US3083712A - Device for producing electrical muscle trerapy - Google Patents

Description

April 2, 1963 Filed Nov. 29. 1961 EVERSION PERONEUS LONGUS PERONEUS BREVIS J. E. KEEGAN, JR 3,083,712

DEVICE FOR PRODUCING ELECTRICAL MUSCLE THERAPY 3 Sheets-Sheet 1 FIG. 1

INVENTOR. JAMES E. KEEGAN JR.

ATTORNEY April 2, 1963 J. E. KEEGAN, JR 3,083,712

DEVICE FOR PRODUCING ELECTRICAL MUSCLE THERAPY Filed Nov. 29, 1961 5 Sheets-Sheet 2 FIG.3

INVENTOR.

I ATTORNEY Ll JAMES E. KEEGAN JR.

April 2, 1963 J. E. KEEGAN, JR 3,083,712

DEVICE FOR PRODUCING ELECTRICAL MUSCLE THERAPY Filed Nov. 29, 1961 3 Sheets-Sheet 5 FIG.5

FIG.7

1NVENTOR. JAMES E. KEEGAN J P.

niteri rates area 3,083,712 DEVHIE Ft}? FRUDUQZNG ELECEX. iJAL P/IUSQLE '1" 'T;ZEA?Y .iames E. Keegan, in, Eioliywood, Fla, assignor to Heiniclre Instrument Co, Inc, Hollywood, Fla, a corporation of Fiorida Filed Nov. 29, 1361, Ser. No. 156,564 3 Ciairns. (Cl. 12-4=23) This invention relates generally to electrical muscle therapy and more specifically to a programmed sequence for muscle therapy.

All bodily movement is accomplished by the contraction of muscle fibers. The contractions develop tension in the tendons in order to pull one bony attachment of the muscle toward the other. t times, tension is maintained at exactly the level required to hold a fixed relationship between the two points of bony anchorage.

Paralysis results either when the muscle is damaged or destroyed or when the nervous system is affected in such a fashion as to completely prevent a stimulating impulse from reaching the muscle or else the nervous system allows impulses to reach the muscle under poorly controlled conditions making coordinated movement difiicult or impossible.

The most common method of managing a paralysis problem, after all medical and surgical efforts have been exhausted, is the application of a mechanical device in the form of a brace to substitute crudely for the lost function. 30

Additionally, apparatus has been developed to exercise a muscle to a rather limited extent. However, such apparatus available at the present time is bulky and nonportable and usually stimulates only a single muscle and, to my knowledge, has not met with any great therapeutic success.

According to medical theory, if a muscle is synthetically stimulated to produce its correct function, the brain will become re-educated to take over the normal function and control. Therefore, if a portable unit is available which can stimulate the use of a muscle or sets of muscles in proper time relation in the sequence required for the particular muscles involved, persons who have lost partial mental control over these muscles or who have suffered deterioration of muscle fibers will be able to receive continual therapy unavailable from any presently known means.

Accordingly, it is an object of this invention to provide an apparatus and a method of stimulating a muscle or muscles more or less directly in order to control the contraction strength and thus provide a natural function for therapeutic purposes.

Another object of this invention is to provide apparatus for producing sequential programming of synthetic exterior muscle stimulation.

Yet another object of this invention is to provide apparatus for creating an electrical muscle stimulation having a variable control of the muscle reflex time.

Still another object of this invention is to provide apparatus for synthetic muscle stimulation which is actuated in accordance with an inter-related body movement.

A further object of this invention is to provide apparatus having the bove stated attributes which is light in weight and may be Worn continually by a person using it.

A still further object of this invention is to provide portable apparatus for providing continuing therapeutic synthetic muscle stimulation for restoring mental control for the normal functions of the muscle.

Another object of this invention is to provide apparatus for producing sequential programming between an- Federated Apr. 2, 1963 2 tagonistic muscles in a proper time relation required for normal function of the muscles.

One specific application is herein described as illustrative of the present invention, but it is understood that the invention is not limited to this specific example and is to be considered applicable to other bodily muscle stimulations.

The illustrative example of the invention as used in muscle stimulations for the purpose of therapeutics in Walking is described hereinafter and will be understood by those familiar with the art when taken in conjunction with the drawings wherein:

FIG. 1 is an elevation view showing the stimulating electrodes secured adjacent to the particular leg muscles together with the electrical leads to the power source, controls and the foot switch;

FIG. 2 is a schematic showing of the control switch located in the heel of the shoe;

FIG. 3 is a schematic of the electrical circuitry and controls used for a single muscle stimulation;

FIG. 4 is a schematic of the electrical circuitry used for a dual muscle stimulation with sequential programming between the muscles;

FIG. 5 is plan view of a control switch carried by the electrode clamping device;

FIG. 6 is a sectional view of the switch of FIG. 5, taken on line 6-6 of FIGURE 5; and

FIG. 7 is a side elevation of the switch of FIG. 6.

Referring now specifically to the drawings, FIG. 1 shows the leg 11 of a patient having the electrodes attached thereto. These electrodes may be of any shape and of a type which will supply stimulation in a wellknown manner, one such type being sponge electrodes. Electrode 13 is located over the common peroneal nerve and may be secured to the leg by means of strap 15. Electrode 17 is located over the tibialis anterior and is held in position by means of strap 23.

Leads 25 and 27 connect the electrodes 13 and 17 respectively, to the power source and control unit 36 which may be conveniently supported by means such as a belt.

A control switch member 37 is inserted into the heel of the shoe and is connected to the power source and control unit 39 by means of leads 33 and 35 for purposes which will become apparent as the description proceeds.

The heel switch 37 is a normally open switch which may be fitted within the heel portion of the shoe so that pressure exerted by the heel will close the switch. Two contact members 47 and 49 are connected to the leads 33 and 35 respectively whereby the switch 37 may close the control circuit.

The electrodes 13 and 17 when located as shown in FIG. 1 will counteract foot drop when activated. Alternate placement of the electrodes as indicated at 13a and 17:: would innervate the peroneus longus and the peroneus brevis to provide eversion.

Turning now to FIG. 3, there is illustrated schematically the electrical controls for use with the device when only a single electrode is to be used for purposes of therapeutics. In FIG. 1, therefore, the device as used with FIG. 3 would include the electrode 13 and the electrode 17 together with the foot switch and the controls as illustrated in FIG. 3.

The foot switch 37 is illustrated schematically as a means of completing the circuit across terminals 47 and 49. A source of DC. voltage is provided across terminals 51 and 53 the voltage supply being of i3. portable type such as a mercury cell battery which may be connected to the circuit by means of the manual on-ofi switch 55. When switch 55 is closed and the foot switch 37 is depressed, voltage from the battery source passes through the terminals 47 and 49 and adjustable resistor 67, thus charging the capacitor 69. Transistor T which is in a normally non-conductive condition, reaches the point of conduction when capacitor 69 is fully charged. When transistor T conducts, coil 73 is actuatedand, through relay action, closes switch 57, thus connecting terminal 58 to a converter means such as the transistor oscillator 59. The oscillator consists of transistors T and T resistors R R R and R input and feedback coils L and L and output coil L When switch '57 is closed by coil '73 of the relay, a square wave output passes through strap 15 to electrode 13, thus stimulating the nerve and associated muscle.

When switch 37 is open, capacitor 69 discharges through variable resistor 75 and coil 73 to ground. When the capacitor voltage falls below the conductive point of transistor T switch 57 returns to its biased open position.

As can be seen, the time interval between the closing of switch 37 and the energization of electrode 13 is dependent upon the charging time of capacitor 69. Accordingly, this time can be adjusted to predetermined requirements by means of adjustable resistor 67. Similarly, the time interval between the opening of the switch and the de-energization of electrode 13 is dependent upon the discharge time of capacitor 63 and this discharge time can be adjusted to predetermined requirements by means of the variable resistor 75. Additionally, the amplitude of the oscillator output may be controlled in accordance with predetermined requirements by means of adjustable resistor 65.

Operation Following a stroke, brain injury or partial severance of the spinal cord, paralysis and/or weakness may afllict one side of the body. Muscle spasms may or may not be present. A hemiplegic characteristically walks with the toe of the affected side dragging on the floor. He is unable to contract the muscles which raise the toes, the dorsifiexors, with suificient force to elevate the toe and the foot.

The muscles which perform this dorsiflexion are the peronealrnerve. 'Electr'ical stimulation of this nerve causes muscle contraction producing toe elevation, dorsifiexion, and a turning out of the foot, eversion.

The use of the invention as illustrated in FIGS. 1 and 3 may be programmed to provide the above stimulation in the following manner. As the heel strikes the ground, switch 37 is depressed, bridging contacts 47 and 49', thus providing energy from the battery source to the time delay circuit comprised of resistor 67, capacitor 69', resistor 75, transistor T coil 73 and switch 57. Variable resistor 67 is adjusted to control the time of charging of capacitor 69 in accordance withrthe patients normal gait so that transistor T will not conduct and no stimulus occurs during the majority of the timethat the foot is on the ground; This adjustment is such that the stimulus begins at approximately the time that the foot is being lifted from the ground and continues in accordance with the adjusted time of capacitor discharge while the foot is in the air. Accordingly, when the toe is about to leave the ground stimulation through electrode 13 is applied to the peroneal nerve which causes dorsiflexion and a slight eversion, thus assuring that the toes will be lifted while the foot is being swung forward in order to avoid the dragging of the toes as discussed hereinabove.

It is highly advantageous to have a means such as variable resistor 65 for varying the amplitude of the output of the oscillator since such a variable output is required in order to allow the correct amount of stimulus for the different requirements of different users or patients. Care must be taken to get enough stimulation to work the muscle without over stimulation which would cause discomfort and additional muscle fatigue.

It is well known that an additional function of the dorsifiexors is that of slowing down a descent of the toes after heel strike. Equipment could be designed giving a variable control relaxing time to substitute for the sensory feedback accompanying normal body function. However, in the present illustnation, use of the sequential programming described above is used in lieu of such additional apparatus.

The device as illustrated together with the control, apparatus of FIG. 3 provides a sequential programming including three variable time delays; the delay between the time thefoot switch is depressed and the time the current is supplied to the electrode, the holding time during which energization of the electrode occurs and the delay time bet-ween the opening of the heel switch and de-energization of the electrode 13.

As mentioned above, the present invention may be used with the two electrodes for straight muscle control as illustrated in FIG. 3 or it may be used with a plurality of electrodes together with additional electrical circuitry as schematically illustrated in FIG. 4. The operation of the device as illustrated in FIG. 4 is substantially the same as that illustrated in FIG. 3 with the exception of the additional delay or control circuit for transferring a predetermined part of the total time of stimulation between two electrodes according to a programmed sequence. It is to be noted that FIG. 4 is illustrative cf the broad concepts involved in the present invention which is applicable to any two antagonistic or counteracting muscles with the stimulating electrodes placed on the motor points of the two muscles involved.

As illustrated in FIG. 4, the basic time delay circuitry is identical to FIG. 3, as is the oscillator 59 together with the amplitude control resistor 65. However, in FIG. 4 a terminal 77 is added which is contacted by the switch 57 when it is in its open or inactivated position. Accordingly, the power supply from the battery passes through switch 57 and terminal 77 and charges the capacitor 79 during thetime that the foot switch 37 is open. This provides a sufiicient charge on the capacitor to unblock transistor T and when coil 73 activates switch 57 as described in connection with FIG. 3, transistor T fires, thus energizring the coil 81 and connecting switch 83 to electrode 13. The time interval during which switch 83 is held against terminal 85 is determined by the time discharge of capacitor 79 through adjustable resistor 85' and coil 81 to ground. Accordingly, this time can be ad justed to fit a predetermined program. When capacitor 79 is sufiiciently discharged to block transistor T switch 83 returns to its unactivated position against terminal 87, thus transferring the output of the oscillator 59 to electrode 17. It will be obvious that the time interval of discharge of the capacitor 79 should be less than the timev interval of discharge of the capacitor 69 since the time interval discharge capacitor 69'. controls'the total time of energy output of oscillator 59 and this stimulation is programmed in accordance, with normal muscle function by the action of the delay circuit inducing capacitor 79, ad justable resistor 85' and transistor 84.

Operation The operation of the basic. components of the circuit shown in FIG. 4 is identical to that of FIG. 3. However, the final output of the entire circuit is modified as follows. When thefoot switch 37 is closed, transistor T immediately fires and switch '83 is brought into contact with terminal 85. of the'charging of capacitor 69 is reached and switch 57 is activated, the output of the oscillator 59 is delivered to electrode 13 in the same manner as described in connection with FIG. 3. However, when dorsiflexion is no longer required, which time is predetermined according to the specific patient and set by the adjustment of resistor 85, the capacitor 69 is still charged to an extent which allows transistor T to conduct and therefore, energy output from the oscillator 59 is continued. This output is then tnansferred by switch 83 to electrode '17 to stimulate the muscle.

Accordingly, when the delay time interval- The parameters of the circuits will, of course, depend upon the specific application including the particular muscles involved. However, particularly good results were obtained in the specific illustrative example of the inven tion using a mercury cell providing 9 volt source of power for operating the oscillator 59. The output voltage of the oscillator shown is in the form of square wave and is variable between approximately 0 and 70 volts. The frequency output of the oscillator is substantially constant at approximately 900 cycles. The output of the oscillator may also be a combination of a square wave and sine wave. The parameters of the illustrative circuit are as follows:

Resistor 65 0-5000 ohms.

FIGS. 5, 6 and 7 illustrate the use of another type of switch which may be used for the purpose of initiating the operation of the circuits of FIGS. 3 and 4. Electrode 101 is held against the skin over the muscle to be stimulated by means such as clamp 102. Housing 103 is rotatably secured to 102 by means such as a shaft or pin 1%. In order to provide a means for bridging the contacts 47 and 49 of FIGS. 3 and 4, an enclosure 105 is mounted within housing '103' containing fixed terminals 169 and 111 and a small quantity of mercury. The housing is mounted on the clamp 1102 so that its axis is substantially perpendicular to the forward motion of the leg. Accordingly, the mercury will bridge the terminals 109 and 111 only during a certain period during the stride. The time of this period may be adjusted and controlled by rotating the housing 103 about the pin 106 in order to meet the particular requirements of individual patients. The side of housing 103 may be provided with indicia 104 as shown for matching against an indicating mark 108 on clamp 102. A record of the setting may then be made and this calibration may be used to return the housing to this setting each time the electrode is to be reused on the same patient at the same location over the muscle. Plug 107 is provided in order to connect terminals 47 and 49 to leads 33 and 35.

it should be noted that the above discussed mercury switch could also be mounted separate from the clamping device for the electrode. Bodily movements are the result of coordination between separate parts and separate muscles. For instance, the leg to which the electrode is not attached has a definite moving relationship to the other leg and, accordingly, could support and control the circuit if the mercury switch were attached thereto. Likewise, the swinging movement of the arm is coordinated with leg movements and could be used for controlling the mercury switch.

The advantages of this invention will now be obvious to those familiar with the problems involved in muscle therapeutics. The invention not only provides a movement pattern far closer to normal than can be obtained with a device such as a brace, but also presents a nopportunity for retraining and muscle re-educ-ation.

As noted hereinabove, the description and drawings are directed to a specific example of the invention in order that it may be clearly understood. However, it is obvious that the invention is broad in its general aspects and the parameters or specific equipment illustrated are not the only elements which would provide the desired results. It will also be obvious that many of the electronic component parts may be substituted by other equivalent operating devices and these devices are intended to be included in the present invention. Additionally, the control switch for initiating and terminating the basic current supply can take many forms and may be activated in many ways two of which are specifically illustrated. If desired, a timing switch could be used which has a set time pattern and is not dependent upon any of the muscle body movements for control purposes. Such a timing switch would, of course, have a variable timing cycle and these devices are also well known and available.

The basic requirement as set forth by this invention is that the apparatus be capable of providing a means for stimulating a nerve or nerves and associated muscle or sets of counteracting muscles in a programmed sequence which is a synthetic representation of the normal body movement of that muscle and, at the same time, present the portable attributes described above. Accordingly, the scope of this invention is intended to be limited only by the appended claims.

I claim:

1. Apparatus for alternately synthetically stimulating two counteracting muscles in the body comprising a control switch, circuit means for connecting said control switch :to a DC. voltage supply, a delay circuit coup-led to the output of said control switch, a solenoid coupled to said delay circuit and actuated thereby, a two-position switch coupled to said solenoid, said switch being moved from its first to its second position when said solenoid is actuated, means for connecting the input of said twoposition switch to said voltage supply, a storage capacitor coupled to the output of said two position switch in said first position, an oscillator coupled to the output of said two position switch in its second position for providing an alternating voltage output, a second solenoid coupled to said capacitor, means for discharging said capacitor through said second solenoid when said first solenoid is actuated, a second two position switch having its input connected to the output of said oscillator and operated by said solenoid, and an electrode connected to each of the output terminals of said second two position switch.

2. The apparatus of claim 1 further comprising means for adjusting the time period of the delay circuit.

3. The apparatus of claim 2 further comprising means for adjusting the time period of actuation of said first solenoid.

References Cited in the file of this patent UNITED STATES PATENTS 2,295,585 Lindquist Sept. 15, 1942 2,433,782 Murdoch Dec. 30, 1947 2,864,371 Parodi Dec. 16, 1958 3,025,858 Browner Mar. 20, 1962 3,057,356 Greatbatch Oct. 9, 1962 FOREIGN PATENTS 608,693 Canada Nov. 15', 1960

Claims (1)

1. APPARATUS FOR ALTERNATELY SYNTHETICALLY STIMULATING TWO COUNTERACTING MUSCLES IN THE BODY COMPRISING A CONTROL SWITCH, CIRCUIT MEANS FOR CONNECTING SAID CONTROL SWITCH TO A D.C. VOLTAGE SUPPLY, A DELAY CIRCUIT COUPLED TO THE OUTPUT OF SAID CONTROL SWITCH, A SOLENOID COUPLED TO SAID DELAY CIRCUIT AND ACTUATED THEREBY, A TWO-POSITION SWITCH COUPLED TO SAID SOLENOID, SAID SWITCH BEING MOVED FROM ITS FIRST TO ITS SECOND POSITION WHEN SAID SOLENOID IS ACTUATED, MEANS FOR CONNECTING THE INPUT OF SAID TWOPOSITION SWITCH TO SAID VOLTAGE SUPPLY, A STORAGE CAPACITOR COUPLED TO THE OUTPUT OF SAID TWO POSITION SWITCH IN SAID FIRST POSITION, AN OSCILLATOR COUPLED TO THE OUTPUT OF SAID TWO POSITION SWITCH IN ITS SECOND POSITION FOR PROVIDING AN ALTERNATING VOLTAGE OUTPUT, A SECOND SOLENOID COUPLED TO SAID CAPACITOR, MEANS FOR DISCHARGING SAID CAPACITOR THROUGH SAID SECOND SOLENOID WHEN SAID FIRST SOLENOID IS ACTUATED, A SECOND TWO POSITION SWITCH HAVING ITS INPUT CONNECTED TO THE OUTPUT OF SAID OSCILLATOR AND OPERATED

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