U.S. patent application number 17/662942 was filed with the patent office on 2022-08-25 for cassette for a flow control apparatus.
The applicant listed for this patent is KPR U.S., LLC. Invention is credited to Wayne BIERMANN, Kenneth M. BREITWEISER, Daniel SCHNETTGOECKE, Paul TRELFORD.
Application Number | 20220265925 17/662942 |
Document ID | / |
Family ID | |
Filed Date | 2022-08-25 |
United States Patent
Application |
20220265925 |
Kind Code |
A1 |
BIERMANN; Wayne ; et
al. |
August 25, 2022 |
CASSETTE FOR A FLOW CONTROL APPARATUS
Abstract
A pump set for use with a pumping apparatus includes tubing for
carrying a liquid. A valve mechanism is mounted to the tubing
between an inlet section and a pump engagement section. The valve
mechanism includes a first port connected to the inlet section of
the tubing, a second port connected to the pump engagement section
of the tubing, and a valve disposed between the first and second
ports. The valve includes a stem rotatably mounted within a stem
holder. The stem includes a flow passage extending through the stem
and having an open V shape whereby a narrow open end of the flow
passage communicates with the first port and a wide open end of the
flow passage communicates with the second port to place the inlet
section of the tubing in communication with the pump engagement
section of the tubing.
Inventors: |
BIERMANN; Wayne; (St.
Charles, MO) ; TRELFORD; Paul; (St. Louis, MO)
; BREITWEISER; Kenneth M.; (Brighton, IL) ;
SCHNETTGOECKE; Daniel; (O'Fallon, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KPR U.S., LLC |
Mansfield |
MA |
US |
|
|
Appl. No.: |
17/662942 |
Filed: |
May 11, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16280883 |
Feb 20, 2019 |
11331428 |
|
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17662942 |
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62688872 |
Jun 22, 2018 |
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International
Class: |
A61M 5/168 20060101
A61M005/168; A61M 5/142 20060101 A61M005/142; A61M 39/22 20060101
A61M039/22 |
Claims
1-21. (canceled)
22. A pump set for use with a pumping apparatus, the pump set
comprising: tubing for carrying a liquid, the tubing comprising an
inlet section for connection to a liquid source and a pump
engagement section configured for engagement by the pumping
apparatus to pump the liquid through the tubing; and a valve
mechanism attached to the tubing between the inlet section and the
pump engagement section, the valve mechanism comprising a first
port connected to the inlet section of the tubing, a second port
connected to the pump engagement section of the tubing, and a valve
disposed between the first and second ports, the valve including a
rotatable stem to selectively communicate the first port with the
second port, the stem including a flow passage extending through
the stem from an inlet end of the flow passage to an outlet end of
the flow passage whereby the inlet end of the flow passage
communicates with the first port and the outlet end of the flow
passage communicates with the second port to place the inlet
section of the tubing in communication with the pump engagement
section of the tubing, the flow passage increasing in
cross-sectional area from the inlet end toward the outlet end,
wherein the cross-sectional area of the flow passage changes at
different rates through the flow passage from the inlet end to the
outlet end.
23. The pump set as set forth in claim 22, wherein a maximum rate
of increase in the cross-sectional area of the flow passage occurs
generally intermediate the inlet end and outlet end of the flow
passage.
24. The pump set as set forth in claim 22, wherein the tubing
comprises a first tubing for connection to a first liquid source
and a second tubing for connection to a second liquid source, the
first port being connected to the first tubing, the valve mechanism
comprising a third port connected to a third tubing, the stem being
rotatably mounted to selectively communicate the outlet end of the
flow passage with the first and third ports, the outlet end of the
flow passage remaining in communication with the second port when
the inlet end is rotated between the first and third ports.
25. The pump set as set forth in claim 24, wherein longitudinal
axes of the first port, second port, third port and flow passage
are generally coplanar.
26. The pump set as set forth in claim 22, further comprising a
cassette configured for releasable attachment to the pumping
apparatus, the tubing and the valve mechanism being releasably
mounted to the cassette.
27. The pump set as set forth in claim 22, wherein the first port
has a non-uniformly circular-shaped opening for communicating
liquid to the flow passage in the valve stem.
28. The pump set as set forth in claim 22, wherein the valve
includes a stem holder for mounting the stem, the stem holder
defining stops positioned to be engaged by a flange of the stem to
limit rotation of the stem in the stem holder.
29. The pump set as set forth in claim 28, wherein the stem holder
has a recessed portion configured to receive a catch when attached
to the pumping apparatus.
30. The pump set as set forth in claim 28, wherein the flange
projects radially outward from the stem.
31. The pump set as set forth in claim 30, wherein the flange has a
generally fan shape that extends radially around the stem.
32. The pump set as set forth in claim 22, wherein the liquid
source is one of a nutrient liquid bag or a flushing fluid bag.
33. A pumping apparatus comprising: a housing comprising: a pumping
unit for pumping liquid; and a cassette recess configured to
receive a cassette; a pump set comprising: tubing for carrying a
liquid, the tubing comprising an inlet section for connection to a
liquid source and a pump engagement section configured for
engagement by the pumping apparatus to pump the liquid through the
tubing; and a valve mechanism attached to the tubing between the
inlet section and the pump engagement section, the valve mechanism
comprising a first port connected to the inlet section of the
tubing, a second port connected to the pump engagement section of
the tubing, and a valve disposed between the first and second
ports, the valve including a rotatable stem to selectively
communicate the first port with the second port, the stem including
a flow passage extending through the stem from an inlet end of the
flow passage to an outlet end of the flow passage whereby the inlet
end of the flow passage communicates with the first port and the
outlet end of the flow passage communicates with the second port to
place the inlet section of the tubing in communication with the
pump engagement section of the tubing, the flow passage increasing
in cross-sectional area from the inlet end toward the outlet end,
wherein the cross-sectional area of the flow passage changes at
different rates through the flow passage from the inlet end to the
outlet end; and a cassette configured to releasably receive the
pump set, the cassette comprising: a body configured for releasable
attachment to the housing to mount the cassette to the pumping
apparatus; and a fitting releasably mountable to the body, the
fitting including the valve mechanism comprising the first port,
the second port, and the valve disposed between the first and
second ports, the valve including the stem rotatably mounted to
selectively communicate the first port with the second port, the
stem including a flange to secure the fitting to the pumping
apparatus when the stem is rotated to communicate the first port
with the second port.
34. The pumping apparatus as set forth in claim 33, wherein a
maximum rate of increase in the cross-sectional area of the flow
passage occurs generally intermediate the inlet end and outlet end
of the flow passage.
35. The pumping apparatus as set forth in claim 33, wherein the
tubing comprises a first tubing for connection to a first liquid
source and a second tubing for connection to a second liquid
source, the first port being connected to the first tubing, the
valve mechanism comprising a third port connected to a third
tubing, the stem being rotatably mounted to selectively communicate
the outlet end of the flow passage with the first and third ports,
the outlet end of the flow passage remaining in communication with
the second port when the inlet end is rotated between the first and
third ports.
36. The pumping apparatus as set forth in claim 35, wherein
longitudinal axes of the first port, second port, third port and
flow passage are generally coplanar.
37. The pumping apparatus as set forth in claim 33, further
comprising a cassette configured for releasable attachment to the
pumping apparatus, the tubing and the valve mechanism being
releasably mounted to the cassette.
38. The pumping apparatus as set forth in claim 33, wherein the
first port has a non-uniformly circular-shaped opening for
communicating liquid to the flow passage in the valve stem.
39. The pumping apparatus as set forth in claim 33, wherein the
valve includes a stem holder for mounting the stem, the stem holder
defining stops positioned to be engaged by a flange of the stem to
limit rotation of the stem in the stem holder.
40. The pumping apparatus as set forth in claim 39, wherein the
stem holder has a recessed portion configured to receive a catch
when attached to the pumping apparatus.
41. The pumping apparatus as set forth in claim 39, wherein the
flange projects radially outward from the stem.
42. The pumping apparatus as set forth in claim 41, wherein the
flange has a generally fan shape that extends radially around the
stem.
43. The pumping apparatus as set forth in claim 33, wherein the
liquid source is one of a nutrient liquid bag or a flushing fluid
bag.
44. The pumping apparatus as set forth in claim 33, wherein the
housing further comprises a display screen configured to display
information regarding status and operation of the pump.
45. A pumping apparatus comprising: a housing comprising: a pumping
unit for pumping liquid; and a cassette recess configured to
receive a cassette; a fitting assembly, comprising: a first port, a
second port, and a valve disposed between the first and second
ports, the valve including a stem rotatably mounted to selectively
communicate the first port with the second port, the stem including
a flow passage extending through the stem from an inlet end of the
flow passage to an outlet end of the flow passage whereby the inlet
end of the flow passage communicates with the first port and the
outlet end of the flow passage communicates with the second port to
place an inlet section of tubing in communication with a pump
engagement section of the tubing, the flow passage increasing in
cross-sectional area from the inlet end toward the outlet end,
wherein the cross-sectional area of the flow passage changes at
different rates through the flow passage from the inlet end to the
outlet end; and a cassette comprising: a body configured for
releasable attachment to the pumping apparatus to mount the
cassette to the pumping apparatus; and a fitting releasably
mountable to the body, the fitting including a valve mechanism
comprising the first port, the second port, and the valve disposed
between the first and second ports, the valve including the stem
rotatably mounted to selectively communicate the first port with
the second port, the stem including a flange to secure the fitting
to the pumping apparatus when the stem is rotated to communicate
the first port with the second port.
46. The pumping apparatus as set forth in claim 45, wherein a
maximum rate of increase in the cross-sectional area of the flow
passage occurs generally intermediate the inlet end and outlet end
of the flow passage.
47. The pumping apparatus as set forth in claim 45, wherein the
tubing comprises a first tubing for connection to a first liquid
source and a second tubing for connection to a second liquid
source, the first port being connected to the first tubing, the
valve mechanism comprising a third port connected to a third
tubing, the stem being rotatably mounted to selectively communicate
the outlet end of the flow passage with the first and third ports,
the outlet end of the flow passage remaining in communication with
the second port when the inlet end is rotated between the first and
third ports.
48. The pumping apparatus as set forth in claim 47, wherein
longitudinal axes of the first port, second port, third port and
flow passage are generally coplanar.
49. The pumping apparatus as set forth in claim 45, further
comprising a cassette configured for releasable attachment to the
pumping apparatus, the tubing and the valve mechanism being
releasably mounted to the cassette.
50. The pumping apparatus as set forth in claim 45, wherein the
first port has a non-uniformly circular-shaped opening for
communicating liquid to the flow passage in the valve stem.
51. The pumping apparatus as set forth in claim 45, wherein the
valve includes a stem holder for mounting the stem, the stem holder
defining stops positioned to be engaged by a flange of the stem to
limit rotation of the stem in the stem holder.
52. The pumping apparatus as set forth in claim 51, wherein the
stem holder has a recessed portion configured to receive a catch
when attached to the pumping apparatus.
53. The pumping apparatus as set forth in claim 51, wherein the
flange projects radially outward from the stem.
54. The pumping apparatus as set forth in claim 53, wherein the
flange has a generally fan shape that extends radially around the
stem.
55. The pumping apparatus as set forth in claim 45, wherein the
liquid source is one of a nutrient liquid bag or a flushing fluid
bag.
56. The pumping apparatus as set forth in claim 45, wherein the
housing further comprises a display screen configured to display
information regarding status and operation of the pump.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is the nonprovisional application of U.S.
Provisional Application Ser. No. 62/688,872 filed Jun. 22, 2018,
the entirety of which is incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a flow control
system with a flow control apparatus and a feeding set, and more
particularly to a cassette for use with the flow control
apparatus.
BACKGROUND OF THE INVENTION
[0003] Administering medicine or nutrition to a patient who cannot
intake the medicine or nutrition orally can be effected by
utilizing peristaltic flow control systems. Typically in such
systems, fluid is delivered to the patient by a pump set including
a flexible elastomeric tubing loaded on a flow control apparatus,
such as a peristaltic pump, which delivers fluid to the patient at
a controlled rate of delivery. The peristaltic pump usually has a
housing that includes a rotor operatively engaged to a motor
through a gearbox. The rotor drives fluid through the flexible
tubing of the pump set by the peristaltic action effected by
reversible compression created by impingement, e.g., pinching, by
one or more roller on the rotor. Rotation of the rotor
progressively compresses the elastomeric tubing that drives the
fluid at a controlled rate. The pump set may have a valve mechanism
for permitting or preventing fluid flow through the pump set. The
flow control system may also have a controller that operatively
regulates the one or more motors which effectively controls fluid
flow.
[0004] Peristaltic pumps operate by delivering fluid in small
charges called "aliquots". The rotor engages elastomeric tubing of
the pump set, pinching off a portion of the elastomeric tubing and
pushing fluid forward of the pinch point, e.g., closer to the
patient than to the source of fluid toward the patient. Typically,
the volume of fluid to be administered to the patient is controlled
in the pump by counting the number of aliquots, each being of
substantially the same volume, and stopping when the number reaches
an amount corresponding to the total desired volume of fluid to be
delivered. Peristaltic pumps are sanitary and generally accurate,
and therefore very useful in the administration of medication and
therapeutic fluids to the patient.
SUMMARY
[0005] In one aspect, a pump set for use with a pumping apparatus
generally comprises tubing for carrying a liquid. The tubing
comprising an inlet section for connection to a liquid source and a
pump engagement section configured for engagement by the pumping
apparatus to pump the liquid through the tubing. A valve mechanism
attached to the tubing between the inlet section and the pump
engagement section comprises a first port connected to the inlet
section of the tubing, a second port connected to the pump
engagement section of the tubing, and a valve disposed between the
first and second ports. The valve includes a rotatable stem to
selectively communicate the first port with the second port. The
stem includes a flow passage extending through the stem from an
inlet end of the flow passage to an outlet end of the flow passage
whereby the inlet end of the flow passage communicates with the
first port and the outlet end of the flow passage communicates with
the second port to place the inlet section of the tubing in
communication with the pump engagement section of the tubing. The
flow passage increases in cross-sectional area from the inlet end
toward the outlet end.
[0006] In another aspect a fitting assembly for use in a cassette
configured for attachment to a pumping apparatus generally
comprises a first port, a second port, and a valve disposed between
the first and second ports. The valve includes a stem rotatably
mounted to selectively communicate the first port with the second
port. The stem includes a flow passage extending through the stem
from an inlet end of the flow passage to an outlet end of the flow
passage whereby the inlet end of the flow passage communicates with
the first port and the outlet end of the flow passage communicates
with the second port to place the inlet section of the tubing in
communication with the pump engagement section of the tubing, the
flow passage increasing in cross-sectional area from the inlet end
toward the outlet end.
[0007] In yet another aspect, cassette for use with a pumping
apparatus generally comprises a body configured for releasable
attachment to the pumping apparatus to mount the cassette to the
pumping apparatus, and a fitting releasably mountable to the body.
The fitting including a valve mechanism comprising a first port, a
second port, and a valve disposed between the first and second
ports. The valve includes a stem rotatably mounted to selectively
communicate the first port with the second port. The stem including
a flange configured for engagement with a catch on the pumping
apparatus to secure the fitting to the pumping apparatus when the
stem is rotated to communicate the first port with the second
port
[0008] In still another aspect, a cassette for use with a pumping
apparatus generally comprises a body configured for releasable
attachment to the pumping apparatus to mount the cassette to the
pumping apparatus. The body comprises a front, a back, a top, a
bottom, and a curved guide wall extending downward from the top of
body. A fitting is mounted on the body. The fitting has an inlet
port for attaching inlet tubing to the cassette and an outlet port
for attaching outlet tubing to the cassette. The outlet port is
recessed from the top of the body. The curved guide wall extends
adjacent the outlet port of the fitting for supporting the outlet
tubing to prevent kinking of the outlet tubing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of a feeding system with
pumping apparatus and a fragmentary portion of a feeding set and a
cassette;
[0010] FIG. 2 is a perspective view of the system of FIG. 1 showing
the pumping apparatus, but with portions of the cassette
removed;
[0011] FIG. 2A is a fragmentary view of the perspective in FIG. 2
with the feeding set and portions of the cassette removed;
[0012] FIG. 3 is the perspective view of FIG. 1 without the feeding
set and cassette;
[0013] FIG. 4 is front perspective view of the cassette;
[0014] FIG. 5 is a rear perspective view of the cassette;
[0015] FIG. 6 is a rear elevation view of the cassette;
[0016] FIG. 7 is the rear perspective view of the cassette with a
fitting assembly removed from the cassette;
[0017] FIG. 8 is a front perspective view of the fitting
assembly;
[0018] FIG. 9 is a rear perspective view of the fitting
assembly;
[0019] FIG. 10A is a top view of the fitting assembly;
[0020] FIG. 10B is a front perspective view of the fitting assembly
with a stem of a stopcock removed;
[0021] FIG. 11A is a rear and side perspective view of the
stem;
[0022] FIG. 11B is a front and side perspective view of the
stem;
[0023] FIG. 11C is a side view of the stem;
[0024] FIG. 12 is a cross section view of the stem;
[0025] FIG. 13A is a vertical section view of the fitting assembly
showing the stem in a fluid flow blocked position;
[0026] FIG. 13B is a vertical section view of the fitting assembly
showing the stem in a flushing position;
[0027] FIG. 13C is a vertical section view of the fitting assembly
showing the stem in a fluid delivery position;
[0028] FIG. 14 is a perspective view of a cassette of another
embodiment;
[0029] FIG. 15 is an exploded view of the cassette of FIG. 14;
[0030] FIG. 16 is an elevation view of a portion of a feeding set
of the cassette of FIG. 14;
[0031] FIG. 17 is a vertical section view of the feeding set of
FIG. 16;
[0032] FIG. 18 is a perspective view of a cassette of another
embodiment;
[0033] FIG. 19 is an exploded view of the cassette of FIG. 18;
[0034] FIG. 20 is an elevation view of a portion of a feeding set
of the cassette of FIG. 18;
[0035] FIG. 21 is a vertical section view of the feeding set of
FIG. 20;
[0036] FIG. 22 is a perspective view of a cassette of another
embodiment;
[0037] FIG. 23 is an exploded view of the cassette of FIG. 22;
[0038] FIG. 24 is an elevation view of a portion of a feeding set
of the cassette of FIG. 22; and
[0039] FIG. 25 is a vertical section view of the feeding set of
FIG. 24.
[0040] Corresponding reference characters indicate corresponding
parts throughout the drawings.
DETAILED DESCRIPTION
[0041] One or more aspects of the present invention pertain to
peristaltic pumps such as rotary peristaltic pumps and particularly
to rotary peristaltic pumps utilizing a cassette having a valve for
selecting between a plurality of fluid flow configurations. The
cassette also has a configuration for preventing an outlet tube
attached to the cassette from kinking. Any one or more advantageous
features or structures that provide or facilitate any one or more
of such features may be implemented in a peristaltic pump employed
in various commercial and industrial applications. Thus, although
the detailed discussion is directed to an enteral feed pump with a
cassette, any one or more features of the invention may be embodied
or implemented in other peristaltic pumps, with or without a
cassette. For example, although the exemplarily discussed pump is a
rotary peristaltic enteral feeding pump, the present invention has
application to other types of peristaltic pumps (not shown),
including medical infusion pumps. The general construction and
operation of the enteral feeding pump, except as set forth
hereinafter, may be generally the same as disclosed in co-assigned
U.S. Pat. No. 7,608,059 issued Oct. 27, 2009, entitled FLOW CONTROL
APPARATUS; U.S. Pat. No. 7,092,797 issued Aug. 15, 2006, entitled
FLOW MONITORING SYSTEM FOR A FLOW CONTROL APPARATUS; and U.S. Pat.
No. 7,534,099 issued May 19, 2009, entitled ALIQUOT CORRECTION FOR
FEEDING SET DEGRADATION, the disclosures of which are incorporated
herein by reference. One or more of the various features and
aspects of the invention may be implemented in peristaltic pumps
that use mechanisms other than rollers without departing from the
scope of the present invention such as linear peristaltic pumps.
Moreover, although an exemplary feeding set 7 is shown, other types
of pump sets (not shown) can be used without departing from the
scope of the present invention.
[0042] Referring now to the drawings, and in particular FIGS. 1-3,
an exemplary enteral feeding pump (broadly, "pumping apparatus")
constructed according to the any one or more of the principles of
the present invention is generally indicated at 1. The feeding pump
may comprise a housing generally indicated at 3 that is constructed
so as to mount a cassette, generally indicated at 5, and a feeding
set (broadly, a "pump set"), a fragmentary portion generally
indicated at 7, removably received in the cassette 5. The cassette
5 is releasably attachable to the housing 3. In the illustrated
embodiment, the cassette 5 is removably received in a cassette
recess 6 in the housing 3 (FIG. 3). It will be appreciated that
"housing" as used herein may include many forms of supporting
structures (not shown), including without limitation multi-part
structures and structures that do not enclose or house the working
components of the pump 1. In the illustrated embodiment, the pump 1
and pump set 7 form a "feeding system." Moreover, various aspects
and features of the present invention can be implemented without
the recess 6. The pump 1 may also have a display screen 9 on the
housing 3 that is capable of displaying information about the
status and operation of the pump. One or more buttons 11 which can
be proximate the display screen 9 can be provided for use in
controlling and obtaining information from the pump 1, and one or
more light emitting diodes 13 can provide status information for
the pump. Legs (not shown) may be disposed at the bottom of the
housing 3 to support the housing so that the display screen 10 is
angled slightly upward for ease of viewing by a user or
operator.
[0043] The display screen 9 may be part of a front panel (generally
indicated at 19) of the housing 3 and may be removably attached to
the housing. The enteral feeding pump 1 may further include a
pumping unit indicated generally at 23 comprising a pump motor (not
shown) connected to a rotor shaft (not shown). A battery (not
shown) may be received in the housing 3 for powering the pump
motor. A power source other than or in addition to the battery
could be used to energize the pump including one or more prime
movers which drive the pumping unit through the rotor shaft.
[0044] The pumping unit 23 may include a rotor (generally indicated
at 37) which can be coupled to the rotor shaft. The rotor 37 may
include an inner disk 39, an outer disk 41, and four rollers 43
(only three of which are shown) mounted between the inner and outer
disks for free rotation relative to the disks about their
longitudinal axes (FIGS. 2 and 3). The rollers 43 engage a tube 45
(FIG. 2) of the feeding set 7 to deliver fluid through the feeding
set 7 to a subject when the feeding set 7 is received in the
cassette 5 and the cassette 5 is attached to the housing 3. Other
numbers of rollers are also envisioned. For example, five or six
rollers may also be used without departing from the scope of the
disclosure.
[0045] Referring to FIGS. 4-7, the cassette 5 may comprise a
cassette body 51 having a front 53, a back 55, a top 57, and a
bottom 59. Side walls 61 and top wall 63 may extend from the back
55 of the cassette body 51 forming a back cavity configured for
receiving a fitting 65. The tube 45 may be attached to the fitting
65. The fitting 65 may have tabs that allow the fitting 65 to be
secured or snapped into the cassette. In some cases, the fitting
can be removably secured to the cassette 5.
[0046] The fitting 65 can comprise a base 67, an inlet 69, an
outlet 71, and a stem holder 66. The inlet 69 may include a first
attachment portion 73 for insertion into an inlet end of the tube
45, and a pair of second attachment portions 75A, 75B for receiving
inlet tubing 77 (FIG. 2). The outlet port 71 may include a first
attachment portion 79 for engagement or attachment to, such as by
insertion into an outlet end of the tube 45, and a second
attachment portion 81 for attachment to, such as by receiving
outlet tubing 83. An opening of the second attachment portion 81
that receives the outlet tubing 83 may funnel or taper down away
from the opening to secure the tubing in the opening. The outlet
tubing 83 may also be treated with a solvent to soften the tube for
insertion into and bonding with the attachment portion 81. Second
attachment portion 75A may be placed in fluid communication with a
feeding source (e.g., nutrient liquid bag), and second attachment
portion 75B may be placed in fluid communication with a flushing
source (e.g., flushing fluid bag) via the inlet tubing 77. To aid
in the identification of the preferred attachment of the fluid
sources, second attachment portion 75A extends above second
attachment portion 75B. Thus, a user can readily identify the
taller second attachment portion 75A as the feeding source port.
Alternatively, second attachment portion 75B could be attached to
the feeding source and second attachment portion 75A could be
attached to the flushing source.
[0047] The tube 45, fitting 65, inlet tubing 77, and outlet tubing
83 may comprise the pump set 7. It is also envisioned that the
cassette 5 may be considered to be part of the pump set. In a
preferred embodiment, the cassette 5 is made from a polymeric
material such as polycarbonate.
[0048] Referring to FIGS. 8-13C, a stopcock 64 includes a
cylindrical stem 68 received in a cylindrical receptacle 70 in the
stem holder 66 of the fitting 65. The stem 68 is moveable (i.e.
rotatable) in the opening 70 to selectively communicate the second
attachment portions 75A, 75B with the first attachment portion 73
for placing the pump set in one of a fluid delivery configuration,
a flushing configuration, or a fluid flow blocked configuration.
The second attachment portions 75A, 75B each have outlets which
communicate with the opening 70 in the fitting 65, and first
attachment portion 73 has an inlet that communicates with the
opening in the fitting. In one embodiment, the outlet of the second
attachment portions 75A is non-uniformly circular-shaped to
increase the outlet area without increasing the size of the
stopcock 64. The exemplary oval-shaped outlet illustrated in FIG.
10A, for example, allows, for example, thicker and more viscous
feeding solutions to be more readily fed into the pump set 7
without enlarging the stopcock. The stem 68 comprises a cylindrical
body 72 having a first opening 74 (FIG. 11A) and a second opening
76 (FIG. 11B) formed in the body. The first opening 74 has a
circular shape, and second opening 76 is elongate such that a first
dimension of the opening 76 is greater than a second orthogonal
dimension. In the illustrated embodiment, the second opening 76 has
a longer slotted dimension than the diameter of the first opening
74. The first and second openings 74, 76 are located generally on
opposite sides of the body 72 and are positioned such that they are
in the same or substantially similar plane so that fluid flow
through the stem 68 extends downward from the second attachment
portions 75A, 75B to the first attachment portion 73 generally
within a single plane (FIGS. 12 and 13A-C). More specifically,
fluid may flow through the stem 68 along a single axis from the
first opening 74 to the second opening 76. This increases the
efficiency of the valve by providing a straight line flow path
through the stem 68. In other embodiments, the configurations of
openings 74, 76 could be reversed.
[0049] A flow passage 88 extends within the body 72 of the stem 68
from an inlet end at the first opening 74 to an outlet end at the
second opening 76. The passage 88 widens, thereby increasing its
cross sectional area from the first opening 74 to the second
opening 76. The passage 88 may include curved inner walls 92 giving
the passage roughly an inverted modified V-shaped configuration.
The curved inner walls 92 define a first section 130 that widens at
a generally constant rate from the first opening 74 to an end of
the first section, and a second section 132 that widens at a
non-constant rate from the first section 130 to an end of the
second section 132. The rate at which the second section 132 widens
increases toward the end of the second section 132. A third section
134 widens at a non-constant rate from the second section 132 to an
end of the third section 134. The rate at which the third section
134 widens decreases toward the end of the third section. A fourth
section 136 widens at a constant rate from the third section 134 to
the second opening 76. Broadly, the stem 68 and stem holder 66 may
be considered a valve mechanism.
[0050] The contour of the passage 88 provides benefits in the
molding process of the stem 68. In particular, by forming the
passage to have the modified `V` shape, the thickness of the wall
between the passage and cylindrical exterior surface of the stem 68
on each side can be kept smaller. A smaller wall thickness assists
in maintaining a more consistently cylindrical shape of the
exterior surface. This prevents deviations in the exterior surface
of the stem 68 which can create gaps between the stem 68 and the
stem holder 66 permitting fluid flow between the second attachment
portions 75A, 75B when the stem 68 is in the fluid flow blocked
position. To the contrary, a passage having a true `V` shape
(represented by the dashed lines in FIG. 12) can result in the
thickness of the stem 68 around the passage 88, generally near the
middle of the passage, that is too large to be produced in the
molding process without causing inconsistencies in the
circumference of the stem. However, by contouring the passage 88 to
have one or more sections intermediate the inlet end (opening 74)
and the outlet end (opening 76) increase more rapidly in width (an
therefore cross sectional area), the maximum thickness of the wall
is reduced to a thickness that will hold its shape in the molding
process. Thus, the thickness of the wall of the stem 68 around the
second, third, and fourth sections 132, 134, 136 is smaller than if
the passage followed a standard `V` profile. This smaller wall
thickness allows the stem 68 to be molded without producing
irregularities in the outer circumference of the stem 68.
[0051] As shown in FIG. 11B, flange 78 projects radially from the
body 72 of the stem 68 and extends partially around a circumference
of the body 72. In one embodiment, the flange 78 is generally
fan-shaped. A cavity 80 is formed in the body 72 which allows a
shaft 93 (FIG. 3) of the pump 1 to engage the body of the stem 68
for rotating the body in the opening 70. The flange 78 is
configured to engage a hook 108 (FIGS. 2A and 3) in the recess 6 of
the pump 1 to prevent removal of the feeding set 7 when the valve
is open. The hook 108 is received in a recess 110 in the stem
holder 66 (FIG. 10B) when the cassette 5 is attached to the pump 1.
This locates the flange 78 adjacent to and behind at least a
portion of the hook 108. As will be explained in greater detail
below, movement of the stem 68 places the flange 78 behind the hook
108 preventing removal of the feeding set 7 when the valve is open.
This safety feature prevents a free flow condition in the feeding
set 7 where an uncontrolled amount of fluid is delivered to the
patient which can be potentially harmful to the patient.
Additionally, the flange 78 functions as a stop engagement feature
for limiting rotation of the stem 68, as further explained below.
The fitting 65 and stem 68 together may be considered a fitting
assembly 82. The configuration of the fitting assembly 82 removes
the fluid flow selection valve from the inlet tubing 77 and places
it within the body of the cassette 5.
[0052] In the configuration shown in FIGS. 8 and 13A, the fitting
assembly 82 is in the fluid flow blocked configuration where the
body 72 blocks the outlets of the second attachment portions 75A,
75B from communicating with the opening 70 and the inlet of the
first attachment portion 73. Rotation of the stem 68, such as by
the shaft 93 of the pump 1 engaging the cavity 80 and rotating the
body 72 clockwise in the opening 70, will place the first opening
74 in communication with the outlet of second attachment portion
75B and the second opening 76 in communication with the inlet of
first attachment portion 73 thereby placing the fluid source
connected to second attachment portion 75B in fluid communication
with the outlet 71 and outlet tubing 83 via tube 45 (FIG. 13B). The
second attachment portion 75A remains blocked from communication
with the first attachment portion 73. Additionally, when the stem
68 is rotated from a closed position to place the first opening 74
in communication with the outlet of second attachment portion 75B,
the flange 78 moves behind the hook 108 on the pump 1 so that the
feeding set 7 is prevented from being removed from the pump 1 (FIG.
2A). Further rotation of the stem 68 will place the first opening
74 in communication with the outlet of second attachment portion
75A and the second opening 76 will remain in communication with the
inlet of the first attachment portion 73 thereby placing the fluid
source connected to second attachment portion 75A in communication
with the outlet 71 and outlet tubing 83 via tube 45 (FIG. 13C).
This is accomplished because the position and length of the second
opening 76 are such that at least some portion of the second
opening will be in communication with the inlet of the first
attachment portion 73 throughout the movement of the stem 68 to
communicate the first opening 74 with the outlets of the second
attachment portions 75A, 75B. The second attachment portion 75B is
now blocked from communication with the first attachment portion
73. Stops 94 on the stem holder 66 engage the flange 78 to limit
rotation of the body in the opening 70.
[0053] Referring to FIGS. 5-7, the second attachment portion 81 of
the outlet 71 of the fitting 65 is recessed from the top 57 of the
cassette 5 so that the outlet tubing 83 extends down into the body
51 of the cassette prior to being inserted into the second
attachment portion 81. This provides a section of the outlet tubing
83 that extends adjacent a curved guide wall 96 extending down from
the top wall 63. The curved guide wall 96 provides an arcuate
surface of gradually decreasing slope for the outlet tubing 83 to
rest on preventing the tubing from bending sharply on a transverse
edge of the cassette 5. As a result, the outlet tubing 83 is
prevented from kinking, which can inhibit fluid flow through the
tubing. Additionally, because a section of the outlet tubing 83
extends between the top 57 of the cassette 5 and the attachment of
the tubing to the fitting 65, the section of the tubing inserted
into the second attachment portion 81 which may have been softened
by the treatment of the solvent is not located where the tubing is
subject to a bending force. Rather, this section is spaced away
from the top 57 of the cassette 5 and is held generally straight by
the curved guide wall 96. This further reduces the chances of any
kinking or pinching off in the outlet tubing 83.
[0054] As exemplarily illustrated, tabs 84 (FIGS. 8 and 9) can
extend from lateral sides of the base 67 and can be configured to
be received in respective openings 86 (e.g., FIGS. 1 and 4) in the
front 53 of the cassette 5 to releasably attach the fitting 65 to
the cassette 5. A pair of guide ramps 91 (FIGS. 6 and 7) in the
side walls 61 may funnel toward the openings 86. The tabs 84 on the
fitting 65 can ride along the ramps 91 and be received in the
openings 86 to retain the fitting to the cassette body 51. The stem
holder 66 of the fitting 65 is received in a valve holder 98 (FIG.
7) formed in the body 51 of the cassette 5. Alternatively, the
fitting 65 may be formed integrally with the cassette body 51, or
omitted.
[0055] Referring to FIGS. 5 and 7, cutouts 85A, 85B may be formed
in the top wall 63 of the cassette body 51 for receiving the second
attachment portions 75A, 75B of the inlet 69 of the fitting 65, and
the outlet tubing 83, respectively. A locator wall 87 may extend
vertically near the top of the cassette body 51. A generally
U-shaped wall 89 may be disposed between the side walls 61
generally at a center of the cassette body 51. The base 67 of the
fitting 65 is received between the locator wall 87, and the
U-shaped wall 89. The base 67 may engage a bottom of the locator
wall 87 and tops of vertical projections of the U-shaped wall 89 to
position the fitting 65 in the cassette 5.
[0056] An arcuate wall 95 may be disposed generally at a middle of
the cassette body 51 to at least partially define a rotor recess 97
for receiving at least a portion of the rotor 37 of the pump 1 when
the cassette 5 is attached to the housing 3. The rotor recess 97
may include a bump-out 99 on the front 53 of the cassette body 51
(FIG. 4). Inlet and outlet outer curved guide walls 101 may extend
generally parallel to opposite sides of arcuate wall 95. Inlet and
outlet inner curved guide walls 103 may extend upward from the
arcuate wall 95 generally parallel to the inlet and outlet outer
curved guide walls 101, respectively, forming inlet and outlet
openings for receiving and supporting respective inlet and outlet
portions of the tube 45. The guide walls 101, 103 and arcuate wall
95 may form a tube channel 114 for receiving a lower portion of the
tube 45 in a looped configuration to properly position the tube
relative to the rotor 37 when the cassette 5 is attached to the
housing 3. The arcuate wall 95 and curved guide walls 101, 103 may
receive the tube in close fitting relation around the sides of the
rotor recess 97. Tabs 100 may extend over the tube channel 114 to
hold the tube 45 in the tube channel 114 and to retain the tube 45
in the cassette, constraining the tube according to a third axis.
The outer curved guide walls 101 may terminate generally at a
bottom side of the rotor recess 97 so that the tube 45 is not
directly opposed by the guide walls 101, 103 or the arcuate wall 95
at the bottom of the rotor recess 97.
[0057] An insert 105 may be received in the cassette recess 6 in
the housing 3 to aid in securing the cassette 5 and tube 45 in the
cassette recess 6 (FIG. 3). The insert 105 may be positioned in the
recess 6 such that the insert 105 is received in the back cavity of
the cassette 5 above the curved guide walls 101, 103 when the
cassette 5 is attached to the housing 3. The insert 105 may
comprise a pair of opposing first projections 107 disposed at an
inlet side of the insert for receiving the inlet portion of the
tube 45, and a pair of opposing second projections 109 disposed at
an outlet side of the insert for receiving the outlet portion of
the tube. Ribs 111 (FIGS. 6 and 7) on the back 55 of the cassette
body 51 may be positioned to engage the outlet portion of the tube
45 between the second projections 109 to aid in inserting the
outlet portion between the projections. Indicia 112 may be disposed
on at least one of the second projections 109 indicating the
direction of fluid flow in the tube 45. In the illustrated
embodiment, the indicia 112 is in the form of an arrow.
[0058] Referring to FIGS. 5-9, a stator member 113 may be disposed
a bottom portion of the cassette body 51 in a cavity such as stator
opening 115 generally at or proximate the bottom of the rotor
recess 97. Thus, when the cassette 5 is attached to the housing 3,
the stator member 113 is typically positioned generally opposite a
bottom of the rotor 37. In advantageous configurations, the stator
member 113 may support the tube 45 of the feeding set 7 when the
rollers 43 engage the tube, as explained below. In some cases, the
stator member 113 may have an arcuate shape extending along a
length of the stator member. As in the exemplarily illustrated
embodiments, the stator member 113 may be a cantilevered member
anchored only at a first end to the cassette body 51 and at least
partially free to float in the stator opening 115 relative to the
cassette body 51. As shown, the flexible stator member 113 may
pivot about its connection or anchor to the remainder of the
cassette 5 and may partially or fully flatten out upon engagement
with a roller 43. For example, the stator member can have the first
end affixed to the cassette body and a second end that is unfixed
which can float or be displaced to allow a reaction segment having
a surface of the stator member to have a deflection displacement.
For example, as the at least one roller traverses along the tube
while revolving about the axis of rotation of the rotor, the
flexible stator member 113 may be displaced or deflect to a
deflection displacement in reaction to the applied force by the one
or more rollers 43 during revolution thereof about the axis of
rotation.
[0059] Transverse ribs 116 on a bottom of the first section can
provide structural rigidity to the flexible stator member 113 and
can serve as contacting surfaces that facilitate removal, such as
by ejection, of the flexible stator member from a mold cavity. In
the illustrated embodiment, the flexible stator member 113 may be
integrally formed as one piece with the cassette body 51. However,
the flexible stator member 113 could be formed separately from the
cassette body 51 and attached to the cassette body by a suitable
means. For example, a flexible stator (not shown) can have an
elongate extension portion that is engaged in an engagement cavity
in the cassette body wherein the engagement cavity is
correspondingly sized and shaped to receive the extension portion.
In this manner, a stator member can be selected from a plurality of
candidates of differing mechanical characteristics, such as modulus
and radius of curvature, to tailor the cassette operating
parameters, with or without consideration for any of the tube
characteristics, and provide specific flow performance attributes
during pumping operation.
[0060] A stop 117 may be disposed at a bottom of the stator opening
115 to limit the floating movement of the flexible stator member
113 to a maximum displacement. The stop 117 may be spaced relative
to the underside of the flexible stator member 113 to prevent
flexing of the stator member that would result in plastic
deformation of the stator member. For example, the stop member may
be positioned to limit the magnitude of the deflection displacement
distance of the unfixed end to the maximum displacement. In the
illustrated embodiment, the stop 117 is formed as part of the
cassette body 51. However, the stop 117 could be formed separately
from the cassette body 51 and attached to the cassette body in a
suitable fashion. In other cases, stop 117 may be formed on the
housing 3 and configured to limit the displacement of the flexible
stator member 113 to the maximum displacement. The stop 117 may
have a width that is greater than the width of the flexible stator
member 113 so that the stop provides an adequate surface area to
limit movement of the stator member. The stop 117 can serve to
shield the flexible stator member 113 and is typically sized to
prevent or reduce the likelihood of snagging or catching the member
113.
[0061] Prior to attaching the cassette 5 to the pump housing 3, the
inlet and outlet tubing 77, 83 may be attached to the inlet and
outlet 69, 71, respectively, of the cassette. To attach the
cassette 5 to the pump housing 3, one or more pins or raised
projections 119 at the bottom 59 of the cassette body 51 may be
inserted in slots 124 at the bottom of the recess 6 in the housing
3. The engagement between the raised projections 119 and slots 124
generally locates the cassette 5 on the housing 3. The cassette
body 51 can then be rotated up until ledges 123 on a tab 125 at the
top 57 of the cassette body are captured by a catch 127 at the top
of the recess 6. In the illustrated embodiment, the raised
projections 119 and ledges 123 are formed integrally with the
cassette body 51. However, the raised projections 119 and ledges
123 can be formed separately from the cassette body 51 and attached
to the cassette body in a suitable fashion. To detach the cassette
5 from the pump housing 3, the tab 125 can be depressed to
disengage the ledges 123 from the catch 127.
[0062] Once the cassette 5 is attached to the pump housing 3, the
tube 45 of the feeding set 7 is positioned for engagement by the
rollers 43 of the pump 1. The rollers 43 engage the tube 45 at
portions of the tube supported by the flexible stator member 113.
Engagement of the tube 45 by a roller 43 causes the flexible stator
member 113 to flex or move away from the roller. In particular, the
movement allows the tube 45 to at least partially straighten out
into a more linear configuration permitting the rollers 43 to
occlude the tube in a semi-linear fashion. Therefore, instead of
pulling and stretching the tube 45 as can be the case with rollers
in conventional pumps, the rollers 43 slide along the tube and
occlude the tube in a reduced tension state. As a result, the
rollers 43 produce aliquots consistent with the actual linear
dimensions of the tube 45. Accordingly, the calculated aliquot
volume of the pump 1 more closely matches the actual aliquot volume
produced by the pump resulting in more accurate feeding.
[0063] Referring to FIGS. 14-17, a pump set of another embodiment
is generally indicated at 7'. The pump set comprises a cassette 5'
including a cassette body 51', a fitting assembly 82' including a
fitting 65' received in the cassette body and a stem 68' movably
received in the fitting, and a tube 45' attached to the fitting.
The cassette 5' is similar to the cassette of the first embodiment
except for the configuration of the fitting 65', and in particular,
the second attachment portion 81' of the outlet 71' of the fitting.
In this embodiment, the second attachment portion 81' extends
laterally away from the inlet 69' and extends through a notch 102'
in a side wall 61' of the cassette 5'. Outlet tubing 83' is
received in the second attachment portion 81' and extends laterally
away from the housing 51' of the cassette 5'. The laterally
extending outlet tubing 83' provides an orientation that resists
kinking better than an outlet tube extending vertically upward from
the second attachment portion 81'. This is because the downward
force created by fluid flowing through the outlet tubing 83' will
cause less of a bend in the laterally extending outlet tubing
reducing the chances of a kink being formed. Also, because the
outlet tubing 83' generally bends downward from the cassette 5' to
reach the patient, having the outlet tubing extend laterally from
the cassette orients the tubing in a position that is better suited
for reaching the patient without the weight of the fluid causing
the tubing to kink.
[0064] Referring to FIGS. 18-21, a pump set of another embodiment
is generally indicated at 7''. The pump set comprises a cassette
5'' including a cassette body 51'', a fitting assembly 82''
including a fitting 65'' received in the cassette body and a stem
68'' movably received in the fitting, and a tube 45'' attached to
the fitting. The cassette 5'' is similar to the cassette of the
previous embodiments except for the configuration of the fitting
65'', and in particular, the outlet 71'' of the fitting. In this
embodiment, the outlet 71'' comprises an angled arch shaped portion
104'' and a flow guide 106'' received in the arch-shaped portion.
The flow guide 106'' has an open top which is closed by the arch
shaped portion 104'' providing an arched flow passage through the
outlet 71'' of the fitting 65''. A downstream portion of the tube
45'' connects to a first attachment portion 79'' of the flow guide
106'' and a second attachment portion 81'' of the flow guide
connects to outlet tubing 83''. Because of the arched shape of the
outlet 71'', the second attachment portion 81'' extends downward
through an opening 102'' in the front 53'' of the cassette 5''.
Outlet tubing 83'' is received in the second attachment portion
81'' and extends downward adjacent the front 53'' of the housing
51'' of the cassette 5''. The downwardly extending outlet tubing
83'' provides an orientation that resists kinking better than an
outlet tube extending vertically upward from the second attachment
portion 81''. This is because the downward force created by fluid
flowing through the outlet tubing 83'' will cause less of a bend in
the already downwardly extending outlet tubing reducing the chances
of a kink being formed. Also, because the outlet tubing 83''
generally has to bend down from the cassette 5'' to reach the
patient, having the outlet tubing already extending downward from
the cassette orients the tubing in a position that is better suited
for reaching the patient without the weight of the fluid causing
the tubing to kink.
[0065] Referring to FIGS. 22-25, a pump set of another embodiment
is generally indicated at 7''. The pump set comprises a cassette
5''' including a cassette body 51''', a fitting assembly 82''
including a fitting 65''' received in the cassette body and a stem
68'' movably received in the fitting, and a tube 45''' attached to
the fitting. The cassette 5''' is similar to the cassette of the
previous embodiments except for the configuration of the fitting
65''', and in particular, the outlet 71'' of the fitting. In this
embodiment, the outlet 71''' comprises an arch shaped portion
104''' and a flow guide 106''' received over the arch shaped
portion. The arch shaped portion 104''' has an open top which is
closed by the flow guide 106''' providing an arched flow passage
through the outlet 71''' of the fitting 65''. A downstream portion
of the tube 45'' connects to a first attachment portion 79'' of the
arch shaped portion 104''' and a second attachment portion 81''' of
the arch shaped portion connects to outlet tubing 83''. Because of
the arched shape of the outlet 71'', the second attachment portion
81''' extends downward through an opening (not shown) in a side
projection of the cassette 5'''. Outlet tubing 83'' is received in
the second attachment portion 81'' and extends downward adjacent a
side wall 61''' of the cassette 5''. The downwardly extending
outlet tubing 83''' provides an orientation that resists kinking
better than an outlet tube extending vertically upward from the
second attachment portion 81'''. This is because the downward force
created by fluid flowing through the outlet tubing 83'' will cause
less of a bend in the already downwardly extending outlet tubing
reducing the chances of a kink being formed. Also, because the
outlet tubing 83''' generally has to bend down from the cassette
5''' to reach the patient, having the outlet tubing already
extending downward from the cassette orients the tubing in a
position that is better suited for reaching the patient without the
weight of the fluid causing the tubing to kink.
[0066] In one, nonexclusive statement of the invention, a cassette
for use with a pumping apparatus generally comprises a body
configured for releasable attachment to the pumping apparatus to
mount the cassette to the pumping apparatus. The body comprises a
front, a back, a top, a bottom, and a curved guide wall extending
downward from the top of body. A fitting mounted on the body has an
inlet port for attaching inlet tubing to the cassette and an outlet
port for attaching outlet tubing to the cassette. The outlet port
is recessed from the top of the body, and the curved guide wall
extends adjacent the outlet port of the fitting for supporting the
outlet tubing to prevent kinking of the outlet tubing.
[0067] When introducing elements of the present invention or the
preferred embodiments(s) thereof, the articles "a", "an", "the" and
"said" are intended to mean that there are one or more of the
elements. The terms "comprising", "including" and "having" are
intended to be inclusive and mean that there may be additional
elements other than the listed elements.
[0068] In view of the above, it will be seen that the several
objects of the invention are achieved and other advantageous
results attained.
[0069] As various changes could be made in the above constructions
without departing from the scope of the invention, it is intended
that all matter contained in the above description and shown in the
accompanying drawings shall be interpreted as illustrative and not
in a limiting sense.
* * * * *