# US 11,992,316 B2 · System and method for eye-blink based assessment of sustained visual attention of a target > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,992,316 B2 - Document ID: US11992316B2 - Status: Granted - Kind: B2 - Application number: 17/213,371 - Filed: 2021-03-26 - Published: 2022-03-03 - Granted: 2024-05-28 - Earliest claimed: 2020-09-03 - Assignees: Tata Consultancy Services Limited - Applicants: Tata Consultancy Services Limited - Inventors: Rahul Dasharath Gavas; Mithun Basaralu Sheshachala; Debatri Chatterjee; Ramesh Kumar Ramakrishnan; Venkata Subramanian Viraraghavan; Achanna Anil Kumar; Girish Mariswamy Chandra - Web page: https://patentgrep.com/patent/US11992316B2 ## CPC - A61B 5/163: {by tracking eye movement, gaze, or pupil change} - A61B 5/0075: {by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy (A61B5/0071 takes precedence)} - A61B 5/0077: {Devices for viewing the surface of the body, e.g. camera, magnifying lens} - A61B 5/378: Visual stimuli - A61B 5/113: occurring during breathing - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract This disclosure relates generally to a method and system for assessment of sustained visual attention of a target. The conventional methods utilize various markers for assessment of attention, however, blink rate variability (BRV) series signal is not explored yet. In an embodiment, the disclosed method utilizes BRV series signal for assessing sustained visual attention of a target. A gaze data of the target is recorded using an eye tracker and a set of uniformly sampled BRV series signal is reconstructed from each of the BRV series. One or more frequency domain features, including pareto frequency, are extracted from the set of uniformly sampled BRV series signal. The values of frequency domain features extracted from the set of BRV series signals are compared with corresponding threshold values to determine visual sustained attention of the target. ## Claims ### Claim 1 A processor implemented method for assessing sustained visual attention of a target comprising: recording gaze data of the target using an eye tracker, via one or more hardware processors, the gaze data comprising data associated with eye-blink response of the target during a systematic execution of a set of visual tasks; reconstructing from the gaze data, a set of uniformly sampled blink rate variability (BRV) series signals via the one or more hardware processors, each of the BRV series signals comprises a time series data constructed from intervals between consecutive eye-blinks obtained during the systematic execution of the set of visual tasks, wherein reconstructing a uniformly sampled BRV series signal from amongst the set of uniformly sampled BRV series signals comprises performing oversampling and interpolation on the gaze data; extracting, via the one or more hardware processors, one or more time and frequency domain features from the set of uniformly sampled BRV series signals, wherein the one or more frequency domain features comprises at least a pareto frequency feature; comparing values of the one or more features of the set of BRV series signals with a threshold values of the one or more features that are indicative of visual attention via the one or more hardware processors; and determining, via the one or more hardware processors, visual sustained attention of the target based on the comparison. ### Claim 2 (depends on 1) The method of claim 1, wherein the pareto frequency feature comprises a frequency range within which 80% of cumulative power of a frequency spectrum of the BRV series signals resides. ### Claim 3 (depends on 1) The method of claim 1, wherein the gaze data is obtained by systematically recording eye movements and eyelid movements during the set of visual tasks. ### Claim 4 (depends on 1) The method of claim 1, wherein the eye tracker is one of an Infrared based eye tracker and a camera based eye tracker. ### Claim 5 (depends on 1) The method of claim 1, wherein the one or more frequency domain features further comprises frequency, power at mean frequency, dominant frequency, power at dominant frequency and total power. ### Claim 6 (depends on 1) The method of claim 1, further comprises identifying the eye blink positions in the gaze data, and wherein a point in the gaze data is treated as eye blink on performance of one of: determination of occurrence of a threshold number of consecutive zeros and missing data point in the gaze data. ### Claim 7 (depends on 1) The method of claim 1, wherein calculating the one or more frequency domain features comprises performing fast-Fourier transform of the uniformly sampled BRV series. ### Claim 8 (depends on 1) The method of claim 1, wherein the threshold value of the pareto frequency feature indicative of the visual attention is less than or equal to 0.1 Hz. ### Claim 9 A system for assessing visual sustained attention of a target, comprising: a memory storing instructions; one or more communication interfaces; and one or more hardware processors coupled to the memory via the one or more communication interfaces, wherein the one or more hardware processors are configured by the instructions to: record gaze data of the target using an eye tracker the gaze data comprising data associated with eye-blink response of the target during a systematic execution of a set of visual tasks; reconstruct from the gaze data, a set of uniformly sampled blink rate variability (BRV) series signals, each of the BRV series comprises a time series data constructed from intervals between consecutive eye-blinks obtained during the systematic execution of a set of visual tasks, wherein to reconstruct a uniformly sampled BRV series signal from amongst the set of uniformly sampled BRV series signals, the one or more hardware processors are further configured by the instructions to perform oversampling and interpolation on the gaze data; extract one or more time and frequency domain features from the set of uniformly sampled BRV series signals, wherein the one or more frequency domain features comprises at least a pareto frequency feature; compare values of the one or more features of the set of BRV series signals with a threshold values of the one or more features that are indicative of visual attention; and determine visual sustained attention of the target based on the comparison. ### Claim 10 (depends on 9) The system of claim 9, wherein the pareto frequency feature comprises a frequency range within which 80% of cumulative power of a frequency spectrum of the BRV series signal resides. ### Claim 11 (depends on 9) The system of claim 9, wherein the one or more hardware processors are further configured by the instructions to obtain the gaze data by systematically recording eye movements and eyelid movements during the set of visual tasks. ### Claim 12 (depends on 9) The system of claim 9, wherein the eye tracker is one of an Infrared based eye tracker and a camera based eye tracker. ### Claim 13 (depends on 9) The system of claim 9, wherein the one or more frequency domain features further comprises frequency, power at mean frequency, dominant frequency, power at dominant frequency and total power. ### Claim 14 (depends on 9) The system of claim 9, wherein the one or more hardware processors are further configured by the instructions to identify the eye blink positions in the gaze data, further wherein the one or more hardware processors are configured by the instructions to treat a point in the gaze data as eye blink on performance of one of: determination of occurrence of a threshold number of consecutive zeros and missing data point in the gaze data. ### Claim 15 (depends on 9) The system of claim 9, wherein the one or more hardware processors calculating the one or more frequency domain features comprises performing fast-Fourier transform of the uniformly sampled BRV series. ### Claim 16 (depends on 9) The system of claim 9, wherein the threshold value of the pareto frequency feature indicative of the visual attention is less than or equal to 0.1 Hz. ### Claim 17 One or more non-transitory machine readable information storage mediums comprising one or more instructions which when executed by one or more hardware processors cause: recording gaze data of the target using an eye tracker, via one or more hardware processors, the gaze data comprising data associated with eye-blink response of the target during a systematic execution of a set of visual tasks; reconstructing from the gaze data, a set of uniformly sampled blink rate variability (BRV) series signals via the one or more hardware processors, each of the BRV series signals comprises a time series data constructed from intervals between consecutive eye-blinks obtained during the systematic execution of the set of visual tasks, wherein reconstructing a uniformly sampled BRV series signal from amongst the set of uniformly sampled BRV series signals comprises performing oversampling and interpolation on the gaze data; extracting, via the one or more hardware processors, one or more time and frequency domain features from the set of uniformly sampled BRV series signals, wherein the one or more frequency domain features comprises at least a pareto frequency feature; comparing values of the one or more features of the set of BRV series signals with a threshold values of the one or more features that are indicative of visual attention via the one or more hardware processors; and determining, via the one or more hardware processors, visual sustained attention of the target based on the comparison.