scholarly journals Design and Implementation of a Robotic Hip Exoskeleton for Gait Rehabilitation

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 212
Author(s):  
Shi-Heng Hsu ◽  
Chuan Changcheng ◽  
Heng-Ju Lee ◽  
Chun-Ta Chen
Keyword(s):  
Degrees Of Freedom ◽  
Lower Limbs ◽  
Gait Rehabilitation ◽  
Hip Joints ◽  
Gait Control ◽  
Design And Implementation ◽  
Model Free ◽  
Active Flexion ◽  
Flexion Extension ◽  
Linear Extended State Observer

In this paper, a four degrees-of-freedom robotic hip exoskeleton was proposed for gait rehabilitation. The robotic hip exoskeleton was designed with active flexion/extension and passive abduction/adduction at each hip joint to comply with the movement of the thigh. Due to each user’s different lower limbs characteristics and unknown torques at hip joints, model-free linear extended state observer (LESO)-based controllers were proposed for rehabilitation gait control. The prototypes of the robotic hip exoskeleton and controller designs were validated and compared through walking and ascending rehabilitation experiments. Additionally, a motion captured system and EMG signals were used to investigate the walking assistance of the robotic hip exoskeleton.

Optimal Combination of Minimum Degrees of Freedom to be Actuated in the Lower Limbs to Facilitate Arm-Free Paraplegic Standing

2007 ◽  
Vol 129 (6) ◽  
pp. 838-847 ◽  
Author(s):  
Joon-young Kim ◽  
James K. Mills ◽  
Albert H. Vette ◽  
Milos R. Popovic
Keyword(s):  
Lower Limb ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Optimal Combination ◽  
Lower Limbs ◽  
Free Standing ◽  
Joint Torques ◽  
Flexion Extension ◽  
Hip Abduction ◽  
The Individual

Arm-free paraplegic standing via functional electrical stimulation (FES) has drawn much attention in the biomechanical field as it might allow a paraplegic to stand and simultaneously use both arms to perform daily activities. However, current FES systems for standing require that the individual actively regulates balance using one or both arms, thus limiting the practical use of these systems. The purpose of the present study was to show that actuating only six out of 12 degrees of freedom (12-DOFs) in the lower limbs to allow paraplegics to stand freely is theoretically feasible with respect to multibody stability and physiological torque limitations of the lower limb DOF. Specifically, the goal was to determine the optimal combination of the minimum DOF that can be realistically actuated using FES while ensuring stability and able-bodied kinematics during perturbed arm-free standing. The human body was represented by a three-dimensional dynamics model with 12-DOFs in the lower limbs. Nakamura’s method (Nakamura, Y., and Ghodoussi, U., 1989, “Dynamics Computation of Closed-Link Robot Mechanisms With Nonredundant and Redundant Actuators,” IEEE Trans. Rob. Autom., 5(3), pp. 294–302) was applied to estimate the joint torques of the system using experimental motion data from four healthy subjects. The torques were estimated by applying our previous finding that only 6 (6-DOFs) out of 12-DOFs in the lower limbs need to be actuated to facilitate stable standing. Furthermore, it was shown that six cases of 6-DOFs exist, which facilitate stable standing. In order to characterize each of these cases in terms of the torque generation patterns and to identify a potential optimal 6-DOF combination, the joint torques during perturbations in eight different directions were estimated for all six cases of 6-DOFs. The results suggest that the actuation of both ankle flexion∕extension, both knee flexion∕extension, one hip flexion∕extension, and one hip abduction∕adduction DOF will result in the minimum torque requirements to regulate balance during perturbed standing. To facilitate unsupported FES-assisted standing, it is sufficient to actuate only 6-DOFs. An optimal combination of 6-DOFs exists, for which this system can generate able-bodied kinematics while requiring lower limb joint torques that are producible using contemporary FES technology. These findings suggest that FES-assisted arm-free standing of paraplegics is theoretically feasible, even when limited by the fact that muscles actuating specific DOFs are often denervated or difficult to access.

A reciprocal walking orthosis hip joint for young paediatric patients with a variety of pathological conditions

2001 ◽  
Vol 25 (1) ◽  
pp. 47-52 ◽  
Author(s):  
P. J. Woolam ◽  
B. Lomas ◽  
J. Stallard
Keyword(s):  
Hip Joint ◽  
Sagittal Plane ◽  
Vertical Axis ◽  
Lower Limbs ◽  
Knee Joints ◽  
Hip Joints ◽  
Flexion Extension ◽  
Total Body ◽  
Lateral Rigidity ◽  
Adjustable Range

A growing trend in the use of reciprocal walking orthoses for infant paraplegic patients, and their application for control of the lower limbs in very young total body involved cerebral palsy patients, has created a need for smaller components. A prototype design of a hip joint has been produced which provides the following features: adjustable range of flexion/extension control; override on stops to permit sitting; high lateral rigidity; no lateral bearing play; very high rigidity in the sagittal plane; low friction bearings; high resistance to torque about the vertical axis. In addition a size envelope which is more in keeping with the dimensions of infant patients was an important objective. Comparisons were made of the computed structural properties of the prototype joint and existing routinely available standard orthotic hip joints. In each plane of loading the prototype joint had the highest identified structural property. The hinge-bearing material was tested in a representative joint with 200,000 cycles of typical loading. It was also field tested on adult orthoses over a minimum of a 12-month period with the most vigorous of walkers. In neither test did excessive play develop. The mechanical properties of the joint were established using tests advocated in the British Standard on testing lower limb orthosis knee joints. These showed the joint had structurally equivalent performance to a successful reciprocal walking orthosis hip joint, and that the mode of failure was essentially ductile in nature. Production development of the joint is now being undertaken.

scholarly journals Annular Defects Impair the Mechanical Stability of the Intervertebral Disc

2021 ◽  
pp. 219256822110060
Author(s):  
Jun-Xin Chen ◽  
Yun-He Li ◽  
Jian Wen ◽  
Zhen Li ◽  
Bin-Sheng Yu ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Degrees Of Freedom ◽  
Mechanical Stability ◽  
Biomechanical Testing ◽  
Bending Stiffness ◽  
Biomechanical Study ◽  
Torsional Stiffness ◽  
P Value ◽  
Lateral Bending ◽  
Flexion Extension

Study Design: A biomechanical study. Objectives: The purpose of this study was to investigate the effects of cruciform and square incisions of annulus fibrosus (AF) on the mechanical stability of bovine intervertebral disc (IVD) in multiple degrees of freedom. Methods: Eight bovine caudal IVD motion segments (bone-disc-bone) were obtained from the local abattoir. Cruciform and square incisions were made at the right side of the specimen’s annulus using a surgical scalpel. Biomechanical testing of three-dimensional 6 degrees of freedom was then performed on the bovine caudal motion segments using the mechanical testing and simulation (MTS) machine. Force, displacement, torque and angle were recorded synchronously by the MTS system. P value <.05 was considered statistically significant. Results: Cruciform and square incisions of the AF reduced both axial compressive and torsional stiffness of the IVD and were significantly lower than those of the intact specimens ( P < .01). Left-side axial torsional stiffness of the cruciform incision was significantly higher than a square incision ( P < .01). Neither incision methods impacted flexional-extensional stiffness or lateral-bending stiffness. Conclusions: The cruciform and square incisions of the AF obviously reduced axial compression and axial rotation, but they did not change the flexion-extension and lateral-bending stiffness of the bovine caudal IVD. This mechanical study will be meaningful for the development of new approaches to AF repair and the rehabilitation of the patients after receiving discectomy.

scholarly journals Gait Rehabilitation Device in Central Nervous System Disease: A Review

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Kazuya Kubo ◽  
Takanori Miyoshi ◽  
Akira Kanai ◽  
Kazuhiko Terashima
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Central Nervous System Disease ◽  
Gait Training ◽  
Lower Limbs ◽  
Nervous System Disease ◽  
Gait Rehabilitation ◽  
System Disease ◽  
Physical Burden ◽  
Rehabilitation Devices

Central nervous system diseases cause the gait disorder. Early rehabilitation of a patient with central nervous system disease is shown to be benefit. However, early gait training is difficult because of muscular weakness and those elderly patients who lose of leg muscular power. In the patient's walking training, therapists assist the movement of patient's lower limbs and control the movement of patient's lower limbs. However the assistance for the movement of the lower limbs is a serious hard labor for therapists. Therefore, research into and development of various gait rehabilitation devices is currently underway to identify methods to alleviate the physical burden on therapists. In this paper, we introduced the about gait rehabilitation devices in central nervous system disease.

Finite Element Model of the Human Knee Joint to Study Tibio-Femoral Contact Mechanics

2000 ◽  
Author(s):  
Tammy Haut Donahue ◽  
Maury L. Hull ◽  
Mark M. Rashid ◽  
Christopher R. Jacobs
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Degrees Of Freedom ◽  
Soft Tissues ◽  
Element Model ◽  
Human Knee ◽  
Human Knee Joint ◽  
Solid Models ◽  
Flexion Extension ◽  
A New Technique

Abstract A finite element model of the tibio-femoral joint in the human knee was created using a new technique for developing accurate solid models of soft tissues (i.e. cartilage and menisci). The model was used to demonstrate that constraining rotational degrees of freedom other than flexion/extension when the joint is loaded in compression markedly affects the load distribution between the medial and lateral sides of the joint. The model also was used to validate the assumption that the bones can be treated as rigid.

New Redundant Manipulator Robot with Six Degrees of Freedom Controlled with Visual Feedback

2017 ◽  
pp. 231-255
Author(s):  
Claudio Urrea ◽  
Héctor Araya
Keyword(s):  
Visual Feedback ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Vision System ◽  
Artificial Vision ◽  
Correct Operation ◽  
Six Degrees Of Freedom ◽  
Design And Implementation ◽  
Implementation Stages ◽  
Manipulator Robot

The design and implementation stages of a redundant robotized manipulator with six Degrees Of Freedom (DOF), controlled with visual feedback by means of computational software, is presented. The various disciplines involved in the design and implementation of the manipulator robot are highlighted in their electric as well as mechanical aspects. Then, the kinematics equations that govern the position and orientation of each link of the manipulator robot are determined. The programming of an artificial vision system and of an interface that control the manipulator robot is designed and implemented. Likewise, the type of position control applied to each joint is explained, making a distinction according to the assigned task. Finally, functional mechanical and electric tests to validate the correct operation of each of the systems of the manipulator robot and the whole robotized system are carried out.

scholarly journals Assessment of an Assistive Control Approach Applied in an Active Knee Orthosis Plus Walker for Post-Stroke Gait Rehabilitation

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2452
Author(s):  
Ana Cecilia Villa-Parra ◽  
Jessica Lima ◽  
Denis Delisle-Rodriguez ◽  
Laura Vargas-Valencia ◽  
Anselmo Frizera-Neto ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Muscle Activation ◽  
Inertial Sensors ◽  
Lower Limbs ◽  
Trunk Muscles ◽  
Control Group ◽  
Gait Rehabilitation ◽  
Control Approach ◽  
Post Stroke ◽  
Knee Orthosis

The goal of this study is the assessment of an assistive control approach applied to an active knee orthosis plus a walker for gait rehabilitation. The study evaluates post-stroke patients and healthy subjects (control group) in terms of kinematics, kinetics, and muscle activity. Muscle and gait information of interest were acquired from their lower limbs and trunk, and a comparison was conducted between patients and control group. Signals from plantar pressure, gait phase, and knee angle and torque were acquired during gait, which allowed us to verify that the stance control strategy proposed here was efficient at improving the patients’ gaits (comparing their results to the control group), without the necessity of imposing a fixed knee trajectory. An innovative evaluation of trunk muscles related to the maintenance of dynamic postural equilibrium during gait assisted by our active knee orthosis plus walker was also conducted through inertial sensors. An increase in gait cycle (stance phase) was also observed when comparing the results of this study to our previous work. Regarding the kinematics, the maximum knee torque was lower for patients when compared to the control group, which implies that our orthosis did not demand from the patients a knee torque greater than that for healthy subjects. Through surface electromyography (sEMG) analysis, a significant reduction in trunk muscle activation and fatigability, before and during the use of our orthosis by patients, was also observed. This suggest that our orthosis, together with the assistive control approach proposed here, is promising and could be considered to complement post-stroke patient gait rehabilitation.

scholarly journals Displacement Analysis and Design of a (2–RRU)–URR Parallel Mechanism Performing 2R1T Output Motion for Thumb Rehabilitation

Robotics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 67
Author(s):  
Woo-hyeok Choi ◽  
Yukio Takeda
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Human Hand ◽  
Displacement Analysis ◽  
Analysis And Design ◽  
Reachable Workspace ◽  
Flexion Extension ◽  
Basic Characteristics ◽  
Narrow Space ◽  
Input Torque

The thumb assists other fingers, and any damage in its functionality prevents the human hand from performing dexterous functions. In this paper, the kinematic design of the (2–RRU)–URR parallel mechanism as the application of the thumb rehabilitation device is proposed. This mechanism is an over-constrained mechanism capable of achieving the required mobility with fewer joints. Three degrees of freedom exist—two rotational and one translational mobility—that are related to each thumb movement: adduction–abduction and flexion–extension. Considering the narrow space of the hand, actuators are designed to divide its placement into the surface of the palm. To avoid the collisions between the device and the hand, an offset was adopted. The displacement analysis problem is solved by dividing it into two parts: the planar motion generator (PMG) and orientation generator (OG), according to each functional motion, and the corresponding equations and procedures are presented. To clarify the basic characteristics of this mechanism, the reachable workspace of the PMG and rotational ability and sensitivity of the OG is demonstrated numerically. Because a large input torque difference is dangerous in the rehabilitation mechanism, the effective workspace is determined according to the magnitude of the input torque differences and compared with the measured thumb movements.

scholarly journals Ép és mozgásukban korlátozott kajakos sportolók biomechanikai mozgáselemzése és összehasonlító vizsgálata

2019 ◽  
Vol 160 (52) ◽  
pp. 2061-2066
Author(s):  
Bernadett Kertészné Német ◽  
Tamás Terebessy ◽  
Zoltán Bejek
Keyword(s):  
Body Mass ◽  
Mass Range ◽  
Lower Limbs ◽  
Whole Body ◽  
Special Focus ◽  
Upper Limbs ◽  
Height Range ◽  
Flexion Extension ◽  
The Disabled ◽  
Age Range

Abstract: Introduction: During kayaking, the whole body works in a perfect harmony. While the trunk is doing a rotation, flexion-extension helps to the upper limb to create a special cyclic paddle. The purpose of this study was to gain a better understanding of the physical disabled (later disabled) person’s kayaking motions and to probe whether there were any significant differences between disabled and non-disabled kayakers with special focus on the use of footrest. We hypothesised significantly different ranges of motion and muscle activity in lower limbs but no significant differences in those of the upper limbs. Aim: Our goal was to know more about the abled and disbled kayaking and compare the athlete’s kayaking movements. Method: Thirteen (n = 13) elite disabled athletes (age range: 18–40 years, height range: 164–194 cm, body mass range:74–93 kg), eleven (n = 11) elite non-disabled athletes (age range: 18–40 years, height range:172–197 cm, body mass range: 72–96 kg) and nine (n = 9) athletes whose movements were artificially limited to imitate disabled conditions(“imitation disabled” group) (age range: 18–40 years, height range: 172–197 cm, body mass range: 72–96 kg) were measured. Weba sport kayak ergometer, surface electromyography (EMG), and a 3-dimensional Vicon (MX T40) camera system were used to record the data, and a combined Matlab and MS Excel system was used to analyse the results. Results: In line with our basic assumption, range of motion of the upper limbs was not significantly different between disabled athletes and non-disabled athletes (p ≥ 0.05). However, muscle activities were significantly different in the disabled group compared to the non-disabled group (p ≤ 0.05). In the disabled group the knee joint and trunk motions and muscle activities were also significantly different compared to those in the non-disabled group (p ≤ 0.05). The differences in performance force applied to both footrests and force were significant (p ≤ 0.05). Discussion: The assumption that shoulder and elbow ranges of motion were not significantly different in disabled athletes compared to non-disabled athletes was proven. However, muscle activities were significantly different in the disabled group. In the disabled group, knee and trunk motions and muscle activities were also significantly different compared to the non-disabled group. Significant differences were found in performance, force and footrest use. Our results proved our assumption that motions and muscle activities of disabled and non-disabled athletes were significantly different. Orv Hetil. 2019; 160(52): 2061–2066.

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