scholarly journals Functional Evaluation of a Force Sensor-Controlled Upper-Limb Power-Assisted Exoskeleton with High Backdrivability

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6379 ◽  
Author(s):  
Chang Liu ◽  
Hongbo Liang ◽  
Naoya Ueda ◽  
Peirang Li ◽  
Yasutaka Fujimoto ◽  
...  
Keyword(s):  
Motion Capture ◽  
Upper Limb ◽  
Surface Electromyography ◽  
Joint Angle ◽  
Subsequent Development ◽  
Force Sensor ◽  
Functional Evaluation ◽  
Motion Capture System ◽  
Pros And Cons ◽  
Power Assistance

A power-assisted exoskeleton should be capable of reducing the burden on the wearer’s body or rendering his or her work improved and efficient. More specifically, the exoskeleton should be easy to wear, be simple to use, and provide power assistance without hindering the wearer’s movement. Therefore, it is necessary to evaluate the backdrivability, range of motion, and power-assist capability of such an exoskeleton. This evaluation identifies the pros and cons of the exoskeleton, and it serves as the basis for its subsequent development. In this study, a lightweight upper-limb power-assisted exoskeleton with high backdrivability was developed. Moreover, a motion capture system was adopted to measure and analyze the workspace of the wearer’s upper limb after the exoskeleton was worn. The results were used to evaluate the exoskeleton’s ability to support the wearer’s movement. Furthermore, a small and compact three-axis force sensor was used for power assistance, and the effect of the power assistance was evaluated by means of measuring the wearer’s surface electromyography, force, and joint angle signals. Overall, the study showed that the exoskeleton could achieve power assistance and did not affect the wearer’s movements.

scholarly journals Architecture proposal for a support system to upper limb telerehabilitation by capturing biomechanical signals

2015 ◽  
Vol 24 (40) ◽  
pp. 41
Author(s):  
Mauro Callejas-Cuervo ◽  
Manuel Andrés Vélez-Guerrero ◽  
Andrés Felipe Ruíz-Olaya ◽  
Rafael María Gutiérrez-Salamanca
Keyword(s):  
Kalman Filter ◽  
Literature Review ◽  
Motion Capture ◽  
Upper Limb ◽  
Joint Angle ◽  
Inertial Sensors ◽  
Motor Disorders ◽  
Motion Capture System ◽  
Active Videogames ◽  
Therapy Service

<p>This article proposes a system for Telerehabilitation of people with motor disorders of the upper limb, by making a literature review about works related with the provision of the physical therapy service with ICT’s use. Likewise, there is a brief description of the modules integrating the system: motion capture system based on inertial sensors and motion capture with camera; joint angle estimator was implemented through Kalman filter; IT app which registers the electronic medical record and finally, the active videogames module.</p>

scholarly journals Placement Recommendations for Single Kinect-Based Motion Capture System in Unilateral Dynamic Motion Analysis

Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1076
Author(s):  
Laisi Cai ◽  
Dongwei Liu ◽  
Ye Ma
Keyword(s):  
Motion Analysis ◽  
Motion Capture ◽  
Upper Limb ◽  
Kinematic Model ◽  
Sensor Placement ◽  
Motion Capture System ◽  
Kinect Sensor ◽  
3D Motion ◽  
Flexion Extension ◽  
3D Motion Capture

Low-cost, portable, and easy-to-use Kinect-based systems achieved great popularity in out-of-the-lab motion analysis. The placement of a Kinect sensor significantly influences the accuracy in measuring kinematic parameters for dynamics tasks. We conducted an experiment to investigate the impact of sensor placement on the accuracy of upper limb kinematics during a typical upper limb functional task, the drinking task. Using a 3D motion capture system as the golden standard, we tested twenty-one Kinect positions with three different distances and seven orientations. Upper limb joint angles, including shoulder flexion/extension, shoulder adduction/abduction, shoulder internal/external rotation, and elbow flexion/extension angles, are calculated via our developed Kinect kinematic model and the UWA kinematic model for both the Kinect-based system and the 3D motion capture system. We extracted the angles at the point of the target achieved (PTA). The mean-absolute-error (MEA) with the standard represents the Kinect-based system’s performance. We conducted a two-way repeated measure ANOVA to explore the impacts of distance and orientation on the MEAs for all upper limb angles. There is a significant main effect for orientation. The main effects for distance and the interaction effects do not reach statistical significance. The post hoc test using LSD test for orientation shows that the effect of orientation is joint-dependent and plane-dependent. For a complex task (e.g., drinking), which involves body occlusions, placing a Kinect sensor right in front of a subject is not a good choice. We suggest that place a Kinect sensor at the contralateral side of a subject with the orientation around 30∘ to 45∘ for upper limb functional tasks. For all kinds of dynamic tasks, we put forward the following recommendations for the placement of a Kinect sensor. First, set an optimal sensor position for capture, making sure that all investigated joints are visible during the whole task. Second, sensor placement should avoid body occlusion at the maximum extension. Third, if an optimal location cannot be achieved in an out-of-the-lab environment, researchers could put the Kinect sensor at an optimal orientation by trading off the factor of distance. Last, for those need to assess functions of both limbs, the users can relocate the sensor and re-evaluate the functions of the other side once they finish evaluating functions of one side of a subject.

Comparing 3 Different Foot Models for Ankle Joint Motion during Gait

2013 ◽  
Vol 440 ◽  
pp. 135-139
Author(s):  
Hai Bin Liu ◽  
Zhi Qiang He ◽  
Wen Xue Yuan ◽  
Zhou Yang
Keyword(s):  
Ankle Joint ◽  
Motion Capture ◽  
Joint Angle ◽  
Joint Motion ◽  
Motion Capture System ◽  
Motion System ◽  
Correct Definition ◽  
Ankle Joint Motion

Objective is to study different foot models and their corresponding parameters, provide references for foot segment and give the correct definition for ankle joint angle. Methods: The data were captured and analyzed by Vicon Motion System, and compute the joint angle parameters. Conclusion: The Toe Model is no suit for constructing ankle joint, MidJoint Model only for high equipped motion capture system and Phalange Model should be recommended after verification.

scholarly journals A Lightweight Exoskeleton-Based Portable Gait Data Collection System

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 781
Author(s):  
Md Rejwanul Haque ◽  
Masudul H. Imtiaz ◽  
Samuel T. Kwak ◽  
Edward Sazonov ◽  
Young-Hui Chang ◽  
...  
Keyword(s):  
Data Collection ◽  
Motion Capture ◽  
Lower Limb ◽  
Joint Angle ◽  
Motion Capture System ◽  
Collection System ◽  
Data Collection System ◽  
Optical Motion ◽  
Lower Limb Movement ◽  
Optical Motion Capture

For the controller of wearable lower-limb assistive devices, quantitative understanding of human locomotion serves as the basis for human motion intent recognition and joint-level motion control. Traditionally, the required gait data are obtained in gait research laboratories, utilizing marker-based optical motion capture systems. Despite the high accuracy of measurement, marker-based systems are largely limited to laboratory environments, making it nearly impossible to collect the desired gait data in real-world daily-living scenarios. To address this problem, the authors propose a novel exoskeleton-based gait data collection system, which provides the capability of conducting independent measurement of lower limb movement without the need for stationary instrumentation. The basis of the system is a lightweight exoskeleton with articulated knee and ankle joints. To minimize the interference to a wearer’s natural lower-limb movement, a unique two-degrees-of-freedom joint design is incorporated, integrating a primary degree of freedom for joint motion measurement with a passive degree of freedom to allow natural joint movement and improve the comfort of use. In addition to the joint-embedded goniometers, the exoskeleton also features multiple positions for the mounting of inertia measurement units (IMUs) as well as foot-plate-embedded force sensing resistors to measure the foot plantar pressure. All sensor signals are routed to a microcontroller for data logging and storage. To validate the exoskeleton-provided joint angle measurement, a comparison study on three healthy participants was conducted, which involves locomotion experiments in various modes, including overground walking, treadmill walking, and sit-to-stand and stand-to-sit transitions. Joint angle trajectories measured with an eight-camera motion capture system served as the benchmark for comparison. Experimental results indicate that the exoskeleton-measured joint angle trajectories closely match those obtained through the optical motion capture system in all modes of locomotion (correlation coefficients of 0.97 and 0.96 for knee and ankle measurements, respectively), clearly demonstrating the accuracy and reliability of the proposed gait measurement system.

scholarly journals Validation process of an upper limb motion analyzer using OptiTrack motion capture system

2018 ◽  
Vol 11 (2) ◽  
pp. 93-99
Author(s):  
Zoltán Lénárt ◽  
Gergely Nagymáté ◽  
Andor Szabó
Keyword(s):  
Motion Capture ◽  
Upper Limb ◽  
Motion Capture System ◽  
Validation Process

Gender differences in the Achilles tendon load during the fencing lunge

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Jonathan Kenneth Sinclair ◽  
Lindsay Bottoms
Keyword(s):  
Gender Differences ◽  
Achilles Tendon ◽  
Motion Capture ◽  
Tendon Injury ◽  
Force Platform ◽  
Motion Capture System ◽  
3D Motion ◽  
Loading Rates ◽  
Tendon Pathology ◽  
3D Motion Capture

AbstractRecent epidemiological analyses in fencing have shown that injuries and pain linked specifically to fencing training/competition were evident in 92.8% of fencers. Specifically the prevalence of Achilles tendon pathology has increased substantially in recent years, and males have been identified as being at greater risk of Achilles tendon injury compared to their female counterparts. This study aimed to examine gender differences in Achilles tendon loading during the fencing lunge.Achilles tendon load was obtained from eight male and eight female club level epee fencers using a 3D motion capture system and force platform information as they completed simulated lunges. Independent t-tests were performed on the data to determine whether differences existed.The results show that males were associated with significantly greater Achilles tendon loading rates in comparison to females.This suggests that male fencers may be at greater risk from Achilles tendon pathology as a function of fencing training/ competition.

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