Emergency Egress and Information System for Persons With Vision Loss

The purpose of the proposed three-year research project is to develop and evaluate an emergency egress system for persons with visual impairment. This system would use existing lighted exit signage to provide egress information at a distance of up to 100 feet. The distance is the same as the required visibility distance of lighted exit signs for sighted persons. By offering egress information at an equivalent distance, the investigators hypothesize that people with visual impairment can approach the egress performance of sighted persons.

The information transmitted will be equivalent to what a sighted person obtains, namely, the direction of the exit door. In addition, a description of the exit route will be provided including the distance to the exit door; lighting conditions, hazards and obstacles that will be encountered on the exit route; the distance down to the street; and where on the street they will be when they get out of the building. A receiver worn by the person will include a tiny optical array to sense the direction of each exit sign. The receiver will also translate the transmitted signal into a spoken message. A low-profile stereo bone conduction headset will indicate the direction to each exit sign along a path to the exit door. For people with some hearing loss, this same low-profile headset will be used to simulate a light "tap" to one side or other of the head to indicate direction. Such directional "tapping" output may also prove effective when loud alarms are blaring.

The objectives are to:

1. develop Talking Exit Lights with a range of at least 100 feet,
2. write software for the user device to accurately indicate the direction of Talking Exit Lights and provide spoken messages,
3. optimize the user interface to make it easy and intuitive to use,
4. test the accuracy and reliability of the developed system in terms of transmission range and directional accuracy, and
5. conduct subject evaluations of the new system.

Two versions of transmitting exit signs will be developed:

1. a retro-fit design for existing fluorescent light exit signs, and
2. a Light Emitting Diode (LED) design for the LED exit signs now going into newly constructed buildings.

For the retro-fit version, Talking Lights, LLC, will modify the physical shape and size of their Talking Light digital ballast, making it a fully compatible replacement for existing exit sign ballasts. VA investigators will develop the LED version, designing and constructing a microprocessor-controlled system for storing and transmitting information using LEDs. Both designs will use secure power line communications to upload transmittal information to specific exit signs, each of which will have its own ID number. Finally, VA investigators will write software for the existing Talking Lights PocketPC receiver to interpret sensor signals, obtain sign location data, and convert this data into a stereo sound presentation of exit sign direction.

This development will be accomplished via a Cooperative Research and Development Agreement (CRADA) with Talking Lights LLC, which holds a patent on an electronic ballast that converts standard fluorescent bulbs into digital information transmitters. The company will also provide a PocketPC receiver that decodes their proprietary transmission signal, and a 5-sensor optical array capable of picking up their signal over a 150-degree field. As part of this CRADA, Talking Lights will modify their ballast to match the form-factor of ballasts in exit signs. Further, they will release their proprietary encoder design to VA investigators so that the LED Exit Light design can be made fully compatible with the fluorescent light design.

Once developed and optimized, investigators hypothesize a dramatic improvement in egress performance for all ages of two populations:

1. people with severe vision loss who use a white cane or dog for mobility, and
2. people with low vision who do not use a white cane or dog for mobility, yet have problems reading and locating exit signs.

Results will be published and presented for review to the National Fire Prevention Agency (NFPA) for consideration as part of the Life Safety Code, and to the Building Officials and Code Administrators (BOCA) for consideration as part of the National Building Code.

COMPARISONS: Egress using existing emergency exit signage.