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The invention relates to an apparatus and a method for the treatment and
active massage of muscles.
It should be noted that in the present application, the words "treating"
and "treatment" do not intend to relate to the medical meaning of this
word, such as in the sense of "caring for a patient" or a part of his or
her body, or of "seeking cure or relief of a disease", but they relate to
"handling, managing, dealing with" (namely the body of a person or parts
thereof), or to "subjecting the same to some action" or to "process for
improvement", such as appearance, well-being, cleanliness, etc.
It has already been sought to provide treatment and active massage of human
muscles by means of electric currents. The use of direct, so-called
galvanic currents, either continuous or intermittent, has been proposed,
but this has the drawback of causing painful contractions of the muslces,
despite which the method is still used.
Rectified or non-rectified alternating currents with a low frequency of the
order of 50 to 100 Hz have also been tried, but they may involve
tetanization which is unpleasant for the treated person and makes the
method unsuitable. Tetanization is characterized by chronic spasms of the
voluntary muscles of the human body similar to the muscular tetanus, which
is an acute infectious disease.
The use of alternating currents at medium frequency (according to
physiologists' terminology, essentially between 3000 and 100,000 Hz) does
not cause painful sensations. On the contrary, it causes permanent,
painless contractures. The effect is analogous to that of non-intermittent
direct currents with, however, the advantage of not producing unpleasant
sensations. However, permanent contractures are not suitable for the
treatment and active massage of the muscles.
The use of high-frequency alternating currents (again, according to
physiologists' terminology, above 100,000 Hz) simply causes heating of the
tissues (called diathermy) but causes neither contractions nor pain. It is
thus likewise unsuitable for therapeutic treatment of the muscles.
For the re-education of the muscles, i.e. in order to produce active
massage, the muscles must work regularly, that is to say, contract and
relax periodically at a very low frequency, such as a fraction of one
cycle or 1 Hz. Up until now, it has been impossible to provoke such
working of the muscles without pain by means of electrical currents.
Indeed, the use of direct currents, as we have seen, is unsuitable because
painful; the use of alternating currents at low frequencies is likewise
unsuitable because painful; the use of alternating currents at medium
frequency is also unsuitable because it does not provoke periodical
contractions of the muscles.
The inventors have overcome this apparent impossibility of creating a
therapeutic treatment of the muscles by means of electrical currents, by
combining the simultaneous use of (physiologically) medium-frequency
alternating currents and low-frequency alternating currents, in that the
former are modulated by means of the latter. As claimed herein, a
practical range has been established for the medium frequency, between
3000 and 100,000 Hz, the most efficient frequencies being between 5000 and
20,000 Hz. As for the low frequency, the preferred practical frequency has
been found of the order of a fraction of 1 Hz.
The inventors have thus obtained the surprising effect that, due to the
presence of the medium-frequency carrier current, the modulation in
amplitude by means of the low-frequency current allows rhythmical
contractions to be obtained at the frequency of the modulating current,
without producing any disagreeable sensations for the patient.
In other words, the fact that a medium-frequency carrier current is used
eliminates the painful effect which would be felt if the low-frequency
current were applied alone. This painful effect disappears when the
low-frequency current is applied for modulating the carrier current. This
unexpected and surprising effect had never been noticed until the present
inventors conceived the invention.
It is admitted that conventional designations of "low", "medium" and "high
frequencies" in electronics do not exactly coincide with the ranges used
herein, according to the physiologists' determinations. Among
physiologists, the generally accepted medium frequency range runs between
3000 Hz and 100,000 Hz (see for example Takao Kumazava: Excitation of
muscle fibre membrane by means of transversely applied middle-frequency
current pulse, in Helvetica Physiologica et Pharmacologica Acta, 26, 1969,
p. 257).
The explanation of the paradox of the above-explained unexpected and
surprising effect of the present invention is the following: an
alternating current at (physiologically) medium frequency produces a
permanent contraction of the muscles as soon as the maximum amplitude
exceeds a certain limit. By modulating a medium-frequency carrier current
at a very low frequency, the amplitude of the modulated medium-frequency
current is made to vary periodically to the rhythm of the low-frequency
modulation. The rate of modulation is selected so that the amplitude of
the modulated current varies periodically between values respectively
lower and higher than the threshold. The result is a rhythmical
contraction of the muscles at the very low frequency. Since the
low-frequency current does not act as such on the muscle, the treatment is
painless. It is the medium frequency which produces the contractions
(again, in a painless manner), and the modulation gives (similarly
painlessly) a rhythm to these contractions. By varying the low frequency
of the modulating current, the rhythm of the contractions is varied.
Another observation on which the invention is based is that the modulated
current does not produce unpleasant effects when the carrier current, and
also preferably the modulating current is sinusoidal, i.e. it is exempt
from harmonic distortions and abrupt variations which would be liable to
produce painful effects.
It has also been observed that the treatment may be further improved by
using, instead of a monophase modulated current, a polyphase current
modulated in the same way, preferably a triphase current. The use of a
polyphase current offers the advantage that it permits a deeper action on
the muscles than monophase current which latter tends to concentrate its
action along the shortest path.
It is also the object of the present invention to provide the aforesaid
apparatus to promote general well-being, remove fatigue from human
muscles, which apparatus can in some instances also be considered a
substitute for physical exercise.
It is the object of the invention to provide an apparatus and a method for
the treatment and active massage of muscles while avoiding tetanization or
other effects which cause pain.
The apparatus according to the invention is characterized in that it
comprises generator means providing a modulated alternating current that
includes a carrier current with a frequency between 3000 and 100,000 Hz,
and a current for modulating the carrier current, the modulator current
having a frequency of the order of a fraction of 1 Hz, at least the
carrier current of the two currents being sinusoidal, at the exclusion of
intermittent frequency effects, and at least two electrodes for supplying
the resulting variable modulated current to a body portion wherein muscles
are to be treated, in placing the electrodes on the surface of and in
contact with the skin, whereby the resulting modulated current flows
transversally through and acts deeply on the muscles, and produces
painless rhythmic muscular contractions.
The method according to the invention is characterized by essentially
comprising the steps of: generating a modulated alternating current that
includes a carrier current with a frequency between 3000 Hz and 100,000
Hz, and a modulator current having a frequency of the order of a fraction
of 1 Hz; modulating the carrier current with the modulator current wherein
at least the carrier current of the two currents is sinusoidal, leading
the resulting modulated current to at least two electrodes adapted to be
associated with a body portion wherein the muscles are to be treated;
placing the electrodes on the surface of and in contact with the skin of
the body portion; and thereby inducing a transversal flow of the resulting
modulated current through the muscles, acting deeply thereon, and
producing painless rhythmic muscular contractions that treat and massage
those muscles, at the exclusion of intermittent frequency effects being
applied to the body portion.
Other objects and many of the attendant advantages of the invention will be
readily appreciated as the same becomes better understood by reference to
the following detailed description, when considered with the accompanying
drawings which shows, by way of an example, an exemplary embodiment of the
treating and massaging apparatus according to the invention, and an
explanation of the inventive method. Both will be described simultaneously
.
FIG. 1 is an external view of an embodiment of the apparatus according to
the invention, the input current of which is an alternating monophase
current, whereas its output is a modulated triphase current as explained
hereinafter;
FIG. 2 is a block diagram showing the different units of the apparatus
according to FIG. 1;
FIG. 3 is a wiring diagram of a power supply unit (SU);
FIG. 4 is a wiring diagram of a low-frequency alternating modulating
current unit (LF), a modulator (M) and a medium frequency generator unit
(MF), also in FIG. 2;
FIG. 5 is a wiring diagram of a phase shifter (PS) converting the monophase
output modulated current of the MF unit into a triphase modulated current;
and
FIG. 6 is a wiring diagram of three amplifiers A.sub.1, A.sub.2, A.sub.3 in
FIG. 2, amplifying the output three-phase currents of unit PS.
FIG. 7 is a block diagram of a second embodiment of the invention employing
a 90.degree. phase shifter.
Referring to FIGS. 1 and 2, the apparatus comprises a power supply unit
designated SU, a conventional generator MF providing a sinusoidal
alternating carrier current of a sufficiently high frequency as not to be
painful, for example between 3000 and 100,000 Hz, preferably between 3000
and 20,000 Hz, and a generator LF providing a sinusoidal low-frequency
alternating modulating current at a frequency for example of the order of
1/5 to 1/10 Hz. The current delivered by generator MF is a carrier
current, and that delivered by generator LF is a modulating current that
serves to modulate the carrier current. Generator LF is preferably
adjustable both in amperage and frequency, as schematically indicated.
Modulation of the current delivered by generator MF by the output current
of generator LF is performed in a modulator M which is preferably arranged
in a known manner to enable adjustment of the degree of modulation.
The monophase output current of modulator M is optionally delivered to a
phase shifter PS transforming it into a triphase current modulated in the
same manner. The three phases are designated by numerals 1, 2 and 3 and
delivered to respective amplifiers A.sub.1, A.sub.2 and A.sub.3 whose
lead-outs are connected to respective electrodes 4, 5 and 6.
These electrodes are shown applied to a human limb 7, for example an arm,
whose bone is schematically shown at 8 and a muscular part at 9.
The three electrodes 4, 5, 6 are angularly spaced apart, preferably
symmetrically, about the limb 7 being treated. It can readily be
appreciated that the use of a triphase current permits a deep and fairly
uniform action of the current on the muscles 9 of the arm. It can also be
seen from the drawing that the electrodes 4, 5, 6 are placed about and in
contact with the limb 7 so that the modulated current flows transversally
through the muscles 9.
In order that the invention be fully understood, the wiring of the various
units, shown diagrammatically in FIG. 2, is shown in detail in FIGS. 3 to
6, and the apparatus itself is illustrated in FIG. 1 to wich reference
will be had later.
The wiring diagrams of FIGS. 3 to 6 are conventional. Explanations will be
given to the extent necessary for a good understanding of the invention.
Power Supply Unit SU (FIG. 3)
This is a conventional supply, itself supplied with monophase alternating
current and providing a d.c. voltage of -15 V and -35 V in relation to
ground 0.
Three stabilisation transistors BD 136, BD 137 and BDY20 provide direct
current amplification (e.g. a Darlington circuit). The polarization of the
transistor BD136 is controlled by a Zener diode BZY88C6V8. A
potentiometer 1K permits the maximum output voltage to be fixed at -35 V
in relation to the ground O. A condenser 470.mu.F between the -35 V and
the ground serves to improve the filtering of the -35 V. A zener diode
BZY95C15 allows the obtention of a stable voltage of -15 V in relation to
the ground O. A condenser 220.mu.F between the -15 V and the O serves to
improve the filtering of the -15 V. A condenser 1.mu.F between the cursor
of the potentiometer 1K and the ground serves to reduce the residual
undulation voltage. A resistor 10K between the anode of the zener diode
BZY88C6V8 and the ground O has been selected so that the output current
discharged by the power supply unit SU is limited to 2.5 amperes. Thus a
short-circuit between the O and the -35 V cannot cause any damage, since
the transistor BD 136 will be blocked. Thus no current will circulate in
the power transistor BDY20.
Only a low current will pass through a resistor 4K/5W used to provide the
necessary current for the diode BZY88C6V8 at the time of switching on.
Low-frequency alternating modulating current unit LF (FIG. 4)
This is a conventional generator of sinusoidal current the frequency of
which is, in the example shown, optionally of either 1/5 Hz (1 period= 12
seconds) or 1/10 Hz (1 period== 6 seconds). The choice between these two
frequencies is made by means of a switch button S having two positions and
which actuates simultaneously three switches S1, S2, S3 (FIG. 4). The open
positions of these switches correspond to deactivation of one of each of
pairs of condensers 2,2.mu.F and 4,7.mu.F. The closed positions correspond
to the parallel connection of the two condensers in each pair. In the
example, one of the positions (12 sec.) corresponds to a frequency of 1/5
Hz and the other (6 sec.) to a frequency of 1/10 Hz, as was just explained
(see the respective positions of the switch S in FIG. 1.
A transistor BC109C, which has an amplification coefficient of at least
500, oscillates in double T mode and gives a choice of one of the two
frequencies in question.
The low-frequency alternating sinusoidal current generated by the LF unit
serves, as will be seen further on, to modulate a carrier current at
medium frequency.
Modulator unit M (FIG. 4)
The sinusoidal voltage at low frequency generated by the unit LF is drawn
off at a point C of this unit (FIG. 4) and applied to the base of a
transistor 1BC109C of the unit M through a resistor 1M5. This transistor
serves as an impedance changer.
A variable resistor 10K serves to adjust the maximum of the modulation
rate. A variable resistor 22K serves to polarize a second transistor
2BC109C which is a modulator. A potentiometer 25K which is actuated by a
switch MS (ten positions being indentified in FIG. 1) serves to regulate,
as desired, the modulation rate up to a maximum fixed by the resistor 10K.
When the cursor of the switch MS or potentiometer 25K reaches the potential
-15 V, one adjusts the polarization of the base of the transistor 2BC109C
by means of the variable resistor 22K so as to obtain a direct current of
about 1 V between a point X and the -15 V. By moving the cursor of MS away
from the -15 V, a voltage varying according to the rhythm of the LF
oscillation is obtained on the base of the transistor 2BC109C, which
produces a synchronous variation of the voltage at the point X, which
determines the modulation, as will be seen when the unit MF is described
hereinafter.
Medium-frequency generator unit MF (FIG. 4)
This generator is a conventional LC oscillator generating a sinusoidal
current having a frequency between 3000 Hz and 20,000 Hz. In the example
under consideration, this frequency is of 11,000 Hz. This current is
intended for modulation by the low frequency current generated by the unit
LF; it is thus the carrier current.
The transistor BC109C of unit MF performs as a reaction oscillator with
modulation by the collector. T1 is a transformer comprising three coils
N1, N2, N3.
The supply voltage of the collector of this transistor is provided by the
point X of the unit M. The amplitude of the alternating medium-frequency
voltage is thus a function of the instantaneous voltage at the point X.
A cursor of a potentiometer 25K of MF is actuated by a switch P (see the
positions 1 to 10 in FIG. 1) and serves to regulate the output voltage of
the modulated current, i.e. of the output power.
The potentiometer 25K of M, actuated by the switch MS of FIG. 1, serves, as
already stated, to regulate the modulation rate. When its cursor is at -15
V, the generator MF produces a frequency of 11,000 unmodulated Hz at the
potentiometer 25K (switch P) of MF. By moving the cursor away from the
point -15 V, a variable sinusoidal voltage at the frequency of LF is
obtained at X, and this produces the modulation. The modulation rate is
regulated by a potentiometer 25K of M (switch MS), as already stated.
I is a switch between units M and MF controlled by a timer the control
button T of which is shown in FIG. 1. It serves to regulate as desired the
duration of the patient's treatment by means of the apparatus. A resistor
1K and the condenser 470.mu.F of M, inserted after the switch I, produce a
time constant which causes the voltage to vary slowly at X when switched
on and off in order to avoid shocks to the patient.
Phase shifter unit PS (FIG. 5)
This is a phase converter changing the monophase modulated current into a
three-phase modulated current (of the same frequency and modulated in the
same manner as the monophase current provided by the unit MF of FIG. 4).
A first of three transistors, 1BC109C, receives through an input L the
modulated control voltage of a point L of the output of MF, thus through
the switch P or potentiometer 25K (of MF) and a condenser 1.mu.F (both of
MF).
At an output terminal U, i.e. at a cursor of a first potentiometer 220 E,
placed between the emitter of this first transistor and the -35 V, a
voltage is obtained which is in phase with that of 11,000 Hz generated by
MF and modulated by the low frequency of LF.
A second transistor, 2BC109C provides at a terminal V a voltage identical
to that provided at U by the first transistor, but with a lead of
120.degree. relative ro the voltage at U. This dephasing takes place
through a phase-shift network constituted by a resistor 2K2 and a
condenser 10K. A Zener diode BZY88 serves to supply the polarization to
the transistor 2BC109C.
A third transistor, 3BC109C, provides at a terminal W a voltage which is
identical to that of V but with a lead of 120.degree. in relation thereto.
A phase-shift network is identical to that of the second transistor, as
may be seen in FIG. 5. The circuits leading to the terminals V and W are
substantially identical with that described for U.
The three potentiometers 220 E are adjusted once and for all in order to
balance the voltages of the three phases.
Amplifying units A1, A2, A3 (FIG. 6)
Since the voltages at U, V and W (FIG. 5) are low, it is necessary to
amplify them respectively by means of amplifying phase units A1, A2 and
A3. These three units are identical as may be seen in FIG. 6. Hence only
one of them will be described. The respective inputs U, V, W correspond to
the output terminals of unit PS.
A transistor BD235 is a preamplifier. Between its collector and the ground
O, a transformer T2 is inserted comprising a primary coils reactor 1N1 and
two identical secondary coil 1N2, 1N'2 connected to the bases of two
output transistors 1BDY20 and 2BDY20. The emitters of these transistors
are connected to two identical primary coils 2N1 and 2N'1 of a transformer
T3, one of the ends of the secondary 2N2 of which leads to a phase output
terminal Z1 of the unit A1 (terminals Z2, Z3 for A2 and A3, respectively)
by means of a milliamperemeter M1 (and similar meters M2, M3) which latter
also appear in FIG. 1.
The other end of this secondary, Y1, is connected to corresponding outputs
Y2, Y3 of the two other phases in units A2, A3. It may be seen that this
is a star-connected circuit.
On the bottom part of FIG. 6, the right-hand side of FIG. 2 has been
repeated, to make for easier understanding.
Electrodes 4 to 6 are placed on the limb at a location sufficiently distant
from motory points or muscles of the body. FIG. 1 illustrates a preferred,
exemplary embodiment of the inventive apparatus with the various controls
that have been described so far in connection with the FIGS. 4 and 6. The
three instruments identified by M1, M2 and M3 are the milliammeters for
measuring the intensity of the respective phases of the variable modulated
current that is being applied to the patient during the treatment; they
also appear within the circuits of the respective amplifiers A1, A2 and A3
of FIG. 6. Control T identifies the knob of the timer that is set by hand
to the chosen time of application of the apparatus to the patient, also
appearing in FIG. 4 between the units M and MF. Element P is the knob for
adjusting the intensity of the current being applied, the electric
circuitry being shown at the right-hand end of FIG. 4, within unit MF.
Control MS in FIG. 1 is the knob for adjusting the degree of modulation of
the output current, as shown in the circuit of unit M that forms part of
FIG. 4. Finally, S is the knob for adjusting the period, in seconds, of
the modulating current, namely 6 or 12 seconds, as was explained. A
conventional push-button marked "POWER ON/OFF" is also shown underneath
the knob S, for energizing and disconnecting the apparatus; this may
correspond, for example, to a simple switch or interrupter in the primary
220V input of the unit SU in FIG. 3.
As a variation, a modified phase shifter providing a bi-phase current can
be used to supply four application electrodes disposed in principle at
90.degree. to another. Referring to FIG. 7, there is shown a 90.degree.
phase shifter 100 for dividing the output of the modulator M into two
components 90.degree. out of phase with each other. These components are
coupled through amplifiers 101 and 102 to electrodes 103 to 106 which are
angularly spaced apart, preferably symetrically as shown, about the limb
107 being treated, the output of amplifier 101 being coupled across
electrodes 105 and 106 and the output of amplifier 102 being coupled
across electrodes 103 and 104.
As another variation, it might be possible to apply the modulated monophase
current, namely the output of unit M, directly to a single electrode; this
is suitable in cases where it is not essential to have a large
distribution of current in a plane transverse to the muscles. It will be
understood that with only one electrode being applied, ground is used to
constitute the other electrode.
Use of the inventive apparatus and method has shown in practice that it can
absolutely produce painless rhythmic muscular contractions at a variable
frequency; this is exactly what one has to date sought to obtain for the
treatment and active massage of muscles, and for enhancing general
well-being. As has been mentioned in the introduction, intermittent or
impulse-type currents are avoided in the present invention, which cause
painful sensations and unpleasant effects. Experience has shown that
impulse-type stimulation of muscles and body portions results in
synchronized excitatory effects that are liable to become very painful.
The described apparatus enables the production of rhythmic contractions at
the frequency of the modulating current, these contractions being painless
because the modulated current (which alone acts on the muscles) is a
current of sufficiently high frequency, and hence painless. Only the
amplitude of this high-frequency current varies according to the
modulation, and this does not produce tetanization if the carrier and
modulating currents are sinusoidal.
Although the preceding description has been concerned with the treatment of
the muscles of limbs of the human body, it is clear that muscles of other
parts of the body may be treated in a similar manner and with the same
advantages.
It should be understood, of course, that the foregoing disclosure relates
only to preferred embodiments of the inventive apparatus and method, and
that it is intended to cover all changes and modifications of the example
described which do not constitute departures from the spirit and scope of
the invention.
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