Note: Descriptions are shown in the official language in which they were submitted.
CA 02310326 2001-02-OS
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TITLE OF THE INVENTION
INFUSION APPARATUS FOR IV BAGS
TECHNICAL FIELD TO WHICH THE INVENTION RELATES
This invention relates to medical devices employed to
force parenteral fluid from an IV bag into a patient for an
infusion operation. In particular, it relates to those
devices that are pressure-sensitive and automatically re-set
to receive another IV bag for a subsequent operation.
BACKGROUND ART
Apparatus known for use to strip the contents of
flexible, collapsible plastic container:> and tubing are
disclosed in U.S. Patents Nos. 951,101 t:o Clark; 1,352,425
to Boye; 1,460,204 to Maraffi; 1,470,534 to Keiper;
1,692,116 to Greist; 1,716,388 to Sherfy; 2,003,283 to
Chatelain; 2,110,868 to Coates; 2,183,00 to Blake:
2,206,985 to Vogt; 2,542,678 to Keefer; 2,578,472 to
Gunnarson; 2,876,934 to Brim; 3,197,072 to Dick; 3,263,862
to Tazzeo; 3,507,278 to Werding; 3,604,418 to Jones;
4,639,251 to Kirkland; 4,850,971 to Colvin: and 5,118,011 to
Kopp.
Among these known apparatus, the patents to Werding,
Jones, Kirkland and Colvin disclose medical devices which
are used with flexible fluid bags and tubing therefor.
In hospitals and medical facilities, it is known to use
a pressure bag to strip fluid from an TV bag so that the
fluid can be injected into a patient, i.e., subcutaneously,
intramuscularly or intravenously. The conventional pressure
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bag resembles a donut-shaped member with a centrally-located
hole into which a filled IV bag is disposed. The pressure
bag was then inflated by, for example, repetitive squeezing
of an air bulb, to reduce the size of the centrally-located
hole and to exert pressure against the IV bag. The fluid
which was contained in the IV bag was accordingly stripped
or expelled from the container through a catheter. When the
IV bag had been emptied of the fluid contents, the pressure
bag was deflated to remove the stripped container and to
receive another filled IV bag. This procedure was
laborious, time consuming and particularly uncomfortable for
the individual inflating and deflating the pressure bag if a
plurality of IV bags must be employed in, for instance, an
emergency situation where a patient was to receive many
units of blood, plasma, etc.
Another disadvantage was that the known pressure bag
and the related medical devices must be manually re-set to
receive another IV bag for a subsequent stripping and
infusion application.
In addition, known conventional IV pumps can strip a
flexible container of parenteral fluid at a rate of 1,000
cc/hour, while the conventional pressure bags are more
efficient and can strip the parenteral fluid at a rate of
15,000 cc/hour. In emergency situations, however, it is
desirable to have an apparatus which strips the parenteral
fluid from the IV bag at a still higher rate.
3p Moreover, the conventional pressure bag and related
devices were not adapted to sense and monitor the pressure
being exerted on the IV bag so that a determination could be
made as to whether to increase, maintain or reduce the
pressure on the IV bag. This is important because various
IV fluids having different viscosities are used.
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For example, among the devices which are used for
dispensing fluids from IV bags, U.S. Patent No. 3,507,278 to
Werding disclosed an apparatus for dispensing parenteral
fluid, e.g., blood, and which included a casing which forms
a hermetic enclave into which compressed air was introduced
via a valve. A flexible container with fluid was disposed
within the casing and communicates with the outside of the
enclave by a flexible tube. Compressed air introduced into
the casing through the valve forces the fluid from the
container through the tube.
U.S. Patent No. 4,850,971 to Colvin disclosed an
infusion method and means which included a tray for holding
an IV bag. The tray had sides which were formed with
longitudinal slots. A drum had cocking handles at each end
which extend through a corresponding one of the slots to
move from one end of the tray to the opposite end. A coil
spring was mounted to the drum to pull the drum against the
bag to pressure the contents therefrom.
U.S. Patent No. 3,604,418 to Jones disclosed an
apparatus for stripping fluid from flexible plastic tubing,
e.g., tubing used with blood collecting devices. The
apparatus included hinged portions, each of which was
provided with a roller to be in close proximity to one
another yet to permit the flexible plastic tubing to pass
therebetween and be stripped of any fluid remaining in the
tubing. The stripped fluid was returnE:d to the fluid
dispensing bag.
None of the devices discussed above provided an
infusion apparatus for an IV bag which was adapted to force
parenteral fluid from the IV bag under pressure between a
pair of rollers and to sense the pressure to determine
whether the pressure should be increased, maintained or
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reduced with respect to the particular infusion application.
None of the devices are adapted to be automatically re-set
to facilitate removal of an empty IV bag and mounting of a
filled IV bag for the next infusion application.
DESCRIPTION OF THE INVENTION
It is an object of a first aspect of the present
invention to provide a medical apparatus which is adapted
forcibly to feed parenteral fluid from an IV bag in a
controlled manner for an infusion application.
It is an object of a second aspect of the present
invention to provide an apparatus which facilitates loading
of a filled IV bag and removal of the IV bag stripped of the
fluid contents.
It is an object of a third aspect of the present
invention to provide an apparatus that uniformly forces the
fluid from the IV bag so that the flow rate of the fluid can
be monitored and regulated.
It is an object of a fourth aspect: of the present
invention to provide an apparatus which automatically re-
sets upon conclusion of an infusion operation to facilitate
removal of the emptied IV bag and receipt of a filled IV bag
for a subsequent infusion application.
It is an object of a fifth aspect of the present
invention to provide means to sense the pressure which is
employed during the infusion operation and when the IV bag
has been emptied of the parenteral flu_Ld.
It is an object of a sixth aspect of the present
invention to provide means for sensing, maintaining and
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regulating the amount of pressure being exerted on the IV
bag during an infusion operation.
It is an object of a seventh aspect. of the present
invention top provide a method which is adapted forcibly to
feed parenteral fluid from an IV bag in a controlled manner
for an infusion application.
By one broad aspect of the present invention, an
apparatus is provided for feeding parent:eral fluid under
pressure from an IV bag to a patient. The apparatus
includes a support member which is conf:Lgured to support the
IV bag. A roller assembly is provided :including a pair of
spaced-apart rollers which is configured to be placed at
opposed sides of the IV bag, each one of the rollers being
configured to contact a corresponding side of the IV bag to
exert pressure. A drive assembly is provided to drive the
roller assembly so that the rollers are adapted to exert
pressure on the IV bag. A control assembly interconnects
the roller assembly and the drive assembly. The control
assembly is constructed to control the drive assembly to
move the roller assembly in response to the pressure which
is adapted to be exerted on the IV bag. A sensing member is
mounted to the roller assembly to generate a signal to the
control assembly of the pressure which is adapted to be
exerted on the IV bag.
By a first variant of this first broad aspect of the
invention the apparatus further includes a first biasing
member, a first one of the pair of spaced-apart rollers
having first opposed ends, and a second one of the pair of
spaced-apart rollers having second opposed ends, the first
biasing member connecting one of the first opposed ends of
the first roller with one of the second opposed ends of the
second roller. By a first variation thereof, the apparatus
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further includes a second biasing member, the second biasing
member connecting another one of the first opposed ends of
the first roller with another one of they second opposed ends
of the second roller.
By a second variant of this first broad aspect of the
invention and/or the first variant above, the sensing member
comprises piezoelectric material.
By a third variant of this first broad aspect of the
invention and/or the variants above, the apparatus further
includes a housing with an interior compartment which is
constructed to receive the support member, the roller
assembly, the drive assembly and the control assembly. By a
first variation thereof, the housing includes a door which
is hingedly mounted to the housing to permit access to the
interior compartment, and a switch which is responsive to
movement of the door between an open and a closed position
for generating a signal to the control assembly to effect
movement of the drive assembly. By a second variation
thereof, at least one of the door and the housing is formed
from a substantially-transparent material. By a third
variation thereof, the door includes a passage through which
a flexible conduit is disposed for connection to the IV bag.
By a fourth variant of this first broad aspect of the
invention and/or the variants above, the housing further
includes a pair of panels, the pair of panels being
constructed and arranged to partition the interior
compartment into a pair of wing compartments and a central
compartment which is disposed between the pair of wing
compartments, the central compartment containing the support
member and the roller assembly, each one of the wing
compartments containing at least one of the drive assembly
and the control assembly. By a first variation thereof, the
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pair of panels includes a first panel with a first pair of
slots which is arranged to extend in sub>stantially-parallel
relationship with each other along the first panel, and a
second panel with a second pair of slot:> which is arranged
to extend in substantially-parallel relationship with each
along the second panel, the first pair of slots and the
second pair of slots being in registrat_Lon with each other
to receive corresponding portions of the pair of spaced-
apart rollers of the roller assembly. By a second variation
thereof, the first pair of slots is arranged to diverge from
each other after extending in the substantially-parallel
relationship, and the second pair of slots is arranged to
diverge from each other after extending in the
substantially-parallel relationship.
By a fifth variant of this first broad aspect of the
invention and/or the variants above, the support member is a
hook.
By a sixth variant of this first broad aspect of the
invention and/or the variants above, the pair of spaced-
apart rollers includes a first roller having first opposed
end portions, and a second roller having second opposed end
portions, each one of the first opposed end portions of the
first roller being in registration with a corresponding one
of the second opposed end portions of t:he second roller. By
a first variation thereof, the apparatus further includes a
first biasing member connecting one of the first opposed end
portions of the first roller with the corresponding one of
said second opposed end portions of said second roller, and
a second biasing member connecting another one of the first
opposed end portions of the first roller with the
corresponding another end of the second opposed end portions
of the second roller. By a second variation thereof, the
first roller and the second roller each includes an axle
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around which a roller is mounted, and ball bearings which
are disposed between the axle and the roller.
By a second broad aspect of this invention, an
apparatus is provided for feeding parent:eral fluid from an
IV bag to a patient. The apparatus inc7_udes a housing
having a top wall, a bottom wall, a front panel, a rear
panel and opposed side walls surrounding an interior of the
housing. A pair of partition members is disposed at the
interior of the housing. The pair of partition members is
spaced-apart to provide a central compartment, a first wing
compartment and a second wing compartment. The first and
second wing compartments are disposed air opposite sides of
the central compartment. A first one o:E the pair of
partition members is provided with a first pair of slots
extending along the first partition member from a position
near the top wall of said housing to a position near said
bottom wall of said housing. The first pair of slots
converge toward each other at a position near the top wall
of the housing to assume a substantially-parallel
relationship. A second one of the pair of partition members
is provided with a second pair of slots extending along the
second partition member from a position near the top wall of
the housing to a position near the bottom wall of the
housing. The second pair of slots converge toward each
other at a position near the top wall of the housing to
assume a substantially-parallel relationship, slots of the
first pair and the second pair of slots being in
registration with each other. A support member is disposed
in the central compartment and is configured to support the
IV bag at said central compartment. A first roller assembly
is disposed in the central compartment and is configured to
contact a first side of the IV bag, the first roller
assembly including first opposed end portions. One of the
first opposed end portions extends through a corresponding
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one of the first pair of slots, another of the first opposed
end portions extends through a corresponding one of the
second pair of slots. A second roller assembly is disposed
in the central compartment and is configured to contact a
second side of the IV bag opposite to the first side. The
second roller assembly includes second opposed end portions,
one of the second opposed end portions extending through
another corresponding one of the first pair of slots,
another of the second opposed end portions extending through
another corresponding one of the second pair of slots. The
first roller assembly and the second ro:Ller assembly are
thus configured to move between a retracted position, where
the first and the second roller assemblies are positioned in
their respective slots near the top wall of said housing
above the support member with the support member being
disposed therebetween, and an extended position where the
first and the second roller assemblies have exerted pressure
against the first and the second corresponding sides of the
IV bag forcibly to remove fluid therefrom. A first spacer
assembly is disposed in the first wing compartment of the
housing to interconnect one of the first opposed end
portions of the first roller assembly with one of the second
opposed end portions of the second roller assembly, the
first spacer assembly being constructed to bias the end
portions. A drive assembly is provided to move the first
and the second roller assemblies between the retracted
position and the extended position. A sensing element is
mounted to at least one of the first and the second roller
assemblies, the sensing element being responsive to pressure
which is exerted on the IV bag to generate a signal of an
amount of pressure being exerted on the IV bag.
By a first variant of this second broad aspect of the
invention, the apparatus further includes a control assembly
interconnecting at least one of the first and the second
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roller assemblies having the sensing element with the drive
assembly, the control assembly being re:>ponsive to the
signal which is generated by the sensing element to control
the drive assembly to effect movement of. the first and the
second roller assemblies. By a first variation thereof, the
control assembly automatically returns 1=he first and the
second roller assemblies to the retracted position after the
first and the second roller assemblies reach the extended
position.
By a second variant of this second broad aspect of the
invention and/or the above first variant thereof, the
apparatus further includes a second spanker assembly which is
disposed in the second wing compartment of the housing to
interconnect another of the first opposed end portions of
the first roller assembly with another of the second opposed
end portions of the second roller assembly, the second
spacer assembly being constructed to bias the other end
portions.
By a third variant of this second broad aspect of the
invention and/or the variants above, each one of the first
roller assembly and the second roller assembly includes an
axle, a roller which is mounted around the axle for
rotational movement, and a plurality of ball bearings which
are disposed between the axle and the roller to permit the
roller to rotate around the axle.
By a fourth variant of this second broad aspect of the
invention and/or the variants above, the sensing element
comprises piezoelectric material.
By a third broad aspect of this invention, an apparatus
is provided for feeding parenteral fluid under pressure from
an IV bag to a patient. The apparatus includes a support
CA 02310326 2001-02-OS
member which is configured to support the IV bag. A first
guide assembly is provided including a first guide slot and
a second guide slot converging from diverged positions
toward each other. A second guide assembly is provided
comprising a third guide slot and a fourth guide slot
converging from diverged positions toward each other. The
first guide slot of the first guide assembly is in
registration with the third guide slot of the second guide
assembly. The second guide slot of the first guide assembly
is in registration with the fourth guide slot of the second
guide assembly. A roller assembly is proviaea lncluaing a
first roller with first opposed ends, the first roller being
arranged with one of the first opposed finds disposed in the
first guide slot and another of the first opposed ends being
disposed in the third guide slot, the first roller being
configured to contact a first side of said IV bag. The
roller assembly also includes a second :roller with second
opposed ends, the second roller being arranged with one of
the second opposed ends disposed in the second guide slot
and another of the second opposed ends disposed in the
fourth guide slot, the second roller being configured to
contact a second side of said IV bag opposite to said first
side. The first roller and the second roller are configured
to move between a first position diverged from each other at
opposite sides of the IV bag to a second position where the
first and the second rollers converge toward the IV bag for
the first roller to contact the first side of the IV bag,
and for the second roller to contact the second side of the
IV bag opposite to the first side. A drive assembly is
provided to drive the first roller and the second roller of
the roller assembly between the first and the second
positions.
By a first variant of this fourth broad aspect of this
invention, the apparatus further includes a sensor element
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which is mounted to the roller assembly, the sensor element
generating a signal to the drive assembly to control
movement of the roller assembly between the first and the
second positions.
By a fifth broad aspect of this invention, a method is
provided for feeding parenteral fluid from an IV bag to a
patient. The method includes the steps of exerting pressure
on a first side of the IV bag and on a second side of the IV
bag opposed to the first side. The pressure which is
exerted on the IV bag is sensed. The pressure which is
exerted at the first side and on the second side of the IV
bag is then adjusted in response to the pressure which is
sensed.
20
By a first variant of this fifth broad aspect of the
invention, the method further includes the step of
terminating the pressure which is exerted on the IV bag when
the pressure exceeds a predetermined amount.
Thus, as noted above, the present invention, in one
aspect, provides an apparatus for feedi:~g parenteral fluid
under pressure from an IV bag to a patient. The apparatus
includes a support member to support the IV bag, a roller
assembly which includes a pair of spaced-apart rollers at
opposed sides of the IV bag and in parallel relationship
with each other. Each one of the rollers is configured to
contact a corresponding side of the IV bag to exert pressure
thereon. A drive assembly is provided to drive the roller
assembly along the IV bag.
A control assembly is also provided to interconnect the
roller assembly and the drive assembly to control the drive
assembly to move the roller assembly along the IV bag in
response to the pressure which is exerted thereon.
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DESCRIPTION OF THE FIGURES
In the accompany drawings:
Fig. 1 is a perspective view, partially-broken away,
showing a preferred embodiment of the infusion apparatus
according to an aspect of the present invention;
Fig. 2 is a cross-sectional view taken along lines 2-2
in Fig. 1;
Fig. 3 is a partial cross-sectional view taken along
line 3-3 in Fig. 1; and
Fig. 4 is a top view of the apparatus shown in Fig. 1.
AT FEAST ONE MODE FOR CARRYING OUT THE INVENTION
Referring to the drawings, where hike reference
characters indicate like parts, Fig. 1 chows a preferred
embodiment of an infusion apparatus 10 according to an
aspect of the present invention. The infusion apparatus 10
of an aspect of this invention is adapted to receive and
support an IV bag 12 holding parenteral fluid. The
parenteral fluid is forced from the IV :bag 12 through a
conduit 14 or tubing, e.g., a catheter, and into a patient
(not shown).
As shown in Fig. 1, the infusion apparatus 10 of an
aspect of this invention includes a housing 16 having a top
18, a bottom 20, a front panel 22, a rear panel 24 and
opposed side walls 26,28. A pair of spaced-apart panels,
30,32 or partitions extends from the front panel 22 to the
rear panel 24, and between the top 18 and the bottom 20 of
the housing 16. The panels 30,32 form a plurality of
compartments or chambers 34,36,38 within the housing 16.
The compartment 34 is the central compartment, while the
compartments 36,38 are wing compartments which are at
opposed sides of the central compartment 34.
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Each one of the panels 30,32 is provided with a
corresponding pair of spaced-apart slots 40a,40b and
42a,42b. The pairs of slots 40a,40b and 42a,42b are
similarly arranged in their corresponding panels 30,32
respectively. For example, the pair of slots 40a,40b of the
panel 30 extends from a position which is substantially-
adjacent to the bottom 20 of the housing 16 to a position
which is substantially-adjacent to the top 18 of the housing
16. The slots 40a,40b are arranged substantially-parallel
and in close proximity to each other along the panel 30 at a
distance of 0.5 cm. The slots 40a,40b diverge from each
other at a position near the top 18 of the housing 16. This
divergence of the slots 40a,40b facilitates removing and
mounting of the IV bag 12 in the central compartment 34. It
is preferred that the upper ends of the slots 40a,40b
diverge to be spaced from each other at a distance of at
least 2 cm. It is understood that these parameters are by
way of example only, and that the spacing between the slots
40a,40b is selected to accommodate IV bags and their
particular dimensions.
As also shown in Fig. l, the slots 42a,42b in the panel
32 are similarly arranged having the parameters recited.
The pair of slots 42a,42b is aligned with the pair of slots
40a,40b so that a slot of the pair 42a,42b in the panel 32
is in registration with a corresponding one of the slots of
the other pair 40a,40b in the panel 30.
Fig. 1 shows a roller assembly 44 of the infusion
apparatus 10 of an aspect of this invention which is mounted
in the pairs of slots 40a,40b and 42a,42b and extends from
the wing compartments 36,38 across the central compartment
34.
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A retaining hook 46 is secured to t:he top 18 of the
housing 16 and extends into the central compartment 34 to a
position below the roller assembly 44 when the roller
assembly 44 is retracted to a position near the top 18 of
the housing 16. A handle portion 48 of the IV bag 12
receives the hook 46 therethrough. The IV bag 12
accordingly hangs below the roller assembly 44 when the
assembly is in the fully retracted posit:ion as shown in Fig.
1. This arrangement permits quick and Efficient removal of
the IV bag 12 after the fluid has been forced therefrom, and
permits a full IV bag to be easily hung on the hook 46 for a
subsequent infusion application without the roller assembly
44 getting in the way. The IV bag 12 is preferably held by
the hook 46 off the bottom 20 of the housing 16 so that an
outlet means 50 of the IV bag 12 is clear of, and does not
contact, the bottom 20 of the housing 16.
Control assemblies 52,54 shown in Fig. 1 are disposed
in a corresponding one of the wing compartments 36,38. Each
one of the control assemblies 52,54 inc:Ludes a drive means
which is represented by the phantom linE= 56 and a sensing
element 58. The control assemblies 52,54 can be used
individually or in conjunction with each other. The control
assembly 54 is connected to the sensing element 58 by a
signal line 60. The drive means 56 is connected to the
roller assembly 44. The drive means 56 can include any of
the known devices to move the roller assembly from the
retracted position as shown in Fig. 1, -through a deployment
position along the sides of the IV bag, when the roller
assembly 44 proceeds along the pairs of slots 40a,40b and
42a,42b toward the bottom 20 of the housing 16.
A door 62 is hingedly connected to the front panel 22
of the housing 16 as shown in Fig. 1. A retention plate 64
is provided beneath the door 62 to retain any fluids that
CA 02310326 2001-02-OS
may accumulate in the central compartment 34. An edge of
the door 62 is provided with a cut-out Ei6 which functions as
a passage through which the flexible conduit 14, e.g., a
catheter of the IV bag, can extend when the door 62 is
closed. It is preferred that the front panel 22, or at
least the door 62, be formed from a transparent material so
that the central compartment 34 can be seen during an
infusion application.
The front panel 22 of the housing 16 is provided with
controls for the control assembly 54. The controls include
a power switch 68 to initiate power to i~he infusion
apparatus. A flow meter 70 is provided to indicate the flow
rate of the fluid from the IV bag 12 as a result of the
pressure being exerted on the bag 12 as the fluid contents
are forced therefrom by the roller assembly 44. Switches
72,74 are used to deploy the roller assembly and to re-set
the roller assembly, respectively. An :indicator light 76 is
activated by a default switch 78 in the front panel 22 of
the housing 16. The light 76 indicates when the door 62 is
open. The default switch 78 is provided to ensure that the
roller assembly 44 will not function unless the door 62 is
securely closed.
A threaded aperture 80 at the bottom 20 of the housing
16 is adapted to receive a conventional tripod stand (not
shown) which is used in hospitals and physicians' offices.
A handle 82 at the top 18 of the housing 16 is provided
to carry the infusion apparatus 10 of an aspect of this
invention.
Referring to Fig. 2, the roller assembly 44 of the
infusion apparatus 10 of an aspect of this invention is
shown. The roller assembly 44 includes a pair of axles
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84a,84b. Each one of the axles 84a,84b has opposed ends
which are mounted to extend into a corresponding one of the
slots 40a,40b and 42a,42b. The ends of the axles 84a,84b
are disposed in a corresponding one of t:he wing compartments
36,38. The axles 84a,84b are arranged t:o extend across the
central compartment 34 in a spaced para7_lel relationship
with each other.
As shown in Fig. 2, rollers 86a,86b are mounted for
rotation around a corresponding one of t=he axles 84a,84b.
It is preferred that the rollers 86a,86b do not extend
through the slots 40a,40b and 42a,42b arid into the wing
compartments 36,38. The rollers 86a,86b are preferably
formed from synthetic plastic, rubber or other material that
will not puncture or damage the walls o_f the IV bag 12 when
the rollers 86a,86b are brought to bear against the exterior
surface at opposed sides of the bag 12.
A plurality of ball bearings 88 is disposed between
each one of the axles 84a,84b and the corresponding roller
86a,86b mounted thereto. Use of the ba:l1 bearings 88
permits the axles 84a,84b to remain stationary when being
moved along the corresponding slots, whale the rollers
86a,86b are free to spin about a corresponding one of the
axles 84a,84b.
Fig. 2 shows the sensing element 58 which is disposed
at the interior of at least one of the .axles 84a,84b,
preferably near the centre of the axle selected. The
sensing element 58 can be piezoelectric material. Although
the infusion apparatus 10 of an aspect of this invention
will function having only one of the axles 84a,84b provided
with the sensing element 58, it is understood that each one
of the axles 84a,84b can be provided with a corresponding
sensing element 58 disposed therein. The sensing element 58
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is connected to the control assembly 54 via the signal line
60 as shown in Fig. 1.
Fig. 2 also shows the elements of t:he roller assembly
44. The roller assembly 44 includes a pair of spacing
assemblies 92,94. The spacing assembly 92 only is shown due
to the perspective of Fig. 2 (the spacing assembly 94 is
shown in Fig. 1). The spacing assembly 92 interconnects the
ends of the axles 84a,84b which extend .into the wing
compartment 36, as also shown in Fig. 1. The spacing
assembly 94 is similarly arranged in the wing compartment 38
to interconnect the opposite ends of the axles 84a,84b in
the wing compartment 38. By way of example and as shown in
Fig. 2, the spacing assembly 92 includes a first portion 96
having essentially a cylindrical shape. A second portion
100 is also essentially cylindrically-shaped and includes a
biasing member 98, e.g., a spring, disposed therein. The
second portion 100 has a diameter which is greater than that
of the first portion 96 so that the first portion 96 can be
received in the second portion 100. The first portion 96 is
biased against the spring 98 disposed in the second portion
100.
A first arm 102 connects the axle 84a to the first
portion 96 of the spacing assembly 92. A second arm 104
connects the axle 84b to the second portion 100 of the
spacing assembly 92. The spacing assembly 92 is therefore
adapted to bias the axles 84a,84b to be maintained in the
corresponding slots 40a,40b. The spacing assembly 92
ensures that the axles 84a,84b move between the retracted
and extended positions along the slots 40a,40b and 42a,42b
in a uniform manner. The spacing assembly 94 functions in
the same way as the spacing assembly 92.
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Fig. 3 shows the roller assembly 44 being deployed from
the retracted position to force the fluid contents from the
IV bag 12. As the roller assembly 44 is moved from the
retracted position near the top 18 of the housing 16, the
rollers 86a,86b are brought against corresponding opposed
sidewalls 106,108 of the IV bag 12. The rollers 86a,86b
move from the fully retracted position, where the rollers
86a,86b are clear of the hook 46 so that: interchanging
emptied and filled IV bags is quick and easy, downwardly
along the slots 40a,40b and 42a,42b. A portion of the IV
bag 12 below the rollers 86a,86b becomes bulbous as a result
of the pressure being exerted by the rollers 86a,86b to
force the fluid from the IV bag 12 through the outlet means
50 to the conduit 14. The clearance between the outlet
means 50 of the IV bag 12 and the bottom 20 of the housing
16 is sufficient to reduce the possibility of the bottom 20
interfering with the flow of fluid.
Fig. 4 shows a mounting assembly 110 for the infusion
apparatus 10 of an aspect of this invention. The mounting
assembly 110 is employed in those instances where threaded
tripod poles are unavailable. The mounting assembly 110
includes a collar 112 which extends from the rear panel 24
of the housing 16. The collar 112 is substantially U-shaped
with a space 114 sized and shaped to receive a mounting pole
or rack (not shown) which is typically used in hospitals and
physicians' offices. Thumb screws 116,118 are threadedly
engaged to opposed sides of the collar 112. Tightening of
the thumb screws 114,116 moves corresponding ends 120,122 of
the thumb screws into the space 114 to bear against the
mounting pole and to secure the infusion apparatus thereto.
The infusion apparatus 10 of an aspect of this
invention is for use with IV bags holding parenteral fluids,
e.g., D-5 glucose/water solution, saline, lactated ringers,
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CA 02310326 2001-02-OS
whole blood, packed cells, coagulation factors or platelets.
The infusion apparatus 10 of an aspect of this invention can
remove the parenteral fluid from the IV bags 12 much faster
and more efficiently than a standard IV pump or the
conventional pressure bags. The infusion apparatus 10 of an
aspect of this invention is also adapted to remove the
parenteral fluid from the bag in a controlled manner and to
enable the user to select the flow rate, i.e. the stripping
rate, with more accuracy.
During an infusion operation with the IV bag 12, the
roller assembly 44 is in the retracted position near the top
18 of the housing 16. Power to the infusion apparatus 10 of
an aspect of this invention is initiated. The indicator
light 76 will show the status of the door 62, i.e., opened
or closed. The door 62 is opened either to remove an empty
IV bag or to hang a filled IV bag on th~~ hook 46 in the
central compartment 34. If a new IV bag is used, the
flexible conduit 14, e.g., a catheter, which is connected to
the IV bag, is led outwardly from the central compartment 34
through the cut-out 66 in the door 62. The door 62 is
closed, over-riding the default switch '78 and extinguishing
the indicator light 76. The deployment switch 78 is
actuated and the axles 84a,84b of the roller assembly 44
move from the retracted position downwardly along the slots
40a,40b and 42a,42b.
After travelling a short distance, the axles 84a,84b
will begin moving toward each other as -the position of the
slots 40a,40b and 42a,42b converge with respect to each
other. The rollers 86a,86b move closer to a corresponding
one of the sidewalls 106,108 of the IV bag 12. At a point
where the slots 40a,40b and 42a,42b no longer converge and
are disposed in parallel relationship, ~=ach one of the
rollers 86a,86b contacts, and is brought to bear against, a
CA 02310326 2001-02-OS
corresponding one of the sidewalk 106,108 above the fluid
level in the IV bag. As the drive means 56 pulls the axles
84a,84b downwardly along the slots, the rollers 86a,86b
exert pressure on the opposed sidewalk therebetween to
force the fluid in the IV bag downward to the outlet 50. As
a result of this pressure, the IV bag assumes the bulbous
shape shown in Fig. 3.
The piezoelectric material 58 responds to the pressure
which is exerted on the sidewalk 106,108 where the rollers
86a,86b are forced to overcome the pres~~ure of the fluid
remaining in the IV bag 12. The infusic>n apparatus 10 of an
aspect of this invention is adapted to stop the movement of
the rollers 86a,86b if the pressure which is sensed by the
piezoelectric material 58 exceeds a predetermined level for
a safe infusion application. This is particularly
advantageous where, for example, the catheter 14 becomes
clogged or pinched, or where there is an obstruction in the
patient's body near the catheter, which would impede the
steady flow of the fluid from the IV bag and/or possibly
injure the patient or damage the infusion apparatus 10 of an
aspect of this invention. If the pressure which is exerted
is determined to be too high, as sensed by the control
assembly 52,54 and as indicated by the flow meter 70, taking
into account the viscosity of the fluid in the IV bag, the
rate of descent of the roller assembly 44 along the IV bag
is reduced to alleviate the pressure, or is stopped
altogether.
When the fluid has been completely stripped from the IV
bag and the roller assembly 44 contacts the outlet means 50,
the roller assembly 44 automatically moves to the retracted
position (Fig. 1). The outlet means 50 of the IV bag is
generally made of a material which is more dense than the
sidewalk 106,108 of the IV bag. This denser material is
21
CA 02310326 2001-02-OS
sensed by the piezoelectric material 58 which generates a
signal to the control assembly 52 for th.e drive assembly to
return the roller assembly 44 to the retracted position so
that the empty IV bag can be immediately removed and
replaced by another full IV bag which is. easily inserted on
the hook 46 for a subsequent infusion operation.
The infusion apparatus 10 of an aspect of this
invention is portable and is ideally suited for use in the
field, as well as use in hospitals, physicians' offices,
etc. The apparatus 10 of an aspect of this invention
adjusts the flow rate of the fluid being forced from the IV
bag so that an infusion operation is performed accurately
despite the amount and viscosity of the fluid to be removed
from the IV bag.
The infusion apparatus 10 of an aspect of this
invention accepts the standard IV bags, i.e., 1/4, ~, 3/4 or
1 litre sizes, and can be adapted to accept IV bags with
larger volumes.
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