Magnet displacement sensor using MI elements for eyelid movement sensing

Author

Takagi, M. ; Katoh, M. ; Mohri, K. ; Yoshino, S.

Author_Institution

Dept. of Electr. Eng., Nagoya Univ., Japan

Volume

29

Issue

6

fYear

1993

fDate

11/1/1993 12:00:00 AM

Firstpage

3340

Lastpage

3342

Abstract

An improved magnet-displacement sensor constructed using amorphous magneto-inductive (MI) elements for both-eyelid movement sensing is described. Folded amorphous wires without any coils are fixed on a glass frame and sensitively detect a magnetic field generated from a small magnet which is attached on an upper eyelid. These noncontact field sensors detect an eyelid movement accompanied by eyeball motion of as small as 1 μm by canceling disturbance fields. The changing value of a cross correlation of two time series of both eyelids was measured for two subjects with a time interval of 3 h through 24 h. A relation between the magnitude of the cross correlation and sleepiness was obtained when subjects traced a light spot target which oscillated horizontally with a 0.2 Hz sinusoidal waveform

Keywords

biological techniques and instruments; biomechanics; eye; 0.2 Hz; 3 to 24 hr; amorphous magneto-inductive elements; both-eyelid movement sensing; cross correlation; disturbance fields cancelation; eyeball motion; folded amorphous wires; light spot target; magnet-displacement sensor; sinusoidal horizontal oscillation; sleepiness; time series; Amorphous magnetic materials; Amorphous materials; Coils; Eyelids; Glass; Magnetic fields; Magnetic sensors; Motion detection; Sensor phenomena and characterization; Wires;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.281169

Filename

281169