FIELD OF THE INVENTION
The invention relates to an intravenous catheter apparatus comprising a tubular catheter
having a proximal end and a distal end, a needle defining an axial direction and having a
needle shaft and a needle tip at a distal end of the needle shaft, wherein the needle shaf5 t
extends through the catheter such that the needle tip protrudes from the distal end of the
tubular catheter, and wherein the needle shaft comprises an engagement means adapted to
engage with a needle guard slidably arranged on the needle shaft in order to prevent the
needle guard from sliding off the needle tip.
10
BACKROUND OF THE INVENTION
An intravenous catheter apparatus of this kind is generally known and, for example, used to
administer medicine to a patient or to take blood from a patient.
15
In use, the tubular catheter is inserted into a blood vessel of the patient, typically a vein, by
means of the needle which will be withdrawn from the catheter after insertion of the tubular
catheter into the blood vessel. When the needle tip enters the blood vessel, blood flows
through a lumen of the needle into a needle hub provided at a proximal end of the needle,
20 where it can be observed by the person handling the catheter apparatus. The event of blood
entering the needle hub is called blood flashback and is used by the person handling the
catheter apparatus to confirm venipuncture, from which point on the person inserts the
catheter as far as desired under a decreased inclination of the needle in order to not puncture
the back wall of the blood vessel.
25
In the case of delayed blood flashback there is a risk that the person handling the catheter
apparatus continues to push the needle into the blood vessel under the increased original
inclination of the needle unit it exits at the rear side of the blood vessel. This second
venipuncture represents a risk to the health of the patient as it may result in inner bleeding.
30 Apart from that the catheter apparatus will have to be removed and replaced by a new one,
i.e. the process of introducing the catheter will have to be repeated which is unpleasant and
painful to the patient.
3
SUMMARY AND OBJECTS OF THE INVENTION
It is an object of the invention to provide an intravenous catheter apparatus which allows for
safer and more reliable placement of the catheter in the patient's blood vessel.
5
This object is satisfied by an intravenous catheter apparatus in accordance with claim 1.
The intravenous catheter apparatus of the invention comprises a tubular catheter having a
proximal end and a distal end. A needle defines an axial direction and has a needle shaft and
10 a needle tip at a distal end of the needle shaft, wherein the needle shaft extends through the
tubular catheter such that the needle tip protrudes from the distal end of the tubular catheter.
The needle shaft comprises an engagement means adapted to engage with a needle guard
slidably arranged on the needle shaft in order to prevent the needle guard from sliding off
the needle tip. The needle shaft further comprises a lateral opening arranged between the
15 engagement means and the needle tip such that the opening is covered by the tubular
catheter. In another embodiment, the needle shaft further comprises a lateral opening
arranged between the engagement means and the needle tip such that the opening is covered
by the tubular catheter. Thus, in one embodiment, the lateral opening is arranged after the
engagement means distally from the needle tip. In an alternative embodiment, the lateral
20 opening is arranged before the engagement means. The opening can be arranged distally or
proximally from the engagement means.
The lateral opening provides communication between a lumen of the needle and an interior
of the tubular catheter. In the event of first venipuncture blood entering the lumen of the
25 needle can exit the needle through the lateral opening and thus become visible in the interior
of the tubular catheter for the person handling.
Because of the position of the lateral opening close to the needle tip, the blood does not have
to travel the length of the needle to enter the needle hub and into the blood flash back
30 chamber therein in order to become visible. Instead, blood entering the lumen of the needle
upon venipuncture partly exits the needle again near the needle tip, thereby becoming
particularly quickly and, thus, become visible in the interior of the tubular catheter allowing
for particularly fast venipuncture confirmation.
4
In one embodiment, because of the arrangement of the lateral opening between the
engagement means and the needle tip, the blood does not have to pass the engagement means
to become visible in the needle hub. Hence, the time at which blood entering the needle
upon venipuncture becomes visible to the person handing the catheter apparatus, i5 s
independent of the design of the engagement means. Hence, even if the engagement means
is designed such that it would normally slow down the flow of blood through the needle
and, thus, delay blood flashback, it does not have any adverse effect on the timing of
venipuncture confirmation in the apparatus of the invention.
10
As a result, the intravenous catheter apparatus of the invention allows faster and more
reliable confirmation of successful venipuncture which makes the handling of the catheter
apparatus easier both for the person placing it and the patient on whom it is used.
15 In order to improve the visibility of the blood exiting the needle through the lateral opening,
the tubular catheter advantageously comprises a transparent material.
According to a preferred embodiment, the lateral opening comprises a slot cut into the
needle shaft in a direction transverse to the axial direction. Such a slot is easy to manufacture
20 and thus helps to minimize manufacturing costs of the catheter apparatus. The lateral
opening may be formed by a small hole, slit, perforation or the like made into the needle
shaft. The opening is just large enough to provide an early blood flashback close to the
needle tip within the catheter tube such that the medical personnel can recognize that he has
placed the needle correctly within a patient's vein immediately after venipuncture. In case
25 of a correct positioning of the needle, blood pours out of the opening within the needle shaft
into the space between the needle shaft and the inner wall of the transparent catheter tube
and is visible to the medical personnel.
In order to enhance spreading of the blood exiting the needle through the lateral opening
30 inside the tubular catheter, an outer diameter of the needle shaft may be slightly smaller than
an inner diameter of the tubular catheter. The enhanced spreading of the blood improves
visibility of the blood through the tubular catheter and, thus, makes detection of successful
venipuncture faster and more reliable.
5
In order to make the insertion of the tubular catheter into a patient's blood vessel even more
agreeable, the tubular catheter may slightly tapered in its distal end region such that the
distal end of the tubular catheter tightly surrounds the needle shaft.
5
According to an embodiment the engagement means comprises an enlargement of the needle
shaft in at least one direction transverse to the axial direction.
An engagement means that is particularly easy to manufacture comprises a crimped portion
10 of the needle shaft. The manufacturing costs of the needle thus can be further reduced.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The embodiments of the invention are described in the following description and in the
15 accompanying drawings, wherein:
Fig. 1 shows a longitudinal sectional view of a distal end region of an intravenous
catheter apparatus in accordance with an embodiment of the invention.
20 Fig. 2 shows a longitudinal sectional view a distal end region of an intravenous
catheter apparatus as shown in Fig. 1being rotated at 90° in accordance with an embodiment
of the invention.
DETAILED DESCRIPTION OF THE INVENTION
25
Fig. 1 show a distal end portion of a tubular catheter 10 of an intravenous catheter apparatus
of the invention. The tubular catheter 10 is made of a transparent material, for example, a
transparent plastic material.
30 A needle 12 defining an axial direction extends through the tubular catheter 10 such that a
distal tip of the needle 12 protrudes from a distal end 16 of the tubular catheter 10. The
needle 12 has a lumen 18 which extends along the length of the needle 12 in the axial
6
direction and is defined by a wall 20 of the needle 12. The needle wall 20 forms a needle
shaft 22.
The outer diameter of the needle shaft 22 is slightly smaller than the inner diameter of the
tubular catheter 10 in order to provide a small gap 24 between the needle shaft 22. In it5 s
distal end region of the tubular catheter 10 is slightly tapered such that the distal end 16 of
the tubular catheter 10 tightly surrounds the needle shaft 22.
Proximal from the needle tip 14 the needle shaft 22 is provided with an engagement means
10 26 for preventing a needle guard (not shown) slidably arranged on the needle shaft 22 from
moving beyond the needle tip 14. The engagement means 26 may comprise any form of
irregularity of the needle shaft 22, for example, an enlargement of the outer profile of the
needle shaft 22 at least in one direction transverse to the axial direction.
15 In the illustrated embodiment, the engagement means 26 comprises a crimped portion of the
needle shaft 22.
The needle guard may comprise a generally cylindrical base portion made of a plastic
material and having an axial bore through which the needle 12 extends. The inner diameter
20 of the bore is adapted to the principal outer diameter of the needle shaft 22 such that the
needle shaft 22 is free to slide through the bore, but the engagement means 26 of the needle
12 cannot pass the base portion of the needle guard.
The needle guard may further comprise two arms provided at the distal side of the base
25 portion and extending generally in the axial direction therefrom. At least one of the arms
has elastic properties such that it can be deflected slightly off the axial direction by the
needle shaft 22. Both of the arms may be integrally formed with the base portion.
Alternatively, one of the arms may be integral with the base portion whereas the other one
of the arms may be made of a strip of sheet metal.
30
The length of at least one elastic arm is longer than the distance between the needle tip 14
and the engagement means 26, such that a bent distal end section of the arm can move in
7
front of the needle tip 14 and capture the needle tip 14 in the needle guard before the
engagement means 26 of the needle 12 engages with the base portion of the needle guard.
Preferably, the arms are surrounded by an elastic band which biases the arms towards the
needle 12. The elastic band may cover a substantial portion of the arms seen in the axia5 l
direction and, thus, prevent the needle tip 14 captured between the arms from protruding
sideway out of the needle guard.
A lateral opening 28 is provided in the needle wall 20 in a region between the needle tip 14
10 and the engagement means 26. The lateral opening 28 is positioned such that it is covered
by the tubular catheter 10 when the needle tip 14 protrudes from the distal end 16 of the
tubular catheter 10, i.e. it is arranged between the engagement means 26 and the distal end
16 of the tubular catheter 10. The lateral opening 28 thus provides communication between
the lumen 18 of the needle 12 and the interior of the catheter.
15
When the needle 12 together with the tubular catheter 10 is inserted into a blood vessel of a
patient, blood flows into the lumen 18 of the needle 12 in the event of venipuncture. The
blood flowing into the lumen 18 of the needle 12 partly exits the needle 12 through the
lateral opening 28 and enters the gap 24 between the needle shaft 22 and the tubular catheter
20 10. The blood entering the gap 24 between the needle shaft 22 and the tubular catheter 10
spreads in the gap 24 due to capillary action and can be seen through the transparent material
of the tubular catheter 10, thereby allowing prompt confirmation of successful venipuncture.
Referring now to Fig. 2 a longitudinal sectional view of a distal end region of an intravenous
25 catheter apparatus being rotated at 90° in accordance with an embodiment of the invention
is illustrated. It can be seen that the engagement means 26 comprises a crimped portion of
the needle shaft 22. The crimped portion is an enlargement of the needle shaft in at least one
direction transverse to the axial direction. The lateral opening 28 may be formed by a small
hole, slit, perforation or the like made into the needle shaft. The opening 28 is just large
30 enough to provide an early blood flashback close to the needle tip 14 within the tubular
catheter 10 such that the medical personnel can recognize that he has placed the needle 12
correctly within a patient's vein immediately after venipuncture. In case of a correct
positioning of the needle 12, blood pours out of the opening 28 within the needle shaft 22
8
into the space between the needle shaft 22 and the inner wall of the transparent catheter tube
and is visible to the medical personnel.
The geometrical shape/dimension of the lateral opening 28 and engagement means 26 is
smaller than the dimension of a bent distal end section of a needle such that it does not ge5 t
stuck in the slot/hole forming the lateral opening 28 or the engagement means 26 while
withdrawing the needle 12 and thus reduces drag or friction upon withdrawal of the needle
after venipuncture. This also reduces the discomfort to the patient substantially. This
geometrical shape could be rectangular, square, circular, oval or any other such shape or
10 combination thereof.
Although, the invention has been described with reference to certain specific embodiments
and examples, it would be appreciated by those skilled in the art that the invention may be
embodied in many forms without departing from the broader spirit and scope of the
15 invention as set forth in the invention. Thus, variations of preferred embodiments as
disclosed may become apparent to those of ordinary skill in the art upon reading the
foregoing description.
Accordingly, this invention includes all modifications and equivalents of the subject matter
20 recited in the claims appended hereto as permitted by applicable law. Moreover, any
combination of the above-described elements in all possible variations thereof is
encompassed by the invention unless otherwise indicated herein or otherwise clearly
contradicted by context. The specification and drawings, therefore, are to be regarded in an
illustrative rather than a restrictive manner without departing from the spirit and scope of
25 the invention.
Thus, it is intended that the scope of the present invention herein disclosed should not be
limited by the disclosed embodiments described above but should be determined only by a
fair reading of the appended claims.
30
9
Reference Numerals
10 tubular catheter
12 needle
14 needle ti5 p
16 distal end
18 lumen
20 needle wall
22 needle shaft
10 24 gap
26 engagement means
28 lateral opening

WE CLAIM:
1. An intravenous catheter apparatus comprising:
a tubular catheter (10) having a proximal end and a distal end (16);
a needle (12) defining an axial direction and having a needle shaft (22) and a needl5 e
tip (14) at a distal end of the needle shaft (22);
said needle shaft (22) extending through said tubular catheter (10) such that said
needle tip (14) of said needle (12) protrudes from said distal end (16) of said tubular catheter
(10); and
10 characterized in that said needle shaft (22) comprising an engagement means (26)
adapted to engage with a needle guard slidably arranged on said needle shaft (22) in order
to prevent said needle guard from sliding off said needle tip (14),
said needle shaft (22) is provided with a lateral opening (28) arranged after said
15 engagement means (26) distally from said needle tip (14) such that said lateral opening (28)
is covered by said tubular catheter (10) wherein the lateral opening (28) and engagement
means (26) has a geometrical shape/dimension smaller than the dimension of a bent distal
end section of a needle guard.
20 2. The intravenous catheter apparatus as claimed in claim 1, wherein said lateral
opening (28) provides communication between a lumen (18) of said needle (12) and an
interior of said tubular catheter (10).
3. The intravenous catheter apparatus as claimed in claim 1, wherein said lateral
25 opening (28) comprises a slot cut into said needle shaft (22) in a direction transverse to said
axial direction.
4. The intravenous catheter apparatus as claimed in claim 1, wherein an outer diameter
of the needle shaft (22) is slightly smaller than an inner diameter of said tubular catheter
30 (10).
11
5. The intravenous catheter apparatus as claimed in claim 1, wherein said tubular
catheter (10) is slightly tapered in its distal end region such that the distal end (16) of the
tubular catheter (10) tightly surrounds the needle shaft (22).
6. The intravenous catheter apparatus as claimed in claim 1, wherein said engagemen5 t
means (26) comprises an enlargement of said needle shaft (22) in at least one direction
transverse to the axial direction.
7. The intravenous catheter apparatus as claimed in claim 1, wherein said engagement
10 means (26) comprises a crimped portion of said needle shaft (22).
8. The intravenous catheter apparatus as claimed in claim 1, wherein said tubular
catheter (10) comprises a transparent material.
15 9. The intravenous catheter apparatus as claimed in claim 1, wherein said lateral
opening (28) formed by a small hole, slit, perforation or the like made into the needle shaft
(22).
10. The intravenous catheter apparatus as claimed in claim 1, wherein the lateral opening
20 (28) arranged distally or proximally from the engagement means (26).