Cardiopulmonary resuscitating apparatus

Claim 2

A cardiac resuscitation apparatus comprising: a pressure foot pad; means for supporting said pad in a position exteriorly of the body of a supine patient substantially directly over a portion of the sternum of the patient; power means for reciprocating said pressure foot pad at a rate approximately equal to the normal rate of heart beat to alternately inwardly deflect and release the sternum thereby causing an artificial heart pumping action; clutch means for connecting said power means and said foot pad support means; means for disengaging said clutch means at a predetermined point in the downward stroke of said foot pad support means and reengaging said clutch means on the upward stroke; and whereby a predetermined minimum depression of the patient''s sternum is positively provided and the total depression depends upon the upward force exerted by the patient''s body.

Claim 3

The apparatus of claim 1 wherein said means for disengaging said clutch is operative to provide only partial disengagement between said power means and said foot pad support means during the downward stroke, so that said power means supplies a diminished downwardly directed force to said foot pad support means.

Claim 4

The apparatus of claim 2 wherein said means for partially disengaging said clutch between said power means and said foot pad support means during the downward stroke provides a decreasing clutch partial engagement.

Claim 5

The apparatus of claim 3 wherein said clutch means comprises an electrically operated magnetic clutch device which transmits maximum torque when a first voltage is impressed upon said clutch device.

Claim 6

The apparatus of claim 4 wherein said means for partially disengaging said clutch device comprises a normally closed electrical switch and means for opening said switch actuated by the arrival of said foot pad support means at said predetermined point during reciprocation of said foot pad support means.

Claim 7

The apparatus of claim 5 wherein said Means for partially disengaging said clutch device additionally includes circuit means including capacitance means charged, when said electrical switch is closed, to a second voltage less than said first voltage and initially impressing said second voltage upon said magnetic clutch when said electrical switch is opened so that said clutch transmits less than maximum torque between said power means and said foot pad support means.

Claim 8

The apparatus of claim 1 additionally including means for retarding the upward stroke speed of said foot pad support means.

Claim 9

The apparatus of claim 7 wherein said means for retarding the upward stroke speed of said foot pad support means includes said means for disengaging said clutch means, and circuit means for rendering said clutch means particularly operative during at least part of the upward stroke of said foot pad support means.

Claim 10

A closed-chest heart resuscitating apparatus comprising: a pressure applicator pad; means for positioning said pressure pad in a position exteriorly of the body of a patient and substantially over the resilient breastbone of the patient, said means including a reciprocable substantially vertical beam supporting said pressure pad on its lower end and including vertical adjusting means for initially locating and maintaining said beam and said pressure applicator pad with said pad in contact with the patient''s breastbone; power means imparting rhythmic reciprocating motion to said beam at a rate approximately equal to the normal rate of heart beat and with compression downstroke force sufficient to depress the breastbone to effect substantial perfusion of the heart and releasing said beam to be returned upwardly by the breastbone restoring force; clutch means for connecting said power means and said vertical reciprocable beam; means for controlling said clutch connection, said means providing engagement of said clutch during the compression stroke of said beam until the resilient breastbone has been depressed a predetermined distance, said distance being less than the distance required to effect maximum heart perfusion, where after said control means allows no more than partial engagement of said clutch; beam momentum during the compression stroke moving said beam so as to depress the breastbone a distance beyond said predetermined distance, said additional distance being determined by the momentum of said beam and the resiliency of the breastbone; and said controlling means providing reengagement of said clutch when said beam moves upwardly on the successive upstroke.

Claim 11

A closed-chest heart resuscitating apparatus comprising: a pressure applicator pad; means for positioning said pressure pad in a position exteriorly of the body of a patient and substantially over the resilient breastbone of the patient, said means including a reciprocable substantially vertical beam supporting said pressure pad on its lower end and including vertical adjusting means for initially locating and maintaining said beam and said pressure applicator pad with said pad in contact with the patient''s breastbone; power means imparting rhythmic reciprocating motion to said beam at a rate approximately equal to the normal rate of heart beat and with compression downstroke force sufficient to depress the breastbone to effect substantial perfusion of the heart and releasing said beam to be returned upwardly by the breastbone restoring force; clutch means for connecting said power means and said vertical reciprocable beam; means for controlling said clutch connection, said means providing engagement of said clutch during the compression stroke of said beam until the resilient breastbone has been depressed a predetermined distance, said distance being less than the distance required to effect maximum heart perfusion, where after said control means allows no more than partial engagement of said clutch; beam momentum during the compression stroke moving said beam so as to depress the breastbone a distance beyond said predetermined distance, said additional distance being determined by the momentum of said beam and the resiliency of the breastbone; and said controlling means providing reengagement of said clutch when said beam moves upwardly on the successive upstroke.

Claim 12

The apparatus of claim 9 wherein said predetermined distance is less than 1 1/2 inches.

Claim 13

The apparatus of claim 10 wherein the downward momentum of said reciprocating beam when depressing the resilient breastbone of a patient which produces a restoring force of at least 60 pounds when depressed 1 1/2 inches will be equal to said restoring force before the breastbone is depressed a total distance, including said predetermined distance, of no more than 2 inches.

Claim 14

The apparatus of claim 9 additionally including second clutch engagement control means providing virtually total disengagement of said clutch after said beam has moved downwardly beyond said predetermined distance.

Claim 15

The apparatus of claim 12 additionally including spring means resisting downward movement of said vertical beam and having a spring force capable of moving said vertical beam upwardly only when said clutch is virtually totally disengaged.

Claim 16

A cardiac resuscitation apparatus comprising: a pressure foot pad; a substantially vertical reciprocable beam supporting said pressure foot pad in a position exteriorly of the body of a patient substantially directly over a portion of the sternum of the patient, the patient''s sternum producing an upwardly directed restoring force when depressed by said pressure foot pad; power means including an electric motor and gear means foR interconnecting said motor and said substantially vertical reciprocable beam; and means for alternately connecting and releasing said electric motor and said gear means during each reciprocation of said beam so that said power means when connected drives said pressure foot pad downwardly with a force sufficient to depress the sternum to effect perfusion of the heart and when released allows the pressure foot pad to be moved upwardly by the restoring force of the depressed sternum, said reciprocation stroke being at a rate approximately equal to the normal rate of heartbeat.

Claim 17

A cardiac resuscitation apparatus comprising: a pressure foot pad; a substantially vertical reciprocable beam supporting said pressure foot pad in a position exteriorly of the body of a patient substantially directly over a portion of the sternum of the patient, the patient''s sternum producing an upwardly directed restoring force when depressed by said pressure foot pad; power means including an electric motor and gear means foR interconnecting said motor and said substantially vertical reciprocable beam; and means for alternately connecting and releasing said electric motor and said gear means during each reciprocation of said beam so that said power means when connected drives said pressure foot pad downwardly with a force sufficient to depress the sternum to effect perfusion of the heart and when released allows the pressure foot pad to be moved upwardly by the restoring force of the depressed sternum, said reciprocation stroke being at a rate approximately equal to the normal rate of heartbeat.

Claim 18

The apparatus of claim 14 additionally comprising means for controlling said connecting means, said means normally connecting said vertical beam with said power means, and substantially disconnecting said beam from the power means at a predetermined point in the downward stroke of said foot pad.

Claim 19

The apparatus of claim 15 wherein said means for connecting said electric motor and said gear means comprises an electrically operated magnetic clutch.

Claim 20

The apparatus of claim 16 wherein said means for controlling said connecting means, comprises an electric circuit including a normally closed electrical switch for impressing a first voltage upon said magnetic clutch, said switch being mechanically opened by downward motion of said vertical beam past said predetermined point and means for impressing a second voltage upon said clutch, said magnetic clutch transmitting a maximum torque when said first voltage is impressed thereon and transmitting less than maximum torque when said second voltage is impressed thereon.

Claim 21

A cardiac resuscitation device comprising: a portable frame adapted to be positioned over a patient with cardiac arrest; a reciprocating compression beam including a rack gear and slidably supported in said frame; a pressure foot pad and means pivotally mounting said pad on the lower end of said reciprocating compression beam and positioned exteriorly of the patient''s body over the lower third of the patient''s resilient sternum; power means including an electric motor mounted on said frame; an electrically operated magnetic clutch operatively connected to said electric motor; gear means, including speed reducer gears and a pinion gear operatively connected to said magnetic clutch, said pinion gear engaging said reciprocating compression beam rack gear means; said magnetic clutch transmitting maximum torque from said power means to said reciprocating compression beam when a first voltage is impressed upon said clutch and transmitting partial torque when a second voltage is impressed upon the clutch; an electrical contact switch normally closed so that said first voltage is impressed upon said clutch and mechanically actuated by reciprocating motion of said compression beam at a predetermined point in the downstroke of said beam so that no more than said second voltage is impressed upon said clutch until mechanical actuation of said switch at said predetermined point in the successive upstroke of said beam which allows said first voltage to be impressed upon said clutch; circuit means including said contact switch and a timing motor and timing switch for coupling a source of DC current through said mechanically actuated contact switch to said magnetic clutch so that said first voltage is reimpressed upon said magnetic clutch when said mechanically actuated contact switch is closed during the upstroke of said beam; and the resilient upward force exerted by the patient''s sternum being less than the downward force of said compression beam when maximum torque is transmitted through said clutch and being greater than the downward force of said compression beam when partial torque is transmitted through said clutch so as to overcome the downward momentum of said compression beam.

Claim 22

A cardiac resuscitation device comprising: a portable frame adapted to be positioned over a patient with cardiac arrest; a reciprocating compression beam including a rack gear and slidably supported in said frame; a pressure foot pad and means pivotally mounting said pad on the lower end of said reciprocating compression beam and positioned exteriorly of the patient''s body over the lower third of the patient''s resilient sternum; power means including an electric motor mounted on said frame; an electrically operated magnetic clutch operatively connected to said electric motor; gear means, including speed reducer gears and a pinion gear operatively connected to said magnetic clutch, said pinion gear engaging said reciprocating compression beam rack gear means; said magnetic clutch transmitting maximum torque from said power means to said reciprocating compression beam when a first voltage is impressed upon said clutch and transmitting partial torque when a second voltage is impressed upon the clutch; an electrical contact switch normally closed so that said first voltage is impressed upon said clutch and mechanically actuated by reciprocating motion of said compression beam at a predetermined point in the downstroke of said beam so that no more than said second voltage is impressed upon said clutch until mechanical actuation of said switch at said predetermined point in the successive upstroke of said beam which allows said first voltage to be impressed upon said clutch; circuit means including said contact switch and a timing motor and timing switch for coupling a source of DC current through said mechanically actuated contact switch to said magnetic clutch so that said first voltage is reimpressed upon said magnetic clutch when said mechanically actuated contact switch is closed during the upstroke of said beam; and the resilient upward force exerted by the patient''s sternum being less than the downward force of said compression beam when maximum torque is transmitted through said clutch and being greater than the downward force of said compression beam when partial torque is transmitted through said clutch so as to overcome the downward momentum of said compression beam.

Claim 23

The device of claim 18 wherein said circuit means additionally includes capacitance means, charged when said mechanically actuated contaCt switch is closed, and initially impressing said second voltage upon said clutch.

Claim 24

The device of claim 19 additionally including: a second electrical contact switch mechanically actuated by reciprocating motion of said compression rod so as to prevent any voltage from being impressed upon said clutch after a second predetermined point in the downstroke of said beam is reached, said second predetermined point being below said first point and being reached only in the absence of substantial upward force of resilient sternum of a patient, said clutch transmitting substantially no torque when no voltage is impressed thereon; and resilient means operatively engaging said compression beam to exert an upward force thereon less than the downward force of said compression beam when partial or maximum torque is transmitted through said clutch but greater than the downward force of said compression beam when no torque is transmitted through said clutch.

Claim 25

The device of claim 18 wherein said compression beam is hollow and said means for pivotally mounting said pressure foot pad to said compression beam includes a bar telescopically received in said hollow beam and additionally comprising means for adjustably vertically positioning said bar and pressure foot pad relative to said compression beam and the sternum of the patient.

Claim 26

The device of claim 18 additionally comprising means for artificial respiration of the patient and means operatively connecting said compression beam with said artificial respiration means for periodic actuation of said respiration means.

Claim 27

The device of claim 22 wherein said artificial respiration means and connecting means comprises: forced air supply means in fluid communication with the lungs of the patient; power means operatively connected to and actuating said air supply means; and circuit means including at least one electrical contact switch mechanically periodically actuated by said reciprocating compression beam to energize said power means so as to supply a predetermined volume of air to the lungs of the patient.

Claim 28

The device of claim 22 wherein said artificial respiration means and connecting means includes: a bellows mounted on said frame having an air inlet and an air outlet; a flexible air tube having a face mask on one end and connected at the other end to said air outlet; an electric motor mounted on said frame including crank means; an actuating arm pivotally supported at one end in vertical spaced relation to said frame and pivotally connected at the other end to said bellows, said crank means operatively connecting said motor and said actuating arm for reciprocating arcuate operation of said actuating arm and vertical movement of said bellows; and means for periodically and synchronously energizing said motor in response to reciprocation of said compression beam.

Claim 29

The device of claim 24 wherein said respiration means drive motor energizing means comprises: a respiration motor electrical contact switch periodically mechanically actuated by reciprocation of said compression beam to momentarily provide electrical current to said motor; and a respiration actuating arm electrical contact switch mounted adjacent said actuating arm and mechanically actuated by movement of said arm so as to maintain electrical current to said motor through one arcuate cycle of said arm.