U.S. patent number 3,698,494 [Application Number 05/132,476] was granted by the patent office on 1972-10-17 for balance for blood bag.
This patent grant is currently assigned to LABAZ. Invention is credited to Jean Joseph Gaudin.
United States Patent |
3,698,494 |
Gaudin |
October 17, 1972 |
BALANCE FOR BLOOD BAG
Abstract
A balance for weighing and agitating a blood bag into which
blood is fed from a donor, comprises a pivoted beam provided with
an adjustable counterweight on one side of the pivot axis and a pan
on the other side. The pan is mounted on a rocking arm pivotally
supported on the beam and rocked about an axis extending along the
beam by a motor mounted on the beam.
Inventors: |
Gaudin; Jean Joseph
(Bordeaux-Cauderan, FR) |
Assignee: |
LABAZ (Paris,
FR)
|
Family
ID: |
9054241 |
Appl.
No.: |
05/132,476 |
Filed: |
April 8, 1971 |
Foreign Application Priority Data
|
|
|
|
|
Apr 20, 1970 [FR] |
|
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7014176 |
|
Current U.S.
Class: |
177/118;
128/DIG.13; 366/141; 604/245; 128/DIG.6; 177/245; 366/211;
604/903 |
Current CPC
Class: |
G01G
19/00 (20130101); G01G 23/00 (20130101); A61M
1/0245 (20130101); G01G 1/36 (20130101); Y10S
128/06 (20130101); Y10S 128/13 (20130101); Y10S
604/903 (20130101) |
Current International
Class: |
A61M
1/02 (20060101); G01G 1/36 (20060101); G01G
1/00 (20060101); G01G 19/00 (20060101); G01G
23/00 (20060101); A61m 001/00 (); G01g 001/18 ();
G01g 013/30 () |
Field of
Search: |
;177/116,117,118,1,245
;128/214,275,DIG.6,DIG.13 ;259/55,56 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Ward, Jr.; Robert S.
Claims
I claim:
1. In a balance for enabling a predetermined quantity of blood to
be received while being agitated in a blood bag connected by a
filling tube to a source of blood, comprising a beam, a frame,
means pivoting the beam intermediate the length of the beam on the
frame, a support for a blood bag, means mounting said support on an
end of the beam for rocking movement of the support relative to the
beam, and a micromotor carried by the beam for rocking said
support; the improvement in which said beam comprises, on the side
of said pivoting means opposite said support, two rods rigidly
interconnected to each other, and a manually adjustable
counterweight slidable lengthwise along each of said rods.
2. A balance as claimed in claim 1, one of said counterweights
being mounted to slide under its own weight along its associated
said rod.
3. A balance as claimed in claim 1, both of said counterweights
being mounted to slide under their own weight along their
associated said rods.
4. A balance as claimed in claim 1, and a separate releasable
device adjustable in position along one of said rods for stopping
the associated said counterweight.
5. A balance as claimed in claim 1, and an abutment member carried
by one of said rods and movable in response to movement of the beam
to pinch said tube to interrupt the flow of blood through said
tube.
6. In a balance for enabling a predetermined quantity of blood to
be received while being agitated in a blood bag connected by a
filling tube to a source of blood, comprising a beam, a frame,
means pivoting the beam intermediate the length of the beam on the
frame, a support for a blood bag, means mounting said support on an
end of the beam for rocking movement of the support relative to the
beam, and a micromotor carried by the beam for rocking said
support; the improvement comprising an abutment member movable to
pinch said tube to interrupt the flow of blood through said tube,
an electromagnet having a movable core to which said abutment
member is connected, and a switch controlled by movement of the
beam for actuating said electromagnet.
7. In a balance for enabling a predetermined quantity of blood to
be received while being agitated in a blood bag connected by a
filling tube to a source of blood, comprising a beam, a frame,
means pivoting the beam intermediate the length of the beam on the
frame, a support for a blood bag, means mounting said support on an
end of the beam for rocking movement of the support relative to the
beam, and a micromotor carried by the beam for rocking said
support; the improvement comprising an abutment member movable to
pinch said tube to interrupt the flow of blood through said tube, a
catch mechanism having a biasing spring for moving said abutment
member, and a trigger device for said catch mechanism actuated by
movement of the beam.
8. In a balance for enabling a predetermined quantity of blood to
be received while being agitated in a blood bag connected by a
filling tube to a source of blood, comprising a beam, a frame,
means pivoting the beam intermediate the length of the beam on the
frame, a support for a blood bag, means mounting said support on an
end of the beam for rocking movement of the support relative to the
beam, and a micromotor carried by the beam for rocking said
support; the improvement comprising a microswitch for controlling
the flow of electric current to said micromotor, and means
responsive to movement of the beam to actuate said microswitch.
9. In a balance for enabling a predetermined quantity of blood to
be received while being agitated in a blood bag connected by a
filling tube to a source of blood, comprising a beam, a frame,
means pivoting the beam intermediate the length of the beam on the
frame, a support for a blood bag, means mounting said support on an
end of the beam for rocking movement of the support relative to the
beam, and a micromotor carried by the beam for rocking said
support; the improvement comprising electric warning means for
signalling the end of the receipt of blood, a microswitch
controlling the flow of electric current to said warning means, and
means responsive to movement of the beam to actuate said
microswitch.
10. A balance as claimed in claim 9, said warning means comprising
a warning light.
11. A balance as claimed in claim 9, said warning means giving an
audible warning.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to equipment used when
taking blood from a donor, and more particularly to apparatus
intended to permit measurement of the amount of blood taken in this
way.
As is known, equipment of this type comprises a bag, which is
usually flexible and which is connected by a pipe to a venous
puncture needle, an this bag contains in advance an anticoagulant
intended to prevent coagulation of the blood entering the bag.
In taking blood it is important both to check the amount of blood
taken from the donor and to effect continuous stirring of this
blood with the anticoagulant in the bag receiving it, in order to
effect good mixing of these two products.
Devices already exist which effect at least one of these
functions.
Some of these devices are simple spring balances on which the blood
bag is suspended during the taking of the blood. Devices of this
kind do not make it possible for any agitation of the bag to be
effected simultaneously, for the purpose of the above-mentioned
mixing.
Other devices contain a volumetric sensor which senses increasing
volume of the bag as the blood is taken, and the entire arrangement
is placed on an agitator. Devices of this kind lead to bulky,
expensive arrangements, the precision of which moreover usually
leaves much to be desired.
An object of the present invention is to provide a balance for a
blood bag which is exempt from these disadvantages.
SUMMARY
According to the present invention, a balance for weighing and
agitating a blood bag comprises a beam pivotally mounted on a
frame, a weighing counterweight adjustably mounted on the beam on
one side of the pivot axis, and a pan or other support for a blood
bag mounted on the beam on the other side of said pivot axis, the
said pan being carried by an oscillating arm which is arranged to
be rocked on the beam by a drive unit carried by the beam in order
to impart oscillatory movement to the said oscillating arm.
It is preferable for a knife or other abutment member to be
provided which is movable in response to tilting movement of the
beam, in order to nip the tube filling the bag when sufficient
weight of blood has passed into the bag.
This arrangement leads to an economical construction with small
dimensions which is easy to use. The device in an advantageous
manner effects systematic mixing of the blood taken with the
anticoagulant contained in the bag receiving the blood, accurate
weighing of the latter, automatic interruption of the supply of
blood when a determined amount of blood has been taken, and if
necessary a warning may be given to the staff supervising the
taking of the blood.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in elevation of a balance according to the
invention, certain of the casing elements protecting the balance
having been at least partially removed;
FIG. 2 is a view in perspective in solid lines of only the movable
parts of said balance, the other elements of the balance having
been partially indicated diagrammatically in broken lines;
FIGS. 3 and 4 are two diagrams illustrating the operation of the
balance;
FIGS. 5 and 6 each correspond respectively to FIGS. 3 and 4 and
show on a larger scale the method of intervention of one of the
elements of the balance;
FIG. 7 is a partial view in elevation of an alternative
construction of a balance according to the invention at the
beginning of a weighing operation;
FIG. 8 is a view of this alternative similar to FIG. 7, at the end
of a weighing operation;
FIGS. 9 and 10 are views respectively similar to FIGS. 7 and 8 and
relate to another modified embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the embodiment illustrated in FIGS. 1 to 6, a balance
comprises a base 10 on which there is fastened a U-shaped yoke 11
for pivotally supporting a beam 12. This beam 12 comprises a
cylindrical rod 13 which passes through a rectangular pivot block
14 and is keyed on the latter by a pointed screw 15. A pivot pin 16
passes through the pivot block 14, extending transverse to the rod
13, and pivots in the two arms of the yoke 11. On the pivot block
14 there are also attached on the one hand a control finger 17
arranged to control a microswitch 18 carried by the base 10, and on
the other hand a knife 19 the purpose of which will be indicated
hereinbelow.
On one of the ends of the rod 13 of the beam 12 there is mounted
for free sliding a counterweight 20, which will be referred to
hereinafter as a weighing counterweight. Adjacent the end of the
weighing counterweight which is remote from the pivot block 14
there is a separate stop device 21 against which the counterweight
20 may bear to fix temporarily its position along the rod 13. As
illustrated, this stop device 21 has a releasable catch mechanism
for example a ball 22 acted on by a spring 23, and is arranged to
co-operate with reference marks 24 provided along the rod 13; for
the sake of greater clarity in the drawing the depth of the
reference mark 24 visible in FIG. 1 has been exaggerated. In this
way, the stop device 21 can be moved in steps to a required
position along the rod 13.
At its other end the rod 13 carries a plate 25 on which there is
fixed a frame 26 composed of a sole 27 and two side plates 28A, 28B
perpendicular to the sole 27. A casing 29 (FIG. 1) is attached to
the frame 26.
The side plate 28A of the frame 26 carries on the outside a
micromotor 30 on the output shaft 31 of which there is keyed a
connecting rod 32 disposed inside the side plates 28A, 28B of the
frame 26. At its free end this connecting rod 32 is articulated to
a crank 33 which in turn is articulated at 34 on a rocking arm 35.
This rocking arm 35 is mounted pivotally by a pin 36 on the side
plates 28A, 28B of the frame 26 and it carries a pan 40. According
to the embodiment illustrated, this pan is part-cylindrical in
shape and on the inside has at least one fastening hook 41 for
attaching a blood bag.
The micromotor 30, the connecting rod 31, and the crank 32 together
form a drive unit adapted to apply to the rocking arm 35, and
therefore to the pan 40 carried by the latter, alternating
oscillations of about 30.degree. for example on each side of a
middle position in which the pan is horizontal.
In addition to the rod 13, the beam 12 is provided with a second
rod 42 parallel to the rod 13 over part of the length of the
latter.
At one of its ends this rod 42 is carried by a plate 43 connected
to the rod 13, and at its other end it is engaged in a hole 44 in
the knife 19.
A counterweight 45, hereinafter referred to as the adjusting
counterweight, is mounted slidably on the rod 42. A stop device of
the type described above, or any similar detent device, may be
fastened on this adjusting counterweight 45, making it possible for
its position on the rod 42 to be temporarily locked. The rod 42 is
preferably provided for the purpose with reference marks.
The knife 19 carried by the pivot block 14 has a foot 37 engaged in
said block and an overhung head 38 supported by said foot 37.
The yoke 11, the pivot block 14, and the microswitch 18 are
positioned inside a protective casing 46. The latter has two side
plates 47, one of which has been removed in FIG. 1. These side
plates are carried by the base 10 perpendicularly to the latter and
are adapted to be connected by a removable casing 48 provided with
apertures for the passage of the rods 13 and 42 of the beam 12, and
also for the passage of the knife 19; in addition, the ends of the
pivot pin 16 of the beam 12 are engaged in the side plates 47.
Mounted on the protective casing 46 are pilot lights 50, 51 the
purpose of which will be seen hereinbelow, and also a tube support
52 disposed vertically in line with the head 38 of the knife
19.
This tube support 52 is formed by a plate 55 and at least one
elastically deformable retaining claw 56.
The microswitch 18 is connected in the electrical supply system of
the pilot lamps 50 and 51, in the electrical supply of the
micromotor 30, and also in the electrical supply system of any
warning or alarm device provided, for example a bell.
Before a weighing operation, as illustrated in FIGS. 1 and 3, the
finger 17 controlling the microswitch 18 is at a distance from the
latter.
In order to effect the weighing while blood is withdrawn and
supplied to the bag, a blood bag 60 is placed in the pan 40 of the
balance (FIG. 3), the supply tube 61 connecting said bag to a
venous puncture needle (not shown) being passed into the tube
support 52 (FIG. 5) below the claw 56.
By adjustment of the counterweight 45 the weight of the blood bag
60 is then balanced, taking into account the anticoagulant
contained in it, and then with the aid of the weighing
counterweight 20 the required weight of blood to be taken is set in
advance - FIG. 3; in order to do this the stop device 21 is set at
the reference mark on the rod 13 which corresponds to the required
weight of blood, and the counterweight 20 is moved so as to bear
against this stop device 21.
An electricity supply to the balance is then switched on. One of
the pilot lights 50, 51 lights up, for example a green light, and
the micromotor 30 is started up. This micromotor, the output shaft
31 of which rotates for example at about 10 revolutions per minute,
applies a relatively slow alternating rocking movement to the pan
40 and thus to the bag 60 carried by the latter.
The operation of taking blood can then be carried out.
As the blood enters the bag 60 it is intimately mixed with the
anticoagulant contained in said bag, because of the agitating
movement applied to the latter. At the same time, as the bag 60 is
filled with blood the beam 12 of the balance tends to recover its
horizontal equilibrium. As soon as it exceeds this equilibrium and
the right hand side of the arm 13 drops, the knife 19 crushes the
tube 61 (FIG. 6) and thus terminates the operation of taking blood
which is being carried out. At the same time the control finger 17
operates the microswitch 18, which extinguishes the pilot light 50,
51 which was in operation and lights up the other, for example a
red light, and at the same time stops the micromotor 30.
The lighting up of this red light marks the end of the weighing
operation. This pilot light may be associated with a warning means,
such as a bell, which is operated at the same time as this pilot
light lights up.
The action of the knife 19, controlled directly by the beam 12 in
the embodiment illustrated in FIGS. 1 to 6, is assisted by the fact
that as soon as the beam 12 passes beyond its position of
horizontal equilibrium the weighing counterweight 20 loses contact
with the stop device 21 and slides along the rod 13 of said beam in
the direction of the pivot pin of the latter, thus reducing the
balancing effect of this counterweight 20.
In accordance with the modified embodiments illustrated in FIGS. 7
to 10 the knife 19 is separate from the beam 12.
In the modified embodiment illustrated in FIGS. 7 and 8 this knife
is movable axially in the casing 46 and is subjected to the action
of a spring 65 which urges the nipping head of the knife in the
direction of the tube support 52. This spring 65 is interposed
between an annular shoulder 66 of the foot 37 of the knife 19 and
the sole of a stirrup 67 fixed to the base 10. The knife 19 forms a
kind of catch and for this purpose is provided with a notch 68 with
which a trigger device 69 is adapted to co-operate. This trigger
device is pivoted at 70 on the stirrup 67 and is acted on by a
torsion spring 71 which urges it in the direction of the knife 19.
The trigger device is controlled by the pivot block 14 of the beam
12.
Before a weighing operation (FIG. 7) the trigger device 69 is in
engagement with the notch 68 on the knife 19 and the latter is thus
held in the upper position not restricting flow through the tube
61.
At the end of the weighing when the beam 12 has rocked, the block
14 forces the trigger 69 to disengage the notch 68 and thus to
release the catch constituted by the knife 19. The latter, when
thus freed, is returned to the bottom position by the spring 65
and, as previously, crushes the tube 61 engaged in the tube support
52.
The knife 19 is provided with a projecting stud 72. Consequently,
when the right hand side of the beam 12 is raised, the rod 13 comes
into contact with the stud 72 on the knife 19 and moves the latter
into the upper position. Simultaneously, the trigger 69 disengages
from the pivot block 14 and under the action of this return spring
71 comes into engagement with the notch 68 on the knife 19, so as
to hold the latter in the raised position.
In the further alternative embodiment illustrated in FIGS. 9 and
10, the knife 19 is formed as an extension of the movable core 75
of an electromagnet 76, the electrical supply of which is
controlled by the microswitch 18 (not shown in FIGS. 9 and 10).
Before a weighing operation (FIG. 9) this electrical supply is
interrupted and the knife 19 is raised. At the end of the weighing
(FIG. 10) the microswitch 18 supplies voltage to the electromagnet
76 and the latter returns the knife 19 in the downward direction in
order to crush a tube 61 engaged in the tube support 52.
In the modified embodiments illustrated in FIGS. 7 and 8 and also
in FIGS. 9 and 10 movement of the knife 19 itself is sufficient to
close the tube 61. Consequently it is not necessary for the
counterweight 20 to be freely slidable on the rod 13. It is
possible in this case for the stop device 21, which in the
embodiment of FIG. 1 was not secured to the counterweight 20, or
any other suitable releasable stop device, to be fastened to
counterweight 20.
The present invention is not limited to the details of the
embodiments described and illustrated. In particular, in the
embodiment described with reference to FIG. 1 the rod 42 of the
beam 12 is fixed to the knife 19. In other alternative
arrangements, which may for example include the embodiments
illustrated in FIGS. 7 to 10, this rod 42 may be fixed to any part
rigidly connected to the rod 13, such as for example the pivot
block 14. In other modifications the rods 13 and 42 may form the
two opposite limbs of a U-shaped member.
* * * * *