US20070213673A1 - Infusion Device Having Offset Flow Path - Google Patents

Abstract

An infusion device, including: a housing; an infusion cannula extending downwardly away from the housing and capable of receiving an insertion needle; a septum disposed in the housing; a passageway under said septum and in fluid communication with said cannula; and, an infusion needle insertable through the septum, the infusion needle capable of penetrating the septum and entering said passageway thereby forming a flow path between the infusion needle and the infusion cannula and wherein the infusion cannula and the infusion needle are aligned on separate non identical axes.

Description

RELATED APPLICATION
• This application claims priority under 35 U.S.C. Section 119 to U.S. Provisional Application No. 60/459,252 entitled Device For Subcutaneous Medication Using An Offset Flow Path, filed on Mar. 31, 2003, the complete disclosure of which is incorporated herein by reference in its entirety for all purposes.
TECHNICAL FIELD
• The present invention is related to infusion devices, including insulin or other medication infusion devices that are positioned directly on a patient's skin
BACKGROUND OF THE INVENTION
• Numerous medication infusion devices which sit directly on top of a patient's skin have been developed. Such devices typically operate as follows. A housing of the device is placed on the patient's skin such that an infusion cannula (extending downwardly therefrom) pierces through the patient's skin. Typically, the housing is placed against the patient's skin by use of an inserter needle assembly. Specifically, an insertion needle on the inserter needle assembly is received through the housing, passing through the center of the infusion cannula The main body of the inserter needle assembly is then used to press down against the housing, pushing the housing down against the patient's skin while the inserter needle guides the infusion cannula into the patient. Then, the inserter needle assembly is removed, pulling the inserter needle out of the housing, and leaving the hollow infusion cannula in the patient for delivery of medication therethrough. Then, a connecting hub is typically attached onto the housing. Fluid medication is then infused into the connecting hub, passing sequentially through the housing and the infusion cannula and into the patient. Examples of such systems are found in U.S. Pat. Nos. 6,056,718 and 6,685,674.
• As can be seen, a problem common to these systems is that both the inserter needle and an infusion needle (in the connecting hub) pass through the septum in the same location. This is due to the fact that in existing designs, the infusion cannula, inserter needle, and infusion needle are all co-linear with one another.
• A disadvantage of this common design is that the septum must be pierced in the same location by both the inserter needle (which is removed after the housing is placed onto the patient's skin) and the infusion needle (which passes through the septum when the connecting hub is attached to the housing). Re-using the same location in the septum for two different needle entries has the potential for causing septum wear and leakage. As will be further explained herein, other disadvantages of such “in-line” designs also exist.
SUMMARY OF THE INVENTION
• The present invention provides an infusion device, having: a housing; an infusion cannula extending downwardly away from the housing and capable of receiving an insertion needle; a septum disposed in the housing; a passageway under said septum and in fluid communication with said cannula; and, an infusion needle insertable through the septum, the infusion needle capable of penetrating the septum and entering said passageway thereby forming a flow path between the infusion needle and the infusion cannula and wherein the infusion cannula and the infusion needle are aligned on separate non identical axes. Such axes may be parallel, in different planes relative to one another or at oblique angles relative to one another. The infusion needle is positioned to penetrate the septum thereby forming a flow path between the infusion needle and the infusion cannula when the connecting hub is attached to the housing.
• In accordance with the present invention, the infusion cannula and the infusion needle are disposed off-axis to one another. For example, the infusion cannula and the infusion needle may be positioned parallel to one another. In preferred embodiments, the infusion needle is disposed in the center of the connecting hub and the infusion cannula is disposed off-center in the housing; however, the present invention is not so limited.
• In accordance with the present invention, the infusion needle (in the connecting hub) passes through the septum at a location different from where an insertion needle (in the infusion cannula) passes through the septum. An advantage of this design is that there is significantly reduced potential for leakage since the insertion needle (used to initially position the infusion cannula in the patient) passes through the septum at a location different from the location where the infusion needle passes through the septum.
• A further advantage of the present invention is that in embodiments where the infusion needle is positioned at the center of the connecting hub, the connecting hub can be rotatable with respect to the housing. This gives the patient greater comfort and flexibility since an infusion tube extending from the connecting hub can be rotated to different radial positions, as desired As will be explained, the present connecting hub can be rotatable with respect to the housing through a full 360 degrees, some through amount less than 360 degrees, or alternatively, not be rotatable at all.
• Another advantage of the present invention is that there is no torque on the infusion cannula when the connecting hub is rotated. This is particularly advantageous since the infusion cannula is received into the patient. Torque on the infusion cannula would cause irritation to the patient.
• Another advantage of the present invention is that the infusion needle and infusion cannula may be of different diameters. Thus, different connecting hubs having different diameter infusion needles (e.g.: with different flow rates therethrough) can be interchangeably used with a single housing sitting on the patient's skin.
• Another advantage of the present invention is that, by placing the infusion needle and the infusion cannula parallel to one another, the overall height of the assembled device can be reduced as compared to that of a standard “in-line” co-linear design.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a sectional side elevation view of the present invention, prior to attaching the connecting hub onto the housing.
• FIG. 2 is a sectional side elevation view of the present invention with the connecting hub attached to the housing.
• FIG. 3 is a bottom plan view of the lower portion of the housing of the present invention.
• FIG. 4 is a top perspective view of the present invention, showing the connecting hub with flexible handles attached thereto.
• FIG. 5 is a bottom perspective view of the present invention with the adhesive bandage removed.
• FIG. 6 is a bottom exploded perspective view of the housing of the present invention.
• FIG. 7 is a top exploded perspective view of the housing of the present invention.
• FIG. 8 is a bottom exploded perspective view of the connecting hub of the present invention.
• FIG. 9 is a top exploded perspective view of the connecting hub of the present invention.
• FIG. 10 is a sectional side elevation view of the housing with a positioning needle assembly sitting thereon, with a positioning needle received through the infusion cannula.
• FIG. 11 is a bottom exploded perspective view of the positioning needle assembly.
• FIG. 12 is a top exploded perspective view of the positioning needle assembly.
DETAILED DESCRIPTION OF THE DRAWINGS
• The present invention provides an infusion device having an “offset” design in which an infusion cannula (which is received into a patient's skin) is not co-linear with an infusion needle (which extends from a removable connecting hub), as follows:
• Referring first toFIG. 1, aninfusion device10 is provided.Infusion device10 includes ahousing100 which is positioned against a patient's skin. Specifically, anadhesive bandage150 extends outwardly fromhousing100 and aninfusion cannula110 extends downwardly away fromhousing100.Infusion cannula110 pierces through the patient's skin whenadhesive bandage150 is affixed to the patient's skin. Aseptum120 is disposed withinhousing100. In the illustrated embodiment,septum120 is disposed betweenlower portion140 andupper portion130; however, the present invention is not so limited.
• A connectinghub200 is also provided. Connectinghub200 includes amain body220 and aninfusion needle210 extending downwardly therefrom, and a pair offlexible handles230. As can be seen,infusion needle210 is preferably co-linear withaxis300. (In the illustrated embodiment,axis300 passes through the center of both connectinghub200 and housing100). As can therefore be seen,infusion cannula110 is not co-linear withaxis300.
• Connectinghub200 is configured to be attached by a user directly on top ofhousing100. This is seen clearly inFIG. 2. To securely connect connectinghub200 ontohousing100,flexible handles230 may be used. In the illustrated embodiment, each offlexible handles230 includes atab231 which is received into asmall notch135 formed betweenlower portion140 andupper portion130.
• When connectinghub200 is attached on top of housing100 (as shown inFIG. 2),infusion needle210 penetratesseptum120 thereby forming a flow path400 betweeninfusion needle210 andinfusion cannula110, in the preferred embodiment being a lateral passageway. As will be explained herein,infusion needle210 is preferably in fluid communication with an infusion tube connected to the side of connectinghub200, to supply medication infusion therethrough. Becausecannula110 is on one axis and theinfusion needle210 is along another axis and not collinear, it is possible for the entire body to be shallower than if the two axes were aligned. The preferred arrangement has theneedle210 and cannula parallel but in different planes. They need not be parallel. The infusion needle could be inserted at an angle off vertical (such as an oblique angle), so long as it reaches the passageway (flow path)400 so that fluid communication therebetween can occur.
• A further advantage of the design shown inFIG. 2 is that connectinghub200 may be freely rotatable with respect tohousing100 even after connectinghub200 has been attached tohousing100. This is becauseinfusion needle210 is preferably positioned in the center of device10 (i.e.: co-linear with axis300) and becausetabs231 may be freely moveable along through notch135 (which runs aroundhousing100 between upper andlower portions130 and140 respectively). As a result, connectinghub200 may freely rotate to different radial positions with respect tohousing100 since connectinghub200 simply rotates around centrally-locatedinfusion needle210 whiletabs231 slide around withinnotch135 around the perimeter ofhousing100. In optional embodiments, stops (not shown) may be positioned aroundnotch135 to limit rotation of connectinghub200 with respect tohousing100. As a result, the present invention is understood to encompass embodiments wherein connectinghub200 is fully rotatable 360 degrees with respect tohousing100, or rotatable less than 360 degrees with respect tohousing100, or wherein connectinghub200 is not rotatable with respect tohousing100 at all. Consequently, the present invention encompasses embodiments wherein connectinghub200 is attachable tohousing100 at different rotational positions.
• FIG. 3 shows a bottom plan view oflower portion140 ofhousing100. The offsetdistance350 betweeninfusion cannula110 andinfusion needle210 is clearly seen. In such preferred embodiments,infusion cannula110 andinfusion needle210 are positioned parallel to one another. In most preferred embodiments,infusion needle210 is disposed in the center of connecting hub200 (i.e.: along axis300) and theinfusion cannula110 is disposed off-center to the housing (i.e. not along axis300); however, the present invention is not so limited.
• FIG. 4 shows a top perspective view ofmain body220 of connectinghub200. Flexible handles230 are also seen.Connecting hub200 further includes aside infusion port225. An infusion tube215 (FIG. 9) connected intoinfusion port225 is in fluid communication withinfusion needle210. Thus, fluid entering connectinghub200 throughinfusion port225 passes directly throughinfusion needle210, and then throughseptum120, across flow path400, and then down throughinfusion cannula110, and into the patient.
• In preferred embodiments,infusion cannula110 andinfusion needle210 may have different diameters. It is to be understood, therefore, that the present invention encompasses embodiments whereinfusion cannula110 is either larger or smaller in diameter thaninfusion needle210, and also encompasses embodiments whereinfusion cannula110 has the same diameter thaninfusion needle210.
• FIG. 5 shows further details of the bottom of assembledinfusion device10.
• FIGS. 6 and 7 shows the narroweddistal end111 ofinfusion cannula110, which minimizes discomfort to the patient wheninfusion cannula110 pierces the patient's skin.FIG. 6 also shows further details ofseptum120. Specifically, an insertion needle510 (FIGS.10 to12) passes throughseptum120 atlocation121; whereasinfusion needle210 passes throughseptum120 atlocation122.
• FIGS. 8 and 9 show further details ofconnector hub200 andflexible handles230. As shown inFIG. 9, afluid infusion tube215 may be connected intoinfusion port225. Thus, fluid introduced intoinfusion port225 byfluid infusion tube215 will pass out ofinfusion needle210.
• FIG. 10 shows aninsertion needle assembly500 which is used for positioninghousing100 against the patient's skin.Insertion needle assembly500 includes aninsertion needle510 which is initially positioned to extend throughinfusion cannula110, passing throughseptum120 atlocation121, as shown.
• Insertion needle assembly500 further includes ahandle assembly520. The patient typically uses a spring loaded inserter (not shown) that advanceshandle assembly520 therebypressing housing100 downward against their skin such thatinfusion cannula110 andinsertion needle510 together pierce through the patient's skin. Such downward motion continues untiladhesive bandage150 is pressed firmly against the patient's skin. Then, the spring loaded inserter (not shown) is removed, and handle520 is pulled upwardly by the patient away from their skin, thus pullinginsertion needle510 out ofinfusion cannula110. The remaininghollow infusion cannula110 is then used to infuse medication into the patient. Once theneedle510 is removed, that passageway therethrough is no longer required. Instead infusate will pass through the offsetinfusion needle210 across the lateral flow path400 and intocannula110.
• FIGS. 11 and 12 show further details ofinsertion needle assembly500.
• In an alternate embodiment of the present invention, the septum is instead positioned in the connecting hub and the infusion needle is instead disposed in the housing. In such embodiment, the flow path between the infusion needle and the infusion cannula is within the connecting hub, not within the housing.
• In an alternate embodiment,septum120 is pre-slit andinfusion needle210 comprises a hollow tube, which may optionally be made of plastic.
• The present invention also encompasses a method of infusing fluid into a patient, by: positioning aninfusion housing100, having a passageway400, against a patient's skin, such that aninfusion cannula110 extends downwardly away from theinfusion housing100 penetrates the patient's skin along a first axis, thereby providing a pathway for infusate into the patient; and inserting aninfusion needle210 intohousing100 along anaxis300 adjacent, but not identitical with said first axis; and causing infusate to pass throughinsertion needle210, into passageway400 and then intoinfusion cannula110.

Claims (17)

1. An infusion device, comprising:

a housing;

an infusion cannula extending downwardly away from the housing and capable of receiving an insertion needle;

a septum disposed in the housing;

a passageway under said septum and in fluid communication with said cannula and;

an infusion needle insertable through the septum, the infusion needle capable of penetrating the septum and entering said passageway thereby forming a flow path between the infusion needle and the infusion cannula and wherein the infusion cannula and the infusion needle are aligned on separate non identical axes.

2. The device ofclaim 1, wherein the infusion cannula and the infusion needle are positioned parallel to one another.

3. The device ofclaim 1, wherein the infusion cannula and the infusion needle are positioned parallel to one another.

4. The device ofclaim 1, wherein the infusion cannula and the infusion needle are in different planes relative to each other.

5. The device ofclaim 1, wherein the infusion cannula and the infusion needle are at oblique angles relative to each other.

6. The device ofclaim 1, wherein the infusion needle is disposed in the center of the connecting hub and the infusion cannula is disposed off-center to the housing.

7. The device ofclaim 1, wherein the infusion cannula and the infusion needle have different diameters.

8. The device ofclaim 1, wherein the connecting hub is rotatable with respect to the housing.

9. The device ofclaim 8, wherein the connecting hub is rotatable 360 degrees with respect to the housing.

10. The device ofclaim 8, wherein the connecting hub is rotatable less than 360 degrees with respect to the housing.

11. The device ofclaim 1, wherein the connecting hub is attachable to the housing at different rotational positions.

12. The device ofclaim 1, wherein the connecting hub further comprises:

at least one flexible handle configured to attach the connecting hub onto the housing.

13. The device ofclaim 1, wherein the housing further comprises:

an adhesive bandage extending therefrom for holding the housing against the patient's skin.

14. The device ofclaim 1, wherein the connecting hub further comprises:

a fluid infusion tube extending from the connecting hub, the fluid infusion tube being in fluid communication with the infusion needle.

15. The device ofclaim 1, wherein the septum is pre-slit and wherein the infusion needle is a plastic tube.

16. A method of infusing fluid into a patient, comprising:

positioning an infusion housing, having a passageway, against a patient's skin, such that an infusion cannula extends downwardly away from the infusion housing penetrates the patient's skin along a first axis, thereby providing a pathway for infusate into the patient; and

inserting an infusion needle into the housing along an axis adjacent, but not identitical with said first axis; and

causing infusate to pass through said insertion needle, into said passageway and then into said infusion cannula

17. The method ofclaim 16, wherein the passageway in he infusion housing is a lateral passageway.

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