Patent Publication Number: US-2021162123-A1

Title: Fluid transfer device or set with retractable needle and septum

Description:
RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 16/269,323, filed Feb. 6, 2019, entitled FLUID TRANSFER DEVICE OR SET WITH RETRACTABLE NEEDLE AND SEPTUM, which is a divisional of U.S. application Ser. No. 14/326,032, filed Jul. 8, 2014, entitled FLUID TRANSFER DEVICE OR SET WITH RETRACTABLE NEEDLE AND SEPTUM, which are incorporated herein in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a fluid transfer device for transferring fluid to or from a patient, and more particularly to a fluid transfer device having a retractable needle and a sealing septum. 
     BACKGROUND OF THE INVENTION 
     Various types of medical devices employ a needle for piercing the skin of a patient for diagnostic or therapeutic purposes. One such fluid transfer device is a fluid collection device which includes a needle for piercing a blood vessel or other part of the patient to allow a fluid, for example, blood, to be sampled from a patient. When the needle is inserted into the patient, blood or other fluid is withdrawn through the needle, for example, into a vacuum collection tube. Handling of such needle-bearing medical devices after the needle is withdrawn from the patient can result in the unwanted transmission of various pathogens thereby exposing medical personnel and possibly others to serious or fatal illness due to an inadvertent needle stick injuries as well as other blood borne pathogens exposed through fluid or blood which leaks out of the device following use and removal from the patient. 
     BRIEF SUMMARY OF THE INVENTION 
     In light of the foregoing, the present invention provides a medical device having a hollow housing and a needle with a sharpened tip. The needle is operable between an extended, or active position, and a retracted, or inactive position. The sharpened tip projects forwardly from the housing in the extended position, with the sharpened tip being sealably enclosed within the housing in the retracted position. Initially, a needle retainer selectively retains the needle in the extended position. A biasing element biases the needle toward the retracted position. An actuator actuates the needle retainer to release the needle so that the biasing element propels the needle rearwardly toward the retracted position. A rearward stop connected with the needle is operable to retain the needle against continued rearward displacement after the needle is retracted. In some embodiments, a forward stop connected with the needle is operable to retain the needle against forward displacement after the needle is retracted. 
     According to some embodiments, a sealed fluid transfer device comprised of tubing, a proximal fitting, and a sealed retractable distal needle assembly is provided. In some embodiments, the needle assembly includes a needle hub and a needle cannula securely coupled to the needle hub. The needle assembly also includes a resiliently deflectable actuator arm extending from the needle hub and having an actuator button formed at the free end thereof. According to some embodiments, the needle assembly is slidably disposed in a barrel assembly or housing having proximal and distal ends and a passage extending therebetween. In such embodiments, the needle assembly and the actuator arm are axially movable relative to the barrel. In a distal position, the needle cannula projects distally beyond the distal end of the barrel. In a proximal position, the needle cannula is entirely contained within the barrel. 
     The barrel further defines an actuating aperture extending through a side of the barrel. According to various embodiments, the barrel aperture engages the actuator button when the needle assembly is in the distal position. However, the actuator button disengages the aperture when the actuator arm is resiliently deflected. 
     The device further includes a spring that is disposed in the barrel assembly. The spring provides a biasing force for retracting the needle assembly to the proximal position when the actuator arm is deflected and the actuator button disengages the barrel aperture. 
     In various embodiments, the device also includes a septum fitted within the distal end of the barrel. When the needle assembly occupies the distal position, the needle cannula extends through the septum via a slit preformed therein. When the needle assembly is retracted to the proximal position, the needle cannula is withdrawn from the septum slit, whereby the septum seals the barrel assembly to prevent blood or other fluid from exiting therefrom. 
     According to some embodiments, the device also includes an absorbent sponge. The sponge is fitted in proximity to the septum within the distal end of the barrel. When the needle assembly is in the distal position, the needle cannula extends through the sponge. However, as the needle assembly is retracted, the sponge absorbs and retains any fluid that is squeegeed or removed from the outer surface of the needle as it is withdrawn through the septum. 
     In some embodiments, a two-step process is required to disengage the needle assembly such that it can be retracted under spring force into the proximal position. For example, in some embodiments the device includes an annular sleeve rotatably disposed about a circumference of the proximal end of the barrel. In such embodiments, the sleeve is selectively rotatable between a first position and a second position. The safety cover obscures the barrel aperture and the actuator button when the sleeve is in the first position. However, when the sleeve is rotated into the second position, the barrel aperture and the actuator button are exposed and accessible through an access slot of the sleeve. Thus, the first position of the sleeve prevents the needle assembly from being inadvertently retracted into the proximal position. Rather, the sleeve must be rotated to the second position to expose the actuator arm. Once exposed, the actuator arm may be deflected by the user in order to disengage the actuator button from the barrel aperture. The actuator arm is then deflected and the needle assembly is retracted under spring force into the proximal position. 
     In other embodiments, the actuator button includes a first interlocking edge for interacting with a second interlocking edge of the barrel aperture. In such embodiments, the first and second interlocking edges interlock when the needle hub is in the distal position, whereby the actuator button engages the barrel aperture. In such embodiments, the spring biases the first and second interlocking edges into an interlocked engagement when the needle assembly is in the distal position. The interlocked engagement of the first and second interlocking edges prevents the needle assembly from being inadvertently retracted into the proximal position. Accordingly, the needle assembly must be advanced distally by the user until the interlocking edges disengage. Once disengaged, the actuator arm can be deflected, thereby disengaging the actuator button from the barrel aperture and causing the needles assembly to retract under spring force into the proximal position. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In order that the manner in which the above-recited and other features of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. These drawings depict typical embodiments of the invention and are not, therefore, to be considered to limit the scope of the invention. 
         FIG. 1  is an exploded perspective view of a prior art fluid collection or infusion device or set in accordance with some embodiments of the invention. 
         FIG. 2  is a perspective view of the fluid collection or infusion device or set in its assembled condition. 
         FIG. 3A  is an exploded perspective view of a needle assembly. 
         FIG. 3B  is a side elevation view of a needle. 
         FIG. 4  is a perspective view of the needle assembly in its assembled condition. 
         FIG. 5  is a side elevation view of a prior art needle assembly. 
         FIG. 6  is a top plan view of the needle assembly. 
         FIG. 7  is an exploded cross-sectional view of an assembly barrel. 
         FIG. 7A  is a blown up cross-sectional view of the distal end of the assembly barrel. 
         FIG. 8  is a longitudinal cross-sectional view of the barrel in its assembled condition. 
         FIG. 9  is a perspective view of one embodiment of a wing attachment. 
         FIG. 10  is a perspective view of the retractable needle apparatus of some embodiments of the fluid collection or infusion device or set with the needle assembly in its distal, extended, or active position. 
         FIG. 11  is a side elevation view of the retractable needle apparatus shown in  FIG. 10 . 
         FIG. 12  is a cross-sectional view taken along line  12 - 12  in  FIG. 11 . 
         FIG. 13  is a cross-sectional view taken along line  13 - 13  in  FIG. 12 . 
         FIG. 14  is a perspective view similar to  FIG. 10 , but showing the needle assembly in its proximal, retracted, inactive, or deactivated position. 
         FIG. 15  is a side elevation view similar to  FIG. 11  but showing the needle assembly in its proximal, retracted, inactive, or deactivated position. 
         FIG. 16  is a cross-sectional view taken along line  16 - 16  in  FIG. 15 . 
         FIG. 17  is a cross-sectional view taken along line  17 - 17  in  FIG. 16 . 
         FIG. 18A  is a blown up side elevation view of an alternative embodiment of a needle hub. 
         FIG. 18B  is a blown up cross-sectional view of a portion of an alternative embodiment of the barrel assembly. 
         FIG. 18C  is a blown up cross-sectional view of the needle hub of  FIG. 18A  located within the barrel assembly of  FIG. 18B . 
         FIG. 19A  is a perspective view of an alternative embodiment of a fluid collection or infusion device or set having a safety sleeve in accordance with various embodiments. 
         FIG. 19B  is a bottom view of the distal end of the device illustrated in  FIG. 19A . 
         FIG. 19C  is another perspective view of the distal end of the device illustrated in  FIG. 19A  having the safety sleeve rotated into a second position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The presently preferred embodiments of the present invention will be best understood by reference to the drawings, wherein like reference numbers indicate identical or functionally similar elements. It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Moreover, in the drawings, the dimensions of particular components or elements are for illustrative purposes only and may be exaggerated for clarity. Thus, the following more detailed description, as represented in the figures, is not intended to limit the scope of the invention as claimed, but is merely representative of presently preferred embodiments of the invention. 
     As used herein, the term “proximal” refers to a location with respect to the device during normal use that is closest to the clinician and farthest from the patient. Conversely, the term “distal” refers to a location with respect to the device during normal use that is farthest from the clinician and closest to the patient. As used herein, the term “top”, “up” or “upwardly” refers to a location with respect to the device during normal use that is radially away from the longitudinal axis of the device and away from the patient&#39;s skin. Conversely, as used herein, the term “bottom”, “down” or “downwardly” refers to a location with respect to the device during normal use that is radially away from the longitudinal axis of the device and toward the patient&#39;s skin. As used herein, the term “in” or “inwardly” refers to a location with respect to the device during normal use that is toward the inside of the device. Conversely, as used herein, the term “out” or “outwardly” refers to a location with respect to the device during normal use that is toward the outside of the device. 
     Referring now to  FIGS. 1 and 2 , and particularly to  FIG. 1 , an implementation of a fluid collection or infusion device or set  10 , also referred to herein as a fluid transfer device, set, or assembly, is shown. According to various embodiments, device  10  generally includes a length of flexible plastic or rubber tubing  12 , a proximal fitting or connector  14 , a needle assembly  16 , a needle protector  38 , a spring  18 , a barrel or housing assembly that comprises a distal barrel  20 , a proximal barrel  22 , and a wing attachment  24 , and a clamp or fluid control or flow restricting device  58 . 
     Tubing  12  generally includes a proximal end  26  and a distal end  28 , whereby tubing  12  defines a fluid communication pathway extending therebetween. According to some embodiments, tubing  12  is comprised of conventional intravenous tubing used in conventional blood collection sets or infusion sets. In other embodiments, tubing  12  is comprised of relatively large bore tubing conventionally used in dialysis sets. It is contemplated that the structures and devices disclosed herein can be used in connection with tubing of any desirable type or dimension, including tubing conventionally used in various blood control devices, or other fluid collection, infusion, and/or transfer devices or sets. 
     Proximal fitting or connector  14  is generally comprised of plastic materials, such as polycarbonate, polypropylene, polyethylene, acrylic, polystyrene, ABS and/or other plastic materials, or combinations of plastic materials, having desirable properties. In some embodiments, proximal fitting  14  is molded unitarily. In other embodiments, proximal fitting  14  is assembled from discrete components. As illustrated in  FIG. 1 , proximal fitting  14  generally includes a proximal end  30  and a distal end  32 , whereby proximal fitting  14  defines a fluid communication pathway extending therebetween. According to various embodiments, portions of the fluid communication pathway adjacent distal end  32  are configured to mate or telescope tightly over proximal end  26  of tubing  12 . In this way, a fluid tight seal is formed between proximal fitting  14  and tubing  12 , whereby a sealed fluid communication pathway extends therethrough. According to some embodiments, proximal end  30  of proximal fitting  14  defines a female luer connector configured to mate or connect with a corresponding male luer connector. This configuration allows a fluid, such a medication in liquid form, for example, to be infused into a patient via device  10 . 
     In some embodiments, a male luer connector which corresponds to the female luer connector of proximal fitting  14  includes a proximal needle cannula that can be placed in communication with an evacuated tube. In other embodiments, the male luer connector includes an evacuated tube holder mounted to the male luer connector hub. In alternative embodiments, a male luer connector at the distal end of a conventional prior art syringe can be connected directly to proximal fitting  14  for infusing a fluid, such as a medication, into the patient via device  10 . In some instances, a separate male luer cap can be provided for closing or otherwise sealing proximal fitting  14 . 
     It is further contemplated that various fittings may be threadedly engaged with proximal fitting  14 . In other embodiments, proximal connectors of other configurations similar to or dissimilar from connector  14  may be employed to achieve a particular objective. One example of an alternative fitting is a non-patient needle assembly with a male luer hub, a non-patient needle, and a non-patient sleeve mounted over the non-patient needle and secured to male luer hub. In such embodiments, the non-patient sleeve functions as a valve that permits multiple punctures of evacuated tubes or containers. 
     With continued reference to  FIG. 1 , needle assembly  16  generally includes a needle or needle cannula  34  and a needle hub  36 . As illustrated, needle  34  has a proximal end  40  and a distal end  42 , whereby needle  34  defines a fluid communication pathway extending therebetween. According to some embodiments, distal end  42  of needle  34  is beveled or chamfered to form a sharpened tip. In some embodiments, distal end  42  is formed having a single bevel or chamfer. In other embodiments, distal end  42  includes successive chamfered or beveled surfaces to facilitate insertion of needle  34  into a patient. According to some embodiments, needle  34  comprises a trocar having a sharpened  42 . In some further embodiments, needle  34  comprises a guide for placing a catheter using device  10 . 
     Turning briefly to  FIG. 3B , according to some embodiments tip end  42  of needle  34  is configured to provide a consistent, smooth transition for less tissue trauma and greater patient comfort. As shown in  FIG. 3B , for example, the design of tip  42  may include a multi-chamfered surface to provide a gradual transition. In some embodiments, tip end  42  of needle  34  includes a first chamfered surface  42 A and a second chamfered surface  42 B. According to some embodiments, first chamfered surface  42 A includes a chamfer angle θ selected from about 1° to about 30°. In some embodiments, first chamfered surface  42 A comprises a chamfer angle θ selected from about 10° to about 20°. In other embodiments, first chamfered surface  42 A comprises a chamfer angle θ of about 15°. 
     Tip end  42  further includes a second chamfered surface  42 B positioned between first chamfered surface  42 A and the distal extremity of tip end  42 . Second chamfered surface  42 B includes a chamfer angle θ′ selected from about 25° to about 45°. In some embodiments, second chamfered surface  42 B comprises a chamfer angle θ′ selected from about 30° to about 40°. In other embodiments, second chamfered surface  42 B comprises a chamfer angle θ′ of about 35°. According to various embodiments, chamfer angles θ and θ′ of first and second chamfered surfaces  42 A and  42 B, respectively, progressively increase such that tip end  42  of needle  34  tapers inwardly. Thus, chamfer angle θ of first chamfered surface  42 A is less than, or equal to, chamfer angle θ′ of second chamfered surface  42 B according to some embodiments. 
     In embodiments employing the devices and structures disclosed herein in connection with a transparent or translucent catheter coaxially disposed about needle  34 , needle  34  is formed with a notch or opening  42 C, i.e., a hole or opening in the sidewall adjacent to distal end  42  of needle  34 . This configuration allows blood to flow into the open distal end of needle  34  and then out of notch  42 C into the annular space between the catheter and needle  34 . In embodiments having a transparent or translucent catheter, the user will be able to observe blood flashback promptly upon successful venipuncture. 
     According to some embodiments, needle  34  comprises of conventional needle used in conventional blood collection sets or infusion sets. In other embodiments, needle  34  comprises a relatively large gauge needle conventionally used in dialysis sets. It is contemplated that the structures and devices disclosed herein can be used in connection with a needle of any desirable type or dimension, including needles conventionally used in various blood control devices, or other fluid collection, infusion, and/or transfer devices or sets. For example, according to some embodiments device  10  is configured as a blood control dialysis set. In such embodiments, needle  34  generally comprises a large gauge needle, such as a 12 g, 14 g, 16 g, 18 g, etc. Other associated components are sized appropriately, including the use of large bore blood delivery tubes  12 . In other embodiments, such as a standard blood collection set or an I.V. catheter, comparatively smaller gauge needles and tubing are employed in connection with the methods and structures disclosed herein. 
     Returning to  FIGS. 1 and 2 , needle hub  36  is generally comprised of plastic materials, such as polycarbonate, polypropylene, polyethylene, acrylic, polystyrene, ABS and/or other plastic materials, or combinations of plastic materials, having desirable properties. In some embodiments, needle hub  36  is molded unitarily. In other embodiments, needle hub  36  is assembled from discrete components. According to some embodiments, needle hub  36  is molded, formed, comprised, or assembled from transparent or translucent material(s) to enable a user&#39;s observation of fluid flowing through needle hub  36 . Solvent bonding or plastic welding is contemplated in connection with the assembly or manufacture of various embodiments of needle hub  36 . 
     As illustrated, needle hub  36  generally includes a proximal end  46  and a distal end  48 , whereby needle hub  36  defines an internal stepped fluid communication pathway  50  (see  FIGS. 12 and 13 ) extending therebetween. According to various embodiments, passage  50  adjacent proximal end  46  is dimensioned to compatibly couple with distal end  28  of tubing  12 . In some embodiments, proximal end  46  of needle hub  36  comprises a male fitting configured for insertion within distal end  28  of tubing  12 . In other embodiments, proximal end  46  of needle hub  36  comprises a female fitting configured to receive distal end  28  of tubing  12 . In some instances, distal end  28  of tubing  12  mates with or is telescoped into passage  50  of needle hub  36  and is bonded in position to form a fluid tight seal between tubing  12  and needle hub  36 . Similarly, according to various embodiments, passage  50  adjacent distal end  48  of needle hub  36  is dimensioned to compatibly receive proximal end  40  of needle  34  to form a fluid tight seal between needle hub  36  and needle  34 . 
     Turning now to  FIGS. 3A, 4, 5 and 6 , and according to various embodiments, a portion of needle hub  36  adjacent distal end  48  defines a cylindrical tip  52 . In some further embodiments a cylindrical spring mounting section  54  extends proximally from cylindrical tip  52 . A larger diameter cylindrical flange  56  extends radially outwardly at the proximal end of spring mounting section  54 . According to such embodiments, flange  56  defines a limit for proximal movement of spring  18  on needle hub  36  and a limit for distal movement of needle hub  36  relative to distal barrel  20 . In some embodiments, flange  56  includes tabs for guiding movement of needle hub  36  within corresponding guide tracks or grooves formed in the barrel assembly comprised of distal and proximal barrels  20  and  22 . 
     According to some embodiments, a resiliently deflectable actuator arm  60  is flexibly cantilevered to extend outwardly and distally from proximal end  46  of needle hub  36 . This outward projection configuration enables actuator arm  60  to function as a key that maintains a specific rotational orientation of needle hub  36  relative to distal and proximal barrels  20  and  22 . Additionally, actuator arm  60  and beveled tip  42  of needle  34  are axially aligned with one another according to some embodiments. Thus, in such instances, a plane passing through actuator arm  60  would also bisect the ellipse defined by beveled tip  42 . In alternative embodiments, actuator arm  60  may be located on any side of needle hub  36 . 
     According to some embodiments, actuator arm  60  includes a distal free end  62  (see  FIG. 5 ) that is located proximally of flange  56 . In such embodiments, flange  56  does not impede inward deflection of actuator arm  60 . Portions of actuator arm  60  proximally of distal end  62  define an actuator button  64  that projects radially outwardly from actuator arm  60 . In some further embodiments, the proximal end of actuator button  64  defines a locking edge  66  which is undercut relative to remaining portions of actuator arm  60  and oriented at an acute angle relative to the axis of needle hub  36 . Some embodiments of needle hub  36  include a bottom stabilizing rib  67  (see  FIG. 5 ), which rib extends axially along needle hub  36 . More than one stabilizing rib may be used in accordance with various embodiments. 
     As discussed in greater detail below, in some embodiments button  64 , other components of device  10 , and/or a combination of the forgoing is/are configured so as to avoid inadvertent depression of button  64  and the associated premature deactivation of device  10 . In other embodiments, as also discussed further below, other mechanisms are employed in connection with device  10  to avoid the inadvertent depression of button  64  and/or the premature deactivation of device  10 . 
     With reference to  FIGS. 3A and 4 , according to some embodiments needle protector  38  is a rigid cylindrical tube that extends past the projecting length of needle  34  from distal end  72  (see  FIG. 1 ) of distal barrel  20 . As shown, in some embodiments, needle protector  38  attaches to needle hub  36  about cylindrical tip  52  and has a length that exceeds the projecting length of needle  34 . In such embodiments, needle protector  38  defines an inside diameter approximately equal to the outside diameter of distal tip  52  of needle hub  36 . Additionally, in some embodiments, needle protector  38  defines an outside diameter approximately equal to the outside diameter of spring mounting section  54  of needle hub  36 . Thus, as shown most clearly in  FIG. 4 , needle protector  38  can be telescoped over needle  34  and frictionally retained on distal tip  52  of needle hub  36 . Additionally, in this mounted condition, spring mounting section  54  of needle hub  36  and needle protector  38  define a continuous and substantially uniform outside diameter. In some alternative embodiments, needle protector  38  may be retained frictionally on distal end  72  (see  FIG. 1 ) of distal barrel  20 . According to some embodiments, needle protector  38  is not employed. 
     Returning briefly to  FIG. 1 , according to some embodiments spring  18  defines a helical coil with an inside diameter slightly greater than the outside diameter of needle protector  38  and/or spring mounting section  54  of needle hub  36 . Additionally, in some implementations, the inside diameter of spring  18  is less than the outside diameter of flange  56  on needle hub  36 . Thus, according to such embodiments, flange  56  defines a limit to the range of telescoping movement of spring  18  over needle assembly  16 . According to various embodiments, the axial length of spring  18  is selected to conform with the desired range of movement of needle assembly  16  relative to distal and proximal barrels  20  and  22 . In some instances, the axial length of spring  18  in its expanded condition exceeds the distance between distal tip  42  of needle  34  and flange  56  on needle hub  36 . 
     In various implementations, distal barrel  20  includes opposite proximal and distal ends  70  and  72 , whereby distal barrel  20  defines a passage  74  (see  FIGS. 7 and 8 ) extending therebetween. In some embodiments, distal barrel  20  is generally comprised of plastic materials, such as polycarbonate, polypropylene, polyethylene, acrylic, polystyrene, ABS and/or other plastic materials, or combinations of plastic materials, having desirable properties. According to some embodiments, distal barrel  20  is molded unitarily. In other embodiments, however, distal barrel  20  is assembled from discrete components. 
     With reference to  FIGS. 7 and 8 , according to some embodiments portions of passage  74  near distal end  72  define an inwardly extending annular distal flange  76  with an inside diameter less than the outside diameter of spring  18 . Thus, in such implementations, distal flange  76  defines a distal stop or abutment for the distal end of spring  18 , whereby spring  18  may be compressed within distal barrel  20 . According to some additional embodiments, passage  74  further has an annular step  78  proximally of distal flange  76 . In such embodiments, step  78  defines an inside diameter less than the outside diameter of flange  56  on needle hub  36 . Thus, according to such embodiments, step  78  defines a fixed limit for the distal movement of needle hub  36  in distal barrel  20 . According to various embodiments, step  78  is spaced from distal flange  76  by a distance substantially equal to the compressed length of spring  18 . Thus, in such embodiments, the section of passage  74  between distal flange  76  and step  78  effectively defines a spring housing (see  FIGS. 12 and 13 ). According to some embodiments, passage  74  is defined further by an annular locking rib  80  (see  FIG. 7 ) near proximal end  70 . Locking rib  80  permits locked engagement of distal and proximal barrels  20  and  22  as explained herein. 
     In some implementations, the outer circumferential surface of distal barrel  20  is defined by an annular wing-mounting undercut  82  near distal end  72 . According to some further embodiments, annular undercut  82  is provided with projections or detents  83  for positioning wing attachment  24  in a fixed rotational orientation on distal barrel  20 . In other embodiments, undercut  82  of distal barrel  20  has a dampening agent injection port  85  for injecting a dampening agent into passage  74 . Port  85  is covered by wing attachment  24 . 
     As shown in  FIGS. 7A and 8 , some embodiments include a septum  68  in proximity to the distal end of distal barrel  20 . In such embodiments, the distal end of distal barrel  20  is sealed with septum  68  to ensure that fluid does not leak out of the distal end of distal barrel  20 . In some embodiments, septum  68  is comprised of a single portion or otherwise formed unitarily and fitted into the distal end of distal barrel  20 . In other embodiments, however, septum  68  is comprised of or otherwise formed having two or more portions. In such embodiments, one portion of septum  68  provides a primary seal while a second portion of septum  68  provides a secondary seal, and still a third portion of septum  68  provides a third seal. In various embodiments, septum  68  is pre-slit using various methods common to those of skill in the art. The slit formed within septum  68  accommodates or otherwise facilitates locating needle  34  there through. 
     According to some embodiments, suitable materials for septum  68  include a peroxide cured elastomer such as polyisoprene, silicone, and other like materials having a durometer in the range of 35-45 Shore A. In embodiments comprising septum  68  having two or more portions or components, each portion or component may be manufactured of the same material and/or have the same hardness. In other implementations, the discrete portions of a multi-part septum  68  can be manufactured out of different materials and/or have different durometers. 
     As illustrated in the various figures, septum  68  is retained in proximity to the distal end of distal barrel  20  via a septum housing according to various embodiments. For example, in some embodiments, the proximal face of septum  68  abuts the distal face of flange  76  while the distal face of septum  68  is retained by an annular distal flange  72 A. In such embodiments, annular distal flange  72 A extends over a portion of the surface area of the distal face of septum  68 . In this configuration, septum  68  is fit within the cavity or housing defined between flanges  76  and  72 A, whereby septum  68  is held in position in proximity to distal barrel  20 . The proximity of septum  68  relative to distal barrel  20  is maintained as needle cannula  34  is located through the slit formed within septum  68  and subsequently withdrawn therefrom. In various embodiments, septum  68  is held in place and forms a fluid tight seal by various methods known in the art, such as through the use of an adhesive or by ultrasonic welding. 
     According to various embodiments, the septum housing defined by distal barrel  20  is configured to apply a compressive force to septum  68  to encourage a fluid tight seal. For example, in some embodiments, the outside diameter of septum  68  is between 1% and 10% larger than the inside diameter of the septum housing defined by distal barrel  20 . In some embodiments, the outside diameter of septum  68  is at least 5% larger than the inside diameter of the septum housing defined by distal barrel  20 . In this configuration, distal barrel  20  exerts a compressive radial force on the circumference of septum  68 . The compressive radial force retains septum  68  in place and serves to seal septum  68  to prevent fluid from exiting therefrom. 
     As seen in various figures, including  FIGS. 12 and 13 , the open ends  70  and  72  of distal barrel  20  allow distal end  42  of needle  34  to extend through and distally past barrel  20  and septum  68  when device  10  is in an active position. In various embodiments, the radial compressive force discussed above helps to maintain a fluid tight seal after needle  34  has been retracted from septum  68  upon deactivation of device  10 . 
     With brief reference to  FIG. 7A , according to some embodiments, septum  68  defines an internal cavity or hollow interior portion  68 A. In such embodiments, cavity  68 A minimizes drag on needle  34  as it is retracted from septum  68 . Such a configuration reduces splattering of residual fluid during retraction of needle  34 . According to various embodiments, cavity  68 A is sized to minimize drag without being too large. For example, in some embodiments, the cross-section of cavity  68 A should closely approximate the cross-section of the largest bore needle  34  that would be used with device  10 . In some further embodiments, the axial length of cavity  68 A is between about 6 and 8 millimeters. In some instances, cavity  68 A is filled with a material to prevent fluid from becoming trapped therein, such as a lubricious silicone liquid or gel or an antimicrobial solution. 
     Referring still to  FIG. 7A , according to some embodiments, an absorbent material  128 , such as a sponge, a pad, or some other wiping material, is disposed in proximity to septum  68 . In various embodiments, material  128  comprises a non-woven or foam pad suitable for absorbing fluid. In such embodiments, material  128  soaks up, squeegees, or absorbs any residual fluid on the outside of needle  34  during retraction thereof. Such a configuration further reduces splattering of residual fluid during retraction of needle  34 . Material  128  also prevents blood that would collect on the outside of septum  68  during retraction of needle  34  from dripping or otherwise leaking out of distal end  72  of distal barrel  20 . In various embodiments, material  128  is a highly absorbent material capable of absorbing and positively retaining a quantity of residual fluid typically found on the outside of needle  34  during use of device  10  while in an active position. 
     As shown in  FIGS. 16 and 17 , following withdrawal of needle cannula  34 , when the distal end  42  thereof is proximal of septum  68 , fluid, such as blood, cannot flow out of or otherwise exit from device  10  due to the fluid seal formed by septum  68 . In some further embodiments, the retraction of needle  34  also allows absorbent material  128  to squeegee or wipe the outer surface of needle  34  and absorb any residual fluid that may be disposed thereon as needle  34  is withdrawn through the septum. 
     With returning reference to  FIGS. 7 and 8 , and according to various embodiments, some select portions of the outer surface of distal barrel  20  proximally of annular undercut  82  are flared outwardly. According to various embodiments, the outer circumferential surface is necked down to define a reduced diameter portion that extends through approximately 270° around the circumference of distal barrel  20 . Thus, in some embodiments, distal barrel  20  includes a distal major diameter portion  84 , a proximal major diameter portion  86 , and a minor diameter portion  88  therebetween. 
     According to some further embodiments, minor diameter portion  88  of distal barrel  20  includes an actuating opening or barrel aperture  90  extending through distal barrel  20  and communicating with passage  74 . In some embodiments, barrel aperture  90  is dimensioned to receive actuating button  64  and includes a locking edge  92  configured for locking engagement with locking edge  66  of actuating button  64 . According to some embodiments, barrel aperture  90  is positioned angularly at a central location on minor diameter portion  88 , and is aligned with projection  83  on undercut  82  to define a visually apparent top of distal barrel  20 . 
     In some further embodiments, step  78  is spaced from barrel aperture  90  by a distance equal to or slightly greater than the axial distance between distal end  62  of actuator arm  60  and the distal face of flange  56 . Thus, according to such embodiments, actuator button  64  is engaged in barrel aperture  90  when flange  56  of needle hub  36  abuts step  78  of distal barrel  20 . Additionally, according to some embodiments, the internal cross-sectional dimension of passage  74  adjacent to and proximal of locking edge  92  is substantially equal to or slightly larger than the cross-sectional dimension of actuating arm  60  adjacent to and proximally of locking edge  66 . Hence, in some embodiments, locked engagement is assured between locking edges  66  and  92  when needle hub  36  is moved distally in distal barrel  20  until flange  56  abuts step  78 . 
     With brief reference back to  FIGS. 1 and 2 , and continued reference to  FIGS. 7 and 8 , according to various embodiments proximal barrel  22  also is generally a tubular structure with a proximal end  94 , a distal end  96 , and a passage  98  extending therebetween. In some embodiments, proximal barrel  22  is generally comprised of plastic materials, such as polycarbonate, polypropylene, polyethylene, acrylic, polystyrene, ABS and/or other plastic materials, or combinations of plastic materials, having desirable properties. According to various embodiments, proximal barrel  22  is molded unitarily while, in other embodiments, proximal barrel  22  is assembled from discrete components. 
     In some implementations, exterior portions of proximal barrel  22  adjacent distal end  96  define an annular locking bead or ring  100 . In various embodiments, locking bead  100  is configured for snapped locking engagement with annular locking rib  80  in passage  74  of distal barrel  20 . Such locking engagement serves to engage together distal and proximal barrels  20  and  22 . According to some embodiments, the engagement of distal and proximal barrels  20  and  22  can be made more permanent by adhesive bonding, welding, or by increasing the interference between annular locking rib  80  and locking bead  100 . In some alternative embodiments, however, distal barrel  20  and proximal barrel  22  are connected by threaded engagement where one of distal and proximal barrels  20  and  22  has external threads and the other of distal and proximal barrels  20  and  22  has internal threads. According to such embodiments, thread pitch and location are chosen to enable alignment of top and bottom axially extending channels  104  and  106 . In some embodiments, the barrel assembly includes additional channels or guide tracks configured to engage guide tabs located adjacent flange  56  included on needle hub  36 . In such embodiments, the interaction of guide tabs on flange  56  and corresponding guide tracks or channels formed in the barrel assembly facilitate the guided proximal movement of needle hub  36  during retraction or deactivation of device  10 . 
     According to various embodiments, proximal portions of passage  98  through proximal barrel  22  are characterized by an inwardly extending proximal annular flange  102 . Proximal flange  102  has an inside diameter less than the outside diameter of flange  56  on needle hub  36 . Thus, according to some implementations, proximal flange  102  limits proximal movement of needle hub  36  in proximal barrel  22  once distal and proximal barrels  20  and  22  are engaged with one another. 
     As illustrated in  FIG. 7 , according to some embodiments passage  98  of proximal barrel  22  is characterized further by top and bottom axially extending channels  104  and  106 , respectively. According to such embodiments, top channel  104  is aligned with barrel aperture  90  and is dimensioned to slidably receive actuating arm  60  of needle hub  36 . Similarly, bottom channel  106  is dimensioned to slidably receive needle hub  36 . In some embodiments, bottom channel  106  is configured to receive bottom stabilizing rib  67  of needle hub  36 . 
     According to some embodiments, portions of proximal barrel  22  surrounding bottom channel  106  project proximally beyond portions of proximal barrel  22  surrounding top channel  104 . In such configurations, a greater axial length is provided for slidably receiving and supporting bottom stabilizing rib  67  of needle hub  36 . According to some embodiments, additional support for bottom stabilizing rib  67  achieves a more desirable bearing ratio between the cross-sectional and axial dimensions for slidable engagement between needle hub  36  and barrels  20  and  22 . Thus, a more precise axial movement is achieved with less transverse shifting of needle hub  36 . The more precise axial movement enabled by the proximal extension surrounding bottom channel  106  reduces splattering of residual fluid in needle  34  during retraction thereof. 
     In some further embodiments, proximal barrel  22  includes resiliently deflectable locking fingers  108 . Locking fingers  108  are cantilevered distally and inwardly from opposing locations on proximal barrel  22 . Locking fingers  108  are also spaced from top and bottom channels  104  and  106  by approximately 90° according to some embodiments. Thus, each locking finger  108  includes a proximal end  110  that is spaced from proximal stop or retention flange  102  by a distance equal to or slightly greater than the axial thickness of flange  56  on needle hub  36 . Hence, according to such embodiments, flange  56  can be trapped between the distal surface of stop flange  102  and locking  figures 108  as explained below. According to various embodiments, proximal ends  110  of locking  figures 108  are spaced from one another by a distance less than the diameter of flange  56  on needle hub  36 . 
     According to various embodiments, the barrel assembly comprised of distal barrel  20  and proximal barrel  22  is molded, formed, comprised, or assembled from transparent or translucent material(s) to enable observation of blood or other fluid flowing through the barrel assembly. Solvent bonding or plastic welding is contemplated in connection with the assembly or manufacture of various embodiments of the barrel assembly. 
     With brief reference back to  FIGS. 1 and 2 , and specific reference now to  FIGS. 9, 10 and 11 , wing attachment  24  will be discussed in greater detail. According to various embodiments, wing attachment  24  is molded unitarily from an elastic material such as polyolefin, polyvinyl chloride, or other such elastomeric polymers having flexible or semi-flexible properties. According to other embodiments, however, wing attachment  24  is molded of comparatively semi-rigid materials having a desirable amount of shape memory. In still other embodiments, wing attachment  24  is generally molded of elastomeric polymers formed around a comparatively semi-rigid structural skeleton. As shown, wing attachment  24  generally includes flexible opposing side panels  112  and  114  and a mount  116 . In some embodiments, as depicted by way of example, mount  116  is tubular in configuration. In other embodiments, however, mount  116  forms an upside down “u” shape traversing approximately 270° and having an opening at the bottom thereof. 
     In various embodiments, mount  116  includes an interior passage  118  that is dimensioned for snug engagement over and/or around undercut  82  on distal barrel  20 . In some additional embodiments, mount  116  is formed with top and bottom notches  120  and  122 . Notches  120  and  122  are dimensioned to engage with detents  83  on distal barrel  20  to ensure a preferred rotational orientation between wing attachment  24  and distal barrel  20 . According to various alternative embodiments, notches  120  and  122  are symmetrical about a plane that is perpendicular to panels  112  and  114 . 
     According to some embodiments, opposing panels  112  and  114  are molded with a top surface that is relatively smooth. In some embodiments, the top surface of one of panel  112  or  114  includes a pair of arcuate projections  124  at portions remote from mount  116 . Conversely, according to some embodiments, the top surface of the other of panel  112  or  114  includes a pair of arcuate recesses  126  that are dimensioned to receive projections  124  when panels  112  and  114  are folded so that the top surfaces thereof are in face-to-face engagement with one another. According to such embodiments, the inter-engagement of projections  124  with recesses  126  ensures that folded panels  112  and  114  function as a handle without slipping relative to one another when folded and engaged. According to additional embodiments, as seen in  FIG. 11 , the bottom surfaces of panels  112  and  114 , respectively, are provided with a plurality of tactile bumps  132 . In such embodiments, bumps  132  facilitate a user&#39;s grip of folded panels  112  and  114  between a thumb and forefinger of the user. According to the foregoing embodiments, and as depicted in the various figures, the hinged movement described with respect to panels  112  and  114  about mount  116  is facilitated by thinned regions (e.g.,  FIG. 9 ) at the connection of panels  112  and  114  with mount  116 . 
     According to various alternative embodiments, the color of wing attachment  24  is coordinated with, or otherwise designates, the gauge of needle  34 . Alternate embodiments where wing attachment  24  has only one side panel  112  or  114  are contemplated to provide an alternate means to manipulate the needle assembly by the user. 
     With general reference to  FIG. 1  and specific reference to  FIGS. 12 and 13 , according to some embodiments, device  10  is assembled by axially coupling proximal end  40  of needle  34  with passage  50  adjacent distal end  48  of needle hub  36 . Needle  34  may be secured in this position by an adhesive, such as a heat curable or ultraviolet cured epoxy. Similar securing methods or means common to those of skill in the art are also contemplated. According to some embodiments, the bevel or multiple chamfers that define distal tip  42  of needle  34  require a specific orientation. As shown in the various figures, for example, in some embodiments, needle cannula  34  is oriented such that the bevel at distal end  42  of needle  34 , wing attachment  24 , and actuator arm  60  of needle hub  36  are symmetrical about a common plane. In some further embodiments, the orientation of wing attachment  24  relative to distal end  42  of needle  34  is guaranteed by the relative orientation of actuator arm  60  and needle hub  36  with respect to distal and proximal barrels  20  and  22 . The method of assembly continues, according to some embodiments, as needle assembly  16  is completed by telescoping protector  38  over needle  34  sufficiently for frictional engagement on distal tip  52  (see  FIG. 3A ) of needle hub  36 . In various alternative embodiments, protector  38  can be telescoped over needle cannula  34  by fictional engagement with distal barrel  20 . In some instances, protector  38  is not telescoped over needle cannula  34  until after needle cannula  34  has been located through septum  68  as discussed below. 
     According to various embodiments, the assembly of device  10  continues as distal end  28  of tubing  12  is coupled with proximal end  46  of needle hub  36 . In some implementations, tubing  12  is secured in this position by solvent bonding, adhesive bonding, or welding. Other methods of securing suitable tubing common to those of skill in the art are also contemplated. 
     With respect to some embodiments, assembly continues by telescoping spring  18  over needle protector  38  and/or over spring mounting section  54  of needle hub  36 . According to some embodiments, needle assembly  16  and spring  18  are then aligned and telescoped in a distal direction into distal barrel  20 . In embodiments comprising septum  68 , needle assembly  16  and spring  18  are aligned and telescoped into distal barrel  20  such that needle  34  passes through a preformed slit in septum  68  before needle protector  38  is coaxially disposed over needle  34 . For various embodiments, the above-described insertion requires that actuator arm  60  and stabilizing rib  67  (e.g.,  FIG. 5 ) be aligned with channels  104  and  106  (e.g.,  FIG. 10 ). Movement of needle hub  36  into distal barrel  20  causes needle  34  to advance through and beyond septum  68  and distal end  72  of distal barrel  20  whereupon needle protector  38  can be coaxially disposed over needle  34 . Additionally, according to some embodiments, actuator arm  60  (e.g.,  FIG. 5 ) is depressed sufficiently to clear portions of passage  74  immediately proximally of barrel aperture  90  during installation and assembly (e.g.,  FIG. 7 ). 
     As illustrated in  FIGS. 12 and 13 , the distal movement described above causes spring  18  to collapse between distal flange  76  on distal barrel  20  and flange  56  on needle hub  36 . According to various embodiments, the method continues as flange  56  of needle hub  36  approaches step  78  of distal barrel  20  and actuator button  64  aligns with barrel aperture  90 . As seen in  FIG. 13 , as actuator arm  60  fully aligns with barrel aperture  90 , actuator arm  60  resiliently returns toward an undeflected condition and locking edge  66  of actuator button  64  engages locking edge  92  of barrel aperture  90 . As a result of the interaction of locking edges  66  and  92  and the resilient biased orientation of actuator arm  60 , needle assembly  16  is locked in its distal position in distal barrel  20  with spring  18  secured in a compressed condition with significant stored energy. According to various embodiments, when needle assembly  16  is locked in its distal position and needle protector  38  is removed, device  10  is active or otherwise configured for placement of device  10  into fluid communication with a patient via exposed needle  34 . 
     As shown in various Figures, assembly of device  10  continues as wing attachment  24  is mounted over distal end  72  of distal barrel  20 . According to some embodiments, notches  120  and  122  of wing attachment  24  are aligned with detents  83  on distal barrel  20  (e.g.,  FIGS. 10 and 11 ). In some further embodiments, a snug fit between mount  116  of wing attachment  24  and wing-mounting undercut  82  of distal barrel  20  is achieved via the interaction of detents  83  and notches  120  and  122 . This configuration prevents rotation of wing attachment  24  relative to distal barrel  20 . In its mounted condition, panels  112  and  114  of wing attachment  24  define a plane extending substantially normal to the plane of symmetry defined by the bevel at distal tip  42  of needle  34  and actuator arm  60  of needle hub  36 . 
     Returning to  FIG. 1 , according to various embodiments, assembly of device  10  continues by threading proximal end  26  of tubing  12  through proximal barrel  22 . Proximal barrel  22  is moved distally along the length of tubing  12  until distal end  96  of proximal barrel  22  lockedly engages proximal end  70  of distal barrel  20  via locking rib  80  and locking ring  100  (e.g.,  FIG. 7 ). The method continues, according to various embodiments, as fitting  14  is secured to proximal end  26  of tubing  12 . Fitting  14  can be secured to proximal end  26  of tubing  12  by any method common to those of skill in the art. 
     In embodiments in which a viscous dampening agent is utilized via port  85 , passage  74  of distal barrel  20 , the spring mounting section  54  of needle hub  36 , and the distal surface of flange  56  on needle hub  36  define a chamber that constrains the location of the dampening agent or otherwise defines a cavity to be filed with the dampening agent. Alternatively, another silicone part could be used as a bumper. As mentioned above, in such embodiments, an injection port  85  located within the sidewall of distal barrel  20  is provided for dispensing the viscous dampening agent into the dampening agent chamber. In some embodiments, the dampening agent can be injected through a dispensing cannula that has a distal end shaped to fit within injection port  85 . In other embodiments it is also contemplated that the dampening agent can be applied to passage  74 , spring  18 , needle hub  36 , or any of the three components prior to assembly to produce an alteration to retraction speed or velocity when needle assembly  16  is retracted following use of device  10 . 
     According to some embodiments, the viscous dampening agent may be a silicone that functions to dampen the velocity of needle hub  36  relative to distal barrel  20  and proximal barrel  22 . In such embodiments, the viscous dampening agent creates a resistance to slow the retraction of needle hub  36  and needle  34 . In some embodiments a suitable dampening agent is a thixotropic gel, similar to the type of gel used as a separator gel in blood collection tubes. Utilization of a thixotropic gel as a dampening agent provides unique properties relative to spring  18 . In particular, thixotropic gel exhibits the ability to temporarily and elastically bond adjacent coils of spring  18  together. Initiation of retraction releases the stored energy of spring  18 , and permits spring  18  to expand. Nevertheless, the thixotropic gel creates resistance similar to silicone, and hence dampens the velocity of needle hub  36  and needle  34  during the retraction process. However, unlike conventional silicone, the temporary bonding between adjacent coils achieved by the thixotropic gel provides a slower initial acceleration. In such embodiments, the slower initial acceleration results in a reduction in splatter during retraction of needle assembly  16 . 
     According to some embodiments, injection port  85  is positioned on undercut  82  (see  FIGS. 7 and 8 ) and is sealed by placing wing attachment  24  on and covering injection port  85 , thereby constraining the dampening agent to that portion of spring  18  near injection port  85 . In alternative embodiments, it is understood that a dampening agent can be located on surfaces in slidable engagement between needle hub  36  and distal and proximal barrels  20  and  22 . In such embodiments, the dampening agent produces a viscous shearing boundary layer that alters the velocity and acceleration of needle hub  36  during retraction thereof. 
     With reference now to  FIGS. 14 through 17 , and continued general reference to  FIGS. 1 and 2 , methods of using device  10  according to various embodiments are described in further detail. In some embodiments, for example, device  10  is used by folding panels  112  and  114  of wing attachment  24  toward one another and into face-to-face engagement so that projections  124  on the upper surface of one of panel  112  and/or  114  are received in recesses  126  on the upper surface of the other one of panel  112  and/or  114 . This configuration prevents shifting of panels  112  and  114  during use of device  10 . In such embodiments, tactile bumps  132  (e.g.,  FIG. 15 ) on the bottom surfaces of panels  112  and  114 , respectively, facilitate a user&#39;s secure grip of device  10  via pinching panels  112  and  114  between the user&#39;s thumb and forefinger. 
     According to various embodiments, the method of using device  10  continues as needle protector  38  is separated from frictional engagement with either needle hub  36  or distal barrel  20  in order to expose needle  34 . 
     In some embodiments, the plane defined by the abutting surfaces of panels  112  and  114  of wing attachment  24  will lie on the plane of symmetry of beveled distal tip  42  of needle  34 . Such a configuration permits the user, such as a health care worker, a clinician, a nurse, a health care technician, or any other or equivalent health care professional, to guide beveled distal tip  42  of needle  34  into a target location on a patient. According to various embodiments, the method continues as the user employs proximal fitting  14  at proximal end  26  of tubing  12  to connect device  10  to other medical equipment or devices, such as an evacuated container, a source of fluid that will be infused into the patient, a dialysis or blood cleaning/filtering machine, an I.V. tube or bag, or other medical equipment or devices common to those of skill in the art. 
     According to certain implementations, upon completion of the associated medical procedure being performed, the health care worker deactivates device  10  by depressing actuator button  64 . The depression of actuator button  64  enables needle assembly  16  to be retracted, whereby the barrel assembly comprised of distal and proximal barrels  20  and  22  entirely encloses needle  34  once needle assembly  16  is fully retracted. In embodiments comprising septum  68  and or absorbent material  128 , the barrel assembly also contains any residual blood or other fluid inside device  10 . In this configuration, once deactivated, device  10  protects users against needle stick injuries as well as potential blood borne pathogens. 
     As mentioned briefly above, according to some embodiments, actuator button  64  lies within the reduced cross-section or minor diameter portion  88  of distal barrel  20 , and hence is not susceptible to inadvertent actuation or depression. However, in some embodiments, the configuration of minor diameter portion  88  is dimensioned to receive a tip of a user&#39;s finger, such as a user&#39;s forefinger, that is intentionally directed toward actuator button  64 . In some further embodiments, the necked-down shape of distal barrel  20  adjacent barrel aperture  90  provides a clear visual cue for the intended location of manual force for depressing actuator button  64 . In some alternative embodiments, actuator button  64  comprises a low profile such that deliberate and targeted effort is necessary to effectively depress the same. Additional embodiments configured to reduce or prevent incidents of inadvertent actuation or depression of actuator button  64  are discussed in greater detail below. 
     According to some embodiments, in operation, inwardly directed forces on actuator button  64  cause locking edge  66  of actuator button  64  to disengage from locking edge  92  of barrel aperture  90 . In such embodiments, spring  18  is permitted to expand releasing the energy stored therein as locking edges  66  and  92  are disengaged. The disengagement of locking edges  66  and  92  results in the retraction of needle assembly  16 . As most clearly seen in  FIG. 16 , in some implementations, the proximal movement of needle assembly  16  terminates when flange  56  abuts proximal stop flange  102  of proximal barrel  22  and the sharp tip  42  of needle  34  is proximal of septum  68 . In this position, the entirety of needle  34  is disposed safely within distal and proximal barrels  20  and  22  to prevent needle stick injuries. Likewise, in this position, septum  68  seals device  10  so as to contain any residual blood, prevent the user from being exposed to blood borne pathogens, and prevent blood from exiting device  10 . 
     According to some further embodiments, the retraction of needle assembly  16  is guided axially by engagement of bottom stabilizing rib  67  in bottom channel  106  (e.g.,  FIG. 10 ). In various additional embodiments, actuator button  64  travels in top channel  104  (e.g.,  FIG. 10 ) and biases needle assembly  16  toward bottom channel  106  during retraction of needle assembly  16 , including portions of bottom channel  106  in proximal extension of proximal barrel  22 . Thus, according to some embodiments, an effective bearing ratio is maintained to achieve axial movement while reducing incidents, or the probability, of fluid splatter as needle  34  is accelerated proximally under the force of spring  18 . 
     According to various embodiments, as flange  56  of needle hub  36  approaches proximal stop  102  of proximal barrel  22 , flange  56  engages locking fingers  108 . In such embodiments, the rearward movement of flange  56  causes a temporary outward deflection of locking fingers  108  until flange  56  moves proximally beyond the proximal ends  110  of locking fingers  108 . As shown in  FIG. 16 , the method of deactivating device  10  continues as needle assembly is further retracted until flange  56  abuts proximal stop  102 , at which point locking fingers  108  resiliently return toward an undeflected condition and engage the distal face of flange  56 . Hence, according to some embodiments, a return movement of needle assembly  16  is prevented. Thus, according to some embodiments, the interaction of locking fingers  108  of proximal barrel  22 , flange  56  of needle hub  36 , and spring  18  restrains needle assembly  16  against subsequent distal movement following deactivation of device  10 . In this way, device  10  is restrained against inadvertent reactivation. In some further embodiments, the inwardly aligned orientation of locking fingers  108  substantially impedes any intentional outward deflection of locking fingers  108  that would permit a re-exposure or re-activation of needle  34 . Thus, in some implementations, reuse of needle  34  is prevented following deactivation of device  10  or can be achieved only by a destruction of the locking fingers in proximal barrel  22 . 
     As mentioned above, additional embodiments are contemplated for reducing or preventing incidents of inadvertent actuation or depression of actuator button  64  and/or the premature deactivation of device  10 . With reference to  FIGS. 18A through 18C , for example, some embodiments require a two-step deactivation process. As illustrated in  FIG. 18A , in some embodiments, actuator arm  60  includes an interlocking edge  66 ′. In such embodiments button  64 ′ includes texture, raised bumps or protrusions, ridges, grooves, or other means for enhancing the frictional surface of button  64 ′. As seen in  FIG. 18B , in such embodiments, distal barrel  20  includes a correspondingly shaped interlocking edge  92 ′. With reference to  FIG. 18C , interlocking edges  66 ′ and  92 ′ are configured for interlocking or mating engagement with one another when device  10  is active, i.e., when needle  34  is exposed for insertion into the vasculature of a patient. 
     According to some embodiments, in order to deactivate device  10 , i.e., to release the energy stored in spring  18  in order to fully retract needle assembly  16  proximally, a user must first push needle assembly  16  distally a sufficient distance to disengage interlocking edges  66 ′ and  92 ′. The raised or textured surface of button  64 ′ facilitates the user&#39;s frictional grip of button  64 ′. Such a configuration permits the user to adequately apply axial force in the distal direction via button  64 ′ to needle assembly  16 . In this way, the user temporarily overcomes the proximal force of spring  18  and moves needle assembly  16  distally far enough to disengage interlocking edges  66 ′ and  92 ′. Following disengagement of interlocking edges  66 ′ and  92 ′ the user then depresses cantilevered actuator arm  60  and deactivates device  10  as described previously. 
     In various embodiments, the raised or textured surface of button  64 ′ has a sufficiently low profile so as not to interfere with the retraction process once actuator arm  60  is depressed and needle assembly  16  retracts. In some further embodiments, a gap  90 ′ between the distal edge of aperture  90  and the distal end  62  of actuator arm  60  is slightly larger than the interlocking depth of interlocking edges  66 ′ and  92 ′. This configuration permits needle assembly  16  to move far enough distally to permit the disengagement of interlocking edges  66 ′ and  92 ′. 
     Additional embodiments are also contemplated. For example, in some embodiments, actuator button  64 ′ and actuator arm  60  are separate components coupled together via a spring mounting configuration. In this way, button  64 ′ is biased in a locked position and can be moved distally sufficiently to allow interlocking edges  66 ′ and  92 ′ to disengage independently from moving the entire needle assembly distally. Once interlocking edges  66 ′ and  92 ′ are disengaged, actuator arm  60  is depressed and device  10  is deactivated as previously described. In such embodiments, the spring force between button  64 ′ and actuator arm  60  is less than the spring force provided by spring  18 . 
     In the embodiments described with reference to  FIGS. 18A through 18C , the mating engagement of interlocking edges  66 ′ and  92 ′ under the proximal biasing force of spring  18  prevent or minimize incidents of premature deactivation of device  10  via the two-step process discussed above. Nevertheless, deactivation of device  10  may still be accomplished with a simple one-handed operation thus leaving the user&#39;s other hand free for other tasks. 
     With reference to  FIGS. 19A through 19C , yet additional embodiments for reducing or preventing incidents of inadvertent depression of actuator button  64  and the premature retraction of needle assembly  16  are contemplated. As illustrated, in addition to one or more of the various components or features previously described, device  10 ′ further includes an annular sleeve or protective ring  130 . In some embodiments, sleeve  130  forms an outer band or barrel which slips over distal barrel  20  prior to affixing wing attachment  24  thereto. In other embodiments, sleeve  130  is an incomplete band or barrel that extends through approximately 270° around the circumference of distal barrel  20  and which can snap over distal barrel  20  during the assembly process, including after wing attachment  24  has already been installed. In various embodiments, the inside diameter of sleeve  130  is sized relative to the outside diameter of distal barrel  20  such that sleeve  130  snugly but rotatably fits around the circumference of distal barrel  20 . According to various alternative embodiments, sleeve  130  is comprised of plastic materials, such as polycarbonate, polypropylene, polyethylene, acrylic, polystyrene, ABS and/or other plastic materials, or combinations of plastic materials, having desirable properties, including sufficient flexibility and rigidity to operate as described herein. 
     According to some embodiments, sleeve  130  includes or defines an activation tab  132 , a safety cover  134 , and an access slot, cavity or opening  136 . Sleeve  130  is rotatably coupled to distal barrel  20  such that cover  134  covers, obscures, or is otherwise over button  64 . Cavity  136  is located adjacent one side or the other of button  64  while device  10 ′ is active. In some embodiments, activation tab  132  occupies a plane in common with wing attachment  24  while device  10 ′ is active. In this configuration, cover  134  prevents a user from inadvertently depressing button  64 . Nevertheless, sleeve  130  does not obstruct or otherwise interfere with the use of device  10 ′ as described in detail previously. As shown in  FIG. 19B , in various embodiments, prior to deactivating device  10 ′, cavity  136  extends around the circumference of sleeve  130  from approximately adjacent one side or the other of button  64  through approximately 180°. In other embodiments, cavity or slot  136  comprises a window sufficiently wide to allow a user to access button  64  therethrough and thus extends circumferentially through a width approximately consistent with the width of an average user&#39;s fingertip. 
     According to some embodiments, as illustrated in  FIG. 19C , in order to deactivate device  10 ′, i.e., to release the energy stored in spring  18  in order to fully retract needle assembly  16 , a user must first rotate sleeve  130  via tab  132  in a direction  138  until button  64  is exposed through opening  136 . In some embodiments, a user continues to rotate sleeve  130  until button  64  is sufficiently exposed to allow the user to depress button  64  with his or her fingertip. In other embodiments, a user rotates sleeve  130  through approximately 180°, or until tab  132  reoccupies the plane defined by wing attachment  24  on the opposite side of distal barrel  20  from where tab  132  was initially oriented. For example, in some embodiments, tab  132  is initially adjacent side  112  of wing attachment  24  and, following rotation of sleeve  130 , tab  132  is adjacent side  114  of wing attachment  24 . Following a sufficient rotation of sleeve  130  as described above, the user can then depress cantilevered actuator arm  60  via button  64  and deactivate device  10 ′ as described previously. 
     According to some embodiments, sleeve  130  is retained against rotation in a direction opposite to the direction in which it is intended that sleeve  130  be rotated to expose button  64 . In this way, button  64  is prevented from inadvertent activation via coming in contact with the inside diameter of sleeve  130  due to a reverse rotation thereof. For example, in some embodiments, cover  134  is sized and configured to cover button  64  as well as the apexes of distal major diameter portion  84  and proximal major diameter portion  86  of distal barrel  20 . Sleeve  130  is prevented from inadvertent rotation in the wrong direction as the inside diameter of sleeve  130  is obstructed by the apexes of distal major diameter portion  84  and proximal major diameter portion  86  of distal barrel  20 . Cover  134  and slot  136 , on the other hand, are configured to accommodate the apexes of distal major diameter portion  84  and proximal major diameter portion  86  of distal barrel  20  when sleeve  130  is rotated in the intended direction. Thus, button  64  is prevented from inadvertent activation and is protected by the interaction of cover  134  and the distal and proximal major diameter portions  84  and  86  of distal barrel  20 . 
     According to various embodiments, the methods and structures disclosed herein enable a user to safely handle devices  10  and/or  10 ′ during removal from associated packaging, insertion into a patient&#39;s vasculature, use of such devices, and securement of such devices until an associated medical procedure is complete without inadvertently and prematurely deactivating devices  10  and/or  10 ′. In some embodiments, while two steps are required to deactivate the device, deactivation can be performed in a single-handed operation. Upon deactivation, devices  10  and/or  10 ′ provide protection from both needle stick injuries as well as containing residual blood and preventing blood drips or leaks via septum  68   
     The present invention may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.