Apparatus and method for maintaining operator alertness

Claim 1

An apparatus for intermittently detecting operator alertness and altering stimuli in response to the detected degree of operator alertness, comprising: means for initiating successive intermittent first stimuli detectable by the operator; response means actuated by the operator upon detection of each such first stimulus; and, detection means responsive to the initiation of each stimulus and the actuation of said response means for selectively modifying subsequent stimuli in inverse proportion to the operator alertness indicated by the detected actuation of the response means by the operator.

Claim 2

An apparatus for intermittently detecting operator alertness and altering stimuli in response to the detected degree of operator alertness, comprising: means for initiating successive intermittent first stimuli detectable by the operator; response means actuated by the operator upon detection of each such first stimulus; and, detection means responsive to the initiation of each stimulus and the actuation of said response means for selectively modifying subsequent stimuli in inverse proportion to the operator alertness indicated by the detected actuation of the response means by the operator.

Claim 4

An apparatus for intermittently detecting operator alertness and for altering operator stimuli in response to the detected degree of alertness, comprising: means for intermittently initiating successive first stimuli, each of which becomes progressively greater in magnitude so as to be more detectable by the operator; operator actuated response means for terminating said stimulus; and, variable timing means for controlling said initiating means to initiate each stimulus following termination of the preceding stimulus after a time delay inversely related to the magnitude of the preceding stimulus upon termination.

Claim 5

An apparatus for intermittently detecting operator alertness and for altering operator stimuli in response to the detected degree of alertness, comprising: means for intermittently initiating successive first stimuli, each of which becomes progressively greater in magnitude so as to be more detectable by the operator; operator actuated response means for terminating said stimulus; and, variable timing means for controlling said initiating means to initiate each stimulus following termination of the preceding stimulus after a time delay inversely related to the magnitude of the preceding stimulus upon termination.

Claim 9

A system for intermittently detecting operator alertness and for altering the repetition interval between successive stimuli in response to the detected time taken by the operator to respond to each stimulus, comprising: bistable switching means responsive to a stimulus initiating signal for maintaining a constant amplitude output and responsive to an operator response signal for terminating said output; an operator response switch actuated by the operator for applying said operator response signal to said bistable switching means; a first integrator coupled to receive said constant amplitude output for generating a fixed ramp signal of constant slope and for terminating said ramp signal to maintain a constant signal voltage equal to the maximum amplitude of said ramp signal upon termination of said constant amplitude output from said bistable switching means; a second integrator coupled to receive the output of said first integrator to generate a parabolic output in response to said ramp signal and for generating a variable ramp output having a slope proportional to said constant signal voltage maintained by said first integrator; comparator means coupled to receive the output of said second integrator for generating said stimulus initiating signal when the amplitude of said parabolic or variable ramp outputs from said second integrator reach a preselected threshold level; circuit means coupled to the output of said second integrator for discharging said parabolic and ramp outputs to restore an initial zero output level in response to said initiAting signal and to said response signal; and, means for initiating a desired stimulus to be sensed by the operator responsive to said stimulus initiating signal.

Claim 10

A system for intermittently detecting operator alertness and for altering the repetition interval between successive stimuli in response to the detected time taken by the operator to respond to each stimulus, comprising: bistable switching means responsive to a stimulus initiating signal for maintaining a constant amplitude output and responsive to an operator response signal for terminating said output; an operator response switch actuated by the operator for applying said operator response signal to said bistable switching means; a first integrator coupled to receive said constant amplitude output for generating a fixed ramp signal of constant slope and for terminating said ramp signal to maintain a constant signal voltage equal to the maximum amplitude of said ramp signal upon termination of said constant amplitude output from said bistable switching means; a second integrator coupled to receive the output of said first integrator to generate a parabolic output in response to said ramp signal and for generating a variable ramp output having a slope proportional to said constant signal voltage maintained by said first integrator; comparator means coupled to receive the output of said second integrator for generating said stimulus initiating signal when the amplitude of said parabolic or variable ramp outputs from said second integrator reach a preselected threshold level; circuit means coupled to the output of said second integrator for discharging said parabolic and ramp outputs to restore an initial zero output level in response to said initiAting signal and to said response signal; and, means for initiating a desired stimulus to be sensed by the operator responsive to said stimulus initiating signal.

Claim 13

A method for intermittently detecting operator alertness to alter operator stimuli in accordance with the detected degree of alertness, comprising the steps of: initiating successive intermittent stimuli detectable by the operator; determining the time interval between the initiation of each said stimulus and the actuation of a stimulus response means by said operator; and, delaying initiation of the subsequent stimulus for an interval inversely related to the time interval between initiation of the previous stimulus and the operator''s actuation of the stimulus response means.

Claim 14

A method for intermittently detecting operator alertness to alter operator stimuli in accordance with the detected degree of alertness, comprising the steps of: initiating successive intermittent stimuli detectable by the operator; determining the time interval between the initiation of each said stimulus and the actuation of a stimulus response means by said operator; and, delaying initiation of the subsequent stimulus for an interval inversely related to the time interval between initiation of the previous stimulus and the operator''s actuation of the stimulus response means.

Claim 15

A method for intermittently detecting operator alertness and altering the repetition rate of successive operator stimuli in response to the detected time taken by the operator to respond to the preceding stimulus, comprising the steps of: (step 1) generating a fixed input voltage in response to a stimulus initiation signal until terminated by an operator response signal; (step 2) integrating said fixed input voltage to produce a ramp signal having a fixed predetermined slope; (step 3) integrating said ramp signal to generate an increasing signal output with a gradually increasing slope; (step 4) generating an operator response signal when a switch means is actuated by the operator; (step 5) maintaining a constant amplitude signal voltage equal to the amplitude of said ramp signal upon generation of said operator response signal; (step 6) discharging said increasing signal output produced by integrating said ramp signal to restore an initial zero level signal output upon generation of said operator response signal; (step 7) integrating said constant amplitude signal voltage to generate a second ramp signal having a slope proportional to the amplitude of said constant amplitude signal; (step 8) generating said stimulus initiating signal when the amplitude of said second ramp signal reaches a predetermined threshold level or, in the absence of an operator response signal, when the amplitude of said increasing signal output reaches said predetermined threshold level; and, (step 9) repeating steps (1) through (8).

Claim 16

A method for intermittently detecting operator alertness and altering the repetition rate of successive operator stimuli in response to the detected time taken by the operator to respond to the preceding stimulus, comprising the steps of: (step 1) generating a fixed input voltage in response to a stimulus initiation signal until terminated by an operator response signal; (step 2) integrating said fixed input voltage to produce a ramp signal having a fixed predetermined slope; (step 3) integrating said ramp signal to generate an increasing signal output with a gradually increasing slope; (step 4) generating an operator response signal when a switch means is actuated by the operator; (step 5) maintaining a constant amplitude signal voltage equal to the amplitude of said ramp signal upon generation of said operator response signal; (step 6) discharging said increasing signal output produced by integrating said ramp signal to restore an initial zero level signal output upon generation of said operator response signal; (step 7) integrating said constant amplitude signal voltage to generate a second ramp signal having a slope proportional to the amplitude of said constant amplitude signal; (step 8) generating said stimulus initiating signal when the amplitude of said second ramp signal reaches a predetermined threshold level or, in the absence of an operator response signal, when the amplitude of said increasing signal output reaches said predetermined threshold level; and, (step 9) repeating steps (1) through (8).

Claim 18

An apparatus for intermittently detecting and maintaining the alertness of the driver of a vehicle without distraction from normal driving tasks, said vehicle having a steering wheel assembly within a driver compartment, comprising: means for intermittently initiating an audible tone stimulus of increasing volume within the driver compartment to be heard by the driver; a pushbutton response switch mounted adjacent the steering wheel assembly of the vehicle to be manually actuated by the driver upon detection of said audible tone; and, interval detection means responsive to the initiation of each audible tone stimulus and the actuation of said pushbutton response switch for selectively delaying initiation of each subsequent audible tone stimulus for a time period inversely related to the time interval measured between initiation of the preceding stimulus and actuation of the pushbutton response switch by the driver.

Claim 19

An apparatus for intermittently detecting and maintaining the alertness of the driver of a vehicle without distraction from normal driving tasks, said vehicle having a steering wheel assembly within a driver compartment, comprising: means for intermittently initiating an audible tone stimulus of increasing volume within the driver compartment to be heard by the driver; a pushbutton response switch mounted adjacent the steering wheel assembly of the vehicle to be manually actuated by the driver upon detection of said audible tone; and, interval detection means responsive to the initiation of each audible tone stimulus and the actuation of said pushbutton response switch for selectively delaying initiation of each subsequent audible tone stimulus for a time period inversely related to the time interval measured between initiation of the preceding stimulus and actuation of the pushbutton response switch by the driver.