There are numerous diseases that can lead to a total loss of control of the muscles of the body. A specific case is that of Amyotrophic Lateral Sclerosis (ALS) that affects, on average and only in Spain, about 4000 people. In many cases, these patients can reach the state known as the locked-in syndrome (LIS) and others, even worse, the total locked-in syndrome (CLIS), or a state equivalent to the latter in which, without suffering from paralysis of the eye muscles, patients have lost control of these muscles. Sometimes, for these people, the only communication option is based on brain interfaces. The starting hypothesis is that if we want to make progress in research related to communication and control systems based on the detection of the P300 potential, one must identify, on the one hand, parameters that improve the usability of these systems and, on the other hand, look for other alternatives that guarantee a minimum of communication to people in LIS status without eye control or in CLIS state.
The general objectives of this project are focused on carrying out research and application development tasks in order to contribute to the improvement of the quality of life of patients under the locked-in syndrome, as is the case of some patients who suffer from ALS. It is important to indicate that, although it is true that there may be lines of research that may have a greater impact on a greater number of potential users, it is not for this reason that it should not be considered less important to carry out research tasks that contribute to the application development for a smaller number of users, especially, taking into account the enormous benefit they can bring.
OBJECTIVE 1: Development of a communication and control system for people in a state of locked-in syndrome.
The first objective is motivated by the absence of a communication and control system based on the detection of the P300 potential that is flexible, adaptable to each user and, above all, easy to configure by caregivers and / or family members. This application would allow patients, and through their brain activity, a communication and control option, offering them a minimum quality of life. In order to develop this application, the UMA-BCI Speller application already developed in the LICOM project will be used and its main function is to offer a flexible and easy to configure communication system. With the purpose of improving the usability of this communication system, work will be carried out on the incorporation of new text prediction strategies and techniques that facilitate the generation, by users, of their own image templates and pictograms, including, at all times, the possibility of issuing the information to be transmitted through a voice synthesizer. With regard to the control system, and starting again from the application developed in the LICOM project, the resulting application should allow the patient to control some functions and devices in their environment without having to resort to their caregiver. This would allow him not only to increase his self-esteem, but also to execute actions that are not always understood by the caregiver. It must be said that with this objective, in addition, the functionalities of the UMA-BCI Speller tool would be increased, obtaining an application with features and features that have not been available up to now (easy to use, fully configurable, diversity of options, …).
To achieve this goal, 3 partial objectives are established:
- Objective 1.1- Development of algorithms for the improvement of the UMA-BCI Speller communication system
- Objective 1.2- Development of the control system
- Objective 1.3- System test
OBJECTIVE 2: Study and proposal of communication interfaces for patients without oculomotor control.
Although the communication systems based on a BCI-P300 speller give good results when the subject still has some oculomotor control, the benefits are greatly worsened when the patient also loses such control, and even more so if we talk about patients in CLIS status. To date, there are very few studies that address this problem due to its complexity. It is necessary to study control strategies that facilitate communication to these patients, although this is very basic, such as answering Yes / No to questions. The research will focus on studying different alternatives that achieve this goal by using visual, auditory, vibrototactile stimuli or a combination of these. This objective is also intended to incorporate the new communication functionalities from the research results into the UMA-BCI Speller application. In this sense, although the purpose is to propose concrete solutions to specific patients, it must be said that in this objective there is a strong research component.
In this objective 2 two partial objectives are proposed:
- Objective 2.1- Study of solutions based on potential ERP on patients without oculomotor control
- Objective 2.2- Implementation and testing of the complete system
OBJECTIVE 3: Study of stimulation paradigms of the BCI-P300 speller system that improve the usability of these systems.
As mentioned in the state of the art, preliminary studies suggest new strategies based on color and the incorporation of images that must be investigated in order to improve the efficiency of BCI systems applied to the control of a virtual keyboard. This would allow to increase the writing speed and the success rate, while improving the usability of these systems.
In this objective 3, which has an important research component, two partial objectives are raised again:
- Objective 3.1- Study of the effects of color incorporation in the virtual keyboard configuration matrix
- Objective 3.2- Study of the effects of stimulation with images of different emotional characteristics applied to a BCI system based on the P300
It should be noted that all these objectives include an important evaluation task. This evaluation will be carried out in a first phase with healthy people and, in a second phase, with patients