U.S. patent application number 13/950832 was filed with the patent office on 2013-11-21 for medication reservoir.
This patent application is currently assigned to MEDTRONIC MINIMED, INC.. The applicant listed for this patent is Randy W. Adair, Sheldon B. Moberg, Chalirmkiert Srisathapat. Invention is credited to Randy W. Adair, Sheldon B. Moberg, Chalirmkiert Srisathapat.
Application Number | 20130310807 13/950832 |
Document ID | / |
Family ID | 22310289 |
Filed Date | 2013-11-21 |
United States Patent
Application |
20130310807 |
Kind Code |
A1 |
Adair; Randy W. ; et
al. |
November 21, 2013 |
MEDICATION RESERVOIR
Abstract
A method and apparatus for a connection interface between a
reservoir or syringe, infusion set tubing, and an infusion pump is
provided. A base is provided which is adapted to receive a
reservoir. The base has a base engagement member, such as a detent,
projecting therefrom. A cap is provided which is adapted to receive
the base. The cap includes a first cap engagement member, such as a
detent opening, which is adapted to removably engage the base
detent. The cap further includes a second cap detent opening which
is adapted to removably engage the base detent. A piercing member,
such as a needle, is disposed in the interior of the cap in such a
manner that the needle is separated from the reservoir septum when
the base detent is in the first cap detent opening, and the needle
pierces the reservoir septum when the base detent is in the second
cap detent opening. When the reservoir, the base and the cap are
connected to form an integrated unit, this unit is then capable of
being inserted and secured in the infusion pump housing.
Inventors: |
Adair; Randy W.; (Valencia,
CA) ; Moberg; Sheldon B.; (Thousand Oaks, CA)
; Srisathapat; Chalirmkiert; (Sun Valley, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Adair; Randy W.
Moberg; Sheldon B.
Srisathapat; Chalirmkiert |
Valencia
Thousand Oaks
Sun Valley |
CA
CA
CA |
US
US
US |
|
|
Assignee: |
MEDTRONIC MINIMED, INC.
Northridge
CA
|
Family ID: |
22310289 |
Appl. No.: |
13/950832 |
Filed: |
July 25, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13622183 |
Sep 18, 2012 |
8500716 |
|
|
13950832 |
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|
13155641 |
Jun 8, 2011 |
8303572 |
|
|
13622183 |
|
|
|
|
12361203 |
Jan 28, 2009 |
7981105 |
|
|
13155641 |
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|
10923133 |
Aug 20, 2004 |
7628782 |
|
|
12361203 |
|
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|
10328393 |
Dec 23, 2002 |
7658734 |
|
|
10923133 |
|
|
|
|
09428818 |
Oct 28, 1999 |
6585695 |
|
|
10328393 |
|
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|
60106237 |
Oct 29, 1998 |
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Current U.S.
Class: |
604/533 |
Current CPC
Class: |
Y10T 29/49764 20150115;
A61M 5/1452 20130101; A61M 39/12 20130101; A61M 2205/582 20130101;
A61M 2039/205 20130101; A61M 5/16831 20130101; A61M 2039/1033
20130101; A61M 5/14566 20130101; A61M 2039/1072 20130101; A61M
39/10 20130101; A61M 2205/581 20130101; A61M 5/14244 20130101; Y10T
29/53 20150115; A61M 2005/1623 20130101; A61M 5/162 20130101; Y10T
29/49826 20150115 |
Class at
Publication: |
604/533 |
International
Class: |
A61M 39/12 20060101
A61M039/12; A61M 5/162 20060101 A61M005/162 |
Claims
1. An apparatus for engaging or disengaging a fluid medication
reservoir with a fluid conduit, wherein the fluid medication
reservoir is disposed within an infusion device; the apparatus
comprising: a cap having a cylindrical external surface; a fluid
conduit coupled to the cap; a housing engagement member projecting
outward from the cylindrical external surface of the cap and
adapted to engage an engagement member disposed in a housing recess
within the infusion device, wherein the cap is insertable and
removable from the housing recess within the infusion device upon
rotation of the cap; a first tab disposed on the cap so as to
provide a first surface for a user to grip, wherein: the first tab
projects outward from the cap; and gripping and twisting the first
tab rotates the cap and engages or disengages the fluid medication
reservoir.
2. The apparatus of claim 1, further comprising a vent disposed in
the cap that permits venting of air and equalization of pressure
inside the infusion device to atmospheric pressure outside the
infusion device.
3. The apparatus of claim 2, wherein the vent comprises a
hydrophobic material that permits the passage air and
simultaneously inhibits the passage of fluids.
4. The apparatus of claim 1, further comprising a piercing member
disposed in the cap.
5. The apparatus of claim 4, wherein the piercing member creates a
hole in a septum coupled to the reservoir when the reservoir is
coupled and operatively engaged with the cap.
6. The apparatus of claim 1, wherein the housing engagement member
comprises a detent or a thread projecting outward from the
cylindrical external surface of the cap.
7. The apparatus of claim 1, further comprising a second tab
disposed on the cap so as to provide a second surface for the user
to grip and twist to engage the cap with the infusion device upon
rotation of the cap, wherein the second tab projects outward from
the cap such that the second surface of the second tab is disposed
in an orientation perpendicular to the plane defined by the
circumference of the cap.
8. The apparatus of claim 7, wherein the first and second tabs are
disposed on the cap in a diametrically opposed orientation.
9. The apparatus of claim 1, wherein the cap, the housing
engagement member and the tab comprise a homologous one piece
unit.
10. An apparatus for engaging or disengaging a fluid medication
reservoir with a fluid conduit, wherein the fluid medication
reservoir is disposed within an infusion device; the apparatus
comprising: a cap having a cylindrical external surface; a
retractable detent arm formed within and defining a portion of the
circumference of the cap, wherein the cap is insertable and
removable from a housing recess within the infusion device upon
rotation of the cap; a first tab disposed on the cap so as to
provide a first surface for a user to grip, wherein: the first tab
projects outward from the cap; and gripping and twisting the first
tab rotates the cap and engages or disengages the fluid medication
reservoir.
11. The apparatus of claim 10, further comprising a vent disposed
in the cap that permits venting of air and equalization of pressure
inside the infusion device to atmospheric pressure outside the
infusion device.
12. The apparatus of claim 10, further comprising a piercing member
disposed in the cap.
13. The apparatus of claim 10, further comprising a housing
engagement member comprising a detent or a thread projecting
outward from the cylindrical external surface of the cap and
adapted to engage an engagement member disposed in a housing recess
within the infusion device.
14. The apparatus of claim 11, wherein the housing member is
disposed on the cap so that all of the fluid medication reservoir
is disposed within the housing recess during operation of the
infusion device.
15. The apparatus of claim 10, further comprising a conduit cavity
disposed in the cap.
16. The apparatus of claim 1, further comprising a fluid conduit
coupled to the cap.
17. An apparatus for engaging or disengaging a fluid medication
reservoir with a fluid conduit, wherein the fluid medication
reservoir is disposed within an infusion device; the apparatus
comprising: a cap; a fluid conduit coupled to the cap; a needle
disposed in the cap, wherein the needle is in operable contact with
the fluid conduit and pierces a septum coupled to the reservoir
when the reservoir is coupled and operatively engaged with the cap;
a first tab disposed on the cap so as to provide a first surface
for a user to grip, wherein: the first tab projects outward from
the cap; and gripping and twisting the first tab rotates the cap
and engages or disengages the fluid medication reservoir.
18. The apparatus of claim 17, further comprising a vent disposed
in the cap that permits venting of air and equalization of pressure
inside the infusion device to atmospheric pressure outside the
infusion device.
19. The apparatus of claim 17, further comprising a second tab
disposed on the cap so as to provide a second surface for the user
to grip and twist to engage the cap with the infusion device upon
rotation of the cap, wherein the second tab projects outward from
the cap such that the second surface of the second tab is disposed
in an orientation perpendicular to the plane defined by the
circumference of the cap.
20. The apparatus of claim 19, wherein the first and second tab are
spaced 180 degrees radially apart.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. patent
application Ser. No. 13/622,183, filed Sep. 18, 2012, which claims
priority from U.S. patent application Ser. No. 13/155,641, filed
Jun. 8, 2011, now U.S. Pat. No. 8,303,572, which claims priority
from U.S. patent application Ser. No. 12/361,203, filed Jan. 28,
2009, now U.S. Pat. No. 7,981,105, which claims priority from U.S.
patent application Ser. No. 10/923,133, filed Aug. 20, 2004, now
U.S. Pat. No. 7,628,782, which claims priority from U.S. patent
application Ser. No. 10/328,393, filed Dec. 23, 2002, now U.S. Pat.
No. 7,658,734, which claims priority from U.S. patent application
Ser. No. 09/428,818, filed Oct. 28, 1999, now U.S. Pat. No.
6,585,695, which claims priority from provisional patent
application No. 60/106,237 which was filed on Oct. 29, 1998 and
which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to improvements in syringe
and reservoir interfaces for use in infusion pumps such as those
used for controlled delivery of medication to a patient. More
specifically, this invention relates to an improved connection
interface between a reservoir or syringe, infusion set tubing, and
an infusion pump.
[0004] 2. Description of the Related Art
[0005] Infusion pump devices and systems are relatively well-known
in the medical arts, for use in delivering or dispensing a
prescribed medication such as insulin to a patient. In one form,
such devices comprise a relatively compact pump housing adapted to
receive a syringe or reservoir carrying a prescribed medication for
administration to the patient through infusion tubing and an
associated catheter.
[0006] The infusion pump includes a smell drive motor connected via
a lead screw assembly for motor-driven advancement of a reservoir
piston to administer the medication to the user. Programmable
controls are normally provided for operating the drive motor
continuously or at periodic intervals to obtain a closely
controlled and accurate delivery of the medication over an extended
period of time. Such infusion pumps are utilized to administer
insulin and other medications, with exemplary pump constructions
being shown and described in U.S. Pat. Nos. 4,562,751; 4,678,408;
4,685,903; 5,080,653 and 5,097,122, which are incorporated by
reference herein.
[0007] Infusion pumps of the general type described above have
provided significant advantages and benefits with respect to
accurate delivery of medication or other fluids over an extended
period of time. The infusion pump can be designed to be relatively
compact as well as water resistant, and may thus be adapted to be
carried by the user, for example, by means of a belt clip. As a
result, important medication can be delivered to the user with
precision and in an automated manner, without significant
restriction on the user's mobility or life-style, including the
ability to participate in water sports.
[0008] Infusion sets refer to the tubing and connection apparatus
which provide a path for the medication to flow from the reservoir
or syringe located in the pump to the user. The connectors for
attaching the infusion set tubing to the reservoirs can take
various forms. A luer connection is a commonly used connection
method. Nevertheless, it remains desirable to develop improved
designs of connection methods to facilitate infusion procedures and
to provide suitable interface connections which are water resistant
so as to permit a user to participate in water sports.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0009] An apparatus for connecting a reservoir having a septum and
a base to a conduit, such as infusion set tubing, is provided. In
certain aspects of the present invention, the apparatus comprises a
cap and a releasable coupler which is adapted to releasably couple
the base to the cap in one of two positions. A piercing member,
such as a needle, is coupled to the conduit. The needle is disposed
in the cap in a position other than the interior of the reservoir
when the base is in the position. The needle is further disposed to
pierce the reservoir septum when the base is in the second
position.
[0010] In another embodiment, the apparatus is used for connecting
a reservoir having a septum and a base to a housing as well as to a
conduit. The housing has a housing engagement member, such as a
thread. The apparatus comprises a cap and a releasable coupler
which is adapted to releasably couple the base to the cap in one of
two positions. A piercing member, such as a needle, is releasably
coupled to the conduit. The needle is disposed in the cap in a
position other than the interior of the reservoir when the base is
in the first position. The needle is further disposed to pierce the
reservoir septum when the base is in the second position. The cap
further includes an engagement member, such as a thread, which is
adapted to engage with the housing engagement member.
[0011] In another embodiment, the cap further includes a vent port
which is covered with hydrophobic material. This permits air to
pass through the cap while preventing water from doing so.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is an exploded, perspective view of a medication
reservoir connection interface apparatus.
[0013] FIG. 2 is a perspective view of a cap used as a medication
reservoir connection interface apparatus.
[0014] FIG. 3 is an exploded, perspective view of an alternative
embodiment of a medication reservoir connection interface
apparatus.
[0015] FIG. 4 is a side, cut-away view of a cap used as a
medication reservoir connection interface apparatus.
[0016] FIG. 5 is a side, plan cut-away view of a medication
reservoir connection interface apparatus with a needle inserted
into a reservoir.
[0017] FIG. 6 is a side, plan cut-away view of a medication
reservoir connection interface apparatus which is inserted into a
pump housing.
[0018] FIG. 7 is a perspective view of an alternative embodiment of
a medication reservoir connection interface apparatus.
[0019] FIG. 8 is a perspective top view of an alternative
embodiment of a medication reservoir connection interface apparatus
which is secured into a pump housing.
[0020] FIG. 9 is a perspective view of an alternative embodiment of
a medication reservoir connection interface apparatus.
[0021] FIG. 10 is an exploded, perspective view of a cap used as a
medication reservoir connection interface apparatus.
[0022] FIG. 11 is a perspective view of a medication reservoir
connection interface adapter.
[0023] FIG. 12 is a cross-sectional view of a medication reservoir
connection interface adapter.
[0024] FIG. 13 is a perspective view of an alternative embodiment
of a cap used as a medication reservoir connection interface
apparatus.
[0025] FIGS. 14a-14c are cross-sectional views of various
embodiments of venting ports for use with a reservoir connection
interface apparatus or adapter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] 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.
[0027] As shown in the drawings for purposes of illustration, the
invention is embodied in an interface for connecting a syringe or a
medication reservoir to a conduit, such as infusion set tubing or
an external needle, as well as to an infusion pump. In a one
embodiment, a base is provided which is adapted to receive a
reservoir. A cap is provided which is adapted to be releasably
coupled to the base in one of two positions. The releasable coupler
comprises a pair of detents projecting from the base and two pairs
of detent openings in the cap which are adapted to removably engage
the base detents.
[0028] A piercing member, such as a needle, is disposed in the
interior of the cap in such a manner that the needle is separated
from the reservoir septum when the base detents in the first pair
of cap detent openings, and the needle pierces the reservoir septum
when the base detents are in the second pair of cap detent
openings. When the reservoir, the base and the cap are connected,
an integrated unit is formed which is then capable of being
inserted in the infusion pump housing. Engagement members, such as
threads, for the cap and the pump housing are used to secure the
integrated unit in the housing.
[0029] FIGS. 1 and 2 show an infusion set connector interface for
attachment to a medication reservoir. The connector interface is
comprised of a base 2 and a cap 4. The cap 4 includes a needle 9
located internal to the cap housing. FIG. 1 is an exploded view,
and therefore, the base 2 would normally be fixedly attached to a
reservoir 1 by securing it around the swage 3. However, alternative
embodiments of the present invention include a removable base so
that the connector interface could be used with standard
reservoirs, cartridges or syringes which were not initially
manufactured with the base attached.
[0030] The cap 4 portion of the connector interface is removably
attached to the base 2 with a releasable coupler. In one
embodiment, the releasable coupler is comprised of detents formed
on the base 2 and detent openings disposed in the cap 4. Two
detents 8 are disposed on the sides of the base 2 and are spaced
180.degree. radially apart. Only one detent 8 is shown in FIG. 1.
The detents 8 are sized to fit in the two lower detent openings 6,
or alternatively, in the two upper detent openings 7 which are
formed in the cap 4. As with the pair of detents 8, each of the
lower detent openings 6 and each of the upper detent openings 7,
respectively, radially spaced apart by 180.degree..
[0031] In operation, the base 2 and the reservoir 1 form an
integrated unit which in is to be connected to the cap 4. In
connecting this integrated base/reservoir unit to the cap 4, the
base 2 is inserted into the lower end of the cap 4 until the
detents 8 snap into the lower detent openings 6. This is
accomplished by moving the detents 8 over internal cam surfaces 10
toward the lower detent openings 6. The cam surfaces act as ramps
which compress the detents 8 sufficiently to permit them to snap
into the lower detent openings 6. Internal threads 10a guide the
detents 8 into position.
[0032] When the base/reservoir unit is in this first, lower
position, the needle 9 is positioned apart from the septum (not
shown) of the reservoir 1. Thus the needle does not pierce the
septum while the base/reservoir unit is in this first position.
When the base/reservoir unit is connected to the cap in this
fashion, an integrated cap/base/reservoir unit is thereby formed.
Such an integrated cap/base/reservoir unit can be sold or stored
for long periods of time in this fashion. Alternatively the end
user could assemble this unit shortly prior to placing it in the
pump for use.
[0033] When the user desires to insert the cap/base/reservoir unit
in the pump housing and commence dispensing the medication through
a conduit, such as insertion set tubing 5, the base 2 is moved to
the second position within the cap 4. This is accomplished by
twisting the base/reservoir unit while pushing it er into the cap
4. The detents 8 disengage from the lower detent openings 6 and
engage into the upper detent openings 7. Additional internal
threads 10a of the cap 4 serve to guide the detents 8 over
additional cam surfaces 10 from their first position in the lower
detent openings 6 to the second position in the upper detent
openings 7.
[0034] In one embodiment, the threads and the spacing between the
lower detents 6 and the upper detents 7 is such that a one quarter
(1/4) turn of the base will cause the base/reservoir unit to travel
from the to the second position. The needle 9 is disposed so that
when the base/reservoir unit is in the second position, the needle
pierces the septum of the reservoir 1. Thus the movement of the
base/reservoir unit from the first to the second position within
the cap serves to cause the needle to pierce the reservoir's
septum, thus permitting the fluid in the reservoir to flow into the
needle 9 and the insertion set tubing 5.
[0035] After this connection is made, the reservoir, base and cap
form a unit which be releasably secured in the housing of a
medication infusion pump. (not shown) Detents 4a extend radially
from the exterior of the cap and adapted to engage into detent
openings (not shown) in the pump housing. In an alternative
embodiment, the cap 4 include external threads (not shown) which
are used to engage the threads of the pump housing in order to
secure the reservoir/base/cap unit into the housing.
[0036] FIGS. 3 and 4 show an alternative embodiment of the ion set
connector interface. The connector interface is comprised of a base
11 and a cap 12. The cap 12 includes a needle 18 located internal
to the cap housing (FIG. 4). The base 11 would normally be fixedly
attached to the reservoir 1 by securing it around the swage 3.
However, alternative embodiments of the present invention include a
removable base so that the connector interface could be used with
standard reservoirs, cartridges or syringes which were not
initially manufactured with the base attached.
[0037] The cap 12 portion of the connector interface is removably
attached to the base 11 with a releasable coupler. In this
embodiment, the releasable coupler is comprised of detents formed
on the base 11 and detent openings disposed in the cap 12. Two
detents 13 are disposed on the sides of the base 11 and are spaced
180.degree. radially apart. Only one detent 13 is shown in FIG. 3.
The detents 13 sized to fit in two detent openings 14 which are
formed in the cap 12. As with the pair of detents 13, each of the
detent openings 14 are radially spaced apart by 180.degree..
[0038] In operation, the base 11 and the reservoir 1 form an
integrated unit which in is to be connected to the cap 12. In
connecting this integrated base/reservoir unit to the cap 12, the
base 11 is inserted into the lower end of the cap 12. The detents
13 slide into matingly shaped and longitudinally open entry slots
15 formed within the interior of the cap 12. When the base 11 is
fully inserted in the cap 12, the leading edges of the detents 13
abut an annular stop shoulder 16 formed within the cap 12. After
the detents 13 are in this position, the base 11 is rotated within
the cap 12 toward a locked position. Referring to FIG. 4, this
rotation displaces the detents 13 in a rotational direction for
engagement with cam surfaces 17 formed within the cap 12. The
rotational force on the detents 13 over the cam surfaces 17
provides a compression force on the detents 13. Continued rotation
of the base 11 displaces the detents 13 past the cam surfaces 17
and into alignment with the detent openings 14. The detents 13
enter the detent openings 14 with a snap-action. Thus, the detents
13 are effectively locked within the detent openings 14 to prevent
longitudinal separation of the base 11 from the cap 12.
[0039] In the preferred embodiment, the internal needle 18 of the
cap 12 is disposed so that when the base/reservoir unit is fully
inserted in the cap 12, the needle pierces the septum (not shown)
of the reservoir 1. Thus the insertion force of the base/reservoir
to the point where the detents 13 abut the annular stop shoulder 16
causes the needle 18 to pierce the septum, thus permitting the
fluid in the reservoir to flow into the needle 18 and the insertion
set tubing (not shown).
[0040] After this connection is made, the reservoir, base and cap
form a unit which can be releasably secured in the housing of a
medication infusion pump. (not shown) The cap 12 includes external
threads 19 which are used to engage the threads of the pump housing
in order to secure the reservoir/base/cap unit into the housing. In
the preferred embodiment, the threads 19 have an eight threads per
inch ("TPI"), 2 start profile. Moreover, they have a square shaped
cross section which maximizes their holding strength. Other thread
profiles and cross-sections may be used however.
[0041] When disconnection of the base 11 from the cap 12 is
desired, the base 11 must be reverse-rotated within the cap 12, to
move the detents 13 past the cam surfaces 17 into re-alignment with
the entry slots 15. Such reverse-rotation of the coupler can be
performed relatively easily, but essentially requires an
affirmative intent by the user to disconnect the coupling. When the
detents 13 are re-aligned with the entry slots 15, the cap 12 and
base 11 can be separated easily with minimal longitudinal
force.
[0042] FIG. 5 shows a cross sectional view of the
reservoir/base/cap integrated unit in accordance with the
embodiment of FIGS. 3 and 4. The reservoir 1 includes a crimp seal
swage 3 which encloses the outer periphery of the rubber septum 20
in order to secure the septum 20 to the reservoir 1 and form a
water tight seal. With the base 11 in the locked position as shown,
the detents 13 of the base 11 are locked into the detent openings
14 to securely attach the base/reservoir unit into the cap 12. The
needle 18 pierces the rubber septum 20, thus permitting the flow of
liquid through the needle 18 and into the ion set tubing cavity 22.
Infusion set tubing (not shown) is secured into the cavity 22 to
allow the liquid to continue its flow to the user.
[0043] In the preferred embodiment, the conduit from the cap 12 is
infusion set tubing. However in an alternative embodiment, the
conduit comprises a second needle (not shown). This is secured into
the cavity 22 with the point of the second needle extending
outward. With this arrangement, the connector serves as an
apparatus for permitting the refilling of the reservoir 1. The
second, external needle would pierce the septum of a supply vial of
fluid. The fluid could then be drawn into the cap in a reverse flow
and into the reservoir 1 via the internal needle 18.
[0044] In the embodiment shown in FIG. 5, infusion set tubing is
secured to the cavity 22 to allow liquid to flow to the user. The
cavity 22 is disposed in the raised portion of the cap 12. In an
alternative embodiment, however, the raised portion of the cap 12
can be in the shape of a standard luer fitting 47 shown in FIG.
13.
[0045] Referring to FIG. 5, in one embodiment the base 11 is formed
around and fixedly attached to the crimp seal swage 3 portion of
the reservoir 1. In an alternative embodiment, however, the base 11
is not fixedly attached to the reservoir. Rather, the base 11 is a
separate unit which is adapted to be releasably secured to the
reservoir via a friction fit. This arrangement permits the
connector apparatus to be used with standard reservoirs.
[0046] Still referring to FIG. 5, the cap 12 includes threads 19
for securing the assembly into the pump housing (not shown). A
shoulder 23 is formed as part of the cap 12 and is adapted to seat
against the pump housing to form a water tight seal. This prevents
any water which is exterior to the housing from entering, thus
permitting the user to engage in water sports.
[0047] The construction of these pumps to be water resistant can
give rise to operational problems. As the user engages in
activities which expose the pump to varying atmospheric pressures,
such as for example, swimming or traveling in an air plane,
differential pressures can arise between the interior of the air
tight/water-resistant housing and the atmosphere. Should the
pressure in the housing exceed external atmospheric pressure, the
resulting forces could cause the reservoir piston to be driven
inward thus delivering unwanted medication. Alternatively, should
the pressure in the housing be less than the external pressure, the
resulting forces could cause the infusion pump motor to work harder
to advance the reservoir piston.
[0048] To address this problem, a preferred embodiment of the
invention includes a vent which permits water resistant housing
construction. The cap 12 includes a plurality of vent ports 24,
only one of which is shown in FIG. 5. The vent ports 24 permit
equalization of pump housing pressure to atmospheric pressure.
Hydrophobic material (not shown) covers the interior openings of
the vent ports 24. Hydrophobic material permits air to pass through
the material while preventing water or other liquids from doing so,
thus permitting water resistant venting. The preferred embodiment
uses a hydrophobic material such as Gore-Tex.RTM., PTFE, HDPE, or
UHMW polymers from sources such as W.I. Gore & Associates,
Flagstaff, Ariz., Porex Technologies, Fairburn, Ga., DeWAL
Industries, Saunderstown, R.I., or Pall Specialty Materials, Port
Washington, N.Y.
[0049] These materials are available in sheet form or molded (press
and sintered) in a geometry of choice. Referring to FIGS. 14a-14c,
preferred methods to attach this material to the cap 12 include
molding the hydrophobic material into a sphere 50 (FIG. 14a) or a
cylinder 51 (FIG. 14b) and pressing it into a cavity in the
pre-molded plastic housing. Alternatively, a label 52 (FIG. 14c) of
this material could be made with either a transfer adhesive or heat
bond material 53 so that the label could be applied over the vent
port 24. Alternatively, the label could be sonically welded to the
housing. In either method, air will be able to pass freely, but
water will not.
[0050] In an alternative embodiment which is not shown, the venting
is accomplished through a vent port located in the pump housing.
This is described in greater detail in copending application Ser.
No. 09/429,352 filed concurrently herewith, which application is
incorporated by reference in its entirety. Alternatively, vent
ports can be placed both in the cap 12 as well as the pump
housing.
[0051] An advantage of placing the vent port and hydrophobic
material in the cap 12, as opposed to in the pump housing only, is
that the infusion set and its related connectors disposable and are
replaced frequently with each new reservoir or vial of medication.
Thus, new hydrophobic material is frequently placed into service.
This provides enhanced ventilation as compared with the placement
of hydrophobic material in only the pump housing. Material in this
location will not be replaced as often and thus is subject to dirt
or oil build up which will retard ventilation.
[0052] As an alternative to the use of hydrophobic material, water
can be prevented from flowing through the vent port by other
apparatuses, such as the use of relief valves.
[0053] FIG. 6 shows a cross-sectional view of the
reservoir/base/cap unit in accordance with the embodiment of FIGS.
3 and 4 which is secured into a pump housing 30. The threads 19 of
the cap 12 engage the pump housing threads. Rather that the use of
threads, an alternative embodiment (not shown) of the cap 12 could
include detents extending radially from the exterior of the cap 12
which are adapted to engage detent openings in the pump
housing.
[0054] The shoulder 23 portion of the cap 12 seats against the pump
housing 30 to permit water tight construction. Further aiding in
the water tight construction is an O-ring seal 31 which is disposed
in the pump housing 30 and located just above the shoulder 23. In
the preferred embodiment, the vent material 32 is comprised of
hydrophobic material and is sonic welded to the upper interior
surface of the cap 12. Alternatively, the vent material 32 could be
attached to the cap 12 with an adhesive. The vent ports are not
shown in FIG. 6.
[0055] Although the foregoing description of the venting was in
connection with the embodiment of FIGS. 3-6, this feature is also
applicable to the embodiment of FIGS. 1-2.
[0056] FIGS. 7 and 8 show an alternative embodiment of the cap 12.
Referring to FIG. 7, a cap engagement member consists of a detent
arm 34 which is formed in the upper portion of the cap 12. The
purpose of the detent arm 34 is to securely engage the cap 12 into
the pump housing. FIG. 8 shows a top view of the cap 12 positioned
in the pump housing 30. The pump housing 30 has two case lock
recesses 35 disposed in the circular rim of the housing. The detent
arm 34 snaps into either of the case lock recesses 35. This
engagement results in a "click" when the cap 12 is appropriately
seated, thus providing both tactile and audible feedback to the
user that the cap is securely engaged in the pump housing.
Moreover, the detent arm 34 aligning with the recess 35 also serves
as a visual indicator that the cap 12 is appropriately seated.
[0057] FIG. 9 shows an alternative embodiment of the cap 12 which
contains a child safety feature. The cap 12 includes a locking
member which consists of a safety tab 36 disposed in a groove 37.
The safety tab 36 is sized such that it is able to slide along the
length of the groove 37. When the safety tab 36 is in the position
shown in FIG. 9, the detent arm 34 is unable to retract from its
engaged position. Thus when the cap 12 is seated into the pump
housing 30 (not shown) and the detent is seated into the case lock
recess 35 (not shown), the safety tab 36 will prevent the detent 34
from disengaging from the case lock recess 35 thus more securely
locking the cap 12 in the pump housing.
[0058] Thus for example, a parent could slide the safety tab 36
from the unlocked location in the groove 37 to the locked location
shown in FIG. 9 so that it would be more difficult for a young
child or infant to inadvertently remove the cap/base/reservoir unit
from the pump housing. On the other hand, when the safety tab 36 is
moved to the opposite end of the groove 37, the detent arm 34 is
able to retract thus permitting removal of the cap 12 from the pump
housing.
[0059] Although the foregoing description of the cap engagement
member and child safety tab was in connection with the embodiment
of FIGS. 3-9, this feature is also applicable to the embodiment of
FIGS. 1-2.
[0060] FIG. 10 shows an exploded view of the cap 12 and the vent
material 32. In the preferred embodiment, the vent material is made
of hydrophobic material and is formed in a circular shape with a
circular hole in the center. The vent material 32 is attached to
the upper interior surface 38 of the cap 12 via sonic welding or an
adhesive. When it is so attached, the needle 18 protrudes through
the center hole of the vent material 32 but the interior openings
of the vent ports 24 (not shown) are covered.
[0061] FIGS. 11 and 12 show an embodiment of the present invention
where an adapter 40 is provided to allow a standard style syringe
41 with an integrated luer fitting 42 to be mounted and sealed in
the pump housing. The syringe 41 is inserted through the center of
the adapter 40 and held into place by a friction fit. The O-ring
seal 43 in the adapter 40 seats against the syringe wall in order
to prevent water and dirt from entering the pump housing.
[0062] A shoulder 45 is formed as part of the adapter 40 and is
adapted to seat against the interior of the pump housing to form a
water tight seal. Two tabs 44 are formed on the top surface of the
adapter 40 and provide a surface for the user to grip the adapter
40 and twist it so that the adapter threads 19 engage the threads
(not shown) of the pump housing. A detent 34 is formed in the upper
portion of the adapter 40. Its purpose is to securely lock the
adapter 40 into the pump housing (not shown) in the same manner as
is shown in FIG. 8. Although not shown in FIGS. 11 and 12, the
adapter 40 can further contain vent ports covered with hydrophobic
material or a relief valve in order to permit water resistant
venting of the pump housing in the same manner as previously
described with other embodiments.
[0063] FIG. 13 shows another embodiment of the present invention
where an interface is provided to connect a reservoir to a conduit,
such as tubing, via a standard luer fitting connection. This allows
a luer style disposable infusion set to connect to the pump housing
(not shown). A cap 46 is formed with a luer fitting 47 portion as
an integral part thereof. Except for the shape of the luer fitting
47 portion, the cap 46 has all of the other features of the cap 12
shown in FIG. 5. Thus referring to FIG. 13, the cap 46 is comprised
of, among other things, threads 19, detent openings 14, a shoulder
23, vent ports 24, a detent 34, and a needle (not shown) disposed
in the interior of the cap 46.
[0064] 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. 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 therefore intended to be embraced therein.
* * * * *