Patent Publication Number: US-9421352-B2

Title: Infusion apparatuses and methods of use

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. patent application Ser. No. 13/438,586, filed Apr. 3, 2012, now U.S. Pat. No. 8,641,676, which is a division of U.S. patent application Ser. No. 11/380,621, filed Apr. 27, 2006, now U.S. Pat. No. 8,147,455, which claims the benefit of U.S. Patent Application No. 60/675,309, filed Apr. 27, 2005, each of which is incorporated in its entirety by reference into this application. 
    
    
     BACKGROUND 
     Access to a patient&#39;s vascular system may be established by a variety of temporary or permanently implanted devices. For example, temporary access to a patient&#39;s vascular system may be accomplished by the direct percutaneous introduction of a needle into the patient&#39;s blood vessel. While such a temporary and direct approach may be relatively simple and suitable for applications that are limited in frequency or duration, such as intravenous feeding and/or intravenous drug delivery, this temporary approach may not be suitable for procedures that are frequently repeated or that require vascular access for relatively long time periods of time, such as hemodialysis or other similar extracorporeal procedures. 
     Accordingly, a variety of implantable devices have been proposed to provide a convenient method for repeatedly introducing fluids, such as medicaments, into the vasculature of a patient. Typically, such implantable device comprise a housing that encloses an internal fluid chamber or cavity. An access aperture defined through the housing and sealed by a penetrable septum provides access to the internal fluid chamber, which is typically in fluid communication with an implanted catheter attached to a patient&#39;s vasculature. 
     Quantities of fluid, such as medication, blood, or the like, may be introduced into, or withdrawn from, a patient&#39;s vasculature using conventional implantable device by: 1) penetrating the septum of the implanted device using a percutaneously inserted needle; 2) positioning at least the tip of the needle within the internal fluid reservoir or cavity enclosed in the device housing; and 3) discharging fluids through the needle into the internal fluid cavity. The discharged fluids may then be directed through the distal end of the implanted catheter connected to the implanted device to an entry point into the venous system of the body of the patient. Blood may also be aspirated through the implanted device in a similar manner. 
     SUMMARY 
     In at least one embodiment, an infusion apparatus for providing access to an implanted device, such as an access port or a pump (e.g., a so-called pain pump), may comprise an insertion assembly, a hub comprising a sealable path configured to receive at least a portion of the insertion assembly, a flexible catheter attached to the hub and configured to receive at least a portion of the insertion assembly, and an extension tube attached to the hub. In certain embodiments, the hub may comprise a plurality of wing structures and may be configured to provide fluid communication between the flexible catheter and the extension tube. The hub may also comprise a manifold element structured to provide fluid communication between the flexible catheter and the extension tube. In addition, the sealable path may comprise a septum configured to seal the sealable path upon removal of the insertion assembly from the flexible catheter. The extension tube may either be permanently or removably attached to the hub. 
     According to at least one embodiment, the insertion assembly may comprise a slender pointed element and both the sealable path and the flexible catheter may be configured to receive at least a portion of the slender pointed element. Similarly, the extension tube may be configured to receive at least a portion of the slender pointed element. The flexible catheter may also comprise at least one aperture defined proximate a distal end of the flexible catheter and the slender pointed element may comprise at least one longitudinally extending indentation defined along the slender pointed element. In at least one embodiment, a cross-sectional area defined between an exterior surface of the slender pointed element and an interior surface of the flexible catheter may approximate the cross-sectional area of a hollow needle gauge. In addition, the flexible catheter may comprise at least one aperture defined proximate a distal end of the flexible catheter and the slender pointed element may be at least partially hollow and comprise at least one aperture defined within the slender pointed element for communicating fluid with the at least one aperture defined in the flexible catheter. 
     In certain embodiments, at least a portion of the slender pointed element may be retractable into a recess defined in the insertion assembly. In addition, the flexible catheter may have a length that exceeds an anticipated insertion length such that, when the flexible catheter is fully inserted into a device implanted within a patient, a bendable portion of the flexible catheter may extend from a skin surface of the patient. The infusion apparatus may also comprise a receiving enclosure positioned substantially parallel to a skin surface of a patient and configured to receive at least a portion of the hub. Further, the infusion apparatus may comprise a safety clip configured to: 1) retain a pointed end of the slender pointed element within the safety clip when the slender pointed element is removed from the hub; and 2) allow the pointed end of the slender pointed element to pass through the safety clip when the slender pointed element is inserted into the hub. The infusion apparatus may also comprise a reinforcing member, which may be coiled, at least partially imbedded within the flexible catheter. 
     In at least one embodiment, an infusion device for use with an implanted device may comprise a slender pointed element comprising a pointed end, a flexible catheter comprising a sealable path configured to receive at least a portion of the slender pointed element, and an extension tube in fluid communication with the flexible catheter. In certain embodiments, the sealable path may be structured to seal upon removal of the slender pointed element from the flexible catheter. 
     In addition, an infusion apparatus for accessing an implanted device may comprise an insertion assembly comprising a slender pointed element, a hub comprising a sealable path configured to receive at least a portion of the slender pointed element, a flexible catheter attached to the hub and configured to receive at least a portion of the slender pointed element, and an extension tube attached to the hub. In certain embodiments, the hub may comprise a manifold element structured to provide fluid communication between the flexible catheter and the extension tube, and a septum configured to seal the sealable path upon removal of the slender pointed element from the flexible catheter. 
     In at least one embodiment, a method of providing a fluid communication path to an implanted device may comprise positioning at least a portion of a slender pointed element within a flexible catheter, penetrating a septum of an implanted device with the slender pointed element positioned within the flexible catheter, positioning at least a portion of the flexible catheter within the implanted device, removing the slender pointed element from the flexible catheter, and retaining at least a portion of the flexible catheter within the implanted device. The method may also comprise providing a hub in fluid communication with the flexible catheter, and removably attaching an extension tube to the hub to provide fluid communication between the flexible catheter and the extension tube. In addition, the method may comprise sealing a sealable path defined in the hub upon removal of the slender pointed element from the flexible catheter. 
     In certain embodiments, this exemplary method may further comprise positioning at least a portion of the slender pointed element within the extension tube. In addition, this method may further comprise retracting at least a portion of the slender pointed element into the flexible catheter. The method may also further comprise providing a safety clip proximate a pointed end of the slender pointed element, and retaining the pointed end of the slender pointed element within the safety clip upon removal of the slender pointed element from the flexible catheter. 
     Features from any of the above-mentioned embodiments may be used in combination with one another in accordance with the general principles described herein. These and other embodiments, features and advantages will be more fully understood upon reading the following detailed description in conjunction with the accompanying drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate a number of exemplary embodiments and are a part of the specification. Together with the following description, these drawings demonstrate and explain various principles of the instant disclosure. 
         FIG. 1  is a schematic cross-sectional side view of an exemplary device implanted within a patient; 
         FIG. 2  is an exploded perspective view of an exemplary infusion system according to at least one embodiment; 
         FIG. 3A  is a perspective view of an exemplary insertion assembly according to at least one embodiment; 
         FIG. 3B  is a cross-sectional side view of the exemplary insertion assembly illustrated in  FIG. 3A ; 
         FIG. 4A  is a perspective view of an exemplary hub according to at least one embodiment; 
         FIG. 4B  is a cross-sectional side view of the exemplary hub illustrated in  FIG. 4A ; 
         FIG. 4C  is a cross-sectional side view of an exemplary flexible catheter and extension tube attached to the exemplary hub illustrated in  FIG. 4A ; 
         FIG. 5  is a perspective view of an extension tube, clamp device, and tube connector according to at least one embodiment; 
         FIG. 6  is a perspective view of a safety clip according to at least one embodiment; 
         FIG. 7  is a partial perspective view and partial cross-sectional side view of a flexible catheter according to at least one embodiment; 
         FIG. 8A  is an assembled perspective view of the exemplary infusion system illustrated in  FIG. 1 ; 
         FIG. 8B  is a partial cross-sectional side view of the exemplary infusion system illustrated in  FIG. 8A ; 
         FIG. 8C  is a partial perspective view of a slender pointed element according to at least one embodiment; 
         FIG. 8D  is an end view of the exemplary slender pointed element illustrated in  FIG. 8C ; 
         FIG. 8E  is a cross-sectional side view of the exemplary slender pointed element illustrated in  FIG. 8C  positioned within an exemplary flexible catheter; 
         FIG. 9A  illustrates various exemplary geometrical attributes of a longitudinally extending indentation defined along a slender pointed element according to at least one embodiment; 
         FIG. 9B  is a schematic end view of a slender pointed element according to at least one embodiment; 
         FIG. 9C  is a schematic end view of a slender pointed element according to an additional embodiment; 
         FIGS. 10A-10E  are perspective views of various exemplary embodiments of a flexible catheter; 
         FIG. 11A  is a perspective view of an exemplary embodiment of a slender pointed element; 
         FIG. 11B  is a cross-sectional end view of the exemplary slender pointed element illustrated in  FIG. 11A , taken along the line  11 B- 11 B; 
         FIG. 11C  is a perspective view of an additional embodiment of a slender pointed element; 
         FIG. 11D  is a cross-sectional end view of the exemplary slender pointed element illustrated in  FIG. 11C , taken along the line  11 D- 11 D; 
         FIG. 11E  is a perspective view of an additional embodiment of a slender pointed element; 
         FIG. 11F  is a cross-sectional end view of the exemplary slender pointed element illustrated in  FIG. 11E , taken along the line  11 F- 11 F; 
         FIG. 11G  is a perspective view of an additional embodiment of a slender pointed element; 
         FIG. 11H  is a cross-sectional end view of the exemplary slender pointed element illustrated in  FIG. 11G , taken along the line  11 H- 11 H; 
         FIG. 12A  is a cross-sectional side view of a portion of a slender pointed element and a flexible catheter according to at least one embodiment; 
         FIG. 12B  is a schematic perspective view of the exemplary slender pointed element and flexible catheter illustrated in  FIG. 12A ; 
         FIG. 13  is a partial cross-sectional side view of an additional embodiment of a flexible catheter; 
         FIG. 14A  is a simplified cross-sectional side view of an additional embodiment of a hub; 
         FIG. 14B  is a simplified cross-sectional side view of an exemplary insertion assembly positioned within the exemplary hub illustrated in  FIG. 14A ; 
         FIG. 15  is a simplified cross-sectional side view of an additional embodiment of an infusion system; 
         FIG. 16  is a simplified cross-sectional side view of an additional embodiment of a hub; 
         FIG. 17A  is a perspective view of an exemplary embodiment of a receiving enclosure for use with an infusion system; 
         FIG. 17B  is a perspective view of an exemplary infusion system positioned within the exemplary receiving enclosure illustrated in  FIG. 17A ; 
         FIG. 18A  is a perspective view of an additional embodiment of an infusion system; 
         FIG. 18B  is a cross-sectional side view of the exemplary infusion system illustrated in  FIG. 18A ; 
         FIG. 19A  is a perspective view of an additional embodiment of an infusion system; 
         FIG. 19B  is a cross-sectional side view of the exemplary infusion system illustrated in  FIG. 19A ; 
         FIG. 19C  is a cross-sectional side view of an additional embodiment of an infusion system; 
         FIG. 20A  is a perspective view of an additional embodiment of an infusion system; 
         FIG. 20B  is a cross-sectional side view of the exemplary infusion system illustrated in  FIG. 20A ; 
         FIG. 21A  is a perspective view of an additional embodiment of an infusion system; 
         FIG. 21B  is a perspective view of a portion of the exemplary infusion system illustrated in  FIG. 21A ; 
         FIG. 21C  is a perspective view of a portion of the exemplary infusion system illustrated in  FIG. 21A ; 
         FIG. 21D  is a perspective view of a portion of the exemplary infusion system illustrated in  FIG. 21A ; 
         FIG. 21E  is a cross-sectional side view of the exemplary infusion system illustrated in  FIG. 21A ; 
         FIG. 22A  is a cross-sectional side view of an exemplary safety clip housing in a first position; 
         FIG. 22B  is a cross-sectional side view of an exemplary safety clip housing in a second position; 
         FIG. 23A  is a perspective view of an additional embodiment of a safety clip in a first position; 
         FIG. 23B  is a perspective view of an additional embodiment of a safety clip in a second position; 
         FIGS. 24A-24D  are perspective and cross-sectional side views of an additional embodiment of a safety clip; 
         FIG. 25A  is a cross-sectional side view of an exemplary safety clip housing removably attached to a hub; 
         FIG. 25B  is a cross-sectional side view of an exemplary safety clip housing adhered to a hub; 
         FIGS. 26A-26C  are perspective views of an infusion system according to an additional embodiment; 
         FIGS. 27A and 27B  are perspective views of additional embodiments of an infusion system; 
         FIG. 28A  is a perspective view of an infusion system according to an additional embodiment; 
         FIG. 28B  is a cross-sectional side view of the exemplary infusion system illustrated in  FIG. 28A ; 
         FIG. 29  is a cross-sectional side view of an exemplary slender pointed element comprising a scored pointed end; 
         FIGS. 30A-30B  are perspective views of an infusion system according to an additional embodiment; 
         FIGS. 31A-31B  are perspective views of an infusion system according to an additional embodiment; 
         FIGS. 31C-31D  are cross-sectional side views of the exemplary infusion system illustrated in  FIGS. 31A-31B ; 
         FIGS. 32A-32B  are perspective views of an infusion system according to an additional embodiment; 
         FIGS. 32C-32D  are cross-sectional side views of the exemplary infusion system illustrated in  FIGS. 32A-32B ; 
         FIGS. 33A-33C  are perspective views of an insertion assembly according to an additional embodiment; and 
         FIGS. 34A-34C  are perspective views of an exemplary hub for an infusion system according to an additional embodiment; 
     
    
    
     Throughout the drawings, identical reference characters and descriptions indicate similar, but not necessarily identical, elements. While the exemplary embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, one of skill in the art will understand that the exemplary embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, the instant disclosure covers all modifications, equivalents, and alternatives falling within the scope defined by the appended claims. 
     DETAILED DESCRIPTION 
     Generally speaking, one or more of the exemplary apparatuses, devices, and/or methods described and illustrated herein may be employed for percutaneously accessing a device, such as an access port or pump (e.g., a so-called pain pump), implanted within a patient, such as exemplary access port  320  illustrated in  FIG. 1 . Access port  320  generally represents any device capable of being implanted within a patient, such as an access port, pump, or other device known to those of skill in the art. As illustrated in  FIG. 1 , exemplary access port  320  may comprise a housing  322  and a septum  326  defining a chamber  324 . A catheter  332  in fluid communication with the vasculature  316  of a patient may be attached to housing  322  to provide a fluid communication path between exemplary access port  320  and vasculature  316 . In at least one embodiment, access port  320  is implanted within the interior of a patient; namely, below skin surface  310  and within subcutaneous zone  312 . In certain embodiments, access port  320  may be implanted beneath skin surface  310  by a distance in the range from about 3 mm to about 20 mm, and/or from about 5 mm to about 15 mm. Housing  322  of access port  320  may then be secured to deep fascia tissue  314  by a plurality of sutures  328 . Catheter  332  may be surgically implanted, indwelling, or secured within the patient in any other manner known to those of skill in the art. 
       FIG. 2  is an exploded perspective view of an exemplary infusion system  10  for accessing an implanted device, such as exemplary access port  320  illustrated in  FIG. 1 . As seen in  FIG. 2 , exemplary infusion system  10  may comprise an insertion assembly  20 , a safety clip  30 , a hub  40 , a flexible catheter  90 , an extension tube  70 , a clamp device  60 , and a tube connector  80 . Generally, the various components of infusion system  10  may comprise any number or combination of suitable materials known to those of skill in the art, such as metals, plastics, or polymers. For example, the various components of infusion system  10  may comprise polytetrafluoroethylene (PTFE), polypropylene, silicone, stainless steel (e.g., AISI 304 stainless steel), fluorinatedethylenepropylene (FEP), perfluoroalkoxy (PFA), ethylenetetrafluoroethylene (ETFE), polyetheretherketone (PEEK®), polyurethane (including thermoplastic polyurethanes, such as ISOPLAST®, TECOFLEX®, TECOTHANE®, CARBOTHANE®, TECOPLAST®, or TECOPHILIC®-type polyurethanes), or any number of combinations thereof. 
       FIGS. 3A and 3B  are perspective and cross-sectional side views, respectively, of an exemplary insertion assembly  20 . As seen in these figures, exemplary insertion assembly  20  may comprise a slender pointed element  22  attached to a base member  28 . Slender pointed element  22  generally represents any structure capable of penetrating the septum of an implanted device, such as septum  326  of access port  320 . For example, slender pointed element  22  may represent a trocar, a coring or non-coring needle, a cannula, or any other suitable hollow or solid structure. Slender pointed element  22  may be entirely solid, entirely hollow, or may include a solid pointed end  25  and an at least partially hollow body, as discussed in greater detail below. In addition, slender pointed element  22  may comprise any conventional needle, trocar, or cannula material, such as stainless steel (e.g., AISI 304 stainless steel), plastic, or the like. 
     As seen in  FIGS. 3A and 3B , a recess  24  may be defined within base member  28 . In at least one embodiment, recess  24  is configured to receive one or more structural elements, such as, for example, safety clip  30 . Base member  28  may also comprise a coupling structure  26 , which generally represents any structure (e.g., a protrusion) or recess capable of coupling base member  28  to an additional element, such as hub  40 . In at least one embodiment, coupling structure  26  couples to a complimentary coupling recess  44  defined in hub  40  (illustrated in  FIGS. 4A-4C ). In certain embodiments, base member  28  may be injection molded or otherwise formed about slender pointed element  22  so as to capture a portion of slender pointed element  22  within the base member  28 , as best seen in  FIG. 3B . 
       FIGS. 4A and 4B  are perspective and cross-sectional views, respectively, of an exemplary hub  40  according to at least one embodiment. As seen in these figures, exemplary hub  40  may comprise a plurality of wing structures  41 A and  41 B attached to a hub body  50 . In at least one embodiment, wing structures  41 A and  41 B are configured to affix exemplary hub  40  to the skin of a patient. For example, wing structures  41 A and  41 B may be taped, adhesively affixed, or otherwise attached to the surface of a patient&#39;s skin, such as skin surface  310  in  FIG. 1 . Generally speaking, wing structures  41 A and  41 B may be formed in any number of shapes and sizes, including those illustrated in  FIGS. 20A-20B, 22A-22B, 25A-25B, 26A-26C, 27A-27B, 30A-30B, 31A-31B, and 33A-33D . As detailed above, exemplary hub  40  and wing structures  41 A and  41 B may comprise any number or combination of suitable materials known to those of skill in the art, including, for example, TECOFLEX® 85A-B20. 
     As illustrated in  FIG. 4B , in certain embodiments a coupling recess  44  may be defined within hub body  50  and structured to receive the complimentary coupling structure  26  provided on base member  28 . Similarly, a recess  42  may be defined in hub body  50  and configured to receive both a slender pointed element (such as slender pointed element  22 ) and a safety clip (such as safety clip  30 ), as discussed in greater detail below. A retaining lip  43  may also be provided within recess  42  for retaining a safety clip, such as safety clip  30 , within recess  42 . 
     In at least one embodiment, a penetrable septum  48  may be provided in recess  42  and positioned above a manifold element  61  defined in exemplary hub body  50 . A cap element  46  may also be positioned above septum  48  and configured to retain septum  48  within recess  42 . As illustrated in  FIG. 4B , manifold element  61  may define a plenum  49  in communication with a plurality of openings (e.g., openings  51 ,  53 , and  59 ) sealed by at least one septum (e.g., septum  48 ). An aperture  47  may also be defined within cap element  46  generally opposite opening  51  of plenum  49 . In certain embodiments, septum  48  may comprise any suitable material capable of suitably sealing opening  51  of plenum  49 ; including, for example, medical-grade polymers (such as silicone) and monomers (such as Ethylene Propylene Diene Monomer (“EPDM”), or other suitable materials. 
     In at least one embodiment, exemplary hub  40  may be structured to receive at least a portion of insertion assembly  20 . For example, hub  40  may be configured to receive at least a portion of a slender pointed element, such as slender pointed element  22 , within a sealable path defined within hub  40 . In at least one embodiment, such a sealable path may be defined by, for example, recess  42 , aperture  47 , septum  48 , opening  51 , and opening  53 . In this example, slender pointed element  22  may be inserted into aperture  47  in cap element  46  and passed through septum  48  and openings  51  and  53 . In certain embodiments, penetrable septum  48  may be configured to seal opening  51  of plenum  49  upon removal of slender pointed element  22  from hub  40 . Accordingly, slender pointed element  22  of insertion assembly  20  may be inserted through and removed from septum  48  without compromising the seal provided across opening  51 . Further, the presence of cap element  46  may allow for so-called power or high-pressure injection to occur via manifold element  61 , wherein pressures within manifold element  61  may reach about 400 psi or higher. 
     In certain embodiments, manifold element  61  may be configured to provide fluid communication between opening  53  and opening  59 . More particularly, as illustrated in  FIG. 4C , manifold element  61  may comprise a port extension  55  configured to receive at least a portion of an extension tube, such as extension tube  70 , and a port extension  65  configured to receive at least a portion of a flexible catheter, such as flexible catheter  90 . In at least one embodiment, an inner surface area  52  within port extension  55  of manifold element  61  may support the portion of extension tube  70  positioned within manifold element  61 , such that relatively high pressures may be experienced without failure of extension tube  70 . Similarly, an inner surface area  62  within port extension  65  of manifold element  61  may support the portion of flexible catheter  90  positioned within manifold element  61 , such that relatively high pressures may be experienced without failure of flexible catheter  90 . 
     As illustrated in  FIG. 4B , hub  40  may also comprise a channel defined by a surface  57  and extending from opening  54  to opening  59  of manifold element  61 . Such a channel may be sized and configured to receive at least a portion of an extension tube, such as extension tube  70 , and may be formed prior to positioning of an extension tube within manifold element  61  or, in another embodiment, fabricated by forming (e.g., injection molding, curing, etc.) hub body  50  around extension tube  70 . In an additional embodiment, hub body  50  of hub  40  may simply terminate substantially at opening  59  of manifold element  61 . 
     In certain embodiments, flexible catheter  90  may be affixed to inner surface  62  of port extension  65 . Similarly, extension tube  70  may be affixed to surface  52  of port extension  55 . In one example, extension tube  70  and flexible catheter  90  may be chemically bonded to inner surfaces  52  and  62  of manifold element  61 , respectively. In another example, an adhesive may be used to affix extension tube  70  and flexible catheter  90  to inner surfaces  52  and  62  of manifold element  61 , respectively. Optionally, hub body  50  may be injection molded, cured, or otherwise formed around manifold element  61  (and, optionally septum  48 , cap element  46 , or both) and at least a portion of extension tube  70 , as shown in  FIG. 4C . Hub body  50  may also be formed around at least a portion of flexible catheter  90  in a similar manner. In addition, as discussed in greater detail below in connection with  FIGS. 26A-26C and 27A-27B , extension tube  70  and/or flexible catheter  90  may be configured to be removably attached to manifold element  61  and/or hub  40 . 
       FIG. 5  is a perspective view of an extension tube  70 , a clamp device  60 , and a tube connector  80  according to at least one embodiment. Extension tube  70  generally represents any form of medical tubing known to those of skill in the art. Similarly, clamp device  60  generally represents any form of tubing clamp known to those of skill in the art; including, for example, a slide clamp, a so-called pinch clamp, or the like. In addition, tube connector  80  generally represents any form of tubing connection or mechanism known to those of skill in the art; including, for example, a so-called Luer-type fitting or connector. 
       FIG. 6  is a perspective view of a safety clip  30  according to at least one embodiment. Safety clip  30  generally represents any self-actuating device for capturing a pointed end of a slender pointed element, such as pointed end  25  of slender pointed element  22 . In the exemplary embodiment illustrated in  FIG. 6 , safety clip  30  may comprise a plurality of legs  32 A and  32 B having curved end regions  36 A and  36 B, respectively, and a hole  34  sized for receiving a slender pointed element, such as slender pointed element  22 . Safety clip  30  may also be sized to fit within the retaining lips  43  provided in recess  42  of hub  40 . 
     In at least one embodiment, safety clip  30  is attached to slender pointed element  22  by passing the pointed end  25  of slender pointed element  22  through hole  34  of safety clip  30 , past legs  32 A and  32 B, and past curved end regions  36 A and  36 B. Once pointed end  25  of slender pointed element  22  has passed curved end regions  36 A and  36 B, legs  32 A and  32 B may clamp around slender pointed element  22  to removably affix the safety clip to slender pointed element  22 . As slender pointed element  22 , together with safety clip  30 , is inserted into recess  42  defined in hub body  50 , slender pointed element  22  may continue through safety clip  30  and into the sealable path defined in hub body  50 . In addition, legs  32 A and  32 B of safety clip  30  may be biased such that, upon removal of slender pointed element  22  from the sealable path defined in hub body  50 , curved end regions  36 A and  36 B may close around the pointed end  25  of slender pointed element  22  to retain this pointed end  25  within the body of safety clip  30 . Such a safety clip  30  may prevent inadvertent insertion of slender pointed element  22  into another person, such as a medical practitioner utilizing infusion system  10 . 
       FIG. 7  is a partial perspective view and partial cross-sectional side view of a flexible catheter  90  according to at least one embodiment. As seen in this figure, flexible catheter  90  may comprise an elongated lumen  94  extending between a first opening  91  and a second opening  93 . Flexible catheter  90  may also comprise, proximate to second opening  93 , a tapered transition region  95 . As shown in  FIG. 7 , tapered transition region  95  may comprise a first tapered sub-region  96  and a second tapered sub-region  98 . In certain embodiments, second tapered sub-region  98  is tapered more sharply than first tapered sub-region  96 . Optionally, tapered transition region  95  may comprise a single taper and at least one arcuate surface. Exemplary flexible catheter  90  may also comprise at least one aperture  92  defined within flexible catheter  90  proximate second opening  93 . In at least one embodiment, aperture  92  is defined through the tubular body of flexible catheter  90  to provide a fluid communication path between first opening  91  and aperture  92  through lumen  94 . As detailed above, flexible catheter  90  may comprise any number or combination of suitable materials known to those of skill in the art, including, for example, TECOTHANE® (e.g., TECOTHANE® TT1055 D). 
       FIGS. 8A and 8B  are assembled perspective and cross-sectional views, respectively, of the exemplary infusion system  10  illustrated in  FIG. 1 . As seen in these figures, when insertion assembly  20  is coupled to exemplary hub  40  via coupling structure  26  and coupling recess  44 , at least a portion of slender pointed element  22  may extend through safety clip  30 , through aperture  47  of cap element  46 , and into flexible catheter  90 . In at least one embodiment, the length of slender pointed element  22  is chosen such that, when insertion assembly  20  is coupled to the hub body  50  of exemplary hub  40 , the pointed end  25  of slender pointed element  22  extends beyond the second opening  93  of flexible catheter  90 . Accordingly, when so assembled, slender pointed element  22  and flexible catheter  90  provide, in combination, a rigid, pointed structure capable of penetrating the septum of an implanted device, such as septum  326  of the exemplary access port  320  illustrated in  FIG. 1 . 
       FIGS. 8C and 8D  are perspective and end views, respectively, of a slender pointed element  22  according to at least one embodiment. As seen in these figures, slender pointed element  22  may be structured to enable fluid communication within flexible catheter  90 . More particularly, slender pointed element  22  may be sized to allow for clearance between an exterior surface of slender pointed element  22  and an interior surface (i.e., lumen  94 ) of flexible catheter  90 . For example, in certain embodiments slender pointed element  22  may comprise at least one longitudinally extending indentation  27  defined along at least a portion of the length of slender pointed element  22 . In particular, as shown in  FIGS. 8C and 8D , slender pointed element  22  may comprise a plurality of longitudinally extending indentations  27  defined along a longitudinal axis  11  of slender pointed element  22 . In addition, as seen in the end view of  FIG. 8D , longitudinally extending indentations  27  may be defined along the generally circular slender pointed element  22  so as to form a substantially triangular cross section. 
       FIG. 8E  is a cross-sectional side view of a slender pointed element  22  positioned within an exemplary flexible catheter  90 . As shown in this figure, slender pointed element  22  may be configured such that its pointed end  25  extends from second opening  93  of flexible catheter  90 . In addition, as illustrated in  FIG. 8E , slender pointed element  22  and flexible catheter  90  may be sized such that, when slender pointed element  22  is fully inserted within flexible catheter  90 , the exterior surface of slender pointed element  22  snugly fits within and contacts the interior surface of flexible catheter within region  101 . In certain embodiments, longitudinally extending indentations  27  may be sized and positioned to provide a fluid communication path between apertures  92  and first opening  91  of flexible catheter  90 . In other words, longitudinally extending indentations  27  may provide a fluid communication path within an annulus  103  defined by the exterior surface of slender pointed element  22  and the interior surface (i.e., lumen  94 ) of flexible catheter  90 . 
       FIG. 9A  illustrates various exemplary geometrical attributes of a longitudinally extending indentation defined along a slender pointed element according to at least one embodiment. As seen in this figure, the cross-sectional area defined between an exterior surface of slender pointed element  22  and an interior surface of flexible catheter  90  (hereafter, “the total effective cross-sectional area of annulus  103 ”) may be sized so as to approximate the cross-sectional area of a selected hollow needle gauge. For example, the total effective cross-sectional area of annulus  103  may be defined by: 
                     A   =         R   2     ⁢       tan     -   1       ⁡     [         (       R   2     r     )     -   1       ]         -     r   ⁢         R   2     -     r   2               ,           (   1   )               
where, with reference to  FIG. 9A , R is the radius of the circle (i.e., an interior surface of cylindrical flexible catheter  90 ) and r is a perpendicular distance from the center of the circle to the outer circumference of the circle. In contrast, the area of a hollow, cylindrical needle may be defined by:
 
                     A   =       π   ⁡     (       I   ⁢           ⁢   D     2     )       2       ,           (   2   )               
where ID is the diameter of the lumen of the needle.
 
     Accordingly, in light of equations (1) and (2), longitudinally extending indentations  27  may be sized such that the total effective cross-sectional area of annulus  103  (represented by reference numeral Ac in  FIGS. 9B and 9C ) may approximate the cross-sectional area of a selected hollow needle gauge. For example, as illustrated in  FIG. 9B , the approximate cross-sectional area of a 22 gauge needle may be approximated by forming three chord-shaped longitudinally extending depressions  27  to a depth of 0.0047 inches within a cylindrical slender pointed element  22  having a diameter of 0.028 inches. Similarly, as illustrated in  FIG. 9C , the approximate cross-sectional area of a 25 gauge needle may be approximated by forming three chord-shaped longitudinally extending depressions  27  to a depth of 0.0024 inches within a cylindrical slender pointed element  22  having a diameter of 0.028 inches. 
       FIGS. 10A-10E  are perspective views of various exemplary embodiments of a flexible catheter  90 . As illustrated in these figures and as detailed above, one or more apertures  92  may be defined within flexible catheter  90  proximate a second opening  93 . More particularly, as illustrated in  FIGS. 10A-10D , one or more of apertures  92  may be generally circular, oval, or elongated in shape and may be formed within or proximate to tapered transition region  95 . In addition, as illustrated in  FIG. 10E , flexible catheter  90  may comprise a permeable region  97  defined proximate second opening  93 . In at least one embodiment, permeable region  97  is configured to allow fluids, such as blood, to pass therethrough. 
     As illustrated in  FIGS. 11A-11H , slender pointed element  22  may be formed in a variety of shapes and configurations. For example, slender pointed element  22  may be formed to have a substantially triangular cross-section (as illustrated in  FIG. 11B ), a substantially cross-shaped cross-section (as illustrated in  FIG. 11D ), a substantially star-shaped cross-section (as illustrated in  FIG. 11F ), and/or a substantially circular cross-section (as illustrated in  FIG. 11H ). The total effective cross-sectional area of an annulus  103  defined by the interior surface of a flexible catheter  90  and the exterior surface of slender pointed element  22  positioned within the flexible catheter may be varied by varying the cross-sectional shape and size of slender pointed element  22 . In other embodiments, flexible catheter  90  may be configured to allow fluid communication between an exterior surface of slender pointed element  22  and an interior surface of flexible catheter  90 . In a particular embodiment, there is no need to remove material from slender pointed element  22  to provide fluid communication between the interior surface of flexible catheter  90  and the exterior surface of slender pointed element  22 . 
       FIGS. 12A and 12B  are cross-sectional and perspective views, respectively, of an additional embodiment of a slender pointed element  22  positioned within an exemplary flexible catheter  90 . As illustrated in these figures, slender pointed element  22  may comprise a solid pointed end  25  and a lumen  105  defined within at least a portion of the body of slender pointed element  22 . In addition, a plurality of apertures  108  defined within slender pointed element  22  may provide fluid communication between one or more apertures  92  defined through flexible catheter  90  and lumen  105  of slender pointed element  22 . In at least one embodiment, fluid may flow through at least one aperture  92  defined through flexible catheter  90  and through a corresponding aperture  108  defined in slender pointed element  22 . In such a configuration, annulus  103  may be omitted, if desired. 
     In certain embodiments, apertures  108  may be defined such that, when insertion assembly  20  is coupled to hub  40 , apertures  108  are positioned proximate manifold element  61  of hub  40 . In this exemplary configuration, fluid may flow through apertures  92  and  108 , into lumen  105 , through an aperture  33  defined in slender pointed element  22  and a corresponding aperture  37  defined in flexible catheter  90 , through opening  53  of manifold element  61 , out of opening  49  of manifold element  49 , and into an extension tube, such as extension tube  70 . Such a configuration may be desirable for providing a simple and robust fluid communication path between extension tubing  70  and an internal fluid chamber of an implanted device, such as chamber  324  of exemplary access port  320 . 
       FIG. 13  is a partial cross-sectional side view of an additional embodiment of a flexible catheter  90 . As seen in this figure, flexible catheter  90  may further comprise a reinforcing member  102 . In at least one embodiment, reinforcing member  102  may be at least partially imbedded within flexible catheter  90 . Reinforcing member  102  may also comprise a coiled, stainless steel wire (formed of, for example, AISI 304 stainless steel) and may have a generally circular, generally oval, rectangular, triangular, or otherwise shaped cross-section. In certain embodiments, reinforcing member  102  may be coiled within flexible catheter  90  to extend in a substantially spiral or helical fashion. Reinforcing member  102  may also be structured for, among other reinforcing functions, resisting external radial forces applied to flexible catheter  90 , thereby helping to prevent the inward collapse of flexible catheter  90 . In addition, reinforcing member  102  may ameliorate kinking of flexible catheter  90 . Reinforcing member  102  may also be sized and positioned within flexible catheter  90  so as to avoid intersecting with apertures  92  defined in flexible catheter. In this exemplary embodiment, apertures  92  may be formed through flexible catheter  90  by drilling or punching out portions of flexible catheter  90 , or as otherwise known in the art. Optionally, apertures  92  may be defined through coiled reinforcing member  102  if necessary or desirable. 
     As will be appreciated by those of ordinary skill in the art, a number of additional insertion assembly embodiments and hub embodiments fall within the spirit and scope of the instant disclosure. For example, as illustrated in the cross-sectional side view of  FIG. 14A , hub  40  may be configured to have a substantially pear-shaped cross-section. In this exemplary embodiment, hub  40  may generally comprise a hub body  50 , a recess  42  configured to receive a safety clip, and a sleeve  120  positioned about a septum  48 . As shown in  FIG. 14A , a retaining lip  43  may be provided within recess  42  for retaining a safety clip, such as safety clip  30 , therein. An anchor element  126  may also be positioned within and securely affixed to hub body  50 . In certain embodiments, flexible catheter  90  may be affixed to anchor element  126  to effectively secure flexible catheter  90  within hub body  50 . 
     In the exemplary embodiment illustrated in  FIG. 14A , extension tube  70  may be affixed to and positioned at least partially within hub body  50 . A channel  122  may be defined within hub body  50  and structured to extend between the lumen of extension tube  70  and the lumen of flexible catheter  90  to provide a fluid communication path between extension tube  70  and flexible catheter  90 . Exemplary sleeve  120  may also be positioned about septum  48  and securely affixed to hub body  50 . In at least one embodiment, sleeve  120  compresses septum  48  to help seal the various perforations formed in septum  48  by slender pointed element  22 . 
       FIG. 14B  is a simplified cross-sectional side view of an exemplary insertion assembly  20  positioned within the exemplary hub  40  illustrated in  FIG. 14A . As seen in this figure, insertion assembly  20  generally comprises a slender pointed element  22  and a base member  28  configured in accordance with one or more of the exemplary embodiments described and/or illustrated herein. In certain embodiments, insertion assembly  20  may be coupled to hub  40  via a coupling structure  26 , a coupling recess  44 , and a retaining lip  43 . 
       FIG. 15  is a simplified cross-sectional side view of an additional embodiment of an infusion system  10  comprising an insertion assembly  20 , a hub  40 , a flexible catheter  90 , and an extension tube  70 . As with previous embodiments, hub  40  may comprise a recess  42 , a sleeve  120 , and a septum  48 . In certain embodiments, at least a portion of both extension tube  70  and flexible catheter  90  may extend within hub body  50 . In addition, as illustrated in  FIG. 15 , at least a portion of flexible catheter  90  may extend within extension tube  70 . In other words, extension tube  70  may be configured to receive and surround at least a portion of flexible catheter  90 . Accordingly, when insertion assembly  20  is fully inserted within and coupled to hub  40 , slender pointed element  22  may penetrate and pass through flexible catheter  90 , extension tube  70 , or both, as illustrated in  FIG. 15 . As with previous embodiments, sleeve  120  may compress septum  48  to aid in sealing septum  48  upon removal of slender pointed element  22  from flexible catheter  90  and/or extension tube  70 . In an optional embodiment, a single tubular element may extend through hub  40  and function as both flexible catheter  90  and extension tube  70 . 
     As will be appreciated by those of ordinary skill in the art, hub  40  may be formed in any number of shapes and sizes. For example, hub  40  may be substantially cylindrical in shape (as illustrated in  FIG. 16 ), substantially dome-shaped (as illustrated in  FIGS. 19A-19C ), substantially wing-shaped (as illustrated in  FIGS. 20A-20B and 21A-21E ), substantially rectangular or square-shaped (as illustrated in  FIGS. 22A-22B and 25A-25B ), substantially oblong or oval-shaped (as illustrated in  FIGS. 26A-26C, 27A-27B, and 33A-33C ), or formed in any other number of suitable shapes and sizes. As will be appreciated by those of skill in the art, the various possible shapes and configurations of hub  40  and insertion assembly  20  may provide various advantages, such as ease of handling by a user and/or compatibility with additional structures. 
       FIGS. 17A and 17B  are perspective views of an additional embodiment of an infusion system. As illustrated in these figures, this exemplary infusion system may comprise an insertion assembly  20 , a hub  40 , a flexible catheter  90 , an extension tube  70 , a clamp  60 , and a tube connector  80 . In at least one embodiment, the exemplary infusion system illustrated in these figures further comprises a pad member  150  comprising a receiving enclosure  152  configured to receive and at least partially enclose hub  40 . More particularly, receiving enclosure  152  may comprise a pair of opposing retaining walls  155  sized and configured to receive and at least partially enclose a hub, such as hub  40  in  FIG. 17B . Receiving enclosure  152  may also comprise a rounded channel  156  structured and sized to receive at least a portion of flexible catheter  90 . In certain embodiments, rounded channel  156  may aid in ameliorating kinking of extension tube  70  or flexible catheter  90  by preventing sharp bends of flexible catheter  90 . Pad member  150  may also comprise an access notch  158  for positioning pad member  150  about flexible catheter  90 . 
     In at least one embodiment, flexible catheter  90  may have a length that exceeds an anticipated insertion length such that, when flexible catheter  90  is fully inserted into a device (such as exemplary access port  320 ) implanted within a patient, a bendable portion  147  of flexible catheter  90  extends from a skin surface of the patient. More specifically, the length of flexible catheter  90  may be selected such that a portion  147  of the flexible catheter  90  extending outwardly from the skin surface of a patient (such as skin surface  310  illustrated in  FIG. 1 ) may be bent or curved. This exemplary configuration may provide an infusion system that facilitates favorable placement of a hub. For example, after insertion into a device implanted within a patient and upon removal of insertion assembly  20 , flexible catheter  90  may be bent so that hub  40  may lie against the surface of the skin or may be otherwise positioned as desired. In the exemplary embodiment illustrated in  FIGS. 17A-17B , flexible catheter  90  may be bent to allow hub  40  to be positioned within receiving enclosure  152 . Pad  150  may then placed on and/or affixed or taped to the skin surface of a patient. The exemplary infusion system illustrated in  FIG. 17B  thus represents a relatively low profile apparatus for accessing an implanted device. 
     As will be appreciated by those of skill in the art, pad member  150  may comprise a receiving enclosure that is configured to accept and retain a hub (of any geometry), an extension tube, a flexible catheter, or combinations thereof, without limitation. In addition, as illustrated in  FIGS. 18A and 18B , a sleeve member  160  may surround at least a portion of flexible catheter  90 . In particular, as illustrated in  FIGS. 18A and 18B , sleeve member  160  may be configured to surround the portion of flexible catheter  90  that extends between hub  40  and pad member  150 . In certain embodiments, sleeve member  160  may be folded or creased (e.g., with accordion-type folds) to permit the vertical movement of hub  40  relative to pad member  150 . As will be appreciated by those of skill in the art, sleeve member  160  may protect flexible catheter  90 , conceal blood traveling through flexible catheter  90  (if flexible catheter  90  is at least partially transparent), or ameliorate kinking of flexible catheter  90 . 
       FIGS. 19A and 19B  are perspective and cross-sectional side views, respectively, of an additional embodiment of an infusion system  10  comprising an insertion assembly  20 , a hub  40 , a flexible catheter  90 , an extension tube  70 , a clamp  60 , and a tube connector  80 . As illustrated in these figures, hub  40  may comprise a recess  42  defined within a hub body  50  and a sleeve  120  surrounding a septum  48  positioned within recess  42 . In at least one embodiment, fluid communication between extension tube  70  and flexible catheter  90  is provided through a channel  166  formed within hub body  50 . In certain embodiments, channel  166  may be formed after flexible catheter  90  and extension tube  70  have been affixed or molded within hub body  50 . For example, a machine tool, such as a drill bit or milling bit, may pass within extension tube  70 , through a portion of hub body  50 , and into flexible catheter  90  to form channel  166  and an aperture in flexible catheter  90 . In an additional embodiment, a displacement may be positioned within extension tube  70  and into a preformed aperture in flexible catheter  90 , and then hub body  50  may be formed or molded around the assembly. 
       FIG. 19C  is a cross-sectional side view of an additional embodiment of an infusion system. As illustrated in this figure, the vertical (i.e., along the axis of slender pointed element  22 ) height of hub  40  may be reduced by reducing the vertical height of recess  42  and safety clip  30 . As will be appreciated by those of skill in the art, the size and configuration of each component of each exemplary embodiment described and/or illustrated herein may be varied, modified, or otherwise selected, without limitation. 
       FIGS. 20A-20B  are perspective and cross-sectional side views, respectively, of an additional embodiment of an infusion system  10  comprising an insertion assembly  20 , a hub  40 , a flexible catheter  90 , an extension tube  70 , a clamp  60 , and a tube connector  80 . As with previous embodiments, hub  40  may generally comprise a hub body  50 , a manifold element  61 , and a septum  48  compressed by hub body  50  (thus eliminating the need for a sleeve, such as sleeve  120 ). Hub  40  may also comprise a plurality of wing structures  41 A and  41 B configured to affix hub  40  to the skin of a patient. In addition, hub  40  may comprise a coupling recess  44  configured to receive a complimentary coupling structure  26  provided on base member  28  of insertion assembly  20 . Hub  40  may also comprise a recess  42  having a retaining lip  43  for retaining at least a portion of a safety clip, such as safety clip  30 , within recess  42 . A channel  166  extending from extension tube  70  to an upper end of flexible catheter  90  may also be defined within hub body  50  for providing fluid communication between extension tube  70  and flexible catheter  90 . 
       FIGS. 21A-21E  are perspective and cross-sectional views of various exemplary components of an additional embodiment of an infusion system  10 . As seen in  FIG. 21A , exemplary infusion system  10  may comprise an insertion assembly  20 , a hub  40 , a flexible catheter  90 , an extension tube  70 , a clamp  60 , and a tube connector  80 . In at least one embodiment, infusion system  10  may also comprise a winged component  170  positioned between insertion assembly  20  and hub  40 . As shown in  FIG. 21C , winged component  170  may comprise a coupling recess  172  defined within a body  174 . A plurality of wing structures  41 A and  41 B may extend from body  174 , as shown in  FIG. 21C . In certain embodiments, coupling recess  172  may be configured to receive a complimentary coupling structure  26  provided on a base member  28  of insertion assembly  20 . Similarly, as illustrated in  FIG. 21D , hub  40  may comprise an opening  178  for accepting the body  174  of winged component  170 . Hub  40  may also comprise a recess  42  and wing-shaped depressions  177  for accepting wing structures  41 A and  41 B of winged component  170 . In general, winged component  170  may be affixed to hub  40  by any means known to those of skill in the art, including, for example, by adhering body  174  within opening  178  of hub  40  using an adhesive. 
       FIGS. 22A-22B  are cross-sectional side views of an exemplary safety clip housing  240 . Safety clip housing  240  generally represents any structure configured to at least partially enclose a safety clip of any shape or size; including, for example, the various safety clip embodiments described and/or illustrated herein. In the exemplary embodiment illustrated in  FIGS. 22A-22B , safety clip housing  240  may be configured to house a substantially rectangular safety clip  30 . As illustrated in these figures, safety clip housing  240  may comprise a hole  242  sized for receiving a slender pointed element, such as slender pointed element  22 . Safety clip housing  240  may also comprise a base member  244  sized to fit within a recess  42  defined in hub  40 , as illustrated in  FIG. 22B . 
       FIGS. 23A and 23B  are perspective views of an additional embodiment of a safety clip  30 . Safety clip  30  generally represents any self-actuating device for capturing a pointed end of a slender pointed element, such as pointed end  25  of slender pointed element  22  illustrated in  FIG. 3A . In the exemplary embodiment illustrated in  FIG. 23A , safety clip  30  may comprise a plurality of legs  32 A and  32 B having curved end regions  35 A and  35 B, respectively, and a hole  34  sized for receiving a slender pointed element, such as slender pointed element  22 . In at least one embodiment, safety clip  30  may be sized to fit within a recess defined in an insertion assembly, such as recess  24  defined in insertion assembly  20  illustrated in  FIG. 3B . Safety clip  30  may also be sized to fit within a recess defined in a hub of an infusion system, such as recess  42  of hub  40 , or sized to fit within a safety clip housing, such as safety clip housing  240 . 
     In at least one embodiment, safety clip  30  is attached to slender pointed element  22  by passing the pointed end  25  of slender pointed element  22  through hole  34  of safety clip  30 , past legs  32 A and  32 B, and past curved end regions  35 A and  35 B. Once pointed end  25  of slender pointed element  22  has passed curved end regions  35 A and  35 B, legs  32 A and  32 B may clamp around slender pointed element  22  to removably affix the safety clip to slender pointed element  22 . As slender pointed element  22 , together with safety clip  30 , is inserted into recess  42  defined in hub body  50 , slender pointed element  22  may continue through safety clip  30  and into a sealable path defined in a hub body, such as hub body  50 . In addition, legs  32 A and  32 B of safety clip  30  may be biased such that, upon removal of slender pointed element  22  from the sealable path defined in hub body  50 , curved end regions  35 A and  35 B may close around the pointed end  25  of slender pointed element  22  to retain the pointed end  25  within the body of safety clip  30 . Such a safety clip  30  may prevent inadvertent insertion of slender pointed element  22  into another person, such as a medical practitioner utilizing infusion system  10 . 
       FIGS. 24A-24D  are perspective and cross-sectional side views of an additional embodiment of a safety clip  30 . As seen in these figures, safety clip  30  may comprise a hole  34  sized for receiving a slender pointed element (such as slender pointed element  22 ), a first leg  32 A comprising an upper arm portion  35 A and a lower arm portion  39 A, and a second leg  32 B comprising an upper arm portion  35 B and a lower arm portion  39 B. In at least one embodiment, safety clip  30  may be sized to fit within a recess defined in an insertion assembly, such as recess  24  defined in insertion assembly  20  illustrated in  FIG. 3B . Safety clip  30  may also be sized to fit within a recess defined in a hub of an infusion system, such as recess  42  of hub  40 , or sized to fit within a safety clip housing, such as safety clip housing  240 . 
     In at least one embodiment, upper arm portions  35 A and  35 B and lower arm portions  39 A and  39 B of safety clip  30  may be configured to retain the pointed end  25  of slender pointed element  22  within the body of safety clip  30 . For example, legs  32 A and  32 B of safety clip  30  may be biased such that, upon removal of slender pointed element  22  from hub body  50 , lower arm portions  39 A and  39 B may close around the pointed end  25  of slender pointed element  22  to retain the pointed end  25  within the body of safety clip  30 . In addition, upper arm portions  35 A and  35 B may be configured to prevent a protrusion  45  provided on slender pointed element  22  from passing upwards through hole  34 . Similarly, lower arm portions  39 A and  39 B may be configured to allow the protrusion  45  provided on slender element  22  to enter the body of safety clip  30 , but to prevent the protrusion  45  from passing downwards past lower arm portions  39 A and  39 B. Such a safety clip  30  may prevent inadvertent insertion of slender pointed element  22  into another person, such as a medical practitioner utilizing infusion system  10 . 
     As detailed above, one or more of the exemplary safety clip embodiments described and/or illustrated herein may be sized so as to fit within a safety clip housing, such as safety clip housing  240  illustrated in  FIGS. 22A-22B . As will be appreciated by those of skill in the art, such a safety clip housing may be attached or affixed to a slender pointed element, to a hub, or both, in any number of ways. For example, as illustrated in the schematic cross-sectional side view of  FIG. 25A , a safety clip housing  240  may be configured to be removably attachable to a portion of a hub  40 . More specifically, safety clip housing  240  may comprise a base member  244  configured to snap-fit over a plurality of complimentary protrusions  250  provided on hub  40 . Optionally, as illustrated in  FIG. 25B , base member  244  of safety clip housing  240  may be positioned and permanently adhered within a recess  42  provided in hub  40 . 
       FIGS. 26A-26C  are perspective views of an additional embodiment of an infusion system comprising an insertion assembly  20 , a hub  40 , a flexible catheter  90 , an extension tube  70 , and a tube connector  80 . In at least one embodiment, a removable member  180  in fluid communication with extension tube  70  may be configured to be removably attachable to a hub body  50  of hub  40 . For example, hub body  50  may comprise one or more coupling recesses  192  configured to receive complimentary coupling structures  182  provided on removable member  180 . Accordingly, removable member  180  may be coupled to hub body  50  by positioning coupling structures  182  within complimentary coupling recesses  192 . In certain embodiments, removable member  180  may also comprise a pointed tubular element  184  in fluid communication with extension tube  70 . Generally speaking, pointed tubular element  184  may be configured to penetrate a penetrable septum  194  provided within hub body  50 . In at least one embodiment, penetrable septum  194  seals a tubing portion  196  in fluid connection with flexible catheter  90 . Thus, a fluid communication path between flexible catheter  90  and extension tube  70  may be established by inserting tubular element  184  through septum  194  and into tubing portion  196  housed in hub body  50 . 
     Persons of ordinary skill in the art will appreciate that extension tube  70  may be removably attached to hub  40  and/or flexible catheter  90  in any number of ways. For example, as illustrated in  FIG. 27A , extension tube  70  may be removably attached to the hub body  50  of hub  40  by positioning a male tube connector  202  provided on hub body  50  within a complimentary female tube connector  204  attached to extension tube  70 . Generally speaking, complimentary tube connectors  202  and  204  represent any form of tubing connection or mechanism known to those of skill in the art; including, for example, a so-called Luer-type fitting or connector. In an additional embodiment, male tube connector  202  may be positioned within a recess  206  defined within hub body  50  of hub  40 , as illustrated in  FIG. 27B . 
       FIGS. 28A and 28B  are perspective and cross-sectional views, respectively, of an infusion system according to an additional embodiment. As seen in these figures, this exemplary infusion system may comprise an insertion assembly  20 , a base member  40 , a flexible catheter  90 , and an extension tube  70 . In at least one embodiment, a cap element  46  may be inserted within a recess  42  defined in hub body  50 . Cap element  46  generally represents any structure or device capable of sealing any aperture or recess defined within any of the components of the exemplary embodiments described and/or illustrated herein. In certain embodiments, cap element  46  may be positioned above septum  48  and configured to seal recess  42  from the environment, thereby preventing bacteria from entering and forming within recess  42 . In an additional embodiment, a cap element  46  is disposed within each exposed recess and/or aperture defined in each component of exemplary infusion apparatus  10 . Cap element  46  may be formed of any suitable material capable of sealing an aperture or recess; including, for example, medical-grade polymers (such as silicone) and monomers (such as Ethylene Propylene Diene Monomer (“EPDM”), or other suitable materials. 
       FIG. 29  illustrates an exemplary slender pointed element  22  comprising a pointed end  25 . As illustrated in this figure, the pointed end  25  of slender pointed element  22  may be scored or otherwise weakened along line  23 . Accordingly, upon completion of an infusion operation, the pointed end  25  of slender pointed element  22  may break off along line  23  upon removal of slender pointed element  22  from hub body  50 , leaving the broken pointed end  25  of slender pointed element  22  within septum  48 . 
     In at least one embodiment of infusion system  10 , at least a portion of slender pointed element  22  may be retractable into a recess defined in insertion assembly  20 . For example, as illustrated in  FIGS. 30A-30B , a lever  200  coupled to slender pointed element  22  may be provided in a recess  29  defined in base member  28  of insertion assembly  20 . In certain embodiments, lever  200  may be manipulated from a first position illustrated in  FIG. 30A  to a second position illustrated in  FIG. 30B  to retract at least a portion of slender pointed element  22  within base member  28 . After pointed end  25  of slender pointed element  22  has been retracted past a second opening  93  of flexible catheter  90 , a blood draw may be attempted to ensure the proper placement of flexible catheter  90  within the implanted device. 
     Similarly, as illustrated in  FIGS. 31A-31D , a slender pointed element (such as slender pointed element  22  in  FIG. 3A ) may be retracted into base member  28  by depressing opposing buttons  210  and  214  provided on base member  28 . In this exemplary embodiment, buttons  210  and  214  may comprise cantilevered end portions  212  and  216 , respectively, that are configured to manipulate a complimentary cantilevered end portion  220  of slender pointed element  22  generally upwards within a recess defined in base member  28 . In an additional embodiment, as illustrated in  FIGS. 32A-32D , slender pointed element  22  may be retracted into base member  28  by manipulating wing structures  41 A and  41 B from a first position, illustrated in  FIGS. 32A and 32C , into a second position, illustrated in  FIGS. 32B and 32D . More particularly, wing structures  41 A and  41 B may comprise cantilevered end portions  230 A and  230 B, respectively, that are configured to manipulate slender pointed element  22  generally upwards within a recess defined in base member  28 . 
       FIGS. 33A-33C  are perspective views of an additional embodiment of an infusion apparatus  10 . As seen in these figures, infusion apparatus  10  may comprise an insertion assembly  20 , a hub  40 , a flexible catheter  90 , an extension tube  70 , a clamp  60 , and a tube connector  80 . Insertion assembly  20  may comprise a biasing member  232  positioned around a slender pointed element  22  and positioned proximate a safety clip  30 . In at least one embodiment, biasing member  232  may bias safety clip  30  away from insertion assembly  20  such that, upon removal of insertion assembly  20  from hub  40 , safety clip  30  may positioned around a pointed end  25  of slender pointed element  22  by biasing member  232 . 
     As best seen in  FIG. 33C , insertion assembly  20  may also comprise a plurality of coupling arms  234  that define a recess  236  that is configured to receive at least a portion of hub  40 . For example, hub  40  may be sized and shaped so as to fit within the recess  236  defined within insertion assembly  20  by coupling arms  234 . In at least one embodiment, the exemplary configuration of infusion system  10  in  FIGS. 33A-33C  may provide various advantages, such as ease of handling by a user and/or compatibility with additional structures. 
       FIGS. 34A-34C  are perspective views of an exemplary hub  40  for an infusion system according to an additional embodiment. As seen in these figures, exemplary hub  40  may comprise a plurality of wing structures  41 A and  41 B. In at least one embodiment, wing structures  41 A and  41 B are configured to affix exemplary hub  40  to the skin of a patient. For example, wing structures  41 A and  41 B may be taped, adhesively affixed, or otherwise attached to the surface of a patient&#39;s skin, such as skin surface  310  in  FIG. 1 . In additional embodiment, a sheet of material, such as TEGADERM®, may be used to affix hub  40  to the surface of a patient&#39;s skin. 
     As seen in  FIG. 34A , hub  40  may comprise a recess  260  and a receiving enclosure  264 . In at least one embodiment, recess  260  is sized and configured to receive at least a portion of a flexible catheter, such as flexible catheter  90  in  FIGS. 34B-34C . Similarly, receiving enclosure  264  may be sized and configured to retain at least a portion of a flexible catheter, such as flexible catheter  90  in  FIGS. 34B-34C . In certain embodiments, wing structures  41 A and  41 B of hub  40  may be configured to fold inwardly along a folding line  266 . As best seen in  FIGS. 34B and 34C , after positioning at least a portion flexible catheter  90  within recess  260  and receiving enclosure  264 , wing structures  41 A and  41 B may be folded inwardly upward. In one embodiment, wing structures  41 A and  41 B may be affixed to a patient&#39;s skin when in a downward, extended position, illustrated in  FIG. 34B . In addition, flexible catheter  90  and/or a slender pointed element, such as slender pointed element  22  in  FIG. 3A , may be removed from hub  40  when wing structures  41 A and  41 B are in an upward, folded position, illustrated in  FIG. 34C . 
     As detailed above, one or more of the exemplary embodiments described and/or illustrated herein may be employed in accessing a device, such as exemplary access port  320 , implanted within a patient. In at least one embodiment, a method of accessing an implanted device using a infusion system may comprise: 1) positioning at least a portion of slender pointed element  22  within flexible catheter  90 ; 2) penetrating a septum of an implanted device, such as septum  326  of access port  320 , using the slender pointed element  22  positioned within the flexible catheter  90 ; and 3) positioning at least a portion of flexible catheter  90  within the implanted device. For example, a clinician may grasp base member  28  of insertion assembly  20  and may guide the pointed end  25  of slender pointed element  22  into recess  42  of hub  40 , through septum  48 , and into flexible catheter  90 . The clinician may then guide the pointed end  25  of slender pointed element  22  (positioned within flexible catheter  90 ) through the skin surface  310  and subcutaneous zone  312  of a patient and into a port septum  326 . The clinician may then confirm that flexible catheter  90  is positioned within chamber  324  of access port  320  by drawing blood through extension tube  70  using a syringe attached to tube connector  80 . Thus, blood may be drawn through apertures  92  of flexible catheter  90  and through at least one cavity formed between an inner surface of flexible catheter  90  and an outer surface of slender pointed element  22 . Blood may then travel through hub  40  (i.e., manifold element  61 ) and through extension tube  70  to confirm that slender pointed element  22  and flexible catheter  90  of infusion system  10  are properly placed within port chamber  324 . 
     Subsequent to confirmation of proper placement of slender pointed element  22  and flexible catheter  90 , base member  28  of insertion assembly  20  may be grasped and slender pointed element  22  may be removed from hub  40 , while flexible catheter  90  may remain positioned within chamber  324  of access port  320 . Septum  48  may seal any hole or aperture created by the removal of slender pointed element  22 . Upon removal of slender pointed element  22 , flexible catheter  90  may be positioned or oriented in any number of ways; including for example, by positioning flexible catheter  90  substantially perpendicularly to skin surface  310 . Safety clip  30  may remain attached to hub  40  (i.e., within recess  42 ) until the pointed tip  25  of slender pointed element  22  becomes encased by safety clip  30  (via movement of legs  32 A and  32 B), after which time safety clip  30  may be removed from recess  42  of hub  40 . Hub  40 , extension tube  70 , tube connector  80 , or combinations thereof may then be taped to skin surface  310  of the patient. Optionally, wing structures  41 A and  41 B may be adhesively affixed to skin surface  310 . 
     Accordingly, each of the exemplary infusion system embodiments described and/or illustrated herein may provide vascular access (via an implanted device) for any number of procedures; including, for example, infusion, blood aspiration, hemodialysis, hemofiltration, peritoneal dialysis, or other procedures as known in the art. Advantageously, the use of sharp implements may be reduced or eliminated, thereby reducing the danger of inadvertent sticks or punctures. 
     The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments described herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. For example, each component in each exemplary embodiment described and/or illustrated herein may be formed in any number of suitable shapes, sizes, and configurations. In addition, the various infusion system embodiments described herein may be adapted for use in connection with high pressure operations, commonly referred to as “power injection” processes. Accordingly, the various components of the exemplary embodiments provided herein may be adapted to handle pressure of about 400 psi or higher. 
     The embodiments described and/or illustrated herein are in all respects illustrative and not restrictive. Accordingly, reference should be made to the appended claims and their equivalents for determining the scope of the instant disclosure. For ease of use, the words “including” and “having,” as used in the specification and claims, are interchangeable with and have the same meaning as the word “comprising.”