LABORATORY AND ROAD TESTS OF THE PORTABLE ALERTNESS INDICATOR.
Abstract
The 0.23-cu ft, 8.5-lb portable model has a differential input circuit that makes possible the relatively undistorted pickup of biological products when the man is not in an electrostatically shielded location. The model requires 110 AC to insure a constant DC voltage source for the output circuit. To attain dependability in shielding out stray AC and electrostatic effects, a differential amplifier for the input stage and considerable feedback for the other stages were used. On field tests the indicator operated dependably whether or not the car's motor and radio were in operation. On operation along roads of varying roughness and under telephone and power lines, the gain settings necessary to trip the relay varied dependably for different tension levels (closing jaws, looking ahead and alert, eyes closed and relaxed. Since the gain of the alertness indicator can be set to trip the relay at any desired tension level, the subject may be warned automatically whenever his tension level or alertness status goes beyond a predetermined level.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1948
- Accession Number
- AD0639043
Entities
People
- John L. Kennedy
- Roland C. Travis
Organizations
- Tufts University