# US 12,114,224 B2 · Method and device for detection and assessment of marijuana impairment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,114,224 B2 - Document ID: US12114224B2 - Status: Granted - Kind: B2 - Application number: 18/142,209 - Filed: 2023-05-02 - Published: 2023-08-24 - Granted: 2024-10-08 - Earliest claimed: 2015-10-20 - Applicants: Denise A Valenti - Inventors: Denise A Valenti - Web page: https://patentgrep.com/patent/US12114224B2 ## CPC - H04W 4/02: Services making use of location information - A61B 3/0025: {characterised by electronic signal processing, e.g. eye models} - A61B 3/0041: {characterised by display arrangements} - A61B 3/02: Subjective types, i.e. testing apparatus requiring the active assistance of the patient - A61B 3/06: for testing light sensitivity, e.g. adaptation; for testing colour vision - H04B 7/0617: {for beam forming} - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/0634: {Antenna weights or vector/matrix coefficients} - H04B 7/0636: {Feedback format} - H04B 7/0697: {using spatial multiplexing} - H04B 7/12: Frequency diversity - H04L 1/04: using frequency diversity - H04L 1/06: using space diversity - H04W 4/027: {using movement velocity, acceleration information} - H04W 4/029: Location-based management or tracking services - H04W 16/24: Cell structures - H04W 16/32: Hierarchical cell structures - H04W 24/02: Arrangements for optimising operational condition - H04W 48/12: using downlink control channel - H04W 52/00: Power management {, e.g. Transmission Power Control [TPC] or power classes} - H04W 64/00: Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management - H04W 72/04: Wireless resource allocation - H04W 84/18: Self-organising networks, e.g. ad-hoc networks or sensor networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method of identifying individuals impaired by a psychoactive substance such as cannabis. The method includes presenting monocularly to a subject being tested; to each eye separately, a sinusoidal grating pattern of fixed spatial frequency with achromatic contrast or color contrast between grating stripes being temporally alternately modulated at a temporal frequency that ranges between 10 Hz and 60 Hz with a pattern of the contrast being such that the subject being tested can see a frequency doubling in the grating pattern. ## Claims ### Claim 1 A method impairment testing in the field to identify individuals impaired by a psychoactive substance other than alcohol, the method comprising: locating a virtual reality head worn device on the subject's head and so that the subject's visual field is limited by the virtual reality head worn device; monocularly presenting via the virtual reality head worn device to the subject being tested; to each eye separately, at least a first pattern of fixed spatial frequency with achromatic contrast between dark areas and light areas, the achromatic contrast between the dark areas and the light areas being temporally alternately modulated at a temporal frequency that ranges between 10 Hz and 60 Hz with a pattern of the contrast being such that the subject being tested perceives a frequency doubling in the pattern thereby evaluating retinal function, the first pattern having a first contrast ratio/value; monocularly presenting via the virtual reality head worn device to the subject being tested; to each eye separately a second pattern of fixed spatial frequency with achromatic contrast between dark areas and light areas, the achromatic contrast between the dark areas and the light areas being temporally alternately modulated at a temporal frequency that ranges between 10 Hz and 60 Hz with a pattern of the contrast being such that the subject being tested perceives a frequency doubling in the pattern, the second pattern having a second contrast ratio/value different from the first pattern querying whether the subject being tested perceives a frequency doubling for each of the first pattern and second pattern; identifying the first pattern in which frequency doubling is reported and the second pattern in which frequency doubling is not reported; when the first pattern is within the range of expected values, indicating that the test subject is not impaired; and when the first patterns is not within the range of expected values then indicating that the test subject is impaired. ### Claim 2 (depends on 1) The method as claimed in claim 1, further comprising varying the first pattern as to the first contrast ratio/value and varying the first pattern as to temporally alternate modulation in a range from 10 Hz to 60 Hz. ### Claim 3 (depends on 1) The method as claimed in claim 1, further comprising varying the second pattern as to a third contrast ratio/value and varying the second pattern as to temporally alternate modulation in a range from 10 Hz to 60 Hz. ### Claim 4 (depends on 1) The method as claimed in claim 1, further comprising comparing the frequency doubling temporal value values identified to the contrast ratio values combined with temporal values in the modulation (alterations) and comparing the frequency doubling temporal values to the temporal values of a normal population who have not consumed the psychoactive substance and have no pathology effecting the retinal visual functions tested. ### Claim 5 (depends on 4) The method as claimed in claim 4, further comprising comparing the frequency doubling temporal value values to the contrast ratio values combined with temporal values in the modulation (alterations) and comparing them to the temporal values of a normal population who have not consumed the psychoactive substance and have no pathology effecting the functions tested. ### Claim 6 (depends on 1) The method as claimed in claimed in claim 1, further comprising presenting the pattern of fixed spatial frequency as an achromatic sinusoidal grating pattern. ### Claim 7 (depends on 1) The method as claimed in claim 1, further comprising holding the spatial frequency and the temporal frequency fixed of the first pattern while varying a contrast. ### Claim 8 (depends on 1) The method as claimed in claim 1, further comprising using a vehicle ignition interlock wherein if the test subject is found to be impaired the vehicle ignition interlock prevents operation of a motor vehicle. ### Claim 9 (depends on 8) The method as claimed in claim 8, further comprising obtaining biometric recognition wherein a user driving the vehicle is identified to be the test subject who took the test. ### Claim 10 (depends on 6) The method as claimed in claim 6, further comprising presenting the sinusoidal grating patterns at an oblique angle to an ocular meridian. ### Claim 11 (depends on 6) The method as claimed in claim 6, further comprising presenting the sinusoidal grating patterns at a parallel or perpendicular to an ocular meridian. ### Claim 12 A virtual reality head worn device for use in field impairment testing to identify individuals impaired by a psychoactive substance other than alcohol, the device comprising: an enclosure that limits vision of a subject being tested to a display on which images are displayed monocularly to the subject being tested; the virtual reality head worn device being configured to present to each eye separately, at least a first pattern of fixed spatial frequency with achromatic contrast between dark areas and light areas, the achromatic contrast between the dark areas and the light areas being temporally alternately modulated at a temporal frequency that ranges between 10 Hz and 60 Hz with a pattern of the contrast being such that the subject being tested perceives a frequency doubling in the pattern thereby evaluating retinal function, the first pattern having a first contrast ratio/value; the display on which images are displayed monocularly to a subject being tested; to each eye separately a second pattern of fixed spatial frequency with achromatic contrast between dark areas and light areas, the achromatic contrast between the dark areas and the light areas being temporally alternately modulated at a temporal frequency that ranges between 10 Hz and 60 Hz with a pattern of the contrast being such that the subject being tested perceives a frequency doubling in the pattern, the second pattern having a second contrast ratio/value different from the first pattern; the display being coupled to a processor that is programmed with an algorithm by which an operator can control the display to present the following procedure; querying whether the subject being tested perceives a frequency doubling for each of the first pattern and second pattern; identifying the first pattern in which frequency doubling is reported and the second pattern in which frequency doubling is not reported; when the first pattern is within the range of expected values, indicating that the test subject is not impaired; and when the first patterns is not within the range of expected values then indicating that the test subject is impaired. ### Claim 13 (depends on 12) The device as claimed in claim 12, wherein the processor is further programmed with an algorithm varying the first pattern as to the first contrast ratio/value and varying the first pattern as to temporally alternate modulation in a range from 10 Hz to 60 Hz. ### Claim 14 (depends on 12) The device as claimed in claim 12, wherein the processor is further programmed with an algorithm varying the second pattern as to a third contrast ratio/value and varying the second pattern as to temporally alternate modulation in a range from 10 Hz to 60 Hz. ### Claim 15 (depends on 12) The device as claimed in claim 12, wherein the processor is further programmed with an algorithm comparing the frequency doubling temporal value values identified to the contrast ratio values combined with temporal values in the modulation (alterations) and comparing the frequency doubling temporal values to the temporal values of a normal population who have not consumed the psychoactive substance and have no pathology effecting the retinal visual functions tested. ### Claim 16 (depends on 12) The device as claimed in claim 12, wherein the processor is further programmed with an algorithm comparing the frequency doubling temporal value values to the contrast ratio values combined with temporal values in the modulation (alterations) and comparing them to the temporal values of a normal population who have not consumed the psychoactive substance and have no pathology effecting the functions tested. ### Claim 17 (depends on 12) The device as claimed in claim 12, wherein the processor is further programmed with an algorithm presenting the pattern of fixed spatial frequency as an achromatic sinusoidal grating pattern. ### Claim 18 (depends on 12) The device as claimed in claim 12, wherein the processor is further programmed with an algorithm holding the spatial frequency and the temporal frequency fixed of the first pattern while varying a contrast.