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Active Knee Prosthesis Study for Improvement of Locomotion for Above Knee Amputees

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00771589
Recruitment Status : Unknown
Verified October 2008 by Providence VA Medical Center.
Recruitment status was:  Recruiting
First Posted : October 13, 2008
Last Update Posted : October 13, 2008
Massachusetts Institute of Technology
Information provided by:
Providence VA Medical Center

Brief Summary:

The purpose of this study is to develop a robust, low-power, stable, and light weight, active knee prosthetic device that can dramatically increase gait symmetry and walking economy of a transfemoral amputee during walking.

State of the art prosthetic knees can be classified into three main classes: a) mechanically passive, b) variable-damping, and c) powered. Although the devices within each of these classes offer some advantages for above-knee amputees, their overall performance still presents some deficiencies. Artificial knees in the first two groups are predominantly damping devices, incapable of providing positive power output. Moreover, current powered prostheses are heavy and inefficient in their energy consumption, and/or they have a limited range of motion. To overcome such inadequacies, we have designed a novel prosthetic knee device with a biomimetic approach.

The design of the active knee prosthesis is inspired by the antagonistic muscle anatomy of the human knee joint. This device mimics the synergistic muscle activity at the knee using a double series-elastic actuator (SEA) system that resembles the major mono-articular muscle groups that help flex and extend the knee joint. The agonist-antagonist SEA knee architecture will allow for precise force control of the knee joint, mimicking the spring-like behavior of the human knee, as well as providing adequate energy for forward progression of the body. The SEA has been previously developed and tested on legged robots. Also, the SEA has been successfully applied to the development of an actuated ankle-foot orthoses (AAFO) at MIT AI Lab.

The mechanical architecture of the active knee prosthesis allows for independent engagement of flexion and extension tendon-like, series springs for the control of joint position and impedance, as well as net joint torque. Furthermore, this architecture permits a joint rotation with near zero friction, allowing the controller to take advantage of the passive dynamics of the system, thus, augmenting the overall energetic efficiency of the system.

Condition or disease Intervention/treatment Phase
Amputation Device: Active Knee Prosthesis Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 10 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: The Active Knee Prosthesis Will be Tested to Evaluate How Well it Improves the Gait Symmetry and Reduces the Metabolic Cost of an Amputee During Walking. The Prosthesis Will be Attached to the Socket of the Amputee.
Study Start Date : May 2008
Estimated Primary Completion Date : January 2009
Estimated Study Completion Date : April 2009

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Prosthesis
Motorized External Knee prosthesis for above knee amputees. Comprised of agonist and antagonist actuators to mimic behavior of knee joint during locomotion.
Device: Active Knee Prosthesis
Motorized External Knee Prosthesis for above knee amputees.
Other Name: Agonist Antagonist Knee Prosthesis

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • They will be experienced at prosthesis ambulation
  • Capacity of ambulation at least at a K3 level (i.e. having the ability or potential for ambulation with variable cadence).

Exclusion Criteria:

  • Amputee participants will be generally healthy and will have no other musculoskeletal problems or any known cardiovascular, pulmonary or neurological disorders.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00771589

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Contact: Hugh Herr, Ph,D 617 258 6574
Contact: Robert Emerson, CP 978-688-7900

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United States, Massachusetts
Biomechatronics Research Group, MIT Recruiting
Cambridge, Massachusetts, United States, 02142
Contact: Hugh Herr, Ph.D.    617-258-6574   
Contact: Ernesto Martinez, S.M.    617 324 1316   
Principal Investigator: Hugh Herr, Ph.D.         
Sub-Investigator: Ernesto Martinez, S.M.         
Sub-Investigator: Grant Elliott, M.Eng.         
LIfestyle Prosthetics & Orthotics Recruiting
North Andover, Massachusetts, United States, 01845
Contact: Robert Emeson, CP    978-688-7900   
Sponsors and Collaborators
Providence VA Medical Center
Massachusetts Institute of Technology
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Principal Investigator: Hugh Herr, Ph.D. Massachusetts Institute of Technology
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Hugh Herr, Ph.D., Massachusetts Institute of Technology Identifier: NCT00771589    
Other Study ID Numbers: 0804002682
First Posted: October 13, 2008    Key Record Dates
Last Update Posted: October 13, 2008
Last Verified: October 2008