Note: Descriptions are shown in the official language in which they were submitted.
AUTOMATIC PARENTERAL INFUSION APPARArrUS
mis invention relates to apparatus for autom tic
parenteral infusion o~ a liquid. More particularly, the
invention relates to infusion appara~us in which the
liquid to be infused in-to a patient is supplied at a
relatively constant pressure to provide a constan-t,
predetermined rate of infusion.
In the medical field, there is frequent need to introduce
various liquids into the patient's body. rrwO techniques
are commonly practiced but each suf~er drawbacks under
varying circumstances.
First, the liquid rnay be loaded into a conven-tional
syringe and administered to the patient as a single
injection through a hypodermic needle~ As one
example, diabetics may be supplied insulin using this
technique. Medical science has determined, however, -that
it is frequently beneficial in health care -to adn~nister
various medicinal liquids not at one time in a single
dose, but at a slow rate over a prolonged period of
time.
Such recognition gave rise to the second widely practiced
technique for introducing liquids to a patient. Liquids
such as saline solutions, plasma, whole blood and the
like may be administered to a patient by inserting a
needle into t'ne patient's body and hanging a bottle or bag
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of the solution above the level of the patient so that the
liquid is infused into the patient under positive pressure
vla flexible tubing connectirlg the bot-tle or bag and the
needle. These parenteral liquid containers are typically
eleva-ted two to three feet above the patient and may
be supported from a pole fastened to the patient's bed.
This technique suffers Erom the obvious disadvan-tage that
the patient's mobility is limited.
Oftentimes in the emergen~ trea-tment of trauma
patients, intravenous solutions, for example, must be
administered at the accident scene or while the patient is
in route to medical facilities. Under these
circumstances, the requirement of having an elevated
intravenous container above the patient often presents
difficulties because there is no provision for hanging the
container. Thus, medical personnel mus-t accompany the
patient in order to hold the in-travenous container at an
appropriate, elevated position. In ambulances,
helicopters, and similar medical evacuation vehicles,
it may be difficult to properly position the intravenous
bottle. Variations in heiyht of the intravenous bottle
above the patient will affect the pressure head of liquid
and thus vary the flcw rate of the solution to the
patient.
To overcome the requirement of having to elevate an
intravenous (IV) bottle, various appara-tus have been
prcposed in which a flexible IV bag is pressurized either
by gas pressure or by mechanical ~orce. However, as
the IV solution drains from -the IV bag, the pressure force
exerted on the bag also decreases thus lo~ring the
pressure on the IV solution. This is the same problem
encountered in varying the height of the bottle above the
patient. To overcome -this changing pressure problem,
some of the known pressurized IV apparatus have a squeeze
bulb which must be manually operated to increase the
pressure on the IV bag as the IV solution empties
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therefrcn. In other kncwn pressuri~ed IV apparatus,
compressed yas from a source of compressed gas is
regulated b~ means of a press~re regula-tor to maintain
contant pressure on the IV bag. However, the requirement
of a compressed gas source and a regula-tor appreciably
increases the cost and complexity oE the IV apparatus and,
thence, the possibility of malfunc-tion is increased.
r~e foregoing teachings of the prior art are embraced in
the following patents.
U. S. Patent 2,842,123 of Rundhaug, issued July 8, 1958
and entitled "Pressurized Tranfusion Apparatus", discloses
a pressurized tranfusion apparatus having a sealed
pressure container connected to a compressed gas
source and having a collapsible tranfusion bag within the
pressure container whereby the gas pressure acts directly
on the bag to press~rize the liquid -therein and to force
delivery to the patient.
U. S. Patent 3,153,414 by Beall et al, issued October 20,
1964 and entitled "Apparatus Eor the Induced Infusion of
Liquid from a Flexible Liquid Container", discloses
infusion equipment in which an inflatable bladder
encircles an intravenous liquid bag. r~he bladder is
inflatable by a manually operated inflation squeeze bulb
and exerts pressure on the intravenous bag to force fluid
to the patient.
U. S. Patent 3,468,308 of Bierman, issued September
23, 1969 and enti-tled "Pressure Infusion Device for
Ambulato~ Patients with Prxss~re Control Means", teaches
a collapsible bag contained within a rigid pressure shell
equipped with a pressure regulating device to insure
constant pressure and thus control delivery rate of
intravenous liquid.
U. S. Patent 3,507,27~ of Werding, issued April 21, 1970
. , ,
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and entitled "Apparatus for Dispensirlg Parenteral Fluid",
teaches transfusion ap~ra-tus in which a bag of liquid to
be administered is con-tained within a rigid sealed vessel
and is ~essurized by gas pressure ~thin-the sealed
vessel fr~n a remote compressed gas source.
U. S. Patent 3,838,794 by Cogley et al, issued October 1,
1974 and enti~ed "Package Eor S-toring and Dispensing
Liquids", teaches a collapsible IV bag contained wi-thin a
pressurized bladder connected to a regula-ted source of
compressed air.
The teachings of the prior art, as exemplified by the
foregoing references, have not been widely accep-ted in the
medical Eield. As previously mentioned, gas
regulating equipment adds to the cost and complexity of
infusion apparatus of this genre. Medical personnel must
be trained for the specific type of equipment being used
and must be mindful of the varying techniques for
regulating pressure on-the IV solution. In spite of
these significant drawbacks, however, an even more
im~rtant problem exists in this equipmen-t. It is, in
fact, a potential health hazard. In -the case of
pressurized IV bags, the known prior art teaches
pressurizing gas acting directly on the IV bag. In
the event of a rupture of the IV bag, the pressurizing gas
may enter the IV bag and ul-timately be transmitted to the
patient. The danger of air embolism is there-fore thought
to be the primary reason pressurized intravenous delivery
equipment has not been widely utilized. Furthermore,
a pressurizing gas desirable for its physical properties
may be physiologically toxic if accidentally introduced to
a patient due to equipment malfunction.
Accordingly, a need remains in the medical field for
automatic parenteral infusion apparatus which is safe and
which overcomes the drawbacks heretofore experienced with
similar equipment in this art. The primary goal of this
rp 1 7~
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invention is to neet this need.
More particularly, an object of the invention is to
provide pressurized, automatlc parenteral infusion
equipment which delivers parenteral solution at a
prede-termined and substantially constant rate and which
includes features preventing the danger of toxicity or air
embolism to the patient.
Yet another object of-the invention is to provide
automatic parenteral infusion equipment for administering
parenteral solution ~hich does not require the equipment
to be elevated above the level of the person. Thus, the
equipment is particularly useful in -the f,ield of emergency
medical treatment.
A further object of the invention is to provide automatic
infusion equip~ent of the character described which
administers parenteral solution a-t a substantially
constant regulated -flow regardless of the amount of
parenteral solution in the supply source. Thus eliminated
is the need oE continuous regulation and monitoring of the
equipment by medical personnel. As a corollary advan-tage,
the equipment is easily utilized by medical personnel
accustomed to administering parenteral solutions with
conventional equipment and without requiring any special
training for such personnel.
Another object of the invention i5 to provide automatic
parenteral infusion equipment of the character
described which is fully self contained and portable to
facilitate both storage and simplicity of use. Both
disposable and reusable adaptations of the equipment may
be utilized under varying circu~stances.
An additional object of the invention is to provide safe
and convenient parenteral equipment of the character
described being portable and having features particularly
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suitable for ambula-tory patients. Thus, a user may ac-tually
carry on the bocly equipmen-t embodyincJ -this invention to deliver
parenteral medication over an extended period of time~
Thus, in accordance wi-th a broad aspect of the invention
there is provided automatic parenteral infusion apparatus to
deliver infusion liquid to a patient a-t a substantially constant
ra-te and pressure, said apparatus comprisiny: a rigid shell
having a hollow interior; means within said shell deEining an
infusion liquid chamber being reducible in volume and adapted for
containing infusion liquid; means including a pressure source
chamber spaced apart from said infusion liquid chamber to con-tain
a pressure fluid and adapted to supply a substantially constant
pressure within an expandable volume; pressure transmission means
interposed within said shell between said infusion liquid chamber
means and said pressure source chamber means to transmit a
substantially constant pressure from said pressure source chamber
to said infusion liquid chamber; delivery means connected to
said infusion liquid chamber means to deliver infusion liquid
at a controlled and constant rate of flow; and vent means in said
shell intermediate said infusion liquid chamber means and said
pressure source chamber means to provide constant atmospheric
communication with -the interior of said shell at all times
throughout delivery of infusion liquid to a patient whereby any
pressure leakage from said pressure source chamber means is
safely discharged to the atmosphere.
~6a- 1316-608
In accordance with another broad aspect of the
invention there is provided automatic paren-teral infusion
apparatus to deliver infusion liquid -to a patient at a substanti-
ally constant rate and pressure, said apparatus comprising:
a flexible bag containing a volume of liquid to be infused and
having an outlet; flexible tubing means for the flow of said
liquid from said bag to said patient; means for controlliny the
rate of flow of said liquid to said patient; an annular bladder
surrounding said bag; selectively actuable pressurization means
for pressurizing said bladder for effecting pressuriza-tion of
said liquid in said bag and for maintaining said liquid in said
bag under substantially constant pressure as said liquid is
emptied from said bag, said pressurization means comprising
a closed container, a volume of pressure fluid within said
container, and means selectively operable for providing
corr~munication between said container and said bladder so as
-to permit the flow of said fluid from said container to said
bladder; and a nonexpansible housing vented to the atmosphere
enclosing said bladder with said bag therein, said housing
confining said bladder as the latter is pressurized.
Other and further objects of the invention, together
with the features of novelty appurtenant thereto, will appear
in the course of the following description of the drawings.
In the accompanying drawings which form a part of the
specification and are to be read in conjunction therewith, and
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in which like reference nume-cals are employed to indicate
like parts in the various views:
Figure 1 is a sec-tional, side elevational view of
automatic infusion apparatus illustrating a first embodiment
of the invention with. portions of the delivery tube broken
but indicating continuous length;
Figure 2 is a sectional, side elevational view of
parenteral in-Eusion apparatus illustrating a second embodiment
of the invention;
Figure 3 is a sectional, side eleva-tional view of
automatic infusion apparatus illustrating a thir~ embodiment
of the invention;
Figure 4 is an enlarged ~ragmentary view, partly
in section, illustrating the flow regulating fluid delivery
mechanism;
Figure 5 is a perspective view of automatic parenteral
infusion apparatus illustrating a fourth embodiment of the in-
ven-tion;
Figure 6 is a side elevational view of the automatic
parenteral infusion apparatus in a typical operational
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setting;
Fig. 7 is a longitudinal side sectional vi~J of the
infusion apparatus shown in Fig. 5;
Fig. 8 i5 an enlarged fragmentary vlew of a portion of the
apparatus shown in Fig. 7 illustra-ting Ireans for effecting
pressurization of the liquid in the parenteral bag with
the pressurizing ~eans being illustrated in a ready to use
configura-tion;
Fig. 9 is a view similar to that of Fig. ~, but showing
the pressurizing ~eans shifted to an activated
configuration; and
Fig. 10. is a sectional, side elevational view o
auton~atic infusion apparatus illustrating a fifth
embodiment of the invention.
Referring to the drawings in more detail, attention is
first directed to F'ig. 1. The automatic parenteral
infusion apparatus includes a cylindrical container shell
10 constructed of a rigid, and preferably, translucent
m~terial. The shell 10 is necked down at the lower end
lOa thereof and capped with a tubing connector cap
llo Parenteral liquid delivery tubing 12 sealingly
penetrates connector cap 11 to communicate with the
interior of the container 10. The tubing 12 may be of any
suitable length as indicated by the discontinuous lines in
Fig, 1 and is equipped with an on/off flow control
valve 13. The tenninal end of the tubing 12 is fitted
with a tapered hollow nozzle 14. As best shown in F'ig. 4,
the nozzle 14 is positioned within the socket of a flcw
regula-ting member 15 having a preselectedly sized orifice
15a therethrough. Removably fitted to the outer end
of the flow regulating member 15 is a hypodermic needle 16
to penetrate a patient's body for the delivery of
parenteral fluid.
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Within the shell 10 is formed a chamber for containiny the
parenteral fluid desiynated by the letter F. The chamber
lOb containiny fLuid F is defined by the interior wall
surfaces of shell 10 extendiny from the necked down
portion lOa sealed with cap 11 to a movable plug 17
which sealingly engages the interior cylindrical wall of
the shell 10. Thus, the plug 17 bears ayainst the upper
surface of the fluid F in the equipment as oriented in
Fig. 1. Surmounting the plug 17 is an expandable gas
bladder 18 having accordion-like pleats 18a forming
the cylindrical side surface thereof to permit expansion
of the bladder 18 through the lenyth of the shell 10.
Contained within the upper end of the shell 10 is a
replaceable pressure source cannis-ter 19. The cannister
19 has cylindrical side walls with an outside diameter
slightly less than the inside diameter of the shell 10 to
define an annulus lOf therebetween. The lower end wall of
the cannister 19 is fitted with a hollow needle member l9a
adapted to sealingly penetrate the gas bladder 18, The
upper end of the cannister 19 is substantially the
same diameter as the outside diameter of the shell 10 to
overlie the upper edge thereof to properly seat the
cannister 19 in the end of the shell 10. The cannister 19
is held in place by a removable cap lOc secured to the
shell 10 by threads, a compression gasket, or a
similar connection to enable the cap lOc to be removably
locked in place on the shell 10.
The cap lOb may be equipped with a hanger wire lOd for
suspending the apparatus as shown in Eig. 1.
Alternatively, it should be understood that it is not
necessary that the equipment be vertically oriented as
shown in Fig. 1. Indeed, it may be oriented in virtually
any position since delivery of the fluid F to the patient
does not rely upon gravity flow.
Between the upper end of the shell 10 and the movable plug
17 are a plurality of openings lOe which provide
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atmospheric c~nmunication with the interior of the
container shell l0. The uppermost such opening l~e is
positioned adjacent the annulus lOf. The purpose oE such
openinys will be understood shortly~
s
A pressuring fluid P is contained within the pressure
source cannister 19. Preferably, the pressurizing fluid
P is a li~uid which has a boiling point at atmospheric
pressure below room temperature (i.e., below 70F.), and
preferably well below normal ambient telnperatures.
For example, ethyl chloride having a boiling point at
54F., at ambient pressure rnay be selected as pressurizing
fluid P. Those skilled in the art will of course
recognize that other fluids, such as certain fluoro-
hydrocarbon refrigerants, may also be used as thepressurizing fluid P.
So constructed and assembled, the pressurizing fluid P
within cannister 19 communicates through the needle member
l9a to the expandable bladder 18 to exert a pressure
therein substantially equal to the vapor pressure of fluid
P at ambient conditions. The bladder 18 expands to fill
the space between the lower surface of the cannister 19
and the upper surface of the movable plug 17. Further
expansion of the bladder 18, forces the plug 17 to
pressurize the parenteral fluid F which is delivered
through the tubing 12 and the flow regulating member 15 to
the patient via the hypodermic needle 16. Flow is thus
regulated, in accordance with the recognized principles of
fluid mechanics, by the substantially constant
pressure source of the expandable bladder 18 and the
orifice size 15a of the flow regulating device 15.
In the event of rupture or leakage from the cannister 19
or the bladder 18, the pressure fluid P is safely
vented to the atmosphere through openings lOe.
Referring to Fig. 2 of the drawings, alternatlve features
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of the invention are :illustra-ted. The parenteral liquid
container in-the form of a rigid, cylindrical shell 20
having a neck 2Oa on one end thereoE wi-th a fluid
passageway communicating with the in-terior of the
container. The upper end of the shell 20 is sealed by
an end plate 20b. In-teriorly oE the container is a
chamber 20c for the paren-teral Eluid F which is separated
from-the chamber 20d pressure fluid P by a spool piece
21. The spool piece 21 is formed by upper and lcwer
movable plugs 21a and b sealingly engaged with the
interior cylinder wall oE the shell 20 and centrally
in-terconnected by an axial rod 21c. Intermediate the
fluid chamber 20c and the pressure source chamber 20d, the
shell 20 is provided with a plurality of openings 20e
therein communicating with the atmosphere.
In operation, constant pressure supplied by the pressure
fluid P is transmitted through the spool piece 21 to the
fluid F which is delivered through tubing (not shown) of
the character as previously described until the fluid
F is fully discharged. The latter condition is
illustrated as a broken line view o~ the spool piece 21 in
Fig. 2.
In the event oE defect or leakage of pressure around
the upper sealing plug 21a, the pressure fluid P will be
vented to the atmosphere through the openirgs 20e in the
shell wall to prevent embolism or introduction of toxics
to the patient.
Referring to Fig. 3 of the drawings, further modifications
of the invention are illustrated in a third embodiment.
The container is formed of a rigid, cylindrical shell 30
having a neck 30a with a central opening therethrough.
Interiorly of the chamber is a collapsible bag 31
charged wlth parenteral fluid F. An expandable bladder 32
surmounts the bag 31. The bladder 32 has accordion-like
pleats forming the cylindrical side thereof to permit
expansion of the bladder 32. The upper cir~lar end wall
32a of the bladder 32 is immovably secured to the interior
wall of the shell 30. Thus, defined between the bladder
wall 32a and the upper end wall 30b o~ the shell 30 is a
pressure source chamber 30c charged wi-th a
pressurizing ~luid P. Received within the end wall 30b of
the shell 30 is a press~ e activating member 33 having a
sharpened end 33a which penetra-tes in a sealing m~nner the
upper end wall 32a of the bladder 32. The pressure
actuating member 33 includes an interior bore 33b with
spaced radial openings 33c therefrom. When the actuating
member 33 is fully depressed the uppermost openings 33c
are positioned within pressure chamber 30c and the
lowermost set of openings 33c are positioned interiorly oE
the bladder 32 whereby communication is thus
established through bore 33b between the pressure chamber
30c and the interior of the gas bladder 32.
In o eration, the actuating plunger 33 is ~ully depressed
to pressurize at a subs-tantially constan-t pressure the
bladder 32. Delivery tubing 12 is received by a fitting
34 having a hollow needle 34a received through the shell
neck 30a to sealingly penetrate the bag 31. ~xpansion of
the gas bladder 32 thus causes fluid F to be delivered at
a constant rate to the patient-through delivery
equipment of the character as previously described.
Between the upper end of the bag 31 when fully charged
with fluid F and the upper immovable wall of the bladder
32, the shell 30 is provided with a plurality of
openings 30d therein communicating with the atmosphere.
In the event of a pressure leak or rupture of the gas
bladder 32, the pressure fluid will be vented to the
atmosphere through the openings 30d in -the shell wall to
insure the patient's safety.
The embodim~ents of the invention so described with
reference to the embodiments of Figs. 1~3 thus contemplate
;~
-L2-
dis~osable and portable infusion equipment. Depending of
course on the amount of parenteral fluid -to be delivered
-to the patient, the equipment may be so sized as to be
conveniently secured to the body of an ambulatory
patient.
Attention is now directed to the fourth embodiment of the
invention which contemplates larger and rechargeable
equipment which is portable yet, due to its capacity, is
not designed to be secured to the patient's body.
Reference is made to Figs. 5-9.
A 1exible bag 40 contains a volume of parenteral fluid F
to be infused into the patient's body. The bag 40 has an
outlet 40a and a len~th of tubing 42 connected to -the
bag outlet. As generally indicated at 43, a hypodermic
needle is connected to the free end of the tubing Eor
insertion into the patient's body for the flcw of Eluid F
from bag 40 to the patient. An adjustable valve or Elow
regulator 44 is provided along tube 42 for controlling
the rate of flow of fluid F through the tube to the
patient. Alternatively, a fixed regulating device such as
member 15 shown in Fig. 4 may be utilized.
A pressurizable, annular bladder 45 surrounds bag 40
and at least one end of the bladder 45 is open for
reception of the bag 40. As indicated at 46, selectively
actuable means is provided for pressurizing -the bladder
and for thus effecting press~ ization of fluid F in the
bag. In Figs. 7-9, this pressuriza-tion ~eans is shown
to c~nprise a closed tank or container 47 having a volume
of pressure fluid P therein.
Actuator means 46 further cornprlses selectively operable
means, as generally indicated at 48, for providing
communication between container 47 and bladder 45 so as to
permit the flow o pressurizing Eluid P from the container
to the bladder for pressurization of the latter and the
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-1 3~
l iquid F wi thin bag 40 and -to ma intain the liql~id in the
bag under substantially constan-t pressure as -the liquid E'
drains from the bag.
5 More specifically, apparatus 39 includes a
nonexpansible housing 49, preferably cons-tructed of a
rigid, transparent material. The housing '~9 is generally
rectangular in cross section having a removable end
closure 50 at one end thereof constituting its front end
10 and a f ixed closure 51 at the other end of the
enclosure (see Fig. 7). With rernovable closure 50
removed, bladder 45 ~Ith bag 40 therein is insertable in
the housing 49. Closures 50 and 51 have apertures 52
therein to vent the inside of housing 49 to the
15 atrnosphere. With closure 50 snapped in place on
housing 49, it will be noted that the interior of the
housing is at atmospheric pressure.
Bag 40 is a flexible bag having walls 40b and 40c (see
20 Fig. 7) sealed together, such as by heat-sealing,
substantially around the periphery of the bag. Bag outlet
40a is provided at one end of -the bag, this outlet being
shown to comprise a s topper 53 sealingly secured to and
extending out frc~n the end of the bag. Stopper 53 has a
25 pair of ports 53a and b therein into ~,lnich a hollow
lance may be inserted (as will be hereinafter explained)
for connection tube 42 to the bag and for the injection of
various medicants into the bag by means of a hypodennic
needle or the like. Each port 53a & b has a puncturable
3Q seal 53c.
Bladder 45 is made of flexible ma terial, such as a
suitable plastic film, and is shown to have an outer wall
45a and an inner wall 45b joined together a seal 45c ~see
35 Fig. 7). Thus, an annular bladder is defined having
at least one open end which is of sufficien-t size to
permit bag 40 filled with liquid F to be inserted within
the bladder. Upon pressurizing bladder 45, its outer wall
45a expands to bear against the inside surface of housing
~9. As previously stated, h~using ~9 is ~eferably of
rigid const~lction so -that it serves to contain the
outward expansion of-the bladder 45 and to thus force the
bladder to compress bag 40 as the bladder is
pressurized.
As shown in Fig. 7, with a Eilled bag 40 positioned within
bladder 45, with the bladder and bag installed in housing
~9, and with closure 50 in place on the housing,
stopper 53 extends from the bag 40, and passes through an
aperture 50a in closure 50.
As indicated generally at 55 in Fig. 5, a drip chamber is
provided on closure 50. This drip chamber comprises a
transparen-t cylinder 55a of substantially larger diameter
than tube 42 and has an inlet nipple 55b at one end
thereof and an outlet nipple 55c at its other end. The
inlet nipple 55b extends into the cylinder 55a so that
with the drip chamber 55 in its normal operating
position, the chamber 55 is substantially vertical with
the inlet nipple 55b above the outlet nipple 55c, and with
li~uid F entering the drip chamber via the inlet nipple,
drops of substantially uniform size of liquid are formed
at the lower end of the inlet nipple within cylinder
55a at a rate corresp~nding to the flow rate of li~uid
from bag 40. By adjusting valve 44 and by coun-ting the
number of drops in a predetermined length of time, the
flow rate may be determined and may be adjusted within a
limited range. ~s best shown in Figs. 5 and 6, the
drip chamber is carried by a bracket 56 hingedly secured
to closure 50 by hinges 57. Bracket 56 is swingable from
a first position (as shown in Fig. 5) in which it is
generally parallel to closure 50 and a second position (as
shown in Fig. 6) in which it is yenerally
perpendicular to closure 50. As will be hereinaEter
explained, apparatus 39 is operable either when lying in a
horizontal position or when standing ver-tically and facing
-15-
upwardly. When lyiny hori20ntall~ with bra~et 56 in its
first position, it will be no-ted that lnlet nipple 55b of
the drip chamber is at the-top o the drip charnber and
when standing upright on a table 58 (Fig. 6) ~th bracket
56 in its second position the inlet nipple is again at
-the top of the drip chamber. Tubing 42 includes a first
length attached to inlet nipple 5~b and a second length
attached to the outlet nipple 55c. The free end of the
fir~t length of tubing 42 carries a holl~ lance 59 which
0 i9 insertable in a p~r-t 53a or b or stcpper 53 -to
puncture the seal 53c -therein and to permit the outflow of
liquid F. Tubing 42 has valve means 44 located therealong
and has needle 43 at its free end, ~ p~mc-turable port
fitting 60 may be provided in tubing 42 into which
medication may be injected via a hypodermic needle for
infusion into the patient with li~uid F.
In addition to beiny operable in the abovemention~
horizontal and standing position, the apparatus 39 is also
~0 operable by hanging housing 49 with end closure 51
facing downwardly. This permits operation of the
apparatus in the event the pressurization system 46 is
inoperableO ~ hook 61 (see Fig. 7) is provided on end
wall 51 for hanging housing 49 from an IV pole in the same
manner as a conventional IV bag. Hook 61 is
preferably hingedly connected to end wall 51 and may be
*olded flat. With the housing hanging ~rom hook 61, bag
opening 40a is at -the bottom of the bag. Drip monitor 55
may be unclipped from bracket 56 and allowed to hang in a
vertical orientation.
Pressure means 46 includes a length of tubing 62 sealingly
secured to and in communication with bladder 45 and having
a hollow lance 63 at its other end. Lance 63 is held in
fixed relation to housing 49 at one end of a tubular
guide 64. Guide 64 is sec~red to the inside of cLosure 50
and extends along one corner of housing 49. It will be
understood that bladder 45, when pressurized, bears
-16-
against the outside of -the guide 64. Container ~7 has a
puncturable seal 47a at i-ts end adjacent lance 63 and is
axially movable in guide 64 between a Eirst position (Fig.
~) in which the seal is spaced from-the tip of lance 63
and a .second or actuated posi-tion (Fig. 9) in which
the lance has punctured the seal to release fluid P from
container 47 for pressuriza-tion of bladder 4~ with
consequent pressuri~ation oE liquid F in bag 40.
Container 47 has an actuating handle 47b which extends
exteriorly o end closure 50 through an aperture 50b in
closure 50 for permitting manual movement of container 47
relative to lance 63 between its first and second
positions. As best shown in Figs. ~ and 9, container 47
is an elongate cylinder and it has a lug 47c thereon
extending axially on its outer surfaceO Guide 64 has an
axial slot 64a adapted for reception of lug 47c on
container 47 when the container is rotated from a locked
position in which the lug and the slot are out of register
and an actuation position in which -the lug and slot
are aligned with one ano-ther. With handle 47b in its safe
position (Fig. ~), inadvertent puncturing of seal 47a on
container 47 and accidental pressuri~ation of bladder 45
is prevented.
As best shown in Fig. 5, housing 49 has a viewing windcw
49a in one of its sides and a volume indica-ting scale 49b
is provided on-the housing adjacent the window.
Preferably, bladder 45 and bag 40 are of transparent
plastic film or the like so that the quantity of
liquid F re~aining in bag 40 may readily be esti~a-ted by
observing the bag through window 49a and comparing the
volume re~aining in the bag with scale 49b.
On the bottom of housing 49 , strips of pressure
sensitive tape or the like, as indicated at 65, having a
removable outer cover or backing 65a are provided. Upon
use of the apparatus of this invention, covers 65a may be
3~
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peeled away and the housing adhered to a supporting
surface, such as the floor of an ambulance or a bedside
table, to prevent movernent of the apparatus rela-tive to
the patient. Also, a label 66 (see Fig. 5) may be a~hered
to closure 50 listing pertinent information regarding
liquid F and ad~nistration of the liquid to the patient.
As has been heretofore pointed out, bladder 45 and bag 40,
when inser-ted in housing 49 with closure 50 in place, are
open to the a ~osphere. Thus, in the event of a
rupture or a leak of pressure container 47 prior to use,
the pressurizing fluid P is simply vented to the
atmosphere without effecting pressurization of bag 40. In
the event of a leak in bag 40, liquid F is permit-ted to
drain from the bag and from the enclosure. Since the
pressurizing fluid is separated from bag 40 by inner wall
45b of bladder 45 and does not directly act against bag
40, none of the pressurizing Eluid will enter bag 40 in
the event of a leak in the bag. Likewise, in the event of
a rupture of bladder 45 during use, the pressurizing
fluid P is harmlessly vented to atmosphere through vents
52. This significantly reduces the danger of gas embolism
or chemical toxicity to the patient.
By using a fluid P, such as ethyl chloride, having a
boiling point below room temperature, bladder 45 is
readily pressurized to a desired operating pressure at
which liquid F is forced from bag 40 at a predetermined
pressure (i.e., the vapor pressure of fluid P). By
adjusting valve 44, the flow rate of liquid F -to the
patient may readily be controlled. As liquid F drains
from bag 40, fluid P will autom~tically compensate for the
increase in volume of bladder 45 to maintain a relatively
constant pressure on bag 40. l'hus, the pressure with
which liquid F i6 exhausted is not dependent on the
elevation of the equipment above the patient. It can
therefore be seen that the infusion apparatus oE the
present inven-tion may readily be used in battlefields,
r,~ t~ ~5 ;~
-18-
ambulances, hellcopters and hospi-tals without the
requirement of elevating-the equipmen-t.
Attention is now directed to Fig. 10 illustra-ting a final
embodiment of the invention. As contemplated in the
embodiments of Figs. 1-3, the Fig. 10 embodiment includes
a disposable infusion unit along with a reusable pressure
unit, all of which may be conveniently carried on the body
of an ambulatory patient.
The disposable infusion syringe is formed of a rigid,
cylindrical shell 70 having a neck 70a on one end thereof
with a central opening. A suitable fltting and delivery
tubing (not shown) may be connected to -the neck 70a as
will be understood with reference to the prior
embodiments. Bearing against infusion liquid contained
within the infusion chamber 70b of the shell 70 is a spool
piece plunger 71 formed from a central rod 71a having
movable plugs 71b & c on each end thereof sealingly
engaged wi-th the interior cylindrical wall of the
shell 70. Ve~lt openings are provided in the shell to be
positioned between the movable plugs 71b & c irrespective
of the position within the shell 70 of the spool piece 71.
The end of the shell 70 opposite the neck portion 70a
connected to the infusion liquid del,ivery tubing likewise
includes a neck Eortion 70c having a central opening
therethrough. Connected to the ne~ portion 70c is a flow
fitting 72 equipped with a length of tubing 73. The
opposite end of the tubing 73 is fitted with a fl~l
regulating device 74 having an orifice 74a therethrough.
The regulating device 74 is removably connected to a
mechanical pressure source unit.
The pressure source includes a cylindrical housing 75
having a neck 75a at one end thereof with a central
opening therethrough on which is received the flow
regulator 74. The housing 75 contains a movable plunger
~l9_
76 having a plug meMber 76a sealingly, ye-t movably,
enyaged wi-th the interior surface o-the housing 75 with a
handle member 76b which e~tends ou-twardly from -the closed
end 75b of-the housing 75. Captured wi-thin the h~sing 75
and encircling the plunger 76 is a compression spring
77 which bears against the back of the plunger pluy 76a
and urges i-t towards the necked end 75a of the housing 75.
A fluid passageway is thus deEined be-tween -the forward
face of the plunger plug 76a and the rear plug 71c of
the spool piece 71 in the shell 70 which holds the
infusion liquid F. r~h i S f 1 uid passageway is filled with
an incompressible fluid P. Further, -the interior diameter
of the pressure force housing 75 is larger than the
interior dia~ter of the infusion liquid shell 70.
In operation, therefore, -the pressure source forcing the
infusion liquid F to the patient is supplied by the spring
77 urging ayainst the incompressible fluid P which
transmits this force to the 5~001 piece 71 of the
infusion syringe. Because the diameter of the pressure
plunger 76a is larger than the diameter of the spool piece
71 bearing against the infusion liquid F, a small lineal
movement of the plunger 7~ under the influence of the
compression spring 77 will result in a larger lineal
movement of the spool piece 71 to discharge infusion
liquid F from the syringe. The rate of infusion is
controlled by the flow regulating device 74 having an
appropriately sized restriction orifice 74a. The flow
regulating device 74 may be positioned either on one
end or within the hose communicating between the pressure
source and the infusion s~inge or on one end or between
the hose used to deliver the infusion liquid to the
patient.
It should again be no-ted with reference to this final
embodiment of the invention that the pressure transmitting
fluid P, in this case an inccmpressible liquid, does not
- 20--
directly engage the infusion liquid F .itself. Thus, as a
safe-ty feature, if the incompressible ~essure 1uid P
should happen to leak fr~n around the rear plug 71c of the
spool piece 71, it will be harmlessly leaked from the
infusion syringe 70 without presenting any to~ city
ha~ard by introduction to -the pa-tient's body.
From the for~oing it will be seen tha-t this invention is
one well adapted to attain all the ends and object
hereinabove set forth together with -the other
advantages which are obviolls and which are inheren-t to the
5 tructure.
It will be understood that certain features and
subcombinations are of utility and may be employed
without reference to other features and subcombinations.
This is conte~plated by and within the scope of the
claims.
Since many possible embodiments may be made of the
invention without departing from the scope thereof, it is
to be understood that all matter herein set forth or shown
in the accompanying drawngs is to be interpreted as
illustrative and not in a limiting sense.
