scholarly journals A BMI Based on Motor Imagery and Attention for Commanding a Lower-Limb Robotic Exoskeleton: A Case Study

2021 ◽  
Vol 11 (9) ◽  
pp. 4106
Author(s):  
Laura Ferrero ◽  
Vicente Quiles ◽  
Mario Ortiz ◽  
Eduardo Iáñez ◽  
José M. Azorín
Keyword(s):  
Motor Imagery ◽  
Lower Limb ◽  
Motor Impairment ◽  
Wearable Devices ◽  
User Research ◽  
Robotic Exoskeleton ◽  
Lower Limb Exoskeleton ◽  
Average Accuracy ◽  
Preliminary Study

Lower-limb robotic exoskeletons are wearable devices that can be beneficial for people with lower-extremity motor impairment because they can be valuable in rehabilitation or assistance. These devices can be controlled mentally by means of brain–machine interfaces (BMI). The aim of the present study was the design of a BMI based on motor imagery (MI) to control the gait of a lower-limb exoskeleton. The evaluation is carried out with able-bodied subjects as a preliminary study since potential users are people with motor limitations. The proposed control works as a state machine, i.e., the decoding algorithm is different to start (standing still) and to stop (walking). The BMI combines two different paradigms for reducing the false triggering rate (when the BMI identifies irrelevant brain tasks as MI), one based on motor imagery and another one based on the attention to the gait of the user. Research was divided into two parts. First, during the training phase, results showed an average accuracy of 68.44 ± 8.46% for the MI paradigm and 65.45 ± 5.53% for the attention paradigm. Then, during the test phase, the exoskeleton was controlled by the BMI and the average performance was 64.50 ± 10.66%, with very few false positives. Participants completed various sessions and there was a significant improvement over time. These results indicate that, after several sessions, the developed system may be employed for controlling a lower-limb exoskeleton, which could benefit people with motor impairment as an assistance device and/or as a therapeutic approach with very limited false activations.

scholarly journals Brain Symmetry Analysis during the Use of a BCI Based on Motor Imagery for the Control of a Lower-Limb Exoskeleton

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1746
Author(s):  
Laura Ferrero ◽  
Mario Ortiz ◽  
Vicente Quiles ◽  
Eduardo Iáñez ◽  
José A. Flores ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Lower Limb ◽  
Brain Activity ◽  
Control Methods ◽  
Dominant Hemisphere ◽  
Cortical Function ◽  
Lower Limb Exoskeleton ◽  
Computer Interfaces ◽  
Brain Signals ◽  
Sensorimotor Rhythms

Brain–Computer Interfaces (BCI) are systems that allow external devices to be controlled by means of brain activity. There are different such technologies, and electroencephalography (EEG) is an example. One of the most common EEG control methods is based on detecting changes in sensorimotor rhythms (SMRs) during motor imagery (MI). The aim of this study was to assess the laterality of cortical function when performing MI of the lower limb. Brain signals from five subjects were analyzed in two conditions, during exoskeleton-assisted gait and while static. Three different EEG electrode configurations were evaluated: covering both hemispheres, covering the non-dominant hemisphere and covering the dominant hemisphere. In addition, the evolution of performance and laterality with practice was assessed. Although sightly superior results were achieved with information from all electrodes, differences between electrode configurations were not statistically significant. Regarding the evolution during the experimental sessions, the performance of the BCI generally evolved positively the higher the experience was.

scholarly journals Preliminary Study on a Novel Protocol for Improving Familiarity with a Lower-Limb Robotic Exoskeleton in Able-Bodied, First-Time Users

2022 ◽  
Vol 8 ◽  
Author(s):  
Jan C. L. Lau ◽  
Katja Mombaur
Keyword(s):  
Lower Limb ◽  
Biomechanical Analysis ◽  
Task Load ◽  
Lower Limb Exoskeleton ◽  
Healthcare Needs ◽  
System Usability Scale ◽  
Cord Injury ◽  
Preliminary Study ◽  
To Come ◽  
First Time

Lower-limb exoskeletons have been created for different healthcare needs, but no research has been done on developing a proper protocol for users to get accustomed to moving with one. The user manuals provided also do not include such instructions. A pre-test was conducted with the TWIN (IIT), which is a lower-limb exoskeleton made for persons with spinal cord injury. In the pre-test, two healthy, able-bodied graduate students indicated a need for a protocol that can better prepare able-bodied, first-time users to move with an exoskeleton. TWIN was used in this preliminary study and nine users were divided to receive a tutorial or no tutorial before walking with the exoskeleton. Due to COVID-19 regulations, the study could only be performed with healthy, young-to-middle-aged lab members that do not require walking support. The proposed protocol was evaluated with the System Usability Scale, NASA Raw Task Load Index, and two custom surveys. The members who received the tutorial found it easy to follow and helpful, but the tutorial seemed to come at a price of higher perceived mental and physical demands, which could stem from the longer testing duration and the need to constantly recall and apply the things learned from the tutorial. All results presented are preliminary, and it is recommended to include biomechanical analysis and conduct the experiment with more participants in the future. Nonetheless, this proof-of-concept study lays groundwork for future related studies and the protocol will be adjusted, applied, and validated to patients and geriatric users.

scholarly journals Developing a Motor Imagery-Based Real-Time Asynchronous Hybrid BCI Controller for a Lower-Limb Exoskeleton

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7309
Author(s):  
Junhyuk Choi ◽  
Keun Tae Kim ◽  
Ji Hyeok Jeong ◽  
Laehyun Kim ◽  
Song Joo Lee ◽  
...  
Keyword(s):  
Real Time ◽  
Motor Imagery ◽  
Lower Limb ◽  
Neurological Disorders ◽  
Support Vector ◽  
Svm Classifier ◽  
Eeg Signals ◽  
Common Spatial Pattern ◽  
Lower Limb Exoskeleton ◽  
Electroencephalogram Eeg

This study aimed to develop an intuitive gait-related motor imagery (MI)-based hybrid brain-computer interface (BCI) controller for a lower-limb exoskeleton and investigate the feasibility of the controller under a practical scenario including stand-up, gait-forward, and sit-down. A filter bank common spatial pattern (FBCSP) and mutual information-based best individual feature (MIBIF) selection were used in the study to decode MI electroencephalogram (EEG) signals and extract a feature matrix as an input to the support vector machine (SVM) classifier. A successive eye-blink switch was sequentially combined with the EEG decoder in operating the lower-limb exoskeleton. Ten subjects demonstrated more than 80% accuracy in both offline (training) and online. All subjects successfully completed a gait task by wearing the lower-limb exoskeleton through the developed real-time BCI controller. The BCI controller achieved a time ratio of 1.45 compared with a manual smartwatch controller. The developed system can potentially be benefit people with neurological disorders who may have difficulties operating manual control.

DEVELOPMENT OF A COMPACT LOWER-LIMB EXOSKELETON FOR WALKING ASSISTANCE: A CASE STUDY

2019 ◽  
Vol 19 (07) ◽  
pp. 1940039
Author(s):  
TIANJIAO ZHENG ◽  
GANGFENG LIU ◽  
TIANSHUO WANG ◽  
YU ZHANG ◽  
JIE ZHAO ◽  
...  
Keyword(s):  
Lower Limb ◽  
Control Method ◽  
Effective Means ◽  
Steel Cable ◽  
Gait Generation ◽  
Lower Limb Exoskeleton ◽  
Fitting Method ◽  
Finite State ◽  
Reference Trajectories

Lower-limb exoskeletons are an effective means to provide paraplegic and hemiplegic individuals with the ability to walk upright. A lot of studies about lower-limb exoskeletons have been developed to assist the impaired populations. However, the existing devices are still too technically complex and expensive for practicality. In this paper, a compact lower-limb exoskeleton for walking assistance is developed, in which a steel-cable actuator is specially designed. In order to accomplish the different tasks presented to gait generation, a control method with multiple stages is employed. In this approach, four basic states and seven intended motions are designed for the finite-state machine. In addition, the reference trajectories of these intended motions are presented and fitted by a modified first-order polynomial-fitting method. Preliminary motion tests of the exoskeleton with three healthy subjects are performed. The results verify the effectiveness of the system design and the gait-generation approach proposed in this paper. The overall exoskeleton system is compact and the corresponding operations are convenient and reliable.

A Review on Lower-Limb Exoskeleton System for Sit to Stand, Ascending and Descending Staircase Motion

2014 ◽  
Vol 541-542 ◽  
pp. 1150-1155 ◽  
Author(s):  
A. Norhafizan ◽  
R.A.R. Ghazilla ◽  
Vijayabaskar Kasi ◽  
Z. Taha ◽  
Bilal Hamid
Keyword(s):  
Lower Limb ◽  
Intelligent System ◽  
Human Motion ◽  
Rehabilitation Robotics ◽  
Industrial Robots ◽  
Motion Generation ◽  
Robotic Exoskeleton ◽  
Lower Limb Exoskeleton ◽  
Human Power ◽  
Sit To Stand

Robotic exoskeleton system has been found to be an active area of study which being used in human power augmentation, human power assistance, robotic rehabilitation, and haptic interaction in virtual reality developed in recent robotic research. In recent years, the application of robotic exoskeleton has become more prominent as to provide alternative solutions for physically less incapable people (PLIP) support in their daily movements. Most common difficulties faced by PLIP are in sit-to-stand, ascending and descending staircases. Unlike industrial robots, the robotic exoskeleton systems need to consider a special design because they directly interact with human user. In the mechanical design of these systems, human and robotic suitable kinematics, wearer safety, human user comfort wearing, low inertia, and adaptability should be especially considered. Controllability, responsiveness, flexible and smooth motion generation, and safety should especially be considered in the controllers of exoskeleton systems. Furthermore, the controller should generate the motions in accordance with the human motion intention. This paper briefly reviews the lower-limb robotic exoskeleton systems. In the short review, it is focused to identify the brief history, basic concept, challenges, and future development of the robotic exoskeleton systems to assist the physically less incapable people (PLIP) in rising up, sitting, ascending and descending staircases. Furthermore, key technologies of lower-limb exoskeleton systems are reviewed by taking state-of-the-art robot as examples. Keywords: List the Robotic exoskeleton systems, rehabilitation robotics, man-machine intelligent system

Sign in / Sign up

Export Citation Format

Share Document