U.S. patent number 3,902,489 [Application Number 05/372,848] was granted by the patent office on 1975-09-02 for couplings.
This patent grant is currently assigned to Avon Medicals Limited. Invention is credited to Douglas Vaughan Carter.
United States Patent |
3,902,489 |
Carter |
September 2, 1975 |
Couplings
Abstract
A coupling, particularly for blood-processing sets, is shown
which permits the assembly of a "kit of parts" of such a set by a
user not under special conditions of sterility. This is achieved by
terminating the items of the kit e.g. bags and tubes in frangible
diaphragms and joining the items by means of a solvent for the
material of the diaphragms so that they are unified together. They
may then be ruptured to open up a fluid path through the items.
Sleeves surrounding the diaphragms are preferably also unified
together by the same solvent. By the formation of such a solid
layer of the material of the diaphragms between them and uniting
them, ingress of contaminants from the previously exposed faces of
the diaphragms when the diaphragms are ruptured is hindered or
prevented.
Inventors: |
Carter; Douglas Vaughan (Great
Malvern, EN) |
Assignee: |
Avon Medicals Limited
(Melksham, EN)
|
Family
ID: |
10292917 |
Appl.
No.: |
05/372,848 |
Filed: |
June 22, 1973 |
Foreign Application Priority Data
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|
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Jun 23, 1972 [GB] |
|
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29524/72 |
|
Current U.S.
Class: |
604/411; 285/3;
222/83; 604/905 |
Current CPC
Class: |
A61M
39/14 (20130101); A61M 39/221 (20130101); A61J
1/10 (20130101); A61J 1/1475 (20130101); Y10S
604/905 (20130101) |
Current International
Class: |
A61M
39/14 (20060101); A61M 39/22 (20060101); A61M
39/00 (20060101); A61J 1/05 (20060101); A61m
005/00 () |
Field of
Search: |
;128/214R,214C,214D,214.2,215,272 ;285/3 ;137/68 ;141/329,330
;222/80-83 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
1,300,635 |
|
Aug 1969 |
|
DT |
|
1,528,025 |
|
Apr 1968 |
|
FR |
|
Primary Examiner: Truluck; Dalton L.
Claims
What I claim is:
1. Equipment for the handling of fluid which comprises at least two
bags connected together by at least one tube, a coupling between
the tube and at least one of the bags including diaphragms unified
by a solvent for the material of the diaphragms, the diaphragms
respectively forming a barrier to access to the tubes and to the at
least one of the bags, and means inside the coupling for
penetrating the diaphragms when sealed together to open up a fluid
path from the at least one bag to the tube.
2. Equipment as claimed in claim 1 wherein the coupling includes
male and female sleeves surrounding the respective diaphragms and
forming a push-fit together, the coupling parts being unified over
substantially the whole of the interacting surfaces of the sleeves
and the diaphragm by a resolidified region of their respective
materials.
3. Equipment as claimed in claim 2 wherein the diaphragms and
sleeves are all made of polyvinyl chloride.
4. Equipment as claimed in claim 2 wherein the said coupling
includes an axially compressible bellows intermediate at least one
tube and the diaphragms and the said means inside the coupling
includes a needle mounted within the bellows with one end presented
towards the diaphragm and one anchored to the end of the bellows
remote from the diaphragm, whereby axial compression of the bellows
can drive the needle through the diaphragm.
5. Equipment as claimed in claim 4 wherein all of the said sleeves,
diaphragms and bellows are made of polyvinyl chloride.
6. A modular coupled equipment system comprising a plurality of
items of medical or research equipment sealingly attached together
in temporarily nonintercommunicating manner, and adapted to be made
intercommunicating for use, comprising a plurality of
coupled-together sets of individual coupling elements and
respective items of equipment, each set comprising a coupling
element and an item of equipment attached thereto, each coupling
element comprising a housing, and a coupling passage extending
through the housing and open at each end, the coupling element
being attached to the item of equipment so that one open end of the
coupling passage communicates with the item of equipment; a
penetrable diaphragm disposed across the coupling passage and
sealing off the passage from flow therethrough until penetrated;
the housing of each coupling element at the other open end of the
passage being shaped to sealingly interconnect with the coupling
element of another set to which it is sealingly attached, the
coupling passages of interconnected coupling elements being aligned
to form an intercommunicating through passage extending to each
item of equipment closed off by the diaphragm in the coupling
passages; the diaphragms of adjacent coupling elements being in
abutting relation and united by an intermediate layer of
interdiffused diaphragm material, and disposed in at least one of
each two adjacent coupling elements at least one internal means for
each pair of diaphragms for penetration through the diaphragms
thereof to provide intercommunication between the coupled items of
equipment via the passage.
7. A modular coupled equipment system according to claim 6 wherein
the interconnected coupling components comprise interconnected male
and female sleeves surrounding the respective diaphragms and
forming a push-fit together, the coupling components being united
over substantially the whole of the abutting surfaces of the
sleeves and the diaphragms by interdiffusion of diaphragm
material.
8. A modular coupled equipment system according to claim 6 wherein
the diaphragms and the sleeves are all made of plastic
material.
9. A modular coupled equipment system according to claim 8 wherein
the plastic material is polyvinyl chloride.
10. A modular coupled equipment system according to claim 6 wherein
the diaphragms are made of plastic material.
11. A modular coupled equipment system according to claim 6 wherein
the said internal means includes an axially compressible bellows, a
needle mounted within the bellows with one end presented towards
the diaphragm and one anchored to the end of the bellows remote
from the diaphragm, whereby axial compression of the bellows can
drive the needle through the diaphragm.
12. A modular coupled equipment system according to claim 11
wherein all of the said sleeves, diaphragms and bellows are made of
polyvinyl chloride.
13. A modular coupled equipment system according to claim 11
wherein the needle is hollow and has fluid ports opening to its
outside near the end presented towards the diaphragm.
14. Coupling elements for a coupling according to claim 6.
15. Method of coupling together respective coupling elements on
respective items of equipment to be coupled together, each coupling
element having a penetratable diaphragm preventing access to the
interior of the item from the outside, and at least one of the
elements having internal means for penetrating through the
diaphragms, which comprises applying a solvent to the exposed faces
of the diaphragms to form a solution of their material at the said
faces and bringing the said faces into face-to-face contact whereby
to unify the diaphragms by a layer of their material.
16. Method according to claim 15 wherein the said material is
polyvinyl chloride and the solvent is cyclohexanone.
Description
FIELD OF THE INVENTION
This invention relates to couplings used in the medical and
research contexts.
BACKGROUND OF THE INVENTION
In these uses, couplings have to be made between elements such as
bags and tubes to establish a fluid flow path of a particular
character, without however exposing the interior of the coupling or
the other elements or the fluid to harm, e.g. by infection by
harmful microorganisms, or by other entrapped contamination such as
chemical contaminants.
A particular area in which the problem presents great difficulties
is that of blood transfusion and in particular in the handling and
the fractionation of blood once it has been received from the
donor.
For this fractionation, the blood is treated by various methods
most of which include centrifuging and freezing in an array of
three or even more bags linked to each other by closable tubes. A
first separation is done in the first bag and one of the fractions
is pressed from that bag into a second where a further operation is
carried out and then a fraction from the second bag is returned
either to the first or to a third bag and so on.
The interior of all these bags and of the tubes linking them have
to be absolutely sterile. These bag sets have always been
pre-assembled, the whole of the pre-assembly being done under
sterile conditions in the factory and the whole of the assembly
being sent out as a sealed unit to where it is to be used. The bags
containing the various fractions can only be separated by once for
all destruction of the assembly, which is usually carried out by a
heat sealing of the tube.
This system has obvious disadvantages namely that a large number of
different types and sizes of bag sets have to be assembled in the
factory and cannot thereafter be altered. Also the user has to hold
a large stock of different sorts of bag sets according to all the
sorts of operations he may want to perform. Attempts have therefore
been made to provide a kit wherein there would be provided sterile
closed bags preferably only of one or two sizes and tubes
preferably only of a few lengths, any of which may be joined
together by the user in any desired combination. The difficulty
with such a system is the need for sterility in the couplings and
it is to this problem that we direct our attention.
In one proposal for dealing with this difficulty in German
Auslegeschrift No. 1300635 it is proposed to have both the male and
the female parts of the coupling closed by a diaphragm so that the
interior of the bag or the tube as the case may be is kept sterile,
the two parts of the coupling being forced together in a bath of
disinfectant. An internal tube is then used to pierce the
diaphragms, which in the assembled state of the coupling lie face
to face, and establish a fluid path through the coupling. The
coupling remains assembled only because of the tight fit together
of the parts -- there is nothing additional holding it together.
The coupling is assembled in a disinfectant bath because if
microorganisms are trapped between the parts of the coupling and in
particular between the diaphragms they may pass into the fluid
stream or may even be driven into it by the needle when that pushes
through the diaphragms. Clearly it is not desirable that one should
have to do the actions of forming the coupling under the surface of
a bath.
SUMMARY OF THE INVENTION
In the present invention we provide a coupling for medical or
research equipment, for example blood transfusion processing
apparatus, wherein elements coupled together are sealed off by
penetratable diaphragms one diaphragm being associated with each
part of the coupling, the two diaphragms being unified together
face to face by a solvent for the material of the diaphragms, and
an internal means within the coupling for penetrating through the
diaphragms when unified together. We find that as a result (1)
micro-organisms on the respective outer faces of the diaphragms are
frequently rendered non-viable by the effect of the solvent (2)
that any living micro-organisms which may survive this treatment,
or any other harmful contaminants, are in effect locked into the
solid solution of diaphragm material which is formed between the
diaphragms when they are unified by the solvent, and (3) we provide
a positive means (other than a mere push fit) for holding the
coupling assembled viz the unification together of the material of
the diaphragms. Suitably the coupling includes male and female
sleeves surrounding the diaphragm and forming a push-fit together,
and the solvent for the material of the diaphragms is also a
solvent for the sleeve parts and is applied between them whereby
the coupling parts are unified over substantially the whole of the
interacting surfaces of the sleeves and the diaphragms.
In another aspect of the invention we provide equipment for the
handling of fluid which consists of at least two bags connected
together by at least one tube, a coupling between the tube and at
least one of the bags including diaphragms unified by a solvent for
the material of the diaphragms, the diaphragms respectively forming
a barrier to access to the tubes and to the at least one of the
bags, and means inside the coupling for penetrating the diaphragms
when sealed together to open up a fluid path from the at least one
bag to the tube.
It is an advantage of the coupling and of the system that it can be
used not only for assembly by the user of a set of bags to suit his
own requirements without having to work under the surface of a bath
of disinfectant but can also be used within the factory for sending
out pre-assembled bag sets to those who want them, without the need
for setting up in the factory a completely sterile zone for the
assembly.
In the accompanying drawings:
FIG. 1 illustrates schematically a prior art arrangement of bag
set,
FIG. 2 illustrates schematically a bag set embodying the present
invention,
FIG. 3 shows, a male element and FIG. 4 a female element of the
coupling embodying the invention, both in a diametrical
section,
FIG. 5 shows, in a larger scale the elements assembled and with
diaphragms unified together, and
FIG. 6 illustrates how a fluid path is opened through the unified
diaphragms.
In FIG. 1 of the drawing we show a prior art bag set consisting of
bags a, b and c, which are interlinked respectively by tubes 1 and
2 each having socket parts 3 on their ends fitting over plugs
extending from the bags a, b, and c. The sockets 3 may be glued
onto the plugs. Each of these tubes is open ended at each end as
are also the plugs of the bags so that sterility of the whole
assembly is achieved only by sterilisation of the component parts
and their assembly together into a sealed set all under sterile
conditions. It is obvious the set cannot be dis-assembled in any
way while maintaining sterility, except destructively (the method
usually used being sealing-off tubes 1 or 2 by heating them and
then cutting them beyond the seal).
In FIG. 2 we show elements of a bag set embodying the present
invention. The bags a', b' and c' each have at least two female
socket elements 5 embodying the invention incorporating as they do
each a diaphragm preventing access of micro-organisms to the
interior of the bags. They will be described in more detail later.
An inlet 6 to the first bag a' is shown wherein for example blood
from a donor may be first introduced into the bag set. This
connection may be one according to the invention or may be a
conventional one. Each of the bags has a plug 7 which may be one
element of a coupling according to the invention or may be a known
type of plug with a tear-off seal to allow access to the final
contents of the bag when they are to be used. These bags may be
sent out from the factory as they are in sterile and sealed
condition to the user. They may be all the same size as is shown
here or may be of a range of sizes which rationally should include
only two sizes and not more. Since the bags are totally sealed they
cannot be sterilised by ordinary heat treatment since they contain
air and may contain for example anti-coagulants, and they are
therefore sterilised by irradiation preferably by gamma rays. Also
making up part of the bag set are tubes such as 8 which have at
each end a male element 9 for the coupling embodying the invention.
Any of the male elements 9 will fit any of the female elements 5 on
any of the bags a' to c' and thus the user may assemble with the
bags and with the tubes he is given a set of bags which is uniquely
adapted to his own requirements. Each of the male elements 9, which
will be described in more detail later, contains a diaphragm
sealing off the interior of the tube to the outside atmosphere and
the tubes are sent out in internally sterile condition having been
sterilised by irradiation again preferably by irradiation with
gamma rays.
The assembly together of the male and female elements of the
coupling will now be described more particularly with reference to
FIGS. 3 to 6. FIG. 4 also shows how the female socket elements need
not necessarily be integral with bags but may form the end fitting
of a tube. It is equally possible that the male elements 9 may be
integral with the bags.
The female socket part 5 has a sleeve at 10 across which is formed
a diaphragm 11. The sleeve is integral with a fitting 12 for
receiving the end of a tube 8' as shown in FIG. 4 or the sleeve 10
may be moulded integrally with a bag. The male element 9 is sealed
off by a diaphragm 13 at the axially outer end of a sleeve 14 of
which the outer diameter is such that the sleeves 14 and 10 are a
tight push-fit together. A bellows construction 15 allows for
relative axial movement of the sleeve 14 and another sleeve 16 of
similar diameter at the other end of the bellows. This sleeve 16
constitutes a fitting in which the end of a tube such as 8 is
securely fixed. In it there is also positioned an annular collar 17
which is a base for a hollow needle 18 which extends axially from
that base within the sleeve 16 to within the sleeve 14 and presents
a sharp point 19 towards the diaphragm 13. When the bellows
construction is in its relaxed condition as shown in FIG. 3 the
needle point 19 is clear of the diaphragm 13. As best seen in FIG.
5 the needle 18 has a pair of ports 20 near its pointed end so
there may be fluid communication from that pointed end through the
hollow needle and the collar 17 into the tube 8.
Preferably all the parts mentioned including the needle are formed
of plastics material although the needle may of course be of metal.
A preferred material for the plastics is a polyvinyl chloride
material since this is cheap, readily workable and not difficult to
sterilise.
A solvent particularly suitable for use with polyvinyl chloride is
cyclohexanone since this has, incidentally, an appreciable
sterilizing effect of its own.
To assemble the coupling together all that the user has to do is to
coat the outer surface of one or preferably both diaphragms with an
ample coating of a solvent for the material of those diaphragms.
Obviously from the commercial point of view it would be desirable
to make both diaphragms of the same material so that the widest
range of solvents is available but obviously the diaphragms could
be of different materials, and then a common solvent or else a
solvent mixture would have to be used. The diaphragms are then
pressed together face to face and left until the joint has
solidifed. It would be preferable again that the material of the
diaphragms should be the same as that of the sleeves 10 and 14 and
then the same solvent may be also used between the touching
surfaces of the sleeves and a unified joint may be formed overall
to give mechanical strength to the seal. The layer 21 in FIG. 4
between the diaphragms is a solid layer of material common to each
diaphragm while layer 22 is made up of material common to the
sleeves 10 and 14. Any micro-organisms on the formerly exposed
outer surfaces of the diaphragms are locked into the solid joint
formed between the diaphragms by the layer 21 and when the needle
18 is pushed through the diaphragms so as to establish a fluid path
through the coupling there is a statistically negligible risk that
any viable micro-organisms will be introduced into that flow path.
The needle may remain penetrating the diaphragms so that the ports
20 remain beyond the diaphragms and fluid issues from them beyond
the diaphragms, or may be withdrawn again so that the hole that it
has pierced through the diaphragms is used for the passage of
fluid.
Obviously, the assembly step of the coupling need not be done under
sterile conditions, the only precaution necessary being that a
complete and adequate coating of solvent material is applied to the
faces of the diaphragms.
The reduction in the risk of infection resulting from the use of
this coupling and this bag system is particularly valuable when the
long term storage of blood or blood fractions is being
considered.
The internal penetrating elements may be attached to a bellows on
as female socket element rather on a male, as shown here, or may be
entirely loose within either element of the coupling (cf German
Auslegeschrift No. 1300635).
* * * * *