Strategic Research Program 17 (VUB Funding)

Exercise and the Brain in Health & Disease: The Added Value of Human-Centered Robotics

Objectives: The main objectives are to determine neural dynamics during gait using electro-encephalography as well as brain sources and to investigate the attentional demand during walking in able-bodied individuals, and individuals with an amputation.

Materials & Methods: 6 able-bodied individuals conducted one experimental trial, and 6 unilateral transtibial and 6 unilateral transfemoral amputees performed 2 experimental trials; the first with the current and the second with a novel powered transtibial prosthesis, i.e. the Ankle Mimicking Prosthetic foot 4.0. Each experimental trial comprised 2 walking tasks; 6 and 2min treadmill walking at normal speed interspersed by 5min of rest. During 6min walking the sustained attention to response (go-no go) task, with measures reaction time and accuracy, was performed. Electro-encephalographic (EEG) data were gathered when subjects walked 2min. Motor-related cortical potentials and brain activity during gait are extracted using EEG.

Study Overview

• Status: Completed
• Conditions: Prosthesis User; Amputation; Traumatic, Limb, Lower
• Intervention / Treatment: Other: No intervention; Device: AMPfoot 4.0

Detailed Description

Detailed description of the novel device:

The device mainly distinguishes itself from commercial prostheses thanks to its new type of actuation providing a compact and energy efficient solution to the challenge of ankle-foot actuation. This new actuation method consists of using springs, a servo motor and a locking mechanism, coupled with a sensory network providing intelligence to the robotic device. The AMPfoot 4.0 design is also based on previous research conducted on the AMP-Foot 2. However, it is important to note that in contrast with its preceding designs, the AMP-Foot 4.0 does not provide active propulsion at push-off.

During walking, the AMP-Foot 4.0 working principle is divided into two main logic sequences, i.e. the stance and the swing phase. These two phases are detected by analyzing gyroscope and acceleration measurements from an Inertial Measurement Unit chip. During the stance phase, the ankle performs a dorsi-flexing movement while a plantar-flexing torque is applied at the ankle. The person's gravitational potential energy is stored into elastic potential energy by means of the used spring. It is this spring that provides the plantar-flexing torque required at the ankle as reaction to the movement of the user. Due to the use of a locking system, the prosthesis can adapt its so-called zero torque rest point depending on the slope or stride length of the user. This provides adaptability and therefore greater comfort compared to prostheses with a fixed zero torque rest point. During the swing phase, the locking mechanism unlocks to free the ankle movement. Parallel springs external to the stance system are then activated to reset the foot to its initial position. From that moment, the device is ready for a new step.

• Study Type: Interventional
• Enrollment (Actual): 18
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Vlaams Brabant
    • Brussel, Vlaams Brabant, Belgium, 1050
      • Vrije Universiteit Brussel

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Unilateral transfemoral amputees
• Unilateral transtibial amputees
• Able-bodied individuals

Exclusion Criteria:

• Children
• Functional k-level lower than 4 (Amputee has the ability for prosthetic ambulation that exceeds basic ambulation skills, exhibiting high impact, stress or energy levels)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Non-Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Able-bodied individuals	Other: No intervention; The control group included healthy subjects. Comparisons were made between amputees and able-bodied individuals.
Experimental: Transtibial amputee	Device: AMPfoot 4.0; The novel prosthetic device, i.e. AMPfoot 4.0, was tested during walking in amputees. A dual-task was conducted and non-invasive electro-encephalography was used to investigate neural dynamics.
Experimental: Transfemoral amputee	Device: AMPfoot 4.0; The novel prosthetic device, i.e. AMPfoot 4.0, was tested during walking in amputees. A dual-task was conducted and non-invasive electro-encephalography was used to investigate neural dynamics.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Reaction time (in ms) of responses during go - no go cognitive task	Time between visual stimulus and motor response (pushing button)	Through study completion, a period of 2 months
Accuracy (in percentage) of correct responses during go - no go cognitive task	Accuracy of motor responses to visual stimuli	Through study completion, a period of 2 months
EEG extracted brain signals, i.e. motor-related cortical potentials	Non-invasive electro-encephalography was used to determine electro-cortical potentials and brain sources of these potentials	Through study completion, a period of 2 months

Collaborators and Investigators

• Sponsor: Vrije Universiteit Brussel

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2016
• Primary Completion (Actual): December 15, 2016
• Study Completion (Actual): December 15, 2016

Study Registration Dates

• First Submitted: April 3, 2018
• First Submitted That Met QC Criteria: April 13, 2018
• First Posted (Actual): April 17, 2018

Study Record Updates

• Last Update Posted (Actual): April 17, 2018
• Last Update Submitted That Met QC Criteria: April 13, 2018
• Last Verified: April 1, 2018

More Information

Terms related to this study

• Keywords: gait; dual-task walking; AMPfoot; Prosthetics; electro-encephalography
• Additional Relevant MeSH Terms: Wounds and Injuries; Amputation, Traumatic
• Other Study ID Numbers: PROJECT-ID SRP 17

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No