US3512522A

US3512522A - Closed chest cardiac massage apparatus

Info

Publication number: US3512522A
Application number: US709762A
Authority: US
Inventors: Malcolm B Greenlee; Lawrence M Mastracci
Original assignee: Research Corp
Current assignee: Research Corp
Priority date: 1968-03-01
Filing date: 1968-03-01
Publication date: 1970-05-19
Anticipated expiration: 1987-05-19

Description

May 19, 1970 M. B. GREENLEE ETAL 3,5

CLOSED CHEST CARDIAC MASSAGE APPARATUS 3 Sheets-Sheet 1 Filed March 1, 1968 VAR\ABL.E

TKMER FROM PUMP KESEEVO l 2.

SOLENL'HD I32.- TO PUMP s l Tm 6M 5 I Mm Lc 0N E LE AW m FROM RES'E RVO I R TO RESE'RJ/Ql R ATTORNEY i United States Patent 3,512,522 CLOSED CHEST CARDIAC MASSAGE APPARATUS Malcolm B. Greenlee, Rockville, and Lawrence M. Mastracci, Silver Spring, Md., assignors to Research Corporation, New York, N .Y., a nonprofit corporation of New York Filed Mar. 1, 1968, Ser. No. 709,762 Int. Cl. B01d 15/00 US. Cl. 128-53 11 Claims ABSTRACT OF THE DISCLOSURE The patient is strapped on a back plate, whereupon a supporting frame is assembled and carries above the patient an apparatus having a reciprocating stem provided with a cushion foot at its lower end engageable with the patients chest. The shaft is reciprocated, the massage foot being moved away from the patient by fluid pressure and being moved toward the patient by predetermined spring pressure, to bring about cardiac action.

BACKGROUND OF THE INVENTION Cardiac massage as presently used is a manual procedure, which is extremely tiring and requires the full time and attention of trained personnel. This type of massage is highly important in the event of cardiac arrest, and if promptly begun can result in the saving of many lives.

SUMMARY OF THE INVENTION A back plate is laid in position for the strapping thereon of a patient, either on his back or side, and in a supine but not prone position. Framing elements are then assembled relative to the back plate and include spaced upper supporting members for the massage apparatus. This apparatus comprises a casing in which is arranged a cylinder having a piston therein provided with a shaft extending beyond the upper and lower ends of the cylinder. A cushioned foot, carried by the lower end of the shaft, is adapted to press against the patients chest in repeated movements to stimulate the heart action. The spring urges the piston downwardly to apply pressure through the padded foot to the patient, the loading of this spring being adjustable. A fluid, and specifically hydraulic fluid, is supplied the cylinder beneath the piston after the latter reaches the lower limit of movements, to move the piston upwardly against the compression of the spring to load the latter for the following downward movement of the shaft. The supplying of the fluid to the lower end of the cylinder is accomplished automatically so that the piston and its presser foot are reciprocated automatically.

A suitable valve mechanism, automatically controlled, alternately supplies to and releases pressure from the lower end of the cylinder. A reservoir and pump are employed, the valve mechanism controlling communication between the cylinder and reservoir and connecting these elements on the down stroke of the piston. Such valve mechanism closes during upward movement of the piston, and a solenoid actuated valve supplies pumped fluid from the reservoir to the cylinder during upward movement of the piston. When the piston reaches its upper limit of movement, the valve between the cylinder and reservoir opens, and the valve past which fluid is pumped during the upward piston stroke closes so that continuedoperation of the pump bypasses fluid to the reservoir.

To secure proper timed relation of the piston reciprocation, the piston stops at its upper limit of movement under the control of an adjustable timer, the operation of which after a suitable interval, for example one second, causes a reversal of the valve operation to release the piston for downward movement under the influence of the spring.

Manually operable means is provided for predetermining the minimum loading of the spring according to the age and size of the patient. Such minimum spring force will be exerted at the end tof the downward travel of the piston unless restricted by the patients chest.

Means is also provided for adjustably limiting the upward movement of the piston, thus determining the distance of travel of each reciprocation of the piston.

A manual device for actuating the piston is provided in the event of a failure of power for automatically operating the apparatus. This manual means may be very quickly attached and detached.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial sectional view of the reciprocating mechanism and its casing, parts of the latter being broken away and elements of the mechanism being diagrammatically represented;

FIG. 2 is a side elevation of the apparatus including the frame for surrounding and supporting the patient;

FIG. 3 is a plan view of the same;

FIG. 4 is a horizontal sectional view of line 44 of FIG. 2;

FIG. 5 is an enlarged fragmentary sectional view on line 55 of FIG. 4; and

FIG. 6 is a diagrammatic view of the electrical system for the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 2 and 3, the numeral 10 designates a supporting frame as a whole, comprising lower spaced parallel tubes 12 over which is mounted a back plate 14 which is adapted to the patient. End portions of the plate 14 are provided with straps 16 for securing the back plate in position. After the back plate has been strapped in position end tubular members 18 of generally U-shape, having upper and lower

parallel ends

20 and 22, are assembled relative to the tubes, the ends 22 being slipped into the ends of the tube 12. The upper ends 20 are then slipped into the ends of upper horizontal tubes 24 similar to the tubes 12, the tubes 24 having mounted thereon a breast plate 26 which acts as a support for the massage apparatus indicated as a whole in FIG. 2 'by a numeral 28.

Referring to FIG. 1, the apparatus 28 comprises a casing 30 of generally L shape (see FIG. 2) in which is arranged a cylinder 32 supported in the casing in any suitable manner. A piston 34 is reciprocable in the cylinder 32 and is mounted on a shaft 36 which projects down wardly a substantial distance through the lower head 38 of the cylinder. At its lower end the shaft 36 carries a ferrule 40, covered with a soft pad 42 adapted to engage the chest of the patient on the backboard 14, to massage the patients chest. The piston 34 carries a depending hub or boss 44, engageable with a spring washer 46 supported on the cylinder head 38 to cushion downward movement of the piston as it approaches its lower limit of movement.

The cylinder 32 carries an upper head 48 and the shaft 36 projects through and substantially beyond such head.

The two cylinder heads are provided respectively with a suitable bearing 50 and packing 51 for the shaft 36.

A coil spring 52 has its lower end engaging the piston 34 and its upper end engaging a spring seat 54. Vertical racks 56 are secured at their lower ends to the spring seat 54 and project upwardly through openings 58 in the cylinder head 48. Above the cylinder head 48 is arranged a shaft 60 extending transversely of the cylinder and provided with apair of pinions '62 engaging the respective racks 56. Bearings 64 may be provided on the cylinder 3 head 48 for the shaft 60. This shaft extends through opposite walls of the upper portion of the casing 30, and such walls also preferably carry bearings 66 for the shaft 60.

One end of the shaft externally of the casing is provided with a gear 68 meshing with a pinion 70 mounted on a shaft 72 supported in a bearing 74 carried by the adjacent casing wall. A wheel 76, carried by the shaft 72, is provided with a handle 78 for rotating the wheel and consequently the shaft 60 to rotate the pinions 62 and thus move the racks 56 and spring seat 54 vertically. This operation adjusts the loading of the spring 52, and the adjustment is for the minimum loading of the spring when the piston is at its lower limit of movement. The gear 68 may be suitably graduated on its outer face, and the indicia move beneath a pointer 80 carried by the casing 30.

Above the cylinder head 48, the shaft 36 is provided with a fixed collar 82 engageable with the limit switch 120 to detect downward movement of the shaft and reinitiate the cycle. Downward movement of the piston 34 is cushioned by the spring washer 46. On the upper end of the shaft 36 and projecting substantially thereabove is arranged a sleeve 84, the upper end of the shaft being threaded as at 86 for adjustment of the height of the sleeve 84 on the shaft. At its lower end, the sleeve 84 is provided with an annular flange 88 for a purpose to be described.

The upper end of the sleeve 84 is provided with annular rack teeth 90, engageable by the teeth of a gear 92 mounted on a shaft 94 supported in open topped bearings 96 carried by the top of the casing 30. The shaft 94 is provided with a handle lever 98 carrying a spring pressed pawl 100 engageable with the teeth of the gear 92 and having a finger piece 102 adapted to be pressed to release the pawl 100 from the gear teeth under conditions to be described. The pawl mechanism and associated elements is provided for the manual operation of the apparatus in the event of a power failure.

The sleeve 84 is graduated as at 104 and a cooperating index 106 carried by the top of the casing cooperates 'with the graduations 104 to indicate the length of each piston stroke. This stroke, as further described below, is determined by the position of the flange 88 relative to elements with which it is associated. Obviously the sleeve 104 is rotatable to raise and lower the flange 88 with respect to the piston 34.

Within and adjacent to top of the casing 30 is arranged a solenoid 108, the armature of which projects beyond opposite ends of the coil of the solenoid and is urged to the right by a spring 109. One-end of the solenoid rod 110 projects through the adjacent wall of the casing and is provided with a knob 112 for the manual operation of the solenoid coil under conditions to be described. The inner end of the solenoid rod is connected with a pivoted latch 114 having a lower tooth 116 engageable beneath the flange 88 when the piston reaches its upper limit of movement. The solenoid 108 is supported by a bracket 118, fixed at its lower end to the cylinder head 48. This bracket also supports a limit switch 120 having an operating roller 122, engageable with the flange 82 when the piston reaches its lower limit of movement.

The cylinder head 48 also carries a bracket 124 supporting at its upper end a limit switch 126 having an operating roller 128 engageable with the flange 88, when the shaft 36 reaches tis upper limit of movement, this being the position shown in FIG. 1.

Within the casing 30 is arranged a reservoir 130 having an outlet pipe 132 and an inlet pipe 134. The adjacent wall of the cylinder 32 is provided with a port 136 controlled by a valve 138 arranged in a chamber 140 communicating between the port 136 and the reservoir 130. A normally deenergized solenoid 142, diagrammatically shown in FIG. 1, operates the valve 138. This valve is biased to the open position shown and is adapted to be closed upon energization of solenoid 142.

Diametrically opposite to port 136 the cylinder 32 is provided with a port 144 adapted to be controlled by one end of a double-ended valve 146 biased to close port 144 and adapted to open such port upon energization of a solenoid 148. The valve 146 is arranged in a chamber 150, normally communicating with the line 134 leading to the reservoir. An inlet port 152 leads into the chamber from a motorized pump 154 to which fluid is supplied from the reservoir through pipe line 132.

A variable timer 153 is arranged in the casing as shown in FIG. 1 and as shown diagrammatically in FIG. 6. This timer is provided with an adjusting knob 155 for varying the time interval of operation and as further referred to below, the timer is constantly energized and self-resetting. This is a conventional type of timer and accordingly need not be shown or described in detail.

The means for vertically adjusting the apparatus 28 is shown in FIGS. 4 and 5. Four vertical shafts 156 are arranged at the bottom and adjacent the corners of the casing 30. Each of these shafts (FIG. 5) projects downwardly through the casing 30 and through the breast plate 26 and is threaded at its lower end as at 158 for adjustable engagement with a fixed nut 160 secured beneath the breast plate 26.

Each shaft 156 carries a sprocket 162, and a chain 164 extends continuously around these sprockets as shown in FIG. 4. One of the shafts 156 carries a worm gear 166 engageable by worm 168 mounted on a shaft 170. This shaft is supported in a bearing 172 carried by the bottom of the casing 30 and in a bearing 174 carried by the side wall of the casing. A wheel 176, carried by the shaft 170, is provided with a handle 178 whereby the shaft may be rotated. All of the shafts 156 will be simultaneously rotated by the chain 164, and the threading of the shaft 156 in the fixed nuts 160 (FIG. 5) will adjust the height of the casing 30 and thus adjust the lower limit of the stroke of the shaft 36.

In FIG. 6 of the drawings there is illustrated an electrical system which may be employed with the apparatus of the present invention. The system is designed for patient safety and is compatible with the usual 12 volt DC. power generally available in ambulances and other emergency vehicles. Further, all switches, relays, contacts and the like should be of the hermetically sealed type to comply with explosion-proof requirements for devices to be operated in an operating room environment.

In FIG. 6 the lines 188 and 190 are connected to a source, for example, a conventional 12-volt battery of an ambulance. These lines are controlled by a double pole switch 186. The lower travel limit switch 120 is provided with a contact 192 connected to a wire 194. This switch is shown as having an arm 196 normally disengaged from the contact 192 and connected by wire 198 to the line wire 188. In connection with this switch and other elements of the apparatus, it will be noted in FIG. 6 that they have been designated as NO. or N.C. which legends indicate, respectively, that the elements are in normally open or normally closed condition.

Whereas the lower travel limit switch 120 is normally open, as shown, the upper travel limit switch 126 is normally closed and is adapted to be opened when the piston reaches its upper limit of movement. The switch 126 has a stationary contact 200 normally engaged by a switch arm 202 adapted to be opened when the flange 88 contacts with the roller 128 at the upper limit of movement of the piston. The contact 200 is connected to the line wire 190. The switch arm 202 is connected by a wire 204 to one terminal of a relay magnet 206; the other end of which is connected by a wire 208 to which the wire 194 is connected. The armature 210 of the relay 206 is adapted to engage a contact 212 to which the wire 208 is connected.

The switch contact 212 is connected as at 214 to one terminal of each of the

solenoids

142 and 148. The other terminals of these solenoids are connected as at 216 to a return wire 218 connected to the line wire 190. Thus the

solenoids

142 and 148 are simultaneously energized and simultaneously de-energized.

The wire 218 is connected to one terminal of the latch solenoid 120, the other terminal of which is connected to a wire 220 leading to a switch arm 222 of the timer 153. This switch arm is normally open and is operated by the timer to engage a contact 224 connected to a wire 226 leading to the line wire 188. The

wires

218 and 226 are connected to the timer 153 so that the latter is constantly energized. This timer is self-resetting as stated above. A switch 186 controls the connection of the power lines to lines 188 and 190 within the casing. The switch may be operated by a handle 194 (FIG. 2) projecting from the casing 30.

OPERATION With the switch 186 open, the

valves

138 and 146 will be in normal positions (FIG 1), the lower chamber of the cylinder 32 thus communicating with the reservoir 130 through the chamber 140. With the timer 153 adjusted for the desired nominal period of delay in its operation, for example one second, the apparatus may be set in operation by closing the switch 186. With the piston at its lower limit of movement, the normally open switch 120 will have been closed by engagement with the flange 82.

Under such conditions, current will flow from line wire 188 through wire 198, switch arm 196, contact 192, wire 194, wire 208 and relay 206, thence back to the source through wire 204, the normally closed upper travel limit switch 126 and line wire 190.

Energization of the relay 206 closes the armature switch 210, and this establishes a holding circuit in which current flows through the relay 206 and limit switch 126 through wire 188 and relay switch 210. This is important since it will be seen that immediately upon the starting of upward movement of the piston 34, the switch arm 196 will be released to move to its normally open position as soon as the flange 82 moves upwardly beyond the roller 122 (FIG. 1).

The valves 138 and '146 normally occupy the positions shown in FIG. 1, the lower end of cylinder 32 communicating with the reservoir through the port 136 and chamber 140. The closing of the circuit as described above through the relay switch 210 provides a holding circuit which will be maintained after the switch 196 has opened and until the switch 202 is opened when the piston 34 reaches its upper limit of movement. Under such conditions, current will flow through line wire 188, relay switch, 210, wire 214 through

solenoids

142 and 148 and thence back to the source through

wires

216 and 218. Energization of the

solenoids

142 and 148 operates to close the valve 138 and move the valve 146 to the left (FIG; 1) to open the port 144 and close the chamber 150 to the reservoir return pipe '134. At this time it will be noted that a circuit through the latch solenoid 120 depends on the closing of the timer switch 222, and accordingly the latch 116 will be in released condition ready to engage the flange 88 when the piston 34 reaches its upper limit of movement.

The reversing of the positions of the

valves

138 and 146 supplies fluid pressure through port 144 to the lower end of the cylinder 32, whereupon the piston 34 begins its upward movement to release the padded foot 42 from the patients chest. When the piston reaches its upper limit of movement, the flange 88 will operate the limit switch 126 to open it, thus breaking the circuit through the relay 206, whereupon the relay switch 210 will open to deenergize the

valve solenoids

142 and 148. These valve solenoids then return to the normal positions shown in FIG. 1. However, as upward movement of the piston approaches the position at which the limit switch 126 will be open, the latch finger 116 will snap beneath the flange 88 to hold the piston 34 in its upper limit of movement.

After the expiration of the time limit for which the timer 153 has been set, the timer operates to close the switch 222, whereupon current will flow from the line wire 188 through wire 226, switch 222, wire 220 and sole noid 120, and thence back to the source through wire 218 and line wire 190. The latch solenoid 120 thus will be energized and the latch finger 116 will be released from the flange 88 (FIG. 1). The loading of the spring 52 then moves the piston 34 downwardly to cause the resilient foot 42 to exert a pressure against the patients chest.

The application of resilient force for this purpose is important since it is undersirable to exert a positive nonresilient force against the patients chest. It is also desirable that the loading of the spring be adjustable to vary the resilient force applied to the patients chest according to his age and size. For this purpose the spring seat 54 may be moved downwardly to increase the loading of the spring or upwardly to reduce the spring loading. This loading of the spring 52 is adjusted while the apparatus is not in operation and with the piston 34 at its lower limit of movement. The adjustment is accomplished by rotating the wheel 76 to transmit movement through the shaft 60 to the pinions 62 and racks 56.

It will be apparent that immediately after the energization of the latch solenoid 120 to release the latch finger 116 from the flange 88, this flange will move below the roller 128 (FIG. 1) whereupon the switch arm 202 (FIG. 6) will return to its normally closed position. The circuit through the relay 206 will have been opened upon the opening of the switch arm 202 at the upper limit of piston movement, and the relay circuit will not be closed when the switch arm 202 returns to its normally closed position since the switch arm 196 of the lower travel limit switch 120 will be open.

When the piston 34 reaches its lower limit of movement, the flange 82 will engage the roller 122 and close the switch arm 196 to again energize the relay 206 and energize the

valve solenoids

142 and 148 to start the next upward movement of the piston 34 as described above. Thus the piston 34 will continue to reciprocate to effect the cardiac massaging of the patient.

The foregoing operations are carried out with the gear 92 and associated elements removed from the apparatus, it being apparent that the open topped bearing 96 permits the instantaneous placing of the shaft 94 in the bearing and the removal of the shaft therefrom. The gear 92 and associated elements are used in the event of a failure of power in the apparatus. Should power fail, the shaft 94 is placed in the bearing 96, and with the handle 98 in the upper or dotted line position, the operator will move the handle downwardly to the solid line position, thus raising the piston 34 to perform the function normally performed by fluid pressure beneath the piston. When the piston reaches the upper end of its stroke, the operator will push the finger piece 102 to release the pawl from the teeth of the gear 92, the handle being swung upwardly to the dotted line position while holding the pawl 100 released from the gear 92. Pushing the button 112 will release the latch 116, and the spring 52 will then perform its normal function of exerting pressure against the patient. When the piston reaches its lower limit of movement, the operator will release the ratchet 100 and again operate the handle 98 to lift the shaft 36 and piston 34. Thus the functions of the apparatus may be carried out manually in the event of a power failure.

The present invention provides for a simple, reliable and portable means for closed chest cardiac massage for use in a case of cardiac arrest. The device by its simplicity and size is highly cost-effective as a means for reducing the requirement for trained medical personnel during cardiac arrest. The device is small and requires little space and may be quickly set up and placed in automatic operation.

We claim:

1. A closed chest cardiac massage apparatus comprising a reciprocating mechanism having a padded foot at one end engageable with the patient, means for effecting movement of said foot away from the patient, including a cylinder having a piston therein provided with a piston rod connected at one end to said padded foot, said means for effecting movement of said foot away from the patient comprising fluid pressure means for supplying fluid pressure to the end of said cylinder toward the patient, and spring means for effecting movement of said foot into pressure engagement with the patient to produce a cardiac massage effect.

2. Apparatus according to claim 1 wherein said spring means comprises a compression spring arranged in the other end of said cylinder and engaging said piston, said fluid pressure means developing pressure in excess of the maximum loading of said spring to effect movement of said piston against the loading of said spring.

3. An apparatus according to claim 2 provided with a control mechanism for said fluid pressure means for admitting pressure to said first named end of said cylinder when said piston is adjacent thereto, and for maintaining such pressure for a predetermined distance of travel of said piston toward said other end of said cylinder and then relieving said pressure and rendering said spring effective for moving said piston toward said first named end of said cylinder.

4. Apparatus according to claim 3 provided with a latch automatically engageable with said piston rod when said piston has moved said predetermined distance toward said other end of said cylinder, and a timer for releasing said latch after the latter has engaged said piston rod for a predetermined interval of time.

-5. An apparatus according to claim 3 wherein said fluid pressure means comprises a motor-pump unit, a reservoir connected to said unit to continuously supply a hydraulic fluid thereto, and automatic means operable when said piston moves said predetermined distance toward said other end of said cylinder for opening the first named end thereof to said reservoir and for bypassing fluid from the outlet of said pump to said reser- 6. Apparatus according to claim 5 wherein said means for opening said first named end of said cylinder to said reservoir comprises a valve biased to open position, and means for closing the said valve when said piston has moved to its limit of movement toward said first named end of said cylinder.

7. Apparatus according to claim 6 wherein said means for bypassing pumped fluid from said pump to said reservoir comprises a bypass line, a dual valve device, and

means for moving such valve to deliver pumped fluid to said first named end of said cylinder after said piston has reached its limit of movement toward said first named end of said cyinder and for closing communication between said pump and said bypass line, and automatic means operable upon movement of said piston said predetermined distance toward said second named end of said cylinder for opening said first named valve and for reversing the movement of said dual valve device for closing communication between said pump and said first named end of said cylinder and for opening communication between said pump and said bypass line.

8. Apparatus according to claim 3 provided with means including an element carried by said piston rod at the end thereof opposite said foot for adjusting said predetermined travel of said piston toward said second named end of said cylinder.

9. Apparatus according to claim 8 wherein said element carried by said piston rod comprises a sleeve mounted on said piston rod for axial movement therealong, solenoid means energizable for closing said first named valve and opening communication between said pump and said first named end of said cylinder, a circuit for said solenoid means including a limit switch, said limit switch being biased to closed position and being engageable with said element upon the completion of said predetermined distance of travel of said piston for opening said circuit whereby said first named valve opens, said dual valve device being biased to a position opening communication between said pump and said bypass line and closing communication between said pump and said cylinder whereby, when said circuit is broken, said dual valve device Wil move to such position.

10. Apparatus according to claim 9 provided with means for limiting movement of said pressure foot toward References Cited UNITED STATES PATENTS 6/1966 Rand et a1. l285.2 3/1967 Hewson.

L. W. TRAPP, Primary Examiner