US3496932A - Method and apparatus for substernal cardiac massage - Google Patents

Description

Feb. 24, 71970 5, g, p s ETAL METHOD AND APPARATUS FOR SUBS'IERNAL CARDIAC MASSAGE Filed D60. 22, 1967 2 Sheets-Sheet 1 jBerz :15??? 6' BY m2? 0 225m I Feb. 24,1970

BC. PRISK ETAL METHOD AND APPARATUS FOR SUBSTERNAL CARDIAC MASSAGE Filed Dec. 22, 1967 2 Sheets-Sheet 2 x02 [9? CARIDIAC a; W 83 ACHOMETER M3 .93 T/ f TRIGGER INTERNAL LEAD T PACEMAKER 3%??? (A? QuENcY ADJUST T|M|NG UNIT 8.?

RATIO ADJUST f5 f4 l-l m w J z 1 ii i i x I a: if 72 7i TMOSPHERE & STORAGE I TANK i2 fii j NVENTORS BLADDER Barf C Prfsk AT TORNEY United States Patent METHOD AND APPARATUS FOR SUBSTERNAL CARDIAC MASSAGE Bert C. Prisk and Aran S. Johnson, Grosse Pointe Woods,

Mich, assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Dec. 22, 1967, Ser. No. 692,844 Int. Cl. A61h 7/00;A61m 35/00; A61b 17/34 US. Cl. 128-64 7 Claims ABSTRACT OF THE DISCLOSURE To massage a failing heart, an inflatable bladder is inserted in the chest between the heart and the sternum. The bladder is alternately inflated and deflated by varying air pressure to effect pumping of the heart. The bladder comprises a generally cone-shaped plastic film fitted With an air supplying stem extending therethrough from the tip through the base and is attached to a pumping apparatus external of the chest.

This invention relates to a method and apparatus for heart massage of the type which requires no open chest surgery.

In the medical profession it is recognized that it is frequently desirable in the event of a failing heart or a cardiac arrest, to assist the heart in its pumping function. It is believed that if the heart can be assisted for long periods of time, a heart muscle which has had an injury can recover if the assistance is adequate to maintain the blood in the heart muscle.

The technique of closed chest massage is often used, but this is of marginal effectiveness and is suitable for only short periods of application. Moreover, closed chest massage often results in broken ribs and other injuries to the patient. It has been proposed to bypass the heart with various types of pumping devices and to fit around the heart mechanical pumping devices. However, these operations require elaborate open chest surgery which requires long periods of time, highly skilled surgical teams and are very traumatic to the already ill patient.

It is a general object of this invention to provide a method and apparatus for substernal heart massage which does not require open chest surgery.

It is a further object of this invention to provide a device to be inserted into the chest without open chest surgery for elfecting heart pumping.

It is another object of this invention to provide a substernal heart massage device and apparatus for operating the device.

It is an additional object of this invention to provide a method of inserting a heart assisting device into the chest without open chest surgery.

It is yet another object of this invention to provide a method of installing a heart massager which requires less than one minute for installation.

The invention is carried out by providing an inflatable bladder adapted to be placed adjacent the heart. The invention further contemplates an associated pumping device for alternately inflating and deflating the bladder.

The invention is also carried out by providing a method of inserting an inflatable bladder beneath the sternum and adjacent the heart and of pulsating the bladder to effect heart massage.

The above and other advantages will be made more apparent from the following specification taken in conjunction with the accompanying drawings wherein like reference numerals refer to like parts and wherein:

FIGURE 1 is a vertical crosssection of the human chest having installed therein a deflated heart massage device according to the invention;

FIGURE 2 is a vertical cross-section of the human chest having therein an inflated heart massage device according to the invention;

FIGURE 3 is a partly broken away view of a heart massaging bladder according to the invention;

FIGURE 4 is a cross-sectional view of a trocar and cannula assembly, and;

FIGURE 5 is a schematic diagram of the electrical and pneumatic control system for operating the heart massager according to the invention.

FIGURES l and 2 illustrate the human chest which includes the sternum having axyphoid tip 12, a vertebral column 14 and aheart 16 situated therebetween. The heart is surrounded by a membrane known as thepericardial sac 18. A cavity denoted the anterior mediastinum 20 is located between the heart and the sternum. The lower portion of the chest cavity is closed by thediaphragm 22.

A heart massaging bladder 24 according to the invention is inserted between theheart 16 and thesternum 10 and is shown located in the anterior mediastinum 20. In FIGURE 1, the bladder is in deflated condition while in FIGURE 2, it is inflated. The bladder as shown in detail in FIGURE 3 has a generally cone-shaped wall 26 and a generallyflat base portion 28 integral therewith. Astem 30 is attached to thetip 32 of the bladder and extends interiorly thereof adjacent the wall 26 and protrudes eccentrically through thebase portion 28. Thestem portion 30 is a hollow tube and a plurality ofapertures 34 in the tube wall provide air passages between the tube and the interior of the bladder 24. The bladder is comprised of a clinical grade of poly-vinyl chloride. The bladder 24 then is resilient and the walls thereof readily collapse when air is removed from the bladder, but when air pressure is applied to the interior of the bladder, the bladder opens up to its normal conical shape but does not substantially expand beyond its normal size, that is, the poly-vinyl chloride material does not stretch appreciably so that during operation of the bladder, it maintains its conical shape upon expansion. The walls 26 andbase portion 28 of the bladder are about 0.005 to 0.007 of an inch thick. Thestem 30, however, has walls 005 of an inch thick and is 7 of an inch in diameter. The stem, then, is resilient and laterally flexible but has sufficient longitudinal rigidity to allow the bladder to be pushed by means of the stem into position within the chest. In size the bladder is approximately 3 /2 inches in diameter across the base while the distance from thebase 28 to thetip 32 is approximately 4 inches. With these dimensions the inflated volume of the bladder is approximately 200 cc. The stem is about 15 inches long so that it can extend outside the body for connection to a pumping device.

The shape of the bladder and its ability to hold its shape are important. As shown in FIGURE 2, when the bladder is inflated its largest lateral dimension contacts the heart near the bottom so that the heart ventricle is compressed or collapsed first at the bottom and the blood is then forced up into the aorta. While the heart discharges about to cc. of blood per cycle the bladder is designed with a larger volume to compensate for the yielding of the lungs and other organs during bladder inflation.

It is sometimes preferable to place the bladder within the pericardial sac instead of in the anterior mediastinum. The pericardial sac then provides a measure of lateral support for the bladder during inflation.

A trocar andcannula assembly 35 are used as tools to expedite the placement of the bladder within the chest. As shown in FIGURE 4, thecannula 36 is a curved tube /2 inch in diameter and about 4 inches long, open at both ends and having a handle portion 38 at one end.

The tube has a 10 inch radius of curvature. The trocar 40 comprises a three-sided tip 42 attached to a curved rod 44 which in turn is attached to ahandle portion 46. The tip 42 is sized to slidably fit within thecannula 36. One side of the tip 42 is curved as shown so as to facilitate its movement through thecannula 36 and to facilitate the insertion of the assembly into the chest without damaging the heart.

The method of inserting the bladder 24 into the chest comprises making a shallow incision about one inch long below thexyphoid tip 12 of the sternum. The trocar andcannula assembly 35 is then inserted through the incision and manipulated by hand through thediaphragm 22 and into the anterior mediastinum 20. Then the trocar 40 is removed from thecannula 36 and a deflated bladder 24 is inserted through the cannula until it is positioned between thesternum 10 and thepericardial sac 18, with thestem 30 being located nearest the sternum. Then thecannula 36 is removed leaving the bladder 24 in place. This entire operation requires less than one minute when performed by a skilled person. When it is desired to place the bladder within thepericardial sac 18, the procedure is the same except that the trocar is manipulated to puncture and enter the pericardial sac. This is readily accomplished without injury to the heart muscle. The bladder is then inserted through the cannula into the pericardial sac.

After the bladder is in place, it is alternately inflated and deflated as shown in FIGURES l and 2 to effect pumping of the heart. During inflation of the bladder, the sternum serves as a reaction member therefor so that the heart is compressed between the bladder and the vertebral column 14, the vertebral column thus acting as a further reaction member. The bladder may be left in place and pulsated in this manner for several days or several weeks.

The means for inflating and deflating the bladder as shown in FIGURE comprises anelectronic control circuit 50 and a pneumatic operating system 52. The pneumatic system 52 includes avalve housing 53 and a solenoid operated spool valve 54 shown in its normal position, the valve being maintained in that position by aspring member 56. When an electrical signal is applied to the solenoid 58, the valve shifts to the right against the biasing action of thespring 56. The valve has five ports. One of the ports 60 is connected to the high pressure side of apump 62 while a second port 64 is connected to the vacuum side of thepump 62. A further port 66 is connected to astorage tank 68 while another port 70 is vented to atmosphere. The remainingport 72 is connected to thebladder stem 30. The vacuum side of thepump 62 is provided with a vacuum relief valve 73 vented to atmosphere and the pressure side of thepump 62 is provided with a pressure relief valve 74 also vented to atmosphere. When the valve 54 is in normal position, ports 66 and 60 are interconnected andports 64 and 72 are interconnected so that as the pump operates, air will be withdrawn from the bladder to a minimal vacuum as determined by the vacuum relief valve 73, and pumped into thestorage tank 68. Then when the solenoid 58 is energized and the valve 54 shifts to the right,ports 66 and 72 will be interconnected while ports 64 and 70- will be interconnected. Then the air which was previously pumped to thestorage tank 68 is allowed to flow to the bladder. The pump intake is connected to atmosphere while the pump output exhausts through the pressure relief valve 74. The pressure relief valve 74 further insures that the pressure supply to the storage tank and hence to the bladder does not become excessive. Moreover, by use of the storage tank, the pump is isolated from the bladder to provide further assurance that a pump malfunction will not cause excess pressure in the bladder. It will be seen then that in operation, as the valve 54 is moved back and forth, the air under pressure will be alternately supplied to the bladder from the storage tank and withdrawn from the bladder by the pump. The pump and storage tank are so designed that during each cycle up to 200 cc. of air is supplied to the bladder at about 2 or 3 p.s.i.

Theelectrical control circuit 50 comprises a signal producing means for periodically energizing the solenoid 58 as well as means for synchronizing that signal with the patient EKG signals or with internal pacemaker signals. The signal producing means comprises atiming unit 82 which is an astable multivibrator having manual frequency and ratio adjustments so that the signal frequency produced will correspond to a desired heartbeat rate and so that the ratio of the period of bladder inflation to the period of deflation is adjustable. A normally open switch 84 is connected to the output of thetiming unit 82 and when closed connects the timing unit output to the signal line 86 which leads to the valve solenoid 58. The output of the timing unit may be connected to a trigger unit 88 through switch 84 and through normally closedswitches 90 and 92. The trigger unit 88 is a bistable multivibrator. Its output is fed to a cardiac tachometer 94 which is a rate meter for indicating the pulsation rate of the bladder in terms of pulses per minute. The output of the trigger unit 88 is also connectible by normally open switch 96 to aninternal pacemaker 98, i.e., an electrical heart stimulator of the type well known in the art. In this mode of operation, the pacemaker signals will be synchronized with the massaging device. If desired, however, the pacemaker may be operated independently of the massager device. To that end, normally open switch 100 connects the output of thetiming unit 82 to the input of the trigger unit 88 so that if switch 84 is open and swiches 100 and 96 are closed, the pacemaker signals will be applied at a rate determined by thetiming unit 82. In this mode of operation, the cardiac tachometer 94 registers the rate of the pacemaker signals.

Thecontrol circuit 50 also incorporates means for sensing the EKG signals of the patient and for synchronizing the massaging rate with those signals. EKG patient leads 102 are connected to the patient in the conventional manner. A lead selector switch 104 is provided to enable the selection of that signal which is the strongest or which has the preferred phase. The switch 104 is connected to anamplifier 106 which in turn has its output connected through normallyopen switch 108 and switch 92 to the trigger unit 88. Thus, ifswitch 108 is closed and switch 90 is opened, the cardiac tachometer 94 will register the EKG rate. A scope output 110 is provided at the EKG amplifier output so that if desired, an oscilloscope may be attached for direct viewing of the EKG signals. While thus monitoring the EKG signals, the massager may also be placed in operation by closing switch 84. To synchronize the massager with the EKG singals aswitch 112 is provided between the EKG amplifier output and thetiming unit 82 input. The astable oscillator of the timing unit is so arranged to synchronize with the EKG signals when theswitch 112 is closed. It will thus be seen that the electrical control circuit provides a highly versatile tool for monitoring EKG signals or providing internal pacemaker signals as well as controlling the massaging operation and if desired synchronizing the massaging with either the EKG signals or the pacemaker signals. The switches of the circuit may be manually controlled switches although in the preferred embodiment of the circuit they are relay switches, the relays being controlled by a multiple contact mode switch, not shown.

This invention, then, provides means for very rapidly preparing a patient for heart massage with a minimum of trauma, and for effecting eflicient pumping of the heart by mechanical means to allow the heart to rest and to mend.

The embodiment of the invention described herein is for purposes of illustration and the scope of the invention is intended to be limited only by the following claims.

It is claimed:

1. A method of heart massage comprising the steps of (a) making an incision in the skin below the xyphoid tip of the sternum,

(b) inserting a trocar and cannula through the incision into the anterior mediastinum,

(c) removing the trocar from the cannula,

(d) inserting an inflatable bladder through the cannula into the anterior mediastinum adjacent the heart,

(e) removing the cannula, and

(f) periodically pulsating the bladder whereby the heart is compressed periodically to effect the pumping of blood.

2. A method of heart massage comprising the steps of (at) making an incision in the skin below the xyphoid tip of the sternum,

(b) inserting a trocar and cannula through the incision into the pericardial sac,

(c) removing the trocar from the cannula,

(d) inserting an inflatable bladder through the cannula into the pericardial sac adjacent the heart,

(e) removing the cannula, and

(f) periodically pulsating the bladder whereby the heart is compressed periodically to effect the pumping of blood.

3. A method of heart massage comprising the steps of (a) inserting a trocar and cannula assembly into the chest cavity adjacent the heart,

(b) removing the trocar,

(c) inserting a bladder through the cannula into the chest cavity adjacent the heart,

(d) removing the cannula, and

(e) alternately supplying and withdrawing air from the bladder whereby the heart is compressed periodically to effect the pumping of blood.

4. A method of heart massage comprising the steps of (a) inserting a bladder between the sternum and the heart, and

(b) periodically compressing the heart between the bladder and the vertebral column by inflating and deflating the bladder whereby the heart ventricle is compressed periodically to eflect pumping of blood.

5. An inflatable device for substernal heart massage comprising a bladder of flexible substantially non-stretchable material, the bladder having a generally conical side wall and an integral base portion, a stem comprising a tube extending from the tip of the conical side wall eccentrically through the bladder cavity and through the bladder base portion, the stem having longitudinal rigidity and an orifice through the stem communicating with the bladder cavity, whereby the bladder may be inflated by passing air through the stem into the bladder.

6. An inflatable device for substernal heart massage comprising a collapsible bladder of substantially nonstretchable material, means for lending rigidity to the bladder along one direction comprising an axially rigid and laterally flexible tubular stern aflixed to said bladder at spaced points, and a passage connecting the interior of the tubular stem to the interior of the bladder, whereby the bladder has suflicient rigidity to be manipulated into the chest cavity and may be inflated and deflated by way of the tubular stem.

7. An apparatus for substernal heart massage comprising (a) inflatable means adapted to be inserted in the chest between the heart and the sternum,

(b) tubular stem means connected to the inflatable means for passing air to the inflatable means, and

(c) pulsator means connected to the stem means for alternately supplying air to and withdrawing air from the inflatable means including (i) an electrically controlled multi-port valve, having a first port connected to the stem means,

(ii) an air pump having a vacuum side and a pressure side connected to second and third ports of the valve, respectively,

(iii) a chamber connected to a fourth port of the valve,

(iv) the valve being so arranged that in a first position that vacuum side of the pump communicates with the stem means and the pressure side of the pump communicates with the chamber so that air is pumped from the inflatable means and to the chamber to pressurize the chamber, and in a second position the chamber communicates with the inflatable means so that air flows from the pressurized chamber to the inflatable means, and

(v) electrical control means connected to the valve for shifting the valve alternately between the first and second positions so that the inflatable means is pulsated whereby the heart is massaged by the inflatable means.

References Cited UNITED STATES PATENTS 2,101,273 12/1937 Smith 128-64 2,826,193 3/1958 Vineberg 12864 2,893,382 7/1959 Demeny 128-64 3,039,468 6/1962 Price 128-347 3,416,160 12/1968 Arion.

. L. W. TRAPP, Primary Examiner US. Cl. X.R. l28347, 348

zg gy UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,496,932 DatedFebruary 24, 1970 Invent0r(s) Bert c. Prisk and Aran g. ,Ighgg on It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Column 1, after the title, lines 4 6 should read Bert c. Priak, Grosse Pointe Woods, Mich assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware, and Area 8. Johnson, Grosse Pointe Woods $|GNED A-OCT 27 I970 {SEAL} Attest:

WILLIAM E- suHUYLm, IR Edward Fletclm' Gomissioner of Patents Atlasting Officer

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