Lower-limb orthotic devices may be used to aid or restore mobility to the impaired user. Powered orthoses, in particular, hold great potential in improving the quality of life for individuals with locomotor difficulties because active control of an orthosis can aid limb movement in common tasks that may even be impossible if unaided. However, these devices have primarily remained the products of research labs with the number of effective commercial applications for the laity being nearly nonexistent. This paper provides an overview of the current status of powered orthoses and goes on to discuss key issues in modeling and control of powered orthoses so that designers can have a unified framework in developing user-oriented devices. Key concepts are demonstrated for a powered knee-orthosis intended for assisting the sit-to-stand task, and both pneumatic muscle and dc motor actuators are considered in this conceptual design study. In the final analysis, we conclude that the ability to provide sit-to-stand assistance is profoundly dependent on the type of control signal employed to control the actuator from the user–orthosis interface.

1.
Defense Advanced Research Projects Agency, 2006, “
Exoskeletons for Human Performance Augmentation
,” http://www.darpa.mil/dso/thrust/matdev/ehpa.htmhttp://www.darpa.mil/dso/thrust/matdev/ehpa.htm.
2.
Kazerooni
,
H.
,
Steger
,
R.
, and
Huang
,
L.
, 2006, “
Hybrid Control of the Berkeley Lower Extremity Exoskeleton BLEEX
,”
Int. J. Robot. Res.
0278-3649,
25
(
5
), pp.
561
573
.
3.
Guizzo
,
E.
, and
Goldstein
,
H.
, 2005, “
The Rise of the Body Bots
,”
IEEE Spectrum
0018-9235,
42
(
10
), pp.
50
56
.
4.
Kaye
,
H. S.
,
LaPlante
,
M. P.
,
Carlson
,
D.
, and
Wenger
,
B. L.
, 1996,
Trends in Disability Rates in the United States, 1970-1994
, Disability Statistics Abstracts,
17th ed.
,
U.S. Department of Education
, National Institute on Disability and Rehabilitation Research, Washington, D.C.
5.
Hutchinson
,
E.
,
Riley
,
P. O.
, and
Krebs
,
D.
, 1994, “
A Dynamic Analysis of the Joint Forces and Torques During Rising from a Chair
,”
IEEE Trans. Rehabil. Eng.
1063-6528,
2
(
2
), pp.
49
56
.
6.
Schultz
,
A.
,
Alexander
,
N.
, and
Ashton-Miller
,
J.
, 1992, “
Biomechanical Analyses of Rising from a Chair
,”
J. Biomech.
0021-9290,
25
(
2
), pp.
1383
1391
.
7.
Johnson
,
D. C.
,
Repperger
,
D. W.
, and
Thompson
,
G.
, 1996, “
Development of a Mobility Assist for the Paralyzed, Amputee, and Spastic Patient
,”
Proc. of the 1996 15th Southern Biomedical Engineering Conference
, Dayton, OH, March 29-31, pp.
67
70
.
8.
Rosen
,
J.
,
Brand
,
M.
,
Fuchs
,
M. B.
, and
Arcan
,
M.
, 2001, “
A Myosignal-Based Powered Exoskeleton System
,”
IEEE Trans. Syst. Man Cybern., Part A. Syst. Humans
1083-4427,
31
(
3
), pp.
210
222
.
9.
Umetami
,
Y.
,
Yamada
,
Y.
,
Morizono
,
T.
,
Yoshida
,
T.
, and
Aoki
,
S.
, 1999, “
‘Skil Mate,’ Wearable Exoskeleton Robot
,”
Proc. of the IEEE International Conference on Systems, Man and Cybernetics
, Tokyo, Japan, October,
4
, pp.
984
988
.
10.
Yamamoto
,
K.
,
Kyodo
,
K.
,
Ishii
,
M.
,
Matsuo
,
T.
, and
Sawada
,
K.
, 2000, “
Power Assisting Suit Utilizing Muscle Hardness Sensor Using Load Cell and Rotary Actuator Using Pressure Cuff
,”
Proc. of the 6th Triennial International Symposium on Fluid Control Measurement, and Visualization
, Sherbrooke, Canada, August 13-17.
11.
Kawamoto
,
H.
,
Lee
,
S.
,
Kanbe
,
S.
, and
Sankai
,
Y.
, 2003, “
Power Assist Method for hal-3 Using Emg-Based Feedback Controller
,”
Proc. IEEE International Conference on: Systems, Man and Cybernetics
, Washington, DC, October 5-8,
2
, pp.
1648
1653
.
12.
Ferris
,
D. P.
,
Czerniecki
,
J. M.
, and
Hannaford
,
B.
, 2005, “
An Ankle-Foot Orthosis Powered by Artificial Muscles
,”
J. Appl. Biomech.
,
21
(
2
), pp.
189
197
.
13.
Manal
,
K.
, and
Buchanan
,
T. S.
, 2003, “
A One-Parameter Neural Activation to Muscle Activation Model: Estimating Isometric Joint Moments from Electromyograms
,”
J. Biomech.
0021-9290,
36
(
8
), pp.
1197
1202
.
14.
Alkner
,
B. A.
,
Tesch
,
P. A.
, and
Berg
,
H. E.
, 2000, “
Quadriceps EMG/Force Relationship in Knee Extension and Leg Press
,”
Med. Sci. Sports Exercise
0195-9131,
32
(
2
), pp.
459
463
.
15.
Winter
,
D. A.
, 1991,
Biomechanics and Motor Control of Human Gait: Normal, Elderly, and Pathological
,
2nd ed.
University of Waterloo Press
, Waterloo, ON, Canada.
16.
De Luca
,
C. J.
, 1997, “
The Use of Surface Electromyography in Biomechanics
,”
J. Appl. Biomech.
,
13
, pp.
135
163
.
17.
Kawamoto
,
H.
, and
Sankai
,
Y.
, 2002, “
Power Assist System HAL-3 for Gait Disorder Person
,”
Proceedings of the 8th International Conference on Computers Helping People with Special Needs
, Linz, Austria, July 15-20, pp.
196
203
.
18.
19.
Wheeler
,
J. W.
,
Krebs
,
H. I.
, and
Hogan
,
N.
, 2004, “
An Ankle Robot for a Modular Gait Rehabilitation System
,”
Proceedings of 2004 IEEE/ASJ International Conference on Intelligent Robots and Systems
, pp.
1680
1684
.
20.
Buerger
,
S. P.
,
Krebs
,
H. I.
, and
Hogan
,
N.
, 2001, “
Characterization and Control of a Screw-driven Robot for Neurorehabilitation
,”
Proceedings of the 2001 IEEE International Conference on Control Applications
, Mexico City, Mexico, September 5-7, pp.
388
394
.
21.
Hollander
,
K. W.
, and
Sugar
,
T. G.
, 2006, “
Design of Lightweight Lead Screw Actuators for Wearable Robotic Applications
,”
J. Mech. Des.
1050-0472,
128
, pp.
644
648
.
22.
Hollander
,
K. W.
,
Sugar
,
T. G.
, and
Herring
,
D. E.
, 2005, “
Adjustable Robotic Tendon using a Jack Spring
,”
Proceedings of the 2005 IEEE 9th International Conference on Rehabilitation Robotics
, Chicago, IL, June28-July 1, pp.
113
118
.
23.
Repperger
,
D.
, and
Phillips
,
C.
, 2000, “
Developing Intelligent Control from a Biological Perspective to Examine Paradigms for Activation Utilizing Pneumatic Muscle Actuators
,”
Proceedings of the 15th IEEE International Symposium on Intelligent Control
, Rio, Greece, July 17-19, pp.
205
210
.
24.
Hesselroth
,
T.
,
Sarkar
,
K.
, and
Patrik van der Smagt
,
K. S.
, 1994, “
Neural Network Control of a Pneumatic Robot Arm
,”
IEEE Trans. Syst. Man Cybern.
0018-9472,
24
(
1
), pp.
28
38
.
25.
Pack
,
R. T.
,
Christopher
,
J. L.
, Jr.
, and
Kawamura
,
K.
, 1997, “
A Rubbertuator-Based Structure-Climbing Inspection Robot
,”
Proceedings of the 1997 IEEE International Conference on Robotics and Automation
, Albuquerque, NM, April 20-25, pp.
1869
1874
.
26.
Birch
,
M.
,
Quinn
,
R.
,
Hahm
,
G.
,
Phillips
,
S.
,
Drennan
,
B.
,
Beer
,
R.
,
Xinyu
,
Y.
,
Garverick
,
S.
,
Laksanacharoen
,
S.
,
Pollack
,
A.
, and
Ritzmann
,
R.
, 2001, “
A Miniature Hybrid Robot Propelled by Legs
,”
Proceedings of the 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems
, Maui, HI, October/November,
2
, pp.
845
851
.
27.
Caldwell
,
D.
,
Tsagarakis
,
N.
,
Artrit
,
P.
,
Canderle
,
J.
,
Davis
,
S.
, and
Medrano-Cerda
,
G.
, 2001, “
Biomimetic and Smart Technology Principles of Humanoid Design
,”
Proceedings of the 2001 IEEE/ASME International Conference on Advanced Intelligent Mechatronics
, Como, Italy, July,
2
, pp.
965
970
.
28.
Caldwell
,
D.
,
Tsagarakis
,
N.
,
Medrano-Cerda
,
G.
,
Schofield
,
J.
, and
Brown
,
S.
, 1999, “
Development of a Pneumatic Muscle Actuator Driven Manipulator Rig for Nuclear Waste Retrieval Operations
,”
Proceedings of the 1999 IEEE International Conference on Robotics and Automation
, Detroit, MI, May,
1
, pp.
525
530
.
29.
Tsagarakis
,
N.
,
Caldwell
,
D.
, and
Medrano-Cerda
,
G.
, 1999, “
A 7 DOF Pneumatic Muscle Actuator (pMA) Powered Exoskeleton
,”
Proceedings 8th IEEE International Workshop Robot and Human Interaction
,
RO-MAN'99
,
IEEE Press
, pp.
327
333
.
30.
Caldwell
,
D.
,
Tsagarakis
,
N.
,
Badihi
,
D.
, and
Medrano-Cerda
,
G.
, 1998, “
Pneumatic Muscle Actuator Technology: A Light Weight Power System for a Humanoid Robot
,”
Proceedings of the 1998 IEEE International Conference on Robotics and Automation
, Leuven, Belgium, May,
4
, pp.
3053
3058
.
31.
Caldwell
,
D.
,
Medrano-Cerda
,
G.
, and
Goodwin
,
M.
, 1993, “
Braided Pneumatic Actuator Control of a Multi-Jointed Manipulator
,”
Proceedings of the 1993 International Conference on Systems, Man, and Cybernetics
, Le Touquet, France, October 17-20,
1
, pp.
423
428
.
32.
Colbrunn
,
R.
,
Nelson
,
G.
, and
Quinn
,
R.
, 2001, “
Design and Control of a Robotic Leg with Braided Pneumatic Aactuators
,”
Proceedings of the 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems
, Maui, HI,
2
, pp.
992
998
.
33.
Noritsugu
,
T.
, and
Tanaka
,
T.
, 1997, “
Application of Rubber Artificial Muscle Manipulator as a Rehabilitation Robot
,”
IEEE/ASME Trans. Mechatron.
1083-4435,
2
(
4
), pp.
259
267
.
34.
Noritsugu
,
T.
,
Sasaki
,
D.
, and
Takaiwa
,
M.
, 2003, “
Application of Artificial Pneumatic Rubber Muscles to a Human Friendly Robot
,”
Proceedings of the 2003 IEEE International Conference on Robotics and Automation
, Taipei, Taiwan, September 14-19,
2
, pp.
2188
2193
.
35.
Jeong
,
Y.
,
Lee
,
D.
,
Kim
,
K.
, and
Park
,
J. O.
, 2000, “
A Wearable Robotic Arm with High Force-Reflection Capability
,”
Proceedings of the 9th IEEE International Workshop on Robot and Human Interactive Communication
, Osaka, Japan, September, pp.
411
416
.
36.
Prior
,
S.
, and
Warner
,
P.
, 1991, “
A New Development in Low Cost Pneumatic Actuators
,”
Proc. 5th International Conference on Advanced Robotics
, Pisa, Italy, June 2-4,
2
, pp.
1590
1593
.
37.
Festo Corporation
, 2004, “
Fluidic muscle MAS data sheet
,” http://www.festo.comhttp://www.festo.com
38.
Bharadwaj
,
K.
,
Hollander
,
K. W.
,
Mathis
,
C. A.
, and
Sugar
,
T. G.
, 2004, “
Spring Over Muscle (SOM) Actuator for Rehabilitation Devices
,”
Proceedings of the 26th Annual International Conference of the IEEE EMBS
, San Francisco, CA, September 1-5, pp.
2726
2729
.
39.
Bharadwaj
,
K.
,
Sugar
,
T. G.
,
Koeneman
,
J. B.
, and
Koeneman
,
E. J.
, 2005, “
Design of a Robotic Gait Trainer using Spring over Muscle Actuators for Ankle Stroke Rehabilitation
,”
J. Biomech. Eng.
0148-0731,
127
, pp.
1009
1013
.
40.
Medrano-Cerda
,
G.
,
Bowler
,
C.
, and
Caldwell
,
D.
, 1995, “
Adaptive Position Control of Antagonistic Pneumatic Muscle Actuators
,”
Proceedings IEEE/RSJ International Conference on Intelligent Robots and Systems
,
1
, pp.
378
383
.
41.
Tondu
,
B.
, and
Lopez
,
P.
, 2000, “
Modeling and Control of McKibben Artificial Muscle Robot Actuators
,”
IEEE Control Syst. Mag.
0272-1708,
20
(
2
), pp.
15
38
.
42.
Carbonell
,
P.
,
Jiang
,
Z.
, and
Repperger
,
D.
, 2001, “
Nonlinear Control of a Pneumatic Muscle Actuator: Backstepping vs. Sliding-Mode
,”
Proceedings of the 2001 IEEE International Conference on Control Applications
, Mexico City, Mexico, September 5-7, pp.
167
172
.
43.
Caldwell
,
D. G.
,
Medrano-Cerda
,
G. A.
, and
Goodwin
,
M.
, 1994, “
Characteristics and Adaptive Control of Pneumatic Muscle Actuators for a Robotic Elbow
,”
Proceedings of the 1994 IEEE International Conference on Robotics and Automation
, San Diego, CA, May,
4
, pp.
3558
3563
.
44.
Herr
,
H.
, and
Kornbluh
,
R.
, 2004, “
New Horizons for Orthotic and Prosthetic Technology: Artificial Muscle for Ambulation
,”
Proc. of the SPIE
,
5385
, pp.
1
9
.
45.
Kamnik
,
R.
,
Bajd
,
T.
, and
Kralj
,
A.
, 1999, “
Functional Electrical Stimulation and Arm Supported Sit-to-Stand Transfer after Paraplegia: A Study of Kinetic Parameters
,”
Artif. Organs
0160-564X,
23
(
5
), pp.
413
417
.
46.
Mirbagheri
,
M. M.
,
Ladouceur
,
M.
,
Barbeau
,
H.
, and
Kearney
,
R. E.
, 2002, “
The Effects of Long-Term FES-Assisted Walking on Intrinsic and Reflex Dynamic Stiffness in Spastic Spinal-Cord-injured Subjects
,”
IEEE Trans. Neural Syst. Rehabil. Eng.
1534-4320,
10
(
4
), pp.
280
289
.
47.
Weber
,
M.
, and
Pfeiffer
,
F.
, 2003, “
Therapy of Hemiparetic Walking by FES
,”
Proc. of the 2003 IEEE International Conference on Robotics & Automation
, Taipei, Taiwan, September 14-19,
3
, pp.
4002
4007
.
48.
Bogie
,
K. M.
, and
Triolo
,
R. J.
, 2003, “
Effects of Regular Use of Neuromuscular Electrical Stimulation on Tissue Health
,”
J. Rehabil. Res. Dev.
0748-7711,
40
(
6
), pp.
469
476
.
49.
Silverthorn
,
D. U.
, 2001,
Human Physiology: An Integrated Approach
,
2nd ed.
,
Prentice–Hall
, Toronto, ON, Canada.
50.
Andrews
,
B.
, 1991, “
Control of Paraplegic Locomotion using Hybrid FES Systems
,”
Ann. Biomed. Eng.
0090-6964,
19
, pp.
626
627
.
51.
Karu
,
Z. Z.
,
Durfee
,
W. K.
, and
Barzilai
,
A. M.
, 1995, “
Reducing Muscle Fatigue in FES Applications by Stimulating with N-Let Pulse Trains
,”
IEEE Trans. Biomed. Eng.
0018-9294,
42
(
8
), pp.
809
817
.
52.
Patterson
,
R. P.
, and
Lockwood
,
J. S.
, 1993, “
The Influence of Electrode Size and Type on Surface Stimulation of the Quadriceps
,”
IEEE Trans. Rehabil. Eng.
1063-6528,
1
(
1
), pp.
59
62
.
53.
Chae
,
J.
, and
Hart
,
R.
, 1998, “
Comparison of Discomfort Associated with Surface and Percutaneous Intramuscular Electrical Stimulation for Persons with Chronic Hemiplegia
,”
Am. J. Phys. Med. Rehabil.
0894-9115,
77
(
6
), pp.
516
522
.
54.
Hemami
,
H.
, and
Jaswa
,
V.
, 1978, “
On a Three-Link Model of the Dynamics of Standing up and Sitting Down
,”
IEEE Trans. Syst. Man Cybern.
0018-9472,
8
(
2
), pp.
115
120
.
55.
Pai
,
Y.
, and
Rogers
,
M.
, 1991, “
Segmental Contributions to Total Body momentum in Sit-to-Stand
,”
Med. Sci. Sports Exercise
0195-9131,
23
(
2
), pp.
225
230
.
56.
Miller
,
M.
,
Schultz
,
A.
,
Alexander
,
N.
,
Warwick
,
D.
, and
Ashton-Miller
,
J.
, 1989, “
Dynamics of Rising from a Chair: Experimental Data Collection
,”
Proceedings ASME 1989 Biomechanics Symposium
, San Diego, CA, July,
89
, pp.
329
332
.
57.
Ikeda
,
E. R.
,
Schenkman
,
M. L.
,
Riley
,
P. O.
,
Hodge
,
W. A.
, 1991, “
Influence of Age on Dynamics of Rising from a Chair
,”
Phys. Ther.
0031-9023,
71
(
6
), pp.
473
481
.
58.
Lundin
,
T.
,
Grabiner
,
M.
, and
Jahnigen
,
D.
, 1995, “
On the Assumption of Bilateral Lower Extremity Joint Moment Symmetry During the Sit-to-Stand Task
,”
J. Biomech.
0021-9290,
28
(
1
), pp.
109
112
.
59.
Alexander
,
N.
,
Schultz
,
A.
, and
Warwick
,
D.
, 1991, “
Rising from a Chair: Effects of Age and Functional Ability on Performance Biomechanics
,”
J. Gerontol.
0022-1422,
46
, pp.
91
98
.
60.
Gruber
,
K.
,
Ruder
,
H.
,
Denoth
,
J.
, and
Schneider
,
K.
, 1998, “
A Comparative Study of Impact Dynamics: Wobbling Mass Model Versus Rigid Body Models
,”
J. Biomech.
0021-9290,
31
(
5
), pp.
439
444
.
61.
Zatsiorsky
,
V. M.
, 2002,
Kinetics of Human Motion
,
Human Kinetics
, Windsor, ON, Canada.
62.
Winter
,
D. A.
, 1979,
Biomechanics of Human Movement
,
Wiley
, Toronto, ON, Canada.
63.
Chou
,
C.-P.
, and
Hannaford
,
B.
, 1996, “
Measurement and Modeling of McKibben Pnuematic Artificial Muscles
,”
IEEE Trans. Rob. Autom.
1042-296X,
12
(
1
), pp.
90
102
.
64.
Tondu
,
B.
,
Boitier
,
V.
, and
Lopez
,
P.
, 1994, “
Naturally Compliant Robot-Arms Actuated by McKibben Artificial Muscles
,”
Proceedings of the 1994 IEEE International Conference on Systems
, Man, and Cybernetics,
3
, pp.
2635
2640
.
65.
Colbrunn
,
R. W.
,
Nelson
,
G. M.
, and
Quinn
,
R. D.
, 2001, “
Modeling of Braided Pneumatic Actuators for Robotic Control
,”
Proceedings of the 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems
,
4
, pp.
1964
1970
.
66.
Wight
,
D. L.
, 2003, “
Control of a Pneumatically Powered Orthosis
,” Master’s thesis, University of Waterloo, Waterloo, ON, Canada.
67.
Spong
,
M.
, and
Vidyasagar
,
M.
, 1989,
Robot Dynamics and Control
,
Wiley
, Toronto, ON, Canada.
68.
Pai
,
Y.
, and
Rogers
,
M.
, 1991, “
Speed Variation and Resultant Joint Torques During Sit-to-Stand
,”
Arch. Phys. Med. Rehabil.
0003-9993,
72
, pp.
881
885
.
69.
Winter
,
D. A.
, 1990,
Biomechanics and Motor Control of Human Movement
,
2nd ed.
,
Wiley
, Toronto, ON, Canada.
70.
Pezzack
,
J.
,
Norman
,
R.
, and
Winter
,
D.
, 1977, “
An Assessment of Derivative Determining Techniques Used for Motion Analysis
,”
J. Biomech.
0021-9290,
10
, pp.
377
382
.
71.
Robertson
,
D. G. E.
, and
Dowling
,
J. J.
, 2003, “
Design and Responses of Butterworth and Critically Damped Digital Filters
,”
J. Electromyogr Kinesiol
1050-6411,
13
, pp.
569
573
.
72.
Nise
,
N. S.
, 2000,
Control Systems Engineering
,
3rd ed.
,
Wiley
, Toronto, ON, Canada.
You do not currently have access to this content.