U.S. patent number RE29,008 [Application Number 05/601,595] was granted by the patent office on 1976-10-19 for individual identification apparatus and method using frequency response.
This patent grant is currently assigned to Novar Electronics Corporation. Invention is credited to James H. Ott.
United States Patent |
RE29,008 |
Ott |
October 19, 1976 |
Individual identification apparatus and method using frequency
response
Abstract
An electronic apparatus and method suitable for automatic
machine interrogation of individuals for identifying persons such
as those seeking admittance to secure areas or seeking an extension
of credit. Acoustical wave energy is applied by an oscillator and
transducer to the person's body, such as one end of an arm. Another
transducer contacts another body part, such as the other end of the
arm, to receive the body-transmitted energy. The frequency response
characteristics of the body part are then detected by suitable
correlation means to determine the amplitude and phase transfer
functions. Comparison of a previously known transfer function of a
person with a subsequently measured transfer function permits a
machine decision whether the functions represent the same
person.
Inventors: |
Ott; James H. (Akron, OH) |
Assignee: |
Novar Electronics Corporation
(Barberton, OH)
|
Family
ID: |
26985589 |
Appl.
No.: |
05/601,595 |
Filed: |
August 4, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
326832 |
Jan 26, 1973 |
0387244 |
Mar 18, 1975 |
|
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Current U.S.
Class: |
600/587; 181/.5;
73/579; 367/191 |
Current CPC
Class: |
A61B
5/1171 (20160201); A61B 5/4504 (20130101); A61B
5/0051 (20130101) |
Current International
Class: |
A61B
5/103 (20060101); A61B 5/117 (20060101); G06F
001/00 () |
Field of
Search: |
;340/172.5,1 ;73/67.2
;128/2R ;181/.5R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Thesz; Joseph M.
Attorney, Agent or Firm: Foster; Frank H.
Claims
I claim:
1. A method for comparing a subsequently interrogated person to a
previously interrogated person as an aid in identifying individual
persons, the method comprising:
a. applying sinusoidal physical vibration sonic wave energy to the
human body of a first person;
b. detecting frequency response characteristics of at least a
portion of said human body of said first person by detecting the
frequency response of at least said portion to said applied wave
energy;
c. storing data representing said characteristics;
d. subsequently applying sinusoidal physical vibration sonic wave
energy to the human body of a subsequent person;
e. detecting frequency response characteristics of the body of said
subsequent person by detecting the frequency response of at least
said portion to said applied wave energy; and
f. comparing said characteristics of said first person with said
characteristics of said subsequent person to determine whether said
characteristics are within preselected tolerances of each other
wherein the frequency response characteristics which are detected
comprise a transfer function between corresponding body parts of
each said body.
2. A method according to claim 1 wherein both the amplitude and
phase shift portions of the transfer function are detected.
3. A method according to claim 2 wherein said wave energy is sonic
energy and said energy is applied and detected at body parts having
bones near the body exterior.
4. An apparatus for use in comparing a subsequently interrogated
person to a previously interrogated person as an aid in identifying
individual persons, said apparatus comprising:
a. an audio oscillator having means for varying the oscillation
frequency of said oscillator;
b. an electromechanical transmitting, transducer connected to be
driven by oscillations generated by said audio oscillator, said
transmitting transducer being positioned to apply its output
vibratory oscillations to the body of a person;
c. an electromechanical receiving transducer positioned to receive
vibratory oscillations from the body of said person generated by
said transmitting transducer and to convert said vibratory
oscillations to corresponding electronic oscillations;
d. correlation means connected to receive the output of said
receiving transducer for providing an output representing a
transfer function of said body from said transmitting transducer to
said receiving transducer as a function of applied frequency said
correlation means comprising:
an amplitude detector connected to the output of said receiving
transducer, a frequency related signal means connected to said
audio oscillator, and data storage means connected to the amplitude
detector and to the frequency signal means for storing the output
of the amplitude detector as a function of applied frequency;
and
e. a comparator means connected to said data storage means for
comparing a subsequently stored output in said data storage means
to a previously stored output in said data storage means to
determine the difference between said stored outputs and for
comparing said difference to a preselected tolerance and signal
whether said difference is within the preselected tolerance.
5. An apparatus according to claim 4 wherein said data storage
means is an x-y plotter.
6. An apparatus according to claim 4 wherein said data storage
means comprises means for sampling the output of said amplitude
detector at selected frequency intervals and means for storing data
representing the sampled amplitudes.
7. An apparatus for use in comparing a subsequently interrogated
person to a previously interrogated person as an aid in identifying
individual persons, said apparatus comprising:
a. an audio oscillator having means for varying the oscillation
frequency of said oscillator;
b. an electromechanical transmitting, transducer connected to be
driven by oscillations generated by said audio oscillator, said
transmitting transducer being positioned to apply its output
vibratory oscillations to the body of a person;
c. an electromechanical receiving transducer positioned to receive
vibratory oscillations from the body of said person generated by
said transmitting transducer and to convert said vibratory
oscillations to corresponding electronic oscillations;
d. correlation means connected to receive the output of said
receiving transducer for providing an output representing a
transfer function of said body from said transmitting transducer to
said receiving transducer as a function of applied frequency said
correlation means comprising:
a phase detector connected to the output of said receiving
transducer, a frequency related signal means connected to said
audio oscillator, and data storage means connected to the phase
detector and to the frequency signal means for storing the output
of the phase detector as a function of applied frequency; and
e. a comparator means connected to said data storage means for
comparing a subsequently stored output in said data storage means
to a previously stored output in said data storage means to
determine the difference between said stored outputs and for
comparing said difference to a preselected tolerance and signal
whether said difference is within the preselected tolerance.
8. An apparatus according to claim 7 wherein said data storage
means is an x-y plotter.
9. An apparatus according to claim 7 wherein said data storage
means comprises means for sampling the output of said phase
detector at selected frequency intervals and means for storing data
representing the sampled phases.
10. An apparatus according to claim 7 wherein said correlation
means comprises:
a. an amplitude detector connected to the output of said receiving
transducer;
b. a phase detector connected to the output of said receiving
transducer;
c. a frequency related signal means connected to said audio
oscillator; and
d. data storage means connected to the amplitude detector and to
the phase detector for storing selected output of the amplitude
detector as a function of applied frequency. .Iadd. 11. A method
for comparing a subsequently interrogated person to a previously
interrogated person, the method comprising:
a. applying sinusoidal physical vibration sonic wave energy to the
human body of a first person;
b. detecting frequency response characteristics of at least a
portion of said human body of said first person by detecting the
frequency response of at least said portion to said applied wave
energy;
c. storing data representing said characteristics;
d. subsequently applying sinusoidal physical vibration sonic wave
energy to the human body of a subsequent person;
e. detecting frequency response characteristics of the body of said
subsequent person by detecting the frequency response of at least
said portion to said applied wave energy; and
f. comparing said characteristics of said first person with said
characteristics of said subsequent person to determine whether said
characteristics are within preselected tolerances of each other
wherein the frequency response characteristics which are detected
comprise a transfer function between corresponding body parts of
each said body. .Iaddend..Iadd. 12. A method according to claim 11
wherein both the amplitude and phase shift portions of the transfer
function are detected. .Iaddend..Iadd. 13. A method according to
claim 12 wherein said wave energy is sonic energy and said energy
is applied and detected at body parts having bones near the body
exterior. .Iaddend..Iadd. 14. An apparatus for use in comparing a
subsequently interrogated person to a previously interrogated
person, said apparatus comprising:
a. an audio oscillator having means for varying the oscillation
frequency of said oscillator;
b. an electromechanical transmitting, transducer connected to be
driven by oscillations generated by said audio oscillator, said
transmitting transducer being positioned to apply its output
vibratory oscillations to the body of a person;
c. an electromechanical receiving transducer positioned to receive
vibratory oscillations from the body of said person generated by
said transmitting transducer and to convert said vibratory
oscillations to corresponding electronic oscillations;
d. correlation means connected to receive the output of said
receiving transducer for providing an output representing a
transfer function of said body from said transmitting transducer to
said receiving transducer as a function of applied frequency said
correlation means comprising:
an amplitude detector connected to the output of said receiving
transducer, a frequency related signal means connected to said
audio oscillator, and data storage means connected to the amplitude
detector and to the frequency signal means for storing the output
of the amplitude detector as a function of applied frequency;
and
e. a comparator means connected to said data storage means for
comparing a subsequently stored output in said data storage means
to a previously stored output in said data storage means to
determine the difference between said stored outputs and for
comparing said difference to a preselected tolerance and signal
whether said difference is within the
preselected tolerance. .Iaddend..Iadd. 15. An apparatus according
to claim 14 wherein said data storage means is an x-y plotter.
.Iaddend..Iadd. 16. An apparatus according to claim 14 wherein said
data storage means comprises means for sampling the output of said
amplitude detector at selected frequency intervals and means for
storing data representing the sampled amplitudes. .Iaddend..Iadd.
17. An apparatus for use in comparing a subsequently interrogated
person to a previously interrogated person, said apparatus
comprising:
a. an audio oscillator having means for varying the oscillation
frequency of said oscillator;
b. an electromechanical transmitting, transducer connected to be
driven by oscillations generated by said audio oscillator, said
transmitting transducer being positioned to apply its output
vibratory oscillations to the body of a person;
c. an electromechanical receiving transducer positioned to receive
vibratory oscillations from the body of said person generated by
said transmitting transducer and to convert said vibratory
oscillations to corresponding electronic oscillations;
d. correlation means connected to receive the output of said
receiving transducer for providing an output representing a
transfer function of said body from said transmitting transducer to
said receiving transducer as a function of applied frequency said
correlation means comprising:
a phase detector connected to the output of said receiving
transducer, a frequency related signal means connected to said
audio oscillator, and data storage means connected to the phase
detector and to the frequency signal means for storing the output
of the phase detector as a function of applied frequency; and
e. a comparator means connected to said data storage means for
comparing a subsequently stored output in said data storage means
to a previously stored output in said data storage means to
determine the difference between said stored outputs and for
comparing said difference to a preselected tolerance and signal
whether said difference is within the preselected tolerance.
.Iaddend..Iadd. 18. An apparatus according to claim 17 wherein said
data storage means is an x-y plotter. .Iaddend..Iadd. 19. An
apparatus according to claim 17 wherein said data storage means
comprises means for sampling the output of said phase detector at
selected frequency intervals and means for storing data
representing the sampled phases. .Iaddend..Iadd. 20. An apparatus
according to claim 17 wherein said correlation means comprises:
a. an amplitude detector connected to the output of said receiving
transducer;
b. a phase detector connected to the output of said receiving
transducer;
c. a frequency related signal means connected to said audio
oscillator; and
d. data storage means connected to the amplitude detector and to
the phase detector for storing selected output of the amplitude
detector as a function of applied frequency. .Iaddend.
Description
This invention relates to machine identification of persons and
more particularly relates to a method and apparatus for computer
measurement and analysis of the frequency characteristics of a
portion of a person's body for automatically identifying that
person.
The computer industry is presently engaged in developing systems
for rapid, accurate and automatic computer identification of
persons.
A typical use for such a system would be to automatically identify
persons seeking admittance to a secure area in a plant or to
sensitive data stored in a computer memory. For example, a person
seeking sensitive data or admittance to a secure area would be
interrogated by a computer to determine if he is a person
authorized to have access to such area or data.
Similarly, machine identification would be used in credit
transactions, such as is currently being planned for future use. In
such a transaction, a person would not only present his credit card
to a clerk, but in addition, would be subjected to machine
identification for a determination that he is the person who owns
the card being presented. Such a system can reduce the damage from
credit card losses and theft.
Attempts to design a computer identification system have, to date,
been directed toward voice print identification and toward finger
print identification techniques. Signature identification has also
been proposed. To date, however, none of these methods has become
practically feasible.
I have discovered a method and apparatus for individual
identification involving the application of sonic energy to a
person's body and the subsequent detection of the frequency
response of that part of the person's body. Persons can then be
distinguished through the unique frequency response that an arm,
for example, exhibits.
Others have applied sonic energy to a person's body. For example,
sonic energy is applied to provide a "picture" of the internal
condition of the body for medical purposes. Such systems apply
sonic energy in a radar type system or in a holographic system.
Although these systems apply sonic energy to the human body, this
is their only similarity to the present invention. The prior art
methods and apparatus for obtaining and for processing the received
energy differs greatly from that used in the present invention. In
the system of the present invention, a comparison is made of
transfer characteristics. In these prior art systems, radar or
sonar principles are used to obtain "pictures."
The automatic identification capabilities provided by frequency
response identification will have unimaginable impact on many
industries. For example, a computer will now be able to identify
the person operating it so that only proper data will be accessible
to this person. Compact locking devices may be programmed to admit
only certain individuals. A computer can interrogate and identify a
person over the telephone. For example, the identity of a salesman
wanting computer data from a distant city in a motel through an
acoustical coupler can be quickly and accurately verified. Credit
cards and checks may contain a coding which would permit a quick
identity verification at point of purchase with a simple machine.
Automobiles can be programmed to operate for only specific
individuals. Homes, apartments, or any secured property can be made
accessible only to owners. Legal signatures can be obtained by
telephone by permitting the frequency response identification to
function as a legal signature.
Frequency response identification may also be adopted for use in
the medical field. For example, a new means may be at hand which
will provide a quick and simple check for bone aging,
deterioration, disease, and the like. It is believed that various
characteristics of the bones transfer function may be altered by
bone condition, muscular tension, presence of fat, and other
variable health conditions. It may even be possible to determine
the emotional state or tension of the person whose identity has
been established. This can be important where a person who is
authorized to remove information from the computer might be nervous
because he is intending to do this for illegitimate reasons or is
under duress.
SUMMARY OF THE INVENTION
The invention is an apparatus and a method for identifying
individual persons. The apparatus comprises a means for applying
sinusoidal-wave energy to the body of a person. Received wave
energy is electronically processed by suitable means for detecting
the frequency response characteristics of the intermediate body
portion. Data storing means are also connected to the detecting
means for storing data representing an initial measurement of the
frequency response for use in comparing a subsequently detected
frequency response.
The method is performed by applying sinusoidal-wave energy to the
body and using the applied energy to detect the frequency response
characteristics of at least a portion of the body. Data
representing said characteristics is stored and then subsequently
sinusoidal-wave energy is applied to a person being identified. The
frequency response characteristics of the subsequent person is
detected and compared with the characteristics of the first person
to determine if the identical person is represented.
Accordingly, it is an object of the invention to provide an
identification method and apparatus suitable for automatic machine
use.
Further objects and features of the invention will be apparent from
the following specification and claims when considered in
connection with the accompanying drawings illustrating several
embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the preferred embodiment of
the invention.
FIG. 2 is a graph representing a hypothetical transfer function of
an individual.
In describing the invention as illustrated in the drawings,
specific terminology will be resorted to for the sake of clarity.
However, it is not intended to be limited to the specific terms so
selected and it is to be understood that each specific term
includes all technical equivalents which operate in a similar
manner to accomplish a similar purpose. For example, use of the
word "connection" includes not only direct connection, but also
connection through an intermediate circuit where such a connection
is equivalent as known by those skilled in the art.
DETAILED DESCRIPTION
Referring to FIG. 1, a frequency generator 10 is used to generate
the sonic frequency signal to be applied to the body of a person.
Although various portions of the frequency spectrum may be useful,
I believe that the sonic portion of the spectrum is most useful in
the preferred embodiment of the invention. The preferred frequency
generator 10 is a sweep frequency generator which periodically
varys its output frequency from one end of a selected frequency
range to the other end of the selected range. For example, Hz
frequency generator might repeatedly sweep from 100 Hz, to 10 KHz
over a suitable period. It might, for example, comprise an
oscillator having a capacitance diode driven by a sawtooth signal
in a conventional sweep frequency generator circuit.
Alternatively, of course, the generator 10 could be a generator
providing discrete selectable frequencies spaced across a desired
frequency range. The generator can then be sequentially switched
from discrete frequency to discrete frequency in a periodic
manner.
As another alternative, the frequency generator 10 can instead be a
generator which has several output frequencies simultaneously
generated at its output. Suitable filtering means can be provided
in the detecting circuits to distinguish the transfer function at
various frequencies.
In any case, the output of the frequency generator 10 is applied to
a suitable transducer which preferably is in mechanical contact
with the body of a person. For example, as illustrated, the output
contact 14 of the transducer 12 contacts the ulna bone of a person
16 at his elbow 18. A transducer 12 of conventional design may be
used and might be of the piezoelectric type, electromagnetic type,
and so forth. For example, I have used a transducer of the
radio-speaker type and positioned my elbow in contact with its
paper cone.
Thus, the transducer 12 and the frequency generator 10 together
provide a means for applying sinusoidal wave-energy to the body of
a person. This wave energy is preferably sonic energy. Another
electromechanical receiving transducer 20 is positioned with its
contact portion 22 against another part of the person's body. As
shown, in the preferred embodiment, the contact portion 22 of the
transducer 20 is positioned in contact with the ulna bone at the
opposite end of the forearm near the wrist 24. Thus, energy applied
at the elbow 18 is transmitted through the forearm, primarily
through the ulna bone and is received at the wrist 24 by the
transducer 20.
The transducer 20, like the transducer 12 may be any of the well
known electromechanical transducers which convert mechanical
vibratory energy to an electronic signal. For example, I used a
sensitive microphone positioned in contact with the ulna bone.
Amplitude and phase detectors 26 are connected to receive the
output of the transducer 20. This detector 26 senses both the
amplitude of the transmitted wave energy and also its phase
relative to the input wave energy of the transducer 12.
The circuitry of the amplitude and phase detectors is not shown
because they may be any of the well known variety of circuits used
for detecting the amplitude and phase of wave energy. For example,
amplitude is often detected by the conventional diode and capacitor
circuit used in a diode detector of an amplitude modulated radio
receiver. Similarly, phase detectors are likewise well known and
may easily be adapted for use in the present invention by a person
skilled in the art.
The detected amplitude and phase from the detector 26 is then
applied to a correlator means 30. The correlator means 30
preferably functions to process the incoming signal to provide an
output representing a transfer function of the portion of the body
through which the wave energy was transmitted. The transfer
function is the algebraic-trigono-metric statement of the output
divided by the input. In the preferred embodiment, the function of
the correlator means 30 is to compute the transfer function of the
forearm 16.
For example, if the wave energy applied by the transducer 12 is
maintained at a constant amplitude and phase, the correlator means
might comprise a pair of x-y plotters. The x input of each would be
a time varying voltage proportional to the frequency of the
frequency generator 10. For example, the sawtooth driving the sweep
frequency generator 10 could be applied to the x drivers of both
x-y plotters. The y input for one plotter would be the detected
amplitude output of the amplitude and phase detector 26. The y
input of the other plotter would be the detected phase output of
the amplitude and phase detector 26. In this manner, visual,
graphical readouts of the transfer function would be automatically
provided by the correlator means.
Alternatively, the correlator means can periodically sample the
output amplitude and phase and record it digitally as a function of
the frequency. It should also be noted that it may be desirable to
have the correlator means determine only the phase or only the
amplitude part of the transfer function. A typical output from the
correlator means 30 is illustrated in FIG. 2 as a bode plot.
If the amplitude or phase of the input frequency is varied, or if
improved accuracy is desired, the output signal may be applied from
the sweep frequency generator 10 to the correlator means 30 for
comparison by the correlator means 30 with the output from the
amplitude and phase detector 26. The transfer function would be
continuously computed by the correlator means by comparing the
output signal to the input signal at all times.
In an alternative embodiment where the transfer function is not
computed, the portion of a person's body can be considered as a
terminating load rather than as a transmitting medium. In such a
system, both transducers would be positioned at the identical point
of in the alternative, a single transducer would be utilized and
the amplitude and phase detector 26 would be solely an amplitude
detector and would be connected to the input of the single
transducer. The frequency response would then be detected in a
manner analogous to the detection of the frequency response of a
tuned circuit. As the sweeping generator sweeps through the
frequency range, the forearm, for example, of the individual would
exhibit peaks of relative resonance. These peaks can be used to
detect the individual characteristics of a person.
Returning however, to the preferred embodiment of FIG. 1, the
output of the correlator means 30 may be applied to an analog to
digital converter 32 and then stored in a suitable storage means
34. The storage means 34 can be any of the multitude of storage
systems currently available for data processing. For example, the
data representing the transfer function of a person being initially
detected would be stored in the storage means 34 and identified as
being that of a person who is permitted access to sensitive
computer data. At a subsequent time when the person seeks access to
the data, the output of the analog/digital converter 32 would be
applied to a comparator analysis circuit 36. The comparator
analysis circuit 36 simultaneously receives from the storage means
34, the transfer function of the individual stored therein. The
stored information can be withdrawn from the memory by a person's
name or the computer can scan all stored transfer functions. The
subsequently measured transfer function and the previously stored
transfer function are compared by the comparator circuit to
determine if they represent the same person.
Of course, the comparator analysis circuit 36 could include a pair
of x-y plotters on which the subsequently measured transfer
function is printed together with the previously stored transfer
function for visual analysis and comparison by a person.
Preferably however, the circuit compares the two automatically and
may be programmed to reject the person as not being of the proper
identity if the transfer function is not within preselected
tolerances. The comparator analysis circuit 36 electronically
compares the magnitude of the amplitude deviations and the
magnitude of the phase deviations of the subsequently measured
transfer function from the transfer function stored in the storage
means 34. Such comparisons may occur throughout the entire
frequency range for which the transfer function was measured or can
be accomplished at selected discrete frequencies. The comparator
circuit may, for example, include a pair of differential
amplifiers, one for detecting the difference in phase and the other
for detecting the difference in amplitude between the stored
transfer function and the subsequently detected transfer
function.
In operating the circuitry illustrated in FIG. 1, a person's arm is
positioned to extend from the transducer 12 to the transducer 20.
The circuit is activated and energy generated by the sweep
frequency generator 10 is applied to the arm by the transducer 12
and transferred along the forearm 16 to the transducer 20. The
transducer 20 converts the mechanical signal to an electronic
signal and the amplitude and phase of the received signal are
detected by the amplitude and phase detector 26. Thus, the
preferred output of the amplitude and phase detector 26 is a pair
of electronic signals, the amplitude of which are representative of
the amplitude and of the phase of the output signal at the
transducer 20.
The detected amplitude and phase signals are applied to a
correlator means 30 which in effect correlates the output amplitude
and phase as a function of frequency. Thus, the output of the
correlator means 30 is representative of the transfer function of
the forearm 16. This may be converted to digital data if desired by
analog/digital converter 32 and when appropriate, such as when
making initial measurements, is then stored in a suitable storage
means 34. The transfer function data may, however, always be stored
in a storage means for later identifying persons who sought access
to data even when such persons are subsequently rejected.
Data from the storage means 34 which is representative of
previously measured transfer functions and subsequently measured
data directly from the analog/digital converter 32 are applied to
the comparator analysis circuit 36 where the two transfer functions
are compared to determine whether the same person is present at the
transducers 12 and 20. Further computing and decision making
computation circuitry may be connected to the output 40 of the
comparator analysis circuit 36. Such circuitry would be programmed
with the criteria for accepting or rejecting a person and for
suitable means for responding to or signalling an acceptance or
rejection.
It may be found that a person's unique transfer function may have a
unique shape but may also shift upwardly or downwardly in the
frequency spectrum as a result of aging or other factors. Thus,
computing circuitry may be added to shift one of the computed
transfer functions being compared, up or down to seek a point of
minimum deviation. Then comparison is made to accept or reject a
person's identity.
It is to be understood that while the detailed drawings and
specific examples given describe the preferred embodiments of the
invention, they are for the purposes of illustration only, that the
apparatus of the invention as well as the method is not limited to
the precise details and conditions disclosed and that various
changes may be made therein without departing from the spirit of
the invention which is defined by the following claims.
* * * * *