Tuesday, January 5, 2010

HOW TO MAKE AN EYE MOTION CONTROLLED MOUSE?

PROJECT IDEA & DESCRIPTION

When the eyes move, biopotentials are generated. These corneo-retinal potentials (from the back of the eye to the front of the eye) biopotentials are generated by the retinal dipole, and variously called the EOG (Electro-oculogram), ERG (Retinogram) or ENG (Nystagmogram). The potentials vary with a number of factors, e.g. light level, blinking, and tends to drift.EOG electrodes

  • Use electrodes on the forehead, under the eyes on the cheek, and behind the right ear (mastoid) for the grounding point.

    • These three electrodes could be mounted on the eyeglass frame



  • Design and build a suitable instrumenattion amplifier to detect the EOG

    • Suggested circuit schematic - 3-op-amp differential amplifier +  3-pole Butterworth lowpass filter +  Inverting amplifier



  • Characteristics of EOG signal and requirements for mouse

    • Frequency Range DC – 10 Hz

    • Voltage Range 0.05 – 3.5 mV

    • Gain needed  ~5,000

    • Approximately linear over 30 degree arc

    • Accurate to 1 degree



  • Use a TTL comparator to generate a 1 or 0, or generate a signal proportional to the eye angle.

  • Couple to mouse port of PC


CIRCUIT DIAGRAM

EOGcircuit

1 comment:

  1. where i cn gt d ckt dia of d project 4 dt eye vision prject

    ReplyDelete

Your Ad Here