Patent Publication Number: US-2012046649-A1

Title: Medical device connector fitting

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 11/948,807, filed Nov. 30, 2007, and entitled MEDICAL DEVICE CONNECTOR FITTING, which is a divisional of U.S. patent application Ser. No. 09/767,207, filed Jan. 22, 2001, now U.S. Pat. No. 7,316,679, issued Jan. 8, 2008, and entitled MEDICAL DEVICE CONNECTOR FITTING, all of which are hereby expressly incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to a medical line connector fitting, and more specifically, to a releasable connector for use on an elongated medical article. 
     2. Description of Related Art 
     It is frequently desirable in the medical treatment of patients for medical personnel to have some form of access to the vasculature of the patient for delivery or withdrawal of fluids from the bloodstream. When such access is required over any period of time, it is common to introduce a catheter into the bloodstream of the patient to provide reusable access, for instance in order to deliver medication and/or fluids directly into the bloodstream of the patient. It may be desirable to leave such an intravenous catheter in place within the patient throughout treatment to avoid repeatedly having to introduce new catheters. 
     In intravenous applications, the catheter is generally short and includes a luer connector at one end that is designed for attachment to another medical line. Such a connector may also include a spin nut to lock the medical line to the catheter. In this way the same catheter may be connected to and released from different medical lines in order to exchange the medical lines without the need to introduce multiple intravenous catheters. 
     After use over an extended period of time, however, the luer connection between the medical line and the catheter hub may become stuck to each other and difficult to release. In particular, the force which was applied via the spin nut when locking the medical line to the catheter hub may press the medical line into the catheter with enough force that the medical line and catheter do not release upon unlocking the spin nut. In addition, fluid dries between the surfaces of the components of the luer connection, which further exacerbates the adhesion between the components. 
     In such circumstances, the medical technician may need to twist or pull the medical line apart from the catheter. The spin nut has a larger diameter and is easier to grasp than the medical line itself. Therefore a mechanism for transferring force from the spin nut to the medical line may be provided upon the luer connector in order to simplify release of the medical line from the catheter. One example of such a spin nut for use upon a luer connector is seen in U.S. Pat. No. 5,620,427 to Werschmidt et al. 
     The splines provided upon the Werschmidt device, however, allow only rotational force to be transferred between the spin nut and the medical line. The splines also do not impede axial motion of the spin nut in the proximal direction. As a result, the spin nut can migrate up onto the medical line, requiring medical personnel to locate the nut and thread it back into a proper position for usage when the medical line is to be attached or released. 
     Because of the importance and continued use of luer-type connectors between medical lines and intravenous catheters, there is a continued need for improvement in such releasable luer connectors. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention involves a connector fitting that is adapted to cooperate with a corresponding adaptor to couple together two medical components. For example, in one mode, the connector fitting can be adapted to connect to an adaptor on a distal side (i.e., away from the patient) of an indwelling intravenous catheter in order to couple an intravenous medical line to the adaptor. The connector fitting, however, can be disposed on either the upstream or downstream side of the resulting connection. 
     The connector fitting includes an elongated body. A rotatable spin nut is disposed upon the connector fitting body, and also is longitudinally slideable along the length of a portion of the connector fitting. 
     A radially extending member is disposed upon the connector fitting body. The spin nut includes a receptacle that is configured to engage the radially extending member when the spin nut is slid to its most distal position. 
     A possible feature of the connector fitting involves the radially extending member having a multi-sided (e.g., generally hexagonal) external cross section. The receptacle of the spin nut has a cooperating shape so as to receive and engage the radially extending member. The engagement between the spin nut and the radially extending member transfers rotational forces between these components when one of them is rotated. 
     Another possible feature of the connector fitting is that the receptacle of the spin nut has a shape which receives the radially extending member of the connector fitting and also has a wall that abuts axially against the radially extending member when the spin nut is engaged with the member. This allows for the transfer of axial force between the spin nut and the connector fitting when the two components are engaged. 
     In accordance with a more preferred mode, a connector fitting with a spin nut is used to connect a medical line to an adaptor. The connector fitting has an elongated body with a proximal tapering portion and a radially extending member disposed distally of the proximal tapering portion on the elongated body. The elongated body includes a lumen that communicates with ports on the proximal and distal sides of the connector fitting. The radially extending member has a variable radius cross-section. The spin nut is disposed upon the connector fitting proximal of the radially extending member and is both axially slideable and rotatable upon the elongated body of the connector fitting. The spin nut also includes a receptacle formed on its distal side. In order to apply force to the connector fitting, the spin nut is slid distally so that the receptacle of the spin nut engages the radially extending member of the connector fitting. With the spin nut and connector fitting engaged, the medical line may be moved (rotatably and/or axially) relative the adaptor by twisting and/or pulling upon the spin nut. 
     In accordance with another preferred mode, a connector fitting includes an elongated body which includes at least one radially extending member with at least one contact surface. A spin nut is also used which comprises a generally tubular body slidably and rotatably disposed upon the elongated body of the connector fitting. Desirably, the difference in radius between the external radius of the spin nut and the maximum radius of the radially extending member is less than the difference in radius between the maximum radius of the radially extending member and the external radius of the spin nut. 
     A preferred method of using this mode of the connector fitting to secure a medical line to the adaptor involves inserting the tapering portion of the connector fitting into the adaptor. The connector is then secured to the hub by sliding the spin nut to the proximal position and twisting it so that corresponding screw threads of the adaptor and the spin nut engage. To release the connector fitting from the adaptor, the spin nut is unscrewed from the adaptor and slid distally so that the receptacle of the spin nut engages the radially extending member. The spin nut is then twisted and pulled. This motion is transmitted to the body of the connector fitting by the engagement between the receptacle and the radially extending member to dislodge the tapering portion of the connector fitting from the adaptor. 
     Another aspect of the present invention involves a connector system for joining together two medical components (e.g., for joining a medical line and a catheter). The connector system comprises a connector fitting, as described above, and a medical line adaptor (e.g., a catheter hub). The connector fitting and the medical line adaptor are configured so as to engage to form a coupling between two medical components. In one mode, the connector fitting and the medical adaptor include interlocking threads to couple together these components; however, various aspects of the present invention can be practiced apart from such a luer-type connection. 
     The connector system can be used with an anchoring system. This combination provides a secure connection between the medical components and provides a secure anchor of the connection to the patient. The anchoring system includes a retainer which receives a least a portion of the connector fitting. The retainer has at least one receptacle (e.g., slot) that is adapted to receive the radially extending member on the connector fitting to inhibit longitudinal (i.e., axial) movement of the fitting relative to the retainer. In a preferred mode, the retainer includes a plurality of receptacles disposed longitudinally to offer multiple positions in which to position the connector fitting within the retainer. This affords the ability to coarsely align the connector fitting relative to the retainer before inserting the connector fitting into the retainer. The anchoring system also can include an anchor pad, which adheres to the patient&#39;s skin and on which the retainer is mounted. 
     Another aspect of the present invention involves the combination of the above-described connector fitting together with a retainer. The radially extending member of the connector fitting is configured to cooperate with a slot or other receptacle of the retainer when the radial member is not engaged with the spin nut. Such a retainer may include one or more slots so dimensioned to cooperate with the radially extending member of the connector fitting to hold the connector fitting in position relative to the retainer. The retainer also may be part of an anchoring system that further includes a base pad on which the retainer is mounted. 
     For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described above. Of course, it is to be understood that not necessarily all such objects or advantages be achieved in accordance with any particular embodiment of the invention. Those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. Thus, the connector fitting, and its combinations with an anchoring system and/or with a medical adaptor, can take various forms, and not all embodiments need include all of the aspects and features noted above. In addition, further aspects, features and advantages of this invention will become apparent from the detailed description of the preferred embodiments which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above mentioned and other features of the invention will now be described with reference to the drawings of preferred embodiments of the present connector fitting and connector system. The illustrated embodiments are intended to illustrate, but not to limit the invention. The drawings contain the following figures: 
         FIG. 1  is a perspective view of a connector system including a connector fitting configured in accordance with a preferred embodiment of the present invention with the connector fitting and an adaptor of the connector system disconnected. 
         FIG. 2  is a perspective view of the connector system of  FIG. 1  with the connector fitting and adaptor connected to each other. 
         FIG. 3  is a perspective view of the connector fitting of  FIG. 1  with a spin nut of the fitting shown partially in section. 
         FIG. 4A  is a similar view to that shown in  FIG. 3  and illustrates the spin nut engaged with a radially extending member of the connector fitting. 
         FIG. 4B  is an enlarged view of the region within circle  4 B- 4 B of  FIG. 4A  and illustrates the radially extending member abutting a wall of the spin nut receptacle. 
         FIG. 5A  is a perspective view of a distal end of the spin nut showing the receptacle. 
         FIG. 5B  is an enlarged distal end view of the spin nut illustrating the receptacle. 
         FIG. 6  is a cross-sectional view of the connector fitting taken along line  6 - 6  of  FIG. 3  and illustrates a preferred form of the radially extending member. 
         FIG. 7A  is a cross-sectional view of an additional preferred form of the connector fitting. 
         FIG. 7B  is an enlarged distal end view of a spin nut illustrating another preferred form of the spin nut and receptacle. 
         FIG. 8A  is a perspective view of a distal end portion of a connector fitting having radially extending members configured in accordance with another preferred form, and  FIG. 8B  is a perspective view of the distal end of a spin nut with correspondingly shaped receptacles to receive the radially extending members. 
         FIG. 9A  is a perspective view of a distal end portion of a connector fitting having radially extending members configured in accordance with an additional preferred form, and  FIG. 9B  is a perspective view of the distal end of a spin nut with correspondingly shaped receptacles to receive the radially extending members. 
         FIG. 10A  is a perspective view of a distal end portion of a connector fitting having a radially extending member configured in accordance with another preferred form, and  FIG. 10B  is a perspective view of the distal end of a spin nut with correspondingly shaped receptacles to receive the radially extending member. 
         FIG. 11A  is a perspective view of a distal end portion of a connector fitting having a radially extending member configured in accordance with an additional preferred form, and  FIG. 11B  is a perspective view of the distal end of a spin nut with a correspondingly shaped receptacle to receive the radially extending member. 
         FIG. 12A  is a perspective view of a distal end portion of a connector fitting having a radially extending member configured in accordance with an additional preferred form, and  FIG. 12B  is a perspective view of the distal end of a spin nut with a correspondingly shaped receptacle to receive the radially extending member. 
         FIG. 13  is a perspective view of a spin nut in yet another form which may be used with a connection system as shown in  FIG. 14 , below. 
         FIG. 14  is a perspective view of a connector system configured in accordance with another preferred embodiment of the present invention. 
         FIG. 15  is a perspective view of the connector fitting of the system shown in  FIG. 1  with an exemplary anchoring system. 
         FIG. 16  is a perspective view of the connector system of  FIG. 1  in use with an exemplary medical line anchoring system from  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following description and examples illustrate in detail a preferred embodiment of the present connector system disclosed in the context of use with an exemplary medical line and intravenous catheter. The principles of the present invention, however, are not limited to intravenous catheters. It will be understood by those of skill in the art in view of the present disclosure that the releasable connector system described may be applied to other types of medical articles, including without limitation, catheters and fluid delivery or drainage tubes. One skilled in the art may also find additional applications for the devices and systems disclosed herein. Thus the illustration and description of the connector system in connection with the medical line and catheter are merely exemplary of one possible application of the connector system. 
     To assist in the description of these components of the connector system (see  FIG. 1 ), the following coordinate terms are used. A “longitudinal axis” is generally parallel to the axis of the connector fitting  10 . A “lateral axis” is normal to the longitudinal axis and is generally parallel to the plane of the skin of a patient upon which such medical lines are attached. A “transverse axis” extends normal to both the longitudinal and lateral axes. In addition, as used herein, “the longitudinal direction” refers to a direction substantially parallel to the longitudinal axis; “the lateral direction” refers to a direction substantially parallel to the lateral axis; and “the transverse direction” refers to a direction substantially parallel to the transverse axis. 
     The term “axial” as used herein refers to the axis of the medical line, and therefore is substantially synonymous with the term “longitudinal” as used herein. Also, the terms “proximal” and “distal”, which are used to describe the present anchoring system, are used consistently with the description of the exemplary applications. Thus, proximal and distal are used in reference to the center of the patient&#39;s body. Therefore, the proximal end of any apparatus is the portion which is closer to the center of the patient&#39;s body, while the distal end of any structure is that which is located farther from the center of the patient&#39;s body. 
     The terms “upper,” “lower,” “top,” “bottom,” and the like, which also are used to describe the present anchoring system, are used in reference to the illustrated orientation of the embodiment. A detailed description of a preferred embodiment of the anchoring system, and its associated method of use, now follows. 
     Overview 
     As shown in  FIG. 1 , the illustrated and described embodiment of the medical line connector system comprises a connector fitting  10  and an adaptor  12 , for example an adaptor for an intravenous catheter as illustrated in  FIG. 1 . The connector fitting  10  is preferably disposed upon the proximal end  15  of an exemplifying medical line  14 . The medical line  14  may be connected to such devices as are useful in introducing or removing fluid from the patient, for example a drip bag, a dialysis machine, a blood monitor or any other device as is known to those of skill in the art. 
     In regard to the illustrated use of the connector fitting and the connector system to connect an intravenous line to an intravenous catheter, the catheter adaptor  12  is disposed at the distal end of a short percutaneous needle which is inserted proximally into the patient (not shown). The adaptor  12  and needle may desirably be left in position upon the patient during treatment while different medical lines  14  are connected to the adaptor  12  via the connector system. This advantageously allows a medical practitioner to avoid introduction of multiple catheters and multiple needle sticks into the patient for each different medical line which is to be connected. The adaptor  12  desirably includes an elongated tubular tapered region  13  with a central lumen which is in fluid connection with the lumen of the needle. 
     The adaptor  12  also may advantageously include an external screw thread  18  disposed upon the outer surface of the tubular portion  13  of the adaptor  12 . The screw thread  18  may be used in association with a spin nut (described below) of the connector fitting  10  in order to securely interconnect the medical line  14  and the adaptor  12 . In addition to a screw thread, other means may be used to connect the adaptor  12  to the connector fitting (as described below). These may include without limitation, pin and groove arrangements, latch and keeper arrangements, and such other systems as are known to those of skill in the art. 
     The connector fitting  10  comprises an elongated body  20  which is attached distally to the proximal end  15  of the medical line  14 . The connector fitting  10  also comprises a proximal portion  30  which is desirably tapered along at least part of its longitudinal length so as to allow the most proximal region to fit within the tubular tapered portion  13  of the adaptor  12 . The tapered proximal portion  30  of the connector fitting  10  also preferably includes a centrally disposed lumen which communicates with the lumen of the medical line  14 . 
     When the proximal portion  30  of the connector fitting  10  is inserted into the tubular portion  13  of the adaptor  12 , the lumen of the connector fitting is disposed in fluid communication with the lumen of the adaptor. This provides fluid communication between the medical line  14  and the patient, as understood from  FIG. 2 . 
     As shown in  FIG. 1 , the connector fitting  10  also has at least one radially extending member  34  disposed upon a distal region of the elongated body  20  of the fitting  10 . Note that as shown in  FIG. 1 , it may be advantageous for the radially extending member to extend completely around the circumference of the connector fitting  10 . A radially extending member which extends completely around the circumference of the fitting  10  allows the fitting  10  to be more easily inserted onto a retainer (as will be described below) with only a coarse alignment necessary between the fitting and retainer. Additionally, a member  34  which extends over the entire circumference allows the fitting and retainer to be interfaced without concern for any rotation the fitting may have around its own axis, because the member extends from the fitting at every circumferential position. A second radially extending member  44  may also be disposed distally upon the elongated body  20 , as may additional radial members (not shown). The second radially extending member  44  can have a similar shape to the first radially extending member  34  or can have other shapes as well (e.g. circular). 
     A spin nut  50  is disposed upon the connector fitting  10  around the elongated body  20  of the fitting  10 . The spin nut  50  is substantially cylindrical in form and is able to move upon the connector fitting  10 . The spin nut  50  is capable of both rotational motion around the axis of the connector fitting  10  and axial motion in both the proximal and distal directions along the length of the elongated body  20  of the fitting  10 . The range of axial motion of the spin nut is limited by the radially extending member  34  in the distal direction and by a retaining ridge  32  in the proximal direction. The spin nut also includes internal screw threads which are illustrated with phantom lines in  FIG. 1 . 
     As shown in  FIG. 2 , when the proximal portion  30  of the connector fitting  10  is inserted into the tubular portion  13  of the adaptor  12 , the spin nut  50  may be moved in the proximal direction and twisted so as to engage the screw thread  18  of the adaptor  12  and lock the connector fitting  10  to the adaptor  12 . 
     Connector Fitting and Spin Nut 
       FIG. 3  shows the connector fitting  10  with a cut-away view of the spin nut  50  in position upon the elongated body  20  of the fitting  10 . The spin nut  50  is desirably disposed such that the central axis of the spin nut  50  is generally the same as the central axis of the elongated body  20  of the connector fitting  10 . The spin nut  50  is free to rotate about and slide along the axis of the connector fitting  10 . 
     The spin nut  50  desirably has an internal screw thread  28  disposed upon the inner surface of the spin nut  50 . This screw thread  28  will engage with the screw thread  18  of the adaptor  12  when the adaptor  12  is secured to the connector fitting  10 . The distal wall  58  of the spin nut  50  is also visible in the sectioned portion of  FIG. 3 . This wall  58  forms a distal end of the spin nut  50 . 
     As noted above, the spin nut  50  is shown in  FIG. 3  in a position which is neither fully distal nor fully proximal along the length of the elongated body  20  of the connector fitting  10 .  FIG. 4A  shows the spin nut  50  and connector fitting  10  with the spin nut  50  in a fully distal position. When the spin nut  50  is in the distal position, the wall  58  of the spin nut  50  is positioned such that the distal surface  61  of the receptacle  60  of the spin nut  50  is resting against the proximal wall  36  of the radially extending member  34 . This can be seen more clearly in  FIG. 4B , which is an enlarged view of the portion of  FIG. 4A  labeled  4 B- 4 B. In this position, the receptacle  60  receives at least a portion of the radially extending member  34 . 
     With reference to  FIG. 4B , it can be seen that the wall  58  of the spin nut  50  extends inwardly toward the axis of the spin nut  50  and ends in a lip  64  which extends inwardly from the wall  58 . The inner surface of the lip  64  forms the opening  66  (see  FIG. 5B ) in the middle of the spin nut  50  through which the elongated body  20  of the medical line fitting  10  passes. The opening  66  preferably is slightly larger than the diameter of the elongated body  20 . 
     Because the lip  64  is narrower in the axial direction than the wall  58 , as can be seen in  FIG. 4B , the distal surface  61  of the lip  64  and the distal surface of the wall  54  are at different longitudinal positions along the axial length of the spin nut  50 . Because the distal surface  54  of the wall  58  is more distally located than the distal surface  61  of the lip  64 , a recess is formed which comprises the receptacle  60  of the spin nut  50 . When the spin nut  50  is in the fully distal position, as shown in  FIGS. 4A and 4B , the radially extending member  34  is inserted into the receptacle  60 . Preferably, when the spin nut  50  is in the distal position, the receptacle  60  of the spin nut will accept about at least one-third of the axial length of the radially extending member  34 , and more preferably, about two-thirds of the axial length of the radially extending member  34 . 
     As shown in  FIGS. 5A and 5B , the receptacle  60  has a cross-sectional shape which forms a twelve-pointed star. As seen in  FIG. 6 , the radially extending member  34  has a cross-sectional shape which is substantially hexagonal. Other cross-sectional shapes may be used for both the receptacle  60  and the radially extending member  34 , but desirably, the cross-sectional shape of the radially extending member  34  may fit within the cross-sectional shape of the receptacle  60 . More desirably, the cross-sectional shape of the radially extending member  34  and the receptacle  60  are such that when the member  34  is within the receptacle  60  the largest radius of the member  34  is greater than the smallest radius of the receptacle. 
     By having a maximum radius of the member  34  being greater than the minimum radius of the receptacle  60 , the walls of the receptacle will exert a torque upon the member  34  if the spin nut  50  is rotated while in the distal position. In this way, a twisting motion applied to the spin nut when in the distal position will be transferred to the connector fitting  10 , allowing the spin nut  50  to be gripped when attempting to remove the connector fitting  10  from the adaptor  12 . 
     With reference to  FIGS. 7A and 7B , note that it may also be desirable to have the maximum radius R 2  of the radially extending member  34  (see  FIG. 7A ) be closer in size to the external radius of the spin nut (indicated as R 3  on  FIG. 7B ) than radius R 2  is to the radius of the elongated body  20  (indicated as R 1  on  FIG. 7A ) of the fitting  10 . This increases the radial extent of the radially extending member  34  away from the surface of the elongated body  20  and provides for a better surface for the receptacle of the spin nut  50  to grip. 
     As shown in  FIG. 5B , using a receptacle  60  with a twelve-pointed star shape and a member  34  with a hexagonal shape (as shown in  FIG. 6 ), there are 12 different positions in which the receptacle  60  may be moved over the member  34  producing a snug fit. However, those of skill in the art will recognize that it is only necessary that a single position be available in which the receptacle  60  fits over the member  34 , and it is not necessary that such a fit be snug. As pointed out above, as long as the member  34  fits within the cross section of the receptacle and the maximum radius of the member  34  is greater than the minimum radius of the receptacle  60 , it will be possible to transfer torque from the spin nut  50  to the connector fitting  10  when the nut  50  is in the fully distal position. 
     In addition to providing a mechanism for the transfer of torque between the spin nut  50  and the connector fitting  10 , the receptacle  60  also is capable of exerting a distally directed axial force upon the member  34 . When the spin nut  50  is in the distal position, as shown in  FIGS. 4A and 4B , the distal surface  61  of the lip which forms the face of the receptacle  60  is pressed against the proximal wall  36  of the radially extending member  34 . Because of this contact, any force applied in the distal direction when the spin nut  50  is already in the distal position will be transferred, via the contact between these surfaces, to the member  34  and to the connector fitting body  20 . 
     This interaction between the distal surface  61  of the lip  64  and the radially extending member  34  also inhibits migration of the spin nut  50  distally off of the end of the connector fitting  10  and onto the medical line  14 . This maintains the spin nut  50  upon the connector fitting  10 , eliminating the need for medical personnel to locate a spin nut which may have moved off of the fitting  10 . This allows for more rapid and reliable release of the connector fitting  10  from the catheter adaptor  12 . 
     Variations 
     As pointed out above, it is possible to use various shapes for the receptacle  60  and radially extending member  34  in order to allow the spin nut  50  to transfer force to the connector fitting  10 . Several variations of spin nuts  50  and member designs are illustrated in  FIGS. 8A to 12B . Throughout these figures, the spin nut  50  and elongated body  20  of the connector fitting  10  are consistently labeled for clarity. Except as noted below, the designs shown in  FIGS. 8A to 12B  may be substantially similar in construction and usage as the embodiment described above with reference to  FIGS. 1 to 6 . For instance, all of the designs include a distal wall  61  of the lip  64  which presses axially against the radially extending member  34  in order to transfer axial force between the spin nut  50  and the radially extending member  34 . 
     One type of variation for the radial member is shown in  FIGS. 8A ,  9 A and  10 A. Rather than a continuous hexagonal member, as shown in  FIG. 4A , the radial member takes the form of projections  40  which extend radially from the elongated body  20  of the connector fitting  10 . These projections  40  do not surround the entire circumference of the elongated body  20 , but are desirably spaced approximately evenly about the circumference with spaces in between them. 
       FIG. 8A  shows the distal end of a connector fitting  10  which uses a pair of projections  40  for each radially extending member. As can be seen, multiple sets of projections  40  may be included at different axial positions along the length of the elongated body  20 . This corresponds to the use of multiple radially extending members illustrated in the embodiment shown in  FIG. 4A . 
     A spin nut  50  configured to operate in association with the connector fitting  10  of  FIG. 8A  is shown in  FIG. 8B . This spin nut  50  is constructed substantially similarly to that described above, except for the cross sectional shape of the receptacle  60 . The receptacle  60  is desirably configured so that its cross section provides a shape into which the projections  40  of the radially extending member  34  of the connector fitting  10  can be inserted. As seen in  FIG. 8B , this shape may take the form of an inner, circular region and sockets  70  spaced about the circumference of the receptacle  60 . The sockets  70  preferably have a radius larger than that of the inner region, and also larger than the radius of the projections  40  of the fitting  10 . 
     The sockets  70  are desirably each larger than the projections  40  of the fitting  10 . The sockets  70  and projections  40  are also desirably similarly spaced about the circumference of the spin nut  50  and fitting  10 . This allows the spin nut  50  of  FIG. 8B  to be moved distally along the elongated body  20  of the connector fitting  10  of  FIG. 8A  and the projections  40  to fit within the sockets  70  of the spin nut  50 . Because of the two-fold rotational symmetry of the arrangement, there are two positions in which the receptacle  60  will accept the projections  40 . 
     In this distal position, the spin nut  50  is capable of exerting distal force upon the projections  40 , just as the spin nut in the earlier embodiment exerted distal force against the radially extending member  34 . In addition, because the radius of the projection  40  and the elongated body  20  is different, a radial wall  42  is created at the end of each projection. A similar radial wall  72  is created on the spin nut  50  at the end of each socket  70 . 
     When the spin nut  50  is in a distal position, any rotation of the spin nut  50  will eventually bring the radial wall  72  of the spin nut  50  into contact with the radial wall  42  at the end of one or more of the projections  40 . This allows torque to be transferred from the spin nut  50  to the fitting  10  in order to facilitate removal of the connector fitting  10  from the adaptor  12 . 
     Note that it is not necessary that the fit between the projections  40  and the sockets  70  be particularly snug. For instance, in  FIG. 8A , projections  40  are shown which extend through an arc of about 90°. Similarly, in  FIG. 8B , sockets  70  are shown which extend through an arc of about 90°. However, if the projections  40  on the elongated body  20  were only to extend through an arc of about 75°, the receptacle  60  would still accept the projections  40 , and the same spin nut  50  would still be able to exert the same distal force and torque upon the connector fitting  10 . 
     As long as the projections  40  of the radially extending member  34  are able to fit inside the receptacle  60  of the spin nut  50  and the largest radius of the projections  40  is greater than the smallest radius of the receptacle  60 , the spin nut  50  will cooperate with the fitting  10  to transfer the desired distal force and torque. However, when the projections  40  are significantly smaller than the sockets  70 , there will be a certain amount of play in the fit between the radially extending member  34  and the receptacle  60 . This means that if the spin nut  50  is rotated, it may rotate through an arc before a radial wall  72  of the socket  70  comes into contact with a radial wall  42  of a projection  40 . 
       FIGS. 9A and 9B  show a connector fitting  10  and spin nut  50  designed and operating substantially similarly to those shown in  FIGS. 8A and 8B , except that there are three projections  40  for each radial member  34 , and there are three corresponding sockets  70  upon the receptacle  60 . Such an arrangement functions in substantially the same manner as that described above. In the illustrated arrangement, the sockets  70  and projections  40  each extend through an arc of about 60°. Note that it is desirable that the sockets  70  extend through a slightly greater arc than the projections  40  in order to allow the projections  40  to more easily fit within the sockets  70  when the spin nut  50  is in the distal position. 
       FIGS. 10A and 10B  show a connector fitting  10  and spin nut  50  designed and operating substantially similarly to those shown in  FIGS. 8A to 9B , except that there are four projections  40  for each radial member  34 , and there are four corresponding sockets  70  upon the receptacle  60 . Unlike the previous embodiments, the projections  40  and sockets  70  of elongated body  20  and spin nut  50  are not evenly sized with the gap between them. The projections  40  and sockets  70  extend through an arc of only about 10°. 
     Note that it is also possible in some combinations to make use of spin nut  50  with a fitting  10  having a different number of projections  40  than the spin nut  50  has sockets  70 . For instance, the connector fitting  10  of  FIG. 10A  having four projections  40  each extending through 10° and spaced about 90° from one another could be used with a spin nut  50  as in  FIG. 8B , which has only two sockets  70  spaced apart 180°, as long as each socket extends through an arc of more than about 100°. 
     In this way, the fit between the socket  70  and the projections  40  is still fairly snug; however, there are now four positions in which the radial member  34  may fit within the receptacle  60 , as opposed to the two positions which the spin nut  50  may accept the projections of the fitting  10  of  FIG. 8A . 
     Another configuration of the radially extending member  34  and receptacle  60  is shown in  FIGS. 11A and 11B . Here, the radial member  34  comprises a series of twelve curved protrusions  40  which extend around the entire circumference of the elongated body  20 . The receptacle  60  of the spin nut  50  has a set of sockets  70  of shape to snugly accept and engage the protrusions  40 . Those of skill in the art will recognize that the precise profile of the protrusions  40  need not be as shown in the figure, nor need there be twelve protrusions. However, it may be desirable in some circumstances that the number of protrusions  40  match the number of sockets  70  in order to allow the radial member  34  to fit within the receptacle  60 . 
     Unlike the designs shown in  FIGS. 8A to 10B , the protrusions  40  and sockets  70  have a curving profile in this embodiment. As a result, there are no radial walls on either the receptacle  60  or the radial member  34 . However, because the profile of both the protrusions  40  and sockets  70  vary in radius along their length, contact is made between the receptacle  60  and the radial member  34  which allows for rotational torque to be transferred from the spin nut  50  to the adaptor elongated body  20 . 
       FIG. 12A  shows a connector fitting  10  which has a radial member  34  with protrusions  40  having substantially the same profile as the receptacle  60  of the spin nut  50  in  FIGS. 5A and 5B . Such a fitting  10  may be used as a variation to the fitting  10  shown in  FIG. 4A  with the spin nut  50  of  FIGS. 5A and 5B .  FIG. 12B  shows a spin nut  50  with a hexagonal receptacle  60  of substantially the same profile as the radial member  34  of the fitting  10  of  FIG. 4A . This spin nut  50  may be used with the adaptor of  FIG. 4A  as a variation to the spin nut  50  of  FIGS. 5A and 5B . 
     Catheter Adaptor and Spin Nut 
     Another arrangement for a medical line connector system is shown in  FIGS. 13 and 14 . The spin nut  50  used in such a system is shown in  FIG. 13  and is substantially the same as the spin nut  50  shown in  FIG. 12B . However, the spin nut  50  is used differently, as is shown in  FIG. 14 . 
       FIG. 14  shows a medical line adaptor  210  connected to the proximal end of a medical line  14 . The medical line adaptor  210  includes an elongated body  220  and a proximal portion  230 . The elongated body  220  is attached to a medical line  14 . An external screw thread  200  is disposed upon the outer surface of the elongated body  220 . This adaptor  210  provides the same male portion of the connector system that is provided in the connector fitting  10  of  FIG. 1 . 
     Another connector fitting  212  is shown at the distal end of a second medical line  16 . This fitting  212  provides the female portion of the connector system that is provided by the adaptor  12  of  FIG. 1 . The spin nut  50  is disposed along the outside of the tubular section of the connector fitting  212 , rather than along the elongated body  220  of the medical line adaptor  210 . In addition, the radially extending member  234  is disposed upon the connector fitting  212  as well. 
     In essence, the embodiment shown in  FIG. 14  places the spin nut  50  and radial member  234  upon the female member  212  of the connector system, rather than upon the male member, as shown in previous figures. The operation of the system is substantially the same in such an embodiment, however, the spin nut  50  is now used to transfer translational and rotational forces to the female member  212  of the connector system. 
     The features disclosed with respect to the radial member  34  in use upon the connector fitting  10  shown in  FIGS. 1 and 2  may also be applied to the use of the radial member  234  on the connector fitting  212  as well. This includes the various cross sectional shapes of the receptacles  60  and radial member  34 , such as those disclosed in  FIGS. 8A to 12B , and such other features as are known by those of skill in the art. 
     Operation 
     In operation, as seen in  FIGS. 1 and 2 , a connector system in accordance with an embodiment of the present invention may be used to secure a connector fitting  10  to an adaptor  12 , as well as to facilitate removal of the connector fitting  10  from the adaptor  12  when needed. The operation of the system will be described with reference to the embodiment of the device shown in  FIGS. 1 and 2 . However, those of skill in the art will recognize that the same operation may desirably be applied to any of the variations described herein. 
     In connecting the medical line  14  to the adaptor  12 , the medical technician first inserts the proximal end  30  of the connector fitting  10  into the tubular portion  13  of the adaptor  12 . The spin nut  50  is then pushed in the proximal direction until the screw threads  28  of the spin nut  50  contact the screw threads  18  of the adaptor  12 . The spin nut  50  may then be twisted to secure the connection between the connector fitting  10  and the adaptor  12 . This produces the configuration shown in  FIG. 2 . 
     In order to remove the connector fitting  10  from the adaptor  12 , the spin nut  50  is twisted until the screw threads  28  of the spin nut  50  are disengaged from the screw threads  18  of the adaptor  12 . The spin nut  50  is then slid distally along the length of the elongated body  20  of the connector fitting  10  until the receptacle  60  on the distal portion of the spin nut  50  is pressed against the radially extending member  34  of the connector fitting  10 . 
     The spin nut  50  is then rotated while maintaining distal pressure upon it (relative to the connector fitting  10 ), until the radially extending member  34  slides into the receptacle  60  of the spin nut  50 . The medical technician may then twist and pull upon the spin nut  50 , and the force of twisting and pulling will be transferred to the connector fitting  10 . By doing this while holding the adaptor  12  in place, the connector fitting  10  may be removed from the adaptor  12  without having to grip the connector fitting  10  directly. 
     Connector Fitting and Anchoring System 
       FIGS. 15 and 16  illustrate an anchoring system  300  for use with a connector system  10  as is disclosed above. The connector system  10  may be snapped into position upon a retainer  302  of the anchoring system  300 . The retainer  302  is configured to secure the connector fitting  10 . The retainer  203  is disposed upon a base pad  304  which may desirably be used to anchor the retainer to the skin of a patient. 
     Retainer 
     The retainer  302  has a generally parallelepiped shape defining a central channel  306  interposed between a pair of opposing longitudinal walls  308 . The central channel  306  extends through the retainer  302  along an axis which is generally parallel to the longitudinal axis of the retainer  302 . 
     The central channel  306  has a generally circular cross-sectional shape which is truncated at an upper end to form a generally U-shaped channel having an upper opening  310 . The central channel  306  has a diameter sized to receive the radial member  34  of the connector fitting  10 . In a preferred embodiment, the diameter of the central channel  306  generally matches that of the radial member  34  or is slightly larger. 
     In cross-section, the central channel  306  extends through an arc greater than 180° about the channel axis such that the transverse length of the opening  310  is less than the diameter of the central channel  306 . In an exemplary embodiment, the central channel  306  extends through an arc of about 200° about the channel axis. 
     The channel axis is desirably angled relative to the surface of the pad  304 . An incident angle formed between the surface of the pad  304  and the channel axis is desirably less than 45°. The angle desirably ranges between 0° and 30°. In an exemplary embodiment for intravenous use, the angle preferably equals approximately 7°. In another exemplary embodiment for arterial use, the angle preferably equals about 22°. In a further exemplary embodiment, for peripherally inserted central catheters (PICC), the angle preferably equals 0°. 
     Each wall  308  of the retainer  302  comprises a uniform set of slots  312 . While only a single slot  312  need be used, the use of two or more slots  312  requires only coarse alignment between the retainer  302  and the fitting  10  when pressing the radial member or members of the fitting into the slots  312 . More preferably, the set of slots comprises less than seven slots  312 . In an exemplary embodiment, as illustrated in  FIGS. 15 and 16 , the set comprises four slots  312 . 
     Each slot  312  is sized to accept a radial member  34  of the fitting  10  to prevent longitudinal displacement of the connector fitting  10 , as discussed in detail below. Each slot  312  desirably has a rectangular shape. The slots  312  extend through both walls  308  of the retainer  302  and open into the central channel  306 . The width of each slot  312  (measured longitudinally) is desirably slightly greater than the width of a radial member  34  of the connector fitting  10 , measured in the longitudinal direction in order to allow the slot  312  to receive a radial member  34 , as discussed below. 
     Each slot  312  has a height as measured in the transverse direction between an upper edge of the longitudinal wall  308  and the bottom of the central channel  306 . The height of the slot  312  desirably equals approximately the width of the radial member  34  such that the radial member  34  does not protrude from the retainer  302  in the transverse direction. 
     Alternatively, the slots  312  can be replaced by protrusions (not shown) which extend from the longitudinal wall  308  into the central channel  306 . If a plurality of protrusions is used, the radial member  34  is placed between adjacent protrusions. As will be understood by one of skill in the art, the central channel  306  width may need to be increased to accommodate the width of the radial member  34  if protrusions are used instead of slots  312   
     The upper edge of the longitudinal wall  308  comprises a series of chamfers  316 , each of which slopes into a slot  312 . That is, the portion of upper edge of the longitudinal wall  308  which surrounds a slot  312  includes a pair of chamfers  316 , with one chamfer  316  located on either side of the slot  312 . The chamfers  316  slope downward toward the slot  312  to facilitate the insertion of the radial member  34  of the connector fitting  10  into the slot  312 . 
     The retainer  302  is made of relatively stiff plastic material (e.g., polycarbonate), but is somewhat flexible such that the connector fitting  10  forces the upper edges of the longitudinal walls  308  transversely outward when a medical practitioner presses the connector fitting  10  into the central channel  306  of the retainer  302 . When the fitting  10  sits in the central channel  306 , the upper edges of the walls  308  snap transversely inward to their original position to securely hold the fitting  10  within the retainer  302 . 
     An adhesive desirably attaches the retainer  302  to a base pad  304 . Alternatively, the retainer  302  may be attached to the base pad  304  by non-adhesive means (e.g., embedding or otherwise weaving the retainer  302  into the base pad  304 ). 
     Base Pad 
     Still referring to  FIGS. 15 and 16 , the flexible base pad  304  comprises a laminate structure with an upper foam layer  318  (e.g., closed-cell polyethylene foam), and a lower adhesive layer  320 . The lower adhesive layer  320  also forms the lower surface  322  of the base pad  304 . The lower surface  322  desirably is a medical-grade adhesive and can be either diaphoretic or nondiaphoretic, depending upon the particular application. Such foam with an adhesive layer is available commercially from Avery Dennison of Painsville, Ohio. Although not illustrated, it will be understood that the base pad  304  can include suture holes in addition to the adhesive layer  320  to further secure the base pad  302  to the patient&#39;s skin. 
     In an alternative embodiment, a hydrocolloid adhesive may advantageously be used upon the base pad  304  for attaching the pad to the skin of the patient. The hydrocolloid adhesive has less of a tendency to excoriate the skin of a patient when removed. This may be particularly important for patients whose skin is more sensitive or fragile, such as those with a collagen deficiency. 
     A surface of the upper foam layer  318  constitutes an upper surface of the base pad  304 . The upper surface can be roughened by corona-treating the foam layer  318  with a low electric charge. The roughened or porous upper surface can improve the quality of the adhesion between the base pad  304  and the retainer  302  and tub clip  328 . In the alternative, the flexible base pad  304  can comprise a medical-grade adhesive lower layer, an inner foam layer and an upper paper or other woven or non-woven cloth layer. 
     A removable paper or plastic backing  323  desirably covers the bottom adhesive layer  322  before use. The backing  323  preferably resists tearing and is divided into a plurality of pieces to ease attachment of the pad  304  to the patient&#39;s skin. Desirably, the backing is split along the center line of the flexible base pad  304  in order to expose only half of the adhesive bottom surface  322  at one time. The backing  323  also advantageously extends beyond at least one edge of the base pad  304  to ease removal of the backing from the adhesive layer  322 . 
     One or more tabs  325  may be attached to a portion of the backing  323  which extends beyond the flexible base pad  304 . In an exemplary embodiment, the tabs  325  have the same laminate structure as the flexible base pad  304 . The tabs  325  also can be formed by the paper backing  323  extending beyond the edge of the base pad  304 . The tabs  325  may also include indicia in the form of dots, words, figures or the like to indicate the placement of fingers when removing the backing  323  from the base pad  304 . 
     The tabs  325  of course can be designed in a variety of configurations. For example, the tab need not be located along a center line of the base pad; rather, the tab can be located along any line of the base pad in order to ease the application of the pad onto the patient&#39;s skin at a specific site. For example, an area of a patient&#39;s skin with an abrupt bend, such as at a joint, can require that the tab be aligned toward one of the lateral ends of the base pad  304  rather than along the center line. 
     A nurse or other medical practitioner grips a tab  325  and peels the backing  323  off one half of the bottom adhesive layer  322 . The tab overcomes any requirement that the nurse pick at a corner edge or other segment of the backing in order to separate the backing from the adhesive layer. The nurse then places the bottom layer  322  against the patient&#39;s skin to adhere the base pad  304  to the patient. Light pressure over the upper layer  318  assures good adhesion between the base pad  304  and the patient&#39;s skin. The base pad  304 , due to its flexibility, conforms to the contours of the topical surface to which the base pad  304  adheres. The nurse then repeats this procedure for the other half of the pad  304 . Alternatively, the nurse may completely remove the backing  323  from the pad  304  before attaching the pad  304  to the patient&#39;s skin. 
     The base pad  304  desirably comprises a notch  324  positioned distal of the location of the retainer  302  on the pad  304  and adjacent to the point of insertion of the needle or other indwelling medical article. The notch  324  is sized to permit visual inspection of the insertion site. 
     The base pad  304  desirably may comprise indicia  326  in the form of an arrow which indicates the proper orientation of the base pad  304  in reference to insertion site. Although  FIGS. 15 and 16  illustrate the indicia in the form of an arrow, it is contemplated that other forms of indicia could be used as well, for example but without limitation, words or other graphics. The indicia  326  should point in the proximal direction, towards the needle, or otherwise indicate the proper location of the pad  304  in reference to the needle or other proximal attachment to the adaptor  12 . 
     In an exemplary embodiment, the laminate structure of the base pad  304  is preferably formed by rolling a paper tape, such as a micro-porous rayon tape, available commercially as MICRO-PORE tape from 3M (Item No. 1530), over a medical grade polyvinyl chloride foam tape, such as that available commercially from 3M (Item No. 9777L). The foam tape preferably includes the bottom liner or backing  323 . The base pad  304  and the tabs  325  are then stamped out of the laminated sheet of foam and paper. The backing  323  between the tabs and the base pad, however, is desirably not severed such that the tabs  325  remain attached to the backing covering the adhesive section  322  of the base pad  304 . The backing  323  is then cut into two pieces along the centerline of the pad  304  and between the tabs  325 . 
     Tube Clip 
       FIGS. 15 and 16  also illustrate a tube clip  328 . The clip  328  secures the medical line  14  to form a safety loop, as known in the art. 
     The tube clip  328  has a plate-like base  330  adhered to or embedded in the base pad  304 . The tube clip  328  may be located on the base pad  304  on either side of the retainer  302  to accommodate left hand or right hand mounting. The anchoring system  300  may further include a second tube clip (not shown) located on the other side of the retainer  302  from the first tube clip  328 . 
     The clip  328  defines a channel  332  having a generally circular cross-sectional configuration truncated to form an upper orifice  334 . The diameter of the channel  332  is desirably slightly less than that of the medical line  14  so as to ensure a secure interconnection. The channel  332  receives a portion of the medical line  14  through the orifice  334  upon application of gentle pressure or by pulling the line  14  across and through the orifice  334  of the tube clip  328 , as explained below. The clip  328  surrounds a substantial portion of the medical line  14  with the medical line  14  positioned within the channel  332 . 
     The upper edge of the channel may include tapered ends  336  at the proximal and distal ends of the clip  328 . Each tapered end  336  forms a smooth transition between the side edge of the channel  332  and the upper edge, and tapers in lateral width from the side edge toward the center of the tube clip  328 . The tapered ends  336  help guide the medical line  14  into the channel  332  when a medical practitioner pulls the medical line  14  across the clip  328 . Thus, the practitioner does not have to pinch the line  14  to insert it into the clip  328 . Also, the medical practitioner&#39;s gloves do not get stuck in the clip  328  when inserting the line  14 , as is typically the case where if it is required to pinch the line  14  in order to insert it into the clip  328 . 
     Slide Clamp 
     Referring to  FIG. 16 , the anchoring system  300  desirably additionally includes a slide clamp  338  to regulate fluid flow through the medical line  14 , as is known in the art. The clamp  338 , at one end, includes an aperture  340  which receives the medical line  14 , and includes a tab  342  at the opposite end. The clamp  338  has a generally forked shape formed by a pair of prongs  344  that define the aperture  340 . The medical line  14  snaps between the prongs  344  and into the aperture  340 , which has a diameter slightly larger that the medical line  14 . 
     The prongs  344  converge together in the direction towards the tab  342  to form a tapering slot  346  which opens into the aperture  340 . The prongs  344  pinch the medical line  14  closed with the medical line  14  positioned in the slot  346  so as to block fluid flow therethrough. The clamp  338 , however, slides over the medical line  14  with the line  14  positioned through the aperture  340 . 
     Finger Platform 
     With reference to  FIGS. 15 and 16 , a finger platform  348  extends from the sidewalls  308  of the retainer  302 . The finger platform  348  may be located on the base pad  304  on either side of the retainer  302  to accommodate left hand or right hand mounting. The anchoring system  300  may further include a second finger platform (not shown) located on the other side of the retainer  302  from the first finger platform  348 . The finger platforms  348  are sized and configured to enable allow a health care provider to press the retainer  302  against the skin of the patient while pulling up on the connector fitting  10  or when disengaging the fitting  10  from the retainer  302 . 
     The components of the anchoring system  300  other than the base pad  304  (i.e., the retainer  302 , tube clip  328 , slide clamp  338 , and finger platform  348 ), may be constructed in any of a variety of ways well known to one of skill in the art. For instance, each individual component may be integrally molded such as by injection molding or by thermoplasty. The components preferably comprise a durable, flexible material, and more preferably comprise a generally inert, non-toxic material. In a preferred embodiment, the components are molded of plastic, such as, for example, polycarbonate, polyvinylchloride, polypropylene, polyurethane, tetrafluoroethylene (e.g., TEFLON®), polytetrafluoroethylene (a.k.a., PTEF), acetal resin (e.g., DELRIN®), chlorotrifluoroethylene (e.g., KEL-F®), nylon or other polymers. 
     Securing a Connector Using the Anchoring System 
     The following discussion of the method of use will be with reference to  FIGS. 15 and 16 , and initially will be in the context of intravenous catheterization. As the following discussion will illustrate, however, it is understood that the anchoring system  300  can be used in other catheterization procedures as well. 
     A nurse or other medical practitioner typically begins the catheterization process by positioning the catheter at a desired location above a vein. The medical practitioner introduces a needle or other stylus through a cannula portion of the adaptor  12  and into the skin of the patient at a desired angle of incidence. For intravenous use, the needle commonly has an incident angle of approximately 7°. The distal end of the needle is advantageously pre-connected to a female luer-type adaptor  12 . 
     The nurse attaches the proximal portion  30  of the connector fitting  10  into the adaptor  12  as described above. 
     The nurse removes the paper backing  323  which initially covers the adhesive bottom surface  322  of the base pad  304 , and attaches the pad  304  to the patient&#39;s skin proximate to the indwelling needle. Specifically, the nurse grips the backing tab  325  proximate to the retainer  302 . The nurse then pulls on the tab  325  and peels the backing off one half of the bottom adhesive layer  322 . The nurse positions the slot  324  of the pad  304  around the adaptor  12  with the instructing indicia  326  (e.g., indicating arrow) pointing in the direction of the needle. The nurse then places the bottom layer  322  against the patient&#39;s skin to adhere the base pad  304  to the patient. Light pressure over the upper layer  318  assures good adhesion between the base pad  304  and the patient&#39;s skin. The base pad  304 , due to its flexibility, conforms to the contours of the topical surface to which the base pad  304  adheres. The nurse then repeats this procedure for the other half of the pad  304 . Alternatively, the nurse may completely remove the backing  323  from the pad  304  before attaching the pad  304  to the patient&#39;s skin. 
     The nurse orients the radial member  34  of the connector fitting  10  above the series of retainer slots  312 . The nurse then snaps the fitting  10  into the retainer  302 . In doing so, the fitting  10  is pressed between the longitudinal walls  308  of the retainer  302 . As the nurse presses the fitting  10  into the retainer  302 , the chamfered edges  316  around the slots  312  of the longitudinal wall  308  guide the radial member  34  into one of the slots  312 . 
     As mentioned above, the upper opening  310  of the channel  306  has a smaller width measured in the lateral direction than the diameter of the elongated body  20  of the fitting  10 . The lateral walls  308  thus deflect outwardly in a lateral direction. Once the elongated body  20  of the fitting  10  rests within the central channel  306  of the retainer  302 , the lateral walls  308  spring back to snap the fitting  10  in place. The walls  308  of the retainer  302  thus prevent unintentional transverse and lateral movement of the fitting  10  relative to the patient. 
     The design of the retainer  302  provides for a variety of positions in which the fitting  10  may be secured within the retainer  302 ; in this way, the usage of the retainer  302  is not technique or position sensitive. In other words, a nurse or other medical practitioner can simply press the fitting  10  into the retainer  302 , irrespective of the relative positions of the fitting  10  and any particular slot  312 . The radial member  34  will be guided into one of the series of slots  312  by the chamfered edges  316  as long as the member  34  is positioned somewhere above the slots  312 . 
     As  FIG. 16  illustrates, the nurse may also form a safety loop in the medical line  14 , as is known in the art, and secure the safety loop to the patient by inserting a portion of the line  14  into the tube clip  328 . The safety loop absorbs any tension applied to the medical line  14  in order to prevent the connector fitting  10  and/or the adaptor  12  from being pulled. 
     Those of skill in the art will recognize that the above technique for securing the connector system to the anchoring system  300  may be applied equally well to connector systems which make use of the spin nut  50  and radial member  34  disposed upon the adaptor  12 , such as the embodiment shown in  FIG. 14 . In these cases, the adaptor  12  will be secured directly to the retainer  302  of the anchoring system  300 . However, the radial member  34  will be secured within one of the slots  312  of the retainer  302  in the same manner as is described above with respect to  FIGS. 15 and 16 . 
     Furthermore, those of skill in the art will appreciate that the techniques described above regarding releasing the connector fitting  10  from the adaptor  12  may be combined with the technique for securing the connector system to the anchoring system  300 . 
     The various embodiments of the connector fitting described above in accordance with the present invention thus provide a means to connect a connector fitting to an adaptor and easily release the medical line from the adaptor using the spin nut. The spin nut is pressed back against the radial member and can be used to transfer force from the fingers of the medical practitioner to the connector fitting in order to separate it from the adaptor. 
     Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. 
     Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments. For example, the shape of the receptacle and radial member may be taken from one of the alternate embodiments shown in  FIGS. 8A-12B  and applied to a connector system in which the spin nut is on the adaptor, as is shown in  FIG. 14 . In addition to the variations described herein, other known equivalents for each feature can be mixed and matched by one of ordinary skill in this art to construct releasable connector systems in accordance with principles of the present invention. 
     Although this invention has been disclosed in the context of certain preferred embodiments and examples, it therefore will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.