Note: Descriptions are shown in the official language in which they were submitted.
CA 02238118 2002-09-03
1
INFUSION SET
Background of the Invention
Between the infusion containers and the drip chamber in general there is
provided a valve for controlling the amounts. This function in the known
valves is
s supplemented by the construction of the valve as check valves. Such check
valves may contain a diaphragm disk (see, for example, DE 40 39 814 A1; DE 43
04 949 A1 ). Depending on the pressure on the front or rear sides of the
diaphragm disk, a flow path is opened or closed permitting fluid to flow from
the
infusion containers.
io The invention relates to an infusion set having a container for liquid
medicines, which is connected to a drip chamber by a feed-line and a
differential
pressure valve and by a further feed-line connected to a front end being
controlled by a roller clamp. A similar structure is disclosed in US Patent
No.
5,935,100 (formerly US Patent Application Serial No. 08/800,779). In the
is disclosed structure, the differential pressure valve has two inlets, each
with an
associated differential force chamber, wherein the two differential force
chambers are sealingly separated from each other by a diaphragm disk and,
wherein further the two differential force chambers, together are connected to
an
exit line for the liquid medicine. The subject matter of US Patent 5,935,100
may
Zo be summarized as a method and infusion set for consecutively draining
liquid
medicines from a plurality of containers, such as two containers (1, 2)
containing
said liquid medicines, the liquid medicine via a differential pressure valve
(5a) is
fed into a drip chamber (6), wherein the fluid flow is permitted initially
from one
container (1 ) by the higher fluid pressure and differential force area from
the first
2s container (1 ) on a diaphragm disk (15), whereby the fluid flow from the
second
container (2) is stopped and, later an automatic switch to a second container
(2)
as a source of fluid is effected when the fluid flow from the almost drained
first
container (1 ) is at a lower fluid pressure and a smaller differential force
area and
is exceeded by a higher fluid pressure of the second container (2) and the
larger
3o differential force area.
In the infusion set according to US Patent No. 5,935,100 the differential
pressure valve is performed such that it is used to empty sequentially a
number
of containers filled with liquid medicines in a controlled way.
i i I i
CA 02238118 2002-09-03
la
In known infusion sets, an additional check valve is necessary to prevent a
contamination of the set in the case of an occlusion or the like. Further, in
many
cases, it is necessary while the infusion is going on to administer additional
amounts in a surge-like manner or to additionally inject, for example,
contrast
s substances.
Summary of the Invention
In an infusion set of the present invention, this aim is achieved by the fact
that the differential pressure valve is configured as a 3-way check valve
CA 02238118 2002-09-03
2
by the first inlet being connected to the container for the liquid medicine
and
by the second inlet being performed for the connection to a syringe or the
like.
In an preferred embodiment according to the invention, the first inlet is
provided with a male "Luer-Lock"-connector and the second inlet has a
female "Luer-Lock"-connector.
According to a preferred embodiment of the invention, the valve
comprises two valve housing halves being sealingly connectable with each
other, wherein one valve housing half has the first inlet and the second valve
housing half has the exit line and the second inlet.
In detail, it is of advantage that the two valve housing halves are
connectable with each other. Within the differential force chambers each
valve housing has an annular ridge concentric to a liquid inlet or liquid
outlet,
respectively, wherein the first inlet which is connected to the container is
associated with an annular ridge having a larger diameter and the outlet line
is associated with an annular ridge having a smaller diameter.
It is further preferred in this connection that the diaphragm disk with a
part of its circumference is positioned at an opening which is leading to the
second inlet.
A further improvement of the invention consists of the fact that the
liquid outlet of the exit line coaxially opening to the annular ridge having
the
larger diameter has an angular shape and that the liquid inlet of the first
inlet
opening is coaxial to the other annular ridge and extends coaxially to the
first
inlet.
The desired valve action with an excellent sealing at very small .
pressures is achieved by the fact that the diaphragm disk has a circular
shape and is manufactured from a sheet of liquid silicon, silicon or natural
rubber or a strip of liquid silicon, silicon or natural rubber.
3A
2
i i I I
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2a
In one aspect of the invention, there is provided an infusion set having
a container for liquid medicines, which is connected to a drip chamber by a
feed-
line and a differential pressure valve. The drip chamber is connected by a
further feed-line to a front end with a roller clamp. A syringe is connected
to the
differential pressure valve. The differential pressure valve has a housing, a
diaphragm disk retained about the perimeter thereof by the housing, a first
inlet
associated with a first inlet annular ridge and in fluid communication with
the
diaphragm disk, an outlet associated with an outlet annular ridge and in fluid
to communication with the diaphragm disk, and a second inlet in fluid
communication with the diaphragm and the outlet annular ridge and the first
inlet
annular ridge. The differential pressure valve is configured as a 3-way check
valve by the first inlet being connected to the container for the liquid
medicine
and the second inlet being configured for the connection to the syringe. Under
normal valve operation the diaphragm is not sealingly engaging the first inlet
annular ridge and the outlet annular ridge such that the first inlet is in
fluid
communication with the outlet. When pressure is created by the syringe
between the first inlet annular ridge and the outlet annular ridge the
diaphragm
sealingly engages the first inlet annular ridge. When negative pressure is
2 o created by the syringe between the first inlet annular ridge and the
outlet annular
ridge the diaphragm sealingly engages the outlet annular ridge.
In another aspect of the invention there is provided a three way check
valve adapted for connection to a container for liquid medicine, a syringe,
and
an outlet line. The valve comprises a housing, a diaphragm disk retained about
2 s the perimeter thereof by the housing, and a first inlet associated with a
first inlet
annular ridge and in fluid communication with the container for liquid
medicine
and the diaphragm disk. There is also an outlet associated with an outlet
annular ridge and in fluid communication with the outlet line and the
diaphragm
disk. There is also a second inlet in fluid communication with the syringe and
3 o the diaphragm and the outlet annular ridge and the first inlet annular
ridge.
Under normal valve operation the diaphragm is not sealingly engaging the first
inlet annular ridge and the outlet annular ridge such that the first inlet is
in fluid
i ii i
CA 02238118 2002-09-03
2b
communication with the outlet. When pressure is created by the syringe at the
second inlet and between the first inlet annular ridge and the outlet annular
ridge, the diaphragm sealingly engages the first inlet annular ridge. When
negative pressure is created by the syringe between the first inlet annular
ridge
s and the outlet annular ridge the diaphragm sealingly engages the outlet
annular
ridge.
In the following, the invention more detailedly is described with
reference to the drawings.
CA 02238118 2004-11-17
Brief Description of the Drawings
'FIG. 1 is a general side view of an embodiment of the assembled components
for
an infusion set;
FIG. 2 is a side view of an embodiment of a differential pressure valve with
air
s relief lines; .
F1G. 3 is a central axial cross-section of the differential pressure valve of
FIG. 2;
FIG. 4 is a side view of an alternative embodiment of a differential pressure
valve
without air relief lines;
FIG. 5 is a central axial cross-section of the differential pressure valve of
FIG. 4;
io FIG. 6 is a central axial cross-section of another embodiment of a
differential
pressure valve that has a side view similar to that of FIG. 4;
FIG. 6a is a central axial cross-section of a component of the differential
pressure
valve of FIG. 6;
FIG. 6b is a plan view of the differential pressure valve component of FIG.
6a;
is FIG. 7a is a central axial cross-section of a second component of the
differential
pressure valve of FIG. 6;
FIG. 7b is a plan view of the differential pressure valve component of FIG.
7a;
FIG. 8 is a central axial cross-section of another embodiment of the
differential
pressure valve that has a different first component than FIG. 6;
2o FIG. 8a is partially broken-out central axial cross-section of a first
component of
the differential pressure valve of FIG. 8;
FIG. 8b is a plan view of the differential pressure valve component of FIG.
8a;
FIG. 9 is a central axial cross-section of yet another embodiment of the
differential
pressure valve that has another first component than FIG. 6;
2s FIG. 9a is a central axial cross-section of a first component of the
differential
pressure valve of FIG. 9 before insertion of the injection site;
FIG. 9b is a plan view of the differential pressure valve component of FIG.
9a;
F1G. 9c is a central axial cross-section of the differential pressure valve
component
of FIG. 9;
3o FIG. 10 is a magnified partially broken out central axial cross-section of
the
embodiment of the differential pressure valve of FIGS. 8-9;
FiG. 11 is a cross-sectional view of the differential pressure valve in its
embodiment as a 3-way check valve;
FIG. 12 is a bottom view of the valve of FIG. 11; and
35 FIG. 13 is an embodiment of the valve in its actual size.
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~i
Detailed Description of the Drawings and Preferred Embodiment of the
Invention
In the drawings, the further constituents of the infusion set, namely, the
container for the liquid medicines, the lines, the drip chamber, the roller
clamp
s and so on are shown with reference to lJS P~~ttrnt ~~,035,100.
Thr.differential
pressure valve of Figures 11, ~ 2, and 1 ~ forms the core: of th~present
invention.
Figures 1-10 are provided for background purposes to assist in the
understanding of the contents of this document and is not meant to be taken
or construed as prior art.
1o As shown in (=IG. 1, a first contair'rer 1 is used for a cho~~en liquid
medicine
which can be different from the liquid medicine icr a second container :? or
which
can be the same. The liquid medicir7e is introduced by piercing me,~rns such
as
spikes 1a or 2a, respectively, that are for example frrarr~ an ampulla. The
first
container 1 is connected to a first feed line 3 and the second container 2 is
15 connected to a feed line 4 and both feed lines are c.onnecte~J to a valve 5
consisting of a differential pressure valve 5a more dctaifedly described
below.
The fluid medicine communicates with a drip oh~rnbLr i~ via valve :~ and
associated fine and is under the cor~tro! of a roller clamp T that in turn is
fed to
the front end 8 of the infusion set from where as usual it is introduced into
the
body of a patient.
One embodiment of a pressure differential valve is shown in FIGS. 2-3
and another embodiment, with similar features denoted by identical numerals,
is
shown in FIGS. 4-5. The liquid medicine is directed via the differential
pressure
valve 5 from the suspended containers 1 or 2 into the drip chamber 6. A feed
fine
25 3 of the first container 1 and a feed line 4 of the second container a?
leads to the
differential pressure valve 5. Both feed lines 3 and 4 open into respective
differential force chambers 18 and '14 which are sealingly separated from each
other by the diaphragm disk 15. Both differential farce chambers 15 and 14 are
connected to a drain line 16 for the liquid medicine.
With reference to FIGS. 2-5, the differential pressure valve comprises two
valve housing halves 9 and 10 which are adapted to sealingly contact each
other,
and after the mounting of the diaphragm disk 15 therein, the valve housing
CA 02238118 2003-05-02
~i
halves 9 and 10 are sealed together thereby clamping securely diaphragm disk
15 therebetween. tine of the valve housing halves, either half 9 or half 10,
includes a drain line entry 11 for connection to an ~rppropriate drain line
16, and
each valve housing half 9 and 10 al sa ir~rciudr;s a feed line entry 'I 2.
Valve
> housing halves 9 sand 10 when assembled together with diaphragrm disk 15
provide differential force chambers 13 and 14, respectively, within the valve.
Annular ridge 18 of housing half 9 may, depending upon operating conditions as
discussed below, establish a seal with diaphragm disk 15 that demarcates
differential force chamber 13 into a circular ctuarnber 13a and annular
chamber
l0 13b. Similarly, annular ridge 19 of housing half '10 rnay, again depending
upon
the operating conditions more fully explained below, establish a seal with
diaphragm disk 15 that demarcates differential force chamber 14 into a
circular
chamber 14a and annular chamber 14b. Accordingly, the respective annular
ridges 18, 19 may also be termed lip-shaped sealing rings 18, 19. Annular
ridge
rs 18 has a larger diameter than annular ridge 19.
Diaphragm disk 15 includes a perimeter portion 15a positioned at opening
20 that leads to the drain line 16. In this ~tmbodimer~~t, diaphragm disk 15
is
circular and produced from a sheet of liquid silic:onE,, L~ilisor~e rubk~er,
or natural
rubber or from a mat of liquid silicone, silicone rubber ar natural rv.rbber,
and thus
zo portion 15a is a part of the circumference of diaphragm disk 15. Further,
opening
20 is in direct fluid communication with annular chamber 13b and annular
chamber 14b irrespective of wt~etr~er diapt~ragr~~ disk '15 is sealed against
annular
ridges 18, 10. Also, in direct fluid c;orrrmunication witk~ circular chambers
? 3a, 14a
are fluid channels 1 i'. In this embodiroe:nt, fluid char~nc,ls 17 open
coaxially to the
2s respective circular chambers 13a, 14a ~:rnd ~rr~nuiar r°idc~es 18,
19, and provide a
fluid path that is at an angled shape, such as a X30° below.
In an alternative embodiment shown in FIG. ;3, air relief lines 21 and 22,
respectively, are connected to the fluid channels 1 ~, wherein alternatively
such
air relief lines can be dispensed with in view of other v~reil-kno~fvn steps
for air
~o relief (see FIG. 5). In ouch of ttve ~rir relief lir~e:~;~ 21 anci 22,
respectively, there is
inserted a hydrophobic filter diaphragm 23 whichr, ono the one hand, is air-
permeable but, on the other hand, is not permeable far liquids. The
hydrophobic
filter diaphragm may be a hydrophobic membrane ranging from O.i~2 to 0.8
micron pore size.
CA 02238118 2003-05-02
F~
The diaphragm disk 15 is preferably circular, and stamped or die cut from
a sheet or band of liquid silicone, silicone rubber, or natural rubber. 'The
thickness of the diaphragm is preferably uniform and may vary, dependent on
the
desired pressure differential between chamber°s, from 0.2 to 0.5 mm.
The
a thickness tolerance varies loy the rrr~rrouf~,,cturing rnc:thod of thc:
:>iveet or gnat of
the diaphragm material. The; pref<:erred erTObodirnent oor~sists of silicone
rut~ber
and has a diameter of about ~ 3.5 mm, a thickness of about 0.3 rrum, and a
hardness of 40 degrees Shore A.
Further, the annular ridges 18, 10 or lip shaped sealing rinds, are
to preferably about 60° in cross-section and each ridge is integral
with the
respective housing half. The ratio of th a diametric apc;x for the sealing
ridge of
ring 18 to the diametric apex for the sealing ridge or ring 19 is preferably
chosen
to be a ratio of about three to one. In this embodiment, it is thus believed
that the
hydrostatic pressure on the side of the diaphragm disk with the iar-ger
diametric
rs apex for the seating ridge must be less 'than orre-third of the hydrostatic
pressure
of the fluid source associated wittn the sealing ridge with the smaller
diametric
apex before the diaphragm moves to open the side that engages the seating
ridgE: with the smaller c~iamctric apex, and thus permit liquid to be
transported to
the patient from another fluid source ;:~>sociated wikh tl~e: smaller
diametric apex
2o sealing ridge.
Operation of the. embodim~;nfis of the prc;ssure differential ~~~alve is as
follows. The fluid flow starts from the first container because of th:: higher
fluid
pressure and a larger differential force area of the ffirst container
°1 fluid via
circular chamber 13a in front of the diaphragm disk 15 (see e.g., ~=ICS. 3 and
5)
2s while the liquid flow from the second container 2 remains stopped because
the
larger differential force area prevents the flow of the liquid medicine from
the
second container 2. As soon as the liquid level of the first container and
associated feed fine decreases to a point where: they are almost empty, the
liquid
pressure decreases such that the iarger° differerY tial pressure area
on the side of
3o the diaphragm disk 15 corresponding to circular clr~rr~~bor 13a fall,;
below the
opening force created by the high fluid column of the: second container 2
fluid via
circular chamber 14a, whereby automatically ii~uid medicine floe is ;>witched
over from the first Container 1 to the second container 2,
Accordingly, the use of the above-described infusion set embodiment may
CA 02238118 2003-05-02
occur for example when using consecutively two infusion solutions to be
administered to a patient. Under such use conditions, and during the liquid
flow
from the first container 1, the liquid flow rnay suck air from the area of the
second
container 2, which possibly has to be vented. Thereafter the roller clamp 'l7
may
be adjusted to tire desirr::d drippinr~ rate, and t:hc~ first container is
emptied
whereafter the switch over to the second r;ont;~ir~er cyccurs rautomatically.
r-~t the
time of tf~e automatic switch over and thereafter during the fluid flaw
operation,
there is an overpressure of the fluid flow from the second containE:r 2, and
the
diaphragm disk 15 is pressed onto tire ~,~nr~ular ridc~c;~ 1 t3 and also
i:lifted from the
ro annular ridge 19 such that the liquid medicine can drain from the second
container 2 to the patient.
An alternative embodiment is Shawn in FIGS. 6-7b, in whici~ like reference
numerals indicate like parts and features as the above figures. Primary
hauling
half 60 and secondary housing half 30 are sealingly engaged. t_.iker the other
is embodiments, one housing oatf includes annul4or ridgo 1t3 provider with a
sealing
lip apex 18a and the otf7er housinc! h<~lf is provided l~with annular ricage 1
J that
includes sealing lip apex 1 Ja. Secondary housing 30 (see F=IGS. Vila-6b) is
provided with inlet '( 7a, about whiclo is located annular ridge 1 S.
Secondary
housing 30 includes a compression ring 32 that projects from the ~:,econdary
zo housing 30 body arid has a c:~iameter greater thr.~rl annular ridge 1 ~3.
C:ompression
ring 32 is provided with compression ring passage 3~, that in conjr.rnction
with
valve space passage 6d~ (discussed below) allows for fluid oorr~murllGation
between annular chambers 13b and 14b in the assembly of the housing halves
30, 60. Secondary housing 30 is furthor~ provided with first sealing ring
projection
2s 36 that has a diameter greater 'than that of the conipressian ring 32 and
allows
for sealing engagement of the housing ftalves. aecandary f"nousing 3U may also
have a secondary sealing ring 38 tfoat may provide <:rn alternative sealing
engagement member for the assembly.
Primary housing half ~i0 (sec:7 F=IGS. 7a-7b) is provided with inlet 17b about
3u which is located annular ridge 10, that in turn includes sealing lip apex
19a.
Outside of annular ridge 19 is located opening ~:(9 that is in fluid
cc>mrnunication
with drain line 16 (see FIGS. 7a-7b~. encircling annular ridge 19 and opening
20
is ring shaped seat 62 that is discontinuous and provided with a valve; space
passage 64, Ring shaped seafi 62 is adapted to clamp diaphragm disk 15
CA 02238118 2003-05-02
.3
between ring shaped seat 62 and compression ring 32 when the housing halves
are assembled (see FIG. 6). Encircling ring si,raped seat 62 is sealing ring
projection 66 which is continuous r:~nd adapted to er~rgage first sealinca
ring
projection 36 of the secondary housing when the housing halves are assembled.
a Intermediate sealing rirvg projection 66 and ring shaped seat Ei2 is
secondarry
scaling ring G8 that is of sufficit:nt ~~eight to allow for the fluid
cornrT~unication
between compression ring passage 34 and valve space passage ci4 when the
housing halves are assembled. The aforementioned combination of the valve
space passage G4 overlying comprcasicrn ring I,:aass.:agc 3~f providcas a
bypass
~o channel 70 in the assembled housing halves ~soe FIG, G). This bypass
channel
70 is generally radial in canfiguratior~~ in this ~rn~~odimont, and t~~e
overlying radial
passages 34 and 64 are assured in the assembly by way of orienting the
respective feed line entry 12 ~>ass<:~gcin a parallel condition.
!n the assembly of the housing halves, the housing halves ure sealed
is together at the interface between the first sealir~~g ring projection ~b
and sealing
ring projection 66, which in turn clc$mps the diaphragm 15 between ring shaped
seat 62 and compression ring 32. Such joinder rtlay be executed 'ay means of
ultrasonic welding or use of medically af>proved adt°resives (e.g.,
uftraviolc;t curing
adhesives), or a combination thereof. '1"he presently preferred sealing means
2o employs ultrasonic welding. The cl5~mped interfKacc~ bc;tween the disk 15,
ring
shaped seat 62 and compression ring 32 may also be executed by means of
ultrasonic welding or use of medically approved adf°~esives.
An alternative secondary housing halt 40 is shown in FIGS. 8a-8b, that in
turn may be assembled with primary housing half 6t:). ~T~his assembly is shown
in
2s FIG. 8. Referring now in more detail to these drawings, in which like
referc;nce
numerals indicate like; parts and features throuc~houk the several c~f the
above-
discussed views, secondary housing 40 (~>eo FIGS. 8a-8b) is genr~rally
provided
with a threaded connection 41 for connecting trrepausing halt 40 to an
appropriate liquid medicine feedline. With thi:7 cJesign, there is thu:~ tine
possibility
;o to connect the housing half by r7~ear~s of a nualc luer-lack connection or
other
medically accepted thrc;aded conneect'ion.
Further, alternative secondary housing 40 includes a compression ring 42
that projects from the housing 40 that is a diameter greater than annular
ridge
18. Secondary housing 40 is fiurth~er provided with sealing ring projection
46, of a
CA 02238118 2003-05-02
c~
diameter greater than compression ring 42. that permits sealing engagement
between housing halves, and secondary sealing ring 48 may provide an
alternative sealing engagement for the assembly. Compression ring passage 44,
in this embodiment, is generally radial and allotws for fluid communication
s between the annular cl°ramber 13b and anm,rlar° r;h~~nr~el 80
provic9ed in
secandory housinr~ 40. Thus, in this embodiment of the secondary I~ausinc~,
when
assembled with primary housing 6J, f~iuid comrr~uni~ation betweer; secondary
housing inlet 17a and cutlet openir7g 20 is permitted at an appropriate
pressure
differential between chambers 13 and 14 via flr..lid passage over sealing lip
~ 8a,
ro and through annular chamber 13b, compression ring passage: 44, annular
channel 80, valve space passage 64 and annular chamber 14b (~~ee FIG. 10). Of'
note for this embodiment is that a bypass channel generally denoted 82 formed
by the assembly does not require that passages 64, 4~ overlie one anoti~er due
to the provision of annular channel 80. Accordingly, annular channel 80
permits
is greater tolerances in angular orientation of secondary housing 40 with
respect to
primary housing 60, arid thus this design may k~e rnorc suitable for automatic
assembly. For this rea;>on, amoang others, bypass c~oaonel 82, including
annular
channel 80, may be preferably utilized ins the above-described secxondary
pausing
30, as well as 40, and p0 to which discussion i:~ no4v directed.
?o Another alternative embodirner~t of a difl~erer7tial pressure valve is
shown
in FIGS. 9-9c. Referring now irl more dr-aail to ti~esc drawings, in uvhi~ch
like
reference numerals indicate like p~~rts and feat~.ares throughnout thr::
s~:veral
above-discussed VIeWc, there is provided an assembbly that is a differential
pressure valve that incorporates an alternative: secondary housing 50.
Alternative
2s secondary housing 50 is provided 4vitt~ a plurality of iroc~t passages 1
~lc that are in
fluid communication with injection site ;~8. In t~~R.. pre,:ferred embodiment,
the
injection site 58 is secured by annular shouldrer 52 and annular rirn 5~. to
its
embodiment, injection site 58 consists of natural rubber of 60° Shore.A
hardness which is secured in alternative secondary housing 50 by friction
rolling
~o or ultrasonics. Rim 54 is formed by either such r~r~e~~ns due to tire
raised
temperature in combination with the axial corr~pression inherent with these
means (see FIG. 9a). In other respects, alternative secondary housing 50 is
constructed and assembled like the embodiments immediately described above
(see FIG. 10). As can be readily a~preaiated, tire alternative embodiment of
the
CA 02238118 2003-05-02
7. l'~
differential pressure. valve permits the ir~jectiorr of one car more liquids
via a
hypodermic needle or the like introduced through the injection site 58. By way
of
the appropriate pressure differential fror~n the hypodermic needle fluid,
liquid
medicine from the needle or the Like may be introduced into the fluid flow.
in the embodiments of the differential pressure valves, the valve housings
may be r»anufactured of polymeric; rr~~;,~t~;rials th_~t pare c3~:ne:rally
mc;dic:ally
accepted, e.g. polystyrenes, styrenic copolymers (A.B.S.) or polycarbonates.
In
particular, the preferred material is a styrenic c:c~poly~mer (A"B.S.)
manufactured
by BASF Corporation, and sold under the trademark name of Terlux KR2802.
ro In one embodiment far the c:aii~ferential pr..asure: valve differential
force
chambers 13, 14, including circular ~.har~lbers 13a, '14a and annular chambers
13b, 14b, are as follows. With respect to the prirrrary housing 60 (~fCS. 7a-
t'b),
housing inlet 17b is about 2.0 mm and openirng 20 for drainline 16 has a
diameter
of about 2.0 mm. Sealing lip apex 19a which engages diaphragm disk 15 when
is the differential pressure in circular chan'aber'in 'i4a is insufficient,
has a diameter
of about 3.0 mm. In radial dimensions (see FfC~. 7b), ring shaped seat 62 has
a
beginning diameter of about 12.0 mm arid terminat~a at a diameter of about
13.G
rnm, at which point it rises axially to the secondary :>e<~ling ring 68 and
this
surface extends to a diameter of about 16.0 mm. At the termination of
secondary
~o sealing ring 08, sealing ring projection 86 axially ris~.~s and corntinuea
from about
16.0 to a diameter of about 18.0 mm. In axial cross"sectional dirro:nsions,
and
with reference to a datum from the sealing ring pr~j~:ction 66 planE(i.e., the
left
most edge of the housing half depicted ire Ff~~. 7a), the secondary sealing
ring 68
plane is about 0.68 mm from the sealing ring projection 66. Further, and with
2s respect to this datum, ring shaped seat 02 is about '7.84 mm from thE:
sealing ring
projection 66, and further, the member that forms the annular chamber 14b is
about 2.40 mm from this datum. Annular ridge 'l9 in cross-section is about
60° and sealing lip apex 19a is Gc~~ated about 1.54 rnrn from the datum
of
the sealing ring projection 60 plane.
~o The secondary housing half is configcrrr:d as follows, with particular
reference to the features forming circular chamber 13a and annular chamber 13b
of the pressure ~ififsrential v~lv~ ~se~ ~'ICaS, 6~p 6b, ~~r 8b, 9~-9c, 10),
Inlet 17~
is about 2.0 mm in diameter, and sealing lip apc;x 18a has a diameter of about
9.0 mm. Compression ring 32 has an inner diameter of about 12.0 mm and an
CA 02238118 2003-05-02
1I
outer diameter of about 13.6 mrn. Secondary sealing ring 38 has an outside
diameter of about 16.0 mm and inside diameter of about 15.0 mm, and first
sealing ring projection 36 has an outside diameter of about 18.0 mm. In axial
dimensions, and with reference to the datum of t:he leading edge of
compression
s ring 32 (the rightmost edge as viewed in FIGS. 8a, 8a and the uppermost edge
as
viewed in FIGS. Oa, 9c), the sealinc; lip apex 18a 'is at about the carne
plane as
compression ring 32 plane, and apex 18a has an angular crass-section of about
OO° The plane of the secondary sealing ring 38 is about 0.8f:> mm from
the
datum of the compression ring 32, as is the floor of the circular chamber 13a.
The
ro plane of the first sealing ring projection 3G is abr~ut 1.54 mm from the
datum of
the plane of the compression ring 3L, as is the plane of annular passage 8th.
Further, the compression ring passage 34 and valve space passage: 64 may
overlie one another and are of about ~?.0 mm ire ~,vidth (see FIGS. Eab, 8b,
9b). As
noted above, however, for configurations that include annular channel 80,
rs passages 34, 64 need riot overlie each other.
As especially can be seen in Figure 11, the preferred valve 1' has two
inlets 2' and 3', which each are opera to a diffc;rerrtial pressure charr7ber
4' or 5',
respectively. The two differential pressure chambers 4' and 5' are sealingly
separated from each otr~er by a diaphragm disk 0. Both differential pressure
zo chamber 4' and 5' together are in cornrnunication with an exit line 7' for
the liquid
medicine, wherein the exit line 7' is usually connected to the line leading to
the
drip chamber, while the first it°rlet is usually connc;cted to the
flask or container of
the liquid medicine by means of a suitable line.
As shown in FIGS. 11 ~13, the exit line 7' has a male "~unr-Lock"-connector
zs 9' and the second inlet 3' has a female "Luer-~l_ook"-connector 10, wherein
the
sizes are chosen such that by means of the slight to frering of the second
inlet 3',
the front end of a typical syringe care b~; received in a form-fit manner.
The housing of the differential pressure valve 1' is made of r~ro valve ,
housing halves 11' and 12', which are sealingly connectable with each other.
The
~o valve housing half 11' contains the first inlet 2' Kand the second valve
housing half
12' contains the second inlet 3' and the exit lire '~P"'. Tt°re valve
housing f~alf 11' has
an annular ridge 15' within the differential force chamber 4', the ridge 15'
being
concentric to a liquid inlet 13'. The salve housing half 12' has an annular
ridge 16'
within the differential force chamber 5', concentric to a liquid outlet 14'.
CA 02238118 2003-05-02
The sizes of ridges 16' and 15' are such that the annular ridge 15' has. a
larger
diameter, and is associated with the first inlet 2', which is connected to the
container for the liquid medicine. The annular ridge 1 G°, having a
smaller
diameter, is associated with the exit line 7' leading to the drip charr~ber.
s The diaphragm disk 6' is positioned between the two housing halves 11'
and 12' with a part 17' of its c;iroumierence lying at are opening 1 B"
Ic:ading to the
second inlet ~'. The liquid outlet 14° of the exit lir~c; ~7' has an
ar~c~ular shape and is
coaxial to the annular ridge 1G' as shown in FI~. 11. The liquid inlet 13' of
the
inlet 2' is coaxial to the annular r idge 1 ~', which is also coaxial to the
inlet 2'.
to The circular diaphragm disk d° is manufao ured from a sheet of
liquid
silicone, silicone or natural rubber c>r a strip of silicone, liquid silicone,
silicone or
natural rubber.
The operation of the 3-way check valve 8° is such that during a
normal
infusion, the infusion liquid is guided from the ir~ltft ~', to the outlet
line 7'. If liquid
medicine is drawn from the container of the liquid medicine by means of a
syringe at the inlet 3', the diaphragm 6' is pressed against the annular ridge
1 G'
because of the vacuum created on floe k~ottom side, ~vl~ich means i.hat liquid
is
not drawn from the line 7' leading tea the patient. If, on the other hand,
additional
liquid or possibly a different medicine is injected at the second inlet 3',
then
2o because of the correspondingly created pressure:, the diaphragm disk 6' is
pressed against the upper annular ridge 15", which means that tfie additional
liquid is guided exclusively via the exit line 7' from the second inlet 3' to
the
patient, and cannot reach the line leading back to the container connected to
the
first inlet 2'.
25 The preferred ernbodimerrt of the invention thus provides an extremely
compact 3-way check valve which consists merely of three parts, namely, the
first
valve housing half 11', the second valve housing half 12', and the diaphragm
G'
positioned therebetween.
The features disclosed in Figures 1-10 and discussed abovE; has been
_>o patented in US patent 5,935,100.
CA 02238118 2003-05-02
! .~3
It is of note that the above-dc;scribed pressure differential valve has
numerous advantages. The disclosed valve is of simple construction, yet
provides a reliable valve for operating pressures to which it is suited. It is
believed that with the construction of this pressure differential valvE.~ as
disclosed,
a the tension in the diaphragm disk can be accurately predetermined and
provide
automatic switching between fluid sources at pre:det~,rmined hydrostatic
pressures. In this manner, the present invention avoids complicated designs
and
yet may result in reliably achieving the above-noted l,aressure differential
valve
functionality. Further, the design of the above-described embodiments avoids
io complicated assembly methods by way of limiting the number of highly
toleranced dimensions or risen°~bly rne;thods an~:~ the like and thus
they lend
themselves to assemblage by automated equipment.
While the above embodiments of the irwentior~s have been disclosed, they
are not limited to the disclosed examples. Modifications discussed above, as
welt
rs as in addition to those discussed, can be made without departing from the
inventions. The scope of the invention is indicat~act in the appended claims,
and
all changes that come within the meaning and range of equivalency of the
claims
are therefore intended to be embra~:.ed therein. °~i hus, while the
inventions have
been described with reference to particular embodiments, modification of
~o structure, material and the like will be apparent to tflc~s~: skilled ire
the art, yet still
fall within the scope of the invention.
All features, details and advantages of the invention, which can be learned
from the specification, the claims, arrd thr-a drawings, including
constructive details
and positions in space, can be important far the invention each singularly as
well
~s as in random combination.
