Eye line tracking evaluation system (Eye-tracking) for diagnosing the state of integrative brain functions
Konstantin M. Naumov, Il’ya Yu. Chapliev, Igor Litvinenko, Nikolay V. Tsygan, Vladimir Yu. Lobzin, Aleksandr V. Ryabtsev · Russian Military Medical Academy Reports · 2024
BACKGROUND: Currently, against the background of an increase in the proportion of the population of the older age group in the world, the issue of early diagnosis of developing cognitive impairment in patients with various diseases of the nervous system, as well as the search for effective biomarkers that would indicate the beginning of their development, is becoming more and more urgent. Cognitive functions are the highest manifestation of complex integrative processes occurring in the central nervous system, one of the most important ways of information entry into which is the visual analyzer. In the process of assessing the surrounding space, the oculomotor system performs the most difficult work to synchronize the visual axes of the eyes to obtain the clearest possible image. The sequence and duration of fixations on the elements of the object are determined, among other things, by the thinking process, which determines the analysis and assimilation of the received information. It is the disturbances in the work of this system that can occur at the early stages of the development of cognitive dysfunctions, as a result of disintegration processes in the brain. Thus, disintegration markers may be important predictors of developing cognitive impairment in nervous system diseases. AIM: of the work was to develop a method for assessing the state of the eye position system in patients with initial cognitive dysfunctions. MATERIALS AND METHODS: In the process, we developed an experiment in the form of a sequence of visual stimuli with audio and text accompaniment, which were presented with a certain sequence and for a limited time, which was presented to the subjects as part of the solution of the cognitive task. Eye movements were recorded in real time using the Pupil Invisible ai-tracking system, which contains two integrated infrared cameras with a frequency of 200 Hz in its design. Based on the results of assessing the digital characteristics of the parameters of eye movements (the number of fixations, their duration and position on the coordinate axis), the so-called “heat maps” were generated and analyzed. RESULTS: In order to be able to quantify the resulting heat maps, we have developed a methodology for quantifying the results obtained. The developed methods make it possible to start collecting data to identify typical oculomotor patterns in solving cognitive tasks, both in healthy people and in patients with mild cognitive impairment, for the subsequent application of the method in clinical practice.