U.S. patent application number 13/296110 was filed with the patent office on 2012-03-08 for medication infusion set.
This patent application is currently assigned to MEDTRONIC MINIMED, INC.. Invention is credited to Christopher G. Griffin, Arin N. Holecek, Julian D. Kavazov, Paul H. Kovelman, SUSIE E. MAULE, Sheldon B. Moberg.
Application Number | 20120059320 13/296110 |
Document ID | / |
Family ID | 35677446 |
Filed Date | 2012-03-08 |
United States Patent
Application |
20120059320 |
Kind Code |
A1 |
MAULE; SUSIE E. ; et
al. |
March 8, 2012 |
MEDICATION INFUSION SET
Abstract
An infusion set is provided for use in delivering fluid through
a cannula, which is housed on a cannula housing, to a selected
subcutaneous infusion site on a patient. The fluid is generally a
medication, e.g., insulin. The cannula is in fluid communication
with a fluid passageway surrounded by a projection on the cannula
housing that includes one or more rail-like extensions acting as
guides. A connector connects the cannula housing to a fluid
delivery system, e.g., an infusion pump. The connector includes a
needle, one or more guide arms that slide over the rail-like
extensions to guide the needle into the self-sealing septum, and
one or more locking arms, with barbs at the end, to connect with
corresponding recesses in the cannula housing. An introducer having
one or more similar guide arms and locking arms, and a longer
needle, may be used to insert the cannula into the patient.
Inventors: |
MAULE; SUSIE E.; (South
Pasadena, CA) ; Moberg; Sheldon B.; (Thousand Oaks,
CA) ; Holecek; Arin N.; (Lakewood, CA) ;
Griffin; Christopher G.; (Sylmar, CA) ; Kavazov;
Julian D.; (Arcadia, CA) ; Kovelman; Paul H.;
(Simi Valley, CA) |
Assignee: |
MEDTRONIC MINIMED, INC.
Northridge
CA
|
Family ID: |
35677446 |
Appl. No.: |
13/296110 |
Filed: |
November 14, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11975315 |
Oct 18, 2007 |
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13296110 |
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11003225 |
Dec 3, 2004 |
7303543 |
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11975315 |
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Current U.S.
Class: |
604/164.04 ;
604/164.01; 604/165.01 |
Current CPC
Class: |
A61M 2025/028 20130101;
A61M 2025/024 20130101; A61M 5/158 20130101; A61M 2005/1587
20130101; A61M 2025/0266 20130101; A61M 25/02 20130101 |
Class at
Publication: |
604/164.04 ;
604/164.01; 604/165.01 |
International
Class: |
A61B 17/34 20060101
A61B017/34 |
Claims
1. A device for inserting a cannula for subcutaneous administration
of fluid into a patient, comprising: a cannula housing defining a
fluid passageway along a longitudinal axis thereof, the cannula
housing including first and second guide rails and a cannula, said
cannula being in fluid communication with the passageway, wherein,
along substantially the entire length thereof, each of said guide
rails has an outer longitudinal surface with an arcuate profile;
and an introducer configured to be detachably connected to the
cannula housing, the introducer comprising separate first and
second guide arms, each said guide arm being configured to mate
with a respective one of the guide rails, and a
longitudinally-extending needle that is parallel to said guide arms
and has a distal tip that extends beyond respective distal ends of
said first and second guide arms, wherein the introducer is
symmetrical about its longitudinal axis such that it is reversible,
wherein each of the separate first and second guide arms has
opposing inner and outer longitudinal sides, wherein, for each
guide arm, the outer longitudinal side is flat along substantially
the entire length thereof and the inner longitudinal side has an
arcuate profile along substantially the entire length thereof,
wherein the inner side of the first guide arm faces the inner side
of the second guide arm, and wherein the cannula has a distal end
for placement into the patient's skin, and, when the introducer is
connected to the cannula housing, the needle's distal tip extends
beyond the cannula's distal end.
2. The device of claim 1, wherein the introducer further includes a
locking arm having a barb, the cannula housing further defines a
recess therein adjacent said fluid passageway, and said recess is
configured to receive the barb when the introducer is connected to
the cannula housing.
3. The device of claim 2, wherein said locking arm includes a
grip.
4. The device of claim 1, wherein: the introducer includes a
plurality of locking arms, each said locking arm having a barb
associated therewith; the cannula housing defines a plurality of
recesses; and each said recess is configured to receive a
respective one of said barbs so as to detachably connect the
introducer to the cannula housing.
5. The device of claim 1, wherein at least one of the introducer
and the cannula housing is made of material selected from the group
consisting of polycarbonate and polypropylene.
6. The device of claim 1, wherein the cannula housing further
includes a self-sealing septum at an end of the fluid passageway
opposite the cannula.
7. The device of claim 1, wherein said arcuate profile of the outer
longitudinal surface of each of said first and second guide rails
is convex.
8. The device of claim 1, wherein the needle is stationary at all
times with respect to the first and second guide arms.
9. A device for inserting a cannula for subcutaneous administration
of fluid into a patient, comprising: a cannula housing defining a
fluid passageway along a longitudinal axis thereof, the cannula
housing including first and second guide rails and a cannula, said
cannula being in fluid communication with the passageway, wherein,
along substantially the entire length thereof, each of said guide
rails has an outer longitudinal surface with an arcuate profile;
and an introducer configured to be detachably connected to the
cannula housing, the introducer comprising separate first and
second guide arms, each said guide arm being configured to mate
with a respective one of the guide rails, a
longitudinally-extending needle that is parallel to said guide arms
and has a distal tip that extends beyond respective distal ends of
said first and second guide arms, and a plurality of locking arms,
each said locking arm having a barb associated therewith, wherein
each of the separate first and second guide arms has opposing inner
and outer longitudinal sides, wherein, for each guide arm, the
outer longitudinal side is flat along substantially the entire
length thereof and the inner longitudinal side has an arcuate
profile along substantially the entire length thereof, wherein the
inner side of the first guide arm faces the inner side of the
second guide arm, and wherein the cannula housing further defines a
plurality of recesses therein, each said recess being configured to
receive a respective one of said barbs so as to detachably connect
the introducer to the cannula housing.
10. The device of claim 9, wherein the cannula has a distal end for
placement into the patient's skin, and, when the introducer is
connected to the cannula housing, the needle's distal tip extends
beyond the cannula's distal end.
11. The device of claim 9, wherein each said locking arm includes a
grip.
12. The device of claim 9, wherein at least one of the introducer
and the cannula housing is made of material selected from the group
consisting of polycarbonate and polypropylene.
13. The device of claim 9, wherein the cannula housing further
includes a self-sealing septum at an end of the fluid passageway
opposite the cannula.
14. The device of claim 9, wherein said arcuate profile of the
outer longitudinal surface of each of said first and second guide
rails is convex.
15. The device of claim 9, wherein the needle is stationary at all
times with respect to the first and second guide arms.
16. A method of inserting a cannula for subcutaneous administration
of fluid into a patient, comprising: positioning a cannula housing
at an insertion site on a patient, wherein the cannula housing
defines a fluid passageway along a longitudinal axis thereof,
wherein the cannula housing includes first and second guide rails
and a cannula, said cannula being in fluid communication with the
passageway, and wherein, along substantially the entire length
thereof, each of said guide rails has an outer longitudinal surface
with an arcuate profile; connecting an introducer to the cannula
housing, wherein the introducer includes separate first and second
guide arms, each said guide arm being configured to mate with a
respective one of the guide rails, and a longitudinally-extending
needle that is parallel to said guide arms and has a distal tip
that extends beyond respective distal ends of said first and second
guide arms, and wherein the cannula has a distal end for placement
into the patient's skin, and, when the introducer is connected to
the cannula housing, the needle's distal tip extends beyond the
cannula's distal end; inserting the needle and the cannula into the
insertion site; and disconnecting the introducer from the cannula
housing, whereby the needle is removed from the cannula.
17. The method of claim 16, wherein the introducer further includes
a plurality of locking arms, each said locking arm having a barb
associated therewith, and the cannula housing further defines a
plurality of recesses therein, each said recess being configured to
receive a respective one of said barbs so as to detachably connect
the introducer to the cannula housing.
18. The method of claim 16, wherein each said locking arm includes
a grip.
19. The method of claim 16, wherein at least one of the introducer
and the cannula housing is made of material selected from the group
consisting of polycarbonate and polypropylene.
20. The method of claim 16, wherein the cannula housing further
includes a self-sealing septum at an end of the fluid passageway
opposite the cannula.
21. The method of claim 16, wherein said arcuate profile of the
outer longitudinal surface of each of said first and second guide
rails is convex.
22. The method of claim 16, wherein the needle is stationary at all
times with respect to the first and second guide arms.
23. The method of claim 16, wherein the introducer is symmetrical
about its longitudinal axis such that it is reversible.
24. The method of claim 16, wherein the fluid is insulin.
25. The method of claim 16, wherein the cannula housing further
includes a base having an adhesive thereon for adhering the base to
the patient's skin at said insertion site.
Description
RELATED APPLICATION DATA
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/975,315, filed Oct. 18, 2007, which is a
continuation of U.S. patent application Ser. No. 11/003,225, filed
Dec. 3, 2004, now U.S. Pat. No. 7,303,543, all of which are
incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to an infusion set for
subcutaneous delivery of a selected medication or other fluid to a
patient. More particularly, this invention relates to an improved
infusion set having a cannula housing and a connector for
connecting the cannula housing to a delivery device, with the
cannula of the cannula housing being inserted into the patient by a
corresponding introducer.
[0004] 2. Description of Related Art
[0005] Infusion sets are typically used for delivering a selected
medication or other fluid to a patient. Infusion sets may include a
cannula, which may be relatively soft and flexible. The cannula
provides a transcutaneous passageway to administer a medication or
other fluid to a subcutaneous site on a patient. The cannula
generally attached to a cannula housing, which may be placed on the
skin of the patient when the cannula is inserted. A connector
attaches to the cannula housing to connect the cannula to the fluid
delivery system. The fluid delivery system is generally placed in
fluid communication with the connector by way of a length of
infusion tubing. Examples of fluid delivery systems are shown in
U.S. Pat. Nos. 4,562,751, 4,685,903, 5,080,653, 5,097,122, which
are herein incorporated by reference.
[0006] Infusion sets of the type described above are generally used
to deliver medication, such as insulin, to a patient over an
extended period of time. The infusion sets usually are adapted to
rest on the skin of the patient. The cannula housing may remain on
the patient's skin for several days, and the patient may disconnect
the connector when performing certain activities, like showering.
Because a patient changes infusion sets fairly frequently, it is
beneficial to have an infusion set that is easy to insert, easy to
connect properly, and easy to remove and dispose of.
[0007] An infusion set of the above type is described in U.S. Pat.
No. 5,522,803. The infusion set comprises a cannula housing with a
cannula and a needle holder to be connected to the cannula housing.
The cannula housing includes two guide openings and two locking
openings with shoulders for engaging barbs on locking pins of the
needle holder. The needle holder includes guide pins that
co-operate with the guide openings on the cannula housing. The
needle on the needle holder is guided by the guide pins into the
cannula housing so that the needle penetrates a membrane at the
inlet of a fluid passageway of the cannula housing. The fluid
passageway is in fluid communication with the cannula. Thus, when
the needle penetrates the membrane, the fluid may flow through the
connector into the cannula housing and then into the patient. The
guide pins must be guided carefully into the guide openings, as the
guide openings surround the pins on all four sides when the cannula
housing and needle holder are guided together.
[0008] Another infusion set of the above type is described in U.S.
Pat. No. 6,302,866. The infusion set comprises a cannula housing
with a cylindrical extension and a needle holder with a guide
sleeve that closely slides over the cylindrical extension. The
connection must be done carefully, because the cylindrical
extension fits closely into the guide sleeve. The guide sleeve
surrounds a connecting needle that is guided into the passageway of
the cylindrical extension. The passageway in the cylindrical
extension is in fluid communication with the cannula and has a
septum at its inlet that is pierced by the connecting needle. Once
the septum is pierced, fluid can flow from an infusion device
through the needle holder into the cannula housing and then into
the patient.
BRIEF SUMMARY OF THE INVENTION
[0009] In accordance with the invention, an infusion set is
provided for use in delivering fluid through a cannula to a
selected subcutaneous infusion site on a patient. The fluid is
generally a medication, for example, insulin. The cannula is a soft
and flexible cannula and is supported by a cannula housing. The
cannula housing also includes a fluid passageway in fluid
communication with the cannula. At one end of the fluid passageway
is a self-sealing septum. The fluid passageway is surrounded by a
projection on the cannula housing that includes one or more
rail-like extensions acting as connection guides. The rail-like
extensions may be substantially triangular or otherwise suitably
shaped to act as guides. The cannula housing also includes a base
that rests upon a patient's skin when the cannula is inserted into
the skin.
[0010] The infusion set also includes a connector that connects the
cannula housing to fluid tubing that allows fluid to flow from a
fluid source, which may be a fluid delivery system, such as an
infusion pump, through the connector to the cannula housing and
through the cannula into the patient. The connector includes a
connecting needle that is mounted thereon to pierce the
self-sealing septum on the cannula housing to allow flow of fluid
through the needle into the fluid passageway. The connecting needle
is in fluid communication with the fluid tubing. The connector also
includes one or more guide arms that slide over the rail-like
extensions to guide the needle into the self-sealing septum. The
connector includes one or more locking arms, with barbs at the end,
to connect with one or more recesses that are provided in the
cannula housing. Once the barbs are pushed into the recesses, the
connector is essentially locked in place with respect to the
cannula housing. The connector is preferably reversible so that it
may be connected to the cannula housing regardless of which side is
up.
[0011] The cannula housing is inserted into the skin using an
introducer. The introducer has the same guide arms and locking arms
as the connector. It includes an introducing needle that passes
through the self-sealing septum and fluid passageway of the cannula
housing and into the cannula. When connected to the cannula
housing, the tip of the introducing needle is outside the
cannula.
[0012] A method of delivery of a fluid is provided comprising
positioning a cannula housing according to the invention at an
infusion site on a patient and engaging the cannula housing with a
connector according to the invention. The positioning of the
cannula housing may include using an introducer according to the
invention to pierce the skin of the patient, and removing the
introducer from the cannula housing once the cannula housing is
positioned on the infusion site.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A detailed description of embodiments of the invention will
be made with reference to the accompanying drawings, wherein like
numerals designate corresponding parts in the figures.
[0014] FIG. 1 is a perspective view of a cannula housing and
connector in connected form in accordance with an embodiment of the
invention.
[0015] FIG. 1A is a top view of a cannula housing and connector in
connected form in accordance with an embodiment of the
invention.
[0016] FIG. 2 is perspective view of a cannula housing, connector,
introducer, and internal components in accordance with an
embodiment of the invention in an exploded view.
[0017] FIG. 3 is a perspective view of a cannula housing in
accordance with an embodiment of the invention.
[0018] FIG. 4 is a perspective view of a connector in accordance
with an embodiment of the invention.
[0019] FIG. 5 is a perspective view of an introducer in accordance
with an embodiment of the invention.
[0020] FIG. 6 is a horizontal sectional view of a cannula housing
and connector in connected form in accordance with an embodiment of
the invention.
[0021] FIG. 7 is a perspective view of a cannula housing and
introducer in separated form in accordance with an embodiment of
the invention.
[0022] FIG. 8 is a perspective view of a cannula housing and
introducer in separated form in accordance with an embodiment of
the invention.
[0023] FIG. 9 is a perspective view of a cannula housing and
introducer in separated form in accordance with an embodiment of
the invention.
[0024] FIG. 10 is a perspective view of a cannula housing and
connector in separated form in accordance with an embodiment of the
invention.
[0025] FIG. 11 is a top and a bottom perspective view of a cannula
housing and connector in separated form in accordance with an
embodiment of the invention.
[0026] FIG. 12 is a top perspective view of a cannula housing and
introducer in separated form in accordance with an embodiment of
the invention.
[0027] FIG. 13 is a perspective view of a cannula housing and
introducer in separated form in accordance with an embodiment of
the invention.
[0028] FIG. 14 is a top perspective view of a cannula housing and
introducer in separated faun in accordance with an embodiment of
the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] In the following description, reference is made to the
accompanying drawings which form a part hereof and which illustrate
several embodiments of the present invention. It is understood that
other embodiments may be utilized and structural and operational
changes may be made without departing from the scope of the present
invention.
[0030] As shown in FIGS. 1-3, the infusion set comprises a cannula
housing 100 and a connector 120. The cannula housing 100 carries a
soft and flexible cannula 200. The cannula 200 may be tapered at
the end. Any flexible tubing may be used for the cannula, provided
that is biocompatible and insulin compatible. For example, but
without limitation, the cannula 200 may be composed of
polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene
(FEP). The cannula housing 100 has a base 220 that rests upon the
patient's skin when the cannula 200 is inserted into the patient.
The base 220 may be attached to the patient's skin, for example by
an adhesive patch. Although the base 220 is shown as at least
partially circular in nature, it may be square, rectangular or any
other shape that is desired. A projection 240 of the cannula
housing 100 surrounds a fluid passageway (not shown) that is in
fluid communication with the cannula 200. At the end of the fluid
passageway opposite the cannula is a septum 295. This may be a
self-sealing septum, for example a substantially barrel-shaped,
such as a beer-barrel shaped, self-sealing septum. The septum may
also be substantially shaped like a disc or a ball, or any other
preferable shape.
[0031] The projection 240 is generally at least partially attached
along its length to the base 220. However, the projection 240 may
be entirely separate from the base 220 along its length, allowing a
space between the projection 240 and the base 220. The end of the
projection 240 opposite the end with the septum 295 would still be
attached to remainder of the cannula housing 100, such that the
cannula housing 100 is still only one integral piece. The base 220
may also have a groove 260 cut into it to allow for a higher
projection without the need for the entire cannula housing 100 to
be taller. The projection 240 may have a relatively flat top, which
can also reduce the height of the cannula housing 100 and of the
infusion set and can reduce the overall volume of the infusion set.
When the infusion set is thinner, it can have a lower profile and
be less noticeable.
[0032] The two sides of the projection 240 on the cannula housing
100 are rail-like extensions or guide rails 242 and 244. These
guide rails 242 and 244 may be substantially triangular, as shown,
but they may be shaped in any other configuration that allows for
guiding of the connector 120 onto the cannula housing 100. For
example, they could be rectangular or peg-shaped. At the side of
the cannula housing 100 near the cannula 200, there are two
recesses 270 and 272 formed to receive barbs that are on locking
arms of the connector. These guide rails are visible to the user,
making the infusion set easier to connect. Additionally, the base
of the cannula housing assists in guiding the needle, acting as a
bottom boundary for a connector. The cannula is preferably angled
so that the cannula is inserted into the skin at an angle. The
fluid passageway and connector fluid passageway may each be
similarly angled. If both are angled to match the cannula, the
passage of fluid will be one straight line from the point at which
the fluid enters the connector until the end of the cannula, where
the fluid enters the patient's body.
[0033] As shown in FIGS. 1, 2 and 4, the connector 120 connects the
cannula housing 100 to fluid tubing 300, which allows fluid to flow
from a fluid source, which may be a fluid delivery system, such as
an infusion pump 500 (as shown in FIG. 1), to the connector 120.
The connector 120 includes a connecting needle 320, which is in
fluid communication with the fluid tubing 300. Inside the connector
120, a connector fluid passageway allows the connecting needle 320
to be in fluid communication with the fluid tubing 300. The
connector 120 has two locking arms 340 and 342, with barbs 341 and
343 on each that are received by the recesses 270 and 272 on the
cannula housing 100. There may be grips on one or more edges of the
locking arms 340 and 342 for facilitating grasping by the user.
When the barbs 341 and 343 are engaged with the recesses 270 and
272, the connector 120 is essentially locked into the cannula
housing 100. To disconnect the connector 120 from the cannula
housing 120, the user pushes the locking arms 340 and 342 toward
each other and releases the barbs 341 and 343 from the recesses 270
and 272. Alternatively, the locking arms 340 and 342 may be formed
as levers, which would allow the ends of the locking arms to
release outwardly when the user pressed on the ends opposite the
barbs. It is also possible to remove one of the locking arms
entirely or to replace one locking arm with an arm that does not
latch or lock into the cannula housing. In such an embodiment, only
one locking arm would lock into the cannula housing. As another
alternative, the locking arms may have alternative locking
structures to barbs, such as clips or other connecting pieces.
[0034] On either side of the needle 320 on the connector 120 are
guide arms 350 and 352. The guide arms 350 and 352 extend alongside
and past the needle 320. Because the guide arms 350 and 352 extend
past the needle 320, it is difficult for the user to be injured by,
or to injure, the needle 320 when the connector 120 is separated
from the cannula housing 100. The guide arms 350 and 352 have
indentations 351 and 353 that match the guide rails 242 and 244 of
the projection 240 of the cannula housing 100. For example, if the
guide rails 242 and 244 are triangular in shape, the guide arms 350
and 352 will have triangular indentations. When the user connects
the connector 120 to the cannula housing 100, the guide arms 350
and 352 slide along the projection 240, guiding the needle 320 into
the fluid passageway of the cannula housing 100.
[0035] The connector is preferably symmetrical, so that it is
reversible and may be placed into the connector with either of its
top or bottom facing upward. If the connector is symmetrical, the
patient does not have to worry about which way to place the
connector. This will allow for quicker and easier connection.
[0036] The cannula housing may be adhered to the patient's skin by
an adhesive. The adhesive may be on a patch that is attached to the
base of the cannula housing. In one embodiment, as shown in FIGS.
1, 1A and 2, the adhesive is covered with a one or more piece liner
160 (or 165 in FIG. 1A) that the patient removes to release the
adhesive side. The liner 160 protects the adhesive from being
removed or from attaching to anything else until the patient wishes
to use the infusion set. The liner can also keep the adhesive layer
relatively sterile. As shown in FIGS. 1 and 2, the adhesive may be
on a flat patch that is attached to the base. Alternatively, the
adhesive may be folded, as shown in FIG. 1A. In the folded
configuration, the patient removes a small liner piece from the
unfolded portion of the patch. The patient then inserts the cannula
into the skin. Afterward, the user pulls the liner off of the
folded portion of the patch, allowing it to lie flat on the user's
skin. In either configuration, the patch may be colored, patterned,
or a combination of both. In the folded configuration, the small
liner piece from the unfolded portion may have a color and/or
pattern that is different from the color and/or pattern on the
folded portion to more easily differentiate between the two
liners.
[0037] To insert the cannula into the patient, an introducer may be
used. As shown in FIGS. 2 and 5, the introducer 140 has guide arms
450 and 452 and locking arms 440 and 442 that are shaped the same
as those on the connector 120. However, the introducer needle 400
is much longer than the needle on the connector. The introducer
needle 400 is long enough that when the introducer 140 is connected
to the cannula housing 100, the tip of the introducer needle 400
extends beyond the cannula 200. The introducer needle 400 may be
affixed to the introducer 140 by a UV or other type of adhesive, by
welding, by a molding process, or by any other suitable process. To
insert the cannula 200 into the patient, the user grips the joined
introducer 140 and cannula housing 100 and inserts the tip of the
introducer needle 400 into the patient. The introducer needle 400
and cannula 200 are pushed into the patient, so that the cannula
200 is almost entirely under the skin of the patient. The cannula
housing 100 is preferably affixed to the patient's outer skin, and
the introducer 140 is unlocked and removed from the cannula housing
100. The connector 120 can then be inserted and locked into the
cannula housing 100 so that fluid may be infused into the patient.
In further embodiments, rubber grips may be overmolded onto the
grips of the introducer and/or the connector to improve ability to
grasp the introducer and/or connector. In addition, rubber overmold
may be added to the cannula housing 100 to improve the user's
ability to grasp the part during removal of the introducer 140 or
connector 120.
[0038] The cannula housing 100 can be packaged connected to the
introducer. To protect the patient from injury from the needle, a
needle guard may cover the introducer needle, which extends beyond
the cannula. The needle guard may be a small plastic tube that
covers the needle and some or all of the cannula. If a small
plastic tube is used as a needle guard, it may be colored so that
it is easily visible. Thus, the patient easily would be able to see
if the needle guard is in place. The small plastic tube may have
only holes at each end of the tube. Alternatively, it may be slit
down the side for ease of removal and replacement. A slit guard may
reduce damage to the cannula 200 caused by attempting to slide the
small plastic tube onto the needle and cannula. A larger needle
cover may also be used. The larger needle cover may connect or snap
to the cannula housing. It may also act as a cover for the
introducer after insertion of the cannula, when the introducer is
removed from the cannula housing.
[0039] The cannula housing may be made out of a plastic, such as an
acrylic or polypropylene or polycarbonate. A polycarbonate cannula
housing may be transparent, so that the patient can see whether any
bubbles are present in the fluid passageway. The connector may also
be made out of a plastic, such as an acrylic or polypropylene or
polycarbonate. As in the cannula housing, a polycarbonate connector
may be transparent, so that the patient can see whether any bubbles
are present in the connector fluid passageway. The plastics used
for the cannula housing and the connector should be compatible with
the medication or fluid selected for delivery through these parts
and should pass the required biological tests for skin contact.
[0040] The patch or infusion set itself may be time-sensitive, to
indicate to the patient when it is time to remove the infusion set.
A time-sensitive indicator may be chemical, mechanical, or
electrical. The patch itself, a portion of the patch, the infusion
set, or a portion of the infusion set may contain an ink that
changes color or appearance with passage of time. An infusion set
is typically used for a minimum of 3 days, but may be adapted to be
used for any predetermined period of time. Similarly, the
time-sensitive indicator may be designed to be used for any
predetermined period of time. Alternatively, a different colored
patch may be used for a different day of the week, meaning the
first and/or last day for the infusion set, so that the user will
easily know when to change the infusion set. For example, if the
color red means the first day for the set is Monday and the last
day is set for Wednesday, the user will know to insert the infusion
set on Monday and to remove it on Wednesday. Graphics and other
designs may also be printed on the patches.
[0041] FIG. 6 is a cutaway view of the infusion set comprising the
cannula housing 100 and the connector 120. The connecting needle
320 has pierced the substantially beer-barrel shaped septum 295 to
allow flow from the fluid tubing 300 into the fluid passageway 380.
At the end of the cannula housing 100, past the beer-barrel shaped
septum 295 there may be a washer 290, which can assist in holding
the beer-barrel shaped septum 295 in place and provide compression
to the septum to create a seal. The washer 290 may be made of
suitable materials, for example metal or plastic. The washer 290
may be welded to the connector to retain the septum 295. A needle
guide 395 may be used to align the needle with the fluid passageway
380. The needle guide 395 may be a metal guide or a plastic guide.
To seal the needle guide 395 into the cannula housing 100, one or
more sealing points may be used.
[0042] To aid in insertion of the cannula, an injector tool may be
used. Injector tools may be of the type described in PCT
Publication No. WO 02/100457 A2, entitled "Insertion Device for an
Insertion Set and Method of Using Same," published Dec. 19, 2002,
which is herein incorporated by reference. Injector tools are
useful for patients who are reluctant or hesitant to pierce their
own skin with a medical needle. The injector tool is designed to
place the needle through the skin at a selected insertion angle and
with a controlled force and speed of insertion to ensure proper
placement with minimal discomfort.
[0043] Without being limited, several other embodiments of infusion
sets comprising cannula housings and connectors, and the
corresponding introducers, are described below. Because the
structure of the portion of the introducer that mates with the
cannula housing is the same as the portion of the connector that
mates with the cannula housing, each embodiment is described with
respect to the introducer and cannula housing or with respect to
the connector and cannula housing. It is intended that the
connector and/or introducer not described has the same mating
structure as the element that is described.
[0044] As shown in FIG. 7, in one embodiment the introducer 140
does not have guide arms that are separate from locking arms.
Instead, the locking arms 640 and 642 each include barbs (641 and
643) and guide rails (644 and 645). The guide rails 644 and 645
slide into recesses 650 and 652 on the cannula housing 100.
[0045] As shown in FIG. 8, in one embodiment the introducer 140
does not have guide arms. The locking arms 740 and 742 with barbs
741 and 743 are as described with respect to FIGS. 1-4. The
introducer 140 includes a guide sheath 750 that closely slides over
the projection 760 on the cannula housing 120 that surrounds the
fluid passageway (not shown). The guide sheath 750 is also guided
by two guide rails 772 and 774 that contain indentations matching
the exterior of the guide sheath 750. Thus the guide sheath closely
fits in between the projection 760 and the guide rails 772 and 774
to guide the introducer 140 and introducer needle (not shown) into
the cannula housing 100.
[0046] As shown in FIG. 9, in one embodiment the introducer 140
does not have guide arms. The locking arms 840 and 842 with barbs
841 and 843 are as described with respect to FIGS. 1-4. The
introducer 140 has a dove tail 850 that mates with a cut-out 860 to
guide the introducer 140 and introducer needle (not shown) into the
cannula housing 100.
[0047] As shown in FIG. 10, in one embodiment the connector 120
does not have guide arms. The locking arms 940 and 942 with barbs
941 and 943 are as described with respect to FIGS. 1-4. The
connector 120 also includes a guide pin 956 that can mate with one
of two guide openings 960, 962 on the cannula housing 100. As in
other embodiments, the cannula housing 100 and connector 120 are
preferably symmetrical, aside from the one guide pin 956, so that
the user may insert the connector 120 into the cannula housing 100
regardless of which side is up. Thus, whether the one guide pin 956
will slide into a particular guide opening, 960 or 962, is
dependent upon which way the connector 120 is placed with respect
to the cannula housing 100. But it will be equally easy to slide
the connector 120 into the cannula housing 100 in each
placement.
[0048] As shown in FIG. 11, in one embodiment the connector 120
does not have guide arms. Instead, the locking arms 1040 and 1042
each include barbs (1041 and 1043) and guide rails (1044 and 1045).
The guide rails 1044 and 1045 slide into recesses 1050 and 1052 on
the cannula housing 100. Additionally, this embodiment may include
underside rails 1053 and 1054 on the cannula housing 100, which
slide alongside matching underside guide features 1055 and 1056 on
the locking arms 1040 and 1042. Thus, the connector 120 is guided
into the cannula housing 100 by both combinations of the guide
rails 1044, 1045 and recesses 1050, 1052 and the underside rails
1053, 1054 and underside guide features 1055, 1056.
[0049] As shown in FIGS. 12-14, in several embodiments, the
connector 120 does not have guide arms. The locking arms (1140 and
1142, 1240 and 1242, and 1340 and 1342) with barbs (1141 and 1143,
1241 and 1243, and 1341 and 1343) are as described with respect to
FIGS. 1-4. The connector 120 includes a partial guide sheath which
may be a half box sheath 1150, an incomplete box sheath 1250, or an
incomplete oval sheath 1350. The guide sheath (1150, 1250, or 1350)
closely slides over the projection (1160, 1260, or 1360) on the
cannula housing 100 that surrounds the fluid passageway (not
shown). The guide sheath (1150, 1250, or 1350) is also guided by
two guide rails (1172 and 1174, 1272 and 1274, and 1372 and 1374)
that mate with the exterior of the guide sheath (1150, 1250, or
1350). Thus the guide sheath closely fits in between the projection
and the guide rails to guide the connector 120 and connector needle
(not shown) into the cannula housing 100.
[0050] 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.
[0051] The presently disclosed 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 the foregoing description, and all changes which come
within the meaning and range of equivalency of the claims are
therefore intended to be embraced therein.
* * * * *