US3037504A - Extracorporeal blood circulation system having a non-electric drive - Google Patents

Description

Ju ne 5, 1962 F. EVERETT H. EXTRACORPOREAL. BLOOD CIRCULATION SYSTEM HAVING A NON-ELECTRIC DRIVE Filed Oct. 1, 1959 OX YGENA TOE l VENTOR. HAZE ERA/VA :vmerr A TTdZ/VE Y 3,037,504 Patented June 5, 1962 Free 3,037,5194 EXTRACORPOREAL BLOOD CKRCULATION SYS- TEM HAVING A NON-ELECTRIC DRZVE Hazen Frank Everett, Hillsdale, N.J., assignor to The Foregger Company, Inc, Roslyn Heights, NX. Filed Oct. 1, 1959, Ser. No. 843,744 9 Claims. (Cl. l23-214) This invention relates to extracorporeal blood circulation systems and more particularly to apparatus to provide operational power therefor.

Extracorporeal surgical techniques are known whereby for surgical processes the functions of the heart and lungs are performed externally of the body. Generally, this involves tapping blood from the body, oxygenating the blood and returning the oxygenated blood to the body by means of a simulated pulse. This invention is principally concerned with the means employed for pulse simulation although other portions of the apparatus are related to features of the invention as will be seen.

For purposes of pulse simulation, pumps and like mechanisms are conventionally employed, and these mechanisms are usually driven by means employing electrical power. Considering, however, that extracorporeal blood circulation systems invariably involve the use of oxygen, the use of electrical power introduces the hazard of explosion. Accordingly, it is an object of the invention to provide an improved system wherein the use of electrical power is unnecessary.

In addition to avoiding the use of electricity, it is a further object of the invention to make maximum use of the oxygen source which is always available in these systems for oxygenating the blood. For example, according to the invention, an oxygen source is employed not only to supply oxygen to the blood but also to constitute a source of pressure medium adapted to drive a mechanism which efiects pulse simulation. In addition, it is an object of the invention to make the use of oxygen multifold by further driving aspirators and like utilization devices with the same.

One feature of the invention relates to the provision of improved controls for controlling pulse duration and pulse magnitude respectively.

Another feature of the invention relates to the provision of a compact and reliable system which is extremely economical to manufacture.

Still another feature of the invention relates to the provision of improved means for responding to a pneumatic pressure to produce a reciprocating force which is useful in simulating a pulse.

Other objects and features of the invention will be found in the following detailed description of a preferred embodiment thereof as illustrated in the accompanying drawing in which the sole FIGURE diagrammatically illustrates an extracorporeal blood circulation system having a drive provided in accordance with the invention.

The system illustrated in the drawing conventionally comprises an oxygenator 10 and a pump or ventricle means 12. The oxygenator 10 may be a conventional oxygenator such as, for example, illustrated in Patent No. 2,702,035 of February 15, 1955, or in Patent No. 2,693,- 802 of November 9, 1954. The oxygenator functions to receive blood from the body and to expose this blood to oxygen for oxygenating the same. The pump or ventricle means serves to receive the oxygenated blood from the oxygenator and to simulate a pulse for purposes of returning the oxygenated blood to the body and circulating the blood therein.

As illustrated in the drawing there is coupled to oxygenator 10 a line 14 which is adapted to have its free end inserted into the body undergoing surgery for the supply of blood to the oxygenator 10. The oxygenated blood is fed via line 16 to the pump 12 whereat as noted above a pulse is simulated so that the blood can be returned via the line 18 to the body.

The system further comprises an oxygen source 20, a distributing means 22, a drive 24 for the pump 12, a first control 26 for controlling the length of the stroke delivered to the pump 12, and a second control 28 which controls the speed of the stroke as will be shown hereinafter.

As an ancillary feature of the invention there are also provided aspirator means 30 and means 32 for delivering oxygen to the oxygenator 10.

The oxygen source 20 is any conventional source of oxygen conventionally found in an operating room or may be instead a tank of oxygen under pressure. The source 20 discharges oxygen under pressure into the line 34 in which is inserted a filter 36. The filter 36 is provided to filter out solids and moisture and may be any commercially available filter which will serve this purpose. It may comprise, for example, a porous bronze element or a Monel wire screen of, for example, 200 mesh. Moisture may be trapped in the filter by means of a bafile.

Line 34 is connected to a T-connection 38 wherefrom the oxygen flows in either of two directions as indicated by arrows 40 and 42.

The pressure of oxygen flowing in the direction of arrow 40 is controlled by pressure regulator 44 as indicated on a dial 46. The oxygen flowing in the direction of arrow 42 is regulated by a pressure regulator 48, the

pressure being indicated on a dial 50 The oxygen following the path indicated by arrow 40 travels through a line 52 whereat its pressure may be regulated between zero and full line pressure. Preferably this pressure is kept to 100 pounds per square inch maximum in order not to disturb the apparatus coupled to line 52. The pressure in line 54 which is coupled to T-connection 38 may also be regulated between zero and full line pressure and is also preferably kept below a 100 pounds per square inch maximum.

The oxygen flowing through line 52 is employed as any pressure medium might be employed to drive a pneumatic or hydraulic system of the nature which will be described hereinafter. Accordingly, oxygen source 20 not only constitutes a source of oxygen under pressure but may also be considered as constituting simply a source of a pressure medium.

Connected in line 52 is a lubricator 56, the function of which is to provide lubrication for the elements which follow in the system. The lubricator 56 may be any conventional lubricator which provides an inert non-oxidizable oil such as fluorine or silicon oil which will be carried by the pneumatic medium through the line 52 to the elements which follow.

Line 52 is connected to the distributor 22 which is provided with an input port 58, supply ports 60 and 62 and control ports 64 and 66. Oxygen received under pressure via line 52 passes into the distributor '22 via input port 58. The distributor functions to distribute this oxygen selectively and exclusively through one or the other of supply ports 60 and 62. Whether the oxygen is fed through port 60 or port 62 is determined by the pressure balance in the distributor 22 due to the operation of ports 64 and 66. A discharge port 68 is also provided in the distributor 22.

Actually the distributor is a four-way valve which may be any one of a number of commercially available types. Details of one such four-way valve are illustrated in the drawing in a very schematic manner. According to the schematic showing of the details of distributor 22 this part of the system comprises an internal moveable member 7 6 having openings 72, 74, 76, 78 and 80'. One side of the moveable member 70 is operatively associated with control port 66 in a hermetically sealed manner by 3 means of a bafile 82. The other side is operatively associated with control port 64 in a like manner by means of a bafile 84.

Assuming that one of the control ports 64 or 66 is open the pressure of oxygen arriving via input port 58 will drive the moveable member 70 towards that side of the distributor 22 provided with the open port. Movement of the moveable member 70 will selectively register one of openings '74 or 76 with the supply port 60 via channel 86 and one of the openings 78 or 80 with the supply port 62 via channel 88.

While the oxygen arriving via input port 58 is functioning to properly position the moveable member 70 in cooperation with control ports 64 and 66 a portion of the oxygen is also flowing via channel 72 into a central chamber 90 which opens into passages 76 and 78. Depending on which of these passages is coupled to the associated channel 86 or 88 one of the supply ports 60 and 62 will be provided with oxygen under pressure. This means that the lines connected to these supply ports will be conveying oxygen under pressure.

At the same time as one of the ports 60 and 62 is connected as aforesaid to the line 52 the other of these two ports is connected via one of the openings 74 and 80 to the discharge port 68. The purpose of this will become apparent hereinafter.

The above details of the distributor 22 are exemplary only of the commercially available devices which are available to perform the same functions. Thus any suitable valve system or distribution means may be substituted for the arrangement described above.

Connected to control ports 64 and 66 are the lines 92 and 94 respectively. These lines are connected at their free extremities to poppet valves 96 and 98.

Since each of the poppet valves is of similar construction the poppet valve 96 alone will be next described by way of example. This valve comprises simply a chamber 106 having an opening 102 in which seats a valve member 164 which is loaded by a spring 186. The spring 106 operates through the valve member 104 to maintain opening 102 normally closed. This condition exists until the valve member 104 is physically displaced into the chamber 106. Thus it is seen that control ports 64 and 66 can be connected to ambient atmosphere by physical displacement of the valve members comprised by the poppet valves 96 and 98. The mode of operating these valves will be explained hereinafter.

Connected to the supply ports 60 and 62 are the lines 108 and 110 respectively, these lines being connected to the drive provided for the pump 12 which drive is an oscillating or reciprocating drive means.

Actually pump 12 may be any conventional blood pump, such as, for example, that shown in Patent No. 2,689,565 of September 21, 1954 and is preferably a pump which is mechanically driven by means of an oscillating or reciprocating mechanical force.

To this end the drive 24 comprises a piston and cylinder arrangement constituted by a double acting piston 112 slidably accommodated within a cylinder 114. Piston 112 divides cylinder 114 into two chambers 116 and 118 which are connected respectively via ports 120 and 122 to lines 108 and 110. A rigid rod 124 is connected to the piston 112 and transmits the oscillating or reciprocating motion of the latter to the pump 12 which constitutes a ventricle means and operates to simulate a pulse.

From what has been set forth above it will be obvious that a supply of pressure to chamber 118 via port 122 will drive piston 112 to the left whereas a supply of oxygen to chamber 116 via port 120 will drive the piston 112 to the right. Thus the selective supply of oxygen via ports 60 and 6'2 of the distributor 22 will control the operation or reciprocation of the piston 112. Moreover, as will be discussed in greater detail hereinafter the discharge of oxygen from chambers 116 and 118 via lines 108 and and through the distributor 22 wherefrom the oxygen leaves via discharge port 68 Will control the speed of reciprocation or travel of the piston 112.

Connected to the rod 124- is an arm 126. This arm is rigid with the rod 124- and has a free extremity 128 having a path of movement parallel to that of the path of movement of the piston 112. With respect to this extremity 128 the poppet valves 96 and 98 are positioned along the path of travel thereof so as to have their valve members contacted by the extremity 128 when it is desired to reverse the direction of stroke of the piston 112. The positions of poppet valves 96 and 98 are adjustable and for this purpose their are provided adjustable mounting brackets 130 and 132. I have of course provided more sophisticated mounting arrangements for the poppet valves 96 and 98 but the illustrated brackets will serve adequately for purposes of explanation.

A brief indication has been given above as to how the length of stroke of the piston 112 is controlled. It is also necessary to indicate at this point that the speed of the stroke of piston 112 may be controlled by means of the control 28. For this purpose the control 28 which comprises a regulator 134 and a dial 136 is con nected to the discharge port 68 of the distributor 22 by means of the line 138.

Before reference is made to the remainder of the oxygen or pneumatic medium circuit the operation of the drive mechanism heretofore described will next be given.

Oxygen caused to flow via line 52 into the distributor 22 by means of the pressure existing in oxygen source 20 will cause the moveable element 70 in the distributor 22 to move to the left or right depending upon which of poppet valves 96 or 98 is opened due to the position of the arm 126. Line 52 will therefore be connected selectively to one of lines 188 or 110 and oxygen under pressure will therefore flow into one of chambers 116 or 118. This will cause the piston 112 to move in the direction of the chambcr to which oxygen under pressure is not being fed. Whatever oxygen is in this latter chamber will be discharged via the associated one of the lines 108 and 110, the oxygen flowing via discharge port 68 and line 138 through the regulator 134 into the ambient atmosphere. The adjustment of regulator 134 will control the speed of this discharge and consequently the speed of the piston 112.

The piston 1 12 is thus caused to move in one of its two directions of oscillation and carries along with it the arm 126 which alternately depresses the valve member of one of the poppet valves 96 and 98 so as to alternately connect lines 1118 and 110 either to the input line 52 or to the discharge line 138.

It will be appreciated that engagement of extremity 128 with the valve member of one of the poppet valves causes a reversal of movement of the piston 112. The position at which this reversal of movement is effected corresponds to the relative position of valves 96 and 98 and this may be selected as desired through the intermediary of adjustable brackets 130 and 132.

Thus the speed of movement of the piston 112 is controlled by regulator 134 and the length of stroke of the piston 112 is controlled by the positions of the valve members of poppet valves 96 and 98. These parameters control the movement of rod 124 and thus the operation of pump 12 which as noted above is a ventricle means simulating a pulse.

In addition to the provisions made above for the drive of pump 12 the oxygen derived from source 20 is also employed for other useful purposes.

As noted above a portion of the oxygen is transmitted via line 54. In line 54- as noted above is positioned a means for the delivery of oxygen to the oxygenator 10. This means 32 is in effect a conventional flow meter which distributes part of the oxygen via line 140 to the oxygenator it) under the desired pressure or flow rate. This flow rate is generally somewhat less than 65 litres of oxygen per minute and is controllable within the range, for example, of from 0 to about 20 litres per minute. Thus it is seen that the oxygen from the source 20 is not only employed to drive the pump 12 but is further employed to supply oxygen to the blood in the oxygenator 10.

A further portion of the oxygen i distributed from the flow meter 32 to a line 142 wherein are connected the aspirator means 30. The aspirator means may, for example, include two units 144 and 146. These aspirator units may be conventional venturi components wherein the flow of oxygen past an aperture causes a vacuum in the latter. The degree of vacuum provided by each unit is controllable by means of regulators i148 and 150 and the vacuum is provided in flexible conduits 152, and 154. The purpose of these aspirators is for aspiration of blood in the cavity in which surgery is being performed. In a heart operation this cavity would be the thoracic cavity and the aspirators would be provided for surgical assistants who would be performing the function of removing loose blood during the operation.

Thus it is seen that the oxygen source 2%) not only provides the medium for operating the drive employed for pump 12 and for supplying oxygen to the oxygenator but can function in accordance with the invention for the purpose of rendering operative aspirator units or like utilization devices. The invention therefore contemplates the multifold use of an oxygen source and in an operating room where oxygen sources are conventionally provided this means that a system of the invention need not be provided with any conventional power source whatsoever.

It will be noted that in accordance with the invention a complete system is provided without need for relying upon electrical power so that the hazard of explosion is avoided. 'In further accordance with the invention maximum use is made of the oxygen source which is always available in systems of this nature for purposes of oxygenating the blood.

The controls of the system and particularly those controls employed with respect to the piston 112 constitute a feature of the invention whereby the frequency and magnitude of the simulated pulse are readily controlled.

There will now be obvious to those skilled in the art many modifications and variations of the structures set forth above. These modifications and variations will not however depart from the scope of the invention if they are defined by the following claims.

What is claimed is:

1. In an extracorporeal blood circulation system including an oxygenator for oxygenating said blood and artificial ventricle means coupled to said oxygenator and adapted for responding to a reciprocating 'force to circulate the blood; apparatus 'for providing said reciprocating force for said ventricle means comprising: a source of a pressure medium, reciprocating means coupled to said ventricle means and adapted to produce said reciprocating force in response to said pressure medium, distribution means coupling said source to said reciprocating means and selectively applying said pressure medium to said reciprocating means to generate said reciprocating force,

and control means actuated by said reciprocating means and coupled to said distribution means to control the latter.

2. Apparatus as claimed in claim 1 wherein said source is a source of oxygen under pressure, said source being connected to said oxygenator tfor supplying oxygen to the latter for oxygenating said blood.

3. Apparatus as claimed in claim 1 comprising a second control means coupled by said distributor means to said reciprocating means and regulating, at least in part, flow of said pressure medium with respect to said reciprocating means, said reciprocating means generating a reciprocating motion having a speed dependent on said flow.

4. Apparatus as claimed in claim 1 comprising at least one aspirator coupled to said source and operated by said pressure medium.

5. Apparatus as claimed in claim 1 wherein said reciprocating means generates a reciprocating motion and said control means includes means which controls the magnitude of said motion.

6. Apparatus as claimed in claim 1 wherein said distribution means is a pneumatically operated device, said control means and source being coupled to and cooperatively controlling flow of said pressure medium to said pneumatically operated device and thus controlling the operation of the latter.

7. Apparatus as claimed in claim 1 wherein said reciprocating means is a double acting piston and cylinder arrangement and said distribution means is a valve controlling the charging and discharging of said cylinder.

8. Apparatus as claimed in claim 7 wherein said distribution means is controlled by said pressure medium and said control means comprises at least one poppet valve coupled to said distribution means for bleeding the pneumatic medium therefrom and an arm coupled to and actuated by said reciprocating means and, in turn, operating said poppet valve.

9. Apparatus as claimed in claim 8 wherein said reciprocating means oscillates said arm along a determinable path, comprising means adjustably supporting said poppet valve along said path to control the engagement of the arm therewith and thereby the operation of said distribution means.

References (Jilted in the file of this patent UNITED STATES PATENTS 2,652,831 Chesler Sept. 22, 1953 2,659,368 Gibbon et al Nov. 17, 1953 2,689,565 Gobel Sept. 21, 1954 2,884,860 Ellis et a1 May 5, 1959 OTHER REFERENCES Clowes: Experimental Procedures for Entry into Left Heart, from Annals of Surgery, vol. 134, No. 6, December 1951, pp. 958-959.

Helmsworth et al.: Artificial Oxygenation and Circulation During Complete By-pass of the Heart, [from the Journal of Thoracic Surgery, vol. 21, No. 2, August 1952, pp. l17133. i

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