Method And Apparatus For Inducing Sleep By Applying Electrical Pulses To Plural Portions Of The Head

Abstract

A method and apparatus for inducing sleep, treating psychosomatic disorders, and aiding the induction of hypnosis in a patient is disclosed in which electric current pulses are passed through the brainstem via electrodes attached to the back of the head and forehead. The electric current pulses have a frequency of 8 to 10 cycles per second. A second stimulus of electric current pulses having a frequency of four times the first stimulus is passed through the optic nerve via electrodes attached to the temples and forehead. A third auditory stimulus produced by the first electrical stimulus is applied to the ears via sound attenuating chambers in order to acoustically isolate the patient from a noisy environment. The three stimuli are preferably synchronized with each other. A novel electrode is disclosed which is attached to the back of the head protuberance where the hair would normally electrically insulate the electrode from the scalp. Means for filling the hair between the scalp and the electrode with a viscous hygroscopic electrolyte is described.

Description

The present invention relates to a method for treating various psychosomatic ailments by electro-physiological stimulation -- to induce relaxation, a sleep-like state, or sleep -- and to aid the induction of hypnosis.

The novel method consists of the application of a plurality of synchronized energetic stimuli characterized by distinctive waveform, repetition rate, and the manner of applying the waves to a patient's head.

The invention provides apparatus for generating an electrical current consisting of symmetric square-wave pulses occurring at certain frequency rates which are applied to the head via electrodes in order to induce flicker images in the optic system. A second electrical current of symmetric pulses having a frequency rate the same as the alpha rhythm is applied via a different set of electrodes whereby the current will pass through the brainstem control center. Further, a means is provided for synchronizing the two currents entering the electrodes. A third stimulus consisting of pulses of groups of sound wave harmonics produced by a transducer connected to the above-mentioned alpha frequency generator is transmitted to chambers enclosing the ears for purposes to be explained later.

Further, the application of these stimuli to a patient will usually induce a paradoxical state which can lead to hypnosis when accompanied by the suggestive verbalization of an operator.

Electrosleep originated in 1902 when Leduc was able to produce sleep and general anesthesia in rabbits by applying transcerebrally an interrupted low intensity direct current. Contemporary prior art devices use high amplitude (up to 50 Volts) and short duration (10-20 percent of the period) pulses which are superimposed on a DC bias. The pulse frequencies are usually in the electrical flicker range. The current is applied to the head via eye-lid electrodes.

These devices which were developed without a knowledge of electrosleep modus operandi, have several disadvantages. Electrodes over the eyes produce patient apprehension, limit the area of the electrode and, therefore, the current intensity due to eye-lid sensitivity, and prevent the doctor from observing the rapid eye movements which signal the so called REM state required for electrosleep therapy; "REM" standing for "rapid eye movement". The flicker repetition frequencies of 30 to 40, which are most effective for habituating the visual cortex, are least effective for activating the brainstem sleep center where the natural frequencies are the alpha rhythm or lower. The narrow spike-like pulses used are known to be efficient in activating a peripheral nerve but the brainstem system with spontaneous waves which are nearly sinusoidal is most efficiently driven with symmetric square waves. The most important disadvantage of prior art devices is the basic limitation that a single current must provide, functions requiring different locale, current intensities, and waveforms. There are large differences in physiological characteristics between patients so that the settings vary from person to person, and are limited by the eyelid sensititivity. In some patients, the setting may be too low for brainstem activation. Finally, direct currents produce irreversible changes in brain tissue and, therefore, can be used only at a fraction of the intensity of alternating currents. If the devices are used in a noisy room, unconditioned sounds may cause frequent arousal.

The present invention provides an apparatus which obviates all of the foregoing disadvantages while providing the highest performance due to an integrated selection of the most appropriate stimulus and applicator for each necessary function, and at the same time minimizing patient apprehension and arousal where treatments are given in a noisy environment. The apparatus is portable, battery operated for maximum safety, and inexpensive to manufacture using a hybrid of standard integrated transistorized assemblies. All external equipment have pluggable connections to the cabinet panel. The electrodes are mounted on a single elastic band which encircles the head and provides electrode contact pressure. Electrical conductive paste placed between electrodes and forehead, temples, or scalp, as the case may be, provide a low resistance contact. A light-weight, washable, molded plastic headset using air for sound transmission, fits over the ears and delivers the monotone. The flicker currents flow in a local path in the forehead. The brainstem currents flow from the back of the head through the brainstem to the forehead.

In the method of practicing the invention, electrical and acoustical energy is applied to the patent as described. A first electrical energy source preferably consists of a balanced, symmetric square wave potential pulse train with a median repetition rate of 38 cycles/sec. with a median pulse width of approximately 13 milli/seconds. The second electrical energy source has a similar waveform but a frequency which is 9.5 cycles/sec. The 4:1 frequency ratio is preferable to other integral ratios. (Spontaneous alpha rhythms of approximately this frequency are know to contain the maximum power found in such waves.) Thus, a preferred flicker stimulus of 38 cycles/sec. is synchronized with a 9.5 cycles/sec. alpha frequency stimulus which also produces an acoustic monotone of 9.5 clicks/sec. The currents are adjusted until a tingling sensation is felt at the electrodes which is slightly uncomfortable. The sensation is evanescent by adaptation if without pain. The acoustic monotone is adjusted to a comfortable level.

During treatment the patient becomes relaxed, enters a sleep-like state or sleep and finally artificially induced REM state wherein normal sleep patterns are reinstated, tensioned-provoking stresses are relieved, and emotional and psychosomatic disorders are cured.

Further objectives and advantages of the invention will be apparent to those skilled in the art from a reading of the following detailed description thereof, when viewed in the light of the accompanying drawings.

FIG. 1 is illustrated an overall view of the system used for electrosleep and electrohypnosis in accordance with the preferred practice of the invention. For electrosleep, the microphone and the voice control knob on the panel would not appear in this view;

FIG. 2 illustrates an electrode supporting band for attachment to the head of a patient;

FIGS. 3 and 4 illustrate, respectively, views taken from planes 3--3 and 4--4 of FIG. 2;

FIG. 5 illustrates a perspective view of a head-phone used in the system shown in FIG. 1;

FIG. 6 illustrates a block diagram of the circuit used in the electrosleep apparatus;

FIG. 7 illustrates the electrical waveforms generated by the apparatus; and

FIG. 8 illustrates a block diagram of the circuit used in the electrohypnosis apparatus.

Proceeding now to a detailed description of the drawings in FIG. 1, there is illustrated a bed as couch B on which rests the patient P for electrosleep treatment or hypnosis. The principal components of the system providing the electrical and auditory stimuli are contained in cabinet C. The doctor D does not speak to the patient P during electrosleep therapy. For electrohypnosis, however, the doctor D speaks directly into microphone M providing suggestive verbalization concurrently with the stimuli to patient P via headphone 30.

A headband 10 is placed on the head of the patient P as illustrated in FIG. I, and carries either three or four electrodes and insulates them from each other. The headband is made of a suitable insulating material which is preferably elastic. FIG. 1 shows the three electrode arrangement wherein electrodes 11 and 12 placed on the forehead over the eyes or electrode 11 can be placed on the forehead over one eye with electrode 12 placed on the temple adjacent the other eye. The position of the ground or indifferent electrode is such that the mainstem intersects a straight line between electrodes 11 and 13. FIG. 2 exhibits the four electrode arrangement which is preferred. The electrodes 12 and 12a are placed on the temples with the ground or indifferent electrode centered on the forehead. The fourth electrode 13 is centered on the protuberance at the back of the head adjacent to the base of the occipital lobe. Electrically conductive paste is forced from the snout 16 of a squeeze bottle which is inserted into an aperture 14 in electrode 13. The paste aided by groove 15 in face of electrode 13 fills the space between electrode 13 and the scalp and provides a low resistance path for the electrical current.

Each of these electrodes 11, 12, 12a, and 13 connects individually to an insulated wire, respectively denoted 21, 11 and 23 and joined in a cable 20 for insertion in a suitable jack in cabinet C. The electrical potentials applied to wires 21, 22 and 23 are developed by the electrical components contained in cabinet C; the circuit diagrams FIGS. 6 and 8 illustrate the circuits which develop the stimuli potentials.

A second type of connection between the components in cabinet C and the patient P is established by an audio channel which includes a hollow tube 33 and a headset element 30 for defining two ear cavities. Soft rubber pieces, such as 31 form ear cavities proper to fit snugly against the skin around the ears.

An acoustic stimulus is developed inside cabinet C and transmitted through tube 33 into the hollow headset 30. Apertures 32 acoustically connect the air passages with the cavities defined by caps 31 which enclose the ears. The element 30 is made of a light plastic and is washable.

The panel of cabinet C is provided with a plurality of control knobs for adjusting the intensities of the various stimuli. The cabinet C panel also includes two milliammeters for measuring the electrical currents passing through the patient's head in addition to the usual switch, indicator light and jacks.

Turning to a detailed description of FIG. 6 which is a block diagram of a typical circuit for the electrosleep apparatus in accordance with the invention:

The astable multivibrator 40 is a relaxation oscillator in which two capacitors are alternately charged and discharged through respective resistors. The applied potential and the sum of the two time constants determine the frequency of oscillation, and a specific ratio of these time constants determines the duration-period ratio. If the time constants are unequal, the multivibrator is asymmetric, and if no coupling capacitors are employed, the output current will have a DC component. The prior art multivibrators are of this latter type. However, if this multivibrator is AC coupled by connecting a capacitor in series with the load, the current becomes balanced in that at the end of each cycle there will be not net charge displacement but the waveform will remain unsymmetrical.

The subject invention preferably employs a nearly symmetric multivibrator with AC coupling in order to obtain maximum tissue tolerance and the most effective waveform for brainstem stimulation.

Brain tissue is capable of tolerating some types of stimulation over long periods of time. Tissue damage can occur two ways, viz., electrolytically and thermally. Electrolytic damage occurs with any direct current stimulus at any current density, resulting in decomposition of electrolytes and diffusion of metal into tissues. Thermal damage occurs if current density is too high. Tissue tolerance studies have determined that balanced currents can pass through tissue for an indefinite period of time, such as would be required of a permanent implant providing that the amount of electrical charge in each pulse did not exceed 200 micro coulombs. Obviously, much larger charges could be used for infrequent stimulation. Electrosleep devices which use a DC bias can cause electrolytic dissociation and deposition of metallic ions in brain tissue.

Extensive clinical studies with variable duty ratios established that the performance was far superior when the pulse duration was .4 to .6 of the period. This unexpected result was consistent with the fact that spontaneous waves in the brainstem during the sleep cycle more nearly resembled the sinusoidal form than the spike-like pulses of short duration used by prior art stimulators.

At the core of the present invention is the fact that during the sleep cycle the internal impedance of a brainstem oscillator coupled to its load impedance defines oscillation frequencies of the order of the alpha rhythm or lower, and therefore such a frequency should be optimum for the alpha drives.

Referring again to FIG. 6, the output of astable multivibrator 40 with preferred flicker frequencies of 32 to 40 cycles/sec., is connected to amplifier 45 which is connected to the temple electrodes 12 and 12a. Likewise, multivibrator 40 is coupled to astable multivibrator 41 which is set at a frequency slightly lower than multivibrator 40 so that it can pull multivibrator 41 into synchronism. Multivibrator 41 is connected to amplifier 55 which supplies current to protuberance electrode 13. The forehead indifferent electrode 11 is at amplifier ground potential.

Transducer 60 converts the audio electrical currents into sound waves which are then transmitted through air passages 30 and 33 to ear chambers 31.

The application of sound energy to the ears via ear chambers introduces the consideration of ear tolerance to sounds of various intensities. Long continued sound of any frequency is known to cause hair-cell deafness, which is often called nerve deafness. In hair-cell deafness, the major loss of hearing is found to be in the frequencies above 2000-3000 cps. White noise in particular is much more dangerous since the sound energy is distributed uniformly over the entire audible range and therefore stimulates all areas of the basilar membrane of the ear. For these reasons, a low cut-off frequency of 4 to 5 kilocycles is preferred. In the case of ordinary sound, it has been found that continued stimulation of the ear with a sound intensity of 100 db or higher will cause ear damage in many people. The maximum monotone intensity should be substantially less than 100 db's. Thus, the monotone consists of a series of clicks with the alpha drive repetition rate wherein each click consists of the harmonics of the square-wave up to the cut-off frequency of the transducer.

A feature of the present invention is to use the monotone as a means for isolating the patient P from the auditory environment. It is well known that an ambient noise field provides a threshold of audibility which completely masks sounds of lower intensity and that it is difficult to attenuate sound solely by sound absorption materials. The monotone establishes a threshold in the ear cavity which can easily exceed the attenuated sounds filtering into the cavity through a relatively small amount of absorption material. Thus, the dual purpose monotone provides a simple inexpensive means for isolating the patient P in a noisy hospital ward during treatment as well as inducing habituation in the auditory system.

FIG. 7 displays graphically the synchronized waveforms of the currents which pass through the patient's head. The flicker current I.sub.f has a freqyency which is four times the alpha drive current I.sub.a. The square waves are symmetric but the amplitudes are individually adjusted to patient tolerance. The horizontal time axis shows the pulse duration .DELTA. t.sub.f and .DELTA. t.sub.a and the dotted axes O.sub.f and O.sub.a result from capacitor coupling and display graphically the fact that the currents alternate in direction.

FIG. 8 is a block diagram of a typical circuit for electrohypnosis apparatus in accordance with the invention, which also discloses an alternate method for generating the synchronized electrical stimuli.

There is illustrated an astable multivibrator 40 preferably generating a nearly symmetric square-wave voltage train with means for varying the frequency.

Two bistable multivibrators 50 and 51 are connected in frequency divider configuration to multivibrator 40 whereby multivibrator 50 provides a 2:1 reduction of the output frequency of multivibrator 40, and multivibrator 51 provides a 2:1 reduction of the output frequency of multivibrator 50.

Amplifiers 45 and 55 which are preferably of the constant potential type, are connected to the outputs of multivibrators 40 and 51 respectively. The currents delivered to electrodes 12 and 13 from amplifiers 45 and 55 are adjustable. Indifferent electrode 11 is at amplifier ground potential.

Operational amplifier 61 receives voice currents from microphone M and alpha frequency currents from multivibrator 51 concurrently. The intensities of the amplified outputs of these two audio frequency currents are independently adjustable. This is accomplished by a constant potential junction which prevents inter-action between the voice and monotone currents.

Prior art electrosleep devices employ a combination of DC and AC currents. A nerve will be activated by an AC current and will habituate after sufficient stimulation. However, a nerve will be fatigued without activation by DC currents. The previously mentioned disadvantages of using a DC component are obviated in the present invention. FIG. 9 illustrates a diagram of the circuit for electrosleep after providing for a DC component in the alpha drive current. The adjustable DC potential is obtained from the combination of battery 80 and potentiometer 81. The DC current has a maximum value which is determined by resistor 82 and is added to the square-wave current appearing at junction with coupling capacitor 83. This coupling capacitor is included in amplifier 55 in FIGS. 6 and 7 but is not included in amplifier 55a. If the capacitor is electrolytic, it is necessary to use diode 84 to prevent reverse flow in the event that the AC potential is less than the DC potential. FIG. 10 displays graphically the DC component i.sub.d of the alpha drive current i.alpha..

Electrosleep therapy has become a subject of considerable interest to American scientists because of the large amount of American research on sleep since about 1955. This interest stemmed from the discovery of a new kind of sleep and from a number of investigations of the effects of sleep deprivation. This new kind of sleep is most commonly called REM, dream, or deep sleep because its most salient features are rapid eye movements, dreaming, and extreme muscle relaxation. Quiet, or slow-wave, sleep is so named because of the absence of the occasional body movements of REM sleep and the fact that the brain waves have much lower frequencies.

The state of wakefulness is maintained by two entirely different types of activatory processes which are called sensory stimulation and tonic facilitation. In sensory stimulation, there is a flow of information from the sense organs which are located both peripherally and internally through the thalamic nucleus in the brainstem to various regions in the brain which are specific to each type of information. The flow is controlled or modulated by the sensory receptors, various synapses, and by the brainstem control center. These stimuli under certain conditions also may induce a reverse flow from the cerebral cortex to the brainstem causing further arousal activation. The onset of sleep mechanism starts with inhibition in this system. Visual and auditory stimuli, muscle tension, and motor activity all have strong arousal action which are normally inhibited when we lie down and relax in a quiet, dark room. Artificial inhibition of auditory and visual stimulation is most effectively accomplished by habituation of specific monotonous auditory stimuli after some minimum number of clicks are heard, or by a flashing light repeated for a period of 200 to 300 seconds. A far superior visual stimulus, however, is the induction of visual images by electrical stimulation of the optic system, since the frequency of the flicker can be increased by a factor of about three before the flicker disappears by fusion. A by-product of the habituation of the auditory and visual systems is the deactivation of muscle tension inducing a general relaxation. This result is confirmed not only by the observed muscle flaccidity but by the brain-wave pattern as portrayed by the encephalograph which shows a change from the activatory pattern of wakefulness to the alpha form of the relaxed state. The sensory system is inactive during sleep and if no stimulation is present, sleep will follow. This phenomenon is exemplified by the case of a subject who, through injury, lost the sight in one eye and the hearing in one ear, who would fall asleep eventually whenever the good eye and ear were covered and plugged respectively.

In order to prevent unwanted sleep the brain is provided with a continuous stimulation which originates in the mesencephalic hemisphere of the brainstem. This tonic facilitation which keeps the brain awake has a maximum intensity after awakening and it is continuously suppressed during the day with a minimum magnitude at bed-time. The origin of this suppression of tonic facilitation is related to the need for recovery which progresses during the day and terminates in sleep. The time for recovery ranges from magnitudes measured in milliseconds, such as the nerves, to hours in the case of the highest level of cerebral activity. This highest level is found to occur in learning and conditioning which is the reason for the large amount of time spent by a baby in sleep. This activity is believed to produce changes in the large glial cells and synapses in this level, and these changes are considered to progressively suppress the tonic facilitation of the mesencephalon during the day, so that when the sensory stimuli are cut off, sleep will follow.

When the mesencephalon is removed in animals, a sleep-like state characterized by eye closure, muscle relaxation, lowered pulse and respiration rates, and insensibility to tactile pressure has been produced. The same sleep-like state has been induced by inserting micro electrodes and passing a low frequency current through the mesencephalon.

In review, it has been established that three stimuli can provide the conditions for the onset of sleep, namely, an auditory monotone for habituating the auditory cortex, an electrical flicker for habituating the visual cortex -- either one of which will induce a relaxed musculature -- and a low frequency electrical current which must pass through the brainstem in order to deactivate the mesencephalon. If the frequency of the brainstem current is chosen to be the same as the alpha rhythms, and if this current is synchronized with the current inducing the electrical flicker, the intensity of the visual images is about twice as bright when the flicker frequency is four times the alpha frequency. The results were optimum when the auditory monotone was also synchronized with the two electrical stimuli. This synergistic phenomenon provides a method of integrating two electrical stimuli without interference. The three synchronized stimuli -- auditory monotone, alpha drive, and electrical flicker -- induce a state of relaxation, a sleep-like state, or sleep.

Concern over loss of sleep by the Armed Forces during war resulted in numerous studies on the effects of sleep deprivation since it had been known for a long time that sleep deprivation leads to malfunction, permanent damage, and finally death; and also, that temporary sleep loss is made up by increased sleeping time during the recovery period. The mental symptoms of sleep loss follow a slow and predictable pattern, and the changes accelerate as time passes. Some of the changes following sleep deprivation are: inattention, weariness, lack of concentration, loss of memory, slurred and faulty speech, listless behavior, reduced muscular exertion, anxiety, skin sensations, withdrawal from reality, time disorientation, visual distortions, illusions, hallucinations, severe personality changes, and finally a psychotic state. The EEG's of the brain waves showed an alternation between the alpha form and the slow sleep-like waves and these alternations are called "microsleeps."

Sleep is preceded by a decline in activities or performance and by subjective feelings of tiredness, which have been considered to be due to an accumulation during wakefulness of waste products which are disposed of during sleep, or of a depletion during wakefulness of vital chemicals which are replenished during sleep. When cerebrospinal fluid from fatigued dogs is injected into non-fatigued dogs, the latter showed signs of drowsiness and sleep, thus indicating that a hypnogenic substance accumulated during wakefulness. Serotonin, which is a hormone-like substance exhibiting a wide range of powerful effects on the brain and other organs of the body, is found in cerebrospinal fluid. Similar experiments with water-soluble extracts from the brains of sleeping animals produced sleep in the recipient animals. The medulla at the base of the brainstem contains the raphe nuclei which are noted for their production of serotonin. When 80 percent of the cells of these nuclei are destroyed, the experimental animals slept less than 10 percent of their normal period. Similarly, there is a locus coeruleus nucleus just below the raphe nuclei which contains the system for producing REM sleep, and this nucleus uses noradrenalin for its activating agent.

Several studies on REM sleep deprivation were made after overcoming the difficulties of determining the exact time that REM dreaming started and ended. When an individual goes to sleep, his initial quiet slow-wave sleep lasts for a period of 60 to 90 minutes after which he starts dreaming. There are normally four or five of these REM periods, in which the first one is the shortest and the last one is the longest, and only the dreams of the last one are remembered. The total REM sleeping time is, on the average, 20 percent of the total period. These studies disclosed the amazing fact that the loss of REM sleep produced essentially the same malfunctioning that occurred with total sleep deprivation. The subjects actually slept much longer than usual in the quiet slow-wave phases and they were extremely difficult to awaken. The discovery of this basic phenomenon provides the scientist with a new tool for attacking sleep disorders and their derivative ailments. This third state of consciousness can be identified by its salient characteristics such as an EEG pattern resembling that of wakefulness, rapid eye movements, often jerking of the limbs, marked flaccidity of neck muscles, and almost always a report of dreaming when awakened. Another important facet of total sleep deprivation is that there is a change in quality of sleep, and this change is for the worst since there is a larger percentage loss of the REM state.

When REM sleep deprivation is terminated there is a rebound in the recovery period in which the subject sleeps from 11 to 14 hours after several nights of sleep loss with a much higher than normal proportion of REM sleep. With longer periods of deprivation the proportion of REM increased. Animal studies determined that after REM sleep deprivation they seemed to recover about 60 percent of their lost dream periods. Further studies were made on the recovery period phenomenon using two groups of rats deprived of sleep for four or five days where one group was given a slight electric shock by touching the electrode to the ear. The unshocked control group showed the usual incremental compensatory period of REM sleep but the shocked group spent a much smaller period in REM sleep. This key experiment provides a new method of quickly removing REM sleep deprivation effects in the rat which was subsequently verified in the cat -- namely, by passing an electrical current through the heads of these animals. This experiment suggests that the electric current causes the release of a compound that could block the flow of the activating agent for REM sleep, which has been identified as noradrenalin. It has been known for some time that the pontine reticular formation contains a timing device which produces REM sleep at regular intervals but which is interrupted during wakefulness. It has been determined experimentally that a specific dose of resperine in cats leads to a complete elimination of REM sleep for as long as four days. A possible hypothesis is, therefore, that the electric current counteracted the blocking effect of a resperine-like substance of either the timing device or of the excretion of noradrenalin from the locus coeruleus region. If the caudal pontine reticular formation is cut or removed, REM sleep is completely eliminated, but if this region is stimulated electrically while man is in a slow sleep-like state, REM sleep will follow.

Thus, we find that electrical stimulation of the brainstem after sensory habituation leads to a quiet sleep-state followed by the REM state in which symptoms of REM sleep deprivation are reversed. These changes are dramatic in a large number of cases for in many instances a single one-hour stimulation completely reverses the symptology of depression and other similar mental disorders inducing a state of calmness and well-being.

Volumes have been written on the powers of suggestion, but unfortunately, only a select group of people are able to use this powerful phenomenon for their own benefit. The great value of hypnosis lies in the fact that it can transform the potentiality of suggestion into reality. The mechanism is extremely simple. In a state of deep hypnosis, it is only necessary to make a suggestion and post-hypnotically there will be a tremendous compulsion to carry out the suggestion. Deep-seated habits which are difficult to change with ordinary suggestion are easily erased by the force of hypnotic suggestions, e.g., smoking, obesity, phobias of various kinds, and many others. Hypnotic suggestion has a much wider application, however, in its ability to inhibit the sensations of pain. For example, prior to a tooth extraction or childbirth fear, apprehension and pain will be inhibited post-hypnotically. If post-hypnotic suggestion is so effective, why hasn't it been in regular use? The answer is that past methods of inducing hypnosis have failed in two ways. In the first instance, only a small portion of the population can be hypnotized in a practical length of time. Also, only a minor percentage of this group will reach the depth of hypnosis required for analgesia.

The primary goal of hypnosis is to induce a state in which the mind will accept the suggestions of an operator without question, analysis or qualifications of any kind. In the normal state, the mind is receiving a stream of bits of information from the sense organs which are integrated in the mind to produce thoughts. These thoughts will bring into consciousness by association related information or memories of past experiences which are stored in the brain. This combination of transient and associated stored information generates a host of thoughts which will compete with the suggestion of an operator for the attention of the mind. The mechanism of the induction of hypnosis involves a substantial reduction or elimination of these competing thoughts. The hypnoidal state which might be called conscious sleep is preceded by a transitory "paradoxical" state in which the goal is the exclusion of the unwanted thoughts which are competing with the suggestions of the operator. This exclusion process requires a maximal inhibition or shut-off or sensory stimuli and particularly those arising from sound, motion, tension, and light. The "paradoxical" state is thus seen to be similar to the "sleep syndrome" with the exception that the degree of extinction or attenuation of auditory stimuli must not reach a level which would prevent communication with the subject.

Suggestive verbalization is the fundamental catalytic ingredient which can transform the paradoxical state into hypnosis. However, the early attempts to give a subject suggestions after inducing the paradoxical state were unsuccessful for the following reasons. The habituated monotone and other familiar sounds have a mean amplitude during REM sleep of about 15 percent of that of wakefulness, i.e., a very low sound level. In sharp contrast, is the fact that when a subject is in REM sleep, any new sound (unhabituated) will evoke a much larger response in REM sleep than in any other state, resulting in a maximum startle reaction. Consequently, when the operator speaks to a subject in the paradoxical state, the EEG instantly changes to the activatory form, arousal ensues and the state disappears. If instead, the operator gives the suggestive verbalization concurrent with the other stimuli, the induction process is under his complete control and the subject will neither be aroused nor inattentive. An alternative method of induction is for the operator to give suggestions to the effect that when he speaks to the subject later, he will hear the operator's voice, even though asleep, and will not be startled thereby. This method is effective if the suggestions are strong enough to survive the elapsed time interval.

Thus, it has been developed that electrosleep therapy and electrohypnosis have a modus operandi evolved from a varied phenomenology which is briefly summarized herewith.

Relaxation is established in the absence of motor activity by artificial monotonous stimulation of the visual system by an electrical flicker stimulus as evidenced by the EEG wave pattern of the alpha rhythm. This result has also been obtained by stimulating the auditory system with a monotone. The combination of these two sensory stimuli has been most effective due in large part to the masking of external sounds by the monotone when introduced within sound attenuating chambers placed around the ears.

The application of these sensory stimuli to the head of a patient will induce a sleep-like state or sleep but the best results were obtained when the patient was mentally tired. (Tiredness is known to suppress mesencephalic activation which induces wakefulness.) Thus, a first purpose of the concurrent alpha drive stimulus is the deactivation of the mesencephalon, providing a performance which is independent of previous cerebration activity.

Hypnosis can be induced any time after a state of relaxation is obtained by suggestive verbalization if concurrent with the stimuli from the start.

The sleep-like state is defined by many physical changes from the normal state which include: reduced blood pressure, lower pulse rate, flaccid muscles, EEG patterns, etc., and these changes are a maximum when normal sleep is attained.

The genesis of REM sleep is controlled by a clock in the pontine reticular formation but its cyclic activity must be preceded by the slow sleep-like state which is a prerequisite for its activation. REM sleep normally follows slow sleep provided that the excretion of noradrenalin from the locus coeruleus region is not blocked by hypnotoxins derived from REM deprivation process. In any case, the alpha drive stimulus will activate the caudal pontine reticular formation thereby inducing the REM state and hypothetically dissipating the hypnotoxins subsequently.

Men of medicine know that the majority of illnesses, whether they be physical or emotional, have their dominant anxiety components. Tensions and anxieties are normally relieved in the one-fifth of total sleep which constitutes the REM state but the sleep patterns of the emotionally ill are significantly affected with the result that a considerable portion of the anxiety relieving states are excluded. By artificially inducing the REM state and by reinstating normal sleep patterns and relieving tension provoking stress, a cure of emotional and psychosomatic disorders are effected.

This invention provides the most effective method and apparatus for inducing the REM state by finding experimentally a unique set of stimuli in combination whose characteristics individually give optimum performance of the functions of each facet involved in the activation of sleep and the REM state.

The invention is not limited to the embodiments described above but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are inteded to be included.

Claims

We claim:

1. A method of inducing sleep in a patient comprising the steps of:

developing a first train of rhythmical fluctuating electrical currents with a particular fluctuation rate above the alpha rhythm frequency;

applying the fluctuations to the head for stimulating the optic nerve via electrodes to be attached to the head near the ocular region;

developing a second train of rhythmical fluctuating electrical currents with a particular fluctuation rate approximately similar to or lower than the alpha rhythm frequency whereby the duration of each fluctuation is about 40 to 60 percent of the period of the rhythmic fluctuations of the second train; and

applying the second train to the back of the head for stimulating the brainstem region via electrodes attached to the back of the head.

2. The method as set forth in claim 1, placing the electrodes at diametrically opposed locations of the patients head so that the brainstem current flows through the brainstem region along a diametric path between the electrodes.

3. The method as set forth in claim 1, synchronizing the first and second trains so that the optic nerve current is synchronized with the brainstem current.

4. The method as set forth in claim 3, the fluctuation rate of the optic nerve current is four times the fluctuation rate of the brainstem current.

5. The method as set forth in claim 1, including the steps of:

attaching a pair of sound attenuating chambers to the head over the ears of a patient in a noisy environment;

developing a monotone stimulus of variable intensity;

introducing the monotone stimulus into the ear chamber whereby the intensity of the monotone is higher than the attenuated noise intensity after transmission through the ear chamber walls thereby isolating the patient from the noisy environment.

6. The method as set forth in claim 5, the monotone stimulus having a pulse repetition rate approximately similar to the alpha rhythm frequency.

7. The method as set forth in claim 6, synchronizing the first and second train with each other and synchronizing the monotone stimulus with said trains so that the optic nerve current, the brainstem current and the monotone stimulus are synchronized with each other.

8. The method as set forth in claim 1, including the step of:

providing a viscous, hygroscopic solution and filling rhe interstices of the hair between the scalp at the back of the head of a patient and the electrode placed in the back of the head whereby the electrical conductivity of the path from electrode to scalp does not change appreciably during treatment due to viscous flow or evaporation of the solution.

9. Method as set forth in claim 1, including the step of providing electrically conductive path from back of head electrode to scalp comprising:

providing a plate with aperture, and

forcing a viscous electrolyte through plate aperture into hair between plate and scalp of patient.

10. Method as set forth in claim 9, including:

using a plate having a concave surface as inner face, and

using an electrolyte which is hygroscopic.

11. Apparatus for inducing sleep in a patient comprising:

first means providing a first train of rhythmical fluctuating electrical currents with a particular fluctuation rate above the alpha rhythm frequency; electrode means for attachment to the head of the patient near the ocular region, and connected to the first means for receiving the currents and applying the currents to the head for stimulating the optic nerve;

second means providing a second train of rhythmical fluctuating electrical currents with a particular fluctuation rate approximately similar to or lower than the alpha rhythm; and

frequency electrode means to be attached to the head and connected to receive the currents of the second train for applying the currents to the head for stimulating the brainstem region.

12. Apparatus for treating psychosomatic disorders of a patient comprising:

first generator means for producing a train of rhythmical fluctuating electrical potentials with a particular fluctuation rate above 25 per second,

electrode means to be attached to temples or forehead and connected to first generator means for forcing a flow of current trhough the ocular region;

second generator means for producing a train of rhythmical fluctuating electrical potentials with a fluctuation rate below 20 per second;

electrode means to be attached to back of head or nape of neck with indifferent electrode attached to forehead or temple and connected to second generator means for forcing a flow of pulsating current through the brainstem region, whereby the duration of each pulse is about 40 to 60 percent of the duration of a current pulse and the pause following the pulse.

13. Apparatus as set forth in claim 12, the ocular region electrode means comprising two temple electrodes and an indifferent electrode for placement at center of the forehead.

14. Apparatus as set forth in claim 12, the fluctuation rate of first generator means is four times the fluctuation rate of second generator means.

15. Apparatus as set forth in claim 14, transducer means is connected to second generator means for producing a monotone stimulus consisting of a train of sound quanta.

16. Apparatus as set forth in claim 15, the first generator means being connected to the second generator means for being synchronized with second generator means.

17. Apparatus as set forth in claim 15, including:

conduit means connected to transducer means for air transmission of sound;

ear chamber means with sound attenuating walls connected to conduit means for attaching to head of patient in noisy environment;

and means for adjusting the intensity of the monotone transmitted from transducer means through conduit means into ear chamber means to a value greater than environmental noise after transmission through sound attenuating ear chamber walls thereby isolating the patient from the noisy environment.

18. Apparatus as set forth in claim 12, including:

the fluctuation rate of the second generator means being adjusted to be 8 to 10 pulses per second;

the fluctuation rate of the first generator means adjusted to be four times the fluctuation rate of second generator means;

the second generator means connected to run in synchronism with first generator means.