US3851651A

US3851651A - Facial stimulating apparatus having sequentially energized electrodes

Info

Publication number: US3851651A
Application number: US00317725A
Authority: US
Inventors: P Icenbice
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-12-22
Filing date: 1972-12-22
Publication date: 1974-12-03
Anticipated expiration: 1991-12-03

Abstract

Facial Stimulating apparatus including a plurality of pairs of electrodes for delivering electrical energy to different portions of the face of a user, and in which there are delivered to each pair of electrodes a series of intermittent trains of high frequency pulses, with the different trains to a particular pair of electrodes being spaced apart to leave rest periods therebetween, and with the pulse trains to the different pairs of electrodes being delivered thereto in staggered relation so that a pulse train is fed to one pair of electrodes during the rest period for another pair of electrodes, and vice versa.

Description

me ttes 1' tent 1191 1111 3,8 Hcenbice, Jr. Dec. 3, 1974 [54] FACIAL STIMULATING APPARATUS 3,387,l47 6/1968 Radwin 128/422 3,646,940 3/l972 Timm et al. 128/421 ENERGIZED 3,662,758 5/1972 Glover l28/42l [76] Inventor: Phineas J ICenJQEQ JL, 19323 Primary Examiner-William E. Kamm I Halsted, Nofthl'idge, Calif- 91324 Attorney, Agent, or Firm-William P. Green 22 F'] d: D 2 l 7 l I 2 9 2 57 ABSTRACT [2]] Appl' 317725 Facial Stimulating apparatus including a plurality of pairs of electrodes for delivering electrical energy to 52 11s. (:1 128/422, 128/410, 307/41, different portions Of the face of a user, and in Which 307/223 307/244 there are delivered to each pair of electrodes 21 series [51] Int. Cl A61n 1/36 of intermittent trains of high frequency Pulses, with 5 Field f Search 123/410 419 E, 419 R, the different trains to a particular pair of electrodes l28/42l, 422, 423; 307/41, 223, 242, 244 being spaced apart to leave rest periods therebetween,

and with the pulse trains to the different pairs of elec- 5 References Cited trodes being delivered thereto in staggered relation so UNITED STATES PATENTS that a pulse train is fed to one pair of electrodes during the rest period for another pair of electrodes, and 2,838,672 6/1958 Paust 128/422 vice versa 3,077,884 2/1963 Batrow et al. 128/423 3,279,468 /1966 Le Vine 128/410 7 Claims, 4'Drawing Figures CZ it 5 I. no i g 2 14 4 C i if 3 53 [34 1 I g I ,1 m 32 HQ I 135, 12 |3 I l 27 3e I I I I 8 111. 1.}, 1 1 ,1 37 1 1 1 m 49 I I 104- M 1 91L 1 W I so I 1 9 I I" l Ex-r5-s1o- To 1 I 4 1 l I h ELEMENTS I 52% I I I I 43 I J QIMG 42 54* CauNTLE I w 1 5G I ll 0NOFF g 76 SWITCH HO 87 I 55 as l ag 39 I 57 35 L72 a1 75 j: 3/2) I 59" f I I'BZ I '79 I I '78 l q11 J PATENIEL nzc 3|974 sum luv 2 36' avse LEFT BOT ToM QIGHIT I Tl (SELLS) l adia- FACIAL STIMULATING APPATUS HAVING SEQUENTIALLY ENERGIZED ELECTRODES CROSS REFERENCE TO RELATED APPLICATIONS Certain features of the apparatus shown in the present application have been disclosed and claimed in prior applications Ser. No. 104,609 filed .Ian. 7, 1971 on Apparatus for Facil Stimulation by Donald E. Barker, now US. Pat. No. 3,709,228 issued Jan. 9, 1973 and Ser. No. 137,547 filed Apr. 26, 1971 on Method for Adjusting Facial Stimulator to Fit Different Facial Contours by Donald E. Barker, now abandoned and in US. Pat. No. 3,620,219 issued Nov. 16, 1971 to Donald E. Barker on Facial Nerve Stimulator.

BACKGROUND OF THE INVENTION This invention relates to improved apparatus for electrically stimulating a persons facial nerves and muscles to improve the appearance of the face.

Various different types of devices have been proposed in the past for delivering electrical energy to different portions of a users face through a series of electrode structures. The current delivered to the electrodes has in some cases been supplied in the form of a series or train of high frequency pulses, either in alternating current or pulsed unidirectional form. Some types of equipment have utilized a series of intermittent trains of such pulses, with rest periods between successive pulse trains to allow the particular muscle being treated to temporarily return to an unex'cited condition. After such a series of intermittent pulse trains have been fed to one set of electrodes, usually for a period of several minutes, the apparatus is switched to a changed condition in which a series of intermittent pulse trains are delivered to a second set of electrodes, for a second period of several minutes, etc., until the entire face has been treated in this manner.

SUMMARY OF THE INVENTION The present invention provides a unique energizing system which enables completion of an entire facial treatment cycle in a considerably shorter period of time than has been possible with prior arrangements of the above discussed type. As a result, there is less inconvenience to the user, and less wear and tear on the energizing circuitry.

These and other advantageous results are attained in unique manner by providing an energizing and timing circuit which supplies high frequency pulse trains to the different electrode structures of a facial stimulating unit in staggered relation, and specifically in a manner delivering the pulse trains to each pair of electrodes during the rest periods for the other electrodes, that is, between two successive pulse trains to another pair of electrodes. The high frequency pulses for all of the different electrode pairs may be supplied by a common oscillator, which may be switched to deliver its output to the different electrode pairs sequentially, so that for a first short interval a train of pulses is fed to a first of the electrode pairs, following which the oscillator is switched to deliver a second train of pulses to a second pair of electrodes, while the first electrodes are in a rest period. After that second period, the oscillator may be automatically switched to deliver a third train of pulses to a third pair of electrodes, while both the first and second electrodes are resting, etc., and all in an optimum pattern repeating many times through a large number of cycles. This automatic switching from one pair of electrodes to another may be controlled by a second oscillator, producing pulses which repeat at a frequency much lower than that of the first mentioned oscillator. The second oscillator may actuate a ring counter or the like to switch the counter and the electrodes between successive conditions in response to the pulses from the second source. It is contemplated that certain features of this control circuitry may have applicability to other types of multiplexing apparatus as well as the facial stimulating equipment herein disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiment illustrated in the accompanying drawings, in which:

FIG. 1 is a front view of a facial stimulating device constructed in accordance with the invention;

FIG. 2 is an enlarged section taken essentially on line 22 of FIG. 1, and showing one of the electrode assemblies of the device;

FIG. 3 is a presently preferred solid state electronic circuit for supplying electrical pulses to the face contacting electrodes of the FIG. 1 device; and

FIG. 4 is a diagrammatic representation of the staggered relation between the pulse trains which are fed to the different electrodes.

DESCRIPTION OF THE PREFERRED EMBODIMENT I In FIG. 1, l have shown at 10 an electrical facial stimulator including a frame 11 which is worn on the face of the user and which carries a number of electrode structures l2, l3, 14, 15, 16, and 17 energized by power from a small battery operated power source 18 including a small case 19 containing a battery 20 and the circuitry shown schematically in FIG. 3. Frame 11 may be of a type worn in a manner similar to a pair of spectacles, and specifically may have a front frame element or section 21 extending across the front of the face and having a portion 22 resting on the bridge of the users nose. Connected to opposite ends of the forward portion 21, frame 11 may have two ear sections or

temples

23 and 24, which extend rearwardly at the sides of the face and rest on and hook over the users ears. The

electrode structures

12, 13, 14, 15, 16, and 17 may be mounted to the

side section

23 and 24 of the frame by six mounting wires 25, connected at first ends to the frame and at opposite free ends to the electrode structures, and adapted to be deformed to different conditions for placing the electrodes in optimum relationship with respect to the facial contours of a particular user of the device. These wires 25 remain by their own stiffness in any set position until further deformed. Insulated electrical wires extend from the electrodes along mounting wires 25 and within downwardly extending multiple conductor cables 26 to the control box 18 for connection to the circuitry in the manner illustrated in FIG. 3.

Preferably, the two

upper electrode structures

12 and 15 and the two

lower electrode structures

16 and 17 are all single electrodes, connected to and energized by 3 the secondary of output transformer 27 in box 18. Electrode structure 14, on the other hand, may be a double electrode, as seen in FIG 2, having an electrically insulative body 28 carrying two spaced

metal electrodes

29 and 30 for contacting the users face at two spaced locations and connected to the secondary coil of a second output transformer 31. Similarly, the electrode structure may be a double electrode, having an insulative body 32 and two metal electrodes 33 and 34 connected to opposite sides of the output coil of a third transformer 35.

Variable resistors

36, 37, and 38 act as amplitude controls for varying the amplitude of the.

electrical pulses fed from the transformers to the various electrodes. These amplitude controls are adjusted by knobs or other manually actuated regulating elements provided on control box 18 and represented at 36, 37', and 38 respectively in FIG. 1.

All of the circuitry shown in FIG. 3 with the exception of the electrodes themselves is contained within the small control box 18 connected by cable 26 to the electrodes. The main power from battery to the different portions of the FIG. 3 circuitry is controlled by an on-off switch 39, actuable by a manually operated toggle lever or other operating element 39 in FIG. 1. Different functional sections of the FIG. 3 circuit have been enclosed within different broken line boxes, to facilitate an understanding of the circuit, with these sections including a first oscillator 40 for producing high frequency pulses, an amplifier 41, a time generator or second oscillator 42, a ring counter 43, and a solid state isolation switching circuit 44. Oscillator 40 may be of the blocking oscillator type, acting to produce in the output coil of its feed-back transformer 45 a series of very short duration pulses having the wave form represented at 46 in the upper portion of FIG. 3. These pulses desirably have a duration t, which is only a very small fraction of the total cycle interval between corresponding portions of two successive pulses. Preferably, the pulse duration is about 50 microseconds, while the interval 1 is many times that length, and preferably approximately 5,000 microseconds. These pulses are generated by blocking oscillator 40 in known manner, by the illustrated circuitry which renders transistor 47 alternately conductive and nonconductive, with the bias of the transistor and the frequency and pulse duration being controlled by the RC time constant of a resistor 48 and capacitor 49 connected into the base circuit to the transistor, and a resistor 50 and capacitor 51 connected between the midpoint on the primary side of transformer 45 and the emitter of the transistor.

The pulses thus developed by blocking oscillator 40 are amplified by transistor 53 of pulse amplifier 41, and are supplied to the primary coil of a transformer 54 whose secondary coil supplies pulses at the same frequency to isolation switching circuit 44, for delivery sequentially to the various output electrodes. In this connection, it is noted that where the word pulse is utilized in the present disclosure without other limitation, it is contemplated that this term is to include alternating current pulses as well as direct current pulses.

The time generator or second oscillator 42 produces in its output line 55 a series of square wave pulses as represented at 56 in FIG. 3, having a one-half duty cycle. That is, the period between successive pulses in this square wave form at 56 is desirably exactly equal to the duration of the individual pulses themselves. To produce this output, the time generator 42 may include an initial oscillator proper 47 acting to produce the sawtooth wave form represented at 58 in an output line 59. This oscillator 57 includes a transistor'59, which is alternately conductive and noncondu'ctive at a frequency dependent upon the RC constant of aresistor 60 and capacitor 61. A diode 62 functions to provide a low resistance charge path for the capacitor 61 in the charge cycle and a high resistance path for discharge so as to hold the transistor base at a positive charge effectively increasing the circuit RC time constant by the beta of the transistor 59.

The output signal from the oscillator proper is fed through line 59 to the gate of a uni-junction transistor 63, connected in series with two

resistors

64 and 65 between the positive and negative sides of power supply battery 20, with the output signal from the field effect transistor being taken beyond a resistor 66 in a line 67 and producing a series of square wave pulses as represented at 68. This square wave signal, with a one-half duty cycle, is delivered to the base of an amplifying transistor 69, whose collector is connected to the positive side of the power source through a resistor 70, to amplify and invert the square wave 68 to the form represented at 56. g

This square wave output is delivered through line 55 to ring counter 43, which may include a series of silicon controlled switches (SCSs) 71, 72, and 73. The anodes of these silicon controlled switches are all connected in parallel to line 55, to receive the square wave input pulses, while the cathodes are all connected to the negative side of the power source. The anode gates are connected through

resistors

74, 75, and 76 to the positive side of the power source, and the cathode gates are connected through

resistors

77, 78, and 79 to the negative side of the power source. The anode gate of SCS 71 is also connected to the cathode gate of the next successive SCS 72 through a capacitor 80, and similar capacitors 81 and 82 connect the other anode and cathode gates in the same manner as illustrated. A low pass noise and transient capacitor 83 is connected between line 55 and the negative side of the power source, to filter out high frequencies from the line 55.

At any particular time during operation of the circuitry, only one of the three

SCSs

71, 72, or 73 is conducting, while the other two SCSs are in nonconducting condition. Each successive pulse 56 in line 55 turns off the SCS which was previously conducting, and turns on the next successive one, so that output signals are provided successively in

lines

84, 85, and 86 connected to the different SCSs in a constantly repeating sequence timed by the input pulses 56 on line 55. More specifically, when SCS 71 for example is conducting, current flows through the resistor 74 and SCS 71 from the positive side of the power source to its negative side in a manner producing a relatively low voltage at the point 87 by virtue of the IR drop across resistor 74. The other two SCSs are not conducting in this condition, and the potential at

points

88 and 89 is therefore rela tively high and substantially at the value of the positive side of the power source. When the counter is in this condition, the next successive pulse on line 55 acts by virtue of the connection of the cathode gate of SCS 72 to the low potential point 87 through capacitor to turn SCS 72 on, while the higher potential at the oathode gate of the SCS 73 prevents that SCS from being turned on. Also, SCS 71 is turned off by the signal coupled from capacitor 82. Similarly, the next successive pulse 56 on line 55 turns the third SCS 73 on, and turns SCS 72 off; and the following pulse turns SCS 73 off and SCS 71 back on again to the condition assumed at the beginning of this discussion.

The output signals on

lines

84, 85,and 86 act through three isolation and amplifying

transistors

90, 91, and 92 to control the flow of current from the secondary side of transformer 54 through the

collector circuits

93, 94, and 95 of these

transistors

90, 91 and 92, respectively. In particular, assume, for example, the condition in which SCS 71 of the ring counter is conducting, and the point 87 is at low potential. That low potential at point 87 turns transistor 90 on, so that current can flow from line 96 through a biasing resistor 97, decoupling resistor 98, and line 93, and then from the collector of transistor 90 to its emitter to line 84, and then through SCS 71 to the negative side of the power source. When this current flows, the drop across resistor 97 biases the base of an associated transistor 99 to a value rendering that transistor also conductive, from its emitter to its collector, to pass the high frequency pulses in line 96 to the primary side of transformer 35, to thus energize the electrodes 33 and 34 of structure 15. Two

additional transistors

100 and 101 are connected to transformers 27 and 31, respectively, and to

transistors

91, and 92, respectively, in the same manner that transistor 99 is connected to transformer 35 and transistor 90, and with the same type of biasing

resistors

102 and 103 and

decoupling resistors

104 and 105 as are provided at 97 and 98 in conjunction with the two first discussed transistors. In the assumed condition in which a low potential signal is present on line 84 but not on

lines

85 and 86, the higher potentials on the latter two lines maintain

transistors

91 and 92 in their off condition, and similarly maintain

transistors

100 and 101 in their off conditions, so that the high frequency pulse train in line 96 is delivered only to the electrode'structure l5, and not to the

electrodes

12, 13, l4, 1 6, or 17. When the next successive pulse 56 arrives at the ring counter, the point 87 and line 84 return to a higher potential condition, and the line 85 moves to a lower potential condition, with this signal acting to turn on

transistors

91 and 100, and to turn off

transistors

90 and 99, so that the pulse train theretofore being delivered to electrodes 33 and 34 ceases insofar as those electrodes are concerned, and the high frequency pulses in line 96 are thereafter delivered through transformer 27 to the

electrodes

12, 13, 16, and 17. After another timed interval, the next successive pulse 56 reaches the ring counter, and switches the apparatus to a condition in which electrode structure 14 is energized by a train of pulses from transformer 54, while the other two groups of electrodes are de-energized. Similarly, the next pulse 56 in line 55 turns off electrode structure 14, and turns on structure 15, to supply the next successive train of pulses thereto, etc.

Referring now to FIG. 4, this staggering of the various pulse trains is illustrated diagrammatically in that figure. Commencing with the vertical line designated O-Time" in that figure, a first series or train of high frequency pulses is represented at 46a, and delivered to electrode structure which contacts the left side of the users face in FIG. 1. The next successive pulse train 46b is delivered to

electrodes

12, 13, 16, and 17, and the next successive pulse train 46c is delivered to electrode structure 14. The cycle then repeats to deliver the next pulse train 46d to electrode structure 15, the following pulse train 46e to electrodes l2, 13, 16, and 17, etc., through a large number of repeating cycles continuing so long as the main control switch 39 is turned on. Thus, each of the electrode pairs is energized with a series of intermittent pulse trains, with rest periods between those intermittent pulse trains, as, for

' example, at 106 in FIG. 4, and with the pulse trains for the different electrodes staggered so that each pulse train is delivered to a particular set of electrodes during the rest periods for the other two sets of electrodes. In this'way, each set of muscles associated with the different electrodes is actuated for a short interval and then released, and then actuated again and released again, in optimum exercising and toning relation; and the rest intervals between such energizations for one set of electrodes are not wasted but rather are utilized as the active or energizing periods for the other sets of electrodes, all in a manner achieving a'complete face exercising cycle in an overall period much shorter than if the individual intermittent pulse trains were not provided in this staggered relation.

While three sets of electrodes have been illustrated in the typical arrangement shown in the drawings, and are preferred for most purposes, it will be apparent that the number of sets of electrodes may be extended to any desired number, by increasing the number of SCS switches in the ring counter, and by correspondingly increasing the number of associated isolation switching circuits and amplitude control circuits.

For best results, it is preferred that each of

thepulse trains

46a, 46b, 46c, etc. have a total duration not over a few seconds, preferably not over about 5 seconds, and optimally between about one-fourth of a second and 2 seconds (typically about one second as assumed in FIG. 4). Similarly, it is preferred that the rest period between successive pulse trains to a particular set of electrodes have a duration not over a few seconds, preferably not over about 10 seconds, and optimally between about one-half of a second and 4 seconds. As a result, the pulse trains to a particular set of electrodes, and the intermediate rest periods between successive pulse trains to the particular set of electrodes, repeat several times per minute, desirably at least about four times and for best results between about 10 and times, optimally about 20 times.

Each of the pulse trains should include a large number of individual pulses, desirably at least about 50 pulses, repeating at a frequency corresponding to many cycles per second, say about 200 cycles per second. To achieve this result, the frequency of oscillator 40 (i.e. the frequency of the pulses in each pulse train) should be many times as great as, desirably at least about 50 times as great as, the frequency of oscillator 57 (i.e., the frequency at which the electrode energization is changed from one set of electrodes to the next set).

A capacitor 110 may be connected across the battery 20 as a DC. power supply filter to suppress transients and prevent unwanted coupling of signals between the different circuits.

To assure completeness of the present disclosure, the various electrical components of the circuit of FIG. 3 may, in the presently preferred form of the invention, have the following values.

9 volts and 38 O-SK potentiometers Transistor 47 Type 2N3906 Resistor 48 51K Capacitor 49 l microfarad Resistor 50 100K Capacitor 5] l microfarad Resistor 52 1.0K Transistor 53 Type 258405 Transformer 54 3.2 ohms primary- 500 ohmssecondary Transformer 45 3.2 ohms primary- 500 ohms secondary Transistor 59 2N3906 Resistor 60 33K Capacitor 6l to L0 microfarad Transistor 63 2N2646 I5 Resistor 64 470 ohms Resistor 65 100 ohms Transistor 69 2N3646 Resistor 70 4.7K

S05

71, 72, and 73

Type 3N84 Resistors

74, 75, and 76

68K Resistors

77, 78, and 79 5lK Capacitors K0, 8], and 82, .002 Capacitor 83 .02 Transistors )0, )l. and 92 Type 2N5S50 Resistors 97, I02, and I03 lOK Resistors 98, I04, and I05 33K Resistors 99, l0(), and I01 Type 2N5400 Transformers 27, 3 l, and l to l Capacitor 1 l0 l25 microfarads While a certain specific embodiment of the present invention has been disclosed as typical, the invention is 35 of course not limited to this particular form, but rather is applicable broadly to all such variations as fall within the scope of the appended claims.

l claim:

1. in facial stimulating apparatus including a plurality of electrode means to be positioned near and stimulate different facial nerves respectively, the combination with said electrode means of:

a first oscillator producing first pulses at a relatively high frequency to be delivered to and energize said 5 electrode means, said first pulses being of very short duration with intervals between successive pulses much longer than the pulses themselves;

a second oscillator producing control pulses at a frequency much lower than the frequency of said first pulses;

a ring counter connected to said second oscillator for actuation thereby and including a series of semiconductor switches actuable between conducting and non-conducting states, and circuit means re- 5 sponsive to said control pulses to actuate said switches successively to a predetermined one of said states in a sequence repeating through many cycles;

a plurality of additional semiconductor switches connected between said first oscillator and said different electrode means respectively and each actuable between a conducting state for delivering a train of said first pulses from the first oscillator to a corresponding one of said electrode means and a nonconducting state blocking off such pulses; and circuit means connecting said additional switches to said switches of the ring counter respectively for control thereby in a relation to simultaneously, in response to the same control pulse from said second oscillator, commence conduction of said first pulses through one of said additional switches to the corresponding electrode means and at the same time terminate conduction through a preceding one of said additional switches to the preceding electrode means,

said second oscillator having a frequency causing each of said additional switches, on each actuation, to pass to the corresponding electrode means a pulse train consisting of many of said first pulses but continuing for not more than a few seconds.

2. The combination as recited in claim 1, including a plurality of transformers connected between said additional semiconductor switches and said electrode means respectively.

3. The combination as recited in claim said first oscillator is a blocking oscillator.

4. The combination as recited in claim 1, in which said switches of the ring counter are silicon controlled switches, and said additional switches are transistors.

5. The combination as recited in claim 1, in which said switches of the ring counter are silicon controlled switches, and said additional switches are transistors, there being a plurality of driver transistors connected between said silicon controlled switches and said additional switches, respectively.

6. The combination as recited in claim 1, in which said second oscillator has a frequency giving said individual trains of pulses a duration in time between about one fourth of a second and 2 seconds.

1, in which 7. The combination as recited in claim 1, in which said switches of the ring counter are silicon controlled switches, and said additional switches are transistors, there being a plurality of driver transistors connected between said silicon controlled switches and said additional switches respectively, an amplifier for amplifying the output of said first oscillator, a transformer between said amplifier and said additional switches, a plurality of additional transformers connected between said additional switches and said electrode means respectively, and a plurality of adjustable attenuating means between said additional transformers and their respective electrode means operable to separately and controllably vary the intensity of the pulse trains delivered to the different electrode means, said first oscillator being a blocking oscillator,- and said second oscillator having a frequency giving said individual trains of pulses a duration in time between about one fourth of a second and 2 seconds.

Claims

1. In facial stimulating apparatus including a plurality of electrode means to be positioned near and stimulate different facial nerves respectively, the combination with said electrode means of: a first oscillator producing first pulses at a relatively high frequency to be delivered to and energize said electrode means, said first pulses being of very short duration with Intervals between successive pulses much longer than the pulses themselves; a second oscillator producing control pulses at a frequency much lower than the frequency of said first pulses; a ring counter connected to said second oscillator for actuation thereby and including a series of semi-conductor switches actuable between conducting and non-conducting states, and circuit means responsive to said control pulses to actuate said switches successively to a predetermined one of said states in a sequence repeating through many cycles; a plurality of additional semiconductor switches connected between said first oscillator and said different electrode means respectively and each actuable between a conducting state for delivering a train of said first pulses from the first oscillator to a corresponding one of said electrode means and a non-conducting state blocking off such pulses; and circuit means connecting said additional switches to said switches of the ring counter respectively for control thereby in a relation to simultaneously, in response to the same control pulse from said second oscillator, commence conduction of said first pulses through one of said additional switches to the corresponding electrode means and at the same time terminate conduction through a preceding one of said additional switches to the preceding electrode means, said second oscillator having a frequency causing each of said additional switches, on each actuation, to pass to the corresponding electrode means a pulse train consisting of many of said first pulses but continuing for not more than a few seconds.

3. The combination as recited in claim 1, in which said first oscillator is a blocking oscillator.

7. The combination as recited in claim 1, in which said switches of the ring counter are silicon controlled switches, and said additional switches are transistors, there being a plurality of driver transistors connected between said silicon controlled switches and said additional switches respectively, an amplifier for amplifying the output of said first oscillator, a transformer between said amplifier and said additional switches, a plurality of additional transformers connected between said additional switches and said electrode means respectively, and a plurality of adjustable attenuating means between said additional transformers and their respective electrode means operable to separately and controllably vary the intensity of the pulse trains delivered to the different electrode means, said first oscillator being a blocking oscillator, and said second oscillator having a frequency giving said individual trains of pulses a duration in time between about one fourth of a second and 2 seconds.