Abstrict In a blood bag system for plasma transfusion and cell return including
two or more blood bags containing anticoagulant and connected to
a puncture needle through two or more branch tubes and a common
main tube, a cell return port is connected to the branch and a breakable
flow path closure is inserted in one branch tube adjacent the branch.
When broken, the flow path closure allows fluid communication through
the branch tube. Blood is first collected in the first blood bag,
which bag is sealed when filled and separated from the system. Then,
the flow path closure is manually broken to permit blood collection
into the second blood bag.
Claims What we claim is:
1. An autoclave sterilized blood bag system, comprising:
a first blood bag having an inlet for blood collection and at least
one outlet for blood transfusion;
a second blood bag having an inlet for blood collection and at
least one outlet for blood transfusion;
first and second sections of tubing for blood transfer, each having
one end connected to the inlet of said first and second blood bags,
respectively;
a branch pipe including a straight pipe portion, and further including
one branch pipe portion and another branch pipe portion each extending
angularly from said straight pipe portion and each having an open
end;
a main tube having one end connected to one end of said straight
pipe portion of said branch pipe so as to communicate with said
other ends of said first and second sections of tubing in common
through said branch pipe;
a needle connected to the other end of said main tube for collecting
blood;
return means for returning a cell component of blood;
breakable flow path control means positioned in and enclosed by
the second section of tubing corresponding to said second blood
bag at a point near the branch pipe, said breakable flow path control
means blocking fluid communication through the corresponding second
section of tubing, but, when broken, allowing fluid communication
through said corresponding second section of tubing;
wherein said straight pipe portion has another end connected to
another end of said second section of tubing and extending straight
with respect to said main tube and said second section of tubing
to the second blood bag at junctions therebetween, the open end
of said one branch pipe portion being connected to the other end
of the first section of tubing to the first blood bag, and the open
end of said another other branch pipe portion being directly connected
to said return means; and
anticoagulant distributed throughout inner surfaces of the blood
bags, the first and second sections of tubing, the main tube, the
branch pipe, and the needle, which anticoagulant becomes wet during
an autoclave sterilization of the whole blood bag system carried
out before use.
2. The blood bag system of claim 1 wherein said breakable flow
path control means comprises an annular base portion disposed in
and sealed to said second section of tubing, and a plug member integrally
connected to an end of said base portion which is positioned on
the side of said second blood bag, said plug member blocking a flow
path through said base portion and having a roughened outer surface,
said plug member being breakable apart from said base portion to
open said flow path of said base portion.
3. The blood bag system of claim 2 wherein said roughened outer
surface of said plug member is embossed to provide said roughening.
4. The blood bag system of claim 2 wherein said roughened outer
surface of said plug member has slots therein, to thereby provide
said roughening.
5. The blood bag system of claim 2 wherein said roughened outer
surface of said plug member has ribs thereon, to thereby provide
said roughening.
6. The blood bag system of claim 2 wherein said base portion comprises
an annular sleeve, and said plug member comprises a conical plug
having a bottom portion connected to said sleeve.
7. The blood bag system of claim 2 wherein said base portion comprises
an annular sleeve, and said plug member comprises a flat tip portion.
8. The blood bag system of claim 2 wherein said return means comprises
a section of tubing closed with a plug which is puncturable by a
hypodermic needle.
9. The blood bag system of claim 1 wherein said needle comprises
shield means at the tip thereof for shielding said needle from the
outside.
10. The blood bag system of claim 9 wherein said needle comprises
a hub at a base portion thereof, and a protector engaged with said
hub in a fluid-type manner to enclose the needle therein.
11. The blood bag system of claim 1 wherein said first and second
blood bags each having an outlet for transfusion of a plasma component,
and another outlet for back transfusion of a cell component of blood.
12. The blood bag system of claim 1 wherein said tubing sections
are formed of a flexible polyvinyl chloride resin and wherein said
flow path control means is formed of a relatively rigid material
different from the material of said tubing sections.
13. The blood bag system of claim 12 wherein said relatively rigid
material of which said flow path control means is formed is selected
from the group consisting of rigid polyvinyl chloride and polycarbonate.
14. Method for carrying out a plasma transfusion by using the blood
bag system of claim 1 comprising the step of:
puncturing the collecting needle into the donor's vein;
collecting blood from the donor into the first blood bag through
the needle punctured into the donor's vein, the main tube, said
straight pipe portion, one branch pipe portion of the branch pipe
which is angularly extended with respect to the main tube, and the
first section of tubing, with the anticoagulant distributed throughout
inner surfaces of the blood bags, the first and second section of
tubing, the main tube, the branch pipe, and the needle;
heat sealing over some area of the first section of tubing and
cutting said first section of tubing at an intermediate portion
of the sealed area to separate the first blood bag from the blood
bag system;
placing the separated bag in a centrifuge wherein the blood in
the separated bag is centrifuged into plasma and cell components;
transfusing the separated plasma components to the patient through
the outlet of the separated bag while the cell components are transfused
back to the donor through said outlet, said return means, said another
branch pipe portion, said straight pipe portion, said main tube
and said needle which is kept punctured into the donor's vein;
manually breaking the flow path control means in the second section
of tubing to place the flow path in communication with the second
section of tubing;
collecting the blood into the second blood bag through the needle
which is kept punctured into the donor's vein, the main tube, the
straight pipe portion of the branch pipe which is straight with
respect to the main tube and the second section of tubing to the
second blood bag at junctions therebetween, and the second section
of tubing, the anticoagulant on inner surfaces of the needle, the
main tube and the straight pipe portion of the branch pipe having
already been lost during the collection of blood into the first
blood bag;
heat sealing over some area of the second section of tubing and
cutting said section of tubing at an intermediate portion of the
sealed area to separate the second blood bag from the blood bag
system;
placing the separated second blood bag in a centrifuge where the
blood in the separated second blood bag is centrifuged into plasma
and cell components;
transfusing the separated plasma components to the patient through
the outlet of the separated second blood bag while the cell components
are transfused back to the donor through the outlet, return means,
said another branch pipe portion, the straight pipe portion, the
main tube and needle which is kept punctured into the donor's vein;
and
removing the needle from the donor's vein.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a blood bag system, and more particularly,
to a blood bag system capable of transfusing a necessary component
(e.g. plasma) and returning the remaining component (e.g. corpuscle
or cell) of blood to the donor.
2. Description of Prior Art
Prior art blood bag systems will be discussed with reference to
the drawings.
Referring to FIG. 1 there is diagrammatically illustrated a typical
blood bag system according to the prior art. The blood bag system
1 comprises first and second blood bags 2A and 2B each having an
inlet 3 for collecting blood, an outlet 4 for transfusing a plasma
component, and another outlet 5 for transfusing a cell or corpuscle
component of blood, and containing a given volume of an anticoagulant
previously injected therein. First and second sections of tubing
6A and 6B are connected at one end to the inlets 3 of the blood
bags 2A and 2B, and at the other end collectively to one end of
a main section of tubing 8 via a branch pipe 7. A hypodermic needle
9 for collecting blood is connected to the other end of the main
section of tubing 8. Cell return means 11 is connected to one of
the collecting sections of tubing, 6B in the illustrated embodiment,
via a branch pipe 10.
To carry out plasma transfusion, the blood bag system 1 may be
operated as follows. The needle 9 is inserted into the donor's vein
and blood is collected in the first blood bag 2A. Thereafter the
first blood bag 2A is disconnected from the first section of tubing
6A, and placed in a centrifuge to separate the blood into plasma
and cell components. The thus separated plasma component is transfused
from the bag 2A to the patient through the plasma outlet 4 while
the separated cell component is returned or transfused back from
the bag 2A to the donor through the cell outlet 5 return means
11 and needle 9. The procedures of blood collection, separation,
transfusion, and return are repeated for the second blood bag 2B.
With this blood bag system, a necessary amount of plasma can be
collected by repeating the procedures of blood collection, transfusion
and return without unnecessarily increasing the volume of blood
taken out of the donor in each collecting process. Furthermore,
the need for inserting the puncture needle into the donor's vein
for every blood collecting process is eliminated to minimize the
damage to the vascular wall and the pain to the donor by puncture.
In the above-illustrated blood bag system 1 for the purpose of
preventing the anticoagulant in each of the blood bags 2A and 2B
from being transferred to the other blood bag during autoclave sterilization
as well as for the purpose of ensuring that the blood collected
in each of the blood bags 2A and 2B be kept anticoagulant, the blood
collecting inlet 3 of one of the blood bags, for example, blood
bag 2B is removably fitted with a spherical bead 12 to block the
flow path of the inlet 3.
However, in the manufacture of the blood bag system 1 the step
of mounting the bead 12 at the blood collecting inlet 3 of the second
blood bag 2B is complicated and troublesome. When blood is to be
collected in the second blood bag 2B, the bead 12 must be removed
from the inlet 3 and dropped into the bag 2B. Not only the step
of removal of the bead 12 is cumbersome, but the periphery of the
inlet 3 might be damaged or fractured by the nail or the like. Moreover,
during the centrifugal separation after blood collection, the bead
12 in the second blood bag 2B might be centrifugally forced against
the inner wall of the bag with possible fracture. When the bead
12 is mounted only at the inlet 3 of the second blood bag 2B, the
anticoagulant contained in the first blood bag 2A will flow into
all the flow paths of the sections of tubing 6A and 6B and the main
section of tubing 8 to wet the tube inner surface By this reason,
the volume of anticoagulant contained in the first blood bag 2A
must be somewhat larger than that in the second blood bag 2B, further
complicating the manufacture process. In addition, since the flow
paths to be wetted by the anticoagulant contained in the first blood
bag 2A total to a considerable length, it becomes difficult to previously
distribute the anticoagulant properly throughout the flow paths
because of flow resistance and other factors.
FIG. 2 diagrammatically illustrates another prior art blood bag
system as disclosed in Nevens et al., U.S. Pat. No. 4407660. This
blood bag system 13 is similar to the blood bag system 1 but different
from the previous system in that it uses a plug 14 capable of blocking
and allowing communication through both the connection between the
second section of tubing 6B and the main section of tubing 8 and
the connection between the cell return means 11 and the main section
of tubing 8.
In this blood bag system, when the plug 14 blocks communication
through the connection between the second section of tubing 6B and
the main section of tubing 8 the anticoagulant contained in the
first blood bag 2A wets the first section of tubing 6A and the main
section of tubing 8 and the anticoagulant in the second blood bag
2B wets the second section of tubing 6B. It is thus possible to
substantially equalize the volumes of anticoagulant contained in
the blood bags 2A and 2B and to cause the anticoagulant to be properly
or uniformly distributed throughout the flow paths because the flow
paths to be wetted are individually assigned to the respective anticoagulant
fractions in the bags.
The above-described blood bag system, however, requires careful
operation of withdrawing the plug 14 halfway to communicate the
second section of tubing 6B with the main section of tubing 8 when
blood is to be collected in the second blood bag 2B. Care must be
taken so as not to fully remove the plug 14 from the cell return
means 11. Further, when the cell transfusion outlet 5 of each of
the blood bags 2A and 2B is connected to the cell return means 11
the plug 14 must be fully withdrawn from the cell return portion
11 with the possible entry of bacteria from the atmosphere into
the main section of tubing 8.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide
an improved blood bag system including a plurality of blood bags
connected to a main section of tubing through a corresponding plurality
of sections of tubing, wherein substantially equal volumes of anticoagulant
may be contained in the blood bags to ensure that the anticoagulant
be properly and uniformly distributed throughout the sections of
tubing and main section of tubing.
It is another object of the present invention to provide a blood
bag system which is efficient to manufacture, easy to operate and
safe in service.
The present invention is directed to a blood bag system comprising
a plurality of blood bags each having an inlet for blood collection
and an outlet for blood transfusion and containing a given volume
of an anticoagulant therein, a corresponding plurality of sections
of tubing for blood transfer each having one end connected to the
inlet of one blood bag, and a main section of tubing having one
end connected to the other ends of the sections of tubing in common.
A needle is connected to the other end of said main section of tubing
for collecting blood. Return means is connected to the main section
of tubing or any one of the sections of tubing for returning a cell
component of blood to the donor.
According to a first aspect of the present invention, provided
that N is the number of blood bags in the system, flow path control
means is positioned in each of sections of tubing corresponding
to at least (N-1) blood bags at a point near to the main section
of tubing, but on the side of the blood bag with respect to said
return means. The control means normally blocks communication through
the corresponding section of tubing, but when broken, allows communication
through the section of tubing.
In a preferred embodiment of the present invention, the flow path
control means comprises an annular base disposed in and sealed to
the inner surface of the section of tubing and defining a flow path
therethrough. A breakable plug member is integrally connected to
that end of the base which is positioned on the side of the blood
bag, to block the flow path of the base. The plug member is breakable
from the base to open the flow path.
Preferably, the plug member is a conical plug having the bottom
breakably connected to the annular base. Alternatively, the plug
member has a flat tip or is truncated. That portion of the section
of tubing which encloses the flow path control means has a larger
diameter than the remaining portion. The outer diameter of the flow
path control means is selected to be larger than the inner diameter
of the remaining portion of the section of tubing.
Preferably, the return means is connected to the main section of
tubing through a branch pipe while one end of the main section of
tubing is connected to the other ends of tubing through the same
branch pipe. The return means consists of a short section of tubing
closed with a plug of a material puncturable with a hypodermic needle.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present
invention will be more fully understood by reading the following
description taken in conjunction with the accompanying drawings,
in which:
FIG. 1 illustrates a prior art blood bag system;
FIG. 2 illustrates another prior art blood bag system;
FIG. 3 illustrates one embodiment of the blood bag system according
to the present invention; and
FIG. 4 is an enlarged cross section of the flow path control means
inserted in the blood bag system shown in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 diagrammatically shows one embodiment of a blood bag system
2 of the present invention. The blood bag system 21 includes first
and second blood bags 22A and 22B in which an anticoagulant is previously
admitted in a sufficient amount corresponding to the volume of blood
to be contained in the bag to prevent coagulation of blood to be
collected therein. Each of the blood bags 22A and 22B is provided
with an inlet 23 for collecting blood, an outlet 24 for transfusing
blood plasma, and another outlet 25 for transfusing blood cells.
The first and second sections of tubing 26A and 26B are connected
at one end to the blood bags 22A and 22B, respectively, and at the
other end collectively to one end of a main section of tubing 28
via a branch pipe 27. A needle 29 for collecting blood is connected
to the other end of the main section of tubing 28. Cell return means
30 is connected to the main section of tubing 28 via the branch
pipe 27. The cell return means 30 in the form of a short section
of tubing is fitted with a plug formed of a material puncturable
with a hypodermic needle, for example, a rubber plug. Although the
cell return means 30 may be located intermediate each of the sections
of tubing 26A and 26B, it is preferably connected directly to the
main section of tubing 28 as illustrated in order to minimize the
length of a path for back transfusion. In the illustrated embodiment,
a protector 29A is fluid-tightly engaged with a hub 29B on the needle
29 for the purpose of preventing leakage of anticoagulant in the
first blood bag 22A. Furthermore, the plasma outlet 24 cell outlet
and cell return means 30 are covered with caps 24A, 25A and 30 A,
respectively.
At that position in the second section of tubing 26B which is located
near to the main section of tubing 28 (but on the side of the blood
bag 22B with respect to the cell return means if the cell return
means 30 is connected to the second section of tubing 26B), is provided
flow path control means 31 which blocks communication through the
second section of tubing 26 B in normal or unbroken conditions,
but allows communication through the second section of tubing 26B
when broken.
As best shown in FIG. 4 the flow path control means 31 comprises
an annular base in the form of a sleeve member 33 joined to the
inner surface of the section of tubing 26B by adhesion or heat welding
and defining a flow path 32 therein. A breakable plug member 34
is integrally connected to that end of the sleeve member 33 which
is positioned on the side of the blood bag, to block or close the
flow path 32 of the sleeve member 33. The plug member 34 is breakable
from the sleeve member 33 to open the flow path 32 and is thus called
a click-tip. As illustrated, a notch 35 is circumferentially formed
at the connection between the sleeve member 33 and the plug member
34 to facilitate the breakage of the plug member from the sleeve
member.
It will be understood that the flow path control means 31 may be
additionally provided in the first section of tubing 26A. In this
case, the engagement of the protector 29 A with the hub 29B of the
needle 29 need not be fluid tight. That portion 36 of the second
section of tubing 26B which encloses the flow path control means
31 has an increased diameter as compared with the remaining portion.
Preferably the flow path control means 31 has an outer diameter
larger than the inner diameter of the remaining tubing portion.
This diameter selection, after the plug member 34 is broken, prevents
the plug member 34 from blocking the downstream flow path of the
section of tubing 26B or flowing into the blood bag 22B. Entry of
the broken plug member 34 into the blood bag is undesirable because
it will damage the blood bag during centrifugation. The surrounding
portion 36 of an increased diameter may be a tubular member separate
from the collecting section of tubing 26B.
The breakable plug member 34 may have a conical shape or truncated
shape or a flat tip 37 (FIG. 4) such that the plug member 34 after
breakage, may not block the second section of tubing 26B. Further,
the plug member 34 is preferably rugged or roughened on the outer
surface thereof to prevent the section of tubing 26B, particularly,
the surrounding portion 36 from fusing to the plug member 34. Otherwise,
when the blood bag is subject to autoclave sterilization or high
pressure steam sterilization, the surrounding portion 36 is heat
welded to the plug member 34 (this phenomenon is usually called
"blocking") and then, the flow path is not fully opened
by breaking the flow path control means 31. Surface roughening reduces
the contact surface area between the plug member 34 and the surrounding
portion 36. Surface roughening may be carried out by any of well-known
techniques including embossing, slotting, ribbing and the like.
In general, blood bags and tubes are formed of a flexible polyvinyl
chloride resin which is liable to "blocking". The flow
path control means is preferably formed of a relatively rigid material
different from the material of which the bags and tubes are formed,
for example, rigid polyvinyl chloride and polycarbonate resins,
the polycarbonate resin being most preferred because of easy and
complete breakage.
The blood bag system 21 described above is operated as follows
when it is applied to plasma exchange therapy.
In collecting blood from the donor, the collecting needle 29 is
punctured into the donor's vein. Since the second section of tubing
26B is blocked or closed by the flow path control means 31 at this
point, that is, in normal or unbroken state, blood is collected
into the first blood bag 22A through the needle 29 main section
of tubing 28 and first section of tubing 26A. Thereafter, the first
section of tubing 26A is heat sealed over some area, for example,
along line X--X in FIG. 3 and then cut intermediate of the sealed
area. The first blood bag 22A together with the first section of
tubing 26A which is thus separated from the system is placed in
a centrifuge where the blood in the bag is centrifuged into plasma
and cell components. The thus separated plasma component is then
transfused to the patient through the plasma outlet 24 while the
cell component is transfused back to the donor through the cell
outlet 25 cell return means 30 and needle 29.
Next, the flow path control means 31 in the second section of tubing
26B is manually broken to disconnect the plug member 34 from the
sleeve member 33 to place the path 32 in communication with the
downstream section of tubing 26B, and blood is collected in the
second blood bag 22B through the needle 29 which is kept punctured
into the donor's vein. The blood collected in the second blood bag
22B is subjected to the same successive procedures of centrifugation,
transfusion and back transfusion as described for the first blood
bag 22A.
In the above-described embodiment, during autoclave sterilization
with the flow path control means 31 in non-conductive state, the
anticoagulant in the first blood bag 22A wets the first section
of tubing 26A and the main section of tubing 28 while the anticoagulant
in the second blood bag 22B wets the second section of tubing 26B.
This permits the blood bags 22A and 22B to be filled with a substantially
equal volume of anticoagulant. Since the flow paths to be wetted
with the anticoagulant in the blood bags A and 22B are not too long,
the anticoagulant may be properly distributed over the respective
flow paths.
Since the plug member 34 of the flow path control means 31 which
is to be disconnected from the annular base 33 is located in the
section of tubing 26B downstream of the annular base 33 with respect
to the flow of blood being collected, there is no likelihood that
the broken plug member 34 is entrained by the collecting blood flow
toward the annular base 33 to again close the flow path 32. This
ensures steady blood collection.
The flow path control means 31 may be readily joined to the section
of tubing 26B, for example, by heat welding or adhesion, resulting
in increased productivity. If that end of the second section of
tubing 26B which is remote from the second blood bag 22B is joined
to the sleeve member 33 of the flow path control means 31 at a position
shown by line Y--Y in FIG. 4 a subassembly of the first blood bag
22 A and the first section of tubing 26A may be identical with a
subassembly of the second blood bag 22B and the second section of
tubing 26B with the benefit of further improved productivity.
Since the flow path control means 31 is readily breakable irrespective
of being enclosed in the section of tubing, ease of operation and
safety in service are improved over the prior art systems using
a bead or plug.
The flow path control means 31 is located adjacent the cell return
means 30 and thus actually placed nearer to the donor and hence,
at a relatively high level above the floor. The operator need not
squat down for breaking.
Although the flow path control means 31 is provided solely in the
second section of tubing 26B in the above-described embodiment,
an additional flow path control means may be provided in the first
section of tubing 26A.
Although the blood bag system of the present invention is described
with respect to the embodiment using two blood bags, the present
invention is, of course, applicable to blood bag systems including
three or more blood bags.
It is also contemplated that each blood bag is provided with a
single transfusion outlet which serves for both plasma and cell
transfusion purposes.
In a blood bag system comprising a plurality of blood bags each
having an inlet for blood collection and at least one outlet for
blood transfusion and containing a given volume of an anticoagulant
therein, a corresponding plurality of sections of tubing for blood
transfer each having one end connected to the inlet of one blood
bag, a main section of tubing having one end connected to the other
ends of the sections of tubing in common, a needle connected to
the other end of the main section of tubing for collecting blood,
and return means connected to the main section of tubing (or any
one of the sections of tubing) for returning a cell component of
blood, according to the present invention, provided that N is the
number of blood bags in the system, flow path control means is positioned
in each of sections of tubing corresponding to at least (N-1) blood
bags at a point near to the main section of tubing (but on the side
of the blood bag with respect to the return means if the return
means is connected to the section of tubing), the control means
normally blocking or closing fluid communication through the corresponding
section of tubing, but when broken, allowing communication through
the section of tubing. The volumes of anticoagulant contained in
the plurality of blood bags may be substantially equal and properly
and uniformly distributed over the sections of tubing and the main
section of tubing prior to blood collecting process, offering the
advantages of ease of operation and safety in service as well as
ease of manufacture.
In one preferred embodiment, the flow path control means comprises
an annular base disposed in and sealed to the inner surface of the
section of tubing and defining a flow path therethrough, and a plug
member integrally connected to that end of the base which is positioned
on the side of the blood bag to block the flow path of the base
is breakable from the base to open the flow path of the base. With
this arrangement, the plug member which is breakable from the base
of the flow path control means is located in the blood collecting
section of tubing downstream of the base with respect to the collecting
blood flow, and there is no likelihood that the broken plug member
will be entrained by the collecting blood flow to close the flow
path of the base, ensuring steady blood collection. |