Title
Determination of ocular torsion by means of automatic pattern recognition
Author
Groen, E.L.
Bos, J.E.
Nacken, P.F.M.
de Graaf, B.
TNO Technische Menskunde
Publication year
1996
Abstract
A new, automatic method for determination of human ocular torsion (OT) was devel-oped based on the tracking of iris patterns in digitized video images. Instead of quanti-fying OT by means of cross-correlation of circular iris samples, a procedure commonly applied, this new method automatically selects and recovers a set of 36 significant patterns in the iris by the technique of template matching as described by In den Haak et al. [16]. Each relocated landmark results in a single estimate of the torsion angle. A robust algorithm estimates OT from this total set of individually determined torsion angles, hereby largely correcting for errors which may arise due to misjudgement of the rotation centre. The new method reproduced OT in a prepared set of images of an artificial eye with an accuracy of 0.1 deg. In a sample of 256 images of human eyes, a practical reliability of 0.25 deg. was achieved. To illustrate the method's usefulness, an experiment is described in which ocular torsion was measured during two dynamic conditions of whole-body roll, namely during sinusoidally pendular motion about either an earth horizontal or earth vertical axis (that is "with" and "without" otolith stimula-tion, respectively).
Subject
Image processing
Algorithms
Automation
Biomechanics
Cameras
Charge coupled devices
Error correction
Estimation
Eye movements
Pattern recognition
Tissue
Torsional stress
Video signal processing
Human ocular torsion
Iris patterns
Otolith stimulation
Template matching
Torsion angles
Biomedical engineering
algorithm
article
eye
human
human experiment
iris
pattern recognition
rotation
torsion
Algorithms
Eye Movements
Humans
Image Processing, Computer-Assisted
Iris
Pattern Recognition, Visual
Pupil
Reproducibility of Results
Rotation
Videotape Recording
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http://resolver.tudelft.nl/uuid:e4a54858-8ffb-4ec0-bd29-97a412c294b4
DOI
https://doi.org/10.1109/10.488795
TNO identifier
8582
Source
IEEE Transactions on Biomedical Engineering, 43 (5), 471-479
Document type
article