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Patent No. 6091994 Pulsative manipulation of nervous systems (Loos, Jul 18, 2000)
Abstract
Method and apparatus for manipulating the nervous system by imparting subliminal pulsative cooling to the subject's skin at a frequency that is suitable for the excitation of a sensory resonance. At present, two major sensory resonances are known, with frequencies near 1/2 Hz and 2.4 Hz. The 1/2 Hz sensory resonance causes relaxation, sleepiness, ptosis of the eyelids, a tonic smile, a "knot" in the stomach, or sexual excitement, depending on the precise frequency used. The 2.4 Hz resonance causes the slowing of certain cortical activities, and is characterized by a large increase of the time needed to silently count backward from 100 to 60, with the eyes closed. The invention can be used by the general public for inducing relaxation, sleep, or sexual excitement, and clinically for the control and perhaps a treatment of tremors, seizures, and autonomic system disorders such as panic attacks. Embodiments shown are a pulsed fan to impart subliminal cooling pulses to the subject's skin, and a silent device which induces periodically varying flow past the subject's skin, the flow being induced by pulsative rising warm air plumes that are caused by a thin resistive wire which is periodically heated by electric current pulses.
Notes:
BACKGROUND
OF THE INVENTION
The invention relates to influencing the nervous system of a subject by pulsative
stimulation of sensory receptors, relying on the mechanisms of sensory resonance
and frequency modulation of spontaneous spike patterns, as discussed in U.S.
Pat. No. 5,782,874. [1]. In that patent, the stimulation is provided by an external
electric field applied to the skin of the subject. The electric field appears
to cause a modulation of the spiking patterns of certain cutaneous receptors,
so that a pulsative field gives rise to a frequency modulation (fm) of the produced
spike trains. Afferent nerves carry the frequency modulated spike trains to
the brain, where in certain neural circuits the evoked fm signals cause excitation
of a resonance with observable physiological consequences. One such "sensory
resonance" that occurs near 1/2 Hz causes sleepiness, relaxation, a tonic smile,
ptosis of the eyelids, a tense feeling in the stomach, or sexual excitement,
depending on the precise pulse frequency used. The 1/2 Hz sensory resonance
can also be excited by magnetic fields, as discussed in U.S. Pat. No. 5,935,054
[2].
Another known sensory resonance occurs near 2.4 Hz and causes a slowing of certain
cortical activities.
SUMMARY
Experiments have shown that sensory resonances can be excited by imparting cooling
pulses to the skin, when the pulse frequency is set to the resonance frequency
of the sensory resonance, and the pulses have a proper subliminal amplitude.
The sensory resonance near 1/2 Hz causes autonomic responses characterized by
relaxation, sleepiness, ptosis of the eyelids, a tonic smile, a "knot" in the
stomach, or sexual excitement, depending on the precise frequency used. The
sensory resonance near 2.4 Hz causes slowing of certain cortical activities
and is indicated by a large increase in the time needed to count silently backward
from 100 to 60, with the eyes closed. The described effects occur only if the
amplitude of the cooling pulses falls in a certain range called the effective
intensity window.
The stimulation is thought to involve the following. The subliminal pulsative
cooling of the skin causes a slight frequency modulation (fm) of the spike trains
that are produced by cutaneous thermoreceptors. The spiking is transmitted to
the brain by afferent nerves that report skin temperature. The frequency modulation
of the spike train from a single thermoreceptor cannot be spotted by the brain,
because the fm variations in the spike train are swamped by the much larger
stochastic spiking variations. However, if afferents of a large number of affected
thermoreceptors synapse on a single summing neuron, then the fm variations add
coherently in the hillock potential, whereas the stochastic variations largely
even out. Consequently, the signal to noise ratio for the fm signal is increased,
and the more so the larger the skin area exposed to the cooling pulses. The
fm signal is demodulated by further neural circuitry and the resulting signal
can cause excitation of a resonance in certain subsequent processing circuits.
The upper bound of the effective intensity window is thought to arise from the
action of nuisance guarding neural circuits that block substantial repeditive
nuisance signals from higher processing. The lower boundary of the window is
simply due to a detection threshold.
Reliance on periodic frequency modulation of afferent spike trains, together
with exploitation of the resonance phenomenon, leads to a method and apparatus
for manipulation of nervous systems by imparting subliminal cooling pulses to
the subject's skin. The invention can be used by the general public to induce
relaxation, sleep, or sexual excitement, and clinically for control and perhaps
a treatment of tremors and seizures, as well as autonomic disorders, such as
panic attacks.
The cooling pulses may be imparted to the skin by convective or conductive means.
In the latter case heat is extracted from the skin in pulsative fashion by a
fast Peltier junction that is placed on the skin. In the convective method,
cooling is provided through convective and evaporative heat transfer by means
of a pulsed air jet aimed at the skin of the subject, or alternatively by a
device wherein a periodic air sink draws atmospheric air past the skin of a
nearby subject, the periodic air sink being induced by pulsative rising warm
air plumes produced by a thin resistive wire that is heated by current pulses
passed by a field effect transistor which is controlled by voltage pulses from
a generator.
Using the latter device, the 2.4 Hz sensory resonance has been explored, employing
the silent count from 100 to 60 as a resonance detector. The measured counting
times define an excitation footprint in the plane which has pulse power and
pulse frequency as coordinates.
A compact embodiment is shown in the form of a battery powered device, in which
the resistive wire and the voltage generator are contained in a single small
casing.
------------------------------------
It has been observed that lower temperature
pulse amplitudes suffice for the excitation of sensory resonances when the skin
area of pulse administration is increased. This "bulk" effect is important for
the proper use of the invention, and can be understood as follows. The skin
temperature oscillations cause a frequency modulation of the stochastic firing
of the cutaneous thermoreceptors. If the afferent fibers of these receptors
synapse, either directly or indirectly, upon a summing neuron, then the sequence
of current injection spikes into the dendrite of the neuron will be a slightly
modulated Poisson stream. For zero modulation a Poisson distribution is expected
on theoretical grounds if the number of synapsing afferents is large, since
the afferent spike trains add and interlace. This results in a high-frequency
sequence of charge injections, in which the features of the individual afferent
spike trains are substantially washed out, in much the same way as density nonuniformities
of a substance suspended in a fluid are removed by stirring. Whereas the stochastic
variations are diminished, the fm variations caused by the skin temperature
oscillation add coherently in the hillock potential. As a result, the signal
to noise ratio of the fm signal increases with the number of afferents affected
[1]. This explains the bulk effect and to some extent the observed sensitivity
to very small temperature pulse amplitudes.
The invention is not limited by the
embodiments shown in the drawings and described in the specification, which
are given by way of example and not of limitation, but only in accordance with
the scope of the appended claims.
REFERENCES
[1] H. G. Loos, "Method and Apparatus for Manipulating Nervous Systems", U.S.
Pat. No. 5,782,874, Jul. 21, 1998
[2] U.S. Pat. No. 5,935,054, Aug. 10, 1999
[3] E. R. Kandel, J. H. Schwartz, and T. M. Jessel, PRINCIPLES OF NEURAL SCIENCE,
3th Edition, Elsevier, N.Y., 1991
[4] H. Hensel, THERMAL SENSATIONS AND THERMORECEPTORS IN MAN, Charles C. Thomas,
Springfield, Ill., 1982
[5] A. Longtin and K. Hinzer, "Encoding with Bursting, Subthreshold Oscillations,
and Noise in Mammalian Cold Receptors", Neural Computation 8, 215, (1996)
[6] U.S. Pat. No. 6,017,302, Jan. 25, 2000
[7] Basic Stamp, PARALAX, INC. Rocklin, Calif. 95765
[8] H. G. Loos, "Thermal Excitation of Sensory Resonances", U.S. Pat. No. 5,800,481,
Sep. 1, 1998
[9] H. Schlichting, BOUNDARY-LAYER THEORY, McGraw-Hill, New York 1968