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 Lower Limb Exoskeleton Gait Planning Based on Crutch and Human-Machine Foot Combined Center of Pressure

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7216
Author(s):  
Wei Yang ◽  
Jiyu Zhang ◽  
Sheng Zhang ◽  
Canjun Yang
Keyword(s):  
Lower Limb ◽  
Stride Length ◽  
Center Of Pressure ◽  
Balance Control ◽  
Effective Means ◽  
Stability Control ◽  
Planning Method ◽  
Gait Planning ◽  
Lower Limb Exoskeleton ◽  
Cord Injury

With the help of wearable robotics, the lower limb exoskeleton becomes a promising solution for spinal cord injury (SCI) patients to recover lower body locomotion ability. However, fewer exoskeleton gait planning methods can meet the needs of patient in real time, e.g., stride length or step width, etc., which may lead to human-machine incoordination, limit comfort, and increase the risk of falling. This work presents a human-exoskeleton-crutch system with the center of pressure (CoP)-based gait planning method to enable the balance control during the exoskeleton-assisted walking with crutches. The CoP generated by crutches and human-machine feet makes it possible to obtain the overall stability conditions of the system in the process of exoskeleton-assisted quasi-static walking, and therefore, to determine the next stride length and ensure the balance of the next step. Thus, the exoskeleton gait is planned with the guidance of stride length. It is worth emphasizing that the nominal reference gait is adopted as a reference to ensure that the trajectory of the swing ankle mimics the reference one well. This gait planning method enables the patient to adaptively interact with the exoskeleton gait. The online gait planning walking tests with five healthy volunteers proved the method’s feasibility. Experimental results indicate that the algorithm can deal with the sensed signals and plan the landing point of the swing leg to ensure balanced and smooth walking. The results suggest that the method is an effective means to improve human–machine interaction. Additionally, it is meaningful for the further training of independent walking stability control in exoskeletons for SCI patients with less assistance of crutches.

scholarly journals An Adaptive Neuromuscular Controller for Assistive Lower-Limb Exoskeletons: A Preliminary Study on Subjects with Spinal Cord Injury

2017 ◽  
Vol 11 ◽  
Author(s):  
Amy R. Wu ◽  
Florin Dzeladini ◽  
Tycho J. H. Brug ◽  
Federica Tamburella ◽  
Nevio L. Tagliamonte ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Lower Limb ◽  
Cord Injury ◽  
Preliminary Study

Learning and planning of stair ascent for lower-limb exoskeleton systems

2019 ◽  
Vol 46 (3) ◽  
pp. 421-430
Author(s):  
Qiming Chen ◽  
Hong Cheng ◽  
Rui Huang ◽  
Jing Qiu ◽  
Xinhua Chen
Keyword(s):  
Dynamic Model ◽  
Lower Limb ◽  
Simulation Environment ◽  
Content Type ◽  
Lower Limb Exoskeleton ◽  
Stair Ascent ◽  
Cord Injury ◽  
Machine Learning Approach ◽  
External Forces ◽  
The Cost

Purpose Lower-limb exoskeleton systems enable people with spinal cord injury to regain some degree of locomotion ability, as the expected motion curve needs to adapt with changing scenarios, i.e. stair heights, distance to the stairs. The authors’ approach enables exoskeleton systems to adapt to different scenarios in stair ascent task safely. Design/methodology/approach In this paper, the authors learn the locomotion from predefined trajectories and walk upstairs by re-planning the trajectories according to external forces posed on exoskeleton systems. Moreover, instead of using complex sensors as inputs for re-planning in real-time, the approach can obtain forces acting on exoskeleton through dynamic model of human-exoskeleton system learned by an online machine learning approach without accurate parameters. Findings The proposed approach is validated in both simulation environment and a real walking assistance exoskeleton system. Experimental results prove that the proposed approach achieves better performance than the traditional predefined gait approach. Originality/value First, the approach obtain the external forces by a learned dynamic model of human-exoskeleton system, which reduces the cost of exoskeletons and avoids the heavy task of translating sensor input into actuator output. Second, the approach enables exoskeleton accomplish stair ascent task safely in different scenarios.

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 Design of Lower Limb Exoskeleton using Gearbox for Rehabilitation of Paralyzed Patients

2020 ◽  
Vol 9 (5) ◽  
pp. 112-115
Keyword(s):  
Dynamic Analysis ◽  
Lower Limb ◽  
Mechanical Design ◽  
Design Procedure ◽  
Primary Analysis ◽  
Static And Dynamic Analysis ◽  
Lower Limb Exoskeleton ◽  
Standard Design ◽  
Cord Injury ◽  
Paralyzed Patient

The number of people with mobility disorder cause by stroke spinal cord injury or related disease is increasing rapidly.To improve quality of life of this people device that can assist them to regain the ability to work are of great demand. Robotic devices are generally used for purpose.The aim of this paper is to present the design and analysis of lower limb exoskeletons.The Exoskeleton is designed by Mechanical Design Procedure for linkages and against the Position values obtained from Gait Analysis.The Gearbox is designed using standard design procedure. This exoskeleton work on the principle of robotics by using sensors, actuator like DC motor. Gait analysis is used as a primary analysis followed by static and dynamic analysis of designed model.Static and Dynamic Analysis is performed in ANSYS Workbench. This exoskeleton will be used for paralyzed patient (paraplegia)as well as for the people who have had accidents for lower body.The limitation of this work is the same exoskeleton cannot be used for all person and a small defect in sensor and other electronic devices will stop the exoskeleton. Using this exoskeleton a paralyzed patient will be able to rehabilitate they will be able to perform stand to sit motion.

scholarly journals User-Centered Design and Development of the Modular TWIN Lower Limb Exoskeleton

2021 ◽  
Vol 15 ◽  
Author(s):  
Matteo Laffranchi ◽  
Stefano D'Angella ◽  
Christian Vassallo ◽  
Chiara Piezzo ◽  
Michele Canepa ◽  
...  
Keyword(s):  
Medical Device ◽  
Lower Limb ◽  
Formative Evaluation ◽  
Physical Therapists ◽  
Battery Life ◽  
User Centered Design ◽  
Lower Limb Exoskeleton ◽  
Cord Injury ◽  
Personal Use ◽  
User Centered

For decades, powered exoskeletons have been considered for possible employment in rehabilitation and personal use. Yet, these devices are still far from addressing the needs of users. Here, we introduce TWIN, a novel modular lower limb exoskeleton for personal use of spinal-cord injury (SCI) subjects. This system was designed according to a set of user requirements (lightweight and autonomous portability, quick and autonomous donning and setup, stability when standing/walking, cost effectiveness, long battery life, comfort, safety) which emerged during participatory investigations that organically involved patients, engineers, designers, physiatrists, and physical therapists from two major rehabilitation centers in Italy. As a result of this user-centered process, TWIN's design is based on a variety of small mechatronic modules which are meant to be easily assembled and donned on or off by the user in full autonomy. This paper presents the development of TWIN, an exoskeleton for personal use of SCI users, and the application of user-centered design methods that are typically adopted in medical device industry, for its development. We can state that this approach revealed to be extremely effective and insightful to direct and continuously adapt design goals and activities toward the addressment of user needs, which led to the development of an exoskeleton with modular mechatronics and novel lateral quick release systems. Additionally, this work includes the preliminary assessment of this exoskeleton, which involved healthy volunteers and a complete SCI patient. Tests validated the mechatronics of TWIN and emphasized its high potential in terms of system usability for its intended use. These tests followed procedures defined in existing standards in usability engineering and were part of the formative evaluation of TWIN as a premise to the summative evaluation of its usability as medical device.

Analysis of Human–Exoskeleton System Interaction for Ergonomic Design

2020 ◽  
pp. 001872082091378
Author(s):  
Yilin Wang ◽  
Jing Qiu ◽  
Hong Cheng ◽  
Xiaojuan Zheng
Keyword(s):  
Lower Limb ◽  
Pressure Sensors ◽  
Gait Training ◽  
Average Pressure ◽  
Interaction Forces ◽  
Lower Limb Exoskeleton ◽  
Pressure Threshold ◽  
Pain Pressure Threshold ◽  
Cord Injury ◽  
And Control

Objective Lower-limb exoskeleton systems are defined as gait training or walking-assisting devices for spinal cord injury or hemiplegic patients. Crutches, straps, and baffles are designed to protect subjects from falling. However, skin abrasions occur when the interaction forces are too large. In this study, the interaction forces between the human body and an exoskeleton system named the AIDER were measured to confirm whether the design was ergonomic. Background The AIDER system is a wearable lower-limb exoskeleton. It secures a subject by binding on the waist, thighs, shanks, and feet. Method Eight healthy subjects participated in the study. The interaction forces of the waist strap, thigh baffles, shank baffles, and crutch handles were measured by pressure sensors. Ten repetitions were completed in this study. After one repetition, custom comfort questionnaires were completed by the subjects. Results Although a few of the peak values of the maximum intensities of pressure between the hands and crutch handles reached the minimum value of the pain–pressure threshold (PPT), the average pressure intensities were much smaller than the PPT value. Conclusions The results indicated that the mechanical structure and control strategy of the AIDER must be improved to be more ergonomic in the future.

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