Dimensional Synthesis of a Passive Eight-Bar Slider Exo-Limb for Grasping Tasks

2016 ◽  
Author(s):  
Guan Rong Tan ◽  
Nina Robson ◽  
Gim Song Soh
Keyword(s):  
Motion Capture ◽  
Index Finger ◽  
Synthesis Method ◽  
Wearable Devices ◽  
Least Square ◽  
Dimensional Synthesis ◽  
Infra Red ◽  
Optical Motion ◽  
3D Printed ◽  
Optical Motion Capture

This paper describes a dimensional synthesis method used in the design of a passively actuated finger exoskeleton that takes into account the user limb anthropometric dimensions and contact requirements for grasping objects. The paper is the first step in our current efforts on design of wearable devices that use a common slider at the hand to passively actuate each exo-finger. The finger exoskeleton is comprised of a 3R serial limb and is constrained to an eight-bar slider mechanism. To design the exo-limb, the pose of the index finger was captured using an optical motion capture and its dimensions were determined using a constrained least square optimization of its center of rotation. To facilitate the data capture, a 3D printed wearable Infra-red (IR) marker system was designed and placed on the finger’s phalanx. To illustrate the approach, an example of the design of an index exo-finger is described.

scholarly journals Motion Generation of Passive Slider Multiloop Wearable Hand Devices

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Guan Rong Tan ◽  
Nina Patarinsky Robson ◽  
Gim Song Soh
Keyword(s):  
Human Skin ◽  
Motion Capture ◽  
Synthesis Method ◽  
Middle Finger ◽  
Wearable Devices ◽  
Least Square ◽  
Dimensional Synthesis ◽  
Motion Generation ◽  
Optical Motion ◽  
Optical Motion Capture

This paper describes a dimensional synthesis method used in the design of a passive finger exoskeleton that takes into account the user limb anthropometric dimensions and contact requirements for grasping objects. The paper is the first step in our current efforts on the design of wearable devices that use a common slider at the hand to passively drive each exofinger. The finger exoskeleton is comprised of a 3R serial limb and is constrained to multiloop eight-bar slider mechanism using two RR constraints. To design the exolimb, the pose of the limb was captured using an optical motion capture and its dimensions were determined using a constrained least square optimization, which takes into account human skin movement. To illustrate the generality of our approach, an example of the design of an index and middle finger exolimb is described.

scholarly journals Accuracy of a Low-Cost 3D-Printed Wearable Goniometer for Measuring Wrist Motion

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4799
Author(s):  
Calvin Young ◽  
Sarah DeDecker ◽  
Drew Anderson ◽  
Michele L. Oliver ◽  
Karen D. Gordon
Keyword(s):  
Motion Capture ◽  
Low Cost ◽  
Wearable Device ◽  
Matching Task ◽  
Motion Capture System ◽  
Wrist Motion ◽  
Flexion Extension ◽  
Optical Motion ◽  
3D Printed ◽  
Optical Motion Capture

Wrist motion provides an important metric for disease monitoring and occupational risk assessment. The collection of wrist kinematics in occupational or other real-world environments could augment traditional observational or video-analysis based assessment. We have developed a low-cost 3D printed wearable device, capable of being produced on consumer grade desktop 3D printers. Here we present a preliminary validation of the device against a gold standard optical motion capture system. Data were collected from 10 participants performing a static angle matching task while seated at a desk. The wearable device output was significantly correlated with the optical motion capture system yielding a coefficient of determination (R2) of 0.991 and 0.972 for flexion/extension (FE) and radial/ulnar deviation (RUD) respectively (p < 0.0001). Error was similarly low with a root mean squared error of 4.9° (FE) and 3.9° (RUD). Agreement between the two systems was quantified using Bland–Altman analysis, with bias and 95% limits of agreement of 3.1° ± 7.4° and −0.16° ± 7.7° for FE and RUD, respectively. These results compare favourably with current methods for occupational assessment, suggesting strong potential for field implementation.

scholarly journals Biomechanical Evaluation and Strength Test of 3D-Printed Foot Orthoses

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Kuang-Wei Lin ◽  
Chia-Jung Hu ◽  
Wen-Wen Yang ◽  
Li-Wei Chou ◽  
Shun-Hwa Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Motion Capture ◽  
Reaction Force ◽  
Three Dimensional ◽  
Compressive Load ◽  
Foot Orthoses ◽  
Significant Difference ◽  
Optical Motion ◽  
3D Printed ◽  
Optical Motion Capture

Foot orthoses (FOs) are commonly used as interventions for individuals with flatfoot. Advances in technologies such as three-dimensional (3D) scanning and 3D printing have facilitated the fabrication of custom FOs. However, few studies have been conducted on the mechanical properties and biomechanical effects of 3D-printed FOs. The purposes of this study were to evaluate the mechanical properties of 3D-printed FOs and determine their biomechanical effects in individuals with flexible flatfoot. During mechanical testing, a total of 18 FO samples with three orientations (0°, 45°, and 90°) were fabricated and tested. The maximum compressive load and stiffness were calculated. During a motion capture experiment, 12 individuals with flatfoot were enrolled, and the 3D-printed FOs were used as interventions. Kinematic and kinetic data were collected during walking by using an optical motion capture system. A one-way analysis of variance was performed to compare the mechanical parameters among the three build orientations. A paired t-test was conducted to compare the biomechanical variables under two conditions: walking in standard shoes (Shoe) and walking in shoes embedded with FOs (Shoe+FO). The results indicated that the 45° build orientation produced the strongest FOs. In addition, the maximum ankle evertor and external rotator moments under the Shoe+FO condition were significantly reduced by 35% and 16%, respectively, but the maximum ankle plantar flexor moments increased by 3%, compared with the Shoe condition. No significant difference in ground reaction force was observed between the two conditions. This study demonstrated that 3D-printed FOs could alter the ankle joint moments during gait.

scholarly journals Gap Reconstruction in Optical Motion Capture Sequences Using Neural Networks

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6115
Author(s):  
Przemysław Skurowski ◽  
Magdalena Pawlyta
Keyword(s):  
Neural Networks ◽  
Motion Capture ◽  
Matrix Completion ◽  
Input Sequence ◽  
Feedforward Neural Networks ◽  
Network Architectures ◽  
Motion Data ◽  
Optical Motion ◽  
Body Kinematic ◽  
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.

scholarly journals Use of computer innovative technologies in improving the dartsmen training

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.

Human Motion Capture Driven by Orientation Measurements

1999 ◽  
Vol 8 (2) ◽  
pp. 187-203 ◽  
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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