Application and repeatability of ocular biometric measures for gaze position calibration in children

2021 ◽  
Author(s):  
Michael Ntodie ◽  
Eugene B Enimah ◽  
Yaw O Akoto ◽  
Joseph N Yennu ◽  
Samuel Abokyi ◽  
...  
Keyword(s):  
Position Calibration ◽  
Gaze Position

Utility of Theoretical Hirschberg Ratio for Gaze Position Calibration

2014 ◽  
Vol 91 (7) ◽  
pp. 778-785 ◽  
Author(s):  
Kishore Kumar Jagini ◽  
Harini Vaidyanath ◽  
Shrikant R. Bharadwaj
Keyword(s):  
Position Calibration ◽  
Gaze Position

scholarly journals Comparison of Three Gaze-position Calibration Techniques in First Purkinje Image–based Eye Trackers

2019 ◽  
Vol 96 (8) ◽  
pp. 587-598 ◽  
Author(s):  
Michael Ntodie ◽  
Shrikant R. Bharadwaj ◽  
Swaathi Balaji ◽  
Kathryn J. Saunders ◽  
Julie-Anne Little
Keyword(s):  
Position Calibration ◽  
Calibration Techniques ◽  
Gaze Position

Exophoria: clinical features, diagnosis, treatment. The modern view on the problem. Literature review

2021 ◽  
pp. 52-55
Author(s):  
O.A. Lipunova ◽  
◽  
I.L. Plisov ◽  
V.V. Cherhykh ◽  
N.G. Antsiferova ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Type A ◽  
The State ◽  
Type A Pattern ◽  
Direct Gaze ◽  
Modern View ◽  
Convergence Insufficiency ◽  
Horizontal Type ◽  
Type V ◽  
Gaze Position

Purpose. Create a summary classification of exophoria. To propose an optimal algorithm for optometric and surgical methods of treatment. A modern view of the problem. It is optimal to subdivide exophoria according to the state of the vergent-duction balance into divergence excess, basic exophoria, convergence insufficiency, divergence pseudo-excess, lateral gaze incomitance. By the degree of compensation for compensated, subcompensated, uncompensated, decompensated. In combination with alphabetic pattern for exophoria without pattern, exophoria in combination with horizontal type A pattern, exophoria in combination with vertical type A pattern, exophoria in combination with horizontal type V pattern, exophoria in combination with vertical type V pattern. Features of optimal optical and prismatic correction depend on the state of the vergent-duction balance. In cases of exophoria without pattern surgical treatment is carried out during the transition from a state of subcompensation to non-compensation. In case of exophoria with horizontal-type alphabetical pattern, combined horizontal-transpositional surgery is optimal: elimination of exophoria, the protocol is based on the amount of deviation in the direct gaze position; elimination of the pattern, the protocol is based on vertical transposition of muscles of horizontal action. In cases of exophoria with vertical-type pattern, it is necessary to perform staged vertical-horizontal surgery: stage 1 – elimination of vertical heterotropy in adduction; stage 2 – elimination of exophoria (the protocol is based on the amount of deviation in the direct gaze position). Conclusions. The treatment protocol should be based on a reliably diagnosed diagnosis and consists at the pre-surgical stage in the optimal optical and prismatic correction, the appointment of orthopto-diplopto-prismatic treatment. The effectiveness of treatment is assessed by the dynamics of the disease: the magnitude of exodeviation and the stage of compensation. The protocol of surgical treatment must be reasonable and timely. Key words: exophoria, divergence excess, convergence insufficiency, basic exotropia, lateral gaze incomitance, alphabet pattern.

Visual-Vestibular Interaction Hypothesis for the Control of Orienting Gaze Shifts by Brain Stem Omnipause Neurons

2007 ◽  
Vol 97 (2) ◽  
pp. 1149-1162 ◽  
Author(s):  
Mario Prsa ◽  
Henrietta L. Galiana
Keyword(s):  
Brain Stem ◽  
Head Movements ◽  
Gaze Control ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Switching Mechanism ◽  
Interaction Hypothesis ◽  
Visual Vestibular Interaction ◽  
Motor Error ◽  
Gaze Position

Models of combined eye-head gaze shifts all aim to realistically simulate behaviorally observed movement dynamics. One of the most problematic features of such models is their inability to determine when a saccadic gaze shift should be initiated and when it should be ended. This is commonly referred to as the switching mechanism mediated by omni-directional pause neurons (OPNs) in the brain stem. Proposed switching strategies implemented in existing gaze control models all rely on a sensory error between instantaneous gaze position and the spatial target. Accordingly, gaze saccades are initiated after presentation of an eccentric visual target and subsequently terminated when an internal estimate of gaze position becomes nearly equal to that of the target. Based on behavioral observations, we demonstrate that such a switching mechanism is insufficient and is unable to explain certain types of movements. We propose an improved hypothesis for how the OPNs control gaze shifts based on a visual-vestibular interaction of signals known to be carried on anatomical projections to the OPN area. The approach is justified by the analysis of recorded gaze shifts interrupted by a head brake in animal subjects and is demonstrated by implementing the switching mechanism in an anatomically based gaze control model. Simulated performance reveals that a weighted sum of three signals: gaze motor error, head velocity, and eye velocity, hypothesized as inputs to OPNs, successfully reproduces diverse behaviorally observed eye-head movements that no other existing model can account for.

scholarly journals Uncertainty visualization of gaze estimation to support operator-controlled calibration

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Almoctar Hassoumi ◽  
Vsevolod Peysakhovich ◽  
Christophe Hurter
Keyword(s):  
Qualitative Evaluation ◽  
Point Of View ◽  
Angular Error ◽  
Qualitative Assessment ◽  
Gaze Estimation ◽  
Uncertainty Visualization ◽  
Estimation Uncertainty ◽  
The Mean ◽  
Gaze Position ◽  
Do So

      In this paper, we investigate how visualization assets can support the qualitative evaluation of gaze estimation uncertainty. Although eye tracking data are commonly available, little has been done to visually investigate the uncertainty of recorded gaze information. This paper tries to fill this gap by using innovative uncertainty computation and visualization. Given a gaze processing pipeline, we estimate the location of this gaze position in the world camera. To do so we developed our own gaze data processing which give us access to every stage of the data transformation and thus the uncertainty computation. To validate our gaze estimation pipeline, we designed an experiment with 12 participants and showed that the correction methods we proposed reduced the Mean Angular Error by about 1.32 cm, aggregating all 12 participants’ results. The Mean Angular Error is 0.25° (SD=0.15°) after correction of the estimated gaze. Next, to support the qualitative assessment of this data, we provide a map which codes the actual uncertainty in the user point of view. 

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