scholarly journals Gravity Balancing Conditions for an Upper Arm Exoskeleton

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Venketesh Dubey ◽  
Sunil Agrawal
Keyword(s):  
Shoulder Joint ◽  
Analytical Study ◽  
Upper Arm ◽  
Functional Training ◽  
Free Length ◽  
Shoulder Joints ◽  
Joint Forces ◽  
Human Arm ◽  
Wearable Exoskeleton ◽  
Balancing Conditions

An upper-arm wearable exoskeleton has been designed for assistance and functional training of humans. One of the goals of this design is to provide passive assistance to a user by gravity balancing, while keeping the transmitted forces to the shoulder joints at a minimum. Consistent with this goal, this paper addresses the following questions: (i) an analytical study of gravity balancing design conditions for the structure of the human arm, (ii) minimization of transmitted shoulder joint forces while satisfying the gravity balancing conditions, and (iii) possible implementation of these conditions into practical designs using zero-free length springs.

Study of an upper arm exoskeleton for gravity balancing and minimization of transmitted forces

2011 ◽  
Vol 225 (11) ◽  
pp. 1025-1035 ◽  
Author(s):  
V N Dubey ◽  
S K Agrawal
Keyword(s):  
Numerical Optimization ◽  
Parameter Variation ◽  
Upper Arm ◽  
Functional Training ◽  
Shoulder Joints ◽  
Joint Forces ◽  
Support Device ◽  
Design Idea ◽  
Wearable Exoskeleton ◽  
Balancing Conditions

An upper-arm wearable exoskeleton has been designed for the assistance and functional training of humans. One of the goals of this design is to provide passive assistance to a user by gravity balancing, while keeping the transmitted forces to the shoulder joints at a minimum. Consistent with this goal, this paper discusses: analytical gravity balancing design conditions for the structure of the exoskeleton; a possible implementation of these conditions into practical designs; the minimization of transmitted joint forces to the shoulder while satisfying the gravity balancing conditions; the numerical optimization of the system for gravity balancing and minimization of transmitted forces; and the effect of parameter variation on joint moments and joint forces via numerical optimization. An implementation of the design was undertaken using zero-free-length springs. The design idea presented in this paper may be useful in relieving the actuators effort of exoskeletons to support the weight of the arm and therefore the possibility of using small actuators and making the system light and portable or even a stand-alone passive support device can be developed based on these gravity balancing conditions.

Modeling of Relative Damping in Defining the Equilibrium Point Trajectory for the Human Arm Movement Control

2008 ◽  
Author(s):  
Kai Chen ◽  
Richard A. Foulds ◽  
Sergei Adamovich ◽  
Qinyin Qiu ◽  
Katharine Swift
Keyword(s):  
Equilibrium Point ◽  
Inverse Kinematics ◽  
Movement Control ◽  
Arm Movement ◽  
Forward Kinematics ◽  
The Novel ◽  
Upper Arm ◽  
Shoulder Joints ◽  
Human Arm ◽  
Damping Model

Existing research suggests that limb motion can be represented as an Equilibrium Point (EP) trajectory in combination with a trajectory that reflects specified damping and stiffness at each joint. This model utilizes the concept of relative damping, an integral factor in defining the Equilibrium Point trajectory, to help maintain stability during the arm movement. By using commercialized Flock of Bird® (FOB) sensor, we can obtain experimental trajectories and angular information for human elbow and shoulder joints, as well as forearm and upper arm position during reaching in slow and fast movements. We replaced the complicated inverse kinematics computation of brain with our simple relative damping model, and then calculated the EP trajectories of the elbow and shoulder to use as inputs to our following forward kinematics model. The model generated trajectories which closely match the experimental data. The novel features of this model include the EP trajectory input generated by relative damping. Therefore, we conclude that multi-joint manipulations can be modeled by an appropriate EP trajectory along with relative damping.

Dynamics of the Shoulder and Elbow Joints of the Throwing Arm during a Baseball Pitch

1986 ◽  
Vol 2 (4) ◽  
pp. 235-259 ◽  
Author(s):  
Michael Feltner ◽  
Jesús Dapena
Keyword(s):  
Internal Rotation ◽  
Linear Transformation ◽  
Shoulder Joint ◽  
Elbow Joint ◽  
External Rotation ◽  
Three Dimensional ◽  
Kinematic Parameters ◽  
Upper Arm ◽  
Joint Forces ◽  
Coordinate Data

Fastball pitches of eight intercollegiate varsity baseball pitchers were filmed using the direct linear transformation (DLT) method of three-dimensional cinematography. Coordinate data were obtained, and the resultant joint forces and torques at the shoulder and elbow joints were calculated. Various kinematic parameters were also calculated to help describe the motions of the shoulder and elbow joints throughout the pitch. At the instant of stride foot contact, a horizontal adduction torque was present at the shoulder joint, and the shoulder was externally rotating. After the onset of the horizontal adduction torque, abduction and internal rotation torques were also present at the shoulder joint and a varus torque was present at the elbow joint. After the instant of maximum external rotation (30 ms prior to ball release), the upper arm started to internally rotate, but it was still in a position of external rotation at the instant of release. This paper discusses the roles of the torques in producing the observed motions of the throwing arm.

The Correlation of the Limitations of Movement of the Shoulder Joint with the Functional Ability of Frozen Shoulder Patients at the Medical Rehabilitation Institute Dr. Mohammad Hoesin Palembang

2020 ◽  
Vol 3 (3) ◽  
pp. 88-96
Author(s):  
Ine Sintia ◽  
Nyimas Fatimah
Keyword(s):  
Functional Ability ◽  
Shoulder Joint ◽  
Frozen Shoulder ◽  
Limited Range ◽  
Medical Rehabilitation ◽  
Cross Sectional ◽  
Shoulder Joints ◽  
Limited Range Of Motion ◽  
Active Flexion ◽  
Cross Sectional Design

Background: Frozen shoulder is a condition of the shoulder joint that experiences inflammation, pain, adhesions, atrophyand shortening of the joint capsule resulting in limited motion. In frozen shoulder patients, the limited range of motion ofthe shoulder joint can affect and reduce functional ability. This study aims to analyze the correlation between the limitedarea of motion of the shoulder joint with the functional ability of frozen shoulder patients at the Medical RehabilitationInstallation Dr. Mohammad Hoesin Palembang. Methods: This study was an observational analytic study, correlationtest, with a cross sectional design. There were 29 frozen shoulder patients who met the inclusion criteria in the MedicalRehabilitation Installation Dr. Mohammad Hoesin Palembang in November 2018 was taken as a sample using consecutivesampling techniques. Functional ability was assessed using the quickDASH questionnaire and the area of motion wasmeasured using a goniometer, then analyzed. Results: The results of the correlation test showed significant resultsbetween functional abilities and the area of motion of the shoulder joints. Active flexion (p = 0.000; r = -0.669), activeextension (p = 0.004; r = -0.520), active abduction (p = 0.000; r = -0.663), active adduction (p = 0.022; r = -0.423 ), passiveflexion (p = 0.001; r = -0.589), passive extension (p = 0.002; r = -0.543), passive abduction (p = 0.000; r = -0.676), passiveadduction (p = 0.038; r = -0.388). Conclusion: There is a significant correlation between limited joint motion andfunctional ability in frozen shoulder patients at the Medical Rehabilitation Installation of Dr. Mohammad HoesinPalembang

scholarly journals Optimal Design of a Bio-Inspired Anthropocentric Shoulder Rehabilitator

2006 ◽  
Vol 3 (3) ◽  
pp. 199-208 ◽  
Author(s):  
S. K. Mustafa ◽  
G. Yang ◽  
S. H. Yeo ◽  
W. Lin
Keyword(s):  
Performance Evaluation ◽  
Shoulder Joint ◽  
Stroke Rehabilitation ◽  
Design Methodology ◽  
Anatomical Structure ◽  
Robotic Arm ◽  
Analysis And Design ◽  
Non Invasive ◽  
Performance Requirements ◽  
Human Arm

This paper presents the design of a bio-inspired anthropocentric 7-DOF wearable robotic arm for the purpose of stroke rehabilitation. The proposed arm rehabilitator synergistically utilizes the human arm structure with non-invasive kinematically under-deterministic cable-driven mechanisms to form a completely deterministic structure. It offers the advantages of being lightweight and having high dexterity. Adopting an anthropocentric design concept also allows it to conform to the human anatomical structure. The focus of this paper is on the analysis and design of the 3-DOF-shoulder module, called the shoulder rehabilitator. The design methodology is divided into three main steps: (1) performance evaluation of the cable-driven shoulder rehabilitator, (2) performance requirements of the shoulder joint based on its physiological characteristics and (3) design optimization of the shoulder rehabilitator based on shoulder joint physiological limitations. The aim is to determine a suitable configuration for the development of a shoulder rehabilitator prototype.

IN VIVO SHOULDER JOINT FORCES AT ISOLATED MOTIONS

2008 ◽  
Vol 41 ◽  
pp. S144 ◽  
Author(s):  
Peter Westerhoff ◽  
Antonius Rohlmann ◽  
A. Bender ◽  
Friedmar Graichen ◽  
Georg Bergmann
Keyword(s):  
Shoulder Joint ◽  
Joint Forces

Experimental Study and Modeling of Equilibrium Point Trajectory Control in Single and Double-Joint Arm Movements

2009 ◽  
Author(s):  
Kai Chen ◽  
Richard A. Foulds ◽  
Katharine Swift ◽  
Sergei Adamovich
Keyword(s):  
Equilibrium Point ◽  
Time Delays ◽  
Arm Movement ◽  
Neuromuscular Control ◽  
Muscle Stimulation ◽  
Time Varying ◽  
Shoulder Joints ◽  
Human Arm ◽  
Neural Transmission ◽  
Human Joint

This paper discusses a new model of neuromuscular control of elbow and shoulder joints based on the Equilibrium Point Hypothesis (EPH). The earlier model [1] suggests that the incorporation of relative damping within reflex loops can maintain the dynamic simplicity of the EPH, while being robust over the range of human joint velocities. The model presented here, extends previous work with the use of experimental Electromyography data of 2 muscles to determine the timing parameters of the virtual trajectories and the inclusion of physiological time delays to account for neural transmission and muscle stimulation/activation delays. This model uses delays presented in the literature by other researchers, with a goal of contributing to a resolution of arguments regarding the controversial arguments in the planning sequences. Therefore, this study attempts to demonstrate the possibility for using descending CNS signals to represent relatively simple, monotonic virtual trajectories of the time varying Equilibrium Point for the control of human arm movement. In addition, the study demonstrates that these virtual trajectories were robust enough to control and coordinated movement of elbow and shoulder joints discussed.

Experience in Arthroscopic Treatment of Adhesive Shoulder Joint Capsulitis

2013 ◽  
Vol 20 (1) ◽  
pp. 34-37
Author(s):  
E. Sh Lomtatidze ◽  
F. L Lazko ◽  
A. A Kubashev ◽  
P. P Savitskiy ◽  
A. P Prizov
Keyword(s):  
Shoulder Joint ◽  
Surgical Procedure ◽  
Adhesive Capsulitis ◽  
Excellent Result ◽  
Mean Value ◽  
Arthroscopic Treatment ◽  
Joint Function ◽  
Treatment Results ◽  
Shoulder Joints

Arthroscopic treatment results were presented for 74 patients, aged 38— 69 years, with adhesive capsulitis (78 shoulder joints). In 68 cases idiopathic capsulitis was diagnosed. Tactics of arthroscopic intervention was proposed and surgical procedure was described in detail. Active movements were initiated on 5-7 day. Mean value of shoulder joint function prior to operation made up 11 (7—14) points, in 2 weeks after intervention — 27 (23—30) points that corresponded to good and excellent result. In 6 months after operation range of movements in the operated joint was equal to that in the healthy joint.

scholarly journals Optimization and Design of a Cable Driven Upper Arm Exoskeleton

2009 ◽  
Author(s):  
Sunil K. Agrawal ◽  
Venketesh N. Dubey ◽  
John J. Gangloff ◽  
Elizabeth Brackbill ◽  
Vivek Sangwan
Keyword(s):  
Laboratory Test ◽  
Parameter Optimization ◽  
Kinetic Models ◽  
Arm Movements ◽  
Stroke Survivors ◽  
Research Experience ◽  
Test Bed ◽  
Joint Angles ◽  
Upper Arm ◽  
Wearable Exoskeleton

This paper presents the design of a wearable upper arm exoskeleton that can be used to assist and train arm movements of stroke survivors or subjects with weak musculature. In the last ten years, a number of upper-arm training devices have emerged. However, due to their size and weight, their use is restricted to clinics and research laboratories. Our proposed wearable exoskeleton builds upon our extensive research experience in wire driven manipulators and design of rehabilitative systems. The exoskeleton consists of three main parts: (i) an inverted U-shaped cuff that rests on the shoulder, (ii) a cuff on the upper arm, and (iii) a cuff on the forearm. Six motors, mounted on the shoulder cuff, drive the cuffs on the upper arm and forearm, using cables. In order to assess the performance of this exoskeleton, prior to use on humans, a laboratory test-bed has been developed where this exoskeleton is mounted on a model skeleton, instrumented with sensors to measure joint angles and transmitted forces to the shoulder. This paper describes design details of the exoskeleton and addresses the key issue of parameter optimization to achieve useful workspace based on kinematic and kinetic models.

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