PURPOSE: This study compared the performance of a video-based infrared three-dimensional eye tracker device (Chronos) with the scleral search coil method. METHODS: Three-dimensional eye movements were measured simultaneously with both systems during fixation, saccades, optokinetic stimulation, and vestibular stimulation. RESULTS: Comparison of fixation positions between -15 degrees and +15 degrees showed that horizontal and vertical eye position signals of the two systems were highly correlated (R2 = 0.99). Torsion values measured by coils and the video system were significantly different (P < 0.001). Saccade main sequence parameters of coil and video signals were in good agreement. Gains of torsion in response to optokinetic stimulation (cycloversion and cyclovergence) were not significantly different (P > 0.05). Gain values of the vestibulo-ocular reflex as determined from coil and video signals showed good agreement for rotations. However, there was more variability in the video signals for translations, possibly due to relative motion between the head and cameras. CONCLUSIONS: Lower time resolution, possible instability of the head device of the video system, and inherent small instabilities of pupil tracking algorithms make the coil system the best choice when measuring eye movement responses with high precision or when involving high-frequency head motion. For less demanding and for static tests and measurements longer than a half an hour, the latest generation infrared video system is a good alternative to scleral search coils. However, the quality of torsion of the infrared video system is less compared with scleral search coils and needs further technological improvement.
PURPOSE: This study compared the performance of a video-based infrared three-dimensional eye tracker device (Chronos) with the scleral search coil method. METHODS: Three-dimensional eye movements were measured simultaneously with both systems during fixation, saccades, optokinetic stimulation, and vestibular stimulation. RESULTS: Comparison of fixation positions between -15 degrees and +15 degrees showed that horizontal and vertical eye position signals of the two systems were highly correlated (R2 = 0.99). Torsion values measured by coils and the video system were significantly different (P < 0.001). Saccade main sequence parameters of coil and video signals were in good agreement. Gains of torsion in response to optokinetic stimulation (cycloversion and cyclovergence) were not significantly different (P > 0.05). Gain values of the vestibulo-ocular reflex as determined from coil and video signals showed good agreement for rotations. However, there was more variability in the video signals for translations, possibly due to relative motion between the head and cameras. CONCLUSIONS: Lower time resolution, possible instability of the head device of the video system, and inherent small instabilities of pupil tracking algorithms make the coil system the best choice when measuring eye movement responses with high precision or when involving high-frequency head motion. For less demanding and for static tests and measurements longer than a half an hour, the latest generation infrared video system is a good alternative to scleral search coils. However, the quality of torsion of the infrared video system is less compared with scleral search coils and needs further technological improvement.
Authors: Karin Eibenberger; Bernhard Eibenberger; Dale C Roberts; Thomas Haslwanter; John P Carey Journal: Med Biol Eng Comput Date: 2015-06-16 Impact factor: 2.602
Authors: Kenneth Holmqvist; Saga Lee Örbom; Ignace T C Hooge; Diederick C Niehorster; Robert G Alexander; Richard Andersson; Jeroen S Benjamins; Pieter Blignaut; Anne-Marie Brouwer; Lewis L Chuang; Kirsten A Dalrymple; Denis Drieghe; Matt J Dunn; Ulrich Ettinger; Susann Fiedler; Tom Foulsham; Jos N van der Geest; Dan Witzner Hansen; Samuel B Hutton; Enkelejda Kasneci; Alan Kingstone; Paul C Knox; Ellen M Kok; Helena Lee; Joy Yeonjoo Lee; Jukka M Leppänen; Stephen Macknik; Päivi Majaranta; Susana Martinez-Conde; Antje Nuthmann; Marcus Nyström; Jacob L Orquin; Jorge Otero-Millan; Soon Young Park; Stanislav Popelka; Frank Proudlock; Frank Renkewitz; Austin Roorda; Michael Schulte-Mecklenbeck; Bonita Sharif; Frederick Shic; Mark Shovman; Mervyn G Thomas; Ward Venrooij; Raimondas Zemblys; Roy S Hessels Journal: Behav Res Methods Date: 2022-04-06