Dwell-free input methods for people with motor impairments

Millions of individuals affected by disorders or injuries that cause severe motor impairments have difficulty performing compound manipulations using traditional input devices. This thesis first explores how effective various assistive technologies are for people with motor impairments. The following questions are studied: (1) What activities are performed? (2) What tools are used to support these activities? (3) What are the advantages and limitations of these tools? (4) How do users learn about and choose assistive technologies? (5) Why do users adopt or abandon certain tools? A qualitative study of fifteen people with motor impairments indicates that users have strong needs for efficient text entry and communication tools that are not met by existing technologies. To address these needs, this thesis proposes three dwell-free input methods, designed to improve the efficacy of target selection and text entry based on eye-tracking and head-tracking systems. They yield: (1) the Target Reverse Crossing selection mechanism, (2) the EyeSwipe eye-typing interface, and (3) the HGaze Typing interface. With Target Reverse Crossing, a user moves the cursor into a target and reverses over a goal to select it. This mechanism is significantly more efficient than dwell-time selection. Target Reverse Crossing is then adapted in EyeSwipe to delineate the start and end of a word that is eye-typed with a gaze path connecting the intermediate characters (as with traditional gesture typing). When compared with a dwell-based virtual keyboard, EyeSwipe affords higher text entry rates and a more comfortable interaction. Finally, HGaze Typing adds head gestures to gaze-path-based text entry to enable simple and explicit command activations. Results from a user study demonstrate that HGaze Typing has better performance and user satisfaction than a dwell-time method

Longitudinal Study of Two Virtual Cursors for People With Motor Impairments: A Performance and Satisfaction Analysis on Web Navigation

The lack of dexterity in the upper limbs of people with motor impairments may prevent the use of standard pointing devices, such as mice, to access graphical user interfaces. In these cases, pointing and clicking are usually performed by means of alternative devices such as joysticks, trackballs or standard keyboards. However, target acquisition can still be challenging for this group of people due to their physical condition. Based on previous works, we developed two virtual cursors: the novel cross cursor and the standard area cursor. They are devoted to assist two different groups of users with link selection within web pages: keyboard-only users, and joystick and trackball users, respectively. Both virtual cursors have been evaluated and compared with the original unassisted cursor in a longitudinal study. Eight people with motor impairments participated in an unsupervised experiment from their own personal computers at home. For a period of six weeks, each participant used both a virtual cursor and the original unassisted cursor to freely navigate the Web, and to perform predefined target acquisition tasks. Interaction data was automatically logged throughout the study along with subjective assessments concerning the usability of the virtual cursor being tested. Results show significant improvements for both virtual cursors in six of the seven cursor parameters studied, albeit with performance variations between some participants. The virtual cursors were extensively used for free web navigation and in their subjective assessments both were positively endorsed by participants who also put forward improvement suggestions for future developments

Virtual reality and its role in removing the barriers that turn cognitive impairments into intellectual disability

Early expectations of the contribution that virtual reality (VR) could make to education far exceeded actual applications. This was largely due to the initial immaturity of the technology and a lack of evidence base on which to base design and utilisation. While the early developments in computer based learning largely concentrated on mainstream education, leaving those with special needs behind, the potential of VR as an educational tool was exploited for those with intellectual disabilities right from the start. This paper describes the empirical evidence that has contributed to the development of educational virtual reality for those with intellectual disabilities: studies on transfer of learning from the virtual to the real world; how teachers might support those using VR; the design of virtual environments and what input/control devices best facilitate use of desktop VR. Future developments and ethical issues are also considered

Assisted Interaction for Improving Web Accessibility: An Approach Driven and Tested by Userswith Disabilities

148 p.Un porcentaje cada vez mayor de la población mundial depende de la Web para trabajar, socializar, opara informarse entre otras muchas actividades. Los beneficios de la Web son todavía más cruciales paralas personas con discapacidades ya que les permite realizar un sinfín de tareas que en el mundo físico lesestán restringidas debido distintas barreras de accesibilidad. A pesar de sus ventajas, la mayoría depáginas web suelen ignoran las necesidades especiales de las personas con discapacidad, e incluyen undiseño único para todos los usuarios. Existen diversos métodos para combatir este problema, como porejemplo los sistemas de ¿transcoding¿, que transforman automáticamente páginas web inaccesibles enaccesibles. Para mejorar la accesibilidad web a grupos específicos de personas, estos métodos requiereninformación sobre las técnicas de adaptación más adecuadas que deben aplicarse.En esta tesis se han realizado una serie de estudios sobre la idoneidad de diversas técnicas de adaptaciónpara mejorar la navegación web para dos grupos diferentes de personas con discapacidad: personas conmovilidad reducida en miembros superiores y personas con baja visión. Basado en revisionesbibliográficas y estudios observacionales, se han desarrollado diferentes adaptaciones de interfaces web ytécnicas alternativas de interacción, que posteriormente han sido evaluadas a lo largo de varios estudioscon usuarios con necesidades especiales. Mediante análisis cualitativos y cuantitativos del rendimiento yla satisfacción de los participantes, se han evaluado diversas adaptaciones de interfaz y métodosalternativos de interacción. Los resultados han demostrado que las técnicas probadas mejoran el acceso ala Web y que los beneficios varían según la tecnología asistiva usada para acceder al ordenador

Augmenting Graphical User Interfaces with Haptic Assistance for Motion-Impaired Operators

Haptic assistance is an emerging field of research that is designed to improve human-computer interaction (HCI) by reducing error rates and targeting times through the use of force feedback. Haptic feedback has previously been investigated to assist motion-impaired computer users, however, limitations such as target distracters have hampered its integration with graphical user interfaces (GUIs). In this paper two new haptic assistive techniques are presented that utilise the 3DOF capabilities of the Phantom Omni. These are referred to as deformable haptic cones and deformable virtual switches. The assistance is designed specifically to enable motion-impaired operators to use existing GUIs more effectively. Experiment 1 investigates the performance benefits of the new haptic techniques when used in conjunction with the densely populated Windows on-screen keyboard (OSK). Experiment 2 utilises the ISO 9241-9 point-and-click task to investigate the effects of target size and shape. The results of the study prove that the newly proposed techniques improve interaction rates and can be integrated with existing software without many of the drawbacks of traditional haptic assistance. Deformable haptic cones and deformable virtual switches were shown to reduce the mean number of missed-clicks by at least 75% and reduce targeting times by at least 25%

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

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

CIRCLING INTERFACE: AN ALTERNATIVE INTERACTION METHOD FOR ON-SCREEN OBJECT MANIPULATION

An alternative interaction method, called the circling interface, was developed and evaluated for individuals with disabilities who find it difficult or impossible to consistently and efficiently perform pointing operations involving the left and right mouse buttons. The circling interface is a gesture-based interaction technique. To specify a target of interest, the user makes a circling motion around the target. To specify a desired pointing command with the circling interface, each edge of the screen is used. The user selects a command before circling the target. Empirical evaluations were conducted with human subjects from three different groups (individuals without disability, individuals with spinal cord injury, and individuals with cerebral palsy), comparing each group's performance on pointing tasks with the circling interface to performance on the same tasks when using a mouse button or dwell-clicking software. Across all three groups, the circling interface was faster than the dwelling interface (although the difference was not statistically significant). For the single-click operation, the circling interface was slower than dwell selection, but for both double-click and drag-and-drop operations, the circling interface was faster. In terms of performance accuracy, the results were mixed: for able-bodied subjects circling was more accurate than dwelling, for subjects with SCI dwelling was more accurate than circling, and for subjects with CP there was no difference. However, if errors caused by circling on an area with no target or by ignoring circles that are too small or too fast were automatically corrected by the circling interface, the performance accuracy of the circling interface would significantly outperform dwell selection. This suggests that the circling interface can be used in conjunction with existing pointing techniques and this combined approach may provide more effective mouse use for people with pointing problems. Consequently, the circling interface can improve clinical practice by providing an alternative pointing method that does not require physically activating mouse buttons and is more efficient than dwell-clicking. It is also expected to be useful for both computer access and augmentative communication software

Augmenting the Spatial Perception Capabilities of Users Who Are Blind

People who are blind face a series of challenges and limitations resulting from their lack of being able to see, forcing them to either seek the assistance of a sighted individual or work around the challenge by way of a inefficient adaptation (e.g. following the walls in a room in order to reach a door rather than walking in a straight line to the door). These challenges are directly related to blind users' lack of the spatial perception capabilities normally provided by the human vision system. In order to overcome these spatial perception related challenges, modern technologies can be used to convey spatial perception data through sensory substitution interfaces. This work is the culmination of several projects which address varying spatial perception problems for blind users. First we consider the development of non-visual natural user interfaces for interacting with large displays. This work explores the haptic interaction space in order to find useful and efficient haptic encodings for the spatial layout of items on large displays. Multiple interaction techniques are presented which build on prior research (Folmer et al. 2012), and the efficiency and usability of the most efficient of these encodings is evaluated with blind children. Next we evaluate the use of wearable technology in aiding navigation of blind individuals through large open spaces lacking tactile landmarks used during traditional white cane navigation. We explore the design of a computer vision application with an unobtrusive aural interface to minimize veering of the user while crossing a large open space. Together, these projects represent an exploration into the use of modern technology in augmenting the spatial perception capabilities of blind users

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