US2276995A - Electrotherapy - Google Patents

Description

March 17, 1942..

A. S. MILINOWSKI ELECTRQTHERAPY 'Original Filed Jan. 22, 1938 INVENTOR ATTORNEY Patented Mar. 1 7, 1942 UNITED ISTAT-EsI PATENT OFFICE ELEc'rRo'rHERAPY Arthur S. Milinowski, New York, N. Y., assignor to A. J. Ginsberg, New York, N. Y.

Original application January 22, 1938, Serial No. .186,329. Divided and this application August 30, 1940, Serial No. 354,799

s claims. (ci. 12s-423i Broadly stated, my invention, in one of its y aspects, relates generally to an apparatus for creating periodic high frequency pulses 'preferably of relatively short duration with relation to the time intervals between pulses, and the application of such high fr'equency pulses to matter to produce differential effects; and in another of its aspects it relates to the use of high frequency pulses of the character referred to for therapeutic treatment by electrotherapy, by.

tolerance, and this end I attain as a result of the independent control of the thermal and electrical eiects.

By so increasing the voltage I am Venabledto bring into play more .powerful electrical forces without increasing the thermal eiects, and where the application is to living matter,A these powerful electricalforcesproduce effects hitherto impossible of attainment.

As the applications ofv my invention are further investigatedit may be found that by the use of sufliciently high voltages, radiations, such as X-radiations, may perhaps be .produced within the body, as a result of the increased electron. velocities therein, and such radiations may have d valuable therapeutic ee'cts'.

While I have pointed out the desirability of .increased electrical effects, my invention in one are subjected to the action of electrical forces,

changes in their normal condition are produced. In the case of bacteria, their virulence varies with their electrical charge, while in the case of body cells it seems probable that departure from the normal condition will result in pathological conditions.

In the. application of electrical forces to matter, and in particular to living matter, the thermal phenomena accompanying the passage of electrical currents therethrough` are to be distinguished from effects that are purely electrical. It is only the latter that will directly affect the electrical characteristics of matter, while the effects of the former are those associated. with heat. It is at once evident that independent control ofthe thermal factors associated with'the applicationv of electrical forces to matter areof the highest importance for the attainment of predetermined desired effects.

The importance of such independent control has been demonstrated in the practice of ultrashort Wave therapy. When the high frequency oscillations are applied for an appreciable time to a patient, it is found that the amount of 'current, or stated dierently, the voltage, that may be applied, is limited because of the heated generated in the patients body. That is, stated in technical language, thelimit of heat tolera-nce peutic technique.

of its phases alsorelates to the practice of dia-v thermy, in whichthe heating eiects of the electric current are utilized, and in which the electrodes are customarily placed in direct contact with the patient. `As a result of the direct contact a large amount of current can betransmitted through the body at relatively low frequencies, but as a result of the heat produced in the body, both the voltage and the frequency that are applied are limited because of the aforementioned heat tolerance of the patient. If it is attempted to practice diathermy by spaced electrodes, it is necessary, however, to increase the voltage or. to increase the frequency of the -applied current in order to cause sufficient energy to pass into the patients body. Heretofore higher frequency has been resorted to'because it was found impossible with the existing apparatus to secure a sufficient input into the patient by raisf ing the voltage, the latter being limited due to shortcomings of the apparatus employed'. By the use ofmy apparatus,'however, I am enabled to crease the voltage to such-"apoint that it isl possible to use lower oscillation frequencies thanv have'been heretofore employed in contact diathermy, thus opening up a new branche! thera- It is further among lthe objects of my invention to increasethe eiiiciency of ultra-short wave treatment land apparatus by the employmentl in connection therewith of nat-topped electrical 1mpulses, and to providev apparatus for producing vsuch vfiat-topped impulses. 'I'he advantages thereof` will be fully.v discussed hereinafter, butV it may be briey stated 'at this point' that .by theirl use the maximum 'eiiiciencybf action is ob# tained .throughout thev duration of the pulse,

whereas other pulse forms give a maximum emciency only at the peak point or. points and a reduced efliciency -at other times, whereby of course thel average efliciency during the pulse is reduced.

It is also among the objects of my invention to provide electrical circuits for the desired purposes that will perform their function eiciently and reliably, and that may be arranged compactly; and further to provide apparatus of the type described that will be economical in manufacture and operation. For the attainment of these objects and such other objects as will .hereinafter appear or be pointed out, I have shown an illustrative embodiment of my inventionV in the drawing, in which:

Fig. 1 is a diagram of the circuits of one embodiment of my invention;

Fig. 2 is a voltage diagram of vthe electrical pulses that are used to generate the high frequency oscillations; and

Fig. 3 is a diagrammatic view on an enlarged scale of a detail of the circuit of Fig. 1.

In Fig. 1 I have shown an electrical circuit that is adapted for the production of high frequency oscillations of the character called for by my invention.

The illustrative apparatus shown in the drawing comprises first of all a pulse producing circuit, which includes electronic means such as triodes I and I2 connected in parallel, and having their ductance .44 to which are also connected the plates of the triodes 46 and 48. The grids of triodes 46 and 48 are connected in parallel through a resistor 50 with thatterminal of the secondary of the pulse transformer 22 that becomes negative during the pulse, and each grid has an inductance 52 in series with'it and is further connected with one of a pair of condenser plates 54 and 56, the condenser plate 54 being electrically adjacent to the electrode 40 and the condenser plate 56 being electrically adjacent to the electrode 42.

The other terminal of the pulse transformer 22 is connected to the inductance 44 at the midpoint thereof. The filaments of the triodes 46 and 48 are energized from the transformer 58, connected to a source of alternating current such as the aforementioned 110 volt lighting circuit,

' the midpoint of the secondary of which is controdes 40 and 42.

filaments energized from a transformer I4 connected to an alternating current lighting circuit. While a single triode would serve my purpose, I have shown a pair-to obtain sumcient power. The triodes I0 and I2 are normally biased beyond cut-off by means of a cathode resistor I6 shunted by an electrolytic condenser I8 'of suiicient capacity to keep the bias voltage nearly constant. The resistor I6 and 'condenser I8 are connected as shown, between the midpoint of the secondary of the transformer I4 and the ground. The plate circuit of the triodes III and I 2 includes the primary of the pulseA transformer 22 and across it is connected the condenser` 24, the latter being energized from a center-tapped power transformer and a full wave rectifier indicated as a whole by 26, which is connected to a source of alternating current such as the aforementioned 110 volt lighting circuit and which may, by way of example, deliver current at up to 3000 volts. A ballast resistor 20 may also be placed in the plate circuit ofthe triodes I0 and l2. The circuit also includes a choke coil 28 and a milliameter 2 9. The coil 28 may have a capactiy of 20 henries. The grids of the pulse tubes I0 and I2 are connected periodically to their plates through the resistor 30 by means of a rotating contactor 32, having studs thereon that are adapted to make contact with a knife edge 38. A condenser 31, which may have a capacity of .O02 microfarad and a choke coil 38 are shown as placed across the contactor gap and serve to prevent arcing. The result is-the transmission of intermittent pulses through a primary of the pulse transformer 22.

Coupled to the pulse producing circuit just described, through the transformer 22,' which may have a step-up ratio of the order of 11:1, is a high frequency oscillating circuit comprising at its output end the electrodes 4I)- and 4.2 in the,

form of plates, which in the normal use thereof are spaced from the patient who is placed between them. The electrodes 40 and 42 are shown as connected to the terminals of an in- The transformer 58 is preferably of special design so as to provide sufficient insulation and low capacity' between the'primary and the secondary coils. I have found that a transformer consisting of a coil of soft iron wire nine inches in diameter, on which the primary is wound, and a secondary coil of about eight inches in diameter looped about the primary and so-spaced that it is everywhere more than two inches from the primary, 'is v`ery satisfactory in practice.

In the operation of my device it will be understood that the pulse transformer 22 receives electrical impulses from the pulse producing circuit and steps up the voltage to that desired to be applied to the plates of the oscillating tubes of the high frequency oscillating circuit, while the latter functions to supply high voltage ultra high frequency waves during each pulse to the electrodes 4I! and 42.

In Fig'. 2 will be found a time-voltage diagram indicating the fiat top voltage wave form that may be lproduced in the pulse circuit for transmission to the high frequency circuit. This fiat top wave form may be obtained by suitable ad'- Justment of the resistor 30 in the grid circuit of the pulse tubes I0 and I2. It is found that when the resistance is reduced to a point where vthe heat loss in the resistor becomes appreciable, the voltage drops substantially without slope and the voltage pulse ends abruptly, as shown in Fig. 2, which represents the results of actual oscillograph tests.

- The pulse frequency and duration are determined by the characteristics of the contactor 32, which maybe driven by an electric motor. The pulses may be produced as the studs 34 thereof move past the knife edge 36 and contact the same. l which a stud 34 is shown spaced from the knife edge 36.' It will be evident thai-l the pulsefrequency is determined by the number of studs on the contactor and the contactor speed, while the consisting of a duralumin disc having eight equally spaced studsl on its periphery and driven at a speed of 7000 R. P. M. to be very satisfactory,

when used with a knife edge of phosphor bronze.'

At this speed t'he pulse frequencyv is about 900 per second. The length of the studs is' such as to produce at this speed a pulse duration of Fig. 3 is a detail view of a contactor in plete pulse cycle, a transformer secondary coil, intended for an output voltage o f 2500 at 60 cycles, broken down at 11,000 volts, while when the pulse duration was reduced to one-twentieth and the construction of Fig. 3 is used. -However,

in order to produce a satisfactory flat top pulse,

the electrical contact must be made instantaneously when the leading edge of the stud, a, is.

nearest the knife edge. Also, the electrical contact must be broken instantaneously when the trailing edge of the stud, b, leaves the knife edge. 'The circuit is uniquely designed to accomplish this by making use of the electronic action of the pulse tubes, in the following manner:

At the moment when the leading edge of the stud approaches the knife edge, the full voltage of the lter condenser 2l is across the pulse tubes and across the contactoi points. This voltage is sufficient to jump a small air gap between the contactor points and establish contact. During the pulse, however, a current ows in the pulse tubes and the voltage drop across these tubes is reducedto a small'fraction of the voltage ofA condenser 24, and it is only this greatly reduced voltage which must be broken when the trailing edge b of the stud leaves the knifeedge. Any tendency' to arc due to this smaller voltage is removed by placing the previously mentioned small. condenser 31 of about .002 microfarad,

' across the contactor points.` lThe radio frequency choke coil 39 is placed in series with this condenser to prevent oscillations in the condenr circuit during the pulse. Y

The following actual test will serve as an illustrative example of the comparativeheating effects of continuous high frequency oscillations and of pulsating high frequency oscillations.

A 0.1 normal sodium chloride solution in water was placed in a special glass tube, 2 cm. in diameter by 15 cm. long, having metal electrodes at the ends and special provision for a thermometer. The tube was insulated with cloth to reduce heat loss and placed between the applicators `of a therapeuticoscillator such as shown in the drawing.

When this oscillator was activated by a constant voltage of 3300 volts, the temperature of the solution rose from 22 C. to 45 C. in ten .minutes The oscillator was then activated by 3300 volt pulses, the pulses having a duration of about l/zonoo sec. and afrequency of about 900 per second. An identical solution in the` tube placed in the same position rose from 22 C. to less than 24 C. in ten minutes. The frequency produced in the oscillator was 25 megacycles per sec. v

It will be obvious that a flat top wave pulse as just described will have the advantage that the desired maximum voltage effects are attained throughout the duration of each pulse, so that n o provision need be made for any higher voltages.

Among the many advantages of short duration pulses, and in particular of iiat top short pulses, may be mentioned that short duration pulses do not strain the insulation of the apparatus as severely as a continuously applied equivalent constant voltage would, and consequently the voltage of a cycle, it did not break-down at.20,000 volts.

vThe voltage of the pulse may be stepped up or down directly by means of a suitable trans-vk e former without further rectification. The transformer'may be designed so ythat no appreciable flux is builtup in the transformer core during been-found possible to use pulsating voltages up l to 20,000 on a pair of PF a196.tubes which `in normal service are not adapted for voltages over The emission requirements of oscillating tube ifilaments for an equivalent power output are con.

' tried, but as these voltage pulses drop exponen--v used in the apparatus may bestepped up. As

an example of how reducing the time of application of the voltage will increasethe breakdown resistance, it may be mentioned that, with a pulse duration of about one-tenth of the comsiderably reduced for pulsating current, due to the use of a higher effectivey voltage during the pulse.

`The practical frequency limit ofthe tubes is increased due to the higher effective voltage made possible by the use of a pulsating voltage. The increased plate voltage reduced the transit time of the electrons from lament to plate, .and since this transit time limits the frequency limit of a tube, shortening this time raises the frequency limit toa considerable degree.

Byattening the top of the wave pulse additional advantages are obtained. When used for the excitation of X-ray tubes mono-chromatic X-radiation may be attained, because the exciting voltage is constant. Where it is attempted to use -a sustained high voltage for this purpose, electrical insulation difficulties are usually encountered, or over-heating may result, or abnormal spark tension on the tube laments. To overcome these difficulties high voltage pulses originating from spark discharges have 'been tially the radiation is not mono-chromatic, With a flat top voltage pulse, as in my apparatus,

,mono-chromatic radiation coupled with the advantages of interrupted voltage are obtained.

The same vadvantagesalso-make this type of pulsating voltage useful vvfor .the excitationof Lenard ray tubes, or any ion accelerating devices.

Although my theory has not as yet been definitely confirmed it is that the high voltage causes an electrical; transformation or stimulation to the living cells not heretofore attainable;`

As previously herein mentioned therapeutic apparatusemployed up to the present time has been limited as to voltage to a maximum of 'ap' lproximately 3000 volts because of accompanying generation of heat to about the limit of'human tolerance.

This apparatus causes two types of cell stimulation, namely, thermal and electrical with the former retarding the electrical transformation 'of the living cells, In other Words, thermal stimulation' changes the molecular motion of the cells.

and hence causes fatigue, coagulation, etc. very rapidly followed by complete destruction of the resulting fatigue' even though the treatment is continued for a much greater time than is possible in thermal stimulation.

Moreover, due to the periodicity of the current pulses, `since they are of much shorter duration than the longer off periods of no current flow,

the living cells have ample time to recover from the stimulation which I believe eliminates fatigue and accompanying thermal stimulation thus ac- .,.counting for my being able to employ such exceedingly high voltages with amazing therapeu tical results.

While I have shown and described an `illustrative embodiment of my invention and illustrative methods of practicing the same, it is to be understoodthat the same may be embodied in many other forms and practiced in many other ways without departing from the spirit thereof, as-will be obvious to those skilled in the art, and that the disclosure is by way ofv illustration only, and is not to be interpreted in a limiting sense, and that I do not limit myself in any way other than as called for by the prior art.

I claim: A

1. An ultra short wave apparatus for administering therapeutical treatments comprising a source of relatively high voltage electrical current, independent means connected to said source and operable to modulate the potential ofsaid means electrically connected to said independent istering therapeutical treatments comprising a means' and energizable by the modulated potenenergized by the ultra high voltagepulsating current for generating high frequency oscillations and for applying the sameto a patient;

2. An ultra short wave apparatus for administering therapeutical treatments comprising a source of relatively high voltage uni-directional electrical current, independent means connected to said source and'oper'able to modulate the potential of said original source and convert the same into pulsating current of a pulse duration of less than l/ion of a second with an interval between pulses of the order of ten or more times the pulse duration, means electrically associated with said source and energizable by the modulated potential for transforming the pulsating current into still higher voltage pulsating current of not less than 25,000 volts, and meansenergized by the ultra high voltage pulsating current for generating ultra high frequency oscillations and applying such oscillations to a patient.

3. An ultra short Wave apparatus for administering therapeutical treatments comprising a source of relatively high voltage uni-directional electrical current, independent means connected to said source and operable to modulate the potential of said original source and convert the same into pulsating current of a pulse duration of less than M00 of a second with an interval between pulses of the order of ten or more times the pulse duration, means electrically associated with said source and energizable by the modulated potential for transforming the pulsating current into still higher voltage pulsating current, and means energized by thelultra hi'gh voltage pulsating current for generating high frequency oscillations having a frequency of approximately 25 megacycles per second and for applying the same to a' patient.

4. An ultra short wave apparatus for administering therapeutical treatments comprising a source of relatively high voltage uni-directional electrical current, control means connected to said source and operable to modulate the potential of said original source and convert the same into pulsating current of a pulse duration of less than tino of a second with an interval between pulses of the order of ten or more times the pulse duration including energy storage means and a thermionic discharge device operable to periodi- Vcally release a charge from said energy storage means, means electrically associated with said source and energizable by the release of charge from said energy storage means for transforming the pulsating current into still higher voltage pulsating current, and means energized by the ultra high voltage pulsating current for generating ultra high frequency oscillations and applying such oscillations to a patient.`

5. An ultra short wave apparatus for adminsource of relatively high voltage uni-directional current, independent means connected to said source and operable to modulate the potential of said source and convert the same into pulsat' ing current of a pulse duration of less than l/wn of a second with an interval between pulses of the order of ten or moretimes the pulse duration, said independent means comprising a pulse-pro.

ducing circuit including a condenser adapted to be charged from said source, a thermionic device having its plate and filament connected across said condenser, and means operable to periodically vary the grid potential of said thermionic device for controlling the release of charge from said condenser to produce a pulsating current; means electrically associated with said source and said independent means for transforming the pulsating current into still higher voltage pulsating current, and means energized by the 'A ultra high voltage pulsating vcurrent for generating ultra high frequency oscillations and-for applying such oscillations to a patient.:

6. An -ultra short wave apparatus for administering therapeutical treatments comprising a thermionic device for controlling the release of I charge` from said condenser to produce a pulsating current; means electrically associated with said source and said independent means for transforming the pulsating current into still higher voltage pulsating current of not less than 25,000 volts, and means energized by the ultra high voltage pulsating current for generating ultra high frequency oscillations and for applying such oscillations to a patient.

'LAn ultra short wave apparatus for administering therapeutical treatments comprising a source of relatively high voltage uni-directional electrical current, independent means connected to said source and operable to modulate the potential of said source and convert the same into pulsating current of a pulse duration of less than M00 of a second with an interval betweenl pulses of the order of ten or more times the-pulse duration, said means comprising a pulse-producing circuit including a. condenser adapted to be charged from said source, a thermionic device having its plate and lament connected across said condenser, and means operable to periodically vary the grid potential of said thermionic device forcontrolling the release of charge from said condenser to produceva pulsating current;

and means electrically associated withsaid source 8. An ultra short wave apparatus for administering therapeutical treatments comprising a source of relatively high voltage uni-directional l electrical current, independent means connected to said source and operable to modulate the potential of said source and convert the' same into pulsating current of a pulse duration of less than Moo of a second with an interval between pulses of the order of ten or more times the duration of pulse, said means comprising a pulse-producing circuit including va condenser adapted to be charged from said source, a thermionic device having its plate and iilament connected across said condenser, and means operable to periodically vary the grid potential of said thermionic device for controlling the release of charge from said condenser to produce a pulsating current; and `means electrically associated with said source and Asaid independent means .for transforming.

the pulsating current into still higher pulsating current at a voltage of not less than 25,000 volts and for generating ultra high frequency oscillations comprising a step-up transformer connected to an oscillating circuit including a thermionic device, an inductance element -connected -in the plate circuitof said therinionic device,

and out-put terminals connected to said inductance for applying the high voltage ultra high frequency oscillations to a patient.

- ARTHUR S. MILINOWSKI.

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