U.S. patent application number 10/904959 was filed with the patent office on 2006-06-08 for reusable pump cartridge.
This patent application is currently assigned to DEPUY MITEK, INC.. Invention is credited to Ian D. McRury, Kevin J. Ranucci, Mehmet Z. Sengun, Christopher Weinert.
Application Number | 20060120899 10/904959 |
Document ID | / |
Family ID | 36046702 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060120899 |
Kind Code |
A1 |
Sengun; Mehmet Z. ; et
al. |
June 8, 2006 |
REUSABLE PUMP CARTRIDGE
Abstract
A pump cartridge for use in a high pressure fluid jet system is
provided. In an exemplary embodiment, the pump cartridge can be
adapted to couple to a drive mechanism for driving fluid from a
fluid source, through the pump cartridge, to a fluid jet delivery
device, and the pump cartridge can be reusable to allow the pump
cartridge to be sterilized between uses.
Inventors: |
Sengun; Mehmet Z.;
(Framingham, MA) ; Weinert; Christopher;
(Mansfield, MA) ; Ranucci; Kevin J.; (North
Attleboro, MA) ; McRury; Ian D.; (Medway,
MA) |
Correspondence
Address: |
NUTTER MCCLENNEN & FISH LLP
WORLD TRADE CENTER WEST
155 SEAPORT BOULEVARD
BOSTON
MA
02210-2604
US
|
Assignee: |
DEPUY MITEK, INC.
Norwood
MA
|
Family ID: |
36046702 |
Appl. No.: |
10/904959 |
Filed: |
December 7, 2004 |
Current U.S.
Class: |
417/417 ;
417/416 |
Current CPC
Class: |
F04B 53/007 20130101;
F04B 53/16 20130101; A61B 17/3203 20130101; A61B 17/32037
20130101 |
Class at
Publication: |
417/417 ;
417/416 |
International
Class: |
F04B 35/04 20060101
F04B035/04; F04B 17/04 20060101 F04B017/04 |
Claims
1. A reusable pump cartridge, comprising: a housing having a
chamber adapted to allow fluid flow therethrough, and a drive
assembly adapted to drive fluid through the chamber when the
housing is coupled to a drive mechanism, the chamber being adapted
to have a sealed configuration when the housing is coupled to the
drive mechanism, and the chamber being adapted to be in an open
configuration when the housing is disengaged from a drive mechanism
such that the housing, the chamber, and the drive assembly can be
steam sterilized between uses.
2. The reusable pump cartridge of claim 1, wherein the chamber
includes an inlet, and outlet, and an opening formed between the
chamber and the drive assembly.
3. The reusable pump cartridge of claim 2, further comprising a
seal disposed within the opening and adapted to have an open
configuration when the housing is disengaged from a drive
mechanism, and adapted to receive a portion of the drive assembly
when the housing is coupled to the drive mechanism such that the
chamber is sealed.
4. The reusable pump cartridge of claim 3, wherein the drive
assembly includes a piston movably disposed through the seal, the
piston being adapted to receive a push rod on a drive mechanism for
moving the piston relative to the seal to drive fluid through the
chamber.
5. The reusable pump cartridge of claim 4, wherein the piston
floats within the housing such that it is movable about a
longitudinal axis thereof.
6. The reusable pump cartridge of claim 4, further comprising a
biasing element coupled to the piston and effective to bias the
piston to a first position in which the piston is fully removed
from the chamber and the seal is open.
7. The reusable pump cartridge of claim 2, wherein the inlet in the
chamber includes a one-way inlet valve adapted to allow fluid to
flow into the chamber, and the outlet in the chamber includes a
one-way outlet valve adapted to allow fluid to flow out of the
chamber.
8. The reusable pump cartridge of claim 7, wherein the inlet and
outlet valves comprise ball-in-aperture valves.
9. A reusable pump cartridge, comprising: a housing removably
matable to a drive mechanism, the housing including a fluid flow
chamber, a coupling chamber, and a seal separating the fluid flow
chamber and the coupling chamber; a piston movably disposed through
the seal and including a receiving portion disposed within the
coupling chamber and adapted to receive a push rod on a drive
mechanism for moving the piston relative to the seal to drive fluid
through the fluid flow chamber; and a biasing element coupled to
the piston and effective to bias the piston to a first position in
which the piston is fully disposed within the pump chamber and the
seal is open.
10. The reusable pump cartridge of claim 9, wherein the piston
floats within the housing such that it is movable about a
longitudinal axis thereof.
11. The reusable pump cartridge of claim 9, wherein the receiving
portion comprises a substantially planar surface.
12. The reusable pump cartridge of claim 9, wherein the piston
comprises an elongate shaft and the receiving portion comprises an
enlarged head formed on an end of the elongate shaft, and wherein
the enlarged head includes a substantially planar surface for
receiving a push rod on a drive mechanism.
13. The reusable pump cartridge of claim 9, wherein the piston is
formed from an autoclavable material.
14. The reusable pump cartridge of claim 9, wherein the piston is
formed from sapphire.
15. The reusable pump cartridge of claim 9, wherein the seal is
formed from an autoclavable material.
16. The reusable pump cartridge of claim 9, wherein the seal is
formed from an impregnated fluoropolymer.
17. The reusable pump cartridge of claim 9, wherein the biasing
element comprises a coil spring disposed around at least a portion
of the piston.
18. The reusable pump cartridge of claim 9, wherein the piston
comprises a head having a first end defining the receiving portion,
and a second end having an elongate shaft extending therefrom and
movably disposed through the seal.
19. The reusable pump cartridge of claim 18, wherein the biasing
element extends around a portion of the elongate shaft and applies
a biasing force to the second end of the head.
20. The reusable pump cartridge of claim 9, wherein the fluid flow
chamber includes a one-way inlet valve adapted to allow fluid to
flow into the fluid flow chamber, and a one-way outlet valve
adapted to allow fluid to flow out of the fluid flow chamber.
21. The reusable pump cartridge of claim 20, wherein the inlet and
outlet valves comprise ball-in-aperture valves.
22. A reusable pump cartridge, comprising: a housing adapted to
couple to a fluid source, a fluid delivery tool, and a drive
mechanism for driving fluid from the fluid source, through the
housing, to the fluid delivery tool; wherein the housing is adapted
to have a first, sealed configuration when the housing is coupled
to a fluid source, a fluid delivery tool, and a drive mechanism,
and a second, open configuration when the housing is disengaged
from the fluid source, the fluid delivery device, and the drive
mechanism; and wherein the housing is adapted to be steam
sterilized in the second, open configuration.
23. A method for using a pump cartridge, comprising: coupling a
drive assembly in a pump cartridge to a drive mechanism, and
coupling a fluid flow chamber in the pump cartridge to a fluid
source and a fluid delivery tool; activating the drive mechanism to
drive fluid from the fluid source, through the fluid flow chamber,
to the fluid delivery tool; disengaging the pump cartridge from the
drive mechanism, the fluid source, and the fluid delivery tool;
sterilizing the pump cartridge; and repeating the steps of coupling
and activating.
24. The method of claim 23, wherein sterilizing the pump cartridge
comprises autoclaving the pump cartridge.
25. The method of claim 23, wherein the fluid delivery tool
comprises a high pressure fluid jet.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to high pressure fluid jet
tools, and in particular to a reusable pump cartridge for use with
a high pressure fluid jet.
BACKGROUND OF THE INVENTION
[0002] High pressure fluid jets for cutting tissue can offer
several advantages over traditional cutting tools. In particular,
high pressure fluid jets tend to emulsify soft tissue, thus
avoiding thermal damage and necrosis which can arise from using
laser cutters and electrosurgical cutters. The emulsified tissue
can also be easily transported by aspiration away from the surgical
site. Indeed, the fact that many fluid jet cutting devices include
aspiration and evacuation as an integral portion of the device can
be an added benefit for many surgical procedures.
[0003] One drawback with current high pressure fluid jets used in
surgical procedures is that they require a sterile fluid flow
pathway from an external pump mechanism to a nozzle that forms the
fluid jet. Most current high pressure fluid jets use a disposable
fluid pathway that is sterilized during manufacturing, and that is
discarded after use. The materials and the configuration of the
fluid pathway often prevent the device from being sterilized after
use.
[0004] Accordingly, there remains a need for an improved high
pressure fluid jet, and in particular for a reusable pump cartridge
for a high pressure fluid jet system.
SUMMARY OF THE INVENTION
[0005] In one exemplary embodiment, a reusable pump cartridge is
provided for use in a high pressure fluid jet system. The pump
cartridge can be adapted to couple to a drive mechanism for driving
fluid through the pump cartridge. Between uses, the pump cartridge
can be disengaged from the drive mechanism, sterilized, and
reused.
[0006] While the pump cartridge can have a variety of
configurations, in one exemplary embodiment the pump cartridge can
include a housing having a chamber adapted for fluid flow
therethrough, and a drive assembly disposed therein and adapted to
drive fluid through the chamber when the housing is coupled to a
drive mechanism. The chamber can be adapted to have a sealed
configuration when the housing is coupled to the drive mechanism,
and the chamber can be adapted to have an open configuration when
the housing is disengaged from a drive mechanism to allow the pump
cartridge to be sterilized. In one exemplary embodiment, the
chamber can include a one-way inlet valve that is adapted to allow
fluid to flow into the chamber, and a one-way outlet valve that is
adapted to allow fluid to flow out of the chamber. By way of
non-limiting example, the inlet and outlet valves can be
ball-in-aperture valves.
[0007] The drive assembly can have a variety of configurations, but
in one exemplary embodiment the drive assembly can include a piston
that is movably disposed through a seal that separates the chamber
from the drive assembly. The piston can be adapted to receive a
force from a push rod on a drive mechanism for moving the piston
relative to the seal to drive fluid through the chamber. In one
exemplary embodiment, the piston can float within the housing such
that it is movable about a longitudinal axis thereof. The drive
assembly can also include a biasing element that is coupled to the
piston and that is effective to bias the piston to a first position
in which the piston is fully removed from the chamber and the seal
is open.
[0008] In another aspect of the present invention, a reusable pump
cartridge is provided and it can include a housing that is
removably matable to a drive mechanism and that includes a fluid
flow chamber, a coupling chamber, and a seal separating the fluid
flow chamber and the coupling chamber. The reusable pump cartridge
can also include a piston that is movably disposed through the seal
and that includes a receiving portion disposed within the coupling
chamber and that is adapted to receive a push rod on a drive
mechanism for moving the piston relative to the seal to drive fluid
through the fluid flow chamber. The pump cartridge can also include
a biasing element coupled to the piston and effective to bias the
piston to a first position in which the piston is fully disposed
within the pump chamber and the seal is open. The biasing element
can also have a variety of configurations, but in one embodiment
the biasing element can be a coil spring that is disposed around at
least a portion of the piston to apply a biasing force to the
second end of the head of the piston.
[0009] The piston can have a variety of configurations, and in one
exemplary embodiment the piston can be, for example, an elongate
shaft having an enlarged head formed thereon. The head can include
a substantially planar surface for receiving a push rod, or in
another embodiment it can include a recess formed therein and
defining the receiving portion. In another exemplary embodiment,
the piston can be formed from an autoclavable material, such as
sapphire. The seal in the housing can also be formed from an
autoclavable material, such as, for example, an impregnated
fluoropolymer, such as a polymer-filled TEFLON.RTM..
[0010] Exemplary methods for using a pump cartridge are also
provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be more fully understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0012] FIG. 1 is an illustration of a high pressure fluid jet
system having a pump console with a pump cartridge connected
thereto and in communication with a fluid jet delivery device in
accordance with one exemplary embodiment of the present
invention;
[0013] FIG. 2 is a perspective view of the pump cartridge of the
high pressure fluid jet system of FIG. 1;
[0014] FIG. 3A is a cross-sectional view of the pump cartridge
shown in FIG. 2
[0015] FIG. 3B is a perspective view of a portion of the pump
cartridge shown in FIG. 3A;
[0016] FIG. 4A is a cross-sectional view of another exemplary
embodiment of a pump cartridge for use with a high pressure fluid
jet system;
[0017] FIG. 4B is a cross-sectional view of a portion of the pump
cartridge shown in FIG. 4A; and
[0018] FIG. 5 is a cross-sectional view of one exemplary embodiment
of a valve mechanism for use with a pump cartridge.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present invention provides a pump cartridge for use in a
high pressure fluid jet system. The pump cartridge can be adapted
to couple to a drive mechanism for driving fluid from a fluid
source, through the pump cartridge, to a fluid jet delivery device.
In an exemplary embodiment, the pump cartridge can be reusable to
allow the pump cartridge to be sterilized between uses. A person
skilled in the art will appreciate that the pump cartridge can be
used with a variety of high pressure fluid jet systems for use in a
variety of applications.
[0020] FIG. 1 illustrates one exemplary embodiment of a high
pressure fluid jet system 10. As shown, the system 10 can include a
drive mechanism 12 and a reusable pump cartridge 50 that can be
releasably attached to the drive mechanism 12. The system 10 can
also include a fluid source 16, such as a saline bag, for
delivering fluid to the reusable pump cartridge 50. The fluid
source 16 can be coupled to the pump cartridge 50 using a variety
of techniques, but in one exemplary embodiment the fluid source 16
includes a tube 16a that extends between the fluid source 16 and
the pump cartridge 50. The system 10 can also include a fluid jet
delivery device, which in the illustrated embodiment includes a
fluid delivery tube 18 and fluid jet device 20, for receiving fluid
from the pump cartridge 50 and forming a high pressure fluid jet.
While the high pressure fluid jet can operate at various pressures
depending on the intended use, in one exemplary embodiment the high
pressure fluid jet system 10 is adapted to operate at a pressure in
the range of about 1,000 to 20,000 psi, and more preferably in the
range of about 5,000 to 15,000 psi. A person skilled in the art
will appreciate that the high pressure fluid jet system can include
a variety of other components, and that each component can have a
variety of configurations. Moreover, the components can be
integrally formed with one another or they can be removably
attached to one another. A person skilled in the art will also
appreciate that the exemplary pump cartridges disclosed herein can
be used with a variety of other fluid jet systems, and that the
exemplary fluid jet system disclosed herein is merely disclosed for
reference purposes.
[0021] While virtually any drive mechanism known in the art can be
used, in one exemplary embodiment the drive mechanism can be part
of a pump console 12 for pumping fluid through the pump cartridge
50 at a controlled rate. The exemplary pump console 12 can include
a push rod 22 (shown in FIG. 4) that is driven by a motor disposed
within the pump console 12, and controls for allowing a user to
input the desired pump parameters. The push rod 22 can have a
variety of shapes and sizes, but in one exemplary embodiment the
push rod 22 has a shape and size that enables it to extend from the
pump console 12 and into the pump cartridge 50 to apply a force to
a piston disposed within the pump cartridge 50, as will be
discussed in more detail below. In use, the motor (not shown) is
effective to reciprocate the push rod 22 along its axis, thereby
reciprocating the piston disposed within the pump cartridge 50 to
pump fluid through the cartridge 50, as will also be discussed in
more detail below.
[0022] The fluid delivery tube 18 can also have a variety of
configurations. In one exemplary embodiment, the fluid delivery
tube 18 can be formed from a material which has sufficient burst
strength to safely deliver fluid at a high pressure to the fluid
jet device 20, and which has good maneuverability for the surgeon.
As shown in FIG. 1A, the fluid delivery tube 18 can be coiled to
provide good maneuverability. The fluid delivery tube 18 can also
include connectors, which in an exemplary embodiment can be hand
tightened, to connect the ends of the fluid delivery tube 18 to the
pump cartridge 50 and the fluid jet device 20, where detachable
components are desired. As previously indicated, the fluid delivery
tube 18 can be integrally formed with or fixedly mated to the pump
cartridge 50 and/or the fluid jet device 20.
[0023] The fluid jet device 20 can also have a variety of
configurations, and virtually any device for forming a high
pressure fluid jet can be used with the various embodiments
disclosed herein. In the illustrated exemplary embodiment, the
fluid jet device 20 is in the form of a hand-held wand that
includes a lumen in communication with the delivery tube 18 and a
nozzle for forming a high pressure fluid jet. The fluid jet device
20 can also include an evacuation lumen for collecting the fluid
jet, as well as a variety of other features for facilitating use of
the device. By way of non-limiting example, one exemplary
embodiment of a fluid jet device is disclosed in commonly owned
U.S. patent application Ser. No. 10/904,456 filed on Nov. 11, 2004
and entitled "Methods and Devices for Selective Bulk Removal and
Precision Sculpting of Tissue" by McRury et al.
[0024] As previously indicated, the high pressure fluid jet system
10 can include a pump cartridge 50 that is adapted to couple to the
pump console 12, and that is disposed between and effective to
transfer fluid from the fluid source 16 to the fluid jet delivery
device 18, 20. The pump cartridge 50 can have a variety of
configurations, but in one exemplary embodiment, shown in FIGS. 3A
and 3B, the pump cartridge 50 can be in the form of a housing
having a first or fluid flow chamber 56 that is adapted to deliver
fluid from the fluid source 16 to the fluid delivery tube 18 and
pressure jet device 20, and a second or coupling chamber 58 having
a drive assembly 60 disposed therein and adapted to drive fluid
through the fluid flow chamber 56 when the cartridge 50 is coupled
to the console 12. The exemplary pump cartridge 50 can also be
adapted to be sterilized, thus allowing the pump cartridge to be
reused. This can be achieved by configuring the pump cartridge 50
such that the internal chambers, e.g., the fluid flow chamber 56
and the coupling chamber 58, of the cartridge 50 are in an open
configuration when the pump cartridge 50 is disengaged from the
console 12.
[0025] A person skilled in the art will appreciate that the pump
cartridge is described as having a second or coupling "chamber" for
reference purposes only, and that the components disposed within
the second chamber of the pump cartridge does not necessarily need
to be disposed within a "chamber" or a defined space.
[0026] The fluid flow chamber 56 can have a variety of
configurations, but in an exemplary embodiment, as shown, it
includes an inlet port 56a that is adapted to mate to the fluid
source 16, and an outlet port 56b that is adapted to mate to the
fluid delivery tube 18. The inlet and outlet ports 56a, 56b can
each include a valve mechanism disposed therein for controlling
fluid flow therethrough. While a variety of valve mechanisms can be
used, in one exemplary embodiment the inlet and outlet ports 56a,
56b each include a one-way ball-in-aperture valve 100 having a ball
102 that is sits within an aperture 104, as shown in more detail in
FIG. 5. The valve 100 can also include a ball-retaining member 106,
such as a rod extending across the inlet and/or outlet ports 56a,
56b, that is adapted to retain the ball 102 within the valve
housing 100. In use, when the pump cartridge 50 is attached to the
console 1 2, the ball 1 02 can prevent fluid from flowing out the
inlet 56a and in the outlet 56b in the fluid flow chamber 56. When
the pump cartridge 50 is disengaged from the console 12, the
cartridge 50 can be laid on its side such that the ball 102 moves
away from the aperture 104, thereby allowing the pump cartridge 50
to be sterilized as the fluid flow chamber 56 is in an open
configuration, as will be discussed in more detail below.
[0027] As is further shown in FIGS. 3A and 3B, the exemplary fluid
flow chamber 56 can be in communication with the coupling chamber
58 to allow the drive assembly 60 within the coupling chamber 58 to
drive fluid through the fluid flow chamber 56. While various
techniques can be used to couple the two chambers 56, 58, in the
illustrated exemplary embodiment a seal 62 can be disposed between
the two chambers 56, 58. The seal 62 can have a variety of shapes
and sizes, but in one exemplary embodiment the seal 62 separates
the fluid flow chamber 56 and the coupling chamber 58. The seal 62
can, however, include an opening 62a formed therein for slidably
receiving a piston 64 that is part of the drive assembly 60
disposed within the coupling chamber 58. As will be discussed in
more detail below, the piston 64 can be adapted to extend through
the opening 62a in the seal 62 when the pump cartridge 50 is
attached to the console 12, and it can retract into the coupling
chamber 58 when the pump cartridge 50 is disengaged from the pump
console 12 such that the fluid flow chamber 56 and the coupling
chamber 58 are in communication with one another, thereby allowing
the pump cartridge 50 to have an open configuration for
sterilization. Thus, while the opening 62a in the seal 62 can have
virtually any shape and size, in an exemplary embodiment the
opening 62a has a shape and size that complements a shape and size
of the piston. For example, the opening can be circular to match a
cylindrical-shaped piston. A person skilled in the art will
appreciate that the seal 62 can be formed from a variety of
materials. Exemplary materials include, by way of non-limiting
example, an impregnated fluoropolymer, such as a polymer-filled
TEFLON.RTM..
[0028] The coupling chamber 58 of the pump cartridge 50 can also
have a variety of configurations, but as indicated above an
exemplary coupling chamber 58 includes a drive assembly 60 disposed
therein that is adapted to receive a force from the push rod 22 on
the console 12, and that is adapted to drive fluid through the
fluid flow chamber 56. As shown in FIGS. 3A and 3B, an exemplary
drive assembly 60 can include a piston 64 having a first portion or
a head 64a that is adapted to receive a force applied by the push
rod 22 on the console 12, and a second portion 64b that extends
through the seal 62 and into the fluid flow chamber 56 for driving
fluid therethrough. The first and second portions 64a, 64b can have
virtually any shape and size, but in one exemplary embodiment the
second portion 64b of the piston 64 can have a generally elongate
cylindrical shape with an extent, e.g., a diameter D.sub.p that
substantially corresponds to an extent, e.g., a diameter D.sub.o,
of the opening 62a in the seal 62, and the first portion or head
64a of the piston 64 can have a substantially planar configuration
to allow the push rod 22 to abut there against. The head 64a can be
enlarged such that it has an extent, e.g., a diameter D.sub.h, that
is greater than the diameter D.sub.p of the second portion 64b, and
that is greater than an extent, e.g., a diameter D.sub.c, of the
push rod 22 (shown in FIGS. 4A and 4B). Such a configuration allows
the push rod 22 to contact any portion of the piston 64, i.e., it
allows a central axis of the push rod 22 to be aligned or
misaligned with a central axis of the piston 64. Thus, a mechanical
interlocking fixation between the push rod 22 and the piston 64 is
not necessary as the components do not need to be axially aligned.
Accordingly, the piston 64 can float within the pump cartridge 50
and relative to the push rod 22. As a result, the push rod 22 will
not cause the piston 64 to be misaligned with the seal 62, thereby
reducing or avoiding potential wear on the seal 62. While not
shown, the head 64a of the piston 64 can include one or more
openings or other features formed therein to facilitate
sterilization of the pump cartridge 50, and in particular to
prevent the piston 64 from sealing the second chamber 58 when the
pump cartridge is disengaged from the drive mechanism 12.
[0029] In another exemplary embodiment, the piston 64 can include a
recess formed in a proximal end thereof for receiving the push rod
22. FIGS. 4A and 4B illustrate another embodiment of a pump
cartridge 50' that is similar to pump cartridge 50 shown in FIGS.
3A and 3B, but that includes a recess 64c' formed in the piston 64'
for receiving the push rod 22. In particular, the piston 64' can
have an enlarged head 64a' formed thereon with a recess 64c' formed
within the head 64'. The recess 64c' can have virtually any shape
and size, but in an exemplary embodiment it has an extent, e.g., a
diameter D.sub.R, that is substantially larger than an extent,
e.g., the diameter D.sub.C, of the push rod 22, as shown in FIG.
4B. Again, such a configuration allows the push rod 22 to be
received within any portion of the recess 64c', and does not
require a mechanical connection to axially align the piston 64 with
the push rod 22. Accordingly, the piston 64' can float within the
pump cartridge 50 and relative to the push rod 22. As a result, the
push rod 22 will not cause the piston 64' to be misalignment with
the seal 62, thereby reducing or avoiding potential wear on the
seal 62'.
[0030] The piston 64, 64' can also be formed from a variety of
materials, but in one exemplary embodiment the piston 64, 64' is
formed from a material that is impervious to sterilization. One
suitable exemplary material is sapphire. Sapphire is also
particularly advantageous in that the use of a sapphire piston can
be highly polished and is extremely hard such that it will remain
stable in high temperature and high pressure environments.
[0031] Referring back to FIGS. 3A and 3B, while the piston 64 can
float within the coupling chamber 58 and it does not need to be
axially aligned with or mated to the push rod 22 on the console 12,
the pump cartridge 50 can include features to facilitate axial
alignment of the piston 64 with the opening 62a in the seal 62.
Various techniques can be used to achieve this, but in one
exemplary embodiment the pump cartridge 50 can include an alignment
mechanism, such as a ring member 70 shown in FIGS. 3A and 3B, that
is adapted to facilitate alignment of the second elongate portion
64b of the piston 64 with the seal 62. The exemplary ring member 70
can have a substantially cylindrical shape with an opening 72
formed therein for slidably receiving the elongate portion 64b of
the piston 64. It can also include one or more projections 74 for
guiding the piston 64 into the opening 72 during initial
engagement, and/or for facilitating sterilization of the device as
the projections will allow steam communication between the
chambers. For example, as shown in FIG. 3B, the ring member 70 is
castellated. FIG. 3A illustrates the ring member 70 disposed within
the pump cartridge 50, and as shown the ring member 70 can be
fixedly attached to the housing within the coupling chamber 58 such
that the opening 72 is aligned with the opening 62a of the seal 62.
As a result, when the piston 64 moves toward the seal 62, the
projections 74 guide the piston 64 toward the opening 72, thereby
substantially aligning the piston 64 with the opening 62a in the
seal 62. The ring member 70 can also be effective to maintain the
seal 62 in a substantially fixed position within the pump cartridge
50.
[0032] In another embodiment, shown in FIGS. 4A and 4B, the piston
64' can be self-aligning. In particular, a biasing element 68',
which will be discussed in more detail below, can be disposed
around the piston 64 and used to maintain and substantially align
the piston 64 with the opening in the seal 62a. The piston 64,
however, can move laterally about its axis such that the piston 64
can self-align with the seal opening 62a. A person skilled in the
art will appreciate that a variety of other techniques can be used
to axially align the piston 64 with the seal 62.
[0033] As indicated above, the drive assembly 60, 60' in the pump
cartridge 50, 50' can also include a biasing element 68 that is
adapted to bias the piston 64, 64' into the coupling chamber 58,
58'. While virtually any biasing element 68 can be used, in the
exemplary embodiment shown in FIG. 3A the biasing element 68 can be
in the form of a coil spring that is disposed around the elongate
portion 64b, 64b' of the piston 64, 64' and that is positioned
between the head 64a of the piston 64 and the ring member 70. FIGS.
4A and 4B also illustrate a coil spring 68'. As noted above, the
spring 68' can maintain and substantially align the piston 64' with
the seal 62 while allowing some lateral movement of the piston 64'
such that the piston 64' is self-aligning with the seal 62.
[0034] In use, when the pump cartridge 50 is attached to the
console 12, the biasing element 68 will apply a force in the
direction of the console 12, thereby forcing the piston 64 into
contact with the push rod 22. As a result, when the motor is
actuated and the push rod 22 is reciprocated along its axis, it
will apply a counter-force to the biasing element 68, thereby
reciprocating the piston 64 through the seal 62 and into the fluid
flow chamber 56 to pump fluid therethrough. When the pump cartridge
50 is removed or disengaged from the console 12, the biasing
element 68 can force the piston 64 out of the opening 62a in the
seal 62 and completely into the second chamber 58 such that the
fluid flow chamber 56 and the coupling chamber 58 are open or in
communication with one another. The pump cartridge 50 can also be
turned on its side to cause the valves 100 to open, such that the
entire pump cartridge 50 is open. As a result, the pump cartridge
50 can be sterilized, e.g., using an autoclave, cleaning agents,
steam, gas, etc., for reuse.
[0035] A person skilled in the art will appreciate that the
cartridge 50 can be coupled to the console 12 using a variety of
engagement techniques. By way of non-limiting example, suitable
engagement mechanisms include a twist-lock mechanism, a threaded
mechanism, or any other technique known in the art. The pump
cartridge 50 can also include a lever 54, shown in FIG. 2, for
facilitating attachment to and removal from the pump console 12.
For example, the lever 54 can be used to rotate the pump cartridge
50 relative to the console 12, thereby causing flanges, threads, or
some other engagement mechanism on the cartridge 50 to engage the
console 12. In certain exemplary embodiments, the pump cartridge 50
can releasably engage the console 12.
[0036] One skilled in the art will appreciate further features and
advantages of the invention based on the above-described
embodiments. Accordingly, the invention is not to be limited by
what has been particularly shown and described, except as indicated
by the appended claims. All publications and references cited
herein are expressly incorporated herein by reference in their
entirety.
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