The long term goal of this project is to develop a controller for an upper extremity neuroprosthesis targeted for people with C5/C6 spinal cord injury (SCI). The challenge is to determine how to simultaneously stimulate different paralyzed muscles based on the EMG activity of muscles under retained voluntary control. The proposed controller extracts information from the recorded EMG signals and processes this information to generate the appropriate stimulation levels to activate the paralyzed muscles. The goal of this project was to design and evaluate this controller using a dynamic, three-dimensional musculoskeletal model of the arm. Different arm movements were recorded from able bodied subjects and these kinematics served as input to the model. The model was modified to reflect C5/C6 SCI, and inverse simulations were run to provide muscle activation patterns corresponding to the movements recorded. A set of "voluntary" and "paralyzed" muscles was selected for the controller based on each muscle's relevance as suggested by the simulations. Activation patterns were then used to train a dynamic neural network that predicts "paralyzed" muscle activations from "voluntary" muscle activations. The neural network controller was able to predict the activation level of three paralyzed muscles with less than 2% average prediction error, using four input muscles as inputs
[1]
J. Giuffrida,et al.
Synergistic Neural Network Control of FES Elbow Extension After Spinal Cord Injury Using EMG
,
2004
.
[2]
Bryan Buchholz,et al.
ISB recommendation on definitions of joint coordinate systems of various joints for the reporting of human joint motion--Part II: shoulder, elbow, wrist and hand.
,
2005,
Journal of biomechanics.
[3]
J. D. de Groot,et al.
A three-dimensional regression model of the shoulder rhythm.
,
2001,
Clinical biomechanics.
[4]
F. V. D. van der Helm.
A finite element musculoskeletal model of the shoulder mechanism.
,
1994,
Journal of biomechanics.
[5]
R. Kirsch,et al.
EMG-based prediction of shoulder and elbow kinematics in able-bodied and spinal cord injured individuals.
,
2000,
IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society.
[6]
Frans C. T. van der Helm,et al.
A standardized protocol for motion recordings of the shoulder
,
2002
.
[7]
H. E. J. Veeger,et al.
Toward standardized procedures for recording and describing 3-D shoulder movements
,
2003,
Behavior research methods, instruments, & computers : a journal of the Psychonomic Society, Inc.