Abstract:
A low pierce force needle port including a compressible resilient seal puncturable by a needle and compressing apparatus composed of a sealing cap and a sealing gland for compressing the seal. Provision of the compressing apparatus enables the seal to be very thin and still effectively seal before, during, and after needle penetration. Annular beveled and rounded shouldered surfaces on the sealing cap and sealing gland, respectively, serve to guide needles entering and passing through the low pierce force needle port; and a handle, a wide planar area, or other feature of the sealing cap provides a degree of protection against inadvertent needle punctures of the practitioner.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application includes subject matter bearing similarity to subject matter disclosed in commonly assigned co-pending application Ser. No. 10/838,464 filed May 4, 2004, entitled “Gas Inflation/Evacuation System and Sealing System Incorporating a Compression Sealing Mechanism for Guidewire Assembly Having Occlusive Device,” pending. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention is for a medical device, and more specifically, for a low pierce force needle port for receiving and sealing about a needle used for injection of drugs or medicines into tubes utilized for delivery of drugs or medicines into the body or, alternatively, used to withdraw fluid from the body or from an associated fluid system. 
         [0004]    2. Description of the Prior Art 
         [0005]    Prior art needle ports incorporated a puncturable seal of rubber or other material requiring a certain force to effect a needle puncture. Some seal materials, such as latex rubber for example, or certain other known rubber materials, would offer variable degrees of penetration resistance depending upon the age and/or thickness of the material. A typical prior art rubber seal could harden, thereby offering an increased puncture resistance; or could harden and become brittle, thereby offering resistance to a needle puncture as well as incurring the possibly of rubber particles detaching themselves from the seal to contaminate the interior of the sealed region into which the drug or medicine was being delivered. Suitable resealing upon needle retraction with hardened or brittle material also was a concern. The present invention offers a seal comprised of long lasting silicone offering long lasting structural integrity. 
         [0006]    Prior art seals offered resistance to penetration according to the thickness of the seal material and, as such, the practitioner had very little control over the thickness of a seal, as the seals were attached to the surrounding support structure during the manufacturing process. If the force to overcome the resistance of a seal when using different size needles was objectionable, the practitioner was offered few options. The present invention offers a seal which can be removed and subsequently replaced by another seal of other thickness to meet the requirements of the practitioner. 
         [0007]    Also in prior art seals, reliance is made on the properties of the materials of the seals to close a puncture site (e.g., in the case of rubber, the rubber tends to flow back to close any puncture), and thicker seals would close more readily. The seal of the present invention uses the force imparted by a compressing apparatus to close a puncture; that is, squishing the seal causes it to expand radially inwardly and outwardly to close a puncture. The compressing apparatus allows the seal to be much thinner and easier to puncture; and suitable sealing no longer depends solely on the material of the seal, as was the case in the prior art. 
         [0008]    Safety of the practitioner is another consideration. Prior art needle ports are small in size and, hence, offer a small overall target for the end of the puncturing needle. As such, inadvertent puncture of the practitioner&#39;s fingers by poor coordination or a poorly aimed needle can result. The present invention offers a surround area about an initial target area to provide a zone for misdirected or poorly aimed needles. 
       SUMMARY OF THE INVENTION 
       [0009]    The general purpose of the present invention is to provide an improved needle port. 
         [0010]    According to one embodiment of the present invention, there is provided a low pierce force needle port having a sealing gland, a sealing cap connected to one end of the sealing gland, a fluid connector connected to the other end of the sealing gland, and a resilient seal residing in the sealing gland. The fluid connector is preferably a male Luer connector, but may be any other convenient fluid connector as known in the art. The seal, preferably of silicone or other such long lasting resilient and self-sealing material, resides in a cavity in the sealing gland and is sealingly compressed between an annular planar sealing face at the end of a tubular extension of the sealing cap and a planar sealing seat in the sealing gland. Compressing the silicone allows one to make a thin seal that still seals effectively when punctured because the silicone material is forced together from all sides. While the presently preferred seal material is silicone elastomer, other natural or synthetic rubbers or elastomeric polymers can be utilized, such as resilient foams, fibrous mats, or solid layers, or other forms, composites, or combinations. For example, a fibrous elastomeric mat with a solid layer may be utilized. The seal is removable and may be exchanged for a seal of different thickness or qualities according to the requirements and needs of the practitioner. An annular bevel for guidance of a needle to a passageway and to the seal is located at the proximal portion of the sealing cap. A planar area separating the annular bevel from the peripheral edge of the sealing cap provides spacing of a practitioner&#39;s fingers from the area of needle insertion at the annular bevel. The low pierce force needle port can be attached to an intravenous or other fluid system, and used to provide access to deliver medicine, diagnostic medium, or other fluid, or to withdraw fluid from the body or fluid system. 
         [0011]    One significant aspect and feature of the present invention is a low pierce force needle port having a sealing gland, a sealing cap, a fluid connector, and a seal. 
         [0012]    Another significant aspect and feature of the present invention is a low pierce force needle port including a seal of silicone composition to provide a seal which is readily puncturable by a needle. 
         [0013]    Yet another significant aspect and feature of the present invention is a low pierce force needle port including a seal which is long-lived and resistant to the rigors of age. 
         [0014]    Still another significant aspect and feature of the present invention is a low pierce force needle port having a compressing apparatus which can vary the degree of compressibility of a seal, thereby enabling the seal to be very thin yet still seal effectively, the thinness of the seal also reducing the pierce force required to puncture it and thus making for a safer construction. 
         [0015]    A further significant aspect and feature of the present invention is a low pierce force needle port having an annular bevel leading to a passageway and thence to a seal. 
         [0016]    A still further significant aspect and feature of the present invention is a low pierce force needle port which provides a region of separation between the practitioner&#39;s fingers and an annular bevel, where such bevel is the first point of needle insertion. 
         [0017]    Yet a further significant aspect and feature of the present invention is a low pierce force needle port having an annular rounded shoulder internal to a sealing gland for guidance of a needle into a passageway of a connector tube and along or near the longitudinal axis of the low pierce force needle port. 
         [0018]    Another significant aspect and feature of the present invention is a low pierce force needle port having elongated and narrowed internal structure of a sealing cap for the purpose of early and accurate alignment of a needle within the sealing cap to facilitate suitable and more accurate needle alignment distal to the sealing cap within a passageway located in a connector tube. 
         [0019]    Another significant aspect and feature of the present invention is a low pierce force needle port having a handle extending from a sealing cap. 
         [0020]    Having thus described an embodiment of the present invention and set forth significant aspects and features thereof, it is the principal object of the present invention to provide an improved needle port. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein: 
           [0022]      FIG. 1  is an isometric view of a low pierce force needle port in assembled condition; 
           [0023]      FIG. 2  is an exploded view of the low pierce force needle port shown in  FIG. 1 ; 
           [0024]      FIG. 3  is an exploded cross section view taken along line  3 - 3  of  FIG. 2 ; 
           [0025]      FIG. 4  is a cross section view of the assembled low pierce force needle port taken along line  4 - 4  of  FIG. 1 ; 
           [0026]      FIG. 5  is a cross section view like  FIG. 4  but showing the low pierce force needle port in use with a syringe and a needle as well as with a female Luer connector; 
           [0027]      FIG. 6 , a first alternative embodiment, is a longitudinal cross section view of a low pierce force needle port incorporating the general structure of the low pierce force needle port of  FIGS. 1-5  but having elongated and narrowed structure internal to the sealing cap; and, 
           [0028]      FIG. 7 , a second alternative embodiment, is an isometric view of a low pierce force needle port incorporating the general structure of the low pierce force needle port of  FIGS. 1-5  but in addition including a handle extending from the sealing cap. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]      FIG. 1  is an isometric view of a low pierce force needle port  10  in assembled condition, and  FIG. 2  is an exploded view of the low pierce force needle port  10  shown in  FIG. 1 . Immediately visible components in the views include a sealing cap  12 , a configured one-piece sealing gland  14 , and a fluid connector  16 . While in the figures the fluid connector  16  is shown in a preferred configuration as a male Luer connector, any suitable known fluid connector may be utilized. The standard Luer taper connectors are typically used for syringes and infusion sets, but other connectors may be used for particular applications, including custom or proprietary design connectors intended only to connect to other compatible custom or proprietary design connectors in a system. In the figures, fluid connector  16  is further illustrated as a male Luer connector with a threaded locking component; the threaded locking component is preferred to provide a more secure connection, but is not always required. The illustrated male Luer connector is shown as consisting of two components: a Luer taper component  16   a  which forms a fluid seal with a Luer taper of a mating female Luer connector (item  66 ,  FIG. 5 ) and a threaded locking component  16   b  which provides a secure mechanical attachment to tabs or thread portions of a mating female Luer connector (item  66 ,  FIG. 5 ). 
         [0030]      FIG. 2 , in addition to showing the sealing cap  12 , the sealing gland  14 , and the fluid connector  16 , shows a seal  18  constructed of a resilient material of suitable composition, preferably silicone, which is self-sealing to an extent with regard to needle punctures and the like and which is substantially unaffected by the rigors of time and temperature. The seal  18  is imperforate, axially compressible, and sealingly radially expandable, and is shaped as a disc having two substantially flat faces substantially parallel to each other and separated by a thickness. The sealing gland  14  serves as a mount for the sealing cap  12  and together with the sealing cap  12  constitutes a compressing apparatus for the seal  18 . Sealing gland  14  also serves as a mount for the fluid connector  16 . One end of the sealing gland  14  includes external threads  22  for receiving and mounting the sealing cap  12 . Located along the longitudinal axis of the sealing gland  14  at the end thereof opposite to the external threads  22  is a connector tube  24  which forms a part of the Luer taper component  16   a  and which has an annular ramp  26  over which the threaded locking component  16   b  is mounted by snap engagement and by which the threaded locking component  16   b  is captured and rotatably retained upon the connector tube  24  proximal to the annular ramp  26  and adjacent to a plurality of support struts  28   a - 28   n  extending along a portion of the connector tube  24  and terminating at an annular ridge  30 , which is shown to be continuous, but which could be spaced segments, for manual grasping. 
         [0031]      FIG. 3  is an exploded cross section view taken along line  3 - 3  of  FIG. 2 . Shown in particular is a proximally located cavity  34  extending along and about the longitudinal axis of the sealing gland  14 . The cavity  34  includes a circular peripheral wall  36  intersecting a surface in the form of a sealing seat  38  which is planar in nature and ring-like in shape. A passageway  32  extends partially along and about the longitudinal axis of the sealing gland  14  and within the connector tube  24  in communication with the cavity  34 . An annular shoulder  39  bridges the planar sealing seat  38  and the passageway  32  of the connector tube  24 . The annular shoulder  39  is shown as a rounded shoulder but could be conical or other tapered shape and functions as a guide to direct the end of a needle into the passageway  32  of the connector tube  24 , if required. As stated previously, the fluid connector  16  in this example is a male Luer connector comprising Luer taper component  16   a  and threaded locking component  16   b . The threaded locking component  16   b  includes an interior cavity  40  which is cylindrical and which includes a raised threaded surface  42  for accommodation and fixation to desired appliances. A hole  44  having an annular ridge  46  is located in the end wall  48  of the threaded locking component  16   b . The annular ridge  46  snappingly engages over and about the annular ramp  26  of the connector tube  24  to rotatably retain the threaded locking component  16   b  upon the connector tube  24  of Luer taper component  16   a , as previously described. The sealing cap  12  includes internal threads  50  suitable for threadingly engaging the external threads  22  of the sealing gland  14 . A tubular extension  52  extends distally from the end wall  54  of the sealing cap  12  and terminates in an annular planar sealing face  56 . The planar sealing seat  38  and the annular planar sealing face  56  are substantially parallel to one another, so that, when the annular planar sealing face  56  of the sealing cap  12  is in contact with one flat face of the resilient seal  18 , the annular planar sealing face  56  transmits compressive force to the resilient seal  18  to force the other flat face of the resilient seal  18  against the planar sealing seat  38 , thereby compressing the resilient seal. A passageway  58  having a proximally located annular bevel  60  extends from the end wall  54  through the tubular extension  52  and intersects the annular planar sealing face  56 . A planar area  59  between the annular bevel  60  and the peripheral edge  61  of the sealing cap  12  offers a wide zone of protection surrounding and extending beyond the annular bevel  60  to distance the practitioner&#39;s fingers from a target area which is considered to be the annular bevel  60  co-located with the proximal portion of the passageway  58 . The annular bevel  60  functions as a guide to direct the end of a needle into the passageway  58  of the tubular extension  52  for subsequent needle penetration of the seal  18 . 
         [0032]      FIG. 4  is a cross section view of the assembled low pierce force needle port  10  taken along line  4 - 4  of  FIG. 1 . Shown in particular is the compression of the seal  18  as influenced by the position of the sealing cap  12 . 
       MODE OF OPERATION 
       [0033]      FIG. 5  is a cross section view like  FIG. 4  but showing the low pierce force needle port  10  in use with a syringe  64  and a needle  62  as well as with a mating fluid connector illustrated as a female Luer connector  66 . The fluid connector  16  at the distal end of the low pierce force needle port  10  can be connected to the mating female Luer connector  66  for delivery of the contents of the syringe  64  through the mating female Luer connector  66  to regions downstream thereof. The mating female Luer connector  66  can be connected at its distal end to communicate with various types of devices, such as an IV port, an IV bag, or other such devices for the delivery or injection of medicines or drugs.  FIG. 5  incorporates the elements of  FIG. 4  showing the compression of the seal  18 . In use, the seal  18  is aligned in the cavity  34  ( FIG. 3 ), preferably in initial contact with the planar sealing seat  38  at one end of the cavity  34 , followed by threaded engagement of the sealing cap  12  to the sealing gland  14  to capture the seal  18 . Alternatively, the seal  18  could be factory installed and compressed, if desired. The internal threads  50  of the sealing cap  12  threadingly engage the external threads  22  of the sealing gland  14 , and the sealing cap  12  is rotatingly advanced with respect to the sealing gland  14  to bring the annular planar sealing face  56  of the tubular extension  52  into intimate contact with the seal  18 . Such advancing rotation causes the annular planar sealing face  56  of the sealing cap  12  to forcibly engage the seal  18  to compress the seal  18  between the annular planar sealing face  56  of the sealing cap  12  and the planar sealing seat  38  of the sealing gland  14  to expand the periphery of the seal  18  radially outwardly and inwardly, thereby providing a seal against the circular peripheral wall  36  ( FIG. 3 ) of the sealing gland  14  and against an inserted needle, as well as providing a seal against the planar sealing seat  38  and the annular planar sealing face  56 . A needle  62  extending from a syringe  64  or other like device is introduced into the annular bevel  60  and guided by the annular bevel  60 , as required, into the passageway  58  of the sealing cap  12 , and advanced distally to penetrate and sealingly pass through the seal  18  and into and through the passageway  32  of the connector tube  24  for communication with the mating female Luer connector  66 . Preferably, the needle  62  or other like penetrating fluid delivery device substantially maintains a coaxial relationship to the annular bevel  60 , the passageway  58 , the seal  18 , the cavity  34 , the passageway  32 , the hole  44 , the annular ridge  46 , and the interior cavity  40  of the threaded locking component  16   b  of the fluid connector  16 , all of which preferably have a direct mutual coaxial relationship or mutual coaxial relationship along a central longitudinal axis. Should a coaxial relationship as described not occur, allowances in the included geometry provide for usability even though a non-coaxial relationship results. Such geometry includes the annular shoulder  39 , which alternately could be a bevel, which is available to guide and direct an off-center needle  62  into the passageway  32 . Such geometry also includes the annular bevel  60  which is available to guide and direct a needle  62  into the passageway  58  of the sealing cap  12 . During active penetration of the seal  18  by the needle  62  and during static penetration of the seal  18  by the needle  62 , the resiliency of the seal  18  automatically forces the parted region of the seal  18  to be firmly and sealingly engaged against the sidewall of the needle  62  to maintain a seal against the needle  62  and to maintain the sealed integrity of the passageway  32  into which the needle  62  has been urged. Subsequent to delivery of the medicine or drug from the syringe  64  and needle  62 , the retraction of the needle  62  from the passageway  32  and from the seal  18  is followed by self-closure of the puncture of the seal  18  as caused by the resiliency of the seal  18 , thereby maintaining the integrity of seal  18  and the integrity of the passageway  32 . 
         [0034]    Overall, the increased physical size of the low pierce force needle port  10  contributes to desirable attributes of the present invention. Prior art needle ports generally are of a smaller size than that of the present invention. The increased size as provided by the present invention presents the practitioner with an object more readily graspable, especially when wearing surgical gloves, than that object of smaller dimension. Having attributes which promote easier handling is beneficial to providing for a safe and more expedient and accurate puncture involving the low pierce force needle port  10 , especially in providing a reduced possibility and occurrence of inadvertent needle stabs inflicted upon the practitioner. Also included in the invention is initial needle guidance to the puncture zone, i.e., the seal  18 , such as is provided by the annular bevel  60  of the sealing cap  12 . The use of a seal  18  of silicone instead of a conventional rubber seal provides for a more predictable and consistent force for puncturing of the seal  18  by a needle  62 , thereby facilitating ease of use. Further, the use of a seal  18  of silicone is preferable to the use of conventional rubber seals because conventional rubber seals tend to deteriorate over a short time span. 
         [0035]    A further improvement over prior art needle ports can be provided by the disclosed structure as next set forth. The amount of axial compression and corresponding radial expansion force on seal  18  can be adjusted by the practitioner, if desired. By rotating sealing cap  12  relative to sealing gland  14 , the amount of axial compression of seal  18  can be adjusted, resulting in corresponding modification of radial expansion of seal  18  and thereby altering the sealing efficiency of seal  18  against circular peripheral wall  36 , sealing seat  38 , and sealing face  56 . Also, rotation of sealing cap  12  relative to sealing gland  14  will change the overall compressive state of seal  18  which can affect the force required to puncture seal  18  with needle  62  and can affect the frictional force on movement of needle  62  with respect to the punctured seal  18  thereabout. Thus, the practitioner, by rotation of sealing cap  12  relative to sealing gland  14 , is provided with means to adjust the sealing and the puncture force, and can adjust the low pierce force needle port to provide increased sealing ability, if required, to reduce leakage, or to adjust the needle penetration force. Further, such adjustments may be made at various points in the procedure; for example, a lower needle penetration force may be desired initially, and an improved seal may be desired later, and a further low needle penetration force may again be desired for subsequent penetrations, and still higher sealing force may be desired after needle withdrawal. These and other similar combinations of adjustments may be made utilizing the features of the present inventive low pierce force needle port, and are not provided by typical prior art devices. 
         [0036]      FIG. 6 , a first alternative embodiment, is a longitudinal cross section view of a low pierce force needle port  10   a  incorporating the general structure of the low pierce force needle port  10  of  FIGS. 1-5  and subscribing to the teachings thereof but featuring a sealing cap  12   a  which is similar in many respects to the sealing cap  12  but which has elongated structure for accommodation of a needle. Specifically, the annular bevel  60  of previous figures has been elongated to provide an annular bevel  60   a  of greater length and having a steeper side truncated conical surface. Further, the previous passageway  58  is replaced by passageway  58   a  which is correspondingly elongated. Also, the proximally located radius of the annular bevel is reduced to narrow the passageway  58   a . Such elongations and narrowing reduces the cross section of the entry zone for a needle to provide early and more accurately guided alignment of a needle within the sealing cap  12   a , thereby facilitating suitable and more accurate alignment distal to the sealing cap  12   a  with the passageway  32  located in the connector tube  24 . 
         [0037]      FIG. 7 , a second alternative embodiment, is an isometric view of a low pierce force needle port  10   b  incorporating the general structure of the low pierce force needle port  10  of  FIGS. 1-5  and subscribing to the teachings thereof but additionally including a handle  68  extending preferably radially from the periphery of a sealing cap  12   b . The health care giver can grasp the handle  68  with a thumb and one or more fingers of one hand, instead of grasping the sealing cap directly with the same appendages of that hand, and can maneuver a needle into and through the sealing cap  12   b  with the other hand. The distancing of the grasping hand from the general structure of the sealing cap  12   b  or the other substantial regions of the low pierce force needle port  10   b  greatly reduces the possibility of accidental needle stabs of the grasping hand. 
         [0038]    The invention also includes methods of sealingly accessing a fluid system. One method of accessing a fluid system includes the steps of providing a needle port with a seal and with means for adjusting the compression of the seal, inserting a needle into the needle port and penetrating the seal, and adjusting the compression of the seal. 
         [0039]    Various modifications can be made to the present invention without departing from the apparent scope thereof.