Development of an eye camera for measuring eyelid and eyeball movements indomestic animals

The analysis of the resting behavior of domestic animals must include the a nalysis of eyelid and eyeball movements and bodily motion. We developed an apparatus for measuring the movement of eyelids and eyeballs of domestic an imals. The apparatus consists of a charge-coupled device (CCD) camera place d in the eyelid region of a head mask, and an infrared light-emitting diode as a light source. Two types of apparatus have been developed: one, using a wire system and the other, using a measurable telemetry system in an unre stricted state. The weight of the device with the wire system was about 50 g and that with the telemetry system was about 880 g. The operating time of the telemetry system was 24 h or more when nickel-hydrogen was used in the power supply. By using the wire system in calf, the movements of the eyeli d and eyeball could be divided into four categories: fully open eyelid move ment, half-closed eyelid movement, fully closed eyelid movement and eyeball movement. The results showed that the time of half-closed eyelids and full y closed eyelids while the animal was lying down was longest from midnight to 7:00 a.m. and eyelids were half-closed or fully closed even during rumin ation. In the horse, the telemetry system device could be used continuously without discomfort for 24 h. Comparison of the eyelid movement and cortex brain waves, showed that the power spectrum of the cerebral cortex brain wa ves in an animal lying down with a half-open eyelid mainly consisted of del ta waves while when the animal was standing with a fully open eyelid, a wav es also appeared.