US 8,427,326 B2 · Method and system for detecting the physiological onset of operator fatigue, drowsiness, or performance decrement

Abstract

A method for detecting the onset of drowsiness in an operator of a vehicle or other apparatus. The operator grips a steering wheel or similar control handle, which continuously outputs gripping signals. The method provides for dynamic offset removal to obtain baseline signals, selection of physiologically-significant signals, combining and processing signals to form a proxy signal, analysis of the proxy signals to detect patterns indicative of the onset of drowsiness, and generating alerts as appropriate. The method provides for multiple sliding windows, for dynamic baseline adjustment; and statistical processing to detect physiologically-meaningful patterns indicative of the onset of drowsiness, as distinct from incidental changes in operator gripping through hand position readjustment during normal operation.

Claims17

Dependent claims

A method for detecting the physiological onset of fatigue of an operator, comprising:

providing a plurality of like sensors on an operating handle to be gripped by the operator, wherein the sensors output a plurality of signals, each signal of the plurality of signals indicating a gripping force exerted by the operator;
removing an offset from at least one signal of the plurality of signals by:
collecting signal values over an update window into a collection;
removing values from the collection which were collected prior to a value change exceeding a predetermined threshold;
determining an offset threshold corresponding to a lowest quantile in a distribution of the values;
taking the average of the values below the offset threshold as the offset;
and
subtracting the offset from the at least one signal;
selecting at least two physiologically-significant signals from the plurality of signals;
combining the at least two physiologically-significant signals to form a proxy grip signal;
processing the proxy grip signal to detect a pattern indicative of the onset of operator fatigue;
and
generating an alert in response to detecting the pattern.

10 more elements

A system for detecting the physiological onset of fatigue of an operator, comprising:

a signal interface operative to accept a plurality signals from a plurality of operator gripping sensors;
and
a data processor;
wherein the system is configured to perform:
removing an offset from at least one signal of the plurality of signals;
selecting at least two physiologically-significant signals from the plurality of signals, wherein selecting a physiologically-significant signal comprises:
collecting consecutive signal values over a collection window;
dividing the collection window into an integral number of consecutive equal time intervals;
for each of the time intervals, calculating a pair of statistical parameter values for each of the signal values in the time interval;
plotting at least two signal values according to the corresponding statistical parameter values thereof in a two-dimensional space;
dividing the at least two signal values into two clusters and determining the coordinates of the centers of the clusters;
determining a score according to the two clusters for a signal in the latest time interval;
if the score of the signal is less than a predetermined threshold, then discarding the signal as not physiologically-significant;
and
if the score of the signal is not less than the predetermined threshold, then keeping the signal as physiologically-significant;
combining the at least two physiologically-significant signals to form a proxy grip signal;
processing the proxy grip signal to detect a pattern indicative of the onset of operator fatigue;
and
generating an alert in response to detecting the pattern.

16 more elements

A computer product for detecting the physiological onset of fatigue of an operator, the product comprising tangible non-transient computer-readable data storage that includes a set of executable commands for a computer, which commands, when executed by the computer, cause the computer to perform:

receiving a plurality of signals, each signal of the plurality of signals indicating a gripping force exerted by the operator;
removing an offset from at least one signal of the plurality of signals by:
collecting signal values over an update window into a collection;
removing values from the collection which were collected prior to a value change exceeding a predetermined threshold;
determining an offset threshold corresponding to a lowest quantile in a distribution of the values;
taking the average of the values below the offset threshold as the offset;
and
subtracting the offset from the at least one signal;
selecting at least two physiologically-significant signals from the plurality of signals;
combining the at least two physiologically-significant signals to form a proxy grip signal;
processing the proxy grip signal to detect a pattern indicative of the onset of operator fatigue;
and
generating an alert in response to detecting the pattern.

10 more elements

Dependencies are inferred from the claim text.

Method and system for detecting the physiological onset of operator fatigue, drowsiness, or performance decrement

Life of this patent

Method and system for detecting the physiological onset of operator fatigue, drowsiness, or performance decrement

Life of this patent

Abstract

Claims17