Active Knee Prosthesis Study for Improvement of Locomotion for Above Knee Amputees
Recruitment status was: Recruiting
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.
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: 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 Study Completion Date:||April 2009|
|Estimated Primary Completion Date:||January 2009 (Final data collection date for primary outcome measure)|
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
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00771589
|United States, Massachusetts|
|Biomechatronics Research Group, MIT|
|Cambridge, Massachusetts, United States, 02142|
|LIfestyle Prosthetics & Orthotics|
|North Andover, Massachusetts, United States, 01845|
|Principal Investigator:||Hugh Herr, Ph.D.||Massachusetts Institute of Technology|