US3664339A - Drip chamber and method - Google Patents

Abstract

A drip chamber having a flexibly resilient sleeve with memory and one-way inlet and outlet valves in each end of the sleeve, the valves respectively being in communication with a fluid source and an infusion tube. A control unit can be fingeractuated to determine a continuous drip at a constant rate from the inlet to the outlet valve. The method includes squeezing the sleeve to force fluid through the outlet valve into the infusion tube and thereafter allowing the sleeve to expand to draw fluid through the inlet tube into the sleeve.

Description

United States Patet 51 May 23, 1972 2,784,733 3/1957 Martinez r. 1 37/399 FOREIGN PATENTS OR APPLICATIONS 1,235,482 5/1960 France 128/214 1,118,247 3/1956 France ..l28/2l4 Primary Examiner-Dalton L. Truluck Att0rney-Lynn G. Foster [57] ABSTRACT A drip chamber having a flexibly resilient sleeve with memory and one-way inlet and outlet valves in each end of the sleeve, the valves respectively being in communication with a fluid source and an infusion tube. A control unit can be finger-actuated to determine a continuous drip at a constant rate from the inlet to the outlet valve. The method includes squeezing the sleeve to force fluid through the outlet valve into the infusion tube and thereafter allowing the sleeve to expand to draw fluid through the inlet tube into the sleeve.

5 Claims, 9 Drawing Figures PATENTEUMAY 2 3 I972 INVENTOR.

LOUIS S. SANTO ERI BY I ATTORNEY DRIP CHAMBER AND METHOD BACKGROUND 1. Field of the Invention The invention relates to medical infusion apparatus and more particularly to a novel infusion fluid drip chamber and method.

2. The Prior Art It is well known to use drip chambers with infusion apparatus for accommodating visual observation of the rate at which infusion fluid is conducted into a patient. Conventional drip chambers are normally a generally cylindrical enlargement of an infusion tube and are in direct open communication simultaneously with a source of infusion fluid and with the end of the infusion tube used to penetrate the patients circulatory system. A constricted opening in the drip chamber causes the fluid to flow through the chamber in droplets. It has been common practice to place a filter within the drip chamber to filter the fluid droplets as they fall by gravity through the chamber.

The rate at which the fluid drips through the chamber is most frequently determined by a pinch valve or the like located on a portion of the infusion tube between the drip chamber and the fluid source.

Frequently, it is necessary or desirable to force infusion fluid such as blood into the patient at a rapid rate. This is particularly true where physical injury to the patient has caused loss of a dangerous volume of blood. Until this present invention it has be necessary to use auxiliary pumping apparatus for delivering the fluid to the patient. For example, a hypodermic syringe can be used to rapidly inject the fluid. If the fluid is plasma, isotonic saline or the like, it becomes necessary to perform repeated venipunctures in order to rapidly inject the increased fluid volume. The use of the hypodermic syringe is not a safe way of rapidly infusing a large volume of whole blood because use of the hypodermic syringe causes hemolysis of the blood cells.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION The present invention, including apparatus and method, includes a flexible drip chamber having an interiorly confined control unit and spaced unidirectional valves so that infusion fluid is pumped when the chamber is finger-squeezed to force fluid within the chamber into an attached infusion tube and thereafter expanded to draw fluid from the source into the chamber.

It is therefore a primary object of the present invention to provide an improved drip chamber and method.

It is another object of the present invention to provide a novel drip chamber and method which accommodate safe, forceful pumping of infusion fluid into a patient.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic representation of infusion apparatus shown infusing fluid into a patients arm;

FIG. 2 is a perspective illustration of a presently preferred drip chamber embodiment of the invention;

FIGS. 3-6 are longitudinal cross sections respectively taken along lines 3-3, 44, 5-5 and 6-6 of FIG. 2;

FIG. 7 is a cross sectional illustration of another presently preferred unidirectional valve embodiment of the invention;

FIG. 8 schematically illustrates the method of pumping fluid through the drip chamber; and

FIG. 9 is still another unidirectional valve embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference is now made to the several embodiments of the invention as illustrated in the Figures, like parts being designated with like numerals throughout.

THE STRUCTURE The infusion apparatus generally designated 16 conveys infusion fluid from a source such as a bottle 18 through a conventional infusion tube 20 to an intravenous needle 22 which has previously been properly placed within the vein of a patients arm 24. Infusion fluid, as used herein, means isotonic saline, blood, plasma or any other biologically acceptable fluid used for medical treatment of patients. The bottle 18 is normally suspended in the air so that the fluid contained thereby falls by force of gravity through the infusion tube 20. Preferably, a drip chamber generally designated 26 is interposed between the infusion tube 20 and the bottle 18.

The drip chamber 26 is best illustrated in FIG. 2 and preferably comprises a cylindrically shaped sleeve 28 which is formed of transparent plastic material with memory, the sleeve 28 being elongated and terminating in upper and lower ends 30 and 32 respectively. An annular collar 34 is situated adjacent the end 30, collar 34 having four radially projecting ribs 36. The sleeve 28 is heat sealed or otherwise connected to the collar 34 and ribs 36 in a fluid-tight relation.

The collar 34 circumscribes a portion of conduit 38. A portion of the conduit 38 projects out of the sleeve 28 through the collar 34 and comprises a conically tapered tip 40 which is used to penetrate the rubber seal (not shown) in the neck 42 (FIG. 1) of the bottle 18. The exposed portion of conduit 38 has at least one elongated slot 44 which allows fluid within the bottle 18 to enter the interior of conduit 38. Conduit 38 is integrally connected to and in fluid communication with the interior of a control unit generally designated 46. The control unit has spaced annular discs 48 and 50 which urge the sleeve 28 outwardly away from the cylindrical central portion 52 of the unit 46. Central portion 52 has opposed annular bosses 58 and a transverse bore 54 opening to the exterior of the unit central of each boss 58.

A spool valve 56 is reciprocably situated within the bore 54, the spool valve 56 having a transverse through-bore (not shown) which is incrementally displaced into and out of alignment with the hollow interior of conduit 38. Thus, the amount of fluid flowing from the bottle 18 through the conduit 38 to the interior of sleeve 28 may be selected by finger-squeezing the sleeve 28 between discs 48 and 50 to axially displace the spool valve 56 until the desired drip rate is achieved, as will be subsequently more fully described.

As shown in FIGS. 3 and 4, the interior of central portion 52 is in open communication with the open end 39 of a terminal projection 60 disposed through an aperture 62 in the disc 50. The projection 60 has opposed inwardly tapered sides 64 which converge to a point 66. The projection 60 is annularly reduced adjacent the tapered sides 64 so as to form a recess 68. A length of highly flexible rubber tubing 70 is concentrically surmounted upon the recess 68 and preferably bonded to the projection 60 in the position illustrated in FIGS. 3 and 4. The tube 70 is substantially longer than the recess 68 so that the free end 72 is allowed to flex and bend.

The sloping sides 64 cause the flexible tube 70 to converge toward the free end 72. The projection 60 and tube 70 cooperate to form a unidirectional flutter or flap valve which closes to the solid line position illustrated in FIG. 3 when the pressure exterior of the valve is greater than the pressure exerted by the fluid within projection 60 and which opens to the dotted line position of FIG. 3 when the pressure exterior of the tube 70 drops below the pressure exerted by the fluid within the projection 60. When the tube 70 opens to the dotted line position, fluid is allowed to flow through the opening 74 in the free end 72 of the tube.

Reference is now made to FIGS. 5 and 6 wherein a second unidirectional valve assembly generally designated 76 is illustrated. Valve assembly 76 comprises a valve housing 78 which is cylindrical in configuration and which is adapted to telescopically receive the sleeve 28. An annularly enlarged flange 80 integral with the housing 78 provides a seat for the sleeve 28 and, preferably, the sleeve 28 is bonded or otherwise sealed in fluid-tight relation to the housing 78. Housing 78 has a conically tapered intermediate portion 82 which merges with an outwardly projecting boss 84. The tapered intermediate portion 82 defines an annular shoulder 86 upon which a filter cone 88 is disposed. The filter cone 88 is preferably formed of a mesh fabric material having a cylindrical base 90 which telescopes tightly over the boss 84. Cone 88 also has outwardly directed corners 92, the sides of the cone converging to an apex 94. The configuration of the filter is particularly advantageous because maximum filtration can be accomplished with a minimum of exposed surface area of the filter material. The filter removes fibrin and clot material which may exist in blood communicated through the drip chamber 26 and also serves to insure that foreign particles which may exist in other intravenous fluid material do not enter the infusion tube 20.

The housing 78 is interiorly hollow comprising cylindrical bore 96 in the boss 84 which diverges outwardly at 98 to the diametrally enlarged cylindrical bore 100. The bore 100 is in open communication with a hollow conduit 102 interior of a downwardly projecting male coupling 104. The infusion tube 20 is press-fit upon the male coupling 104 as illustrated in FIGS. 2 and 6.

A highly flexible synthetic tube 106, which may be substantially the same as rubber tube 70 above described, is bonded to the periphery of the bore 96 so as to project into the bore 100. The tube 106 functions as a flutter valve so that when fluid pressure within the bore 100 is greater than the fluid pressure conducted through the bore 96, the valve 106 will be collapsed, thereby preventing fluid from backing to the interior of sleeve 28. Conversely, when the pressure within the sleeve 28 is greater than pressure in the bore 100, fluid will flow freely through the opening 108 to the infusion tube 20.

Alternatively, the unidirectional valve embodiment illustrated in FIG. 7 and generally designated 110 could be used. The valve 110 differs from the valve 76 in that the rubber tube 106 has been replaced with a buoyant spherical ball 112. The ball 112 has a diameter which is smaller than the diameter of bore 100 and larger than the diameter 96. Thus, as fluid 114 is backed up into the bore 100, the ball 112 will seat at the juncture of bore 96 and diverging bore 98 as shown in FIG. 7 thereby preventing the fluid 114 from flowing interior of the sleeve 28.

Another presently preferred unidirectional valve embodiment is illustrated in FIG. 9 and is generally designated 116. The valve 116 differs from the valve embodiment 76 in that elongated male coupling 104 is replaced with a shorter male coupling 118 upon which is telescoped the infusion tube 20. If desired, the infusion tube may be bonded or otherwise permanently attached to the male coupling 118. The opening 120 between the bore 100 and the exterior of male coupling 118 provides a location for bonding the rubber tube 106 in a manner substantially identical to the bonding of tube 106 in the bore 96 as above described. In the FIG. 9 embodiment, the tube 106 projects directly to the interior of the infusion tube 20 and assumes an open or closed position depending upon the pressure within the tube 20.

THE M ETHOD With continuing reference to FIGS. 1-6 and with particular reference to FIG. 8, the method of the present invention will now be described. The described embodiments of the invention accommodate a regulated, continuous drip from the flutter valve 70 into the interior of sleeve 28. The rate at which the fluid drips into the sleeve 28 will depend upon the particular position of spool valve 56 within the bore 54. Once the position has been set, it is protected from inadvertent displacement by the radially projecting discs 48 and 50.

When it is desired to change or otherwise adjust the setting of spool valve 56, the fingers may be positioned between the discs 48 and 50 and the sleeve 28 thereafter squeezed between the fingers until the spool valve 56 can be manually displaced in either axial direction to adjust the drip rate.

Frequently, it is desirable to accelerate the flow of fluid through the infusion tube 20 into the patients arm 24 (FIG. 1). This is accomplished by first partially filling the sleeve 28 with fluid 114 as shown in FIG. 8. Thereafter, the thumb and forefinger 122 and 124, respectively, may be placed on opposite sides of the sleeve 28 and the sleeve squeezed as shown in FIG. 8.

As the sleeve 28 is forcefully collapsed, the pressure interior of sleeve 28 will be sufficiently great to force open flutter valve 106 (FIGS. 5 and 6) or to force the ball 112 (FIG. 7) away from its seated position so that fluid will be forced into the tube 20. At the same time, the increased pressure within the sleeve 28 will force the flutter valve to the collapsed or closed position as shown in solid lines in FIG. 3, thereby preventing air within sleeve 128 from being conducted to the interior of the bottle 18. Thus, since air is confined within the sleeve 28, substantial pressure can be developed within the sleeve 28 by collapsing the sleeve only a relatively small amount.

After a volume of fluid has been forced into the infusion tube 20, the fingers may be removed from the sleeve 28 thereby allowing the sleeve, by force of the memory of the material forming sleeve 28, to return to the configuration illustrated in FIG. 2. As sleeve 28 expands to the FIG. 2 configuration, the pressure interior of sleeve 28 will be substantially reduced thereby allowing fluid to flow through conduit 38 and valve 70 in a stream to the interior of sleeve 28. At the same time, the reduced pressure within the sleeve 28 will cause the flutter valve 106 to collapse as shown in FIGS. 5 and 9 or, if the FIG. 7 embodiment is used, the ball 112 will seat. Thus, fluid within the valve 20 cannot be drawn again into the interior of the sleeve 28.

When equilibrium pressure is reached within the sleeve 28, fluid will again assume a continuous constant drip from the flutter valve 70 to the interior of sleeve 28 and flutter valve 106 will allow fluid to pass slowly into the tube 20. Alternatively, the ball 112 will be unseated at equilibrium pressure so that fluid will flow into the tube 20 as described above. It is clear that repeatedly squeezing and releasing the sleeve 28 will cause the fluid to flow, pulsating under pressure through the infusion tube 20 into the patients arm 24. Thus, the present invention provides unitary structure and simplified method for pumping infusion fluid through an infusion tube under pressure and, when pumping is no longer necessary, a uniform drip flow will be conducted through the infusion tube 20.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. A drip chamber for use with intravenous infusion apparatus comprising:

an elongated tube of flexible material with memory in fluid communication with a source of infusion fluid through an upper end coupling and in fluid communication with an infusion tube through a lower end coupling,

a first one-way valve delivering fluid from the source to the interior of the tube,

second one-way valve delivering fluid from the interior of said tube to the infusion tube, and

flow rate regulating means located within said tube interposed between said upper end coupling and said first oneway valve and formed with upper and lower radial flanges extending transversely of said tube and a central portion of lesser diameter than said flanges extending longitudinally of said tube between said flanges formed with axial and transverse intersecting bores and having a finger-positionable flow regulating member positioned within said transverse bore to regulate the rate of flow of fluid to said first one-way valve.

2. The drip chamber of claim 1 wherein said tube is manually deformable intermediate said first and second oneway valves to permit manual pumping of fluid through said drip chamber.

3. A drip chamber for use with intravenous infusion apparatus comprising:

an exterior wall of flexible material with memory formed into a closed sleeve, the sleeve being adapted to be in fluid communication with a source of intravenous fluid through an upper end coupling and adapted to be in fluid communication with an infusion tube through a lower end coupling, the upper and lower end couplings forming a fluid-tight seal in the respective sleeve ends;

a first one-way valve delivering fluid from the source to the interior of the sleeve;

a second one-way valve delivering fluid from the interior of the sleeve to the infusion tube;

at least one of said one-way valves comprising a unidirectional flap valve, the lumen of which is normally occluded and is selectively additionally occluded by collapsing of the walls of the flap valve as a result of pressure on the outside of the walls of the flap valve, the lumen being selectively dialated by pressure on the inside of the walls of the flap valve, and flow rate regulating means located within said sleeve interposed between said upper end coupling and said first one-way valve and formed with upper and lower radial flanges extending transversely of said tube and a central portion of lesser diameter than said flanges extending longitudinally of said tube between said flanges formed with axial and transverse intersecting bores and having a finger positionable flow regulating member positioned within said transverse bore to regulate the rate of flow of fluid to said first one-way valve.

4. A chamber is defined in claim 3 wherein the second valve comprises a ball check valve and the first valve comprises said flap valve.

5. A chamber as defined in claim 3 wherein each one-way valve comprises one said flap valve.

Claims (5)

1. A drip chamber for use with intravenous infusion apparatus comprising: an elongated tube of flexible material with memory in fluid communication with a source of infusion fluid through an upper end coupling and in fluid communication with an infusion tube through a lower end coupling, a first one-way valve delivering fluid from the source to the interior of the tube, second one-way valve delivering fluid from the interior of said tube to the infusion tube, and flow rate regulating means located within said tube interposed between said upper end coupling and said first one-way valve and formed with upper and lower radial flanges extending transversely of said tube and a central portion of lesser diameter than said flanges extending longitudinally of said tube between said flanges formed with axial and transverse intersecting bores and having a finger-positionable flow regulating member positioned within said transverse bore to regulate the rate of flow of fluid to said first one-way valve.

2. The drip chamber of claim 1 wherein said tube is manually deformable intermediate said first and second one-way valves to permit manual pumping of fluid through said drip chamber.

3. A drip chamber for use with intravenous infusion apparatus comprising: an exterior wall of flexible material with memory formed into a closed sleeve, the sleeve being adapted to be in fluid communication with a source of intravenous fluid through an upper end coupling and adapted to be in fluid communication with an infusion tube through a lower end coupling, the upper and lower end couplings forming a fluid-tight seal in the respective sleeve ends; a first one-way valve delivering fluid from the source to the interior of the sleeve; a second one-way valve delivering fluid from the interior of the sleeve to the infusion tube; at least one of said one-way valves comprising a unidirectional flap valve, the lumen of which is normally occluded and is selectively additionally occluded by collapsing of the walls of the flap valve as a result of pressure on the outside of the walls of the flap valve, the lumen being selectively dialated by pressure on the inside of the walls of the flap valve, and flow rate regulating means located within said sleeve interposed between said upper end coupling and said first one-way valve and formed with upper and lower radial flanges extending transversely of said tube and a central portion of lesser diameter than said flanges extending longitudinally of said tube between said flanges formed with axial and transverse intersecting bores and having a finger positionable flow regulating member positioned within said transverse bore to regulate the rate of flow of fluid to said first one-way valve.

4. A chamber is defined in claim 3 wherein the second valve comprises a ball check valve and the first valve comprises said flap valve.

5. A chamber as defined in claim 3 wherein each one-way valve comprises one said flap valve.

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