Vol. 4, No. 4, July/August 1996	Previous Issues Subscribe to AT Messenger Download PDF Viewer
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Environmental Control: Technology That Can Do Ordinary Things

by Michael Meyreles, Rehab Engineer, New Castle County ATRC

Most of us think of technology as performing extraordinary tasks. Environmental controls have the potential to assist in the performance of extraordinary things but, generally, environmental controls assist in accomplishing ordinary tasks like turning a light on, dialing a phone, or opening a door. Environmental controls can be as simple as a switch or as sophisticated as using a voice recognition computer control system. The most common environmental control unit (ECU) is referred to as the "X-10 unit." These units are available at Radio Shack or other electronic stores and cost approximately $10.00 to $15.00. With an X-10 ECU system, a person with a disability can control up to 16 electrical devices at home or work.

The X-10 ECU system consists of three parts: a transmitter, a transceiver module, and the X-10 module(s). Each X-10 module is set with an individual unit code and provides the switch activation for the electrical device it is controlling. When a person presses a button on the transmitter, the transmitter broadcasts a radio signal corresponding to the electrical device the user wishes to control. The radio signal is picked up by the transceiver, which is plugged into a wall receptacle. The transceiver then sends a carrier current through the existing house wiring that will be recognized only by the X-10 module. Fans, lights, thermostats, radios, and other electrical devices all can be controlled in this way using X-10 appliance modules.

Infrared systems operate in a similar manner. Many people use a remote control that utilizes an infrared signal. Remote controls for TVs and VCRs are the most common type of infrared systems. The remote control (transmitter) sends an infrared signal to the transceiver, which then sends the corresponding signal to the desired X-10 module. Infrared systems are compatible with X-10 systems, but with the added ability to control TVs and VCRs.

ECUs can be built in as added features on power wheelchairs and augmentative communication devices. Using the same mechanism that controls the wheelchair-sip and puff, single switch, or joystick-a person can control their environment. With an infrared or radio transmitter connected to the electronics of the wheelchair, and the wheelchair set to ECU mode, a person can control lights, fans, and other appliances. Augmentative communication devices such as the Liberator, DynaVox and the System 2000 offer options for environmental control.

Voice activated environmental control systems may assist an individual with quadriplegia in achieving independence. Using voice recognition software, such as DragonDictate or Kurzweil Voice, and environmental control software, such as Cintex2 or Butler in a Box, a person can talk to his or her computer and control up to 256 X-10 compatible devices. This is accomplished using a software package and either an infrared or radio transmitter connected to the computer and a transceiver with additional X-10s. An environmental control system as sophisticated as this can manage a home security system, control lighting and thermostats, operate an intercom, operate an automatic door opening system, and run a home entertainment system, all with the sound of a person's voice.

Most people today use some form of environmental control, whether it is a remote control for the TV or a garage door opener. These remotes can perform some of life's ordinary tasks. The technology can be very important for a person with a disability as it allows the individual to be more independent. Environmental control units are a simple solution to removing some of the barriers at home, school, or at work. For a demonstration of simple X-10 units, environmental control software, and infrared systems, contact your local ATRC. X-10 modules are available through the DATI equipment loan program.