|United States Patent
|| April 20, 1976
Apparatus and method for remotely monitoring and altering brain waves
Apparatus for and method of sensing brain waves at a position remote from a
subject whereby electromagnetic signals of different frequencies are
simultaneously transmitted to the brain of the subject in which the
signals interfere with one another to yield a waveform which is modulated
by the subject's brain waves. The interference waveform which is
representative of the brain wave activity is re-transmitted by the brain
to a receiver where it is demodulated and amplified. The demodulated
waveform is then displayed for visual viewing and routed to a computer for
further processing and analysis. The demodulated waveform also can be used
to produce a compensating signal which is transmitted back to the brain to
effect a desired change in electrical activity therein.
Malech; Robert G. (Plainview, NY)
Dorne & Margolin Inc. (Bohemia, NY)
August 5, 1974|
|Field of Search:
128/1 C,1 R,2.1 B,2.1 R,419 R,422 R,420,404,2 R,2 S,2.05 R,2.05 V,2.05 F,2.06 R
340/248 A,258 A,258 B,258 D,229
References Cited [Referenced By]
U.S. Patent Documents
|2860627||Nov., 1958||Harden et al.||128/2.
|3096768||Jul., 1963||Griffith, Jr.||128/420.
|3555529||Jan., 1971||Brown et al.||128/2.
|3773049||Nov., 1973||Rabichev et al.||128/1.
Primary Examiner: Kamm; William E.
Attorney, Agent or Firm: Darby & Darby
1. Brain wave monitoring apparatus comprising
means for producing a base frequency signal,
means for producing a first signal having a frequency related to that of
the base frequency and at a predetermined phase related thereto,
means for transmitting both said base frequency and said first signals to
the brain of the subject being monitored,
means for receiving a second signal transmitted by the brain of the subject
being monitored in response to both said base frequency and said first
mixing means for producing from said base frequency signal and said
received second signal a response signal having a frequency related to
that of the base frequency, and
means for interpreting said response signal.
2. Apparatus as in claim 1 where said receiving means comprises
means for isolating the transmitted signals from the received second
3. Apparatus as in claim 2 further comprising a band pass filter with an
input connected to said isolating means and an output connected to said
4. Apparatus as in claim 1 further comprising means for amplifying said
5. Apparatus as in claim 4 further comprising means for demodulating said
amplified response signal.
6. Apparatus as in claim 5 further comprising interpreting means connected
to the output of said demodulator means.
7. Apparatus according to claim 1 further comprising
means for producing an electromagnetic wave control signal dependent on
said response signal, and
means for transmitting said control signal to the brain of said subject.
8. Apparatus as in claim 7 wherein said transmitting means comprises means
for directing the electromagnetic wave control signal to a predetermined
part of the brain.
9. A process for monitoring brain wave activity of a subject comprising the
transmitting at least two electromagnetic energy signals of different
frequencies to the brain of the subject being monitored,
receiving an electromagnetic energy signal resulting from the mixing of
said two signals in the brain modulated by the brain wave activity and
retransmitted by the brain in response to said transmitted energy signals,
interpreting said received signal.
10. A process as in claim 9 further comprising the step of transmitting a
further electromagnetic wave signal to the brain to vary the brain wave
11. A process as in claim 10 wherein the step of transmitting the further
obtaining a standard signal,
comparing said received electromagnetic energy signals with said standard
producing a compensating signal corresponding to the comparison between
said received electrogagnetic energy signals and the standard signal, and
transmitting the compensating signals to the brain of the subject being
BACKGROUND OF THE INVENTION
Medical science has found brain waves to be a useful barometer of organic
functions. Measurements of electrical activity in the brain have been
instrumental in detecting physical and psychic disorder, measuring stress,
determining sleep patterns, and monitoring body metabolism.
The present art for measurement of brain waves employs
electroencephalographs including probes with sensors which are attached to
the skull of the subject under study at points proximate to the regions of
the brain being monitored. Electrical contact between the sensors and
apparatus employed to process the detected brain waves is maintained by a
plurality of wires extending from the sensors to the apparatus. The
necessity for physically attaching the measuring apparatus to the subject
imposes several limitations on the measurement process. The subject may
experience discomfort, particulary if the measurements are to be made over
extended periods of time. His bodily movements are restricted and he is
generally confined to the immediate vicinity of the measuring apparatus.
Furthermore, measurements cannot be made while the subject is conscious
without his awareness. The comprehensiveness of the measurements is also
limited since the finite number of probes employed to monitor local
regions of brain wave activity do not permit observation of the total
brain wave profile in a single test.
SUMMARY OF THE INVENTION
The present invention relates to apparatus and a method for monitoring
brain waves wherein all components of the apparatus employed are remote
from the test subject. More specifically, high frequency transmitters are
operated to radiate electromagnetic energy of different frequencies
through antennas which are capable of scanning the entire brain of the
test subject or any desired region thereof. The signals of different
frequencies penetrate the skull of the subject and impinge upon the brain
where they mix to yield an interference wave modulated by radiations from
the brain's natural electrical activity. The modulated interference wave
is re-transmitted by the brain and received by an antenna at a remote
station where it is demodulated, and processed to provide a profile of the
suject's brain waves. In addition to passively monitoring his brain waves,
the subject's neurological processes may be affected by transmitting to
his brain, through a transmitter, compensating signals. The latter signals
can be derived from the received and processed brain waves.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to remotely monitor electrical
activity in the entire brain or selected local regions thereof with a
Another object is the monitoring of a subject's brain wave activity through
transmission and reception of electromagnetic waves.
Still another object is to monitor brain wave activity from a position
remote from the subject.
A further object is to provide a method and apparatus for affecting brain
wave activity by transmitting electromagnetic signals thereto.
DESCRIPTION OF THE DRAWINGS
Other and further objects of the invention will appear from the following
description and the accompanying drawings, which form part of the instant
specification and which are to be read in conjunction therewith, and in
which like reference numerals are used to indicate like parts in the
FIG. 1 is a block diagram showing the interconnection of the components of
the apparatus of the invention;
FIG. 2 is a block diagram showing signal flow in one embodiment of the
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, specifically FIG. 1, a high frequency
transmitter 2 produces and supplies two electromagnetic wave signals
through suitable coupling means 14 to an antenna 4. The signals are
directed by the antenna 4 to the skull 6 of the subject 8 being examined.
The two signals from the antenna 4, which travel independently, penetrate
the skull 6 and impinge upon the tissue of the brain 10.
Within the tissue of the brain 10, the signals combine, much in the manner
of a conventional mixing process technique, with each section of the brain
having a different modulating action. The resulting waveform of the two
signals has its greatest amplitude when the two signals are in phase and
thus reinforcing one another. When the signals are exactly 180.degree. out
of phase the combination produces a resultant waveform of minimum
amplitude. If the amplitudes of the two signals transmitted to the subject
are maintained at identical levels, the resultant interference waveform,
absent influences of external radiation, may be expected to assume zero
intensity when maximum interference occurs, the number of such points
being equal to the difference in frequencies of the incident signals.
However, interference by radiation from electrical activity within the
brain 10 causes the waveform resulting from interference of the two
transmitted signals to vary from the expected result, i.e., the
interference waveform is modulated by the brain waves. It is believed that
this is due to the fact that brain waves produce electric charges each of
which has a component of electromagnetic radiation associated with it. The
electromagnetic radiation produced by the brain waves in turn reacts with
the signals transmitted to the brain from the external source.
The modulated interference waveform is re-transmitted from the brain 10,
back through the skull 6. A quantity of energy is re-transmitted
sufficient to enable it to be picked up by the antenna 4. This can be
controlled, within limits, by adjusting the absolute and relative
intensities of the signals, originally transmitted to the brain. Of
course, the level of the transmitted energy should be kept below that
which may be harmful to the subject.
The antenna passes the received signal to a receiver 12 through the antenna
electronics 14. Within the receiver the wave is amplified by conventional
RF amplifiers 16 and demodulated by conventional detector and modulator
electronics 18. The demodulated wave, representing the intra-brain
electrical activity, is amplified by amplifiers 20 and the resulting
information in electronic form is stored in buffer circuitry 22. From the
buffers 22 the information is fed to a suitable visual display 24, for
example one employing a cathode ray tube, light emitting diodes, liquid
crystals, or a mechanical plotter. The information may also be channeled
to a computer 26 for further processing and analysis with the output of
the computer displayed by heretofore mentioned suitable means.
In addition to channeling its information to display devices 24, the
computer 26 can also produce signals to control an auxiliary transmitter
28. Transmitter 28 is used to produce a compensating signal which is
transmitted to the brain 10 of the subject 8 by the antenna 4. In a
preferred embodiment of the invention, the compensating signal is derived
as a function of the received brain wave signals, although it can be
produced separately. The compensating signals affect electrical activity
within the brain 10.
Various configurations of suitable apparatus and electronic circuitry may
be utilized to form the system generally shown in FIG. 1 and one of the
many possible configurations is illustrated in FIG. 2. In the example
shown therein, two signals, one of 100 MHz and the other of 210 MHz are
transmitted simultaneously and combine in the brain 10 to form a resultant
wave of frequency equal to the difference in frequencies of the incident
signals, i.e., 110 MHz. The sum of the two incident frequencies is also
available, but is discarded in subsequent filtering. The 100 MHz signal is
obtained at the output 37 of an RF power divider 34 into which a 100 MHz
signal generated by an oscillator 30 is injected. The oscillator 30 is of
a conventional type employing either crystals for fixed frequency circuits
or a tunable circuit set to oscillate at 100 MHz. It can be a pulse
generator, square wave generator or sinusoidal wave generator. The RF
power divider can be any conventional VHF, UHF or SHF frequency range
device constructed to provide, at each of three outputs, a signal
identical in frequency to that applied to its input.
The 210 MHz signal is derived from the same 100 MHz oscillator 30 and RF
power divider 34 as the 100 MHz signal, operating in concert with a
frequency doubler 36 and 10 MHz oscillator 32. The frequency doubler can
be any conventional device which provides at its output a signal with
frequency equal to twice the frequency of a signal applied at its input.
The 10 MHz oscillator can also be of conventional type similar to the 100
MHz oscillator herebefore described. A 100 MHz signal from the output 39
of the RF power divider 34 is fed through the frequency doubler 36 and the
resulting 200 MHz signal is applied to a mixer 40. The mixer 40 can be any
conventional VHF, UHF or SHF frequency range device capable of accepting
two input signals of differing frequencies and providing two output
signals with frequencies equal to the sum and difference in frequencies
respectively of the input signals. A 10 MHz signal from the oscillator 32
is also applied to the mixer 40. The 200 MHz signal from the doubler 36
and the 10 MHz signal from the oscillator 32 combine in the mixer 40 to
form a signal with a frequency of 210 MHz equal to the sum of the
frequencies of the 200 MHz and 10 MHz signals.
The 210 MHz signal is one of the signals transmitted to the brain 10 of the
subject being monitored. In the arrangement shown in FIG. 2, an antenna 41
is used to transmit the 210 MHz signal and another antenna 43 is used to
transmit the 100 MHz signal. Of course, a single antenna capable of
operating at 100 MHz and 210 MHz frequencies may be used to transmit both
signals. The scan angle, direction and rate may be controlled
mechanically, e.g., by a reversing motor, or electronically, e.g., by
energizing elements in the antenna in proper synchronization. Thus, the
antenna(s) can be of either fixed or rotary conventional types.
A second 100 MHz signal derived from output terminal 37 of the three-way
power divider 34 is applied to a circulator 38 and emerges therefrom with
a desired phase shift. The circulator 38 can be of any conventional type
wherein a signal applied to an input port emerges from an output port with
an appropriate phase shift. The 100 MHz signal is then transmitted to the
brain 10 of the subject being monitored via the antenna 43 as the second
component of the dual signal transmission. The antenna 43 can be of
conventional type similar to antenna 41 herebefore described. As
previously noted, these two antennas may be combined in a single unit.
The transmitted 100 and 210 MHz signal components mix within the tissue in
the brain 10 and interfere with one another yielding a signal of a
frequency of 110 MHz, the difference in frequencies of the two incident
components, modulated by electromagnetic emissions from the brain, i.e.,
the brain wave activity being monitored. This modulated 110 MHz signal is
radiated into space.
The 110 MHz signal, modulated by brain wave activity, is picked up by an
antenna 45 and channeled back through the circulator 38 where it undergoes
an appropriate phase shift. The circulator 38 isolates the transmitted
signals from the received signal. Any suitable diplexer or duplexer can be
used. The antenna 45 can be of conventional type similar to antennas 41
and 43. It can be combined with them in a single unit or it can be
separate. The received modulated 110 MHz signal is then applied to a band
pass filter 42, to eliminate undesirable harmonics and extraneous noise,
and the filtered 110 MHz signal is inserted into a mixer 44 into which has
also been introduced a component of the 100 MHz signal from the source 30
distributed by the RF power divider 34. The filter 42 can be any
conventional band pass filter. The mixer 44 may also be of conventional
type similar to the mixer 40 herebefore described.
The 100 MHz and 110 MHz signals combine in the mixer 44 to yield a signal
of frequency equal to the difference in frequencies of the two component
signals, i.e., 10 MHz still modulated by the monitored brain wave
activity. The 10 MHz signal is amplified in an IF amplifier 46 and
channeled to a demodulator 48. The IF amplifier and demodulator 48 can
both be of conventional types. The type of demodulator selected will
depend on the characteristics of the signals transmitted to and received
from the brain, and the information desired to be obtained. The brain may
modulate the amplitude, frequency and/or phase of the interference
waveform. Certain of these parameters will be more sensitive to
corresponding brain wave characteristics than others. Selection of
amplitude, frequency or phase demodulation means is governed by the choice
of brain wave characteristic to be monitored. If desired, several
different types of demodulators can be provided and used alternately or at
the same time.
The demodulated signal which is representative of the monitored brain wave
activity is passed through audio amplifiers 50 a, b, c which may be of
conventional type where it is amplified and routed to displays 58 a, b, c
and a computer 60. The displays 58 a, b, c present the raw brain wave
signals from the amplifiers 50 a, b, c. The computer 60 processes the
amplified brain wave signals to derive information suitable for viewing,
e.g., by suppressing, compressing, or expanding elements thereof, or
combining them with other information-bearing signals and presents that
information on a display 62. The displays can be conventional ones such as
the types herebefore mentioned employing electronic visual displays or
mechanical plotters 58b. The computer can also be of conventional type,
either analog or digital, or a hybrid.
A profile of the entire brain wave emission pattern may be monitored or
select areas of the brain may be observed in a single measurement simply
by altering the scan angle and direction of the antennas. There is no
physical contact between the subject and the monitoring apparatus. The
computer 60 also can determine a compensating waveform for transmission to
the brain 10 to alter the natural brain waves in a desired fashion. The
closed loop compensating system permits instantaneous and continuous
modification of the brain wave response pattern.
In performing the brain wave pattern modification function, the computer 60
can be furnished with an external standard signal from a source 70
representative of brain wave activity associated with a desired
nuerological response. The region of the brain responsible for the
response is monitored and the received signal, indicative of the brain
wave activity therein, is compared with the standard signal. The computer
60 is programmed to determine a compensating signal, responsive to the
difference between the standard signal and received signal. The
compensating signal, when transmitted to the monitored region of the
brain, modulates the natural brain wave activity therein toward a
reproduction of the standard signal, thereby changing the neurological
response of the subject.
The computer 60 controls an auxiliary transmitter 64 which transmits the
compensating signal to the brain 10 of the subject via an antenna 66. The
transmitter 64 is of the high frequency type commonly used in radar
applications. The antenna 66 can be similar to antennas 41, 43 and 45 and
can be combined with them. Through these means, brain wave activity may be
altered and deviations from a desired norm may be compensated. Brain waves
may be monitored and control signals transmitted to the brain from a
It is to be noted that the configuration described is one of many
possibilities which may be formulated without departing from the spirit of
my invention. The transmitters can be monostratic or bistatic. They also
can be single, dual, or multiple frequency devices. The transmitted signal
can be continuous wave, pulse, FM, or any combination of these as well as
other transmission forms. Typical operating frequencies for the
transmitters range from 1 MHz to 40 GHz but may be altered to suit the
particular function being monitored and the characteristics of the
The individual components of the system for monitoring and controlling
brain wave activity may be of conventional type commonly employed in radar
Various subassemblies of the brain wave monitoring and control apparatus
may be added, substituted or combined. Thus, separate antennas or a single
multi-mode antenna may be used for transmission and reception. Additional
displays and computers may be added to present and analyze select
components of the monitored brain waves.
Modulation of the interference signal retransmitted by the brain may be of
amplitude, frequency and/or phase. Appropriate demodulators may be used to
decipher the subject's brain activity and select components of his brain
waves may be analyzed by computer to determine his mental state and
monitor his thought processes.
As will be appreciated by those familiar with the art, apparatus and method
of the subject invention has numerous uses. Persons in critical positions
such as drivers and pilots can be continuously monitored with provision
for activation of an emergency device in the event of human failure.
Seizures, sleepiness and dreaming can be detected. Bodily functions such
as pulse rate, heartbeat reqularity and others also can be monitored and
occurrences of hallucinations can be detected. The system also permits
medical diagnoses of patients, inaccessible to physicians, from remote
* * * * *