The Eyedrivomatic Electronic Hand is a gimbal system that fits over the wheelchairs normal joystick and can provide approximately 20 degrees of movement in any direction.
We decided on this approach, rather than interfacing directly with the wheelchair’s electronics for several reasons. Although some protocols are more common than others, not all chairs use the same protocol. Additionally, most chair manufacturers use proprietary sockets, or may not even include a socket for external control! Interfacing on many chairs would involve splicing directly into the wheelchairs wiring. This is a significant issue because many people don’t actually own their chairs.
By using a device that physically moves the joystick, we emulate the only protocol used by every wheelchair… the human hand.
Another benefit to using the Electronic Hand is that it can be fitted to a users wheelchair in a few minutes. Simply unscrew the joystick grip (usually simply by twisting it), select an appropriately sized adapter, strap the Electronic Hand over the controller using the provided Velcro, and plug it into the eyegaze computer.
The Electronic Hand also includes three relays that can be used to operate external switched controls on the wheelchair – or anything else. Many wheelchairs have tilt/recline functions, mode selections, power toggle, etc. that can be controlled using buttons plugged into sockets on the wheelchair’s joystick unit. Thus Eyedrivomatic can control all of the chair’s functions. An additional relay is used internally as part of a safety system to disable the electronic hand when not in use. Typically a wheelchair will use two of the three relays for “power” and “mode” operations. The third relay can then be used for any number of other purposes.