Assistive Context-Aware Toolkit (ACAT)

A dedicated key on the keyboard can act as a switch to select the highlighted item on the scanning interface. ACAT uses F12 as the default key, and it can be reassigned to other function keys (F1 through F11). While the keyboard can be used as a mechanical switch, it may not be suitable for people with limited movement.

This switch is suitable for someone who does not have much muscle movement but can move facial muscles voluntarily. ACAT uses the laptop’s built-in webcam or an external USB camera connected to the laptop to detect facial muscle movement, such as a cheek twitch or raised eyebrow, to select the highlighted item on the scanning interface.

A variety of off-the-shelf switches are available for assistive needs. These switches employ various mechanisms, such as push buttons, foot pedals, sip-and-puff devices, and proximity sensors. They typically connect to laptops directly through USB, through a switchbox, or wirelessly via Bluetooth® technology. Activating a switch simulates pressing a keyboard button, and ACAT detects this as the trigger to select the highlighted item on the scanning interface. For off-the-shelf switch vendors, search the internet for assistive switches.

A brain computer interface (BCI) is reserved for people with the most extreme communication needs (often called locked-in). These individuals are cognitively aware but physically cannot move. Setting up a BCI can be challenging; it should be reserved only for situations where no other switch can be used.