scholarly journals An Attention-Controlled Hand Exoskeleton for the Rehabilitation of Finger Extension and Flexion Using a Rigid-Soft Combined Mechanism

2019 ◽  
Vol 13 ◽  
Author(s):  
Min Li ◽  
Bo He ◽  
Ziting Liang ◽  
Chen-Guang Zhao ◽  
Jiazhou Chen ◽  
...  
Keyword(s):  
Finger Extension ◽  
Hand Exoskeleton ◽  
Combined Mechanism

scholarly journals Modeling and Evaluation of a Novel Hybrid-Driven Compliant Hand Exoskeleton Based on Human-Machine Coupling Model

2021 ◽  
Vol 11 (22) ◽  
pp. 10825
Author(s):  
Qiaoling Meng ◽  
Zhijia Shen ◽  
Zhiyang Nie ◽  
Qingyun Meng ◽  
Zhiyu Wu ◽  
...  
Keyword(s):  
Design Method ◽  
Variable Stiffness ◽  
Coupling Model ◽  
Modeling Method ◽  
The Novel ◽  
Finger Extension ◽  
Finger Flexion ◽  
Final Design ◽  
Series Of Experiments ◽  
Hand Exoskeleton

This paper presents the modeling design method for a novel hybrid-driven compliant hand exoskeleton based on the human-machine coupling model for the patients who have requirements on training and assisting. Firstly, the human-machine coupling model is established based on the kinematics characteristics of human fingers and the Bernoulli beam formula. On this basis, the variable stiffness flexible hinge (VSFH) is used to drive the finger extension and the cable-driven mechanism is used to implement the movement of the finger flexion. Here, a hand orthosis is designed in the proposed hand exoskeleton to act as the base and maintain the function position of the hand for patients with hand dysfunction. Then, a final design prototype is fabricated to evaluate the proposed modeling method. In the end, a series of experiments based on the prototype is proceeded to evaluate its capabilities on stretching force for extension, bio-imitability, finger flexion capability, and fingertip force. The results show that the prototype has a significant improvement in all aspects of the ability mentioned above, and has good bionics. The proposed design method can be utilized to implement the rapid design of the hybrid-driven compliant hand exoskeleton with the changed requirements. The novel modeling method can be easily applied in personalized design in rehabilitation engineering.

scholarly journals Design and characterization of a lightweight underactuated RACA hand exoskeleton for neurorehabilitation

2021 ◽  
pp. 103828
Author(s):  
Victor Moreno-SanJuan ◽  
Ana Cisnal ◽  
Juan-Carlos Fraile ◽  
Javier Pérez-Turiel ◽  
Eusebio de-la-Fuente
Keyword(s):  
Hand Exoskeleton

scholarly journals Improving the Dyeability and Anti-Wrinkle Properties of Cotton Fabric via Oxidized Raffinose

2021 ◽  
Vol 11 (10) ◽  
pp. 4641
Author(s):  
Jiangfei Lou ◽  
Jinfang Zhang ◽  
Dan Wang ◽  
Xuerong Fan
Keyword(s):  
Catalyst Concentration ◽  
Structural Characteristics ◽  
Cotton Fabrics ◽  
Difficult Problem ◽  
Curing Temperature ◽  
Dyeing Performance ◽  
Finishing Process ◽  
Combined Mechanism ◽  
Recovery Angle ◽  
Butanetetracarboxylic Acid

In the anti-wrinkle finishing of cotton fabrics, the decreased dyeability of the finished fabrics has always been a difficult problem. A new anti-wrinkle finishing mode was developed to solve this problem by changing the finishing sequence of fabric dyeing and anti-wrinkle. In this research, the partial oxidization of raffinose with sodium periodate generated multiple aldehydes, which acted as multifunctional cross-linkers and endowed cotton fabrics with anti-wrinkle and hydrophilic properties. The structural characteristics of oxyRa were analyzed by FTIR and 13C-NMR. Through response surface methodology (RSM), the finishing model of oxyRa was established from the influencing factors of catalyst concentration, pH, curing temperature and time, and the optimized finishing process: the catalyst concentration was 20.12 g/L, pH was 4.32, curing temperature was 150 °C and curing time was 120 s. Under this condition, the predicted wrinkle recovery angle (WRA) of the finished fabric was up to 249.76°, Tensile strength (TS) was 75.62%, Whiteness index (WI) was 70.69. Importantly, comparing the anti-wrinkle and dyeing performance of the fabric with anti-wrinkle and then dyeing and anti-wrinkle after dyeing, the oxyRa-treated fabrics showed better dyeing properties compared with previously reported dimethyldihydroxyethylene urea (DMDHEU), glutaraldehyde (GA), and 1,2,3,4-butanetetracarboxylic acid (BTCA). Analysis of the combined mechanism of different finishing agents and cellulose, demonstrated the reason why oxyRa can be used to change the order of dyeing and anti-wrinkle finishing.

scholarly journals Improvement of hand functions of spinal cord injury patients with electromyography-driven hand exoskeleton: A feasibility study

2020 ◽  
Vol 1 ◽  
Author(s):  
Youngmok Yun ◽  
Youngjin Na ◽  
Paria Esmatloo ◽  
Sarah Dancausse ◽  
Alfredo Serrato ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Degrees Of Freedom ◽  
Standardized Test ◽  
Hand Function ◽  
Severe Disabilities ◽  
Finger Movements ◽  
Control Approach ◽  
Cord Injury ◽  
Hand Exoskeleton

Abstract We have developed a one-of-a-kind hand exoskeleton, called Maestro, which can power finger movements of those surviving severe disabilities to complete daily tasks using compliant joints. In this paper, we present results from an electromyography (EMG) control strategy conducted with spinal cord injury (SCI) patients (C5, C6, and C7) in which the subjects completed daily tasks controlling Maestro with EMG signals from their forearm muscles. With its compliant actuation and its degrees of freedom that match the natural finger movements, Maestro is capable of helping the subjects grasp and manipulate a variety of daily objects (more than 15 from a standardized set). To generate control commands for Maestro, an artificial neural network algorithm was implemented along with a probabilistic control approach to classify and deliver four hand poses robustly with three EMG signals measured from the forearm and palm. Increase in the scores of a standardized test, called the Sollerman hand function test, and enhancement in different aspects of grasping such as strength shows feasibility that Maestro can be capable of improving the hand function of SCI subjects.

A Mathematical Principle and Application on Design of Planar Six-Bar Mechanism with unto Three-Ordered Intermission at Limit Position(s)

2010 ◽  
Vol 37-38 ◽  
pp. 9-13
Author(s):  
Hong Xin Wang ◽  
Ning Dai
Keyword(s):  
Design Method ◽  
Optimization Method ◽  
Basic Function ◽  
Mathematical Principle ◽  
Transmission Characteristics ◽  
Basic Functions ◽  
Combined Mechanism ◽  
Limit Position ◽  
Derivatives Of ◽  
Better Than

A non-iterative design method about high order intermittent mechanisms is presented. The mathematical principle is that a compound function produced by two basic functions, and then one to three order derivatives of the compound function are all zeroes when one order derivative of each basic function is zero at the same moment. The design method is that a combined mechanism is constructed by six bars; the displacement functions of the front four-bar and back four-bar mechanisms are separately built, let one order derivatives of two displacement functions separately be zero at the same moment, and then get geometrical relationships and solution on the intermittent mechanism. A design example shows that this method is simpler and transmission characteristics are better than optimization method.

Clinical findings in C5-C6 and C5-C7 root palsies with brachial plexus traction lesions

2012 ◽  
Vol 38 (3) ◽  
pp. 237-241 ◽  
Author(s):  
J. A. Bertelli ◽  
M. F. Ghizoni
Keyword(s):  
Brachial Plexus ◽  
External Rotation ◽  
Elbow Flexion ◽  
Clinical Findings ◽  
Hand Strength ◽  
Shoulder Abduction ◽  
Finger Extension ◽  
Root Injury ◽  
Flexion Extension

Stretch injuries of the C5-C7 roots of the brachial plexus traditionally have been associated with palsies of shoulder abduction/external rotation, elbow flexion/extension, and wrist, thumb, and finger extension. Based on current myotome maps we hypothesized that, as far as motion is concerned, palsies involving C5-C6 and C5-C7 root injuries should be similar. In 38 patients with upper-type palsies of the brachial plexus, we examined for correlations between clinical findings and root injury level, as documented by CT tomomyeloscan. Contrary to commonly held beliefs, C5-C7 root injuries were not associated with loss of extension of the elbow, wrist, thumb, or fingers, but residual hand strength was much lower with C5-C7 vs C5-C6 lesions.

On Integration of Additive Manufacturing During the Design and Development of a Rehabilitation Robot: A Case Study

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Kaci E. Madden ◽  
Ashish D. Deshpande
Keyword(s):  
Additive Manufacturing ◽  
Neurological Disorders ◽  
Development Process ◽  
Mechanical Design ◽  
Rehabilitation Robotics ◽  
Critical Design ◽  
Rehabilitation Robots ◽  
Time Optimization ◽  
Hand Exoskeleton

The field of rehabilitation robotics has emerged to address the growing desire to improve therapy modalities after neurological disorders, such as a stroke. For rehabilitation robots to be successful as clinical devices, a number of mechanical design challenges must be addressed, including ergonomic interactions, weight and size minimization, and cost–time optimization. We present additive manufacturing (AM) as a compelling solution to these challenges by demonstrating how the integration of AM into the development process of a hand exoskeleton leads to critical design improvements and substantially reduces prototyping cost and time.

scholarly journals A Multicomponent Blend as a Diesel Fuel Surrogate for Compression Ignition Engine Applications

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Yuanjiang Pei ◽  
Marco Mehl ◽  
Wei Liu ◽  
Tianfeng Lu ◽  
William J. Pitz ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Flow Reactor ◽  
Expert Knowledge ◽  
Combustion Model ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Combined Mechanism ◽  
Fuel Surrogate ◽  
Skeletal Mechanism

A mixture of n-dodecane and m-xylene is investigated as a diesel fuel surrogate for compression ignition (CI) engine applications. Compared to neat n-dodecane, this binary mixture is more representative of diesel fuel because it contains an alkyl-benzene which represents an important chemical class present in diesel fuels. A detailed multicomponent mechanism for n-dodecane and m-xylene was developed by combining a previously developed n-dodecane mechanism with a recently developed mechanism for xylenes. The xylene mechanism is shown to reproduce experimental ignition data from a rapid compression machine (RCM) and shock tube (ST), speciation data from the jet stirred reactor and flame speed data. This combined mechanism was validated by comparing predictions from the model with experimental data for ignition in STs and for reactivity in a flow reactor. The combined mechanism, consisting of 2885 species and 11,754 reactions, was reduced to a skeletal mechanism consisting 163 species and 887 reactions for 3D diesel engine simulations. The mechanism reduction was performed using directed relation graph (DRG) with expert knowledge (DRG-X) and DRG-aided sensitivity analysis (DRGASA) at a fixed fuel composition of 77% of n-dodecane and 23% m-xylene by volume. The sample space for the reduction covered pressure of 1–80 bar, equivalence ratio of 0.5–2.0, and initial temperature of 700–1600 K for ignition. The skeletal mechanism was compared with the detailed mechanism for ignition and flow reactor predictions. Finally, the skeletal mechanism was validated against a spray flame dataset under diesel engine conditions documented on the engine combustion network (ECN) website. These multidimensional simulations were performed using a representative interactive flame (RIF) turbulent combustion model. Encouraging results were obtained compared to the experiments with regard to the predictions of ignition delay and lift-off length at different ambient temperatures.

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