The words+ Infrared/Sound/Touch Switch (IST) is a unique single switch that is activated by slight movement or faint sound. The switch provides user control when connected to a device driven by a single switch. Individuals are currently accessing a wide variety of communication and computer systems with movement ranging from 
finger or toe to eyelid and eyeball movement using the IST Switch.
The control module consists of a small plastic box which houses the electronics, a 9-volt battery compartment, a sensitivity knob, LED indicators, and a switch to turn auditory feedback on or off. There is also a power jack that lets the IST be used continuously. When a sensor is activated, the Control Module closes an internal relay, which then activates a communication device or computer.
The Sound Sensor uses a miniature microphone to detect sounds ranging from loud voice sounds down to slightly sharp breaths from the mouth or nose. Voice sound can be detected with the microphone sensor supported against the user's neck, or positioned in front of the nose or mouth. The sensitivity is fully adjustable to filter out normal breathing noises, background room noises or someone else speaking nearby.
The Infrared Sensor operates by sending out a very low power infrared invisible light beam. The Sensor is activated when a body surface in front of the beam reflects enough of the light back to the receiver. The body surface can activate the IST by coming closer to the sensor or by coming into the field of view of the sensor from the side. The sensitivity knob lets you set the precise activation distance. The Infrared Sensor compensates for ambient lighting, eyeglasses, and other variations. A headband can be used to mount the infrared sensor for eyeblink, or just eye movement if the user does not wear glasses.
The Touch Sensor uses a small metal button to detect skin contact. The slightest touch can be detected, using any part of the body, so that no force is required to activate the Sensor.
To try out the IST Switch, call LINC for an appointment, or call Rachel Clarke at words+ in Baltimore at (410) 244-1769 or (800) 877-7180. (Fall 1999)
