Novel swing-assist un-motorized exoskeletons for gait training
- Title
- Novel swing-assist un-motorized exoskeletons for gait training
- Author
- Sunil K.Agrawal
- Issue Date
- 2009-07
- Publisher
- BIOMED CENTRAL LTD
- Citation
- JOURNAL OF NEUROENGINEERING AND REHABILITATION, v. 6, no. 1, Article no. 24, 13pp
- Abstract
- Background: Robotics is emerging as a promising tool for functional training of human movement.
Much of the research in this area over the last decade has focused on upper extremity orthotic
devices. Some recent commercial designs proposed for the lower extremity are powered and
expensive – hence, these could have limited affordability by most clinics. In this paper, we present
a novel un-motorized bilateral exoskeleton that can be used to assist in treadmill training of motorimpaired patients, such as with motor-incomplete spinal cord injury. The exoskeleton is designed such that the human leg will have a desirable swing motion, once it is strapped to the exoskeleton. Since this exoskeleton is un-motorized, it can potentially be produced cheaply and could reduce the physical demand on therapists during treadmill training.
Results: A swing-assist bilateral exoskeleton was designed and fabricated at the University of
Delaware having the following salient features: (i) The design uses torsional springs at the hip and
the knee joints to assist the swing motion. The springs get charged by the treadmill during stance
phase of the leg and provide propulsion forces to the leg during swing. (ii) The design of the
exoskeleton uses simple dynamic models of sagittal plane walking, which are used to optimize the
parameters of the springs so that the foot can clear the ground and have a desirable forward
motion during walking. The bilateral exoskeleton was tested on a healthy subject during treadmill
walking for a range of walking speeds between 1.0 mph and 4.0 mph. Joint encoders and interface
force-torque sensors mounted on the exoskeleton were used to evaluate the effectiveness of the
exoskeleton in terms of the hip and knee joint torques applied by the human during treadmill
walking.
Conclusion: We compared two different cases. In case 1, we estimated the torque applied by the
human joints when walking with the device using the joint kinematic data and interface force-torque sensors. In case 2, we calculated the required torque to perform a similar gait only using the kinematic data collected from joint motion sensors. On analysis, we found that at 2.0 mph, the
device was effective in reducing the maximum hip torque requirement and the knee joint torque
during the beginning of the swing. These behaviors were retained as the treadmill speed was
changed between 1–4 mph. These results were remarkable considering the simplicity of the
dynamic model, model uncertainty, non-ideal spring behavior, and friction in the joints. We believe
that the results can be further improved in the future. Nevertheless, this promises to provide a
useful and effective methodolgy for design of un-motorized exoskeletons to assist and train swing
of motor-impaired patients.
- URI
- https://eds.a.ebscohost.com/eds/detail/detail?vid=0&sid=3e3ea427-256d-4c24-9c32-b0451b3f5e06%40sessionmgr4008&bdata=Jmxhbmc9a28mc2l0ZT1lZHMtbGl2ZQ%3d%3d#AN=edselc.2-52.0-68249113687&db=edselchttps://repository.hanyang.ac.kr/handle/20.500.11754/166010
- ISSN
- 1743-0003
- DOI
- 10.1186/1743-0003-6-24
- Appears in Collections:
- COLLEGE OF ENGINEERING SCIENCES[E](공학대학) > MECHANICAL ENGINEERING(기계공학과) > Articles
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