TY - JOUR
T1 - Volitional control of a prosthetic knee using surface electromyography
AU - Ha, Kevin H.
AU - Varol, Huseyin Atakan
AU - Goldfarb, Michael
N1 - Funding Information:
Manuscript received March 27, 2010; revised July 23, 2010; accepted August 12, 2010. Date of publication August 30, 2010; date of current version December 17, 2010. This work was supported by the National Institutes of Health under Grant R01EB005684–01. Asterisk indicates corresponding author. *K. H. Ha is with the Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235 USA (e-mail: kevin.h.ha@vanderbilt.edu). H. A. Varol and M. Goldfarb are with the Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235 USA (e-mail: atakan.varol@vanderbilt.edu; michael.goldfarb@vanderbilt.edu). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TBME.2010.2070840
PY - 2011/1
Y1 - 2011/1
N2 - This paper presents a method for providing volitional control of a powered knee prosthesis during nonweight-bearing activity such as sitting. The method utilizes an impedance framework, such that the joint can be programmed with a given stiffness and damping that reflects the nominal impedance properties of an intact joint. Volitional movement of the knee joint is commanded via the stiffness set-point angle of the joint impedance, which is commanded by the user as a function of the measured surface electromyogram (EMG) from the hamstring and quadriceps muscles of the residual limb. Rather than using the respective EMG measurements from these muscles to directly command the flexion or extension set point of the knee, the presented approach utilizes a combination of quadratic discriminant analysis and principal component analysis to align the user's intent to flex or extend the knee joint with the pattern of measured EMG. The approach was implemented on three transfemoral amputees, and their ability to control knee movement was characterized by a set of knee joint trajectory tracking tasks. Each amputee subject also performed the same set of trajectory tracking tasks with his sound side (intact) knee joint. The average root mean square trajectory tracking errors of the prosthetic knee employing the EMG-based volitional control and the intact knee of the three subjects were 6.2 and 5.2, respectively.
AB - This paper presents a method for providing volitional control of a powered knee prosthesis during nonweight-bearing activity such as sitting. The method utilizes an impedance framework, such that the joint can be programmed with a given stiffness and damping that reflects the nominal impedance properties of an intact joint. Volitional movement of the knee joint is commanded via the stiffness set-point angle of the joint impedance, which is commanded by the user as a function of the measured surface electromyogram (EMG) from the hamstring and quadriceps muscles of the residual limb. Rather than using the respective EMG measurements from these muscles to directly command the flexion or extension set point of the knee, the presented approach utilizes a combination of quadratic discriminant analysis and principal component analysis to align the user's intent to flex or extend the knee joint with the pattern of measured EMG. The approach was implemented on three transfemoral amputees, and their ability to control knee movement was characterized by a set of knee joint trajectory tracking tasks. Each amputee subject also performed the same set of trajectory tracking tasks with his sound side (intact) knee joint. The average root mean square trajectory tracking errors of the prosthetic knee employing the EMG-based volitional control and the intact knee of the three subjects were 6.2 and 5.2, respectively.
KW - Electromyography
KW - lower-limb prosthesis
KW - myoelectric control
KW - powered prosthesis
KW - transfemoral prosthesis
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U2 - 10.1109/TBME.2010.2070840
DO - 10.1109/TBME.2010.2070840
M3 - Article
C2 - 20805047
AN - SCOPUS:79551569624
VL - 58
SP - 144
EP - 151
JO - IEEE Transactions on Biomedical Engineering
JF - IEEE Transactions on Biomedical Engineering
SN - 0018-9294
IS - 1
M1 - 5559403
ER -