Patent No. 5507291 Method and an associated apparatus for remotely determining information as to person's emotional state

 

Patent No. 5507291

Method and an associated apparatus for remotely determining information as to person's emotional state (Stirbl, et al., Apr 16, 1996)

Abstract

In a method for remotely determining information relating to a person's emotional state, an waveform energy having a predetermined frequency and a predetermined intensity is generated and wirelessly transmitted towards a remotely located subject. Waveform energy emitted from the subject is detected and automatically analyzed to derive information relating to the individual's emotional state. Physiological or physical parameters of blood pressure, pulse rate, pupil size, respiration rate and perspiration level are measured and compared with reference values to provide information utilizable in evaluating interviewee's responses or possibly criminal intent in security sensitive areas.

Notes:

BACKGROUND OF THE INVENTION

This invention relates to a method and an associated apparatus for remotely determining information pertaining to an individual's emotional and/or metabolic state.

In many situations, to make decisions it would be helpful to have objective information regarding a person's emotional state. Such information is useful in ascertaining the person's thoughts and intentions. For example, in an interview situation, objective information as to the interviewee's emotional state provides a better basis on which to judge the truthfulness of the interviewee's responses to questions. Such information has been conventionally obtained, in certain applications, by so-called lie detectors. A problem with such devices is that the interviewee is necessarily aware of the testing. This introduces a complication in evaluating the results of the lie detector testing. Accordingly, it would be desirable to provide a means for objectively determining emotional state parameters without the knowledge of the subject.

Such technology would also be useful for medical purposes, to determine, for example, whether a person is in danger of a life-threatening heart attack. Some of the physiological parameters which indicate emotional stress are also indicative of the physical stress of a heart condition. Such physiological parameters include blood pressure and pulse rate. An irregular pulse is especially indicative of a cardiac arrythmia which may be a prelude to myocardial infarction.

Technology which serves to objectively identify emotional state without the knowledge of the subject is also useful in security applications. It would be beneficial, for example, to detect an individual contemplating a robbery or hijacking prior to entry of that individual into a bank or an airplane.

OBJECTS OF THE INVENTION

An object of the present invention is to provide a method for obtaining information pertinent to a person's emotional state, without the person's knowledge.

Another object of the present invention is to provide such a method for use in determining the truthfulness or sincerity of the person during an interview.

An alternative object of the present invention is to provide such a method for use in checking the health of the person.

Another alternative object of the present invention is to provide such a method for use in detecting those contemplating a criminal act.

Another, more particular, object of the present invention is to provide such a method which is implemented remotely, without touching the subject.

Yet another object of the present invention is to provide an associated apparatus or system for obtaining information pertinent to a person's emotional state, without the person's knowledge.

These and other objects of the present invention will be apparent from the drawings and detailed descriptions herein.

SUMMARY OF THE INVENTION

A method for remotely determining information relating to a person's emotional state, comprising the steps of (a) generating waveform energy having a predetermined frequency and a predetermined intensity, the step of generating being implemented at a location remotely spaced from a target individual, (b) wirelessly transmitting the waveform energy towards the individual, (c) detecting energy emitted or reflected from the individual in response to the waveform energy, and (d) automatically analyzing the emitted or reflected energy to derive information relating to the individual's emotional state.

According to another feature of the present invention, the step of analyzing includes the steps of determining a value related to a physiological parameter taken from the group consisting of blood pressure, pulse rate, respiration rate, pupil size, and perspiration, and comparing the value with a stored reference value to identify a change in the parameter.

Where the parameter is respiration rate and the detected energy is reflected from the individual's chest wall, the method further comprises the steps of processing the reflected energy to determine location of the individual's chest wall, and automatically monitoring the individual's position and compensating for changes in the individual's position in determining changes in location of the individual's chest wall.

Alternatively, respiration rate may be determined by monitoring the differential remote absorption of the individual subject's exhalation gases. Invisible electromagnetic radiation from a source such as a light emitting diode (e.g., a laser diode) is directed towards the subject's mouth. The diode generated radiation is modulated at a high rate with a phase-locked component. Radiation returning from the subject and particularly from gases at the subject's mouth are filtered via an electro-optical modulating polarization component. This polarization component may take the form of a filter wheel rotating, for example, at a speed between 300 and 1,000 Hz. An opto-electric detector senses the radiation penetrating the filter wheel. An amplifier phase-locked with the modulator component serves to detect signals only at the frequency of modulation. Any ambient constant energy which is not part of the measuring signal is filtered out.

In remotely monitoring a person's respiration rate, the waveform energy may be modulated electromagnetic radiation or ultrasonic or subsonic pressure waves. Where the measuring waveform is electromagnetic, the measurement may be effectuated using the principles of differential backscatter absorption or interferometery to detect phase changes owing to a change in position of the subject surface (the individual's chest wall). The wavelength or frequency of the modulated electromagnetic radiation is selected from the infrared and near-millimeter portions of the spectrum so as to penetrate clothing material and be reflected from the underlying skin surface. Where the measuring waveform is an ultrasonic or subsonic pressure wave, changes in position of the chest wall may be detected via phase changes and/or by changes in travel time.

Where the monitored parameter is pulse rate, the measuring energy may be modulated electromagnetic radiation, in the near-ultraviolet, infrared or near-millimeter ranges. A collimated beam of radiation is generated and directed or aimed towards a predetermined point on the individual overlying or on a blood vessel. The emitted or reflected energy is processed to determine (1) intensity, change in intensity or change in polarization or fluorescence of the emitted or reflected energy and (2) amount of transdermal absorption. Changes in transdermal absorption can be tracked to determine changes in volume of blood and, accordingly, the pulse of the target individual. If necessary, variance in the emitted or reflected radiation due to surface moisture (perspiration) can be compensated for by automatically measuring emitted or reflected radiation at an additional point proximate to the predetermined point to determine a level of surface moisture. Any differential owing to varying surface moisture can be isolated and removed or used as an indication of metabolic activity or emotional state.

The surface moisture is detected by measuring the intensity of the radiation returning to a detector from a selected point on the skin surface of the target individual. Surface moisture is indicative of stress, as is known by galvanic skin response, the electrical measure which forms the basis for conventional lie detection.

It is to be noted that some measurements made in accordance with the present invention can be improved by taking into account movements of the subject. For example, where pulse rate is measured by monitoring changes in transdermal radiation absorption, the individual's position can be automatically monitored. Thus, the radiation beam's direction can be adjusted to track the target blood vessel. The individual's position and configuration (posture) can be tracked by a simple pattern recognition program analyzing input from a camera (e.g., charge coupled device).

Where the parameter is blood pressure, the measuring medium may be ultrasonic or subsonic pressure waves. An incoming ultrasonic or subsonic pressure wave which has been reflected from a blood vessel below the skin surface of the subject (e.g., at the temple or in the retina) is monitored to determine the instantaneous blood flow rate or velocity. The principles of this measurement procedure are known from conventional ultrasonic Doppler devices. These devices are generally placed in contact with a patient or inserted into the body and only determine blood flow rate. In accordance with the present invention, ultrasonic measurements of blood flow rate are implemented remotely, i.e., the ultrasonic wave generator and the detector are spaced by at least several feet from the individual subject. In addition, in analyzing the incoming ultrasonic waves, a blood pressure parameter is automatically calculated using Bernoulli's equation.

An alternative technique for measuring blood pressure utilizes Doppler speckle interferometery. The speed of the measurement pulses are matched to the average speed of the blood so that there is a modulation in the self interference term of the emitted or reflected light and the reference light. Basically, this is a kind of temporal interferometry.

Where the monitored parameter is pupil size, detection may be implemented by counting pixel receptors of a camera corresponding to the subject's pupil. In this case, the measuring energy is electromagnetic (infrared, near-millimeter).

Generally, a monitored physiological or emotional-state parameter is compared with a reference value which includes a previously measured value for the parameter. For example, the pressure value obtained through calculations based on blood vessel flow rate is compared with previous blood pressure values computed seconds or minutes before by the same technique. An average value for the pressure parameter may be computed and used to detect rises or falls in blood pressure possibly indicative of emotional stress. Such emotional stress may be connected with prevarication, with criminal intent, or with a cardiovascular malfunction. Where people entering a bank or airplane, for example, are being monitored, the blood pressure parameter must be correlated with other measured parameters, such as pulse rate and respiration rate, and with average ranges for those parameters, based on age, size and sex.

Similarly, the pulse rate may be measured and compared with prior pulse rates of the individual test subject or with an average pulse rate for people of the same age, sex and size. These prior values of the monitored parameter or of average ranges are stored in encoded form in a memory.

Changes in any physiological or physical parameter measured or monitored as described herein can be used at least as indicators or alert signals that an emotional state exists or has come into being in the targeted individual. Where the individual is an interviewee, the parametric changes may be correlated with the subjects of the conversation with the interviewee. This correlation may be executed subsequently to the interview, where the interview is recorded on audio and/or video tape.

Where the waveform energy is collimated modulated electromagnetic radiation, the step of generating includes the steps of producing an electromagnetic waveform of the predetermined frequency and collimating the electromagnetic waveform. Then the step of transmitting includes the step of directing the waveform to a predetermined point on the individual. This target point may overlie a preselected blood vessel (pulse rate, blood pressure). Alternatively, it may lie in the retina or carotid artery of the targeted individual or test subject (pulse rate, blood pressure). It may be the subject's chest wall (respiration rate). In the case of perspiration rate, the target point is preferably a point having a characteristically high number of sweat glands.

According to another feature of the present invention, the directing of the collimated beam of (modulated) electromagnetic radiation includes the steps of monitoring the location of the individual. Thus, the direction of the beam is controlled to take into account the individual's voluntary and involuntary movements so that the selected target point is effectively tracked.

This monitoring of the individual's position and configuration may be implemented via video processing technology, for example, by deriving a contour of the individual and comparing the contour with previously determined generic contour data. Such technology is similar to that used in so-called "smart bombs" in military applications.

According to an additional feature of the present invention, the step of analyzing the incoming emitted or reflected waveform energy includes the step of measuring the emitted or reflected energy to determine at least one parameter selected from the group including frequency, fluorescence, amplitude or intensity, change in intensity, change in phase, and change in polarization. The step of analyzing also includes the step of automatically comparing the determined parameter with a reference value, which may incorporate at least one prior measurement of the selected parameter with respect to the individual.

Pursuant to another feature of the present invention, the methodology further comprises the step of changing a frequency of the waveform during a sequence of successive measurements.

A system for remotely determining information relating to a person's emotional state comprises, in accordance with the present invention, a waveform generator for generating waveform energy having a predetermined frequency and a predetermined intensity, the generator being remotely spaced from a target individual. A transmitter is operatively connected to the waveform generator for wirelessly transmitting the waveform energy towards the individual. A detector is provided for detecting energy emitted or reflected from the individual in response to the waveform energy. A processor is operatively connected to the detector for analyzing the emitted or reflected energy to derive information relating to the individual's emotional state. The processor is also operatively connected to at least one of the waveform generator and the transmitter for controlling emission of energy towards the individual. The processor is thus able to correlate the incoming energy with that transmitted towards the targeted individual.

In accordance with another feature of the present invention, the processor includes first componentry for determining a value related to a monitored physiological or physical parameter taken from the group consisting of blood pressure, pulse rate, respiration rate, pupil size, skin fluorescence, and perspiration. The processor further includes second componentry operatively connected to the first componentry for comparing the determined value with a stored reference value to identify a change in the parameter.

Where the monitored parameter is respiration rate, the transmitter is controlled in one particular embodiment by the processor to direct the measuring energy towards the individual's chest wall. The first componentry of the processor includes means for processing the emitted or reflected energy to determine location of the individual's chest wall and means for automatically monitoring the individual's position and compensating for changes in the individual's position in determining changes in location of the individual's chest wall. In measuring respiration rate, the measuring waveform energy is modulated electromagnetic radiation or ultrasonic or subsonic pressure waves. The waveform generator includes either an electromagnetic energy generator or an electro-acoustic transducer for producing ultrasonic or subsonic pressure waves.

Where the monitored parameter is pulse rate, the waveform energy is modulated electromagnetic radiation, in the near-ultraviolet, infrared or near-millimeter ranges and the transmitter is controlled by the processor to direct the waveform energy towards a predetermined point on the individual overlying or on a blood vessel. The first processing componentry of the processor then includes means for deriving (1) intensity of the emitted or reflected energy and (2) amount of transdermal absorption. In addition, the processor may include structure and/or programming for automatically measuring emitted or reflected radiation at an additional point proximate to the predetermined point to determine a level of surface moisture (e.g., perspiration) and means for compensating for surface absorption due to surface moisture in determining the amount of transdermal absorption.

In accordance with another feature of the present invention, the system further comprises tracking circuitry operatively connected to the processor for automatically and remotely monitoring the individual's position, thereby enabling the processor to track changes in position of the predetermined point from which measurements are remotely taken.

Where the monitored parameter is blood pressure, the waveform energy takes the form of an ultrasonic or subsonic pressure wave. The processor then includes architecture and programming for processing a reflected, incoming ultrasonic or subsonic pressure wave to derive a rate of blood flow in a preselected blood vessel of the individual. The processor also includes means for automatically calculating a blood pressure parameter from the derived blood flow rate. In analyzing the incoming ultrasonic or subsonic waves, the processor automatically calculates a blood pressure parameter using Bernoulli's equation or Doppler speckle interferometery. In the latter case, the speed of the measurement pulses are matched to the average speed of the blood so that there is a modulation in the self interference term of the emitted or reflected light and the reference light. Basically, this is a kind of temporal interferometry.

Where the monitored parameter is pupil size and the waveform energy is electromagnetic radiation, the detector includes pixel receptors of a camera. The processor includes means for automatically counting pixels corresponding to a diameter of the individual's pupil.

Generally, the processor compares a monitored physiological or emotional-state parameter with a reference value which includes a previously measured value for the parameter. The reference value is stored in a memory of the processor. A pressure value obtained through calculations based on blood vessel flow rate is compared with previous blood pressure values computed and stored by the processor during the same testing or measurement session. The processor may compute an average value for the pressure parameter and use the average value to detect rises or falls in blood pressure possibly indicative of emotional stress.

Where the parameter is perspiration, the waveform energy is modulated electromagnetic radiation and the detector includes means for measuring a change in polarization or intensity at the incident or fluorescent wavelength of the radiation emitted or reflected from a predetermined point on the individual. Generally the amount emitted or reflected will vary as a function of the amount of perspiration on the skin surface.

Where the waveform energy is collimated modulated electromagnetic radiation, the waveform generator includes a source for producing an electromagnetic waveform of the predetermined frequency and elements for collimating the electromagnetic waveform. The transmitter includes components (e.g., lens, directional antennae, mechanical drives) for directing the waveform to a predetermined point on the individual.

In accordance with a further feature of the present invention, the system also comprises a monitoring unit operatively connected to the processor for monitoring the location of the individual, the monitoring unit being operatively connected to the directional components of the transmitter for controlling the operation thereof. The location monitoring unit may include means for deriving a contour of the individual and means connected thereto for comparing the contour with previously determined generic contour data. More specifically, the position and configuration of the target may be tracked by processing video input from a camera such as a charge coupled device. The techniques of pattern recognition may be utilized to track changes in location of a selected target point as the individual subject moves during the course of the testing period. Ultrasonic or subsonic waves may also be used to determine the position of the individual subject.

In an actual application of the instant invention, the transmitter and detector may be located in a wall of a room and camouflaged by decorative features. Of course, multiple transmitters and detectors may be located in different locations about the subject individual. Where an individual is moving along a path, multiple transmitters and detectors may be necessary to obtain sufficient information. Input from a series of detectors are analyzed to obtain information as to emotional or physical state of the individual.

In accordance with yet another feature of the present invention, the detector includes means for measuring the emitted or reflected energy to determine at least one parameter selected from the group including frequency, fluorescence, amplitude or intensity, change in intensity, change in phase, and change in polarization, while the processor includes means for comparing the determined parameter with a previously determined reference value. As discussed above, the reference value may incorporate at least one prior measurement of the selected parameter with respect to the individual. The processor then includes means for deriving the reference value from the prior measurement.

Where the waveform energy is electromagnetic, several frequencies may be used to collect data. The different frequencies may be multiplexed or transmitted in sequence from a single transmitter or generated and transmitted simultaneously in the case of multiple transmitters. Where a single waveform generator is used, the generator includes means for changing a frequency of the waveform during a sequence of successive measurements.

A method and associated apparatus in accordance with the present invention enable information pertinent to a person's emotional state to be obtained without the person's knowledge. This information is useful in determining the truthfulness or sincerity of an interviewee. Thus, people being interviewed for sensitive job positions or in connection with a criminal investigation may be monitored to elicit information pertinent to their veracity. Of course, legal limitations may exist in using the garnished information as evidence in criminal trials.

A method and associated apparatus in accordance with the present invention are also useful for automatically checking health of individuals. A company may have the apparatus installed for checking the health of employees. Hospitals may use the invention for an additional check on patients.

A method and apparatus in accordance with the present invention can provide information useful in evaluating people entering a high security area for purposes of determining whether anybody is possibly contemplating a criminal act. Usually, people with such criminal intent will betray themselves by elevated pulse rates, increased blood pressure, heightened respiration rates, and/or excessive amounts of perspiration. In the event that one or more of these physiological/physical parameters exceed pre-established limits, an alert signal is automatically given to security personnel who can then attend to the suspected individuals. The alert signal may take the form of an indicator on a video monitor. An arrow pointing to the suspect or a circle about the suspect may be generated on the monitor. In addition, the processor or computer may provide details on the monitor, such as which physiological parameters are involved and the magnitude by which those parameters exceed the respective pre-established limits.

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Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are profferred by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.