Massage Apparatus

Abstract

Apparatus for use exteriorly of the human body for massaging and reactivating a heart by rhythmic depression of the breastbone, comprising: rigid support means including a base member having a platform for placing beneath the back of patient's body; a vertically reciprocable, breastbone-engaging, pressure application means spaced from said platform and oriented toward said platform to reciprocate toward and away from it; said base member including portions adjacent one end of said platform; upright means securely mounted to said portions of said base, and extending over said platform at a spacing therefrom to enable a patient to be positioned therebetween, said upright means mounting said pressure application means on said base and over said platform; pressure-supplying means operably connected to said pressure application means to move it repeatedly toward said platform for depressing the breastbone and heart of a patient on said platform and then release to allow the rib cage of the patient to elastically expand again for expansion and filling of the heart to provide a massaging action on the heart; control means operably connected with said pressure application means for causing rhythmic cyclic movement of the pressure application means alternately toward and away from the heart at approximately the normal rate of heartbeat; and an augmentation control device for cyclically supplying output signals in response to heartbeat detection signals comprising a first electrical circuit adapted to transmit electrical power, a first switch means and a second switch means in said first electrical circuit, a second electrical circuit having a first relay means adapted to actuate said first switch means and a second relay means adapted to actuate said second switch means, a signal-receiving means adapted to receive electrical signals corresponding to said heartbeat detection signals and having a first signal input means and a first output means, a signal delay means, having a second input means and a second output means, said first output means connected to said second input means and to said first relay means whereby said first relay means is activated by an output of said signal-receiving means to thereby activate said first switch means, said second output means being connected to said second relay means whereby said second relay means is activated by an output of said signal delay means to thereby actuate said second switch means, and a feedback means connecting said second output means to said signal-receiving means, wherethrough an output of said signal delay means is fed back to said signal-receiving means to terminate the output of said signal-receiving means, at a period of time after the initiation thereof substantially equivalent to the physiological delay in the systolic cardiac contraction.

Description

This invention relates to a cardiac massage apparatus. More particularly this invention relates to an apparatus for closed-chest cardiac massage and to a method for performing such massage.

In the medical history of animals, including the human species, events often occur which result in cardiac arrest. To prevent irreversible damage, the blood circulation of the subject must be promptly restored. One method of aiding the restoration of circulation is to open the chest and massage the exposed heart. Another is the closed-chest method of heart massage as described by Kouwenhoven et al. in a publication appearing in J.A.M.A., Vol. 173, No. 10, page 1,064, July 9, 1960. The external massage method described consists of compressing the heart between the sternum and the spine of the subject by a manual application of force. The amount of force required may be up to about 100 lbs. or more depending on the size, age and bone structure of the thorax region. The massage may sometimes be required for a comparatively long period of time as when the subject is being transported to a surgical place of treatment for additional medical care. Such manual massage may be difficult for a person to apply over a comparatively extended period of time especially when it is considered that artificial respiration should accompany the heart massage treatment. Hence it would be helpful to have available an apparatus which could be manipulated to provide external cardiac massage.

It is, therefore, an object of this invention to provide a cardiac massage apparatus to be used not only in cardiac arrest cases, but also to augment a weak heartbeat. It is also an object to provide an apparatus which may be operated with the aid of pressurized fluid, such as oxygen which is readily available in ambulances and other medical aid facilities. Another object is to provide a method for external heart massage employing a mechanical apparatus. Still other objects will become apparent from the discussion which follows.

The above and other objects of this invention are accomplished by an apparatus comprising a base member, a cylinder disposed opposite said base member and having its axis substantially perpendicular to the base member, a supporting member connecting the cylinder to the base member, and a piston slidably mounted for reciprocal motion within the cylinder.

The apparatus and method of this invention will be more fully described with the aid of the accompanying drawings in which:

FIG. 1 is a perspective view of the apparatus with the position of the subject in relation thereto shown by means of a dotted outline of the subject's form.

FIG. 2 is a side view of the apparatus as viewed from a point on an extension of a line joining the feet to the head of the subject shown in FIG. 1, with the piston partially retracted within the cylinder.

FIG. 3 is a view of the apparatus of FIG. 2 rotated 90.degree. with the piston fully retracted within the cylinder.

FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 3.

FIG. 5 is a view similar to that of FIG. 4 but with the piston in extended position.

FIG. 6 is a view of an alternate embodiment of this invention.

FIG. 7 shows a schematic diagram of an automatic cycling unit.

FIG. 8 shows a schematic diagram of an augmentation control unit that is employed with the heart resuscitator.

FIG. 1 provides a perspective view of the cardiac resuscitator 11 with the base of the piston 16 resting on the rib cage of subject 111.

In FIG. 2 is shown a side view of the cardiac resuscitator 11, the components of which are made of metal or other structural material except as otherwise indicated in this writing. The conduits are made of metal, rubber, plastic, or reinforced rubber or plastic and other materials well known in the art. The cardiac resuscitator has a base member 12 and a cylinder means 13 having its axis substantially normal to the plane of the base member surface on which the subject 111 is positioned. The end of the cylinder farthest removed from the base member is closed by a cylinder cap 14, which is mounted or fastened onto the cylinder 13 by means of bolts 35. Supporting member 15 fixedly connects the cylinder 13 with the base member 12 and rigidly mounts the cylinder above the base member. Piston 16 is slidably mounted in cylinder 13, one end of the piston being external of the cylinder. End plate 17 closed the terminal of the piston at the one end which extends beyond the confines of the cylinder during reciprocal motion. A resilient member 18, made of a flexible material such as rubber, is mounted on the lower surface of the end plate 17. It serves to cushion the force with which the piston 16 depresses the rib cage during cardiac massage operation. A fluid inlet port 19 in cap 14 connects the interior of the cylinder 13 with a source of actuating fluid such as a cylinder of oxygen or nitrogen, or hydraulic fluid under pressure. A pressure release safety valve 20 is connected to cap 14 and communicates with the chamber inside cylinder 13. The pressure relief valve functions to prevent too great a pressure being exerted on the rib cage of the subject by the piston 16. The pressure release valve can be set to function at any predetermined pressure. For human beings, the force employed to depress a rib cage during a heart resuscitation operation falls within the range of from about 20 to above 100 pounds. Conduit 50 leading from a pressure fluid source is connected to conduit 46 through a solenoid valve 44 having outlet port 45. The solenoid valve can be electrically time controlled by means of an automatic cycling control 53 through an electrical connecting cable 54 which leads to the coil 69 in the solenoid valve. Alternatively, the solenoid valve can be controlled by an augmentation control 55 through electrical cable 75 and 54.

When an augmentation control unit is employed, an electrical signal representing a faint heartbeat is detected by electrocardiogram (EKG) electrodes. This signal is fed through terminals 56 to the augmentation control which in turn operates the solenoid valve 44 thereby timing the reciprocal motion of the piston 16 so that the external massage by the cardiac resuscitator coincides with the detected faint heartbeat. In this way the cardiac resuscitator aids the heart function. The augmentation control is connected to a source of power through terminal 58.

The autocycle control unit 53 is connected to a source of line power through terminals 59 which may be a 110-volt, 60-cycle source, or, alternatively, it may be connected through terminals 60 to a direct current source through a vibrator inverter (not shown). A 12-volt direct current source may be used as a power supply, for example.

The construction of the cylinder and piston are shown in FIGS. 4, 5 and 6. The cylinder 13 is shown mounted on support members 15 above the base member 12. The upper end of the cylinder, that is, the end farthest removed from the base member 12, is closed by a cylinder cap 14 having a cavity 61 which communicates with the chamber 62 within the cylinder 13. A port 19 communicates between conduit 46 and cavity 61. The cylinder cap 14 is mounted either on cap 14 as shown in FIG. 6, and communicates with cavity 61, or it is mounted on conduit line 46 or some other convenient location so long as it communicates with chamber 62 on the inside of the cylinder. Mounted within the first end portion of the cylinder, that is the end portion of the cylinder nearest base member 12, is an annular guide sleeve 23. Sleeve 23 has an outwardly or radially extending flange 26 at its first end nearest the base member 12. A plurality of bolts 40 are used to secure the sleeve to flange 27, which extends radially outward from the cylinder 13 at its first or lower end. The sleeve or sleeve bushing 23 may be made of metal, or, metal lined with nylon or Teflon, or other suitable material not shown.

A piston 16 of tubular construction having an outer surface 24 and an inner surface 25 is slidably mounted for reciprocal motion within cylinder 13 and sleeve bushing 23. The piston 16 has a radially outward extending flange 21 at its first end which is farthest removed from base member 12. The second end, which is the end nearest base member 12, is closed off by end plate 17. End plate 17 is mounted on the second end of the piston 16 by means of the upstanding cylindrical member 29 which is threadedly engaged with the inner surface of piston 16 at the second end. The cylindrical member 29 is fixed onto the end plate 17. It is seen from FIGS. 4 and 5 that the piston 16 is slidingly mounted for reciprocal motion within the cylinder 13, the length of the stroke being limited by the flange 21 and the end plate 17 coming in contact with the sleeve bushing 23 at the extreme limits of travel of the piston. The bushing 23 serves as a sealing member which cooperates with the outer surface 24 of the piston 16 to inhibit leadage of the pressurized fluid which actuates the piston to its extended position. When the sleeve bushing 23 has a lining on the inner surface of Teflon or other suitable material, the lining serves to protect the piston surface from galling, and also serves as a seal around the outer surface of the piston 16.

A stud member 30 having a head 31, is fixedly mounted on the lower or first surface 32 of the end plate 17. The stud member can be mounted on the end plate by means of welding. Alternatively, the neck 67 of the stud member is passed through opening 64 in the end plate 17, and nut 65 threadedly engaged with the end 66 of the stud member opposite the head 30.

The resilient member 18 has a cavity 33 in its base 34. The cavity has an internal diameter or cross section which is smaller that that of the head 31 of stud member 30. The depth of cavity 33 is great enough to accommodate stud member 30 when the base 34 of the resilient member 18 lies in contact with the surface 32 of the end plate 17.

Fluid under pressure admitted through port 19 to the chamber 62 causes the piston 16 to move downward toward the base member 12, contacting the rib cage of the subject positioned between the piston 16 and the base member 12. The permissible travel distance of the piston 16 is a distance sufficient to cause a compression of the rib cage of the subject. The amount of compression or the distance that the piston travels after contacting the rib cage is a function of the pressure of the activating fluid within the cylinder chamber 62 and of the reacting pressure of the rib cage of the subject. Activating fluid is applied having a pressure of a magnitude capable of compressing the rib cage sufficiently to cause pressure to be exerted on the heart, and thereby causing blood to be expelled therefrom. A release of the pressure on the activating fluid, as by permitting the fluid to escape through port 45 in a solenoid valve 44 as shown in FIG. 2, or by venting the fluid to the atmosphere by means of a manually controlled valve, not shown, allows the spring action of the rib cage to cause the piston 16 to be retracted with in the cylinder 13. This releases the pressure on the heart, allowing it to fill with blood. Repeated cyclic application of the pressure by means of the activating fluid to the piston 16, followed by a release of that pressure, results in a compression and decompression of the heart and serves as a massage to provide blood circulation or to enhance the circulation in an arrested heart, without the necessity of opening the chest.

FIG. 6 shows another embodiment of the cardiac resuscitator of this invention. The structure of the cylinder and piston assembly 13 and 16 is the same as that shown in FIGS. 1-5. The solenoid valve 44 is equipped with a manual override control 68 so that the apparatus may be satisfactorily used without electrical power as may be required for certain emergencies away from a source of power, or in the event of electrical power failure. The solenoid valve terminals lead either to an automatic cycling control or to an augmentation control as hereinabove described. In FIG. 6, the cylinder assembly is fixedly connected to arm member 70 which, in turn, is slidably mounted on upright member 71. The upright member 71 is fixedly mounted on the base member 12. In FIG. 6, the upright member is of tubular or hollow member construction. Its upper end is closed by cap member 76. The lower end of the tubular member is closed by a portion of the base member 12. An inlet port 74 at the base of the hollow member 71 communicates with the chamber within member 71 and pressurized fluid inlet conduit 77, and also with solenoid valve 44. The arm 70 may be located at any predetermined height on upright member 71, above base member 12, and held in position by means of clamping means 72 which can be of a split-cylinder type, with a screw clamp, similar to the construction commonly used for drill presses. The height to which the arm 70 and, therefore, the cylinder 13 is clamped above the base member 12, is a function of the chest thickness of the subject that is to receive artificial cardiac massage. This embodiment of the invention permits the positioning of the cylinder and piston at a height above the chest cage of the subject such that when the piston is fully extended the chest cage of the subject will be compressed to just the required amount for heart massage, regardless of the pressure exerted by the pressure fluid within the cylinder chamber. This provides a safety feature which is in addition to the pressure release valve connected to the cylinder. Also, this embodiment of the invention reduces the total volume of gas needed to effectively apply cyclic massage pressure.

The chamber in member 71 serves as a buffer tank for the pressure fluid which activates the reciprocating piston 16. When the solenoid valve 44 admits pressurized fluid to the cylinder 13, causing the piston 16 to extend outwardly from the cylinder and exert pressure on the rib cage of the subject, the pressurized fluid is supplied from the buffer tank 71 which is fed by a pressurized fluid source such as a cylinder 128 (FIG. 6) of compressed gas. This serves to minimize pressure fluctuations associated with fluid flow restraints in the regulator valve, and in the line leading to the apparatus.

An alternate embodiment of this invention is a modification of the cylinder-piston assembly wherein the piston is powered by pressurized fluid during both the upward and downward strokes. This is accomplished by incorporating a reciprocating piston in the cylinder 13. A pressurized fluid inlet port is provided at the base of the cylinder in addition to the one present at the top of cylinder. The piston is then moved either up or down by the application of pressure by means of the pressurized fluid on either the lower or the upper face of the piston respectively. The piston in this embodiment has an arm member which extends through a close-fitting opening in an end plate covering the base of the cylinder, that is, the end of the cylinder nearest the base member 12. An end member equivalent to the end plate 17 is attached to the extended end of the piston arm member. The end member has a resilient member 18 mounted on its lower surface as illustrated in the drawings. The advantage inherent in this embodiment is that the upward stroke of the piston is not dependent on the elastic or resilient force of the rib cage of the subject undergoing artificial cardiac massage.

Still another embodiment of this invention is the substitution of an electric motor activating a cam or linkages in place of the cylinder-piston assembly. Another embodiment of this invention is the substitution of an electrically excited coil, moving in a magnetic field, for the cylinder-piston assembly. Either of the above embodiments could be used as prime motivation for the external cardiac massage technique.

In FIG. 7 is illustrated a schematic of the automatic cycling control unit shown in FIG. 2. A pair of terminal leads 80 lead to a source of power such as 110-volt, 60-cycle AC line source, or to a vibrator inverter (not shown) for DC use with a 12-volt DC battery, for example. A second pair of terminals 81 lead to a solenoid valve 44 in the pressurized fluid line which leads to the cylinder chamber. A power switch 82 controls the admission of power from an outside source to the automatic cycling control unit. The automatic cycling unit can be bypassed by closing the manual switch 83 and thus sending the current from the power source directly to the solenoid valve. However, if the manual switch is not depressed, and the automatic cycling switch 84 is closed, the automatic cycling unit is put into operation. Current flows through the motor 85 which rotates a shaft 86, shown here by means of dotted lines, at the end of which is located a cam 87. As the cam 87 rotates, the raised portion 88 comes in contact with switching member 89, causing it to contact a point 90 and thereby closing the circuit to the solenoid valve. When the cam wheel has been rotated so that the raised portion no longer contacts the switching member 89, the switch 91 is opened and no current flows to the solenoid valve. Thus, a rotation of cam 87 produces a cyclic opening and closing of the solenoid valve 44.

FIG. 8 shows a diagram of the components of the augmentation control unit. A pair of terminals 92 lead to an outside power source, while terminals 93 lead to the solenoid valve. Terminals 94 lead from electrocardiogram electrodes to an electrical circuit connected to a power supply (not shown). The pulse from the EKG electrodes is fed to a preamplifier 95, the output from which is fed to a squaring and pulse generator 96. The output from the squaring and pulse generator is fed to a pulse delay unit 97 which can be adjusted by first control means 98 for the desired delay time between the EKG signal and the application of pressure, in accordance with the similar, normal, physiological delay in the systolic cardiac contraction.

The output from the pulse start delay unit is maintained until a "reset" input pulse is received. It is fed to a first relay means 99 which closes first switching means 100, and also to pulse duration delay unit 101 which can be adjusted by second control means 102 in order to control the duration of the application of pressure, which adjustment would be made nominally to coincide with the normal systolic period. The output from the pulse duration delay unit 101 is fed to second relay means 103 which, when activated, serves to open second switching means 104, and also supplies the "reset" signal to the pulse start delay unit, thus returning it to the condition whereby it can respond to the next incoming pulse. When the switching means 100 is closed, current flows through terminals 93, leading to solenoid valve 44, admitting pressurized fluid to the cylinder chamber 62. When second relay means 103 is activated by the pulse after having passed through the pulse duration delay unit 101, switching means 104 is opened. Concurrently, first relay means 99 is no longer activated and first switching means 100 opens. The solenoid valve is then deactivated and cutting off the flow of pressurized fluid, and the cylinder chamber is vented through the vent part 45.

The drawings illustrating the cardiac resuscitator of this invention show a solenoid valve in the pressure fluid conduit system leading to the cylinder for the purpose of controlling the time period during which the fluid exerts pressure on the inside of the cylinder and on the piston to cause the latter to be propelled towards or extended from the lower end of the cylinder, followed by the time period during which the pressure on the inside of the cylinder is released permitting the retraction of the piston into the cylinder. However, other means may be substituted for the solenoid valve. For example, a three-way valve may be employed in the repressurized fluid conduit system which can be manually controlled to permit fluid to flow into the cylinder for the downward stroke of the piston. Then, the valve is turned in order to connect cylinder with an exhaust port thus relieving the pressure on the inside of the cylinder. As a result, the chest cage of the subject can expand and cause the piston to be retracted into the cylinder, or moved away from the base member.

The pressurized fluid employed for the operation of the resuscitator can be a hydraulic fluid or a gaseous substance such as air, nitrogen, helium, oxygen, etc. It is preferably to use compressed gases since the conduit lines and apparatus specifications need not be kept to excessively closed tolerances. For example, if a pressurized gas is used, some leakage between the piston and cylinder can be tolerated. Also, the pressurized gas can be vented to the atmosphere whereas a hydraulic fluid would require the use of an exhaust reservoir. The pressurized gas can be supplied by a compressor or used out of a compressed gas storage vessel. The pressurized fluid is supplied through a pressure control means 130 on cylinder 128 (FIG. 6), including a tank pressure gauge 132 and a line pressure gauge 134, to the apparatus conduit system. In the case of a pressurized gas such as oxygen or nitrogen, it can be supplied through a pressure reduction valve of the diaphragm, or like type. Examples of the valve are those commonly used with compressed gas cylinders for applications such as gas welding, and the like. In the case of resuscitator apparatus having a fixed distance between the base member and the bottom of the cylinder as in FIG. 2, so that the piston during the chest compressor stroke, is extended through a length sufficient to compress the chest cage in an amount which will cause the heart to contract and expel blood therefrom, the pressure of the fluid fed to the cylinder is adjusted to provide sufficient piston force to accomplish this.

With an apparatus such as illustrated in FIG. 6, in which the cylinder and piston assembly can be raised or lowered relative to the base member, and the height of the cylinder above the base member is adjusted so that a full extension of the piston below the cylinder is just sufficient to provide for a contraction of the heart and expulsion of the blood therefrom, the pressure of the fluid supplied to the cylinder need not be controlled within as close a range of pressure values as in the case of the apparatus shown in FIG. 2. It will be recalled that in the operation of the apparatus of FIG. 2, the downward travel of the piston is halted by a reaction pressure of the rib cage of the subject, when such reaction pressure is equal and opposite to the pressure exerted downwardly on the piston. The range of pressures that can be applied for use of various subjects, is medically available. The rib cage of the average male adult compresses approximately 1 inch for 40 pounds of applied force. In general, good perfusion may be maintained with cyclic compression of approximately 2 inches, requiring, accordingly, approximately 80 pounds of force. As stated hereinabove the apparatus is equipped with a pressure relief valve which can be of an adjustable type so that a variety of predetermined pressure conditions can be achieved within the cylinder. The apparatus of FIG. 6 has a further advantage in that the height of the cylinder above the subject can be adjusted so that a full extension of the piston, regardless of pressure, is just sufficient to provide the desired heart contraction.

An example of one embodiment of the apparatus of this invention is a cardiac massage apparatus having a geometry such that 2 pounds of force correspond to 1 p.s.i.g. The equipment can be designed, for example, for a maximum of 100 pounds force (50 p.s.i.g.). The force is reduced to zero (except for weight of piston per se) by venting the cylinder to the atmosphere.

For effective perfusion of blood, as stated hereinabove, the application and removal of pressure must be cyclically repeated at intervals of about 1 second. The application of pressure corresponds to the systole of the heart and the release of pressure corresponds to the diastole. Preferably, diastole should hold for a longer period than systole, to permit the heart to adequately fill. An example is to permit one complete cycle time period to consist of 60 percent diastole and 40 percent systole. Adequate control with manual massage would, of course, be difficult, and thus, the advantages of a mechanized method, making use of an automatic cycling control with the apparatus of this invention, is self-evident.

In certain cases it is highly desirable to use massage to augment a natural but weak heartbeat. This has been done with some success manually with the operator monitoring the patient's electrocardiogram wave, as with the use of an oscilloscope, and synchronizing his application of pressure with the detected heartbeat. This, of course, is more effectively accomplished by a fully automatic control of the mechanical massager in response to the EKG electrical impulse. This mode of operation is termed as augmentation and is another distinct advantage of the use of the cardiac resuscitator of this invention employed in conjunction with the augmentation control illustrated in FIG. 8.

The cardiac resuscitator of this invention can be employed in a variety of tactical situations. In the case of a field emergency where a source of pressurized gas is present but in the absence of electrical power, the mechanical gas valve in the pressurized fluid conduit system leading to the cylinder of the resuscitator can be manually controlled for resuscitation operation. In an ambulance, the cardiac resuscitator can be employed with a solenoid gas valve in the fluid supply line controlled by an automatic cycling control unit as shown in FIG. 7, powered by a 12-volt DC motor connected to the ambulance power.

In a hospital or a doctor's or dentist's office the heart resuscitator can be operated with an automatic cycling control unit powered by 110-volt, 60-cycle line current. In the hospital the resuscitator can be employed with an augmentation control unit as shown in FIG. 8 powered either by 110-volt, 60-cycle line current or by an auxiliary power unit. In case of power failure the unit can always be operated manually insofar as the control of the flow of pressure exerting fluid to and from the cylinder is concerned.

This invention also provides a method for providing reciprocal motion to the piston of the apparatus of FIG. 2. This method comprises admitting a fluid under pressure into said cylinder through the inlet means for a first period of time, thereby causing said piston to move toward the base, and thereafter releasing the pressure on the fluid in the cylinder for a second period of time.

The following examples illustrate the use of the heart-resuscitating apparatus of this invention.

EXAMPLE I

The apparatus of this invention was employed in external cardiac massage of an animal. An anesthetized dog was put into cardiac fibrillation by application of an electric shock. The animal had been previously cannulated at the abdominal aorta and the arterial pressure, as well as the animal's electrocardiogram, were recorded prior to and after fibrillation, and during massage. The animal was placed on its side on the base member 12 of the apparatus shown in FIG. 2, so that its rib cage was positioned between the base member and the piston 16. The cardiac massaging apparatus was then operated with oxygen supplied from a pressurized storage vessel. The pressure of oxygen supplied was approximately 40 p.s.i.g. The pressure was applied to the chamber of the cylinder for a first cyclic period of 0.4 seconds corresponding to systole. The oxygen in the cylinder was next vented to the atmosphere for a second cyclic period of 0.6 seconds, corresponding to diastole. At intervals during this time, external manual massage was applied to obtain a comparison between the manual and automatic techniques. It was found that the apparatus of this invention was capable of maintaining adequate blood pressure to sustain the life of the dog, and in all cases was at least as good as the manual technique. Pressure of 65/25, referring to systolic and diastolic pressures respectively, in mm. of Hg, were recorded with mechanical massage. With manual massage, pressures of 55/12 were recorded. In both cases, perfusion was adequate to support the dog's life. In both cases, perfusion was sufficient to support the dog's life for a duration of time to permit ancillary treatment to restore normal cardiac function.

EXAMPLE II

The apparatus of this invention was again employed in the artificial heart massage of another dog. An anesthetized dog was put into fibrillation by applying electric shock across the animal's chest. The animal had been previously cannulated at the abdominal aorta and the arterial pressure as well as the animal's electrocardiogram, were recorded prior to, and after fibrillation and during massage. The animal was placed, in this example, on its back in a supine position on the base member 12 of the apparatus shown in FIG. 2 so that its rib cage was positioned between the base member and the piston 16. The cardiac-massaging apparatus was then operated with oxygen supplied from a pressurized storage vessel. The pressure of the oxygen supplied to the cylinder was approximately 40 p.s.i.g. The pressure was applied to the chamber of the cylinder for a first cyclic period in this example of 0.2 seconds corresponding to systole. The oxygen in the cylinder was next vented to the atmosphere for a second cyclic period of 0.3 seconds corresponding to diastole. The resulting pulse rate of 120 pulse beats per minute, twice that of the first example, more closely approximates the normal canine function. The external massage technique was carried out for approximately 1 hour with the apparatus of this invention employed for this purpose approximately one-half of the time, with manual massage technique applied for the remainder of the time. During this total period the dog did not develop any measurable normal arterial pressure despite the application of defibrillation shock and medication. Vitality of the dog, however, during the period, was satisfactorily maintained, as judged by breathing, blood color, and general physiological observation, and it can be positively stated that, during this time, the dog's life was maintained by external cardiac massage. During approximately one-half of this period the dog's life was maintained by the action solely of the apparatus of this invention.

EXAMPLE III

An unconscious male adult with heart in ventricular fibrillation, having a chest depth of approximately 10 inches, is placed on the base member of the cardiac resuscitator of FIG. 2. Pressure is adjusted to 40 p.s.i.g. The resilient pad 18 is placed on the patient's sternum, approximately centered at a point 2 inches from the xiphoid region, as indicated in FIG. 1. The autocycle control is switched on, and the resuscitator starts its periodic compression of the rib cage. Upon application of this technique, a definite peripheral pulse is detectable. This pulse is monitored in the carotid arteries, supplying the brain.

Along with cardiac resuscitation, the patient is ventilated using a positive pressure apparatus. After approximately 5 minutes of combined cardiac resuscitation and ventilation, sufficient oxygenated blood perfusion is accomplished to restore body tone, as evidenced by reduced pupil dilation, general color and return of respiratory movements. When cardiac resuscitation is stopped momentarily and ventricular fibrillation still persists, as is evidenced by EKG signal, and lack of normal pulse, the resuscitation is again started, and an external electric defibrillator, similar to that described by Kouwenhoven, Jude, and Knickerbocker, in the Journal of the American Medical Assn., 173:1064, 1960, is readied. After approximately 3 more minutes, the resuscitator is stopped again. The defibrillator electrodes are placed on the patient's chest and a defibrillating impulse is applied. Immediately following this, the EKG trace indicates the cessation of fibrillation, and complete cardiac arrest. The resuscitator is again energized. Immediately the EKG indicates the resumption of a normal heartbeat. The resuscitator is stopped, and normal cardiac function is indicated by EKG, peripheral pulse, body tone, and finally the return of the patient to a conscious condition. In this example, the external cardiac resuscitator maintains adequate blood perfusion to sustain life, external defibrillation is accomplished, and the patient is restored to normalcy without performing a thoracotomy with its attendant disadvantages.

EXAMPLE IV

In this example, an average-size female adult suffers a rapidly diminishing level of cardiac function known medically as hypotension, brachycardia, with poor peripheral circulation, during the administration of anesthesia in preparation for a surgical operation. The patient, as part of the surgical procedure, is previously cannulated, for the monitoring of arterial pressures, electrocardiographic electrodes are applied and EKG is monitored. The diminishing level of cardiac function is demonstrated by these monitoring systems.

Immediately, the external cardiac resuscitator of FIG. 2 is employed connected to the output 93 of the augmentation control of FIG. 8. The EKG signal is connected to the input 94 of the augmentation control unit. Pressure, in this case, is set at 35 p.s.i.g., and the external resuscitator system is turned on. Immediately, the resuscitator augments the normal, weak cardiac perfusion, in synchronism with the normal cardiac pulses, and body tone begins to improve. After approximately 5 minutes of this treatment, and with the administration of proper medicinals, the external resuscitator is stopped and the monitoring devices indicate the return of normal, adequate cardiac function. the cardiac resuscitator is removed, and the surgical process is resumed.

EXAMPLE V

A 6-year-old made chile is found to be in ventricular fibrillation after suffering an accidental electrical shock in his home. The emergency ambulance crew arrives on the scene within 4 minutes of the accident. Immediately the apparatus of FIG. 6 is applied. The apparatus is adjusted such that with the piston fully extended against its stop, rib cage compression will be limited to 1 inch. Pressure, not being critical under these conditions, is set at 30 p.s.i.g. Because an electrical supply is not immediately available, the apparatus is cyclically controlled using the manual override control. Simultaneously, oxygen is supplied with a positive pressure breathing apparatus. Almost immediately, body tone is observed to improve. Next, electrical power is made available, and operation is switched to autocycle control. After 5 minutes of this technique, body tone is restored, and the resuscitator is stopped and removed temporarily, and the patient is quickly moved to the ambulance. The external cardiac resuscitator is again immediately applied, in the autocycle mode, this time powered from the DC ambulance power through a vibrator inverter. Upon arrival at the hospital, the patient is transferred to emergency where external defibrillation methods and proper medication are administered, along with continuing use of the external resuscitator. These administrations successfully restore normal cardiac function.

Although the apparatus and method of this invention have been illustrated and described in detail, the same is by way of illustration nd example only and is not to be taken by way of limitation, the spirit and scope of this invention being limited only by the appended claims.

Claims

I claim:

1. Apparatus for use exteriorly of the human body for massaging and reactivating a heart by rhythmic depression of the breastbone, comprising:

rigid support means including a base member having a platform for placing beneath the back of patient's body;

a vertically reciprocable, breastbone-engaging, pressure application means spaced from said platform and oriented toward said platform to reciprocate toward and away from it;

said base member including portions adjacent one end of said platform;

upright means securely mounted to said portions of said base, and extending over said platform at a spacing therefrom to enable a patient to be positioned therebetween, said upright means mounting said pressure application means on said base and over said platform;

pressure-supplying means operably connected to said pressure application means to move it repeatedly toward said platform for depressing the breastbone and heart of a patient on said platform and then release to allow the rib cage of the patient to elastically expand again for expansion and filling of the heart to provide a massaging action on the heart;

control means operably connected with said pressure application means for causing rhythmic cyclic movement of the pressure application means alternately toward and away from the heart at approximately the normal rate of heartbeat; and

an augmentation control device for cyclically supplying output signals in response to heartbeat detection signals comprising a first electrical circuit adapted to transmit electrical power, a first switch means and a second switch means in said first electrical circuit, a second electrical circuit having a first relay means adapted to actuate said first switch means and a second relay means adapted to actuate said second switch means, a signal-receiving means adapted to receive electrical signals corresponding to said heartbeat detection signals and having a first signal input means and a first output means, a signal delay means, having a second input means and a second output means, said first output means connected to said second input means and to said first relay means whereby said first relay means is activated by an output of said signal-receiving means to thereby activate said first switch means, said second output means being connected to said second relay means whereby said second relay means is activated by an output of said signal delay means to thereby actuate said second switch means, and a feedback means connecting said second output means to said signal-receiving means, wherethrough an output of said signal delay means is fed back to said signal-receiving means to terminate the output of said signal-receiving means, at a period of time after the initiation thereof substantially equivalent to the physiological delay in the systolic cardiac contraction.

2. Apparatus for use exteriorly of the human body for massaging and reactivating a heart by rhythmic depression of the breastbone, comprising:

rigid support means including a base member having a platform for placing beneath the back of a patient's body;

a vertically reciprocable, breastbone-engaging, pressure application means spaced from said platform and oriented toward said platform to reciprocate toward and away from it, said pressure application means comprising a telescoping cylinder and fluid-responsive means, said cylinder comprising an outer member closed at one end and a fluid-responsive member which is closed at the end nearest said body and disposed oppositely to said one end, comprising in addition a fluid inlet means to the interior of said telescoping cylinder means through which a fluid is admitted and removed to provide for actuation of said fluid-responsive member, a source of pressurized fluid, and conduit means connecting said source to said inlet means, said conduit means having valve means therein adapted to permit flow of fluid from said source to said telescoping cylinder means and to vent fluid from said telescoping cylinder means;

said base member including portions adjacent one end of said platform;

upright means securely mounted to said portions of said base, and extending over aid platform at a spacing therefrom to enable a patient to be positioned therebetween, said upright means mounting said pressure application means on said base and over said platform;

pressure-supplying means operably connected to said pressure application means to move it repeatedly toward said platform for depressing the breastbone and heart of a patient on said platform and then release to allow the rib cage of the patient to elastically expand again for expansion and filling of the heart to provide a massaging action on the heart;

control means operably connected with said pressure application means for causing rhythmic cyclic movement of the pressure application means alternately toward and away from the heart at approximately the normal rate of heartbeat; and

an augmentation control device comprising a first electrical circuit adapted to transmit electrical power from a power source to said valve means, a first switch means and a second switch means in said first electrical circuit, a second electrical circuit having a first relay means adapted to actuate said first switch means and a second relay means adapted to actuate said second switch means, a signal receiving means adapted to receive electrical signals, and having a first signal input means and a first output means, a signal delay means, having a second input means and a second output means, said first output means connected to said second input means and to said first relay means whereby said first relay means is activated by an output of said signal-receiving means to thereby activate said first switch means, said second output means being connected to said second relay means whereby said second relay means is activated by an output of said signal delay means to thereby actuate said second switch means, and a feedback means connecting said second output means to said signal-receiving means, wherethrough an output of said signal delay means is fed back to said signal-receiving means to terminate the output of said signal receiving means.

3. Apparatus for use exteriorly of the human body for massaging and reactivating a heart by rhythmic depression of the breastbone, comprising:

rigid support means including a base member having a platform for placing beneath the back of a patient's body;

a vertically reciprocable, breastbone-engaging, pressure application means spaced from said platform and oriented toward said platform to reciprocate toward and away from it;

said base member including portions adjacent one end of said platform;

upright means securely mounted to said portions of said base, and extending over said platform at a spacing therefrom to enable a patient to be positioned therebetween, said upright means mounting said pressure application means on said base and over said platform;

pressure-supplying means operably connected to said pressure application means to move it repeatedly toward said platform for depressing the breastbone and heart of a patient on said platform and then release to allow the rib cage of the patient to elastically expand again for expansion and filling of the heart to provide a massaging action on the heart;

control means operably connected with said pressure application means for causing rhythmic cyclic movement of the pressure application means alternately toward and away from the heart at approximately the normal rate of heartbeat; and

means for detecting a heartbeat and providing a detecting signal, and means for adjusting said control means responsive to said detective signal to synchronize the rhythmic, cyclic movement of the pressure application means with said detected heartbeat.