Note: Descriptions are shown in the official language in which they were submitted.
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BACK(;ROUND OF THE INVENTION
This invention concerns a novel set for the
administration of parenteral liquid to a patient, and
more particularly, to an improved drip chamber for use
with an administration set.
~; In the prior art patent to Bobo, et al. U.S.
No. 3,886,937, issued June 3, 1975, it has been proposed
to provide a check type valve along the tubing in an
administration set between the drip chamber and an
1`0 injection site commonl~ referred to as a "Y" site. In
one embodiment, this check type val~e is illustrated
as a duckbill valve, which is positioned within a housing
that is connected in series with the tubing. The
present invention provides an improvement over the
administration set disclosed in the Bobo, et al. patent.
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BRIEF DESCRIPTION OF THE }NVENTION
In accordance with the present invention, an
administration set is provided having a drip chamber the
inlet of which is adapted for coupling to a source of
parenteral liquid and the outlet of which is adapted
.
for coupling via appropriate tubing to a patient~ The
improvement comprises the drip chamber outlet having
a housing connected at the downs~ream end thereof. The
housing includes an upstream inlet portion and a down-
stream outlet portion. The upstream inlet portion of
the housing includes a valve seat defining a liquid
passage therethrough and the downstream outlet portion
comprises a wall defining a liquid passage.
A ball is located within the housing. The
valve seat and wall are spaced a sufficient distance to
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enable the ball to float within the housing when liquid
is flowing in the upstream to downstream direction.
The valve seat and ball are dimensioned and cooperative
to close the liquid passage when li~uid flows in the
downstream to upstream direction.
The valve seat has a resilient portion which
extends axially inwardly for contact with the ball and
is shaped to provide substant:iall~ line contact along
the surface of the ball. The resilient portion is
peripherally free to enabIe inward flexing thereof.
In the illustrative embodiment, the hausing
includes a top portion and a bottom portion. Means are
provided for ~ealing the top portion to the bottom
portion. The drip chamber includes a flexible plastic
casing which surrounds the ~op portion and is coupled
to the sealing means.
In the illustrative embodiment, the valve seat
comprises a symmetrical resilient member having a
central bore forming the liquid passage. The resilient
member also includes an annular ring facing the ball
for sealing engagement therewith. The resilient member
is formed 1n a unitar~, integral construction. The
valve seat and ball are cooperatively dimensioned so
that the resilient portion which contacts the ball
circumscribes a segment of the ball defining an arc of
about ~0.
In the illustrative embodiment, tubing is
connected between the outward liquid passage of the
drip chamber and one of the inlets of an injection site
having two inlets and an outlet. Tubing is also con-
nected between the injection site outlet and an inlet
of a second injection site having two inlets and an
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outlet. In this manner, s`econdary liquids can be sequen~
tially and automatically provided to the patient.
A more detailed explanation of the invention
is provided in the following description and claims, and
is illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
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FIGURE 1 is a view of an administration set
constructed in accordance with the principles of the
present invention;
FIGURE 2 is an enlarged~ fragmentary cross-
sectional view of a drip chamber constructed in accor-
dance with the principles of the present invention;
FIGURE 3 is a cross-sectional view taken along
the plane of the line 3-3 of FIGURE 2;
- FIGURE 4 is a greatly enlarged cross-sectional
view, taken along the plane o~ the line 4-4 of FIGURE 4;
FiGURE 5 is a view of the administration set
of FIGURE 1 with the fluid containers connected thereto
and the set being hung for use with a patient;
FIGURE 5 is an enlarged cross-sectional view
of a valve seat used in the FIGURE 2 drip chamber;
FIGURE 7 is a bottom plan view of the valve
seat of FIGURE 6; and
: FIGURE 8 is a view showing the cooperation of
the valve seat of FIGURE 6 with the ball.
DETAILED DESCRIPTION OF THE
ILLUSTRATIVE EMBODIMENT
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Referring first to FIGURE 1, an a~ministration
set 10 is shown therein, including a drip chamber 12,
the inlet 14 of which is connacted by a suitable spike
to a plastic or glass container 16 containing parenteral
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solution. A backflow check valve 18, which is described
in more detail below, forms the out:Let of drip chamber
12. Tubing 20 is connected between drip chamber 12 and
inlet 22 of an injection site 24. Injection site 24 is
preferably of the type disclosed in Mittleman U.S. Patent
No. 4,048,995, issued September 20, 1977, having two
inlets and an outlet. While tubing 20 is connected to
inl~t 22, a secondary liquid may be connected to the
other inlet 26. The outlet 28 of injection site 24 is
coupled to a tube 80 which is connected to the inlet 32
of a second injection site 34. Another secondary, or
tertiary, source of liquid may be connected to the other
inlet 36 of injection site 34, and the outlet 38 of
injection site 34 is coupled to tubing 40 which is
connected to a needle adapter 42 having a needle 44
coupled thereto. A regulator clamp 46 may be positioned
along tubing 40.
Administration s~t 10 is formed of plastic
materials and is disposable in accordance with conven-
tional practice. Needle 44 is coupled to a patient so
that the parenteral fluid from bag or bottle 16 will
flow to the patientO
Referring now to FIGURE 2, drip chamber 12 is
shown in more detail therein. The main body 48 of drip
chamber 12 comprises a flexible cylindrical elongated
plastic member, the top or upstream end of which is heat
sealed to a prong member in the conventional manner, and
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the bottom of which comprises a housing(50~. Housing 50 t
includes a top portion 52 and a bottom portion 54. Top
portion 52 :includes a central member 56 defining an
opening 58 and a downwardly depending member 60 which
cooperates with central member 58 to receive a resilient
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valve sea-t 62, preferably formed of rubber.
Valve seat 62 is formed in an in-tegral,
unitary construction and defines a central bore 64.
The valve seat has a downwardly depending annular por-
tion 66 forming a ring 67 which faces a spherical ball
68 for cooperation therewith. Ball 68 is preferably
for~ed of polypropylene so as to have a specific gravity
that is less than 1.0, thereby enabling the ball 68 to
float, as will be described.
In prior art ball valve constructions, the
proper sealing of a spherical ball has often been a
serious problemL Prior art ball valves typically
utilize a valve seat which contacts the ball to circum-
scribe a segment of the ball defining an arc of about
45. I have discovered, however, that a more efficient
seal is provided when the valve seat and ball are
cooperatively dimensioned so that a resilient portion
of the ~alve seat will contact the ball and circumscribe
a:segment of the ball defining an arc of about 60. I
have also discovered that a more effective seal can be
provided when the valve seat maintains a line contact
with the ball, thereby providing optimum pressure
against the ball. To this end, valve seat 62 includes
an upper portion 62a for coupling to a recess portion
within the housing carrying the valve seat, and a
resilient portion 62b which extends downwardly and
axially inwardly to form ring 67 which is adapted for
contact witll the ball. As shown in FIGURE 2, resilient
portion 62 is peripherally free to enable inward flexing
thereof. ~y shaping the valve seat with an undercut 62c,
as illustrated most clearly in FIGURE 6, a relatively
flexible system is provided, giving the resilient portion 62
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the ability to roll inwardly as the ball moves upwardly
under the liquid force. By utilizing an unsupported
external wall with the undercut as just described; the
resilient portion 62, which is preferably formed of
rubber, will roll up as the ball pushes into the valve
seat and will maintain a line contact between the valve
seat and the ball.
It is desirable that ring 67 be smoothly rounded.
- Thus if the val~e seat 62 is formed in a unitary, molded,
one-piece constxuction, it is important that the parting
;~ line be above ring 67 so that there is no flash at the
ring. In this manner, the contact o ring 67 with the
spherical ball will be line contact as is desirable.
Referring to FIGU~E 8, it is seen that when
the ball 68 contacts ball valve 62, ring 67 will circum-
scribe a segment of the ball defining an arc of 60.
As stated previously, this 60~ arc has been found to be
optimum in providing an effective seal.
Although no limitation is intended, as a
specific example of parameters which could be utilized
in forming ~he valve seat illustrated in FIGURE 6, the
following dimensions are given with respect to the
: .
FIGURE 6 embodiment:
Reference Letter (FIG. 6) Example Dimension
a .48 inch
b .275 inch
c .15 inch
d .115 inch
e .325 inch
f .145 inch
g .055 inch
h .087 inch
7-
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Reference Letter ~FIG._5) Exam~le Dimension
i .02 inch
j .1 inch
k .01 inch
1 .36 inch
m .219 inch
n .005 inch radius
o .03 inch x 45 chamfer
Top portion 52 also includes an external radial
flange 70 which asfines a groove 72 enabling the fit of
main portion 48 of drip chamber 12 into groove 72. The
external diameter of top portion 52 is substantially
equal to the internal diameter of main portion 48 of
drip chamber 12, thereby providing a frictional fit
- between main portion 48 and top portion 52.
Bottom portion 54 of housing 50 is shaped
generally complementary to top portion 52 and includes
a mating portion 74 which cooperates with flange 70,
enabling a sonic weld between the top portion 52 and
bottom portion 54. Bottom portion 54 has a bottom wall
76 wXich defines a central opening 78 and carries a
plurality of ribs 80 (see FIGURES 3 and 4) which ribs
prevent ball 68 from engaging and closing opening 78.
An outlet tube connector member 82 is formed integrally
with bottom portion 54 for connecting the plastic
1 tubing 20 to member 82.
i, In the operation o the device, the spike from
the drip chalmber inlet is pierced into an IV solution
container c~r the like. ~he drip chamber is then squeezed
by the operator to prime the set. ~hen the drip chamber
is released, the llquid will enter from the top with the
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drip chamber being approximately one-third to one-half
full.
The valve seat 62, ball 68 and ribs 80 are
spaced so that the liquid will flow through the ball
valve, around the ball and through outlet 78. The
ball will, of course, float within the liquid. In this
manner, the administration set, when coupled to a
patient, will operate to feed the primary liquid to the
patient.
FIGURE S shows an embodiment in which two
secondary administration sets are also couplsd to the
patient. Referring to FIGURE 5, it can be seen that a
secondary solution 90 is coupled to inlet 36 and another
secondary solution g2 is coupled to inlet 26. Solution
90 is at a higher level than solution 92 and solution 92
is at a higher leval than primary solution 16. Solution
90 is connected to inLet 36 by means of plastic tubing
94 which extends from a drip chamber 96. Solution 92
i3 connected to inlet 26 via plastic tubing 98 which
extends from a drip chamber 12'. Drip chamber 12' is
identical in construction to drip chamber 12 described
above, and includes the ball check valve outlet described
above.
By utilizing the system illustrated in FIGURE 5,
- a sequential administration system is achieved. Thus
secondary so:Lution from container 90 will flow to the
patient and because secondary solution 90 is at a higher
level than s~condary solution 92 and primary solution 16,
the balls in the check valves of drip chambers 12' and
12 will be urged upwardly against the valve seats thereby
preventing flow from secondary container 92 and primary
container 16. Once secondary container 90 is empty, the
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ball in the check valve of drip chamber 12' will drop
thereby allowing flow from secondary container 92 to
the patient. However, the ball in the check valve of
drip chamber 12 will continue to be urged upwardly
against the valve seat, thereby preventing ~low of the
primary liquid to the patient. Once secondary container
92 is empty, however, the ball of drip chamber 12 will
drop thereby allowing the primary solution from
container 16 to flow to the patient.
By utilizing a ball valve as described, it is
not necessary to provide a four-way heat seal (for
example as illustrated in U.S. Patent No. 2,702,036)
between the outlet o the drip chamber and the tubing
connected thereto. It has been found that the ball
valve operates as a very effective connector between
the drip chamber and the outlet tubing.
It is preferred that housing 50 be transparent
and b~ll 68 have a distinctive color, so that tha
operator can notice the position of the ball with respect
to the housing. It has been found desirable to have the
ability to view the operation of the check valve during
use.
Although an illustrative embodiment of the
invention has been shown and described, it is to be
understood that various modifications and substitutions
may be made by those skilled in the art without departing
! from the novel spirit and scope of the present invention.
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