NCT00771589

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.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
10

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started May 2008

Geographic Reach
1 country

2 active sites

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

May 1, 2008

Completed
5 months until next milestone

First Submitted

Initial submission to the registry

October 8, 2008

Completed
5 days until next milestone

First Posted

Study publicly available on registry

October 13, 2008

Completed
3 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 1, 2009

Completed
3 months until next milestone

Study Completion

Last participant's last visit for all outcomes

April 1, 2009

Completed
Last Updated

October 13, 2008

Status Verified

October 1, 2008

Enrollment Period

8 months

First QC Date

October 8, 2008

Last Update Submit

October 10, 2008

Conditions

Study Arms (1)

Prosthesis

EXPERIMENTAL

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

Interventions

Motorized External Knee Prosthesis for above knee amputees.

Also known as: Agonist Antagonist Knee Prosthesis
Prosthesis

Eligibility Criteria

Age18 Years - 50 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • 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).

You may not qualify if:

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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

Biomechatronics Research Group, MIT

Cambridge, Massachusetts, 02142, United States

RECRUITING

LIfestyle Prosthetics & Orthotics

North Andover, Massachusetts, 01845, United States

RECRUITING

Related Publications (1)

  • Martinez-Villalpando EC, Herr H. Agonist-antagonist active knee prosthesis: a preliminary study in level-ground walking. J Rehabil Res Dev. 2009;46(3):361-73.

Study Officials

  • Hugh Herr, Ph.D.

    Massachusetts Institute of Technology

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Hugh Herr, Ph,D

CONTACT

Robert Emerson, CP

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NA
Masking
NONE
Purpose
DIAGNOSTIC
Intervention Model
SINGLE GROUP
Sponsor Type
FED

Study Record Dates

First Submitted

October 8, 2008

First Posted

October 13, 2008

Study Start

May 1, 2008

Primary Completion

January 1, 2009

Study Completion

April 1, 2009

Last Updated

October 13, 2008

Record last verified: 2008-10

Locations