Pressurized fluid delivery apparatus

Information

  • Patent Grant
  • 6401975
  • Patent Number
    6,401,975
  • Date Filed
    Friday, August 17, 2001
    23 years ago
  • Date Issued
    Tuesday, June 11, 2002
    22 years ago
Abstract
A fluid delivery apparatus is provided that includes a pressure tube and a first cap assembly having a control system, with the first cap assembly coupled to a first end of the pressure tube for forming a gas-tight seal thereat. The apparatus also includes a second cap assembly coupled to a second end of the pressure tube for forming a gas-tight seal thereat, with the second cap assembly supporting a fluid container that is housed in the interior space of the pressure tube.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates generally to fluid delivery apparatus, and in particular, to a fluid delivery system in which direct and uniform pressure can be applied onto the surface of a flexible container, to cause the fluid contained inside the flexible container to be delivered therefrom.




2. Description of the Prior Art




Effective and reliable fluid delivery is important in many applications, but is especially important in the medical field. Fluid delivery is often a critical and essential part of many medical procedures and in the care of patients. The most basic application is in the delivery of fluids, such as saline, blood or other medicine, that are stored in a flexible bag. Such fluids are often delivered intravenously to a patient during medical procedures, or during recovery or other treatments.




There currently exists several fluid delivery systems that are used to deliver fluids to a patient. One such system utilizes a pump to deliver the fluids from a fluid bag. However, fluid pumps can be expensive and subject to mechanical or other failure.




Other systems utilize bladders which are inflated or otherwise pressurized to expand and thereby impinge (i.e., apply pressure) on a fluid bag, causing fluid from the fluid bag to be expelled therefrom. However, such systems suffer from the drawback that the pressure applied to the fluid bag is not uniform and consistent, so that folds in the material of the fluid bag can develop as fluid is being expelled. This results in inconsistent flow of fluid from the fluid bag.




Thus, there still remains a need for a fluid delivery system in which pressure is provided in an effective and reliable manner.




SUMMARY OF THE DISCLOSURE




It is an object of the present invention to provide a fluid delivery apparatus in which pressure is provided in an effective and reliable manner.




It is another object of the present invention to provide a fluid delivery apparatus in which pressure is provided in a direct and uniform manner.




It is yet another object of the present invention to provide a fluid delivery apparatus which is simple to use, and which reduces the costs of the apparatus.




In order to accomplish the objects of the present invention, the present invention provides a fluid delivery apparatus that includes a pressure tube, and a first cap assembly having a control system, with first cap assembly coupled to a first end of the pressure tube for forming a gas-tight seal thereat. The apparatus also includes a second cap assembly coupled to a second end of the pressure tube for forming a gas-tight seal thereat, with the second cap assembly supporting a fluid container that is housed in the interior space of the pressure tube.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a front perspective view of a fluid delivery apparatus according to a first embodiment of the present invention.





FIG. 2

is a rear perspective view of a fluid delivery apparatus of FIG.


1


.





FIG. 3

is an exploded front perspective view of a fluid delivery apparatus of FIG.


1


.





FIG. 4

is a perspective view of an embodiment of the bottom cap assembly for the fluid delivery apparatus of

FIGS. 1 and 3

.





FIG. 5

is a perspective view of another embodiment of the bottom cap assembly for the fluid delivery apparatus of FIG.


1


.





FIG. 6

is a perspective view of a hanger assembly that can be used with the bottom cap assembly of FIG.


4


.





FIG. 7

is a perspective view of another hanger assembly that can be used with the bottom cap assembly of FIG.


4


.





FIG. 8

is a perspective view of yet another hanger assembly that can be used with the bottom cap assembly of FIG.


4


.





FIG. 9

is a perspective view of the hanger and bottom cap assemblies of

FIG. 7

shown in use with a fluid container suspended therefrom.





FIG. 10

is a cross-sectional view of the control system of the fluid delivery apparatus of FIG.


1


.





FIG. 11

is a cross-sectional view of a portion of the fluid delivery apparatus of

FIG. 1

illustrating its operation.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




The following detailed description is of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating general principles of embodiments of the invention. The scope of the invention is best defined by the appended claims. In certain instances, detailed descriptions of well-known devices, compositions, components, mechanisms and methods are omitted so as to not obscure the description of the present invention with unnecessary detail.




The present invention provides a fluid delivery apparatus


20


that utilizes pressure to cause fluid from a fluid container to be delivered therefrom. The fluid delivery apparatus applies direct and uniform pressure onto most of the entire surrounding surface area of the outer surface of the fluid container, thereby promoting the application of uniform pressure onto the fluid container to ensure the effective and reliable delivery of fluid.





FIGS. 1-3

illustrate a fluid delivery apparatus


20


according to one embodiment of the present invention. In this embodiment, the apparatus


20


is a system that includes three basic assemblies or components: a control system


22


that is embodied in a top cap assembly


30


, a pressure tube


24


, and a bottom cap assembly


26


. The control system


22


can be embodied in a top cap assembly


30


that is illustrated in greater detail in FIG.


10


. The top cap assembly


30


forms a seal for one (i.e., top) end of the pressure tube


24


.




The pressure tube


24


is generally cylindrical, and defines an inner chamber


31


(see

FIG. 11

) that functions to house or retain a fluid container


32


(which is described in greater detail below), and to promote the application of pressure onto the fluid container


32


such that the pressure is applied over 360 degrees around the circumference of the fluid container


32


, and along at least 75 percent of the length of the fluid container


32


. The pressure tube


24


is preferably made from a material that is capable of withstanding at least 20 percent more gas exerted load than the fluid container


32


without experiencing volumetric distortion. The greater load bearing capacity of the pressure tube


24


ensures that the gas pressure created inside the pressure tube


24


is effectively transferred to the outer surface of the fluid container


32


. In addition, the stable volumetric design of the pressure tube


24


also ensures that proper and stable pressure is exerted onto the fluid container


24


during use.




The bottom cap assembly


26


functions to form a seal for the other (i.e., bottom) end of the pressure tube


24


, and includes a mechanism for puncturing the fluid container


32


to couple the fluid contained in the fluid container


32


with a fluid transfer line


34


. The fluid transfer line


34


can be an IV line that is inserted inside the body of a patient to deliver the fluid from the fluid container


32


to the patient.




Referring to

FIG. 3

, the bottom cap assembly


26


can also include a hanger assembly


80


that functions to hold and support the fluid container


24


in a manner that promotes the uniform application of pressure onto most of the entire surrounding surface area of the outer surface of the fluid container


32


. The hanger assembly


80


, and alternatives thereof, will be described in connection with

FIGS. 6-8

below. As shown in

FIG. 3

, the top cap assembly


30


of the control system


22


can be coupled to the top


38


of the pressure tube


24


to form a gas seal, and the bottom cap assembly


26


can be removably coupled to the bottom


40


of the pressure tube


24


to form another gas seal.




The bottom cap assembly


26


will now be described in connection with FIG.


4


. The bottom cap assembly


26


has a bottom wall


46


and a circumferential wall


48


extending therefrom to form a dish-like configuration. Threads


50


can be provided on the internal surface of wall


48


for engaging the bottom


40


of the pressure tube


24


, and a gasket


52


can be provided at the base of the wall


48


against the bottom wall


46


. The gasket


52


is used to form the gas-tight seal for the bottom


40


of the pressure tube


24


. A plurality of legs


54


can be provided in spaced-apart manner about the circumference of the bottom wall


46


to raise the bottom cap assembly


26


(and therefore, the apparatus


20


) above a supporting table top or other surface, so that there is room under the bottom wall.


46


for the fluid line


34


to pass from the bottom wall


46


to the patient. The bottom wall


46


can further include a domed section


56


at about the center thereof, with a spike


58


provided at and extending vertically upwardly from the domed section


56


. The spike


58


may be embodied in the form of a thin generally cylindrical tube having an angled top end


60


that defines a sharp tip that can be used to pierce the spike port of the fluid container


32


. A guide tube


70


extends from the bottom wall


46


, and can be used to guide and receive a support pole


72


, such as that shown in FIG.


7


.




As described above, the bottom cap assembly


26


has internal threads


50


that can be threaded to external threads


62


provided on the outer surface of the pressure tube


24


to secure the bottom cap assembly


26


to the bottom


40


of the pressure tube


24


. However, to assist in this engagement, and to thereby increase the safety and reliability of the apparatus


20


, two or more spaced-apart clips


64


can be provided. Each clip


64


extends vertically upwardly from the wall


48


and has a flange


66


that extends radially inwardly and which is adapted to clip onto corresponding notches (not shown) provided on the outer surface of the pressure tube


24


(see FIG.


3


). In use, when the bottom cap assembly


26


is initially inserted into the bottom


40


of the pressure tube


24


, the flanges


66


clip into the notches to temporarily grip or hold the pressure tube


24


while the user tightens the threaded connection between threads


50


and


62


. Once the user turns bottom cap assembly


26


to engage the threads


50


and


62


, the flanges


66


come out of the notches and the threaded connections take over the responsibility of gripping the pressure tube


24


. The gas-tight seal is created by the gasket


52


after the threaded engagement has been completed.





FIG. 5

illustrates another possible embodiment of a bottom cap assembly


26




a


. Assembly


26




a


is essentially the same as assembly


26


, so the same elements are designated by the same numerals except that an “a” has been added in FIG.


5


. Assembly


26




a


differs from assembly


26


in that the spike


58




a


is deflected at its top end


60




a


. The deflected top end


60




a


can be helpful in mounting the fluid container


32


onto the spike


58




a


. For example, where the fluid container


32


is a conventional sterile fluid bag, these sterile fluid bags are provided with a standardized spike port through which the spike


58




a


is to be inserted. A deflected top end


60




a


assists in the mounting procedure because it provides direct access to the spike port.




A hanger assembly can be coupled to the bottom cap assembly


26


to support a fluid container


32


. The hanger assemblies described herein are provided in an integrated manner with the spike


58


(via the bottom cap assembly


26


), which makes it easier and more convenient to install the fluid container


32


inside the pressure tube


24


for use.




One example of a hanger assembly


80


is shown in FIG.


6


. The hanger assembly


80


has a U-shaped support arch


82


that acts as a frame. The two legs


84


,


86


of the support arch


82


can be mounted to the bottom wall


46


of the bottom cap assembly


26


. A hanging loop


88


can be provided at the top of the support arch


82


for hanging the support arch


82


(and the bottom cap assembly


26


) to a hook (not shown) provided inside the pressure tube


24


or from the top cap assembly


30


(e.g., from wall


140


described below). A hook


90


can be provided at the top of the support arch


82


for hanging the fluid container


32


.




Another example of a hanger assembly


96


is shown in FIG.


7


. The hanger assembly


96


has a support pole


98


having a bottom end that is received inside the guide tube


70


of the bottom cap assembly


26




a


. A cantilevered arm


100


is provided at the top end of the support pole


98


. As with support arch


82


, a hanging loop


102


and another loop


104


can be provided on the cantilevered arm


100


.




Yet another example of a hanger assembly


108


is shown in FIG.


8


. The hanger assembly


108


has an arcuate support wall


110


having a bottom end that is mounted to the bottom wall


46


of the bottom cap assembly


26


. A cantilevered arm


112


is provided at the top end of the support wall


110


. As with support arch


82


, a hanging loop


114


and another loop


116


can be provided on the cantilevered arm


112


. The arcuate nature of the support wall


110


allows the flexible fluid container


32


to be rested on the wall


110


when the apparatus


20


is laid flat on its side on a table or other surface. To facilitate this, the wall


110


should be positioned on the bottom wall


46


of the bottom cap assembly


26


at a slight angle to the fluid port


148


(see

FIG. 2

) in the control system


22


so that the fluid will flow towards the port


148


when the entire apparatus


20


is laid flat on its side.





FIG. 9

illustrates the bottom cap assembly


26




a


and hanger assembly


96


in use, holding a fluid container


32


. The fluid container


32


can be any flexible or compliant fluid container, including standard sterile fluid or IV bags made by Baxter Healthcare Corp. of Illinois, Abbott Laboratories of Illinois, and B. Braun of Germany, among others. In

FIG. 9

, the fluid container


32


is embodied in the form of a sterile fluid bag, such as an IV bag or a blood bag. As shown in

FIG. 9

, the fluid container


32


has a bar


120


provided at its top end which can be suspended from the hook


104


. In addition, the spike


58




a


has been inserted through the spike port adjacent the bottom end of the fluid container


32


.




The top cap assembly


30


and control system


22


will be described with reference to

FIGS. 1

,


2


and


10


. The top cap assembly


30


has a lower housing


130


and an upper housing


132


. The lower housing


130


defines a cylindrical bore


134


having internal threads


136


that are adapted to engage external threads provided on the outer surface of the pressure tube


24


. A gasket


138


is also provided at the top of the bore


134


adjacent the wall


140


that divides the lower and upper housings


130


,


132


.




Inside the upper housing


132


is provided an air pressure regulator


142


that is supported on the wall


140


. The air pressure regulator


142


operates to maintain constant pressure in the apparatus


20


. An air regulator knob


144


is coupled to the top of the air pressure regulator


142


, and allows the user to adjust the incoming air down to the required pressure rating used for the apparatus


20


. An air line


146


extends through a first port


148


(see

FIG. 2

) in the upper housing


132


, and passes through air pressure regulator


142


and a second port


150


in the wall


140


. Thus, the air line


146


communicates between a source


152


and the interior of the pressure tube


24


(i.e., of which the bore


134


becomes a part after the lower housing


130


is threadably engaged with the top


38


of the pressure tube


24


). The source


152


can be a container that is used to contain air, and in the present invention, “air” can be defined to include ambient air and specific gases, such as but not limited to argon, carbon dioxide, and nitrogen. In addition, the upper housing


132


can include an air relief valve


158


that is coupled to a lever arm


160


. The relief valve


158


operates to release pressure in the event the pressure in the apparatus


20


exceeds a pre-determined safety limit (i.e., “over-pressure situation”). Even though the air pressure regulator


142


is expected to maintain constant pressure, the relief valve


158


provides additional safety in the event the air pressure regulator


142


fails or malfunctions. A pressure gauge


162


can be mounted on to the air pressure regulator


142


at a mount hole


164


.




The set-up, use and operation of the apparatus


20


will now be described with reference to

FIGS. 1-3

and


10


-


11


. First, the upper cap assembly


30


can be provided integral with the pressure tube


24


, or can be provided separately, and then secured together by threaded engagement in the manner described above. Thereafter, the user takes the fluid container


32


, hangs it on the appropriate hanger assembly, and then causes the spike


58


or


58




a


to pierce the spike port on the fluid container


32


. The user then takes the bottom cap assembly


26


and its hanger assembly and inserts the hanger assembly and fluid container


32


into the chamber


31


of the pressure tube


24


via the opening in the bottom


40


thereof. The clips


64


initially latch on to the notches


68


, but this is disengaged when the user turns the bottom cap assembly


26


to cause the threads


50


,


62


to engage. After the top and bottom cap assemblies


30


,


26


have been secured in place, a gas-tight seal is created inside the pressure tube


24


, and the apparatus is ready for use.




To begin use, the user turns the air regulator knob


144


, which introduces air from the source


152


into the apparatus


20


. Turning the knob


144


also allows the user to adjust the pressure in apparatus


20


to the desired pressure rating. This adjustment can be viewed at the gauge


162


, which displays the pressure. The air from the source


152


enters the pressure tube


24


via the air line


146


. Referring now to

FIG. 11

, the air that enters the chamber


31


exerts gas pressure on to the wall of the flexible fluid container


32


to cause fluid to be discharged from inside the fluid container


32


. Since the fluid container


32


is supported by a hanger assembly to be positioned at the center of the chamber


31


, uniform gas pressure can be applied (see arrows


170


) to a large portion of the surface area of the fluid container


32


, thereby ensuring that the fluid contained therein is discharged at a consistent flow rate. The fluid is discharged via the spike


58


or


58




a


to the fluid line


34


for delivery to the patient or other intended recipient.




In the event of an over-pressure situation, the air relief valve


158


will open automatically to vent to the atmosphere. Such relief valves and their operations are well-known in the art, and such will not be described in greater detail herein.




When the fluid inside the fluid container


32


has been depleted and it is desired to replace the fluid container


32


, the user can turn the air regulator adjustment knob


144


down to zero pressure, and then manually release the gas (i.e., pressure) from apparatus


20


by pressing on the lever


160


. As shown in

FIG. 10

, the lever is rotatably coupled to the relief valve


158


by a pin


172


, so that when the lever


160


is pressed vertically downward, the relief valve


158


is raised to vent the chamber


31


via a vent port


174


provided in the wall


140


. The supply of air from the source


152


can be turned off either by the air regulator adjustment knob


144


, an on/off switch (not shown, but can be provided), or at the base of the air line


146


. The bottom cap assembly


26


can then be unscrewed from the bottom


40


of the pressure tube


24


, and the fluid container


32


disposed of. In one embodiment, the entire bottom cap assembly


26


and hanger assembly is disposed as well, and a new bottom cap assembly


26


and hanger assembly is introduced together with a new fluid container


32


in the manner described above. In another embodiment, the existing bottom cap assembly


26


and hanger assembly can be re-used by hanging a new fluid container


32


on to the hanger assembly, and securing the existing bottom cap assembly


26


and hanger assembly (with the new fluid container


32


) to the bottom


40


of the pressure tube


24


in the manner described above.




While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.



Claims
  • 1. A method for infusing a therapeutic dose of fluid into a vein, comprising:providing a preselected number of assemblies, each assembly comprising a hangar with a proximal and a distal end, a base to which is mounted the proximal end of the hangar, and a spike integrated with the base, and each assembly being dimensionally adapted for holding at least one container containing fluid suitable for delivery into the vein; providing at least one pressure tube comprising a pressure inlet, an interior chamber and an open end; providing a preselected number of containers containing fluid suitable for delivery into a vein, each container comprising a top end, a bottom end and a spike port; providing an intravenous tubing suitable for delivering fluid into the vein; preparing each of the preselected number of assemblies by loading each assembly with at least one container, said loading comprising the steps of attaching the top end of the at least one container to the distal end of the hanger of each assembly and affixing each container so that it extends axially from the distal end of the hangar to the base in each assembly; positioning the spike port of the at least one container in proximity to the spike of its respective assembly; inserting a first assembly bearing a first container into the at least one pressure tube; sealing the first assembly within the at least one pressure tube with a gas-tight seal; establishing fluid communication between the container and the intravenous tubing; admitting pressurized air into the interior chamber of the at least one pressure tube through the pressure inlet to apply a preselected amount of pressure to the first container; delivering a preselected amount of fluid from the first container into the intravenous tubing; stopping fluid flow from the first container into the intravenous tubing; releasing the pressure within the at least one pressure tube; removing the first assembly from the at least one pressure tube; and repeating the steps of sequentially inserting each of the preselected number of assemblies into the pressure tube, sealing each assembly within the at least one pressure tube, establishing fluid communication between the at least one container carried on each assembly and the intravenous tubing, admitting pressurized air into the interior chamber of the at least one pressure tube, delivering a preselected amount of fluid into the intravenous tubing, stopping the fluid flow, releasing the pressure within the at least one pressure tube and removing each assembly until the therapeutic dose of fluid has been infused into the vein.
  • 2. The method of claim 1, wherein the assembly is disposable.
  • 3. The method of claim 1, wherein the pressure tube is disposable.
  • 4. The method of claim 1, wherein the fluid is a crystalloid.
  • 5. The method of claim 1, wherein the fluid is a colloid.
  • 6. The method of claim 1, wherein the fluid comprises a blood component.
  • 7. The method of claim 6, wherein the blood component comprises blood cells.
  • 8. The method of claim 6, wherein the blood component comprises blood plasma.
Parent Case Info

This application is a divisional application of Ser. No. 09/280,759 filed on Mar. 29, 1999, U.S. Pat. No. 6,276,567 The aforementioned patent application is incorporated herein by reference.

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