Mouse Emulation Software
Mouse emulation software is a simple program which replaces the functionality of a mouse by enabling the user to operate a switch/key to click on screen objects.
As shown in the picture, a horizontal line appears at the top of the screen and then starts to move slowly downwards. The user activates the switch when the line is over the desired object on the screen, thus making the line freeze at its current position. If the user does nothing, the line will continue its way to the bottom of the screen and then start over again from the top. To select the exact object from those located under the frozen line, a pointer (arrow, finger, etc.) appears and starts moving from left to right along the line. When the pointer reaches the desired object, the user activates the switch once again and this is then equivalent to a click on an object with a mouse. Again, until a choice is made, the pointer repeats its journey over and over again.
The described horizontal/vertical scanning is not the only possible scheme. For example, in a 'radar' approach, the user also freezes moving line and pointer, but this time the line is radial and circles around the centre of the screen until the switch is activated. A more demanding way to emulate a mouse is to use keypad buttons to move the pointer in various directions and to click on objects – such option can be found among Windows Accessibility Options.
From the technical aspect, running mouse emulation software does not require a powerful PC, even somewhat outdated machines should be able to handle it. Operating system-specific setup program may be required, though.
As mouse emulation software works in connection with a button/switch, you may require additional hardware (a special switch/knob and, if necessary, a switch interface box to connect the switch(es) to the computer) in case you cannot use one of the buttons on your keyboard/mouse.
Mouse emulation software is very affordable, if not available free of charge on the internet.