FR2504395A1 - Medical electric equipment for treating injured muscles - includes circuit providing pulses of increasing amplitude to electrodes to determine appropriate amplitude level which is memorised - Google Patents

Abstract

The medical electrical equipment for diagnosis and treatment of muscular injuries includes electrodes for applying pulses of controlled slope to the muscles. A series of pulses of fixed frequency and fixed duration, but increasing amplitude are applied. A manual control is provided to stop the increase in amplitude when a muscular reaction is observed in the patient. This partic. amplitude value is memorised. A second series of pulses of different fixed duration is then applied and the process repeated. Once the results of these two tests are known, then treatment using pulses of constant amplitude may be applied at the most suitable level. A clock and digital logic circuit control the operation of the two test sequences.

Description

 The present invention relates to an electrological apparatus for the diagnosis and treatment of muscle damage.

 Known therapies of this kind consist in causing muscle contraction either by depolarization of the motor nerve or by direct action on the muscle fibers. They are used for the medical rehabilitation of sluggish or denervated muscles, or to give normal physical exercise to a healthy muscle.

 The devices generally used for treatments of this kind most often target the case of partially or totally denervated muscles. To this end, they make it possible to apply to the muscle a series of pulses in the form of a ramp having a given slope, selectable from a series of simple values.

 In addition to the fact that these devices do not lend themselves to other types of treatment, such as those applicable to healthy muscles, they do not in any way make it possible to establish an accurate diagnosis of the state of the muscle. However, in this matter, inappropriate treatment can cause serious damage, often irreparable, eliminating any possibility of subsequent recovery.

 There is an electro-diagnostic procedure known as the De Bisschop procedure, which allows on the one hand to locate the category in which the muscle in question falls (healthy, partially edgy or totally denervated), and secondly, in the most typical case - of the partially denervated muscle, to select between limits the effective values of the ramps of the curative impulses.

More precisely, according to this procedure, the category of muscle to which we are dealing is determined by determining, in a first test, the minimum intensity F of a pulse of a millisecond necessary to observe a contraction, and, in a second test, the minimum intensity G of a pulse of 300 ms necessary to observe a contraction. It has been shown that the value of the quotient
F / G was significant for muscle condition.

 In currently known devices, it is only possible to try a certain number of slopes of pulses until a contraction is observed, then to apply pulses having such a ramp for a curative purpose.

 We are therefore in the presence on the one hand of an uncertain diagnosis, since it is carried out by trial and error, and on the other hand of an incomplete treatment which, by the uniqueness of the slope used, in fact only applies a specific category of muscle fibers.

The present invention aims to produce an apparatus which, by application of the De Bisschop procedure, provides
an accurate diagnosis, which then allows for appropriate and effective treatment.

According to the invention, the electrological apparatus for the diagnosis and treatment of muscular lesions comprises means for applying to the muscle, by means of electrodes, electrical pulses of predetermined slope. It is characterized in that it includes:
means for applying to the muscle, in a first test, a first series of pulses of fixed frequency, of fixed given duration corresponding to a first test value and of increasing amplitude;
manual control means for stopping the growth of the amplitude on observation of a muscular reaction of the patient and for storing the current value (F) of the amplitude; and
analogous means for applying to the muscle, in a second test, pulses of different fixed duration corresponding to a second test value and for storing the value (G) of the amplitude reached in the second test.

 The determination of the quantities F and G allows, by the calculation of their quotient, the immediate determination of the state of the muscle and the nature of the treatment which must be applied to it. The device therefore allows an accurate and efficient diagnosis.

 According to an advantageous embodiment of the invention, the apparatus comprises a logic discrimination stage connected to the storage stages for emitting a signal as a function of the relative values of the values (F; G) contained in these stages.

 The device provides directly and without calculation the indication of the diagnosis and the treatment to be carried out.

 According to a preferred embodiment of the invention, the logic discrimination stage is linked to a certain number of diagnostic and processing systems to selectively activate one of these systems according to the relative values of the signals applied to the input of the logical stage.

 Thanks to this provision, any error by the therapist is excluded since it is impossible to apply inappropriate treatment.

 The apparatus comprises, for this purpose, a first processing system for healthy muscle for applying to the muscle a sinusoidal signal at constant frequency of amplitude modulated according to a predetermined frequency.

 It also includes a second diagnostic and treatment system for partially denervated muscle, this system comprising means for applying to the muscle a series of triangular pulses of decreasing slope and means for memorizing the respective slopes of the first and last of those impulses that cause the muscle to contract.

 In this case, it is important to specify the treatment to be applied by an additional test.

 To apply the treatment, the second diagnostic and treatment system comprises means for applying to the muscle successive trains of triangular pulses whose slope varies, in each train, between the aforementioned slopes of the first and the last pulse which cause muscle contraction.

 Finally, the device includes a third treatment system for fully denervated muscles, this system comprising a pulse transmitter of fixed frequency and constant amplitude.

 Other features and advantages of the invention will emerge from the detailed description which follows.

In the accompanying drawings, given by way of nonlimiting example:
Figure 1 is a block diagram of the entire apparatus;
Figure 2 is a diagram of a pulse generator for applying the initial tests;
FIG. 3 is a time diagram relating to this generator;
Figures 4 and 5 show the pulses applied respectively during the two initial tests;
Figure 6 is a diagram # of the discrimination stage;
FIG. 7 is a diagram of the treatment stage for healthy innervated muscles;
Figures 8 to 13 show the signal values at different points in the circuit of Figure 7;
FIG. 14 is a diagram of part of the diagnostic and treatment stage for partially denervated muscles, corresponding to the test function of this stage; ;
Figures 15 and 16 show the test pulses successively applied by the stage portion shown in Figure 14;
FIG. 17 is a diagram of another part of the preceding stage, corresponding to the processing function of this stage;
FIG. 18 represents pulses emitted by the stage part represented in FIG. 14.

 With reference to FIG. 1, the apparatus comprises two pulse generators 1 and 1 arranged to emit pulses of regularly increasing intensity, of fixed duration, respectively equal to 1 ms for the generator 1 and to 300 ms for the generator the.

 These generators are activated via respective pedals 2 and 2a which can be actuated by the therapist.

 The pulses emitted, I and la respectively are applied to the muscle and stop growing when the pedals 2, 2a are released. Their respective values F and G are then kept in storage steps 3, 3a connected to the generators 1, la.

 The memories 3, 3a are connected at the output to a discrimination stage 5 which, depending on whether the F / G quotient is less than 2, between 2 and 20, or greater than 20, respectively activates a treatment stage 6 for healthy muscles , a diagnostic and treatment stage 7 for partially denervated muscles, or a treatment stage 8 for totally denervated muscles.

 We will now describe in detail, with reference to FIG. 2, the generator 1, it being understood that this description will be valid, with certain details, for the generator 1a.

 A clock 9 emits pulses with a period equal to one second and attacks a monostable 11 adjusted by means of a resistance-capacitance system over a period of one millisecond.

The monostable output attacks, via an AND gate 12, a binary counter 13. The other input of the AND gate is connected to an activation circuit which can be closed by pedal 2.

 The counter 13 is connected to an analog digital converter 14, the output of which is connected to the input of an analog switch 15, the control input of which is connected to the output of the monostable 11.

 The pulses I appear on output 16 of switch 15, which is connected to ground via a resistor R.

 FIG. 3 shows a time diagram of the operation of this stage.

 The pulses of the clock 9 (curve A) give rise to pulses (curve B) of duration 1 ms defined by the monostable 11 which attack, by their falling edge, the counter 13, as long as the door 12 is open.

 The converter 14 delivers a staircase voltage (curve D) which increases with each incrementation of the counter 13. This voltage appears on the output 16 only during the duration of the pulses from the monostable 11 (curve E).

 One thus obtains, as long as the pedal 2 is depressed, a series of isochronous pulses I, of fixed duration and of increasing intensity (FIG. 4).

 When the pedal 2 is released, the activation signal (curve C) driving the door 12 drops to zero and the content of the counter 13 remains constant. The converter 14 delivers a constant signal and the pulses I stop increasing in intensity.

 The counter 13 therefore plays the role of the memory 3 mentioned above.

 To use the device, the therapist applies output 16 to the muscle to be studied and presses on pedal 2.

Pulses I of period ls, of duration 1 ms and of increasing intensity from 0 to 60 m A in steps of 1 m A are applied to the muscle. As soon as he notices a contraction of the muscle, he releases the pedal and the intensity F of the first impulse which caused the contraction is kept in memory.

 Then the therapist repeats the same operation with the generator 1a which differs from generator 1 only by the duration of the monostable which is here 300 ms. When he releases the pedal, the intensity G of the first of the pulses la (FIG. 5) which caused the contraction is stored in memory.

 The outputs 16 and 16a of the generator are connected to the discrimination stage 5.

 This stage (FIG. 6) includes two comparators 17, 18. The first has its input - connected to output 16 by means of a divider by two 19 to receive the quantity F / 2, and its input + connected to the output 16a to receive the quantity G. The second has its input - connected to the output 16a to receive the quantity G and its input + connected to the output 16 via a divider by twenty 21 to receive the quantity F / 20.

 We understand that these two comparators compare the F / G ratio to 2 and 20 respectively.

Comparator 17 attacks three doors in parallel
AND 22,23,24, the first directly, and the other two via an inverter 25.

 The comparator 18 drives the same three doors, the first two via an inverter 26, and the third directly.

 Protection diodes 27 are provided at the output of the comparators.

It is understood that the three processing stages 6,7,8 connected at the output to the doors are activated respectively if
F / G is less than 2, between 2 and 20 or more than 20.

 We will now describe in detail the treatment stage 6, reserved for healthy innervated muscles. The principle of this treatment consists in applying to the muscle isochronous impulses of the order of 4500 Hz, the intensity of which can be modulated according to a rectified or non-rectified sinusoid and the frequency of which can be wobulated according to an exponential between 1 and 200 Hz.

 This stage (FIG. 7) comprises a voltage-frequency converter 28 with sinusoidal output, the input 29 of which can be connected, via a switch 31, either to an exponential signal generator 32, or to a source of constant voltage V1. The converter is supplied via an AND gate 33, an input of which is connected to the output of gate 22 of the discrimination stage 5, so that the processing stage 6 can only operate if it is the type of corresponding treatment that has been prescribed.

 The rest of the stage can be connected by a switch 34 either to the converter 28, or to a constant voltage source V2.

 The common point of the switch 34 is connected in parallel to the negative input of an inverting amplifier-amplifier 35 and to the negative input of an amplifier-summator 36. To this same input is also connected the output of the 'inverting amplifier 35. The positive inputs of these two amplifiers are connected to ground via resistors.

 The two lines attacking the negative input of the amplifier-summator 36 can be grounded by analog switches 37,38 whose control input is connected to a rectangular signal generator 39, the first directly and the other via an inverter 41.

 The curves of FIGS. 8 and 9 represent the voltages U1 and U2 applied to the input of the switches 37 and 38 on the assumption that the input of the converter 28 is connected to the constant tensio # n V1 and where the switch 34 is connected to the converter output 28.

It results from the action of the analog switches 37,38 and the summation in the amplifier 36 that the pulses J collected on the output 42 of this amplifier
sounds of isochronous rectangular pulses of alternating sign whose intensity is modulated according to a sinusoid (figure 10).

 This modulation can be eliminated by connecting the switch 34 to the constant voltage V2. It is also possible to wobble the modulation by connecting the switch 31 to the exponential signal generator 32.

We can also plan to carry out the pulses
J following successive trains separated by rest times using a device of the type described in French patent 81 03 718.

 The output 42 of the summing amplifier 36 drives an active low-pass filter 40 arranged to put the series of pulses J in the form of a sinusoidal signal S1 (Figure 11). This signal leads on the one hand to a terminal B1 to be applied to the muscle and on the other hand to a rectifier 50 comprising two output terminals 52, B3 delivering a rectified signal with single alternation S2 respectively (FIG. 12) and with double alternation S3 (figure 13), for application to the muscle according to the therapeutic choice made.

 We will now describe, with reference to FIGS. 14 to 17, the second stage 7 of diagnosis and treatment applicable to partially denervated muscles. This stage is broken down into a "diagnostic" part ~ 7a (FIG. 14), which makes it possible to perform a additional test, and a "treatment" part 7b (FIG. 1 #).

 In general, this mode of treatment consists in applying to the muscle, in a known manner, triangular pulses having a certain slope. The "diagnostic" part allows you to determine the optimal value of this slope.

 In reality, the two parts of floor 7 are closely interleaved and have common elements, and it is only for convenience of representation and description that they have been dissociated.

 A clock 43, with a period of 4 seconds, is supplied via an AND gate 44 which also receives the output signal from gate 23 of the discrimination stage. The pulses of this clock are received by a binary counter 45 having reset inputs 46.

 The binary outputs of this counter are respectively connected, via a series of inverters 47, to the control inputs of switches 48 whose drain-source circuit respectively shunts resistors 49 connected in series on the circuit of emitter of a transistor 51. The base of this transistor is biased at a constant voltage thanks to a divider bridge 52 and its collector is connected to ground via a capacitor 53.

 A diode D mounted between the base and the emitter of the transistor preserves the base-emitter voltage of the latter.

 The collector of the transistor is also connected to ground via a resistor R2 of a monostable 54 driven by the clock 43, and of a resistor R1.

In parallel, this collector is connected to the negative input of an inverting amplifier 55 of gain equal to unity by means of a resistor 56. This amplifier comprises a feedback loop including a resistor 57 of same value.

 The value of the resistor R1 determines the value of the charge of the capacitor which causes the latter to short-circuit through the monostable 54.

 The inverting amplifier has a high input impedance, which ensures that the capacitor 53 cannot be discharged other than by the monostable 54.

It is understood that the discrete variation, in time, of the emitter charge of the transistor 51 causes variations in the charging speed of the capacitor 53, therefore the formation of triangular pulses of variable slope at the input of the amplifier. -inverter 55. Thanks to the monostable 54, the start of each pulse takes place every
4 seconds.

The discharge of the capacitor 53, due to the resistor R2,
is not instantaneous but exponential, which has a therapeutic advantage
canic regarding the sensation perceived by the patient.

The resistance R2 is calculated so that the descent of the pulse
lasts 1 second. In Figures 12, 13 and 15, this descent time is not
to scale, for reasons of space.

The output of the inverting amplifier 55 is connected
at the negative input of a gain-inverting amplifier 58
variable. This variable gain is obtained by serialization
in the resistance feedback loop 59 which
can be selectively short-circuited with shunts fitted
switches 61 whose control input is connected to the
binary outputs of a memory 62 which contains the value G
mentioned above. To this end, the memory 62 is connected
on the storage stage-3a described in relation to the
figure 2.

The entire inverting amplifier circuit
58 is calculated so that the amplitude of the triangular pulses
laires K which appear on its output 63 is equal to 1.36 G
for therapeutic reasons.

 These K pulses (FIGS. 15 and 16) have an increasing establishment time which, in the example described, ranges from 10 to 100 ms.

In operation, the binary counter being initially set to zero, the series of pulses K is applied to the muscle and, in a first test Bî, the duration tl of the first pulse which causes a muscular contraction is noted, for example 40 ms (figure 15). Then, in a second test
B2, note the duration t2 of the last pulse which causes a contraction, ie for example 70 ms (FIG. 16, with a more reduced time scale}.

 The object of the "treatment" part 7b of stage 7, which will be described below, is to apply to the muscle pulses of variable durations between tl and t2 which are considered to be effective and which sweep the muscle fibers sensitive to any of these durations.

 Part 7b (FIG. 17) includes a counter 64 connected to the clock 43 and also to the counter 45 mentioned above and to a counter 65 for charging them simultaneously. The counter 64 has a manual input M1 which, upon intervention by the therapist, blocks the counting. This counter is also connected, via a counter 66, and a decoder 67, to a display 68.

 In the same way as the counter 64, the counter 65 has a manual input M2 for blocking the counting.

 There is shown, at the output of the counter 45, the whole of the part 7a described above, which delivers the pulses K.

 A comparator 69 has its inputs connected to the outputs of the counters 45 and 65, and its output connected to a control input of the counter 45, this command being such that, on its intervention, the counter 45 is loaded by the content of the counter 64.

 On the output of comparator 69 is interposed an AND gate 71 which also receives a signal T emitted by the therapist after the completion of tests B1 and B2.

 During the test B1, the four counters, initially reset to zero, increment as the duration of the pulses K increases. At the end of this test, by manual intervention on the input Ml, the incrementation of the counter 64 ceases and the value tl which it contains is memorized and displayed on the display 68.

 During test B2, only counters 45 and 65 are incremented. At the end of this test, by manual intervention on the M2 input, the increment of the counter 65 stops and it stores the duration t2.

The therapist then applies the processing signal
T and re-initializes the counter 45 at the value tl.

 By incrementing counters 45 and 66, part 7a.

then delivers pulses K the duration of which increases from tl (FIG. 18). When this duration reaches t2, the comparator 69 switches and causes the counters 45 and 66 to be reinitialized at tl, so that the cycle begins again (FIG. 18
Treatment stage 8 will not be described in detail for completely denervated muscles. The treatment then consists in applying pulses of 150 ms with an adjustable intensity and the constitution of the stage necessary for this function falls within the normal knowledge of the specialist.

 These pulses are expected to exhibit exponential rise and fall.

 The apparatus which is the subject of the invention therefore makes it possible, in a first phase, to diagnose the state of the muscle and, in a second phase, to apply the optimal treatment corresponding to this state, without risk of error, since the suitable treatment stage is automatically selected.

 Of course, the invention is not limited to the example described but covers any variant within the reach of ordinary skill in the art.

Claims (13)

 1. Electrological apparatus for the diagnosis and treatment of muscular damage, comprising means for applying to the muscle, by means of electrodes, electrical pulses of predetermined slope, characterized in that it comprises:  means (1) for applying to the muscle, in a first test, a first series of pulses (I) of fixed frequency, of fixed given duration corresponding to a first test value and of increasing amplitude;  means (2) for manual control to stop the growth of the amplitude on observation of a muscular reaction of the patient and means (3) for memorizing the current value (F) of the amplitude; and  analogous means (la) for applying to the muscle, in a second test, pulses (la) of different fixed duration corresponding to a second test value and means (3a) for memorizing the value (G) of the amplitude reached in the second test.  2. Apparatus according to claim 1, characterized in that the means for applying the pulses in the two tests each comprise, in series:  . a clock (9) delivering isochronous signals;  . a monostable flip-flop (11) of a duration shorter than that of the clock signals;  . a binary counter (13);  . a digital to analog converter (14) for defining an increasing amplitude as a function of the content of the counter (13); and  an analog switch (15) whose control input is connected to the output of the monostable (11) to deliver pulses of increasing amplitude whose duration corresponds to that of the monostable.  3. Apparatus according to one of claims 1 or 2, characterized in that it comprises a logic stage (5) of discrimination connected to the storage stages (3.3a) for emitting a signal as a function of the relative values of the values ( F, G) contained in these stages.  4. Apparatus according to claim 3, characterized in that the logic stage of discrimination is connected to a number of diagnostic and treatment systems (6,7,8) to selectively activate one of these systems in function relative values of the signals (F, G) applied to the input of the logic stage.  5. Apparatus in accordance with one of the desXrevendicåtions 1 to 4, characterized in that it comprises a first treatment system (6) for healthy muscle to apply to the muscle a sinusoidal signal (S1, S2, S3) at constant frequency amplitude modulated according to a predetermined frequency.  6. Apparatus according to claim 7, characterized in that the first processing system comprises an overmodulation stage (28,32) for emitting a periodic signal defining the envelope of the sinusoidal signal (S1, S2, S3) of amplitude modulated.  7. Apparatus according to claim 6, characterized in that the overmodulation stage comprises a voltage / frequency converter (28) connected by its input to a transmitter (32) of successive signals with exponential profile.  8. Apparatus according to one of claims 6 or 7, characterized in that the overmodulation stage (28,32) is connected to an output stage comprising an output amplifier (36) whose input is attacked in parallel by two channels connected to the output (34) of the overmodulation stage (28), one of these channels comprising an inverter (35), and switches (37,38) being placed on these channels to connect selectively either of the two channels to the output amplifier (36).  9. Apparatus according to claim 8, characterized in that the switches (37,38) are connected by their control input to a rectangular signal generator (39), one of the connections-comprising an inverter (41).  10. Apparatus according to claim 9, characterized in that the output amplifier (36) is connected to an active low-pass filter (40) arranged to transform the series of pulses (3) emitted by the amplifier ( 36) into a sinusoidal signal (S1).  11. Apparatus according to one of claims 1 to 10, characterized in that it comprises a second system (7) for diagnosis and treatment for partially denervated muscle, this system comprising means (7a) for applying a series of triangular pulses (K) of decreasing slope and means (64,65) for memorizing the respective slopes of the first and last of these pulses (K) which cause the muscle to contract.  12. Apparatus according to claim 11, characterized in that the second system (7) for diagnosis and treatment comprises means (7a, 64,65) for applying to the muscle successive trains of triangular pulses (K), the slope varies, in each train, between the aforementioned slopes of the first and last pulse which cause the muscle to contract.  13. Apparatus according to one of claims 1 to -12, characterized in that it comprises a third treatment system (8) for totally denervated muscles, this system comprising a pulse emitter of fixed frequency and constant amplitude adjustable, exponential rise and fall.