Graph Matching for Marker Labelling and Missing Marker Reconstruction with Bone Constraint by LSTM in Optical Motion Capture

Optical motion capture is a mature contemporary technique for the acquisition of motion data; alas, it is non-error-free. Due to technical limitations and occlusions of markers, gaps might occur in such recordings. The article reviews various neural network architectures applied to the gap-filling problem in motion capture sequences within the FBM framework providing a representation of body kinematic structure. The results are compared with interpolation and matrix completion methods. We found out that, for longer sequences, simple linear feedforward neural networks can outperform the other, sophisticated architectures, but these outcomes might be affected by the small amount of data availabe for training. We were also able to identify that the acceleration and monotonicity of input sequence are the parameters that have a notable impact on the obtained results.

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Use of computer innovative technologies in improving the dartsmen training

BIO Web of Conferences ◽

10.1051/bioconf/20202600061 ◽

2020 ◽

Vol 26 ◽

pp. 00061

Author(s):

Elina Makarova ◽

Vladislav Dubatovkin ◽

Nataliya Berezinskaya ◽

Lyudmila Barkhatova ◽

Elena Oleynik

Keyword(s):

Motion Capture ◽

Body Parts ◽

Visual Material ◽

Video Cameras ◽

Dart Throwing ◽

Optical Motion ◽

Optical Motion Capture ◽

Effective Use ◽

Near Future ◽

Motion Capture Systems

The research is focused on studying the possibility of effective use of the dart grip system, the work of the athlete’s hand, to prepare the dartsman for competitions using the MOSAR complex. The experiment uses optical motion capture systems, a set of video cameras, led parameter sensors, and devices that allow to record the movement of body parts and a dart. This method of training and controlling dart throwing can serve as educational and visual material for training future athletes. The use of such motion capture systems in the near future may become one of the main aspects of training, both beginners and professionals, in many sports.

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Human Motion Capture Driven by Orientation Measurements

Presence Teleoperators & Virtual Environments ◽

10.1162/105474699566161 ◽

1999 ◽

Vol 8 (2) ◽

pp. 187-203 ◽

Cited By ~ 24

Author(s):

Tom Molet ◽

Ronan Boulic ◽

Daniel Thalmann

Keyword(s):

Motion Capture ◽

Human Motion ◽

High Rate ◽

Position Measurement ◽

Human Motion Capture ◽

Fast Tracking ◽

Optical Motion ◽

Optical Motion Capture ◽

Tracking Object ◽

Capture Techniques

Motion-capture techniques are rarely based on orientation measurements for two main reasons: (1) optical motion-capture systems are designed for tracking object position rather than their orientation (which can be deduced from several trackers), (2) known animation techniques, like inverse kinematics or geometric algorithms, require position targets constantly, but orientation inputs only occasionally. We propose a complete human motion-capture technique based essentially on orientation measurements. The position measurement is used only for recovering the global position of the performer. This method allows fast tracking of human gestures for interactive applications as well as high rate recording. Several motion-capture optimizations, including the multijoint technique, improve the posture realism. This work is well suited for magnetic-based systems that rely more on orientation registration (in our environment) than position measurements that necessitate difficult system calibration.

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Measuring Spinal Mobility Using an Inertial Measurement Unit System: A Validation Study in Axial Spondyloarthritis

Diagnostics ◽

10.3390/diagnostics10060426 ◽

2020 ◽

Vol 10 (6) ◽

pp. 426

Author(s):

I. Concepción Aranda-Valera ◽

Antonio Cuesta-Vargas ◽

Juan L. Garrido-Castro ◽

Philip V. Gardiner ◽

Clementina López-Medina ◽

...

Keyword(s):

Outcome Measures ◽

Motion Capture ◽

Axial Spondyloarthritis ◽

Human Motion ◽

Spinal Mobility ◽

Measurement Unit ◽

Human Motion Analysis ◽

Inertial Measurement ◽

Optical Motion ◽

Optical Motion Capture

Portable inertial measurement units (IMUs) are beginning to be used in human motion analysis. These devices can be useful for the evaluation of spinal mobility in individuals with axial spondyloarthritis (axSpA). The objectives of this study were to assess (a) concurrent criterion validity in individuals with axSpA by comparing spinal mobility measured by an IMU sensor-based system vs. optical motion capture as the reference standard; (b) discriminant validity comparing mobility with healthy volunteers; (c) construct validity by comparing mobility results with relevant outcome measures. A total of 70 participants with axSpA and 20 healthy controls were included. Individuals with axSpA completed function and activity questionnaires, and their mobility was measured using conventional metrology for axSpA, an optical motion capture system, and an IMU sensor-based system. The UCOASMI, a metrology index based on measures obtained by motion capture, and the IUCOASMI, the same index using IMU measures, were also calculated. Descriptive and inferential analyses were conducted to show the relationships between outcome measures. There was excellent agreement (ICC > 0.90) between both systems and a significant correlation between the IUCOASMI and conventional metrology (r = 0.91), activity (r = 0.40), function (r = 0.62), quality of life (r = 0.55) and structural change (r = 0.76). This study demonstrates the validity of an IMU system to evaluate spinal mobility in axSpA. These systems are more feasible than optical motion capture systems, and they could be useful in clinical practice.

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Comparative Analysis of Inertial Sensor to Optical Motion Capture System Performance in Push-Pull Exertion Postures

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1541931213601224 ◽

2016 ◽

Vol 60 (1) ◽

pp. 970-974 ◽

Cited By ~ 1

Author(s):

Sol Lim ◽

Andrea Case ◽

Clive D’Souza

Keyword(s):

Motion Capture ◽

Inertial Sensors ◽

Inertial Sensor ◽

Interactive Effects ◽

Flexion Angle ◽

Task Demand ◽

Optical Motion ◽

Physical Task ◽

Target Force ◽

Optical Motion Capture

This study examined interactions between inertial sensor (IS) performance and physical task demand on posture kinematics in a two-handed force exertion task. Fifteen male individuals participated in a laboratory experiment that involved exerting a two-handed isometric horizontal force on an instrumented height-adjustable handle. Physical task demand was operationalized by manipulating vertical handle height, target force magnitude, and force direction. These factors were hypothesized to influence average estimates of torso flexion angle measured using inertial sensors and an optical motion capture (MC) system, as well as the root mean squared errors (RMSE) between instrumentation computed over a 3s interval of the force exertion task. Results indicate that lower handle heights and higher target force levels were associated with increased torso and pelvic flexion in both, push and pull exertions. Torso flexion angle estimates obtained from IS and MC did not differ significantly. However, RMSE increased with target force intensity suggesting potential interactive effects between measurement error and physical task demand.

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Finger-String Interaction Analysis in Guitar Playing With Optical Motion Capture

Frontiers in Computer Science ◽

10.3389/fcomp.2019.00008 ◽

2019 ◽

Vol 1 ◽

Author(s):

Alfonso Perez-Carrillo

Keyword(s):

Motion Capture ◽

Interaction Analysis ◽

Optical Motion ◽

Optical Motion Capture

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IMU gyroscopes are a valid alternative to 3D optical motion capture system for angular kinematics analysis in tennis

Proceedings of the Institution of Mechanical Engineers Part P Journal of Sports Engineering and Technology ◽

10.1177/1754337120965444 ◽

2020 ◽

pp. 175433712096544 ◽

Cited By ~ 1

Author(s):

Gabriel Delgado-García ◽

Jos Vanrenterghem ◽

Emilio J Ruiz-Malagón ◽

Pablo Molina-García ◽

Javier Courel-Ibáñez ◽

...

Keyword(s):

Angular Velocity ◽

Motion Capture ◽

Correlation Coefficients ◽

Strong Relationship ◽

System Level ◽

Optical Motion ◽

Measurement Units ◽

The Difference ◽

Optical Motion Capture ◽

Level Of Agreement

Whereas 3D optical motion capture (OMC) systems are considered the gold standard for kinematic assessment in sport science, they present some drawbacks that limit its use in the field. Inertial measurement units (IMUs) incorporating gyroscopes have been considered as a more practical alternative. Thus, the aim of the study was to evaluate the level of agreement for angular velocity between IMU gyroscopes and an OMC system for varying tennis strokes and intensities. In total, 240 signals of angular velocity from different body segments and types of strokes (forehand, backhand and service) were recorded from four players (two competition players and two beginners). The angular velocity of the IMU gyroscopes was compared to the angular velocity from the OMC system. Level of agreement was evaluated by correlation coefficients, magnitudes of errors in absolute and relative values and Bland-Altman plots. Differences between both systems were highly consistent within players’ skill (i.e. along the broad range of velocities) and axes ( x, y, z). Correlations ranged from 0.951 to 0.993, indicating a very strong relationship and concordance. The magnitude of the differences ranged from 4.4 to 35.4 deg·s−1. The difference relative to the maximum angular velocity achieved was less than 5.0%. The study concluded that IMUs and OMC systems showed comparable values. Thus, IMUs seem to be a valid alternative to detect meaningful differences in angular velocity during tennis groundstrokes in field-based experimentation.

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