GB1587153A

GB1587153A - Needle and hub assembly for a catheter assembly and a catheter placement assembly incorporating the same

Info

Publication number: GB1587153A
Application number: GB751177A
Authority: GB
Original assignee: Taut Inc
Current assignee: Taut Inc
Priority date: 1977-02-22
Filing date: 1977-02-22
Publication date: 1981-04-01

Description

(54) A NEEDLE AND HUB ASSEMBLY FOR A CATHETER ASSEMBLY, AND A CATHETER PLACEMENT ASSEMBLY INCORPORATING THE SAME (71) We, TAUT, INC., a corporation organised under the laws of the State of Delaware, United States of America, of 9300 South Dadeland Boulevard, Miami, Florida, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a catheter placement assembly, and, more particularly, to a needle assembly therefor.

In the past, there have been numerous types of catheters which are flexible which are provided with rigid adapters on one end to connect to a medical device, for example, tubing for intravenous feeding, after a rigid needle or stylet has been removed from within the catheter following a venipuncture operation.

It is an object of this invention to provide a needle assembly for a catheter placement assembly which protects the mouth or luer of the adapter, to avoid contamination of it, by removing the fingers of the therapist handling the placement assembly from the luer's edge or lip while the placement assembly is manipulated during a venipuncture operation.

It is another object to provide a needle assembly including a vented chamber which is arranged so that, upon introduction of the needle into a vein there will be a flow of blood into the chamber and the therapist can visually observe that the tip of the needle is in the correct position within a vein.

According to the present invention there is provided a needle and hub assembly for a catheter placement assembly comprising: a hollow, rigid, elongate needle having a pointed distal end; and a hub of rigid plastics material including a central hub portion secured about the proximal end portion of the needle, said central hub portion having a distally-extending generally cylindrical skirt, spaced from the needle, and defining an annular, distally-opening, axially extending chamber dimensioned to receive the mouth of an adapter of a catheter assembly with the skirt encircling and protectively shrouding said mouth, said central hub portion also having a proximally-extending tubular wall defining a proximally-opening chamber, the proximal end portion of said needle being in open communication with said proximallyopening chamber to receive blood via the needle, and a vented removable cap closing said proximally-opening chamber.

The invention also provides a catheter placement assembly including a needle and hub assembly as above defined, and a catheter assembly including a relatively flexible catheter tube snugly jacketing the needle from its pointed distal end along an intermediate length of the needle, and a rigid tubular adapter for connecting the catheter assembly to a tubular member, and through which the needle is introduced into the catheter tube, the adapter having a proximally-opening end defining a mouth, being fixed to the catheter tube, and being releasably snugly received within said distally-opening chamber with said mouth protectively shrouded by the skirt.

In order that the invention may be more readily understood, one embodiment will now be described with reference to the accompanying drawings, in which: Figureisaside view illustrating a complete or assembled catheter placement assembly after venipuncture; Figure 2 is a view similar to Figure 1, illustrating the catheter assembly of Figure 1, after removal of the needle and hub assembly, and after flexing of the tubular flexible body of the catheter assembly away from the patient; Figure 3 is an exploded view of the catheter placement assembly of Figure 1, and a needle and catheter tube-protector member which is shown partly in cross-section; Figure 4 is a cross-section taken on the longitudinal centerline of the catheter placement assembly of Figure 1, on an enlarged scale; Figure 5 is a cross-section in the plane indicated by the line 5-5 of Figure 3, and looking in the direction of the arrows, on an enlarged scale; and Figure 6 is a fragmentary cross-section. on an enlarged scale, of an alternative connection of the catheter tube to the tubular flexible body of the catheter assembly.

Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, and referring particularly to Figure 4, there is shown what is often termed in the art a catheter placement assembly. It is composed of two main components or subassemblies, namely: (a) a needle and hub assembly 12; and (b) a catheter assembly 16.

Generally speaking, the needle and hub assembly 12 comprises a relatively rigid, hollow, elongate needle 15 which is pointed at its distal end, and a hub 18 of relatively rigid, translucent plastics material fixed to the proximal end of the needle. The hub is structured to define a proximally extending and opening blood-receiving chamber indicated generally at 20 (referred to hereinafter as a flash chamber). The catheter assembly 16 comprises a tubular, elongate, flexible catheter tube 22 sized to receive and jacket the main length of the needle 15. To the proximal end of the catheter tube is fixed a proximally extending and opening flexible, tubular body or housing 24 of a material which is rubber-like in so far as its property of flexibility or bendability is concerned. The proximally opening end of the body 24 is provided with an annular connector or adapter 25, and said proximally opening end is sized to nest removably within a protective skirt 32 extending axially from the needle hub when the two main components are assembled as a catheter placement assembly.

-Referring in more detail to the first main component, namely the needle and hub assembly 12, this comprises a conventional, hollow, distally-pointed, elongate needle or rigid stylet 15 connected to a hub 18 by conventional means. The connecting means includes a tubular fitting 23, fixed to the proximal end portion 27 of the needle located in an axial bore in an internal or central portion 30 of the hub, and having first and second radially outwardly projecting flanges 26 and 28 which engage axially opposite end faces of the central hub portion 30, to captivate the needle against axial separational movement relative to the central hub portion 30.

In addition to the central portion 30 having the aforementioned through bore, the hub 18 includes a generally cylindrical, circumferentially continuous skirt 32 which extends distally from the central portion 30 and beyond the distal-most extremity of the latter, and is generally co-axial with respect to the needle 15. The skirt 32 is spaced from the proximal end portion or shank of the needle and defines therewith a distally and axially-opening annular receptacle or chamber 34. The distal end of the skirt 32 is provided with an out-turned or radially projecting rim 44 to facilitate axial movement of the catheter placement assembly during venipuncture; and the exterior surface of this skirt includes gripping means in the form of radially-projecting, axiallyextending ribs 46.

The hub also includes the flash chamber 20 which is constituted by a tapered, i.e.

generally truncated conical, translucent wall 36 which extends proximally from the central portion 30 and is generally co-axial with respect to the needle. The wall 36 defines an internal reservoir 38 which is in open communication with the passage in the needle, and terminates proximally in an open mouth 40. The purpose of the flash chamber 20 is to enable ready visual observation, through the translucent wall, of blood received in the reservoir 38 via the needle, which is indicative that the point of the needle is properly inserted into a vein of a patient. The reservoir 38 is closed by a removable generally cup-shaped cap 42, and for this purpose, the cap is provided with a tapered wall which corresponds or matches with the taper of the wall 36. The exterior surface of the end cap is also provided with gripping means comprising ribs 48 to rotatingly manipulate the cap. The end cap is also provided with a radial flange or rim 5, to serve as a gripping means to facilitate removal of the end cap when the needle and hub assembly is to be connected to another medical device, by means of the wall 36 of the hub which serves as a fitting or connector.

The flash chamber is vented by suitable venting means associated with the end cap.

In the preferred embodiment, a filter disk 50 is secured by suitable means to span an opening in the proximal end 52 of the cap.

The filter disk is formed of bacteriological filter material through which air may pass, but the blood components cannot readily pass. One such commercially available material possessing these characteristics, from which the disk may conveniently be made, is known as, TYVEK (a trademark of the E.I.

duPont de Nemours Company), which consists of a thin sheet of polyethylene fibers in mat form. The disk 50 is secured by bonding to the material of the end cap, and this may be achieved by heating means which fuses the margin of the disk to the wall of the end cap about the opening in the latter.

The catheter assembly 16 includes a flexible catheter tube 22 formed, for example, from a length of Teflon (a trademark of the E.I. duPont de Nemours Company). The catheter tube completely jackets or sheaths the main length of the needle from the flexible body 24 to the bevelled needle point proper. Preferably the end 53 of the catheter tube 22 is tapered towards the needle surface proximally of the needle point proper to facilitate entry of the catheter tube after venipuncture has initially been effected by the sharp exposed point of the sheathed needle.

Retention means secure the proximal end of the catheter tube to the flexible body, with the catheter tube in fluid communication with the axial through passageway (lumen) in the flexible body. The retention means may comprise a short, tubular, and in particular cylindrical, segment 54, of a relatively rigid plastics material, having an axially extending region which is both tele-scoped over, and engages, the proximal end of the catheter tube, and is telescoped into the flexible body and is bonded or vulcanized to the rubber-like material of the latter.

The segment 54 may be fixed to the proximal end of the catheter tube by being a tight fit thereon as in Fig. 4. Alternatively, as shown in Fig. 6 where, for example, the catheter tube is made of Teflon (Trade Mark), a tubular segment 54, may be provided, the proximal end 61 of the catheter tube passing through the segment and being turned back on itself at 64 around the end 63 of the segment to form a mechanical lock against axial movement relative to the body 24. The lock may be supplemented by a bond between the material of the body 24 which is, in effect, vulcanized to the rigid plastics segment. In both alternatives the external cross-sectional dimension or diameter of the tubular segment is less than that of the distal end of the flexible body, so that the exterior of the tubular segment is set or telescoped into the flexible body.

To the proximal end of the flexible body 24, the adapter 25 is connected. The exterior of the adapter 25 is sized to be receivable and nestable, snugly yet removably, within the skirt 32 of the hub 18. The skirt is preferably interiorly tapered to cooperate with a rigid rim 69 at the proximal end of the adapter, the rim 69 seating in the skirt to limit axial movement of the rim 69 into the skirt, the skirt thus serving as stop means to predetermine the distance by which the needle point projects from the catheter tube, and optionally also serving to orient the bevelled point of the needle. Preferably, the rim 69 is square as viewed axially or in cross-section. Within the axiallyextending passage in the body 24, as shown in Fig. 5, longitudinally-extending ribs 70 are provided which prevent occlusion of the passage when the body is flexed as shown in Figure 2, or when external pressure is applied to the body.

In one specific preferred embodiment, the flash chamber 20 is about one-eighth inch in diameter and about one inch in axial length, which is of sufficient size to enable visual observation of blood in the flash chamber to be readily made. The hub 18, the adapter 25 and the retention means 54 or 54' are molded from relatively rigid plastics material, for example, from polypropylene. The rubber-like material of the flexible body is moldable Kraton (a product of the Shell Oil Company). This rubber-like material should be such that, as shown in Fig. 2, flexing of the body 24 is possible for manipulating it into the most favorable orientation of the adapter mouth or luer, to facilitate connection to tubing or another medical device.

Because this material is relatively soft it is comfortable when in place for long periods of time. The rubber-like material of the body 24 is bonded or vulcanized by heat to the adapter 25 and to the retention means 54 or 5 ',the latter being effective to positively lock the catheter tube to the body as explained above. The adapter 25 is provided, at its distal end, with an annular, symmetrical, axial nose 72 which projects into the through passage in the body 24 as shown. Furthermore, as shown in Figure 3, stabilizing wings or ears 73 and 75 are provided on the exterior surface of the distal end of the body 24 to provide stability against rolling relative to the body of a patient and to provide means for connecting the catheter assembly by tape to the patient's body when properly positioned. A weakened zone, as shown at the tip of the leading line to reference 75, may be provided in each ear to anchor it in place by sutures.

The axial length of the flexible body 24 is greater than one-half inch and is preferably not greater than one inch, while, in crosssection, the body 24 has an outside diameter of about one-quarter of an inch between its center and proximal end and its passage has a diameter of about one-eighth of an inch, so that the body will have a substantial mass and resistance to buckling in response to axial force application. The stabilizing wings are of the same rubbery material as, and formed integrally with, the body 24. The body 24 comprises a readily bowable or bendable member, serving as a hinge connection between the tubular retention means 54 or 54', and the adapter 25, which are relatively rigid. The axial depth of the chamber 34 in the skirt 32 of the needle hub 18, between its open mouth and the open mouth or rim 69 of the adapter 25, determines the protected location of the mouth of the adapter at the proximal end of the catheter assembly; preferably this depth is at least one-quarter inch, and between one-quarter inch and one half-inch. The axial length of the gripping area of the skirt 32, that is, between the rim 44 and the flash chamber 20, is about one-half inch and between one-quarter and three quarters of an inch.

Preferably, an elongate protector member 81 of relatively rigid plastics material is provided, which includes an elongate, reduced-diameter receptacle 82, which may be closed at one end 3. The other end of the protector member is open, and comprises an enlarged-diameter socket 85 sized to receive and rcleasably grip the rim 44 of the needle hub 18, with the needle and catheter tube of the placement assembly suspended in, and protected by, the receptacle 82, prior to use of the placement assembly. The wall of the socket 85 adjacent the open end of the protector member is preferably inwardly tapered, and includes a shoulder 84 which abuts the rim 44 when the placement assembly is assembled to the protector member, which shoulder serves as a stop to limit penetration of the needle into the receptacle 82.

To use the catheter placement assembly, the protector member 81, is first removed to expose the catheter tube and needle. The venipuncture operation is then performed in the usual manner. In this respect, the hub 18, which is of sufficient axial length to manipulate it conveniently, is grasped about the skirt 32 which protectively houses the rim 69, and in particular the mouth of the adapter 25. When the vein has been punctured, blood will flow through the hollow needle and into the flash chamber 20 whilst the needle and hub assembly 12 and the catheter assembly 16 are assembled together as in Figure 4, i.e. with the needle 15 passing through the co-axial passages in the flexible body 24 and catheter tube 22 respectively, and the mouth of the adapter 25 encircled and protectively shrouded by the skirt 32.

Then, by handling the exposed portion of the flexible body 24, the catheter tube is advanced until it reaches the desired position in the vein, while the needle assembly is held in a relatively stationary position by continuing to grasp the hub 18. It will be seen that the fingers do not contaminate the proximal opening or mouth of the adapter 25 in so doing. After this has been accomplished, the needle is completely removed so that the vein is then in communication with the passage in the adapter via the catheter tube. The end of a tube of an I.V. set is then connected to the rim 69 of the adapter 25.

Finally the catheter assembly is taped or otherwise anchored in place.

It is thus seen that the needle and hub assembly 12 provides a protective annular chamber within the skirt 32 of the hub 18 which completely encircles and therefore protectively houses the proximal end or mouth of the adapter 25, i.e. of the catheter assembly, during the venipuncture operation; and that the exterior of the skirt 32 may be gripped to hold the needle 15 in position while the catheter assembly is advanced by gripping the portion of the flexible body 24 extending from the distallyopening mouth of the skirt 32 to advance the catheter tube into the vein relative to the needle point and thus properly position the catheter tube. When the needle is removed, the proximal end of the catheter assembly can be displaced away from the patient, by bowing the flexible body 24 as shown in Figure 2, for connection to another medical device, such as a tube, for intravenous feeding.

The catheter assembly and the catheter placement assembly herein described form the subject, respectively, of copending divisional applications Nos. 7 938 922 and 7 933 753 (Serial Nos. 1 587 155 and 1 587154).

WHAT WE CLAIM IS: 1. A needle and hub assembly for a catheter placement assembly comprising: a hollow, rigid, elongate needle having a pointed distal end; and a hub of rigid plastics material including a central hub portion secured about the proximal end portion of the needle, said central hub portion having a distally-extending, generally cylindrical skirt, spaced from the needle, and defining an annular, distally-opening, axially extending chamber dimensioned to receive the mouth of an adapter of a catheter assembly with the skirt encircling and protectively shrouding said mouth, said central hub portion also having a proximally-extending tubular wall defining a proximally-opening chamber, the proximal end portion of said needle being in open communication with said proximally- opening chamber to receive blood via the needle and a vented removable cap closing said proximally-opening chamber.

2. An assembly as claimed in claim 1, wherein the distally-opening chamber in the skirt extends distally beyond the distal extremity of the central hub portion.

3. An assembly as claimed in claim 1 or 2, wherein the skirt is circumferentially continuous over substantially its entire axial length.

4. An assembly as claimed in claim 1, 2 or 3, wherein the portion of the skirt defining the distally-opening end of said distally-opening chamber is provided with a generally radially outwardly extending rim to facilitate manual axial movement of the needle in a distal direction.

5. An assembly as claimed in any preceding claim, wherein the exterior surface of the skirt includes means to enhance manual

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the gripping area of the skirt 32, that is, between the rim 44 and the flash chamber 20, is about one-half inch and between one-quarter and three quarters of an inch. Preferably, an elongate protector member 81 of relatively rigid plastics material is provided, which includes an elongate, reduced-diameter receptacle 82, which may be closed at one end 3. The other end of the protector member is open, and comprises an enlarged-diameter socket 85 sized to receive and rcleasably grip the rim 44 of the needle hub 18, with the needle and catheter tube of the placement assembly suspended in, and protected by, the receptacle 82, prior to use of the placement assembly. The wall of the socket 85 adjacent the open end of the protector member is preferably inwardly tapered, and includes a shoulder 84 which abuts the rim 44 when the placement assembly is assembled to the protector member, which shoulder serves as a stop to limit penetration of the needle into the receptacle 82. To use the catheter placement assembly, the protector member 81, is first removed to expose the catheter tube and needle. The venipuncture operation is then performed in the usual manner. In this respect, the hub 18, which is of sufficient axial length to manipulate it conveniently, is grasped about the skirt 32 which protectively houses the rim 69, and in particular the mouth of the adapter 25. When the vein has been punctured, blood will flow through the hollow needle and into the flash chamber 20 whilst the needle and hub assembly 12 and the catheter assembly 16 are assembled together as in Figure 4, i.e. with the needle 15 passing through the co-axial passages in the flexible body 24 and catheter tube 22 respectively, and the mouth of the adapter 25 encircled and protectively shrouded by the skirt 32. Then, by handling the exposed portion of the flexible body 24, the catheter tube is advanced until it reaches the desired position in the vein, while the needle assembly is held in a relatively stationary position by continuing to grasp the hub 18. It will be seen that the fingers do not contaminate the proximal opening or mouth of the adapter 25 in so doing. After this has been accomplished, the needle is completely removed so that the vein is then in communication with the passage in the adapter via the catheter tube. The end of a tube of an I.V. set is then connected to the rim 69 of the adapter 25. Finally the catheter assembly is taped or otherwise anchored in place. It is thus seen that the needle and hub assembly 12 provides a protective annular chamber within the skirt 32 of the hub 18 which completely encircles and therefore protectively houses the proximal end or mouth of the adapter 25, i.e. of the catheter assembly, during the venipuncture operation; and that the exterior of the skirt 32 may be gripped to hold the needle 15 in position while the catheter assembly is advanced by gripping the portion of the flexible body 24 extending from the distallyopening mouth of the skirt 32 to advance the catheter tube into the vein relative to the needle point and thus properly position the catheter tube. When the needle is removed, the proximal end of the catheter assembly can be displaced away from the patient, by bowing the flexible body 24 as shown in Figure 2, for connection to another medical device, such as a tube, for intravenous feeding. The catheter assembly and the catheter placement assembly herein described form the subject, respectively, of copending divisional applications Nos. 7 938 922 and 7 933 753 (Serial Nos. 1 587 155 and 1 587154). WHAT WE CLAIM IS:

1. A needle and hub assembly for a catheter placement assembly comprising: a hollow, rigid, elongate needle having a pointed distal end; and a hub of rigid plastics material including a central hub portion secured about the proximal end portion of the needle, said central hub portion having a distally-extending, generally cylindrical skirt, spaced from the needle, and defining an annular, distally-opening, axially extending chamber dimensioned to receive the mouth of an adapter of a catheter assembly with the skirt encircling and protectively shrouding said mouth, said central hub portion also having a proximally-extending tubular wall defining a proximally-opening chamber, the proximal end portion of said needle being in open communication with said proximally- opening chamber to receive blood via the needle and a vented removable cap closing said proximally-opening chamber.

gripping of the skirt.

6. An assembly as claimed in any preceding claim, wherein said cap is generally cup-shaped, and is provided with a tapered surface which cooperates with a matching tapered surface associated with the portion of the tubular wall defining the proximal end portion of the proximally-opening chamber to removably attach the cap to the tubular wall.

7. An assembly as claimed in any preceding claim, wherein the cap is vented via a piece of bacterial filter material which is effectively porous to air and non-porous to liquids, and which is fixed in spanning relation with respect to an opening in the proximal end of the cap.

8. An assembly as claimed in claim 7, wherein the filter material is a sheet of polyethylene fibers in mat form.

9. An assembly as claimed in claim 8, wherein the margin of the sheet of filter material is fused to the cap, and said cap is formed of rigid plastics material.

10. An assembly as claimed in any preceding claim, including a protector member having an elongate receptacle dimensioned to receive the needle, and means to releasably connect the member to the needle hub.

11. An assembly as claimed in claim 10, wherein the receptacle is sized to receive the distal end of the skirt, and includes stop means to limit the extent of insertion of the needle hub into said receptacle.

12. A needle and hub assembly for a catheter placement assembly, substantially as hereinbefore described with reference to the accompanying drawings.

13. A catheter placement assembly including a needle and hub assembly as claimed in any preceding claim, and a catheter assembly including a relatively flexible catheter tube snugly jacketing the needle from its pointed distal end along an intermediate length of the needle, and a rigid tubular adapter for connecting the catheter assembly to a tubular member, and through which the needle is introduced into the catheter tube, the adapter having a proximally-opening end defining a mouth, being fixed to the catheter tube, and being releasably snugly received within said distally-opening chamber with said mouth protectively shrouded by the skirt.

14. A catheter placement assembly as claimed in claim 13, wherein the catheter assembly includes a generally tubular flexible body of a predetermined axial length fixed at one end to said adapter and at the other end to the catheter tube.

15. A catheter placement assembly as claimed in claim 14, wherein the catheter assembly includes a rigid tubular segment of plastics material telescoped over the proximal end portion of the catheter tube and connected to the flexible body to secure the catheter tube to the flexible body, the portion of the flexible body intermediate the rigid tubular segment and adapter providing a hinge connection therebetween.

16. A catheter placement assembly as claimed in claim 15, wherein the catheter tube has a tapered distal end, and the tubular flexible body has an axial through passageway interconnecting, and generally co-axial with, the adapter and catheter tube, and accommodating, and generally co-axial with, the needle, the proximal end of the catheter tube being secured, via said rigid tubular segment, within the distal end of the passageway, and the adapter being secured within the proximal end of the passageway.

17. A catheter placement assembly as claimed in claim 16, wherein the tubular flexible body is provided with a plurality of ribs extending into the passageway so that, on flexing of said body along its length, the passageway is not occluded.

18. A catheter placement assembly as claimed in claim 14, 15, 16 or 17, wherein the catheter assembly includes oppositely extending ears of a substantially common size provided on the flexible body at the said other end to stabilize the body, and wherein the flexibility of said body permits it to be bowed intermediate its length by lifting its said one end.

19. A catheter placement assembly as claimed in any of claims 13 to 18, wherein the proximally-opening end of the rigid adapter projects into the distally-opening chamber of the needle hub by distance of at least one-quarter of an inch.

20. A catheter placement assembly as claimed in any of claims 13 to 19, wherein the axial length of said flexible body is at least one-half of an inch.

21. A catheter placement assembly as claimed in claim 20, wherein the diameter of said flexible body is about one-quarter of an inch between its centre and proximal end.

22. A catheter placement assembly as claimed in claim 19, 20 or 21, wherein the distally-opening chamber of the needle and hub assembly is one-quarter to one-half of an inch in axial depth.

23. A catheter placement assembly as claimed in any of claims 19 to 22, wherein the proximally-opening chamber of the needle and hub assembly is about one-eighth of an inch in diameter and about one inch in axial length.