Enabling self-directed computer use for individuals with cerebral palsy: a systematic review of available assistive devices and technologies

Aim  The purpose of this study was to systematically review published evidence on the development, use, and effectiveness of devices and technologies that enable or enhance self-directed computer access by individuals with cerebral palsy (CP). Methods  Nine electronic databases were searched using keywords ‘computer’, ‘software’, ‘spastic’, ‘athetoid’, and ‘cerebral palsy’; the reference lists of articles thus identified were also searched. Thirty articles were selected for review, with 23 reports of development and usability testing of devices and seven evaluations of algorithms to increase computer recognition of input and cursor movements. Results  Twenty-four studies had fewer than 10 participants with CP, with a wide age range of 5 to 77 years. Computer task performance was usually tested, but only three groups sought participant feedback on ease and comfort of use. International standards exist to evaluate effectiveness of non-keyboard devices, but only one group undertook this testing. None of the study designs were higher than American Academy for Cerebral Palsy and Developmental Medicine level IV. Interpretation  Access solutions for individuals with CP are in the early stages of development. Future work should include assessment of end-user comfort, effort, and performance as well as design features. Engaging users and therapists when designing and evaluating technologies to enhance computer access may increase acceptance and improve performance

Investigation of Unintentional Movement in People with Cerebral Palsy to Improve Computer Target Aquisition

People with Cerebral Palsy (CP) have difficulty using computer pointing devices due to unintentional movement in their upper extremities. Fifty percent of people with CP have impaired arm-hand function which limits their ability to interface with pointing devices and effectively control cursor movement on the computer screen. This thesis involves two studies which utilize an Isometric Joystick in order to access the computer and complete target acquisition tasks. The first study titled "Quantification of Cursor Movement of People with Athetoid and Spastic Cerebral Palsy to Improve Target Acquisition," aims to guide real-time digital filter development for people with athetoid and spastic CP for target acquisition tasks. By investigating the cursor movement measures throughout the target acquisition trajectory we gained a better insight as to when and how to compensate for unintentional movement in people with CP. Results showed that both people with athetoid CP and spastic CP have more difficulty hovering over the target than they did moving to the target, indicating that filter development should focus on the hovering portion of the target acquisition task in order to improve target acquisition time. The second study titled "Customized Control for People with Athetosis and Dystonia to Improve Computer Access," aims to develop a method to prescribe appropriate switch/scanning control for people with athetosis and dystonia as well as to determine if customized switch/scanning control is more effective in completing icon selection tasks than the proportional isometric control. Results of this study suggest that switch/scanning control could be useful in moving on the most direct path to the target as shown by a significantly smaller percent distance error for customized control as compared to proportional isometric control (F(1,6) = 361.2, p < 0.01)

A Robust Kalman Algorithm to Facilitate Human-Computer Interaction for People with Cerebral Palsy, Using a New Interface Based on Inertial Sensors

This work aims to create an advanced human-computer interface called ENLAZA for people with cerebral palsy (CP). Although there are computer-access solutions for disabled people in general, there are few evidences from motor disabled community (e.g., CP) using these alternative interfaces. The proposed interface is based on inertial sensors in order to characterize involuntary motion in terms of time, frequency and range of motion. This characterization is used to design a filtering technique that reduces the effect of involuntary motion on person-computer interaction. This paper presents a robust Kalman filter (RKF) design to facilitate fine motor control based on the previous characterization. The filter increases mouse pointer directivity and the target acquisition time is reduced by a factor of ten. The interface is validated with CP users who were unable to control the computer using other interfaces. The interface ENLAZA and the RKF enabled them to use the computer

Augmenting User Interfaces with Haptic Feedback

Computer assistive technologies have developed considerably over the past decades. Advances in computer software and hardware have provided motion-impaired operators with much greater access to computer interfaces. For people with motion impairments, the main di�culty in the communication process is the input of data into the system. For example, the use of a mouse or a keyboard demands a high level of dexterity and accuracy. Traditional input devices are designed for able-bodied users and often do not meet the needs of someone with disabilities. As the key feature of most graphical user interfaces (GUIs) is to point-and-click with a cursor this can make a computer inaccessible for many people. Human-computer interaction (HCI) is an important area of research that aims to improve communication between humans and machines. Previous studies have identi�ed haptics as a useful method for improving computer access. However, traditional haptic techniques su�er from a number of shortcomings that have hindered their inclusion with real world software. The focus of this thesis is to develop haptic rendering algorithms that will permit motion-impaired operators to use haptic assistance with existing graphical user interfaces. The main goal is to improve interaction by reducing error rates and improving targeting times. A number of novel haptic assistive techniques are presented that utilise the three degrees-of-freedom (3DOF) capabilities of modern haptic devices to produce assistance that is designed speci�- cally for motion-impaired computer users. To evaluate the e�ectiveness of the new techniques a series of point-and-click experiments were undertaken in parallel with cursor analysis to compare the levels of performance. The task required the operator to produce a prede�ned sentence on the densely populated Windows on-screen keyboard (OSK). The results of the study prove that higher performance levels can be i ii achieved using techniques that are less constricting than traditional assistance

Advanced and natural interaction system for motion-impaired users

Human-computer interaction is an important area that searches for better and more comfortable systems to promote communication between humans and machines. Vision-based interfaces can offer a more natural and appealing way of communication. Moreover, it can help in the e-accessibility component of the e-inclusion. The aim is to develop a usable system, that is, the end-user must consider the use of this device effective, efficient and satisfactory. The research's main contribution is SINA, a hands-free interface based on computer vision techniques for motion impaired users. This interface does not require the user to use his upper body limbs, as only nose motion is considered. Besides the technical aspect, user's satisfaction when using an interface is a critical issue. The approach that we have adopted is to integrate usability evaluation at relevant points of the software developmen

An investigation into gaze-based interaction techniques for people with motor impairments

The use of eye movements to interact with computers offers opportunities for people with impaired motor ability to overcome the difficulties they often face using hand-held input devices. Computer games have become a major form of entertainment, and also provide opportunities for social interaction in multi-player environments. Games are also being used increasingly in education to motivate and engage young people. It is important that young people with motor impairments are able to benefit from, and enjoy, them. This thesis describes a program of research conducted over a 20-year period starting in the early 1990's that has investigated interaction techniques based on gaze position intended for use by people with motor impairments. The work investigates how to make standard software applications accessible by gaze, so that no particular modification to the application is needed. The work divides into 3 phases. In the first phase, ways of using gaze to interact with the graphical user interfaces of office applications were investigated, designed around the limitations of gaze interaction. Of these, overcoming the inherent inaccuracies of pointing by gaze at on-screen targets was particularly important. In the second phase, the focus shifted from office applications towards immersive games and on-line virtual worlds. Different means of using gaze position and patterns of eye movements, or gaze gestures, to issue commands were studied. Most of the testing and evaluation studies in this, like the first, used participants without motor-impairments. The third phase of the work then studied the applicability of the research findings thus far to groups of people with motor impairments, and in particular,the means of adapting the interaction techniques to individual abilities. In summary, the research has shown that collections of specialised gaze-based interaction techniques can be built as an effective means of completing the tasks in specific types of games and how these can be adapted to the differing abilities of individuals with motor impairments

Methods and metrics for the improvement of the interaction and the rehabilitation of cerebral palsy through inertial technology

Cerebral palsy (CP) is one of the most limiting disabilities in childhood, with 2.2 cases per 1000 1-year survivors. It is a disorder of movement and posture due to a defect or lesion of the immature brain during the pregnancy or the birth. These motor limitations appear frequently in combination with sensory and cognitive alterations generally result in great difficulties for some people with CP to manipulate objects, communicate and interact with their environment, as well as limiting their mobility. Over the last decades, instruments such as personal computers have become a popular tool to overcome some of the motor limitations and promote neural plasticity, especially during childhood. According to some estimations, 65% of youths with CP that present severely limited manipulation skills cannot use standard mice nor keyboards. Unfortunately, even when people with CP use assistive technology for computer access, they face barriers that lead to the use of typical mice, track balls or touch screens for practical reasons. Nevertheless, with the proper customization, novel developments of alternative input devices such as head mice or eye trackers can be a valuable solution for these individuals. This thesis presents a collection of novel mapping functions and facilitation algorithms that were proposed and designed to ease the act of pointing to graphical elements on the screen—the most elemental task in human-computer interaction—to individuals with CP. These developments were implemented to be used with any head mouse, although they were all tested with the ENLAZA, an inertial interface. The development of such techniques required the following approach: Developing a methodology to evaluate the performance of individuals with CP in pointing tasks, which are usually described as two sequential subtasks: navigation and targeting. Identifying the main motor abnormalities that are present in individuals with CP as well as assessing the compliance of these people with standard motor behaviour models such as Fitts’ law. Designing and validating three novel pointing facilitation techniques to be implemented in a head mouse. They were conceived for users with CP and muscle weakness that have great difficulties to maintain their heads in a stable position. The first two algorithms consist in two novel mapping functions that aim to facilitate the navigation phase, whereas the third technique is based in gravity wells and was specially developed to facilitate the selection of elements in the screen. In parallel with the development of the facilitation techniques for the interaction process, we evaluated the feasibility of use inertial technology for the control of serious videogames as a complement to traditional rehabilitation therapies of posture and balance. The experimental validation here presented confirms that this concept could be implemented in clinical practice with good results. In summary, the works here presented prove the suitability of using inertial technology for the development of an alternative pointing device—and pointing algorithms—based on movements of the head for individuals with CP and severely limited manipulation skills and new rehabilitation therapies for the improvement of posture and balance. All the contributions were validated in collaboration with several centres specialized in CP and similar disorders and users with disability recruited in those centres.La parálisis cerebral (PC) es una de las deficiencias más limitantes de la infancia, con un incidencia de 2.2 casos por cada 1000 supervivientes tras un año de vida. La PC se manifiesta principalmente como una alteración del movimiento y la postura y es consecuencia de un defecto o lesión en el cerebro inmaduro durante el embarazo o el parto. Las limitaciones motrices suelen aparecer además en compañía de alteraciones sensoriales y cognitivas, lo que provoca por lo general grandes dificultades de movilidad, de manipulación, de relación y de interacción con el entorno. En las últimas décadas, el ordenador personal se ha extendido como herramienta para la compensación de parte de estas limitaciones motoras y como medio de promoción de la neuroplasticidad, especialmente durante la infancia. Desafortunadamente, cerca de un 65% de las personas PC que son diagnosticadas con limitaciones severas de manipulación son incapaces de utilizar ratones o teclados convencionales. A veces, ni siquiera la tecnología asistencial les resulta de utilidad ya que se encuentran con impedimentos que hacen que opten por usar dispositivos tradicionales aun sin dominar su manejo. Para estas personas, los desarrollos recientes de ratones operados a través de movimientos residuales con la cabeza o la mirada podrían ser una solución válida, siempre y cuando se personalice su manejo. Esta tesis presenta un conjunto de novedosas funciones de mapeo y algoritmos de facilitaci ón que se han propuesto y diseñado con el ánimo de ayudar a personas con PC en las tareas de apuntamiento de objetos en la pantalla —las más elementales dentro de la interacción con el ordenador. Aunque todas las contribuciones se evaluaron con la interfaz inercial ENLAZA, desarrollada igualmente en nuestro grupo, podrían ser aplicadas a cualquier ratón basado en movimientos de cabeza. El desarrollo de los trabajos se resume en las siguientes tareas abordadas: Desarrollo de una metodología para la evaluación de la habilidad de usuarios con PC en tareas de apuntamiento, que se contemplan como el encadenamiento de dos sub-tareas: navegación (alcance) y selección (clic). Identificación de los tipos de alteraciones motrices presentes en individuos con PC y el grado de ajuste de éstos a modelos estándares de comportamiento motriz como puede ser la ley de Fitts. Propuesta y validación de tres técnicas de facilitación del alcance para ser implementadas en un ratón basado en movimientos de cabeza. La facilitación se ha centrado en personas que presentan debilidad muscular y dificultades para mantener la posición de la cabeza. Mientras que los dos primeros algoritmos se centraron en facilitar la navegación, el tercero tuvo como objetivo ayudar en la selección a través de una técnica basada en pozos gravitatorios de proximidad. En paralelo al desarrollo de estos algoritmos de facilitación de la interacción, evaluamos la posibilidad de utilizar tecnología inercial para el control de videojuegos en rehabilitación. Nuestra validación experimental demostró que este concepto puede implementarse en la práctica clínica como complemento a terapias tradicionales de rehabilitación de la postura y el equilibrio. Como conclusión, los trabajos desarrollados en esta tesis vienen a constatar la idoneidad de utilizar sensores inerciales para el desarrollo de interfaces de accesso alternativo al ordenador basados en movimientos residuales de la cabeza para personas con limitaciones severas de manipulación. Esta solución se complementa con algoritmos de facilitación del alcance. Por otra parte, estas soluciones tecnológicas de interfaz con el ordenador representan igualmente un complemento de terapias tradicionales de rehabilitación de la postura y el equilibrio. Todas las contribuciones se validaron en colaboración con una serie de centros especializados en parálisis cerebral y trastornos afines contando con usuarios con discapacidad reclutados en dichos centros.This thesis was completed in the Group of Neural and Cognitive Engineering (gNEC) of the CAR UPM-CSIC with the financial support of the FP7 Framework EU Research Project ABC (EU-2012-287774), the IVANPACE Project (funded by Obra Social de Caja Cantabria, 2012-2013), and the Spanish Ministry of Economy and Competitiveness in the framework of two projects: the Interplay Project (RTC-2014-1812-1) and most recently the InterAAC Project (RTC-2015-4327-1)Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Juan Manuel Belda Lois.- Secretario: María Dolores Blanco Rojas.- Vocal: Luis Fernando Sánchez Sante

The effects of technology use by an individual with severe or multiple disabilities within the educational environment: A case study.

Assistive technology was found to impact the educational environment in many ways. Communication and computer use were the areas where the most significant impact was observed in Travis' educational program. Technology use also impacted affective issues, such as motivation and self-esteem. In addition, the expectations and beliefs of significant others were positively impacted by Travis' technology use. Technology was found to have little effect on his curricular goals, social interaction, or inclusion.The provision of augmentative and alternative communication devices and materials, when properly implemented, provided some opportunities for increased communication. However, little effort by the staff to keep the devices or materials accessible to Travis (within his reach), and inconsistent reinforcement by the staff for the use of those materials was noted as an inhibiting factor.A number of recommendations for practice were suggested, including the need for proper training of both certified and noncertified staff members.Travis' assistive technology preferences included picture icons and low-tech devices (such as loop tapes or single-switch activities). Effective computer access was accomplished by single switch adaptations, and Travis was highly motivated by autonomous computer use. Travis' performance during structured learning activities at the computer, however, showed great variability. Significant oppositional behaviors occurred at times, particularly when the assigned task was developmentally inappropriate, when communication efforts went unrecognized, or when Travis' control options were limited. Teachers who used techniques designed to enhance intrinsic motivation saw significantly better attention to task, perseverance, and cooperation from Travis.This case study examined the impact of technology use by a student with severe and multiple disabilities on factors such as achievement, learning, inclusion, social interactions, motivation, behavior, self-esteem, or the attitudes of significant others (teachers, peers, etc.) in the educational setting. Qualitative methodologies were used to follow the educational activities of Travis, an 11-year old student entering the 4th grade, for a seven month period. Because of severe limitations in the areas of communication, mobility, cognition, range of motion, and motor skills, Travis was a prime candidate for assistive technology

Some problems of designing for augmentative and alternative communication users: an enquiry through practical design activity

The submission is concerned with, and addresses, problems of designing for people with disabilities, with specific reference to people who are illiterate and cannot speak. People with such disabilities often depend on electronic AAC (Augmentative and Alternative Communication) devices for interpersonal communication. A central theme of the thesis, however, is that such products, and products intended for people with disabilities more generally, have characteristics that inadequately attend to users' needs. Through a combination of practical product development and literature reviews, the thesis demonstrates how improvements to AAC devices 'can be made through user-participatory, usercentred and more sensitive and perceptive design. Literature reviews in the following subjects are reported: AAC; the operational knowledge base for design and disability; user participatory design; and wearable computing. At the core of the thesis is the presentation and discussion of an empirical case study, carried out by the researcher, to design and develop the Portland Communication Aid (PCA). The PCA was conceived as an AAC product that would attempt to redress the inadequacies of predecessor devices. The design activity for the PCA is traced in the thesis, from initial concepts and development models through to a working prototype. Key ideas and essential principles of the design are illustrated. Throughout the work on the PCA, many problems associated with designing for people with severe communication disabilities were encountered. These problems, as with their resolutions, comprised matters of both designing (as an activity) and design (as product specification). The thesis contains comprehensive exposure and analysis of these problems and resolutions. In particular, the value of shaping meaning, metaphor, and other product semantics into devices intended for use by people with disabilities is explored. The study provides two substantive conclusions. First, that both the activity and the outcomes of Industrial Design have a valuable role in the empowerment and rehabilitation of AAC users. And second, that key principles have been identified that will enable designers to better identify, articulate and respond to the needs of people with communication disabilities (and the needs of people with disabilities more generally

Proceedings of the 4th international conference on disability, virtual reality and associated technologies (ICDVRAT 2002)

The proceedings of the conferenc