant. Available functions include (1) the setting of reference positions, areas, and trajectories of interest; (2) recording of the 3-D coordinates for each marker over the trial duration; and (3) the detection of events to use as triggers for external reinforcers (e.g., lights, sounds, or odors). Through fast online communication between the hardware controller and RTMocap, automatic trial selection is possible by means of either a preset or an adaptive criterion. Rapid preprocessing of signals is also provided, which includes artifact rejection, filtering, spline interpolation, and averaging. A key example is detailed, and three typical variations are developed (1) to provide a clear understanding of the importance of real-time control for 3-D motion in cognitive sciences and (2) to present users with simple lines of code that can be used as starting points for customizing experiments using the simple MATLAB syntax. RTMocap is freely available (http://sites.google.com/site/RTMocap/) under the GNU public license for noncommercial use and open-source development, together with sample data and extensive documentation.

  7. Development of posture-specific computational phantoms using motion capture technology and application to radiation dose-reconstruction for the 1999 Tokai-Mura nuclear criticality accident

    Science.gov (United States)

    Vazquez, Justin A.; Caracappa, Peter F.; Xu, X. George

    2014-09-01

    The majority of existing computational phantoms are designed to represent workers in typical standing anatomical postures with fixed arm and leg positions. However, workers found in accident-related scenarios often assume varied postures. This paper describes the development and application of two phantoms with adjusted postures specified by data acquired from a motion capture system to simulate unique human postures found in a 1999 criticality accident that took place at a JCO facility in Tokai-Mura, Japan. In the course of this accident, two workers were fatally exposed to extremely high levels of radiation. Implementation of the emergent techniques discussed produced more accurate and more detailed dose estimates for the two workers than were reported in previous studies. A total-body dose of 6.43 and 26.38 Gy was estimated for the two workers, who assumed a crouching and a standing posture, respectively. Additionally, organ-specific dose estimates were determined, including a 7.93 Gy dose to the thyroid and 6.11 Gy dose to the stomach for the crouching worker and a 41.71 Gy dose to the liver and a 37.26 Gy dose to the stomach for the standing worker. Implications for the medical prognosis of the workers are discussed, and the results of this study were found to correlate better with the patient outcome than previous estimates, suggesting potential future applications of such methods for improved epidemiological studies involving next-generation computational phantom tools.

  8. Uniformity Study of Two-Functional Luminescent Dyes Adsorbed over an Anodized Aluminum Coating for Motion-Capturing Pressure- and Temperature-Sensitive Paint Imaging.

    Science.gov (United States)

    Ishii, Masato; Miyazaki, Takeshi; Sakaue, Hirotaka

    2017-12-23

    The pressure- and temperature-sensitive paint (PSP/TSP) technique, for steady-state and unsteady-state measurements, is becoming widespread. However, unsteady quantitative measurement is still difficult because non-uniform distribution of the probes over a test model may cause errors in the results. We focus on the dipping method that applies two luminophores into a binding material to improve sensitivity uniformity over a model surface. A bullet-shaped axisymmetric test model with motion-capturing TSP was used to evaluate the sensitivity uniformity, and three dipping methods (static, convectional, and rotational) were examined. The average peak ratios in the longitudinal direction were 1.17-1.46 for static, 1.38-1.51 for convectional, and 1.42-1.45 for rotational dipping. The standard deviations in the transverse direction were the smallest for rotational (0.022-0.033), relative to static (0.086-0.104), and convectional (0.044-0.065) dipping.

  9. Development of posture-specific computational phantoms using motion capture technology and application to radiation dose-reconstruction for the 1999 Tokai-Mura nuclear criticality accident.

    Science.gov (United States)

    Vazquez, Justin A; Caracappa, Peter F; Xu, X George

    2014-09-21

    The majority of existing computational phantoms are designed to represent workers in typical standing anatomical postures with fixed arm and leg positions. However, workers found in accident-related scenarios often assume varied postures. This paper describes the development and application of two phantoms with adjusted postures specified by data acquired from a motion capture system to simulate unique human postures found in a 1999 criticality accident that took place at a JCO facility in Tokai-Mura, Japan. In the course of this accident, two workers were fatally exposed to extremely high levels of radiation. Implementation of the emergent techniques discussed produced more accurate and more detailed dose estimates for the two workers than were reported in previous studies. A total-body dose of 6.43 and 26.38 Gy was estimated for the two workers, who assumed a crouching and a standing posture, respectively. Additionally, organ-specific dose estimates were determined, including a 7.93 Gy dose to the thyroid and 6.11 Gy dose to the stomach for the crouching worker and a 41.71 Gy dose to the liver and a 37.26 Gy dose to the stomach for the standing worker. Implications for the medical prognosis of the workers are discussed, and the results of this study were found to correlate better with the patient outcome than previous estimates, suggesting potential future applications of such methods for improved epidemiological studies involving next-generation computational phantom tools.

  10. Training Attention to the Other’s Need Improves Helping Behaviors in Children with Autism Spectrum Disorder: A Behavioral Analysis Using a Two-dimensional Motion Capture System

    Directory of Open Access Journals (Sweden)

    Yosuke Kita

    2017-09-01

    Full Text Available While children with autism spectrum disorder (ASD can acquire helping behaviors through appropriate interventions, changes in behaviors prior to helping (pre-helping behaviors remain unclear. In the present study, we examined the effects of social skills training (SST on helping and pre-helping behaviors in two children with ASD by using a two-dimensional motion capture system. During the SST, the children learned one helping behavior that they lent their items to their partners, and we measured their head movements before initiating the helping behavior (i.e., pre-helping behavior. As a result of SST, the participants became able to help others in response to less-explicit social stimuli after the intervention. Regarding pre-helping behaviors, the children with ASD before the intervention looked straight at the helpee (i.e., recipient of the help more often than did typically developing peers, and such a behavior was shown to increase after SST. These results indicate that although spontaneous attention to social stimuli may be reduced in children with ASD, success in attending to a helpee could lead to the emergence of helping behaviors. Moreover, the changes in pre-helping behavior indicate an increase in children’s attention to the helpee after the intervention, which may have enhanced their sensitivity to persons in need.

  11. An effortless procedure to align the local frame of an inertial measurement unit to the local frame of another motion capture system.

    Science.gov (United States)

    Chardonnens, Julien; Favre, Julien; Aminian, Kamiar

    2012-08-31

    Inertial measurement units (IMUs) offer great opportunities to analyze segmental and joints kinematics. When combined with another motion capture system (MCS), for example, to validate new IMU-based applications or to develop mixed systems, it is necessary to align the local frame of the IMU sensors to the local frame of the MCS. Currently, all alignment methods use landmarks on the IMU's casing. Therefore, they can only be used with well-documented IMUs and they are prone to error when the IMU's casing is small. This study proposes an effortless procedure to align the local frame of any IMU to the local frame of any other MCS able to measure the orientation of its local frame. The general concept of this method is to derive the gyroscopic angles for both devices during an alignment movement, and then to use an optimization algorithm to calculate the alignment matrix between both local frames. The alignment movement consists of rotations around three more or less orthogonal axes and it can easily be performed by hands. To test the alignment procedure, an IMU and a magnetic marker were attached to a plate, and 20 alignment movements were recorded. The maximum errors of alignment (accuracy±precision) were 1.02°±0.32° and simulations showed that the method was robust against noise that typically affect IMUs. In conclusion, this study describes an efficient alignment procedure that is quick and easy to perform, and that does not require any alignment device or any knowledge about the IMU casing. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Objective analysis of surgeons' ergonomy during laparoendoscopic single-site surgery through the use of surface electromyography and a motion capture data glove.

    Science.gov (United States)

    Pérez-Duarte, F J; Lucas-Hernández, M; Matos-Azevedo, A; Sánchez-Margallo, J A; Díaz-Güemes, I; Sánchez-Margallo, F M

    2014-04-01

    Adding to the ergonomic inconveniences already presented by traditional laparoscopy (LAP), laparoendoscopic single-site (LESS) surgery has been found to entail other more specific problems, including greater reduction in movement freedom, in-line vision with loss of triangulation, and greater proximity of instruments. The objective of this study was to evaluate surgeons' ergonomy during LESS surgery, through the study of muscular activity, wrist angle, and hand movements, and compare it with conventional laparoscopy. The study group was composed by 14 experienced laparoscopic surgeons, all right-handed. Each one performed dissection tasks on a physical simulator through LAP and LESS approaches. For LAP, straight laparoscopic scissors and dissector were used, whilst for LESS articulating tip scissors and dissector were chosen. During both tasks, muscular activity of biceps brachii, triceps brachii, forearm flexors and extensors, and trapezius muscles was registered through surface electromyography. Simultaneously right-hand movements and wrist angles were obtained through a motion capture data glove (CyberGlove(®)), which allowed for the use of a modified RULA test applied to the recorded angles with subsequent establishment of risk levels for the wrist joint. Muscular activity for trapezius (LAP 6.94 ± 4.12 vs. LESS 11.32 ± 4.68; p ≤ 0.05) and forearm extensor muscles (LAP 9.2 ± 2.45 vs. LESS 37.07 ≤ 16.05; p ≤ 0.001) was significantly lower in conventional laparoscopy compared with LESS approach. No statistical significance was obtained between the different sensors, except in 3 of the 11 analyzed CyberGlove(®) sensors. The modified RULA test showed a score of 3 for laparoscopy (unacceptable), whereas for LESS a score of 2 was obtained (acceptable), with statistically significant differences between them (p ≤ 0.05). The LESS approach entails greater level of muscular activity in the trapezius and forearm extensor muscles, but we have found evidences

  13. Capturing Thoughts, Capturing Minds?

    DEFF Research Database (Denmark)

    Nielsen, Janni

    2004-01-01

    Think Aloud is cost effective, promises access to the user's mind and is the applied usability technique. But 'keep talking' is difficult, besides, the multimodal interface is visual not verbal. Eye-tracking seems to get around the verbalisation problem. It captures the visual focus of attention....... However, it is expensive, obtrusive and produces huge amount of data. Besides, eye-tracking do not give access to user's mind. Capturing interface/cursor tracking may be cost effective. It is easy to install, data collection is automatic and unobtrusive and replaying the captured recording to the user...

  14. Can the Functional Movement Screen™ be used to capture changes in spine and knee motion control following 12 weeks of training?

    Science.gov (United States)

    Frost, David M; Beach, Tyson A C; Campbell, Troy L; Callaghan, Jack P; McGill, Stuart M

    2017-01-01

    To examine whether objective measures of spine and frontal plane knee motion exhibited during Functional Movement Screen™ (FMS) task performance changed following a movement-guided fitness (MOV) and conventional fitness (FIT) exercise intervention. Secondary analysis of a randomized controlled experiment. Before and after 12 weeks of exercise, participants' kinematics were quantified while performing the FMS and a series of general whole-body movement tasks. Biomechanics laboratory. Fifty-two firefighters were assigned to MOV, FIT, or a control (CON) group. Peak lumbar spine flexion/extension, lateral bend and axial twist, and frontal plane knee motion. The post-training kinematic changes exhibited by trainees while performing the FMS tasks were similar in magnitude (effect size spine and frontal plane knee motion control (effect size > 0.5). Whether graded qualitatively, or quantitatively via kinematic analyses, the FMS may not be a viable tool to detect movement-based exercise adaptations. Amendments to the FMS tasks and/or scoring method are needed before it can be used for reasons beyond appraising the ability to move freely, symmetrically, and without pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. 4DCAPTURE: a general purpose software package for capturing and analyzing two- and three-dimensional motion data acquired from video sequences

    Science.gov (United States)

    Walton, James S.; Hodgson, Peter; Hallamasek, Karen; Palmer, Jake

    2003-07-01

    4DVideo is creating a general purpose capability for capturing and analyzing kinematic data from video sequences in near real-time. The core element of this capability is a software package designed for the PC platform. The software ("4DCapture") is designed to capture and manipulate customized AVI files that can contain a variety of synchronized data streams -- including audio, video, centroid locations -- and signals acquired from more traditional sources (such as accelerometers and strain gauges.) The code includes simultaneous capture or playback of multiple video streams, and linear editing of the images (together with the ancilliary data embedded in the files). Corresponding landmarks seen from two or more views are matched automatically, and photogrammetric algorithms permit multiple landmarks to be tracked in two- and three-dimensions -- with or without lens calibrations. Trajectory data can be processed within the main application or they can be exported to a spreadsheet where they can be processed or passed along to a more sophisticated, stand-alone, data analysis application. Previous attempts to develop such applications for high-speed imaging have been limited in their scope, or by the complexity of the application itself. 4DVideo has devised a friendly ("FlowStack") user interface that assists the end-user to capture and treat image sequences in a natural progression. 4DCapture employs the AVI 2.0 standard and DirectX technology which effectively eliminates the file size limitations found in older applications. In early tests, 4DVideo has streamed three RS-170 video sources to disk for more than an hour without loss of data. At this time, the software can acquire video sequences in three ways: (1) directly, from up to three hard-wired cameras supplying RS-170 (monochrome) signals; (2) directly, from a single camera or video recorder supplying an NTSC (color) signal; and (3) by importing existing video streams in the AVI 1.0 or AVI 2.0 formats. The

  16. A quasi-static method for determining the characteristics of a motion capture camera system in a "split-volume" configuration

    Science.gov (United States)

    Miller, Chris; Mulavara, Ajitkumar; Bloomberg, Jacob

    2002-01-01

    The purpose of this study was to determine the accuracy, repeatability and resolution of a six-camera Motion Analysis system in a vertical split-volume configuration using a unique quasi-static methodology. The position of a reflective marker was recorded while it was moved quasi-statically over a range of 2.54 mm (0.100 inches) via a linearly-translating table. The table was placed at five different heights to cover both sub-volumes and the overlapping region. Data analysis showed that accuracy, repeatability and resolution values were consistent across all regions of the split-volume, including the overlapping section.

  17. Construction of a novel coarse grain model for simulations of HIV capsid assembly to capture the backbone structure and inter-domain motions in solution

    Directory of Open Access Journals (Sweden)

    Xin Qiao

    2015-12-01

    Full Text Available We show the construction of a novel coarse grain model for simulations of HIV capsid assembly based on four structural models of HIV capsid proteins: isolated hexamer 3H47.pdb, tubular assembly 3J34.pdb, isolated pentamer 3P05.pdb and C-terminus dimer 2KOD.pdb. The data demonstrates the derivation of inter-domain motions from all atom Molecular Dynamics simulations and comparison with the motions derived from the analysis of solution NMR results defined in 2M8L.pdb. Snapshots from a representative Monte Carlo simulation with 128 dimeric subunit proteins based on 3J34.pdb are shown in addition to the quantitative analysis of its assembly pathway. Movies of the assembly process are compiled with snapshots of representative simulations of four structural models. The methods and data in this article were utilized in Qiao et al. (in press [1] to probe the mechanism of polymorphism and curvature control of HIV capsid assembly.

  18. Letter regarding 'Comparison between low-cost marker-less and high-end marker-based motion capture systems for the computer-aided assessment of working ergonomics' by Patrizi et al. and research reproducibility.

    Science.gov (United States)

    2017-04-01

    The reporting of research in a manner that allows reproduction in subsequent investigations is important for scientific progress. Several details of the recent study by Patrizi et al., 'Comparison between low-cost marker-less and high-end marker-based motion capture systems for the computer-aided assessment of working ergonomics', are absent from the published manuscript and make reproduction of findings impossible. As new and complex technologies with great promise for ergonomics develop, new but surmountable challenges for reporting investigations using these technologies in a reproducible manner arise. Practitioner Summary: As with traditional methods, scientific reporting of new and complex ergonomics technologies should be performed in a manner that allows reproduction in subsequent investigations and supports scientific advancement.

  19. Development of a wearable motion capture suit and virtual reality biofeedback system for the instruction and analysis of sports rehabilitation exercises.

    Science.gov (United States)

    Fitzgerald, Diarmaid; Foody, John; Kelly, Dan; Ward, Tomas; Markham, Charles; McDonald, John; Caulfield, Brian

    2007-01-01

    This paper describes the design and development of a computer game for instructing an athlete through a series of prescribed rehabilitation exercises. In an attempt to prevent or treat musculoskeletal type injuries along with trying to improve physical performance, athletes are prescribed exercise programmes by appropriately trained specialists. Typically athletes are shown how to perform each exercise in the clinic following examination but they often have no way of knowing if their technique is correct while they are performing their home exercise programme. We describe a system that allows an automatic audit of this activity. Our system utilises ten inertial motion tracking sensors incorporated in a wearable body suit which allows a bluetooth connection from a root hub to a laptop/computer. Using our specifically designed software programme, the athlete can be instructed and analysed as he/she performs the individually tailored exercise programme and a log is recorded of the time and performance level of each exercise completed. We describe a case study that illustrates how a clinician can at a later date review the athletes progress and subsequently alter the exercise programme as they see fit.

  20. Validity of an inertial measurement unit to assess pelvic orientation angles during gait, sit-stand transfers and step-up transfers: Comparison with an optoelectronic motion capture system.

    Science.gov (United States)

    Bolink, S A A N; Naisas, H; Senden, R; Essers, H; Heyligers, I C; Meijer, K; Grimm, B

    2016-03-01

    An inertial measurement unit (IMU) allows kinematic evaluation of human motion with fewer operational constraints than a gold standard optoelectronic motion capture (MOCAP) system. The study's aim was to compare IMU and MOCAP measurements of dynamic pelvic orientation angles during different activities of daily life (ADL): gait, sit-to-stand (STS) transfers and block step-up (BS) transfers. A single IMU was attached onto the lower back in seventeen healthy participants (8F/9 M, age 19-31 years; BMI < 25) and optical skin markers were attached onto anatomical pelvic landmarks for MOCAP measurements. Comparisons between IMU and MOCAP by Bland-Altman plots demonstrated that measurements were between 2SD of the absolute difference and Pearson's correlation coefficients were between 0.85 and 0.94. Frontal plane pelvic angle estimations achieved a RMSE in the range of [2.7°-4.5°] and sagittal plane measurements achieved a RMSE in the range of [2.7°-8.9°] which were both lowest in gait. Waveform peak detection times demonstrated ICCs between 0.96 and 1.00. These results are in accordance to other studies comparing IMU and MOCAP measurements with different applications and suggest that an IMU is a valid tool to measure dynamic pelvic angles during various activities of daily life which could be applied to monitor rehabilitation in a wide variety of musculoskeletal disorders. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  1. Capture by colour: evidence for dimension-specific singleton capture.

    Science.gov (United States)

    Harris, Anthony M; Becker, Stefanie I; Remington, Roger W

    2015-10-01

    Previous work on attentional capture has shown the attentional system to be quite flexible in the stimulus properties it can be set to respond to. Several different attentional "modes" have been identified. Feature search mode allows attention to be set for specific features of a target (e.g., red). Singleton detection mode sets attention to respond to any discrepant item ("singleton") in the display. Relational search sets attention for the relative properties of the target in relation to the distractors (e.g., redder, larger). Recently, a new attentional mode was proposed that sets attention to respond to any singleton within a particular feature dimension (e.g., colour; Folk & Anderson, 2010). We tested this proposal against the predictions of previously established attentional modes. In a spatial cueing paradigm, participants searched for a colour target that was randomly either red or green. The nature of the attentional control setting was probed by presenting an irrelevant singleton cue prior to the target display and assessing whether it attracted attention. In all experiments, the cues were red, green, blue, or a white stimulus rapidly rotated (motion cue). The results of three experiments support the existence of a "colour singleton set," finding that all colour cues captured attention strongly, while motion cues captured attention only weakly or not at all. Notably, we also found that capture by motion cues in search for colour targets was moderated by their frequency; rare motion cues captured attention (weakly), while frequent motion cues did not.

  2. Development of a Quadrotor Test Bed — Modelling, Parameter Identification, Controller Design and Trajectory Generation

    National Research Council Canada - National Science Library

    Dong, Wei; Gu, Guo-Ying; Zhu, Xiangyang; Ding, Han

    2015-01-01

    In this paper, a quadrotor test bed is developed. The technical approach for this test bed is firstly proposed by utilizing a commercial quadrotor, a Vicon motion capture system and a ground station...

  3. Statistics of bicycle rider motion

    NARCIS (Netherlands)

    Moore, J.K.; Hubbard, M.; Schwab, A.L.; Kooijman, J.D.G.; Peterson, D.L.

    2010-01-01

    An overview of bicycle and rider kinematic motions from a series of experimental treadmill tests is presented. The full kinematics of bicycles and riders were measured with an active motion capture system. Motion across speeds are compared graphically with box and whiskers plots. Trends and ranges

  4. Animating with Stop Motion Pro

    CERN Document Server

    Sawicki, Mark

    2010-01-01

    Animating with Stop Motion Pro is comprehensive, hands-on guide to achieving professional results with Stop Motion Pro 7.0 software. Gone are the days of stop motion guesswork and waiting to see the finalized result of your meticulous, labor intensive animations. With the push of a mouse button and the Stop Motion Pro software, animators have ten times the capability of simple camera stop motion capture. Re-visualize stop motion character movements, graph these movements and composite characters into a flawless animations with the techniques and step by step tutorials featured in Animating wit

  5. Markerless Motion Tracking

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis; Czarowicz, Alex

    2012-01-01

    This contribution focuses on the Associated Technologies aspect of the ICDVRAT event. Two industry leading markerless motion capture systems are examined that offer advancement in the field of rehabilitation. Residing at each end of the cost continuum, technical differences such as 3D versus 360...

  6. Fixation not required: characterizing oculomotor attention capture for looming stimuli.

    Science.gov (United States)

    Lewis, Joanna E; Neider, Mark B

    2015-10-01

    A stimulus moving toward us, such as a ball being thrown in our direction or a vehicle braking suddenly in front of ours, often represents a stimulus that requires a rapid response. Using a visual search task in which target and distractor items were systematically associated with a looming object, we explored whether this sort of looming motion captures attention, the nature of such capture using eye movement measures (overt/covert), and the extent to which such capture effects are more closely tied to motion onset or the motion itself. We replicated previous findings indicating that looming motion induces response time benefits and costs during visual search Lin, Franconeri, & Enns(Psychological Science 19(7): 686-693, 2008). These differences in response times were independent of fixation, indicating that these capture effects did not necessitate overt attentional shifts to a looming object for search benefits or costs to occur. Interestingly, we found no differences in capture benefits and costs associated with differences in looming motion type. Combined, our results suggest that capture effects associated with looming motion are more likely subserved by covert attentional mechanisms rather than overt mechanisms, and attention capture for looming motion is likely related to motion itself rather than the onset of motion.

  7. Human motion analysis and modeling

    Science.gov (United States)

    Prussing, Keith; Cathcart, J. Michael; Kocher, Brian

    2011-06-01

    Georgia Tech has investigated methods for the detection and tracking of personnel in a variety of acquisition environments. This research effort focused on a detailed phenomenological analysis of human physiology and signatures with the subsequent identification and characterization of potential observables. As a fundamental part of this research effort, Georgia Tech collected motion capture data on an individual for a variety of walking speeds, carrying loads, and load distributions. These data formed the basis for deriving fundamental properties of the individual's motion and supported the development of a physiologically-based human motion model. Subsequently this model aided the derivation and analysis of motion-based observables, particularly changes in the motion of various body components resulting from load variations. This paper will describe the data acquisition process, development of the human motion model, and use of the model in the observable analysis. Video sequences illustrating the motion data and modeling results will also be presented.

  8. Motion Sickness

    Science.gov (United States)

    Motion sickness is a common problem in people traveling by car, train, airplanes, and especially boats. Anyone ... children, pregnant women, and people taking certain medicines. Motion sickness can start suddenly, with a queasy feeling ...

  9. Motion sickness

    NARCIS (Netherlands)

    Bles, W.; Bos, J.E.; Kruit, H.

    2000-01-01

    The number of recently published papers on motion sickness may convey the impression that motion sickness is far from being understood. The current review focusses on a concept which tends to unify the different manifestations and theories of motion sickness. The paper highlights the relations

  10. 3D Human Motion Editing and Synthesis: A Survey

    Science.gov (United States)

    Wang, Xin; Chen, Qiudi; Wang, Wanliang

    2014-01-01

    The ways to compute the kinematics and dynamic quantities of human bodies in motion have been studied in many biomedical papers. This paper presents a comprehensive survey of 3D human motion editing and synthesis techniques. Firstly, four types of methods for 3D human motion synthesis are introduced and compared. Secondly, motion capture data representation, motion editing, and motion synthesis are reviewed successively. Finally, future research directions are suggested. PMID:25045395

  11. Learning Silhouette Features for Control of Human Motion

    National Research Council Canada - National Science Library

    Ren, Liu; Shakhnarovich, Gregory; Hodgins, Jessica K; Pfister, Hanspeter; Viola, Paul A

    2004-01-01

    .... The system combines information about the user's motion contained in silhouettes from several viewpoints with domain knowledge contained in a motion capture database to interactively produce a high quality animation...

  12. Motion Analysis of Thumb in Cellular Phone Use

    Directory of Open Access Journals (Sweden)

    Naotaka Sakai

    2010-01-01

    Full Text Available The thumb motion of 10 normal subjects during cellular phone use was measured using a reflective marker detection system to compare the maximum, minimum and range of flexion angles of the interphalangeal (IP, metacarpophalangeal (MP and carpometacarpal (CM joints. Two micro-reflective markers 3 mm in diameter were each placed on the dorsal surface of the distal phalanx, basal phalanx and metacarpal bone of the thumb. Three markers were placed on the dorsal hand in order to define the dorsal hand plane. Each subject pushed the 12 keys of a folding cellular phone with an 85-mm-long and 40-mm-wide keypad, sequentially from ‘1’ to ‘#’, and the pushing motion was recorded by six infrared video cameras for 12 seconds, using the VICON 612 system. The mean maximum flexion angle of the MP joint was significantly (p < .05 larger than the CM joint, and the mean minimum flexion angle of the CM joint was significantly (p < .01 smaller than the IP and MP joints. The mean range of motion of the IP joint was significantly (p < .05 larger than the MP and the CM joints. In a comparison of different key-pushing motions, only the CM joint was significantly (p < .05 larger in its range of motion. In conclusion, thumb motion on pushing the keys of the cellular phone was produced mainly by the MP and the CM joints. In addition, the ability to reach keys in different areas of the cellular phone keypad is regulated by changing the flexion angle of the CM joint.

  13. Relighting Character Motion for Photoreal Simulations

    National Research Council Canada - National Science Library

    Lamond, Bruce; Chabert, Charles-Felix; Einarsson, Per; Jones, Andrew; Ma, Wan-Chun; Hawkins, Tim; Bolas, Mark; Sylwan, Sebastian; Debevec, Paul

    2006-01-01

    .... The known rotation of the treadmill, repeatability of the actor's motion, timing of the lighting pattern and capture rate of the cameras are all carefully synchronized so that the actor is imaged in (approximately...

  14. Comparing motion induction in lateral motion and motion in depth

    OpenAIRE

    Harris, Julie; German, KJ

    2008-01-01

    Induced motion, the apparent motion of an object when a nearby object moves, has been shown to occur in a variety of different conditions, including motion in depth. Here we explore whether similar patterns of induced motion result from induction in a lateral direction (frontoparallel motion) or induction in depth. We measured the magnitude of induced motion in a stationary target for: (a) binocularly viewed lateral motion of a pair of inducers, where the angular motion is in the same directi...

  15. The phenomenon of motion in photography

    OpenAIRE

    Hižová, Katarína

    2015-01-01

    The purpose of this thesis is to explore distinct techniques of capturing motion in still and animated photography. It also concentrates on describing the history, types and use of stop motion animation in the field of movie production, music, computer games and marketing communication. Practical part deals with the production process of short stop motion animations and its implementation to the communication strategy of a bachelor project called Kapustové Zelí.

  16. Video Screen Capture Basics

    Science.gov (United States)

    Dunbar, Laura

    2014-01-01

    This article is an introduction to video screen capture. Basic information of two software programs, QuickTime for Mac and BlueBerry Flashback Express for PC, are also discussed. Practical applications for video screen capture are given.

  17. Capture Their Attention: Capturing Lessons Using Screen Capture Software

    Science.gov (United States)

    Drumheller, Kristina; Lawler, Gregg

    2011-01-01

    When students miss classes for university activities such as athletic and academic events, they inevitably miss important class material. Students can get notes from their peers or visit professors to find out what they missed, but when students miss new and challenging material these steps are sometimes not enough. Screen capture and recording…

  18. Motion Analysis Based on Invertible Rapid Transform

    Directory of Open Access Journals (Sweden)

    J. Turan

    1999-06-01

    Full Text Available This paper presents the results of a study on the use of invertible rapid transform (IRT for the motion estimation in a sequence of images. Motion estimation algorithms based on the analysis of the matrix of states (produced in the IRT calculation are described. The new method was used experimentally to estimate crowd and traffic motion from the image data sequences captured at railway stations and at high ways in large cities. The motion vectors may be used to devise a polar plot (showing velocity magnitude and direction for moving objects where the dominant motion tendency can be seen. The experimental results of comparison of the new motion estimation methods with other well known block matching methods (full search, 2D-log, method based on conventional (cross correlation (CC function or phase correlation (PC function for application of crowd motion estimation are also presented.

  19. Human motion analysis and characterization

    Science.gov (United States)

    Cathcart, J. Michael; Prussing, Keith; Kocher, Brian

    2011-06-01

    Georgia Tech has investigated methods for the detection and tracking of personnel in a variety of acquisition environments. This research effort focused on a detailed phenomenological analysis of human physiology and signatures with the subsequent identification and characterization of potential observables. Both aspects are needed to support the development of personnel detection and tracking algorithms. As a fundamental part of this research effort, Georgia Tech collected motion capture data on an individual for a variety of walking speeds, carrying loads, and load distributions. These data formed the basis for deriving fundamental properties of the individual's motion and the derivation of motionbased observables, and changes in these fundamental properties arising from load variations. Analyses were conducted to characterize the motion properties of various body components such as leg swing, arm swing, head motion, and full body motion. This paper will describe the data acquisition process, extraction of motion characteristics, and analysis of these data. Video sequences illustrating the motion data and analysis results will also be presented.

  20. Carbon Capture and Storage

    NARCIS (Netherlands)

    Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.

    2012-01-01

    Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2

  1. CAPTURED India Country Evaluation

    NARCIS (Netherlands)

    O'Donoghue, R.; Brouwers, J.H.A.M.

    2012-01-01

    This report provides the findings of the India Country Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the End Evaluation has assessed that results are commendable. I-AIM was able to design an approach in which health

  2. Captured by Motion: Dance, Action Understanding, and Social Cognition

    Science.gov (United States)

    Sevdalis, Vassilis; Keller, Peter E.

    2011-01-01

    In this review article, we summarize the main findings from empirical studies that used dance-related forms of rhythmical full body movement as a research tool for investigating action understanding and social cognition. This work has proven to be informative about behavioral and brain mechanisms that mediate links between perceptual and motor…

  3. Exploiting motion capture to enhance avoidance behaviour in games

    NARCIS (Netherlands)

    Basten, B.J.H. van; Jansen, S.E.M.; Karamouzas, I.

    2009-01-01

    Realistic simulation of interacting virtual characters is essential in computer games, training and simulation applications. The problem is very challenging since people are accustomed to real-world situations and thus, they can easily detect inconsistencies and artifacts in the simulations. Over

  4. Application of Hand Motion Capture System for Piano Education

    National Research Council Canada - National Science Library

    水戸部, 一孝; 鈴木, 雅史; 吉村, 昇

    2011-01-01

    It is important to measure the dexterous finger movements for piano education. But there are some problems to measure accurately of finger movements with angular position due to the complex finger bones construction...

  5. New generation of wearable goniometers for motion capture systems

    Science.gov (United States)

    2014-01-01

    Background Monitoring joint angles through wearable systems enables human posture and gesture to be reconstructed as a support for physical rehabilitation both in clinics and at the patient’s home. A new generation of wearable goniometers based on knitted piezoresistive fabric (KPF) technology is presented. Methods KPF single-and double-layer devices were designed and characterized under stretching and bending to work as strain sensors and goniometers. The theoretical working principle and the derived electromechanical model, previously proved for carbon elastomer sensors, were generalized to KPF. The devices were used to correlate angles and piezoresistive fabric behaviour, to highlight the differences in terms of performance between the single layer and the double layer sensors. A fast calibration procedure is also proposed. Results The proposed device was tested both in static and dynamic conditions in comparison with standard electrogoniometers and inertial measurement units respectively. KPF goniometer capabilities in angle detection were experimentally proved and a discussion of the device measurement errors of is provided. The paper concludes with an analysis of sensor accuracy and hysteresis reduction in particular configurations. Conclusions Double layer KPF goniometers showed a promising performance in terms of angle measurements both in quasi-static and dynamic working mode for velocities typical of human movement. A further approach consisting of a combination of multiple sensors to increase accuracy via sensor fusion technique has been presented. PMID:24725669

  6. Markerless 3D motion capture for animal locomotion studies

    Directory of Open Access Journals (Sweden)

    William Irvin Sellers

    2014-06-01

    Full Text Available Obtaining quantitative data describing the movements of animals is an essential step in understanding their locomotor biology. Outside the laboratory, measuring animal locomotion often relies on video-based approaches and analysis is hampered because of difficulties in calibration and often the limited availability of possible camera positions. It is also usually restricted to two dimensions, which is often an undesirable over-simplification given the essentially three-dimensional nature of many locomotor performances. In this paper we demonstrate a fully three-dimensional approach based on 3D photogrammetric reconstruction using multiple, synchronised video cameras. This approach allows full calibration based on the separation of the individual cameras and will work fully automatically with completely unmarked and undisturbed animals. As such it has the potential to revolutionise work carried out on free-ranging animals in sanctuaries and zoological gardens where ad hoc approaches are essential and access within enclosures often severely restricted. The paper demonstrates the effectiveness of video-based 3D photogrammetry with examples from primates and birds, as well as discussing the current limitations of this technique and illustrating the accuracies that can be obtained. All the software required is open source so this can be a very cost effective approach and provides a methodology of obtaining data in situations where other approaches would be completely ineffective.

  7. Emotion recognition using Kinect motion capture data of human gaits

    Directory of Open Access Journals (Sweden)

    Shun Li

    2016-09-01

    Full Text Available Automatic emotion recognition is of great value in many applications, however, to fully display the application value of emotion recognition, more portable, non-intrusive, inexpensive technologies need to be developed. Human gaits could reflect the walker’s emotional state, and could be an information source for emotion recognition. This paper proposed a novel method to recognize emotional state through human gaits by using Microsoft Kinect, a low-cost, portable, camera-based sensor. Fifty-nine participants’ gaits under neutral state, induced anger and induced happiness were recorded by two Kinect cameras, and the original data were processed through joint selection, coordinate system transformation, sliding window gauss filtering, differential operation, and data segmentation. Features of gait patterns were extracted from 3-dimentional coordinates of 14 main body joints by Fourier transformation and Principal Component Analysis (PCA. The classifiers NaiveBayes, RandomForests, LibSVM and SMO (Sequential Minimal Optimization were trained and evaluated, and the accuracy of recognizing anger and happiness from neutral state achieved 80.5% and 75.4%. Although the results of distinguishing angry and happiness states were not ideal in current study, it showed the feasibility of automatically recognizing emotional states from gaits, with the characteristics meeting the application requirements.

  8. Emotion recognition using Kinect motion capture data of human gaits.

    Science.gov (United States)

    Li, Shun; Cui, Liqing; Zhu, Changye; Li, Baobin; Zhao, Nan; Zhu, Tingshao

    2016-01-01

    Automatic emotion recognition is of great value in many applications, however, to fully display the application value of emotion recognition, more portable, non-intrusive, inexpensive technologies need to be developed. Human gaits could reflect the walker's emotional state, and could be an information source for emotion recognition. This paper proposed a novel method to recognize emotional state through human gaits by using Microsoft Kinect, a low-cost, portable, camera-based sensor. Fifty-nine participants' gaits under neutral state, induced anger and induced happiness were recorded by two Kinect cameras, and the original data were processed through joint selection, coordinate system transformation, sliding window gauss filtering, differential operation, and data segmentation. Features of gait patterns were extracted from 3-dimentional coordinates of 14 main body joints by Fourier transformation and Principal Component Analysis (PCA). The classifiers NaiveBayes, RandomForests, LibSVM and SMO (Sequential Minimal Optimization) were trained and evaluated, and the accuracy of recognizing anger and happiness from neutral state achieved 80.5% and 75.4%. Although the results of distinguishing angry and happiness states were not ideal in current study, it showed the feasibility of automatically recognizing emotional states from gaits, with the characteristics meeting the application requirements.

  9. Captured by motion: dance, action understanding, and social cognition.

    Science.gov (United States)

    Sevdalis, Vassilis; Keller, Peter E

    2011-11-01

    In this review article, we summarize the main findings from empirical studies that used dance-related forms of rhythmical full body movement as a research tool for investigating action understanding and social cognition. This work has proven to be informative about behavioral and brain mechanisms that mediate links between perceptual and motor processes invoked during the observation and execution of spatially-temporally coordinated action and interpersonal interaction. The review focuses specifically on processes related to (a) motor experience and expertise, (b) learning and memory, (c) action, intention, and emotion understanding, and (d) audio-visual synchrony and timing. Consideration is given to the relationship between research on dance and more general embodied cognition accounts of action understanding and social cognition. Finally, open questions and issues concerning experimental design are discussed with a view to stimulating future research on social-cognitive aspects of dance. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Preparing to Capture Carbon

    National Research Council Canada - National Science Library

    Daniel P. Schrag

    2007-01-01

    .... Scientific and economic challenges still exist, but none are serious enough to suggest that carbon capture and storage will not work at the scale required to offset trillions of tons of carbon...

  11. Marine turtle capture data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To estimate abundance, growth, and survival rate and to collect tissue samples, marine turtles are captured at nesting beaches and foraging grounds through various...

  12. Ubiquitous human upper-limb motion estimation using wearable sensors.

    Science.gov (United States)

    Zhang, Zhi-Qiang; Wong, Wai-Choong; Wu, Jian-Kang

    2011-07-01

    Human motion capture technologies have been widely used in a wide spectrum of applications, including interactive game and learning, animation, film special effects, health care, navigation, and so on. The existing human motion capture techniques, which use structured multiple high-resolution cameras in a dedicated studio, are complicated and expensive. With the rapid development of microsensors-on-chip, human motion capture using wearable microsensors has become an active research topic. Because of the agility in movement, upper-limb motion estimation has been regarded as the most difficult problem in human motion capture. In this paper, we take the upper limb as our research subject and propose a novel ubiquitous upper-limb motion estimation algorithm, which concentrates on modeling the relationship between upper-arm movement and forearm movement. A link structure with 5 degrees of freedom (DOF) is proposed to model the human upper-limb skeleton structure. Parameters are defined according to Denavit-Hartenberg convention, forward kinematics equations are derived, and an unscented Kalman filter is deployed to estimate the defined parameters. The experimental results have shown that the proposed upper-limb motion capture and analysis algorithm outperforms other fusion methods and provides accurate results in comparison to the BTS optical motion tracker.

  13. The development of a methodology to determine the relationship in grip size and pressure to racket head speed in a tennis forehand stroke

    DEFF Research Database (Denmark)

    Christensen, Jonas; Rasmussen, John; Halkon, Ben

    2016-01-01

    kinematic data taken from the racket arm and trunk were obtained by means of a Vicon motion capture system. One elite male tennis player was recruited. Fifty topspin forehand strokes per grip at two nominal grip pressures were performed in a laboratory environment with balls being tossed towards the player...

  14. Barefoot running causes acute changes in lower limb kinematics in ...

    African Journals Online (AJOL)

    camera T10 Vicon motion capture system (200Hz). In the barefoot condition runners landed with significantly greater knee flexion (p<0.01; ES=2.61) and less ankle dorsi-flexion (p<0.05; ES=1.12) compared to in the shod condition. No significant ...

  15. Motion control report

    CERN Document Server

    2013-01-01

    Please note this is a short discount publication. In today's manufacturing environment, Motion Control plays a major role in virtually every project.The Motion Control Report provides a comprehensive overview of the technology of Motion Control:* Design Considerations* Technologies* Methods to Control Motion* Examples of Motion Control in Systems* A Detailed Vendors List

  16. US Spacesuit Knowledge Capture

    Science.gov (United States)

    Chullen, Cinda; Thomas, Ken; McMann, Joe; Dolan, Kristi; Bitterly, Rose; Lewis, Cathleen

    2011-01-01

    The ability to learn from both the mistakes and successes of the past is vital to assuring success in the future. Due to the close physical interaction between spacesuit systems and human beings as users, spacesuit technology and usage lends itself rather uniquely to the benefits realized from the skillful organization of historical information; its dissemination; the collection and identification of artifacts; and the education of those in the field. The National Aeronautics and Space Administration (NASA), other organizations and individuals have been performing United States (U.S.) Spacesuit Knowledge Capture since the beginning of space exploration. Avenues used to capture the knowledge have included publication of reports; conference presentations; specialized seminars; and classes usually given by veterans in the field. More recently the effort has been more concentrated and formalized whereby a new avenue of spacesuit knowledge capture has been added to the archives in which videotaping occurs engaging both current and retired specialists in the field presenting technical scope specifically for education and preservation of knowledge. With video archiving, all these avenues of learning can now be brought to life with the real experts presenting their wealth of knowledge on screen for future learners to enjoy. Scope and topics of U.S. spacesuit knowledge capture have included lessons learned in spacesuit technology, experience from the Gemini, Apollo, Skylab and Shuttle programs, hardware certification, design, development and other program components, spacesuit evolution and experience, failure analysis and resolution, and aspects of program management. Concurrently, U.S. spacesuit knowledge capture activities have progressed to a level where NASA, the National Air and Space Museum (NASM), Hamilton Sundstrand (HS) and the spacesuit community are now working together to provide a comprehensive closed-looped spacesuit knowledge capture system which includes

  17. Motion cues that make an impression: Predicting perceived personality by minimal motion information.

    Science.gov (United States)

    Koppensteiner, Markus

    2013-11-01

    The current study presents a methodology to analyze first impressions on the basis of minimal motion information. In order to test the applicability of the approach brief silent video clips of 40 speakers were presented to independent observers (i.e., did not know speakers) who rated them on measures of the Big Five personality traits. The body movements of the speakers were then captured by placing landmarks on the speakers' forehead, one shoulder and the hands. Analysis revealed that observers ascribe extraversion to variations in the speakers' overall activity, emotional stability to the movements' relative velocity, and variation in motion direction to openness. Although ratings of openness and conscientiousness were related to biographical data of the speakers (i.e., measures of career progress), measures of body motion failed to provide similar results. In conclusion, analysis of motion behavior might be done on the basis of a small set of landmarks that seem to capture important parts of relevant nonverbal information.

  18. Dizziness and Motion Sickness

    Science.gov (United States)

    ... Find an ENT Doctor Near You Dizziness and Motion Sickness Dizziness and Motion Sickness Patient Health Information ... other respiratory infections If you are subject to motion sickness: •Do not read while traveling •Avoid sitting ...

  19. Continuum secondary structure captures protein flexibility

    DEFF Research Database (Denmark)

    Anderson, C.A.F.; Palmer, A.G.; Brunak, Søren

    2002-01-01

    with different hydrogen bond thresholds. The final continuous assignment for a single NMR model successfully reflected the structural variations observed between all NMR models in the ensemble. The structural variations between NMR models were verified to correlate with thermal motion; these variations were...... captured by the continuous assignments. Because the continuous assignment reproduces the structural variation between many NMR models from one single model, functionally important variation can be extracted from a single X-ray structure. Thus, continuous assignments of secondary structure may affect future...

  20. The relationship between action-effect monitoring and attention capture.

    Science.gov (United States)

    Kumar, Neeraj; Manjaly, Jaison A; Sunny, Meera Mary

    2015-02-01

    Many recent findings suggest that stimuli that are perceived to be the consequence of one's own actions are processed with priority. According to the preactivation account of intentional binding, predicted consequences are preactivated and hence receive a temporal advantage in processing. The implications of the preactivation account are important for theories of attention capture, as temporal advantage often translates to attention capture. Hence, action might modulate attention capture by feature singletons. Experiment 1 showed that a motion onset and color change captured attention only when it was preceded by an action. Experiment 2 showed that the capture occurs only with predictable, but not with unpredictable, consequences of action. Experiment 3 showed that even when half the display changed color at display transition, they were all prioritized. The results suggest that action modulates attentional control.

  1. Obesity does not influence prostate intrafractional motion.

    Science.gov (United States)

    Brown, Amy; Tan, Alex; Cooper, Scott; Fielding, Andrew

    2018-01-23

    Motion of the prostate is problematic in the accurate delivery of external beam radiation therapy (EBRT) for prostate cancer. This study investigated the relationship between body mass index (BMI), an easily measured indicator of obesity, and prostate motion. Prostate motion during EBRT was assessed by measuring the displacement of fiducial markers implanted within the prostate in 130 prostate cancer patients. Interfractional motion was corrected on daily imaging through pre-treatment cone-beam-computed tomography (CBCT) and intrafractional motion measured using movie sequences captured using an electronic portal imaging device (EPID) during treatment delivery. There was no statistically significant relationship between the mean intrafractional motion and BMI, except in the left-right (LR) translation (P = 0.049) over the study population. For each BMI category, there was no statistical significance (P > 0.05) between any of the translations/rotations except LR (P = 0.003). While intrafractional motion is an important consideration, prostate motion cannot be reliably predicted through measurement of patient's BMI. © 2018 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

  2. Motion in radiotherapy

    DEFF Research Database (Denmark)

    Korreman, Stine Sofia

    2012-01-01

    This review considers the management of motion in photon radiation therapy. An overview is given of magnitudes and variability of motion of various structures and organs, and how the motion affects images by producing artifacts and blurring. Imaging of motion is described, including 4DCT and 4DPE...

  3. Capturing the Future: Direct and Indirect Probes of Neutron Capture

    Energy Technology Data Exchange (ETDEWEB)

    Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-31

    This report documents aspects of direct and indirect neutron capture. The importance of neutron capture rates and methods to determine them are presented. The following conclusions are drawn: direct neutron capture measurements remain a backbone of experimental study; work is being done to take increased advantage of indirect methods for neutron capture; both instrumentation and facilities are making new measurements possible; more work is needed on the nuclear theory side to understand what is needed furthest from stability.

  4. Wearable Stretch Sensors for Motion Measurement of the Wrist Joint Based on Dielectric Elastomers

    Directory of Open Access Journals (Sweden)

    Bo Huang

    2017-11-01

    Full Text Available Motion capture of the human body potentially holds great significance for exoskeleton robots, human-computer interaction, sports analysis, rehabilitation research, and many other areas. Dielectric elastomer sensors (DESs are excellent candidates for wearable human motion capture systems because of their intrinsic characteristics of softness, light weight, and compliance. In this paper, DESs were applied to measure all component motions of the wrist joints. Five sensors were mounted to different positions on the wrist, and each one is for one component motion. To find the best position to mount the sensors, the distribution of the muscles is analyzed. Even so, the component motions and the deformation of the sensors are coupled; therefore, a decoupling method was developed. By the decoupling algorithm, all component motions can be measured with a precision of 5°, which meets the requirements of general motion capture systems.

  5. Wearable Stretch Sensors for Motion Measurement of the Wrist Joint Based on Dielectric Elastomers.

    Science.gov (United States)

    Huang, Bo; Li, Mingyu; Mei, Tao; McCoul, David; Qin, Shihao; Zhao, Zhanfeng; Zhao, Jianwen

    2017-11-23

    Motion capture of the human body potentially holds great significance for exoskeleton robots, human-computer interaction, sports analysis, rehabilitation research, and many other areas. Dielectric elastomer sensors (DESs) are excellent candidates for wearable human motion capture systems because of their intrinsic characteristics of softness, light weight, and compliance. In this paper, DESs were applied to measure all component motions of the wrist joints. Five sensors were mounted to different positions on the wrist, and each one is for one component motion. To find the best position to mount the sensors, the distribution of the muscles is analyzed. Even so, the component motions and the deformation of the sensors are coupled; therefore, a decoupling method was developed. By the decoupling algorithm, all component motions can be measured with a precision of 5°, which meets the requirements of general motion capture systems.

  6. Causal capture effects in chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Matsuno, Toyomi; Tomonaga, Masaki

    2017-01-01

    Extracting a cause-and-effect structure from the physical world is an important demand for animals living in dynamically changing environments. Human perceptual and cognitive mechanisms are known to be sensitive and tuned to detect and interpret such causal structures. In contrast to rigorous investigations of human causal perception, the phylogenetic roots of this perception are not well understood. In the present study, we aimed to investigate the susceptibility of nonhuman animals to mechanical causality by testing whether chimpanzees perceived an illusion called causal capture (Scholl & Nakayama, 2002). Causal capture is a phenomenon in which a type of bistable visual motion of objects is perceived as causal collision due to a bias from a co-occurring causal event. In our experiments, we assessed the susceptibility of perception of a bistable stream/bounce motion event to a co-occurring causal event in chimpanzees. The results show that, similar to in humans, causal "bounce" percepts were significantly increased in chimpanzees with the addition of a task-irrelevant causal bounce event that was synchronously presented. These outcomes suggest that the perceptual mechanisms behind the visual interpretation of causal structures in the environment are evolutionarily shared between human and nonhuman animals. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Multisegmental Foot and Ankle Motion Analysis After Hallux Valgus Surgery

    Science.gov (United States)

    Canseco, Karl; Long, Jason; Smedberg, Thomas; Tarima, Sergey; Marks, Richard M.; Harris, Gerald F.

    2015-01-01

    Background Gait changes in patients with hallux valgus, including altered kinematic and temporal-spatial parameters, have been documented in the literature. Although operative treatment can yield favorable clinical and radiographic results, restoration of normal gait in this population remains unclear. Segmental kinematic changes within the foot and ankle during ambulation after operative correction of hallux valgus have not been reported. The aim of this study was to analyze changes in multisegmental foot and ankle kinematics in patients who underwent operative correction of hallux valgus. Methods A 15-camera Vicon Motion Analysis System was used to evaluate 24 feet in 19 patients with hallux valgus preoperatively and postoperatively. The Milwaukee Foot Model was used to characterize segmental kinematics and temporal-spatial parameters (TSPs). Preoperative and postoperative kinematics and TSPs were compared using paired nonparametric methods; comparisons with normative data were performed using unpaired nonparametric methods. Outcomes were evaluated using the SF-36 assessment tool. Results Preoperatively, patients with hallux valgus showed significantly altered temporal-spatial and kinematic parameters. Postoperatively, kinematic analysis demonstrated restoration of hallux position to normal. Hallux valgus angles and intermetatarsal angles were significantly improved, and outcomes showed a significant increase in performance of physical activities. Temporal-spatial parameters and kinematics in the more proximal segments were not significantly changed postoperatively. Conclusion Postoperative results demonstrated significant improvement in foot geometry and hallux kinematics in the coronal and transverse planes. However, the analysis did not identify restoration of proximal kinematics. Clinical Relevance Further investigation is necessary to explore possible causes/clinical relevance and appropriate treatment interventions for the persistently altered kinematics

  8. LUMBAR CORSETS CAN DECREASE LUMBAR MOTION IN GOLF SWING

    Directory of Open Access Journals (Sweden)

    Koji Hashimoto

    2013-03-01

    Full Text Available Swinging a golf club includes the rotation and extension of the lumbar spine. Golf-related low back pain has been associated with degeneration of the lumbar facet and intervertebral discs, and with spondylolysis. Reflective markers were placed directly onto the skin of 11young male amateur golfers without a previous history of back pain. Using a VICON system (Oxford Metrics, U.K., full golf swings were monitored without a corset (WOC, with a soft corset (SC, and with a hard corset (HC, with each subject taking 3 swings. Changes in the angle between the pelvis and the thorax (maximum range of motion and angular velocity in 3 dimensions (lumbar rotation, flexion-extension, and lateral tilt were analyzed, as was rotation of the hip joint. Peak changes in lumbar extension and rotation occurred just after impact with the ball. The extension angle of the lumbar spine at finish was significantly lower under SC (38° or HC (28° than under WOC (44° conditions (p < 0.05. The maximum angular velocity after impact was significantly smaller under HC (94°/sec than under SC (177°/sec and WOC (191° /sec conditions, as were the lumbar rotation angles at top and finish. In contrast, right hip rotation angles at top showed a compensatory increase under HC conditions. Wearing a lumbar corset while swinging a golf club can effectively decrease lumbar extension and rotation angles from impact until the end of the swing. These effects were significantly enhanced while wearing an HC

  9. Motion Transplantation Techniques: A Survey

    NARCIS (Netherlands)

    van Basten, Ben|info:eu-repo/dai/nl/30484800X; Egges, Arjan|info:eu-repo/dai/nl/304822779

    2012-01-01

    During the past decade, researchers have developed several techniques for transplanting motions. These techniques transplant a partial auxiliary motion, possibly defined for a small set of degrees of freedom, on a base motion. Motion transplantation improves motion databases' expressiveness and

  10. A Motion Planning Approach to Studying Molecular Motions

    KAUST Repository

    Amato, Nancy M.

    2010-01-01

    While structurally very different, protein and RNA molecules share an important attribute. The motions they undergo are strongly related to the function they perform. For example, many diseases such as Mad Cow disease or Alzheimer\\'s disease are associated with protein misfolding and aggregation. Similarly, RNA folding velocity may regulate the plasmid copy number, and RNA folding kinetics can regulate gene expression at the translational level. Knowledge of the stability, folding, kinetics and detailed mechanics of the folding process may help provide insight into how proteins and RNAs fold. In this paper, we present an overview of our work with a computational method we have adapted from robotic motion planning to study molecular motions. We have validated against experimental data and have demonstrated that our method can capture biological results such as stochastic folding pathways, population kinetics of various conformations, and relative folding rates. Thus, our method provides both a detailed view (e.g., individual pathways) and a global view (e.g., population kinetics, relative folding rates, and reaction coordinates) of energy landscapes of both proteins and RNAs. We have validated these techniques by showing that we observe the same relative folding rates as shown in experiments for structurally similar protein molecules that exhibit different folding behaviors. Our analysis has also been able to predict the same relative gene expression rate for wild-type MS2 phage RNA and three of its mutants.

  11. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to capture greater than 90 percent of sulfur gases evolved during thermal treatment of lunar soils....

  12. Improved motion description for action classification

    Directory of Open Access Journals (Sweden)

    Mihir eJain

    2016-01-01

    Full Text Available Even though the importance of explicitly integrating motion characteristics in video descriptions has been demonstrated by several recent papers on action classification, our current work concludes that adequately decomposing visual motion into dominant and residual motions, i.e.: camera and scene motion, significantly improves action recognition algorithms. This holds true both for the extraction of the space-time trajectories and for computation of descriptors.We designed a new motion descriptor – the DCS descriptor – that captures additional information on local motion patterns enhancing results based on differential motion scalar quantities, divergence, curl and shear features. Finally, applying the recent VLAD coding technique proposed in image retrieval provides a substantial improvement for action recognition. These findings are complementary to each other and they outperformed all previously reported results by a significant margin on three challenging datasets: Hollywood 2, HMDB51 and Olympic Sports as reported in (Jain et al. (2013. These results were further improved by (Oneata et al. (2013; Wang and Schmid (2013; Zhu et al. (2013 through the use of the Fisher vector encoding. We therefore also employ Fisher vector in this paper and we further enhance our approach by combining trajectories from both optical flow and compensated flow. We as well provide additional details of DCS descriptors, including visualization. For extending the evaluation, a novel dataset with 101 action classes, UCF101, was added.

  13. Cost-effective solution to synchronized audio-visual capture using multiple sensors

    NARCIS (Netherlands)

    Lichtenauer, Jeroen; Valstar, Michel; Shen, Jie; Pantic, Maja

    2009-01-01

    Applications such as surveillance and human motion capture require high-bandwidth recording from multiple cameras. Furthermore, the recent increase in research on sensor fusion has raised the demand on synchronization accuracy between video, audio and other sensor modalities. Previously, capturing

  14. Macro motion vector quantization

    Science.gov (United States)

    Lee, Yoon Y.; Woods, John W.

    1995-04-01

    A new algorithm is developed for reducing the bit rate required for motion vectors. This algorithm is a generalization of block matching motion estimation in which the search region is represented as a codebook of motion vectors. The new algorithm, called macro motion vector quantization (MMVQ), generalized our earlier MVQ by coding a group of motion vectors. The codebook is a set of macro motion vectors which represent the block locations of the small neighboring blocks in the previous frame. We develop an interative design algorithm for the codebook. Our experiments show that the variances of displaced frame differences (DFDs) are reduced significantly compared to block matching algorithm (BMA) with the macroblock size.

  15. EDITORIAL: Nanotechnology in motion Nanotechnology in motion

    Science.gov (United States)

    Demming, Anna

    2012-02-01

    , Toshio Ando from the University of Kanazawa provides an overview of developments that have allowed atomic force microscopy to move from rates of the order of one frame a minute to over a thousand frames per second in constant height mode, as reported by Mervyn Miles and colleagues at Bristol University and University College London [8]. Among the pioneers in the field, Ando's group demonstrated the ability to record the Brownian motion of myosin V molecules on mica with image capture rates of 100 x 100 pixels in 80 ms over a decade ago [9]. The developments unleash the potential of atomic force microscopy to observe the dynamics of biological and materials systems. If seeing is believing, the ability to present real motion pictures of the nanoworld cannot fail to capture the public imagination and stimulate burgeoning new avenues of scientific endeavour. Nearly 350 years on from the publication Micrographia, images in microscopy have moved from the page to the movies. References [1] Binnig G, Quate C F, and Gerber Ch 1986 Phys. Rev. Lett. 56 930-3 [2] Ando T 2012 Nanotechnology 23 062001 [3] J G 1934 Nature 134 635-6 [4] Bharadwaj P, Anger P and Novotny L 2007 Nanotechnology 18 044017 [5] The Nobel Prize in Physics 1986 Nobelprize.org [6] Kim K K, Reina A, Shi Y, Park H, Li L-J, Lee Y H and Kong J 2010 Nanotechnology 21 285205 [7] Phillips D B, Grieve J A, Olof S N, Kocher S J, Bowman R, Padgett M J, Miles M J and Carberry D M 2011 Nanotechnology 22 285503 [8] Picco L M, Bozec L, Ulcinas A, Engledew D J, Antognozzi M, Horton M A and Miles M J 2007 Nanotechnology 18 044030 [9] Ando T, Kodera N, Takai E, Maruyama D, Saito K and Toda A 2001 Proc. Natl. Acad. Sci. 98 12468

  16. Full-motion video analysis for improved gender classification

    Science.gov (United States)

    Flora, Jeffrey B.; Lochtefeld, Darrell F.; Iftekharuddin, Khan M.

    2014-06-01

    The ability of computer systems to perform gender classification using the dynamic motion of the human subject has important applications in medicine, human factors, and human-computer interface systems. Previous works in motion analysis have used data from sensors (including gyroscopes, accelerometers, and force plates), radar signatures, and video. However, full-motion video, motion capture, range data provides a higher resolution time and spatial dataset for the analysis of dynamic motion. Works using motion capture data have been limited by small datasets in a controlled environment. In this paper, we explore machine learning techniques to a new dataset that has a larger number of subjects. Additionally, these subjects move unrestricted through a capture volume, representing a more realistic, less controlled environment. We conclude that existing linear classification methods are insufficient for the gender classification for larger dataset captured in relatively uncontrolled environment. A method based on a nonlinear support vector machine classifier is proposed to obtain gender classification for the larger dataset. In experimental testing with a dataset consisting of 98 trials (49 subjects, 2 trials per subject), classification rates using leave-one-out cross-validation are improved from 73% using linear discriminant analysis to 88% using the nonlinear support vector machine classifier.

  17. Capturing the Daylight Dividend

    Energy Technology Data Exchange (ETDEWEB)

    Peter Boyce; Claudia Hunter; Owen Howlett

    2006-04-30

    Capturing the Daylight Dividend conducted activities to build market demand for daylight as a means of improving indoor environmental quality, overcoming technological barriers to effective daylighting, and informing and assisting state and regional market transformation and resource acquisition program implementation efforts. The program clarified the benefits of daylight by examining whole building systems energy interactions between windows, lighting, heating, and air conditioning in daylit buildings, and daylighting's effect on the human circadian system and productivity. The project undertook work to advance photosensors, dimming systems, and ballasts, and provided technical training in specifying and operating daylighting controls in buildings. Future daylighting work is recommended in metric development, technology development, testing, training, education, and outreach.

  18. Robust automated knowledge capture.

    Energy Technology Data Exchange (ETDEWEB)

    Stevens-Adams, Susan Marie; Abbott, Robert G.; Forsythe, James Chris; Trumbo, Michael Christopher Stefan; Haass, Michael Joseph; Hendrickson, Stacey M. Langfitt

    2011-10-01

    This report summarizes research conducted through the Sandia National Laboratories Robust Automated Knowledge Capture Laboratory Directed Research and Development project. The objective of this project was to advance scientific understanding of the influence of individual cognitive attributes on decision making. The project has developed a quantitative model known as RumRunner that has proven effective in predicting the propensity of an individual to shift strategies on the basis of task and experience related parameters. Three separate studies are described which have validated the basic RumRunner model. This work provides a basis for better understanding human decision making in high consequent national security applications, and in particular, the individual characteristics that underlie adaptive thinking.

  19. The KIT Motion-Language Dataset.

    Science.gov (United States)

    Plappert, Matthias; Mandery, Christian; Asfour, Tamim

    2016-12-01

    Linking human motion and natural language is of great interest for the generation of semantic representations of human activities as well as for the generation of robot activities based on natural language input. However, although there have been years of research in this area, no standardized and openly available data set exists to support the development and evaluation of such systems. We, therefore, propose the Karlsruhe Institute of Technology (KIT) Motion-Language Dataset, which is large, open, and extensible. We aggregate data from multiple motion capture databases and include them in our data set using a unified representation that is independent of the capture system or marker set, making it easy to work with the data regardless of its origin. To obtain motion annotations in natural language, we apply a crowd-sourcing approach and a web-based tool that was specifically build for this purpose, the Motion Annotation Tool. We thoroughly document the annotation process itself and discuss gamification methods that we used to keep annotators motivated. We further propose a novel method, perplexity-based selection, which systematically selects motions for further annotation that are either under-represented in our data set or that have erroneous annotations. We show that our method mitigates the two aforementioned problems and ensures a systematic annotation process. We provide an in-depth analysis of the structure and contents of our resulting data set, which, as of October 10, 2016, contains 3911 motions with a total duration of 11.23 hours and 6278 annotations in natural language that contain 52,903 words. We believe this makes our data set an excellent choice that enables more transparent and comparable research in this important area.

  20. Detection and Compensation of Periodic Motion in Magnetic Particle Imaging.

    Science.gov (United States)

    Gdaniec, N; Schluter, M; Moddel, M; Kaul, M G; Krishnan, K M; Schlaefer, A; Knopp, T

    2017-07-01

    The temporal resolution of the tomographic imaging method magnetic particle imaging (MPI) is remarkably high. The spatial resolution is degraded for measured voltage signal with low signal-to-noise ratio, because the regularization in the image reconstruction step needs to be increased for system-matrix approaches and for deconvolution steps in x -space approaches. To improve the signal-to-noise ratio, blockwise averaging of the signal over time can be advantageous. However, since block-wise averaging decreases the temporal resolution, it prevents resolving the motion. In this paper, a framework for averaging motion-corrupted MPI raw data is proposed. The motion is considered to be periodic as it is the case for respiration and/or the heartbeat. The same state of motion is thus reached repeatedly in a time series exceeding the repetition time of the motion and can be used for averaging. As the motion process and the acquisition process are, in general, not synchronized, averaging of the captured MPI raw data corresponding to the same state of motion requires to shift the starting point of the individual frames. For high-frequency motion, a higher frame rate is potentially required. To address this issue, a binning method for using only parts of complete frames from a motion cycle is proposed that further reduces the motion artifacts in the final images. The frequency of motion is derived directly from the MPI raw data signal without the need to capture an additional navigator signal. Using a motion phantom, it is shown that the proposed method is capable of averaging experimental data with reduced motion artifacts. The methods are further validated on in-vivo data from mouse experiments to compensate the heartbeat.

  1. Male Spine Motion During Coitus

    Science.gov (United States)

    Sidorkewicz, Natalie

    2014-01-01

    Study Design. Repeated measures design. Objective. To describe male spine movement and posture characteristics during coitus and compare these characteristics across 5 common coital positions. Summary of Background Data. Exacerbation of pain during coitus due to coital movements and positions is a prevalent issue reported by low back pain patients. A biomechanical analysis of spine movements and postures during coitus has never been conducted. Methods. Ten healthy males and females engaged in coitus in the following preselected positions and variations: QUADRUPED, MISSIONARY, and SIDELYING. An optoelectronic motion capture system was used to measure 3-dimensional lumbar spine angles that were normalized to upright standing. To determine whether each coital position had distinct spine kinematic profiles, separate univariate general linear models, followed by Tukey's honestly significant difference post hoc analysis were used. The presentation of coital positions was randomized. Results. Both variations of QUADRUPED, mQUAD1 and mQUAD2, were found to have a significantly higher cycle speed than mSIDE (P = 0.043 and P = 0.034, respectively), mMISS1 (P = 0.003 and P = 0.002, respectively), and mMISS2 (P = 0.001 and P spine movement varied depending on the coital position; however, across all positions, the majority of the range of motion used was in flexion. Based on range of motion, the least-to-most recommended positions for a male flexion-intolerant patient are mSIDE, mMISS2, mQUAD2, mMISS1, and mQUAD1. Conclusion. Initial recommendations—which include specific coital positions to avoid, movement strategies, and role of the partner—were developed for male patients whose low back pain is exacerbated by specific motions and postures. Level of Evidence: N/A PMID:25208042

  2. Objects in Motion

    Science.gov (United States)

    Damonte, Kathleen

    2004-01-01

    One thing scientists study is how objects move. A famous scientist named Sir Isaac Newton (1642-1727) spent a lot of time observing objects in motion and came up with three laws that describe how things move. This explanation only deals with the first of his three laws of motion. Newton's First Law of Motion says that moving objects will continue…

  3. Registration of Large Motion Blurred Images

    Science.gov (United States)

    2016-05-09

    AFRL-AFOSR-JP-TR-2016-0055 Registration of Large Motion Blurred Images Ambasamudram Rajagopalan INDIAN INSTITUTE OF TECHNOLOGY MADRAS Final Report 05...5e.  TASK NUMBER 5f.  WORK UNIT NUMBER 7.  PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) INDIAN INSTITUTE OF TECHNOLOGY MADRAS SARDAR PATEL ROAD...in handling the dynamics of the capturing system, for example, a drone . CMOS sensors, used in recent times, when employed in these cameras produce

  4. Biophone: Physiology monitoring from peripheral smartphone motions

    OpenAIRE

    Hernandez Rivera, Javier; McDuff, Daniel Jonathan; Rosalind W. Picard

    2015-01-01

    The large-scale adoption of smartphones during recent years has created many opportunities to improve health monitoring and care delivery. In this work, we demonstrate that motion sensors available in off-the-shelf smartphones can capture physiological parameters of a person during stationary postures, even while being carried in a bag or a pocket. In particular, we develop methods to extract heart and breathing rates from accelerometer data and compare them with measurements obtained with FD...

  5. Lung respiration motion modeling: a sparse motion field presentation method using biplane x-ray images

    Science.gov (United States)

    Chen, Dong; Xie, Hongzhi; Zhang, Shuyang; Gu, Lixu

    2017-10-01

    Respiration-introduced tumor location uncertainty is a challenge in the precise lung biopsy for lung lesions. Current statistical modeling approaches hardly capture the complex local respiratory motion information. In this study, we formulate a statistical respiratory motion model using biplane x-ray images to improve the accuracy of motion field estimation by efficiently preserving local motion details for specific patients. Given CT data sets of 18 healthy subjects at end-expiratory and end-inspiratory breathing phases, the respiratory motion field is constructed based on deformation vector fields which are extracted from these CT data sets, and a lung contour motion repository respiratory is generated dependent on displacements of boundary control points. By varying the sparse weight coefficients of the statistical sparse motion field presentation (SMFP) method, the newly-input motion field is approximately presented by a sparse linear combination of a subset of the motion repository. The SMFP method is employed twice in the coefficient optimization process. Finally, these non-zero coefficients are fine-tuned to maximize the similarity between the projection image of reconstructed volumetric images and the current x-ray image. We performed the proposed method for estimating respiratory motion field on ten subject datasets and compared the result with the PCA method. The maximum average target registration error of the PCA-based and the SMFP-based respiratory motion field estimation are 3.1(2.0) and 2.9(1.6) mm, respectively. The maximum average symmetric surface distance of two methods are 2.5(1.6) and 2.4(1.3) mm, respectively.

  6. How sailfish use their bills to capture schooling prey

    DEFF Research Database (Denmark)

    Domenici, P.; Wilson, A.D.M.; Kurvers, R.H.J.M.

    2014-01-01

    The istiophorid family of billfishes is characterized by an extended rostrum or ‘bill’. While various functions (e.g. foraging and hydrodynamic benefits) have been proposed for this structure, until now no study has directly investigated the mechanisms by which billfishes use their rostrum to fee...... and rapid motion make the sailfish bill an extremely effective feeding adaptation for capturing schooling prey....... an evasive response and (ii) subsequently use their bill to either tap on individual prey targets or to slash through the school with powerful lateral motions characterized by one of the highest accelerations ever recorded in an aquatic vertebrate. Our results demonstrate that the combination of stealth...

  7. Selected static foot assessments do not predict medial longitudinal arch motion during running.

    Science.gov (United States)

    Langley, Ben; Cramp, Mary; Morrison, Stewart C

    2015-01-01

    Static assessments of the foot are commonly advocated within the running community to classify the foot with a view to recommending the appropriate type of running shoe. The aim of this work was to determine whether selected static foot assessment could predict medial longitudinal arch (MLA) motion during running. Fifteen physically active males (27 ± 5 years, 1.77 ± 0.04 m, 80 ± 10 kg) participated in the study. Foot Posture Index (FPI-6), MLA angle and rearfoot angle were measured in a relaxed standing position. MLA motion was calculated using the position of retro-reflective markers tracked by a VICON motion analysis system, while participants ran barefoot on a treadmill at a self-selected pace (2.8 ± 0.5 m.s(-1)). Bivariate linear regression was used to determine whether the static measures predicted MLA deformation and MLA angles at initial contact, midsupport and toe off. All three foot classification measures were significant predictors of MLA angle at initial contact, midsupport and toe off (p static foot classification measures were significant predictors of MLA deformation during the stance phase of running. Selected static foot measures did not predict dynamic MLA deformation during running. Given that MLA deformation has theoretically been linked to running injuries, the clinical relevance of predicting MLA angle at discrete time points during the stance phase of running is questioned. These findings also question the validity of the selected static foot classification measures when looking to characterise the foot during running. This indicates that alternative means of assessing the foot to inform footwear selection are required.

  8. Investigation of the electron capture process in semiclassical plasma

    Directory of Open Access Journals (Sweden)

    Seisembayeva Madina M.

    2016-06-01

    Full Text Available In this work, the process of electron capture in partially ionized plasma is considered. Electron-atom interaction was described by the effective interaction potential, which takes into account the screening effect at large distances and the diffraction effect at the small distances. The results of numerical calculations of the electron capture radius, differential cross-section for different values of the coupling and density parameters are presented. The differential cross-section was obtained on the basis of perturbation theory and also by solving of the equation of motion of the projectile electron.

  9. Individuality and reproducibility in high-speed motion of volleyball spike jumps by phase-matching and averaging.

    Science.gov (United States)

    Tokuyama, Mitsuru; Ohashi, Hirotsugu; Iwamoto, Hisao; Takaoka, Kunio; Okubo, Mamoru

    2005-10-01

    For analysis of knee injuries in volleyball, we developed a system to obtain kinematic waveforms about the high-speed motion of volleyball spike jumps that could examine their individuality and reproducibility, with phase-matching and averaging. The form of six female players was recorded in two sessions of ten jumps each, with a video motion-analysis system, VICON, at the sampling frequency of 240 Hz. To identify individual jump characteristics despite differences from jump to jump, we averaged up to ten data sets with phases matched. For such matching, we defined and used a statistic, epsilon, as the arithmetic mean of all absolute differences in each of the angles at each time sampled, based on the least squares method. Statistical evaluation with adjusted coefficients of multiple determination and epsilon showed that intra-individual variation between the two sessions was significantly smaller than inter-individual variation; their means differed by more than 2 standard deviations (SD) and 3SD, respectively. Regression analysis showed that this system was reliable (p < 0.001). We concluded that the averaged data sets obtained by the system could embody the individuality of spike jumps, with satisfactory reproducibility.

  10. Improved Leg Tracking Considering Gait Phase and Spline-Based Interpolation during Turning Motion in Walk Tests.

    Science.gov (United States)

    Yorozu, Ayanori; Moriguchi, Toshiki; Takahashi, Masaki

    2015-09-04

    Falling is a common problem in the growing elderly population, and fall-risk assessment systems are needed for community-based fall prevention programs. In particular, the timed up and go test (TUG) is the clinical test most often used to evaluate elderly individual ambulatory ability in many clinical institutions or local communities. This study presents an improved leg tracking method using a laser range sensor (LRS) for a gait measurement system to evaluate the motor function in walk tests, such as the TUG. The system tracks both legs and measures the trajectory of both legs. However, both legs might be close to each other, and one leg might be hidden from the sensor. This is especially the case during the turning motion in the TUG, where the time that a leg is hidden from the LRS is longer than that during straight walking and the moving direction rapidly changes. These situations are likely to lead to false tracking and deteriorate the measurement accuracy of the leg positions. To solve these problems, a novel data association considering gait phase and a Catmull-Rom spline-based interpolation during the occlusion are proposed. From the experimental results with young people, we confirm   that the proposed methods can reduce the chances of false tracking. In addition, we verify the measurement accuracy of the leg trajectory compared to a three-dimensional motion analysis system (VICON).

  11. Looming motion primes the visuomotor system.

    Science.gov (United States)

    Skarratt, Paul A; Gellatly, Angus R H; Cole, Geoff G; Pilling, Michael; Hulleman, Johan

    2014-04-01

    A wealth of evidence now shows that human and animal observers display greater sensitivity to objects that move toward them than to objects that remain static or move away. Increased sensitivity in humans is often evidenced by reaction times that increase in rank order from looming, to receding, to static targets. However, it is not clear whether the processing advantage enjoyed by looming motion is mediated by the attention system or the motor system. The present study investigated this by first examining whether sensitivity is to looming motion per se or to certain monocular or binocular cues that constitute stereoscopic motion in depth. None of the cues accounted for the looming advantage. A perceptual measure was then used to examine performance with minimal involvement of the motor system. Results showed that looming and receding motion were equivalent in attracting attention, suggesting that the looming advantage is indeed mediated by the motor system. These findings suggest that although motion itself is sufficient for attentional capture, motion direction can prime motor responses.

  12. Rolling Shutter Motion Deblurring

    KAUST Repository

    Su, Shuochen

    2015-06-07

    Although motion blur and rolling shutter deformations are closely coupled artifacts in images taken with CMOS image sensors, the two phenomena have so far mostly been treated separately, with deblurring algorithms being unable to handle rolling shutter wobble, and rolling shutter algorithms being incapable of dealing with motion blur. We propose an approach that delivers sharp and undis torted output given a single rolling shutter motion blurred image. The key to achieving this is a global modeling of the camera motion trajectory, which enables each scanline of the image to be deblurred with the corresponding motion segment. We show the results of the proposed framework through experiments on synthetic and real data.

  13. Smoothing Motion Estimates for Radar Motion Compensation.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    Simple motion models for complex motion environments are often not adequate for keeping radar data coherent. Eve n perfect motion samples appli ed to imperfect models may lead to interim calculations e xhibiting errors that lead to degraded processing results. Herein we discuss a specific i ssue involving calculating motion for groups of pulses, with measurements only available at pulse-group boundaries. - 4 - Acknowledgements This report was funded by General A tomics Aeronautical Systems, Inc. (GA-ASI) Mission Systems under Cooperative Re search and Development Agre ement (CRADA) SC08/01749 between Sandia National Laboratories and GA-ASI. General Atomics Aeronautical Systems, Inc. (GA-ASI), an affilia te of privately-held General Atomics, is a leading manufacturer of Remotely Piloted Aircraft (RPA) systems, radars, and electro-optic and rel ated mission systems, includin g the Predator(r)/Gray Eagle(r)-series and Lynx(r) Multi-mode Radar.

  14. Inland capture fisheries.

    Science.gov (United States)

    Welcomme, Robin L; Cowx, Ian G; Coates, David; Béné, Christophe; Funge-Smith, Simon; Halls, Ashley; Lorenzen, Kai

    2010-09-27

    The reported annual yield from inland capture fisheries in 2008 was over 10 million tonnes, although real catches are probably considerably higher than this. Inland fisheries are extremely complex, and in many cases poorly understood. The numerous water bodies and small rivers are inhabited by a wide range of species and several types of fisher community with diversified livelihood strategies for whom inland fisheries are extremely important. Many drivers affect the fisheries, including internal fisheries management practices. There are also many drivers from outside the fishery that influence the state and functioning of the environment as well as the social and economic framework within which the fishery is pursued. The drivers affecting the various types of inland water, rivers, lakes, reservoirs and wetlands may differ, particularly with regard to ecosystem function. Many of these depend on land-use practices and demand for water which conflict with the sustainability of the fishery. Climate change is also exacerbating many of these factors. The future of inland fisheries varies between continents. In Asia and Africa the resources are very intensely exploited and there is probably little room for expansion; it is here that resources are most at risk. Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production.

  15. Capture-recapture methodology

    Science.gov (United States)

    Gould, William R.; Kendall, William L.

    2013-01-01

    Capture-recapture methods were initially developed to estimate human population abundance, but since that time have seen widespread use for fish and wildlife populations to estimate and model various parameters of population, metapopulation, and disease dynamics. Repeated sampling of marked animals provides information for estimating abundance and tracking the fate of individuals in the face of imperfect detection. Mark types have evolved from clipping or tagging to use of noninvasive methods such as photography of natural markings and DNA collection from feces. Survival estimation has been emphasized more recently as have transition probabilities between life history states and/or geographical locations, even where some states are unobservable or uncertain. Sophisticated software has been developed to handle highly parameterized models, including environmental and individual covariates, to conduct model selection, and to employ various estimation approaches such as maximum likelihood and Bayesian approaches. With these user-friendly tools, complex statistical models for studying population dynamics have been made available to ecologists. The future will include a continuing trend toward integrating data types, both for tagged and untagged individuals, to produce more precise and robust population models.

  16. Inland capture fisheries

    Science.gov (United States)

    Welcomme, Robin L.; Cowx, Ian G.; Coates, David; Béné, Christophe; Funge-Smith, Simon; Halls, Ashley; Lorenzen, Kai

    2010-01-01

    The reported annual yield from inland capture fisheries in 2008 was over 10 million tonnes, although real catches are probably considerably higher than this. Inland fisheries are extremely complex, and in many cases poorly understood. The numerous water bodies and small rivers are inhabited by a wide range of species and several types of fisher community with diversified livelihood strategies for whom inland fisheries are extremely important. Many drivers affect the fisheries, including internal fisheries management practices. There are also many drivers from outside the fishery that influence the state and functioning of the environment as well as the social and economic framework within which the fishery is pursued. The drivers affecting the various types of inland water, rivers, lakes, reservoirs and wetlands may differ, particularly with regard to ecosystem function. Many of these depend on land-use practices and demand for water which conflict with the sustainability of the fishery. Climate change is also exacerbating many of these factors. The future of inland fisheries varies between continents. In Asia and Africa the resources are very intensely exploited and there is probably little room for expansion; it is here that resources are most at risk. Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production. PMID:20713391

  17. Structural motion engineering

    CERN Document Server

    Connor, Jerome

    2014-01-01

    This innovative volume provides a systematic treatment of the basic concepts and computational procedures for structural motion design and engineering for civil installations. The authors illustrate the application of motion control to a wide spectrum of buildings through many examples. Topics covered include optimal stiffness distributions for building-type structures, the role of damping in controlling motion, tuned mass dampers, base isolation systems, linear control, and nonlinear control. The book's primary objective is the satisfaction of motion-related design requirements, such as restrictions on displacement and acceleration. The book is ideal for practicing engineers and graduate students. This book also: ·         Broadens practitioners' understanding of structural motion control, the enabling technology for motion-based design ·         Provides readers the tools to satisfy requirements of modern, ultra-high strength materials that lack corresponding stiffness, where the motion re...

  18. Strong ground motion prediction using virtual earthquakes.

    Science.gov (United States)

    Denolle, M A; Dunham, E M; Prieto, G A; Beroza, G C

    2014-01-24

    Sedimentary basins increase the damaging effects of earthquakes by trapping and amplifying seismic waves. Simulations of seismic wave propagation in sedimentary basins capture this effect; however, there exists no method to validate these results for earthquakes that have not yet occurred. We present a new approach for ground motion prediction that uses the ambient seismic field. We apply our method to a suite of magnitude 7 scenario earthquakes on the southern San Andreas fault and compare our ground motion predictions with simulations. Both methods find strong amplification and coupling of source and structure effects, but they predict substantially different shaking patterns across the Los Angeles Basin. The virtual earthquake approach provides a new approach for predicting long-period strong ground motion.

  19. Robotics-based synthesis of human motion

    KAUST Repository

    Khatib, O.

    2009-05-01

    The synthesis of human motion is a complex procedure that involves accurate reconstruction of movement sequences, modeling of musculoskeletal kinematics, dynamics and actuation, and characterization of reliable performance criteria. Many of these processes have much in common with the problems found in robotics research. Task-based methods used in robotics may be leveraged to provide novel musculoskeletal modeling methods and physiologically accurate performance predictions. In this paper, we present (i) a new method for the real-time reconstruction of human motion trajectories using direct marker tracking, (ii) a task-driven muscular effort minimization criterion and (iii) new human performance metrics for dynamic characterization of athletic skills. Dynamic motion reconstruction is achieved through the control of a simulated human model to follow the captured marker trajectories in real-time. The operational space control and real-time simulation provide human dynamics at any configuration of the performance. A new criteria of muscular effort minimization has been introduced to analyze human static postures. Extensive motion capture experiments were conducted to validate the new minimization criterion. Finally, new human performance metrics were introduced to study in details an athletic skill. These metrics include the effort expenditure and the feasible set of operational space accelerations during the performance of the skill. The dynamic characterization takes into account skeletal kinematics as well as muscle routing kinematics and force generating capacities. The developments draw upon an advanced musculoskeletal modeling platform and a task-oriented framework for the effective integration of biomechanics and robotics methods.

  20. Motion cues that make an impression☆

    Science.gov (United States)

    Koppensteiner, Markus

    2013-01-01

    The current study presents a methodology to analyze first impressions on the basis of minimal motion information. In order to test the applicability of the approach brief silent video clips of 40 speakers were presented to independent observers (i.e., did not know speakers) who rated them on measures of the Big Five personality traits. The body movements of the speakers were then captured by placing landmarks on the speakers' forehead, one shoulder and the hands. Analysis revealed that observers ascribe extraversion to variations in the speakers' overall activity, emotional stability to the movements' relative velocity, and variation in motion direction to openness. Although ratings of openness and conscientiousness were related to biographical data of the speakers (i.e., measures of career progress), measures of body motion failed to provide similar results. In conclusion, analysis of motion behavior might be done on the basis of a small set of landmarks that seem to capture important parts of relevant nonverbal information. PMID:24223432

  1. Resource capture by single leaves

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.P.

    1992-05-01

    Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

  2. Visualizing and Quantifying Oceanic Motion

    Science.gov (United States)

    Rossby, T.

    2016-01-01

    Here I review the use of two highly complementary acoustical technologies for measuring currents in the ocean: acoustically tracked neutrally buoyant floats and vessel-mounted acoustic Doppler current profilers (ADCPs). The beauty of floats lies in their ability to efficiently and accurately visualize fluid motion in fronts and vortices and the dispersion caused by mesoscale eddy processes. Floats complement classical hydrography by articulating mechanisms and pathways by which waters spread out from their source region. Vessel-mounted ADCPs can profile the water column at O(1 km) horizontal resolution to depths greater than 1,000 m. These vessel-based scans capture in detail the cross-stream structure of fronts and eddies as well as the impact of bathymetry on currents. Sustained sampling along selected routes builds up valuable databases both for statistical studies of the submesoscale velocity field and for accurate estimates of fluid transport, as well as how these vary over time.

  3. A video-based system for hand-driven stop-motion animation.

    Science.gov (United States)

    Han, Xiaoguang; Fu, Hongbo; Zheng, Hanlin; Liu, Ligang; Wang, Jue

    2013-01-01

    Stop-motion is a well-established animation technique but is often laborious and requires craft skills. A new video-based system can animate the vast majority of everyday objects in stop-motion style, more flexibly and intuitively. Animators can perform and capture motions continuously instead of breaking them into increments and shooting one still picture per increment. More important, the system permits direct hand manipulation without resorting to rigs, achieving more natural object control for beginners. The system's key component is two-phase keyframe-based capturing and processing, assisted by computer vision techniques. With this system, even amateurs can generate high-quality stop-motion animations.

  4. Robot arm system for automatic satellite capture and berthing

    Science.gov (United States)

    Nishida, Shinichiro; Toriu, Hidetoshi; Hayashi, Masato; Kubo, Tomoaki; Miyata, Makoto

    1994-01-01

    Load control is one of the most important technologies for capturing and berthing free flying satellites by a space robot arm because free flying satellites have different motion rates. The performance of active compliance control techniques depend on the location of the force sensor and the arm's structural compliance. A compliance control technique for the robot arm's structural elasticity and a consideration for an end-effector appropriate for it are presented in this paper.

  5. Motion lecture annotation system to learn Naginata performances

    Science.gov (United States)

    Kobayashi, Daisuke; Sakamoto, Ryota; Nomura, Yoshihiko

    2013-12-01

    This paper describes a learning assistant system using motion capture data and annotation to teach "Naginata-jutsu" (a skill to practice Japanese halberd) performance. There are some video annotation tools such as YouTube. However these video based tools have only single angle of view. Our approach that uses motion-captured data allows us to view any angle. A lecturer can write annotations related to parts of body. We have made a comparison of effectiveness between the annotation tool of YouTube and the proposed system. The experimental result showed that our system triggered more annotations than the annotation tool of YouTube.

  6. An analysis of human motion detection systems use during elder exercise routines.

    Science.gov (United States)

    Alexander, Gregory L; Havens, Timothy C; Rantz, Marilyn; Keller, James; Casanova Abbott, Carmen

    2010-03-01

    Human motion analysis provides motion pattern and body pose estimations. This study integrates computer-vision techniques and explores a markerless human motion analysis system. Using human-computer interaction (HCI) methods and goals, researchers use a computer interface to provide feedback about range of motion to users. A total of 35 adults aged 65 and older perform three exercises in a public gym while human motion capture methods are used. Following exercises, participants are shown processed human motion images captured during exercises on a customized interface. Standardized questionnaires are used to elicit responses from users during interactions with the interface. A matrix of HCI goals (effectiveness, efficiency, and user satisfaction) and emerging themes are used to describe interactions. Sixteen users state the interface would be useful, but not necessarily for safety purposes. Users want better image quality, when expectations are matched satisfaction increases, and unclear meaning of motion measures decreases satisfaction.

  7. Iodine neutron capture therapy

    Science.gov (United States)

    Ahmed, Kazi Fariduddin

    A new technique, Iodine Neutron Capture Therapy (INCT) is proposed to treat hyperthyroidism in people. Present thyroid therapies, surgical removal and 131I treatment, result in hypothyroidism and, for 131I, involve protracted treatment times and excessive whole-body radiation doses. The new technique involves using a low energy neutron beam to convert a fraction of the natural iodine stored in the thyroid to radioactive 128I, which has a 24-minute half-life and decays by emitting 2.12-MeV beta particles. The beta particles are absorbed in and damage some thyroid tissue cells and consequently reduce the production and release of thyroid hormones to the blood stream. Treatment times and whole-body radiation doses are thus reduced substantially. This dissertation addresses the first of the several steps needed to obtain medical profession acceptance and regulatory approval to implement this therapy. As with other such programs, initial feasibility is established by performing experiments on suitable small mammals. Laboratory rats were used and their thyroids were exposed to the beta particles coming from small encapsulated amounts of 128I. Masses of 89.0 mg reagent-grade elemental iodine crystals have been activated in the ISU AGN-201 reactor to provide 0.033 mBq of 128I. This activity delivers 0.2 Gy to the thyroid gland of 300-g male rats having fresh thyroid tissue masses of ˜20 mg. Larger iodine masses are used to provide greater doses. The activated iodine is encapsulated to form a thin (0.16 cm 2/mg) patch that is then applied directly to the surgically exposed thyroid of an anesthetized rat. Direct neutron irradiation of a rat's thyroid was not possible due to its small size. Direct in-vivo exposure of the thyroid of the rat to the emitted radiation from 128I is allowed to continue for 2.5 hours (6 half-lives). Pre- and post-exposure blood samples are taken to quantify thyroid hormone levels. The serum T4 concentration is measured by radioimmunoassay at

  8. Carbon Capture and Storage

    Energy Technology Data Exchange (ETDEWEB)

    Friedmann, S

    2007-10-03

    Carbon capture and sequestration (CCS) is the long-term isolation of carbon dioxide from the atmosphere through physical, chemical, biological, or engineered processes. This includes a range of approaches including soil carbon sequestration (e.g., through no-till farming), terrestrial biomass sequestration (e.g., through planting forests), direct ocean injection of CO{sub 2} either onto the deep seafloor or into the intermediate depths, injection into deep geological formations, or even direct conversion of CO{sub 2} to carbonate minerals. Some of these approaches are considered geoengineering (see the appropriate chapter herein). All are considered in the 2005 special report by the Intergovernmental Panel on Climate Change (IPCC 2005). Of the range of options available, geological carbon sequestration (GCS) appears to be the most actionable and economic option for major greenhouse gas reduction in the next 10-30 years. The basis for this interest includes several factors: (1) The potential capacities are large based on initial estimates. Formal estimates for global storage potential vary substantially, but are likely to be between 800 and 3300 Gt of C (3000 and 10,000 Gt of CO{sub 2}), with significant capacity located reasonably near large point sources of the CO{sub 2}. (2) GCS can begin operations with demonstrated technology. Carbon dioxide has been separated from large point sources for nearly 100 years, and has been injected underground for over 30 years (below). (3) Testing of GCS at intermediate scale is feasible. In the US, Canada, and many industrial countries, large CO{sub 2} sources like power plants and refineries lie near prospective storage sites. These plants could be retrofit today and injection begun (while bearing in mind scientific uncertainties and unknowns). Indeed, some have, and three projects described here provide a great deal of information on the operational needs and field implementation of CCS. Part of this interest comes from several

  9. Nonequilibrium Diffusion and Capture Mechanism Ensures Tip Localization of Regulating Proteins on Dynamic Filaments.

    Science.gov (United States)

    Reithmann, Emanuel; Reese, Louis; Frey, Erwin

    2016-08-12

    Diffusive motion of regulatory enzymes on biopolymers with eventual capture at a reaction site is a common feature in cell biology. Using a lattice gas model we study the impact of diffusion and capture for a microtubule polymerase and a depolymerase. Our results show that the capture mechanism localizes the proteins and creates large-scale spatial correlations. We develop an analytic approximation that globally accounts for relevant correlations and yields results that are in excellent agreement with experimental data. Our results show that diffusion and capture operates most efficiently at cellular enzyme concentrations which points to in vivo relevance.

  10. An optoelectronic based approach for handwriting capture.

    Science.gov (United States)

    Ancillao, Andrea; Galli, Manuela; Vimercati, Sara Laura; Albertini, Giorgio

    2013-08-01

    Clinical practice for the evaluation of motor and cognitive capabilities often relies upon writing and drawing tests. A non-invasive method to capture handwriting and analyze data is therefore needed. In this work a method to capture motion of a pen through a mo-cap optoelectronic system was developed, which could solve the limits of systems based on graphic tablets. Four IR passive markers were placed on a pen cap. Once a pen was equipped with the cap, track of tip was computed through a numeric algorithm using the 3D coordinates of markers provided by the optoelectronic system. Some tests were performed to estimate the error in track reconstruction and to compare the new protocol with previous reconstruction methods. The results showed a higher accuracy of the new method. The new protocol also overcomes the problems related to pen grasping and marker covering that affected other methods described in the literature and permits the evaluation of writing and drawing kinematics as well as postural behaviour related to them. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Motion and relativity

    CERN Document Server

    Infeld, Leopold

    1960-01-01

    Motion and Relativity focuses on the methodologies, solutions, and approaches involved in the study of motion and relativity, including the general relativity theory, gravitation, and approximation.The publication first offers information on notation and gravitational interaction and the general theory of motion. Discussions focus on the notation of the general relativity theory, field values on the world-lines, general statement of the physical problem, Newton's theory of gravitation, and forms for the equation of motion of the second kind. The text then takes a look at the approximation meth

  12. Brain Image Motion Correction

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Benjaminsen, Claus; Larsen, Rasmus

    2015-01-01

    The application of motion tracking is wide, including: industrial production lines, motion interaction in gaming, computer-aided surgery and motion correction in medical brain imaging. Several devices for motion tracking exist using a variety of different methodologies. In order to use such devices...... offset and tracking noise in medical brain imaging. The data are generated from a phantom mounted on a rotary stage and have been collected using a Siemens High Resolution Research Tomograph for positron emission tomography. During acquisition the phantom was tracked with our latest tracking prototype...

  13. Measurement of visual motion

    Energy Technology Data Exchange (ETDEWEB)

    Hildreth, E.C.

    1984-01-01

    This book examines the measurement of visual motion and the use of relative movement to locate the boundaries of physical objects in the environment. It investigates the nature of the computations that are necessary to perform this analysis by any vision system, biological or artificial. Contents: Introduction. Background. Computation of the Velocity Field. An Algorithm to Compute the Velocity Field. The Computation of Motion Discontinuities. Perceptual Studies of Motion Measurement. The Psychophysics of Discontinuity Detection. Neurophysiological Studies of Motion. Summary and Conclusions. References. Author and Subject Indexes.

  14. Circular Orbit Target Capture Using Space Tether-Net System

    Directory of Open Access Journals (Sweden)

    Guang Zhai

    2013-01-01

    Full Text Available The space tether-net system for on-orbit capture is proposed in this paper. In order to research the dynamic behaviors during system deployment, both free and nonfree deployment dynamics in circular orbit are developed; the system motion with respect to Local Vertical and Local Horizontal frame is also researched with analysis and simulation. The results show that in the case of free deployment, the capture net follows curve trajectories due to the relative orbit dynamic perturbation, and the initial deployment velocities are planned by state transformation equations for static and floating target captures; in the case of non-free deployment, the system undergoes an altitude libration along the Local Vertical, and the analytical solutions that describe the attitude libration are obtained by using variable separation and integration. Finally, the dynamics of postdeployment system is also proved marginally stable if the critical initial conditions are satisfied.

  15. Materials For Gas Capture, Methods Of Making Materials For Gas Capture, And Methods Of Capturing Gas

    KAUST Repository

    Polshettiwar, Vivek

    2013-06-20

    In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure, in one aspect, relate to materials that can be used for gas (e.g., CO.sub.2) capture, methods of making materials, methods of capturing gas (e.g., CO.sub.2), and the like, and the like.

  16. Human motion correction and representation method from motion camera

    Directory of Open Access Journals (Sweden)

    Hong-Bo Zhang

    2017-06-01

    Full Text Available Motion estimation is a basic issue for many computer vision tasks, such as human–computer interaction, motion objection detection and intelligent robot. In many practical scenes, the object movement goes with camera motion. Generally, motion descriptors directly based on optical flow are inaccurate and have low discrimination power. To this end, a novel motion correction method is proposed and a novel motion feature descriptor called the motion difference histogram (MDH for recognising human action is proposed in this study. Motion estimation results are corrected by background motion estimation and MDH encodes the motion difference between the background and the objects. Experimental results on video shot with camera motion show that the proposed motion correction method is effective and the recognition accuracy of MDH is better than that of the state-of-the-art motion descriptor.

  17. Capture methods for Musk Ducks

    Science.gov (United States)

    McCracken, K.G.; Hemmings, J.; Paton, D.C.; Afton, A.D.

    2003-01-01

    Musk Ducks Biziura lobata are endemic to wetlands, river systems and coastal oceanic waters of temperate Australia. Individuals of this species are difficult to capture because of their excellent swimming and diving abilities and frequent use of deep-water habitats. Night-lighting, baited clover-leaf traps and walk-in-nest-traps were used to capture Musk Ducks at Murray Lagoon, Cape Gantheaume Conservation Park, Kangaroo Island, South Australia. These techniques should be useful for capturing Musk Ducks at other locations in Australia.

  18. Teaching Projectile Motion

    Science.gov (United States)

    Summers, M. K.

    1977-01-01

    Described is a novel approach to the teaching of projectile motion of sixth form level. Students are asked to use an analogue circuit to observe projectile motion and to graph the experimental results. Using knowledge of basic dynamics, students are asked to explain the shape of the curves theoretically. (Author/MA)

  19. Measuring the 3D motion space of the human ankle.

    Science.gov (United States)

    Xiao, Jinzhuang; Zhang, Yunchao; Zhao, Shuai; Wang, Hongrui

    2017-07-20

    The 3D motion space of the human ankle is an important area of study in medicine. The 3D motion space can provide significant information for establishing more reasonable rehabilitation procedures and standards of ankle injury care. This study aims to measure the 3D motion space of the human ankle and to use mathematical methods to quantify it. A motion capturing system was used to simultaneously capture the 3D coordinates of points marked on the foot, and convert these coordinate values into rotation angles through trigonometric functions and vectors. The mathematical expression of the ankle's motion space was obtained by screening, arranging, and fitting the converted data. The mathematical expression of the 3D motion space of the participants was obtained. We statistically analyzed the data and learned that, in terms of 3D motion space, the right foot is more flexible than the left foot and the female foot is more flexible than the male foot. The adduction and abduction rotation ranges are affected by the plantar flexion or dorsal flexure rotation angles. This relationship can be expressed mathematically, which is significant in the study of the ankle joint.

  20. Robust object tracking techniques for vision-based 3D motion analysis applications

    Science.gov (United States)

    Knyaz, Vladimir A.; Zheltov, Sergey Y.; Vishnyakov, Boris V.

    2016-04-01

    Automated and accurate spatial motion capturing of an object is necessary for a wide variety of applications including industry and science, virtual reality and movie, medicine and sports. For the most part of applications a reliability and an accuracy of the data obtained as well as convenience for a user are the main characteristics defining the quality of the motion capture system. Among the existing systems for 3D data acquisition, based on different physical principles (accelerometry, magnetometry, time-of-flight, vision-based), optical motion capture systems have a set of advantages such as high speed of acquisition, potential for high accuracy and automation based on advanced image processing algorithms. For vision-based motion capture accurate and robust object features detecting and tracking through the video sequence are the key elements along with a level of automation of capturing process. So for providing high accuracy of obtained spatial data the developed vision-based motion capture system "Mosca" is based on photogrammetric principles of 3D measurements and supports high speed image acquisition in synchronized mode. It includes from 2 to 4 technical vision cameras for capturing video sequences of object motion. The original camera calibration and external orientation procedures provide the basis for high accuracy of 3D measurements. A set of algorithms as for detecting, identifying and tracking of similar targets, so for marker-less object motion capture is developed and tested. The results of algorithms' evaluation show high robustness and high reliability for various motion analysis tasks in technical and biomechanics applications.

  1. Motion control systems

    CERN Document Server

    Sabanovic, Asif

    2011-01-01

    "Presents a unified approach to the fundamental issues in motion control, starting from the basics and moving through single degree of freedom and multi-degree of freedom systems In Motion Control Systems, Šabanovic and Ohnishi present a unified approach to very diverse issues covered in motion control systems, offering know-how accumulated through work on very diverse problems into a comprehensive, integrated approach suitable for application in high demanding high-tech products. It covers material from single degree of freedom systems to complex multi-body non-redundant and redundant systems. The discussion of the main subject is based on original research results and will give treatment of the issues in motion control in the framework of the acceleration control method with disturbance rejection technique. This allows consistent unification of different issues in motion control ranging from simple trajectory tracking to topics related to haptics and bilateral control without and with delay in the measure...

  2. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  3. Carbon capture and sequestration (CCS)

    Science.gov (United States)

    2009-06-19

    Carbon capture and sequestration (or storage)known as CCShas attracted interest as a : measure for mitigating global climate change because large amounts of carbon dioxide (CO2) : emitted from fossil fuel use in the United States are potentiall...

  4. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to recover sulfur compounds from lunar soil using sorbents derived primarily from in-situ resources....

  5. Chaotic Capture of Neptune Trojans

    National Research Council Canada - National Science Library

    Nesvorný, David; Vokrouhlický, David

    2009-01-01

    ... than that of Jupiter Trojans and orbital inclinations reaching ∼25 ◦ . The high inclinations of NTs are indicative of capture instead of in situ formation. Here we study a model in which NTs were...

  6. Toward transformational carbon capture systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David C. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Litynski, John T. [Office of Fossil Energy, U.S. Dept. of Energy, Washington DC (United States); Brickett, Lynn A. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Morreale, Bryan D. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States)

    2015-10-28

    This paper will briefly review the history and current state of Carbon Capture and Storage (CCS) research and development and describe the technical barriers to carbon capture. it will argue forcefully for a new approach to R&D, which leverages both simulation and physical systems at the laboratory and pilot scales to more rapidly move the best technoogies forward, prune less advantageous approaches, and simultaneously develop materials and processes.

  7. Large scale track analysis for wide area motion imagery surveillance

    NARCIS (Netherlands)

    Leeuwen, C.J. van; Huis, J.R. van; Baan, J.

    2016-01-01

    Wide Area Motion Imagery (WAMI) enables image based surveillance of areas that can cover multiple square kilometers. Interpreting and analyzing information from such sources, becomes increasingly time consuming as more data is added from newly developed methods for information extraction. Captured

  8. Motion visualization and estimation for flapping wing systems

    Science.gov (United States)

    Hsu, Tzu-Sheng Shane; Fitzgerald, Timothy; Nguyen, Vincent Phuc; Patel, Trisha; Balachandran, Balakumar

    2017-04-01

    Studies of fluid-structure interactions associated with flexible structures such as flapping wings require the capture and quantification of large motions of bodies that may be opaque. As a case study, motion capture of a free flying Manduca sexta, also known as hawkmoth, is considered by using three synchronized high-speed cameras. A solid finite element (FE) representation is used as a reference body and successive snapshots in time of the displacement fields are reconstructed via an optimization procedure. One of the original aspects of this work is the formulation of an objective function and the use of shadow matching and strain-energy regularization. With this objective function, the authors penalize the projection differences between silhouettes of the captured images and the FE representation of the deformed body. The process and procedures undertaken to go from high-speed videography to motion estimation are discussed, and snapshots of representative results are presented. Finally, the captured free-flight motion is also characterized and quantified.

  9. Superluminal motion in astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Falla, D.F.; Floyd, M.J. [Department of Physics, University of Wales, Aberystwyth (United Kingdom)

    2002-01-01

    Several examples of 'intrinsic-type' superluminal motion in astronomy are taken. A simple signal-delay transformation is devised and shown to be sufficient to explain the superluminal effect as resulting from differential signal delay across an expanding source. The distinction between relativistic motion and relativistic kinematics is made. The key kinematical equation used to describe superluminal motion is an alternative statement of the Doppler effect. Relativistic transformations, which are relevant when intervals in different reference frames are compared, then lead to the relativistic Doppler factor ({delta}), which is applicable to measurements on a photographic image, for example that of a relativistic quasar jet with superluminal components. (author)

  10. Method through motion

    DEFF Research Database (Denmark)

    Steijn, Arthur

    2016-01-01

    Contemporary scenography often consists of video-projected motion graphics. The field is lacking in academic methods and rigour: descriptions and models relevant for the creation as well as in the analysis of existing works. In order to understand the phenomenon of motion graphics in a scenographic...... context, I have been conducting a practice-led research project. Central to the project is construction of a design model describing sets of procedures, concepts and terminology relevant for design and studies of motion graphics in spatial contexts. The focus of this paper is the role of model...

  11. Role Identification of Yaw and Sway Motion in Helicopter Yaw Control Tasks

    NARCIS (Netherlands)

    Ellerbroek, J.; Stroosma, O.; Van Paassen, M.M.; Mulder, M.

    2008-01-01

    A set of experiments has been conducted to investigate the relative effect of translational and rotational motion cues on pilot performance. Two helicopter yaw control tasks were performed on the SIMONA: a yaw capture task and a target-tracking task with simulated turbulence. The yaw capture task

  12. Motion Alters Color Appearance

    Science.gov (United States)

    Hong, Sang-Wook; Kang, Min-Suk

    2016-01-01

    Chromatic induction compellingly demonstrates that chromatic context as well as spectral lights reflected from an object determines its color appearance. Here, we show that when one colored object moves around an identical stationary object, the perceived saturation of the stationary object decreases dramatically whereas the saturation of the moving object increases. These color appearance shifts in the opposite directions suggest that normalization induced by the object’s motion may mediate the shift in color appearance. We ruled out other plausible alternatives such as local adaptation, attention, and transient neural responses that could explain the color shift without assuming interaction between color and motion processing. These results demonstrate that the motion of an object affects both its own color appearance and the color appearance of a nearby object, suggesting a tight coupling between color and motion processing. PMID:27824098

  13. Projectile Motion with Mathematica.

    Science.gov (United States)

    de Alwis, Tilak

    2000-01-01

    Describes how to use the computer algebra system (CAS) Mathematica to analyze projectile motion with and without air resistance. These experiments result in several conjectures leading to theorems. (Contains 17 references.) (Author/ASK)

  14. Projectile Motion Details.

    Science.gov (United States)

    Schnick, Jeffrey W.

    1994-01-01

    Presents an exercise that attempts to correct for the common discrepancies between theoretical and experimental predictions concerning projectile motion using a spring-loaded projectile ball launcher. Includes common correction factors for student use. (MVL)

  15. A Projectile Motion Bullseye.

    Science.gov (United States)

    Lamb, William G.

    1985-01-01

    Explains a projectile motion experiment involving a bow and arrow. Procedures to measure "muzzle" velocity, bow elastic potential energy, range, flight time, wind resistance, and masses are considered. (DH)

  16. Molecular Motion Machine

    Science.gov (United States)

    Shourd, Melvin L.

    1977-01-01

    Describes the construction of an inexpensive apparatus which utilizes the oscillatory motion of 60 cycle AC current in conjunction with an electromagnetic to illustrate various principles and processes in geology. (SL)

  17. Toying with Motion.

    Science.gov (United States)

    Galus, Pamela J.

    2002-01-01

    Presents a variety of activities that support the development of an understanding of Newton's laws of motion. Activities use toy cars, mobile roads, and a seat-of-nails. Includes a scoring rubric. (DDR)

  18. Travelers' Health: Motion Sickness

    Science.gov (United States)

    ... motion by sea, car, train, air, and virtual reality immersion. Given sufficient stimulus all people with functional ... retching Sweating Cold sweats Excessive salivation Apathy Hyperventilation Increased sensitivity to odors Loss of appetite Headache Drowsiness ...

  19. Attentional Capture in Driving Displays

    Science.gov (United States)

    Arexis, Mahé; Maquestiaux, François; Gaspelin, Nicholas; Ruthruff, Eric; Didierjean, André

    2016-01-01

    Drivers face frequent distraction on the roadways but little is known about situations placing them at risk of misallocating visual attention. To investigate this issue, we asked participants to search for a red target embedded within simulated driving scenes (photographs taken from inside a car) in three experiments. Distraction was induced by presenting, via a GPS unit, red or green distractors positioned in an irrelevant location at which the target never appeared. If the salient distractor captures attention, visual search should be slower on distractor-present trials than distractor-absent trials. In Experiment 1, salient distractors yielded no such capture effect. In Experiment 2, we decreased the frequency of the salient distractor from 50% of trials to only 10% or 20% of trials. Capture effects were almost five times larger for the 10% occurrence group than for the 20% occurrence group. In Experiment 3, the amount of available central resources was manipulated by asking participants to either simultaneously monitor or ignore a stream of spoken digits. Capture effects were much larger for the dual-task group than for the single-task group. In summary, these findings identify risk factors for attentional capture in real-world driving scenes: distractor rarity and diversion of attention. PMID:28369841

  20. Karate moves recognition from skeletal motion

    Science.gov (United States)

    Bianco, Simone; Tisato, Francesco

    2013-03-01

    This work aims at automatically recognizing sequences of complex karate movements and giving a measure of the quality of the movements performed. Since this is a problem which intrinsically needs a 3D model, in this work we propose a solution taking as input sequences of skeletal motions that can derive from both motion capture hardware or consumer-level, off the shelf, depth sensing systems. The proposed system is constituted by four different modules: skeleton representation, pose classification, temporal alignment, and scoring. The proposed system is tested on a set of different punch, kick and defense karate moves executed starting from the simplest case, i.e. fixed static stances (heiko dachi) up to sequences in which the starting stances is different from the ending one. The dataset has been recorded using a single Microsoft Kinect. The dataset includes the recordings of both male and female athletes with different skill levels, ranging from novices to masters.

  1. Inverse Dynamics and the Immeasurable Motions

    DEFF Research Database (Denmark)

    Rasmussen, John; Andersen, Michael Skipper; Damsgaard, Michael

    remains extremely computationally challenging. In this paper, we attempt prediction of forces as well as small movements in the knee based upon knowledge of large movements, i.e. flexion/extension, from camera-based motion capture. The applied method, force-dependent kinematics, is rooted....../adduction in the knee as a function of the knee flexion angle. Benoit, D.L., Ramsey, D.K., Lamontagne, M., Xu, L., Wretenberg, P. & Renström, P. 2006, "Effect of skin movement artifact on knee kinematics during gait and cutting motions measured in vivo", Gait & posture, vol. 24, no. 2, pp. 152-164....... the precise 3-D marker locations, certain movements are inherently difficult to register, for instance the movement of the scapula relative to the thorax or glenohumeral superior migration. This paper, however, focuses on the knee. Knee flexion/extension is a large articulation in most practical cases...

  2. Motion of a Pendulum

    Directory of Open Access Journals (Sweden)

    Jared Wynn

    2010-01-01

    Full Text Available The objective of this project is to derive and solve the equation of motion for a pendulum swinging at small angles in one dimension. The pendulum may be either a simple pendulum like a ball hanging from a string or a physical pendulum like a pendulum on a clock. For simplicity, we only considered small rotational angles so that the equation of motion becomes a harmonic oscillator.

  3. Perpetual Motion Machine

    Directory of Open Access Journals (Sweden)

    D. Tsaousis

    2008-01-01

    Full Text Available Ever since the first century A.D. there have been relative descriptions of known devices as well as manufactures for the creation of perpetual motion machines. Although physics has led, with two thermodynamic laws, to the opinion that a perpetual motion machine is impossible to be manufactured, inventors of every age and educational level appear to claim that they have invented something «entirely new» or they have improved somebody else’s invention, which «will function henceforth perpetually»! However the fact of the failure in manufacturing a perpetual motion machine till now, it does not mean that countless historical elements for these fictional machines become indifferent. The discussion on every version of a perpetual motion machine on the one hand gives the chance to comprehend the inventor’s of each period level of knowledge and his way of thinking, and on the other hand, to locate the points where this «perpetual motion machine» clashes with the laws of nature and that’s why it is impossible to have been manufactured or have functioned. The presentation of a new «perpetual motion machine» has excited our interest to locate its weak points. According to the designer of it the machine functions with the work produced by the buoyant force

  4. Example-Based Automatic Music-Driven Conventional Dance Motion Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Songhua [ORNL; Fan, Rukun [University of North Carolina, Chapel Hill; Geng, Weidong [Zhejiang University

    2011-04-21

    We introduce a novel method for synthesizing dance motions that follow the emotions and contents of a piece of music. Our method employs a learning-based approach to model the music to motion mapping relationship embodied in example dance motions along with those motions' accompanying background music. A key step in our method is to train a music to motion matching quality rating function through learning the music to motion mapping relationship exhibited in synchronized music and dance motion data, which were captured from professional human dance performance. To generate an optimal sequence of dance motion segments to match with a piece of music, we introduce a constraint-based dynamic programming procedure. This procedure considers both music to motion matching quality and visual smoothness of a resultant dance motion sequence. We also introduce a two-way evaluation strategy, coupled with a GPU-based implementation, through which we can execute the dynamic programming process in parallel, resulting in significant speedup. To evaluate the effectiveness of our method, we quantitatively compare the dance motions synthesized by our method with motion synthesis results by several peer methods using the motions captured from professional human dancers' performance as the gold standard. We also conducted several medium-scale user studies to explore how perceptually our dance motion synthesis method can outperform existing methods in synthesizing dance motions to match with a piece of music. These user studies produced very positive results on our music-driven dance motion synthesis experiments for several Asian dance genres, confirming the advantages of our method.

  5. Example-based automatic music-driven conventional dance motion synthesis.

    Science.gov (United States)

    Fan, Rukun; Xu, Songhua; Geng, Weidong

    2012-03-01

    We introduce a novel method for synthesizing dance motions that follow the emotions and contents of a piece of music. Our method employs a learning-based approach to model the music to motion mapping relationship embodied in example dance motions along with those motions' accompanying background music. A key step in our method is to train a music to motion matching quality rating function through learning the music to motion mapping relationship exhibited in synchronized music and dance motion data, which were captured from professional human dance performance. To generate an optimal sequence of dance motion segments to match with a piece of music, we introduce a constraint-based dynamic programming procedure. This procedure considers both music to motion matching quality and visual smoothness of a resultant dance motion sequence. We also introduce a two-way evaluation strategy, coupled with a GPU-based implementation, through which we can execute the dynamic programming process in parallel, resulting in significant speedup. To evaluate the effectiveness of our method, we quantitatively compare the dance motions synthesized by our method with motion synthesis results by several peer methods using the motions captured from professional human dancers' performance as the gold standard. We also conducted several medium-scale user studies to explore how perceptually our dance motion synthesis method can outperform existing methods in synthesizing dance motions to match with a piece of music. These user studies produced very positive results on our music-driven dance motion synthesis experiments for several Asian dance genres, confirming the advantages of our method.

  6. Motion prediction of a non-cooperative space target

    Science.gov (United States)

    Zhou, Bang-Zhao; Cai, Guo-Ping; Liu, Yun-Meng; Liu, Pan

    2018-01-01

    Capturing a non-cooperative space target is a tremendously challenging research topic. Effective acquisition of motion information of the space target is the premise to realize target capture. In this paper, motion prediction of a free-floating non-cooperative target in space is studied and a motion prediction algorithm is proposed. In order to predict the motion of the free-floating non-cooperative target, dynamic parameters of the target must be firstly identified (estimated), such as inertia, angular momentum and kinetic energy and so on; then the predicted motion of the target can be acquired by substituting these identified parameters into the Euler's equations of the target. Accurate prediction needs precise identification. This paper presents an effective method to identify these dynamic parameters of a free-floating non-cooperative target. This method is based on two steps, (1) the rough estimation of the parameters is computed using the motion observation data to the target, and (2) the best estimation of the parameters is found by an optimization method. In the optimization problem, the objective function is based on the difference between the observed and the predicted motion, and the interior-point method (IPM) is chosen as the optimization algorithm, which starts at the rough estimate obtained in the first step and finds a global minimum to the objective function with the guidance of objective function's gradient. So the speed of IPM searching for the global minimum is fast, and an accurate identification can be obtained in time. The numerical results show that the proposed motion prediction algorithm is able to predict the motion of the target.

  7. A Study on the Bio-mimetic Motion of Reptiles

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hochelo; Kim, Changhoi; Eom, Heungseop; Jeong, Kyungmin; Jung, Seungjo

    2013-10-15

    After investigating the locomotion based on the biological characteristics about the from a literature search about the reptile, the locomotion of lizards is captured with marker based motion capture system. Tested lizards are Cuban anole, bearded dragon, domestic lizards such as a white-striped grass lizard and a leopard lizard, After analyzing the motion of the lizards with the measured data, a 25 DOF kinematics model of a lizard was proposed. A periodic gait of the lizard was modeled by defining gait parameters. The body structure of the lizard was analyzed with a bone specimen for the kinematics modeling. Dynamics parameters such as a mass and a inertia of a link are obtained by measuring the weight and the volume of each link. The crawl and the trot gait were simulated with the dynamics model. To control the poly-morphic motion of snake robot, various locomotions of snakes and the motion algorithm of snake robots were investigated. A test model of snake robot and a control system were developed to analyzed the motion and energy efficiency according to the gaits and to realize the poly-morphic motion control.

  8. Hierarchical Aligned Cluster Analysis for Temporal Clustering of Human Motion.

    Science.gov (United States)

    Zhou, Feng; De la Torre, Fernando; Hodgins, Jessica K

    2013-03-01

    Temporal segmentation of human motion into plausible motion primitives is central to understanding and building computational models of human motion. Several issues contribute to the challenge of discovering motion primitives: the exponential nature of all possible movement combinations, the variability in the temporal scale of human actions, and the complexity of representing articulated motion. We pose the problem of learning motion primitives as one of temporal clustering, and derive an unsupervised hierarchical bottom-up framework called hierarchical aligned cluster analysis (HACA). HACA finds a partition of a given multidimensional time series into m disjoint segments such that each segment belongs to one of k clusters. HACA combines kernel k-means with the generalized dynamic time alignment kernel to cluster time series data. Moreover, it provides a natural framework to find a low-dimensional embedding for time series. HACA is efficiently optimized with a coordinate descent strategy and dynamic programming. Experimental results on motion capture and video data demonstrate the effectiveness of HACA for segmenting complex motions and as a visualization tool. We also compare the performance of HACA to state-of-the-art algorithms for temporal clustering on data of a honey bee dance. The HACA code is available online.

  9. Categorization of compensatory motions in transradial myoelectric prosthesis users.

    Science.gov (United States)

    Hussaini, Ali; Zinck, Arthur; Kyberd, Peter

    2017-06-01

    Prosthesis users perform various compensatory motions to accommodate for the loss of the hand and wrist as well as the reduced functionality of a prosthetic hand. Investigate different compensation strategies that are performed by prosthesis users. Comparative analysis. A total of 20 able-bodied subjects and 4 prosthesis users performed a set of bimanual activities. Movements of the trunk and head were recorded using a motion capture system and a digital video recorder. Clinical motion angles were calculated to assess the compensatory motions made by the prosthesis users. The video recording also assisted in visually identifying the compensations. Compensatory motions by the prosthesis users were evident in the tasks performed (slicing and stirring activities) as compared to the benchmark of able-bodied subjects. Compensations took the form of a measured increase in range of motion, an observed adoption of a new posture during task execution, and prepositioning of items in the workspace prior to initiating a given task. Compensatory motions were performed by prosthesis users during the selected tasks. These can be categorized into three different types of compensations. Clinical relevance Proper identification and classification of compensatory motions performed by prosthesis users into three distinct forms allows clinicians and researchers to accurately identify and quantify movement. It will assist in evaluating new prosthetic interventions by providing distinct terminology that is easily understood and can be shared between research institutions.

  10. PROMOTIONS: PROper MOTION Software

    Science.gov (United States)

    Caleb Wherry, John; Sahai, R.

    2009-05-01

    We report on the development of a software tool (PROMOTIONS) to streamline the process of measuring proper motions of material in expanding nebulae. Our tool makes use of IDL's widget programming capabilities to design a unique GUI that is used to compare images of the objects from two epochs. The software allows us to first orient and register the images to a common frame of reference and pixel scale, using field stars in each of the images. We then cross-correlate specific morphological features in order to determine their proper motions, which consist of the proper motion of the nebula as a whole (PM-neb), and expansion motions of the features relative to the center. If the central star is not visible (quite common in bipolar nebulae with dense dusty waists), point-symmetric expansion is assumed and we use the average motion of high-quality symmetric pairs of features on opposite sides of the nebular center to compute PM-neb. This is then subtracted out to determine the individual movements of these and additional features relative to the nebular center. PROMOTIONS should find wide applicability in measuring proper motions in astrophysical objects such as the expanding outflows/jets commonly seen around young and dying stars. We present first results from using PROMOTIONS to successfully measure proper motions in several pre-planetary nebulae (transition objects between the red giant and planetary nebula phases), using images taken 7-10 years apart with the WFPC2 and ACS instruments on board HST. The authors are grateful to NASA's Undergradute Scholars Research Program (USRP) for supporting this research.

  11. Geologically current plate motions

    Science.gov (United States)

    DeMets, Charles; Gordon, Richard G.; Argus, Donald F.

    2010-04-01

    We describe best-fitting angular velocities and MORVEL, a new closure-enforced set of angular velocities for the geologically current motions of 25 tectonic plates that collectively occupy 97 per cent of Earth's surface. Seafloor spreading rates and fault azimuths are used to determine the motions of 19 plates bordered by mid-ocean ridges, including all the major plates. Six smaller plates with little or no connection to the mid-ocean ridges are linked to MORVEL with GPS station velocities and azimuthal data. By design, almost no kinematic information is exchanged between the geologically determined and geodetically constrained subsets of the global circuit-MORVEL thus averages motion over geological intervals for all the major plates. Plate geometry changes relative to NUVEL-1A include the incorporation of Nubia, Lwandle and Somalia plates for the former Africa plate, Capricorn, Australia and Macquarie plates for the former Australia plate, and Sur and South America plates for the former South America plate. MORVEL also includes Amur, Philippine Sea, Sundaland and Yangtze plates, making it more useful than NUVEL-1A for studies of deformation in Asia and the western Pacific. Seafloor spreading rates are estimated over the past 0.78 Myr for intermediate and fast spreading centres and since 3.16 Ma for slow and ultraslow spreading centres. Rates are adjusted downward by 0.6-2.6mmyr-1 to compensate for the several kilometre width of magnetic reversal zones. Nearly all the NUVEL-1A angular velocities differ significantly from the MORVEL angular velocities. The many new data, revised plate geometries, and correction for outward displacement thus significantly modify our knowledge of geologically current plate motions. MORVEL indicates significantly slower 0.78-Myr-average motion across the Nazca-Antarctic and Nazca-Pacific boundaries than does NUVEL-1A, consistent with a progressive slowdown in the eastward component of Nazca plate motion since 3.16 Ma. It also

  12. MACHINE MOTION EQUATIONS

    Directory of Open Access Journals (Sweden)

    Florian Ion Tiberiu Petrescu

    2015-09-01

    Full Text Available This paper presents the dynamic, original, machine motion equations. The equation of motion of the machine that generates angular speed of the shaft (which varies with position and rotation speed is deduced by conservation kinetic energy of the machine. An additional variation of angular speed is added by multiplying by the coefficient dynamic D (generated by the forces out of mechanism and or by the forces generated by the elasticity of the system. Kinetic energy conservation shows angular speed variation (from the shaft with inertial masses, while the dynamic coefficient introduces the variation of w with forces acting in the mechanism. Deriving the first equation of motion of the machine one can obtain the second equation of motion dynamic. From the second equation of motion of the machine it determines the angular acceleration of the shaft. It shows the distribution of the forces on the mechanism to the internal combustion heat engines. Dynamic, the velocities can be distributed in the same way as forces. Practically, in the dynamic regimes, the velocities have the same timing as the forces. Calculations should be made for an engine with a single cylinder. Originally exemplification is done for a classic distribution mechanism, and then even the module B distribution mechanism of an Otto engine type.

  13. Protein folding by motion planning.

    Science.gov (United States)

    Thomas, Shawna; Song, Guang; Amato, Nancy M

    2005-11-09

    We investigate a novel approach for studying protein folding that has evolved from robotics motion planning techniques called probabilistic roadmap methods (PRMs). Our focus is to study issues related to the folding process, such as the formation of secondary and tertiary structures, assuming we know the native fold. A feature of our PRM-based framework is that the large sets of folding pathways in the roadmaps it produces, in just a few hours on a desktop PC, provide global information about the protein's energy landscape. This is an advantage over other simulation methods such as molecular dynamics or Monte Carlo methods which require more computation and produce only a single trajectory in each run. In our initial studies, we obtained encouraging results for several small proteins. In this paper, we investigate more sophisticated techniques for analyzing the folding pathways in our roadmaps. In addition to more formally revalidating our previous results, we present a case study showing that our technique captures known folding differences between the structurally similar proteins G and L.

  14. Protein folding by motion planning

    Science.gov (United States)

    Thomas, Shawna; Song, Guang; Amato, Nancy M.

    2005-12-01

    We investigate a novel approach for studying protein folding that has evolved from robotics motion planning techniques called probabilistic roadmap methods (PRMs). Our focus is to study issues related to the folding process, such as the formation of secondary and tertiary structures, assuming we know the native fold. A feature of our PRM-based framework is that the large sets of folding pathways in the roadmaps it produces, in just a few hours on a desktop PC, provide global information about the protein's energy landscape. This is an advantage over other simulation methods such as molecular dynamics or Monte Carlo methods which require more computation and produce only a single trajectory in each run. In our initial studies, we obtained encouraging results for several small proteins. In this paper, we investigate more sophisticated techniques for analyzing the folding pathways in our roadmaps. In addition to more formally revalidating our previous results, we present a case study showing that our technique captures known folding differences between the structurally similar proteins G and L. This research was supported in part by NSF CAREER Award CCR-9624315, NSF Grants ACI-9872126, EIA-9975018, EIA-0103742, EIA-9805823, ACR-0113971, CCR-0113974, EIA-9810937, EIA-0079874 and the Texas Higher Education Coordinating Board grant ATP-000512-0261-2001. ST was supported in part by an NSF Graduate Research Fellowship. GS was supported in part by an IBM PhD Fellowship.

  15. Physical interpretation of phase- and group-motion in auroras

    Science.gov (United States)

    Semeter, J. L.

    2015-12-01

    It is well established that fine-scale features in the aurora (motion than the mesoscale arcs (order 10-km) within which they are embedded. These scale-dependent distinctions may be conveniently captured and quantified through the formalism of phase- and group- motion from classical wave theory. But less clear is how such empirical propagation models should be connected to the underlying physics of energy release and dissipation in the magnetosphere. This paper seeks to connect multi-scale models of auroral motion to dynamic wave-particle interactions in the magnetotail and near-Earth auroral acceleration region (AAR). Our focus is on auroras associated with the established phases of the substorm cycle (growth, onset, expansion, recovery). A unifying construct is the 'backward wave' (oppositely directed phase- and group- motion), which is argued to be a natural consequence of magnetic reconnection and concomitant release of magnetic stress, applicable to both the magnetotail and the AAR domains.

  16. Prey detection and prey capture in copepod nauplii

    DEFF Research Database (Denmark)

    Bruno, Eleonora; Borg, Marc Andersen; Kiørboe, Thomas

    2012-01-01

    Copepod nauplii are either ambush feeders that feed on motile prey or they produce a feeding current that entrains prey cells. It is unclear how ambush and feeding-current feeding nauplii perceive and capture prey. Attack jumps in ambush feeding nauplii should not be feasible at low Reynolds...... numbers due to the thick viscous boundary layer surrounding the attacking nauplius. We use high-speed video to describe the detection and capture of phytoplankton prey by the nauplii of two ambush feeding species (Acartia tonsa and Oithona davisae) and by the nauplii of one feeding-current feeding species...... current that pulls in the prey from behind towards the mouth. The feeding-current feeding nauplius detects prey arriving in the feeding current but only when the prey is intercepted by the setae on the feeding appendages. This elicits an altered motion pattern of the feeding appendages that draws...

  17. Neutrino Signals in Electron-Capture Storage-Ring Experiments

    Directory of Open Access Journals (Sweden)

    Avraham Gal

    2016-06-01

    Full Text Available Neutrino signals in electron-capture decays of hydrogen-like parent ions P in storage-ring experiments at GSI are reconsidered, with special emphasis placed on the storage-ring quasi-circular motion of the daughter ions D in two-body decays P → D + ν e . It is argued that, to the extent that daughter ions are detected, these detection rates might exhibit modulations with periods of order seconds, similar to those reported in the GSI storage-ring experiments for two-body decay rates. New dedicated experiments in storage rings, or using traps, could explore these modulations.

  18. Perpetual Motion Machine

    OpenAIRE

    D. Tsaousis

    2008-01-01

    Ever since the first century A.D. there have been relative descriptions of known devices as well as manufactures for the creation of perpetual motion machines. Although physics has led, with two thermodynamic laws, to the opinion that a perpetual motion machine is impossible to be manufactured, inventors of every age and educational level appear to claim that they have invented something «entirely new» or they have improved somebody else’s invention, which «will function henceforth perpetuall...

  19. Ship Roll Motion Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2010-01-01

    The technical feasibility of roll motion control devices has been amply demonstrated for over 100 years. Performance, however, can still fall short of expectations because of deciencies in control system designs, which have proven to be far from trivial due to fundamental performance limitations....... This tutorial paper presents an account of the development of various ship roll motion control systems and the challenges associated with their design. The paper discusses how to assess performance, the applicability of dierent models, and control methods that have been applied in the past....

  20. Elements of spin motion

    Science.gov (United States)

    Fukushima, Toshio; Ishizaki, Hideharu

    1994-06-01

    For use in numerical studies of rotational motion, a set of elements is introduced for the torque-free rotational motion of a rigid body around its barycenter. The elements are defined as the initial values of a modification of the Andoyer canonical variables. A computational procedure is obtained for determining these elements from the combination of the spin angular momentum vector and a triad defining the orientation of the rigid body. A numerical experiment shows that the errors of transformation between the elements and variables are sufficiently small. The errors increase linearly with time for some elements and quadratically for some others.

  1. Leap Motion development essentials

    CERN Document Server

    Spiegelmock, Mischa

    2013-01-01

    This book is a fast-paced guide with practical examples that aims to help you understand and master the Leap Motion SDK.This book is for developers who are either involved in game development or who are looking to utilize Leap Motion technology in order to create brand new user interaction experiences to distinguish their products from the mass market. You should be comfortable with high-level languages and object-oriented development concepts in order to get the most out of this book.

  2. Current plate motions

    Science.gov (United States)

    Demets, C.; Gordon, R. G.; Argus, D. F.; Stein, S.

    1990-05-01

    A global plate motion model, named NUVEL-1, which describes current plate motions between 12 rigid plates is described, with special attention given to the method, data, and assumptions used. Tectonic implications of the patterns that emerged from the results are discussed. It is shown that wide plate boundary zones can form not only within the continental lithosphere but also within the oceanic lithosphere; e.g., between the Indian and Australian plates and between the North American and South American plates. Results of the model also suggest small but significant diffuse deformation of the oceanic lithosphere, which may be confined to small awkwardly shaped salients of major plates.

  3. Timing of electromyographic activity and ranges of motion during simple motor tasks of upper extremities

    Directory of Open Access Journals (Sweden)

    Syczewska Małgorzata

    2017-10-01

    Full Text Available Study aim: Improvement of the upper extremities’ performance is one of the key aims in the rehabilitation process. In order to achieve high effectiveness of this process the amount of functional improvement achieved by a patient during the therapy needs to be assessed. The aim of this study was to obtain electromyographic (EMG activity profiles of the upper extremity muscles during execution of simple tasks in healthy subjects. Additionally the ranges of wrist, elbow and shoulder joints were measured and reported during performed trials. The second aim was to determine whether the movement execution and ranges of move­ments and muscular activity depend on age. Material and methods: Twenty-eight healthy adults, age range 21 to 65 years old, participated in the study. Surface electrodes were placed bilaterally on 7 upper extremity muscles. To obtain information about the beginning and end of the movement task and ranges of upper extremity joints, 13 markers were placed on the elbows and wrists of both upper extremities. The move­ments of the segments were calculated (distal vs proximal in five simple functional tasks (each task involved only one joint, performed while sitting. Kinematic data were collected by the VICON 460 system, and electromyographic data with the Mo­tion Lab EMG system. Results: Charts of timing of EMG activity of the upper extremity muscles together with ranges of upper extremity joint motion were obtained. Conclusion: The results show that the number of muscles activated and the time (or percentage of the task during which they are active depend on the type of the task and age. These data can be used as a reference in evaluation of functional deficits of patients.

  4. Optimal capture occasion determination and trajectory generation for space robots grasping tumbling objects

    Science.gov (United States)

    Luo, Jianjun; Zong, Lijun; Wang, Mingming; Yuan, Jianping

    2017-07-01

    This paper presents an optimal trajectory planning scheme for robotic capturing of a tumbling object. Motion planning of a space robot is much more complex than that of a fixed-based robot, due to the dynamic coupling between the manipulator and its base. In this work, the Path Independent Workspace (PIW), in which no dynamic singularity occurs, and Path Dependent Workspace (PDW) of the space robot are first calculated by the proposed algorithm. The motion equations of the tumbling object are formulated based on the Euler dynamics equations and the quaternion, which are used to predict the long-term motion of a grasping point on the tumbling object. Subsequently, the obtained PIW workspace and predicted motion trajectories are used to plan the trajectory of the end-effector to intercept the grasping point with zero relative velocity (to avoid impact) in an optimal way. In order to avoid dynamic singularity occurring at the capture moment, the optimal capture occasion is first determined by three proposed criterions guaranteeing the capture can be safely, reliably and rapidly performed, then the optimal trajectory of the end-effector is generated minimizing a cost function which acts as a constraint on acceleration magnitude. Simulations are presented to demonstrate the trajectory planning scheme for a space robot with a 3-degree of freedom (DOF) manipulator grasping a tumbling satellite, the results show that the manipulator end-effector can smoothly intercept the grasping point on the tumbling satellite with zero relative velocity.

  5. Hand in motion reveals mind in motion

    Directory of Open Access Journals (Sweden)

    Jonathan eFreeman

    2011-04-01

    Full Text Available Recently, researchers have measured hand movements en route to choices on a screen to understand the dynamics of a broad range of psychological processes. We review this growing body of research and explain how manual action exposes the real-time unfolding of underlying cognitive processing. We describe how simple hand motions may be used to continuously index participants’ tentative commitments to different choice alternatives during the evolution of a behavioral response. As such, hand-tracking can provide unusually high-fidelity, real-time motor traces of the mind. These motor traces cast novel theoretical and empirical light onto a wide range of phenomena and serve as a potential bridge between far-reaching areas of psychological science—from language, to high-level cognition and learning, to social cognitive processes.

  6. Motion Tracking by Sensors for Real-time Human Skeleton Animation

    Directory of Open Access Journals (Sweden)

    S.P. Kasthuri Arachchi

    2016-12-01

    Full Text Available Human Computer Interaction based Research has emerged in the early 1980s with the advent of computer technology. Human Motion Capture is the process of recording the movement of people. Among many kinds of human motion capture devises, Microsoft Kinect sensor and inertial sensors are most popular nowadays. In this paper we propose an efficient motion tracking mechanism to construct real time human skeleton animation using inertial sensors. We compare the results of our proposed method with the Microsoft Kinect sensor over the complicated motion tracking and joint position. During the experiment we observed that our results are much steady than Microsoft Kinect results. Some motions like hand cross over or leg cross over, our method showed better results than Kinect because the Kinect may lose skeleton of the blocked parts. On the other hand, since we use radio frequency inertial sensors, our method has a larger working area than Kinect.

  7. Apparent diffusive motion of centrin foci in living cells: implications for diffusion-based motion in centriole duplication

    Science.gov (United States)

    Rafelski, Susanne M.; Keller, Lani C.; Alberts, Jonathan B.; Marshall, Wallace F.

    2011-04-01

    The degree to which diffusion contributes to positioning cellular structures is an open question. Here we investigate the question of whether diffusive motion of centrin granules would allow them to interact with the mother centriole. The role of centrin granules in centriole duplication remains unclear, but some proposed functions of these granules, for example, in providing pre-assembled centriole subunits, or by acting as unstable 'pre-centrioles' that need to be captured by the mother centriole (La Terra et al 2005 J. Cell Biol. 168 713-22), require the centrin foci to reach the mother. To test whether diffusive motion could permit such interactions in the necessary time scale, we measured the motion of centrin-containing foci in living human U2OS cells. We found that these centrin foci display apparently diffusive undirected motion. Using the apparent diffusion constant obtained from these measurements, we calculated the time scale required for diffusion to capture by the mother centrioles and found that it would greatly exceed the time available in the cell cycle. We conclude that mechanisms invoking centrin foci capture by the mother, whether as a pre-centriole or as a source of components to support later assembly, would require a form of directed motility of centrin foci that has not yet been observed.

  8. Natural materials for carbon capture.

    Energy Technology Data Exchange (ETDEWEB)

    Myshakin, Evgeniy M. (National Energy Technology Laboratory, Pittsburgh, PA); Romanov, Vyacheslav N. (National Energy Technology Laboratory, Pittsburgh, PA); Cygan, Randall Timothy

    2010-11-01

    Naturally occurring clay minerals provide a distinctive material for carbon capture and carbon dioxide sequestration. Swelling clay minerals, such as the smectite variety, possess an aluminosilicate structure that is controlled by low-charge layers that readily expand to accommodate water molecules and, potentially, carbon dioxide. Recent experimental studies have demonstrated the efficacy of intercalating carbon dioxide in the interlayer of layered clays but little is known about the molecular mechanisms of the process and the extent of carbon capture as a function of clay charge and structure. A series of molecular dynamics simulations and vibrational analyses have been completed to assess the molecular interactions associated with incorporation of CO2 in the interlayer of montmorillonite clay and to help validate the models with experimental observation.

  9. An estimation of knee and ankle joint angles during extension phase of standing up motion performed using an inertial sensor

    National Research Council Canada - National Science Library

    FANG JIN; TAKAYUKI NAGASAKI; CHIKAMUNE WADA

    2017-01-01

    [Abstract.] [Purpose] Motion capture system is difficult to use in daily life. The aim of this study was to propose an estimation model for knee and ankle joint angle measurements and locate body center of gravity (COG...

  10. An estimation of knee and ankle joint angles during extension phase of standing up motion performed using an inertial sensor

    National Research Council Canada - National Science Library

    Jin, Fang; Nagasaki, Takayuki; Wada, Chikamune

    2017-01-01

    [Purpose] Motion capture system is difficult to use in daily life. The aim of this study was to propose an estimation model for knee and ankle joint angle measurements and locate body center of gravity (COG...

  11. Motion dazzle and camouflage as distinct anti-predator defenses

    Directory of Open Access Journals (Sweden)

    Stevens Martin

    2011-11-01

    Full Text Available Abstract Background Camouflage patterns that hinder detection and/or recognition by antagonists are widely studied in both human and animal contexts. Patterns of contrasting stripes that purportedly degrade an observer's ability to judge the speed and direction of moving prey ('motion dazzle' are, however, rarely investigated. This is despite motion dazzle having been fundamental to the appearance of warships in both world wars and often postulated as the selective agent leading to repeated patterns on many animals (such as zebra and many fish, snake, and invertebrate species. Such patterns often appear conspicuous, suggesting that protection while moving by motion dazzle might impair camouflage when stationary. However, the relationship between motion dazzle and camouflage is unclear because disruptive camouflage relies on high-contrast markings. In this study, we used a computer game with human subjects detecting and capturing either moving or stationary targets with different patterns, in order to provide the first empirical exploration of the interaction of these two protective coloration mechanisms. Results Moving targets with stripes were caught significantly less often and missed more often than targets with camouflage patterns. However, when stationary, targets with camouflage markings were captured less often and caused more false detections than those with striped patterns, which were readily detected. Conclusions Our study provides the clearest evidence to date that some patterns inhibit the capture of moving targets, but that camouflage and motion dazzle are not complementary strategies. Therefore, the specific coloration that evolves in animals will depend on how the life history and ontogeny of each species influence the trade-off between the costs and benefits of motion dazzle and camouflage.

  12. An Improved Approach for Nonstationary Strong Ground Motion Simulation

    Science.gov (United States)

    Li, Yanan; Wang, Guoxin

    2016-05-01

    A new stochastic ground motion model for generating a suite of ground motion time history with both temporal and frequency nonstationarities for specified earthquake and site characteristics is proposed based on the wavelet method. This new model is defined in terms of 6 key parameters that characterize the duration, evolving intensity, predominant frequency, bandwidth and frequency variation of the ground acceleration process. All parameters, except for peak ground acceleration (PGA), are identified manually from a database of 2444 recorded horizontal accelerations. The two-stage regression analysis method is used to investigate the inter- and intra-event residuals. For any given earthquake and site characteristics in terms of the fault mechanism, moment magnitude, Joyner and Boore distance and site shear-wave velocity, sets of the model parameters are generated and used, in turn, by the stochastic model to generate strong ground motion accelerograms, which can capture and properly embody the primary features of real strong ground motions, including the duration, evolving intensity, spectral content, frequency variation and peak values. In addition, it is shown that the characteristics of the simulated and observed response spectra are similar, and the amplitude of the simulated response spectra are in line with the predicted values from the published seismic ground motion prediction equations (SGMPE) after a systematic comparison. The proposed method can be used to estimate the strong ground motions as inputs for structural seismic dynamic analysis in engineering practice in conjunction with or instead of recorded ground motions.

  13. Event-related alpha suppression in response to facial motion.

    Directory of Open Access Journals (Sweden)

    Christine Girges

    Full Text Available While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors.

  14. Event-related alpha suppression in response to facial motion.

    Science.gov (United States)

    Girges, Christine; Wright, Michael J; Spencer, Janine V; O'Brien, Justin M D

    2014-01-01

    While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors.

  15. Metazen - metadata capture for metagenomes.

    Science.gov (United States)

    Bischof, Jared; Harrison, Travis; Paczian, Tobias; Glass, Elizabeth; Wilke, Andreas; Meyer, Folker

    2014-01-01

    As the impact and prevalence of large-scale metagenomic surveys grow, so does the acute need for more complete and standards compliant metadata. Metadata (data describing data) provides an essential complement to experimental data, helping to answer questions about its source, mode of collection, and reliability. Metadata collection and interpretation have become vital to the genomics and metagenomics communities, but considerable challenges remain, including exchange, curation, and distribution. Currently, tools are available for capturing basic field metadata during sampling, and for storing, updating and viewing it. Unfortunately, these tools are not specifically designed for metagenomic surveys; in particular, they lack the appropriate metadata collection templates, a centralized storage repository, and a unique ID linking system that can be used to easily port complete and compatible metagenomic metadata into widely used assembly and sequence analysis tools. Metazen was developed as a comprehensive framework designed to enable metadata capture for metagenomic sequencing projects. Specifically, Metazen provides a rapid, easy-to-use portal to encourage early deposition of project and sample metadata. Metazen is an interactive tool that aids users in recording their metadata in a complete and valid format. A defined set of mandatory fields captures vital information, while the option to add fields provides flexibility.

  16. Molecular capture in protein nanotubes.

    Science.gov (United States)

    Qu, Xue; Komatsu, Teruyuki

    2010-01-26

    We describe molecular capturing properties of protein nanotubes with a controllable ligand binding affinity and size selectivity. These practical biocylinders were prepared using an alternating layer-by-layer (LbL) assembly of protein and oppositely charged poly(amino acid) into the nanoporous polycarbonate (PC) membrane (pore diameter, 400 nm), with subsequent dissolution of the template. The tube wall typically comprises six layers of poly-L-arginine (PLA) and human serum albumin (HSA) [(PLA/HSA)(3)]. Use of high molecular weight PLA (M(w) = ca. 70 000) yielded robust nanotubes, which are available as lyophilized powder. The (PLA/HSA)(3) nanotubes swelled considerably in water, although the outer diameter was almost unaltered. Uranyl ion, 3,3'-diethylthiacarbocyanine iodide, and zinc(II) protoporphyrin IX (ZnPP) were bound to the HSA component in the cylinder wall. Similar nanotubes comprising recombinant HSA mutant [rHSA(His)], which has a strong binding affinity for ZnPP, captured this ligand more tightly. Furthermore, addition of excess myristic acid released ZnPP from the tubes through a ligand replacement reaction. The hybrid nanotubes bearing a single avidin layer as an internal surface captured FITC-biotin efficiently. Biotin-labeled nanoparticles are also incorporated into the tubes when their particle size is sufficiently small to enter the pores. Subsequent TEM observation revealed a line of loaded nanoparticles (100 nm) in the one-dimensional space interior.

  17. Smooth pursuit eye movements and motion perception share motion signals in slow and fast motion mechanisms.

    Science.gov (United States)

    Matsumiya, Kazumichi; Shioiri, Satoshi

    2015-08-01

    Pursuit eye movements correlate with perceived motion in both velocity and direction, even without retinal motion. Cortical cells in the monkey medial temporal region generate signals for initiating pursuit eye movements and respond to retinal motion for perception. However, recent studies suggest multiple motion processes, fast and slow, even for low-level motion. Here we investigated whether the relationship with pursuit eye movements is different for fast and slow motion processes, using a motion aftereffect technique with superimposed low- and high-spatial-frequency gratings. A previous study showed that the low- and high-spatial-frequency gratings adapt the fast and slow motion processes, respectively, and that a static test probes the slow motion process and a flicker test probes the fast motion process (Shioiri & Matsumiya, 2009). In the present study, an adaptation stimulus was composed of two gratings with different spatial frequencies and orientations but the same temporal frequency, moving in the orthogonal direction of ±45° from the vertical. We measured the directions of perceived motion and pursuit eye movements to a test stimulus presented after motion adaptation with changing relative contrasts of the two adapting gratings. Pursuit eye movements were observed in the same direction as that of the motion aftereffects, independent of the relative contrasts of the two adapting gratings, for both the static and flicker tests. These results suggest that pursuit eye movements and perception share motion signals in both slow and fast motion processes.

  18. Motion Control with Vision

    NARCIS (Netherlands)

    Ir Dick van Schenk Brill; Ir Peter Boots

    2001-01-01

    This paper describes the work that is done by a group of I3 students at Philips CFT in Eindhoven, Netherlands. I3 is an initiative of Fontys University of Professional Education also located in Eindhoven. The work focuses on the use of computer vision in motion control. Experiments are done with

  19. Seeing Objects in Motion

    Science.gov (United States)

    Burr, D. C.; Ross, J.; Morrone, M. C.

    1986-03-01

    This paper reports estimates of the conjoint spatiotemporal tuning functions of the neural mechanisms of the human vision system which detect image motion. The functions were derived from measurements of the minimum contrast necessary to detect the direction of drift of a sinusoidal grating, in the presence of phase-reversed masking gratings of various spatial and temporal frequencies. A mask of similar spatial and temporal frequencies to the test grating reduces sensitivity considerably, whereas one differing greatly in spatial or temporal frequency has little or no effect. The results show that for test gratings drifting at 8 Hz, the tuning function is bandpass in both space and time, peaked at the temporal and spatial frequency (SF) of the test (SFS were 0.1, 1 or 5 c deg-1; c represents cycles throughout). For a grating of 5 c deg-1 drifting at 0.3 Hz, the function is bandpass in space but lowpass in time. Fourier transform of the frequency results yields a function in space-time which we term the `spatiotemporal receptive field'. For movement detectors (bandpass in space and time) the fields comprise alternating ridges of opposing polarity, elongated in space-time along the preferred velocity axis of the detector. We suggest that this organization explains how detectors analyse form and motion concurrently and accounts, at least in part, for a variety of perceptual phenomena, including summation, reduction of motion smear, metacontrast, stroboscopic motion and spatiotemporal interpolation.

  20. Superluminal motion (review)

    Science.gov (United States)

    Malykin, G. B.; Romanets, E. A.

    2012-06-01

    Prior to the development of Special Relativity, no restrictions were imposed on the velocity of the motion of particles and material bodies, as well as on energy transfer and signal propagation. At the end of the 19th century and the beginning of the 20th century, it was shown that a charge that moves at a velocity faster than the speed of light in an optical medium, in particular, in vacuum, gives rise to impact radiation, which later was termed the Vavilov-Cherenkov radiation. Shortly after the development of Special Relativity, some researchers considered the possibility of superluminal motion. In 1923, the Soviet physicist L.Ya. Strum suggested the existence of tachyons, which, however, have not been discovered yet. Superluminal motions can occur only for images, e.g., for so-called "light spots," which were considered in 1972 by V.L. Ginzburg and B.M. Bolotovskii. These spots can move with a superluminal phase velocity but are incapable of transferring energy and information. Nevertheless, these light spots may induce quite real generation of microwave radiation in closed waveguides and create the Vavilov-Cherenkov radiation in vacuum. In this work, we consider various paradoxes, illusions, and artifacts associated with superluminal motion.

  1. Projectile Motion Revisited.

    Science.gov (United States)

    Lucie, Pierre

    1979-01-01

    Analyzes projectile motion using symmetry and simple geometry. Deduces the direction of velocity at any point, range, time of flight, maximum height, safety parabola, and maximum range for a projectile launched upon a plane inclined at any angle with respect to the horizontal. (Author/GA)

  2. Choosing a Motion Detector.

    Science.gov (United States)

    Ballard, David M.

    1990-01-01

    Examines the characteristics of three types of motion detectors: Doppler radar, infrared, and ultrasonic wave, and how they are used on school buses to prevent students from being killed by their own school bus. Other safety devices cited are bus crossing arms and a camera monitor system. (MLF)

  3. Fly motion vision.

    Science.gov (United States)

    Borst, Alexander; Haag, Juergen; Reiff, Dierk F

    2010-01-01

    Fly motion vision and resultant compensatory optomotor responses are a classic example for neural computation. Here we review our current understanding of processing of optic flow as generated by an animal's self-motion. Optic flow processing is accomplished in a series of steps: First, the time-varying photoreceptor signals are fed into a two-dimensional array of Reichardt-type elementary motion detectors (EMDs). EMDs compute, in parallel, local motion vectors at each sampling point in space. Second, the output signals of many EMDs are spatially integrated on the dendrites of large-field tangential cells in the lobula plate. In the third step, tangential cells form extensive interactions with each other, giving rise to their large and complex receptive fields. Thus, tangential cells can act as matched filters tuned to optic flow during particular flight maneuvers. They finally distribute their information onto postsynaptic descending neurons, which either instruct the motor centers of the thoracic ganglion for flight and locomotion control or act themselves as motor neurons that control neck muscles for head movements.

  4. Structure from Motion

    Science.gov (United States)

    1988-11-17

    differential motion Pouu:v tangential to the edge orientation. -iows one irame from a sentience in which tile T is moving b ehind IC uci daes signal...occiuded sides. :esvr. sinme templiate matching may not he etfective fo, recogni- .!on. Viumvre .I shows contrast edges in tileT sentience . lie edges

  5. Wiimote Experiments: Circular Motion

    Science.gov (United States)

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-01-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a…

  6. Global Motion Model for Stereovision-Based Motion Analysis

    Directory of Open Access Journals (Sweden)

    Hu Zhencheng

    2006-01-01

    Full Text Available An advantage of stereovision-based motion analysis is that the depth information is available, thus motion can be estimated more precisely in D stereo coordinate system (SCS constructed by the depth and the image coordinates. In this paper, stereo global motion in SCS, which is induced by 3D camera motion in real-world coordinate system (WCS, is parameterized by a five-parameter global motion model (GMM. Based on such model, global motion can be estimated and identified directly in SCS without knowing the physical parameters about camera motion and camera setup in WCS. The reconstructed global motion field accords with the spatial structure of the scene much better. Experiments on both synthetic data and real-world images illustrate its promising performance.

  7. Development and Validation of a Portable and Inexpensive Tool to Measure the Drop Vertical Jump Using the Microsoft Kinect V2.

    Science.gov (United States)

    Gray, Aaron D; Willis, Brad W; Skubic, Marjorie; Huo, Zhiyu; Razu, Swithin; Sherman, Seth L; Guess, Trent M; Jahandar, Amirhossein; Gulbrandsen, Trevor R; Miller, Scott; Siesener, Nathan J

    Noncontact anterior cruciate ligament (ACL) injury in adolescent female athletes is an increasing problem. The knee-ankle separation ratio (KASR), calculated at initial contact (IC) and peak flexion (PF) during the drop vertical jump (DVJ), is a measure of dynamic knee valgus. The Microsoft Kinect V2 has shown promise as a reliable and valid marker-less motion capture device. The Kinect V2 will demonstrate good to excellent correlation between KASR results at IC and PF during the DVJ, as compared with a "gold standard" Vicon motion analysis system. Descriptive laboratory study. Level 2. Thirty-eight healthy volunteer subjects (20 male, 18 female) performed 5 DVJ trials, simultaneously measured by a Vicon MX-T40S system, 2 AMTI force platforms, and a Kinect V2 with customized software. A total of 190 jumps were completed. The KASR was calculated at IC and PF during the DVJ. The intraclass correlation coefficient (ICC) assessed the degree of KASR agreement between the Kinect and Vicon systems. The ICCs of the Kinect V2 and Vicon KASR at IC and PF were 0.84 and 0.95, respectively, showing excellent agreement between the 2 measures. The Kinect V2 successfully identified the KASR at PF and IC frames in 182 of 190 trials, demonstrating 95.8% reliability. The Kinect V2 demonstrated excellent ICC of the KASR at IC and PF during the DVJ when compared with the Vicon system. A customized Kinect V2 software program demonstrated good reliability in identifying the KASR at IC and PF during the DVJ. Reliable, valid, inexpensive, and efficient screening tools may improve the accessibility of motion analysis assessment of adolescent female athletes.

  8. Dynamics and control of robot for capturing objects in space

    Science.gov (United States)

    Huang, Panfeng

    . After capturing the object, the space robot must complete the following two tasks: one is to berth the object, and the other is to re-orientate the attitude of the whole robot system for communication and power supply. Therefore, I propose a method to accomplish these two tasks simultaneously using manipulator motion only. The ultimate goal of space services is to realize the capture and manipulation autonomously. Therefore, I propose an affective approach based on learning human skill to track and capture the objects automatically in space. With human-teaching demonstration, the space robot is able to learn and abstract human tracking and capturing skill using an efficient neural-network learning architecture that combines flexible Cascade Neural Networks with Node Decoupled Extended Kalman Filtering (CNN-NDEKF). The simulation results attest that this approach is useful and feasible in tracking trajectory planning and capturing of space robot. Finally I propose a novel approach based on Genetic Algorithms (GAs) to optimize the approach trajectory of space robots in order to realize effective and stable operations. I complete the minimum-torque path planning in order to save the limited energy in space, and design the minimum jerk trajectory for the stabilization of the space manipulator and its space base. These optimal algorithms are very important and useful for the application of space robot.

  9. PET motion correction using PRESTO with ITK motion estimation

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Melissa [Institute of Biophysics and Biomedical Engineering, Science Faculty of University of Lisbon (Portugal); Caldeira, Liliana; Scheins, Juergen [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich (Germany); Matela, Nuno [Institute of Biophysics and Biomedical Engineering, Science Faculty of University of Lisbon (Portugal); Kops, Elena Rota; Shah, N Jon [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich (Germany)

    2014-07-29

    The Siemens BrainPET scanner is a hybrid MRI/PET system. PET images are prone to motion artefacts which degrade the image quality. Therefore, motion correction is essential. The library PRESTO converts motion-corrected LORs into highly accurate generic projection data [1], providing high-resolution PET images. ITK is an open-source software used for registering multidimensional data []. ITK provides motion estimation necessary to PRESTO.

  10. Independent motion detection with a rival penalized adaptive particle filter

    Science.gov (United States)

    Becker, Stefan; Hübner, Wolfgang; Arens, Michael

    2014-10-01

    Aggregation of pixel based motion detection into regions of interest, which include views of single moving objects in a scene is an essential pre-processing step in many vision systems. Motion events of this type provide significant information about the object type or build the basis for action recognition. Further, motion is an essential saliency measure, which is able to effectively support high level image analysis. When applied to static cameras, background subtraction methods achieve good results. On the other hand, motion aggregation on freely moving cameras is still a widely unsolved problem. The image flow, measured on a freely moving camera is the result from two major motion types. First the ego-motion of the camera and second object motion, that is independent from the camera motion. When capturing a scene with a camera these two motion types are adverse blended together. In this paper, we propose an approach to detect multiple moving objects from a mobile monocular camera system in an outdoor environment. The overall processing pipeline consists of a fast ego-motion compensation algorithm in the preprocessing stage. Real-time performance is achieved by using a sparse optical flow algorithm as an initial processing stage and a densely applied probabilistic filter in the post-processing stage. Thereby, we follow the idea proposed by Jung and Sukhatme. Normalized intensity differences originating from a sequence of ego-motion compensated difference images represent the probability of moving objects. Noise and registration artefacts are filtered out, using a Bayesian formulation. The resulting a posteriori distribution is located on image regions, showing strong amplitudes in the difference image which are in accordance with the motion prediction. In order to effectively estimate the a posteriori distribution, a particle filter is used. In addition to the fast ego-motion compensation, the main contribution of this paper is the design of the probabilistic

  11. Segmenting Continuous Motions with Hidden Semi-markov Models and Gaussian Processes

    Directory of Open Access Journals (Sweden)

    Tomoaki Nakamura

    2017-12-01

    Full Text Available Humans divide perceived continuous information into segments to facilitate recognition. For example, humans can segment speech waves into recognizable morphemes. Analogously, continuous motions are segmented into recognizable unit actions. People can divide continuous information into segments without using explicit segment points. This capacity for unsupervised segmentation is also useful for robots, because it enables them to flexibly learn languages, gestures, and actions. In this paper, we propose a Gaussian process-hidden semi-Markov model (GP-HSMM that can divide continuous time series data into segments in an unsupervised manner. Our proposed method consists of a generative model based on the hidden semi-Markov model (HSMM, the emission distributions of which are Gaussian processes (GPs. Continuous time series data is generated by connecting segments generated by the GP. Segmentation can be achieved by using forward filtering-backward sampling to estimate the model's parameters, including the lengths and classes of the segments. In an experiment using the CMU motion capture dataset, we tested GP-HSMM with motion capture data containing simple exercise motions; the results of this experiment showed that the proposed GP-HSMM was comparable with other methods. We also conducted an experiment using karate motion capture data, which is more complex than exercise motion capture data; in this experiment, the segmentation accuracy of GP-HSMM was 0.92, which outperformed other methods.

  12. Segmenting Continuous Motions with Hidden Semi-markov Models and Gaussian Processes.

    Science.gov (United States)

    Nakamura, Tomoaki; Nagai, Takayuki; Mochihashi, Daichi; Kobayashi, Ichiro; Asoh, Hideki; Kaneko, Masahide

    2017-01-01

    Humans divide perceived continuous information into segments to facilitate recognition. For example, humans can segment speech waves into recognizable morphemes. Analogously, continuous motions are segmented into recognizable unit actions. People can divide continuous information into segments without using explicit segment points. This capacity for unsupervised segmentation is also useful for robots, because it enables them to flexibly learn languages, gestures, and actions. In this paper, we propose a Gaussian process-hidden semi-Markov model (GP-HSMM) that can divide continuous time series data into segments in an unsupervised manner. Our proposed method consists of a generative model based on the hidden semi-Markov model (HSMM), the emission distributions of which are Gaussian processes (GPs). Continuous time series data is generated by connecting segments generated by the GP. Segmentation can be achieved by using forward filtering-backward sampling to estimate the model's parameters, including the lengths and classes of the segments. In an experiment using the CMU motion capture dataset, we tested GP-HSMM with motion capture data containing simple exercise motions; the results of this experiment showed that the proposed GP-HSMM was comparable with other methods. We also conducted an experiment using karate motion capture data, which is more complex than exercise motion capture data; in this experiment, the segmentation accuracy of GP-HSMM was 0.92, which outperformed other methods.

  13. Ultrasound based skeletal motion capture : the development and validation of a non-invasive knee joint motion tracking method

    NARCIS (Netherlands)

    Niu, Kenan

    2018-01-01

    Musculoskeletal disorders, particularly in the lower limb, are the most common cause of severe long-term pain and physical disability, and affect hundreds of millions of people around the world. Accurate measurement tools are required to diagnose these pathologies and to evaluate the efficacy of

  14. Capture of Planetesimals by Gas Drag from Circumplanetary Disks

    Science.gov (United States)

    Fujita, Tetsuya; Ohtsuki, K.; Tanigawa, T.

    2012-10-01

    The regular satellites of the giant planets (e.g. Galilean satellites) have nearly circular and coplanar prograde orbits, and are thought to have formed by accretion of solid particles in the circumplanetary disk. Because a significant amount of gas and solids are likely to be supplied to growing giant planets through the circumplanetary disk, the amount of solid material in circumplanetary disks is important not only for satellite formation but also for the growth and the origin of the heavy element content of giant planets. Solid particles smaller than meter-scale are strongly coupled with the gas flow from the protoplanetary disk and delivered into the disk with the gas. On the other hand, trajectories of large planetesimals are decoupled from the gas. When these large planetesimals approach a growing giant planet, their orbits can be perturbed by gas drag from the circumplanetary disk depending on their size and random velocity, and some of them would be captured by the disk. In the present work, we examine orbital evolution of planetesimals approaching a growing giant planet with a circumplanetary disks by integrating Hill’s equation including the gas drag term. We assume that the gas in the disk rotates in circular orbits around the planet. We found that the condition for capture of planetesimals approaching in the prograde direction (i.e., trajectory in the same direction as the circular motion of the gas) is different from that for those approaching in the retrograde trajectories. We obtained analytic expressions for energy dissipation, critical approach distance from the planet for capture, and capture probability for prograde and retrograde orbits in the coplanar case. We will discuss results of orbital integration for capture rates, including the cases of inclined orbits of planetesimals.

  15. Realistic costs of carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Al Juaied, Mohammed (Harvard Univ., Cambridge, MA (US). Belfer Center for Science and International Affiaris); Whitmore, Adam (Hydrogen Energy International Ltd., Weybridge (GB))

    2009-07-01

    There is a growing interest in carbon capture and storage (CCS) as a means of reducing carbon dioxide (CO2) emissions. However there are substantial uncertainties about the costs of CCS. Costs for pre-combustion capture with compression (i.e. excluding costs of transport and storage and any revenue from EOR associated with storage) are examined in this discussion paper for First-of-a-Kind (FOAK) plant and for more mature technologies, or Nth-of-a-Kind plant (NOAK). For FOAK plant using solid fuels the levelised cost of electricity on a 2008 basis is approximately 10 cents/kWh higher with capture than for conventional plants (with a range of 8-12 cents/kWh). Costs of abatement are found typically to be approximately US$150/tCO2 avoided (with a range of US$120-180/tCO2 avoided). For NOAK plants the additional cost of electricity with capture is approximately 2-5 cents/kWh, with costs of the range of US$35-70/tCO2 avoided. Costs of abatement with carbon capture for other fuels and technologies are also estimated for NOAK plants. The costs of abatement are calculated with reference to conventional SCPC plant for both emissions and costs of electricity. Estimates for both FOAK and NOAK are mainly based on cost data from 2008, which was at the end of a period of sustained escalation in the costs of power generation plant and other large capital projects. There are now indications of costs falling from these levels. This may reduce the costs of abatement and costs presented here may be 'peak of the market' estimates. If general cost levels return, for example, to those prevailing in 2005 to 2006 (by which time significant cost escalation had already occurred from previous levels), then costs of capture and compression for FOAK plants are expected to be US$110/tCO2 avoided (with a range of US$90-135/tCO2 avoided). For NOAK plants costs are expected to be US$25-50/tCO2. Based on these considerations a likely representative range of costs of abatement from CCS

  16. SU-E-T-570: New Quality Assurance Method Using Motion Tracking for 6D Robotic Couches

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, W; Cho, J [SungKyunKwan University, Seoul (Korea, Republic of); Ahn, S [Samsung Medical Center, Seoul (Korea, Republic of); Han, Y; Choi, D [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: To accommodate geometrically accurate patient positioning, a robotic couch that is capable of 6-degrees of freedom has been introduced. However, conventional couch QA methods are not sufficient to enable the necessary accuracy of tests. Therefore, we have developed a camera based motion detection and geometry calibration system for couch QA. Methods: Employing a Visual-Tracking System (VTS, BonitaB10, Vicon, UK) which tracks infrared reflective(IR) markers, camera calibration was conducted using a 5.7 × 5.7 × 5.7 cm{sup 3} cube attached with IR markers at each corner. After positioning a robotic-couch at the origin with the cube on the table top, 3D coordinates of the cube’s eight corners were acquired by VTS in the VTS coordinate system. Next, positions in reference coordinates (roomcoordinates) were assigned using the known relation between each point. Finally, camera calibration was completed by finding a transformation matrix between VTS and reference coordinate systems and by applying a pseudo inverse matrix method. After the calibration, the accuracy of linear and rotational motions as well as couch sagging could be measured by analyzing the continuously acquired data of the cube while the couch moves to a designated position. Accuracy of the developed software was verified through comparison with measurement data when using a Laser tracker (FARO, Lake Mary, USA) for a robotic-couch installed for proton therapy. Results: VTS system could track couch motion accurately and measured position in room-coordinates. The VTS measurements and Laser tracker data agreed within 1% of difference for linear and rotational motions. Also because the program analyzes motion in 3-Dimension, it can compute couch sagging. Conclusion: Developed QA system provides submillimeter/ degree accuracy which fulfills the high-end couch QA. This work was supported by the National Research Foundation of Korea funded by Ministry of Science, ICT & Future Planning. (2013M2A2A

  17. Negotiation in Motion

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2010-01-01

    related to interaction, mobility, and transit that focus on notions of the “mobile with,” “negotiation in motion,” “mobile sense making,” and “temporary congregations.” The theoretical approach aims at seeing public transit spaces as sites where cars, pedestrians, mopeds, and bikes on a regular basis...... “negotiate” not only routes in and across the space but also express dynamic flows of interaction in motion. The claim is that what seems like ordinary urban movement patterns are more than this. By moving in the city among buildings, objects, and people, one interacts with the “environment,” making sense...

  18. Visible Motion Blur

    Science.gov (United States)

    Watson, Andrew B. (Inventor); Ahumada, Albert J. (Inventor)

    2014-01-01

    A method of measuring motion blur is disclosed comprising obtaining a moving edge temporal profile r(sub 1)(k) of an image of a high-contrast moving edge, calculating the masked local contrast m(sub1)(k) for r(sub 1)(k) and the masked local contrast m(sub 2)(k) for an ideal step edge waveform r(sub 2)(k) with the same amplitude as r(sub 1)(k), and calculating the measure or motion blur Psi as a difference function, The masked local contrasts are calculated using a set of convolution kernels scaled to simulate the performance of the human visual system, and Psi is measured in units of just-noticeable differences.

  19. Motion Representation with Acceleration Images

    OpenAIRE

    Kataoka, Hirokatsu; He, Yun; Shirakabe, Soma; Satoh, Yutaka

    2016-01-01

    Information of time differentiation is extremely important cue for a motion representation. We have applied first-order differential velocity from a positional information, moreover we believe that second-order differential acceleration is also a significant feature in a motion representation. However, an acceleration image based on a typical optical flow includes motion noises. We have not employed the acceleration image because the noises are too strong to catch an effective motion feature ...

  20. Force and motion

    CERN Document Server

    Robertson, William C

    2002-01-01

    Intimidated by inertia? Frightened by forces? Mystified by Newton s law of motion? You re not alone and help is at hand. The stop Faking It! Series is perfect for science teachers, home-schoolers, parents wanting to help with homework all of you who need a jargon-free way to learn the background for teaching middle school physical science with confidence. With Bill Roberton as your friendly, able but somewhat irreverent guide, you will discover you CAN come to grips with the basics of force and motion. Combining easy-to-understand explanations with activities using commonly found equipment, this book will lead you through Newton s laws to the physics of space travel. The book is as entertaining as it is informative. Best of all, the author understands the needs of adults who want concrete examples, hands-on activities, clear language, diagrams and yes, a certain amount of empathy. Ideas For Use Newton's laws, and all of the other motion principles presented in this book, do a good job of helping us to underst...

  1. Relative motion of orbiting bodies

    Science.gov (United States)

    Butikov, Eugene I.

    2001-01-01

    A problem of relative motion of orbiting bodies is investigated on the example of the free motion of any body ejected from the orbital station that stays in a circular orbit around the earth. An elementary approach is illustrated by a simulation computer program and supported by a mathematical treatment based on approximate differential equations of the relative orbital motion.

  2. Capturing Reality at Centre Block

    Science.gov (United States)

    Boulanger, C.; Ouimet, C.; Yeomans, N.

    2017-08-01

    The Centre Block of Canada's Parliament buildings, National Historic Site of Canada is set to undergo a major rehabilitation project that will take approximately 10 years to complete. In preparation for this work, Heritage Conservation Services (HCS) of Public Services and Procurement Canada has been completing heritage documentation of the entire site which includes laser scanning of all interior rooms and accessible confined spaces such as attics and other similar areas. Other documentation completed includes detailed photogrammetric documentation of rooms and areas of high heritage value. Some of these high heritage value spaces present certain challenges such as accessibility due to the height and the size of the spaces. Another challenge is the poor lighting conditions, requiring the use of flash or strobe lighting to either compliment or completely eliminate the available ambient lighting. All the spaces captured at this higher level of detail were also captured with laser scanning. This allowed the team to validate the information and conduct a quality review of the photogrammetric data. As a result of this exercise, the team realized that in most, if not all cases, the photogrammetric data was more detailed and at a higher quality then the terrestrial laser scanning data. The purpose and motivation of this paper is to present these findings, as well provide the advantages and disadvantages of the two methods and data sets.

  3. Bubble capture by a propeller

    Science.gov (United States)

    Caillé, François; Clanet, Christophe; Magnaudet, Jacques

    2006-08-01

    A small air bubble (radius a) is injected in water (kinematic viscosity nu) in the vicinity (distance r_0) of a propeller (radius r_p, angular frequency omega). We study experimentally and theoretically the conditions under which the bubble can be ‘captured’, i.e. deviated from its vertical trajectory (imposed by gravity g) and moved toward the centre of the propeller (r {=} 0). We show that the capture frequency omega_{scriptsizecapt} follows the relationship [omega_{hboxriptsizeit capt}=left(frac{2ga^2}{9betanu r_p f(hboxRe_b)}right)left(frac{r_0}{r_p}right)^2(1+\\cos\\varphi_0),] where beta is a dimensionless parameter characterizing the propeller, f(Re_b) is an empirical correction to Stokes' drag law which accounts for finite-Reynolds-number effects and pi/2-varphi_0 is the angle between the axis of the propeller and the line between the centre of the propeller and the point where the bubble is injected. This law is found to be valid as long as the distance d between the propeller and the water surface is larger than 3r_0. For smaller distances, the capture frequency increases; using an image technique, we show how the above expression is modified by the presence of the surface.

  4. Motion Control of Robot by using Kinect Sensor

    OpenAIRE

    Hussein, Mohammed A.; Ali, Ahmed S.; F.A. Elmisery; Mostafa, R.

    2014-01-01

    In the presented work, a remote robot control system is implemented utilizes Kinect based gesture recognition as human-robot interface. The movement of the human arm in 3 d space is captured, processed and replicated by the robotic arm. The joint angles are transmitted to the Arduino microcontroller. Arduino receives the joint angles and controls the robot arm. In investigation the accuracy of control by human's hand motion was tested.

  5. A Method to Capture Macroslip at Bolted Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, Ronald Neil; Heitman, Lili Anne Akin

    2015-10-01

    Relative motion at bolted connections can occur for large shock loads as the internal shear force in the bolted connection overcomes the frictional resistive force. This macroslip in a structure dissipates energy and reduces the response of the components above the bolted connection. There is a need to be able to capture macroslip behavior in a structural dynamics model. A linear model and many nonlinear models are not able to predict marcoslip effectively. The proposed method to capture macroslip is to use the multi-body dynamics code ADAMS to model joints with 3-D contact at the bolted interfaces. This model includes both static and dynamic friction. The joints are preloaded and the pinning effect when a bolt shank impacts a through hole inside diameter is captured. Substructure representations of the components are included to account for component flexibility and dynamics. This method was applied to a simplified model of an aerospace structure and validation experiments were performed to test the adequacy of the method.

  6. Motion Artifact Quantification and Sensor Fusion for Unobtrusive Health Monitoring

    Directory of Open Access Journals (Sweden)

    Christoph Hoog Antink

    2017-12-01

    Full Text Available Sensors integrated into objects of everyday life potentially allow unobtrusive health monitoring at home. However, since the coupling of sensors and subject is not as well-defined as compared to a clinical setting, the signal quality is much more variable and can be disturbed significantly by motion artifacts. One way of tackling this challenge is the combined evaluation of multiple channels via sensor fusion. For robust and accurate sensor fusion, analyzing the influence of motion on different modalities is crucial. In this work, a multimodal sensor setup integrated into an armchair is presented that combines capacitively coupled electrocardiography, reflective photoplethysmography, two high-frequency impedance sensors and two types of ballistocardiography sensors. To quantify motion artifacts, a motion protocol performed by healthy volunteers is recorded with a motion capture system, and reference sensors perform cardiorespiratory monitoring. The shape-based signal-to-noise ratio SNR S is introduced and used to quantify the effect on motion on different sensing modalities. Based on this analysis, an optimal combination of sensors and fusion methodology is developed and evaluated. Using the proposed approach, beat-to-beat heart-rate is estimated with a coverage of 99.5% and a mean absolute error of 7.9 ms on 425 min of data from seven volunteers in a proof-of-concept measurement scenario.

  7. Dynamic motion planning for the design of robotic gait rehabilitation.

    Science.gov (United States)

    Wang, Chia-Yu E; Bobrow, James E; Reinkensmeyer, David J

    2005-08-01

    In this paper we examine a method to control the stepping motion of a paralyzed person suspended over a treadmill using a robot attached to the pelvis. A leg swing motion is created by moving the pelvis without contact with the legs. The problem is formulated as an optimal control problem for an underactuated articulated chain. The optimal control problem is converted into a discrete parameter optimization and an efficient gradient-based algorithm is used to solve it. Motion capture data from an unimpaired human subject is compared to the simulation results from the dynamic motion optimization. Our results suggest that it is feasible to drive repetitive stepping on a treadmill by a paralyzed person by assisting in torso movement alone. The optimized, pelvic motion strategies are comparable to "hip-hiking" gait strategies used by people with lower limb prostheses or hemiparesis. The resulting motions can be found at the web site http://ww.eng.uci.edu/-chwang/project/stepper/stepper.html.

  8. Outward-looking circular motion analysis of large image sequences.

    Science.gov (United States)

    Jiang, Guang; Wei, Yichen; Quan, Long; Tsui, Hung-tat; Shum, Heung Yeung

    2005-02-01

    This paper presents a novel and simple method of analyzing the motion of a large image sequence captured by a calibrated outward-looking video camera moving on a circular trajectory for large-scale environment applications. Previous circular motion algorithms mainly focus on inward-looking turntable-like setups. They are not suitable for outward-looking motion where the conic trajectory of corresponding points degenerates to straight lines. The circular motion of a calibrated camera essentially has only one unknown rotation angle for each frame. The motion recovery for the entire sequence computes only one fundamental matrix of a pair of frames to extract the angular motion of the pair using Laguerre's formula and then propagates the computation of the unknown rotation angles to the other frames by tracking one point over at least three frames. Finally, a maximum-likelihood estimation is developed for the optimization of the whole sequence. Extensive experiments demonstrate the validity of the method and the feasibility of the application in image-based rendering.

  9. Apparent diffusive motion of centrin foci in living cells: implications for diffusion-based motion in centriole duplication

    OpenAIRE

    Rafelski, Susanne M.; Keller, Lani C.; Jonathan B Alberts; Marshall, Wallace F.

    2011-01-01

    The degree to which diffusion contributes to positioning cellular structures is an open question. Here we investigate the question of whether diffusive motion of centrin granules would allow them to interact with the mother centriole. The role of centrin granules in centriole duplication remains unclear, but some proposed functions of these granules, for example in providing pre-assembled centriole subunits, or by acting as unstable “pre-centrioles” that need to be captured by the mother cent...

  10. A Modeling of Cerebral Blood Flow Changes due to Head Motion for fNIRS

    Science.gov (United States)

    Takahashi, Kosuke; Tanaka, Takayuki; Nara, Hiroyuki; Kaneko, Shun'ichi; Inoue, Masao; Shimizu, Shunji; Kojima, Satoru

    2013-04-01

    A method is proposed for measuring brain activity during exercises involving head motion by using functional near-infrared spectroscopy (fNIRS), which investigates cerebral hemodynamics. Obtaining measurements during exercise is difficult because cerebral blood flow changes due to the head motion component (HMC), in addition to neural activity. HMC is an undesirable artifact in the measurement of hemodynamic response caused by neural activity, and as such, it must be estimated and eliminated. In our experiments, cerebral blood flow and head motion were measured during repeated passive forward bending of the subjects. Head motion was measured by 3-D motion capture, and HMC was estimated by deriving a relation between head motion and cerebral blood flow, where the pitch angle was found to be suitable for estimating HMC. In this research, an assumption was made that cerebral blood flow caused by neural activity and that caused by postural change were additive, and thus HMC was eliminated by subtraction.

  11. Mathematical Modeling and Evaluation of Human Motions in Physical Therapy Using Mixture Density Neural Networks

    Science.gov (United States)

    Vakanski, A; Ferguson, JM; Lee, S

    2016-01-01

    Objective The objective of the proposed research is to develop a methodology for modeling and evaluation of human motions, which will potentially benefit patients undertaking a physical rehabilitation therapy (e.g., following a stroke or due to other medical conditions). The ultimate aim is to allow patients to perform home-based rehabilitation exercises using a sensory system for capturing the motions, where an algorithm will retrieve the trajectories of a patient’s exercises, will perform data analysis by comparing the performed motions to a reference model of prescribed motions, and will send the analysis results to the patient’s physician with recommendations for improvement. Methods The modeling approach employs an artificial neural network, consisting of layers of recurrent neuron units and layers of neuron units for estimating a mixture density function over the spatio-temporal dependencies within the human motion sequences. Input data are sequences of motions related to a prescribed exercise by a physiotherapist to a patient, and recorded with a motion capture system. An autoencoder subnet is employed for reducing the dimensionality of captured sequences of human motions, complemented with a mixture density subnet for probabilistic modeling of the motion data using a mixture of Gaussian distributions. Results The proposed neural network architecture produced a model for sets of human motions represented with a mixture of Gaussian density functions. The mean log-likelihood of observed sequences was employed as a performance metric in evaluating the consistency of a subject’s performance relative to the reference dataset of motions. A publically available dataset of human motions captured with Microsoft Kinect was used for validation of the proposed method. Conclusion The article presents a novel approach for modeling and evaluation of human motions with a potential application in home-based physical therapy and rehabilitation. The described approach

  12. Mathematical Modeling and Evaluation of Human Motions in Physical Therapy Using Mixture Density Neural Networks.

    Science.gov (United States)

    Vakanski, A; Ferguson, J M; Lee, S

    2016-12-01

    The objective of the proposed research is to develop a methodology for modeling and evaluation of human motions, which will potentially benefit patients undertaking a physical rehabilitation therapy (e.g., following a stroke or due to other medical conditions). The ultimate aim is to allow patients to perform home-based rehabilitation exercises using a sensory system for capturing the motions, where an algorithm will retrieve the trajectories of a patient's exercises, will perform data analysis by comparing the performed motions to a reference model of prescribed motions, and will send the analysis results to the patient's physician with recommendations for improvement. The modeling approach employs an artificial neural network, consisting of layers of recurrent neuron units and layers of neuron units for estimating a mixture density function over the spatio-temporal dependencies within the human motion sequences. Input data are sequences of motions related to a prescribed exercise by a physiotherapist to a patient, and recorded with a motion capture system. An autoencoder subnet is employed for reducing the dimensionality of captured sequences of human motions, complemented with a mixture density subnet for probabilistic modeling of the motion data using a mixture of Gaussian distributions. The proposed neural network architecture produced a model for sets of human motions represented with a mixture of Gaussian density functions. The mean log-likelihood of observed sequences was employed as a performance metric in evaluating the consistency of a subject's performance relative to the reference dataset of motions. A publically available dataset of human motions captured with Microsoft Kinect was used for validation of the proposed method. The article presents a novel approach for modeling and evaluation of human motions with a potential application in home-based physical therapy and rehabilitation. The described approach employs the recent progress in the field of

  13. Human motion simulation predictive dynamics

    CERN Document Server

    Abdel-Malek, Karim

    2013-01-01

    Simulate realistic human motion in a virtual world with an optimization-based approach to motion prediction. With this approach, motion is governed by human performance measures, such as speed and energy, which act as objective functions to be optimized. Constraints on joint torques and angles are imposed quite easily. Predicting motion in this way allows one to use avatars to study how and why humans move the way they do, given specific scenarios. It also enables avatars to react to infinitely many scenarios with substantial autonomy. With this approach it is possible to predict dynamic motion without having to integrate equations of motion -- rather than solving equations of motion, this approach solves for a continuous time-dependent curve characterizing joint variables (also called joint profiles) for every degree of freedom. Introduces rigorous mathematical methods for digital human modelling and simulation Focuses on understanding and representing spatial relationships (3D) of biomechanics Develops an i...

  14. 'Dicty dynamics': Dictyostelium motility as persistent random motion

    DEFF Research Database (Denmark)

    Li, Liang; Cox, Edward C; Flyvbjerg, Henrik

    2011-01-01

    than the usual tracking by centroid or nucleus. Our data account for cell individuality and dictate a model that extends the cell-type specific models recently derived for mammalian cells. Two generalized Langevin equations model stochastic periodic pseudopod motion parallel and orthogonal...... to the amoeba's direction of motion. This motion propels the amoeba with a random periodic left–right waddle in a direction that has a long persistence time. The model fully accounts for the statistics of the experimental trajectories, including velocity power spectra and auto-correlations, non......-Gaussian velocity distributions, and multiplicative noise. Thus, we find neither need nor place in our data for an interpretation in terms of anomalous diffusion. The model faithfully captures cell individuality as different parameter values in the model, and serves as a basis for integrating the local mechanics...

  15. Motion Planning in Multi-robot Systems using Timed Automata

    DEFF Research Database (Denmark)

    Andersen, Michael. S.; Jensen, Rune S.; Bak, Thomas

    This paper dscribes how interacting timed automata can be used to model, analyze, and verify motion planning problems for systems with multiple mobile robots. The method assumes an infra-structure of simple unicycle type robots, moving om a planar grid. The motion of the robots, including simple...... kinematics, is captured in an automata formalism that allows formal composition and symbolic reasoning. The verification software UppAal is used to verify specification requirements formulated in computational tree logic (CTL), generating all feasible trajectories that satisfy specifications. The results...... of the planning are demonstrateted in a testbed that allows execution of the planned paths and motion primitives by synchronizing the planning results from UppAal with actual robotic vehicles. The planning problem may be modified online by moving obstacles in the physical environment, which causes a re...

  16. Cage-based performance capture

    CERN Document Server

    Savoye, Yann

    2014-01-01

    Nowadays, highly-detailed animations of live-actor performances are increasingly easier to acquire and 3D Video has reached considerable attentions in visual media production. In this book, we address the problem of extracting or acquiring and then reusing non-rigid parametrization for video-based animations. At first sight, a crucial challenge is to reproduce plausible boneless deformations while preserving global and local captured properties of dynamic surfaces with a limited number of controllable, flexible and reusable parameters. To solve this challenge, we directly rely on a skin-detached dimension reduction thanks to the well-known cage-based paradigm. First, we achieve Scalable Inverse Cage-based Modeling by transposing the inverse kinematics paradigm on surfaces. Thus, we introduce a cage inversion process with user-specified screen-space constraints. Secondly, we convert non-rigid animated surfaces into a sequence of optimal cage parameters via Cage-based Animation Conversion. Building upon this re...

  17. Subsurface capture of carbon dioxide

    Science.gov (United States)

    Blount, Gerald; Siddal, Alvin A.; Falta, Ronald W.

    2014-07-22

    A process and apparatus of separating CO.sub.2 gas from industrial off-gas source in which the CO.sub.2 containing off-gas is introduced deep within an injection well. The CO.sub.2 gases are dissolved in the, liquid within the injection well while non-CO.sub.2 gases, typically being insoluble in water or brine, are returned to the surface. Once the CO.sub.2 saturated liquid is present within the injection well, the injection well may be used for long-term geologic storage of CO.sub.2 or the CO.sub.2 saturated liquid can be returned to the surface for capturing a purified CO.sub.2 gas.

  18. Neutron capture therapy for melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Coderre, J.A.; Glass, J.D.; Micca, P.; Fairchild, R.G.

    1988-01-01

    The development of boron-containing compounds which localize selectively in tumor may require a tumor-by-tumor type of approach that exploits any metabolic pathways unique to the particular type of tumor. Melanin-producing melanomas actively transport and metabolize aromatic amino acids for use as precursors in the synthesis of the pigment melanin. It has been shown that the boron-containing amino acid analog p-borono-phenylalanine (BPA) is selectively accumulated in melanoma tissue, producing boron concentrations in tumor that are within the range estimated to be necessary for successful boron neutron capture therapy (BNCT). We report here the results of therapy experiments carried out at the Brookhaven Medical Research Reactor (BMRR). 21 refs., 5 figs., 3 tabs.

  19. Workshop on neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fairchild, R.G.; Bond, V.P. (eds.)

    1986-01-01

    Potentially optimal conditions for Neutron Capture Therapy (NCT) may soon be in hand due to the anticipated development of band-pass filtered beams relatively free of fast neutron contaminations, and of broadly applicable biomolecules for boron transport such as porphyrins and monoclonal antibodies. Consequently, a number of groups in the US are now devoting their efforts to exploring NCT for clinical application. The purpose of this Workshop was to bring these groups together to exchange views on significant problems of mutual interest, and to assure a unified and effective approach to the solutions. Several areas of preclinical investigation were deemed to be necessary before it would be possible to initiate clinical studies. As neither the monomer nor the dimer of sulfhydryl boron hydride is unequivocally preferable at this time, studies on both compounds should be continued until one is proven superior.

  20. Leap Motion Device Used to Control a Real Anthropomorphic Gripper

    Directory of Open Access Journals (Sweden)

    Ionel Staretu

    2016-06-01

    Full Text Available This paper presents for the first time the use of the Leap Motion device to control an anthropomorphic gripper with five fingers. First, a description of the Leap Motion device is presented, highlighting its main functional characteristics, followed by testing of its use for capturing the movements of a human hand's fingers in different configurations. Next, the HandCommander soft module and the Interface Controller application are described. The HandCommander is a software module created to facilitate interaction between a human hand and the GraspIT virtual environment, and the Interface Controller application is required to send motion data to the virtual environment and to test the communication protocol. For the test, a prototype of an anthropomorphic gripper with five fingers was made, including a proper hardware system of command and control, which is briefly presented in this paper. Following the creation of the prototype, the command system performance test was conducted under real conditions, evaluating the recognition efficiency of the objects to be gripped and the efficiency of the command and control strategies for the gripping process. The gripping test is exemplified by the gripping of an object, such as a screw spanner. It was found that the command system, both in terms of capturing human hand gestures with the Leap Motion device and effective object gripping, is operational. Suggestive figures are presented as examples.

  1. Earth-Mars transfers with ballistic capture

    Science.gov (United States)

    Topputo, F.; Belbruno, E.

    2015-04-01

    We construct a new type of transfer from the Earth to Mars, which ends in ballistic capture. This results in substantial savings in capture from that of a classical Hohmann transfer under certain assumptions as well as an alternate way for spacecraft to transfer to Mars. This is accomplished by first becoming captured at Mars, very distant from the planet, and then from there, following a ballistic capture transfer to a desired altitude within a ballistic capture set. This is achieved by using stable sets, which are sets of initial conditions whose orbits satisfy a definition of orbital stability. This transfer type may be of interest for Mars missions because of low capture , flexibility of launch period from the Earth, moderate flight time, and the benign nature of the capture process.

  2. SOFIA image motion compensation

    Science.gov (United States)

    Dunham, Edward; Collins, Peter; Reinacher, Andreas; Lampater, Ulrich

    2010-07-01

    We describe a laboratory simulation of an image motion compensation system for SOFIA that uses high-speed image acquisition from the science instrument HIPO as the sensing element of the system and a Newport voice-coil actuated fast steering mirror as the correcting actuator. Performance of the system when coupled to the SOFIA secondary mirror is estimated based on the known current performance of the secondary mirror controller. The system is described and the observed performance is presented together with expectations for applicability in flight with SOFIA.

  3. Electromechanical motion devices

    CERN Document Server

    Krause, Paul C; Pekarek, Steven D

    2012-01-01

    This text provides a basic treatment of modern electric machine analysis that gives readers the necessary background for comprehending the traditional applications and operating characteristics of electric machines-as well as their emerging applications in modern power systems and electric drives, such as those used in hybrid and electric vehicles. Through the appropriate use of reference frame theory, Electromagnetic Motion Devices, Second Edition introduces readers to field-oriented control of induction machines, constant-torque, and constant-power control of dc, permanent-magnet ac

  4. Influence of Rigid Body Motions on Rotor Induced Velocities and Aerodynamic Loads of a Floating Horizontal Axis Wind Turbine

    DEFF Research Database (Denmark)

    de Vaal, Jacobus B.; Hansen, Martin Otto Laver; Moan, Torgeir

    2014-01-01

    This paper discusses the influence of rigid body motions on rotor induced velocities and aerodynamic loads of a floating horizontal axis wind turbine. Analyses are performed with a simplified free wake vortex model specifically aimed at capturing the unsteady and non-uniform inflow typically......, and captures the essential influences of rigid body motions on the rotor loads, induced velocities and wake influence....... experienced by a floating wind turbine. After discussing the simplified model in detail, comparisons are made to a state of the art free wake vortex code, using test cases with prescribed platform motion. It is found that the simplified model compares favourably with a more advanced numerical model...

  5. Motion data classification on the basis of dynamic time warping with a cloud point distance measure

    Science.gov (United States)

    Switonski, Adam; Josinski, Henryk; Zghidi, Hafedh; Wojciechowski, Konrad

    2016-06-01

    The paper deals with the problem of classification of model free motion data. The nearest neighbors classifier which is based on comparison performed by Dynamic Time Warping transform with cloud point distance measure is proposed. The classification utilizes both specific gait features reflected by a movements of subsequent skeleton joints and anthropometric data. To validate proposed approach human gait identification challenge problem is taken into consideration. The motion capture database containing data of 30 different humans collected in Human Motion Laboratory of Polish-Japanese Academy of Information Technology is used. The achieved results are satisfactory, the obtained accuracy of human recognition exceeds 90%. What is more, the applied cloud point distance measure does not depend on calibration process of motion capture system which results in reliable validation.

  6. Quaternion correlation for tracking crystal motions

    Science.gov (United States)

    Shi, Qiwei; Latourte, Félix; Hild, François; Roux, Stéphane

    2016-09-01

    During in situ mechanical tests performed on polycrystalline materials in a scanning electron microscope, crystal orientation maps may be recorded at different stages of deformation from electron backscattered diffraction (EBSD). The present study introduces a novel correlation technique that exploits the crystallographic orientation field as a surface pattern to measure crystal motions. Introducing a quaternion-based formalism reveals crystal symmetry that is very convenient to handle and orientation extraction. Spatial regularization is provided by a penalty to deviation of displacement fields from being the solution to a homogeneous linear elastic problem. This procedure allows the large scale features of the displacement field to be captured, mostly from grain boundaries, and a fair interpolation of the displacement to be obtained within the grains. From these data, crystal rotations can be estimated very accurately. Both synthetic and real experimental cases are considered to illustrate the method.

  7. Biophone: Physiology monitoring from peripheral smartphone motions.

    Science.gov (United States)

    Hernandez, Javier; McDuff, Daniel J; Picard, Rosalind W

    2015-01-01

    The large-scale adoption of smartphones during recent years has created many opportunities to improve health monitoring and care delivery. In this work, we demonstrate that motion sensors available in off-the-shelf smartphones can capture physiological parameters of a person during stationary postures, even while being carried in a bag or a pocket. In particular, we develop methods to extract heart and breathing rates from accelerometer data and compare them with measurements obtained with FDA-cleared sensors. We evaluated their accuracy on 12 people across different still body postures (pre- and post- exercise) and were able to reach mean absolute errors of 1.16 beats per minute (STD: 3) and 0.26 breaths per minute (STD: 0.5) when considering different conditions. Furthermore, we evaluated the same methods during regular phone activities, such as when watching a video or listening to a conversation, yielding increased but still comparable error rates for some conditions.

  8. Empirical ground motion prediction

    Directory of Open Access Journals (Sweden)

    R. J. Archuleta

    1994-06-01

    Full Text Available New methods of site-specific ground motion prediction in the time and frequency domains are presented. A large earthquake is simulated as a composite (linear combination of observed small earthquakes (subevents assuming Aki-Brune functional models of the source time functions (spectra. Source models incorporate basic scaling relations between source and spectral parameters. Ground motion predictions are consistent with the entire observed seismic spectrum from the lowest to the highest frequencies. These methods are designed to use all the available empirical Green’s functions (or any subset of observations at a site. Thus a prediction is not biased by a single record, and different possible source-receiver paths are taken into account. Directivity is accounted for by adjusting the apparent source duration at each site. Our time-series prediction algorithm is based on determination of a non-uniform distribution of rupture times of subevents. By introducing a specific rupture velocity we avoid the major problem of deficiency of predictions around the main event's corner frequency. A novel notion of partial coherence allows us to sum subevents' amplitude spectra directly without using any information on their rupture times and phase histories. Predictions by this spectral method are not Jependent on details of rupture nucleation and propagation, location of asperities and other predominantly phase-affecting factors, responsible for uncertainties in time-domain simulations.

  9. Stochastic Blind Motion Deblurring

    KAUST Repository

    Xiao, Lei

    2015-05-13

    Blind motion deblurring from a single image is a highly under-constrained problem with many degenerate solutions. A good approximation of the intrinsic image can therefore only be obtained with the help of prior information in the form of (often non-convex) regularization terms for both the intrinsic image and the kernel. While the best choice of image priors is still a topic of ongoing investigation, this research is made more complicated by the fact that historically each new prior requires the development of a custom optimization method. In this paper, we develop a stochastic optimization method for blind deconvolution. Since this stochastic solver does not require the explicit computation of the gradient of the objective function and uses only efficient local evaluation of the objective, new priors can be implemented and tested very quickly. We demonstrate that this framework, in combination with different image priors produces results with PSNR values that match or exceed the results obtained by much more complex state-of-the-art blind motion deblurring algorithms.

  10. Waves in Motion

    Science.gov (United States)

    McGourty, L.; Rideout, K.

    2005-12-01

    "Waves in Motion" This teaching unit was created by Leslie McGourty and Ken Rideout under the Research Experience for Teachers (RET) program at MIT Haystack Observatory during the summer of 2005. The RET program is funded by a grant from the National Science Foundation. The goals of this teaching unit are to deepen students' understanding about waves, wave motion, and the electromagnetic spectrum as a whole. Specifically students will comprehend the role radio waves play in our daily lives and in the investigation of the universe. The lessons can be used in a high school physics, earth science or astronomy curriculum. The unit consists of a series of interlocking lectures, activities, and investigations that can be used as stand alone units to supplement a teacher's existing curriculum, as an independent investigation for a student, or as a long exploration into radio astronomy with a theme of waves in space: how and where they carry their information. Special emphasis is given to the Relativity theories in honor of the "World Year of Physics" to celebrate Einstein's 1905 contributions. The lessons are currently being implemented at the high school level, the preliminary results of which will be presented. At the end of the academic year, the units will be evaluated and updated, reflecting student input and peer review after which they will be posted on the internet for teachers to use in their classrooms.

  11. Perceptually Uniform Motion Space.

    Science.gov (United States)

    Birkeland, Asmund; Turkay, Cagatay; Viola, Ivan

    2014-11-01

    Flow data is often visualized by animated particles inserted into a flow field. The velocity of a particle on the screen is typically linearly scaled by the velocities in the data. However, the perception of velocity magnitude in animated particles is not necessarily linear. We present a study on how different parameters affect relative motion perception. We have investigated the impact of four parameters. The parameters consist of speed multiplier, direction, contrast type and the global velocity scale. In addition, we investigated if multiple motion cues, and point distribution, affect the speed estimation. Several studies were executed to investigate the impact of each parameter. In the initial results, we noticed trends in scale and multiplier. Using the trends for the significant parameters, we designed a compensation model, which adjusts the particle speed to compensate for the effect of the parameters. We then performed a second study to investigate the performance of the compensation model. From the second study we detected a constant estimation error, which we adjusted for in the last study. In addition, we connect our work to established theories in psychophysics by comparing our model to a model based on Stevens' Power Law.

  12. Vision-Based 3D Motion Estimation for On-Orbit Proximity Satellite Tracking and Navigation

    Science.gov (United States)

    2015-06-01

    34 B. ALGORITHM’S LIBRARIES .....................................................................36 1. Initializer...screenshot of the telemetry software and the SSH terminals. ...........61 Figure 25. View of the VICON cameras above the granite flat floor of the FSS...spacecraft robotics laboratory SSH secure shell STS space transportation system SURF speeded-up robust features SVD singular value decomposition

  13. The adaptation of GDL motion recognition system to sport and rehabilitation techniques analysis.

    Science.gov (United States)

    Hachaj, Tomasz; Ogiela, Marek R

    2016-06-01

    The main novelty of this paper is presenting the adaptation of Gesture Description Language (GDL) methodology to sport and rehabilitation data analysis and classification. In this paper we showed that Lua language can be successfully used for adaptation of the GDL classifier to those tasks. The newly applied scripting language allows easily extension and integration of classifier with other software technologies and applications. The obtained execution speed allows using the methodology in the real-time motion capture data processing where capturing frequency differs from 100 Hz to even 500 Hz depending on number of features or classes to be calculated and recognized. Due to this fact the proposed methodology can be used to the high-end motion capture system. We anticipate that using novel, efficient and effective method will highly help both sport trainers and physiotherapist in they practice. The proposed approach can be directly applied to motion capture data kinematics analysis (evaluation of motion without regard to the forces that cause that motion). The ability to apply pattern recognition methods for GDL description can be utilized in virtual reality environment and used for sport training or rehabilitation treatment.

  14. PET motion correction using MR-derived motion parameters

    Energy Technology Data Exchange (ETDEWEB)

    Bickell, Matthew [Department of Nuclear Medicine, Medical Imaging Research Center, KU Leuven (Belgium); Koesters, Thomas; Boada, Fernando [Center for Advanced Imaging Innovation and Research, New York University (United States); Department of Radiology, NYU School of Medicine, New York, Bernard & Irene Schwartz Center for Biomedical Imaging, New York (United States); Nuyts, Johan [Department of Nuclear Medicine, Medical Imaging Research Center, KU Leuven (Belgium)

    2014-07-29

    With the improving resolution of modern PET scanners, any slight motion during the scan can cause significant blurring and loss of resolution. MRI scanners have the capacity to perform quick successive scans and thus provide a means to track motion during a scan. Hence, with the advent of simultaneous PET-MR scanners, it has become possible to use the MR scanner to track the motion and thereby provide the necessary motion parameters to correct the PET data. Using a suitable segmentation approach a separate MR scan can provide the attenuation map to produce quantitative PET images.

  15. Earthquake ground motion: Chapter 3

    Science.gov (United States)

    Luco, Nicolas; Kircher, Charles A.; Crouse, C. B.; Charney, Finley; Haselton, Curt B.; Baker, Jack W.; Zimmerman, Reid; Hooper, John D.; McVitty, William; Taylor, Andy

    2016-01-01

    Most of the effort in seismic design of buildings and other structures is focused on structural design. This chapter addresses another key aspect of the design process—characterization of earthquake ground motion into parameters for use in design. Section 3.1 describes the basis of the earthquake ground motion maps in the Provisions and in ASCE 7 (the Standard). Section 3.2 has examples for the determination of ground motion parameters and spectra for use in design. Section 3.3 describes site-specific ground motion requirements and provides example site-specific design and MCER response spectra and example values of site-specific ground motion parameters. Section 3.4 discusses and provides an example for the selection and scaling of ground motion records for use in various types of response history analysis permitted in the Standard.

  16. Thermophoretic motion behavior of submicron particles in boundary-layer-separation flow around a droplet.

    Science.gov (United States)

    Wang, Ao; Song, Qiang; Ji, Bingqiang; Yao, Qiang

    2015-12-01

    As a key mechanism of submicron particle capture in wet deposition and wet scrubbing processes, thermophoresis is influenced by the flow and temperature fields. Three-dimensional direct numerical simulations were conducted to quantify the characteristics of the flow and temperature fields around a droplet at three droplet Reynolds numbers (Re) that correspond to three typical boundary-layer-separation flows (steady axisymmetric, steady plane-symmetric, and unsteady plane-symmetric flows). The thermophoretic motion of submicron particles was simulated in these cases. Numerical results show that the motion of submicron particles around the droplet and the deposition distribution exhibit different characteristics under three typical flow forms. The motion patterns of particles are dependent on their initial positions in the upstream and flow forms. The patterns of particle motion and deposition are diversified as Re increases. The particle motion pattern, initial position of captured particles, and capture efficiency change periodically, especially during periodic vortex shedding. The key effects of flow forms on particle motion are the shape and stability of the wake behind the droplet. The drag force of fluid and the thermophoretic force in the wake contribute jointly to the deposition of submicron particles after the boundary-layer separation around a droplet.

  17. Investigating the Feasibility of Rapid MRI for Image-Guided Motion Management in Lung Cancer Radiotherapy

    Directory of Open Access Journals (Sweden)

    Amit Sawant

    2014-01-01

    Full Text Available Cycle-to-cycle variations in respiratory motion can cause significant geometric and dosimetric errors in the administration of lung cancer radiation therapy. A common limitation of the current strategies for motion management is that they assume a constant, reproducible respiratory cycle. In this work, we investigate the feasibility of using rapid MRI for providing long-term imaging of the thorax in order to better capture cycle-to-cycle variations. Two nonsmall-cell lung cancer patients were imaged (free-breathing, no extrinsic contrast, and 1.5 T scanner. A balanced steady-state-free-precession (b-SSFP sequence was used to acquire cine-2D and cine-3D (4D images. In the case of Patient 1 (right midlobe lesion, ~40 mm diameter, tumor motion was well correlated with diaphragmatic motion. In the case of Patient 2, (left upper-lobe lesion, ~60 mm diameter, tumor motion was poorly correlated with diaphragmatic motion. Furthermore, the motion of the tumor centroid was poorly correlated with the motion of individual points on the tumor boundary, indicating significant rotation and/or deformation. These studies indicate that image quality and acquisition speed of cine-2D MRI were adequate for motion monitoring. However, significant improvements are required to achieve comparable speeds for truly 4D MRI. Despite several challenges, rapid MRI offers a feasible and attractive tool for noninvasive, long-term motion monitoring.

  18. Making noise: emergent stochasticity in collective motion.

    Science.gov (United States)

    Bode, Nikolai W F; Franks, Daniel W; Wood, A Jamie

    2010-12-07

    Individual-based models of self-propelled particles (SPPs) are a popular and promising approach to explain features of the collective motion of animal aggregations. Many models that capture some features of group motion have been suggested but a common framework has yet to emerge. Key to all of these models is the inclusion of "noise" or stochastic errors in the individual behaviour of the SPPs. Here, we present a fully stochastic SPP model in one dimension that demonstrates a new way of introducing noise into SPP models whilst preserving emergent behaviours of previous models such as coherent groups and spontaneous direction switching. This purely individual-to-individual, local model is related to previous models in the literature and can easily be extended to higher dimensions. Its coarse-grained behaviour qualitatively reproduces recently reported locust movement data. We suggest that our approach offers an alternative to current reasoning about model construction and has the potential to offer mechanistic explanations for emergent properties of animal groups in nature. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Does imminent threat capture and hold attention?

    Science.gov (United States)

    Koster, Ernst H W; Crombez, Geert; Van Damme, Stefaan; Verschuere, Bruno; De Houwer, Jan

    2004-09-01

    According to models of attention and emotion, threat captures and holds attention. In behavioral tasks, robust evidence has been found for attentional holding but not for attentional capture by threat. An important explanation for the absence of attentional capture effects is that the visual stimuli used posed no genuine threat. The present study investigated whether visual cues that signal an aversive white noise can elicit attentional capture and holding effects. Cues presented in an attentional task were simultaneously provided with a threat value through an aversive conditioning procedure. Response latencies showed that threatening cues captured and held attention. These results support recent views on attention to threat, proposing that imminent threat captures attention in everyone. (c) 2004 APA, all rights reserved

  20. Weigh - in - motion (WIM

    Directory of Open Access Journals (Sweden)

    Todorović Neven B.

    2014-01-01

    Full Text Available The biggest wealth of every country lies in its transportation infrastructure so the protection of negative impacts on infrastructure must be provided. The progress of sensor technology proposes today several types of weigh-in-motion systems, which have been tested for their efficiency, accuracy and cost-effectiveness. Technologies of piezoelectric sensors, bending plates and load cells are used for a number of applications comprising weigh enforcement, traffic data collection, bridge and toll control systems and so on. Advantages of using WIM technology are various and its benefits affects all road users (transport companies, public, public transport authorities. Potential of WIM application has been recognized in the leading EU countries, so the existence of the numerous WIM projects.

  1. Techniques for capturing bighorn sheep lambs

    Science.gov (United States)

    Smith, Joshua B.; Walsh, Daniel P.; Goldstein, Elise J.; Parsons, Zachary D.; Karsch, Rebekah C.; Stiver, Julie R.; Cain, James W.; Raedeke, Kenneth J.; Jenks, Jonathan A.

    2014-01-01

    Low lamb recruitment is a major challenge facing managers attempting to mitigate the decline of bighorn sheep (Ovis canadensis), and investigations into the underlying mechanisms are limited because of the inability to readily capture and monitor bighorn sheep lambs. We evaluated 4 capture techniques for bighorn sheep lambs: 1) hand-capture of lambs from radiocollared adult females fitted with vaginal implant transmitters (VITs), 2) hand-capture of lambs of intensively monitored radiocollared adult females, 3) helicopter net-gunning, and 4) hand-capture of lambs from helicopters. During 2010–2012, we successfully captured 90% of lambs from females that retained VITs to ≤1 day of parturition, although we noted differences in capture rates between an area of high road density in the Black Hills (92–100%) of South Dakota, USA, and less accessible areas of New Mexico (71%), USA. Retention of VITs was 78% with pre-partum expulsion the main cause of failure. We were less likely to capture lambs from females that expelled VITs ≥1 day of parturition (range = 80–83%) or females that were collared without VITs (range = 60–78%). We used helicopter net-gunning at several sites in 1999, 2001–2002, and 2011, and it proved a useful technique; however, at one site, attempts to capture lambs led to lamb predation by golden eagles (Aquila chrysaetos). We attempted helicopter hand-captures at one site in 1999, and they also were successful in certain circumstances and avoided risk of physical trauma from net-gunning; however, application was limited. In areas of low accessibility or if personnel lack the ability to monitor females and/or VITs for extended periods, helicopter capture may provide a viable option for lamb capture.

  2. Visual motion influences the contingent auditory motion aftereffect

    NARCIS (Netherlands)

    Vroomen, J.; de Gelder, B.

    2003-01-01

    In this study, we show that the contingent auditory motion aftereffect is strongly influenced by visual motion information. During an induction phase, participants listened to rightward-moving sounds with falling pitch alternated with leftward-moving sounds with rising pitch (or vice versa).

  3. Motion-Matching: A Challenge Game to Generate Motion Concepts

    Science.gov (United States)

    Schuster, David; Adams, Betty; Brookes, David; Milner-Bolotin, Marina; Undreiu, Adriana

    2009-01-01

    Motion is a topic that is taught from elementary grades through to university at various levels of sophistication. It is an area that can be challenging for learning in a conceptually meaningful way, and formal kinematics instruction can sometimes seem dry and boring. Thus, the nature of students' initial introduction to motion is important in…

  4. Smartphone viewing distance and sleep: an experimental study utilizing motion capture technology

    OpenAIRE

    Yoshimura M; Kitazawa M; Maeda Y.; Mimura M; Tsubota K; Kishimoto T

    2017-01-01

    Michitaka Yoshimura,1,* Momoko Kitazawa,1–3,* Yasuhiro Maeda,2 Masaru Mimura,4 Kazuo Tsubota,1 Taishiro Kishimoto,4,5 1Department of Ophthalmology, Keio University School of Medicine, Tokyo, 2RIKEN Center for Advanced Photonics, Wako, Saitama, 3Department of Nursing, Aino University Junior College, 4Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan; 5Department of Psychiatry, Hofstra Northwell School of Medicine, NY, USA *These authors contributed equal...

  5. Modular finger and hand motion capturing system based on inertial and magnetic sensors

    Directory of Open Access Journals (Sweden)

    Valtin Markus

    2017-03-01

    Full Text Available The assessment of hand posture and kinematics is increasingly important in various fields. This includes the rehabilitation of stroke survivors with restricted hand function. This paper presents a modular, ambulatory measurement system for the assement of the remaining hand function and for closed-loop controlled therapy. The device is based on inertial sensors and utilizes up to five interchangeable sensor strips to achieve modularity and to simplify the sensor attachment. We introduce the modular hardware design and describe algorithms used to calculate the joint angles. Measurements with two experimental setups demonstrate the feasibility and the potential of such a tracking device.

  6. Leveraging Two Kinect Sensors for Accurate Full-Body Motion Capture

    National Research Council Canada - National Science Library

    Gao, Zhiquan; Yu, Yao; Zhou, Yu; Du, Sidan

    2015-01-01

    .... Different from previous monocular depth camera systems, we leverage two Kinect sensors to acquire more information about human movements, which ensures that we can still get an accurate estimation...

  7. Estimation of ground reaction forces and moments during gait using only inertial motion capture

    NARCIS (Netherlands)

    Karatsidis, Angelos; Bellusci, Giovanni; Schepers, H. Martin; de Zee, Mark; Andersen, Michael S.; Veltink, Petrus H.

    Ground reaction forces and moments (GRF&M) are important measures used as input in biomechanical analysis to estimate joint kinetics, which often are used to infer information for many musculoskeletal diseases. Their assessment is conventionally achieved using laboratory-based equipment that cannot

  8. Application of a motion capture data glove for hand and wrist ergonomic analysis during laparoscopy.

    Science.gov (United States)

    Sánchez-Margallo, Francisco M; Pérez-Duarte, Francisco J; Sánchez-Margallo, Juan A; Lucas-Hernández, Marcos; Matos-Azevedo, Ana Maria; Díaz-Güemes, Idoia

    2014-12-01

    This study aims to analyze the surgeons' hand spatial configuration during the use of two different instrument handles for laparoscopy, by obtaining information from the data glove CyberGlove®, and establishing existing risk levels for wrist disorders. Fifty surgeons participated in this study and were distributed into three groups (novices, intermediate and experts). Each subject carried out suturing and dissection tasks on a physical simulator, using axial-handled or ring-handled instruments, respectively. Hand and wrist positions were registered by the CyberGlove® and a modified RULA method was applied to establish appropriate risk levels for wrist disorders. We found statistically significant differences in seven of the eleven glove sensors when comparing both tasks. RULA method showed that all subjects, with the exception of the experts using an axial-handled instrument, assume a prejudicial wrist posture during the practice of suturing and dissection tasks on the simulator. Data glove CyberGlove® allows for the distinction between two laparoscopic exercises performed with different instruments. Also, laparoscopic intracorporeal suturing when performed with an axial-handled needle holder entails a more ergonomic posture for the wrist joint. Previous minimally invasive surgical experience is a positive influencing factor on the surgeons' wrist postures during laparoscopy.

  9. Collaborative Embodied Learning in Mixed Reality Motion-Capture Environments: Two Science Studies

    Science.gov (United States)

    Johnson-Glenberg, Mina C.; Birchfield, David A.; Tolentino, Lisa; Koziupa, Tatyana

    2014-01-01

    These 2 studies investigate the extent to which an Embodied Mixed Reality Learning Environment (EMRELE) can enhance science learning compared to regular classroom instruction. Mixed reality means that physical tangible and digital components were present. The content for the EMRELE required that students map abstract concepts and relations onto…

  10. Pengembangan Game Simulasi Tari Kreasi Khas Semarangan dengan Memanfaatkan Sensor Gerak (Motion Capture)

    OpenAIRE

    Rahina Nugrahani; Usreg Tani Utina; Wandah Wibawanto

    2017-01-01

    Pengembangangan game simulasi tari kreasi khas Semarangan ini dilatarbelakangi oleh semakin menurunnya minat dan pengetahuan remaja mengenai kesenian tradisional seperti tari, namun di sisi lain animo remaja pada produk aplikasi game tari (dance game) seperti Pump It Up, Dance Dance Revolution dan Danz Base yang dikembangkan oleh game developer Asing semakin tinggi. Penelitian dilaksanakan dengan mengadaptasi pendekatan Research and Development (R & D.) Kegiatan penelitian dimulai dengan meme...

  11. Perancangan Exoskeleton Motion Capture System Sebagai Panduan Gerakan Tari Pada Robot Humanoid Krsi

    OpenAIRE

    Ir. Nanang SUlistiyanto, MT., Tanshuda Alfauzi., Ir. Nurussa'adah, MT

    2014-01-01

    Kontes Robot Seni Indonesia (KRSI) merupakan suatu ajang kompetisi perancangan dan pembuatan Robot yang disertai dengan unsur-unsur seni dan budaya. Divisi KRSI mengambil tema robot penari untuk menampilkan seni budaya yang diinginkan sesuai dengan tema setiap tahun. Robot KRSI berjenis humanoid, harus mampu menari. Sistem perekam gerakan yang bisa langsung dipasang pada penari profesional atau orang yang mengerti bagaimana gerakan yang artistik dibutuhkan dengan tujuan mendapatkan gerakan Ro...

  12. Smartphone viewing distance and sleep: an experimental study utilizing motion capture technology

    National Research Council Canada - National Science Library

    Yoshimura M; Kitazawa M; Maeda Y; Mimura M; Tsubota K; Kishimoto T

    2017-01-01

    ...: There are studies reporting the negative impact of smartphone utilization on sleep. It is considered that reduction of melatonin secretion under the blue light exposure from smartphone displays is one of the causes...

  13. Embodied science and mixed reality: How gesture and motion capture affect physics education.

    Science.gov (United States)

    Johnson-Glenberg, Mina C; Megowan-Romanowicz, Colleen

    2017-01-01

    A mixed design was created using text and game-like multimedia to instruct in the content of physics. The study assessed which variables predicted learning gains after a 1-h lesson on the electric field. The three manipulated variables were: (1) level of embodiment; (2) level of active generativity; and (3) presence of story narrative. Two types of tests were administered: (1) a traditional text-based physics test answered with a keyboard; and (2) a more embodied, transfer test using the Wacom large tablet where learners could use gestures (long swipes) to create vectors and answers. The 166 participants were randomly assigned to four conditions: (1) symbols and text; (2) low embodied; (3) high embodied/active; or (4) high embodied/active with narrative. The last two conditions were active because the on-screen content could be manipulated with gross body gestures gathered via the Kinect sensor. Results demonstrated that the three groups that included embodiment learned significantly more than the symbols and text group on the traditional keyboard post-test. When knowledge was assessed with the Wacom tablet format that facilitated gestures, the two active gesture-based groups scored significantly higher. In addition, engagement scores were significantly higher for the two active embodied groups. The Wacom results suggest test sensitivity issues; the more embodied test revealed greater gains in learning for the more embodied conditions. We recommend that as more embodied learning comes to the fore, more sensitive tests that incorporate gesture be used to accurately assess learning. The predicted differences in engagement and learning for the condition with the graphically rich story narrative were not supported. We hypothesize that a narrative effect for motivation and learning may be difficult to uncover in a lab experiment where participants are primarily motivated by course credit. Several design principles for mediated and embodied science education are proposed.

  14. AM06-28-009 Flow related Propulsive Motion of a Jellyfish

    OpenAIRE

    市川, 誠司; 望月, 修; Seiji, ICHIKAWA; Osamu, MOCHIZUKI; 東洋大; Toyo University

    2006-01-01

    The purpose of this study is to understand a propulsion mechanism of a jellyfish for applying its mechanism to a soft-matter micro robot. We observed the motion of a jellyfish by a motion-capture camera, and measured the vector field of flow around a jellyfish by using a PIV measurement. A jellyfish is principally propelled by a vortex ring ejected at the contracting phase of a jellyfish motion. If that is true, it is interesting that a jellyfish never stops traveling even at the expanding ph...

  15. Algorithmic Issues in Modeling Motion

    DEFF Research Database (Denmark)

    Agarwal, P. K; Guibas, L. J; Edelsbrunner, H.

    2003-01-01

    This article is a survey of research areas in which motion plays a pivotal role. The aim of the article is to review current approaches to modeling motion together with related data structures and algorithms, and to summarize the challenges that lie ahead in producing a more unified theory...

  16. Rolling motion in moving droplets

    Indian Academy of Sciences (India)

    2015-02-19

    Feb 19, 2015 ... Drops moving on a substrate under the action of gravity display both rolling and sliding motions. The two limits of a thin sheet-like drop in sliding motion on a surface, and a spherical drop in roll, have been extensively studied. We are interested in intermediate shapes. We quantify the contribution of rolling ...

  17. Motion management in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bert, Christoph [GSI, Helmholtzzentrum fuer Schwerionenforschung, Abteilung Biophysik, Darmstadt (Germany)

    2009-07-01

    Radiotherapy of tumors that move during irradiation requires dedicated means to ensure target coverage despite the motion influence. Motion can occur inter-fractionally (e.g. position of the prostate) or intra-fractionally; the most dominant reason for intra-fractional motion is respiration. The standard procedure to reduce the influence of target motion is the use of margins encompassing the clinical target volume (CTV) to form a planning target volume (PTV) that covers all uncertainties. This approach ensures CTV coverage for most treatment modalities but results in therapeutic dose to normal tissue. With the opportunities given by improved imaging techniques such as time-resolved computed tomography (CT) or (cone-beam) CT in treatment position as well as motion mitigation techniques such as gating or tracking the dosimetric influence of target motion could be reduced. Especially for conformal techniques such as intensity modulated radiotherapy (IMRT) or particle therapy only advanced motion mitigation techniques and/or adaptive therapy concepts lead to preservation of the target conformation established for stationary targets in treatments of moving targets. In the scope of the talk an introduction to motion management is given with an emphasis on application in scanned particle beam therapy.

  18. Rigid Motion and Adapted Frames

    Science.gov (United States)

    Lyle, Stephen N.

    The aim here is to describe the rigid motion of a continuous medium in special and general relativity. Section 7.1 defines a rigid rod in special relativity, and Sect. 7.2 shows the link with the space coordinates of a certain kind of accelerating frame in flat spacetimes. Section 7.3 then sets up a notation for describing the arbitrary smooth motion of a continuous medium in general curved spacetimes, defining the proper metric of such a medium. Section 7.4 singles out rigid motions and shows that the rod in Sect. 7.1 undergoes rigid motion in the more generally defined sense. Section 7.5 defines a rate of strain tensor for a continuous medium in general relativity and reformulates the rigidity criterion. Section 7.6 aims to classify all possible rigid motions in special relativity, reemphasizing the link with semi-Euclidean frames adapted to accelerating observers in special relativity. Then, Sects. 7.7 and 7.8 describe rigid motion without rotation and rigid rotation, respectively. Along the way we introduce the notion of Fermi-Walker transport and discuss its relevance for rigid motions. Section 7.9 brings together all the above themes in an account of a recent generalization of the notion of uniform acceleration, thereby characterizing a wide class of rigid motions.

  19. Recent developments in motion planning

    NARCIS (Netherlands)

    Overmars, M.H.

    2002-01-01

    Motion planning is becoming an important topic in many application areas, ranging from robotics to virtual environments and games. In this paper I review some recent results in motion planning, concentrating on the probabilistic roadmap approach that has proven to be very successful for many

  20. Smart Sensor-Based Motion Detection System for Hand Movement Training in Open Surgery.

    Science.gov (United States)

    Sun, Xinyao; Byrns, Simon; Cheng, Irene; Zheng, Bin; Basu, Anup

    2017-02-01

    We introduce a smart sensor-based motion detection technique for objective measurement and assessment of surgical dexterity among users at different experience levels. The goal is to allow trainees to evaluate their performance based on a reference model shared through communication technology, e.g., the Internet, without the physical presence of an evaluating surgeon. While in the current implementation we used a Leap Motion Controller to obtain motion data for analysis, our technique can be applied to motion data captured by other smart sensors, e.g., OptiTrack. To differentiate motions captured from different participants, measurement and assessment in our approach are achieved using two strategies: (1) low level descriptive statistical analysis, and (2) Hidden Markov Model (HMM) classification. Based on our surgical knot tying task experiment, we can conclude that finger motions generated from users with different surgical dexterity, e.g., expert and novice performers, display differences in path length, number of movements and task completion time. In order to validate the discriminatory ability of HMM for classifying different movement patterns, a non-surgical task was included in our analysis. Experimental results demonstrate that our approach had 100 % accuracy in discriminating between expert and novice performances. Our proposed motion analysis technique applied to open surgical procedures is a promising step towards the development of objective computer-assisted assessment and training systems.

  1. Motion Predicts Clinical Callus Formation

    Science.gov (United States)

    Elkins, Jacob; Marsh, J. Lawrence; Lujan, Trevor; Peindl, Richard; Kellam, James; Anderson, Donald D.; Lack, William

    2016-01-01

    Background: Mechanotransduction is theorized to influence fracture-healing, but optimal fracture-site motion is poorly defined. We hypothesized that three-dimensional (3-D) fracture-site motion as estimated by finite element (FE) analysis would influence callus formation for a clinical series of supracondylar femoral fractures treated with locking-plate fixation. Methods: Construct-specific FE modeling simulated 3-D fracture-site motion for sixty-six supracondylar femoral fractures (OTA/AO classification of 33A or 33C) treated at a single institution. Construct stiffness and directional motion through the fracture were investigated to assess the validity of construct stiffness as a surrogate measure of 3-D motion at the fracture site. Callus formation was assessed radiographically for all patients at six, twelve, and twenty-four weeks postoperatively. Univariate and multivariate linear regression analyses examined the effects of longitudinal motion, shear (transverse motion), open fracture, smoking, and diabetes on callus formation. Construct types were compared to determine whether their 3-D motion profile was associated with callus formation. Results: Shear disproportionately increased relative to longitudinal motion with increasing bridge span, which was not predicted by our assessment of construct stiffness alone. Callus formation was not associated with open fracture, smoking, or diabetes at six, twelve, or twenty-four weeks. However, callus formation was associated with 3-D fracture-site motion at twelve and twenty-four weeks. Longitudinal motion promoted callus formation at twelve and twenty-four weeks (p = 0.017 for both). Shear inhibited callus formation at twelve and twenty-four weeks (p = 0.017 and p = 0.022, respectively). Titanium constructs with a short bridge span demonstrated greater longitudinal motion with less shear than did the other constructs, and this was associated with greater callus formation (p callus formation, while shear inhibited

  2. Topographic Structure from Motion

    Science.gov (United States)

    Fonstad, M. A.; Dietrich, J. T.; Courville, B. C.; Jensen, J.; Carbonneau, P.

    2011-12-01

    The production of high-resolution topographic datasets is of increasing concern and application throughout the geomorphic sciences, and river science is no exception. Consequently, a wide range of topographic measurement methods have evolved. Despite the range of available methods, the production of high resolution, high quality digital elevation models (DEMs) generally requires a significant investment in personnel time, hardware and/or software. However, image-based methods such as digital photogrammetry have steadily been decreasing in costs. Initially developed for the purpose of rapid, inexpensive and easy three dimensional surveys of buildings or small objects, the "structure from motion" photogrammetric approach (SfM) is a purely image based method which could deliver a step-change if transferred to river remote sensing, and requires very little training and is extremely inexpensive. Using the online SfM program Microsoft Photosynth, we have created high-resolution digital elevation models (DEM) of rivers from ordinary photographs produced from a multi-step workflow that takes advantage of free and open source software. This process reconstructs real world scenes from SfM algorithms based on the derived positions of the photographs in three-dimensional space. One of the products of the SfM process is a three-dimensional point cloud of features present in the input photographs. This point cloud can be georeferenced from a small number of ground control points collected via GPS in the field. The georeferenced point cloud can then be used to create a variety of digital elevation model products. Among several study sites, we examine the applicability of SfM in the Pedernales River in Texas (USA), where several hundred images taken from a hand-held helikite are used to produce DEMs of the fluvial topographic environment. This test shows that SfM and low-altitude platforms can produce point clouds with point densities considerably better than airborne LiDAR, with

  3. Nonlinear Synchronization for Automatic Learning of 3D Pose Variability in Human Motion Sequences

    Directory of Open Access Journals (Sweden)

    Mozerov M

    2010-01-01

    Full Text Available A dense matching algorithm that solves the problem of synchronizing prerecorded human motion sequences, which show different speeds and accelerations, is proposed. The approach is based on minimization of MRF energy and solves the problem by using Dynamic Programming. Additionally, an optimal sequence is automatically selected from the input dataset to be a time-scale pattern for all other sequences. The paper utilizes an action specific model which automatically learns the variability of 3D human postures observed in a set of training sequences. The model is trained using the public CMU motion capture dataset for the walking action, and a mean walking performance is automatically learnt. Additionally, statistics about the observed variability of the postures and motion direction are also computed at each time step. The synchronized motion sequences are used to learn a model of human motion for action recognition and full-body tracking purposes.

  4. Establishing motion control in children with autism and intellectual disability: Applications for anatomical and functional MRI.

    Science.gov (United States)

    Cox, Alison D; Virues-Ortega, Javier; Julio, Flavia; Martin, Toby L

    2017-01-01

    Excessive motion makes magnetic resonance imaging (MRI) extremely challenging among children with autism spectrum disorder (ASD). The medical risks of sedation establish the need for behavioral interventions to promote motion control among children with ASD undergoing MRI scans. We present a series of experiments aimed at establishing both tolerance of the MRI environment and a level of motion control that would be compatible with a successful MRI. During Study 1, we evaluated the effects of prompting and contingent reinforcement on compliance with a sequence of successive approximations to an MRI using a mock MRI. During Study 2, we used prompting and progressive differential reinforcement of other behaviors (DRO) to promote motion control in a mock MRI for increasing periods of time. Finally, during Study 3, some of the participants underwent a real MRI scan while a detailed in-session motion analysis informed the quality of the images captured. © 2016 Society for the Experimental Analysis of Behavior.

  5. Energy harvesting from walking motion of a humanoid robot using a piezoelectric composite

    Science.gov (United States)

    Cha, Youngsu; Hong, Seokmin

    2016-10-01

    In this paper, we investigate the energy harvesting of a piezoelectric composite in a knee pad during walking motion. We use a humanoid robot as a test bed for the experiments using the knee pad. The humanoid wears the knee pad hosting the piezoelectric composite, and its operating knee motion mimics the walking based on the data captured from a human. The use of the humanoid enables the motion to be completely repeatable. We quantitatively study the energy harvesting by using the repeated motion. An electromechanical model for the piezoelectric energy harvester is used to estimate power transferred to varied load resistances under the repeated knee motion. With a good agreement between the experiments and the model predictions, we demonstrate power harvesting on the order of ten microWatts.

  6. Ocular tracking of biological and nonbiological motion: the effect of instructed agency.

    Science.gov (United States)

    Zwickel, Jan; Hegele, Mathias; Grosjean, Marc

    2012-02-01

    Recent findings suggest that visuomotor performance is modulated by people's beliefs about the agency (e.g., animate vs. inanimate) behind the events they perceive. This study investigated the effect of instructed agency on ocular tracking of point-light motions with biological and nonbiological velocity profiles. The motions followed either a relatively simple (ellipse) or a more complex (scribble) trajectory, and agency was manipulated by informing the participants that the motions they saw were either human or computer generated. In line with previous findings, tracking performance was better for biological than for nonbiological motions, and this effect was particularly pronounced for the simpler (elliptical) motions. The biological advantage was also larger for the human than for the computer instruction condition, but only for a measure that captured the predictive component of smooth pursuit. These results suggest that ocular tracking is influenced by the internal forward model people choose to adopt.

  7. The Perception of Auditory Motion

    Science.gov (United States)

    Leung, Johahn

    2016-01-01

    The growing availability of efficient and relatively inexpensive virtual auditory display technology has provided new research platforms to explore the perception of auditory motion. At the same time, deployment of these technologies in command and control as well as in entertainment roles is generating an increasing need to better understand the complex processes underlying auditory motion perception. This is a particularly challenging processing feat because it involves the rapid deconvolution of the relative change in the locations of sound sources produced by rotational and translations of the head in space (self-motion) to enable the perception of actual source motion. The fact that we perceive our auditory world to be stable despite almost continual movement of the head demonstrates the efficiency and effectiveness of this process. This review examines the acoustical basis of auditory motion perception and a wide range of psychophysical, electrophysiological, and cortical imaging studies that have probed the limits and possible mechanisms underlying this perception. PMID:27094029

  8. An effective box trap for capturing lynx

    Science.gov (United States)

    Jay A. Kolbe; John R. Squires; Thomas W. Parker

    2003-01-01

    We designed a box trap for capturing lynx (Lynx lynx) that is lightweight, safe, effective, and less expensive than many commercial models. It can be constructed in approximately 3-4 hours from readily available materials. We used this trap to capture 40 lynx 89 times (96% of lynx entering traps) and observed no trapping related injuries. We compare our box...

  9. Radiative proton capture on He-6

    NARCIS (Netherlands)

    Sauvan, E.; Marqués, F.M.; Wilschut, H.W.; Orr, N.A.; Angelique, J.C.; Borcea, C.; Catford, W.N.; Clarke, N.M.; Descouvemont, P.; Diaz, J.; Grevy, S.; Kugler, A.; Kravchuk, V.; Labiche, M.; Le Brun, C.; Lienard, E.; Löhner, H.; Mittig, W.; Ostendorf, R.W.; Pietri, S.; Roussel-Chomaz, P.; Saint Laurent, M.G.; Savajols, H.; Wagner, V.; Yahlali, N.

    2001-01-01

    Radiative capture of protons is investigated as a probe of clustering in nuclei far from stability. The first such measurement on a halo nucleus is reported here for the reaction He-6(p, gamma) at 40 MeV. Capture into Li-7 is observed as the strongest channel. In addition, events have been recorded

  10. Motion words selectively modulate direction discrimination sensitivity for threshold motion

    Science.gov (United States)

    Pavan, Andrea; Skujevskis, Māris; Baggio, Giosuè

    2013-01-01

    Can speech selectively modulate the sensitivity of a sensory system so that, in the presence of a suitable linguistic context, the discrimination of certain perceptual features becomes more or less likely? In this study, participants heard upward or downward motion words followed by a single visual field of random dots moving upwards or downwards. The time interval between the onsets of the auditory and the visual stimuli was varied parametrically. Motion direction could be either discriminable (suprathreshold motion) or non-discriminable (threshold motion). Participants had to judge whether the dots were moving upward or downward. Results show a double dissociation between discrimination sensitivity (d′) and reaction times depending on whether vertical motion was above or at threshold. With suprathreshold motion, responses were faster for congruent directions of words and dots, but sensitivity was equal across conditions. With threshold motion, sensitivity was higher for congruent directions of words and dots, but responses were equally fast across conditions. The observed differences in sensitivity and response times were largest when the dots appeared 450 ms after word onset, that is, consistently with electrophysiology, at the time the up/down semantics of the word had become available. These data suggest that word meanings can alter the balance between signal and noise within the visual system and affect the perception of low-level sensory features. PMID:23596407

  11. Capturing intraoperative deformations: research experience at Brigham and Women's Hospital.

    Science.gov (United States)

    Warfield, Simon K; Haker, Steven J; Talos, Ion-Florin; Kemper, Corey A; Weisenfeld, Neil; Mewes, Andrea U J; Goldberg-Zimring, Daniel; Zou, Kelly H; Westin, Carl-Fredrik; Wells, William M; Tempany, Clare M C; Golby, Alexandra; Black, Peter M; Jolesz, Ferenc A; Kikinis, Ron

    2005-04-01

    During neurosurgical procedures the objective of the neurosurgeon is to achieve the resection of as much diseased tissue as possible while achieving the preservation of healthy brain tissue. The restricted capacity of the conventional operating room to enable the surgeon to visualize critical healthy brain structures and tumor margin has lead, over the past decade, to the development of sophisticated intraoperative imaging techniques to enhance visualization. However, both rigid motion due to patient placement and nonrigid deformations occurring as a consequence of the surgical intervention disrupt the correspondence between preoperative data used to plan surgery and the intraoperative configuration of the patient's brain. Similar challenges are faced in other interventional therapies, such as in cryoablation of the liver, or biopsy of the prostate. We have developed algorithms to model the motion of key anatomical structures and system implementations that enable us to estimate the deformation of the critical anatomy from sequences of volumetric images and to prepare updated fused visualizations of preoperative and intraoperative images at a rate compatible with surgical decision making. This paper reviews the experience at Brigham and Women's Hospital through the process of developing and applying novel algorithms for capturing intraoperative deformations in support of image guided therapy.

  12. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone....... The CO2 capture capacity of limestone in the raw meal is lower than for pure limestone. The difference in the CO2 capture capacity decreases with an increase in cycle number. The calcination conditions and composition are major factors that influence the CO2 capture capacity of limestone. At 850 °C in N2...

  13. Encapsulated liquid sorbents for carbon dioxide capture.

    Science.gov (United States)

    Vericella, John J; Baker, Sarah E; Stolaroff, Joshuah K; Duoss, Eric B; Hardin, James O; Lewicki, James; Glogowski, Elizabeth; Floyd, William C; Valdez, Carlos A; Smith, William L; Satcher, Joe H; Bourcier, William L; Spadaccini, Christopher M; Lewis, Jennifer A; Aines, Roger D

    2015-02-05

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  14. Suitability of digital camcorders for virtual reality image data capture

    Science.gov (United States)

    D'Apuzzo, Nicola; Maas, Hans-Gerd

    1998-12-01

    Today's consumer market digital camcorders offer features which make them appear quite interesting devices for virtual reality data capture. The paper compares a digital camcorder with an analogue camcorder and a machine vision type CCD camera and discusses the suitability of these three cameras for virtual reality applications. Besides the discussion of technical features of the cameras, this includes a detailed accuracy test in order to define the range of applications. In combination with the cameras, three different framegrabbers are tested. The geometric accuracy potential of all three cameras turned out to be surprisingly large, and no problems were noticed in the radiometric performance. On the other hand, some disadvantages have to be reported: from the photogrammetrists point of view, the major disadvantage of most camcorders is the missing possibility to synchronize multiple devices, limiting the suitability for 3-D motion data capture. Moreover, the standard video format contains interlacing, which is also undesirable for all applications dealing with moving objects or moving cameras. Further disadvantages are computer interfaces with functionality, which is still suboptimal. While custom-made solutions to these problems are probably rather expensive (and will make potential users turn back to machine vision like equipment), this functionality could probably be included by the manufacturers at almost zero cost.

  15. Prey detection and prey capture in copepod nauplii.

    Directory of Open Access Journals (Sweden)

    Eleonora Bruno

    Full Text Available Copepod nauplii are either ambush feeders that feed on motile prey or they produce a feeding current that entrains prey cells. It is unclear how ambush and feeding-current feeding nauplii perceive and capture prey. Attack jumps in ambush feeding nauplii should not be feasible at low Reynolds numbers due to the thick viscous boundary layer surrounding the attacking nauplius. We use high-speed video to describe the detection and capture of phytoplankton prey by the nauplii of two ambush feeding species (Acartia tonsa and Oithona davisae and by the nauplii of one feeding-current feeding species (Temora longicornis. We demonstrate that the ambush feeders both detect motile prey remotely. Prey detection elicits an attack jump, but the jump is not directly towards the prey, such as has been described for adult copepods. Rather, the nauplius jumps past the prey and sets up an intermittent feeding current that pulls in the prey from behind towards the mouth. The feeding-current feeding nauplius detects prey arriving in the feeding current but only when the prey is intercepted by the setae on the feeding appendages. This elicits an altered motion pattern of the feeding appendages that draws in the prey.

  16. 49 CFR 230.105 - Lateral motion.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lateral motion. 230.105 Section 230.105... Tenders Running Gear § 230.105 Lateral motion. (a) Condemning limits. The total lateral motion or play... require additional lateral motion. (c) Non-interference with other parts. The lateral motion shall in all...

  17. Optimization of wave energy capture of wave-powered navigational lighting buoys of seadromes

    Directory of Open Access Journals (Sweden)

    WANG Guangda

    2017-12-01

    Full Text Available [Objectives] This paper proposes an optimized design for wave-power navigational lighting buoys of seadromes.[Methods] Based on the theory of three-dimensional potential flow, the buoyant motion response of a buoy is calculated. A type of array of wave-power navigational lighting buoys located in an offshore seadrome is proposed,and a procedure for the design optimization of its component buoys is presented. Matching the best Power Take-Off(PTO damping, the diameter to draft ratio and array distance with the best energy capture width ratio are acquired, and the energy capture for the short-term forecast of the buoy array is accomplished. On this basis, combined with the actual sea conditions, energy capture for the long-term forecast of an individual buoy is accomplished. The influence of the buoy diameter, buoy draft and array distance on the energy capture width ratio is discussed.[Results] The results show that the energy capture width ratio is at its greatest when the diameter to draft ratio is between 2.4-2.6; the smaller the distance between array buoys, the greater the energy capture width of each buoy.[Conclusions] The results can provide a reference and suggestions for the optimization of the design of wave energy generation for arrays buoy.

  18. CT Reconstruction from Simultaneous Projections: A Step towards Capturing CT in One Go

    CERN Document Server

    Saha, Sajib; Lambert, Andrew; Pickering, Mark

    2014-01-01

    This paper focuses on minimizing the time requirement for CT capture through innovative simultaneous x-ray capture method. The state-of-the-art CT imaging methodology captures a sequence of projections during which the internal organ movements may lead to poor reconstruction due to motion artefacts. Traditional CT scanners' minimize such effect by taking more projections than necessary. In this work we focus on an innovative CT capture method that captures projections simultaneously, promising super fast scans along with possible radiation dose reductions. While the simultaneous CT capture model has already been proposed in our earlier work 'Multi-axial CT Reconstruction from Few View Projections' (in SPIE Optical Engineering and Applications, pp. 85000A-85000A. International Society for Optics and Photonics, 2012) and 'A New Imaging Method for Real-time 3D X-ray Reconstruction' (in SPIE Medical Imaging, pp. 86685G-86685G. International Society for Optics and Photonics, 2013), in this work we enhance the mode...

  19. The Capturing of Space Debris with a Spaceborne Multi-fingered Gripper

    Directory of Open Access Journals (Sweden)

    Zhang Yin

    2017-01-01

    Full Text Available With the massive launching of spacecraft, more and more space debris are making the low Earth orbit (LEO much more crowded which seriously affects the normal flight of other spacecrafts. Space debris removal has become a very urgent issue concerned by numerous countries. In this paper, using SwissCube as a target, the capturing of space debris with a spaceborne four-fingered gripper was studied in order to obtain the key factors that affect the capturing effect. The contact state between the gripper fingers and SwissCube was described using a defined contact matrix. The law of momentum conservation was used to model the motion variations of the gripper and SwissCube before and after the capturing process. A zero-gravity simulation environment was built using ADAMS software. Two typical kinds of capturing processes were simulated considering different stiffness of fingers and different friction conditions between fingers and SwissCube. Comparisons between results obtained with the law of momentum conservation and those from ADAMS simulation show that the theoretical calculations and simulation results are consistent. In addition, through analyzing the capturing process, a valuable finding was obtained that the contact friction and finger flexibility are two very important factors that affect the capturing result.

  20. Predictions to motion stimuli in human early visual cortex : Effects of motion displacement on motion predictability

    NARCIS (Netherlands)

    Schellekens, W.|info:eu-repo/dai/nl/413971309; Ramsey, N. F.|info:eu-repo/dai/nl/07313774X; Raemaekers, M.|info:eu-repo/dai/nl/31370709X

    2015-01-01

    Recently, several studies showed that fMRI BOLD responses to moving random dot stimuli are enhanced at the location of dot appearance, i.e., the motion trailing edge. Possibly, BOLD activity in human visual cortex reflects predictability of visual motion input. In the current study, we investigate