Video Lesson: Demonstration of Assistive Technology for Computer Access

Assistive technology for computer access is essential for digital inclusion, and some available solutions will be presented in the video lesson: Demonstration of Assistive Technology for Computer Access.

Watch the video lesson: Demonstration of Assistive Technology for Computer Access.

Duration: 9 minutes and 42 seconds

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Transcript

Assistive technology for computer access is a guarantee of digital inclusion. Specifically, standard computers and their peripherals (keyboard, mouse, screen) are primarily designed for users without significant physical, motor, sensory, or cognitive limitations.Assistive technology for computer access replaces or supplements standard peripherals for      students without upper extremities, and students with motor difficulties primarily affecting the upper extremities, with or without associated sensory and cognitive difficulties or specific learning difficulties.

All instruments that replace a standard computer mouse are called emulators, and they enable an alternative input method by emulating (mimicking) the functionality of a standard mouse using different input methods adapted to the user's abilities.

There is a wide range of computer mouse emulators. For students without upper extremities, or for those with somewhat preserved movements of the shoulder, arm, hand, and fingers, there is the trackball mouse. Unlike a standard mouse that requires moving the entire device by hand across a surface, a trackball mouse has a fixed ball that the user controls with their fingers, thumb, or palm to move the pointer on the screen. A trackball mouse requires less extensive, but precise and voluntarily controlled movements of the hand and/or fingers. We can divide them into those where the ball is controlled by the thumb and those with a ball controlled by the fingers or palm. All trackball mouses can be further software-customized by adjusting the speed and sensitivity of the pointer on the screen.

Joystick devices are widely known from the gaming world, but these can also be of immense assistance to students. The student controls the emulator by moving a handle in different directions to control the pointer on the screen. The buttons for the left and right click are usually located on the joystick itself or nearby. The handle can come in various models and shapes, from a ball to a shaft or an anchor. The joystick can be controlled by different body parts, such as the arm, palm, chin, or mouth. These are robust devices that can withstand rough, intense movements with reduced control without being damaged or broken. They are      often used by students with muscle spasticity, dystonic movements, tremors, etc. Tilting the lever in the desired direction (up, down, left, right, and sometimes diagonally) moves the pointer on the screen, and its speed usually depends on the degree of the lever's tilt. Most models also have programmable buttons. These emulators can, or in some cases must, be used in combination with additional external switches.

The next emulator I want to introduce belongs to the family of gyroscopic mouse. These are emulators that use sensors to detect rotational movement in space and then translate them into pointer movement on the screen. We use them for individuals who, due to their body and head position, cannot have a good view of the workspace intended for peripherals and the screen. These are students sitting inclined in a wheelchair or who are lying down. Such emulators can be controlled by various body parts (head, arms, legs, fingers). Students who are candidates for such an emulator only have subtle and very fine movements of these      body parts, and tire quickly due to their medical condition. These are students with tetraplegia or progressive neuromuscular diseases. This type of instrument requires a certain amount of training to achieve precision. It is intended for students with preserved cognitive abilities. Additional sensors can be added to them to improve student productivity and reduce fatigue.

For students who present minimal or no control over the movements of their arms, legs, or head due to cervical spinal cord injuries, advanced Amyotrophic Lateral Sclerosis (ALS), severe forms of cerebral palsy, or other conditions that cause complete or near-complete paralysis of the limbs and trunk, we use sip and puff emulators. Such an emulator interacts with the computer by using air from the mouth or nostrils. Instead of physical movements, the user controls the device by inhaling (sip) and exhaling (puff) air through a special tube/straw. Different specific patterns of air intake and expulsion, e.g., shorter or longer sips/puffs, or a combination of sip and puff, different intensity and duration of inhaling or exhaling, are converted into functions for mouse pointer control, left and right click, macros, and scrolling. Specially designed sip and puff systems can also be used with the respiratory support of people on mechanical ventilation. With these instruments, it is important to note regular cleaning and replacement of the tubes is necessary, primarily for hygiene, but also for instrument functionality, as candidates for this type of emulator often have difficulty controlling salivation.

Eye trackers are emulators that enable complete computer control exclusively through eye movements. This technology uses specialized cameras and infrared light to track the position and movement of the user's pupils, translating these movements into precise commands for operating the computer interface. The cameras track eye movement, and the software translates these movements into precise cursor movement on the screen. There are different methods of clicking or selecting with the gaze. Dwell clicking is a function where the click is registered on a certain screen element for a specific, individually adjusted number of seconds while the gaze is held on the desired element on the screen. Blink is a function where the student uses intentional blinking to make the desired selection. The user can use external switches or other sensors activated by another part of the body for clicking while looking at the desired element. We use them for students with the most severe motor limitations who cannot functionally move any other part of their body. With instruments of this type, it is necessary to emphasize from the outset that there are certain medical contraindications related to individuals with specific subtypes of epilepsy. The candidate must have intact eye movement (oculomotor function) in one or both eyes and take care of their eye health. Strong sunlight or reflections from eyeglasses can sometimes affect eye tracking performance.

Infrared sensors and navigation cameras are used for individuals who can voluntarily control head movements and facial muscles. Special cameras or sensors capture visual information (head movements, reflective dots, eyes, blinks), and the software analyzes this information to determine the user's input and translate the movement into pointer movement on the screen. With such emulators, it is important to emphasize that additional instruments for functional commands, such as special switches or dwell software, are very often necessary here.

Under the category of other sensors, we will mention a diverse range of simple instruments whose activation is converted into the desired command on the computer with the help of a special interface. Such sensors exploit various physiological signals or movements to enable computer control. They come in different shapes, sizes, and activation methods, allowing users to use them with the part of the body over which they have the best voluntary control (hand, foot, head, elbow, eye blink, etc.). There are mechanical switches (by pressing), pneumatic switches (by blowing or sucking air), sensory switches (activated by movement or proximity), and specialized switches such as those activated by an eye blink. It is important to also mention EMG sensors that detect muscle electrical activity. They are placed on the skin above the muscles that the user can voluntarily contract, even if that movement is not visible or functional.

Assistive technology for computer access enables students with disabilities to use computers more efficiently and independently. These technologies can include software, hardware, and other tools that provide alternative methods for input, output, and interaction with computers, thus enabling independent and high-quality completion of assigned tasks.