Fluid delivery apparatus - Patent Review 5019047

I claim:

1. A device for expelling fluids at a controlled rate comprising:

(a) a base having a width;

(b) a distendable membrane constructed of an elastic material which is fitted over said base to form a chamber having a fluid outlet and a height substantially less than said width of said base, said distendable membrane being distendable in a manner to establish internal stresses therewithin tending to return said membrane to a less distended configuration, whereby fluid will be urged to flow from said fluid outlet; and

(c) flow control means disposed internally of said chamber for controlling the rate of flow of fluid through said outlet, said flow control means comprising a thin permeable member superimposed over said base.

2. A device as defined in claim 1 further including distendable membrane engagement means, disposed intermediate said distendable membrane and said flow control means, for engagement with said distendable membrane

3. A device as defined in claim 2 further including a cover superimposed over said base, said distendable membrane, said distendable membrane engagement means and said flow control means.

4. A device as defined in claim 2 in which said base is generally plate-like in configuration, having at least one fluid flow channel formed therein for conducting fluid toward said outlet.

5. A device as defined in claim 4 in which said distendable membrane engagement means comprises a body portion and at least one upstanding protuberance having a fluid flow opening therein in communication with said fluid flow channel.

6. A device as defined in claim 5 in which said base, said distendable membrane, said distendable member engagement means and said flow control means are yieldably deformable.

7. A device as defined in claim 5 further including a hollow needle operably interconnected with said outlet of said chamber.

8. A device as defined in claim 5 further including a fluid outlet passageway interconnected with said outlet of said chamber and connection means interconnected with said fluid outlet passageway for permitting said device to be connected to an external system.

9. A device for use in infusing pharmaceutical fluids into an ambulatory patient at a controlled rate comprising;

(a) a plate-like base having at least one fluid conduit formed therein, said fluid conduit terminating in a fluid outlet;

(b) a distendable membrane constructed of an elastic material which is fitted over said base to define a chamber, said membrane being at least partially under tension, being distendable by liquid introduced into said chamber under pressure and having a tendency to return to a substantially non-deformed configuration;

(c) at least one fluid flow control means disposed internally of said chamber for controlling the rate of flow of fluid toward said fluid conduit;

(d) means disposed intermediate said distendable membrane and said fluid flow control means for creating an ullage within said chamber; and

(e) infusion means connected to said fluid outlet for infusing fluid into the patient.

10. A device as defined in claim 9 further including filling means connected to said base for introducing fluid under pressure into said fluid chamber.

11. A device as defined in claim 9 in which said fluid flow control means comprises a thin film, planar shaped permeable membrane.

12. A device as defined in claim 10 in which said base is provided with first and second fluid conduits and in which said fluid flow control means comprises first and second permeable members operably associated with said first and second fluid conduits respectively, each of said permeable members having different permeability, whereby the rate of fluid flow through each of said fluid conduits is controllably regulated.

13. A device as defined in claim 10 in which said base and said permeable membrane are yieldably deformable.

14. A device as defined in claim 10 in which said infusion means comprises a hollow needle.

15. A device as defined in claim 14 in which said hollow needle is integral with said base.

16. A device as defined in claim 15 further including an integrally formed web member and needle cover connected to said base, said needle cover being separable from said web member.

17. A device as defined in claim 16 further including adhesive means connected to said base for releasably interconnecting said base to the anatomy of the patient.

18. A device for use in infusing medicinal fluids into a patient at a controlled rate comprising:

(a) a thin, generally planar base having a fluid conduit formed therein, said fluid conduit terminating in a fluid outlet;

(b) means for forming a fluid chamber comprising a thin, generally planar distendable film member superimposed over said base, said member being distendable out of plane by liquid introduced into said fluid chamber under pressure to establish internal stresses in said member said stresses tending to return said member to a less distended configuration;

(c) a thin, generally planar, permeable member of a size substantially corresponding to the size of said base disposed internally of said chamber for controlling the flow of fluid toward said fluid conduit in said base;

(d) a distendable film member engaging element disposed within said chamber intermediate said permeable member and said distendable film member, said distendable film member engaging element comprising an upstanding protuberance provided with a fluid flow chamber in communication with said fluid conduit in said base; and

(e) a hollow needle integrally formed with said base in operable communication with said fluid outlet.

19. A device as defined in claim 18 in which said distendable film member is permeable to gases.

20. A device as defined in claim 18 in which said distendable film member is at least partially bonded to said distendable film member engaging element.

21. A device as defined in claim 18 in which said distendable film member engagement element is provided with filling means for introducing fluid into said chamber.

22. A device as defined in claim 21 in which said filling means comprises:

(a) a fluid passageway formed in said distendable film member engaging element having first and second ends, said first end being in communication with said fluid conduit in said base; and

(b) septum means mounted within said second end of said fluid passageway for receiving therethrough a needle of a hypodermic syringe.

23. A device as defined in claim 22 further including adhesive means connected to said base for removably connecting said device to the patient's anatomy.

24. A device as defined in claim 23 in which said base, said distendable film member and said distendable film member engaging element are flexible yieldably deformable out of plane.

25. A device as defined in claim 24 further including a sheet of foam disposed intermediate said adhesive means said base.

26. A device for expelling fluids at a controlled rate, comprising:

(a) a base;

(b) means for forming a fluid chamber comprising a distendable membrane constructed of an elastic material superimposed over said base;

(c) flow control means disposed internally of said chamber for controlling the rate of flow of fluid through said outlet, said flow control means comprising a thin permeable member superimposed over said base;

(d) distendable membrane engagement means, disposed intermediate said distendable membrane and said flow control means, for engagement with said distendable membrane; and

(e) a cover superimposed over said base, said distendable membrane, said distendable membrane engagement means and said flow control means.

27. A device for expelling fluids at a controlled rate, comprising:

(a) a base having a width and first and second surfaces;

(b) means for forming a fluid chamber comprising a distendable membrane constructed of an elastic material spanning said first surface of said base, said fluid chamber having a fluid outlet and being of a height substantially less than said width of said base, said distendable membrane being distendable in a manner to establish internal stresses therewithin tending to return said membrane to a less distended configuration whereby fluid will be urged to flow from said fluid outlet; and

(c) flow control means disposed internally of said chamber for controlling the rate of flow of fluid through said fluid outlet.

28. A device as defined in claim 27 in which said distendable membrane includes edge portions and in which said first and second surfaces of said base are substantially planar, said first surface being disposed within said chamber and said second surface being disposed exteriorly of said chamber.

29. A device as defined in claim 28 in which said fluid chamber is bounded by said first surface of said base and said edge portions of said distendable membrane, said fluid chamber being substantially arch-shaped in cross-section.

30. A device as defined in claim 27 further including means disposed intermediate said distendable membrane and said flow control means for creating ullage within said chamber.

31. A device for expelling fluids at a controlled rate, comprising:

(a) a plate-like base having first and second surfaces;

(b) means for forming a fluid chamber having a fluid outlet comprising a sheet-like distendable membrane constructed of an elastic material spanning said first surface of said base, said distendable membrane being terminally bound to said first surface of said base and being distendable in a manner to establish internal stresses therewithin tending to return said membrane to a less distended configuration whereby fluid will be urged to flow from said fluid outlet; and

(c) flow control means disposed internally of said chamber for controlling the rate of flow of fluid through said outlet.

32. A device as defined in claim 31 in which a substantial portion of said first surface of said base is disposed internally of said fluid chamber and in which said second surface of said base is disposed externally of said fluid chamber.

Description Submit all comments and votes

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates generally to fluid delivery devices. More particularly, the invention concerns an improved apparatus for infusing medicinal agents into an ambulatory patient at specific rates over extended periods of time.

DISCUSSION OF THE INVENTION

Many medicinal agents require an intravenous route for administration thus bypassing the digestive system and precluding degradation by the catalytic enzymes in the digestive tract and the liver. The use of more potent medications at elevated concentrations has also increased the need for accuracy in controlling the delivery of such drugs. The delivery device, while not an active pharmacologic agent, may enhance the activity of the drug by mediating its therapeutic effectiveness. Certain classes of new pharmacologic agents possess a very narrow range of therapeutic effectiveness, for instance, too small a dose results in no effect, while too great a dose results in toxic reaction.

In the past, prolonged infusion of fluids has generally been accomplished using gravity flow methods, which typically involve the use of intravenous administration sets and the familiar bottle suspended above the patient. Such methods are cumbersome, imprecise and require bed confinement of the patient. Periodic monitoring of the apparatus by the nurse or doctor is required to detect malfunctions of the infusion apparatus.

Devices from which liquid is expelled from a relatively thick-walled bladder by internal stresses within the distended bladder are well-known in the prior art. Such bladder, or "balloon" type, devices are described in U.S. Pat. No. 3,469,578, issued to Bierman and in U.S. Pat. No. 4,318,400, issued to Perry. The devices of the aforementioned patents also disclose the use of fluid flow restrictors external of the bladder for regulating the rate of fluid flow from the bladder.

The prior art bladder type infusion devices are not without drawbacks. Generally, because of the very nature of bladder or "balloon" configuration, the devices are unwieldly and are difficult and expensive to manufacture and use. Further, the devices are somewhat unreliable and their fluid discharge rates are frequently imprecise.

The apparatus of the present invention overcomes many of the drawbacks of the prior art by eliminating the bladder and making use of recently developed elastomeric films and similar materials, which, in cooperation with a, plate-like base defines a fluid chamber that contains the fluid which is to be dispensed. The elastomeric film membrane controllably forces fluid within the chamber into fluid flow channels provided in the base. In one form of the apparatus of the invention, a thin, planar shaped flow rate control member is strategically located within the chamber to precisely control the rate of flow of the liquid toward the fluid flow channels. The flow rate control member can be very thin and can be selected to have a very precise degree of permeability so that the rate of flow of fluid into the fluid flow channels can be controlled with great accuracy.

The use of state of the art thin membranes and films permits the construction of compact, low profile, laminated structures which are easy to use and inexpensive to manufacture. When the devices of the invention are to be used with ambulatory patients they are constructed of flexible materials and are provided with a thin adhesive backing which permits the device to be conveniently self-affixed to the patient's arm or other parts of the body.

The apparatus of the invention can be used with minimal professional assistance in an alternate health care environment, such as the home. By way of example, devices of the invention can be used for the continuous infusion of antibiotics, hormones, steroids, blood clotting agents, analgesics, and like medicinal agents. Similarly, the devices can be used for I-V chemotherapy and can accurately deliver fluids to the patient in precisely the correct quantities and at extended microfusion rates over time.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an apparatus for expelling fluids at a precisely controlled rate which is of a compact, low profile, laminate construction. More particularly, it is an object of the invention to provide such an apparatus which can be used for the precise infusion of pharmaceutical fluids to an ambulatory patient at controlled rates over extended periods of time.

It is another object of the invention to provide an apparatus of the aforementioned character which is highly reliable and easy-to-use by lay persons in a non-hospital environment.

Another object of the invention is to provide an apparatus which can be factory prefilled with a wide variety of medicinal fluids or one which can readily be filled in the field shortly prior to use.

Another object of the invention is to provide an infusion device in which fluids can be delivered either at a fixed rate or at variable rates and one which is operational in all altitudes and attitudes.

Still another object of the invention is to provide an apparatus of the class described which is soft, conformable and compliant so as to readily conform to the patient's anatomy proximate the point of infusion.

Yet another object of the invention is to provide an apparatus as described in the preceding paragraph which is provided with a thin, flexible foam backing with adhesive for self-attachment. The apparatus can be unobtrusively worn under clothing.

A further object of the invention is to provide a low profile, fluid delivery device of laminate construction which can be manufactured inexpensively in large volume by automated machinery.

Another object of the invention is to provide a device of the character described in which fluid is dispelled from the apparatus through either an integral infusion needle, or through a luer type connector, by a thin, distendable membrane cooperatively associated with a thin, plate-like base.

Another object of the invention is to provide an apparatus of the aforementioned character in which the distendable member is permeable to gases at least in one direction, whereby gases within the medicinal agent can be released from the fluid chamber and not injected into the patient.

Still another object of the invention is to provide an apparatus as described in the preceding paragraphs in which the rate of fluid flow from the apparatus is precisely controlled by a thin planar shaped, fluid permeable member which forms a part of the low profile, laminate construction of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a generally perspective view of one form of the fluid dispensing apparatus of the invention.

FIG. 2 is an exploded, generally perspective view of the apparatus of FIG. 1.

FIG. 3 is a top view of the apparatus partly broken away to show internal construction.

FIG. 4 is an enlarged cross sectional view taken along lines 4--4 of FIG. 3.

FIG. 5 is a cross sectional view taken along lines 5--5 of FIG. 4.

FIG. 6 is a fragmentary view taken along lines 6--6 of FIG. 4.

FIG. 7 is a cross sectional view taken along lines 7--7 of FIG. 4.

FIG. 8 is a view similar to FIG. 4, but illustrating the separation of the molded needle cover from the device.

FIG. 9 is a cross sectional view taken along lines 9--9 of FIG. 8.

FIG. 10 is a generally perspective exploded view of another embodiment of the fluid dispensing apparatus of the present invention.

FIG. 11 is a top view of the apparatus shown in FIG. 10.

FIG. 12 is a cross sectional view taken along lines 12--12 of FIG. 11.

FIG. 13 is a cross sectional view taken along lines 13--13 of FIG. 12.

FIG. 14 is a cross sectional view taken along lines 14--14 of FIG. 12.

FIG. 15 is a fragmentary view taken along lines 15--15 of FIG. 12.

FIG. 16 is a view similar to FIG. 12, but showing the molded needle cover separated from the device.

FIG. 17 is a greatly enlarged fragmentary view illustrating the method of fluid fill of the apparatus of this form of the invention.

FIG. 18 is a generally perspective exploded view of another embodiment of the apparatus of the present invention.

FIG. 19 is a fragmentary top view of the apparatus of this form of the invention.

FIG. 20 is a cross sectional view taken along lines 20--20 of FIG. 19.

FIG. 21 is a cross sectional view taken along lines 21--21 of FIG. 20.

FIG. 22 is a generally perspective exploded view of still another form of the apparatus of the present invention.

FIG. 23 is a plan view of the apparatus of FIG. 22 partly broken away to show internal construction.

FIG. 24 is a greatly enlarged fragmentary perspective view of a portion of the apparatus illustrating the arrangement of the rate control membranes of the device.

FIG. 25 is a cross sectional view taken along lines 25--25 of FIG. 23.

FIG. 26 is a fragmentary view taken along lines 26--26 of FIG. 25.

FIG. 27 is a cross sectional view taken along lines 27--27 of FIG. 25.

FIG. 28 is a cross sectional view taken along lines 28--28 of FIG. 25.

FIG. 29 is a fragmentary, cross sectional view similar to FIG. 25, but showing the needle cover separated from the apparatus of the invention.

DESCRIPTION OF THE INVENTION

Referring to the drawings and particularly to FIGS. 1 through 9, one embodiment of the apparatus for use in infusing medicinal fluids into a patient is there illustrated and generally designated by the numeral 12. As indicated in FIG. 1, the apparatus of this form of the invention comprises a laminate, or layered, structure made up of a plurality of thin plate-like components. As best seen by referring to FIG. 2, the apparatus comprises a thin, generally planar plate-like base 14, having a pair of flow rate control channels provided here as longitudinally extending fluid conduits 16 and 18. Conduits 16 and 18 are interconnected by a fluid transfer manifold, or transverse conduit 20, which, in turn, is interconnected with a fluid outlet passageway 22. A thin, generally planar distendable elastomeric membrane, or member, 24 cooperates with base 14 to form a chamber 25 (FIG. 4). Member 24 is distendable out of plane in the manner shown in FIG. 4 by the introduction of fluid into the chamber under pressure. As the distendable member 24 is distended by the fluid pressure, internal stresses are formed in the member which continuously urge it to return to its original planar configuration. The method of introduction of fluids into chamber 25 will presently be described.

Forming an important aspect of the apparatus of the invention is the provision of flow control means which is disposed internally of chamber 25 for controlling the rate of fluid flow through the outlet 22 formed in base member 14. In the embodiment of the invention hereshown, the flow control means is provided in the form of a thin, permeable member 26 which is superimposed over base 14 in the manner shown in FIG. 4. As will presently be described, member 26 precisely controls the rate of fluid flow from chamber 25 into fluid conduits 16, 18 and 20 formed in base 14. It is this precise control of the rate of fluid flow which enables infusion into the patient of medicinal fluids at an extremely precise rate over extended periods of time ranging from several hours to in excess of 24 hours depending on sized reservoir volume.

Superimposed over flow control member 26 is a distendable membrane engagement means. This means is here provided in the form of a generally planar member 28 having a peripheral portion 28a to which the margins of distendable member 24 are bonded, as by adhesive or thermo-bonding. Member 28 also has a pair of longitudinally extending, spaced apart upstanding protruberances 30. Each of the protruberances 30 is provided with a longitudinally extending first fluid passageway or conduit 32. When the apparatus is assembled in the manner shown in FIG. 9, passageways 32 are superimposed over fluid conduits 16 and 18 and protruberances 30 extend upwardly into fluid chamber 26 so as to define ullage "U" within chamber 25. In operation of the device, as distendable membrane 24 attempts to return to its original planar configuration (FIG. 9), it will move toward engagement with the upper surfaces of protruberances 30 and in so doing will efficiently force the fluid contained within chamber 25 uniformly through the flow control member 26 and into passageways 16 and 18. The configuration of protuberances 30 ensure that all of the fluid within chamber 25 will be dispelled therefrom as the membrane returns toward its starting configuration. Passageways 16, 18, and 32 can be alternately configured to provide various degrees of fluid exposure to rate control membrane 26 whereby the active surface area of membrane 26 is increased or decreased.

Superimposed over the assembly comprising base 14, distendable membrane 24, flow control member 26, and distendable membrane engaging member 28 is a porous plastic cover 34 which functions to provide a superstructure and a venting means for venting gases, if any, contained within the medicinal agent. Affixed to the top of cover 34 is a medicant and use instruction label 36 which can be used to identify the medicinal fluid contained within chamber 25 of the device.

Affixed to the bottom of base 14 is a cushioning means shown here as a thin, planar shaped foam pad 38. Foam pad 38 is provided with adhesive on both its upper and lower surfaces. The adhesive on the upper surface of pad 38 enables the pad to be affixed to the lower surface of base 14. As indicated in FIGS. 2 and 4, a peel strip 40 is connected to the bottom surface of foam pad 38 by the adhesive provided thereon. When the device is to be used, peel strip 40 can be stripped away from pad 38 so that the adhesive on the lower surface of the foam pad 38 can be used to releasably affix the apparatus of the invention to the anatomy of the patient.

Turning now to FIGS. 4 and 8, a needle assembly 42 is integrally formed with base 14. Needle assembly 42 which includes a distal portion 42a and a proximal portion 42b, is provided with a longitudinally extending bore 44. As best seen in FIG. 4, bore 44 is in communication with outlet passageway 22 formed in base 14. Fixedly received within that portion of passageway 44, which extends through distal portion 42a, is a hollow infusion needle 46 of the character typically used for injecting fluids into a patient. The fluid outlet end of needle 46 is received within that portion of passageway 44 which extends through proximal portion 42b. Intermediate portions 42a and 42b is a reduced diameter frangible portion 42c which can be broken so as to separate portions 42a and 42b to expose the outlet end of needle 46 in the manner shown in FIG. 8. Also forming a part of proximal portion 42b is a protective sheath 48 for encapsulating and protecting needle 46. Needle assembly 42 also includes web means for further assisting in securing and maintaining the needle in an appropriate invasive position to preclude inter-vascular trauma. The web means are here provided as a soft, flexible butterfly assemblage 49, which, as shown in FIGS. 1 and 7, is integrally formed with base 14 and joined therewith by webbing 49a. Butterfly assembly 49 also provides appropriate surface area for tape adhesion covering the injection site.

Turning now to FIGS. 2, 3, 4 and 6, the distendable membrane engagement element 28 which comprises the means for creating an ullage within chamber 25, also includes an upstanding transversely extending portion 50 having a fluid passageway 52 extending therethrough. In the present embodiment of the invention, the open end 52a of passageway 52 is closed by a closure member 54 which is adapted to sealably close passageway 52 after chamber 25 has been filled with the selected medicinal agent. Passageway 52 can also be closed by any suitable means such as thermal or mechanical sealing. As best seen by referring to FIG. 4, passageway 52 is in communication with a pair of longitudinally extending passageways 56 formed in element 28. Passageways 56 are, in turn, in communication with chamber 25 via passageways 58. As illustrated in FIG. 2, passageways 58 extend through protuberances 30 and are disposed in the ends of protuberances 30 located proximate transversely extending passageway 52.

The apparatus of this first embodiment of the invention is adapted to be filled with the selected medicinal fluid at time of manufacture. This is accomplished by removal of plug 54 so that fluid under pressure can be forced into passageway 52 and thence into chamber 25 via passageways 56 and 58. As the fluid under pressure flows through passageways 58, it will cause the membrane 24 to distend upwardly into initial engagement with cover 34 in the manner shown in FIG. 4. After chamber 25 has been filled with the medicinal fluid, closure plug 54 is bonded or otherwise affixed in place within the open end 52a of conduit 52 so as to seal chamber 25 with respect to atmosphere.

So long as needle assembly 42 remains intact in the manner shown in FIG. 4, the fluid will be retained within chamber 25. However, upon twisting and breaking the frangible section 42c so that portion 42b of the needle assembly can be removed as shown in FIG. 8, distendable membrane 24 will begin to expel fluid through the needle 46. The rate of expulsion of fluid is, of course, controlled by the permeable membrane 26 which is disposed intermediate the fluid flow passageways 32 of member 28 and fluid flow passageways 16 and 18 formed in base 14.

As previously mentioned, the state of the art materials used in the construction of the apparatus of the invention markedly contribute to the reliability, accuracy and manufacturability of the apparatus. Before discussing the alternate forms of the invention shown in the drawings, a brief review of the materials used in constructing the apparatus is in order.

With respect to the base 14, a wide variety of materials can be used, including; metals, rubber or plastics that are compatible with the liquids they contact and ar