Estimating Wrist Joint Torque Using Regression Ensemble of Bagged Trees under Multiple Wrist Postures

Author(s):  
Ali H. Al-Timemy ◽  
Andrea Zonnino ◽  
Fabrizio Sergi
Keyword(s):  
1988 ◽  
Vol 4 (4) ◽  
pp. 326-341 ◽  
Author(s):  
Spiros G. Prassas

A biomechanical model of the press handstand was developed to evaluate and predict the shoulder joint torque requirements as well as the motion of a gymnast’s center of mass (CM) from an initial to a final (handstand) position. Five press handstands executed by gymnasts of differing abilities were filmed and analyzed. The results were compared to the predicted parameters of simulated presses. It was found that execution of the skill with fewer fluctuations in trunk and lower extremities angular velocity—a characteristic of skilled performance—required smoother and at times larger shoulder joint torques. Reduction of the hip joint angle by only 5 or 10° did not substantially reduce the shoulder joint torque requirements. Regarding CM motion, it was found that during performance the CM continuously elevated and remained close to a vertical line passing through the center of the wrist joint. All gymnasts, however, were found to be leaning slightly backward during the first part of the movement and slightly forward during the later phases. Modifications in wrist joint angle required to maintain each gymnast’s CM precisely above the center of the wrist joint were investigated.


2013 ◽  
Vol 109 (11) ◽  
pp. 2658-2665 ◽  
Author(s):  
Ernest N. Kamavuako ◽  
Erik J. Scheme ◽  
Kevin B. Englehart

In this paper, the predictive capability of surface and untargeted intramuscular electromyography (EMG) was compared with respect to wrist-joint torque to quantify which type of measurement better represents joint torque during multiple degrees-of-freedom (DoF) movements for possible application in prosthetic control. Ten able-bodied subjects participated in the study. Surface and intramuscular EMG was recorded concurrently from the right forearm. The subjects were instructed to track continuous contraction profiles using single and combined DoF in two trials. The association between torque and EMG was assessed using an artificial neural network. Results showed a significant difference between the two types of EMG ( P < 0.007) for all performance metrics: coefficient of determination (R2), Pearson correlation coefficient (PCC), and root mean square error (RMSE). The performance of surface EMG (R2 = 0.93 ± 0.03; PCC = 0.98 ± 0.01; RMSE = 8.7 ± 2.1%) was found to be superior compared with intramuscular EMG (R2 = 0.80 ± 0.07; PCC = 0.93 ± 0.03; RMSE = 14.5 ± 2.9%). The higher values of PCC compared with R2 indicate that both methods are able to track the torque profile well but have some trouble (particularly intramuscular EMG) in estimating the exact amplitude. The possible cause for the difference, thus the low performance of intramuscular EMG, may be attributed to the very high selectivity of the recordings used in this study.


2012 ◽  
Vol 24 (5) ◽  
pp. 908-916 ◽  
Author(s):  
Yu Okamoto ◽  
◽  
Kotaro Tadano ◽  
Kenji Kawashima ◽  

In a master-slave system, operators control the master device based on visual information and sensory feedback. This suggests that the position sensors on the slave side are not always necessary. However, position signals are required to estimate the acting force conveyed to the slave using an observer which realize the force sensorless control. In this paper, we focused on the biological signals of the operator to estimate the slave side’s condition which can be used to estimate the external force. In the early stage of the research, we investigate biological signals just with 1-DOF masterslave system. First, we measured electromyographic (EMG) and gripping force of operators when pushing objects. We verified that predictive signals can be used for estimation of touching the objects. Second, we propose a method, which uses wrist joint torque and Total Contraction Level (TCL) calculated by the EMG when pushing the virtual elastic films, of estimating the acting force conveyed to the slave. We verify that the proposed method can estimate external force under specific conditions with a trained subject.


2015 ◽  
Vol 04 (S 02) ◽  
Author(s):  
M. Rizzo ◽  
A. Hooke ◽  
K. An ◽  
W. Cooney

Author(s):  
Karim Mowla ◽  
Elham Rajaee M. D. ◽  
Mehrdad Dargahi-MalAmir M. D. ◽  
Neda Yousefinezhad ◽  
Maryam Jamali Hondori

Background: Rheumatoid arthritis is a systemic multifactor disease that presented with symmetrical polyarthritis more preferably in small wrist joint and ankle. Synovial pannus cause destruction and deformities in joints. The main reason of this disease in unknown, but past researchesshowed that genetically factor play important role beside environmental factors in susceptibility to this entity. Method:100 patients with rheumatoid arthritis diagnosed upon ACR 2010 criteria enrolled study. 92 healthy patents also enrolled DNA studying. of both group was extracted through DNA extraction kits by blood sampling. HLA-DRB1 typing was done by PCR-SSP method. Results: There were no significant differences in HLADRB1 *04, HLADRB1*08 and HLADRB1*11 alleles presentation between patients and healthy controls. Only there were statically significant correlation between HLA-DRB1*08 and Rheumatoid factor positive patents. (P = 0.025).


2013 ◽  
Vol 1 (1) ◽  
pp. 42-25
Author(s):  
Nabil N. Swadi

This paper is concerned with the study of the kinematic and kinetic analysis of a slider crank linkage using D'Alembert's principle. The links of the considered mechanism are assumed to be rigid. The analytical solution to observe the motion (displacement, velocity, and acceleration), reactions at each joint, torque required to drive the mechanism and the shaking force have been computed by a computer program written in MATLAB language over one complete revolution of the crank shaft. The results are compared with a finite element simulation carried out by using ANSYS Workbench software and are found to be in good agreement. A graphical method (relative velocity and acceleration method) has been also applied for two phases of the crank shaft (q2 = 10° and 130°). The results obtained from this method (graphical) are compared with those obtained from analytical and numerical method and are found very acceptable. To make the analysis linear the friction force on the joints and sliding interface are neglected. All results, in this work, are obtained when the crank shaft turns at a uniform angular velocity (w2 = 188.5 rad/s) and time dependent gas pressure force on the slider crown.


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