US2815715A - Surgical pump - Google Patents

Description

1 1957 JEAN-LOUIS TREMBLAY 2,815,715

SURGICAL PUMP Filed llay 29, 1953 4 Sheets-Sheet 1 JEAN-Lows TREMBLAY (Inventor Attorneys l957 JEAN-LOUIS TREMBLAY 2,815,715

SURGICAL PUMP v Filed May 29, .1953 V 4 Sheets-Sheet 2 n m m m JEAN-L IS msuaur 'n'ventor Dec. 10, 1957 JEAN-Louis TREMBLAY 2,815,715

SURGICAL PUMP Filed May 29, 1953 4 Sheets-Sheet s JEAN-LOUIS mavaur Um'aentor Dec. 10, 1957 JEAN-LOUIS TREMBLAY SURGICAL PUMP -Filed May 29, 1953 4 Sheets-Sheet 4 JEAN-LOUIS TREMBLA) Jnven tor Attorneys 2,815,715 Patented Dec. 10, 1957 SURGICAL PUMP Jean-Louis Tremblay, Quebec, Quebec, Canada Application May 29, 1953, Serial No. 358,4tl1

6 Claims. (Cl. 103-53) The present invention relates in general to devices for pumping liquids and more particularly to a blood pump adapted to partially or completely replace the heart during surgical operations.

The general object of the present invention is the provision of a surgical pump of the character described so constructed and designed as to imitate as closely as possible the action of a human heart, or more particularly the action of a ventricle of the human heart.

A specific object of the present invention resides in the provision of a surgical pump which will have a sufficient rate of flow to be able to replace, at least temporarily, the human heart during surgical operations.

Yet another object of the present invention is the provision of surgical pump of the character described provided with valves similar in shape to the mitral or tricuspid valves of a human heart and designed to prevent damage to the blood cells.

Still another important object of the present invention is the provision of a surgical pump of the character clescribed the working speed of which may be readily and very easily adjusted.

Still another important object of the present invention is the provision of a surgical pump in which means are provided for adjusting the pulse pressure of the blood being pumped that is, the difference between the systolic and diastolic pressures in the blood circulating system.

Still another important object of the present invention is the provision of the surgical pump of the character described in which all the elements coming in direct contact with the blood being circulated, may be very easily disassembled and sterilized.

Still another important object of the present invention is the provision of a surgical pump which, due to its simplicity of design and construction, will give a prolonged service without any possibility of failure or interruption during surgical operations.

Yet another important object of the present invention is the provision of a surgical pump of the character described the working volume of which is very small relatively to the rate of flow of the pump, thereby requiring only a small amount of transfusion blood for use in conjunction therewith.

The foregoing and other important objects of the present invention will become more apparent during the following disclosure and by referring to the drawings in which:

Figure l is a perspective view of the casing housing Figure 6 is an end view of the check valve;

Figure 7 is a cross-section of the check valve taken through the lips thereof;

Figure 8 is an enlarged fractional section of one pair of lips shown in closed position; and

Figure 9 is a section similar to that of Figure 8 showing the lips in open position.

Referring now more particularly to the drawings in which like reference characters indicate like elements throughout, the pump, according to the invention, is preferably housed within the casing, generally indicated at 1, and provided with a panel 2 mounting three knobs 3, 4 and 5 and three switch levers 6, 7 and 8. The knob 3 serves to adjust the rate of pulsating of the pump, the knobs 4 and 5 are respectively a coarse and a fine adjustment of the pulse pressure of the circulating fluid. The switch 6 controls the operation of the rotary contactor device, the switch 7 controls the filaments of the rectifying tubes and the switch 8 controls the solenoid circuits of the medical pump.

The casing 1 is furthermore provided with a manometer 9 for indicating the pressure of the circulated blood. A cover 10, hinged at 10' may be opened for removing the pump assembly housed within casing 1. The numeral 11 indicates an electric cord for supplying electric current to the pump, while the numeral 12 indicates one of the tubes connecting the pump to the heart of the person or animal being operated on.

Figure 2 shows the pump itself. The numeral 14 denotes an oil reservoir constituted by a housing preferably of rectangular shape and made of metal. An oil filling opening 15 is made in the top 18 of reservoir 14 and is normally closed by a threaded plug 16 engaging a collar 17 secured to the top 13. An electric stirrer 19 is mounted on the plug 16 and comprises an electric motor 20 secured to the plug 16 by means of bolts 21, said motor having a driving shaft 22 passing through the plug 16 and mounting a propeller 23 immersed in the oil 24 for circulating the latter around the pump solenoids in order to maintain the oil bath at a uniform temperature throughout.

The oil temperature is regulated by means of a water circulation system comprising the coil pipe 26 passing through the oil reservoir 14.

The two end walls 25 of the reservoir 14 are recessed inwardly in their middle portion to form frustoconical cavities 27 apertured to receive a rigid straight tube 28 made of nonmagnetic material and extending longitudinally through the reservoir 14. The tube 28 and walls 25 are welded at their points of contact 29 to make leakproof joints. Three solenoids 30, 31 and 32 are wound around the tube 28 inside the oil reservoir 14 and are separated from each other by discs 33 of insulating material. The solenoid 3G is evenly wound while the windings of both solenoids 31 and 32 are deeper towards the right hand side of said solenoids as viewed from Figure 2, in order to increase the magnetic field acting on the armtaure 34 as the latter moves towards the right hand side of the tube 28.

Two coaxial intercommunicating vessels or bellows 3S and 36 are mounted in tube 28. They are preferably made of natural rubber and have imbedded therein reinforcing threads 37 and 38 disposed circumferentially of the bellows portions of maximum and minimum diameter, respectively. The armature 34 is secured to the inner ends of said bellows and is slidable in tube 28, while the outer ends of the bellows are fixed with respect to said .tube.

The tube 28 projects at both ends within the recesses .27 and nipples 39 and 1-0 are respectively secured to said projecting ends by means of unions 4-1 and 42. On the outer ends of the nipples 39 and 4c are threadedly secured caps 43 and 44 respectively having bores coaxial with the tube 23 to receive the glass 'tubes 45 and 46 respectively.

The inlet and outlet flexible tubes 12 and 48 are respectively secured to the outer projecting ends of the tubes 45 and 46. Rubber bands 29 and 50 surround .the abutting ends of the tube 12 and cap 43, and of the tube 48 and cap 14 respectively.

A rubber band 51 tightly surrounds the inner projecting end of the glass tube 45' in order to prevent removal of said tube 45 through cap 43. Similarly the inner projecting end of glass tube 46 is provided with an enclosing rubber sleeve 54 serving to prevent removal of said tube through the cap 44. The outer tubular end 55 of the bellows 36 frictionally engages the rubber band 54 and abuts against the cap 44, while the outer tubular end 53 of bellows 35 frictionally engages the sleeve portion of check valve 52 which is in turn inserted over the rubber band 51 on glass tube 45.

The communicating ends of the bellows 35 and 36 form abutting tubular portions 56 and 57 which extend within the cylindrical armature 34 and are in contact with the inner face thereof. A check valve 58 has a tubular portion extending within the armature 54 and contacting the tubular portions 56 and 57 of the bellows 35 and 36. A thick rubber sleeve 59 is inserted Within the tubular portion of the check valve 58 and exerts an outward I'Eh,

dial pressure against the inner face of the armature 34 thereby preventing disengagement of the bellows from said armature.

As shown in Figure 4, the armature 34 is made of two semi-cylindrical sections 60 and 61 having rabbeted ends 62 adapted to receive a retaining band 63, shown in Figure 2. The lower cylindrical portion 61 is provided with a longitudinal groove 64 to permit air passage from one side of the armature to the other during its reciprocal back and forth movement within tube 28. The construction of the armature 34 permits disassembly of the bellows and the check valves for sterilization or repairs.

The two check valves 52 and 58 are similar in construction and are illustrated in more detail in Figures to 9.

The tubular portion of said check valves is terminated at one end by a conical part 65, the apex 66 of which points in the direction of flow of the blood Within the pump. Said conical part 65 is provided with three equally spaced longitudinally extending slits 67 each defined by a pair of lips 68 each of which forms an integral outward longitudinal projection of the conical part 65. The inner face 69 of each lip 63 of a pair is substantially flat to contact each other over a substantial area, as shown in Figure 8, when said lips are in closed position. The lips are outwardly tapered to form a thin free edge 70 and they are normally urged in closed position due to the resiliency of the rubber from which they are made. It will be noted that the shape of the lips 68 is similar to the shape of the lips of the mitral or tricuspid valves of a human heart. Due to the relatively large contact area between the lips 68 and consequently due to the limited pressure per unit area on said contacting surfaces, the blood cells trapped between the lips when the latter are in closed position will not be damaged.

From the foregoing description, the operation of the pump, according to the invention, will become apparent: Upon energization of the left solenoid 30, the armature 34 will move to the left whereby the blood already in bellows 35 will pass through check valve 58 into the right hand side bellows 36. During this return stroke corresponding to the diastole of the human heart, there is no blood actually discharged through the outlet tube 48, and the blood is prevented from flowing back into inlet tube 12 because the pressure is acting in a direction to close the check valve 52.

Upon simultaneous euergization of the solenoids 31 and 32, the armature 34 is displaced towards the outlet tube 48 thereby pumping out the blood inside bellows 36 and at the same time creating a suction within bellows 35 to admit blood therein through the inlet tube 12 and check valve 52. During this compression stroke corresponding to the systole of a human heart, the check valve is closed.

Figure 3 shows a manner of connecting the surgical pump to a human heart in which case the blood is in a large part derived from the heart through the pump and through an artificial lung schematically shown at B. The inlet tube 12 is connected to the inferior vena cava C while the outlet tube 48 passes through the lung B and is connected to the arch of the aorta at 47.

Of course other types of connection may be effected, for instance, the inlet tube 12 may be connected to one of the pulmonary veins D, in which case no artificial lung would be required.

Figure 3 shows also a preferred manner of energizing the solenoids 30, 31, 32. The electric cord 11, shown in Figure 1, is connected to a supply of alternating current and may be provided with a main switch 71. An electric motor 72 is connected to the cord 11 and its driving shaft has a worm meshing with a worm wheel 73 driving a rotary contactor 74 at a speed which may be adjusted by the knob 3 on the panel 2 of the housing 1, as shown in Figure 1, which controls a governor 75 secured to the motor 72. The outer surface of the contactor 74 is made of electric conducting material except for two longitudinal side strips 76 and 7'7 respectively extending on opposite portions of the contactor for an arc of approximately 150 and 210, and corresponding to the respective duration of energization of the return stroke solenoid 30 and of the compression stroke solenoids 31 and 32. Stationary contacts 73, 79 and are respectively mounted to contact the middle portion and each side of the rotary contactor 74 so that the middle contact 78 will always be electrically connected to said contactor 74 while the contact 79 will be disconnected when contacting the insulating strip 76 and the contact 80 will be disconnected when passing over insulating strip 77.

The electric cord 11 feeds a double transformer 81, the primary winding 82 of which is connected in series with a rheostat 83 for varying the voltage across the same. One terminal of the winding 84 of said transformer is connected to the terminals 85, $6 and 87 of the solenoids 30, 31 and 32 respectively and also to contact 78 of the rotary contactor 74. The other terminal of the secondary winding 84 is connected through switch 7 to the anodes of the rectifying tubes 88 and 89 and also to one terminal of the windings of relays 9t) and 91. The other terminals of said relays are respectively connected to the contacts 79 and 80.

The other secondary winding 92 of the transformer 81 is connected through switch 8 to the filaments of the rectifying tubes 88 and 89 for energizing the same.

The second terminal 95 of the solenoid 30 is connected to the cathode of the rectifying tube 89 by passing through the armature 96 of the relay 90. Similarly, the second terminals 97 and 98 of solenoids 31 and 32 are connected to the cathode of the rectifying tube 88 by passing through armature 99 of the relay 91.

The rectifying tube 88 has a grid 100 positively biased by means of the battery 1G1 and rheostat 102.

The rheostat 83 is controlled by knob 4 of panel 2 of the pump casing 1 and serves as a coarse adjustment of the intensity of energization of the solenoids 30, 31 and 32, while the rheostat 102, controlled by knob 5 shown in Figure 1, serves as a fine adjustment of the current passing through the solenoids 31 and 32.

In the position of the rotary contactor 74 shown in Figure 3, solenoid 30 is de-energized while the solenoids 31 and 32 are energized through the following circuit: terminals 36, 37, secondary winding 84, switch 7, tube 88, relay armature 99 and terminals 98 and 97. The

relay 91 is maintained in circuit closing position by the circuit; secondary winding 84, relay 91, contact 80, rotary contactor 74, contact 78 and secondary winding 84.

When the rotary contactor 74 has turned through a certain angle from the position shown in Figure 3, the electrical connection between contacts 811 and 78 is broken de-energizing solenoids 3i and 32, and electrical con-- nection between contacts 78 and 79 is established thereby energizing the relay 90 which closes relay armature 96 and therefore closes the energizing circuit of solenoid 30 through rectifying tube $9.

From the above described arrangement it will be seen that the energization of the two groups of solenoids is effected alternately, corresponding to the compression and return strokes of the pump.

The pressure exerted by said pump may be contrcled by rheostats 83 and 102, and is indicated on manometer 9 connected to the outlet tube 48.

The speed of the pump pulsations is easily controlled by the governor 75 of the motor 72 through the means of the knob Si.

in the embodiment described, the solenoid 30 is wound in a direction opposite to the direction of winding of solenoids 31 and 32 so as to produce a magnetic field causing the return stroke of armature 34.

It should be noted that the distance travelled by the soft iron armature 34 does not need to be of great length to pump the blood at a rate of flow equal to that of the human heart. In practice the armature 34- will move from its center position, shown in Figure 2, in the middle or" solenoid 31 to a right limit position across solenoids 31 and 32 due to the taper of said solenoids, and will return to a left limit position substantially in the middle of solenoid 30.

in order to obtain frictionless working of the bellows 35 and 36 and of armature 34 within tube 38, the latter may be lubricated by a suitable powdered lubricant such as talc powder.

While a preferred embodiment according to the present invention has been illustrated and described, it is understood that various modifications may be resorted to without departing from the spirit and scope of the appended claims.

I claim:

1. A surgical pump comprising a tube of nonmagnetic material, at least two solenoids wound around said tube longitudinally of said tube, electrical means for alternately energizing said solenoids during unequal periods of time to create a magnetic field through said tube alternating for unequal periods of time from one portion of said tube to another portion of said tube, two bellows disposed within said tube having their outer ends secured to the outer ends of said tube and having their inner ends in communication with each other, a cylindrical armature of magnetic material secured around the communicating ends of said bellows and slidable back and forth within said tube under the action of said alternating magnetic field, a check valve secured within said bellows adjacent their communicating ends and a second check valve secured near one of said outer ends of said tube and disposed within the corresponding end of one of said bellows, said check valves being oriented to permit circulation of liquid from said last to said first mentioned check valve and to prevent circulation of said liquid in the reverse direction, a housing surrounding said solenoids and secured to said tube, a liquid bath in said housing, in which said tube and solenoids are immersed and means to maintain said liquid bath at a constant temperature.

2. A pump as claimed in claim 1, wherein the winding 3. A surgical pump comprising a casing provided with open ends, two coaxial fluid receiving bellows disposed within said casing, communicating with each other at one end and having their other outer ends fixed to the open ends of said casing to provide for fluid flow, an armature made of magnetic material secured to and surrounding said communicating ends of said bellows, at least two solenoids spacedly wound around said bellows and coaxial therewith, an electric supply circuit for each of said solenoids, contactor means in each of said circuits, means to close said contactor means alternately and for unequal periods of time whereby said solenoids will be energized for unequal periods of time and will generate a magnetic field displacing said armature back and forth, and two check valves disposed within said bellows, one of which is secured near the fixed end of one of the bellows and the other is secured to the communicating ends of said bellows, both said check valves being oriented to block fluid circulation from said last named valve to said first named valve and to permit circulation of said fluid in the reverse direction.

4. A pump as claimed in claim 3, wherein said check valves consist of a sleeve of elastic material forming a closed conical portion at one end, said conical portion having longitudinal slits and lips extending on each side of said slits, said lips having an inner surface adapted to contact with each other to close said slits.

5. A surgical pump comprising a casing provided with two open ends, two coaxial liquid receiving bellows disposed within said casing in axial alignment, communicating with each other at one end and having their other outer ends fixed to the open ends of said casing to provide for fluid flow, two check valves disposed within said bellows, one of which is secured near the fixed end of one of the bellows and the other is secured to the communicating ends of said bellows, both said check valves being oriented to block fluid circulation from said last named valve to said first named valve and to permit circulation of said fluid in the reverse direction, a cylindrical armature made of magnetic material secured to and surrounding said communicating ends of said bellows, and slidable within said casing, two groups of solenoids wound around said casing longitudinally thereof, one group of said solenoids creating a magnetic field to displace the armature in a direction to cause the compression stroke of said pump and the other group of said solenoids creating a magnetic field to displace the armature in the reverse direction corresponding to the return stroke of said pump, electric supply circuits connected to said respective groups of solenoids, contactor means in each of said circuits, and means to close said contactor means alternately and for unequal periods of time, said last named means closing the contactor means of the circuit of said one group of solenoids for a longer time than the contactor means of the circuit of said other group of solenoids whereby the compression stroke of said pump will last longer than the return stroke of said pump.

6. A pump as claimed in claim 5 including means to adjust the speed of operation of said closing means to thereby adjust the speed of the reciprocable back and forth movement of said armature.

References Cited in the file of this patent UNITED STATES PATENTS (No number) Whitfield June 2, 1836 1,580,479 Frankenfield Apr. 13, 1926 2,061,869 Gilbert Nov. 24, 1936 2,194,535 Von Delden Mar. 26, 1940 FOREIGN PATENTS 547,566 France Sept. 26, 1922 597,046 Great Britain J an. 16, 1948 928,381 France June 2, 1947

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