Separable Catheter Insertion Device

Abstract

A disposable catheter insertion device has a longitudinal slot running the length of the needle and of the hub member secured to the needle. The slot facilitates removal of the catheter from the needle after insertion of the catheter into a patient. A clip member slidably coacts with the hub member and a coupling sleeve to prevent longitudinal movement of the catheter during insertion into a patient.

Description

BACKGROUND OF THE INVENTION

This invention relates to medical devices for subcutaneous introduction of fluids into a patient, and more specifically to a catheter and insertion device therefor. These devices are generally used for intravenous infusion, however, they also can be used for infusion or withdrawal of fluids into or from other regions of the body. Hereafter, for purposes of simplicity, the devices will be referred to in relation to intravenous infusion.

Catheters of the general type disclosed herein are available commercially and have been disclosed in the prior art. For example, self-contained catheters and insertion devices therefor are disclosed in U.S. Pat. Nos. 3,000,380; 3,010,453; 3,017,884, and 3,055,361. This general type of catheter was developed for usage where administration of fluids to a patient had to be either continuous or where such administration was intermittent over a prolonged period.

Prior to the development of the self-contained catheters and insertion devices, intravenous or other infusion of fluid into a patient was accomplished by means of a sterile needle. This needle was utilized to puncture the skin and vein of a patient. The needle was then taped to the surface of the skin. A conduit coupled to a source of intravenous fluid, for example, a syringe or gravity bottle type infusion fluid source, was then connected to the needle. Generally, this type of device has been unsatisfactory. Due to the rigidity of the needle and muscle flexure of the patient, it was necessary to remove the needle when an infusion was finished, and to reinsert the needle each time a new infusion was to be given. The repetitive removal and reinsertion of the needle caused puncture damage and bruising to the area of the patient into which the needle was being inserted. Therefore, those in the medical field have come to prefer the flexible catheter infusion method. The prior art flexible catheters for infusion of fluids into the veins of patients generally include a hollow needle and a fairly long flexible hollow cannula, the catheter. One end of the catheter usually has a coupling means or mechanism thereon, for example of the luer type, for connection to a source of infusion liquid. The other end of the catheter is slidably disposed within the bore of the hollow needle. The hollow needle is then inserted into a vein of a patient. The catheter is pushed through the hollow portion of the needle into the vein. The needle is then removed leaving the catheter protruding from the body of the patient. One of the advantages of this type of injection apparatus is that the needle, catheter and coupling means can be completely enclosed in a sterile package which is unopened until the time it is to be used with a patient. In addition, the materials utilized can be sufficiently economic to render such devices disposable after use. Thus, the chances of contamination or the spreading of infection is substantially lessened compared to the reusable type injection devices which must be resterilized after every use.

One of the significant drawbacks of this prior art is that once the insertion needle is withdrawn from the body of the patient leaving the catheter, the needle cannot be removed from the catheter. It has been impossible to remove the needle since the catheter at its protruding end usually contains a coupling mechanism of larger diameter than the needle bore, as above explained. Since the needle cannot be removed, it is continuously present on the catheter outside the patient's body. In the past, the presence of the needle has been troublesome due to its bulkiness and to the fact that the patient's skin can easily be accidentally punctured by the needle point.

Damage to the catheter from the needle can also result. But more importantly, a catheter must sometimes be partially withdrawn during the insertion process resulting in accidental cutting or severing of the catheter by the needle point within the patient's body. Not only can the severed end of the catheter thus lodge within the patient, but also small chips or shavings from the catheter wall can remain within the patient's body. These results are, of course, intolerable.

Various means have been proposed for resolving these problems. The initial method proposed was merely to tape the needle with the catheter running through it to the patient's arm thereby keeping it out of the way. However, the danger of damage to the catheter and to the patient's skin still was present although not in as great a proportion. Another solution is disclosed in U.S. Pat. No. 3,055,361. In that patent, a sleeve which is slidably inserted around the needle prior to its insertion into the patient's arm is disclosed. The sleeve is positioned on the portion of the needle which remains exterior to the patient's body. After the catheter has been inserted and the needle withdrawn from the patient, the sleeve is moved toward the pointed end of the needle to cover it. Frictional contact between the portion of the sleeve not extending beyond the pointed end of the needle retains the sleeve on the needle. Thus, the pointed end of the needle is covered preventing damage to the patient. This apparatus, however, still has drawbacks. The possibility of damage to the catheter itself still exists since it is not protected from the pointed end of the needle by the sleeve. In addition, the bulky needle is still present and still must be taped or tied to the patient's arm.

Still another approach to the problem, representing an advance over the prior attempts, is disclosed in U.S. Pat. No. 3,472,232. This patent discloses a hollow needle containing a longitudinal slot running along its entire length. The needle, of course, is pointed at one end. A pressure member is connected to the other end which serves as a needle hub. Hinged to the pressure member or needle hub is a projection which can be moved in and out of a slot in the pressure member and through the needle slot to contact a catheter slidably disposed in the needle. After the catheter is inserted into a patient, the needle can be withdrawn from the patient's body and separated from the catheter by pulling upwardly on the projection to remove it from the slot in the pressure member and pulling the catheter through the slot in the needle and the pressure member. Although representing an advance over prior attempts at dealing with the needle after removal from the patient's body, this concept still retains significant disadvantages. For example, in order to operate the catheter insertion device of the aforementioned patent, two hands are necessary; one to hold the needle and the other to release the pressure member so that the catheter can be inserted. Usually it is desirable for a sole operator of such a catheter insertion device to have one hand free to manipulate or hold a patient's appendage while holding onto the needle insertion device with the other hand. In addition, the device disclosed in the above-mentioned patent makes no provision for maintaining the catheter in a sterile environment during insertion. This also is important in that the atmosphere surrounding the patient during insertion of the catheter may not be sufficiently sterile to prevent the spread of infection into the puncture wound made by the catheter insertion needle. In addition, the pressure member of the device disclosed in the above-mentioned patent must also be held down with one finger of the hand inserting the catheter insertion needle into a patient in order to seize the catheter. It is important that the pressure member seize or contact the catheter to prevent the catheter from sliding longitudinally backwardly in the needle while it is being inserted. It is most desirable to maintain the forward end of the catheter near the pointed tip of the insertion needle while the two are being initially inserted into a patient's body.

It is, therefore, found desirable to develop a catheter insertion device in which the needle can be completely separated from the catheter containing a coupling mechanism at its distal end. In addition, it is desirable to possess a catheter insertion device which allows manipulation and insertion of the needle and catheter into a patient with only one hand of the operator. In addition, it is desirable to maintain the catheter in the sterile environment while inserting it or sliding it longitudinally through the needle into a patient's body, still providing for complete removal of the needle from the catheter. In addition, it is also desirable to maintain such a device at a low manufacturing cost while incorporating the additional features heretofore described. A low manufacturing cost is desirable since it will allow production of disposable catheter insertion devices incorporating the needle removability feature.

SUMMARY OF THE INVENTION

The present invention, therefore, solves the foregoing problems while incorporating the desirable attributes of a disposable catheter insertion device. The subcutaneous catheter insertion device of the present invention comprises a needle having a longitudinal bore therethrough, one end of said needle adapted to facilitate puncture of and insertion into subcutaneous tissue, said needle having a longitudinal slot extending the length thereof, a hub member secured to the distal end of the needle having a longitudinal slot therein, a flexible catheter having one end slidably disposed in the bore of the needle and extending rearwardly therefrom, a coupling member connected operatively to the hub member, and means associated with the coupling member and movable to coact with a portion of the catheter between a first position and a second position, the means in the first position preventing longitudinal movement of the catheter in the needle. In an alternative embodiment of the subcutaneous catheter insertion device, the means can be removably associated with the hub member and longitudinally movable between a first and a second position, the means in the first position preventing longitudinal movement of the catheter in the needle.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention will be derived from reading the ensuing specification in conjunction with the accompanying drawings, in which:

FIG. 1 is a partially exploded perspective view of the catheter and insertion device of the present invention;

FIG. 2 is a side perspective view of the present invention showing it completely assembled and partially enclosed by an internally sterile plastic bag;

FIG. 3 is a partial longitudinal cross-sectional view of the catheter and insertion device of the present invention;

FIG. 4 is a full cross-sectional view of the device taken along a section similar to that of 4--4 of FIG. 3;

FIG. 5 is an enlarged top view of the insertion needle of the present invention;

FIGS. 6, 7, and 8 are respectively top, front and side views of the stop button of the present invention;

FIG. 9 is a schematic illustration of the method of insertion of the catheter of the present invention into a patient's vein;

FIG. 10 is a partial cross-sectional view of the insertion device and coupling member of the present invention showing the release position for the stop button;

FIG. 11 is a perspective view of the needle insertion device of the present invention showing removal of the catheter from the slot thereof;

FIG. 12 is a schematic view of the catheter after the needle has been removed therefrom;

FIG. 13 is a top view of an alternate embodiment of the insertion needle of the present invention;

FIG. 14 is a cross-sectional view of the alternate embodiment of FIG. 13 taken along section line 14--14.

DESCRIPTION OF PREFERRED EMBODIMENTS

As heretofore explained, the present invention will be described in relation to an intravenous catheter insertion device. It is to be understood that other subcutaneous punctures can be effected with the present invention for insertion of the catheter disclosed herein into other portions or regions of the body of the patient. Therefore, the invention is intended to be limited only by the definition contained within the appended claims.

Referring now to FIG. 1, a view of a partially disassembled catheter and insertion needle of the present invention is illustrated. Hollow needle 10, preferably made of a surgical steel, has one end which is cut at a taper to form a point 12. The other end of the needle is secured in a hub member 14. Both needle 10 and hub member 14 contain longitudinal slots (better seen in later figures). A coupling sleeve 16 is arranged for sliding and removable attachment to a rearward projection 18 on the hub member 14. A clip member 20 is positioned in a channel formed when the coupling sleeve 16 is slidably disposed upon the rearward projection 18. The hub member 14 is also provided with a circular portion 22 of reduced diameter onto which a needle cover 24 can be removably fitted. The needle cover protects the needle point 12 as well as the entire needle 10, and prevents the needle from puncturing packaging material for the entire device. The needle cover 24 also prevents the persons handling the catheter from being accidentally punctured by the needle point 12.

Slidably disposed in the bore of the hollow needle 10 is an elongated flexible tubular catheter 26. The catheter can be composed of polyurethane, polytetrafluoroethylene, or other suitable material. The catheter extends through the hub member 14 and along a trough (better seen in later figures) contained in the rearward projection 18. It extends through the coupling sleeve 16 and terminates at its distal end in a suitable fitting 28, for example a luer female fitting. A luer plug 30 is provided for sealingly closing the open end of the fitting 28. The plug 30 is provided to prevent egress of body fluids from the catheter when it is being inserted and also when the catheter is not attached to a fluid infusion device.

In FIG. 2, the needle cover 24 is shown secured onto the reduced diameter portion 22 of the hub member 14. In addition, plug 30 is disposed in the luer fitting 28. The coupling sleeve 16 has sealed around its distal circumference a flexible, preferably transparent sac 32 sealed at its distal end 34. One function of the coupling sleeve 16 is to maintain the sac 32 around the catheter 26, the luer fitting 28 and plug 30 to provide a sterile environment. Primarily, the coupling sleeve 16 serves to retain the clip member 20 in contact with the catheter 26, as will be better seen later.

The hub member 14, including its rearward projection 18, needle cover 24, coupling sleeve 16, and clip member 20 are preferably molded from synthetic polymeric materials such as polyethylene, polytetrafluoroethylene, polyamides, or some other material which is capable of being molded. The flexible sac 32, manufactured from, for example polyurethane, polyethylene or polyester film, can be attached to the coupling sleeve 16 by heat sealing or can be merely taped about the sleeve member utilizing a thin strip of adhesively backed tape.

Normally, the interior and exterior of the needle 10, the interior of cover 24, the catheter 26, luer fitting 28, and plug 30 as well as the entire interior of the flexible sac 32 are sterilized during manufacture of the catheter device. Of course, the interior of the coupling sleeve 16 is also sterilized as well as the interior portion of the clip member 20. After the catheter device as shown in FIG. 2 is completely assembled, it is housed in a package (now shown) in which the sterilization procedure takes place. The package and contents are usually rendered sterile by the introduction of a gas, such as ethylene oxide, into the package. The device can also be easily transported and handled in the package without danger of contamination prior to use.

Referring now to the cross-sectional views of FIG. 3 and FIG. 4, the needle 10 has formed therein a longitudinal slot 54. The needle cover 24 is secured upon the reduced diameter portion 22 of the hub 14. The clip member 20 is slidably disposed in a channel 40 formed by the rearward projection 18 of the hub member 14 and coupling sleeve 16. The clip 20 is composed of a bottom portion 42 of sufficient vertical height so as to intimately contact the upper interior wall of the coupling sleeve 16 and also to press the catheter 26 against the upper interior surface of the rearward projection 18 of the hub member 14. This coaction of the lower portion 42 of the clip member 20 operates to prevent longitudinal movement of the catheter 26 as it is introduced into a patient. A second portion 44 of the clip member 20 extends upwardly through a longitudinal slot 46 in the coupling sleeve 16. The portion 44 of the clip 20 terminates above the coupling sleeve 16 in a finger or thumb grip 48 containing serrations or ridges on the top thereof. During insertion of the needle and catheter into a patient, the clip member rides in the position shown in FIG. 3.

FIG. 4 is a full transverse cross-sectional view taken along a line similar to line 4--4 of FIG. 3, which better illustrates the operation of the clip 20 in relation to the catheter 26. The rearward projection 18 of the needle hub 14 contains a trough or channel 50 generally of semi-circular cross section extending the full length of the projection 18. The catheter 26 rides therein. The upper surface of the bottom portion 42 of clip 20 contacts the upper interior wall of coupling sleeve 16. As it does so, it is forced down upon the top surface of the catheter 26 so as to deform the catheter, thus frictionally engaging the catheter between the bottom surface of the bottom portion 42 of the clip member 20 and the walls of the channel 50 in the projection 18. The frictional engagement between the channel 50 and the bottom portion 42 prevents longitudinal movement of the catheter 26 as it is inserted into a patient.

The construction of the hub member 14 and the rearward projection 18 integrally a part thereof as well as the channel 50 is better understood by reference to FIG. 5. There the needle is shown secured in the hub member 14, preferably integrally molded therewith. The longitudinal slot 52 in the hub member 14 and the longitudinal slot 54 in the needle 10 are provided so that after the catheter has been inserted into a patient and the needle removed leaving the catheter in the patient, the catheter can be separated from the needle and hub member as shown in conjunction with FIG. 11.

Optionally, a wire stylet 58 as illustrated in FIG. 3 can be attached to the luer plug 30. The stylet extends from the plug 30 to ordinarily within a half inch from the end of the catheter as shown. The stylet lends rigidity to the catheter for easier insertion into a patient. It should be noted that the interior opening through the coupling sleeve 16 is of sufficient diametral size such that the luer fitting 28 and plug 30 can pass through the sleeve 16 so that the sleeve and sac 32 can be completely removed from the assembly. In addition, it should be noted that the upwardly extending walls 60 shown both in FIGS. 3 and 5 are provided so that the coupling sleeve 16 will have additional surface area on the rearward projection to contact so that it will be held sufficiently tight merely by frictional contact. The distance between the interior sides of the upwardly extending walls 60 must be sufficiently wide to allow free passage of the bottom portion 42 of the clip member 20 therebetween.

FIGS. 6, 7, and 8 present top, front and side views, respectively, of the clip member 20. It is seen that the clip member is generally T-shaped and includes a lower portion 42 which is slidably disposed in the channel formed by the coupling sleeve and the rearward projection on the hub member. The middle portion 44 extends upwardly through the slot 52 in the coupling sleeve and terminates in the thumb grip 48. Thumb grip 48 has the ridges 56 for increasing a frictional grip between the thumb and the clip member.

With respect to operation of the catheter device, refer to FIGS. 9 through 12. The needle cover 24 is first removed. The exterior sides of the hub member 14 as well as the sides of the coupling sleeve 16 are then grasped between a thumb and forefinger. The skin and vein 70 are punctured with the pointed end of the needle. Thereafter, the thumb is utilized to move the clip member 20 forward to a position as shown in FIG. 10. The catheter 26 is thus released from the grasp of the lower portion 42 of the clip member so that is is freely and slidably disposed within the coupling sleeve, hub member and needle. As can be seen in FIG. 10, the raised portion 72 at the front end of the coupling sleeve 16 contacts the lower surface of the thumb grip 48 such that the lower portion 42 of the clip 20 is raised from contact with the catheter. Thereafter, the catheter is grasped with the opposite hand and manipulated through the coupling sleeve, hub member and needle into the patient's vein. After the catheter has been inserted the desired distance into a patient's vein, the needle is removed from the patient's body leaving the catheter in place in the vein. Thereafter, the coupling sleeve 16 is removed from the rearward projection 18 of the hub member 14. It is also removed completely over the luer fitting and plug attached to the distal end of the catheter. The coupling member, sac and clip member 20 then can be discarded.

Thereafter, the catheter can be separated from the needle and hub member by pulling the catheter through the slot 54 in the needle 10 and through the slot 52 in the hub member 14 as shown in FIG. 11. The luer fitting 28 can be attached to an infusion source such as the intravenous bottle 74 shown in FIG. 12 at any time after the sac is removed. It is, of course, to be understood that the catheter is made from a sufficiently flexible material to allow radial deformation thereof as it is removed through the slot 54. Such materials include polyurethane and polytetrafluoroethylene as mentioned above. The slot 54 in the needle is preferably of a slightly smaller width than the diameter of the catheter 26 so that it must necessarily be deformed in order to be removed. This size relationship of the catheter and slot is important since it will cause the catheter to be retained in the needle at all times until it is forceably removed. The width of the slot 52 in the hub member 14 is generally of slightly greater width than the catheter 26 so that removal therefrom can be accomplished with ease.

An alternative embodiment of the present invention is shown in FIGS. 13 and 14. In this embodiment, the hub member, rearward projection and coupling sleeve are combined into one assembly, generally designated 80. Referring to both FIGS. 13 and 14, a needle 82 is integrally molded into the assembly 80. The needle is provided with a slot like that of needle 10 referred to above in conjunction with the preferred embodiment. The assembly 80 contains a longitudinal slot 83 correspondent with the needle slot along its entire length. A forward wall 84, a rear wall 86 and the top portion 88 of the assembly 80 form an interior channel 90 in which is slidably mounted a clip member 92 similar to that described above. An opening 94 is provided in the top of the assembly 80 communicating with the slot 83 in assembly 80. The opening 94 is so sized that the bottom portion of clip member 92 can be removed therethrough. During insertion of the catheter, the clip member 92 is in a rearward position so that it frictionally engages the catheter 96 between the bottom portion of the clip member and the bottom of the channel 90 thus holding the catheter longitudinally stable during insertion. After the needle and catheter have been inserted into a patient's body, the clip member 92 is moved forward in the direction of arrow 98 and removed through opening 94. Thus the catheter 96 is freed so that it is slidably disposed in the assembly 80 and needle 82, allowing manipulation of the catheter into a patient's body. Once the needle has been removed from the patient leaving the catheter inserted, the catheter can be separated from the needle and clip member through the needle slot and the slot 83 in the needle assembly 80.

As one of ordinary skill in the art to which the devices of the subject invention pertain is aware, many variations and alternatives of the present device can be provided without departing from the basic invention. The invention, therefore, is to be limited only as defined in the appended claims.

Claims

What is claimed is:

1. A subcutaneous catheter insertion device comprising:

a needle having a longitudinal bore therethrough, one end of said needle adapted to facilitate puncture and insertion into subcutaneous tissue, said needle having a longitudinal slot extending the length thereof;

a hub member secured to the distal end of the needle having a longitudinal slot therein aligned with said needle slot;

a walled casing having a hollow interior extending rearwardly of said hub, and an aperture means through said casing walls;

catheter bearing plate means positioned within said casing opposite said aperture means;

a flexible catheter having one end slidably disposed in said bore of said needle and extending rearwardly through the hub and the said hollow interior of said casing over said catheter bearing plate means and terminating in a distal end rearwardly of said casing;

releasable catheter holding means having a part carried internally of said hollow interior of said casing and an actuating means extending externally therefrom through said aperture means;

said holding means being movable by manipulation of said actuating means to move the said part carried internally from a normal locked position in the said hollow interior to an unlocked position in said hollow interior; and

said catheter located on said catheter-bearing plate means being frictionally engaged by said part carried internally when in the normal locked position and being released to permit longitudinal movement when the said part carried internally is moved into the unlocked position in said hollow interior.

2. The device of claim 2 wherein said enlargement is provided by an increased diametrical portion of said casing.

3. A subcutaneous catheter insertion device comprising:

a needle having a longitudinal bore therethrough, one end of said needle adapted to facilitate puncture of and insertion into subcutaneous tissue, said needle having a longitudinal slot extending the length thereof;

a hub member secured to the distal end of the needle having a longitudinal slot therein aligned with said needle slot;

a walled casing having a hollow interior extending rearwardly of said hub, said casing having an enlargement only in a portion of said hollow interior, said casing further having aperture means through said casing walls;

catheter bearing plate means positioned within said casing opposite said aperture means;

a flexible catheter having one end slidably disposed in said bore of said needle and extending rearwardly through the hub and the said hollow interior of said casing and over said catheter bearing plate means and terminating in a distal end rearwardly from said casing;

releasable catheter holding means having a part carried internally of said hollow interior of said casing and a part extending externally therefrom through said aperture means;

said holding means being movable by manipulation of said part extending externally to move the said part carried internally from a normal position in the said hollow interior to the enlargement in said hollow interior;

said catheter located on said catheter bearing plate means being frictionally engaged by said part carried internally when in the normal position and being released to permit longitudinal movement thereof when the said part carried internally is moved into the enlargement in said hollow interior.

4. The device of claim 2 wherein said casing is a coupling removably engaged with said hub member.

5. The device of claim 4 further comprising an integral rearward projection from said hub member.

6. The device of claim 5 wherein said enlargement is provided by an increased diametrical portion of said casing; and

the said normal position is rearward of said enlargement in said hollow interior.

7. The device of claim 6 further comprising a pliable elongated sac attached to said coupling member and surrounding and fully enclosing the said distal end.

8. A subcutaneous catheter insertion device comprising:

a needle having a longitudinal bore therethrough, one end of said needle adapted to facilitate puncture of and insertion into subcutaneous tissue, said needle having a longitudinal slot extending the length thereof;

a hub member secured to the distal end of the needle having a longitudinal slot therein, said hub member having a projection extending rearwardly therefrom with a longitudinal slot in register with the slot in said hub member;

a flexible catheter having one end slidably disposed in said bore of said needle and extending rearwardly therefrom through the said longitudinal slot in said hub and the said longitudinal slot in said projection;

a walled casing having a hollow interior, said casing overlying said projection with said hollow interior in communication with said slot in said projection;

said casing having an enlarged diametrical portion and aperture means through said walls;

a frictional lug riding in the hollow interior of said casing just over the slot in said projection, said lug having a finger button extending externally from said casing through said aperture;

said lug being movable by manipulation of said finger button from a position in frictional contact with a catheter disposed in said longitudinal slot in said projection to a position in the enlarged diametrical portion of said casing where said lug is out of frictional engagement of said catheter.

9. The device of claim 8 wherein said casing is a removable coupling carried over said hub projection into engagement with said hub member.

10. The device of claim 8 wherein said casing and said hub are integral, said casing having a channel extending its full length to permit a catheter to be completely removed from said casing.

11. The device of claim 10 further comprising an enlargement in a portion only of the said channel to permit the said lug to be removed from said casing.

12. The device of claim 8 wherein said increased diametrical portion is provided by enlarged external dimensions of portions of said walled casing which have a uniform wall thickness.

13. The device of claim 8 wherein said increased diametrical portion is provided by enlarged internal dimensions of said casing with the external dimensions of said casing being substantially uniform.