DRIP CHAMBER

CHAMBRE GOUTTE-A-GOUTTE

English Abstract

Abstract of the Disclosure
A drip chamber comprising a tubular body made
of synthetic resin and provided with attachment tubes
for liquid-introducing tubes at an upper portion and at
a lower portion of the tubular body respectively. A
screwed bar is provided in the upper attachment tube.
Infusion liquid drips in a drop of uniform size at
equal intervals, so that liquid infusion can be carried
out always without anxiety when parenteral solution is
infused into a patient s vein, especially, children'
vein.

Claims

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WHAT IS CLAIMED IS:
1. A drip chamber comprising a tubular body
made of synthetic resin and provided with attachment
tubes for liquid-introducing tubes at an upper portion
and at a lower portion of the tubular body respectively,
a screwed bar being provided in the attachment tube at
the upper portion of the tubular body, and a drip tube
being provided at a lower end of the attachment tube at
the upper portion of the tubular body.

Description

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D_ CHAMBER
BACKGROUND OF THE~ TENTION
The present invention relates to a drip
chamber, particularly a drip chamber for children, in a
drip set widely used in infusion of liquids, and the
5 like. A drip chamber is generally made of transparent
synthetic resin, and is provided with attachment tubes
for liquid-introducing tubes at its upper portion and
lower portion. A drip tube is provided in the attachment
tube at the upper portion of the drip chamber.
As is well known, drip chambers of this kind
are incorporated into parenteral fluid sets for the
use. When infusion liquid such as glucose and
physiological salt solution contained in, for example, a
vial is infused into the body from an intravenous needle
15 by way of the above fluid set by usual method, the
infusion liquid in the vial continuously drips by
gravity into the drip chamber through a vial needle.
The dripping rate is generally set to about 4 mQ per 60
drips for adults, or about 1 mQ per 60 drips for
20 children. For maintaining such dripping rate, inner
diameter of the drip tube is generally designed to be
about 0. 9 mm for children while the same is designed to
be about 4.1 mm for adults.
In the above-mentioned drip chamber, no problem
25 occurs in general in the case of drip chambers for
adults in relation to dripping rate. In the case of
drip chambers for children, however, child patients are
sometimes endangered because of receiving a shock
coming from irregular drips.
3 0 In order to remove such ununiformity of
dripping, a stainless pipe having a length of 10 to 4 0
mm, an outer diameter of about 0. 9 mm and an inner
diameter of 0. 5 mm has been used as a drip pipe.
However, it has been found that sufficient effect cannot
3 5 be obtained by the above stainless pipe. It has been
also found that uniform drops drip at equal intervals if

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the stainless pipe is much longer. However, such long
stainless pipe requires large space so that the size of
a drip chamber goes beyond practical range, thereby it
is hard to realize the drip chamber.
The present invention was made to solve the
above-mentioned drawback of the conventional drip
chamber, and it is an object of the present invention to
provide a drip chamber capable of dripping drops of
uniform size at equal intervals.
SUMMARY OF THE INVENTION
In accordance with the present invention, there
is provided a drip chamber comprising a tubular body
made of synthetic resin and provided with attachment
tubes for liquid-introducing tubes at an upper portion
and at a lower portion of the tubular body respectively,
a screwed bar being provided in the attachment tube at
the upper portion of the tubular body, and a drip tube
being provided at a lower end of the attachment tube at
2 0 the upper portion of the tubular body.
BRIEF EXPLANATION OF THE DRAWING
Fig. 1 is a sectional view of an embodiment of
a drip chamber of the present invention.
DETAILED DESCRIPTION
Now, a drip chamber of the present invention is
explained based on the accompanying drawing.
As shown in Fig. 1, a drip chamber comprises a
3 0 tubular body 1 made of transparent synthetic resin such
as polyvinyl chloride and polyolefine. The tubular body
1 has attachment tubes 6, 7 for liquid-introducing tubes
2, 3 at its upper end and lower end respectively. A
screwed bar 5 is provided in the upper attachment tube
3 5 6. A drip tube 4 is provided at a lower end of the
upper attachment tube 6. In the embodiment of Fig. 1,
the drip tube 4 is formed integrally with the upper
attachment tube 6. At one end portion of the screwed

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bar 5, there is formed a longitudinal groove 9
communicating with the drip tube 5.
In order to achieve an object of the present
invention, i.e. in order to realize drops of uniform
5 volume at equal intervals, i t is important that the
infusion liquid is in the form of laminar flow just
before it drips from the drip tube 4. For this purpose,
it is advantageous that the infusion liquid passes
through a narrow drip pipe. Such narrow drip pipe,
10 however, requires some degree of length so that it
cannot be contained in an ordinary drip chamber. ~)n the
contrary, the screwed bar 5 is used in the present
invention so that it does not require a large space. By
employing such a screwed bar, each portion of the
15 infusion liquid is not mixed with one another in the
drip tube 4 and flows so smoothly as to draw a locus.
Next, the effect of the present invention is
concretely explained based on Example.
0. 9 % sodium chloride solution was dripped
20 using a drip chamber having a spiral tube (pitch: 1.0
to 1. 2 mm, total length : 5 0 mm) and a straight drip
tube (length : 8 mm, inner diameter : 0. 5 mm) connected
to the spiral tube.
As Comparative Example, 0. 9 % sodium chloride
25 solution was dripped using a drip chamber having a drip
tube (length: 25 mm, inner diameter: 0.5 mm).
Dripping intervals (second) of Example and
Comparative Example were measured with respect to eleven
drops (that is to say, ten dripping intervals were
30 measured). The results are shown in Table 1.

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Table 1
... . .. . . .
Dripping Intervals (second)
1 2 3 4 5 6 7 8 9 10 Average R~
Ex. 1.3 1.3 1.4 1.3 1.4 1.4 1.3 1.3 1.3 1.3 1.33 0.1
Com. 1.5 1.2 1.4 1.2 1.5 1.1 1.4 1.1 1.4 1.1 1.29 0.4
* Range
As it is clear from Table 1, very stable
dripping can be realized by employing a drip tube
15 comprising a spiral tube.
As explained above, according to the drip
chamber of the present invention, a screwed bar is
provided in the upper attachment tube so that the
infusion liquid drips drops by drops at equal intervals
20 and transforms into drops of uniform volume.
Accordingly, when parentera] solution is infused into a
patient s vein, especially, children' vein through
liquid-introducing tubes and an intravenous needle by
usual method, infusion of liquids can be carried out
25 always without anxiety.

Representative Drawing