IV catheter abstract
A device for delivering an IV catheter to an IV infusion site is
disclosed. The device includes a cylindrical housing adapted to
fit into the hand of the clinician. A catheter assembly is disposed
in the housing and can be advanced to an extended position and retracted.
The catheter assembly includes a needle adapted to be inserted into
the vein and the catheter is mounted on the needle to allow the
catheter to be removed at will. The catheter assembly is rotated
as the needle is inserted into the vein. Preferably the catheter
assembly is rotated during the insertion of the needle and catheter.
After the needle and catheter are inserted into the vein, the needle
is retracted into the housing leaving the catheter in place. The
housing and the needle can now be discarded.
IV catheter claim
I claim:
1. A device for establishing an IV catheter by a clinician comprising:
a housing sized and shaped to fit in the hand of the clinician;
a catheter assembly including a catheter member with a front portion
adapted to be inserted into the vein of a patient; a control member
adapted to reciprocate said catheter assembly within said housing
between a retracted position in which said catheter assembly is
completely contained in said housing and an extended position in
which said catheter member extends outwardly of said housing, said
control member being movable with respect to said catheter assembly
for selectively locking said catheter assembly with respect to said
housing; and rotating means adapted to rotate said catheter assembly
about an axis as said catheter assembly is reciprocated by said
control means.
2. The device of claim 1 wherein said catheter member is removably
attached to said catheter assembly so that it can be removed in
said extended position.
3. The device of claim 1 wherein said catheter assembly indudes
a needle member including a needle which extends outwardly of said
housing when said catheter member is in the extended position, said
needle being arranged and constructed for insertion in the vein,
said catheter member being telescopically associated with said needle
member.
4. The device of claim 3 wherein said catheter member is removably
attached to said needle member.
5. The device of claim 1 wherein said catheter member and said
housing cooperate to rotate said catheter assembly about a longitudinal
axis as said catheter assembly is reciprocated by said control member.
6. The device of claim 1 further comprising locking means for locking
said catheter assembly with respect to said housing.
7. The device of claim 6 wherein said locking means is adapted
to lock said catheter assembly in said retracted position.
8. The device of claim 6 wherein said locking means is adapted
to lock said catheter assembly in said extended position.
9. The device of claim 1 further comprising disabling means adapted
to selectively disable said catheter assembly within said housing
to prevent said catheter assembly for being moved extend outside
said housing.
10. A device adapted to establish a catheter for providing IV infusions
to a patient through a vein, said device comprising: a cylindrical
housing having a front end, a rear end and a cylindrical surface
extending therebetween; a catheter assembly including a needle member
with a needle and a catheter member removably attached to said needle
member and telescopically arranged on said needle; control means
for reciprocating said catheter assembly between a retracted position
wherein said catheter assembly is completely disposed within said
cylindrical and an extended position wherein said needle and said
catheter member are operative to be inserted in the vein, said control
means and said catheter assembly being rotatably joined to allow
said catheter assembly to rotate with respect to said housing during
said reciprocating; and rotating means adapted to rotate said catheter
assembly about an axis as said catheter assembly is reciprocated
by said control means.
11. The device of claim 10 wherein said catheter assembly further
comprises a piston, said needle member and said catheter member
being connected to said piston.
12. The device of claim 10 further comprising a first locking means
for locking said catheter assembly in said retracted position.
13. The device of claim 10 further comprising a second locking
means for locking said catheter assembly in said extended position.
14. The device of claim 10 further comprising control disabling
means adapted to disable said control means to prevent said catheter
assembly from being moved to extend outside said cylindrical housing.
15. The device of claim 10 further comprising biasing means for
biasing said catheter assembly toward said retracted position.
16. The device of claim 1 wherein said housing and said control
member cooperate to lock said catheter assembly in a retracted position
in which said catheter is disposed within said housing.
17. The device of claim 1 wherein said housing and said control
member cooperate to lock said catheter assembly in an extended position
in which said catheter extends outwardly of said housing.
18. The device of claim 1 wherein said housing includes at least
a hole and said control member is pivoting with respect to said
housing and said catheter assembly between two positions, including
a first position in which said control member engages said hole,
and a second position that allows the catheter assembly to be reciprocated
within said housing.
19. A device for establishing an IV catheter by a clinician comprising:
a housing sized and shaped to fit in the hand of the clinician:
a catheter assembly including a catheter member with a front portion
adapted to be inserted into the vein of a patient; a control member
adapted to reciprocate said catheter assembly within said housing
between a retracted position in which said catheter assembly is
completely contained in said housing and an extended position in
which said catheter member extends outwardly of said housing; and
control disabling means adapted to disable said control means to
prevent said catheter assembly from being moved to extend outside
said housing.
20. A device adapted to establish a catheter for providing IV infusions
to a patient through a vein, said device comprising: a cylindrical
housing having a front end, a rear end and a cylindrical surface
extending therebetween; a catheter assembly including a needle member
with a needle and a catheter member removably attached to said needle
member and telescopically arranged on said needle; control means
for reciprocating said catheter assembly between a retracted position
wherein said catheter assembly is completely disposed within said
cylindrical and an extended position wherein said needle and said
catheter member are operative to be inserted in the vein; and control
disabling means adapted to disable said control means to prevent
said catheter assembly from being moved to extend outside said housing.
21. A device for establishing an IV catheter by a clinician comprising:
a housing sized and shaped to fit in the hand of the clinician;
a catheter assembly including a catheter member with a front portion
adapted to be inserted into the vein of a patient; a control member
adapted to reciprocate said catheter assembly within said housing
between a retracted position in which said catheter assembly is
completely contained in said housing and an extended position in
which said catheter member extends outwardly of said housing, said
control member being movable with respect to said catheter assembly
with respect to said catheter assembly for selectively locking said
catheter assembly with respect to said housing; and control disabling
means adapted to disable said control means to prevent said catheter
assembly from being moved to extend outside said housing.
22. A device adapted to establish a catheter for providing IV infusions
to a patient through a vein, said device comprising: a cylindrical
housing having a front end, a rear end and a cylindrical surface
extending therebetween; a catheter assembly including a needle member
with a needle and a catheter member removably attached to said needle
member and telescopically arranged on said needle; control means
for reciprocating said catheter assembly between a retracted position
wherein said catheter assembly is completely disposed within said
cylindrical and an extended position wherein said needle and said
catheter member are operative to be inserted in the vein, said control
means and said catheter assembly being rotatably joined to allow
said catheter assembly to rotate with respect to said housing during
said reciprocating; and control disabling means adapted to disable
said control means to prevent said catheter assembly from being
moved to extend outside said cylindrical housing.
IV catheter description
BACKGROUND OF THE INVENTION
a. Field of Invention
This invention pertains to a device used to establish an IV catheter
in a patient. More particularly, the invention pertains to a safety
infusion device that includes a handpiece used to store and to selectively
extend the IV catheter so that it can be introduced into the patient,
the handpiece being constructed and arranged to insure that the
IV catheter and the so-called underlying needle can be retracted
into the barrel at will to protect clinicians from accidental needlesticks.
b. Description of the Prior Art
IV infusion is one of the most widely used procedures performed
in hospitals and other healthcare provider sites. These infusions
involve continuously injecting one or more liquids into the veins
of a patient to achieve various results. Simple infusion systems
may consist of a catheter inserted into the vein and secured to
the patient, a pole holding a bottle or bag used as the source of
the liquid, a flexible tube feeding the liquid to the catheter either
directly, or though some kind of fluid control device. More complex
devices include fusion pumps that can deliver fluids to the patient
at carefully metered rates using specific profiles.
However, independent of which infusion system is used, the IV catheter
must first be established. Many different devices are used to perform
this step. A popular system consists of a cylindrical receptacle.
A hollow steel needle is attached co-axially to one end of the receptacle.
A hollow catheter is mounted on the steel needle in a coaxial arrangement.
The hollow catheter has a shaft, preferably made of a plastic material
and terminating in a standard connector, such as a male Luer lock.
A spring is disposed in the receptacle so that when a latch mounted
on the receptacle is activated, the steel needle separates from
the catheter and is snapped into the receptacle. Once the steel
needle is snapped into the receptacle, it is locked in place so
that it cannot be extended and reused. Since the needle and the
catheter are normally exposed, a protective cap is generally provided
over the needle.
Using this type of system a catheter is established as follows.
First, the clinician finds and preps a proper site on the skin.
Next, the system is removed from a sealed enclosure, and its protective
cap is removed. The needle and the catheter mounted thereon are
inserted through the skin until the tip of the needle and the catheter
reaches a predetermined site. The catheter is then secured with
the forefinger of one hand and the latch is activated to cause the
needle to snap into the receptacle before a needlestick. The receptacle
with the captured needle is then disposed. Systems of this kind
are available from Becton Dickinson of Franklin Lakes, N.J.; Johnson
& Johnson Medical, Inc. of Arlington, Tex., and described in
the following patents, incorporated herein by reference:
5688249 5520654 5304136 5700250 5141497 5683365 5755709
D378405 5348544 5749857 5755709 5411486 5792122 5795339
5676658 D381418 5690619
However, these systems are not satisfactory for several reasons.
As is well known in the art, the catheter has to extend into a vein
and must be oriented properly in order for it to be effective. However,
very often clinicians cannot find the proper vein or the proper
infusion site on their first try. Therefore, after the needle and
catheter have been inserted, the whole system becomes contaminated.
Often, before the system can be reinserted, a new site has to be
found and prepared.
The clinician, especially if she is alone, cannot select and prepare
a new site while holding the contaminated system and therefore must
make a decision on what to do with it. At least one manufacturer
suggests that the system should be discarded. However, obviously,
this is a wasteful step.
The clinician can also decide to recap the needle and then place
it on a horizontal position. However, this process requires two
hands and is exactly the situation that subjects people to inadvertent
needlesticks.
Another disadvantage of existing systems is that they normally
require a linear or translational motion of the needle during insertion.
This is disadvantageous because it causes the needle to bend thereby
causing pain to the patient. Moreover, if the needle bends during
insertion, it will miss the vein and the process has to be repeated.
Commonly assigned application Ser. No. 09/506484 filed Feb. 17
2000 entitled HAND-PIECE FOR INJECTION DEVICE WITH A RETRACTABLE
AND ROTATING NEEDLE, now U.S. Pat. No. 6428517 issued Aug. 6
2002 and incorporated herein by reference, discloses an injection
device with a barrel from which a needle is selectively extended
and retracted using a translational and rotational motion for dispensing
an anesthetic to a patient.
Commonly assigned patent application Ser. No. 09/745751 filed
Dec. 21 2000 entitled METHOD OF PERFORMING AN INJECTION USING
A BI-DIRECTIONAL ROTATIONAL INSERTION TECHNIQUE, now 2001/10051798
and incorporated herein by reference discloses the advantages of
using a bi-directional rotational technique for dispensing anesthetics.
OBJECTIVES AND SUMMARY OF THE INVENTION
An objective of the present invention is to provide a system for
establishing a catheter which overcomes the above-mentioned disadvantages.
A further objective is to provide a system that can be used easily
by clinicians.
Other objectives and advantages will become apparent from the following
description.
Briefly, the subject application pertains to a device for establishing
an IV catheter by a clinician. The device includes a housing sized
and shaped to fit in the hand of the clinician; a catheter assembly
including a catheter member with a front portion adapted to be inserted
into the vein of a patient; and a control member adapted to reciprocate
the catheter assembly within said housing between a retracted position
in which said catheter assembly is completely contained in said
housing and an extended position in which said catheter member extends
outwardly of said housing.
A catheter member can be removably attached to the catheter assembly
so that it can be removed in the extended position.
The catheter assembly includes a needle member with a needle extending
outwardly of the housing when the catheter member is in the extended
position. The needle is arranged and constructed for insertion in
the vein with the catheter member being telescopically associated
with the needle member. The catheter member is removably attached
to the needle member.
In one embodiment the catheter member and the housing cooperate
to rotate the catheter assembly about a longitudinal axis as the
catheter assembly is reciprocated by said control member.
The device also can include locking means for locking the catheter
assembly or the needle after the catheter replacement with respect
to the housing. These locking means can be adapted to lock the catheter
assembly in either the retracted position or the extended position.
In addition, the control member can be disabled by the use of the
same, or a different locking means so that after the catheter element
is properly established, the needle used to establish the catheter
cannot be reused.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a sectional side view of a device in a retracted position
constructed in accordance with this invention;
FIG. 2 shows a sectional side view of the device of FIG. 1 in the
extended position;
FIG. 3 shows a sectional side view of the device of FIG. 1 in the
extended position with the catheter partly removed;
FIG. 4 shows a sectional side view of the device of FIG. 1 in the
extended position with the catheter completely removed;
FIG. 5 shows a sectional side view of the device of FIG. 1 with
the needle retracted and the catheter removed;
FIG. 6 shows an orthogonal view of a barrel for the device of FIG.
1;
FIG. 6A shows a plan view of a barrel for the device of FIG. 1;
FIG. 7 shows an orthogonal view of a control button;
FIG. 8 shows an orthogonal view of the piston for the device of
FIG. 1;
FIG. 9 shows a side view of the needle member for the device of
FIG. 1; and
FIG. 10 shows a side view of the catheter for the device of FIG.
1.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the Figures, a device 10 constructed in accordance
with this invention consists of a cylindrical housing or barrel
12 having an outer surface 14 an inner surface 16 a front end
18 and a rear end 20. An end piece 22 is attached to the rear end
20 of the barrel. The barrel 12 defines a cylindrical housing.
As shown in FIG. 1 a catheter assembly 21 is provided in the barrel
12. This catheter assembly is biased toward a retracted position
by a biasing means such as a coil spring 23.
FIGS. 6 and 6A show more details of the barrel 12. It includes
a longitudinal slot 24. The slot 24 is formed with two ledges 26
extending along the sides of the slot 24. These ledges terminate
at a gap near the front end 18 to define a front key 28. In addition,
gaps in the ledges 26 near the rear end 20 define a rear key 32.
Two radial ribs 32A form an outer surface 14 of the barrel 12 to
provide a better grip. At the rear end of the slot 24 a portion
of the barrel is cut to form an arcuate tongue 34. The purpose of
this tongue 34 is described in more detail below. The barrel is
preferably made of a plastic material and is preferably transparent
so that the clinician can see its contents. For example, the barrel
could be made of an acrylic-based multipolymer such as Cyrolite
#GS-90.
As seen in FIG. 1 the inside surface 16 of the barrel 12 is formed
with a helical groove 36. The rear end 20 is threaded. The front
end 18 is formed with an annular end wall 38 with an orifice 40.
The catheter assembly 21 consists of a piston 50 shown in detail
in FIG. 8 a catheter member 52 and a needle member 54. The piston
is formed of an axle 56 supporting a rear hub 58 a center hub 60
and a front hub 62. The rear and front hubs 58 62 have approximately
the same radial dimension and they are sized to allow the piston
50 to fit into the barrel 12 with the hubs 58 62 slidingly engaging
the inner surface 16. The axial spacing between the two hubs is
sufficient to stabilize the piston 50 and the elements attached
thereto (and described below) as they reciprocate through the barrel
12. The center hub 60 has a smaller diameter and a somewhat curved
cross section. The circumferential surface of hub 62 is optionally
provided with a knob 64 which is sized and shaped to fit into helical
groove 36. Therefore, as the piston 50 is reciprocated through the
barrel, it is also rotated about its longitudinal axis by the caming
action on the knob 64 as it travels through groove 36.
Hub 62 also includes a tubular wall 66 disposed about an end portion
68 of axle 56. The inner surface of the tubular wall 66 is formed
with a helical groove 70. The wall 66 and the end portion 68 cooperate
to define a female Luer lock 72.
Details of the needle member 54 are shown in FIG. 9. It includes
a disk 80 a cylindrical body 82 a frustoconical extension 84 and
a hollow steel needle 86. These elements are attached to each other
as shown. The disk 80 is sized and shaped so that it can be introduced
into the Luer lock 72. In this manner, the needle member 54 is firmly
attached to the piston 50. The needle member 54 can be secured to
the piston 50 by other means as well, for example, by using an adhesive.
As best seen in FIGS. 3 and 10 the catheter member 52 is formed
with a hollow substantially cylindrical body 90 with a rear portion
92 which has a relatively large diameter. The body 90 also has a
front portion 94 which is much thinner than the rest of the body
90. The body 90 also includes several circumferential ribs 96 forming
a grip for the catheter. A portion of one of the ribs is extended
radially to form a tab 98.
The catheter member 52 is made of a flexible plastic material.
Preferably catheter member 52 is somewhat translucent.
The catheter member 52 and the needle member 54 are sized and shaped
so that the catheter member 52 fits over the needle member 54 as
shown in FIG. 2 with the steel needle 86 extending through and beyond
the front portion 94. Moreover, the rear portion 92 is sized to
form an interference fit with the extension 84. The catheter member
52 is freely removable by a clinician from the needle member 54.
Of course, there is sufficient interference fit provided to insure
that the catheter member 54 does not separate easily from the needle
member without substantial force applied thereto. This force may
be applied to tab 98 as explained in more detail below.
Finally, the device 10 includes a control member or control means
100 shown in more detail in FIG. 7. The control member 100 is formed
of an upper body 102 a lower body 104 and an intermediate portion
106. The lower body 104 is formed with an arcuate surface 108 designed
to conform to the shape of the hub 60 on piston 50. The upper body
102 is formed with two wings 110 112 and a depression 114 defined
therebetween. The depression 114 is sized and shaped to accommodate
the finger of a clinician. The wing 112 is formed with a tab 116
extending downwardly and is sized and shaped to fit into the keys
30 and 32 on barrel 12. The control member 100 is made of a plastic
material.
The control member 100 is sized and shaped to fit into the slot
24 with the upper body 102 disposed outside the barrel 12 and riding
on the ledges 26 and the lower body 104 being disposed inside the
barrel with the hub 60 being captured by curved surface 108.
The device 10 is assembled by attaching the catheter member 52
to the needle element 54 and attaching the needle element to the
piston 50 thereby completing the catheter assembly 21. The spring
23 and catheter assembly 21 are then inserted through a hole (not
shown) in the rear end 20 of barrel 12. The control member 100 is
also mounted on the barrel 12. Next, the end piece 22 is attached
thereto by screwing the same over the threads of the rear end. Preferably
an adhesive is also used to insure that the end piece 22 does not
separate from the barrel. Alternatively, the end piece 22 is attached
to the barrel 12 without any threading action. Once the end piece
is installed, the elements described above are captured by the barrel
(except for the catheter member 52) and cannot be removed without
breakage.
Initially the elements of the device 10 are arranged in a closed
or retracted position as shown in FIG. 1. Spring 23 has a diameter
which is slightly larger than the diameter of wall 66. In this retracted
position, the spring 23 is expanded and applies a biasing force
between the end wall 38 of the barrel 12 and the wall 66 on piston
50. The control member 100 is positioned over the piston 50 with
the hub 60 being captured by the curved surface 108.
The control member 100 is formed so that its tab 116 extends downwardly
in the rear key 32 of slot 26. Moreover the control member 100 is
formed and arranged so that as the control member 100 is shifted
to the right to the retracted position, a bottom wail 118 of wing
110 (shown in FIG. 7) comes into contact with the end of tongue
34. The tongue 34 being slightly higher, and in effect pushes the
wing 110 slightly upward as well. As a result, the opposite wing
112 with the tab 116 is pushed downward into the key 30. In this
manner the control member 100 and the catheter assembly 21 is locked
into the retracted position by the locking means formed by the cooperation
between the control member 100 and key 32. The device 10 is sealed
in a suitable package (not shown) and stored in this position.
The device 10 is used to establish the catheter member 52 as follows.
Typically, an infusion procedure is initiated by a clinician by
selecting and prepping the infusion site. The clinician then removes
the device 10 from its package and holds it in a pinching grip.
In this grip the thumb is positioned on the control member 100
and the remaining fingers being wrapped around the barrel to stabilize
it. The device 10 is sized and shaped so that in this pinching grip,
the pinky finger wraps around the end piece 22.
The clinician then pushes on the wing 110 axially inward causing
the top body to twist slightly radially inward, and lift the tab
116 out of rear key 32. This action unlocks the control member 100.
Next, the clinician advances the control member 100 slightly forward.
Because the surface 108 captures the hub 60 this movement forces
the whole catheter assembly 21 to move forward as well. The clinician
continues the translation of the control member 100 forward until
a portion of the needle 96 extends through the hole 40 (FIG. 6).
Next, the clinician positions the device 10 next to the infusion
site with the tip of the needle 86 resting against the skin. The
clinician then continues to advance the control member 100 until
it reaches the front key 30. The clinician can lock the control
member 100 and the catheter 21 by pushing the wing 112 inwardly
thereby causing the tab 112 to pivot counterclockwise and engage
front key 30. In this position, a portion of needle member 54 and
most of the catheter member 52 extend out of the barrel 12 as shown
in FIG. 2. This position is the extended position of the device
and the control member 100 and front key 30 provide a locking means
for locking the catheter assembly in the extended position.
It should be appreciated that as the control member 100 is advanced
from the rear key 32 to the front key 30 in a translational motion
through the slot 26 because of the caming action between the knob
64 and spiral groove 36 the catheter assembly 21 is translated
forward as well from the retracted to the extended position, and
is simultaneously rotated about its longitudinal axis and the longitudinal
axis of the barrel 12. Thus, the knob 64 and spiral groove 36 provide
a means of rotating the catheter assembly 21. As explained in the
above-identified application Ser. No. 09/506484 filed Feb. 17
2000 and in application Ser. No. 09/745751 filed Dec. 21 2000
this combined or bidirectional motion is very advantageous because
as the needle 86 penetrates the skin and the tissues and advances
to the vein, its simultaneous rotation insures that the patient
suffers less pain. In addition, it prevents the needle 86 from bending
and insures that the needle advances precisely in the direction
and to the location desired by the clinician.
The needle 86 must be advanced sufficiently so that the front portion
94 is in fluid communication with the vein as well. The front portion
94 is thin enough so that it slips easily through the sidewalls
of the vein. As discussed above, needle 86 is hollow and has an
opening at its tip. A second opening may be provided on the needle
86 under the front end 94. When the needle 86 and front end 84 are
inserted into the vein, blood from the vein flows into the needle
86 and oozes out of this second opening, under the front end 94.
Since the catheter 52 is translucent, this blood is easily visible
to the clinician. Moreover, since the needle 86 is hollow, some
of the blood also flows back in the housing where it becomes visible
as well. This provides confirmation that the needle 86 and the catheter
member 52 are properly positioned in the vein.
If for any reason the clinician has to move to a different infusion
site, he can withdraw the needle from the patient. If this motion
occurs before the control member 100 reached front key 30 then the
clinician can merely release the control member 100 and the catheter
assembly 21 is then automatically returned to the retracted position
by the spring 23. If this motion is desired after the front key
30 is reached, then the clinician must first unlock the control
member from the front key by pressing inwardly on wing 110.
Once the catheter assembly 21 is returned to its retrieved position,
the device 10 can be rested on a flat surface and the clinician
can go on with other tasks (such as prepping the new site) without
fear of needlesticks even if the needle 86 has been contaminated.
After the needle 86 and the catheter member 52 are properly positioned
in the vein, the needle 86 is withdrawn as follows. The clinician
shifts his forefinger to rest on the front end 94 of the catheter
member 52. The rest of his fingers are still wrapped around the
barrel 12. In this position, the clinician unlocks the control member
100 as discussed above and releases it. The spring 23 forces the
needle member 54 to withdraw telescopically and separate from the
catheter 52. The needle member 54 and the piston 50 are then snapped
back to the retracted position. During this motion, the clinician
holds the catheter member 52 in place (i.e., inserted in the vein).
Thus, the clinician needs to use only a single hand from the beginning
of the process until the catheter member 54 is established in the
vein and is separated from device 10. As explained above, in prior
art devices this same operation requires the use of two hands.
FIG. 3 shows the catheter member 52 being removed from the needle
member 54.
FIG. 4 shows the catheter member 52 being separated from the rest
of the device 10.
FIG. 5 shows the catheter assembly 21 without the catheter member
52 in the retracted position.
Once the device 10 is in the retracted position of FIG. 5 it can
be disposed. The catheter member 52 can be connected to a standard
IV tube by attaching to a standard Luer lock, or by using other
well known means.
Importantly, in many instances the clinician may want to insure
that once its catheter member 54 has been properly established,
the device 10 is not reused in any way and that the needle member
54 stays in the retracted position. This is accomplished by providing
a control disabling means for the device which insures that the
control member 100 is inoperative and cannot be used to advance
the needle. This disabling means can be implemented by making the
intermediate portion 106 of the control member 100 frangible. Then,
once the catheter member 52 is properly established in the vein,
the top body 102 is broken off from the bottom body 104. Once this
step is completed, the piston 50 and the needle member 54 are trapped
inside the barrel 12 and cannot be removed without breaking the
barrel.
The device may be used in a different manner as well. For example,
if the clinician does not want to take advantage of the simultaneous
translation and rotation of the needle member 54 he can advance
the catheter assembly 21 from the retracted to the extended position
first, and then with the needle member being fully extended, he
can start inserting the needle 86 through the skin toward the selected
vein. For this type of operation, since the rotation of the needle
86 is not required, the knob 64 and the groove 26 may be omitted.
Other modifications may be made to the device 10 as well. For example,
the means for locking the control member 100 either in the retracted
position, the extended position, or both, may be omitted.
While the invention has been described with reference to several
particular embodiments, it is to be understood that these embodiments
are merely illustrative of the principles of the invention. Accordingly,
the embodiments described in particular should be considered as
exemplary, not limiting, with respect to the following claims. |