The goal of the LOPES project (LOwer-extremity Powered ExoSkeleton) is to design and implement a gait
rehabilitation
Rehabilitation or Rehab may refer to:
Health
* Rehabilitation (neuropsychology), therapy to regain or improve neurocognitive function that has been lost or diminished
* Rehabilitation (wildlife), treatment of injured wildlife so they can be retur ...
robot for
treadmill training. The target group consists of people who have had a
stroke
A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...
and have impaired
motor control
Motor control is the regulation of movement in organisms that possess a nervous system. Motor control includes reflexes as well as directed movement.
To control movement, the nervous system must integrate multimodal sensory information (both f ...
.
The main goals of LOPES are:
*Reduction of the physical load on the
therapist /
patient;
*More efficient
gait
Gait is the pattern of movement of the limbs of animals, including humans, during locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on speed, terrain, the need to maneuver, and energetic efficiency. Di ...
training for stroke patients;
*Selective support of gait functions;
*Therapist stays in charge of
high-level
High-level and low-level, as technical terms, are used to classify, describe and point to specific goals of a systematic operation; and are applied in a wide range of contexts, such as, for instance, in domains as widely varied as computer scienc ...
decisions.
The mechanical construction should offer assistance in leg movements in the forward direction and in keeping lateral balance. Within the LOPES project, it has been decided to realize this by connecting the limbs of the patient to an
exoskeleton so that robot and patient move in parallel. Most gait rehabilitation robots that are currently being developed focus on the support of the entire gait cycle as a single unit. These robots use joint trajectories of the entire gait cycle and offer a uniform (more or less) stiff control along this trajectory. This means that the patient receives support in gait phases where support is necessary but also in phases where support isn't necessary. Studies have been done on an exoskeleton that propose adaptive control methods which minimize the interaction forces with the patient with respect to an adaptable reference pattern, but these still control the entire gait cycle. Studies have also shown that walking with the
Lokomat requires significantly less energy than normal walking . LOPES aims to support and not take over those tasks that the patient is unable to perform without help using an impedance control scheme. This will lead to a more active participation from the patient's side. The tradeoff for more active walking will likely be a smaller overall distance during therapy sessions. The implication of selective function support is that the robot will have two extreme modes in which it should be able to function, these are:
*Patient in charge: The goal of the robot is to minimize the interaction forces between the patient and the robot in order for the patient to walk freely without feeling the robot. This mode will be active mostly for the non-paretic side of the patient and during those phases of the walking cycle that the robot does not need to assist.
*Robot in charge: The goal of this mode is to take control of the patient. The robot will take over the functions which the patient is unable to perform. The robot will most likely operate somewhere between these extremes offering some support at those phases when it is needed to guide the patient towards desirable behavior.
The first prototype has been completed. This prototype has 8 actuated DOF (series elastic actuation) following the design.
Clinical evaluations will be done in the course of 2007.
References
External links
*
{{DEFAULTSORT:Lopes (Exoskeleton)
Robotic exoskeletons
Robots of the United States
Rehabilitation robots
2006 robots