Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
  • A61N1/36014—External stimulators, e.g. with patch electrodes
  • A61N1/36021—External stimulators, e.g. with patch electrodes for treatment of pain
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/02—Details
  • A61N1/04—Electrodes
  • A61N1/06—Electrodes for high-frequency therapy

Definitions

• the present invention relates to an electrostimulation device, by high frequency currents modulated by low frequency currents.
• This device is particularly intended for the withdrawal and detoxification of drug addicts, the regulation of biorhythms, electro-analgesia for chronic and post-operative pain, stress suppression, and electro-drug anesthesia for major operations.
• the regimes of the currents used are varied continuously, in the hope of thus achieving regimes useful for stimulation, without however these having been identified.
• the present invention aims to improve the efficiency of such an alternating emission of different current regimes by defining the most appropriate regime changes to avoid habituation of the patient.
• the object of the present invention is a device for electrostimulation by high frequency currents, comprising electrodes intended to be applied to the skull of a patient, characterized in that it comprises means for modulating in all or nothing these high frequency signals by different regimes of low frequency signals which sporadically take their values among a set of low frequency regimes whose emission periods are between, approximately 10 and 15 ms and whose duty cycle, that is to say -to say the ratio of the duration of transmission of the signal to its period, is between approximately 0.19 and 0.41.
• the signals transmitted by the device of the invention satisfy the condition, corollary of the preceding ones, according to which the duration of transmission of the signals is between approximately 2.9 and 4.1 milliseconds.
• one of the regimes of the set of low frequency regimes is chosen as a pilot regime, that is to say as the main signal for modulating the high frequency signal, while the other low frequency regimes intersect successively, the pilot regime being systematically restored between two of these regimes.
• the pilot scheme is the low frequency regime systematically chosen to succeed any other low frequency regime.
• the pilot regime is chosen which has the highest duty cycle.
• the pilot regime begins the modulation, then it is followed by the regime with the lowest duty cycle. Then the pilot speed is restored and again replaced by the speed with the highest duty cycle, that is to say immediately lower than that of the pilot speed.
• the set of low frequency regimes is constituted by a first regime of period close to 12 ms and duty cycle of about 0.33; by a second regime whose period is around 13 ms and whose duty cycle is close to 0.23; and by a third regime of approximately 10 ms of period and a duty cycle close to 0.30.
• the succession of the plans obeys the following succession rules:
• the speed with the highest duty cycle (ie the first speed or pilot speed) is used to transmit the low frequency signals for a few hours, preferably two hours.
• the regime with the lowest duty cycle (ie the second regime) replaces the pilot regime.
• the pilot scheme is again emitted for a period of between half an hour and two hours - preferably one hour.
• the low frequency regimes succeed each other with an alternation of pilot regimes and non-pilot regimes following a repetitive cycle which comprises at least four phases, the first phase corresponding to the emission of the pilot regime for a period of between one hour and three hours, and preferably for two hours, the second phase corresponding to the emission of a regime different from the pilot regime and whose duty cycle is lower for a period of between ten and thirty minutes, and preferably for twenty minutes, the third phase corresponding to the emission of the pilot regime for a period of between half an hour and two hours, preferably for one hour, and the fourth phase corresponding to the emission of a regime different from the regime pilot and whose duty cycle is higher than that of the second phase regime for a period of between fifteen and thirty minutes your, preferably twenty minutes.
• the high frequency signal, modulated by the various low frequency signal regimes, is advantageously two-phase. - h -
• the high frequency voltage is positive while it is negative during the rest of the period of emission of the high frequency signal.
• the values of the period and duration of transmission of the high frequency signal are chosen such that the variation curve of the voltage of the high frequency signal delimits, on either side of the zero voltage axis, two algebraic surfaces whose sum is zero.
• the average intensity delivered by this high frequency current is zero, which allows the patient to tolerate a voltage of several tens of volts while the energy transmitted to his brain has a fairly low value. but not null, which results from the modification of the electrical characteristics of the signal after crossing of the particular dielectric which constitutes the skull of the patient.
• the duration of positive transmission of the high frequency signal is between 0.9 and 3.75 ⁇ s and its period is between 4 and 10 ⁇ s.
• the ratio of these two times namely the duty cycle, must be between 0.20 and 0.40.
• the device of the present invention comprises, for carrying out transcutaneous brain stimulation, an ophryaque electrode and a pair of retro-mastoid electrodes, the latter two being electrically connected.
• the signals are also applied between the ophryaque electrode and a low occipital electrode.
• the ophryaque electrode then operates alternately with the pair of retro-mastoid electrodes and with the low occipital electrode, the signals of this application being out of phase with those applied between the ophryaque electrode and the retro-mastoid electrodes.
• the device according to the invention comprises means making it possible to send alternately to the retro-mastoid electrodes and to the low occipital electrode and with a determined phase shift the high frequency signals modulated at low frequency.
• the signals are also applied between a second ophryaque electrode and a low occipital electrode, which makes it possible to make the two sets of electrodes thus formed completely independent. It is in fact understood that, in this way, each set of electrodes has its own ophryaque electrode.
• the two ophryaque electrodes are electrically distinct but physically merge, so as to apply their signals to the same place.
• two electric fields appear which are strictly electrically distinct.
• a phase shift can be determined so as to imply a partial overlap of the two electric fields during a common interval of emission of the signals.
• the common action of two alternating or partially alternating electric fields in these regions of the skull has the advantage of stimulating the peri-aqueductal region, the analgesic role of which is known, without however creating local current density thanks to the phase shift between the signals.
• FIG. 2 represents a modulation by a low frequency signal of the high frequency current of FIG. 1, in accordance with the invention
• FIG. 3 represents, according to one embodiment of the invention, electrodes placed on the head of a patient
• FIG. 4 represents two high frequency currents modulated in low frequency phase shifted, emitted according to the embodiment of FIG. 3
• FIG. 5 represents two high frequency currents modules in low frequency phase shifted emitted according to an embodiment similar to that of FIG. 3.
• the high frequency signal has a period equal to 6 ⁇ s and a transmission time t ′ equal to 1.2 ⁇ s.
• This high frequency voltage goes from a negative value to a positive value in an extremely short so-called “rise time”, between 50 and 150 ns.
• the “fall time”, that is to say the time from a positive value to a negative value, of the voltage of the high frequency signal is of the same order of magnitude, ie approximately 50 ns.
• the duty cycle of high frequency waves or in other words the ratio of the duration of positive emission t 'to the emission period ⁇ * is equal to 0.20, a value which is well understood in l '' range 0.20 to 0.40.
• this signal has a zero mean current, that is to say that it defines around the zero voltage axis a surface SI in its positive part equal to that delimited in its negative part S2.
• the signal in Figure 1 is modulated by a low frequency signal.
• This low frequency signal has a period T and a duty cycle whose values are close to 12 ms and 0.33.
• the duration t of emission of the low frequency signals corresponds to the time of passage of the high frequency wave train.
• the unit of the time scale is the millisecond, while the period of the high frequency signals is of the order of a microsecond, which is why the shape of the high frequency signal is represented by rectangles thin vertical.
• FIG. 3 represents electrodes placed on the skull of a patient, according to an embodiment of the invention.
• Electrodes la and lb_ are said to be ophryaque while two electrodes 2a_ are said to be retromastoid and one electrode 2b_ is said to be low occipital. To clarify the drawing, the two ophthalmic electrodes la and lb_ have been shown next to each other, but it is obvious that these two electrodes are merged in one place.
• they can be replaced by a single ophryaque electrode which simultaneously plays the role of both.
• the electrodes form two sets of electrodes generally designated by a_ and b_.
• the first a_ consists of the ophryac electrode la_ and the pair of retromastoid electrodes 2a_, while the second b_ comprises the other ophryac electrode lb and the low occipital electrode 2b.
• Another electric field is applied between the ophryaque electrode 1b and the low occipital electrode 2b_.
• neuro-stimulation therefore takes place thanks to the joint action of two electric fields, which in particular makes it possible to reach the PAPEZ circuit which is composed of the crosslinked formation, the hippocampus, the amygdala, the hypothalamus and the ventral peri-aqueductal region which is known to have analgesic properties.
• the wave trains of the signals of each electric field applied to the sets a_ and b of electrodes are phase shifted by a time y as shown in FIG. 4.
• Va represents the voltage applied between the electrodes la and 2a while Vb represents the potential difference between lb_ and 2b_.
• FIG. 5 represents two signals emitted by another embodiment of the invention, similar to that represented in FIG. 3.
• the signal offset here is total, without partial overlap of the wave trains a and b_.
• phase shift is strictly equal to the duration of transmission of the signals, so that the voltage Vb immediately succeeds the voltage Va.
• the duration without emission is also identical to ⁇ .
• the period T is divided into three portions of identical durations ⁇ f: the emission of a signal by the set of electrodes a., The emission of a signal by the set of electrodes b_- and the absence of emission.

Applications Claiming Priority (3)

Publications (1)

Family

ID=9419908

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• 1991
  • 1991-12-11 FR FR9115353A patent/FR2684872B1/fr not_active Expired - Fee Related
• 1992
  • 1992-12-11 CA CA 2125497 patent/CA2125497A1/fr not_active Abandoned
  • 1992-12-11 JP JP5510671A patent/JPH07504829A/ja active Pending
  • 1992-12-11 EP EP93902322A patent/EP0616546A1/de not_active Withdrawn
  • 1992-12-11 WO PCT/FR1992/001175 patent/WO1993011831A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

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