Abstract:
A positive engagement/disengagement catheter sleeve to reduce risks of needle sticks. The sleeve has a base and a body which define a pair of grooves. The grooves define a deformable region of the sleeve therebetween. At least one detent is provided inside the base within the deformable region. A mechanism is provided to cause the detent to disengage when the mechanism is actuated.

Description:
BAGKGROUND 
     (1) Field of the Invention 
     The invention relates to catheters. More specifically, the invention relates to a sleeve that positively engages an introducer to reduce the risk of unintentional needle sticks. 
     (2) Background 
     Catheters and sleeves therefor have been ubiquitous in the medical supplies market for some time. A typical catheter assembly arrives in sterile packaging and comprises a catheter, the introducer, and a sleeve. The purpose of the sleeve is to protect the needle tip during shipping and to prevent unintentional needle sticks as the catheter and introducer are removed from the sterile packaging. To that end, the sleeve needs to have sufficient retention force that it does not unintentionally become disengaged from the introducer as the sterile packaging is removed. However, if the retention force is too great, the incidence of needle pricks in the course of removing the sleeve actually increases. By way of example, a user typically grabs the sleeve in one hand and the introducer in the other, then pulling the sleeve in one direction and the introducer in the opposite direction, when the introducer snaps free, the arms of the user recoil, causing the user to inadvertently stick themself. This has been an area of substantial concern. 
     One common way of retaining the sleeve on the introducer is to mold three detents into the sleeve to engage an annular flange on the introducer. This works adequately for certain types of catheters. However, catheters have been developed that have wings that permit the catheter to be more easily secured to a patient after introduction. These wings necessitate grooves in the sleeve to accommodate the wings while the catheter is sleeved. With the introduction of the grooves, the structural integrity of the sleeve is such that disengagement from the detents is highly likely, as only a very loose hold is possible. Attempts to accommodate this problem by increasing the size of the detent between the grooves has resulted in cases of both an unreliable hold and too strong a hold, both resulting in increased risk for unintentional needle sticks. 
     BRIEF SUMMARY OF THE INVENTION 
     A positive engagement/disengagement catheter sleeve to reduce risks of needle sticks is disclosed. The sleeve has a base and a body which define a pair of grooves. The grooves define a deformable region of the sleeve therebetween. At least one detent is provided inside the base within the deformable region. A mechanism is provided to cause the detent to disengage when the mechanism is actuated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a catheter with introducer and sleeve of one embodiment of the invention. 
     FIG. 2 is a perspective view of the sleeve of the embodiment of FIG.  1 . 
     FIG. 3 is a partial cross-section view of the catheter assembly and sleeve of the embodiment of FIG.  1 . 
     FIG. 4 is a partial sectional view of a sleeve and catheter assembly of FIG. 3 with the arm depressed, thus releasing the detent 
     FIG. 5 is a perspective view of an alternative embodiment of the invention. 
     FIG. 6 is a partial cross-sectional view of the sleeve of FIG. 5 with a catheter assembly inserted therein. 
     FIG. 7 is a partial sectional view of a third alternative embodiment of the sleeve installed on a catheter assembly. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 is a perspective view of a catheter with introducer and sleeve of one embodiment of the invention. The catheter  22  is coupled to a catheter hub  26 . Hub  26  has wings  24  formed as part thereof. Introducer  30  has an annular flange  28  as part thereof to engage sleeve  10 . Sleeve  10  has a pair of grooves  12  disposed to receive the wings  24  of catheter hub  26 . Sleeve  10  has a base  11  at an insertion end and a body  13  terminating in a distal end. The grooves define a deformable region  14  therebetween. Attached to the deformable region  14  is an arm  16 . Arm  16  has a first end where it attaches to the deformable region  16  and a free end down the sleeve from the base. Pressure on the arm  16  at its distal end causes the deformable region at the base to move away from an axis of the sleeve. 
     FIG. 2 is a perspective view of the sleeve of the embodiment of FIG. 1. A plurality of detents  18 ,  20  are disposed within base  11 . While only two of the detents are shown in the figure, a third detent is typically positioned symmetrically on the base  11  across from the detent  20 . Detent  18  is disposed on deformable region  14  between grooves  12  on the base  11 . The detents  18 ,  20  engage the annular flange ( 28  of FIG. 1) when the introducer  30  is seated in the sleeve  10 . Because the grooves  12  reduce the structural integrity, in some embodiments, it may be necessary to make detent  18  larger than detents  20  to ensure engagement even if the flexibility caused by the grooves  12  results in deformable region  14  holding less tightly against the annular flange  28 . Notably, even with grooves  12 , sleeve  10  would be suitable for a wingless catheter provided that the detents  18 ,  20  provide sufficient holds so that the sleeve  10  does not easily become unintentionally disengaged. 
     FIG. 3 is a partial cross-section view of the catheter assembly and sleeve of the embodiment of FIG.  1 . As shown in FIG. 1, detent  18  engages annular flange  28 , and the wings  24  are seated in the slot  12  such that pressure on the distal end of arm  16  results in maximum translation away from the axis of the sleeve  10 . Arm  16  has a thickness  40 , which is greater than the distance  42  between the arm  16  and the body  13  of sleeve  10 . In one embodiment, the arm  16  is approximately aligned with detent  18 . By keeping the distance between the arm  16  and the body  13  of the sleeve, less than the thickness of the arm, inadvertent nesting, or interlocking of sleeves during manufacture is prevented. 
     FIG. 4 is a partial sectional view of a sleeve and catheter assembly of FIG. 3 with the arm depressed, thus releasing the detent. In this view, pressure is shown as being applied to the distal end of arm  16 , thereby releasing the engagement of detent  18  from annular flange  28 . Once detent  18  releases annular flange  28 , the remaining detents  20  provide little or no holding force and the catheter assembly may be easily withdrawn from the sleeve without the recoil risk present in the prior art. 
     FIG. 5 is a perspective view of an alternative embodiment of the invention. Sleeve  60  has a base  61  coupled to a shaft  63 , and a pair of grooves  62  define a deformable region  64  therebetween. A thin or flexible region  66  is provided partway down the deformable region  64 . Flexible region  66  is flexible relative to the remainder of deformable region  64 . This may be accomplished by making flexible region  66  of the same material as the rest of the deformable region  64 , only thinner. Alternatively, different material having different rigidities may be used. The detents (not shown) within the base  61  are as previously described. 
     FIG. 6 shows a partial cross-sectional view of the sleeve of FIG. 5 with a catheter assembly inserted therein. Pressure on the deformable region  64  distal to the thin region  66  causes detent  68  on the base within the deformable region to translate away from the axis of the sleeve and disengage from annular flange  28  of the introducer  30 . 
     FIG. 7 is a partial sectional view of a third alternative embodiment of the sleeve installed on a catheter assembly. This embodiment is similar to the embodiment of FIGS. 5 and 6, except that a pivot protrusion  86  is provided on the inner surface of the sleeve within the deformable region  84 . The pivot protrusion  86  contacts the catheter hub, such that pressure on the deformable region  84  distal to the pivot protrusion  86  causes the deformable region  84  to act like a teeter-totter about the pivot protrusion, such that the detent  88  translates away from the axis of the sleeve and disengages from annular flange  28 . 
     Each of the described embodiments permits the introducer catheter assembly to be withdrawn from the sleeve with little or no resistance. The sleeve could be injection molded or formed in any other conventional means. In one embodiment, the entry sleeve is integrally formed as one continuous unit. Notably, the sleeves described above with the grooves, are suitable for many types of catheters, including both winged and wingless catheters. Thus, a single sleeve design can be used for a wide variety of different catheters, thereby reducing the tooling and manufacturing costs which would otherwise be necessary to produce the several different sleeve types. 
     In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. Therefore, the scope of the invention should be limited only by the appended claims.