Rehabilitación para pacientes postinfarto cerebral utilizando sistemas BCI/FES
Herrera Sánchez, Daniel | 2019
According to the article “Stroke: A global response is needed”, at a worldwide level, brain strokes are the second cause of death and the third cause of disability on people (Johnson et al, 2016).
Some of the complications that people who have suffered brain stroke can experience, listed by the Mayo Clinic, include paralysis or loss of muscle movement, difficulty speaking of swallowing, loss of memory or difficulty thinking, emotional problems, severe pain or changes in behavior and the ability of selfcare (Mayo Clinic, 2018).
The methods of rehabilitation available right now are limited by the fact that they possess a short populational reach compared to the large amount of people who are affected by it. Such methods only manage to provide considerable results to those people who have suffered mild damages in their motor functions. In a study carried out by Dobkins, it was shown that only a 25% of the people who suffered from brain stroke were capable of eventually returning to an everyday life similar to the one of a healthy person (Dobkins, 2005).
Currently, the market already offers devices of electrostimulation for the rehabilitation of motor functions using electromyography signals (electrical signals that result from muscle contractions) like the NESS H200. The people who have suffered from mild cerebral damages are able to activate this device due to the fact that most of them are still able to generate electrical impulses strong enough to be detected by electromyography (EMG) but not strong enough to surpass the action potential threshold needed to contract the muscle.
For this reason, the necessity to develop a device that works under the same concept of electrostimulation mentioned previously but is not dependent on the residual motor functioning of the patient arises, and this way directly increasing the amount of people with more severe damages to their nervous system who can benefit from it.
A brain computer interface (BCI) allows the user to control an external device by identifying specific brain signals and converting them into a series of digital commands. Such signals can be obtained by numerous ways, one of them being through electroencephalography (EEG) equipment. Once those signals are obtained, they are classified using a computational algorithm so that they can be further on expressed as electrical impulses in order to induce muscle contractions.
Considering the fact that the brain signals generated when a motor movement is imagined (MI or motor imagery) are very similar to the signals generated when the actual movement is carried out, the activation of the electrostimulation device will not be affected by the residual motor capacity present on the affected patient.