Assistive Technology in the Science Laboratory: A Talking Laboratory Work Station for Visually Impaired Science Students

Much assistive technology for people with disabilities has been developed in the last ten years or so, but the developers of such technology usually quit as soon as they have provided access to computers. But to chemists, physicists, and engineers, that seems to be only half the job: computers are great laboratory tools, and if you connect a suitably adapted computer to instruments and sensors in a laboratory and provide it with suitable data acquisition and data analysis software, you have a great way to make careers in science and engineering more accessible to people with disabilities. Robert C. Morrison and I first became interested in the problems of disabled students in the laboratory in 1977, when Richard V. Hartness, a blind chemistry student, brought them to our attention. We decided to use high technology to develop a flexible, microcomputer-based aid that could give visually impaired college science students independent access to accurate measurements performed with scientific instruments. Our research group's efforts (which were funded by the U. S. Department of Education) culminated in a luggable, 42-pound, talking, whistling, industrial-strength data acquisition computer that cost $8000 a copy and was custom-built from expensive industrial modules. The group had written about 300 pages of FORTRAN software for the machine, and it could help a visually impaired chemistry student to perform many instrumental measurements with maximum independence. It was an impressive machine, but I couldn't find any company that was willing to build it. I was sure that we had designed a great tool for visually impaired chemistry students, but the prevailing political climate was not receptive to expensive high tech adaptations for disabled students. Also, we were just too far ahead of widely available technology. (This was in the mid-eighties.) The available technology has now finally caught up with us, and it is now possible to replicate most of the functions of our original $8000 machine at much lower cost. For example, IBM has introduced the Personal Science Laboratory (PSL), a versatile, modular data acquisition system designed for performing computer-aided experiments in school laboratories. The PSL communicates with a host computer through a standard serial port, and reads its various sensor probes upon receiving commands from the host. (It has sensors for pH, temperature, light intensity, and distance.) The cost of the PSL is moderate: the price of a PSL starter kit is about $500. Also, sound cards have now made it possible to produce highly intelligible synthetic speech and all sorts of other noises at quite low cost: for example, the low end Sound Blaster card by Creative Labs has street price of about $75. We are taking advantage of these new developments to write software intended to make laboratory measurements more accessible to visually impaired students from the middle school through college, using a talking, whistling, musical, large text laboratory work station assembled from widely available, moderately priced components. The work station hardware consists of an IBM-compatible personal computer, IBM's Personal Science Laboratory, a digital multimeter with computer output, a Creative Labs Sound Blaster sound card, and an electronic balance. The thorough documentation that IBM provides for the PSL has made it possible for us to write our own software for reading the output of the PSL's temperature, light, and pH probes; the readings are spoken by the Sound Blaster. This software is not complete yet, but the core procedures for reading and controlling the PSL have been written, and adding additional features should be straightforward. With the addition of an electronic balance to the PSL-computer system, we have a lab work station which can enable a visually impaired student to make independent measurements of the basic quantities mass, temperature, pH, and light intensity. …