MX2008010409A - Enclosed needle device with duckbill release mechanism - Google Patents

Abstract

An enclosed needle catheter insertion device (10) includes a catheter (12) and a needle insertion device (14) which are held together by cooperating arms (52, 53) with one or more detents (56) cooperating with a radially projecting surface (26) of the catheter hub (16). Insertion device (14) includes a guard housing (30) to enclose a needle (34) in a shielded position and a support housing (32) supporting the needle (34) for movement between a ready position, with the tip (36) of the needle (34) exposed, to the shielded position. Cooperating lock elements (47, 78) are provided for the housings (30, 32) which are positioned to define a lock actuation stage between the ready and shielded positions, whereat the needle is still within a passageway (54) defined by the cooperating arms (52, 53).

Description

NEEDLE DEVICE LOCKED WITH DUCK PEAK RELEASE MECHANISMS FIELD OF THE INVENTION The present invention relates to enclosed needle devices and more particularly to release mechanisms for selectively holding the needle device enclosed in a catheter hub.

DESCRIPTION OF PREVIOUS TECHNIQUE Catheters on the needle are well known in the art. In such devices a needle projects through a catheter tube with its sharp tip projecting out of the end of the tube. The sharp tip of the needle is used to prepare the skin and blood vessel so that it carries the end of the catheter to the vessel. Once the catheter is in place, the needle is removed leaving the catheter hub exposed for use for example for a connection to a medical fluid line or the like to administer or withdraw fluids. In order to reduce the risks of accidental stings with the needle after the needle has been removed from the catheter, various proposals have been made to cover the tip of the needle. A class of devices is designed to protect the tip of the needle and includes an elongated needle shield housing into which the needle is received as it is pulled out of the catheter. The cover housing may include as part of its distal end a protrusion similar to a male luer connection which is adapted to frictionally engage a tapered inner luer-like surface of the catheter hub such that the housing of the cover it is pulled free from the catheter hub. The cover housing is of sufficient length so that it essentially encloses the entire length of the needle therein when the needle is pulled out of the catheter, and in this way the tip of the needle is protected. In some cases, the ridged tip is completely inside the housing of the cover while in others the sharp tip may be inside the projection to thereby maintain the alignment of the needle. In any field, however, the needle is considered to be enclosed in the covered tip. To this end, the needle is supported on a needle support hub or housing that can be moved within the housing housing from a first ready position in which the distal end of the support housing is positioned towards the distal end of the housing of the housing. covered with the needle extending out of the protrusion of the cover housing (and through the catheter with the tip of the needle exposed when the cover housing is secured to the catheter hub), to a second position protected with the distal end of the housing support positioned away from the distal end of the cover housing so as to remove the needle to be enclosed by the cover housing.

The support housing can be deflected by springs to automatically move the needle to the second position when a bolt is activated as shown, for example, in the U.S. patent. No. 4,747,831 and on the IV AutoGuard covered catheter commercially available from Becton Dickinson and Company. Or the support housing can be moved manually to the second position for example by manipulation of walls or fins or attached to the support housing. In the type of manual device a mobilization structure such as a projection and a groove retainer mechanism in the housings cooperate to retain the housings with the needle in the second position enclosed in the cover housing and thus protect the tip of the housing. the needle and thus the needle holder can not be easily manipulated to project the tip of the needle back into the cover housing. An example of such a handheld device is the highly successful PROTECTIV Safety I.V. Catheter marketed by Medex, Inc., the assignee of this. After moving to its second position protected from the needle, the cover housing can be pulled out of the catheter hub and discarded with the needle protected therein, leaving the catheter hub accessible as needed.

BRIEF DESCRIPTION OF THE INVENTION Although devices that use an elongate housing to cover the tip of the needle enclosing the needle have been well accepted and further improvements are desired. By way of example, the cover housing is fixed to the catheter hub only by friction so that it is possible to uncouple the components with the tip of the needle still exposed. In addition, it is often desirable to be able to rotate the catheter hub relative to the housing housing to press the catheter tube into the patient. The friction fit of the projection to the catheter hub to retain the hub housing to the hub limits the ability to obtain such rotation while maintaining the components together. In addition, with the catheter in place, overcoming the friction fit to remove the protected needle from the catheter hub after removing the needle in the housing housing can result in unwanted movement or removal of the catheter tube. Duckbill release mechanisms have been proposed for other types of catheter insertion devices and it is considered that such mechanisms can be advantageously applied for enclosed needle devices as well. Such duckbill release mechanisms typically include a pair of co-operating members that extend from a housing and have a size to fit within the catheter hub. The members, which may be in the form of arms, normally define a passage therebetween which is sized to slidably receive the body of the needle therethrough. One or both of the members has a holding portion, such as a detent radially outwardly and / or radially inwardly, at or near the distal end to cooperate with a radially inner projecting surface such as a recess that is extends radially outwardly or a rib extending radially inwardly of the catheter hub. The foregoing is referred to as a duckbill release mechanism due to the duckbill appearance of one or more of the members created by the retainer and / or the recess thereof. The duckbill release mechanism is considered advantageous because it is strongly retained when a needle is present and is easily released when the needle is not present. For example, when the needle is present in the passage between the duckbill members, the compression (i.e., radially inward flexure) of the limbs is limited so that the limit of the grasping portion of the bill member is Duck and the interior of catheter hub radially project surfaces which provides a very large clamping force to hold the components together. The force that is required to separate the components in this circumstance, referred to as the "catheter separation force" is typically very large since the separation typically requires some deformation of the components. In contrast, when a needle is removed from the conduit, the force required to separate the components, termed as the "catheter release force" is somewhat less than the catheter separation force since deformation is no longer required. Instead, one or both of the duckbill members are capable of easily compressing or flexing towards the conduit so that a slight pull of the housing causes the duckbills to bend against the radially inner projecting surface of the container. catheter hub which allows the components to separate. The duckbill release mechanisms have the additional advantage that, based on the shape and location of the clamping portion and the radially projecting surface, the housing can be rotatable relative to the catheter hub, even during periods of a large clamping force. In the context of an enclosed needle device, the members will be defined on or in the outgoing deck housing. However, the application of a duckbill release mechanism to an enclosed needle device requires more than simply providing the interlocking aspects of the projection and the catheter hub. For example, in the manual type of enclosed needle device, the holder and the cover housings are generally locked together only after the needle tip has passed into the cover housing so that it is maintained in a protected state. With the addition of a duckbill release mechanism, the tip of the needle can pass from the duckbill passage before the support and cover housings are immobilized together. When this occurs, the catheter hub can be loosened from the cover housing before the support latch and cover housings allow the needle of the support housing to be pushed back out of the housing housing.

In enclosed needle devices, the nature of the mobilization structure makes it more likely that the components can be separated before the housings are immobilized. In this regard, in order that there is projection of the mobilization structure for coupling the groove retainer, it is necessary to advance through a locking or immobilization actuation step such as when a projection ramp passes between and open cams of a pair of fingers defined by the groove retainer. The forces encountered during the bolt actuation step are typically greater than the catheter release force. In addition, the entry in the bolt actuation stage exerts increased resistance preventing movement of the needle support housing as the fingers disperse away against the ramp. In this way, there is a risk of premature disconnection in normal use of an enclosed needle device when equipped with a duckbill release mechanism. The present invention provides a catheter delivery mechanism for an enclosed needle device which has the advantages of duckbill catheter hub release mechanisms and in which disconnection is more reliable. For this purpose, in accordance with the principles of the present invention, the immobilization structure is positioned so that the needle holder can be moved within the bolt actuation stage with the needle still in the duckbill passage ( and therefore before the needle holder moves to the protected state), where a relatively high catheter spacing force is involved. It will be appreciated that the force exerted on the inlet within the bolt actuation step involves the flexing of the components instead of deformation thereof, so that the forces encountered at the entrance into the bolt actuation stage are advantageously below the catheter separation force. As a consequence, the forces exerted by the entry within the bolt actuation stage are presented while the duckbill release mechanism holds the cover housing and the catheter hub tightly together, thereby preventing premature release before that the bolt is engaged. Advantageously, the immobilization structure is positioned so that the support housing moves through a reduced force stage to activate the bolt as the needle finally exits the passage. For this purpose, the bolt projection may include a section of fixed or reduced height, such as a sliding wall, after the ramp so that excessive force by the fingers thereon as the needle continues to be pulled out of the passage is less than the forces exerted at the entrance within the bolt actuation stage and / or is reduced from here. In this way, even as the needle moves away from the passage, the forces in the bolt may continue to remain below the forces necessary to separate the components in the duckbill release mechanism. Once immobilized, the forces required to overcome the lock are extremely high while the catheter release force is very low and in this way the components are allowed to separate easily after the needle has been completely enclosed with the immobilized accommodations in that state. By virtue of the foregoing, therefore, a catheter delivery mechanism for an enclosed needle device is provided here which has the advantages of duckbill catheter hub release mechanisms and in which disconnection is more trustworthy. These and other objects and advantages of the present invention will become apparent from the accompanying drawings and description thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which incorporate and constitute a part of this specification, illustrate an exemplary embodiment of the invention and, together with a general description of the invention provided in the foregoing and the detailed description provided in the following, serve to explain the invention. Figure 1 is a perspective view of a needle catheter insertion device enclosed in a ready state and having a duckbill catheter hub release mechanism in accordance with the principles of the present invention; Figure 2 is a cross-sectional view along line 2-2 of Figure 1; Figure 3 is a partial bottom plan view of the catheter insertion device of Figure 1 in a seen state; Figure 4 is a cross-sectional view of the catheter of the catheter insertion device of Figure 1; Figure 5 is a cross-sectional view of a distal or protruding cover of the cover housing of the catheter insertion device of Figure 1; Figures 6A to 6E are partial cross-sectional views of the catheter insertion device of Figure 1 showing the progress of the needle, the needle support housing and the housing housing from the ready state to the protected state for the purposes of explaining the principles of the present invention, with the distal portion of the device being rotated 90 ° relative to the proximal portion thereof for ease of explanation; and Figure 7 is a perspective view of the catheter insertion device of Figure 1 in the protected state with the needle cover separate from the catheter after the progress of Figures 6A to 6E.

DETAILED DESCRIPTION OF THE DRAWINGS With reference to the appended figures (which are not necessarily to scale in order to more easily show the various components) an exemplary embodiment of a needle catheter insertion device enclosed in accordance with the principles of the present invention is shown. . The catheter insertion device 10 includes a catheter 12 and a needle insertion assembly 14 of the needle type enclosed as will become apparent. With specific reference to Figure 4, it can be seen that the catheter 2 is constituted by a catheter hub 16 having an open mouth 17 (which, in the embodiment shown is a female luer coupling) at its end 18 proximal and a catheter tube 19 extending distally from the distal end of the hub 16 to a bevelled end 21, as is conventional. The catheter tube 19 may be secured to the hub 16 in any suitable manner, said securing may be by an eye 22 in the embodiment 10 shown herein. The catheter hub 16 has an internal wall 23 defining the interior 24 of the catheter hub 16. Associated with the inner wall 23 and extending radially inward therefrom is an annular rib 25 (which may be a single rib or one or more arcuate segments) to define a radially projecting, distally directed surface 26 interior, for purposes that will be explained. The proximal portion 27 of the inner wall 23 extending between the mouth 17 and the rib 25 is tapered according to the luer standards to define a female luer connection. The rib 25 has a more inward aspect 28 defined by an internal diameter D1 of catheter hub for purposes to be explained. With particular reference to Figure 2, it can be seen that the needle insert assembly 14 includes an elongated cylindrical, advantageously outer needle cover housing 30; a support chamber or advantageously cylindrical needle housing 32 received telescopically in the housing housing 30 and a needle 34 having a body portion 35 supported by the support housing 32 and extending distally therefrom to a distal tip 36 bevelled and sharp. The cover housing 30 has a side wall 40 which extends between the distal end or cover 32 and the proximal end 43 and which defines between them a space 41 through which the support housing 32 moves and within which the needle 34 is finally received to be locked, as will be described in the following. As seen, for example in Figure 3, the cover housing 30 includes a longitudinal notch 44 running through the side wall 40 along a portion of its length between the ends 42 and 43. The proximal end 45 from notch 44 defines a receiving area for the purpose to be described. Distal to the receiving area 45 is a cutout or notch 46 of a U-shaped groove which defines a pair of fingers 47, the fingers define a groove 48 therebetween. The fingers 47 are each adapted to cam or driven away from each other to extend the slot 48 for the purposes to be described. As seen in greater detail in Figure 5, the distal cap 42 includes a projection 50 that is sized to be removably adjusted within the interior 24 of the catheter hub 16 in close proximity to the internal wall 23 thereof. Extending from, and in the mode of the figures forming the portion of the projection 50 are a pair of cooperating members in the form of arms 52, 53 defining a divided cylinder which also has a size to fit within a hub 16. The arms 52, 53 are adapted to compress or flex radially towards each other but in the uncompressed normal state define a passage 54 therebetween which is normally sized to slidably receive the needle 34 therethrough. The end of each arm 52, 53 (or at least one of them) includes a retaining portion in the form of a detent 56 defining a recess 58 or a thinned portion of the arm 52 or 53 behind it. One or more of the detents 56 provide the respective arms 52, 53 with the appearance of a duckbill and, in the uncompressed state, define on their outer periphery 60 an annular ring having a duckbill diameter D2 that is at least slightly greater than the internal diameter D1 of catheter hub for purposes to be explained. The detents 56 can be bevelled distally as in 61. Advantageously, one or more of the recesses 58 define an area within which the rib 25 is detachably received without compressing or only slightly compressing one or more of the arms 52, 53. interaction of the arms 52, 53 and especially the holding portions 56 thereof and the rib 25 to define a duckbill release mechanism will be described in greater detail in the following. Referring again to Figure 2, the support housing 32 has a side wall 65 extending from the distal end 66 to the proximal end 67 and defining therebetween a fluid or light path 68. The needle 34 is supported, and advantageously can be fixed to, a support housing 32 so that the body 35 thereof extends distally from the distal end 66. The fluid path 68 of the support housing 32 is in fluid communication with the light (not shown) of the needle 34 so that blood (not shown) can be observed by extraction through the needle 34 into the path 68. of fluid so that the housing 38 also serves as a verification chamber. To prevent blood (not shown) from leaving the support housing 32 during the verification, a stopper prevents the material 70 adapted to pass air but not blood or other fluids to be advantageously placed at the proximal end 67. The support housing 32 and the housing housing 30 are received telescopically so that one can move relative to the other along a common axis 72. In this regard, the support housing 32 has a first ready position with the needle 34 extending through and beyond the passage 54 (FIG. 5) so as to expose the sharp tip 36 of the catheter tube 9, as noted in Figures 1 and 2. In the ready position, the cover housing 30 is maintained in the catheter hub 16 by interaction of the clamping portions 56 and the radially projecting surface 26. More particularly, the needle body 35 is in the passageway 54 between the engaging members 52, 53 and therefore limits the ability of either or both of the cooperating members 52, 53 to compress (i.e., flex radially inwardly). At the same time, because the duckbill diameter D2 is slightly larger than the internal diameter D1 of the catheter hub, a rigid hold is generally provided that defines the relatively high catheter spacing force that is needed to disconnect the catheter hubs. components. In addition, the detents 56 are advantageously accommodated by passing the rib 25 with a slight friction fit which desirably allows the healthcare service user (not shown) to rotate the catheter hub 16 relative to the insertion assembly 14 of the catheter. needle. The support housing 32 can be moved axially to a second position or position protected with the needle 34 substantially enclosed by the cover housing 30 as seen in Figures 6E and 7. In that protected position, the needle 34 is no longer located in the passage 54 between the arms 52, 53, so that these arms 52, 53 easily flex against the surface 26. The force required to flex the arms 52, 53 is very low, defining the catheter release force , which is easily overcome to disconnect the needle insert assembly 14 from the hub 16. In particular, in the protected state, the detents 56 flex easily against the surface 26 (as exemplified in FIG. 6E) and then flex or decompress back to the nominal state after passing the rib 25 (as exemplified in Figure 7). Advantageously, the proximal portion 27 of the inner wall 23 of the hub has a minimum internal diameter generally not less than the external diameter D2 of the duckbill. To facilitate the movement of the support housing 32 from the ready position to the protected position, a pair of adjacent locking flaps 76, 77 is placed but outside the side housing cover wall 40. A projection or rib 78 (FIGS. 3 and 6A), for example, extends through the longitudinal notch 44 and joins the plate 79 which supports the fastening flaps 76, 77 to the side wall 65 of the support housing 32. A medical practitioner can pull on holding the wings 76, 77 (or push against the wings 76, 77 by producing a lever against the push tab 80 of the housing housing 30 at its distal end 42) to cause relative movement between the housings 30 and 32 from the ready position to the protected position. The flaps 76, 77 can also be attached across the top to create, in effect, a tubular member (not shown) around the housing housing 30. The tubular member may be elongated (either as a cylinder or by the addition of a lid portion, for example) to match the length of the housing housing 30.

The rib 78 is advantageously shaped so that the elongate proximal portion 82 defines a slide wall, which terminates proximally on a cam ramp or surface 84. A receiving gap 86 is formed in the distal rib 78 of the slide wall 82 leaving the distal rib piece 89. The slot 48 defined by the fingers 47 is usually narrower than the width of the rib 78. As the support housing 32 moves towards the protected position, the rib 78 and particularly the ramp 84 thereof engages the fingers 47 and begins to propel them away so as to expand the slot 48 for the passage of the rib 78 therethrough. As the fingers are propelled apart, the needle holder 32 can be said to have moved to a bolt actuation stage. In the bolt actuation step, the forces generated by the camming action of the ramp 84 against the fingers 47 exert an increased resistance to the movement of the needle holder 32. The foregoing is visually shown in Figures 6B (entry to the bolt actuation stage) and 6C (passage through the bolt actuation stage). After the fingers 47 are driven away from each other enough so that the rib 78 passes into the slot 48, the forces generated therein descend with the continuous movement of needle support 32 into the protected state since now the only force that it avoids the sliding action of the fingers 47 along the sliding wall 82 of the rib 78 which is exemplified by Figure 6D. The continuous movement of the needle holder 32 within the protected state places the separation 86 of the receiver in alignment with the fingers 47 so as to flex or clamp back towards its original state and within the gap 86 behind the wall 82. of sliding, as exemplified in the figure in 6E. The above movements also place the sliding wall 82 and the associated ramp 84 in the receiving area 45. The ramp 84 can make contact against the most proximal end of the receiving area 75 to prevent any further proximal movement of the needle holder 32 relative to the housing housing 30. Further, with the fingers 47 pressed backwardly around the sliding wall 82 and within the gap 86, the needle holder 32 is immobilized in the covered condition such that the needle 34 can not be easily pushed backwards. outside housing 30 of cover. It is thus observed that the fingers 47 and the rib 78, or at least a portion thereof, define cooperating bolt elements for locking the needle holder 32 in the protected position. It is also recognized that, in an immobilized state, the interaction of the surface of the cooperating bolt elements generates a situation where extremely large forces can be applied in a proximal direction on the housings 30 and / or 32 and away from the catheter 12 for facilitating the disconnection of the insertion device 14 from the catheter 12 with the needle 34 protected by the cover housing 30, at which point essentially only the relatively small catheter release force needs to be overcome.

In order to provide reliable disconnection it is desired that the forces created at the inlet within the bolt actuation stage are not so great as to exceed the forces needed to maintain the clamping of the cover housing 30 to the hub 16 of catheter. For this purpose, and in accordance with the principles of the present invention, the cooperating bolt elements are positioned to take advantage of the high catheter separation force due to the presence of the needle 34 in the passage 54 between the arms 52, 53 during the increased resistance to the needle support movement 32 encountered as the needle holder 32 moves within the bolt actuation step. In this way, in the enclosed needle catheter insertion device 10 shown here, the fingers 47 and the ramp 84 are positioned remote from the duckbill release mechanism so that the ramp 84 begins to engage the fingers 47 while the needle 34 is still in the passage 54, as seen in Figure 6B. More particularly as seen in Figure 6A, the fingers 47 are positioned to define a slot 48 separated by a first distance L1 measured through the passage 54 and a housing housing 30 one or more portions 60 and the ramp 84 is positioned to be separating a second distance L2 measured through the needle 34 from the sharp point 36 thereof, wherein the second distance L2 is greater than the first distance L1. As a consequence, the increased resistance to movement of the needle holder 32 is found while the clamping between the catheter hub 16 and the housing housing 30 is at the highest. The continuous proximal movement of the needle support housing 32 relative to the housing 30 continues through the bolt actuation step (FIG. 6C), in which forces are required to fully flex the fingers 47 that are in its position. upper part, the whole while the clamping between the catheter hub 16 and the engaging members 52753 is also at the maximum due to the catheter separation force. It is advantageous to minimize the force required to flex the fingers 47, for example by minimizing the cross-sectional area thereof which can be done by causing the fingers 47 to be thinner or narrower. For this purpose, in the embodiment shown here, the width of the fingers 47 is reduced by approximately 20 thousandths in comparison with a standard PROTECTIV Safety I.V catheter. As the bolt actuation step is completed, the needle holder 32 moves within the slide stage (Figure 6D) while the fingers 47 now rest against the side wall 82. In said sliding step there is no need for additional bending of the fingers 47. Instead of this, the forces relax and involve a lower level of resistance to movement of the needle holder 32. Said lower resistance level is advantageously used to provide minor forces as the needle 34 begins to approach within the passage 54 whereby the force ratio between the catheter hub 16 and the members 52, 53 starts to move from the raised forces involved. for the requirement of catheter separation force, to the much smaller forces needed to overcome the catheter release force. The sliding wall 82 can even be tapered distally (not shown) to reduce the width and further decrease the forces acting between the fingers 47 and the sliding wall 82 during the sliding stage. In the final movement of the needle holder 32 in the protected position, the fingers 47 press fit within the receiving gap 86 whereby substantial forces can be applied without separating the cooperating mobilizing elements. In this step, the needle holder 32 is in the protected position and the needle 34 is out between the members 52, 53. The forces holding the housings 30 and 32 immobilized in the protected position are very strong, while the force of catheter release is very low such that the clamping positions 60 and members 52, 53 are easily and simply flexed against one or more surfaces 26 projecting as the cover 30 begins to be pulled away from the hub 16 of the catheter, as exemplified in Figures 6E. The continuous pulling of the needle holder 32 and / or the cover housing 30 easily removes the catheter insertion device 12 so that they are now disconnected, as shown in Figure 7. With the components disconnected, the hub 16 is exposed for use by the medical practitioner, with the needle insert assembly 14 immobilized in the protected position ready to be discarded.

The projection 50 advantageously includes one or more internal or external seals such as a co-molded elastomeric seal 100, integrally associated with the exterior wall 12 of the projection 50 to form a seal with the inner wall 23 of the catheter hub 16 and / or a co-molded elastomeric seal 104 integrally associated with the inner wall 106 of the projection 50 defining the proximal passage 108 through which the needle 34 is received to form a seal therewith, as shown herein and as shows and describes more particularly in the US patent application presented concurrently and entitled "Sealing Catheter Hub Attachment", File of the attorney-in-fact number MDXVA-104US, whose description is incorporated herein by reference as if it had been fully presented herein. The size of the passage 54 can be narrow to the diameter of the needle arrow 35 so that the passage 54 is largely captured by the presence of the needle body 35. The compression or other inward bending of the co-operating members 52, 53 is therefore limited, thereby restricting the release of the co-operating members 52, 53 of the catheter hub 16. Tolerance of the spacing between the relative internal diameter of the passage 54 of the co-operating members 52, 53 and the outer diameter of the needle body 35 can be selected to reduce the likelihood of separation of the duckbill 52, 53 from the hub 16 of the catheter when the needle 34 is present. In addition, with the needle body 35 outside the interior of the passage 54, the duck peaks 52, 53 can be easily loaded into the catheter hub 16 by pushing them into the hub 16 (or by pushing the hub 16 on the arms 52, 53) so that the detents 56 impact against the rib 25 to cause the cooperating members 52, 53 to flex slightly until the detents 56 are distally passing the rib 25, at which point they flex back out to slightly hold the catheter hub 16. The body 35 of the needle can then be loaded to withstand inward flexion of the members 52, 53, which greatly increases the clamping force. Alternatively, with the body 35 in place, the duck peaks 52, 53 can be urged into the hub 16. The bevels 61 can assist with said loading. The members 52, 53 are shown by defining a divided cylinder. The forces required to bend the arms 52, 53 are defined, in part, by the thickness of the plastic in the detents 56 and / or the recesses 58. An additional adjustment is provided by the depth of the notches 120 that are formed in the projection 50 (FIG. 5) while the arms 52, 53 may be arcuate in cross section, instead of this they may have a half-moon cross-section. In addition, each arm 52, 53 can be provided with an internally dependent longitudinal ridge (not shown) to define, in effect, the internal diameter size of the passage 54, as described in the U.S. patent application. serial number 11/161, 554 filed August 8, 2005 whose description is incorporated herein by reference. The cooperating members 52, 53 may be upper and lower segments of a divided cylinder or may define respective large and small aspects and / or side-by-side segments of a divided cylinder. In addition, although both are described as being susceptible to flexion and with detents at their distal ends, it will be recognized by those skilled in the art that in only one member may be resilient enough to flex easily, only one member may include a retainer and / or the seals which may be remote from the distal ends. In addition, although the rib 25 (and therefore the surface 26) is shown to be generally continuous, it may have one or more spacings (not shown). Advantageously, any of said spacings, if provided, may each be smaller than the circumferential width of the retainer 56. In use of the enclosed needle catheter insertion device 10, any protective liner (not shown) and with the device are removed. 10 in the ready position, the needle tip 36 inserted in a patient (not shown) for positioning the catheter tube 19 as desired, included by rotation of the catheter hub 16 relative to the needle insertion assembly 14, if needs to. Once the tube 19 is positioned as desired, the needle support housing 32 moves proximally within the cover housing 30 within the bolt actuation step with the needle 34 still in the passage 54. In the increased resistance the movement of the needle holder 32 is not sufficient to overcome the separation force of the catheter. The needle holder 32 continues in its movement through the sliding stage where the movement resistance of the needle holder 32 is reduced. The continuous movement carries the needle holder 32 into the protected state where it is immobilized. In the protected state, the forces to overcome the bolt are very large so that, because the needle 34 is no longer in the passage 54 between the arms 52, 53, the catheter release force is very small. In this way, the arms 52, 53 are flexed against the rib 25 which allows the needle insertion assembly 14 to be disconnected from the catheter tube 16. Although the present invention has been illustrated by the description of the embodiments thereof and although the modalities have been described in considerable detail, it is not intended to restrict or limit in any way the scope of the appended claims to said details. Additional advantages and modifications will be readily apparent to those skilled in the art. For example, although the surface 26 has been described as a distally directed aspect of a rib 25 projecting radially inward, alternatively the surface can be defined as a proximal aspect of a groove (or grooves) projecting radially towards outside. In addition, although latch elements with two fingers 47 are shown, operation is possible with only one flexible finger 47. Further, although the needle holder 32 is shown with a size so that it is completely within the housing housing 30 in the ready position, the support housing 32 may be elongated (not shown) so as to provide path access. of fluid as shown and described in the US patent application Commonly assigned and filed concurrently entitled "Enclosed Needle Device with Fluid Path Access" attorney's file number MDXVA-103US, the description of which is incorporated herein by reference in its entirety. The invention in its broader aspects is therefore not limited to the specific details, apparatus and representative methods and the illustrated examples that are shown and described. Accordingly, deviations from said details may exist without thereby departing from the scope or spirit of the applicant's general inventive concept.

Claims (19)

NOVELTY OF THE INVENTION CLAIMS

1. A medical device comprising a safety catheter device having a catheter (12) including a catheter hub (16) having a radially inner projecting surface (25) and a catheter tube (19) and extending from the distal end of the catheter hub (20); and a capped needle cover (14) removably coupled to the catheter hub including a needle holder (32) with a needle (34) extending therefrom; a cover housing (30) movably receiving the needle holder (32) and having a pair of cooperating members (52, 53) extending from one end thereof and having a size to fit within the hub (16) of catheter, the members (52, 53) have a normally uncompressed position defining a passageway (54) therebetween which has a size to freely receive the needle (34) therethrough, at least one member (52, 53) that includes a holding portion (56) adapted to cooperate with the radially projecting surface (25) of catheter hub to releasably hold the housing housing (30) to the catheter hub (16). so that the fastening portion (56) released from the surface (25) projecting radially by compression of the member (52 or 53) to narrow the passage (54) where the presence of the needle (34) in the passage ( 54) substantially limits said compression to thereby limit After releasing the cover housing (30) from the catheter hub (34), the needle holder (32) can be moved from a ready position with the needle (34) extending through and past the passage (54) so as to expose a sharp tip (36) of the needle from the catheter tube (19) to a position protected with the needle (34) substantially enclosed by the cover housing (30), the needle holder (32) is can move to a bolt actuation stage with the needle (34) in the passage (54) before moving to the protected position; and cooperating latch elements (47, 48) on the needle holder (32) and a cover housing (30) that immobilizes the needle holder (32) in the protected position, the needle holder (32) can be moved from the ready position towards a bolt actuation step with the cooperating locking elements (47, 84) exerting an increased resistance to the movement of the needle support (32) as the bolt actuation step enters, characterized in that the surface that radially projecting is a rib (25) that projects radially inward.

The medical device according to claim 1, further characterized in that the needle holder (32) includes a projection (78) extending therefrom through a notch (44) in the cover housing (30). , the cooperating bolt element (47 or 78) is associated with the projection (78).

3. The medical device according to claim 2 or claim 3, further characterized in that the rib (25) is continuous.

4. The medical device according to any of the preceding claims, further characterized in that the members (52, 53) co-operators are received within the catheter hub (16) through the open mouth (17) thereof, the catheter hub (16) has a portion (27) of inner surface extending along of a taper between the open mouth (17) and the radially projecting surface (25).

5. The medical device in accordance with the claim 4, further characterized in that the tapered inner surface portion (27) has a minimum internal diameter generally not less than the maximum outer diameter of the cooperating members (52, 53) defined in the fastening portion (56).

The medical device according to any preceding claim, further characterized in that each member (52, 53) including a holding portion (56) is adapted to cooperate with the radially projecting surface (25) of the catheter hub (36).

The medical device according to claim 6, further characterized in that each member (52, 53) is compressible to the deflection of its holding portion to narrow the passage (54).

The medical device according to any preceding claim, further characterized in that the cover housing (30) is elongated, the needle holder (32) can be moved axially from the ready position, in the bolt actuation step, to the protected position.

The medical device according to any of claims 1 to 7, further characterized in that the needle holder (32) can be moved from the bolt actuation stage through the sliding step as the needle (34) is moved. moving through the duct (54), the cooperating locking elements (47, 78) exert reduced resistance to the movement of the needle support (32) through the sliding stage.

The medical device according to claim 9, further characterized in that the cover housing (30) is elongated, the needle holder (32) can be moved axially from a ready position, in the bolt actuation step, to through the sliding stage and inside the protected position.

The medical device according to any preceding claim, further characterized in that the cooperating latch elements (47, 78) are adapted to generate forces on the input in the bolt actuation step less than the force required to substantially compress the limb. (52 or 53) with the needle (34) in the passage (54).

The medical device according to any preceding claim, further characterized in that the cooperating bolt elements (47, 78) including a bolt finger (47) define a slot (46) and a bolt ramp (84), the The bolt ramp is adapted to drive the bolt finger so that it extends the groove as the needle holder (32) enters the bolt actuation stage.

13. The medical device in accordance with the claim 12, further characterized in that it comprises a slide wall (82) extending from the bolt ramp (84) and passing along the finger (47) of the bolt as the needle holder (32) moves through the bolt. the bolt action cover.

14. The medical device in accordance with the claim 13, further characterized in that the bolt ramp (84) is defined on the slide wall (82).

The medical device according to claim 12 or claim 13, further characterized in that the bolt ramp (84) is on the needle holder (32) and the bolt finger (47) is on the housing (30) covering.

The medical device according to any of claim 12 to 15, further characterized in that the cooperating bolt elements (47, 48) further include cooperating surfaces adapted to hold the needle holder against movement away from the protected portion.

The medical device according to any preceding claim, further characterized in that the cooperating latch element (47 or 78) on the cover housing is separated a first distance measured through the passage (54) and the housing (30) of cover of the holding portion (56), the cooperating bolt member (78 or 47) on the needle holder (32) is spaced a second distance measured through the needle (34) from the sharpened tip (36) of the needle (34). the needle, the second distance is greater than the first distance.

18. The medical device according to any preceding claim, further characterized in that the holding portion (56) is on a free end of the member. The medical device according to any preceding claim, further characterized in that the needle (34) has an elongated body (35) of a predetermined diameter, the size of the passage (54) is determined in size approximately to the diameter of the body of the needle.