Eyelid vigilance detector system

Claim 2

A vigilance monitoring system comprising: a sensor, attached to the eyelid of a subject, that produces an electric signal in response to each eyelid movement, wherein the strength of the signal depends on the magnitude of the eyelid movement; and a processor, electrically coupled to the sensor, that monitors the frequency of electric signals received having a signal strength above a threshold level corresponding to a small active eyelid movement, and produces an output signal if the frequency of received electric signals having the signal strength is less than a predetermined frequency.

Claim 3

A vigilance monitoring system as claimed in claim 1 wherein the sensor is made from a piezoelectric material.

Claim 4

A vigilance monitoring system as claimed in claim 1 wherein the output signal includes an audio alarm signal provided to an output loudspeaker.

Claim 5

A vigilance monitoring system as claimed in claim 1 wherein the processor includes a signal recording circuit and a programmable microprocessor, the signal recording circuit being electrically connected between the sensor and the microprocessor.

Claim 6

A vigilance monitoring system comprising: a sensor, attached to the eyelid of a subject, that produces an electric signal in response to each eyelid movement, wherein the strength of the signal depends on the magnitude of the eyelid movement; and a processor, electrically coupled to the sensor, that monitors the frequency of electric signals received having a signal strength above the threshold level corresponding to a small active eyelid movement, and produces an output signal if the frequency of received electric signals having the signal strength is less than a predetermined frequency, wherein the processors includes a signal recording circuit and a programmable microprocessor, the signal recording circuit being electrically connected between the sensor and the microprocessor, wherein the signal recording circuit includes: a peak detection circuit, coupled to the sensor, that stores the highest strength electric signal received during each predetermined time period; a comparator, coupled to the peak detection circuit, that compares the highest strength electric signal to a threshold level signal during each predetermined time period; and a short term event buffer, coupled to the microprocessor and comparator, having a number of address locations, each address location corresponding to a separate time period and temporarily storing a number representing whether an electric signal having the signal strength greater than the threshold level was received during a corresponding time period.

Claim 7

A vigilance monitoring system comprising: a sensor, attached to the eyelid of a subject, that produces an electric signal in response to each eyelid movement, wherein the strength of the signal depends on the magnitude of the eyelid movement; and a processor, electrically coupled to the sensor, that monitors the frequency of electric signals received having a signal strength above the threshold level corresponding to a small active eyelid movement, and produces an output signal if the frequency of received electric signals having the signal strength is less than a predetermined frequency, wherein the processors includes a signal recording circuit and a programmable microprocessor, the signal recording circuit being electrically connected between the sensor and the microprocessor, wherein the signal recording circuit includes: a peak detection circuit, coupled to the sensor, that stores the highest strength electric signal received during each predetermined time period; a comparator, coupled to the peak detection circuit, that compares the highest strength electric signal to a threshold level signal during each predetermined time period; and a short term event buffer, coupled to the microprocessor and comparator, having a number of address locations, each address location corresponding to a separate time period and temporarily storing a number representing whether an electric signal having the signal strength greater than the threshold level was received during a corresponding time period.

Claim 8

A vigilance monitoring system as claimed in claim 5 wherein the microprocessor is programmed to produce a first output signal if the frequency of received signals having the signal strength is less than a first predetermined frequency and to produce a second output signal if the frequency of received signals having the signal strength is less than a second predetermined frequency.

Claim 9

A vigilance monitoring system as claimed in claim 5 wherein the predetermined time period is approximately equal to 250 ms.

Claim 10

A vigilance monitoring system comprising: a sensor, attached to the eyelid of a subject, that produces an electric signal in response to each eyelid movement, wherein the strength of the signal depends on the magnitude of the eyelid movement; and a processor, electrically coupled to the sensor, that monitors the frequency of electric signals received having a signal strength above the threshold level corresponding to a small active eyelid movement, and produces an output signal if the frequency of received electric signals having the signal strength is less than a predetermined frequency, wherein the processors includes a signal recording circuit and a programmable microprocessor, the signal recording circuit being electrically connected between the sensor and the microprocessor, wherein the microprocessor is programmed to produce a first output signal if the frequency of received signals having the signal strength is less than a first predetermined frequency and to produce a second output signal if the frequency of received signals having the signal strength is less than a second predetermined frequency.

Claim 11

A vigilance monitoring system comprising: a sensor, attached to the eyelid of a subject, that produces an electric signal in response to each eyelid movement, wherein the strength of the signal depends on the magnitude of the eyelid movement; and a processor, electrically coupled to the sensor, that monitors the frequency of electric signals received having a signal strength above the threshold level corresponding to a small active eyelid movement, and produces an output signal if the frequency of received electric signals having the signal strength is less than a predetermined frequency, wherein the processors includes a signal recording circuit and a programmable microprocessor, the signal recording circuit being electrically connected between the sensor and the microprocessor, wherein the microprocessor is programmed to produce a first output signal if the frequency of received signals having the signal strength is less than a first predetermined frequency and to produce a second output signal if the frequency of received signals having the signal strength is less than a second predetermined frequency.

Claim 14

The method as claimed in claim 9 wherein the step of using a sensor includes the step of using a piezoelectric sensor.

Claim 15

The method as claimed in claim 9 wherein the step of producing an output signal includes producing an audio alarm signal if the frequency of produced electric signals having the signal strength is less than a predetermined frequency.

Claim 18

The method as claimed in claim 12 wherein the step of producing an output signal includes the steps of: producing a first output signal if the frequency of produced signals having the signal strength is less than a first predetermined frequency; and producing a second output signal if the frequency of produced signals having the signal strength is less than a second predetermined frequency.