Initial Assessment of Hand Orthosis
Implications for BCI-Driven Motor Rehabilitation
Stroke is the fourth leading cause of death in the United States, killing over 133,000 people each year, and a leading cause of serious, long-term adult disability. The estimated direct and indirect cost of stroke in the United States in 2010 was $73.7 billion. One of the major consequences of stroke, an emergency and a brain attack which cuts off vital blood flow and oxygen to the brain, is the hand plegia syndrome, in which the arm or hand is paralyzed with or without cortical sensory abnormalities. Recovery of hand function is of importance for patients to master activities of daily living. Despite intensive treatment and rehabilitation, however, novel rehabilitative interventions recently applied in the chronic stage, like bilateral arm training or constraint-induced movement therapy, do not even cause significant improvements in the most severe cases of motor impairment. The one major drawback of these treatments is that patients are required to perform actions with the affected arm or hand. However, many patients do not have such residual function so that they cannot use their plegic hand or arm at all for such training purposes. There is currently no effective treatment available for this condition.
A new interaction capability has recently emerged by which the human brain can directly interface with a computer, and through this mechanism, control an effector action. Brain-Computer Interface (BCI) does not depend on the brain’s normal output pathways of peripheral nerves and muscles. As a result, a BCI can function for individuals who have severe motor disabilities caused by cerebrovascular brain damage (e.g., stroke) and other neurological conditions. BCI has recently gained considerable research interest, in particular as a promising approach to rehabilitation. Several studies reported some potentials of a BCI-based technique on motor rehabilitation.
We conducted two studies. In the first study, an experiment was carried out to evaluate the wearing sensation and usability of the hand orthosis we developed. In the second study, we investigated how well the developed BCI-driven hand orthosis can be controlled only through. Finally we conclude with some preliminary remarks on future research and implications for rehabilitation.
Three important factors were found for grasping capability: thickness, geometry and surface of the objects:
- Simple geometrical objects fitted better inside of the subject’s palm therefore easier to grasp
- Holding other factors, smaller size objects were more successfully grasped
- Rough surfaces that allow friction were observed to be easier to grasp than the smooth surfaces
- Smaller objects like toothbrush, pen and pencil were not grasped successfully, but pinching works