FR2703593A1 - Connection device and assembly for flexible catheter - Google Patents

Abstract

The invention relates to a removable connection assembly comprising a rigid rod (23) having a radial collar (47) on its outer surface; a flexible tube (7) receiving the rod, including its collar; a first sleeve (25) through which is received the rod surrounded by the tube, this sleeve having on the inside an annular guide ramp (33) which is inclined with respect to its axis (23a); and a second sleeve (29) which can slide inside the first sleeve and comprises a part (43), which can be radially deformed elastically in order, in a defined sliding direction, reversibly to clamp the tube (7) on the rod (23), while being guided in this by the said inclined peripheral ramp (33) which, in this direction, defines a convergent surface. Application to connecting a medical catheter to the adaptor of an implantable chamber.

Description

 The invention relates generally to the connection of a catheter.

 In particular, the object of the invention is to propose improvements to the connecting devices provided for connecting, via a rigid rod, a flexible or flexible infusion catheter to a source of liquid suitable for being infused very particularly in the human body.

 The treatment of diseases or physiological disturbances of living bodies requires, in a certain number of cases and over a more or less long term, the infusion of drugs, blood or nutritional products, or even other fluids, most often towards the vascular system, even in some cases and for certain products to organs of the body.

 Increasingly, for the "comfort" of the patient, that is to say in fact to limit the risks of infections and the inconvenience due to these infusions, recourse is made to fully implanted diffusion systems, of the type which will be described below, comprising an implantable chamber under the skin of the patient and into which the treating product can be infused via a needle provided for this purpose. Comparable devices, which are also fully implemented, also exist today to allow frequent blood samples.

 All these systems, and others, require the use of catheters, that is to say thin tubes, usually of synthetic material, flexible, flexible which therefore extend into the appropriate places of the body.

 All the more if these catheters are to be implanted over the long term and connected to diffusion devices also implanted under the skin, it is understandable that special care must be taken with the connection between the catheters and the diffusion devices.

 In particular, it is absolutely necessary to avoid leaks and ensure very strict hygienic conditions to limit possible infections and inflammations by guaranteeing perfect reliability, whatever the duration of implantation, while proposing an inexpensive connection system, easy to set up, mechanically resistant and compact.

Various connecting systems for catheters are already known in the art, among which mention may be made in particular of those of patents US-A-4,963,133 and US
A-4 723 948.

 In US-A-4,963,133, first of all, there is proposed a connection system for separably connecting an elastic, flexible catheter, to a rigid tip (or rod) in the form of a tube, integral with an implantable chamber adapted to receive around it one end of the catheter. This system comprises a first part fixed to the chamber and to its connecting end piece, as well as a second movable part adapted to pinch the catheter against the end piece, this pinching taking place at the place where the end piece has a peripheral bead.

However interesting it may be, this solution nevertheless offers an accessible catheter locking zone, since pinching is ensured by the mobile external part of the holding system. In addition, the pinching is obtained via an inner annular rim which said movable part has at its free end. The security of the fixing is therefore a function of the "anchoring" of this annular rim. However, given its elasticity, the catheter could tend to push the movable part axially, by unlocking the system more or less.

 The solution proposed by US-A-4 723 948 consists in the use of an inner sleeve which can be opened in two parts, the locking of the two parts once they have closed around the tube and the catheter, being ensured by an external ring slidably mounted around the inner sleeve.

 Since this internal sleeve necessarily has a hinge axis for the relative articulation between them of its two constituent parts, it could constitute a potential area of weakness there. However, the connection must in practice be perfectly sealed. In addition, the opening and closing operations require two operations, one for folding down the two parts of the inner sleeve, the other for sliding the outer sheath. One can also note manufacturing costs certainly higher than the previous solution of US-A-4,963,133.

 The object of the invention is to propose a solution which overcomes the drawbacks or potential risks of the prior art and which meets the abovementioned requirements.

To do this, the invention first of all proposes that the imagined connection device comprises
a first axial external sleeve, suitable for receiving through it the rigid rod and the catheter, this sleeve having internally at least one peripheral ramp for guidance inclined relative to the axis of the sleeve, and
a second internal sleeve capable of sliding substantially coaxially inside said first sleeve and comprising an elastically deformable part radially so as, in a determined direction of sliding inside said first sleeve, to tighten the catheter on the rod, guided in this by said inclined peripheral ramp which, in this sliding direction, defines a converging surface in the direction of said sleeve axis.

 Thus, the locking of the catheter on its rod will take place at the location of an interior zone of the device, the elastically deformable nature of the tightening part of the second sleeve guaranteeing the maintenance of the locking over time, since in the locked position. this deformable part is in fact sandwiched between, internally, the catheter which it clamps on the rod and, externally, the zone of the external sleeve situated essentially towards the narrowest base of the guide ramp.

 To further promote the relative guidance of the first and second sleeves as well as the positioning of the entire device relative to the catheter and to the connecting rod, the inclined ramp of the first sleeve will preferably be located at an intermediate location between the two ends. opposite free of this first sleeve, defining in the latter an internal portion of reduced section, which section may be further reduced at one end of the sleeve.

 Furthermore, in a preferred embodiment, the second sleeve may be split axially in a cross, for example substantially over half of its length from one of its free ends, to present several independent tabs, thus promoting locking. and the reliability of the system.

 Still for the sake of safety, the first and second sleeves may further advantageously comprise on their inner and outer peripheries, respectively, male and female zones of relative locking, so that in the catheter tightening position, the male zone of the one of the sleeves enters the female area of the other sleeve.

In addition to the connection device which has just been presented, the invention also quite naturally relates to a connection assembly, removable, comprising
- a relatively rigid axial rod with a free end and a radial bead on its outer surface,
- a flexible tube or catheter having an internal passage for closely receiving at least one segment of said rod, including its radial bead,
- As well as said first and second sleeves, the second sleeve being capable of reversibly tightening the catheter on the rod, guided in this by the inclined peripheral ramp of said first sleeve.

 In accordance with a favorable arrangement of the invention, the elastically deformable clamping part of the second sleeve will preferably clamp the tube slightly beyond the bead of the rod, in the immediate vicinity of the edge of the latter farthest from the end. free from that same stem.

 In this way, the catheter can be optimally retained substantially at the level of the primer of the bead.

In the context of a preferred use of the invention, it will also be noted that
the rod will advantageously consist of a hollow external endpiece secured to an implantable reservoir-chamber for a treatment requiring the injection of a medicinal fluid,
the tube to be connected will preferably be a medical catheter through which said fluid coming from the implantable chamber can flow,
and said first and second sleeves will be separable from one another while also being independent of the chamber and of its rod forming a nozzle.

Other characteristics and advantages of the invention will appear from the following description made with reference to the accompanying drawings in which
FIG. 1 is a schematic top view of an implantable chamber connected to a catheter,
FIG. 2 is a front view of this same assembly when an injection or a puncture is made inside the volume of said chamber,
FIG. 3 shows in longitudinal, middle section the connecting device of the invention,
FIG. 4 is a perspective view of the inner sleeve,
- And Figures 5 and 6 show two successive stages of use of the device of Figure 3 for locking a catheter on the connecting piece of an implantable chamber.

 In what follows, we will limit ourselves for the sake of clarity to the sole case of use of the invention in the context of the connection of a catheter implantable in a human body and a chamber itself implantable in a subcutaneous region, although the device of the invention may well be used in other cases.

 Thus, in FIG. 1 first of all, we see illustrated an implantable capsule or chamber 3 connected at the outlet, at 5, to a catheter 7 for dispensing, puncture or injection tube for liquid medicament towards an appropriate place of the body. In 9, the device of the invention is identified for the connection between the catheter and the chamber.

 The catheter 7 is advantageously made of a breakable, biocompatible material such as silicone or polyurethane. It can have a constant section with an outside diameter of around 2 to 3 mm and an inside diameter of around a millimeter.

 In FIG. 2, the implantable chamber 3 appears more clearly. It can thus be seen that it is intended to be implanted shallow, under the skin 11 of a patient. At 13, a needle has been identified suitable for any suitable injection and / or puncture system which can be used, in the first case, to inject the treatment product towards the catheter 7. Closing the top of its internal volume 15 forming a reservoir for product, the capsule 3 comprises an upper wall 17 that can be pierced by the needle 13 while being self-sealing and made of any known suitable material, for example a block of silicone plastic. On its other sides, the reservoir chamber 15 is delimited by a hollow metallic body in the form of a bowl 19, coated with a biocompatible, electrically insulating material, forming a protective envelope 21, such as a relatively rigid plastic of suitable quality. The reservoir 15 communicates with the catheter 7, via a lateral tip 23 extending to the outside of the chamber where it can be connected to the catheter and locked to it by means of the connecting device 9 which will now be described. , while specifying that for any additional detail of embodiment of the capsule 3, reference may be made to US-A-4,781,685.

 In FIG. 3 in particular, it can be seen that this device 9 comprises a first external sleeve 25, of axis 27, inside which a second sleeve 29 is coaxially slid, the two sleeves being essentially cylindrical of circular section and separable l of each other.

 Significantly at half its length L and on its inner surface 30 which peripherally delimits its axial central passage 31, the first sleeve 25 has a first truncated cone 33, while in the immediate vicinity of one of its free ends, it has a second internal truncated cone 35, so that the section of the passage 31 is therefore restricted twice along the length of the sleeve.

 The role of the first truncated cone 33 is essentially to guide, towards its locking position, the elastically radially deformable part 37 of the second sleeve 29.

 As illustrated, this second sleeve consists of a hollow cylindrical body 39 terminated axially at one end by a peripheral external flange 41 and, towards its second opposite end 29a (engagement side inside the sleeve 25 ), by said deformable locking part 37. Advantageously, and as can be seen more clearly in FIG. 4, this hollow part 37 can be split axially into a star or a cross, from the end 29a, to thus define several legs 43, in the form of a cylinder portion, for example four in number. At their free end, each tab 39 has a small external flange 45 intended, as will be seen below, to constitute locking notches.

 In FIGS. 5 and 6, it is more clearly seen how the connection end piece 23 secured to the capsule 3 can be produced.

 In this case, this tip is presented as a rigid tube, in particular metallic, of axis 23a.

 Near its free end 23b, the tip has a peripheral bead 47. Around this bead is tightly threaded the catheter 7, and this substantially up to the base 23c of the tip close to the capsule.

 Already thus placed, the catheter is firmly retained due to its own elasticity and its inner diameter smaller than the minimum outside diameter of the tip.

 To install the device 9, we will first of all slide substantially to the side wall 21a of the capsule, the internal sleeve 29 whose length L ′ is here adapted so that the free end of its legs 43 are located just before the start of the bead 47 (see FIG. 5). In this position of "rest", unconstrained, the legs 43 extend substantially parallel to the axis 23a. Around the sleeve 29, the sleeve 25 is then engaged, first presenting its side with a larger internal section, which is substantially equal, or even slightly greater, than that of the sleeve 29 at the location of its notches, it being specified that the internal section of this second sleeve 29 will preferably be substantially constant and equal to or slightly greater than the external section of the bead 47 of the nozzle increased by the thickness of the catheter 7 (the legs 43 not being constrained).

 As soon as the elastic tabs 43 reach the cone 33 (which, in this sense, therefore presents itself as a converging cone), they are forced to approach radially from the axis 23a, guided in this by the walls of the cone, up to 'to present the configuration of Figure 6, the arrow 49 symbolizing the direction of movement of the sleeve 25. At the end of the race, these tabs 43 compress the catheter on the nozzle just before the start of the bead 47, the angle of the peripheral ramp 33 having been adapted for this purpose. For safety and to inform the practitioner of the locked state, the protuberances 45 are provided to then come to engage in a peripheral groove 51 of the sleeve 25 formed in the vicinity of the base of the cone 33 where its section is most reduced. (Of course, we could reverse the bleeding and the growths on the parts).

 It will be noted that for the sake of reliability, once the sleeves are in place, the narrowest base diameter of the cone 33, in line with the bead 47, is substantially equal, or very slightly greater, to the maximum external section of this increased bead the thickness of the catheter (area marked A in Figure 6).

 In the same way, at the base of its second cone 35, the minimum end section of the same sleeve 25 is substantially equal to the normal outside diameter of the catheter, this end 25a of the sleeve 25 advantageously ending beyond the end free of the end piece 23 so that, the external section of this end piece being greater than the normal internal section of the catheter, the latter is already radially prestressed.

 Still in FIG. 6, it will further be noted that in the locked position the external peripheral flange 53 that the sleeve 25 has at its end 25b, comes into substantial abutment against that 41 of the sleeve 29.

 Thus positioned, the connection device of the invention can be left in place as long as necessary, the separation of the sleeves and therefore the release of the catheter being effected by simply reversing the operating sequences.

Claims (11)

 1. - Connecting device for connecting a flexible catheter (7) to a relatively rigid rod (23) intended to engage inside a free end of the catheter, characterized in that it comprises  - a first external sleeve (25) with a sleeve axis, suitable for receiving through it the rod and the catheter, this sleeve having internally at least one peripheral guide ramp (33) inclined relative to the axis (27, 23a) of the sleeve, and  - a second internal sleeve (29) with a sleeve axis, capable of sliding substantially coaxially inside said first sleeve (25) and comprising a radially elastically deformable part (37, 43) for, in a determined direction of sliding at inside said first sleeve, tighten the catheter (7) on the rod (23), guided in this by said inclined peripheral ramp (33) which, in this direction, defines a converging surface in the direction of said sleeve axis.  2. - Device according to claim 1 characterized in that said inclined ramp (33) of the first sleeve (25) is located at an intermediate location between the two opposite free ends of this sleeve, defining in the latter an internal portion of reduced section (31), which section is further reduced near one of said free ends where the sleeve has a second section narrowing (35).  3. - Device according to claim 1 or claim 2 characterized in that said second sleeve (29) comprises a hollow axial body (39), split substantially in its axis from one end, to present several independent tabs (43 ), radially deformable.  4. - Device according to claim 3 characterized in that in a state of rest, not constrained, the tabs (43) extend essentially substantially parallel to the axis (27) of the sleeve (29), while when they tighten said tube (23), these legs are essentially inclined relative to this same axis, approaching the side of their free end.  5. - Device according to any one of the preceding claims, characterized in that said first and second sleeves (25, 29) comprise, respectively, on their inner and outer periphery of the male and female zones (45, 41) of relative locking , so that in the catheter tightening position, the male zone (45) of one of the sleeves penetrates into the female zone (51) of the other sleeve.  6. - Device according to any one of claims 3 to 5 characterized in that the tabs have externally, at their free end, notches (45) for locking, while the first sleeve (25) has at least one groove ( 51) for receiving the notches located in the immediate vicinity of the connection between the guide ramp (33) and said narrowed section (31) of this same sleeve.  7. - Removable connection assembly comprising  - a relatively rigid axial rod (23) with a free end and a radial bead (47) on its outer surface,  - a flexible tube (7) having an internal passage for closely receiving at least one segment of said rod, including its radial bead (47),  - A first outer sleeve (25) with a sleeve axis, receiving through it the rod (23) surrounded by the tube (7), this sleeve having internally, between a first inner section of sleeve of larger section and a second section interior (31) of smaller cross section, an annular guide ramp (33) inclined relative to the axis (27) of the sleeve, and  - a second internal sleeve (29) with a sleeve axis, capable of sliding inside said first sleeve and comprising an elastically deformable portion radially (37, 43) for, in a determined direction of sliding inside said first sleeve, reversibly tighten the catheter (7) on the rod (23), guided in this by said inclined peripheral ramp (33) which, in this direction, defines a converging surface in the direction of said sleeve axis.  8. - The assembly of claim 7 characterized in that said section of smaller section of the first outer sleeve has a section substantially equal to or slightly greater than the largest section of the annular bead (47) of the rod, substantially increased by thickness of the tube (7), this internal section of the first sleeve (25) further reducing to a free end (25a) of the latter where the latter has a section substantially equal to or slightly greater than the normal external section of the tube (7 ).  9. - An assembly according to claim 7 or claim 8 characterized in that in the tube clamping position, said elastically deformable portion (37, 43) for clamping the second sleeve (29) clamps the tube (7) in the immediate vicinity from the edge of the bead (47) of the rod (23) furthest from the free end of the latter.  10. - An assembly according to any one of claims 7 to 9 characterized in that the second sleeve (29) comprises a hollow axial body (39) split at one end, to present substantially in its axis several independent legs (43) radially elastically deformable.  11. - assembly according to any one of claims 7 to 10 characterized in that  said rod (23) consists of a hollow external endpiece of a chamber (23) implantable in the human body for a treatment requiring the injection of a medicinal fluid,  the tube (7) is a medical catheter through which said medicinal fluid coming from the implantable chamber (3) can flow,  - Said first and second sleeves (25, 29) are separable from each other and are independent of the rod (23) and the chamber (3).