A proposed orthotic model for locomotor rehabilitation.
Barbu, Daniela Mariana ; Dumitriu, Adrian ; Lache, Simona 等
1. INTRODUCTION
A new rehabilitation mechatronical device equipped with suitable
inertial sensors is presented, which enables training of a leg affected
by strokes or injuries, in coordination with the movements of the other,
normal, leg. The main purpose of our work (that is a part of ID_147
Project) is acquiring and implementation of an intelligent orthesis used
for recovery training of the subject with neuromotor problems. It is
destined especially to inferior and superior limbs joints recovery but
performing the corresponding exercises will affect also the muscles. It
will be conceived in a modular way (the mechanic module, the electronic
module and the interface module). It is attached to the leg or hand, in
the area that need recovery; it is programmed for each subject depending
on the program type of every subject. It is made from easy and
unassuming materials. As it was demonstrated as well in the evaluation
of the actual status, this project's subject is compliant with the
European and world trends and priorities for developing robotics systems
for medical recovery. Being designed for a large range of people with
locomotors and neuromotors problems and with a highly degree of
adaptation, the system we want to implement can have an important
contribution to knowledge evolvement in rehabilitation robotics field.
(Barbu et al., 2007)
[FIGURE 1 OMITTED]
So, thru this research work, we want to design, to realize and to
implement mechatronical system, which could help people with a specific
neuromotory rehabilitation therapy. Here we speak about the knee and
elbows joint, but the system can be adapted to the hands, ankles,
shoulders or haunches joint.
Therefore, our intention is to realize a robotic
mechanical-electronic system, which can be a device that helps an organ
to have a proper functionality, makes this project to be very important
for some category of people. The main contribution which this project
can bring to robotics and recovery orthotics, taking in account the
experience of the team members are: identifying new methods for
neuromotory recovery; adopting new approaches in the biomechanics of the
locomotory system; designing, making and implementation of a intelligent
orthosis for jointing problems recovery; evaluating from the user's
point of view, the efficiency of the recovery method recommended by the
therapist. The system's proposed structure represents a new
approach in the afferent area of the subject. (Barbu et al., 2007)
This paper presents mainly the virtual and experimental prototyping
of the orthotic system.
2. VIRTUAL PROTOTYPING OF THE ORTHESIS
Virtual engineering is defined as integrating geometric models and
related engineering tools such as analysis, and simulation,
optimization, and decision making tools, etc., within a
computer-generated environment that facilitates multidisciplinary
collaborative product development. By making the virtual prototype was
intended to determine the parameters involved in establishing the law of
motion of the mechanical system, for dimensioning in terms of mechanical
strength and electric motor to drive the election. By establishing the
law of motion can also see, the deviation from the law required, and
other parameters of movement that are not incorporated into the
functional (for example, the work area must be within the mechanical).
Virtual prototype mechanical system orthotics specialized software
was developed using a MBS (multi-body systems) from LMS International,
aiming at the next stages:
* acquisition of CAD elements of mechanical components orthotics;
* calculate, using MBS software, the mechanical characteristics of
bodies forming machine for sizing their system;
* development operation in terms of kinematic, and dynamic
mechanical system orthotics by geometric restrictions imposed on
movement of bodies in the program;
* imposition of various laws of motion of the mobile body using a
hyperbolic function in order to calculate the engine when needed and
tasks that appear in the joint system. These results are needed to elect
the type of engine (speed and power necessary to achieve the
experimental prototype of Orthotics).
Study and analysis of kinematics and dynamics of the two legs, the
active and involved, leading to these conclusions:
--equipping of both legs with sensors to measure movements of the
knee joint, i.e. the angle of movement.
--measuring the angular velocity of leg movement actively and
realization of a movement with a similar angular velocity of the foot
involved.
--measuring the corresponding acceleration active leg movements and
movements to achieve a similar acceleration of the leg resulted.
[FIGURE 2 OMITTED]
3. EXPERIMENTAL PROTOTYPING
The analysis of virtual prototype, it requires active leg fitted
with several types of sensors for measuring the position, angular
velocity and acceleration. He studied the use of distinct sensors for
measuring kinematic parameters of each part. This solution has the
advantage of a lower price, but increases the number of wires connecting
more and more complicated data acquisition and evaluation. Since the
research had inertial measurement units and MTI MTX capable of
simultaneously measuring the 3D orientation angles, angular velocity and
acceleration, it was decided that the experiments with the prototype is
used orthotics these sensory systems.
Regarding orthotics trained foot operated actuator current one,
have considered two options for tracking movement, both will be tested
during the experiments:
--Use an engine equipped with an incremental travel sensor which
allows measurement of foot movement involved and ensure a command
position of the engine side. The derivation of information from this
sensor to determine the angular velocity of movement of coupling
Orthotics and engine control, the PWM, to achieve an angular velocity to
a copy while on the active leg;
--Fitting leg trained with inertial measurement unit mounted on the
leg similar to that asset, which allows simultaneous measurement of
position, angular velocity and acceleration and engine side control
position and speed.
Therefore, the main components that have been acquired are:
--Base orthotics Stabilopro shaped support open, from Bort,
Germany--Dry wearing feeling due to naturally breathing and humidity
draining material. Polycentric aluminium gear segment hinge for
additional medial and lateral stabilization. Functional
guidance/stabilization of patella by special patella ring. With 4
circular velcro straps for optimal support. Can be opened completely,
lockable with velcro closure. Adjustable extension at 0[degrees] to
45[degrees]. Adjustable flexion at 0[degrees] to 90[degrees].
(http://www.bort.de).
--Micro motors 82-802-0 series from Crouzet U.S.A.--These products
are particularly suitable for use in medical equipment, valves, pumps,
access control (barrier, turnstile, lift doors, etc), water treatment,
billboards, etc. (http://www.crouzet.com/)
--XBus Kit, from XSens, Holland--The Xbus Master is a lightweight,
portable device that controls multiple Motion Trackers (MTx) on the
Xbus, Xsens' digital data bus system. The Xbus Master samples
digital data from the MTx's and supplies power to the MTx's.
The Xbus Master samples digital data from the MTx's and supplies
power to the MTx's. The Xbus Master can be connected to a PC or PDA
via serial cable or wireless connection, where the data is logged or
used in any real-time software application. The Xbus Master enables
ambulatory measurement of human motion. The MTx's provide
drift-free 3D orientation as well as kinematic data: 3D acceleration, 3D
rate of turn and 3D earth-magnetic field.
(http://www.xsens.com/en/general/xbus-kit)
[FIGURE 3 OMITTED]
4. CONCLUSIONS
After assembly was found, orthotics support the must be changed. We
need a more rigid material as physiological resistance is generated by
leg slightly larger than originally estimated. Follow orthotics testing
and optimization, a topic first 20 years with a paraplegic leg. Together
with physicians profile will be a recovery program and will follow its
evolution over time.
5. ACKNOWLEDGEMENTS
This paper is supported by the Exploratory Research Programme
(PCE), financed by the Romanian Ministry of Education, Research and
Innovation--the National Council for Scientific Research in Higher
Education, under the contract number ID_147/2007-2010, named
"Contributions to Analysis, Modeling and Simulation of the Modern
Mechatronical Systems Used for Medical Rehabilitation".
6. REFERENCES
Barbu, D. et al. (2007). Contributions to Analysis, Modeling and
Simulation of the Modern Mechatronical Systems Used for Medical
Rehabilitation. CNCSIS Project ID_147
Lache, S. & Barbu, D. & Barbu, I. (2009). Modeling and
simulation of a knee orthosis active part, The 3rd International Conf.
on "Computational Mechanics and Virtual Engineering" COMEC
2009, 29-30 Oct. 2009, Brasov, Romania
*** (2009) http://www.bort.de/englisch/, Accesed on:.2009-09-09
*** (2009) http://www.crouzet.com/english/, Accesed on: 2009-09-09
*** (2009) http://www.xsens.com/en/general/xbus-kit, Accesed on:
2009-09-09
