Catheter Placement Unit

Abstract

A catheter placement unit comprising means for maintaining a catheter in alignment with the bore of a stylet needle and support means extendable through the bore of said catheter and advanceable with said catheter through said needle to prevent misalignment of said catheter with said needle during placement.

Description

BACKGROUND

FIELD OF INVENTION

This invention relates to catheters and particularly to catheter placement units of the type wherein the catheter is inserted telescopically within a hollow needle for placement.

Prior Art

In the medical arts, it is frequently necessary or desirable to place a catheter within a patient's vein in order to permit infusion of fluids, such as plasma, whole blood, saline solution, and the like, into the patient's circulatory system. To accomplish such placement, it is frequently desirable to perform a venipuncture by means of a stylet needle and to pass the catheter through the bore of the needle to the desired location within the vein. Unfortunately, in order to properly position the catheter within the vein, it is sometimes necessary to reverse or partially withdraw the catheter. When this has occurred with the placement units of the prior art, the catheter has occasionally become misaligned with the bore of the needle and, upon reversal, has been drawn against the edge of the needle with the result that the outer surface of the catheter becomes burred and tends to irritate the wall of the vein. In extreme instances, portions of the catheter may actually be sheared off and carried away by the blood flow. Obviously, this condition can have serious, or even fatal consequences.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION

These disadvantages of the prior art are overcome with the present invention and a novel catheter placement unit is provided which assures proper alignment of the catheter with the bore of the needle during both forward and reverse movement and, thereby, minimizes the likelihood of burring or shearing of the catheter.

The advantages of the present invention are preferably attained by providing a catheter placement unit comprising a stylet needle having a bore dimensioned to permit passage therethrough of a catheter, adapter means secured to the proximal end of the needle and connectable to the catheter to maintain the catheter in alignment with the bore of the needle, and a rigid tube extending through the bore of the catheter and advanceable with the catheter to project beyond the distal and of the needle.

Accordingly, it is an object of the present invention to provide an improved catheter placement unit.

Another object of the present invention is to provide a catheter placement unit including means for preventing burring or shearing of the catheter during reverse movement in the course of placement.

A further object of the present invention is to provide a catheter placement unit including means for assuring alignment of the catheter with the bore of the needle.

A specific object of the present invention is to provide a catheter placement unit comprising a stylet needle having a bore adapted to permit passage therethrough of a catheter, adapter means secured to the proximal end of the needle and connectable to the catheter to maintain the catheter in alignment with the bore of the needle, and a rigid tube extending through the bore of the catheter and advanceable with the catheter to project beyond the distal end of the needle.

These and other objects and features of the present invention will be apparent from the following detailed description, taken with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal section through a catheter placement unit embodying the present invention;

FIG. 2 is a transverse section taken, on the line 2--2 of FIG. 1; and

FIG. 3 is a view, similar to that of FIG. 1, showing the placement unit of FIG. 1 with the parts in the extended position.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In that form of the present invention chosen for purposes for illustration, FIGS. 1-3 show a catheter placement unit, indicated generally at 2, comprising stylet needle 4 formed with a bore 6 extending axially therethrough and having a beveled point 8 at the distal end thereof. The proximal end 10 of the needle 4 is permanently secured, as by welding, to a hub 12 having a foward projection 14 exteriorly dimensioned to mate with the interior of a suitable needle sheath, not shown, and formed with a bore 16 extending axially through the hub 12. An annular sleeve 18 circumscribes the hub 12 and extends a short distance rearwardly therefrom. The sleeve 18 is formed with a radially projecting flange 20 and the distal end 22 of a rigid connecting rod 24 is permanently secured, as by epoxy, to the sleeve 18 in abutting relation with flange 20. The proximal end 26 of connecting rod 24 is received in and permanently secured to a boss 28 which projects from the front of a cylindrical housing 30. The housing 30 is formed with an axial bore 32 provided with annular ridges 34 and 36 extending circumferentially thereabout. As shown, ridge 36 circumscribes the proximal end of bore 32, while ridge 34 is located forwardly of ridge 36 about two-thirds of the length of housing 30 at its proximal end, housing 30 is provided with a pair of opposed, outwardly projecting flanges 37. At the distal end, housing 30 is provided with a plurality of radially inwardly projecting tabs 38 which extend nearly into engagement with catheter 40. As seen in FIG. 1, the catheter 40 comprises a hollow tube 42 having its distal end 44 situated in the bore 6 of needle 4 and having a connector 46 secured to the proximal end of the tube 42. Connector 46 is formed with a recess 48 which communicates with the bore 50 of catheter tube 42 and serves to couple the catheter 40 to a suitable fluid infusion unit, not shown. If desired, connector 46 may also be provided with outwardly projecting Luer tabs. A steel tube 52 extends substantially completely through bore 50 of catheter tube 42 and has its distal end 54 located adjacent the distal end 44 of catheter tube 42. The proximal end of tube 52 is permanently secured in the axial bore 56 of a plunger 58 having a male projection 60 which encircles the tube 52 and is formed to mate with recess 48 of the connector 46 of catheter 40. The plunger 58 is also provided with a radially projecting flange 62 having a diameter substantially equal to that of bore 32 of housing 30, such that the flange 62 is freely slideable within bore 32, but frictionally engages ridges 34 and 36. In addition, the plunger 58 has a rearwardly projecting annular portion 64 which encircles and extends rearwardly beyond the proximal end of the tube 52. The interior of the annular portion 64 forms a chamber 66 which communicates with the exterior at the proximal end thereof and which is dimensioned to mate with the male connector of a fluid infusion unit, not shown. The exterior of the proximal end of the annular portion 66 is provided with Luer dogs 68 and a suitable flow control plug 70 is provided to frictionally close the proximal end of the annular portion 66. Finally, a transparent flexible sleeve 72 has one end thereof secured to sleeve 18 in circumscribing relation therewith, while the other end of sleeve 72 telescopically receives the distal end of housing 30.

In use, the connector 46 of catheter 40 is attached to the male projection 60 of plunger 58 and plunger 58 is placed in its retracted position, as seen in FIG. 1. The distal end 44 of the catheter 40 is fed through bore 16 in the needle hub 12 and into bore 6 of needle 4. The tube 52 is then inserted, as described above, and the free end of the transparent sleeve 72 is slid onto the housing 30 and releasably secured thereto. It will be seen that, as thus assembled, hub 12, connecting rod 24, housing 30 and tube 52 cooperate to maintain the catheter 40 in alignment with the bore 6 of needle 4. When the catheter 40 is to be placed, a venipuncture is performed, in the usual manner. Thereafter, the doctor grips plunger 58 and flanges 37 and urges plunger 58 forward, advancing plunger 58, tube 52, and catheter 40, until flange 62 of plunger 58 engages ridge 34 in bore 32 of housing 30, as seen in FIG. 2. As shown, this advancement causes the distal ends of tube 50 and catheter 44 to project beyond the leading end 8 of needle 4 and advances connector 46 of catheter 40 to a position where it may be conveniently gripped. The end of sleeve 72 is then removed from about the housing 30 and the connector 46 is detached from male projection 60 of plunger 58. The catheter 40 is then slid along tube 52 for placement. It will be seen that during the advancement of catheter 40 and tube 52, and during subsequent movement of the catheter 40 along tube 52 for placement, the tube 52 assures that the catheter 40 is properly aligned with the bore 6 of needle 4 and that the catheter 40 does not become undulated or kinked in passing through bore 6 of needle 4. Moreover, during movement of catheter 40 along tube 52 for placement, if reverse movement of the catheter 40 is necessary, tube 52 assures that the catheter 40 is properly aligned with bore 6 of the needle 4, since tube 52 projects beyond the end of needle 4, and, thus, prevents burring or shearing of the catheter 44. Once the catheter 40 is placed, the tube 52 may be withdrawn.

Obviously, numerous variations and modifications may be made without departing from the present invention. Accordingly, it should be clearly understood that the form of the present invention described above and shown in the accompanying drawing is illustrative only and is not intended to limit the scope of the invention.

Claims

What is claimed is:

1. A catheter placement unit comprising:

a needle having an axial bore,

a hub secured to one end of said needle,

a housing spaced a distance from said hub;

a rigid rod secured to said hub and said housing and serving to maintain said housing in alignment with said needle,

a plunger carried by and movable axially of said housing formed with a bore extending therethrough and having means for releasably coupling a catheter tube to said plunger,

a catheter tube formed with an axial bore and having one end of said catheter tube coupled to said plunger and having the other end extending into the bore of said needle, and

an elongated rigid tube dimensioned to fit telescopically within the bore of said catheter tube, said rigid tube extending through the bore of said plunger and said catheter and having one end of said rigid tube secured within said bore of said plunger.

2. A catheter placement unit comprising:

a hollow needle having a forward sharpened end and a female hub end;

a catheter tube, the distal end of which is normally disposed within the hollow of the needle and the proximal end of which extends to a position remote from the needle hub;

a female hub at the remote proximal end of the catheter tube;

a rigid stiffener having a dull distal end, the stiffener being disposed within and running coextensively along substantially the entire length of the catheter tube;

plunger means disposed proximal of the female hub of the catheter tube and coupled thereto for pushing said female hub and the associated catheter tube forward beyond the sharpened end of the needle;

guide means disposed around the female hub of the catheter tube and adjacent the plunger means and rod means anchoring the guide means to the female hub of the needle, to maintain axial alignment of the stiffener and catheter tube with the needle both before and during said pushing action.

3. The catheter placement unit of claim 2 wherein the guide means comprise a generally hollow cylindrical member in which the plunger means is displaced and wherein the anchoring means comprise at least one substantially rigid connecting rod located eccentric of but generally parallel to the catheter tube.

4. A catheter placement unit comprising:

a hollow rigid needle having a forward sharpened end comprising the exposed distal end of the unit for making a venipuncture and a female hub end;

a flexible catheter tube the distal end of which is (a) slidably disposed within the hollow of the needle at venipuncture and (b) extended beyond the needle following venipuncture and a proximal end of which extends to a position remote from the needle hub;

a catheter female hub at the remote proximal end of the catheter tube;

a hollow rigid stiffener having a dull distal end spaced rearward of the distal end of the flexible catheter tube, the stiffener otherwise being disposed within and running coextensively along substantially the entire length of the flexible catheter tube to prevent shirring of the catheter tube by the sharp end of the needle during relative movement of the two parts, the proximal end of the hollow stiffener projecting beyond the proximal end of the flexible catheter tube whereby flashback at venipuncture instantaneously passes through the hollow of the stiffener;

light-transmitting flashback means disposed proximal of and in direct connected communication with the hollow interior at the proximal end of the stiffener and the proximal end of said female catheter hub whereby at venipuncture blood instantaneously passes through the hollow of the stiffener into the light-transmitting flashback means for visual observation and whereby axial displacement of the flashback means causes a corresponding displacement of the hollow stiffener whereby the flashback means and the stiffener may be jointly removed from the catheter tube and the female catheter hub.