WO1989000868A1

WO1989000868A1 - Pneumatic device for withdrawing/dispensing fluids

Info

Publication number: WO1989000868A1
Application number: PCT/IT1988/000055
Authority: WO
Inventors: Rosaria Bongiorno; Alberto Roncan
Original assignee: Rosaria Bongiorno; Alberto Roncan
Priority date: 1987-07-23
Filing date: 1988-07-21
Publication date: 1989-02-09
Also published as: AU2134988A

Abstract

There is disclosed herein a pneumatic device for withdrawing or dispensing fluids, substantially comprising an outer non-deformable container (1) and an inner deformable container (2), each communicating separately with the outside environment, at least one of them holding a compressible fluid therein (gas or vapour). The device is actuated by subjecting the compressible fluid held in one of said two containers to an overpressure or to a vacuum, whereby the pressure unbalance obtained is transmitted, owing to the flexibility of one of the containers, to the second container which is thereby caused to eject the contents thereof or to draw gas or other substances from the outside environment. The device described herein may be provided in different shapes, according to the end use thereof, like for instance sample taking syringes, perfusion containers, spray cans, clinical test-tubes, and so on.

Description

PNEUMATIC DEVICE FOR WITHDRAWING/DISPENSING FLUIDS

This invention relates to a pneumatic device for

controllably withdrawing and/or dispensing fluids, as

well as several application methods for the subject

device, in the various embodimental forms thereof. This invention is particularly concerned with devices for

withdrawing or dispensing fluids to be analyzed or administered, mainly for medical reasons, by means

of an overpressure or a vacuum which can be either

constant or variable according to the particular needs. The technique of withdrawals for diagnostic or therapeutic

reasons is usually performed manually by means of a

plunger syringe or by means of hypobaric test-tubes, if

the taking is performed directly from a live organism, otherwise if the taking is performed from a reservoir holding the liquid to be analyzed the taking can be per¬

formed as well by mouth-applied suction or by means of

rubber-syringes, bellows and so on. However these methods are affected by the following

drawbacks: a) the withdrawal velocity is not constant

whereby damaging flows can take place for the integrity

of the fluid to be analyzed (for instance, said non-

uniformity may cause red blood corpuscle traumatic hemo-

lysis during an intravenous blood taking); b) since any sample taking out of a vein or other hollow vessel by

means of a vacuum syringe or test-tube requires use of a

needle inserted within the vein or hollow vessel, the

operational motions made by the operator, for instance

5 while driving the plunger, can be transmitted to the

needle and therefore they can pos^'sibly damage the vein

walls; c) there is a possibility of microbiological or

chemical pollution due to contact of the fluid to be

analyzed or administered, with the environment; d) the

10 operator himself is liable to be microbiologically or

chemically infected by the fluid being taken since a

fraction of the liquid can spill out of the syringe or

out of the needle and come into contact with the skin or

mucous membranes of the operator and also, during a

15 mouth applied vacuum withdrawal operation chances are

that a certain amount of the blood or liquid is "drunk";

in any case, for sure, the vapours coming out of the

test blood or liquid are inhaled.

Therefore, an object of this invention is to provide a

device adapted to avoid the drawbacks mentioned above,

and additional problems which may be apparent to those

skilled in this art. The inventive device substantially

comprises an outer rigid and non-deformable container

holding therewithin a second container derived from a deformable and resiliently flexible sheet or web, each

container being independently in communication with the

outside through a suitably positioned opening, the outer

rigid container being sized according to the amount of fluid to be analyzed or utilized. Within said rigid

container there is positioned a second deformable and

resiliently flexible container, adapted to expand through gas or liquid injection, up to a point where it reaches

its full volume, or else adapted to shrink and to reduce its volume while ejecting the contents thereof. Said

filling and emptying operations are performed by the

application of a pneumatic overpressure or vacuum, by

means of a suitable vacuum- or pressure-applying device connected to one of the openings mentioned above.

This description will be more apparent if reference is made to the attached drawings in which some embodiments

of the subject matter of this invention are shown, with¬

out any meaning of limitation, and wherein:

Figure 1 is a schematic sectional view of a first

embodiment of a device adapted for intravenous blood

taking;

Figure 2 shows, in a sectional view as well, the device

according to Figure 1, during a blood taking operation;

Figure 3 shows a second embodiment of a device for intra- venous blood taking;

Figure 4 shows the device according to Figure 3, during

the suction step;

Figure 5 is a sectional view of a -third embodimen^'t of

the inventive device, which is particularly adapted in evaluating the blood sedimentation rate;

Figure 6 shows, still in cross-section, the device of Fi¬

gure 5 during an ejection step of the contents thereof;

Figure 7 shows schematically how the device represented

in Figures 1 and 2 may be used in practice;

Figure 8 is a schematic sectional view of a fourth

embodiment of the inventive device, adapted for liquid

dispensing by perfusion; Figure 9 -shows a further embodiment of the inventive

device, which is particularly adapted for the dispensing of beverages by the so-called draught system; and Figure 10 is a schematic sectional view of a general and

simpler embodiment of the inventive device.

Referring now to the drawings, and in particular to

Figure 10, a rigid container 1 provided with an opening

3 in communication with the outside environment,encloses

therewithin a flexible container 2 provided in turn with

an opening 4 communicating as well- with the outside

environment. Referring now more particularly to Figures 1, 2 and 7, as it is shown opening 4 of flexible

container 2 is connected, through line 6, to a

vacuum/pressure generator -device 10, and line 6 is

provided with an opening 7 for '^'communication with the

outside environment. When the vacuum generator device 10 is actuated, the vacuum generated within line 6 draws

outside air through opening 7 whereby substantially no

action takes place within the device; on the other hand,

when opening 7 is closed, for instance by a finger, as

it is shown in Figures 2, 4 and 7, the vacuum establish¬

ed within line 6 draws the air held within flexible container 2 whereby said container progressively

collapses; this fact in turn generates a vacuum within

container 1 propagating outside said container through

opening 3 which has been previously communicated with a

vessel holding the liquid to be withdrawn, said vessel being for instance a vein, as it is shown in particular

in Figure 7. Therefore, the liquid held within said

vessel is drawn through opening^" 3 towards the inside of

rigid container 1.

An alternate embodiment of the device described above is

shown in Figures 3 and 4. In this case, vacuum line 6 is

connected to an opening 3 of rigid container 1 , flexible

container 2 being initially collapsed, as it is shown in Figure 3. The vacuum established inside line 6 after

opening 7 has been closed as described propagates within

rigid container 1 causing flexible container 2 to

progressively extend and inflate, whereby opening 4 5 thereof which was previously communicated with the

» liquid to be withdrawn, draws said liquid therewithin up

to a point where deformable container 2 gets full to the

desired amount. A further embodiment of the inventive device is shown in

^'"-' Figures 5 and 6 which are schematic sectional views of a

device adapted to measure the sedimentation rate of

particles contained in suspension in a liquid, and more particularly to determine blood sedimentation rate. In

this case, Inside rigid container 1 there is previously

15 introduced a certain amount of blood, and the container

is then sealed by means of a special plug provided with

two openings 3 and 4 whose lower ends are closed by

thin membranes or diaphragms which can be punctured.

Underneath the diaphragm which can be punctured pertain¬ 0 ing to opening 4 there is sealingly welded a deformable

container 2. In use, both diaphragms 3 and 4 are

punctured, the first by means αf a transparent tube 8, open at

both ends, and respectively the second by means of a small fitting tube

9 for a pneumatic pressure device, both tubes 8 and 9 having the lower end thereof cut slantwise or according

to any other suitable shape to assist in puncturing the

diaphragm. In use, air under pressure originating from

the special compressor device, proceeding along tube 9

5 enters opening 4 and progressively inflates deformable

container 2 which displaces the liquid underneath and makes it to rise along transparent tube 8 up to the desir¬

ed height. In order to allow for liquid to rise along tube 8, the upper end of the latter is provided with a

^ - hood 11 which,in the same way as deformable container 2,is made of a flexible sheet or web allowing air or gases initially contained within tube 8 to leave the lat¬

ter, while preventing any contact or pollution by the

outside environment. Transparent tube 8 may bear a scale 15 or else the liquid level therewithin can be observed

against a scale provided on a suitable backing support, whereby the red blood corpuscles sedimentation amount or

rate can be observed and measured.

A still further embodiment of the inventive device is

--^■ - shown in Figure 8 which is a schematic cross-section of a

phleboclysis or perfusion bottle, generally shown at 1,

similarly to the previously described embodiments,

holding therewithin a deformable pouch 2 in communicat¬

ion with the outside environment by means of an opening 4 through the bottle sealing plug. When bottle 1 is

overturned and connected, at a second opening 3, to a

normal flexible phleboclysis tube, and the liquid held within the bottle is communicated for instance with a

patient's vein, a gradual and controlled outflow of said

liquid 5 is enabled by the air flowing through opening 4

and progressively expanding container 2, whereby the

volume left empty by the outflowing liquid is compensat¬ ed. As it is apparent, in this case, the compressive action, which in other cases is performed by a special

compressor device, is performed by the atmospheric

pressure itself.

A further possible embodiment of the inventive device is

shown In Figure 9, wherein a rigid container 1 is represented, holding any beverage 5_. such as beer, fruit

juice, syrups and so on, while in the upper part of

container 1 there is provided a flexible container 2

adapted to be inflated under pressure, by means of a

suitable compressor device 10, in order to subject

beverage 5 to a pressure which is high enough to push it

out of opening 3 towards a suitable so called "draught"

dispensing spigot.

Figure 10 shows, in the most schematic and synthetic

way the basic simplest arrangement, common to all the embodiments described above, as well as to any other

that might be contrived.

Depending on the various devices described above, fill¬

ing a fluid to be analyzed or used in a suitable

5 container thoroughly sealed from the outside environment

is performed by means of a continuous,either constant or

variable vacuum suction, according to needs, in order to avoid alterations in the subject fluid. Similarly,

decanting of the fluid from the container to another

^■ - vessel may be performed by means of compression or

simply by gravity, always in the same conditions of

isolation from the outside environment and in particular

from the operator. Therefore, the application field of

this invention extends to sample taking of blood or

5 other liquids from a human-or animal body, or of liquids from the vegetable and mineral kingdom, in order to

perform any kind of analysis or measurements. In view of the same analytical objective, the above withdrawals may

be performed as well within the general scope of 0 environmental analysis (bodies of water, rivers,

atmospheres, and so on) and production analysis, both

during the intermediate steps of operation, and on the

finished product. Said devices may also be used to

perform any kind of fluid sampling, both pure fluids and - T O - fluids in solutions, in mixtures or emulsions, or else

during the various steps of a chemical reaction. Therefore, the same devices described above can be used to create either a vacuum or an overpressure in the

^"region overlying the subject fluid. The same device may

then be used to draw liquids in order to inject,

perfuse or decant them subsequently simply by inverting

the suction-compression function which is a feature of

the inventive devices. Given the basic features of the

above described devices, any of the operations mentioned

above can be performed without the outside air or any other outside fluid Interacting with the subject fluid,

and without said fluid coming into contact with the

operator.

In the case of the device of Figures 1 to 4 and Figure

7, suction will be interrupted when the desired quantity

of fluid to be analyzed, or used in any way, has entered

the subject container. When opening 7, having a larger

size than openings 3 and 4, is opened, suction within

the subject container will stop, with no need to stop

the compression-vacuum suction device, since opening 7

enables a quantity of air enough to compensate the suct¬

ion power of vacuum device 10 to enter the system. As it

is apparent, said suction interruption could also be obtained by stopping the compressor-vacuum suction

device. In this case opening 7 communicating with the outside environment may be omitted. Needless to say, on

the other hand, that said compressor-vacuum suction

device is able to switch from the compression to the suction function simply by operating a suitable switch

inside the compressor-vacuum suction device. Opening 3, 4 for collecting the fluid to be withdrawn or used may

be located either close to the respective suction-compression

opening 4, 3, or in any other position on rigid contain¬

er 1. Said openings 3, 4 which have to be connected with the compressor-vacuum suction device or with the fluid to be withdrawn, are preferably gathered through

the body of a suitable and adjustable plug, cap or hood, which is either sealingly fastened in a known way to

rigid container 1 , after flexible container 2 has been inserted therewithin, or is a part of said body of rigid

container 1. Thereafter, the fluid withdrawn is caused to flow to suitable test-tubes or different vessels, either by

gravity or through injection of air or other fluid under

pressure inside the intended container. In order to pre¬

vent contact "of the fluid to be analyzed or used with

the environment, the connection opening 3 or 4 for

communication between the subject opening and the sample taking needle or with the tube for other withdrawal or

dispensing operations may be provided with a suitable

interceptor device, such as a spigot or a valve. Said Intercepting action will have to be performed before the 5 sample taking device is separated from the fluid with¬ drawing position. In that way air is prevented to enter

from the environment into the liquid container, whereby

the outside environment is protected from possible

pollution by vapours and/or microorganisms emanating

10 from the collected liquid; the same is true for protect¬

ing the operator from possible infections or exposure, the above measures on the other hand protecting the

collected liquid from chemical or microbiological pollution, by the outside environment or by the operator

15 himself.

Said interceptor device will be opened only at the time

when the fluid has to be dispensed to the various

containers for analysis or fractioning, while it will be

closed when going from one container to the other during

--^■- the distribution operations in view of the several

analysis to be performed.

In the case shown in Figures 5 and 6 , the inventive

device substantially comprises a test-tube 1 having a

plug inserted through the open end thereof, said plug thickness being such as to ensure a fast and tight

connection, whereby slight overpressures acting from the

inside towards the outside can be sustained. Said plug

is provided with a pair of round cross section openings 5 3 and 4, each of them being interrupted at the lower end thereof by a diaphragm adapted to be punctured by a tube

having a diameter slightly larger than the openings and whose end is cut slantwise or according to any other

shape suitable to assist in puncturing the diaphragm.

10 The amount by which the diamater of tubes 8 and 9 is

larger than the diameter of openings 3 and 4 is such as

to ensure a tight sealing connection between the

outer wall of each tube and the plug. After having

poured in said test-tube 1 a suitable amount of blood 15 mixed with anticoagulant, or other liquid to be tested,

and having sealed the test-tube with its own plug which

is and has to remain unaltered until the time of the

test, test-tube 1 is positioned on a fixed rack in order to ensure its keeping in an upright position. The rack

*-- - is provided with a scale for each test-tube which makes

it possible to analyze the sedimentation rate even

though tube 8 is not provided with a scale.

In order to measure the sedimentation rate, two

tubes 8 and 9 whose lower ends are cut slantwise are in- troduced respectively through openings 3 and 4, one of said tubes (8) being a common disposable glass or plastic pipette which

is driven through the plug all the way until it reaches the bottom of test-tube 1 whereby it enters the liquid

5 body or blood to be sampled, allowing the liquid or blood contained within the test-tube to rise inside said

tube 8.

Second tube 9, having a slantwise cut end as well, is

driven through opening 4 so that it punctures the

^*• - associated diaphragm, whereby it is communicated with flexible container 2. The outer portion of tube 9 is

connected with a suitable compression system, comprising

a syringe, a rubber syringe, a small pump or other

device, while between said compression system and the

15 connection 9 thereof with test-tube 1 , a suitable inter¬

ceptor system can be provided, such as a valve or a

pinching or throttling device applied to the flexible

connecting tube. Due to the pressure generated within

said deformable container 2 by said compression device

20 10, the blood or liquid to be tested is made to rise

within tube 8 all the way to the desired height while

flexible hood 11 progressively expands.

Once the test is over, the connection with compressor

device 10 is interrupted whereby the blood or liquid previously contained inside tube 8 will lower down

towards the bottom of test-tube 1, and hood 11 will

collapse again while keeping separation from the outside

environment. While some particular embodiments of this invention have

been described, it will be apparent to those skilled in the art that variations and/or modifications can be made

thereto without exceeding the scope of protection of

this invention.

Claims

- .6-

CLAIMS 1. A pneumatic device for withdrawing and/or dispens¬ ing fluids, substantially comprising a rigid pressure

resisting container, provided with at least one opening (3) communicating with the outside, characterized in

that within said rigid container ( 1 ) there is inserted a

flexible and deformable container (2) provided with an

opening (4) connected to the outside through the wall or

the closure cap of said rigid container ( 1 ) , and in¬

dependently of said opening (3).

2. The device of Claim 1, characterized in that said

rigid container (1) and flexible container (2) are mutually sealingly separated.

3. The device of Claim 2, characterized in that one of said openings (3, 4) is connected to a duct adapted to

withdraw, dispense or collect fluids or freely flowing

powders (5) , while the second between said openings (4,

3) respectively communicates through a line (6) with a

positive or negative pressure source (10).

4. The device of Claim 3, characterized in that said

positive or negative pressure source (10) comprises a

compression-vacuum suction device.

5. The device of Claims 3 or 4, characterized in that on line

(6) for connecting to compression-vacuum suction device (10) -1? - an opening (7) is provided, connected to the outside and manually or mechanically closable.

6. The device according to Claim 2, ^'for administering

liquids through phleboclysis or perfusion.

7. The device according to Claim 4 adapted for blood

sedimentation rate measurements.

8. The device according to Claim 4, adapted for

beverage dispensing.

9. The device according to Claim 5, for withdrawal of blood samples to be subjected to clinical analysis.