US 2652831 A
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Description (OCR text may contain errors)
A. E. cHEsLl-:R 2,652,831
HEART-LUN@ APPARATUS Filed Jan. 31, 1952 ria-iz @9' Sept. 22, 1953 JNVEN TOR. 45k/:HAM E @man /17' 70k/VE Y Patented Sept. 22, 1953 UNITED sTA'rizA sassi ENT oFFicE 1 This invention relates to apparatus for providing an eXtra-corporeal blood circuit for humans and other animals as during surgery ofthe heart and when it is desirable to halt the heart action. Prior attempts to provide such apparatus have shown that anatomical limitations dictate n the impracticability of by-passing the heart only.
Hence, research has been along a line seeking Y apparatus that performs not only the pumping function of the heart but also the 'oxygenating function of the lungs. Accordingly, the present apparatus comprises a heart-lung machine that induces rhythmic circulation of the blood ina body while simultaneously and alternately drawing olf carbon dioxide from the venous blood and replacing the same with oxygen, thereby providing suitably oxygenated arterial blood to the body.
An object of the present invention is to p-rovide a heart-lung machine that functions to provide a closed blood-circulating system to, thereby, eliminate introduction into the circulation of foreign bodies or elements which may contaminate the blood stream.
Another object of the invention vis to provide apparatus of theV character described that em'- bodies simple, improved and effective means for' oxygenating the'blood'being circulated, the same entailing the alternate application of vacuum and introduction of oxygen under pressure in contradistinction to prior mechanical devices that film or attenuate the blood in the undepen'dlable expectation that the same will absorb suIi-` cient oxygen.
VA further object of the invention is to provide a heart-lung apparatus that has high oxygenating eiiciency coupled with a minimum of foaming (which may result in loss of blood), and a minimum of hemolysis or other damage and/or dilution of the blood cells of the blood stream.
Another object of the invention is to provide heart-lung apparatus in which the receptacles or vessels and the conduits or tubes that circulate the blood are adapted for Veasy sterilization by steam or other recognized and readily available media. l
The invention comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description and which is based on the accompanying drawing. However, the drawing merely shows and the description merely describesone embodiment of the invention, which i's given by way of example or illustration only.
In the drawing:
Fig. 1 is a systematic view showing the present apparatus, several components thereof being shown in section. i
Fig. 2 is an end view of cam means employed in the invention to synchronize the functionof the apparatus.
The present vapparatus is connected Vin the blood stream 'of a body by inserting a cannula, connected'to tube 5, in theinferior vena cava, and inserting a cannula, connected to tube into the left supercial femoral artery. Since this artery leads to the aorta,'it will be seen from the following description that venous blood is drawn from the vena cava vinto the apparatus, oxygen-i ated in said apparatus, and, in suitable pulsations; discharged into vthe femoral artery to, thereby, establish a closed blood-circulating system. It should beunderstood that the body connections may be varied, providing tube 5 has a venal connection vandV tube S an arterial connection, without affectingthe function of; the apparatus. 1 p g The present apparatus comprises, generally,V an oXygenatingunit-l, a-stabilizing unit 8 lconnected in series with unit 'I and discharging into tube 5, a source vof negative pressure or Vacuum-,9, a source of oxygen under pressure le, valve means I I to alternately operatively connect unit 'l to the vacuum and oxygenrsources, and means I2 to control the valve means. I
Unit 1 is shown as comprising an enclosed receptacle or Yvessel "I3, preferably made of glass, and provided with three downwardly directed `ports I4, I Sand I5." Port I d is controlled by a check valve I1 that checks flow from receptacle I3 and permits flow thereinto. Port I5 'is controlled by a check valve I8 similar yto valve Il and also checks now from the receptacle and permits flow thereinto. Port I 6' isv controlled by a check valve I9 that checks flow into receptacle i3 and permits flow therefrom.
At the top, or at least above the level of a quantity of blood 20 in receptacle I3, an vinlet port 2| is provided,-as well asa pressure relieiC or safety valve 22, an inlet 23 for replenishing blood from a reserve, and a gauge 24thatindicates the vacuum-pressure fluctuationsin said receptable.
Unit 8 is shown as van enclosed glass receptacle` 25 somewhat smaller in capacity than receptacle I3. Receptacle 25 isprovided with two downwardly directed vports 26 andk 2l and, above the level Aof blood 28ltherein, saidV receptacle is provided with a relief or Safety valvea, an inlet 29 for'replenishing blood from a reserve, andan inlet 30 for secondary oxygen,
The source of vacuum 9 may comprise any conn ventional means such as a suction pump and the same is connected to a tube or pipe 3l, the new in which is controlled as by a solenoid valve In practice, the degree of Vacuum is approximately fifteen inches of mercury. The source of xygen I may comprise a tank of said gas conventionally valve controlled to supply oxygen at approximately iifteen pounds to tube or pipe 33. A sclenoid valve 34 controls flow in the latter pipe.
Valve means II comprises, generally, two similar valves 35 and 35, cam means 31 controlling said valves, and a drive 38 for the cam means.
Valves 35 and 36 are shown as of the reciproeating type. Each comprises a cylinder 39, a piston 4G operating in said cylinder, and a stem 4I extending from the piston beyond one end of the cylinder. Each piston 55, on its opposite faces, is provided with a compressible sealing disc 42. An expansion spring 43, in a hollow provided in each stem 4I, bears against an end wall 44 of each cylinder to normally project the pistons away from their respective walls I4 and allow inter-communication of ports 35 and l5 in wall 44 of valve 35, and of ports 3l, I8 and 49 in wall 44 of valve 35.
From the foregoing it will be clear that, when spring 43 is eiective to project piston 55 away from wall 44 of either valve, the ports in said wall are in communication through cylinder 39 while one disc 42 seals against cylinder abutment 53 and, that when piston 4B is moved against the force of spring 43 to press the opposite disc 42 against wall 44, the ow between the respective ports in said valves is shut off. It will be noted that the faces of discs 42 seal at the ends or the piston strokes while the edges thereof seal against the cylindrical walls of cylinders 33 to prevent leakage past the pistons during the strokes. In the usual way, each cylinder is pro vided with a vent I to relieve counteracting back-pressure on the pistons.
Cam means 31 controls reciprocation of pistons 39 so that, as one is projected, the other is retracted. Thus, when ports 45 and 55 are in communication, ports 41, 43 and 49 are closed to flow and vice versa. In the present case, means 3l comprises cams 52 and 53 on a common shaft 54 and relatively phased 180, the cams being in respective operative engagement with the stems 4I of valves 35 and 36. As seen from Fig. 2, only one of said cams, at any one time, is engaged to close one valve, the other valve being held open by the spring 43 therein. Slight variations in the phasing of cams 52 and 53 may be effected by rotational adjustment thereof on shaft 54 so that valves 35 and 35 may be timed or synchronized as desired.
Drive 38 may operate at a speed to alternately open and close valves 35 and 36 according to a desired pulse rate. In practice, shaft 54 is driven at approximately 68 R. P. M. as by an electric motor 55 and a speed reducer unit 55 of which shaft 54 is the output.
Tube 5 is connected to port I4 to supply venous blood to receptacle I3. A tube 51 connects ports I6 and 2E to transfer blood from receptacle I3 to receptacle 25, a flow-controlling clamp 53 being applied to said tube. Tube 5 is connected to port 21 and is controlled by a clamp 59. A iiow meter 60 is provided in tube 5 to show the rate of ow in said tube as regulated by clamp 59. If desired, the temperature of the blood flowing in tube 6 may be regulated as by a heating device 6I.
Tube 3l is connected to port 45 of valve 35, and tube 33 to port 41 of valve 36. A tube 52 connects ports I5 and 48 and iiow in the latter tube is regulated by a clamp 63.
A tube 54, connected to port 2l, is divided into branches 55 and 55 and said branches are connected to ports 45 and 49, respectively. Branch 55 is provided with a flow-regulating clamp 61.
Operation After a suitable amount of donors blood is placed in receptacles I3 and 25 through the respective inlets 23 and 29, said inlets are plugged or otherwise closed. Motor 55 is started and, at the same time, valves 32 and 34 are opened, simultaneously.
Assuming the positions of valves 35 and 3B as shown, the oxygen flow is closed and receptacle I3 is subjected to vacuum from source 9. This suction opens valve I'l while closing valve I9 and draws venous blood from tube 5 into the receptacle. Since he pressure in said receptacle is now below atmospheric, the blood therein releases contained gases, particularly carbon dioxide, said gases nrst being drawn into ther rareiied atmosphere above blood 25 andY then outward through tubes 64, 55 and 3|. This condition continues during the period that valve 35 is open, or one-half rotation of shaft 54.
When cam 52 closes valve 35 and cam 53 substantially simultaneously opens valve 36, the vacuum to receptacle I3 is shut orf and the atmosphere above the blood therein is supplied with oxygen from source IIB through tubes 33, 55 and 55. upwardly through blood 25 from tube 52 and past valve I3 which is opened by the pressure oi the oxygen now. Some of the carbon dioxide, if not previously removed by the vacuum, will be displaced by the upwardly bubbling oxygen. In this manner, the blood 25 is thoroughly oxygenated.
As the incoming oxygen builds up the pressure in receptacle I3, valve I'I closes to shut off venous ow and when said pressure increases beyond that in the stabilizing receptacle 25, valve I9 opens and oxygen-enriched blood flows through tube 5l into said receptacle 25. There may be some bubbles of oxygen in blood 20. However, because of the bottom discharge of port I5, bubble-free blood passes into receptacle 25.
The atmosphere in receptacle 25 that is supplied by the secondary oxygen through inlet 3S is regulated, in practice, to substantially equal normal blood pressure. This pressure may be read on gauge 53. Consequently, as pressure iluid from receptacle I3 enters receptacle 25 and fluid from the latter receptacle simultaneously discharges through tube 6, the pressure in re.
ceptacle 25 is stabilized through the medium of the secondary oxygen. In this manner, the variable pressure at which blood is delivered to receptacle 25 is stabilized in said receptacle and, therefore, arterial blood is supplied to and through tube 5 at a substantially uniform and desired pressure.
The discharge from tube 5 is continuous and at greatest pressure when valve 35 is open, the pressure gradually diminishing as the pressure in receptacle I3 decreases. Clamp valves 53 and 5l control the supply of oxygen to the blood in receptacle I3 and cla-mp valves 55 and 59 control the rate of blood flow between the receptacles and in the vconnection 6 to the artery. The
Simultaneously, oxygen percolatesV safety valves 22 and 28a are set to relieve when pressures become too high in the receptacles, and gauge 24, by its teetering pointer, shows the vacuum-pressure cycle of the operation.
Although the source 9 provides a vacuum of about Hg and source Ml about fteen pounds pressure of oxygen, due to the rapid alternating application of vacuum and pressure to receptacle I3, as controlled by the means l2, such vacuum and pressure in the receptacledo not reach the full degrees of the sources. At 68 R. P. M. of the cam means, the atmosphere in receptacle I3 varies between approximately five pounds above atmospheric and 3" Hg vacuum. To insure that such positive and negative pressures in said receptacle are never exceeded, valves 32 and 34 must be opened and closed simultaneously and, therefore, are solenoid controlled rather than manually controlled. Thus, the solenoids of said valves may be connected in a common electric circuit E0 and one switch 'il in said circuit provided to simultaneously energize or deenergize the solenoids and, thereby, simultaneously open and close valves 32 and 34 to avoid excessive build up of oxygen pressure should valve 34 be opened iirst or excessive reduction of vacuum should valve 32 be opened rst. Such common electric control is exemplary of means effecting simultaneous actuation of valves 32 and 34 It will be seen from the foregoing that unit 'I serves not only as a lung apparatus to oxygenate the blood and rid the same of carbon dioxide, but also as a heart because the vacuum-pressure cycle therein, without the aid of any outside pump, sets up a flow of oxygenated blood comparable to the ilow resulting from the pulsations of the heart.
While I have described what I now regard as the preferred form of my invention, the same, of course, may be varied within the spirit and scope of the invention. Therefore, I do not wish to restrict myself to the particular form of construction illustrated and described, but desire to avail myself of all modications of my invention that may fall within the scope of the appended claims.
Having thus described my invention, what I claim and desire to obtain by Letters Patent, is:
1. Apparatus of the character described comprising a closed receptacle, a connection to the bottom of said receptacle to conduct venous blood thereto, means to apply vacuum to said receptacle above the blood therein to withdraw carbon dioxide and other gases from said blood and a1- ternately to introduce oxygen under pressure into said blood to replace the gases withdrawn, a second closed receptacle, a ilow connection between the bottoms of said receptacles to transfer blood from the first receptacle to the second receptacle under pressure of said oxygen, and a bottom discharge for oxygenated blood from said second receptacle.
2. Apparatus according to claim 1: a connection to the second receptacle above the level of blood therein to supply secondary oxygen to said second receptacle at a pressure lower than the pressure of the oxygen introduced into the first receptacle.
3. Apparatus according to claim 1: said vacuum-applying and oxygen-introducing means comprising a valve-controlled vacuum connection to the first receptacle above the level of blood therein, and a similar valve-controlled oxygen-conducting connection to both the lower portionof the latter'receptacle and to a portion thereof above said blood level.
v 4. Apparatus according to claim l: said vacuum-applying and oxygen-introducing means comprising a valve-controlled vacuum connection to the first receptacle above the level of blood therein, a similar valve-controlled oxygen-conducting connection to both the lower portion of the latter receptacle and to a portion thereof above said blood level, and means `to operate the valves of said connections to alternately and synchronously open and close said valves to alternate the vacuum and the pressure of oxygen in said receptacle. V
5. In apparatus of` the character described, a closed lliquid-containing receptacle having three downwardly opening ports, a check valve controlling one of said ports against ilow into the receptacle, a check valve controlling each of the other two ports against flow outward from the receptacle, an inlet for oxygen under pressure to the receptacle above the level of liquid therein, a connection to one of said other two ports to conduct oxygen under pressure to the liquid in said receptacle, a connection for venous blood to the other of said two ports, a discharge connection from the first-mentioned of the three ports, means intermittently admitting oxygen simultaneously to said inlet and said oxygenadmitting port, means connected to said inlet to apply vacuum to the receptacle, and means to synchronize and alternate the oxygen-supplying and vacuum-applying means.
6. In combination, a blood-oxygenating unit, means to alternately apply vacuum to said unit to induce release of gases contained in the blood therein and supply oxygen under pressure to said unit to oxygenate the blood after release of said gases, a venous blood connection to the bottom of said unit, a stabilizing unit, a check-valvecontrolled connection between the units t0 conduct oxygenated blood from the oxygenating unit to the stabilizing unit, a connection for secondary oxygen to said stabilizing unit to stabilize the pressure in said latter unit, and a discharge connection for oxygenated blood from the latter unit.
7. The combination according to claim 6: the means supplying oxygen to the oxygenating unit including a conductor discharging directly into the blood in the latter unit and a conductor discharging into said latter unit above the level of blood therein.
8. In combination, a blood-oxygenating unit, means to alternately apply vacuum to said unit to induce release of gases contained in the blood therein and supply oxygen under pressure to said unit to oxygenate the blood after release of said gases, a venous blood connection to the bottom of said unit, a stabilizing unit, a check-valvecontrolled connection between the units to conduct oxygenated blood from the oxygenating unit to the stabilizing unit, a connection for secondary oxygen to said stabilizing unit to stabilize the pressure in said latter unit, a discharge connection for oxygenated blood from the latter unit, and flow rate controlling means in the checkvalve-controlled connection and in the discharge connection.
9. In apparatus of the -character described, a closed receptacle, a port in the lower part of the receptacle for admitting blood into the receptacle, a check valve controlling said port to open to admission of blood only when the pressure in the receptacle is lowered, a second port in the lower part of the receptacle to admit oxygen under amasar pressure to the blood in the receptacle and to raise the pressure in the receptacle and on the blood therein, a check Valve controlling said second port to open only to said admission of pressure oxygen, a discharge port in the lower part of the receptacle, a check Valve controlling discharge of blood from the latter port and open only when the pressure in the receptacle is raised during admission of pressure oxygen, a port in the upper part of the receptacle and above the blood therein, and means connected to the last-mentioned port to lower the pressure in the receptacle and connected to the oxygen-admitting port to alternately supply pressure oxygen to the receptacle and raise the pressure therein.
10. In apparatus according to claim 9: said ABRAHAM E. CHESLER.
References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,696,496 McMurdo Dec. 25, 1928 1,937,566 Hanan et al Dec. 5, 1933 2,406,207 Desmet Aug. 20, 1946 2,474,665 Guarino June 28, 1949