Nathan R. Finney
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Artwork | Science Projects
Modern Physics Lab | R.E.M. Sleep Detector | Magnets | Biology

Science Projects [R.E.M. Sleep Detector]

All materials here were produced during the final project phase of a course entitled "Physics 111: Basic Semiconductor Circuits" at UC Berkeley in Fall 2006. My lab partner for this project was Henry Silva--photographer, scientist, tutor, programmer, etc. Check out his blog here.

Abstract (click link below to read the full write up)

"A Rapid Eye Movement (REM) Sleep Detector and Alarm Clock was designed, built/programmed, and tested. The signal for the analog component of the detector/alarm was collected using an Infrared Light Emitting Diode (IR LED) pointed at the right eyelid, which reflected the light into a phototransistor at different amplitudes due to changing orientations of the eyelid/eyelashes. The signal was then treated so that it could input safely into the microphone jack on a laptopís soundcard. A LabVIEW program then called the data from the soundcard, displayed it, decided whether or not the amplitude of a given point was above some critical value, which would deem it an instance of REM sleep, then it counted all the instances of REM sleep for a given interval (10-seconds). The number of instances per sample interval was then saved to an array, which would later all be saved into a .txt file. The program had a functional alarm that could be set to go off after a given amount of time (tA). The alarm also compared the current run time (tR) with tA and if their difference was less than or equal to 1 hour and the person sleeping had been out of REM sleep for more than a minute then the alarm would go off. This logic intended to keep the sleeping person from awakening during REM sleep. The data logged in the early morning hours of Friday (12/8/06) shows cyclic behavior (Fig. 23), with peak densities of activity occurring in approximately 90-minute intervals. Functionally the circuit and the program worked perfectly, though more research must be done to fine tune the input values that determine the behavior of the alarm clock."

Report for R.E.M. Sleep Detector/Alarm Clock Project (PDF 3.7 MB)

R.E.M. Sleep Detector/Alarm Clock Goggle Schematic
This diagram depicts the basic configuration of the infared LED source and the photo-sensitive transistor relative to the eye.
Physics 111 (Basic Semiconductor Circuits), Fall 2006