1. Introduction Persons with Amyotrophic Lateral Sclerosis (ALS) experience a progressive loss of muscle strength that eventually prevents any movement. In this course, independence and communication ability are increasingly impaired. In each phase of the disease, this condition can be temporarily compensated by adopting an assistive device, tailored to the current functional deficit. When muscular contraction is eventually made impossible, BCIs could represent a solution by detecting the voluntary modulation of brainwaves, and convert them into messages and commands to interact with the environment [Millán et al., 2010; Vaughan et al., 2006; Cincotti et al., 2008]. The Brindisys project (Brain-computer interface devices to support individual autonomy in locked-in individuals) aims to develop a new assistive system designed to preserve communication and interaction with the external world in people with ALS. 2. Material and Methods 2.1. The Brindisys System The Brindisys system consists of two main components: a tablet PC which allows several applications for communication and environmental control, and an application that can overlay BCI stimuli on the user interface. The novelty of the proposed prototype lays in making its functions accessible both with conventional/assistive input devices relying on the current user’s residual motor abilities (touch screen, mouse, keyboard, joystick, buttons and head tracker) and with a P300-based BCI. It was indeed designed in order to follow the user from the onset of the disease to the complete loss of motor abilities, in this way the user can start using the system and familiarize with it before the BCI becomes the only way to communicate with the external world. All calibration and configuration procedures of the BCI have been simplified, so that the system can be operated by people with limited technical competence. Moreover, new classification algorithms have been developed in order to increase system reliability and usability [Aloise et al., 2011]. 2.2. The role of end users and system functionalities The Brindisys project focused on users through the planning, design and development of the system (user centered approach). To identify users’ requirements 7 end users, 13 caregivers and 20 stakeholders were interviewed about both communication and environment control needs of people with ALS. Two focus groups about the potentialities of a brain computer interface were carried out. As a result of this first phase, a design solution was created defining the system functionalities. As regards the communication the system provides three main applications: i) alarm bell to draw the attention of the caregiver; ii) text writing function for both face to face and remote (e-mail, SMS) communication; and iii) fixed sentences or keywords for quick communication. Regarding environmental control simple functions have been required by users such as TV control, movement of armchair/bed, lights control and doors opening. These functions have been implemented using the KNX standard to control the devices available at the “Casa Agevole” premises (IRCSS Fondazione Santa Lucia, Rome), which is an apartment designed for people with limited mobility and were preliminary assessment took place. Users were also involved in the phase of evaluation of the prototype. 2.3. Evaluation Usability of the Brindisys system was evaluated in terms of effectiveness (reliability), efficiency (workload, NASA-tlx), and satisfaction (Visual Analogue Scale -VAS- for overall satisfaction and System Usability Scale -SUS- for perceived satisfaction and usability). Three end users with ALS (2 male, 1 female; age= 56, 59, 75 years; ALSfrs =9, 37, 38) were involved in the evaluation protocol which included two sessions: during the first one the subjects operated the prototype using the input device coping with their motor abilities (buttons and automatic scanning, touchscreen and keyboard and mouse respectively), while during the second session they operated the prototype by mean of BCI. The required tasks were the same for both sessions, and each sessions consisted of i) a communication task: spelling of predefined sentences and ii) an environmental control task: performing of some actions on the environment mimicking real-life situations. During the experimentation users’ feedback and suggestions were collected in order to improve system features for the final release of the prototype. 3. Results The three end users successfully completed the experimental protocol. All subjects were able to complete the proposed tasks controlling the Brindisys prototype with the P300 based BCI and reaching on average the 95% classification accuracy (ranging from 89% to 100%). The end users showed an high satisfaction (VAS, 0-10) with both the BCI-devices (ranging between 8.3 and 10, average 9.4) and conventional/assistive input device (ranging between 9 and 10, average 9.6). The usability perceived by the end users and measured by means of the SUS (0-100) was on average 73.75 for the BCI and 59.1 for the conventional/assistive input device. Furthermore the BCI exhibited a comparable efficiency in terms of required workload (29.2) with respect to muscular input devices (31.5) 4. Discussion This work provides an overview of the first prototype of the Brindisys system and reports the preliminary results about assessment with end users. The classification accuracies reached with the BCI Brindisys prototype far exceeded the 70% thereby fulfilling the criterion for satisfactory communication [Kübler et al., 2006]. Furthermore all subjects exhibited an high level of satisfaction and usability comparable to the one exhibited with conventional/assistive input device. Despite not conclusive, these results indicate the potential effectiveness and usability of the proposed system. The assessment of the system with end-users is currently ongoing. References Millán JDR, Rupp R, Müller-Putz GR, Murray-Smith R, Giugliemma C, Tangermann M et al. "Combining Brain-Computer Interfaces and Assistive Technologies: State-of-the-Art and Challenges". Front Neurosci. 2010;4. Vaughan TM, McFarland DJ, Schalk G, Sarnacki WA, Krusienski DJ, Sellers EW et al. "The Wadsworth BCI Research and Development Program: at home with BCI". IEEE Trans Neural Syst Rehabil Eng. 2006 Giu;14(2):229–33. Cincotti F, Mattia D, Aloise F, Bufalari S, Schalk G, Oriolo G et al. "Non-invasive brain-computer interface system: towards its application as assistive technology". Brain Res. Bull. 2008 Apr 15;75(6):796–803. Aloise F, Schettini F, Aricò P, Salinari S, Guger C, Rinsma J et al. "Asynchronous P300-based brain-computer interface to control a virtual environment: initial tests on end users" Clin EEG Neurosci. 2011 Ott;42(4):219–24. Kübler A, Mushahwar VK, Hochberg LR, Donoghue JP, “BCI Meeting 2005--workshop on clinical issues and applications,” IEEE Trans Neural Syst Rehabil Eng, vol. 14, no. 2, pp. 131–134, Jun. 2006.
Schettini, Francesca ; Riccio, Angela ; Simione, Luca ; Liberati, Giulia ; Caruso, Mario ; et. al. Brain Computer Interface as assistive technology for people with ALS.Fifth International Brain-Computer Interface Meeting 2013 (Pacific Grove, California, du 03/06/2015 au 07/06/2015). In: Proceedings of the Fifth International Brain-Computer Interface Meeting: Defining the Future, 2013
Caruso, Mario
[Santa Lucia]
Cincotti, Febo
[Santa Lucia]
