Detection of mental state and reduction of artifacts using functional near infrared spectroscopy (FNIRS)
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsAngela Harrivel, Tristan Hearn
Life of this patent
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Abstract
fNIRS may be used in real time or near-real time to detect the mental state of individuals. Phase measurement can be applied to drive an adaptive filter for the removal of motion artifacts in real time or near-real time. In this manner, the application of fNIRS may be extended to practical non-laboratory environments. For example, the mental state of an operator of a vehicle may be monitored, and alerts may be issued and/or an autopilot may be engaged when the mental state of the operator indicates that the operator is inattentive.
Claims20
A computer-implemented method, comprising:
- receiving, by a computing system, data measured using frequency-domain fNIRS instrumentation pertaining to hemoglobin levels in an individual's brain;
- determining, by the computing system, presence of a potential artifact based on a phase shift in the data measured using frequency-domain fNIRS instrumentation by comparing a signal intensity of a source signal to a detected signal intensity;
- determining, by the computing system, whether changes in the hemoglobin levels and changes in the phase shift are correlated to confirm that the potential artifact is an artifact;
- and
- reducing or removing the artifact, by the computing system, using Kalman filtering when the changes in the hemoglobin levels and changes in the phase shift are correlated.
A computer program embodied on a non-transitory computer-readable medium, the program configured to cause at least one processor to:
- receive data pertaining to hemoglobin levels in an individual's brain;
- and
- determine presence of a potential artifact based on a phase shift in the data measured using the sensor array by comparing a signal intensity of a source signal to a detected signal intensity,
- determine whether changes in the hemoglobin levels and changes in the phase shift are correlated to confirm that the potential artifact is an artifact, and
- reduce or remove the artifact using Kalman filtering when the changes in the hemoglobin levels and changes in the phase shift are correlated
- analyze a mental state of the individual based on [measured hemoglobin levels in the individual's brain] the filtered signals;
- and
- determine whether the mental state indicates that the individual is attentive enough to perform a task.
A system, comprising:
- a sensor array configured to provide analog data pertaining to hemoglobin levels in an individual's brain;
- a microcontroller configured to receive the analog data from the sensor array and convert the analog data into digital data;
- and
- a computing system configured to receive the digital data from the microcontroller, the computing system configured to:
- determine presence of a potential artifact based on a phase shift in the data measured using the sensor array by comparing a signal intensity of a source signal to a detected signal intensity,
- determine whether changes in the hemoglobin levels and changes in the phase shift are correlated to confirm that the potential artifact is an artifact, and
- reduce or remove the artifact using Kalman filtering when the changes in the hemoglobin levels and changes in the phase shift are correlated.
Dependencies are inferred from the claim text.