An open-source, FireWire camera-based, Labview-controlled image acquisition system for automated, dynamic pupillometry and blink detection

• Published in: Computer methods and programs in biomedicine Vol. 112; no. 3; pp. 607 - 623
• Main Authors: de Souza, John Kennedy Schettino, Pinto, Marcos Antonio da Silva, Vieira, Pedro Gabrielle, Baron, Jerome, Tierra-Criollo, Carlos Julio
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ireland Ltd 01.12.2013; Elsevier
• Subjects: Applied sciences; Artificial intelligence; Automation; Biological and medical sciences; Blink detection; Blinking; Computer programs; Computer science; control theory; systems; Computer systems and distributed systems. User interface; Computers; Dynamical systems; Dynamics; Estimating; Exact sciences and technology; Humans; Image acquisition; Image acquisition system; Image processing; Internal Medicine; Investigative techniques of ocular function and vision; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Other; Pattern recognition. Digital image processing. Computational geometry; Photography; Pupil; Pupillometry; Pupils; Reproducibility of Results; Security Measures; Software; Blink detection; Image acquisition system; Pupillometry; Eyelid; Parameter estimation; Image processing; Video cameras; Bus(channel); Software component; Interoperability; Open source software; Sampling frequency; Pupil; Document image processing; Data acquisition system; Dynamic measurement; Scientific research; Graphical interface; Camera; Blinking; Spatial resolution
• ISSN: 0169-2607; 1872-7565; 1872-7565
• DOI: 10.1016/j.cmpb.2013.07.011

The dynamic, accurate measurement of pupil size is extremely valuable for studying a large number of neuronal functions and dysfunctions. Despite tremendous and well-documented progress in image processing techniques for estimating pupil parameters, comparatively little work has been reported on practical hardware issues involved in designing image acquisition systems for pupil analysis. Here, we describe and validate the basic features of such a system which is based on a relatively compact, off-the-shelf, low-cost FireWire digital camera. We successfully implemented two configurable modes of video record: a continuous mode and an event-triggered mode. The interoperability of the whole system is guaranteed by a set of modular software components hosted on a personal computer and written in Labview. An offline analysis suite of image processing algorithms for automatically estimating pupillary and eyelid parameters were assessed using data obtained in human subjects. Our benchmark results show that such measurements can be done in a temporally precise way at a sampling frequency of up to 120Hz and with an estimated maximum spatial resolution of 0.03mm. Our software is made available free of charge to the scientific community, allowing end users to either use the software as is or modify it to suit their own needs.