| United States Patent |
4,305,402 |
| Katims |
December 15, 1981 |
Method for transcutaneous electrical stimulation
Abstract
A method and apparatus for monitoring and obtaining actual bio-electrical
characteristics of a subject, such as EEG, or determinants of the
psycho-electro-physiological state of the subject, under predetermined
conditions of evoked response stimuli, and by interaction with a computer, apply
cutaneous electrical stimulation to the subject, using a signal generator to
modify current amplitude and frequency in a direction to achieve bio-electrical
characteristics in the subject related to the actual bio-electrical
characteristics monitored. The signal generator may have an output of several
frequencies simultaneously, and uses a sinusoidal waveform output, with battery
power passed through a transformer to power a transconductance amplifier to
obtain constant current output despite resistance changes in the line with the
subject, and with the transformer not placed in the signal path of the
sinusoidal waveform.
| Inventors: |
Katims; Jefferson J. (3939 Tiverton Rd.,
Randallstown, MD 21133) |
| Appl. No.: |
053568 |
| Filed: |
June 29, 1979 |
| Current U.S. Class: |
600/554; 128/905; 600/545;
607/54; 607/58; 607/62; 607/66 |
| Intern'l Class: |
A61B 005/05; A61N 001/32 |
| Field of Search: |
128/1 C,741,731,732,733,734,419
R,420 R,421,422,423 R,905,791-793 35/22 R |
References Cited
U.S. Patent Documents
| 1257555 |
Feb., 1918 |
Vreeland |
128/422. |
| 3032029 |
May., 1962 |
Cunningham |
128/732. |
| 3255753 |
Jun., 1966 |
Wing |
128/1. |
| 3464416 |
Sep., 1969 |
Williams |
128/421. |
| 3495596 |
Feb., 1970 |
Condict |
128/1. |
| 3640284 |
Feb., 1972 |
De Langis |
128/422. |
| 3659614 |
May., 1972 |
Jankelson |
128/791. |
| 3791373 |
Feb., 1974 |
Winkler et al. |
128/1. |
| 3817254 |
Jun., 1974 |
Maurer |
128/421. |
| 3835833 |
Sep., 1974 |
Limoge |
128/1. |
| 3881495 |
May., 1975 |
Panozzo et al. |
128/422. |
| 3893450 |
Jul., 1975 |
Ertl |
128/731. |
| 3951134 |
Apr., 1976 |
Malech |
128/731. |
| 3967616 |
Jul., 1976 |
Ross |
128/1. |
| 3971365 |
Jul., 1976 |
Smith |
128/734. |
| 4094307 |
Jun., 1978 |
Young, Jr. |
128/731. |
| 4121593 |
Oct., 1978 |
Kastrubin et al. |
128/1. |
| Foreign Patent Documents |
| 635994 |
Dec., 1978 |
SU |
128/419. |
Primary
Examiner: Cohen; Lee S.
Attorney, Agent or Firm: Flocks; Karl W.
Claims
What is claimed is:
1. A method of diagnostic and therapeutic
treatment of a patient comprising the steps of attaching a source of
cutaneous electrical stimulation at the head area of the patient,
applying alternating constant current electrical stimulation from said
source in the form of a continuous sine wave, controlling the current and
frequency of the stimulation within current and frequency parameters which
initiate the non-adversive sensation which the patient characterizes as
tingling, controlling the frequency to a range within which the visual
field of the patient appears to be pulsating or oscillating, controlling
the frequency to a range within which the patient perceives a flickering pale
white light, controlling the frequency to a range within which the
patient experiences a resonance or vibratory sensation emanating from his head.
2. The method of diagnostic and therapeutic treatment of claim 1,
further characterized by controlling the frequency to a range between 5
to 10 hertz within which range there appears to the patient to be the distinct
sensation of a pulsating or oscillating visual field.
3. The method of
diagnostic and therapeutic treatment of claim 1, further characterized by
controlling the frequency to a range between 10 to 70 hertz within which
the patient perceives a distinct sensation of a flickering pale white light.
4. The method of diagnostic and therapeutic treatment of claim 1,
further characterized by controlling the frequency to a range between 70
to 130 hertz within which the patient experiences a distinct resonating or
vibratory sensation emanating from his head.
5. The method of claim 1,
further characterized by providing a unique individual profile or medical record
of a patient's electrophysiological state or sensations which are evoked in
response to various parameters of cutaneous electrical stimulation.
6.
The method of claim 5, further characterized by returning to the frequency
parameters determined by the profile to be therapeutic.
Description
BACKGROUND OF THE INVENTION
The present invention relates to
bio-electric stimulators utilized and more particularly to stimulation by
transcutaneous application of electricity as a therapeutic tool.
In
medicine the earliest known bio-electric stimulators for the direct application
of electricity to the human skin as a therapeutic tool appeared around 1750. The
direct application of electrical stimulation to human neuronal tissue or
stimulation has also been in a therapeutic use for the past 20 years.
Various therapeutic applications of mild electric stimulation, in
contrast to gross stimulation such as electroconvulsive shock, directly applied
to human skin has been purported to include sleep induction or curing of
insomnia, anesthesia, analgesia, attenuation of withdrawal from drug addiction,
relief from asthma, as well as relief from anxiety and depression.
The
therapeutic applications of direct electrical stimulation to neural tissue or
subcutaneous stimulation includes induction of analgesia, allevation of symptoms
of multiple sclerosis, cerebral palsy, epilepsy and spasticity, facilitation of
the healing of non-union bone fractures, cardiac and diaphragm pacemakers, as
well as electrical bladder control. Another application of electrical
stimulation is in the field of bio-research, primarily electrophysiology.
SUMMARY OF THE INVENTION
It is an object of the present
invention to be able to provide a unique medical record of the brain's
electrophysiological state and its response to different frequencies and types
of stimulation which is of great value in the field of neurology. The present
invention can also be utilized for the study of intelligence and
psychoneurological disorders.
Eventually, a doctor, after completing a
profile on a patient, utilizing the present invention, would be able to
prescribe machine settings in order to help the patient wake up, go to sleep,
replace drugs, play a song, or a game of pinball.
A further advantage of
the present invention is its use in the electrical stimulator of a constant
current output. The advantage of a constant current output is that it
automatically accounts and corrects for any fluctuations in electrical
resistance that may occur within the over-all system. This would not be
accounted for by a constant voltage output. Constant current also provides a
superior margin of electrical safety in comparison with constant voltage where
fluctuations in electrical resistance can cause shocking to the subject. Changes
in resistance could be due to natural endogenous fluctuations in the resistance
of human tissue; i.e. perspiration, or exogenous resistance fluctuations caused
by the drying out of electrode paste used with the electrodes.
Another
advantage is use of constant current which resembles the natural current flow in
neuro-electrophysiology. Caution must be exercised if a constant voltage source
is applied instead of constant current since a person could serve as a
rectifying load thereby leaving a net charge on their self which would lead to
desensitization.
An additional safety feature of the present invention
is a clipping system used in the electrical stimulator.
It is a further
object of the present invention to establish a system for back and forth
interaction between an electrical stimulator and a control computer.
Another object of the present invention is to disclose a method and
apparatus which operates in response to an actual psycho-electro-physiological
state to modify current amplitude and frequency in a direction to achieve the
desired such state. In a more limited aspect, in response to an actual EEG, to
modify amplitude of current and frequency in a direction to achieve a desired
EEG.
Further, it is an object to achieve such state by cutaneous
electrical stimulation.
Also it is an object to obtain therapy for the
subject by producing altered subjective electro-physiological states in the
subject. Value of the present invention is shown in the relief of subjective
physiological distress associated with disease as well as creating a favorable
subjective physiological state in the normal subject.
BRIEF DESCRIPTION
OF THE DRAWINGS
The invention can best be understood by referring to the
accompanying drawings in which:
FIG. 1 is an illustration of the system
of the present invention connected to a subject;
FIG. 2 is a block
diagram illustration of the overall system;
FIG. 3 is an enlarged view
of the front panel of a signal generator used in the system;
FIG. 4 is
an enlarged view of the front panel of the electrical stimulator used in the
system;
FIG. 5 is a block-schematic diagram of the signal generator and
electrical stimulator of FIGS. 3 and 4, respectively;
FIG. 6 is a graph
showing frequency outputs for the knob settings of the signal generator of FIG.
3;
FIG. 7 is a graph showing frequency band outputs for knob settings on
the electrical stimulator of FIG. 4; and
FIG. 8 is a graph of the
current output level of the electrical stimulator of FIG. 4 with respect to
amplitude control knob settings.
DESCRIPTION OF THE PREFERRED
EMBODIMENTS
First the theoretical basis of the present invention is
discussed in terms of its output wave shape, frequency coding and physiology, as
well as human neuroanatomy, neurochemistry, and neuropsychology.
A
sinusoidal wave shape is the choice for use in the present invention based upon
the desire to minimize the amplitude of the stimulating current and the
observation by the present inventor that a sinusoidal wave shape is
approximately 15 times more effective than a square wave in affecting the
physiological state of mammilian neuronal tissue. A pilot study performed in
conjunction with studies for the present invention showed unpleasant subjective
side effects for a square wave form and none such side effects for a sinusoidal
wave form. A further convenience of the sinusoid is its simple frequency domain
representation.
The frequency coding of individual neurons for both
communication and in response to electrical stimulation, as well as the ability
to induce electrocortical activity; e.g., recruitment of EEG, are well
established facts in neuroscience. The frequency coding phenomenon may have to
do with the temporal summation of the excitatory effect of a neurotransmitter at
the synapse between neurons, or endogenous electrical time constants of neuronal
membrances which are independent of neurotransmitters. It is the intent of the
electrical stimulator in the present invention to try to excite endogenous
rhythms within the brain as well as to stimulate particular brain regions to
produce a psychotherapeutic affect. The frequency coding properties of a human's
brain subjective psychological states in response to cutaneous application of
this stimulator are demonstratable by experiments of the present invention.
By placing two electrodes on a human subject's skin over the jawbone in
front of each earlobe and passing a current between them, there is created an
electron flow of which approximately 95% passes through the face and 5% passes
through the cranium. This 5% has been demonstrated to be capable of inducing
slight fluctuations in brain electrical potentials for the duration of the
stimulation in humans. These fluctuations could account for one of the ways in
which the machine used in the present invention could induce electrocortical
activity; the other possible type of electrocortical induction is discussed
later in dealing with the nucleus of the reticular formation.
The 95% of
the current flow passing through the face is capable of directly inducing
fluctuations in the resting membrane potentials of the nerve fibers innervating
the face and the entire underlying musculature. The sensory and motor fibers
being stimulated primarily involve the fifth (V) cranial nerve, the trigeminal.
Other cranial nerve fibers are stimulated as well including nerves VII, X, XI
and XII. The primary locus of the theoretical basis of the mechanism of action
of the machine in the present invention concerns the trigeninal nerve. The cell
bodies of its primary sensory fibers are located deep within the midbrain in the
trigeminal nucleus. These cell bodies are the only unencapsulated primary
sensory neurons within the central nervous system. It is the intent of the
stimulator of the present invention, by the method of the present invention, to
selectively stimulate these neurons with different frequencies of electrical
stimulation, in effect to affect their activity and the activity of associated
neurons in other brain stem nuclei. Through this process one is able to induce
neuroelectrical and endogenous neurochemical changes in the human brain state.
Stimulation of the trigeminal nucleus and its sensory fibers as well as
classical acupuncture has been demonstrated to be capable of inducing
electrocortical activity. Both the putative neurotransmitters, Substance P and
Enkephalin, have been found in neurons within this nucleus. Both of these
putative neurotransmitters have been postulated to be involved with limbic
emotional brain functions. It should be mentioned here that the Enkaphalins have
been demonstrated to be our own endogenous opiate-like substance. Both the
antidepressants and the tranquilizers are drugs which exert an influence on this
nucleus within the brain.
The following brain stem nuclei mentioned all
have intimate neuronal connections with the trigeminal nucleus.
The
nucleus ambiguus contains some of the cell bodies of cranial nerves IX, X and
IX. The auricular branch of the vagus nerve (X) enters the trigeminal nucleus
from the nucleus ambiguus. The fibers from the vagus nerve (X) provide primary
central sensory and motor innervations of the heart, lungs, and the
gastrointestinal tract.
The primary role of the nucleus of the reticular
formation is in the regulation of all types of electrocortical activity.
The portion of the reticular formation comprising the nucleus
gigantocellularis within the pontine tegmentum has been found to be essential
for dreaming to occur. The nucleus gigantocellularis has also been demonstrated
to have intimate neurochemical associations with the trigeminal nucleus.
The central gray region contains amon the densest concentration of
Enkephalins within the brain; if stimulated electrically it will induce
analgesia in humans.
The neurons within the raphae nuclei utilize the
neurotransmitter serotonin which is involved in the fundamental regulation of
the sleep-wakefulness cycle and is a system which is affected by psychedelic
drugs.
The locus coeruleui, blue in their natural state within the
brain, contain cell bodies which are adjacent to cell bodies of the trigeminal
nucleus. This close anatomical relationship would facilitate an electrotonic
interaction between these two groups of cell bodies. The locus coeruleus in one
of the primary sources of the noradrenergic neurotransmitter system with the
human brain. This system is involved with learning and memory, depression and
pleasure, and certain psychotic disorders. It is affected by drugs such as
cocaine and heroin.
The vestibular nucleus is involved with our sense of
balance as well as nausea.
The inferior and superior colliculi are
associated with a primitive body, space, auditory, and visual sense system.
The cerebellum portion of our brain represents a primitive motor cortex
and plays a role in complex timing functions, learning and memory, and execution
of complex motor tasks.
The present invention is concerned with the
above theoretical basis but it is from investigations by the inventor that the
method and apparatus of the invention has evolved.
FIGS. 1 and 2 show
the over-all system. The signal generator electrical stimulator apparatus 10 is
composed of a triple output signal generator 11 and electrical stimulator 12
interfaced to be under control of computer 13. Although signal generator 11 and
electrical stimulator 12 are shown in the illustrated embodiment of FIGS. 1 and
2; as many generators as necessary may be utilized or electrical stimulator 12
may be used alone. Outputs from apparatus 10 go to the subject S and to computer
13.
Evoked response system 15 may be any audio, visual, tactile, or
situational stimuli whatsoever and this system is also interfaced with computer
13.
Examples of evoked-response stimuli are:
1. Audio stimuli
such as any good commercial music synthersizer which can be interfaced to
computer 13. A well interfaced and controlled sound reproduction system is also
desired.
2. Visual stimuli such as any standard video camera and monitor
system in closed circuit television. A video synthesizer would also be included
in this system.
3. Tactile stimuli which could include such things as a
solenoid or piezoelectric activated skin stimulator, an electric vibrator, such
as the type used for massage, or bone conduction hearing aids.
4.
Psychological stimuli which concern the conditions under which the subject is
being tested. This could be programmed into computer 13.
Monitoring
system 17 which is also interfaced with computer 13 and receives outputs from
subjects, is composed of three sub-systems (now shown). These sub-systems are:
1. A transducer system which receives inputs from any
electrophysiological parameter which may be monitored from the subject; e.g.,
electrocardiogram (EKG), electromyelogram (EMG), galvanized skin resistance
(GSR), electro-oculogram (EOG), blood pressure, breathing, etc. This system also
utilizes a video camera, microphone, or electric light pencil as a type of
input.
2. A preprocessing signal conditioning system which receives
input from the transducer system and is interfaced such that it may be
computer-controlled. This serves to provide a usable signal for the computer 13
and signal analysis (see following) systems. This system sends outputs to
computer 13 and the signal analysis system. This system consists of
preamplifiers, amplifiers, band pass amplifiers, etc.
3. A signal
analysis system to perform real time analysis of the incoming data for the
controlling computer 13. Examples of types of signal analysis performed include
statistical temporal correlation, photo and accoustic spectroscopy, EEG
filtering techniques, Fourier analysis, and other forms of linear and non-linear
signal analysis. Many components of this system could be incorporated into
computer 13.
Monitoring here is done at the subject leads instead of at
the primary side of the transformer in order to better account for variable
impedances at the subject such as at the electrodes.
Computer 13 is a
high-speed digital type of computer, capable of performing statistical
correlative analysis and possessing a large amount of memory circuitry. Computer
13 is fully interfaced with the signal generator electrical system 10, the
evoked response system 15, the preprocessing signal conditioning system and the
signal analysis system, both described above as parts of monitoring system 17.
The function of computer 13 is to interactively simulate the subject S
with the signal generating system 10 and the evoked response system 15 and
monitor and analyze the data from the monitoring system 17 to induce a
particular electrical or subjective state.
Computer 13 analyzes the EEG
from output obtained via the signal analysis system in terms of evoked
potentials, event-related potentials, pre- or post-stimulus potentials of an
extremely long or short duration, habituation or dishabituation of evoked
response, synchronization of output, fluctuations in negative or positive pre-
or post-stimulus potentials, and recruitment of EEG frequencies with respect to
frequencies of stimulation. Computer 13 is then programmed to correlate the EEG
analysis data with the chemical, physiological, and psychological state of the
subject S.
The chemical state refers to whether the subject is under the
influence or addicted to any drugs. The physiological state refers to any
electrophysiological parameters being monitored by the computer. The
psychological state refers to the subjective or objective psychological state
and the state of attention of the subject, as well as psychological profiles of,
say, a movie being observed (e.g., male vs. female characters) or performance in
a pinball game (e.g., a hit vs. a miss).
Computer 13 will continually
interface or mediate a two-way interaction between a subject's
psychoelectrophysiological state and the stimuli to which the subject is being
exposed or with which the subject is interacting. This application of computer
13 can be under control of either the subject or the observer.
For
example, computer 13 can be programmed to automatically be able to compare and
contrast different combinations and permutations of different frequencies of
cutaneous electrical stimulation to determine which has the most efficient
output in evoking the recruitment of synchronization of EEG activity. The latter
is associated with a pleasurable or sedated state of consciousness. Computer 13
may modulate the evoked response system 15 as well, to achieve the same effect.
By comparing the components of electrocortical pre- post stimulus
potentials evoked responses and utilizing amplitude discrimination and
monitoring the sequential frequency over time, computer 13 is able to modulate
cutaneous current levels and frequencies utilizing the signal generator
electrical stimulator system to prevent habituation or desensitization of the
subject's electrophysiological state. This is a method by which computer 13
quantitatively maintains tingling subjective levels of electrical current.
Biofeedback parameters such as blood pressure, electrocardiogram, or
breathing, which are monitored by the transducer system of monitoring system 17,
may be analyzed by computer 13 and can be systematically correlated with the
frequency dimension of the cutaneous electrical stimulation. Computer 13 can
systematically evoke different frequencies of cutaneous stiulation to modulate
cardiovascular or pulmonary rates to desired therapeutic levels.
For
example, in therapeutic applications, while listening to a song, certain notes
or patterns in the rhythm are correlated by computer 13 with the subject's
electrophysiological state. Computer 13 can either accentuate the stimulus (in
this case by affecting either the volume or timing of the music through the
evoked response system 15), or the brain's electrical state (utilizing signal
generator electrical stimulator system 10), or both in order to heighten the
subject's awareness of both. This same logic may be applied towards a game of
pinball, or a movie, any type of stimulus which may be applied therapeutically,
or to maintain a high state of attentiveness in a subject for performance of a
complex task.
Signal generator 11 is shown as connected to computer 13
and is a triple output signal generator used to send a large range of
frequencies and combinations of these frequencies, through electrical stimulator
12 to a pair of electrodes 18 placed on the skin of subject's approximately 1/4
inch anterior to each earlobe. The electrodes 18 may be dime electrodes, made in
size, shape, and material similar to that coin. Although signal generator 11 is
illustrated here, it is possible to practice the present invention with only
electrical stimulator 12 of signal generator electrical stimulator apparatus 10,
but at a sacrifice in general useful range. As illustrated in the enlarged view
of its front panel in FIG. 3 and one portion of the block-schematic diagram of
FIG. 5, signal generator 11 is composed of three waveform generators 21A, 21B,
21C, each with its frequency control 22A, 22B and 22C, respectively, and its
bandswitch control 23A, 23B and 23C, respectively. Power is supplied to the
waveform generators 21A, 21B, 21C through power charge switch 24 from two 6-volt
batteries connected in series for a 12-volt power supply (rechargeable as two
6-volt batteries in parallel). A battery low indicator 25 shown here as a light
which indicates a need to recharge batteries is connected to power charge switch
24. Current output controls 26A, 26B, 26C from each of the waveform generators
21A, 21B, 21C, respectively, are illustrated as potentiometers 26A', 26B', 26C'
and are connected to output terminal 29 through inverting amplifier 27 and
master current control 28, noted as potentiometer 28'. A power switch and
power-on indicator light are also shown for their normal purposes. All ground
connections for signal generator 11 and electrical stimulator 12 are connected
as a common ground.
Each of the frequency bandswitch controls 23A, 23B,
23C have bandswitch positions A, B, and C designated with A designating the low
frequency band, B designating a medium frequency band, and C designating a high
frequency band. The frequency output for the knob settings on each of frequency
controls 22A, 22B, 22C in each of the three bands A, B, and C is shown on the
graph of FIG. 6. The three curves thereon designate the frequency in hertz for
the knob settings on the particular signal generator used but this can be worked
out for other signal generators which preferably will operate in the same
ranges. For the particular signal generator used, the master control 28
regulated the over-all current output with a 10 mA maximum output current from
amplifier 27. Each of waveform generators 21A, 21B, 21C in the preamplifier had
a 1.3 V peak signal. This signal generator's amplifier had a 10 mA/V transfer
function with the amplifier's level control at the full clockwise position.
The amplitude controls on the signal generator were calibrated within
5%. The individual level controls may be viewed as weighing factors and the
master controls as an over-all multiplier. The signals add in quadrature, i.e.:
Peak output voltage (V)=A.sub.0 (A.sub.1 .sup.2 +A.sub.2.sup.2
+A.sub.3.sup.2).sup.1/2 (1.3)
where A.sub.0 is the setting of the master
level control.
A.sub.1, A.sub.2, and A.sub.3 are the settings of the
individual level controls.
1.3 V is the peak output of the device.
It should be noted that the controls as illustrated read ten times the
actual level (i.e., 0 to 10 instead of 0 to 1).
The particular signal
generator specifications are to clearly illustrate a working embodiment but
should not be construed as absolute limits since other signal generators that
can be operated in these frequency ranges with similar output waveforms,
particularly sinusoidal waveforms, can be used. Also the use of a triple output
signal generator illustrated allows a wider range of results but the output of
simulator 12 alone is sufficient for some more limited purposes.
Signal
generator output terminal 29 is connected to electrical stimulator 12 as shown
in FIG. 5, mainly utilizing amplifier characteristics of electrical stimulator
12 by passing the signal from terminal 29 through current amplitude control
potentiometer 31', input amplifier 32, and output transconductance amplifier 33
to electrodes 18 contacting the subject S. Transconductance amplifier 33
maintains the constant current output despite fluctuations in the load.
Referring to FIG. 4, the front panel of electrical stimulator 12 has a
frequency 34, current output control 35, frequency band switch 36, with clipping
indicator lights 37, battery low indicator light 38 and a pilot light with the
on-off switch with capabilities of a single output instead of the triple output
of signal generator 11.
Referring to the block-schematic of FIG. 5,
electrical stimulator 12 has a 6-volt battery supply. To this is connected
battery low comparator 38', used in conjunction with a diode reference (not
shown), and relaxation oscillator 41. Most any DC input can be used but the
battery connection illustrated is preferred. From relaxation oscillator 41 a
square wave output is buffered by inverting buffer 42, and non-inverting buffer
43 with their complementary outputs driving a pair of power transistors 44 which
chop the 6-volt battery voltage at a rate of several kilohertz and drive step-up
transformer 45. The induced voltage in the primary is full wave rectified to
provide +10 volt supply 46. The secondary drives a full wave doubler circuit
that provides .+-.50 volt supply 47.
Transformer 45 is used to match a
high impedance load (the subject) and simple, safe, low-voltage circuitry
without having the transformer in the signal path. In other machines of the type
for electrical stimulation that use transformers, the fact that the transformer
is in the signal path implies that all sorts of distortions that are inherent to
the transformer such as frequency limiting effects and the fact that no DC
current may pass through a transformer will interfere with the signal output
from these other simulators.
In the machine of the present invention,
the transformer is run at the optimal frequency and only as a power supply in
order to produce the high voltage output and rectify it back to DC. Therefore,
in this circuit a low-voltage battery has been transformed into a high-voltage
battery which powers a high-voltage circuit, namely the transconductance
amplifier 33 which puts out a constant current independent of load impedance.
Because it has been shown that sensation is proportional to current and not to
power, this type of constant current output prevents any problems concerning
changing resistance of skin or electrode paste on neuron resting membrane
potential. Therefore, in this machine nothing inherently limits the bandwidth
within the circuit.
The 10 V supply 46 powers waveform generator 48. The
frequency is set by 3 band-switched capacitors 36' and the frequency control 34
potentiometer. Sine, sawtooth, and square wave outputs are provided by the
present invention uses the sine wave output. Due to the different levels and
output impedences of the outputs, compensating resistor networks 49 are
included. The .+-.50 V supply 47 supplies power to high compliance
transconductance amplifier 33. A .+-.15 V supply is provided by a zener
regulated supply for operation of input amplifier 32 which drives
transconductance output stage amplifier 33.
The load is driven in a
floating configuration with the current sensed across at 100 Ohm resistor 51
which provides a 10 mA/V transfer function.
Sense resistor 51 is used
since monitoring is done at the subject leads and not on the primary side of
variable loss transformer 45.
The setting for the frequency output on
each of bands A, B, and C for the knob settings on frequency control 34 is shown
on the graph of FIG. 7. The current output level for the knob settings on
current output control 35 is shown on the graph of FIG. 8. These figures give a
basis for frequency ranges and current levels used in the present invention.
An example of operation of apparatus of the present invention which
demonstrates the frequency coded properties of human subjective psychological
brain states as evoked by cutaneous electrical stimulation is as follows.
The subject should sit or lie down, relaxed, in a quiet room without any
loud auditory or visual distractions. Dime electrodes 18 are placed
approximately 1/4 inch anterior to each earlobe with electrode paste placed
between the skin and each electrode to serve as a conducting medium. The
electrodes 18 may be held in place by the use of a standard athletic headband as
shown. The current setting on the stimulator 12 is increased until a tingling
sensation is felt at the electrodes. The initial frequency of stimulation may be
randomly set.
Sufficient current must be emitted at the electrodes at
all times so that a subjective non-adversive sensation of which patients
characterize as a slight tingling be felt at the electrodes. Any changes in the
sensation at the electrodes may require adjustment of current intensity in order
to continue to evoke the slight tingling sensation. The subjective sensation of
cutaneous electrical stimulation is a function of the current, the frequency of
the stimulation, both adjusted by electrical stimulator 12 (or signal generator
11), and the state of relaxation of the subject S.
In obtaining a
profile of an individual subject adjustments of apparatus are made based on
verbal feedback from the subject. The frequency output is adjusted to maintain
the "slight tingling sensation" at electrodes 18. The subject reports any
unusual auditory, visual, sensual vibration, or other sensastion experienced.
The subject may control stimulator 12 himself to effect various frequency
sensitive subjective psychological states. Frequency outputs of stimulator 12
may also be adjusted without the subject's knowledge to collect further data.
Alternatively because of monitoring system 17 effects of the stimulation
are obtainable even if the subject is unconscious and electrical stimulation can
be applied without verbal feedback from the subject.
Within the range of
the equipment of the present invention several distinct frequency sensitive
subjective psychological states may be observed in the subject.
Between
the frequency range of 5 and 10 hertz subjects reported that their visual field
appeared to be pulsating or oscillating. This was not accompanied by any
apparent movement of the eyeballs.
At the next higher frequency of
stimulation, from 10 Hz to 70 Hz, subjects reported a flickering pale white
light, usually in the periphery of their visual fields which got faster with
increasing frequencies of stimulation and eventually disappeared at 70 Hz.
At the 70 Hz to 130 Hz frequencies, subjects reported the feeling of a
unique sensation of a relaxing hum, buzz, or vibration resonating from deep
within their heads. In most most cases this sensation peaks at 70 Hz.
When more than one frequency is applied such as when using triple output
signal generator 11 in the system, psychological states of the several
frequencies will be experienced.
The present invention is used to induce
different psychological states but due to the apparatus of this invention such
states can be reached more quickly and with less current, thus reducing the
danger from such currents to the subject.
The present invention has
numerous practical applications dependent on attainment of these psychological
states and controlled maintaining of such a state.
The subject first
performs an act or is subjected to evoked response system 15. Such evoked
response could include listening to certain sounds, seeing certain pictures,
stimulation of the skin, subjection to a particular environment, or taking of a
drug, such as by an addict. The monitoring system 17 receives
electro-physiological parameters monitored from the subject and feeds this
information to computer 13. Using this information, the electrical parameters of
stimulation by the signal generator electrical stimulator apparatus 10 to
electrically mimick the effects of the evoked response system in the subject can
be determined. Computer 13 can be connected to control stimulation apparatus 10
to vary in accordance with maintaining a particular state based on information
being received from monitoring system 17.
An important aspect of such a
system is that by cutaneous electrical stimulation to produce particular
psychological states, the need of the original evoked response system may be
then eliminated and the subject may then be subjected or brought to the desired
psychological state without repeating of the evoked response system which system
as originally applied to the subject, may have deleterious effects on the
subject. One such case may be in respect to additive drugs where their effect on
the body may be stimulated by cutaneous electrical stimulation at the point
where the electrodes 18 of the present invention are placed on the subject. Such
electrical stimulation being possible of close control may help in overcoming
withdrawal symptoms without the use of the deleterious drug. Concomitantly with
the cutaneous electrical stimulation for attenuation of withdrawal symptoms the
subject may self-admininster nitrous oxide gas (N.sub.2 O) (or a similar type
cognitive activator) at physiological concentrations of approximately 60%
N.sub.2 and 40% oxygen where conscious awareness is maintained. Such
self-administration of N.sub.2 is to facilitate the formation of neuronal
connections and the consolidation of the memory of the experience and should
lessen the time needed for withdrawal than use of cutaneous stimulation alone.
This process will serve to permit the former drug addicts to have conscious
awareness of their natural electro-cotical and electrochemical state which they
had been artifically inducing with the drugs. By sensitizing these natural
systems within the brain through the use of cutaneous electrical stimulation,
this process will induce an antibuse type of physiological state in the event of
further drug use. Since the effects of cutaneous electrical stimulation involve
primarily regions of the brain involved with non-verbal conscious states of
awareness, this therapy should include psychotherapy to bring to the subject's
conscious awareness, through verbal communication, the effects of the electrical
stimulation being administered. This may be done by electronically inducing a
hypnotic state of awareness in the subject at which time a trained
psychotherapist can explain to the subject that future self-administration of
the drug is not necessary. If the desire for the drug should occur this desire
can be relieved by the electrical stimulator which would reduce the
physiological creaving for the drug as well as evoking a psychoelectrical
stimulus which is associated with a psychological state in which the drug is
unnecessary.
Other uses may be made of the apparatus of the present
invention and the method of the present invention may be applied to obtain other
therapeutic results.
It will be ovbious to those skilled in the art that
various changes may be made without departing from the scope of the invention
and the invention is not to be considered limited to what is shown in the
drawings and described in the specification.
* * * * *