The primary objective of the current project is to develop and test a real-time accurate neuro-mechanical model-based controllers of the lower limb The hypothesis are that the synergy-driven approach would adapt to changes in speed, the enhanced…
ID
Source
Brief title
Condition
- Other condition
- Bone and joint injuries
Synonym
Health condition
amputations
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The main study parameters are comparisons between measurements performed with
different controllers of the EMPOWER to evaluate their effect:
• Gait kinematics (a), obtained from patients
Comparison with the default controller
Left-to-right asymmetry
• Peak of the joint torque and timing of joint torque (a)
Comparison with the default controller
Analysis between the sound side and the prosthetic side
• Ankle and knee power (a)
Comparison with the default controller
Analysis between the sound side and the prosthetic
side
• Differences between control input (e)(b)(a)
• Data from all sensors are used to evaluate the step length, step height,
speed estimation, loading of the prosthesis, foot placement, healthy and
prosthetic joint torques, and evaluate correct switching between different
speeds
• COM, COP and GRF signals (a) to evaluate the balance strategies (recovery)
Secondary outcome
The secondary study parameters are:
• Joint compression load at the ankle and knee (a)
Comparison with the default controller
Analysis between the sound side and the prosthetic side
• Joint torque and timing of joint torque (a)
Comparison with the default controller
Analysis between the sound side and the prosthetic side
• Output from the prosthesis
• Work at the ankle joint on the prosthetic side
• Muscle activity (b) to evaluate changes in the use of different controllers
Background summary
Powered ankle prosthetics have the potential to improve the mobility of
patients supporting individuals to walk better reducing energy consumptions
thanks to the support they give during push off phase compared to non-powered
prosthesis. However, the control of such devices has still weaknesses that
prevent the user to perform various activities in a natural and safe manner and
regain balance after perturbations. Creating a new interface between the
powered prosthetic for the lower limb and the patient could overcome these
before mentioned problems.
This study proposes three different control approaches that implement a control
system that mimics the muscle dynamics and motor control strategies in humans.
The goal of this research is to assess a neuro-mechanical model able to online
control a prosthetic ankle joint according to subject-specific and motor
task-specific properties. We will test an EMG-driven model-based controller, a
synergies-driven model-based controller, and an enhanced reflex-driven
model-based controller. ln comparison with the default controller of the
Empower prosthetic foot from Ottobock, which already includes a neuromuscular
reflex-based model.
Study objective
The primary objective of the current project is to develop and test a real-time
accurate neuro-mechanical model-based controllers of the lower limb The
hypothesis are that the synergy-driven approach would adapt to changes in
speed, the enhanced reflex-driven approach with additional feedback pathways
would support balance, and the EMG-driven controller would improve voluntary
control of the prosthesis especially to execute movement that are not accounted
for in the previous mentioned models, like ascending and descending
stairs/ramps.
The secondary objective is to assess the mechanical loads on the healthy side
comparing each system to the default one.
Additionally, the difference in adaptation rate and preferences of patients to
the device are going to be investigated by a qualitative questionnarie.
Study design
Observational study in which a maximum of ten transtibial amputees will perform
different session walking on the treadmill to compare three different
controllers: an EMG-driven model, a synergy-driven model , and a reflex-driven
model.
Patients will undergo the following measurements in two days:
On the first day, the subject is included in the study (model calibration) and
he/she will interface the prosthesis device with the default control of the
empower and test the first developed enahnced reflex-driven controller
including perturbed walking trials to evaluate balance recovery. On the second
day, thesynergy-driven controller and EMG-driven controller would be tested.
There will also be a third day of trials , which is optional.
Study burden and risks
The patients will not have any personal benefit from participation.
The risks for the subjects participating in this study are small. All
experiments are performed wearing a fall prevention system (safety harness or
the ZeroG system, which is CE-marked). This creates a safe and controlled
environment for all activities investigated in this study.
There are no immediate risks of physical harm associated with the proposed
study.
• Measurement equipment: The used measurement equipment, is certified for its
use, and at most causes discomfort for the subject: The EMG electrodes and
motion capture markers can cause skin irritation (shaving, cleaning or removal
or tape).
• Experimental equipment: A potential risk might be unexpected behaviour of the
prosthetic ankle. Participants will use a safety harness in the Rehabilitation
Lab or the ZeroG system, which is CE-marked, in the Wearable Robotics Lab. In
case the prosthetic ankle acts differently than expected, the user can regain
balance using either the safety harness or the handlebars around the treadmill.
Moreover, the treadmill is safe to use. The treadmill can be stopped with an
emergency button at any time.
Drienerlolaan 5
Enschede 7522LW
NL
Drienerlolaan 5
Enschede 7522LW
NL
Listed location countries
Age
Inclusion criteria
In order to be eligible to participate in this study, a subject must meet all
of the following criteria:
Person is minimum 18 and maximum 60 years old.
Person has unilateral transtibial amputation
Person is able to walk with everyday prosthesis
Person with a body weight of less than 120 kg and BMI in the range from
18.5 to 29.9 kg/m^2 ( normal to overweight)
Person who is willing and able to independently provide informed consent
Person who is willing to comply with study procedures
Person who finished rehabilitation trajectory and using own prosthesis
at home for > 3 months.
Person who has an adequate, well-fitted socket
Functional level from K3 to K4 ( even if balance issues occurs more for
K2, for the current protocol that includes walking sessions on the treadmill it
is better to exclude them to be able to complete the trial):
Level 3: The patient has the ability or potential for ambulation with variable
cadence. Typical of the community ambulatory who has the ability to traverse
most environmental barriers and may have vocational, therapeutic, or exercise
activity that demands prosthetic utilization beyond simple locomotion.
Level 4: The patient has the ability or potential for prosthetic ambulation that
exceeds basic ambulation skills, exhibiting high impact, stress, or energy
levels. Typical of the prosthetic demands of the child, active adult, or
athlete.
Exclusion criteria
A potential subject who meets any of the following criteria will be excluded
from participation in this study:
* Pregnant women
* Person with conditions that would prevent participation and pose increased
risk (e.g. unstable cardiovascular conditions that preclude physical activity
such as walking)
* Person with weakened bones (e.g. osteoporosis)
* Person with a history of chronic skin breakdown of the residual limb
* Person who falls at least once a week for reasons that are not related to
prosthetic use (e.g. problems with vestibular system)
* Person who has life-threatening medical condition (e.g. terminal cancer,
severe heart disease)
* Person who is using under arm axillary crutches or walker
* Person in an emergency, life threatening situation
* Person who underwent osseointegration operation
* Person who is allergic to band aids or glue
Design
Recruitment
Medical products/devices used
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In other registers
| Register | ID |
|---|---|
| CCMO | NL81380.091.22 |