The novel BackHome system offers individuals with disabilities a range of useful services available via brain-computer interfaces (BCIs), to help restore their independence. This is the time such technology is ready to be deployed in the real world, that is, at the target end users’ home. This has been achieved by the development of practical electrodes, easy to use software, and delivering telemonitoring and home support capabilities which have been conceived, implemented, and tested within a user-centred design approach. The final BackHome system is the result of a 3-year long process involving extensive user engagement to maximize effectiveness, reliability, robustness, and ease of use of a home based BCI system. The system is comprised of ergonomic and hassle-free BCI equipment; one-click software services for Smart Home control, cognitive stimulation, and web browsing; and remote telemonitoring and home support tools to enable independent home use for nonexpert caregivers and users. BackHome aims to successfully bring BCIs to the home of people with limited mobility to restore their independence and ultimately improve their quality of life.
Research efforts have improved brain computer interface (BCI) technology in many ways and numerous applications have been prototyped. Motivated by the aim of restoring independence to individuals with severe disabilities, the focus has centred on developing applications [
In this context, the EU project BackHome (
The project was designed with a user centred design (UCD) approach at the heart of the whole R&D process in order to move BCIs from the lab towards systems that are easy to use and can be operated by nonexpert caregivers and target end users at home. In this R&D field, UCD was proposed to bridge the translational gap between BCI systems and their target end users [
This paper presents the UCD process employed to research and develop a multifunctional BCI system, including the collection of user requirements, the iterative development process together with the analysis of test results, and feedback recommendation from able-bodied and disabled end users. Last but not least, the paper presents the outcome of this UCD process, which is the final BackHome system that is currently installed in target end users’ homes for final testing and evaluation.
The rest of paper is organized as follows. Section
Until recently, BCI research focused primarily on validating devices with healthy volunteers in laboratory settings. This has begun to change [
In the following subsections, we briefly summarize the main work on practical electrodes, easy to use software, and telemonitoring and home support for independent home use of BCIs.
To advance existing BCI systems into a more practical solution for home use it is necessary to improve the hardware and software of existing BCI systems. Since the majority of BCIs are based on electroencephalography (EEG) it is one of the main objectives to improve the sensors, namely, the EEG electrodes, which capture brain activity. One of the biggest problems with most noninvasive BCI systems is the need for sensors that rely on electrode gel. Surveys of able-bodied and disabled users [
Software currently adopted for research on BCI offers the researchers many options and functionalities [
Three main aspects have to be considered to assess the usability of a BCI system: (i) the effectiveness, (ii) the efficiency, and (iii) the satisfaction of the user with the system. The effectiveness is indicated by the accuracy of the BCI system (correct selections of total selections). Accuracies lower than 70% are not acceptable for BCI systems [
Different questionnaires are used to determine the satisfaction of the user with a system. For example, Zickler et al. introduced in [
According to the UCD, the users’ feedback is used to improve the current version of the software or to develop a new, better version. Consequently, using UCD principles make the BCI software easier to use and therefore more accepted by the target users.
Home sensor technology may create a new opportunity to reduce healthcare costs by helping people to stay healthy longer as they age. An interest has therefore emerged in using home sensors for health promotion [
In summary, a TMHSS allows (i) improving the quality of clinical services, by facilitating the access to them, helping to break geographical barriers; (ii) keeping the objective of a patient-centred assistance, facilitating the communication between different clinical levels; (iii) extending the therapeutic processes beyond hospitals or primary care centres, like at patient’s home; and (iv) saving unnecessary costs and achieving a better costs/benefits ratio.
In the literature, several TMHSSs have been proposed [
BackHome focuses on restoring independence of people that are affected by severe motor impairment due to acquired brain injury or disease, with the overall aim of increasing inclusion. In order to keep the user engaged, BackHome continuously provides feedback to therapist for the follow-up and for personalization and adaptation of rehabilitation plans.
The BackHome system integrates the developments undertaken through a UCD life cycle, main innovation driver of the project towards the goal of advancing a practical solution for independent home use. It includes a user station with wireless EEG biosignal acquisition system, a dynamic environmental sensor network, and an easy to use BCI software to access a range of services to facilitate activities of daily living. Additionally, the therapist station provides services for remote planning and assessment of user activity, rehabilitation tasks, and quality of life indicators.
Figure
BackHome architecture overview.
The end user interacts with the user station, the BCI-based subsystem which comprises the modules responsible for the BCI components (a screen user interface together with a BCI block and BCI equipment) connected to the services of Smart Home control, cognitive stimulation, and web access through the AmI block, which holds the intelligence of the system. To execute and control its functionalities the user station, the BCI equipment, home sensors, and actuators must be installed and completely integrated at the user’s home. The AmI block is the central control and intelligence component of the user station. It communicates and interacts with all other components of the system. It provides control to all services for Smart Home control, cognitive stimulation, and web access, receives the user selections from the BCI system, and reports indicators relevant to the user assessment to be checked out through the therapist station. The BCI block is connected to the user through the BCI hardware and the user interface, which displays the stimuli for the BCI and the interfaces of all the services. With the proposed BCI, all applications can be operated via control matrices that were first proposed in [
The therapist station is a web-based easy to use service which allows a remote therapist, teleassistance service operator, or another professional to access information stored in the cloud and gathered from users and sensors around them: users’ inputs, activities, selections, and sensor data. This information takes the form of system usage reports, rehabilitation tasks results, and quality of life assessment and supports those professionals to make informed decisions on rehabilitation planning and personalisation as well as remote assistance and support action triggering. The scalable and robust cloud storage of data and ubiquitous web access provides the needed flexibility in order to get the maximum potential out of the telemonitoring and home support features because the therapist can access the station at any moment with any device that is connected to the Internet.
As shown in Figure
More details about the functioning of these services are provided below in Section
UCD is a process of engagement with target end users that adopts a range of methods to place those who may benefit most from the technology at the centre of the design process in terms of development and evaluation. Thus, the system development has been iterative and incremental to enable reflections with users, their families, caregivers, and therapists prior to implementation of the final system [
Figure
The adopted user centred design (UCD) approach.
UCD is important to gather the preferences of target end users in the design and development of emerging technologies. The novelty within this approach is successfully gaining ethical approval to work directly with target end users, that is, people who have acquired brain injury. The challenges are many to engage in such innovative research with people who are considered to be more vulnerable than the general population. Achieving this helps align technical innovation to end user needs, increasing the likelihood of adoption and sustained use. The very fact that the technology is in the design and evolving phase brings a host of ethical issues to consider, which may be more crystallized when the target end users are considered to have cognitive impairment. An ethical framework developed within the project created a robust structure to unpin the research approach.
The core ethical principles of autonomy, beneficence, nonmaleficence, and justice were kept central to this framework. European legislation, international conventions, and local ethics committees were also incorporated.
The selection of appropriate end users was important within the ethical framework developed. People with neurological conditions including acquired brain injury (ABI) and amyotrophic lateral sclerosis (ALS) are considered vulnerable groups and it is imperative to safeguard their wellbeing. It is important that potential end users have a thorough understanding of the device and what it can actually do rather than what can be perceived as a result of film or the media. Additionally, informed consent is central to the ethical framework. Key workers within the end user organizations were contacted and asked to make the first contact with potential participants to identify those interested. Next an initial meeting was undertaken to introduce the potential participants to the project, watch videos of BCI, and ask questions before they were given an information leaflet to consider. A cooling off period of one week was given before the potential participant was contacted to assess her/his interest and desire to participate and give consent. Once the consent form was signed participants were invited to an interview to identify if the participant met the inclusion criteria. It is highly probable within BackHome as we are recruiting participants for home-based evaluation that not all participants will be able to give verbal or written consent. The researchers would incorporate a number measures to try to establish consent in this instant and may also have to consult with the family, and key caregivers when seeking consent from this target participant group.
Maintaining realistic expectations around the project is essential. Recent media attention around BCI technologies has portrayed the systems as a life changing assistive device [
We collected the user requirements that emerged from focus groups with potential target end users, family members, caregivers, and therapists and from prior studies involving users of AT in general and BCIs in particular. We then created a prioritized list that contains the requirements in order of importance for the prototypes (see Table
Recommendations from users in order of priority.
Key aspects of the system | User requirements | Recommendations/planned system specs |
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Effectiveness | With the system users should achieve the task as accurately and completely as possible | Implementation of famous faces paradigm for the P300 matrix, dynamic stopping method, and error suppression |
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Reliability | The system must be stable during everyday use | Only those services that are stable (after an initial test with preliminary test users) will be evaluated during independent home Use/software bugs will be fixed during initial testing phase |
Robustness | The system has to be robust with respect to anomalies, malfunctioning or in case some sensors or services stop working; in all those situations, the system should continue to work with reduced functionalities | |
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Functionality | The system should allow the user to perform as many (simple) tasks as possible to increase autonomy of user | Spelling, web browser, multimedia player, Cognitive Rehabilitation Games, Smart Home control, Brain Painting |
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Ease of use | (i) The system should be simple to operate (menus should be intuitive) |
(i) Assured through the evaluation of a mockup of the software |
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Efficiency | Workload and speed of communication should be at an acceptable level, ideally comparable or better than the AT in use | A dynamic stopping method during usage of the services will assure that only the necessary amount of repetitions will be used to maximize speed |
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Safety | The system must not constitute a risk to the health of the user; this concerns especially the safety of the individual parts (electrodes, wires, etc.) | The system does not constitute a risk to the health of the user; the hardware is CE certified/this will be communicated to increase its acceptance |
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Comfort | (i) The EEG cap should be comfortable to wear for several hours |
(i) Only P300 will be implemented because this control signal offers the best compromise of accuracy and stability |
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Privacy | (i) No information should be transmitted or be visible to persons except to those it is intended for or the user has agreed to share the information with |
(i) A secure protocol will be used for transmission of data over the internet (hypertext transfer protocol secure (HTTPS)) |
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Mobility | (i) To allow for maximum mobility, the system should be small and wireless |
The EEG system will be both small and wireless |
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Possibility of independent use | The user should be able to operate the system with as little help from the caregiver as possible | After the EEG setup is done and the system started, the user can switch between applications or pause the system by himself and because of the planned noncontrol state detection system, the BCI will refrain from making selections if the user is not concentrating on the control matrix |
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Aesthetic design | (i) The design of the interface should be appealing |
(i) The design of the cap could not be influenced without compromising its functionality |
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Configurable to the needs of the user | The system should contain the possibility to adjust the system to the needs of the individual user (e.g., store prerecorded sentences or implement shortcuts) | The system will cover many services already but the software will also be implemented such that it allows for extensibility with other applications that are desired by the user |
We assigned effectiveness to the highest priority, which goes hand in hand with functionality. The user should be able to achieve the desired task with satisfactory accuracy from the system and this is a prerequisite for its usability. Further, the system stability is of utmost importance for independent home use and has been critical during the UCD testing phases. Since the need of the user to request software support should be kept at a minimum, only those applications that have run stable during previous testing phases will be deployed and tested in the final independent home use testing. A key theme that emerged during the focus groups and evaluation phase and has become a crucial objective of the BackHome project is to improve the ease of use of the system. For this matter, both the end user interface that is used to control the applications and the caregiver interface used to launch the system need to be simple enough to be operated without requiring much training. Also the BCI hardware needs to be easy to set up. In order to assure that the main caregiver user interface will be easier to operate, mockups were evaluated by BCI experts and healthcare professionals. The goal was to have a “one-click interface” once the initial setup is done and the caregivers have been trained. Regarding the BCI hardware, during the focus groups phase users criticized the aesthetic appearance of the electrode cap as well as the limited mobility of the system. Users were, however, not involved in the aesthetic design of the cap, since good signal quality and thus effectiveness has a higher priority than the visual appearance. The dry electrodes should help to further reduce the time-needed for the setup of the system. For both the hardware and software setup the recommendation was to create an easy to understand user guide including a FAQ Section explaining the solutions to the most common problems and a video that explains the setup of the system visually.
Of course safety and privacy concerns that were raised during the discussions are of importance, but we did not list them on top of the priority list, because the necessary measures were already undertaken to assure both. Regarding the safety of the system, the EEG hardware needs to be certified as a medical device. Nevertheless precautions will be taken during testing with end users, for instance, no person suffering from epilepsy should use the system because of the fast flashing of rows and columns of the control matrix. To assure the privacy and data security of the study participants, we use a hypertext transfer protocol secure (HTTPS) for data that will be transmitted over the Internet. All experimental procedures need to be previously approved by the local ethics committees. To increase acceptance of the system, these measures need to be communicated to the study participants, their caregivers, and family members.
Independent use means that the BCI can be used without the need of an expert or the caregiver to be present, once the initial setup is complete as the end users will always need the help of another person (i.e., a caregiver or family member) to setup the BCI hardware and software. To promote the autonomy of the user, the navigation should be easy and enable the user to independently switch from one application to the next.
Last but not least, users asked for the possibility to personalize the system and adjust it to their specific needs. For instance, they suggested using shortcuts to frequently used applications and actions or the option to select prerecorded sentences.
Our UCD-based system stems from the engagement with target end users at all stages of the development and design of the system. The effectiveness of the system is identified by recording how accurate the system was at responded the user. The effort and workload required to operate the system is defined as efficiency and this was identified within an electronic version of the NASA-TLX. This test delivers a task load index which can be used for comparing the effort necessary to operate each tested system. Satisfaction with the system was measured by a visual analogue scale (VAS). This quick method has brought insight into general satisfaction with the system during continuous use. It informs us about the likelihood that the system will be used regularly. Additionally, a customized usability questionnaire was developed to identify user preferences with the system and an extended version of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0 [
Several commercially available electrodes and amplifiers were tested to identify the most user friendly and reliable solutions for the final system. This testing assessed key issues like preparation time, signal quality, comfort, and robustness to noise but also technical aspects like signal to noise ratios, delay times, amplifier quality, and frequency response.
After initial tests some insufficient electrode systems were excluded and the remaining systems (see Figure
Overview of electrode systems.
First, the preparation phase included the mounting of each EEG cap and the instruction of the participants. Second, the experimental protocol containing five parts is as follows.
We tested the systems with seven preliminary test subjects and the performed tests provided useful feedback about features of interest, weaknesses, and problems of the different systems.
The evaluation of the VAS test reveals a high satisfaction of the users with all systems. Some users scaled systems with lower than 0.5 which means “not satisfied.” The three most important features, evaluated by the eQUEST2.0 questionnaire, are (1) speed, (2) effectiveness, and (3) durability together with learnability. The values for the most important feature, speed, were between 3.3 and 3.7. These values were lower compared to the values of the other eleven questions, so the participants were mainly unsatisfied with the speed. During the following advanced testing period the focus was on increasing the speed of the system. Regarding the electrode system, increasing the speed means reducing the time needed for the setup of the system and improves the signal quality.
The provided services have been tested separately before integrating them into the overall system. During the development phase, an evolutionary approach has been followed for the definition, implementation, and integration of the services. The corresponding feedback was passed on to the software developers and was carefully acknowledged for the implementation of the final system.
The evaluation of the provided services already integrated in the overall system was undertaken by a control group of preliminary test users and subsequently brought to target end users. Fourteen test users participated in the study as a control group (9 females, M = 28.1 years ± 8.6, range: 21–46) [
Average accuracies for the first session achieved by preliminary test users for the five tasks and for switching between tasks (menus).
Overall, the end users indicated that they were more or less to quite satisfied on the eQuest2.0. Additionally, satisfaction with the BCI on the VAS was reported as high (7.64). The key recommendations from end users included the system being easier to use, reducing fatigue, and enabling independent use once the cap was placed and more effective selections. However, users also stated that stability of the software should be improved and that the time needed for one selection was still slow. The items that were rated as most important on the eQuest2.0 were speed, ease of use, effectiveness, reliability, and comfort.
The findings of the evaluation outlined that seven key areas were important to enhance the user interface: simplification of the interface for the user, the terms and language used, the design, ability to navigate the interface, feedback from the interface, signal acquisition, and the ability to personalize the caregiver interface. Very clear and simple steps through the interface to help in the setup of the BCI were recommended. Recommendations such as a start-up checklist, troubleshooting support when an issue emerges and video instructions were outlined. The terms and language used were also important. Nontechnical terms must be used plus the ability to get an explanation by hovering the mouse over the term or click on the icon to find out more. Navigating the interface and the overall design were still not intuitive. Questions were also raised about the feedback the user would get from the system such as what happens when one electrode does not have satisfactory signal. And whether there is enough information for the user to be able to rectify a problem that occurs. Additionally, during testing signal acquisition and quality emerged as one of the most challenging issues particularly for nonexpert users. Signal acquisition is fundamental to BCI control and needs to be achieved in the most simplified form with additional information when the user is finding it more difficult.
The therapists provided invaluable input into the cognitive rehabilitation in terms of the usefulness of the task, difficulty levels, presentation, language, outcomes, sequencing, number of steps, and application to practice. A framework for the development of cognitive skills has been created against which cognitive tasks were mapped during the collaborative stage of development. The domains emerging within the framework reflect various levels of cognitive complexity [
A total of 53 therapists took part in an overall evaluation of the services offered by the therapist station. Following a presentation of BackHome functionalities each participant was asked to evaluate the platform in terms of its application to everyday community based practice on a specifically developed usability questionnaire. Overwhelming, therapists reported that the station would facilitate their day-to-day practice and benefit their client. Recommendations included having a greater range of cognitive rehabilitation tasks increase the clarity of the results and instructions to support therapists without IT skills.
Subsequently, 36 of the therapists completed a protocol on the station which included setting up a client as a user, scheduling quality of life assessments and cognitive rehabilitation sessions, and reviewing the results of a clients scheduled assessment and their cognitive rehabilitation session. Each therapist then completed a second questionnaire to evaluate the technical components of using the therapist station. Therapists evaluated positively the therapist station, and they found it easy to use and appreciated both functionality and graphical aspect.
Also in the conception and development of the TMHSS a UCD methodology has been adopted. Similarly to [
General results from the questionnaire showed that users considered telemonitoring and home support as an opportunity to facilitate their daily life, they felt quite confident with the use of technology, and they preferred easy to use devices and adapted interfaces. Participants reported that data collected by the sensor-based system should be provided in a secure and simple way, being worried about their privacy and the use of their personal information.
According to the evolutionary prototyping, a first version of the implemented sensor-based system was installed, tested, and evaluated in a test user’s home in Barcelona. The corresponding user is a 40-year-old woman who lives alone [
The outcome from the user centred evaluation of the system as well as the requirements gathered at the earlier stages of the development life cycle gives as output a list of recommendations that have been carefully addressed during the system development. Those recommendations, ordered according to the priority list, together with the corresponding user requirements, are shown in Table
As stated above, the main innovation driver of the BackHome project is the use of UCD for the first time throughout all development stages of a multifunctional BCI which has resulted in the delivery and deployment of the final BackHome system. The overall architecture result of the UCD process was depicted in Figure
Based upon the user feedback and the results of an advanced electrode testing described in Section
g.Nautilus headset with gel based (a) and dry electrodes (b).
A base station which is connected to the host system through USB is used to receive the recorded and digitized EEG signals. The biosignal amplification unit consists of the headset including the wireless biosignal amplifier electrodes, an EEG cap, and the base station including a USB cable for connecting it to the host computer and a QI compatible wireless charging station. The 34 electrodes including reference channel and ground are preconnected to the amplifier using a preconfigured set of electrode positions.
The user interface of the headset consists of the power switch and the status LED. Both are located on the top face of the head set. The electrodes are connected to two groups of monopolar amplifiers. The first group is connected to the ground electrode and the first 16 EEG channels and the second group is connected to the electrode positions 17 to 32 and the reference channel. The main advantage of this system which we labeled as key innovation (ii) is its wireless technology and the choice of dry electrodes. Both factors have often been criticized from test users as well as target end users when they used other nonwireless technologies. Most notably the fact that no hair wash is needed when using dry electrodes is a big increase in terms of usability. Furthermore the quick and easy montage of the system makes it also practical and comfortable especially for target end users.
This long section describes all the novelties related to the user friendly software to access multifunctional applications through BCI which we labeled as key innovation (iii). The BCI user interface is based upon the screen overlay control interface (SOCI) library [
Figure
Primary user interface showing the main screen of the Smart Home service.
The user interface for the caregiver (see Figure
Care giver interface. The interface has been designed to optimally guide the care giver through the setup process step by step (a) and provide access to help and support information (b) on every screen. Only those information and controls are shown which are necessary to accomplish the current step (c) or advance to the next one when finished or go back to the previous one.
All the Smart Home control, cognitive stimulation, and web access services rely on a P300 spelling and control system. In the adopted speller the highlighting happens with freely selectable images (famous faces) instead of just changing the color of the background [
Apart from controlling devices through the P300 control interface, the user can also interact with a multimedia player to see photos, videos, movies, and so on. The implemented media player application is XBMC (available:
Screenshot of the XBMC application (a) and the P300 controller (b).
Daily-life activities game (level 2) screenshot.
Brain Painting entitled “Die EU Muskeltiere, the EU Muscleteers,” with kind permission from the artist.
PUI of the web access services.
The web browser was evaluated both as a standalone version, together with the multimedia player and the P300 speller [
Screenshot of the Gmail home page (a) and the P300 controller (b).
To monitor users at home, we develop a sensor-based system able to observe the evolution of the daily life activity of the user using a BCI [
Let us summarize here the main features of the implemented system, and the interested reader may refer to [
As for outdoor activities, we are currently using the user’s smartphone as a sensor by relying to MOVES, an app for smartphones able to recognize physical activities (such as walking, running, and cycling) and movements by transportation. MOVES is also able to store information about the location in which the user is, as well as the corresponding performed route(s). MOVES provides an API through which it is possible to access all the collected data.
Information gathered by the sensor-based system is also used to provide context-awareness by relying on ambient intelligence [
The therapist station (
As for the cognitive rehabilitation sessions, using the therapist station, healthcare professionals can remotely manage a caseload of people recently discharged from acute sector care. They can prescribe and review rehabilitation sessions (see Figure
Scheduling cognitive rehabilitation tasks.
One of the goals of the sensor-based system is to automatically assess quality of life of the users. Accordingly, results and statistics are sent to the therapist station in order to inform the therapist about improvement/worsening of user’s quality of life (please refer to [
Finally, through the therapist station, therapists may consult a summary of activities performed at home by the user; for example, visited rooms, sleeping hours, and time elapsed at home. Moreover, also the BCI usage is monitored and high-level statistics are provided. This information includes BCI session duration, setup time, and training time as well as the number of selections, the average elapsed time per selection, and a breakdown of the status of the session selections. Therapists have also the ability to browse the full list of selections executed by a user, such as context information as application running, selected value, grid size, and selected position.
The BackHome project was designed according to a user centred design approach, used for the first time throughout all development stages of a multifunctional BCI. Driven by that approach, the project achieved five key innovations: (i) an architecture able to meet the requirements of BCI multifunctionality and remote home support; (ii) a light, autonomous, comfortable, and reliable BCI equipment; (iii) an easy to use software to control multifunctional applications; (iv) a telemonitoring and home support system for BCI independent use; and (v) a therapist station to manage BCI-based remote services.
Currently, the system has been installed and is running in four target end users’ homes in Belfast and one in Würzburg for a final period of testing. The main purpose of the on-going final testing is to assess user acceptance of the BackHome system when deployed in a continuous way in real world scenarios, that is, at users’ homes, and to analyze the impact of the use of such technology on the quality of life of individuals in need. The potential socioeconomic impact of the exploitation of such a system as well as barriers and facilitators for future deployment and spreading of such technologies will therefore be analyzed and reported. In that sense the BackHome project is also adapting and testing the commercial telehealth product called HomePod aimed to remotely monitor and assist one target population of the BackHome project, stroke patients. This so-called StrokePod, which integrates sensors and services of the BackHome system, is a promising by-product of the project targeted to larger audiences.
We decided to discard the integration of other research advances explored in the project such as a multimodal fatigue support component and hybrid BCI capabilities because we considered that they were not mature enough for real world deployment, but they will be further researched and might be eventually integrated in the future.
This BackHome platform and the services provided make a significant contribution to enhancing the opportunities for social inclusion and eHealth for people living with physical and cognitive impairment who would otherwise struggle to exert autonomy and independence in a world that is much more digitally enabled than ever before.
This paper reflects only the authors’ views and funding agencies are not liable for any use that may be made of the information contained herein.
The authors declare no conflict of interests.
The study was funded by the European Community for research, technological development, and demonstration activities under the Seventh Framework Programme (FP7, 2007–13), Project Grant agreement no. 288566 (BackHome).