US3811800A - Blood pump - Google Patents

Abstract

This invention relates to a pump for an ''''artificial kidney machine'''', or hemodialysis device; and primarily is designed for the pumping of blood for purification in such a system using the recently announced procedure of ''''single needle'''' dialysis, whereby a single needle is temporarily inserted into a vein or artery of a patient through which blood is withdrawn from the vein for purification and returned to the patient through the same needle. Such a dialysis system requires, in addition to the filter and pump, a device commonly called an ''''occluder'''' by means of which purified blood from the filter is prevented from flowing to the needle during the suction stroke of the pump when blood is withdrawn from the patient and is open to flow during the pumping stroke.

Description

[.111 3,811,800 ['4 May 21, 1974 [5 BLOOD PUMP [76] Inventor: Karl Shill, 38171 Ashford Way,

Fremont, Calif. 94536 [22] Filed: July 12,1972

i211 Appl. No.: 271,011

[ 52] US. Cl 417/317, 417/394,417/478, 417/479, 128/214 B [51] Int. Cl....F04b 43/10,F04b 45/06, A61m 5/00 [58] Field of Search....'... 128/1316. 3,214 B, 214 R, v 128/214.2; 417/317, 394, 479, 474, 478, 395

[56] References Cited UNITED STATES PATENTS 3,518,033 6/1970 Anderson 417/478 3,606,596 9/1971 Edwards 417/479 3,658,445 4/1972 Pulmun et a 417/474 3,478,695 1 H1969 Goranson 417/394 3,515,640 6/1970 Rudlin 417/394 X 3,007,416 11/1961 Childs 417/479 X 3,575,161- 4/1971 Landon 128/214RX 2,383,193 8/1945 Herbert 417/317 2,836,121 5/1 958 Browne 417/394 X 3,406,633 10/1968 Schomburg 417/394 2,812,716 11/1957 Gray 128/214R 1,988,624 1/1935 Kipp 417/479 X DlLlViR-Y OCCLUDER HEP SUCTION TUBE 2,625,932 1/1953 Salisbury 128/2142 3,428,042 2/1969 Chesnut 128/214 R X FOREIGN PATENTS OR APPLICATIONS 632,579 9/1936 Germany 128/214 B Primary Examiner-William L. Freeh Assistant Examiner-Richard E. Gluck Attorney, Agent, or FirmRobyn Wilcox [57.1 TR C This invention relates to a pump for an artificial kid- :ney machine-, or hemodialysis device; and primarily is designed for the pumping of blood for purification in such a system using the recently announced procedure of single needle" dialysis, wherebyasingle needle is temporarily inserted into a vein or artery of a patient through which blood is withdrawn from the vein for i purification and returned to'the patient through the same needle. Such a dialysis system requires, in addition to the filter and pump, a device commonly called an occluder by means of which purified blood from the filter is prevented from flowing to the needle during the suction stroke of the-pump when blood is withdrawn from the patient and is open to flow during the pumping stroke.

, 5 Claims, 5 Drawing Figures 5 .FlLTER caste TlZAP 14 N PUMP IENIEnmzu I974 v 3.811.800sum 1 of 2 DELWERY FlLTER BUBBLE TRAP OCCLUDER.

HEPARIN PUMP SUCTION ruse PJ E "15 PATENTEDIAYZI 1974 saw 2 or 2 wmw P E m% JW. L N m m mOUTLET VALVE 101 PRESSURE OPEN ' OPEN TO PRESSURE 1 c .osE

sucTlou OPEN TO DRAN TU BE 59 PRESSURE l INLETOPEN VALVE 127 CLOSE OCCLUDER OPEN VALVE 156 LUDER I CLOSE D I TIME BLOOD PUMP BACKGROUND OF THE INVENTION- One of the important medical advances of our time is the invention and development of the artificial kidney machine referred to in medical circles as a hemodialysismachine, by Dr. Willem Kolff, now associated with the University of Utah. The dialysis machine was invented by Dr. Kolff about 25 years ago. While. a modern hemodialysis, system for purifying blood is often categorized as an artificial kidney machine, it is in fact an assemblage of specialized laboratory or clinical apparatus which, can be made to filter out waste material normally processed by the kidneys and expelled'from the body through the urine. Such a system generally comprises:

a. a means for conducting waste laden blood from the patient and the purified blood back to the patient;

b. a filter having a membrane through which will pass waste solutes while preventing the passage of blood, and thereby separate the waste fluids from the blood;

0.- a dialysate fluid which. acts through the membrane of the filter in order to withdraw the fluid wastes in the blood from the blood;

I d. a dialy'sate proportioning and'delivery system;

as to force the purified blood backinto the body and permit the withdrawal of waste laden blood from the body;

f. aheparin pump which injectsa minute quantity of anti-coagulant into the blood being purified to control the blood clotting which would otherwise occur;

g. much miscellaneous hardware such as bubble traps, medicine injection cuffs, metering devices, heaters and controls for maintaining the dialysate and blood within clinical limits, monitoring devices to sound an alann and/or control the procedure so as to protect the patient,and the instruments normally used by a doctor in such a procedure. I i

This invention is concerned with item (e), the specialized blood pump which performs an auxiliary heart function for a prolonged period, and preferably does so with minimal damage to the blood.

Since the original invention, much time and effort hasbeen spent in trying to improve the operation of thesedevices in order to make them more efficient, to make the complete system truly portable and less expensive, and to develop one that could be used in the home rather than requiring treatment in a hospital or clinic. One of the defects of prior machines has been the factthat they have been very large, very expensive and required expert medical attention under clinical or surgical conditionsThis made treatment not only expensive, but also required the patient to go to a hospital or clinic every two or three days for treatment which automatically limited patients to an urban area and to those'who could spend considerable time in travel to and from the hospital or clinic. Thus, most patients were financially unable to get treatment because such machines could be supplied only by large hospitals or well-endowed clinics. Many people just dont have the time or resources necessary for such a procedure. In

the past, for dialysis treatment, a patient had to undergo a surgical procedure by means of which an artificial plug-in connection, or canula, was placed in the artery and also in a vein, blood being withdrawn from the artery for treatment in the machine and then returned to the vein. Since there are relatively few spots in the body where an artery is close to the skin, the number of places where such a canula could be placed in an artery was very limitedrThe life of such a canula is quite short, as the natural bodily processes make it unuseable (a period sometimes as short as 6 weeks and seldom as long as a year) and a new, costly and painful surgical procedure was required. Eventuallythere is no place left to place such a canula, and the patient is doomed.

In 1971 the researchers under the direction of Dr. Kolff developed a new technique called the single needle dialysis technique whereby the canula problems are eliminated. In this procedure a single needle is inserted into a vein (many of which are quite close to the skin and therefore readily accessible, for withdrawing blood samples, taking blood .for a transfusion or storage in a blood bank, etc.) and after this blood is purified in the machine, it is injected into the patient through the same needle. Dr. Kolfi, at the University of Utah, has very recently announced a truly inexpensive dialysis machine which would be within the price range of most American families and, which is more important, could be utilized in the home. Such a system requires that a very small amount of blood be withdrawn through any suction stroke, in order to avoid collapsing the vein. The volume of each stroke is usually within the range of 1.5' to 2.5 cc. perstroke at the rate of between and strokes per minute, depending upon the age, size of the patient, and size of the available vein. During the suction stroke of the pump, the blood is taken from the body of the patient through the single needle and one leg of a Y-connection; and then during the pumping stroke, passes through the filter and back into the patients body through the other leg of the Y- connection and through the same needle. Patients can be readily trained to insert the needle themselves.

Such a system requires the use of at least one valve device, or occluder, which preferably is located in the tube delivering purified blood to the patient, and is operative to shut off the flow of purified blood to the patient during the suction stroke of the pump. Furthermore, this occluder, as it-is commonly called, must operate in timed. sequence to the operation of the pump. Obviously, the occluder must be open for. the passage of blood during the time that the pump is pushing blood through the filter and back intothe body of a patient, but should completely close the purified blood delivery line during that portion of the cycle in which the pumpis withdrawing blood from the body of a patient.

.One of the features of the present invention is that the volume of blood pumped in each stroke is variable through a wide range and adjustments can be made easily and accurately while the pump is in operation. An-

other feature is that the force applied to the blood in the conduit is also variable over a considerable range, and again adjustments can be made while the pump is in operation. More important is the fact that the pump and occluder of the present invention are isolated from the tubes carrying the blood from the patient to the dialysis filter and returning it to the body, so that neither the pump nor the occluder need to be sterilized between uses. It will be understood that in such a procedure as dialysis, the needle, the blood tubes, and the filter will have to be sterilized or replaced between each use, and this is commonly done; but it is unnecessary to sterilize either the pump or the occluder of the present invention, as the sterilized tubes are inserted through the pump and occluder and the blood does not come into direct contact with these devices.

OBJECTS It is a primary object of the present invention to provide a small, light-weight pump for a dialysis machine.

It is a further object of the present invention to provide a small, light-weight pump which can be operated by hydraulic pressure that does not need to be as great as that ordinarily supplied in a city water supply, and in fact can be operated from a portable hydraulic supply, such as those found in many recreational vehicles.

It is a further object of the present invention to provide an artificial kidney pump with an infinitely variable volumetric adjustment.

It is another object of the present invention to provide a'pump for a dialysis machine that is adapted to be used with a single needle dialysis system, i.e. one in which a single needle is used to withdraw blood from, and return it to the patient.

It is still another object of the present invention to provide a quiet and positive operation for an occluding device which controls the flow of the patients blood from, and the delivery of the purified blood back to, the patient through a single hypodermic needle.

It is a further object of the present invention to provide a surgical pump, which may include an occluder, that does not have to be sterilized, since only the tubes through which the blood passes and the filter needs to be sterile since the tube or tubes may be readily insertedthrough the above-mentioned devices.

A still further object of the present invention is to provide a blood pump which may be used for prolonged periods of time without causing blood cell rupture known as hemolysis.

Theseand other objects of the present invention will be apparent from the specification which follows taken in conjunction with the accompanying drawings in which:

' FIG. 1 is a diagrammatic view of the dialysis system with which the present invention is designed to be associated, showing the pump of the present invention interposed between the supply tube to the dialysis filter for withdrawing blood from'the patient and passing it to the filter.

FIG. 2 is a cross-sectional view through one of the valves of the pump, such as taken along the plane indicated by the line 2-2 of FIG. 1.

FIG. 3 is a cross-sectional view of the power section of the present invention showing also the means for supplying hydraulic power and releasing it.

FIG. 4 is a diagrammatic cross-sectional view of the pump of the present invention showing the various hydraulic supply valves in the positions they would occupy at the start of the suction phase of a cycle of operation during which blood is to be withdrawn from the body of a patient. I

FIG. 5 is a timing diagram showing the operation of the three important valves and the supply of hydraulic fluid to the pressure chamber.

The single needle dialysis system with which the pump of the present invention is particularly adapted to control is shown in FIG. 1. The usualsurgical hypodermicneedle 10 can be inserted into any suitable vein of the patient. A Y-member II is affixed to theneedle 10, and asuction hose 12 leads from one leg of the Y- member 11 to and through thepump 40, the section of thesuction tube 12 leading from the pump to adialysis filter 15 being indicated by thereference character 14. It will be understood that thetube 12 and 14 is integral, the two reference characters being used to indicate the two sections of a single tube. The other leg of the Y- member 11 is connected to thedelivery tube 13 leading from thefilter 15.

It is conventional in an apparatus of this kind to pass blood through thefilter 15 in two or more diverging and converging streams, and accordingly thesection 14 of thetube 12 is provided with a Y-member 16 which divides the blood flowing therethrough into two tubes l4a and 14-h. Similarly, the blood discharged from the filter passes through discharge tubes 13-a and 13-1) to a common Y-member 17 and thence to abubble trap 18. Since thefilter 15 andbubble trap 18 are of known construction, it is believed unnecessary to refer further to them. It can also be noted that it is conventional practice to inject a very minute amount (usually in the order of 1.5 milliliters per hour) of heparin (an anticoagulant) into thesuction tube 12 as by means of aheparin pump 21 operated from a source of power 22, the heparin passing throughtube 23 to a suitable T-connection 24 in the suction tube 22. It is customary in this art to form the tubes l2, l4, l4-a, 14-b, 13-0, 13- b and 13 of surgical plastic tubing, as such tubing under treatment conditions does not cause blood to coagulate, and,.is quite flexible while being of sufficient strength to withstand any pressure to which it need be subjected. Such tubing also can be readily sterilized, packed in sealed containers and sold quite inexpensively.

The single needle technique above-mentioned requires the use of an occluder which is operative to prevent flow of blood from the dialysis filter to the patient during the period of time that thepump 40 is in its suction phase and is withdrawing blood from the patient. In FIG. 1 theoccluder 19 is shown associated with thedelivery tube 13. In that situation, theoccluder 19 is timed to close thedelivery tube 13 to the flow of blood during the suction portion of a pumping cycle and is open to permit the flow of blood during the pumping phase of that cycle. It will be obvious, however, that theoccluder 19 could be placed in thesuction tube 12, in which event it would have to operate in exact time with the pump, so that thetube 12 would be open to the passage of blood during the time that the 'pump was in its suction phase and closed to the passage of blood during the pumping phase ofpump 40, which is the reverse of the preferred form shown in FIG. 1.

PUMP

Thepump 40 of the present invention will be contained in any suitable casing which, preferably, can be constructed of three sections: a pressure, or operating,section 41; asection 42 containing the passages for supply of hydraulic fluid under pressure, and 43 a simv pie casing for enclosing the control solenoids to be hereafter mentioned. Preferably,casing sections 41 and 42 are formed of some readily extrudable material, such as aluminum or some forms of plastic, so that longitudinal passageways can be formed therein and thereby avoid the expensive drilling operation required when such passageways are drilled longitudinally through the casing.

The power, or operating,section 41 is provided with alongitudinal bore 44 for theblood tube 12 and aparallel bore 45, the two communicating throughout their length, as shown in FIGS. 2 and 3. Thebore 44 is somewhat larger than thetube 12, preferably as much as one-quarter or three-eighths of an inch larger in diameter than thetube 12. The parallel bore 45 is partially contained within thecasing 41 and thereby provides an open slot, not identified, throughout the length of thecasing block 41. This bore is adapted to permit the ready insertion oftheblood tube 12 anditsencompassing rubber tube 50 from the outside without the neces sity of threading the tube therethrough. Thebore 45 is also adapted toreceive a lockingmember 46 provided with asuitable handle 47 so that themember 46 can readily be inserted into or removed from thebore 45. The lockingmember 46, when positioned in thebore 45, holdsthe'blood tube 12 and its encompassingrubber tube 50 within theblock 41 and also provides an anvil against which thetubes 12 and 50 can be pressed during operation of the pump, whereby the .tubes can be completely compressed by ahydraulic pressure tube 56 described below. The alternate contraction and relaxation of thetubes 12, 50 forces blood from thepump 40 and suction of blood thereinto.

The central, or supply,section 42 of the casing is'provided with two longitudinal bores: atube 48 for supplying hydraulic fluid under pressure, and adrain 49.

, Thecasing members 41 and 42 will have auxiliary passageways drilled therein, will be described more in detail hereafter. It will readily be understood that the three sections of thecasing 41, 42 and43 can be rigidly attached one to another by any suitable means, such as by means of bolts, not shown, cementing, or other suitable procedure.

As mentioned before,theblood tube 12 is, throughout its length adapted to be inserted in thepump 40, encompassed within a larger;tube 50. Preferably, thetube 50 is formed of soft but strong rubber and is of sufficient thickness to rather strongly resist collapsing and has such resiliency that once pressure'is released it will resume its natural round shape with a force sufficiently strong and rapid to create a negative, or suction pres- It should be noted at this point that in FIG. 3 thetube 56 is shown in its relaxed position in which it communicates with thedrain 49 and hence the resilient force of the tube 511 forces thetube 56 to the semi-collapsed position shown and expels pressure fluid therefrom, FIG. 3 showing the relations of the partsduring the suction phase of a cycle of pump operation. It will be understood, however, that when hydraulic fluid under pressure is admitted intotube 56 it will assume a round shape throughout its length, thereby forcibly displacing thetube 50 and its enclosedblood supply tube 12 to a semi-collapsed position (thedischarge valve 86 then being open) and forcing blood throughtube 12, 14 toconduit 58 and a two-position, two-way flow valve 59 sure. Preferably, the two tubes are cemented together so that they must act as one, particularly when pressure is'released from against the tubes and. thetube 50 resumes its normal round shape shown in both FIGS. 2 and 3.

Throughout the major portion of the length of thetubes 12 and 50 within thecasing 41, an enlargement is milled into the casing adjacent thebore 44. This can readily be done by a milling machine-operating through the sides of the twobores 44 and 45 (see FIG. 3). Within theenlarged bore 55 is placed ahydraulic pressure tube 56 which is sealed at its lower end as shown in FIG. 4. Thetube 56 communicates withconduit 57 and thence to the hydraulicpressure supply conduit 48 and thedrain 49 through a two-position, two-way flow valve 59, as will be described hereafter.

(shown in these figures as being in the drain position). For purposes of exemplification only, thevalve 59 is shown as having adiametric bore 60 and a radial, or T- shaped, bore 61 extending from the periphery of the valve member to the bore 611. In the position shown in FIGS. 3 and 4,conduit 57 communicates with anauxiliary drain 62 which, in turn, communicates with thedrain 49, thebore 61 in thevalve member 59 communicating withconduit 57 and bore 60 communicating withconduit 62. If thevalve member 59 is activated (rocked in the exemplification shown) through an angle of (clockwise in this figure), thenconduit 58 will communicate withconduit 57 throughbore 60 and theconduit 61 will be blocked by registering with the interior wall of the valve casing. In the latter condition, fluid under pressure fromconduit 48 will pass throughconduit 58, bore 61),conduit 57, intotube 56 and compress the blood tubes 51) and 12. However, in the position shown in FIG. 3, the resiliency of theouter tube 50 tending to resume its round shape will collapse thetube 56, forcing the immediate discharge of the fluid inpressure tube 56 throughconduit 61 and intodrain 62. The inherent resilient force'in thetube 50 acts with such strength and with such speed that it not only collapses tube 56v to permit blood to entertube 12, but it does so with some negativepressure to suck blood from the patient into the pump.

The activation of thevalve 59 is readilysecured by operation of asmall solenoid 115, as will now be described. The solenoid is mounted in thecasing section 43 and comprises the usual winding 116 andarmature 117. In the exemplification shown, thearmature 117 normally lies in the position shown in FIG. 3 whereby itslink 118 rocks thevalve member 59 90 counter-clockwise so that thebores 61, 60 register withducts 56 and 62, respectively. Upon energization of the solenoid, thesolenoid armature 1 17 moves to the right, rocking valve member 90 clockwise so that bore 60 registers withducts 58 and 57 and liquid under pressure is allowed to enter thepressure tube 56, whereby it will compress theblood tube 12, 50. The solenoid is. supplied with power throughsuitable leads 119 from a circuit in a timer 120 (FIG. 1) of conventional construction. The timing of the device will be described in a subsequent section. It will be understood that instead ofvalves 59 and 181 being rotary as shown, one can use any two-way, two-position valve, such as the straight line valves known in this art.

In connection with all dialysis techniques, it is necessary to know the volume of blood being pumped per minute. Since the volume of pressure fluid entering and leavingtube 56 is a measure of the throughput of blood throughtube 12, the amount of blood pumped can readily be measured by measuring the output from thetube 56. Normal procedure is to collect this throughput for six seconds and multiply it by 10. This can readily be accomplished in the present invention by means of a graduate 70 (FIG. 4) provided with suitable indicia for volumetric measurement thereon. Such agraduate 70 communicates with thedrain line 62 by means of a bypass conduit 71 which communicates withdrain 62 by means of a two-position, two-way flow valve 72. The valve member includes adiametric bore 73 and a perpendicular radial bore 74 communicating with the periphery of the valve member and thediametric bore 73. Normally, the valve is in the position shown in FIG. 4 in which drain 62 communicates through aprimary drain tube 75 that communicates with themain drain 40 through thebore 73. However, if the valve member is rocked counter-clockwise through an angle of 90, then drain 62 communicates with the radial bore 74, one-half ofdrain 73 and the flow passes into conduit 71 andgraduate 70. This valve can be operated by any suitable means, such as thepushbutton 76 shown in FIGS. 1 and 3. The valve will be held in the position to ing of thevalve member 101 counter-clockwise from pass flow into the graduate for a period of six secends and then returned to its normal position. A glance at thegraduate 70 will show the amount of volume of liquid contained therein, and this if multiplied by 10,

VALVE CONSTRUCTION It is obvious to those skilled in the art that a pump such as that herein described requires two valves: an inlet valve andanoutlet valve 86. When the pump of the present invention is utilized for single needle dialysis, a third valve is required in the occluder. Since in the preferred construction all three valves are identical in construction, only one will be described in detail, and for this purpose the outlet valve shown in FIGS. 2 and 4 will be used for exemplification. The various valves, such asoutlet valve 86 shown in FIG. 2, comprise apiston 87 operating withinelongated cylinder 88. Thepiston 87 is provided with anelongated nipple 89 which, in the retracted position of the cylinder 87 (shown in FIG. 2) registers with the outer surface of theouter tube 50, and in the projected, or operative, position so deforms thetubes 50 and 12 that they are comthe closing position shown in FIGS. 2 and 4, thediametrical bore 102 registers with a shortauxiliary inlet 104 which communicates with thepower supply conduit 48, and with a short conduit 105 that leads to the cylinder. In the valve open position in which thepiston 87 is retracted to permit flow of blood throughtube 12, duct 105 registers with T-duct 103, part ofduct 102, which then registers withinduct 106 that leads to drain 49. This draining position is secured by rotating a valve counter-clockwise through an angle of 90. The rockthe position shown in FIGS. 2 and 4, is preferably secured by the operation of asolenoid 115, such as was described in connection withvalve 59 above.

The inlet valve 85 is of the same construction asvalve 86 just described, its cylinder 87-a being supplied with fluid under pressure by branch ducts and 126, flow through the system being controlled by a two-position two-way flow valve 127. Thevalve 127 also registers with anauxiliary drain duct 128 which communicates with themain drain 49. The valve is operated by asolenoid 115 and in the same manner as that described above.

Preferably, theoccluder 19 is a valve similar in all respects to those heretofore described, except that it is located near the Y-member 11 andneedle 10. It can be supplied with fluid under pressure from thesupply line 48 by means of a branch duct (FIG. 4), avalve 136, and atube 137 which leads from the casing of thepump 40 to theoccluder 19. It should be noted, however, that' thevalve 136 operates out of phase withvalve 127 and in phase withvalve 101, as shown in FIG. 4. In fact, it would be possible to connecttube 137 to supply duct 105 leading fromvalve 101 tocylinder 88, but it is believed that the use of aseparate valve 136 will be more readily understood. That is, thevalve 136 is open to the flow of fluid under pressure to apply pressure to the occluder valve fromconduit 137 simultaneously with the operation ofvalve 101 to supply fluid under pressure to thecylinder 87, at whichtime valve 127 is positioned to permit the flow of water from its pletely closed to the flow of blood therethrough. It

' should be'noted at this point that both FIGS. 2 and 4 show the position of the parts at the start of the valveclosing operation, and that FIG. 4 shows in dotted line its fully projected, or closed, position. Preferably, the

a two-position, two-way flow valve 101 which, for purposes of exempliflcation, is shown as including adiametrical bore 102 and aperpendicular Tbore 103. In

cylinder 87-to drain 128, 48. It should also be noted that when thevalve 136 is rocked counter-clockwise from the position shown in FIG. 4, fluid can pass fromtube 137 to thedrain duct 138 which connects to drain 128 and thence tomain drain 49.

It will be understood that a preferred liquid fluid for operating the various valves and thepressure tube 56 will be water from a residential or hospital supply, such as that provided bywater line 145. Since most water supplies have greater pressure than is needed or desired for operation of the pump of the present invention, it is expected that apressure regulating valve 146 will be interposed between the water line and thepump supply line 48. It is expected that water will normally be used in the operation of the pump of the present invention, as it is not only relatively cheap, but is available in practically all homes and all hospitals.

TIMING As indicated above, the various valves and thepressure tube 56 are operated through their respective twowayflow control valves 127, 101, 136 and 59. These valves are operated by electric power through asequence timer 120. The timer is supplied with power through any suitableelectrical conduit 121 which can be connected to any suitable power supply. The timing v Phase of operation erative to open'the outlet and occluder two-way control-valves 101 and 13610 drain and to positioninlet valve 127 andpressure chamber valve 59 to conduct enough water under pressure to chamber 87-11 andtube 56, respectively. Conversely, the pressure chamber andinlet flow valves 59 and 127 are positioned to conduct water from thepressure tube 56 and inlet valve cylinder s7-a to drain substantially simultaneously with positioning the outlet andoccluder valves 101 and 136 to conduct water under pressure frompower supply duct 48 to their respective valves. This timing is shown in FIG. and in the table below. It can be noted that the inlet'valve 127 starts to close shortly before outlet and occluder valves'101 and 136 are opened to drain and beforepressure tube 56 comes to position of equilibrium between suction and pressure.

closed'position shown in FIG. 3 and creates a suction on theblood supply line 12. At the end of this phase the valves reverse their position andvalves 101 and 136 are opened to drain andvalves 127 and 159 are positioned to conduct pressure fluid to their respective chambers.

This can perhaps better be explained by a table showing the valve conditions in which the phase open to pressure is used to indicate that the diametrical bore of the respective valves is positioned to conduct water under pressure frommain supply duct 48 to the respec-' tive chambers and the phrase open to drain is used to indicate that the valve is positioned to pass water from the respective chamber to drain:

the pump of the present invention can be used in conliCCliiOIlWitl'l other organs, excised organs in banks; for open heart and heart transplant surgery, and the like. Accordingly, it is intended that all modifications which lie within the scope of the underlying inventive concepts are to be-included within the scope of the claims and that the invention is not to be limited to the particular forms herein shown and described.

7 [claim l. A surgical pump comprising: 1. a casing; 2.a longitudinal duct through said casing adapted to receive a blood. tube; V 3. an inlet valve member in said casing adjacent one end of said duct and an outlet valve member in said casing adjacent the other end of said duct each of said valves comprising:

a. a cylinder within said casing,

b. a piston operating in said cylinder, said piston having a projection engaging said blood tube; and

c. means for alternately supplying fluid under pres sure to and draining fluid from said cylinder;

4. a pressure tube within said duct and lying adjacent said blood'tube;

5. means for supplying fluid under pressure to said pressure tube substantially simultaneously with the opening of said outlet valve and the closing of said inlet valve and for draining said pressure tube and substantially simultaneously opening said inlet valve and closing said outlet valve; and

6. resilient tube adapted to lie in said duct and leading into a discharge line.

2. The apparatus ofclaim 1 comprising also'an occludei' in the discharge lineof said pump and means for operatingsaid occluder to open said discharge line to flow simultaneously with the opening of the outlet valve to flow and closing the occluder to flow simultaneously with the closing of said outlet valve to flow.

3. The apparatus ofclaim 1 comprising also means for measuring the flow from said pressure tube.

PRESS URE CONTROLVALVES Inlet valve 127Discharge valve 101 Open to drain. Inlet' valve 85 is open).

Suction phase in whihblood is drawn from the patient into the section oftube 12 between inlet valve 85 anddischarge valve 86.

Pumping phase in which blood Open to W655i),

within the tube between (Inlet valve 85 is inlet valve 85 and discharge closed). Ivalve 86 is pumped to the filter l5.

Open todrain. (Pressure tube Open to pressure.

56 is collapsed andblood tube 12,50 is extended).

Open to pressure. (Pressure Open-to drain. (Outlet tube 56 is extended to. collapse blood tubelZ;

Occluder valve 136 Open to pressure. (Occluder is'closecl to (Outlet valve 86 is flow of blood).

7 closed).

Open to drain. (Occluder valve 86 is open). I is open).

It is believed that the hereinbefore stated and other advantages of the pump of the present invention will be obvious to those skilled in the art. it isalso obvious that 4. A dialysis pumping system for use inconne'ction with a single needle dialysis technique in a kidney machine in which blood is taken from a patient and returned to the patient after treatment through a single needle, saidpumping system comprising:

2. a longitudinal duct through said casing, said duct 7 being adapted to receive a flexible blood tube, 3. a power supply conduit in said casing for supplying fluid under pressure, v I

8. branch conduits leading from said power supply conduit to said inlet valve cylinder, said pressure tube and said discharge valve cylinder,

9. branch conduits leading from said inlet valve cylinder, said pressure tube and said discharge valve cylinder to said drain conduit,

10. flow valves in said branch conduits,

l 1. means for operating said flow valves,

12. a timer for operating said last mentioned means in sequence to connect said inlet valve and said pressure tube to said pressure supply conduit and close them to' drain and simultaneously opening said discharge valve to drain and closing it to the pressure supply conduit; and alternately open the inlet valve and the pressure tube to drain while closing them to the pressure conduit and simultaneously opening the discharge valve to the pressure conduit while closing it to drain;

13. means for operating an occluder valve simultaneously and in parallel phases with said discharge valve; and

14. a blood tube adapted to lie in said duct and having a strongly resilient tube encompassing and cemented to the portion of said blood tube adapted to lie within said duct, whereby a vacuum will be applied to said blood tube when the pressure tube is draining.

5. The pumping system of claim 4 wherein the inlet and discharge valves are operated by water pressure which is controlled by respective solenoids.

Claims (23)

1. A surgical pump comprising: 1. a casing; 2. a longitudinal duct through said casing adapted to receive a blood tube; 3. an inlet valve member in said casing adjacent one end of said duct and an outlet valve member in said casing adjacent the other end of said duct each of said valves comprising: a. a cylinder within said casing, b. a piston operating in said cylinder, said piston having a projection engaging said blood tube; and c. means for alternately supplying fluid under pressure to and draining fluid from said cylinder; 4. a pressure tube within said duct and lying adjacent said blood tube; 5. means for supplying fluid under pressure to said pressure tube substantially simultaneously with the opening of said outlet valve and the closing of said inlet valve and for draining said pressure tube and substantially simultaneously opening said inlet valve and closing said outlet valve; and 6. resilient tube adapted to lie in said duct and leading into a discharge line.

2. The apparatus of claim 1 comprising also an occluder in the discharge line of said pump and means for operating said occluder to open said discharge line to flow simultaneously with the opening of the outlet valve to flow and closing the occluder to flow simultaneously with the closing of said outlet valve to flow.

2. a longitudinal duct through said casing adapted to receive a blood tube;

2. a longitudinal duct through said casing, said duct being adapted to receive a flexible blood tube,

3. a power supply conduit in said casing for supplying fluid under pressure,

3. an inlet valve member in said casing adjacent one end of said duct and an outlet valve member in said casing adjacent the other end of said duct each of said valves comprising: a. a cylinder within said casing, b. a piston operating in said cylinder, said piston having a projection engaging said blood tube; and c. means for alternately supplying fluid under pressure to and draining fluid from said cylinder;

3. The apparatus of claim 1 comprising also means for measuring the flow from said pressure tube.

4. A dialysis pumping system for use in connection with a single needle dialysis technique in a kidney machine in which blood is taken from a patient and returned to the patient after treatment through a single needle, said pumping system comprising:

4. a pressure tube within said duct and lying adjacent said blood tube;

4. a drain conduit in said casing for draining fluid,

5. an inlet valve at one end of said longitudinal duct and a discharge valve at the other end of said duct, said valves comprising: a. cylinders in said casing communicating with said duct, and b. pistons within said cylinders, said pistons having projections bearing against said blood tube,

5. means for supplying fluid under pressure to said pressure tube substantially simultaneously with the opening of said outlet valve and the closing of said inlet valve and for draining said pressure tube and substantially simultaneously opening said inlet valve and closing said outlet valve; and

5. The pumping system of claim 4 wherein the inlet and discharge valves are operated by water pressure which is controlled by respective solenoids.

6. resilient tube adapted to lie in said duct and leading into a discharge line.

6. an enlarged chamber adjacent to, and communicating with, said duct between said inlet valve and said outlet valve,

7. a resilient pressure tube in said enlarged chamber,

8. branch conduits leading from said power supply conduit to said inlet valve cylinder, said pressure tube and said discharge valve cylinder,

9. branch conduits leading from said inlet valve cylinder, said pressure tube and said discharge valve cylinder to said drain conduit,

10. flow valves in said branch conduits,

11. means for operating said flow valves,

12. a timer for operating said last mentioned means in sequence to connect said inlet valve and said pressure tube to said pressure supply conduit and close them to drain and simultaneously opening said discharge valve to drain and closing it to the pressure supply conduit; and alternately open the inlet valve and the pressure tube to drain while closing them to the pressure conduit and simultaneously opening the discharge valve to the pressure conduit while closing it to drain;

13. means for operating an occluder valve simultaneously and in parallel phases with said discharge valve; and

14. a blood tube adapted to lie in said duct and having a strongly resilient tube encompassing and cemented to the portion of said blood tube adapted to lie within said duct, whereby a vacuum will be applied to said blood tube when the pressure tube is draining.

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