US3841799A - Medical cassette pump - Google Patents

Abstract

A medical cassette pump wherein a drive motor continuously rotates a fluid drive assembly about a principal axis, said fluid drive assembly including a plurality of rollers mounted for free rotation about respective roller axes spaced from said principal axis, said fluid drive assembly carrying said rollers about said principal axis during the rotation thereof. Displaceable cassette means is provided for releasably engaging a fluid carrying tube against said rollers for the advancement of fluid along said tube in response to the rotation of said fluid drive assembly.

Description

United States Patent 1191 Spinosa et al.

[ Oct. 15, 1974 [5 MEDICAL CASSETTE PUMP [75] Inventors: Dom Spinosa, Wantagh, L. 1.; John M. Varga, Bayville, both of NY.

[73] Assignee: East/West Medical Products, Inc.,

. Syossett, NY.

22 Filed: Jan. 17, 1973 21 Appl. No.: 324,464

Related US. Application Data [62] Division of Ser. No. 174,019, Aug. 23, 1971,

abandoned.

52 us. c1. 417/477 [51] Int. Cl. F041) 43/08, F04b 43/12, F04b 45/06 [58] Field of Search 417/477, 476, 475, 360

[56] References Cited UNITED STATES PATENTS.

3,674,383 9/1970 lles 417/476 FOREIGNPATENTS OR APPLICATIONS 727,001 3/1955 Great Britain 417/477 3/1966 Great Britain ....417/477 1/1960 France ..417/477 Primary Examiner-C. J. Husar Assistant Examiner-Richard E. Gluck 57 ABSTRACT A medical cassette pump wherein a drive motor continuously rotates a fluid drive assembly about a principal axis, said fluid drive assembly including a plurality of rollers mounted for free rotation about respective roller axes spaced from said principal axis, said fluid drive assembly carrying said rollers about said principal axis during the rotation thereof. Displaceable cassette means is provided for releasably engaging a fluid carrying tubjeagainst said rollers for the advancement of fluid along said tube in response to the rotation of said fluid drive assembly.

2 Claims, 12 Drawing Figures ATENTEDBBT 1 5 3,841 975 SHEET 1 [If 5 PMENTEDOCT 1 5 I974 sum 3 or s l MEDICAL CASSETTE PUMP BACKGROUND OF THE INVENTION This invention relates to medical pumps of the type utilized for the delivery of fluids to and from patients. Examples of such applications would be procedures wherein cavities of the body are to be washed out, such as the stomach, bladder, etc., or where fluids are to be pumped from the body. Other examplesin which fluid pumps are utilized in medical applications include infusion, dialysis, hemoperfusion, constant irrigation and the suction method of abortion. In such operations, it is important that the user of the pump not be exposed to the fluid to be pumped, both to maintain the sterility of fluid delivered to the patient, and to avoid contamination of or by fluid taken from the patient. The known medical pumps have required threading of the fluid transmission tube through intricate paths in the pump and have otherwise causes breaches in sterile procedures and contamination. Further, the prior art pumps required clean-up and sterilization between uses, due to the exposure of critical parts of the pump to the fluid being processed.

By providing a medical pump with a cassette for engaging a fluid transmission tube to the operative elements of the pump, the foregoing disadvantages have been avoided.

SUMMARY OFTHE INVENTION Generally speaking, in accordance with the invention, the medical cassette pump according to the invention includes a drive means, a fluid drive assembly operatively coupled to said drive means for rotation thereby about a principal axis, said fluid drive assembly least a portion of the inner peripheral wall of said cassette defining said opening being formed with an axially facing channel for receiving said fluid carrying tube with portions of said fluid carrying tube extending laterally from said channel for engagement by said planetary rollers. The medical cassette pump may be formed with a frame means, and said cassette means may be releasably mounted on said frame means for simultaneous removal of said cassette means and fluid carrying tube.

Each of said cassette half members may be formed with a bore therethrough in the end thereof opposite the hinged connection therebetween, each of said bores communicating with said inner peripheral channel for the threading of said fluid carrying tube therethrough. Said cassette means may be pivotably mounted on a shaft upstanding from said frame means, which shaft is adapted to retain said cassette means secured to said-frame means. Spring members mounted the displaceon said frame means may be provided forretaining said cassette means in the closed operative position thereof, and said cassette means may be provided with notches for engagement with said spring members for this purpose. I

Tab means may be provided with a pair of apertures therethrough through which said fluid carrying tube may be threaded to define a loop for extending about said fluid drive assembly, said loop being engageable by said cassette means against said planetary roller means. Said tab means may be provided with a finger engaging switch means, said switch means being operatively coupled to said drive means to prevent the operation thereof unless said switch means is engaged by said tab means finger.

Two sets of said planetary rollers may be provided aligned in two planes spaced'along said principal axis, a pair of fluid carrying tubes being provided, said cassette means being adapted to engage one of said fluid carrying tubes against one of said sets of rollers for the separate advancement of fluid in each of said fluid carrying tubes. A

In an alternate embodiment of the medical cassette pump according to the invention, said planetary rollers consist of a cylindrical portion and a conical portion extending from one end of said cylindrical portion, said cassette means being displaceable relative to said planatary rollers along said principal axis, whereby said fluid carrying tube rides along said conical portion for positioning and gradual compression until engagement by said cylindrical portion, at which point said tube is positioned for pumping.

Accordingly, an object of the medical cassette pump according to the invention is to provide a pump which is adapted to provide efficient and controlled pumping of fluids.

Another object of the invention is to provide a medical cassette pump wherein the pump is isolated from the fluids being processed.

Still another object of the medical cassette pump according to the invention is to provide a pump wherein the fluid carrying tube containing the fluid to be pumpedmay be readily and rapidly changed, permitting the use of disposable collection and dispensing systerns.

Still another object of the medical cassette pump according to the invention is to provide a medical cassette pump which may be utilizzed for the simultaneous suction ancl delivery of fluid 'in a coordinated manner.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification and drawings.

The invention accordingly comprises the features 0 l construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of one embodiment of the medical cassette pump according to the invention;

' FIGS. 2, 4 and 5 are sectional views taken respectively along lines 2 2, 4 4 and 5 5 of FIG. 1;

FIG. 3 is a top plan view of the medical cassette pump of FIG. 1, showing the cassette half members in the open position; 7

FIG. 6 is a partially sectioned top plan view of a second embodiment of the medical cassette pump according to the invention;

FIG. 7 is a fragmented side elevational view of the medical cassette pump of FIG. 6;

FIG. 8 is a sectional view taken alongline 88 of FIG. 6;

FIG. 9 is'a fragmented perspective view of a third embodiment of the medical cassette pump according to the invention;

FIG. 10 is a top plan view of the embodiment of'the medical cassette pump of FIG. 9;

FIG. 11 is a sectional view taken alonglines 11 11 of FIG. 10; and

FIG. 12 is a sectional view taken alonglines 12 12 of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS to a catheter or other delivery device. The fluid carrying tube lSjcould equally be connected to a collection receptical, in which case the pump according to the invention would be adapted to suction fluid from a patientor other source and deliver it to the disposal receptical.

Themedical cassette pump 10 consists of ahousin 22 within which is mounted adrive motor 24 best shown in FIG. 2. An on-off switch 26, and areversing switch 28 are mounted on the exterior ofhousing 22 and would be operativelycoupled to drivemotor 24 for the purposes of turning said drive motor on and off, and for controlling the direction of rotation thereof.Knob 30,- also mounted onhousing 22 is provided for the purpose of controlling the speed of said drive motor and would function in a conventional manner. Provision can be made for timing and sequence controls permitting the automatic operation of the pump for periods of predetermined duration spaced by periods of predetermined duration during which the pump is at rest. The drive motor is preferably substantially noiseless, and arc-less, to permit use in an oxygen environment.

The rotative drive fromdrive motor 24 is transmitted to adrive shaft 32 which defines the principal axis of afluid driveassembly 34. As best shown in FIG. 2, said fluid drive'assembly consists of acentral hub 36 secured to driveshaft 32 by aset screw 38. A pair of spacedplates 40 are mounted onhub 36 byscrews 42 for the rotation of said plates with said drive shaft. Threeplanetary rollers 44 are freely rotatably mounted onplates 40 byroller shafts 46. As best shown in FIG. 3, the three rollers are circumferentially spaced aboutplates 40, and are equally spaced fromdrive shaft 38.

The three rollers are carried about the principal axis defined bydrive shaft 32 in response to the rotation thereof. Acassette 48 is provided consisting ofa pair ofcassette half members 50. Said pair of cassette half members are joined at one end by ahinge 52 best shown in FIG. 5. Said hinge is provided with anaxial aperture 54 therethrough for engaging apost 56 which projects upwardly fromhousing 22.Post 56 serves as an axis for the relative pivotal displacement of the twocassette half members 50, as well as serving to retain the cassette in position on the housing. Where the motor is to be of the unidirection type.aperture 54 could be closed atone end by a wall to prevent accidental reversal of the direction of fluid flow. As shown in FIG. 3, the two cassette half members may be pivoted relative to each other to open same, and may be lifted offpost 56 for removal from the housing. The other end of each of said cassette half members is provided with anotch 58 which cooperates with aspring finger 60 as best shown in FIG. 4. Each of said spring fingers is mounted at one end tohousing 22 by ascrew 62 and extends through anaperture 64 in said housing, said aperture permitting the displacement of said spring finger to the position shownin phantom in FIG. 4 to permit the displacement of the associatedcassette half member 50. Apad 66 at the end ofspring fingers 60 engages the top surface ofcassette half members 50 to prevent the upward displacement of said cassette half members. Each cassette half member is formed with a substantially semicircularinner periphery 68 dimensioned to extend about and receiveplates 40. At least a portion of saidinner periphery 68 of each of said cassettehalf members is formed with achannel 70. As best shown in FIG. 2,rollers 44 are dimensioned to extend intoslots 70 to engagefluid carrying tube 18 against theinner wall 72 of said channel, as shown in the left portion of FIG. 2.Channel 70 is dimensioned to loosely receivefluid carrying tube 18, and to permit the flattening thereof againstinner wall 72. Each of the cassette half members is provided with acurved bore 74 communicating withchannel 70, as best shown in FIG. 3.Fluid carrying tube 18 is threaded through said bores and received withinchannel 70. The cassette is then mounted onpost 56 while in the open position as shown in FIG. 3, andthen, the twocassette half members 50 are brought together into the position shown in phantom lines in FIG. 3. When so positioned, each of the threerollers 44 engages a portion of the fluid con-- ducting tube against theinner wall 72 ofchannel 70 to effectively close said tube. When two of the rollers thus engage the fluid carrying tube, a compartment of fluid is defined therebetween, which compartment of fluid is advanced along the tube as thefluid drive assembly 34 is rotated. Each compartment of fluid is sequentially delivered to the outlet portion of the fluid carrying tube located in one of thebore 74, while new compartments of fluid are continuously formed by adjacent pairs of rollers, transported along the section of the fluid carry- .ing tube in the path of the rollers, and delivered to said outlet portion. In this manner, a smooth and continuous flow in either direction is produced without any of the moving parts of the pump being in contact with the fluid being transmitted.

If desired,cassette 48 may be disposable, and furnished as a unit with a disposable fluid carrying tube andeither a dispensing or disposal system, which system can be sterilized as a unit, utilized as a unit and disposed of as a unit. Even where the cassettes are not disposable, a plurality ofcassettes 48 may be provided, each of said cassettes being threaded on a separate tube, so that uponcompletion of one operation, the pump may be immediately utilized for another operation by merely substituting a new cassette, whichsubstitution is readily and rapidly achievable.

The pump is provided with a pair ofhandles 76 and 78 which permit the carrying of the pump, its mounting on a stand, or the self support thereof.

Turning now to FIGS. 6 8, a second embodiment of the medical cassette pump according to the invention is shown. In this embodiment, drive shaft 32' has a hub 36' mounted thereon byset screw 38. A pair'of circular plates 40' are secured to saidhub by screws 42. In place of the cylindricalplanetary rollers 44 of the embodiment of FIGS. 1 5,planatary rollers 82, which are freely rotatably mounted in circumferentially spaced relation onshafts 46, are formed with acylindrical surface 84 and aconical surface 86. Thecassette 88 consists of aunitary cassette member 90 and ahandle member 92.Cassette member 90 is formed with an innercentral opening 94, the inner periphery of which is defined by a relativelyshallow channel 96.Central opening 94 incassette member 90 is dimensioned to receive thecylindrical portion 84 ofrollers 82.

Cassette member 90 is formed with a pair ofcurved bores 98 communicating withchannel 96.Fluid carrying tube 18*is threaded to said'bore and is received in thechannel 96. Said channel is relatively shallow, so that portions of saidfluid carrying tube 18 extend laterally out of said channel for engagement by thecylindrical portion 84 ofrollers 82, as said rollers are rotated thereby. When so engaged, tube 18-is flattened and compressed between said rollers and'theinner wall 100 ofchannel 96. The pumping operation of the embodiment of FIGS. 6 8 is thus identical to the pumping operation of the embodiment of FIGS. 1 5.Cassette 88 is mounted onhousing 22 ofpump 80 by means of fourupstanding posts 102 which project from the top of said housing. Each of said posts is provided with a spring loadeddetent 104 which engagesa corresponding recess incassette member 90 to releasably retain cassette member 88in position. The cassette is mounted and removed by graspinghandle 92 and displacing said cassette along the principal axis defined by drive shaft 32' toward or away fromhousing 22. Theconical surface 86 ofrollers 82 permit the fluid carrying tube to ride therealong and to be gradually compressed and released, and also serves as a centering device for the positioning of the cassette.

In the alternative,rollers 82 may be substantially cylindrical but mounted for radial displacement relative to the principle axis ofdrive shaft 32. In such an embodiment, the pancake shapedcassette member 90 would be positioned around the fluid drive assembly and the rollers would be displaced outwardly into the Referring now to FIGS. 9-12 of the drawings, a third embodiment of the medical cassette pump according to the invention is depicted. Said third embodiment is similar in structure to the embodiment of FIGS. 1-5, but is particularly adapted for the simultaneous pumping of fluid in two separatefluid carrying tubes 112 and 114. As best shown in FIG. 11, thefluid drive assembly 116 is provided with two sets of threerollers 118 and 120, one roller of each set being mounted on acommon shaft 122 for free rotation thereabout. Each of saidcommon roller shafts 122 are secured to ahub member 124, which in turn is mounted ondrive shaft 125 for rotation thereby. The hingedcassette 126 is provided with a pair ofcassette half members 128, each of which is provided along a portion of the inner periphery thereof'with a pair ofchannels 130 and 132 each of which is dimensioned to receive the corre-Cassette 126 also differs fromcassette 48 of the embodiment of FIGS. 1 5 in that the bores ofcassette 48 are dispensed with, and replaced by open notches 142 which communicate withchannels 130 and 132. This construction permits the insertion of the fluid carrying tubes without threading through the cassette, and further permits the permanent mounting of the cassette on the housing, by means ofpin 136. In order to position and retain the fluid carrying tubes and to permit their easy insertion and removal from thepump 110, atab member 144 is provided.Tab 144 is formed with four apertures 146 therethrough positioned in two aligned spaced pairs. Each offluid carrying tubes 112 and 114 are threaded through one of the pairs of apertures 146 to define a loop in each of said tubes which extends respectively aroundrollers 118 and 120,-so that when the twocassette half members 128 are brought together, said loops are respectively received withinchannels 130 and 132 and are engaged respectively by rollers I18 and 120.Tab 144 is provided with ahandle portion 148 and is also adapted to serve a further safety switching function. For this purpose,tab 144 is provided with a' projectingfinger 150 as best shown in FIGS. 9 and 12. Said finger projects through anaperture 152 inhousing 134 into aswitch block 154. As shown in FIG. 12,finger 150 engages adisplaceable switch member 156 against a fixedswitch member 158 to close an enabling circuit, which when open, will not permit the motor to operate. Said switching circuit is connected byleads 160 and 162 to the drive motor of the pump.Displaceable contact 156, is in the form of a leaf spring, which will displace to the open position whenfinger 150 oftab member 144 is not present. This structure insures that the pump will only operate when the fluid carrying tubes are properly positioned. It is noted that a tab arrangement such astab 144 may also be incorporated inchannel 96 to engage the fluid carrying tube against a medical cassette pump according to the invention incorporating only a single fluid carrying tube, if desired. The two-tubeembodiment of FIGS. 9-12 permits the coordinate suction and delivery of fluids, and would be particularly useful in washing out cavities such as the stomach and the like, and in particular, in drug or poison cases where the stomach must be washed out rapidly. Further, the two sets of planetary rollers could be mounted on separate hubs joined by a clutch mechagle tube as shown above, or concentric tubes one within the other; Two, three or more tubes may be coordinately driven by embodiments of the pump according to the invention. Closed disposable delivery and collection systems may be provided with the fluid receptical, fluid carrying tube and fluid passage means such as a catheter all formed as a unit. The medical cassette pump according to the invention provides a flexible efficient and sanitary pumping system which may be utilized for a wide-range of medical and other functrons.

. It will thus be seen that the objects set forth above, and those .made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained'in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in the limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

l. A medical cassette pump comprising drive means; a fluid drive assembly operatively coupled to said drive means for rotation thereby about a principal axis, said fluid drive assembly including at least two planetray rollers freely rotatably mounted in space relation to said principal axis and to each other, said planetary rollers being formed with a cylindrical portion and a conical portion extending from one end of said cylindrical portion; a fluid carrying tube; and displaceable cassette means for releasably engaging said fluid carrying tube against the cylindrical portion of at least one of said planetary rollers for the displacement of said fluid therealong, saidcassette means being formed with a central opening therein dimensioned to receive said fluid drive assembly, a portion of the inner periphery of said central opening being defined by a channel facing said principal axis dimensioned to receivesaid fluid carrying tube with portions thereof extending laterally from said channel for the gradual riding on and compression of said fluid carrying tube by the conical portion of at least one of said planetary rollers as said cassette means is displaced along said principal axis until said channel is in registration with said cylindrical portion of said planetray rollers.

2. A medical cassette pump as recited inclaim 1, wherein said cassette includes an annular body having said central opening and channel therein, said body being formed with a pair of spaced bores therethrough providing communication to said channel and dimensioned to receive said fluid carrying tube.

Claims (2)

1. A medical cassette pump comprising drive means; a fluid drive assembly operatively coupled to said drive means for rotation thereby about a principal axis, said fluid drive assembly including at least two planetray rollers freely rotatably mounted in space relation to said principal axis and to each other, said planetary rollers being formed with a cylindrical portion and a conical portion extending from one end of said cylindrical portion; a fluid carrying tube; and displaceable cassette means for releasably engaging said fluid carrying tube against the cylindrical portion of at least one of said planetary rollers for the displacement of said fluid therealong, said cassette means being formed with a central opening therein dimensioned to receive said fluid drive assembly, a portion of the inner periphery of said central opening Being defined by a channel facing said principal axis dimensioned to receive said fluid carrying tube with portions thereof extending laterally from said channel for the gradual riding on and compression of said fluid carrying tube by the conical portion of at least one of said planetary rollers as said cassette means is displaced along said principal axis until said channel is in registration with said cylindrical portion of said planetray rollers.

2. A medical cassette pump as recited in claim 1, wherein said cassette includes an annular body having said central opening and channel therein, said body being formed with a pair of spaced bores therethrough providing communication to said channel and dimensioned to receive said fluid carrying tube.

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