Improving Elbow Torque Output of Stroke Patients with Assistive Torque Controlled by EMG Signals

[+] Author and Article Information
Hang-Shing Cheng

Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan 701 Phone: +886-6-2757575, ext. 62263 Fax: +886-6-2352973 e-mail: n1890115@ccmail.ncku.edu.tw

Ming-Shaung Ju

Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan 701 Phone: +886-6-2757575, ext. 62163 Fax: +886-6-2352973 e-mail: msju@mail.ncku.edu.tw

Chou-Ching K. Lin

Department of Neurology, University Hospital, National Cheng Kung University, Tainan, Taiwan 701 Phone: +886-6-2353535, ext. 2692 e-mail: cxl45@mail.ncku.edu.tw

J Biomech Eng 125(6), 881-886 (Jan 09, 2004) (6 pages) doi:10.1115/1.1634284 History: Received September 27, 2002; Revised June 25, 2003; Online January 09, 2004
Copyright © 2003 by ASME
Your Session has timed out. Please sign back in to continue.


Hart,  R. L., Kilgore,  K. L., and Peckham,  P., 1998, “A Comparison Between Control Methods for Implanted FES Hand-Grasp Systems,” IEEE Trans. Rehabil. Eng., 6(2), pp. 208–218.
Saxena,  S., Nikolic,  S., and Popovic,  D., 1995, “An EMG-Controlled Grasping System for Tetraplegics,” J. Rehabil. Res. Dev., 32(1), pp. 17–24.
Sennels,  S., Biering-sørensen,  F., Andersen,  O. T., and Hansen,  S. D., 1997, “Functional Neuromuscular Stimulation Controlled by Surface Electromyographic Signals Produced by Volitional Activation of the Same Muscle: Adaptive Removal of the Muscle Response from the Recorded EMG-Signal,” IEEE Trans. Rehabil. Eng., 5(2), pp. 195–206.
Reinkensmeyer,  D. J., Dewald,  J. P. A., and Rymer,  W. Z., 1999, “Guidance-Based Quantification of Arm Impairment Following Brain Injury,” IEEE Trans. Rehabil. Eng., 7(1), pp. 1–11.
Reinkensmeyer, D., Takahashi C., and Timoszyk, W., 1999, “Evaluation of an Assistive Controller for Reaching Following Brain Injury,” BMES/EMBS Conference, pp. 631.
Cozens,  J. A., 1999, “Robotic Assistance of an Active Upper Limb Exercise in Neurologically Impaired Patients,” IEEE Trans. Rehabil. Eng., 7(2), pp. 254–256.
Kiguchi,  K., Kariya,  S., watanable,  K., Izumi,  K., and Fukuda,  T., 2001, “An Exoskeletal Robot for Human Elbow Motion Support-Sensor Fusion, Adaptation, and Control,” IEEE Trans. Syst. Man Cybern., 31(3), pp. 353–361.
Duche⁁ne,  J., and Hogrel,  T.-Y., 2000, “A Model of EMG Generation,” IEEE Trans. Biomed. Eng., 47(2), pp. 192–201.
Hogan,  N., and Mann,  R. W., 1980, “Myoelectric Signal Processing: Optimal Estimation Applied to Electromyography-Part 1: Derivation of the Optimal Myprocessor,” IEEE Trans. Biomed. Eng., 27(7), pp. 382–395.
Hefftner,  G., Zucchini,  W., and Jaros,  G. G., 1988, “The Electromyogram (EMG) as a Control Signal for Functional Neuromuscular Stimulation-Part 1: Autoregressive Modeling as a Means of EMG Signature Discrimination,” IEEE Trans. Biomed. Eng., 35(4), pp. 230–237.
Zardoshti-Kermani,  M., Wheeler,  B. C., and Hashemi,  R. M., 1995, “EMG Feature Evaluation for Movement Control of Upper Extremity Prostheses,” IEEE Trans. Rehabil. Eng., 3(4), pp. 324–333.
Nishikawa, D., Yu, W., Yokoi, H., and Kakazy, Y., 1999, “EMG Prosthesis Hand Controller Discriminating Ten Motions Using Real-Time Learning Method,” Proc. of the 1999 IEEE/RSJ Intern. Conf. on Intelligent Robots and Systems, 3, pp. 1592–1597.
Wu, C.-H., Houk, J. C., Young, K.-Y., and Miller, L. E., 1990, “Nonlinear Damping of Limb Motion,” Chapter 13, in Multiple muscle systems, edited by J. M. Winters and S. L.-Y. Woo, published by Springer-Verlag.
Park,  E., and Meek,  S. G., 1995, “Adaptive Filtering of the Electromyographic Signal for Prosthetic Control and Force Estimation,” IEEE Trans. Biomed. Eng., 42(10), pp. 1048–1052.


Grahic Jump Location
Schematic diagram of the experimental setup. The EMG signals of the triceps and biceps and the elbow angle are measured to generate the torque command. Meanwhile, the subject is requested to support the applied load and to follow the predefined trajectory displayed on the monitor.
Grahic Jump Location
The subject lies on a bed with his forearm strapped to the manipulator and attempts to match the trajectory displayed on the monitor. The weight hanging on the disk provides the load during movement. (S : monitor, M : DC torque motor, D : disk, W : weight)
Grahic Jump Location
An example of the map produced to show the relationship between Kt, the EMG signal of the triceps, and the elbow angle.
Grahic Jump Location
The predefined trajectory in the tracking experiment. It is noted that the trajectory comprises a series of elbow movements including lifting a weight at a constant speed until the target position is attained, and then holding the weight for a specified period of time before lowering the weight at a slower speed and then holding it in position until the end of the trial.
Grahic Jump Location
The agonist IEMG of able-bodied subjects during the reaching experiment with assistive device activated (G=100%) and with no applied assistance (G=0). It is noted that the results on the left of the figure relate to movements in the flexion direction, while those on the right relate to the extension direction.
Grahic Jump Location
The effects of various parameter sets on the agonist IEMG (the upper plots) and the MPL (the lower plots). The two plots on the left provide the results when the parameter of the adaptive filter, β, is set to 1 in order to test the performance of the nonlinear damping under various conditions, including no assistive torque, and C0=0, 0.2, and 0.4. The two plots on the right present the results when the damping of the adaptive filter, C0, is set to 0 to test the performance of the adaptive filter under various conditions, including no assistive torque, and β=1, 2, and 4.
Grahic Jump Location
The results of stroke patient S3 in the tracking experiment: (a) without assistive torque, and (b) with assisting torque. In the upper plots, the solid lines present the mean values of the six trials, while the dotted lines indicate the range of one standard deviation. Meanwhile, the dashed lines present the desired trajectory. During these experiments, the subject moved the forearm in the extension direction during the ramp-up segment and then supported the load in the flexion direction.
Grahic Jump Location
Summary of results for RMS error, ISJ and IEMG of agonist and antagonist for: (a) able-bodied subjects with no assistive torque and for torque gains of 100% and with 150%, and (b) stroke subjects with no assistive torque and with a torque gain of 100%. Each bar indicates the average of each of these measurements for all test subjects and for all trials.




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In