# IMPULSE CURRENTS

IMPULSE CURRENTS — the electric currents of various polarity applied for the purpose of treatment and the diagnoses arriving to the patient falteringly in the form of separate «pushes», «portions» (impulses). Treatment And. t. it is applied independently or (more often) as a part of complex therapy. Impulses have various form registered by an oscillograph, edges is defined by various speed of increase of tension after a pause and fall before the subsequent pause. They follow one after another or evenly, or in the form of periodically repeating bucketed series between them. Frequency of impulses is expressed in hertz, duration in milliseconds, amplitude and average values of their force and tension — in milliamperes and volts.

To group I. t. belong: 1) And. t. constant polarity and low frequency — Ledyuk's currents, Lapika, tetanizing and diadynamic; 2) And. t. variable polarity and average frequency — interferential, sinusoidal modulated, fluctuating; 3) And. t. variable polarity and high frequency — see. Darsonvalization .

S. Leduc's current — And. t. with the impulses which are abruptly accruing and after a while quickly falling down squared. In practice apply current with a frequency of 5 — 150 Hz. It is for the first time suggested with to lay down. purpose fr. physicist and biologist S. Leduc. Lapik's current — And. t. with impulses, incremental and falling down, i.e. an exponential form. It is for the first time offered by the fr. neurophysiologist L. Lapik. Tetanizing current is characterized by the impulses close to triangular shape, with a frequency of 100 Hz and lasting 1 — 1,5 ms; is an improved version offered by Faraday (M. of Faraday) alternating current of unstable frequency.

Fig. 1. Graphic representation of diadynamic currents: and — single-cycle continuous current (this type of current is used generally at pains); — duple continuous current (it is used for anesthesia, improvement of blood circulation in extremities, for a spasmolysis of peripheral vessels); in — single-cycle discontinuous current — «a rhythm a syncope» (it is applied to electrostimulation of nerves and muscles); — alternation of single-cycle and duple currents — current «the short period» (it is applied to anesthesia, improvement of a trophicity of fabrics, reduction of hypostasis); d — alternation of duple and single-cycle currents — current «the long period» (it is used for anesthesia, improvement of a trophicity, promotes a rassasyvaniye of hems); e — single-cycle wave current (it is used for electrostimulation of nerves and muscles); — duple wave current (it is applied to anesthesia and to electrostimulation of nerves and muscles). On ordinate axis — current (I), on abscissa axis — time (t).

Diadynamic currents — And. t. with impulses of a semi-sinusoidal form (fig. 1) with a frequency of 50 and 100 Hz. Are for the first time suggested by A. N. Obrosov and I. A. Abrikosov for to lay down. uses in 1937. In the 50th 20 century these currents are entered in to lay down. to the practician by P. Bernard. The method of treatment received the name of diadynamotherapy.

Interferential currents (a synonym H. Nemec's currents) result from an interference (imposing) in body tissues of the patient of two alternating currents with impulses of unequal average frequency (4000 and 3900 Hz); are suggested for to lay down. uses avstr. the physicist H. Nemec in 1951.

Fig. 2. The graphic representation of the harmonic modulated currents: and — initial current in the different modes; — currents in the variable mode; in — currents in the constant mode; PM — the «continuous modulation» (which is not changing during the procedure), is applied to electrostimulation of face muscles and unstriated muscles of internals (at the left at not heavy, on the right at severe defeats); Software — «parcel — a pause» — alternation of current with a pause, is applied to electrostimulation of unstriated and cross-striped muscles (at the left at not heavy, on the right at heavy disturbances of electroexcitability); MONDAY — «parcel — the bearing frequency» — alternation of the modulated current with initial; PCh — «the alternating frequencies» — alternation of currents with various frequency: MONDAY and PCh are applied to anesthesia, improvement krovo-and lymphokineses in extremities (at the left at acute pains and the expressed disturbances of a trophicity, on the right — at not acute pains and unsharply expressed disturbances of a trophicity); Hypermarket — «depth of modulation», extent of modulation of current (as a percentage), 0% — the initial modulated current (for treatment it is used seldom); 25 — 5 0 — 7 5% — partially modulated current (at the left — applied at acute pains and the expressed disturbances of a trophicity, on the right — at not acute pains and unsharply expressed disturbances of a trophicity); 100% — completely modulated current (it is applied at not acute pains, to electrostimulation of nerves and muscles); P — overmodulation — completely modulated current with the subsequent pause (it is applied to electrostimulation of hard affected nerves and muscles).

The harmonic modulated alternating currents with a frequency of 5000 Hz and the modulations (low-frequency transformation) arriving later on electrodes in the form of impulses from 10 to 150 Hz are offered and entered in to lay down. to the practician by V. G. Yasnogorodsky in 1966 (fig. 2). The method of treatment by currents is called amplipulsetherapy according to the name of the domestic device generating these currents, the Amplipulse. Fluctuating (aperiodic) currents with the impulses with a frequency from 100 to 2000 Hz which are randomly combined among themselves are offered in 1964. L R. Rubin for the medical purposes in stomatology. The method of treatment is called these currents flyuktuorizatsiy.

## Mechanism of action

Basic in operation And. t. the analgesic effect is. The greatest anesthetizing action currents with a sinusoidal and semi-sinusoidal pulse shape possess (diadynamic, interferential, sinusoidal modulated and fluctuating). In the mechanism of the anesthetizing action of these currents it is possible to allocate two moments. The first — directly brake effect like nervous blockade in a zone of impact on conductors of painful sensitivity. It leads to increase in a threshold of pain, reduction or the termination of a flow of afferent painful impulses in c. N of page, i.e. to emergence of anesthesia of this or that degree. The second stage — creation in c. N of page of a dominant of irritation (according to A. A. Ukhtomsky) in response to a powerful flow rhythmic the arriving impulses from intero-and proprioceptors from a zone of influence And. t. The dominant of rhythmic irritation «blocks» a dominant of pain.

Also the response impulsation from c is as a result normalized. N of page that the rupture of a vicious circle is promoted «by the center of pain — c. N of page — the center of pain». The irritation of vegetative nerve fibrils arising under the influence of current and rhythmical reductions of muscle fibers in a zone of influence promote stimulation of collateral circulation, normalization of a tone of peripheral vessels that improves blood supply and a trophicity in patol, the center.

It agrees obshchebiol. to the law of adaptation a ratio «irritation — reaction» under the influence of treatment And. t. significantly changes in time: the threshold of perception of currents raises, and the anesthetizing action decreases (reaction of accustoming). For reduction of this phenomenon And. t. usually use not only with one frequency, but also in the form of various and consistently applied modulations — alternations And. t. unequal frequencies in various temporary ratios (currents «the short and long period», etc.).

And. t. constant polarity and low frequency render considerable touch and motive irritation owing to bystry increase and a stress decay in an impulse; this irritation is shown even at small current by a burning sensation or prickings under electrodes and amplifies at increase of current, being followed by tetanic reduction of the muscles subjected to influence. Due to the given features of action Ledyuk's currents, Lapika, tetanizing are applied preferential for electrodiagnoses (see) and for electrostimulations (see).

And. t. variable and constant polarity, in particular sinusoidal and semi-sinusoidal forms and average frequencies, cause smaller touch irritation at preservation of motive excitement. It allows to use them both for anesthesia, and for electrostimulation.

Diadynamic currents possess not only soothing action; their use at trophic disturbances and at injury of skin accelerates regeneration, promotes substitution of rough cicatricial fabric of more friable connecting. Influence by diadynamic currents on area of sympathetic nodes contributes to normalization of blood circulation in extremities, at atherosclerosis of vessels of a brain with a syndrome of regional cerebral hypertensia to decrease in a tone of intracerebral vessels and improvement in them of a blood-groove, at migraine stops an attack. The harmonic modulated currents possess most a broad spectrum of activity, causing positive responses from outside of both the touch, and motive sphere and trophic function of a nervous system. In this regard they found application at a number of functional frustration; so, use of the harmonic modulated currents for patients with an initial stage of a lymphostasis of extremities promotes improvement of drainage function limf, systems. At patients with arterial hypertension of renal genesis of I - IIA of a stage use of these currents on area of a projection of kidneys promotes lowering of blood pressure owing to change of glomerular filtering and strengthening of a renal blood-groove etc.

Fluctuating currents possess not only anesthetic, but also antiinflammatory action. Their use at a purulent inflammation promotes strengthening of phagocytosis in the center, to its otgranicheniye from «healthy» fabric and to improvement of a current of a wound process.

## Indications, contraindications

the Main indications to medical use of the diadynamic, interferential, harmonic modulated currents: diseases and injuries of soft tissues of a trunk and extremities (a bruise, sprain and muscles, a miositis, a tendovaginitis, etc.), diseases and effects of spine injuries and joints (the osteochondrosis deforming a spondylosis, an osteoarthrosis, the Spondylarthrosis, etc.); peripheral nerves (radiculitis, plexitis, neuritis, neuralgia, shingles), a spinal cord and its covers (an arachnoiditis, a myelitis) proceeding with pains or paresis and paralyzes of extremities; defeats of vessels of a brain and peripheral vessels of extremities or disturbance of their tone (atherosclerosis of vessels of a brain in an initial stage, a Raynaud's disease, an obliterating endarteritis of the I—III stage, atherosclerotic occlusion of vessels of extremities of the I—II stage, various forms of migraine); hron, diseases of abdominal organs and a state after operations on them proceeding with an atony of unstriated muscles; a number of diseases of the female and men's generative organs (hron, an inflammation of appendages of a uterus and a prostate) which are followed by the expressed pains. Diadynamic currents, besides, apply at vasculomotor rhinitis, hron, average adhesive otitis, sinusitis. The diadynamic and harmonic modulated currents apply to exile of stones from an ureter (at corresponding the Urals, indications and but a special technique). Interferential currents use, except the listed above indications, for electroanaesthesia (see). The harmonic modulated currents apply also to treatment of patients with hron. limf, hypostasis of the lower extremities.

Fluctuating currents received preferential use in stomatology: at neuralgia trigeminal, glossopalatine and other nerves, at arthritis of a temporal and maxillary joint, an alveolitis (alveolar pains), periodontosis, at inflammatory diseases (acute, chronic, aggravated) and acute purulent processes of maxillofacial and submaxillary areas (phlegmon, abscess in the postoperative period).

The main contraindications to use of the diadynamic, interferential, harmonic modulated, fluctuating currents: individual intolerance of currents, fractures of bones and dislocations (until consolidation or reposition), extensive hemorrhages or bent to them, thrombophlebitis, an acute purulent infection (use of fluctuating currents is possible in the postoperative period), new growths, an idiopathic hypertensia II B and III stages, hron, a circulatory unefficiency of the II—III stage; hron, coronary heart disease with the phenomena of stenocardia and the expressed sinus bradycardia, pregnancy of all terms.

Indications, contraindications and to lay down. techniques for an impulse current of Lapik, Ledyuka and tetanizing (a rectangular, triangular and exponential shape) — see. Elektrodiagnostika , Electrosleep , Electrostimulation .

Devices for treatment by impulse currents. For treatment the domestic devices SNIM-1, Model-717, Tone-1 and Tone-2 are available diadynamic currents. Impulses of current with a frequency of 50 and 100 Hz in devices receive by one - and two-half-period straightening of network alternating current.

Fig. 3. The device SNIM-1 for treatment by diadynamic currents (impulse currents with a frequency of 50 and 100 Hz).

The scheme of devices, except rectifiers, includes the generator of squared impulses with the multivibrator (the electronic device, with the help to-rogo receive And. t. with a broad range of frequencies and with the form close to rectangular). This current then in the device is used for receiving And. t. a semi-sinusoidal form with gradual recession of an impulse. The device SNIM-1 (fig. 3) generates seven kinds of currents: single-cycle and duple continuous and wave currents, currents in beat a syncope (alternation single-cycle continuous with a pause), currents «the short and long period» (alternation one - and duple continuous currents in various temporary ratios).

All currents, except continuous, can be used in two forms of parcels — «constant» and «variable». At a «constant» form currents have the constant set parameters. At «variable» — some parameters of currents (duration of the period of parcel, increase and decrease in amplitude of impulses) can be changed in certain limits. It allows to expand considerably to lay down. use of diadynamic currents, in particular to use them for anesthesia at patients with intolerance of continuous currents and for electrostimulation of muscles at diseases of internals and defeats of peripheral nerves. The power consumed by the device from network, 60 W, the weight of 12 kg. Model-717 — the portable device generating the same kinds of currents, as SNIM-1 in a «constant» form of parcels. The power of 35 W consumed by the device, the weight of 4 kg. The device Tone-1 is used in stationary conditions and at home; generates all kinds of currents, as devices, and also single-cycle and duple currents described above in new various combinations. A form of parcels — «constant». The power of 25 W consumed by the device, the weight of 7 kg. Foreign devices for treatment by diadynamic currents — to D patinas and to (Party of Russian Taxpayers), Bipulsator (NRB), etc. — generate diadynamic and galvanic currents which can separately be used also in a combination with each other. A form of parcels — «constant».

Fig. 4. The device Amplipulse-4 for treatment by the harmonic modulated currents (impulse currents with a frequency of 5000 Hz).

Use the domestic devices Amplipulse-3T and the Amplipulse-4 (fig. 4) to amplipulsetherapy. The scheme of devices turns on the generator of the bearing sinusoidal fluctuations of average frequency (5000 Hz), the generator of the modulating fluctuations of low frequency (10 — 150 Hz), the generator of parcels and the electrical power unit. The amplipulse-3T generates the sinusoidal modulated fluctuations continuous («continuous modulation») and in alternation with a pause («parcel — a pause») with impulses of other frequencies («the alternating frequencies») or with the modulated fluctuations («parcel — the bearing frequency»). Duration of parcels can be regulated from 1 to 5 sec. Currents use in the mode of an alternating and direct current. Depth of modulation (degree of its expressiveness) can be changed. With increase in depth of modulation exciting action of currents amplifies. It is considered at a technique to lay down. uses of the device. The power no more than 170 W consumed by the device, the weight of 17 kg. An amplipulse-4 — portable model of the device (weight of 7,5 kg); generates the same kinds of currents, as the Amplipulse-3, but with smaller modifications.

In the domestic device for a flyuktuorization of ASB-2 a source of tension of alternating current of acoustical frequency (from 100 to 2000 Hz) is the germanic diode. Tension in the device moves in three options: in the variable which is partially «straightened» and constant polarity (respectively current No. 1, 2, 3). For use in stomatology to the device a set of intra oral electrodes is given. The weight of the device is 6,5 kg, power consumption is 50 W.

All described devices, behind an exception the Tone-1 and the Amplipulse-4, need grounding during the use.

The devices generating And. t. with a rectangular, triangular and exponential shape of impulses — see. Electrosleep , Elektrodiagnostika , Electrostimulation . There is no serial release of domestic devices for treatment by interferential currents since Amplipulse devices are more effective. Devices for an electroanaesthesia interferential currents — see. Elektronarkoz .

## Medical techniques

Medical techniques (are stated in relation to treatment of a pain syndrome — to the most frequent cases of use And. t.). Influence And. t. it is carried out through electrodes (with the moistened hydrophilic laying) which connect to output terminals of the device and fix on a body of the patient. The size of current «in a chain of the patient» is established on his feelings (before accurate, but painless vibration of fabrics under electrodes) and on gage reading — the milliamperemeter. Procedures are carried out daily, and at acute pains 2 times a day at an interval of 3 — 4 hours. At consecutive impact on several zones duration of all procedure shall not exceed 20 min. Depending on analgesic effect appoint to a course of treatment from 1 — 5 to 12 — 15 procedures. At treatment the cathode on an extremity have currents of constant polarity on a zone of pains, the anode — is more often cross in relation to the cathode; at impact on area of a backbone — paravertebralno.

At diadynamotherapy consistently influence at first duple continuous or duple wave current (in a «constant» or «variable» form of parcels) during 10 sec. — 2 min. (depending on a zone of influence), then currents «short and long» the periods (everyone 1 — 3 min.), depending on expressiveness of pains.

In the course of the procedure switching of polarity (in the presence of several painful points) with observance of safety regulationss is possible (all switchings of handles of the device are carried out at the switched-off «current of the patient»).

At amplipulsetherapy consistently influence 3 — 5 min. modulations «parcel — the bearing frequency» and «the alternating frequencies». The mode of exposure, frequency and depth of modulations are appointed depending on expressiveness of pains. At acute pains — the mode of alternating current, frequency is 90 — 150 Hz, depth of modulation of 25 — 50 — 75%, at not acute — the mode of an alternating or direct current, frequency is 50 — 20 Hz, depth of modulation is 75 — 100%. When sharp exciting action of currents is undesirable, they are applied with a depth of modulation from 25 to 75% (depending on a zone of influence and expressiveness of pains).

Influence by interferential currents is carried out by two couples of electrodes from two separate chains of current, having them so that decussation of power lines was in a zone of a projection patol, the center. The rhythm and frequency of modulations are appointed depending on expressiveness of pains in the range from 50 to 100 Hz.

Influences by fluctuating currents on a mucous membrane of an oral cavity carry out by intra oral electrodes, on skin — lamellar. At the acute and escalated inflammatory processes in maxillofacial area apply current of variable polarity, at hron, inflammatory processes and periodontosis — current of partially straightened or constant polarity.

Repeated courses of treatment And. t. at a wedge, indications it is possible to appoint in 2 — 3 weeks. To children variables I. t. average frequencies (sinusoidal modulated) appoint aged since 1; other types And. t. — more often to children 5 years according to the same indications and using the same methodical receptions, as at adults are more senior.

In complex treatment And. t. widely combine not only with drug treatment, but also with other fizio-and balneoprotsedura — medicinal electrophoresis (see), galvanization (see), the general heat fresh and mineral baths and warm souls, local thermal procedures, massage and to lay down. gymnastics. At the correct holding procedures I. t. complications are not observed. It is not recommended to influence the same zone I. t. and ultraviolet rays in an erythematous dosage.

Bibliography: Bernard P. D. Diadynamic therapy, the lane with fr., M., 1961; Liventsevn.M.Ilivensona.R. Electromedical equipment, M., 1974; Practical guidance on holding physiotherapeutic procedures, under the editorship of A. N. Obrosov, page 40, M., 1970; The Reference book on physical therapy, under the editorship of A. N. Obrosov, page 37, M., 1976; Physical factors in complex treatment and prevention of internal and nervous diseases, under the editorship of A. N. Obrosov, M., 1971.

M. I. Antropova.