U.S. patent application number 10/756310 was filed with the patent office on 2004-07-22 for subcutaneous injection set for use with a reservoir that has a septum.
Invention is credited to Douglas, Joel, Hugo, Robert.
Application Number | 20040143241 10/756310 |
Document ID | / |
Family ID | 27497198 |
Filed Date | 2004-07-22 |
United States Patent
Application |
20040143241 |
Kind Code |
A1 |
Douglas, Joel ; et
al. |
July 22, 2004 |
Subcutaneous injection set for use with a reservoir that has a
septum
Abstract
An infusion set includes a needle hub with a needle to be
inserted in a through passageway of the cannula housing through a
sealing surface of a soft cannula. The infusion set includes a
guide for centering the needle relative to the cannula sealing
surface, a dirt trap, and the through passageway, as well as a
locking device for locking the cannula housing and the needle hub
together to prevent inadvertent disengagement. The guide includes
co-operating guide pins and guide openings and a draft angle on the
needle hub. The pins are located on each side of the needle and the
through passageway. The connecting tube includes an inner tube of
polyethylene and shrink fitted tubing at each end suitable for a
solvent bonding layer. The composite can be reinforced with
monofilament strands sandwiched between the two tubular layers to
prevent kinking, or the inner tube can be formed in a triangular
shape. The triangular shape composite is incased in a thin
polyester shrink tube.
Inventors: |
Douglas, Joel; (Los Altos
Hills, CA) ; Hugo, Robert; (Gilroy, CA) |
Correspondence
Address: |
BURNS DOANE SWECKER & MATHIS L L P
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Family ID: |
27497198 |
Appl. No.: |
10/756310 |
Filed: |
January 14, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10756310 |
Jan 14, 2004 |
|
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|
09675159 |
Sep 29, 2000 |
|
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|
60195702 |
Apr 7, 2000 |
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60188624 |
Mar 13, 2000 |
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60176538 |
Jan 18, 2000 |
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Current U.S.
Class: |
604/533 |
Current CPC
Class: |
A61M 25/0014 20130101;
A61M 25/0009 20130101; A61M 25/0097 20130101 |
Class at
Publication: |
604/533 |
International
Class: |
A61M 025/16 |
Claims
What is claimed is:
1. A medication infusion set comprising: a base tube having an
exterior surface, a proximal end, a distal end, and an inner lumen
extending between the proximal and distal ends, the base tube
formed of a material selected from the group consisting of
polyethylene and polypropylene; a rigid cannula having a proximal
end, a distal end, and a lumen extending between the proximal and
distal ends, the cannula proximal end positioned in the base tube
lumen; and a tube of a heat shrinkable material positioned on the
base tube exterior surface at least in a region of the base tube in
which the cannula is inserted, the heat shrinkable tube having been
heat shrunk to the exterior of the base tube and compressing the
base tube and the cannula together to form a seal.
2. A medication infusion set in accordance with claim 1, further
comprising: a connector including a cylindrical collar having a
hollow interior, a closed end, and an open end, the distal end of
the rigid cannula extending through the collar closed end and into
the hollow interior; and a solvent based adhesive bonding the
connector to the heat shrunk tube.
3. A medication infusion set in accordance with claim 1, further
comprising: a soft cannula having a proximal end, a distal end, and
a lumen extending between the proximal end and distal ends, the
soft cannula proximal end in fluid communication with the base tube
distal end.
4. A medication infusion set in accordance with claim 1, wherein
the heat shrinkable material is selected from the group consisting
of PVC, polyester, and PTFE.
5. A medication infusion set in accordance with claim 1, further
comprising at least one filament between the heat shrunk tube and
the base tube and extending along the base tube.
6. A medication infusion set in accordance with claim 1, wherein
the base tube has a triangular cross-sectional shape.
7. An infusion device comprising: a housing including a proximal
end, a distal end, two lateral sides, and a bore extending between
the proximal end and the distal end; a soft cannula having a
proximal end, a distal end, and a lumen extending between the
proximal end and the distal end, the cannula positioned in part in
the housing bore with the cannula distal end outside of the
housing; a locking device attached to a lateral side of the
housing, the locking device including a locking finger and a lever,
the lever extending distally and the locking finger extending
proximally, the locking finger including a distally facing
surface.
8. An infusion device in accordance with claim 7, wherein the
housing bore includes a proximal opening, and further comprising a
dust door positioned adjacent to the bore proximal opening, the
dust door formed of a resilient and flexible material, the dust
door including a planar sheet having at least one slit through the
sheet to form at least two flaps.
9. An infusion device in accordance with claim 7, wherein the soft
cannula lumen has a first inner diameter and a second smaller inner
diameter, the second inner diameter being in a region adjacent the
cannula proximal end.
10. An infusion device in accordance with claim 7, wherein the soft
cannula further comprises an exterior surface and a bead extending
from the exterior surface between the proximal and distal ends.
11. A connecting device comprising: a hub including a proximal end
face, a distal end face, two lateral sides, and a bore extending
between the proximal end and the distal end; a rigid cannula
including a proximal end, a distal end, and a lumen extending
between the proximal end and the distal end, the rigid cannula
mounted in the hub bore with the rigid cannula distal end exterior
of the hub; a pin extending distally from the hub distal end face
and offset laterally from the rigid cannula; a proximally facing
surface on one of the lateral sides positioned between the proximal
end face and the distal end face.
12. A connecting device in accordance with claim 11, further
comprising a length of tubing having a proximal end, a distal end,
and a lumen extending between the proximal end and the distal end,
the tubing distal end positioned in the hub bore and in fluid
communication with the rigid cannula lumen.
13. A connecting device in accordance with claim 11, wherein the
pin is a first pin, and further comprising a second pin extending
distally from the hub distal end face and offset laterally from the
rigid cannula and from the first pin.
14. A process of forming a medical infusion set, comprising the
steps of: inserting an end of a rigid cannula into the lumen of a
length of tubing; heat shrinking a tube of heat shrinkable material
over the portion of the tubing in which the end of the rigid
cannula is positioned to compress the tubing onto the rigid
cannula.
15. A process in accordance with claim 14, wherein the tubing is
formed of a material selected from the group consisting of
polyethylene and polypropylene.
16. A process in accordance with claim 14, wherein the heat
shrinkable material is selected from the group consisting of PVC,
polyester, and PTFE.
17. A process in accordance with claim 14, further comprising:
solvent bonding a connector to the heat shrunk tube, the connector
including a collar through which the another end of the rigid
cannula extends.
Description
[0001] The present application is related and claimed priority to
U.S. application Ser. No. 09/675,159, filed Sep. 29, 2000; U.S.
application serial number 60.backslash.195,702, filed Apr. 7, 2000;
U.S. application serial number 60.backslash.188,624, filed Mar. 13,
2000; and U.S. application serial number 60.backslash.176,538,
filed Jan. 18, 2000, the entire contents of each of which is
incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to medical connectors and
infusion sets.
[0004] 2. Brief Description of the Related Art
[0005] In general, whenever a therapeutic fluid is to be delivered
subcutaneously to a patient form an external source, a passageway,
such as that provided by a hollow needle or other type of cannula
or catheter device, must be first inserted through the skin of the
patient in order to provide a passageway or channel through which
the fluid may pass from its source external to the patient to the
desired subcutaneous location under the skin of the patient. Once
this passageway has been installed, the desired infusion system may
be used in conjunction with an appropriate catheter connecting the
external source of fluid with the passageway leading to the
subcutaneous delivery point to deliver the fluid to the patient at
an appropriate delivery rate.
[0006] Unfortunately, several problems associated with infusing
fluids into the patient as described above are usually encountered.
Most systems require the patient to use a syringe that is fitted
with a thread or luer fitting. The patient must fill the syringe
and attach the catheter to it. However, in doing so the medication
can become contaminated and is therefore no longer sterile.
Non-sterile solutions can lead to infection. In addition the
inconvenience of having to fill the syringe in the first place, and
then attach and prime the catheter is difficult for many
patients.
[0007] In the early 1990's prefilled insulin cartridges were first
introduced by insulin manufacturing companies for use in insulin
pens. These cartridges are prefilled and make their use very
convenient for the patient. The difficulty is that the prefilled
cartridges need to have a septum to allow the medication to remain
sterile.
[0008] The recent popularity of insulin infusion pumps as an
alternative to multiple daily injections for insulin-dependent
diabetics requires the use of such an injection set to deliver
insulin from a small, portable insulin infusion pump to the
subcutaneous injection location. However, these devices require the
patient to fill a syringe, which defeats the sterility of the
mixture. Furthermore, there exists a substantial problem with the
use of injection sets, as described above, in that flexible PVC is
not completely insulin-compatible. This is in contrast to hard PVC,
which is safe for use with insulin. While the exact nature of the
reaction exhibited by insulin in contact with flexible PVC has not
been determined with certainty, it is believed that the insulin,
which is pH sensitive, reacts with CO.sub.2, the flow of which
therethrough is not inhibited by flexible PVC. In addition, the
large quantities of plasticizer used in flexible PVC may result in
a leaching problem when used with insulin.
[0009] Since flexible PVC is not a barrier for CO.sub.2, the
CO.sub.2 which flows through the flexible PVC tubing will react
with the insulin, causing the insulin to aggregate and to
precipitate out of solution. Such precipitation of the insulin will
likely cause clotting and blockage in the tube or in the needle,
thereby inhibiting the flow of insulin to the subcutaneous
depot.
[0010] Heat will also accelerate the clotting process of insulin in
flexible PVC tubing without the pH change caused by CO.sub.2. The
reason for this has not been finally determined, but it may be due
to zinc in the insulin forming zinc chloride. In any event, heat
will further compound the situation faced by delivery of insulin
through flexible PVC tubing.
[0011] The amount of insulin exiting the injection set will
therefore vary considerably, with portions of the insulin becoming
attached to the interior of the tube and eventually coating the
interior of the tube, even if blockage does not occur. Over time,
the situation will improve somewhat assuming blockage of the tube
per se does not occur, but the amount of insulin actually delivered
to the patient will vary considerable even with the best of
circumstances. It may therefore be appreciated that the use of a
flexible PVC tubing injection set to deliver insulin from an
insulin infusion pump is neither desirable nor medically
acceptable.
[0012] Other substances exhibit reactions when delivered through
flexible PVC tubing. Lipids and proteins have adverse reactions
with flexible PVC delivery systems, and nitroglycerin also reacts
to some degree with a flexible PVC environment.
[0013] One solution which has been proposed to the problem has been
through the use of polyethylene tubing, which does not cause a
reaction with insulin passing therethrough. Polyethylene is a
barrier to CO.sub.2, and the major problem of CO.sub.2 passing
through the tubing is thereby eliminated. Additionally, the problem
of clotting of the insulin due to heat is also substantially
minimized.
[0014] Several problems have arisen with the use of epoxy bonded
polyethylene infusion sets, all of which are due to the relative
disadvantage of the epoxy bonding process to a solvent bonding
process. First of all, an epoxy bond is simply not as strong as a
solvent bond. Secondly, epoxy bonds have substantial aging
problems, which limit shelf life of the injection set. Since the
epoxy bond loses its mechanical bonding properties over time, the
injection set will become less sturdy, with the potential for the
tubing coming loose from the needle increasing substantially over
time. Thirdly, batch control of epoxy used in epoxy bonding is time
consuming and cumbersome. Finally, epoxy bonding or "potting" is a
more expensive process than solvent bonding, resulting in a product
having an economic disadvantage relative to a product made by
solvent bonding.
[0015] It is thereby apparent that there exists a substantial need
for an injection set for delivery of insulin (or other fluids
exhibiting reactions when flowed through flexible PVC tubing),
which injection set utilizes polyethylene tubing to inhibit
reaction and subsequent degradation of insulin flowing
therethrough.
SUMMARY OF THE INVENTION
[0016] According to a first exemplary embodiment, a medication
infusion set comprises a base tube having an exterior surface, a
proximal end, a distal end, and an inner lumen extending between
the proximal and distal ends, the base tube formed of a material
selected from the group consisting of polyethylene and
polypropylene, a rigid cannula having a proximal end, a distal end,
and a lumen extending between the proximal and distal ends, the
cannula proximal end positioned in the base tube lumen, and a tube
of a heat shrinkable material positioned on the base tube exterior
surface at least in a region of the base tube in which the cannula
is inserted, the heat shrinkable tube having been heat shrunk to
the exterior of the base tube and compressing the base tube and the
cannula together to form a seal.
[0017] According to a second exemplary embodiment, an infusion
device comprises a housing including a proximal end, a distal end,
two lateral sides, and a bore extending between the proximal end
and the distal end, a soft cannula having a proximal end, a distal
end, and a lumen extending between the proximal end and the distal
end, the cannula positioned in part in the housing bore with the
cannula distal end outside of the housing, and a locking device
attached to a lateral side of the housing, the locking device
including a locking finger and a lever, the lever extending
distally and the locking finger extending proximally, the locking
finger including a distally facing surface.
[0018] According to a third exemplary embodiment, a connecting
device comprises a hub including a proximal end face, a distal end
face, two lateral sides, and a bore extending between the proximal
end and the distal end, a rigid cannula including a proximal end, a
distal end, and a lumen extending between the proximal end and the
distal end, the rigid cannula mounted in the hub bore with the
rigid cannula distal end exterior of the hub, a pin extending
distally from the hub distal end face and offset laterally from the
rigid cannula, and a proximally facing surface on one of the
lateral sides positioned between the proximal end face and the
distal end face.
[0019] According to a fourth exemplary embodiment, a process of
forming a medical infusion set comprises the steps of inserting an
end of a rigid cannula into the lumen of a length of tubing, and
heat shrinking a tube of heat shrinkable material over the portion
of the tubing in which the end of the rigid cannula is positioned
to compress the tubing onto the rigid cannula.
[0020] Still other objects, features, and attendant advantages of
the present invention will become apparent to those skilled in the
art from a reading of the following detailed description of
embodiments constructed in accordance therewith, taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention of the present application will now be
described in more detail with reference to preferred embodiments of
the apparatus and method, given only by way of example, and with
reference to the accompanying drawings, in which:
[0022] FIG. 1 illustrates a perspective view of a first embodiment
of an infusion set and connector in accordance with the present
invention;
[0023] FIG. 2 illustrates a longitudinal cross-sectional view of
the set of FIG. 1;
[0024] FIGS. 3 and 4 illustrate top plan views, with portions
broken away in FIG. 4, of another embodiment of an infusion set in
accordance with the present invention;
[0025] FIG. 5 is a top plan view of a portion of the devices
illustrated in FIG. 4;
[0026] FIG. 6 is a front elevational view of the device in FIG.
5;
[0027] FIG. 7 is a rear (upsidedown) elevational view of the device
in FIG. 5;
[0028] FIG. 8 is a left side elevational view of the device in FIG.
5;
[0029] FIG. 9 is a cross-sectional view, taken at line 9-9 in FIG.
5;
[0030] FIGS. 10 and 11 illustrate enlarged views of portions of the
device illustrated in FIG. 5;
[0031] FIG. 12 illustrates a top plan view of a portion of the
device illustrated in FIG. 4;
[0032] FIG. 13 illustrates a side elevational (upsidedown) view of
the portion in FIG. 12;
[0033] FIG. 13a illustrates another portion of the device in FIG.
12;
[0034] FIG. 14 illustrates a front elevational view of the device
in FIG. 12;
[0035] FIG. 15 illustrates a top plan view of an insertion device
in accordance with the present invention;
[0036] FIG. 16 illustrates a side elevational view of the device
illustrated in FIG. 15;
[0037] FIG. 17 illustrates a top plan view of a plug in accordance
with the present invention;
[0038] FIG. 18 illustrates a front elevational view of the plug
illustrated in FIG. 17;
[0039] FIG. 19 illustrates a cross-sectional view taken at line
19-19 in FIG. 18;
[0040] FIG. 20 illustrates a longitudinal cross-sectional view of a
cannula in accordance with the present invention;
[0041] FIG. 21 illustrates a perspective view of a pen needle in
accordance with the present invention;
[0042] FIG. 22 illustrates a longitudinal cross-sectional view of
the pen needle illustrated in FIG. 21;
[0043] FIG. 23 illustrates yet another device in accordance with
the present invention;
[0044] FIG. 24 illustrates a perspective view of a portion of the
device illustrated in FIG. 23;
[0045] FIG. 25 illustrates a longitudinal cross-sectional view of
the portion of FIG. 24;
[0046] FIG. 26 illustrates a portion of the device illustrated in
FIG. 25;
[0047] FIG. 27 illustrates yet another aspect of the present
invention;
[0048] FIG. 28 illustrates an enlarged top plan view of a portion
of the device illustrated in FIG. 23;
[0049] FIG. 29 illustrates a side view, partially in cross-section,
of the portion illustrated in FIG. 28;
[0050] FIG. 30 illustrates a longitudinal cross-sectional view
along line 30-30 in FIG. 29;
[0051] FIG. 31 illustrates a cross-sectional view of a tube in
another aspect of the present invention;
[0052] FIGS. 32 and 33 illustrate yet further aspects of the
present invention; and
[0053] FIGS. 34 and 35 illustrate portions of a device in
accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] Referring to the drawing figures, like reference numerals
designate identical or corresponding elements throughout the
several figures.
[0055] The present invention relates to a disposable injection set
that offers the ability for the patient to infuse from a prefilled
insulin cartridge without compromising the sterility of medication
to be infused. Also, utilization of prefilled medication cartridges
to provide a source of infusion material makes it easy and
convenient to use by the average patient. The utilization of a
cannula to pierce the septum of the medication cartridge provides
the sterile means for connecting the catheter to the cartridge and
by combining it with the soft or flexible catheter with needles
fixed on both ends permits the development of a convenient and
sterile infusion device. The cannula that is inserted into the skin
of a patient is held at its insertion location with a low profile
holding pad or housing. The opposite end has a threaded connector
with a cannula fixed in it that permits communication between the
fluid in the reservoir and the catheter. The cannula on the
threaded connector is positioned so that the tubing of the catheter
is fixed over the cannula and attached by adhesive to the catheter
tubing. The adhesive is selected from a set of epoxies or solvent
adhesive that are capable of bonding to the soft tubing. The
adhesive needs to create the appropriate bond and be capable of
being sterilized. The solvent bondable shrink tube is then placed
over the end of the tube and heated to produce a secure joint, and
the adhesive is applied to the outer surface of the shrink tube and
inserted into the connector.
[0056] Turning now to the drawing figures, FIGS. 1 and 2
illustrates a perspective view and a longitudinal cross-sectional
view, respectively, of a first embodiment 100 of an infusion
apparatus in accordance with the present invention. Generally, the
apparatus 100 includes a medication delivery device 102, into which
a medication ampule 108 is releasably installed, and a catheter
infusion set 104. The medication delivery device 102 can be any of
numerous such devices which receive a medication ampule 108,
including "pen" type injectors, programmable medication pumps, and
those described in U.S. application serial No. 60/156,535, filed
Sep. 29, 1999, U.S. application serial No. 60/170,570, filed Dec.
13, 1999, U.S. application serial No. 60/177,762, filed Jan. 24,
2000, and Attorney Docket No. 032994-012, filed Sep. 29, 2000,
"Reusable Medication Delivery Device", to Joel Douglas et al., the
entire contents of each of which are incorporated by reference
herein.
[0057] The device 102 includes a holder 106 which releasably holds
the medication ampule 108 therein so that the ampule's septum 112
is exposed and accessible to be pierced and accessed in a known
fashion. Similarly, the piston 110 of the ampule 108 is accessible
so that it can be moved to expel medication from the ampule, again
in a known fashion. The device 102 includes external threads 114 so
that a medical connector, described in greater detail below, can be
releasably attached to the device to access the ampule's contents
through the septum 112.
[0058] The catheter infusion set 104 includes a proximal connector
116 having a cylindrical collar or shroud 118, which has internal
threads 120 which mate with external threads 114. A piercing
element 122, e.g., a needle, extends proximally from the connector
116. A distal catheter, cannula, needle, or other tubular element
124 extends from the distal end of the set 104, and is in fluid
communication with the piercing element 122 via a tube 130. As can
be seen in FIG. 1, the catheter 124 extends at an angle .alpha. to
the longitudinal axis of the device (when laid straight). Angle
.alpha. is preferably between about 15 degrees and about 90
degrees, and more preferably is about 30 degrees, so that the
catheter can reside comfortably in the subcutaneous tissue layers
of a patient. A holding pad 126 having an adhesive face 128 is
connected to the catheter 124 by any of numerous ways, preferably
by an adhesive 136 (see FIG. 2). At the proximal end of the set
104, the tube 130 is secured to a distal portion 138 of the
connector 116.
[0059] As discussed above, the materials used for tube 130 effect
the way that the connection between the tube and the connector 116
can be made. According to one aspect of the present invention, a
tube 132 is heat shrunk over the exterior of the tube 130 in the
area where the distal portions of piercing element 122 extend into
the lumen of the tube 130. In one aspect of the invention, the tube
132 secures the piercing element 122 and the tube 130 together. In
another aspect, the tube 132 presents an outer surface to which the
distal portions 138 of the connector 116 can be solvent bonded, as
at 134, which outer surface is different from that of the tube 130.
The tube 132 can extend only a short way distally along tube 130,
or can extend distally along the entire length of tube 130.
According to other aspects of the present invention, tube 132 can
be formed of any of a number of materials which permits good
solvent bonding to the connector 116, such as PVC, polyester, or
PTFE.
[0060] The operation of the exemplary embodiment of the present
invention described above and illustrated in FIGS. 1 and 2 will now
be described with reference thereto. A user or patient inserts a
medication ampule 108, such an insulin cartridge, into the delivery
device 102, with the ampule's septum 112 accessible through the
device. The collar 116 is screwed or otherwise placed over the end
of the device 102 so that the piercing element 122 pierces the
septum 112 and places the interior of the ampule in fluid
communication with the cannula 124. The user can then prime the set
104, if desired. If the set 104 is already in place subcutaneously,
the user manipulates the device 102 to move the piston 110 to
deliver an amount of medication to the patient through the cannula
124.
[0061] FIGS. 3 and 4 illustrate top plan views, with portions
broken away in FIG. 4, of another embodiment 200 of an infusion set
in accordance with the present invention. Set 200 includes a
cannula housing 202 which holds a soft cannula 204 for positioning
subcutaneously in a patient. A connecting hub 206 is releasably
positioned to the proximal end of the cannula housing 202. A length
of tubing 208, preferably flexible, is secured to the proximal
portions of the connecting hub. A proximal connector 210 is secured
to the proximal end of the tubing 208. The connector 210 includes a
cylindrical collar or shroud 212, a hub 222, and a piercing element
214. A distal portion 226 of the piercing element 214 extends
proximally through the hub 222 and is in fluid communication with
the tubing 208. An extension 216 of the connector 210 extends
around the proximal portions of the tubing 208 and connects the
tubing to the connector 210. In one aspect of the present
invention, a shrink tube, such as tube 132 described above, is
inserted into extension 216 to facilitate bonding.
[0062] The connecting hub 206 includes distally extending pins 216,
218 which are inserted into and mate with complementarily placed
and configured holes or bores in the cannula housing 202, described
in greater detail below. A distally extending hollow tube 220
extends from the connecting hub 206, and includes proximal portions
224 which are in fluid communication with tubing 208. The proximal
portions 224 can be secured to the tubing 208 in any suitable
manner, including utilizing a shrink tube such as tube 132 and
solvent bonding. Hollow tube 220 may be sharpened at its distal
most end, e.g., be a needle, or can alternatively be blunt.
[0063] Turning now to FIGS. 5-9, several views of the cannula
housing 202 are illustrated. Specifically, FIG. 5 is a top plan
view of the cannula housing; FIG. 6 is a front elevational view;
FIG. 7 is a rear (upsidedown) elevational view; FIG. 8 is a left
side elevational view; and FIG. 9 is a cross-sectional view, taken
at line 9-9 in FIG. 5.
[0064] The cannular housing 202 includes a generally frustoconical,
distally extending portion 230, through which a bore 232 extends.
The bore 232 is widened at its distal end to form a cannula recess
234, for reasons which will be discussed further below. The
proximal end of the bore 232 widens in a frustoconically shaped
proximal portion 236. The proximal portion 236 is tapered in order
to guide a tube, such as tube 220, when inserted into the bore 232
through proximal opening 238. The housing 202 also includes blind
bores for receiving the pins from the connecting hub. When there
are two pins, 216 and 218 as illustrated in FIG. 3, there are two
such blind bores 244, 246, which are sized and positioned to
receive the pins. As will be readily appreciated by one of ordinary
skill in the art, while one such pin-bore combination is less
preferable because it guides the housing 202 and hub 206 together
less effectively, and more than two pin-bore combinations may
provide better registration between the hub and the housing, any
number of pins and bores are within the spirit and scope of the
present invention.
[0065] The proximal end of the housing 202 includes a pair of guide
extensions 242, one on each lateral side of the housing, which
together delimit an open proximal space 240 sized and shaped to
receive portions of the connecting hub 206. Each guide extension
242 includes an laterally inwardly directed, slightly tapered guide
surface 248, 250. The guide surfaces 248, 250 are sized and
oriented so that they provide initial guidance to the outer
surfaces of the hub 206 when the hub and housing 202 are brought
together, described in greater detail below.
[0066] The housing also includes at least one, and preferably two
locks 252, 254, positioned on the lateral sides of the housing. The
locks 252, 254 are provided to releasably lock the hub 206 to the
housing 202 when the hub and housing are properly mated together
(see FIG. 4). The locks 252, 254 include releasable locking fingers
256, 258 which extend proximally from regions where the locks join
with the housing 202. The fingers 256, 258 include a locking
bearing surface 260 which is distally directed for bearing against
portions of the hub 206 which face proximally (again, see FIG. 4).
Adjacent to the locking bearing surface(s) 260, each finger 256,
258 is provided with an angled cam surface 262. The cam surfaces
provide a place for the connecting hub 206 to bear against the
fingers 256, 258 and push them laterally outward, to spread the
fingers and permit the connecting hub to enter the space 240 when
moved distally relative to the housing 202.
[0067] The locks 252, 254 also include levers 264 on their proximal
ends, opposite the fingers 256, 258. The cantilevered levers 264
are positioned laterally spaced from the housing 202 so that there
are spaces 266 between the levers and the housing into which the
levers can be flexed. Flexure of the levers 264 laterally inward
cause the fingers 256, 258 to flex laterally outward, thus
permitting the connecting hub 206 to enter and exit the space 240
more easily. As will be readily appreciated by one of ordinary
skill in the art, pulling proximally on the connecting hub 206,
when positioned in the space 240, with sufficient force will also
result in the fingers 256, 258 spreading apart and the hub being
released from the housing 202 and the locks 252, 254.
[0068] As illustrated in FIGS. 6, 8, and 9, the soft cannula 204,
in some aspects of the present invention, is angled relative to the
bottom surface 268 of the housing 202 at an angle .beta., wherein
.beta. can be any acute angle, and can be the same as a.
[0069] FIGS. 10 and 11 illustrate enlarged views of portions of the
connecting hub 206. Specifically, FIG. 10 illustrates the locks
254, including the channel 270 between the finger 258 and the
housing 202. FIG. 11 illustrates the bore 232, without the soft
cannula 204 positioned in the bore.
[0070] FIGS. 12-13a illustrate the connecting hub 206. More
specifically, FIG. 12 illustrates a top plan view of the connecting
hub 206; FIG. 13 illustrates a side elevational (upsidedown) view;
FIG. 13a illustrates a portion of the hub; and FIG. 14 illustrates
a front elevational view. As discussed above, pins 216, 218 and
tube 220 extend from the hub 206. The hub 206 includes locking
surfaces 280 which are oriented and positioned so that the bearing
surfaces 260 of the locking fingers 256, 258 will bear against the
locking surfaces 280 when the hub is positioned in the space 240.
Cam surfaces 282 are also provided on the distal end of the hub 206
to bear against the cam surfaces 262 of the fingers 256, 258, as
described above.
[0071] The hub 206 includes a proximal portion 284 to which the
tubing 208 is attached, preferably in a permanent manner. A
longitudinally extending lumen or bore 286 extends from the
proximal end to the distal end of the hub 206. The lumen is sized
to receive the tubing 208 therein, with the proximal end 224 of the
tube 220 in fluid communication with the lumen of the tubing.
Although a straight bore 286 can be used, it is preferable that the
bore include a shoulder 292 along its length, with a proximal
portion 288 and an intermediate portion 290 on either side of the
shoulder. The intermediate portion 290 can be of a smaller inner
diameter than the proximal portion 288 so that the tubing 208 is
radially compressed. Intermediate portion 290 can also have a
slightly tapered inner diameter, so that the radial compression of
the tubing is greater at the shoulder than elsewhere along the bore
286. The bore 286 also includes a distal portion 296, in which a
needle hub or positioning block 294 is mounted.
[0072] FIG. 13a illustrates that, in one aspect of the invention,
the block 294 can have a beveled side 300 to assist in aligning the
tube 220 at the same angle as the soft cannula 204. FIGS. 13 and 14
illustrate that the hub 206 can optionally have a slanted top
surface 298.
[0073] FIGS. 15 and 16 illustrate a top plan view and a side
elevational view, respectively, of an insertion device 302 used to
insert the soft cannula into the patient, preferably
subcutaneously. The device 302 includes a needle or stylet 304
extending distally from an insertion handle 306. The insertion
handle 306 is substantially the same shape and size as the hub 206,
and includes a pair of pins 308, 310, substantially similar to pins
216, 218. The needle or stylet 304 is of a length so that the
sharpened distalmost end of the needle or stylet extends beyond the
distalmost end of the soft cannula 204 when the insertion handle
306 is mounted on the housing 202, in the same manner as the
connecting hub 206 is mounted to the housing in FIG. 4. A proximal
end of the needle or stylet 304 is preferably within the handle
306. According to yet another aspect of the present invention, the
needle 304 can include a score line 314 along its length so that
the needle can be broken off and used as an infusion needle. The
handle 306 would then require a lumen similar to lumen 286 in FIG.
12.
[0074] FIGS. 17-19 illustrate several views of a plug in accordance
with one aspect of the present invention. More specifically, FIG.
17 illustrates a top plan view of a plug 330; FIG. 18 illustrates a
front elevational view of the plug, and FIG. 19 illustrates a
cross-sectional view taken at line 19-19 in FIG. 18. The outside
size and shape of plug 330 is the same as the insertion handle 306
and the connecting hub 206, described above. The plug 330 includes
a pair of pins 332, 334 to mate with blind bores 244, 246,
described above. The plug 330 includes a central plugging element
336 having a preferably conical or frustoconical tip 338 extending
distally from the plugging element 336. The plugging element 336 is
formed of a somewhat soft material which is somewhat compressible,
so that when the plug 330 is mounted to the housing 220 in the
manner of hub 206 and handle 306, the plugging element will enter
into and seal the proximal portions of bore 232. By way of example
and not of limitation, element 338 can be formed of a medical grade
silicon rubber. Thus, the plug 330 can be used to seal the bore
232, and therefore access to the patient's body by dirt and
pathogens is greatly restricted when connecting hub 206 is
disconnected from the housing 202.
[0075] The size and taper of plugging element 336 and tip 338 are
preferably selected to plug and seal with tapered portion 236,
although the size and taper can also be selected to seal and plug
the bore 232 at the junction of bore 232 and taper 236, the
junction of taper 236 and proximal opening 238, the opening 238
itself, or any combination of these structures by forming plugging
element 336 with a complementary shape. According to yet another
aspect of the present invention, the material out of which plugging
element 336 is formed can be doped with an antimicrobial or similar
compound to inhibit the growth of microorganisms on the plugging
element itself or on the surfaces against which it seats.
[0076] FIG. 20 illustrates a cross-sectional view of soft cannula
204. The soft cannula 204 includes a longitudinally extending lumen
350, which extends between a proximal end 352 and a distal end 354.
A positioning and retention bead, ring, or lug 356 is formed on the
outer surface of the cannula 204, and is sized to fit into recess
234 of the housing 202. The bead 356, in one aspect of the present
invention, is sized relative to the recess 234 so that the bead can
securely hold the cannula 204 in the housing 202. In another aspect
of the present invention, the bead 356 assists in positioning the
distal end 354 of the cannula 204 at a predetermined distance from
the housing 202. In yet another aspect of the present invention,
the cannula 204 is permanently mounted in the bore 232 by any of
numerous ways, such as solvent or adhesive bonding, ultrasonic
welding, heat staking, or the like.
[0077] The cannula 204, in yet another aspect of the present
invention, includes a restriction surface 358 formed on the inner
surface of the lumen 350 near or at the proximal end 352 of the
cannula. The restriction surface 358 is formed by a reduction in
the inner diameter of the lumen 350 to a diameter which is only
slightly smaller to slightly larger than the outer diameter of tube
220. By forming the inner diameter of the lumen 350 and the outer
diameter of tube 220, and optionally of needle or stylet 304, so
that they are nearly the same, the clearance between the two
surfaces is too small for liquids such as blood and aqueous
solutions of medications to flow. According to yet another aspect
of the present invention, the change in diameter can be formed on
the outside of the tube 220, and optionally on the outside of
needle or stylet 304. Thus, one aspect of the present invention is
a seal against the passage of fluid in and out of the housing 202
along the cannula 204, other than through the lumen 350.
[0078] The operation of the exemplary embodiment of the present
invention described above and illustrated in FIGS. 3-20 will now be
described with reference thereto. The operation of the set 200 is
similar in many respects to set 104. Initially, the housing 202 is
mounted to the handle 306 so that the distal end of the needle or
stylet 304 extends distally from the distal end of the soft cannula
204. As discussed above, the restriction 358 and the external
surface of the needle or stylet 304 provide a fluid seal. The flaps
436 of the dust door 430 have been previously pushed aside by the
needle or stylet 304. The soft cannula 204 and housing 202 can then
be inserted into a patient, e.g., subcutaneously, in a manner
well-appreciated by one of ordinary skill in the art. The handle
306 is then retracted proximally by pressing laterally inwardly on
one or both of the levers 264, which releases the handle from the
housing 202. The flags 436 return to their generally planar
configuration, inhibiting dust and dirt from entering the
device.
[0079] The connecting hub 206, with the tubing 208 and connector
210, is then inserted into the space 240, laterally displacing the
locking fingers 256, 258. With the pins 216, 218 in the bores 244,
246, the guide surfaces 248, 250 guide the outer surfaces of the
hub 206 as the hub moves distally. The locking fingers 256, 258
then snap over the locking surfaces 280, securing the hub 206 to
the housing 202 with the tube 220 extending through the soft
cannula 202. The outer surface of the tube 220 and the restriction
358 form a fluid seal, as described, and the flaps 436 again are
moved aside by the tube 220. The connector 210 can then be attached
to a septum of a medication ampule, and medication delivered
through the tubing 208, through the soft cannula 202, and to the
patient.
[0080] After the medication infusion described above, the hub 206
can be removed proximally by pressing on the levers 264, as
described above, to release the hub from the housing 202. The plug
330 can then be installed in place, as described above, with the
plugging element 338 moving aside the flaps 436 and forming a seal
with one of the proximal structures of the housing 202. The housing
202 and cannula 204 are then prepared for later infusion, while
sterility of the site is enhanced or maintained.
[0081] FIGS. 21 and 22 illustrate a pen needle 370 according to yet
another aspect of the present invention. FIG. 21 illustrates a
perspective view of the pen needle 370; FIG. 22 illustrates a
longitudinal cross-sectional view. The pen needle 370 includes a
cylindrical collar or shroud 372 having an open end 378, a hub 374
forming a part of a closed end 380 of the collar, and a two-ended
needle 376 extending through the hub with one end within the
collar. The pen needle 370 also includes an annular groove 376
formed in the inner surface of the collar, and receives in the
groove a dust door described in greater detail below. The pen
needle 370 can be used in the place of set 104, described above
with reference to FIGS. 1 and 2, by placing the collar 372 around
the septum of an ampule so that the needle 376 pierces the septum.
The other end of the needle 376 can be inserted into a patient, and
an infusion of medication delivered to the patient.
[0082] FIG. 23 illustrates yet another infusion set 400 in
accordance with other aspects of the present invention. The
infusion set 400 can be used with a medication delivery device 102
as described above which includes a medication ampule having a
septum. The infusion set 400 includes an infusion needle or cannula
402 at a distal end, a holding pad 404 to secure the infusion
needle to a patient, tubing 406 extending proximally from and in
fluid communication with the infusion needle 402, and a proximal
connector 408 connected to the proximal end of the tubing. As
discussed in greater detail above, the tubing 406 may be attached
to the proximal connector using shrink tubing and solvent bonding,
for example.
[0083] FIGS. 24-26 illustrate details of the infusion set 400 of
FIG. 23. More specifically, FIG. 24 illustrates a perspective view
of the connector 408; FIG. 25 illustrates a longitudinal
cross-sectional view of the connector; and FIG. 26 illustrates a
portion of the connector. The connector 408 includes a cylindrical
collar or shroud 412 which has an open end 414 and a closed end
416. An annular shoulder 418 is formed in the closed end 416, and a
distal tubular extension 420 extends distally from the closed end.
The extension 420 includes a lumen 422 communicating the open
portion of the collar 412 with the distal end of the connector. The
lumen 422 can have a constant inner diameter, or can include a
distal reduced inner diameter portion 424 which, as described above
with reference to bore 286, can assist in forming a seal with the
tubing 406 when the tubing is inserted into the lumen 422. A fluid
transfer device 426 is mounted in the connector 408 in the annular
shoulder 418, and is secured to the connector, such as by glueing,
ultrasonic welding, or the like.
[0084] Turning to FIG. 26, the fluid transfer device 426 includes a
sharpened proximal end 428 to pierce a septum of a medication
ampule, such as septum 112. The distal end 432 of the shaft 430 can
be either sharpened or blunt. A lumen 434 extends between the
sharpened proximal 428 and distal 432 ends. A mounting block 436 is
mounted to the shaft 430, and has a size and a shape to fit to
annular shoulder 418.
[0085] FIG. 27 illustrates, in a manner similar to FIG. 2, how a
tube 450 can be joined to a needle or rigid cannula 452. With the
end of the needle 454 within the lumen 458 of the tube 450, a tube
456 of shrinkable material is positioned over the outside of the
tube so that it overlaps both the tube and the needle. By shrinking
the tube 456, the tube 450 is clamped down onto the shank of the
needle 452, securing the two together. Thereafter, the outer
surface of the tube 456 can be used to secure the assembly to
another component, such as by solvent bonding.
[0086] FIG. 28 illustrates a top plan view of the distal infusion
end of set 400, FIG. 29 illustrates a side view, partially in
section of the distal end of set 400, and FIG. 30 illustrates a
cross-section view taken at line 30-30 in FIG. 29. As can be seen
in FIG. 29, tubing 406 is formed to be kink-resistant, as described
in greater detail below. A hub 438 fluidly communicates the tubing
406 with the needle or cannula 402. FIG. 30 illustrates that the
holding pads 404 include an outer adhesive layer 410, to secure the
device to a patient.
[0087] FIG. 31 illustrates a cross-sectional view of tubing 406
according to one aspect of the present invention. The tubing 406 is
formed to have a cross-sectional shape that makes the tubing
resistant to kinking. In FIG. 31, the tubing 406 has a triangular
cross-section. A piece of shrink tube 422 is illustrated positioned
around the tube 406 prior to being shrunk down onto the outer
surface of the tubing, for the reasons presented herein. By way of
example and not of limitation, inner tube 406 can be formed of a
polyethylene or polypropylene, and the outer shrink tube 422 can be
formed of a PVC, polyester, or PTFE. FIGS. 32 and 33 illustrate yet
further aspects of the present invention. In FIG. 32, tubing 406 is
formed of a base tube 420, a shrink tube 422 around the base tube,
and at least one filaments, wires, or the like 424 between the base
tube and the shrink tube. The filaments 424 strengthen the tube and
assist in preventing kinking. In FIG. 33, the filaments 424 have
been removed, with the shrink tube 422 acting to assist in
preventing kinking. The shrink tube is 422 is then shrunk over the
base tube 420, resulting in a strengthened tubing 406.
[0088] FIGS. 34 and 35 illustrate a dust door 430 according to yet
another aspect of the present invention. The door 430 is formed of
a thin sheet 432 of relatively strong and pliable material, which
includes intersecting slits 434 which together form two or more
flaps 436. By way of example and not of limitation, sheet 432 can
be formed of Mylar of about 0.003 inches thickness. The door 430
is, in certain aspects of the present invention, preferably
installed in opening 238, 378, or the open end of collar 116, and
prevents dust and dirt from entering these openings. Referring to
FIG. 5 and opening 238, when it is desired to insert, for example,
tube 220 into the bore 232, the flaps 436 are pushed aside by the
advancing tube 220 without interfering with assembly of the device
and without piercing the flaps. When the tube 220 is retracted, the
flaps 436 resume their generally planar configuration.
[0089] The operation of the exemplary embodiment of the present
invention described above and illustrated in FIGS. 23-35 will now
be described with reference thereto. The use of the embodiments of
FIGS. 23-35 is similar to the use of the embodiments of FIGS. 1 and
2. A user or patient inserts a medication ampule 108, such an
insulin cartridge, into the delivery device 102, with the ampule's
septum 112 accessible through the device. The connector 408 is
screwed or otherwise placed over the end of the device 102 so that
the piercing element 428 pierces the septum 112 and places the
interior of the ampule in fluid communication with the cannula 402.
The user can then prime the set 400, if desired. If the set 400 is
already in place subcutaneously, the user manipulates the device
102 to move the piston 110 to deliver an amount of medication to
the patient through the cannula 124.
[0090] While the invention has been described in detail with
reference to preferred embodiments thereof, it will be apparent to
one skilled in the art that various changes can be made, and
equivalents employed, without departing from the scope of the
invention.
* * * * *