Development of a System for Independent Ambulation of Patients with Spinal
Cord Injury Using a Dataglove and a Biped Robotic Model
Alejandro Garcia Blanco¹, Gildardo Jimenez Munguia² & Pedro Ochoa Moreno³
Instituto Tecnológico de Nogales, Ave. Tecnológico 911, Nogales, Sonora México
División de Estudios de Posgrado e Investigación
¹alejandrogarciab@itnogales.edu.mx ²gjimenezm@itnogales.edu.mx
³pochoam@itnogales.edu.mx
Abstract
The general focus of the project is the development
of a simple, portable and economically accessible
device that permits the limited movement of the
inferior extremities on patients with damage on the
spinal cord in the lumbar region. The present work is
limited to the control system.
An electronic dataglove is used as input interface.
To develop the controller it was developed as output
interface a mechanical model of the inferior
extremities, instead of medical experimentation on
patients. The controller implemented in a DSP uses a
Neural Network to translate input signals to the
outputs. The controller by itself is in open loop
configuration. The feedback of the overall system is
planned to be done by the patience’s own senses. All
the compensations as in fatigue (feedback) are
performed by the patient.
1. Introduction
When a person suffers an interruption of the
neuronal connection in the spinal cord at a lumbar
level, the person loses control on its inferior
extremities. This affects the capacity of the person to
develop in society. Between the most evident
affectations it is the capacity to walk and being able to
displace by itself. For a couple of centuries, the
traditional solution has been the use of a wheelchair.
This has allowed the movement of people with
different capacities, when using the still functional
superior extremities. Nevertheless, although the
wheelchair is a solution widely used is not a complete
answer, in comparison to the faculties that the patience
previously had. The movement is limited to the places
through where the wheelchair can pass. Lately it has
been seen a greater awareness of the people in this
respect. Every time it is seen most frequently in public
sites the installation of facilities for wheelchairs. In
advanced countries many improvements have taken
place in the market of the wheelchairs. Between these
are motorized chairs, which do not need manual
impulse. Others have movable wheel axes, which can
even raise stairs. All these options can be only
considered improvements to the actual wheelchair
solution. In the last decades there have been some
investigations in regards to the Functional
Neuromuscular Stimulation or direct electrical
stimulation of muscles [1] to [8]. At the moment there
are a few products in the market based on this
technology, but only the Parastep system has obtained
the approval of the American government for its sale
[9]. This system consists of a control box, external
electrodes for the legs, and some other minor
accessories. It only allows taking small steps, to rise
and to seat. This system has a commercial cost of
around $12.000 USD, way ahead of the scope of an
economic product that this work has as a desirable goal
The first step in any investigation involving the
human body is a study of its anatomy. It was
performed a study to determine the main bone
structures, articulations, and muscular groups involved
in the common normal gait of a person.
2. Theoretical Model
Based on the results of the anatomy study, it was
resolved to use a simplified theoretical model. The
reason of the simplification resides in the use of the
minimum possible degrees of movement necessary for
a reasonable gait. The following restrictions were
assumed based on the use of minimum degrees of
movement:
- The tibio-tarsal joint or the ankle is considered
rigid. Although this joint is important to walk, it’s not
essential. For this work it is not intended that the
patient recovers all the previous abilities, like the
Electronics, Robotics and Automotive Mechanics Conference 2008
978-0-7695-3320-9/08 $25.00 © 2008 IEEE
DOI 10.1109/CERMA.2008.39
461