RESUMEN
PURPOSE: Individuals with tetraplegia depend on alternative interfaces in order to control computers and other electronic equipment. Current interfaces are often limited in the number of available control commands, and may compromise the social identity of an individual due to their undesirable appearance. The purpose of this study was to implement an alternative computer interface, which was fully embedded into the oral cavity and which provided multiple control commands. METHODS: The development of a wireless, intraoral, inductive tongue computer was described. The interface encompassed a 10-key keypad area and a mouse pad area. This system was embedded wirelessly into the oral cavity of the user. The functionality of the system was demonstrated in two tetraplegic individuals and two able-bodied individuals Results: The system was invisible during use and allowed the user to type on a computer using either the keypad area or the mouse pad. The maximal typing rate was 1.8 s for repetitively typing a correct character with the keypad area and 1.4 s for repetitively typing a correct character with the mouse pad area. CONCLUSION: The results suggest that this inductive tongue computer interface provides an esthetically acceptable and functionally efficient environmental control for a severely disabled user. Implications for Rehabilitation New Design, Implementation and detection methods for intra oral assistive devices. Demonstration of wireless, powering and encapsulation techniques suitable for intra oral embedment of assistive devices. Demonstration of the functionality of a rechargeable and fully embedded intra oral tongue controlled computer input device.
Asunto(s)
Equipos de Comunicación para Personas con Discapacidad , Periféricos de Computador , Cuadriplejía/rehabilitación , Dispositivos de Autoayuda , Lengua , Interfaz Usuario-Computador , Adulto , Computadores , Personas con Discapacidad , Diseño de Equipo , Femenino , Humanos , Sistemas Hombre-Máquina , Persona de Mediana Edad , Programas Informáticos , Tecnología InalámbricaRESUMEN
PURPOSE: To evaluate typing and pointing performance and improvement over time of four able-bodied participants using an intra-oral tongue-computer interface for computer control. BACKGROUND: A physically disabled individual may lack the ability to efficiently control standard computer input devices. There have been several efforts to produce and evaluate interfaces that provide individuals with physical disabilities the possibility to control personal computers. METHOD: Training with the intra-oral tongue-computer interface was performed by playing games over 18 sessions. Skill improvement was measured through typing and pointing exercises at the end of each training session. RESULTS: Typing throughput improved from averages of 2.36 to 5.43 correct words per minute. Pointing throughput improved from averages of 0.47 to 0.85 bits/s. Target tracking performance, measured as relative time on target, improved from averages of 36% to 47%. Path following throughput improved from averages of 0.31 to 0.83 bits/s and decreased to 0.53 bits/s with more difficult tasks. CONCLUSIONS: Learning curves support the notion that the tongue can rapidly learn novel motor tasks. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, which makes the tongue a feasible input organ for computer control. IMPLICATIONS FOR REHABILITATION: Intra-oral computer interfaces could provide individuals with severe upper-limb mobility impairments the opportunity to control computers and automatic equipment. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, but does not cause fatigue easily and might be invisible to other people, which is highly prioritized by assistive device users. Combination of visual and auditory feedback is vital for a good performance of an intra-oral computer interface and helps to reduce involuntary or erroneous activations.
Asunto(s)
Periféricos de Computador , Desempeño Psicomotor/fisiología , Dispositivos de Autoayuda , Lengua , Interfaz Usuario-Computador , Adulto , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Práctica PsicológicaRESUMEN
PURPOSE: To investigate the effects of visual and tactile intra-oral sensor-position feedback for target selection tasks with the tip of the tongue. METHOD: Target selection tasks were performed using an inductive tongue-computer interface (ITCI). Visual feedback was established by highlighting the area on a visual display corresponding to the activated intra-oral target. Tactile feedback was established using a sensor-border matrix over the sensor plates of the ITCI, which provided sensor-position tactile queues via the user's tongue. Target selection tasks using an on-screen keyboard by controlling the mouse pointer with the ITCI's was also evaluated. RESULTS: Mean target selection rates of 23, 5 and 15 activations per minute were obtained using visual, tactile and "none" feedback techniques in the 3rd training session. On-screen keyboard target selection tasks averaged 10 activations per minute in the 3rd training session. Involuntary activations while speaking or drinking were significantly reduced either through a sensor-matrix or dwell time for sensor activation. CONCLUSIONS: These results provide key design considerations to further increase the typing efficiency of tongue-computer interfaces for individuals with upper-limb mobility impairments.
Asunto(s)
Equipos de Comunicación para Personas con Discapacidad , Lengua , Interfaz Usuario-Computador , Adulto , Personas con Discapacidad , Retroalimentación Sensorial , HumanosRESUMEN
This study assessed the ability of the tongue tip to accurately select intraoral targets embedded in an upper palatal tongue-computer interface, using 18 able-bodied volunteers. Four performance measures, based on modifications to Fitts's Law, were determined for three different tongue-computer interface layouts. The layouts differed with respect to number and location of the targets in the palatal interface. Assessment of intraoral target selection speed and accuracy revealed that performance was indeed dependent on the location and distance between the targets. Performances were faster and more accurate for targets located farther away from the base of the tongue in comparison to posterior and medial targets. A regression model was built, which predicted intraoral target selection time based on target location and movement amplitude better than the predicted by using a standard Fitts's Law model. A 30% improvement in the speed and accuracy over three daily practice sessions of 30 min emphasizes the remarkable motor learning abilities of the tongue musculature and provides further evidence that the tongue is useful for operating computer-interface technologies.
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Aprendizaje/fisiología , Movimiento/fisiología , Hueso Paladar/fisiología , Análisis y Desempeño de Tareas , Lengua/fisiología , Tacto/fisiología , Interfaz Usuario-Computador , Adulto , Biorretroalimentación Psicológica/métodos , Biorretroalimentación Psicológica/fisiología , Femenino , HumanosRESUMEN
Alternative and effective methods for controlling powered wheelchairs are important to individuals with tetraplegia and similar impairments whom are unable to use the standard joystick. This paper describes a system where tongue movements are used to control a powered wheelchair thus providing users, with high level spinal cord injuries, full control of their wheelchair. The system is based on an inductive tongue control system developed at Center for Sensory-Motor Interaction (SMI), Aalborg University. The system emulates a standard analog joystick in order to interface the wheelchair, thus ensuring that the system works with almost any wheelchair. The total embedment of the tongue interface into the mouth makes the control practically invisible. A fuzzy system combining 8 sensors for directional control allows for multidirectional control of the wheelchair. Preliminary test results show navigation abilities, which are highly competitive when compared to other tongue control system.
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Magnetismo/instrumentación , Sistemas Hombre-Máquina , Lengua/fisiología , Transductores , Silla de Ruedas , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , MasculinoRESUMEN
Typing performance of a full alphabet keyboard and a joystick type of mouse (with on-screen keyboard) provided by a wireless integrated tongue control system (TCS) has been investigated. The speed and accuracy have been measured in a form of a throughput defining the true correct words per minute [cwpm]. Training character sequences were typed in a dedicated interface that provided visual feedback of activated sensors, a map of the alphabet associated, and the task character. Testing sentences were typed in Word, with limited visual feedback, using non-predictive typing (map of characters in alphabetic order associated to sensors) and predictive typing (LetterWise) for TCS keyboard, and non-predictive typing for TCS mouse. Two subjects participated for four and three consecutive days, respectively, two sessions per day. Maximal throughput of 2.94, 2.46, and 2.06, 1.68 [cwpm] were obtained with TCS keyboard by subject 1 and 2 with predictive and non-predictive typing respectively. Maximal throughput of 2.09 and 1.71 [cwpm] was obtained with TCS mouse by subject 1 and 2, respectively. Same experimental protocol has been planned for a larger number of subjects.
Asunto(s)
Periféricos de Computador , Magnetismo/instrumentación , Sistemas Hombre-Máquina , Telemetría/instrumentación , Lengua/fisiología , Transductores , Interfaz Usuario-Computador , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Masculino , Silla de RuedasRESUMEN
Many computer interfaces and assistive devices for people with motor disabilities limit the input dimensionality from user to system, in many cases leading to single switch interfaces where the user can only press one button. This can, either limit the level of direct access to the functionalities of the operating system, or slow down speed of interaction. In this paper we present TongueWise: a software developed for a tongue computer interface that can be activated with the tip of the tongue and that provides direct input that covers most of the standard keyboard and mouse commands.
Asunto(s)
Equipos de Comunicación para Personas con Discapacidad , Periféricos de Computador , Cuadriplejía/rehabilitación , Programas Informáticos , Lengua , Transductores , Interfaz Usuario-Computador , Diseño de Equipo , Análisis de Falla de Equipo , HumanosRESUMEN
This paper presents the development of a character activation time prediction model for tongue-typing. This model is based on a modification of Fitts's law that is more suitable for tip-of-tongue selectivity tasks around the palatal area. The model was trained and evaluated with data from tongue-selectivity experiments using an inductive tongue-computer interface. It takes into account the movement amplitude, target position, interactions between them, character disambiguation time and error correction time.
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Equipos de Comunicación para Personas con Discapacidad , Modelos Biológicos , Desempeño Psicomotor/fisiología , Lengua/fisiología , Tacto/fisiología , Interfaz Usuario-Computador , Procesamiento de Texto , Simulación por Computador , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
This work describes a novel fully integrated inductive tongue computer interface for disabled people. The interface consists of an oral unit placed in the mouth, including inductive sensors, related electronics, a system for wireless transmission and a rechargeable battery. The system is activated using an activation unit placed on the tongue, and incorporates 18 inductive sensors, arranged in both a key area and a mouse-pad area. The system's functionality was demonstrated in a pilot experiment, where a typing rate of up to 70 characters/minute was obtained with an error rate of 3%. Future work will include tests with disabled subjects.
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Equipos de Comunicación para Personas con Discapacidad , Personas con Discapacidad/rehabilitación , Procesamiento de Señales Asistido por Computador/instrumentación , Telemetría/instrumentación , Lengua/fisiología , Interfaz Usuario-Computador , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Sistemas Hombre-Máquina , Integración de SistemasRESUMEN
Effective human input devices for computer control are very important to quadriplegics and others with severe disabilities. This paper describes a framework for computer control without need for special PC software or drivers. The framework is based on a tongue control system recently developed at Center for Sensory-Motor Interaction (SMI), Aalborg University. The framework provides emulation of a standard USB keyboard and mouse, and allows tongue control of any computer using standard USB drivers available in all modern operating systems.
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Equipos de Comunicación para Personas con Discapacidad , Periféricos de Computador , Sistemas Hombre-Máquina , Procesamiento de Señales Asistido por Computador/instrumentación , Telemetría/instrumentación , Lengua , Interfaz Usuario-Computador , Retroalimentación , Humanos , Tacto , TransductoresRESUMEN
Experimental results for pointing tasks using a tongue control system are reported in this paper. Ten untrained subjects participated in the experiment. Both typing and pointing tasks were performed, in three short-term training sessions, in consecutive days, by each subject. The system provided a key pad (14 sensors) and a mouse pad (10 sensors with joystick functionality) whose placements were interchanged (front, back) in half of the subjects. The pointing tasks consisted of selecting and tracking a target circle (of 50, 75 and 100 pixels diameter) that occurred randomly in each of the 16 positions uniformly distributed along the perimeter of a layout circle of 250 pixels diameter. The throughput was of 0.808 bits per second and the time on target was of 0.164 of the total tracking time. The pads layout, the subjects, the sessions, the target diameters, and the angle of the tracking direction had a statistically significant effect on the two performance measures. Long term training is required to assess the improvement of the user capability.