Development of a Parallel Manipulator-Based Multifunction Mobility Assistive Device

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Ahmed Asker ◽  
Samy F. M. Assal
Keyword(s):  
Lower Limb ◽  
Parallel Manipulator ◽  
Upright Position ◽  
Robotic Systems ◽  
Assistive Device ◽  
Finite Element Analyses ◽  
Natural Manner ◽  
Personal Assistance ◽  
Sit To Stand ◽  
Position And Orientation

Abstract Developing robotic systems for reducing the dependence of elderly on personal assistance is one of the most recent hot topics in robotics research. This paper proposes a multifunction mobility assistive device, which consists of an assisting parallel manipulator carried over an active walker. It is developed to interactively assist in various lower limb activities, namely, sit-to-stand, walking, bed or toilet to wheelchair transfer, and support in the upright position. The assisting parallel manipulator is constructed based on two of the nonconventional structure of the 3-RPR parallel manipulator. This structure offers kinematic decoupling between the position and orientation and free of singularity suitable workspace as well as high rigidity and payload capability. Kinematic, dynamic, and finite element analyses are performed to ensure the functionality of the device. A prototype of the device is constructed to verify the applicability of the device. The prototype is shown to be suitable for assisting subjects to stand up in a natural manner.

Improving sit-to-stand transition by the saddle-assistive device in the spinal cord injury: A case study

2021 ◽  
pp. 095441192110033
Author(s):  
Akbar Hojjati Najafabadi ◽  
Saeid Amini ◽  
Farzam Farahmand
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Lower Limb ◽  
Reaction Force ◽  
Assistive Device ◽  
Limb Weakness ◽  
Sit To Stand ◽  
Lower Limb Weakness ◽  
Wide Range ◽  
Cord Injury

Physical problems caused by fractures, aging, stroke, and accidents can reduce foot power; these, in the long term, can dwindle the muscles of the waist, thighs, and legs. These conditions provide the basis for the invalidism of the harmed people. In this study, a saddle-walker was designed and evaluated to help people suffering from spinal cord injury and patients with lower limb weakness. This S-AD works based on body weight support against the previously report designs. This saddle-walker consisted of a non-powered four-wheel walker helping to walk and a powered mechanism for the sit-to-stand (STS) transfer. A set of experiments were done on the STS in the use of the standard walker and the saddle-assistive device(S-AD). A comparison of the results showed that this device could reduce the vertical ground reaction force (GRF) of the legs up to 70%. Using this device could help a wide range of patients with lower limb weakness and SCI patients in changing from sitting to standing.

Application of Sit-To-Stand Assistive Device Based on Hip Support

2021 ◽  
Vol 14 ◽  
Author(s):  
Huaiqiang Zhang ◽  
Qiang Xue ◽  
Shuo Yang ◽  
Tongtong Wang ◽  
Binwei Zhou
Keyword(s):  
Lower Limb ◽  
Independent Living ◽  
Structural Characteristics ◽  
Assistive Devices ◽  
Assistive Device ◽  
Technology Application ◽  
Assist Devices ◽  
Advantages And Disadvantages ◽  
Sit To Stand

Background: Completing the transition from a sitting position to a standing position is a basic skill in people’s daily lives and is crucial for independent living. Lower limb dysfunction will bring many inconveniences into a person’s life and greatly affect their quality of life. Patients with lower limb dysfunction are a specialized group, and nursing problems for this group are becoming increasingly serious. Helping patients with lower limb dysfunction restore their lower limb mobility or assisting them to walk is a social problem necessary to be solved. Objective: : To review the recent sit-to-stand assistive devices based on hip support, classify them systematically and introduce their characteristics, including the mechanisms and the types of patients for which such mechanisms are applicable; to help patients with lower limb dysfunction or doctors (therapists) understand and choose a reasonable sit-to-stand assist device based on hip support. Methods: This paper summarizes literatures and patents about sit-to-stand assistive devices. From the aspects of structural characteristics, drive type and support modes based on the hip and applications situation, the advantages and disadvantages of the typical sit-to-stand assist devices are represented. Results: Current and future development trends on the structural characteristics, drive type and support modes based on the hip and applications situation of sit-to-stand assist devices are discussed to improve the humanization, modularization and applicability of sit-to-stand assist devices. Conclusion: Sit-to-stand assistive devices based on hip support can help patients improve the quality of their life, assist patients carrying out rehabilitation training, and delay the decline of lower limb function. However, the existing sit-to-stand assistive devices based on hip support need further improvement in the aspects of motion mechanism, new technology application and ergonomics design.

Development of parallel manipulator sit to stand assistive device for elderly people

2013 ◽  
Author(s):  
Omar Salah ◽  
Ahmed Asker ◽  
Ahmed M. R. Fath El-Bab ◽  
Samy M. F. Assal ◽  
Ahmed A. Ramadan ◽  
...  
Keyword(s):  
Elderly People ◽  
Parallel Manipulator ◽  
Assistive Device ◽  
Sit To Stand

Trajectory Generation for a Lower Limb Exoskeleton for Sit-to-Stand Transition Using a Genetic Algorithm

2017 ◽  
Author(s):  
Ameya S. Chamnikar ◽  
Gaurav Patil ◽  
Mohammadreza Radmanesh ◽  
Manish Kumar
Keyword(s):  
Genetic Algorithm ◽  
Lower Limb ◽  
Degrees Of Freedom ◽  
Fitness Function ◽  
Trajectory Generation ◽  
The Body ◽  
Assistive Device ◽  
Reference Trajectory ◽  
Lower Limb Exoskeleton ◽  
Sit To Stand

Population of the world above the age of 65 years is increasing rapidly. Aging causes weakening of human joints which increases constraints on mobility of the body. Sit-to-Stand (STS), an important part of Activities of Daily Living (ADL) is one of the motions that is affected because of weakened joints. With the lack of personal care there is going to be a need for devices which can assist the aging population in STS. We propose the use of a lower-limb exoskeleton as an assistive device. One of the main challenges in this area is to generate a human like reference trajectory for exoskeleton to follow. This paper proposes the use of Genetic Algorithm (GA), to generate reference trajectories for the joint angles for lower limb exoskeleton for STS transition. The fitness function for the GA presented here is constructed based on the fact that for a successful STS center of mass (COM) needs to stay in the area of support. After the trajectory generation a simple controller is proposed to control a 3 degrees of freedom exoskeleton. The dynamics of the system being controlled are modelled as an inverse 3 degrees of freedom pendulum and the equations are derived using the Euler-Lagrange equation. The highly non-linear dynamics are linearized using an input-output feedback linearization technique. A PD controller is presented for this linearized dynamic system and the validation of the controller is done using simulations. Simulation results show that GA successfully generates a human like trajectory which eliminates the need to use motion tracking system for measuring human trajectories.

scholarly journals Effects of lower limb resistance exercise on muscle strength, physical fitness, and metabolism in pre-frail elderly patients: a randomized controlled trial

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaoxing Lai ◽  
Lin Bo ◽  
Hongwei Zhu ◽  
Baoyu Chen ◽  
Zhao Wu ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Resistance Exercise ◽  
Frail Elderly ◽  
Lower Limb ◽  
Intervention Group ◽  
Control Group ◽  
Walking Test ◽  
Sit To Stand ◽  
Femoris Muscle ◽  
Activity Energy

Abstract Background Few studies examined interventions in frail elderly in China, while the awareness of applying interventions to prevent frailty in pre-frail elderly is still lacking. This study aimed to explore the effects of lower limb resistance exercise in pre-frail elderly in China. Methods This was a randomized controlled trial of patients with pre-frailty. The control group received routine care, while the exercise group received a 12-week lower limb resistance exercise based on routine care. The muscle strength in the lower limbs, physical fitness, and energy metabolism of the patients was evaluated at admission and after 12 weeks of intervention. Results A total of 60 pre-frail elderly were included in this study. The patients were divided into the exercise group (n = 30) and control group (n = 30) by random grouping. There were 17 men and 13 women aged 65.3 ± 13.4 in the exercise group, and 15 men and 15 women aged 67.6 ± 11.9 years in the control groups. The Barthel index was 80.3 ± 10.6 and 85.1 ± 11.6, respectively. The characteristics of the two groups were not significantly different before intervention (all p > 0.05). The results of repeated measurement ANOVA showed that there was statistically significant in crossover effect of group * time (all p < 0.05), that is, the differences of quadriceps femoris muscle strength, 6-min walking test, 30-s sit-to-stand test, 8-ft “up & go” test, daily activity energy expenditure and metabolic equivalent between the intervention group and the control group changed with time, and the variation ranges were different. The main effects of time were statistically significant (all p < 0.05), namely, femoris muscle strength, 6-min walking test, 30-s sit-to-stand test, 8-ft “up & go” test, daily activity energy expenditure and metabolic equivalent of the intervention group and the control group were significantly different before and after intervention. The main effects of groups were statistically significant (p < 0.05), namely, femoris muscle strength, 6-min walking test, 30-s sit-to-stand test, daily activity energy expenditure and metabolic equivalent before and after intervention were significantly different between the intervention group and the control group, while there was no significant differences in 8-ft “up & go” test between groups. Conclusion Lower limb resistance exercise used for the frailty intervention could improve muscle strength, physical fitness, and metabolism in pre-frail elderly. Trial registration ChiCTR, ChiCTR2000031099. Registered 22 March 2020, http://www.chictr.org.cn/edit.aspx?pid=51221&htm=4

Modular Advantage and Kinematic Decoupling in Gravity Compensated Robotic Systems

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nick Eckenstein ◽  
Mark Yim
Keyword(s):  
Vertical Plane ◽  
Robotic Systems ◽  
Gravity Compensation ◽  
Pulley System ◽  
Free Length ◽  
Low Profile ◽  
Serial Chain ◽  
Manipulator Arm ◽  
Spring Method ◽  
Position And Orientation

Two new designs for gravity compensated modular robotic systems are presented and analyzed. The gravity compensation relies on using zero-free-length springs approximated by a cable and pulley system. Simple yet powerful parallel four-bar modules enable the low-profile self-contained modules with sequential gravity compensation using the spring method for motion in a vertical plane. A second module that is formed as a parallel six-bar mechanism adds a horizontal motion to the previous system that also yields a complete decoupling of position and orientation of the distal end of a serial chain. Additionally, we introduce the concept of vanishing effort where as the number of modules that comprise an articulated serial chain increases, the actuation authority required at any joint reduces. Essentially, this results in a method for distributing actuation along the length of an articulated chain. Prototypes were designed and constructed validating the analysis and accomplishing the functions of a general serial-type manipulator arm.

The Muscle Myogram as a Control Signal for Use in Powered Limb Orthosis

2006 ◽  
Author(s):  
M. Antonelli ◽  
P. Beomonte Zobel ◽  
J. Giacomin
Keyword(s):  
Lower Limb ◽  
Assistive Device ◽  
Sitting Position ◽  
Test Bed ◽  
Disabled People ◽  
Test Protocol ◽  
Prosthetic Devices ◽  
Specific Device ◽  
Definition Of

The choice of the command technique to be used in orthotic and prosthetic devices is very critical for the acceptance and, finally, the success of the specific device. Many variables influence this choice: the general characteristics of the signal, the quality of the correlation between signal and specific actions of the user and the algorithm that is derived, the acceptance of the technique, as applied to the specific device, from the user, etc. Among the command techniques, MMG signal seems to be promising to command an assistive device. In this paper a test protocol for studying MMG signal, to investigate the prospective for its use as a command technique of a powered lower limb orthosis capable of raising elderly and disabled people from the sitting position, is proposed. The definition of the test protocol, including the description of the test bed and the sensors application, is presented. Finally, the experimental results are showed and discussed.

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