U.S. patent number 3,895,631 [Application Number 05/439,137] was granted by the patent office on 1975-07-22 for liquid infusion unit.
This patent grant is currently assigned to ALZA Corporation. Invention is credited to Richard G. Buckles, Seymour Hoff, Sharon Kehr, Su Il Yum.
United States Patent |
3,895,631 |
Buckles , et al. |
July 22, 1975 |
Liquid infusion unit
Abstract
An improved infusion unit for intramuscular, subcutaneous
intravascular delivery of liquid drug to a patient is disclosed and
includes (a) a compartmented housing carrying a (b) removable,
refillable liquid drug cartridge selectively communicating with a
(c) fluid passageway in the housing and suitably connected with a
(d) catheter. The cartridge contains a distensible bladder or
liquid repository leading to an adjustable fluid flow controller
disposed in the passageway and which accurately meters the amount
of liquid drug dispensed from the bladder to the patient. The unit
is completely self-contained and can be conveniently attached to
the patient near the point of infusion for ambulatory use.
Inventors: |
Buckles; Richard G. (Menlo
Park, CA), Hoff; Seymour (San Jose, CA), Kehr; Sharon
(San Jose, CA), Yum; Su Il (Mountain View, CA) |
Assignee: |
ALZA Corporation (Palo Alto,
CA)
|
Family
ID: |
23743442 |
Appl.
No.: |
05/439,137 |
Filed: |
February 4, 1974 |
Current U.S.
Class: |
604/132; D24/111;
604/250; 222/386.5 |
Current CPC
Class: |
A61M
5/152 (20130101); A61M 39/28 (20130101) |
Current International
Class: |
A61M
5/145 (20060101); A61M 39/28 (20060101); A61M
39/00 (20060101); A61M 5/152 (20060101); A61m
005/14 () |
Field of
Search: |
;128/214E,214F,213,215,216,230,260,DIG.12,DIG.13,214.2,214R,218A
;222/95,105,106,206,212,23,47-49,386.5 ;138/40-44 ;251/5-9 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Medical-Surgical Review, "Ject-Ette," First Quarter, 1968, p. 27,
1281218,A..
|
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: McGowan; J. C.
Attorney, Agent or Firm: Ciotti; Thomas E. Sabatine; Paul L.
Mandell; Edward L.
Claims
What is claimed is:
1. A liquid storing and dispensing assembly comprising:
a main housing;
a liquid flow passage in said main housing having inlet and outlet
means, said outlet means communicating exteriorly of said
housing;
flow control means in said housing between said inlet and outlet
means for precisely controlling liquid flow through said
passage;
a cartridge removably engaged with said housing the exterior of
said cartridge cooperating with the exterior of said main housing
such that the assemblage has a contiguous exterior surface, said
cartridge including a repository for a quantity of liquid to be
dispensed; and
said inlet means cooperating with said cartridge to establish
communication between said repository and said passage when said
cartridge in engaged with said housing.
2. Assembly as recited in claim 1 wherein said flow control means
comprises: a deformable tube, a plurality of parallel, linear
elongate fibers coextensively disposed in said tube, and
compressing means disposed about the tube and deforming, to
variable degrees, the tube.
3. Apparatus as recited in claim 1 wherein said assembly has a
concave lower surface and a convex upper surface, the curvature of
the upper surface being greater than that of the lower surface such
that said upper and lower surfaces meet along first and second
opposite sides.
4. Apparatus as recited in claim 3 wherein said cartridge comprises
an elongated generally rectangular shell, one elongated wall of
which is convex and forms a part of said upper surface of said
housing.
5. Apparatus as recited in claim 1 wherein said cartridge includes
valve means at one end thereof connected with said repository for
enabling delivery of fluid to the exterior of said cartridge, said
valve means being normally closed, and wherein said inlet means
cooperates with said valve means to open the same when said
cartridge is engaged with said housing.
6. A fluid storage and dispensing assembly comprising, in
combination:
a generally rectangular support base;
first and second hollow, elongated housing assemblies on said
support base in spaced relationship with each other;
a removable cartridge disposed on said support base in the space
between said first and second housing assemblies;
an expansible bladder in said cartridge for holding fluid under
pressure;
a fluid flow passage in said first housing assembly having inlet
means communicating with said bladder, and outlet means; and
fluid flow control means in said first housing assembly for
controlling the rate of discharge of fluid from said bladder
through said passage to said outlet means.
7. Apparatus as recited in claim 6 further including flow indicator
means in said first housing assembly, said indicator responsive to
fluid flow downstream of said flow control means and having a first
state when fluid is being dispensed and a second state when fluid
flow ceases.
8. Apparatus as recited in claim 7 wherein said flow indicator
means comprises: a chamber connected in said flow passage between
said fluid control means and said outlet means, said chamber
defining an opening in a wall thereof; a diaphragm sealed over said
opening; and signal means responsive to flexure of said diaphragm
to indicate the flow state of fluid in said passage.
9. Apparatus as recited in claim 8 wherein said signal means
comprises an L-shaped lever pivotally mounted at the elbow thereof
in said first housing assembly, and means biasing a first arm of
said lever into engagement with said diaphragm.
10. Apparatus as recited in claim 9 wherein said first housing
assembly defines an opening in an exterior wall thereof, and
wherein a second arm of said lever is movable between a first
position away from said opening when in said first state, and a
second position immediately behind said opening when in said second
state.
11. Apparatus for metered flow of fluid from a selfcontained
supply, comprising:
a housing having fluid outlet means;
a repository of fluid under pressure in said housing;
a fluid passage contained within said housing connecting said
repository with said outlet means;
flow metering means in said passage for accurately maintaining an
established rate of fluid flow from said repository to said outlet
means, said flow metering means including control means contained
within said housing for receiving a tool for adjusting the rate of
fluid flow through said metering means; and
said housing defining an opening in a wall thereof to allow
insertion of said tool into operative engagement with said control
means so as to enable adjustment of said metering means said
opening being of such size as to allow a patient to adjust said
metering means with said tool but not otherwise.
12. Apparatus as recited in claim 11 wherein said flow metering
means comprises: a flexible tube, a mass disposed within said tube
and filling a portion of the space defined therein, and means about
said tube to apply a compressive force thereagainst.
13. Apparatus as recited in claim 12 wherein said force applying
means includes a force applying wedge mounted in said housing for
movement towards and away from said flexible tube; and wherein said
control means includes a control wedge cooperating with said force
applying wedge and movable in a direction generally parallel to the
axial direction of said tube.
14. Apparatus as recited in claim 13 wherein said control wedge
carries a rack gear.
15. Apparatus as recited in claim 14 wherein said control wedge
further carries a pointing arm; and wherein a flow rate scale is
imprinted on said housing, said pointing arm cooperating with said
flow rate scale to indicate the fluid flow rate established by said
control means.
16. Apparatus as recited in claim 12 wherein said flow metering
means further comprises: a by-pass tube connected in said flow
passage in parallel with said flexible tube, means closing said
by-pass tube to the flow of fluid therethrough, said means being
movable to an open position by a second tool inserted through a
second opening in the wall of said housing; said by-pass tube
having a flow rate capacity greater than said flexible tube whereby
rapid bleeding of air from the apparatus may be accomplished and by
which rapid dispensing of liquid may be effected.
17. A fluid storage and dispensing assembly comprising; in
combination:
a hollow housing defining inlet and outlet port means and
containing a liquid flow passageway extending between said inlet
and outlet port means, said passageway including flow control means
for precisely metering fluid flow therethrough;
fluid dispensing means connected to said outlet port means for
dispensing fluid exteriorly of the assembly;
a cartridge removably engaged with said housing and containing a
fluid repository, said cartridge having connector means for
cooperative engagement with said inlet port means of said housing
to enable fluid contained within said repository to be dispensed
through said passageway;
said housing including guide means for aligning said connector
means of said cartridge with said inlet port means for
interconnection thereof; and
means on said cartridge and said housing to hold said cartridge in
operative engagement with said housing such that fluid
communication between said connector means and said inlet port
means is positively established, said cartridge holding means
comprising a pin protruding from a wall of said cartridge and a
locking bar pivotally attached to said housing, said locking bar
defining a surface adapted to slidably engage said pin for urging
said cartridge into a locked position on the housing as the locking
bar is pivotally moved and for holding said cartridge securely in
place.
18. A device for the continuous delivery of a controlled
reproducible flow of liquid comprising, in combination:
a housing defining inlet and outlet port means and containing a
liquid flow passageway extending between said inlet and outlet port
means, said passageway including flow control means for precisely
metering flow therethrough; and
a cartridge removably engaged with said housing and comprising,
a. an elongated, hollow shell having an opening at one end for
fluid transfer coupling with said inlet port means,
b. radial support means disposed in said shell and slidably engaged
with the interior walls of said shell, and
c. an expandable bladder of generally cylindrical geometry
supported at each end between the opening in said shell and said
support means whereby said bladder may be distended with liquid and
subsequently deflated for dispensing such liquid through the
housing with minimal frictional contact with interior walls of said
shell, said support means sliding axially within said shell to
accommodate variations in the axial dimension of said bladder.
19. Apparatus as recited in claim 18 wherein said support means has
a pointing arm and wherein said shell has a volume scale imprinted
thereon, said pointing arm and said scale cooperating to indicate
the volume of fluid contained within said bladder.
20. Apparatus as recited in claim 18 wherein said bladder includes
a valve member at the end connected with said opening in said
shell, said valve member being urged to a closed position by fluid
under pressure in said bladder.
21. Apparatus as recited in claim 20 wherein said bladder includes
filter means at the end connected with said support means for
passing air but not liquid out of said bladder whereby said bladder
may be completely filled with liquid and voided of air by forcing
such liquid into said bladder through said valve end.
22. A device for the continuous delivery of a controlled
reproducible flow of a liquid drug to a patient comprising, in
combination:
a main housing adapted to be carried by the patient;
a liquid flow passage enclosed within said main housing having
inlet and outlet means, said outlet means communicating exteriorly
of the housing;
flow control means enclosed within said housing between said inlet
and outlet means for precisely and reproducibly regulating and
permitting to pass small controlled amounts of liquid through said
passage;
a cartridge removably engaged with said housing the exterior of
said cartridge cooperating with the exterior of said housing to
form an assemblage having a contiguous exterior surface, said
cartridge including a repository for a quantity of the liquid drug
under pressure;
said inlet means cooperating with said cartridge to establish
communication between said repository and said passage when said
cartridge is engaged with said housing; and
means connected with said outlet means for administering the small
controlled amounts of liquid drug to the patient.
23. The device as recited in claim 22 wherein said main housing has
an exterior wall generally conforming to the curvature of an
extremity of the patient and includes means for attaching the
housing to such extremity.
24. The device as recited in claim 22 wherein the liquid drug is a
drug for intravascular, subcutaneous or intramuscular infusion, and
the means for administering the drug to a patient comprises means
for such infusion.
25. An infusion unit for the continuous delivery of a controlled
reproducible flow of a liquid drug to a patient, comprising, in
combination: a housing defining inlet and outlet port means and
containing a liquid flow passageway extending between said inlet
and outlet port means, said passageway including flow control means
for precisely metering fluid flow therethrough, and a liquid drug
supply cartridge removably engaged with said housing at said inlet
port means and comprising:
a. an elongated, hollow shell having an opening at one end
selectively cooperating with said inlet port means for the transfer
of liquid drug to said passageway,
b. radial support means disposed in said shell and slidably engaged
with the interior walls of said shell, and
c. an expandable bladder of generally cylindrical geometry
supported at each end between the opening in said shell and said
support means whereby said bladder may be distended with a quantity
of liquid drug and subsequently deflated with minimal frictional
contact with interior walls of said shell, said support means
sliding axially within said shell to accommodate variations in the
axial dimension of said bladder;
and means connected with said outlet port means for infusion of the
metered amounts of liquid drug from said cartridge to the
patient.
26. A liquid drug supply cartridge for use in an assembly for the
continuous delivery of a controlled reproducible flow of such
liquid drug to a patient, having a housing defining inlet and
outlet port means and containing a liquid flow passageway extending
between said inlet and outlet port means, said passageway including
flow control means for precisely metering fluid flow therethrough,
means connected with said outlet port means for administering the
liquid drug to the patient, said cartridge removably engageable
with said housing at said inlet port means and comprising:
a. an elongated, hollow shell having an opening at one end adapted
for fluid transfer coupling with said inlet port means of said
housing,
b. radial support means disposed in said shell and slidably engaged
with the interior walls of said shell, and
c. an expandable bladder of generally cylindrical geometry
supported at each end between the opening in said shell and said
support means whereby said bladder may be distended with a quantity
of liquid drug and subsequently deflated with minimal frictional
contact with interior walls of said shell to dispense such drug,
said support means sliding axially within said shell to accommodate
variations in the axial dimension of said bladder.
27. An infusion unit for the continuous delivery of a controlled
reproducible flow of a liquid drug to a patient comprising, in
combination:
a main housing adapted to be carried by the patient;
means for attaching said housing to a body portion of the
patient;
a liquid flow passage in said main housing having inlet and outlet
means, said outlet means communicating exteriorly of the
housing;
flow control means in said housing between said inlet and outlet
means for precisely and reproducibly regulating and permitting to
pass small controlled amounts of liquid through said passage, said
flow control means including (a) a deformable tube, (b) a plurality
of parallel, linear elongate fibers coextensively disposed in said
tube, and (c) compressing means disposed about the tube and
deforming, to variable degrees, the tube;
a cartridge removably engaged with said housing to form an
assemblage having a contiguous exterior surface, said cartridge
including a repository for a quantity of the liquid drug under
pressure and comprising (a) an elongated, hollow shell having an
opening at one end selectively cooperating with said inlet means
for the transfer of liquid drug to said passage, (b) support means
slidably disposed in said shell, and (c) an expandible bladder of
generally cylindrical geometry supported at each end between the
opening in said shell and said support means whereby said bladder
may be distended with a quantity of liquid drug and subsequently
deflated with minimal frictional contact with interior walls of
said shell, said support means sliding within said shell to
accomodate variations in the axial dimension of said bladder;
said inlet means cooperating with said cartridge to establish
communication between said bladder and said passage when said
cartridge is engaged with said housing; and
means connected with said outlet means for administering the small
controlled amounts of liquid drug by infusion to the patient.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to devices for the storage and
dispensing of liquid, and more particularly, to an improved
portable apparatus for delivery of precisely controlled amounts of
a liquid drug to a patient.
2. Description of the Prior Art
Many diversified applications exist for systems in which a
relatively small amount of liquid is stored and subsequently
dispensed at a precisely metered rate. One such application, in the
medical field, relates to the infusion of various liquids,
including liquid drugs, at accurate, reproducible flow rates to a
patient. The prior art is generally cognizant of such systems, as
exemplified by U.S. Pat. No. 2,842,123 to Rundhaug, which shows a
transfusion apparatus having a collapsible bag for the fluid to be
dispensed and a pressure container in sealed relationship about the
outside of the bag; U.S. Pat. No. 2,847,007 to Fox, which teaches
the provision of a flexible fluid pouch within a resilient
container for the storage of whole blood or plasma; U.S. Pat. No.
3,469,578 to Bierman, illustrating an infusion device having a
spigot valve for ambulatory use; and U.S. Pat. No. 3,486,539 to
Jacuzzi, which shows another dispensing device having a restricted
outlet passage.
Such structures, while generally satisfactory, have proven to be
disadvantageous in many material respects. For example, a number of
these devices are functional, but only in very crude forms.
Complexity in manufacture, awkward operation, and the aesthetically
displeasing mechanical appearance of such devices has hindered even
their limited acceptance in the marketplace. More importantly,
devices heretofore available, when manufactured on a
production-line basis, exhibit liquid discharge characteristics
varying widely from device to device; varying as the liquid
contents dispensed; and at very low flow-rates in the range of 0.1
to 10 cc's per hour, varying from one flow setting to another.
These failings make such systems unsuitable for application where
variable amounts of fluid are being passed, the amounts passed must
be known with exactness, the fluid must be dispensed at a
consistent rate, calibration after each flow adjustment is either
impossible or inconvenient, and the displeasing appearance of an
overly mechanical assemblage must be minimized.
Accordingly, the need has arisen for a much improved device for the
storage and precise dispensing at reproducible low flow-rates of
fluids. such as liquid drugs, especially in connection with medical
applications such as the infusion of such drugs to a patient.
Furthermore, such a need is particularly evident in those
applications where certain drugs are preferably applied at a
continuous, low rate over relatively long periods of time in dosage
levels which would preclude application of such medications other
than by direct local infusion to the affected area.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to store and
accurately dispense various liquids at precisely metered low
flow-rates.
The present invention has another object in the construction of an
aesthetically pleasing, self-contained infusion unit for the
ambulatory delivery of small amounts of liquid drug over a
relatively extended period.
Another object of this invention is to house a removable fluid
supply cartridge, a precise low flow-rate fluid metering assembly,
and related indicators in a contiguous, self-contained
assemblage.
A further object of the present invention is to construct a
lightweight, portable infusion unit which is disposable and
particularly well suited for ambulatory use.
The present invention is summarized in that an assembly for the
controlled, reproducible flow of a liquid drug from a
self-contained supply to a patient, includes a sectioned housing; a
repository of liquid drug under pressure, removably disposed in a
first section of the housing; a flow metering assembly in a second
section of the housing; a fluid passage in the housing
interconnecting the repository with the flow metering assembly; and
a conduit connected with the flow metering assembly for directing
metered amounts of the liquid drug exteriorly of the housing to the
patient.
This invention is particularly advantageous over the prior art in
that a supply of liquid drug may be comfortably carried by a
patient and applied, by infusion, directly where needed; that an
infusion unit providing precisely metered low flow-rates may be
simply and economically manufactured by production line techniques;
that medical accuracy may be obtained in an ambulatory
self-contained assemblage which is unimposing and aesthetically
pleasing; and that the unit can be calibrated to administer precise
dosages, is simple to operate, and is designed to be disposable
after use.
Other objects and advantages of the present invention will become
apparent from the following description of a preferred embodiment
when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of an
intravascular infusion unit according to the present invention;
FIG. 2 is a top plan view, partially in section, of the infusion
unit of FIG. 1;
FIG. 3 is a sectional view, partially in elevation, of a portion of
the flow control assembly of the infusion unit of FIG. 1;
FIG. 4 is an exploded perspective view of the infusion unit of FIG.
1 with certain parts broken away and certain parts shown in
section;
FIG. 5 is a bottom plan view of the infusion unit of FIG. 1;
FIG. 6 is an exploded perspective view of the fluid repository
cartridge of the infusion unit of FIG. 1; and
FIG. 7 is a sectional view of a detail of the valve assembly of the
cartridge of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a preferred embodiment of an infusion unit
in accordance with the present invention includes a main housing 10
having a generally rectangular support base 12 upon which are
mounted the various subassemblies making up the completed
apparatus. Support base 12 is preferably, slightly curved in order
to accommodatingly conform to the curvature of either a particular
portion of the torso of a patient or an extremity thereof, such as
an arm or leg.
The embodiment illustrated herein is particularly well suited for
use on the arm or leg of a patient, and in order to maintain the
infusion unit in position upon such extremity, any of various
suitable attaching mechanisms, assemblies or devices may be
employed, such as a pair of adjustable elastic bands 14 and 16
affixed to the underside of the base 12 as shown in FIG. 1. While
only support straps have been illustrated herein for the sake of
brevity, it should be understood that any appropriate technique may
be used to attach the infusion unit of the present invention to the
patient. Exemplary devices are synthetic or metallic clips or
bracelets; suitable belts or straps provided with cloth fasteners,
zippers, buckles or the like; or elastic or inelastic ties or
adhesive tapes.
Mounted atop support base 12 are first and second spaced, elongated
compartments or housing sections 18 and 20 each having a generally
triangular cross-section as can best be visualized in FIGS. 1 and
4. Compartment 20 is defined by a generally flat, upright interior
wall 22, an outwardly and downwardly angulated floor 24, and a
generally flat angularly inclined outer wall 26. The end of
compartment 20, to the left as visualized in FIG. 1, is closed by a
triangularly shaped wall 28 which is contiguous at its periphery
with walls 22, 26 and the support base member 12. The opposite end
of compartment 20 is spaced from the right edge of support base 12
and is open to enable communication between compartment 18 and a
generally rectangular slot or recess disposed between housings 18
and 20.
Compartment 18 has along its inner side a generally upright wall
30, which extends from support base 12 to the upper edge of a flat,
inclined outer wall 32 which joins base 12 along its longitudinal
edge. The left end of housing or compartment 18, as visualized in
FIGS. 1 and 4, is closed by a triangular, upright wall 34, with the
opposite end of the compartment 18 open and recessed from the edge
of support base 12 in a manner similar to that of housing or
compartment 20. A convex wall 36 of generally triangular
configuration has a smoothly rounded inwardly directed flange
formed about the upper periphery thereof and closes the right end
of the assembly by joining walls 26 and 32 with the support base
12.
A locking lever 40 is journalled at an end 42 for pivotal rotation
about a pin 44 protruding inwardly from upright wall 30 of
compartment 18. End 42 further supports a flange 46 for cooperative
engagement with a protrusion (not shown) on wall 30 so as to
delimit the degree of upward swing of arm 40 away from the support
base 12. The other end 48 of lever 40 carries a downwardly
extending generally flat plate 50. A locking tang 58 protrudes
laterally below the bottom edge of plate 50 for cooperative
engagement with an aperture 60 (FIG. 5) defined in the support base
12 of the infusion unit 10. Arm 40 also carries a generally
triangular, curved outer wall 62 which acts as a handle and is
shaped such that the lever 40, when in the closed or locked
position, is contiguous at its outer surface boundaries with the
outer surfaces of compartment 18 of the infusion unit.
Referring now to FIG. 4, the floor 24 of compartment 20 carries a
plurality of protrusions which cooperate with the various
components of the flow control system of the present invention
shown in detail in FIG. 3 and also in FIGS. 2 and 4. Leading to the
flow control system is a first, generally U-shaped flow passage 70
which terminates at one end in a needle or pin-like protrusion 72
having a hole 74 therethrough communicating with a small, generally
cylindrical interior chamber 76. Spaced from the front wall of
chamber 76 by a suitable O-ring 78 is a filter assembly 80
consisting of one or more filters designed to trap or retain small
particles or sediment and bacteria and preclude the passage of the
same through the downstream portions of the flow control assembly
to be described more fully below.
Downstream of filter assembly 80 is a flow passage 82 defined by a
groove in the outer wall of element 70 and a suitable flat plate 84
attached thereover. Passage 82 continues through an elbow 86 in
member 70 and is outwardly divergent to provide a second interior
chamber 88. At this point it is noted that element 70 is
constructed so as to join with base 12, the edge of end piece 36,
and upstanding walls 22 and 30 at the right ends of compartments 18
and 20. In this manner, member 70 functions as an end wall of the
generally rectangular slot or void 90 atop base 12 between chambers
18 and 20 and closes off the compartment joining compartments 18
and 20 of the overall housing.
Chamber 88 in elbow 86 has a first outlet port 92 and a second,
smaller outlet port 94 disposed side-by-side in a wall 96. Ports 92
and 94 protrude slightly from the outer surface of wall 96 and have
attached thereto, in sealed relationship, first and second flexible
fluid carrying conduits 98 and 100, respectively. As shown in FIG.
4, a generally rectangular upstanding block 102 is formed in the
floor 24 of compartment 20 and has longitudinally aligned thereupon
a pair of upstanding dividing walls 104 and 106. Walls 104 and 106
are spaced from each other such that the slot defined therebetween
will accommodate flexible conduit 100, with larger flexible conduit
98 disposed on the other side of wall 106.
Conduits 98 and 100 terminate at their opposite ends in a
connecting block 108 having inlet ports 110 and 112 similar to
ports 92 and 94, respectively, and accommodating the ends of
flexible conduits 98 and 100 in a fluid-tight manner. Connector
block 108 is preferably rectangular in configuration, but may be of
any suitable external shape as desired. As shown, block 108 has a
groove running completely thereabout for firm engagement with a
generally U-shaped upstanding protrusion 114 in the floor 24 of
compartment 20.
Interiorly of block 108, a chamber 116 provides communication
between ports 110 and 112 and an outlet port 118 for connection
through the floor of compartment 20 with a flexible surgical tube
120. The end of tube or conduit 120 is suitably connected with a
catheter or needle for intravascular infusion of fluids to a
patient in the conventional manner. Disposed interiorly of conduit
98 are a plurality of elongate fibers 122 which coextensively are
nested in a close relationship and fill a substantial portion of
the cross-sectional volume of the conduit 98.
A spring element 124 (FIG. 2) is held at its proximal end in a
recess 126 formed adjacent elbow 86 in the floor 24 of compartment
20 and has, at its distal end, an offset, curved portion adapted to
engage flexible conduit 100. Spring 124, when disposed in recess
126 exerts a biasing force against the flexible conduit 100 so as
to pinch or crimp the same between the curved offset portion
thereof and the side of upstanding wall 106. In this manner, spring
124 normally precludes the passage of fluid through conduit 100 and
enables fluid flow therethrough only when the spring is lifted away
from wall 106.
A first generally triangular wedge member 128 is mounted on the
opposite side of flexible conduit 98 from wall 106 and is slidable
laterally into engagement with such conduit in a path defined by
stops 130 and 132 in the floor of compartment 20. A control wedge
134 is disposed adjacent wedge 128 such that longitudinal movement
of the control wedge 134 urges wedge 128 into engagement with
flexible conduit 98 which is thereafter compressively entrapped
between the wedge 128 and upstanding wall 106, the floor of block
102 and the wall 26. Such compressive force distorts the
configuration of the conduit 98 such that the area therein
decreases resulting in the elongated fibers 122 taking up more of
the available space within the conduit for fluid flow. At the left
end of control wedge 134, as visualized in FIG. 2, a rack gear 136
is provided having a guide prong 138 protruding from the end
thereof so as to slidably engage the front corner of compartment
20. A pointing arm 140 extends from the end of rack gear 136 in a
direction opposite to the projection 138 and has a scribed line
thereon for cooperation with a flow-rate scale 144 carried upon the
outside of wall 26 (FIG. 1). Pointer 140 can be seen through an
opening 146 in wall 26 and, since the longitudinal position of rack
136 determines the lateral position of wedge 128, indicates the
flow-rate of fluid being dispensed through the infusion unit
according to the present invention.
A second aperture 148 is defined by the wall 26 of compartment 20
for admitting a first end of a tool 150 having a pinion gear 152
formed thereon for cooperative interengagement with the gear teeth
of rack 136. As can be appreciated from FIG. 1, tool 150 may easily
be inserted through aperture 148 and rotated so as to
longitudinally move the control wedge 134 for regulating the force
applied through wedge 128 to the fiber containing conduit 98. The
flow-rate thus established is accurately maintained and is
precisely indicated by the position of pointer 140 with respect to
scale 144.
Chamber 116 in connector block 108 defines a hole or opening 158 in
the wall thereof opposite ports 110 and 112, which hole is closed
by a flexible diaphragm 160 sealed by a suitable annular clamp 162.
Diaphragm 160 thus moves in response to the pressure built up
within the system located between the flow control element 110 and
the outlet tubing 120. An L-shaped indicator arm 164 is pivotally
mounted to the floor 24 of compartment 20 and has a first leg 166
engageable with and responsive to movement of diaphragm 160 of the
connector block 108. The other leg 168 of lever 164 carries a flag
or signal 170 at its distal end. Signal 170 may be painted with a
bright color or provided with any other suitable indicia and has
its arcuate path of travel aligned so as to bisect an aperture 172
in wall 26 of compartment 20. In addition, a small biasing spring
174 is torsionally wound about the axis of arm 164 between leg 168
and a stop 176 in the floor of compartment 20.
In this manner, arm 164 is gently biased such that leg 166 engages
the diaphragm 160, with leg 168 carrying signal 170 to a nested
position hidden behind wall 26 away from aperture 172. Should the
fluid flowing through the system to the catheter or needle become
blocked for some reason, the pressure of the fluid supply causes
diaphragm 160 to bulge outwardly from connector block 108 thereby
rotating arm 164 and transposing signal 170 to a position
immediately behind aperture 172. The visual perception of signal
170 through aperture 172 thereafter apprises the patient or his
attending physician or nurse that infusion has ceased.
A plurality of grooves such as orthogonal grooves 180, 182 and 184
are formed in the undersurface of support base 12 in order to allow
fluid conduit 120 to be guided along the bottom of base 12 and
brought out to the front, rear or side of the infusion unit for
ultimate connection to the catheter at the end of the tube in the
most convenient manner. Of course, it should be understood that any
number of grooves may be provided in the undersurface of support
base 12 and that the three grooves shown in FIG. 5 are merely
exemplary of such structures.
A cartridge assembly 200 formed of left and right cartridge halves
202 and 204, respectively, has a generally rectangular overall
configuration conforming to the void or slot 90 defined above base
12 between compartments 18 and 20. Further, the upper surfaces of
sections 202 and 204 are slightly curved such that when the
cartridge is slidably engaged with the support base and housings,
and arm 40 is pivotally moved to its locked position, the overall
assembly has a smooth contiguous outer surface as shown in FIG. 1.
Portion 204 of cartridge 200 has a first end wall 206 defining an
aperture 208 therein. Aligned over aperture 208 is a valve assembly
210 of a distensible fluid containing bladder or repository 212.
Valve assembly 210 is attached to wall 206 in any suitable manner
such as by means of clamps, bolts, interlocking grooves, etc.
The heart of the valve assembly 210 is a flat, resilient member 214
having a pair of frustoconical apertures 215, which, as shown in
FIG. 7 in solid lines is urged by the internal pressure within the
bladder into a closed position in sealed engagement with wall 206
of the cartridge assembly 200. Of course, it should be understood
that any suitable valve assembly may be incorporated into the
bladder 212 and, in the alternative, valve 210 may be replaced with
a simple flap valve or flexible seal adapted to be punctured by a
needle for admitting or dispensing fluid. Such modification would
be accomplished with like modification of projection 72 or
substitution of a sharp needle therefor.
The opposite end of bladder 212 defines an opening 216 having an
annular flange 218 formed thereabout. Aligned over opening 216
against the surface of flange 218 is a microfilter element 220
which allows the passage of air therethrough but not fluid. Such
microfilters may be formed of any well-known, commercially
available materials and thus will not be described in detail for
the sake of brevity.
Element 220 is firmly clamped between flange 218 and the inner flat
surface of a sliding element or spider 222 having a plurality of
arms 224 extending radially from a central hub thereof. Arms 224
are preferably engaged with the four inner corners of the
rectangular shell provided by portions 202 and 204 of cartridge 200
such that the spider is freely slidable longitudinally within the
compartment. An aperture 226 extends completely through the central
hub of the sliding element 222 such that air passing through filter
220 may be expelled to the atmosphere. A generally L-shaped
indicating arm 228 protrudes upwardly from the central hub of
member 222 and has a first leg which extends over a recessed path
230 longitudinally disposed along a central portion of portion 204.
A suitable volume scale 232 is imprinted upon the upper surface of
portion 204 and cooperates with indicator arm 228 to enable easy
perception of the volume contents of the bladder or repository
212.
As described in detail in copending application Ser. No. 344,713,
assigned to the assignee of the present application, bladder 212
may be distended by the admission of fluid under pressure through
valve 210 such that the bladder is axially and radially enlarged,
as shown in FIG. 2, for storing the liquid under pressure. As the
liquid drug is forced into the bladder 212, the same becomes
axially elongated such that slider 222 moves toward the end away
from the valve 210 indicating a volumetric change by the
cooperation of indicating pointer 228 and scale 232. In addition,
since the fluid repository 212 is supported between the valve
assembly 210 attached with wall 206 of the compartment or cartridge
200 and the central hub of slider 222, the same is maintained at
all times in spaced relationship with the inner walls of the
compartment to allow precise delivery of the entire contents of the
bladder with minimal frictional interference. Furthermore, the
distensible elastic walls of the bladder 212 are constructed of a
material having a characteristic enabling distention of the walls
to approximately the inner dimensions of the cartridge 200 such
that the bladder, even when fully distended, does not engage the
inner walls of the cartridge.
A pair of pins 240 and 241, protrude laterally from the ends of a
side wall of portion 202 of cartridge 200 for cooperative
engagement with the inner edge of plate 50 and flange 46,
respectively. Thus, as the cartridge 200 is slidably moved into
position along the support base 12 (FIG. 4), pin 241 engages flange
46 and as arm 40 is rotated downwardly, pin 240 slides along said
inner edge to firmly urge the cartridge into a nested position with
the pin or nozzle end 72 of the housing fluid passage inserted
through aperture 208 and into engagement with the member 214 of
valve assembly 210.
In operation, a particular liquid drug intended to be administred
by infusion to a patient is first forced into the distensible
bladder 212 through valve assembly 210. An appropriate fitting may
be formed on the valve end of the cartridge 200 for cooperation
with a supply capsule such that the liquid drug supply may be
affixed to the cartridge 200 with a needle-like member engaging
member 214 of the valve assembly to open the same for the admission
of fluid. Such fluid, under pressure, is then forced into the
bladder causing the same to be radially and axially expanded or
distended to a capacity of from about 20 cc to 100 cc. While such
fluid is being forced into the bladder 212, slider 222 will be
moved axially toward the end opposite valve assembly 210,
indicating the volumetric capacity of fluid by the relative
position of pointer arm 228 with respect to volume scale 232.
After bladder 212 has been completely filled, the liquid drug
source is removed from the cartridge allowing member 214 to become
firmly seated against wall 206 of the cartridge 200. The cartridge
is then in a condition for subsequent use and may be stored under
appropriate conditions or immediately inserted into the housing
assembly for use. It should also be noted that during the filling
operation, microfilter 220 allows any air initially contained
within the deflated bladder 212 to pass through aperture 226 in the
slider 222 for assuring complete filling of the repository with the
liquid drug to be dispensed. By tilting the cartridge assembly such
that the end opposite valve assembly 210 is in an elevated position
relative to such valve assembly, the air trapped within the bladder
212 will rise to the top and will be slowly released through filter
220 to the atmosphere. As noted above, mocrofilter 220 may be of
any suitable type, such as that sold under the name "Cellguard",
and enables the passage of air but yet precludes the flow of the
liquid drug out of the repository 212, thereby enabling rapid
bleeding of the cartridge assembly so that it will be filled only
with the liquid drug.
Once the cartridge assembly has been completely filled with liquid
drug, and it is desired to administer the same to a patient, the
cartridge may be properly positioned in the void or slot 90 formed
by the spaced positioning of compartments 18 and 20 atop support
base 12. Preferably, cartridge assembly 200 is positioned at the
left end of the slot 90, with locking arm 40 in approximately the
position illustrated in FIG. 4. The cartridge is then gently slid
to the right, the same being properly guided or aligned between
upstanding walls 22 and 30. As shown in FIGS. 2 and 7, as the
cartridge moves toward the right end of the housing assembly, the
projecting pin 72 of end member 70 first passes through aperture
208 in the right wall 206 of the cartridge assembly and, as the
cartridge is further advanced, engages member 214 so as to
deformingly urge the same to its open position (illustrated in
phantom in FIG. 7) thereby permitting liquid to flow through
apertures 215 and slots or openings in the leading end of pin 72
(not shown) and thus into hole 74.
At this same time, lever arm 40 must be moved downwardly toward its
locking position. This action causes pin 240 to slide along the
inner edge of plate 50 further urging the cartridge assembly 200
into its properly nested position atop the support base 12. After
the cartridge assembly is fully seated to the right as shown in
FIG. 2, locking arm 40 may be further moved such that the locking
tang 58 engages the shoulder of rectangular opening 60 in the base
12 and firmly locks the cartridge in place. As can be appreciated
from FIG. 1, when the cartridge assembly 200 is positioned atop
support base 12, and lever arm 40 is rotated down into its locked
position, the housing has a smooth, continuous exterior surface
whereby the assembly resembles a unitary structure.
With the cartridge in position atop the housing, the cooperative
interaction of pin 72 and member 214 causes the establishment of
communication between the liquid drug contents of the repository
212 and the fluid passageway 82 formed in the right end of the
housing assembly. Such fluid is then enabled to flow through
aperture 74 and into chamber 76 where it must pass through the
filter assembly 80 thereby assuring the removal of any bacteria,
sediment or other small particles which may have inadvertently
entered the system. While the liquid drugs which might be expected
to be used in connection with the apparatus according to the
present invention will not normally contain any particulate matter,
the filter assembly 80 assures the complete removal of all
particles thereby guaranteeing the positive metering of fluid
through the fluid flow control to be described below.
The fluid passage 82 opens into chamber 88 which feeds both the
main flexible conduit 98 and the smaller secondary conduit 100.
These two conduits form parallel paths for the flow of fluid
through the system with the main branch providing precise and
accurate metering of fluid during normal operation and the smaller
conduit 100 enabling rapid bypass or bleeding of the system during
selected times. The controlled flow through the parallel circuit of
flexible conduits 98 and 100 passes through connector block 108
from whence it is delivered through tube 120 for intravascular
infusion. While the particular details of the entire tube assembly
120 have not been shown, it should be understood that any
well-known surgically approved technique may be utilized whereby
the tube 120 terminates in an I.V. catheter or needle for insertion
into the patient for administration of the drug or in a standard
connector for connection to a catheter or needle.
As described above, a spring member 124 (FIG. 2) has an offset,
curved distal and portion which is normally biased into engagement
with flexible conduit 100 so as to pinch the same against
upstanding wall 106 thereby closing the conduit to the passage of
fluid from repository 212. Since the primary flow through conduit
98 is a low-rate flow, it would take considerable time to bleed any
air from the system when initially preparing the apparatus for use.
Thus, spring member 124 is provided for cooperation with bypass
conduit 100 such that as the spring 124 is moved away from the
conduit, a secondary flow is enabled through conduit 100 so as to
rapidly purge the system of any air. Thereafter, spring 124 may be
released whereupon the bypass conduit 100 is again closed-off
enabling the fluid flow to again be precisely metered through
primary conduit 98. As shown in FIG. 1, a generally rectangular
opening may be provided in the wall 26 of compartment 20 to enable
a flat blade of tool 150 to be inserted into the compartment 20 for
the selective flexure of spring 124 away from conduit 100.
Conduit 98 contains a plurality of coextensively disposed elongated
fibers 122 which, as shown, substantially fill the conduit and are
parallel to each other within the conduit 98. Fibers 122 are
essentially linear and are made of a resilient elastomeric
material, such as, for example, the poly(urethane) sold under the
name "Lycra Spandex", silicone rubber, polyisoprene and butyl
rubber. Since conduit 98 rests in position atop block 102 between
upstanding wall 106 and and a flat side of wedge member 128, a
compressive force is applied to the conduit in a direction which is
perpendicular to the flow of fluid therethrough. This compressive
force is applied to the conduit at the point where the axially
aligned fibers 122 are disposed, and may be applied over all or
part of the length of the aligned fibers.
As a compressive force is applied against conduit 98 by the wedge
128, the conduit is selectively caused to be deformed. Since the
circumference of conduit 98 does not change appreciably, this
deformation brings about a decrease in the conduit's
cross-sectional area. The cross-sectional area of the aligned
fibers, however, does not change appreciably so that as the conduit
98 is compressed, the proportion of the space within the conduit
taken up by the fibers is changed to enable precise metering of
fluid flow therethrough. The internally aligned fibers are closely
packed within the conduit and generally should take up at least 50
percent of the internal cross-sectional area of the conduit prior
to compression. Preferably, the fibers are themselves of rounded or
cicular cross-section such that they align themselves in a
close-packed, nested configuration. The number of such internal
fibers and their size relative to the diameter of the conduit's
inside diameter may vary. As a general rule, there must be at least
about six internal fibers and the upper limit, which is not
critical, may be as much as several hundred fibers.
In order to precisely control the flow-rate through the conduit 98,
control wedge 134 is disposed in compartment 20 and coacts with
wedge 128 such that the longitudinal position of control wedge 134
causes very slight movements of wedge 128 perpendicular to the
conduit. In this manner, compressive forces of greater and lesser
magnitude are simply, effectively, and reproducibly generated and
applied by wedge 128 to the conduit 98. The control wedge 134
carries a rack gear 136 which, as noted above, is accessible
through aperture 148 in the outer wall 26 of compartment 20. Pinion
gear 152 of tool 150 may be easily inserted through aperture 148 so
as to engage the rack gear 136 whereupon rotation of the tool
accurately and precisely positions the control wedge 134.
Since the position of the control wedge 134 is determinative of the
compressive force applied to conduit 98, and thus, the flow-rate
established from the system, the position of pointer arm 140
relative to scale 144 enables the simple and precise visual
perception of the preselected flow-rate of the system. Once the
particular flow-rate desired has been established, tool 150 may be
removed so as to preclude inadvertent adjustment or regulation of
the flow-rate setting during use of the system. Of course, by
subsequent reinsertion of the pinion gear 152 of tool 150 the
system flow-rate may be reset as desired.
Conduits 98 and 100, fibers 122, and the distensible bladder 212
may be formed of the same material or of different materials. While
any number of suitable materials may be utilized, certain exemplary
materials are those which are resilient, deformable and are inert
to the fluid or liquid drug stored and administered by the system.
Exemplary materials include natural rubber (preferably suitably
extracted or treated to remove impurities which potentially would
contaminate the fluid), as well as synthetic elastomers, for
example, poly(isoprene), poly(1,4-butadiene), segmented
polyurethane of the poly-ether variety, block co- or ter-polymers
containing butadiene and styrene, silicone rubbers such as the
silastics, butyl rubber, nitrile/butadiene rubber and neoprene.
The present invention is further provided with a flow indicator so
as to apprise the user of the cessation of fluid delivery from the
system. Diaphragm 160 secured over opening 158 in the connector
block 108 responds to the pressure of fluid within the system and
causes a proportionate movement of the pivotally mounted arm 164 in
accordance with such pressure changes. Normally, as fluid is
dispensed through the system, the fluid pressure within connector
block 108 is relatively low such that arm 164 is permitted to be
rotated clockwise by spring 174, thereby carrying the signal 170 to
a nested position away from aperture 172 in the outer wall of the
compartment 20. If, for any reason, a blockage should occur
downstream of the connector 108, the pressure within the entire
system would quite rapidly build up to the internal pressure of
fluid within the dispensing bladder 212 whereupon diaphragm 160
would respond by bulging slightly outwardly against leg 166 of
indicator arm 164. As a result, arm 164 is rotated counterclockwise
thereby carrying signal 170 through an arc whereby it becomes
positioned immediately behind opening 172. The visual perception of
signal 170 through opening 172 thereby signals the patient, his
attending physician, or nurse that the delivery of the liquid drug
has ceased and is no longer being accomplished. Accordingly, the
appropriate steps may be taken to remedy the situation and once
again commence the precisely metered delivery of the liquid drug by
infusion.
Referring to FIG. 1, it should be appreciated that the present
invention is preferably designed to be worn or attached to a
portion of the torso or an extremity of a patient and is
particularly well suited in connection with the direct
administration of liquid drugs which must be applied in very slow
rates over an extended period of time directly to a particular site
of disease, infection, or the like. For example, in certain cancer
chemotherapy, it may be desirable to apply a particular liquid drug
directly to the forearm of a patient where a detected cancer
nucleus has formed. In this case, the infusion unit can, according
to the present invention, be attached to the patient either on the
upper arm or forearm with the slight curvature of the lower surface
of the support base 12 generally conforming to the curvature of
such extremity portion. Straps 14 and 16 may be then adjusted so
that the infusion unit is comfortably held in position about the
arm of the patient.
The surgical tube 120 may then be positioned within one of the
orthogonal grooves 180, 182 or 184 along the bottom of base 12 and
brought out from that side of the infusion unit closest to the
selected point of insertion of the I.V. catheter. Desirably tube
120 is of the nonclosure type, that is, its passageway is of a
generally triangular cross-section which prevents it from being
easily pinched off. Preferably, before the infusion unit is
attached or fitted to the patient, a cartridge 200 which has been
previously filled with the desired drug to be administered is slid
onto the support base 12 in the manner described above. Thereafter,
the blade end of tool 150 may be inserted through the opening in
the housing wall to lift spring 124 away from bypass tube 100
causing the relatively rapid emission of fluid from the repository
212 through the passageways inside the infusion unit and thence
through tube 120 and the catheter so as to discharge all of the air
present within the system. Spring 124 is thereafter released
closing off the bypass passage and allowing the desired, precisely
metered flow-rate to be established by the primary fluid conduit 98
and its contained fibers 122.
The catheter is then inserted into the selected tissue or vascular
passage associated with the disease site to be treated, and the
precise, desired flow-rate is preset by insertion and rotation of
tool 150 through opening 148. The positioning of control wedge 134
is thus easily selected and may be observed by comparison of
pointer 140 with scale 144. The device will then continuously
administer the precisely metered low flow-rate of liquid drug to
the patient.
The infusion unit according to this invention is preferably
constructed of molded plastic so as to be extremely lightweight and
economical to fabricate. Such molding may be accomplished in
accordance with any well-known techniques and, as such, may be
fabricated from a number of individually molded pieces
conventionally attached to form the overall apparatus. In this
manner, the entire assembly may be sufficiently economically
manufactured so as to be disposable after a single or a
predetermined limited number of uses.
It can therefore be appreciated that the present invention provides
a number of material advantages over devices heretofore available
and allows precisely reproducible metered flow-rates of liquid
drugs to be administered to a patient by infusion by apparatus
which is economical, simple, aesthetically pleasing, and allows the
patient to be at all times ambulatory while undergoing treatment.
Further, the infusion unit according to the present invention may
easily accommodate any number of replaceable cartridges containing
the same or different liquid drugs for administration to a patient
at various times, each cartridge being refillable or disposable
after such patient has completed the intended treatment.
Inasmuch as the present invention is subject to many variations,
modifications and changes in detail, it is intended that all matter
contained in the foregoing description or shown in the accompanying
drawings shall be interpreted as illustrative and not in a limiting
sense.
* * * * *