Patent Description:
In the mid-<NUM>'s, concern grew publically worldwide within the healthcare community for a new and potentially lethal virus called the Human Immunodeficiency Virus (HIV) which leads to AIDS (Acquired Immune Deficiency Syndrome). Prior to the AIDS epidemic, IV therapy and blood collection methods utilized hypodermic syringes and IV sets utilizing steel needles and latex injection ports to administer drugs and IV fluids along with blood collection samples. An accidental needle stick injury among healthcare providers was a common occurrence. Various viruses, fungi and bacterial infections (i.e. Hepatitis A, B, and C, Staphylococcus, Tuberculosis) could be transmitted to the healthcare provider via an accidental needle stick injury. Accidental punctures by contaminated needles can inject hazardous fluids into the body through the skin. There is potential for injection of hazardous drugs, but contact with infectious fluids, especially blood, is by far the greatest concern. Even small amounts of infectious fluid can spread certain diseases effectively through an accidental needle stick injury. The AIDS epidemic was the catalyst for change from high risk steel needles to needleless injection port devices for intermittent intravenous therapy and/or blood collection within the healthcare community.

Conventional "standalone" needleless injection ports include a body having a first portion that can be mated at one end to any patient's vascular access catheter, IV extension set, Huber needle set or IV bags and a second portion that can be mated to a standard syringe (without a steel hypodermic needle) or IV administration set (without a steel hypodermic needle) in order to infuse IV fluids, drugs, antibiotics, blood products or other fluids through the injection port and into the patient's bloodstream. Conventional standalone needleless injection ports can also have a second portion that can be mated to a blood collection device or syringe in order to aspirate blood samples from the patient. These conventional needleless injection ports can also be incorporated into an IV pump set or IV administration set in a Y-Injection Port configuration. Among the early and conventional needleless injection port internal fluid path designs introduced into the market since the early <NUM>'s, many had the sole purpose to prevent accidental needlestick injuries for the healthcare provider.

Over the past <NUM> years, various conventional needleless injection ports have been introduced that utilize different functional design methods incorporating a two-way (infusion and aspiration capabilities), valve-type system for intermittent fluid delivery or aspiration. A combination of a resilient barrier(s) or seal(s) (i.e. silicone), steel springs, steel needles, steel blunt needles, and thermoplastic components have been utilized in conventional needleless injection ports. For example, discloses <CIT> a medical connector for use in a fluid pathway including a substantially transparent housing having a proximal end with a proximal opening and a distal end with a distal opening, and a cavity extending therebetween. The connector provides a substantially visible fluid flow path extending through a substantial portion of the connector.

The patient could receive antibiotics, normal saline/heparin, and other drugs or fluids through a standard syringe, or IV therapy through an IV administration set/IV bag. Blood samples are generally taken through a standard syringe or a blood collection device for chemical analysis. As the various fluid delivery medical devices are coupled to the injection port, the male-luer component of each of these fluid delivery medical devices will push down on the resilient barrier or seal to open the fluid pathway of the injection port in order to infuse fluids or draw blood samples through the injection port. Once the infusion or aspiration procedure is completed, the syringe, IV administration set, or blood collection device is removed from the injection port, the internal valve system reseals with the intent to prevent contamination from entering into the injection port fluid pathway system and potential catheter-related bloodstream infections (CR-BSIs).

Ever since needleless, intermittent injection ports were introduced to the markets in the early <NUM>'s, two major patient safety issues have evolved; a significant increase in catheter-related bloodstream infections (CR-BSIs) and intraluminal thrombotic catheter occlusions (blood clots within the vascular-access catheter). Prior to needleless injection ports being introduced to the market in the early <NUM>'s, CR-BSI's or intraluminal thrombotic catheter occlusions were not reported in medical journals when utilizing steel hypodermic needles and latex injection ports. It appears that needleless injection ports solved one major healthcare issue of eliminating accidental needlestick injuries, but, inadvertently created new patient safety issues.

Intravascular catheters play a central role in the care of critically and chronically ill patients; an estimated <NUM> million central venous catheters (CVCs) and peripherally-inserted central catheters (PICCs) and over <NUM> million peripheral IV catheters (PIV's) are inserted in patients each year in the United States alone as an integral part of today's patient care paradigm. These devices allow the administration of, among other things, parenteral nutrition, antibiotics, pain medication and large fluid volumes as well as provide access for blood sampling and blood component delivery. However, more than <NUM>,<NUM> catheter-related bloodstream infections (CR-BSI's) have been reported in medical journals to occur annually, with an estimated mortality rate of <NUM>% to <NUM>% (<NUM>,<NUM> to <NUM>,<NUM> CR-BSI associated deaths every year in the United States). CR-BSI is not only one of the highest mortality infections in the hospital, but it also significantly increases hospital length of stay, with additional health care cost estimates of over $<NUM>,<NUM> per occurrence (over $<NUM> billion annually).

A second patient safety issue that has developed since the introduction of needleless injection ports is intraluminal thrombotic catheter occlusions, or blood clots within the vascular-access catheter. Catheter occlusion is defined as a partial or complete obstruction of the catheter lumen that limits or prevents the ability to withdraw blood, flush the catheter, and/or administer parenteral solutions or medications. Characterized by the inability to withdraw blood or infuse liquids, catheter occlusions occur in up to <NUM>% of all CVCs and PICCs and are associated with interrupted intravascular therapy, often requiring either pharmacologic or even surgical approaches to restore catheter patency. Any of these events can negatively affect the patient's hospital experience. Discomfort associated with catheter restarts and IV site manipulation directly impacts the patient's perception of quality of care. Clinical complications associated with catheter occlusions can cost significant time and money and are also a critical factor in the overall patient care equation. It has been reported in the literature that typically <NUM> CVC/PICC catheters become occluded due to intraluminal thrombosis for every <NUM>,<NUM> catheters placed. Inability to access the patient's vascular system is not the only negative side effect of thrombus formation and catheter occlusion. Defined as a positive blood culture with clinical or microbiological evidence strongly implicating the catheter as the source of infection, catheter-related bloodstream infections (CR-BSIs) have been shown to have a strong correlation with the presence of catheter thrombi and fibrin sheaths in both animal and human studies. It is surmised that an intraluminal thrombosis may serve as a nidus for infections, perhaps due to the blood fibrin and biofilm depositions, thereby affecting the patient's health and increasing hospital costs.

Conventional needleless injection ports may also have other functional design deficiencies that could contribute to the increase in the two critical catheter care and maintenance issues facing healthcare today; catheter-related bloodstream infections (CR-BSIs) and intraluminal thrombotic catheter occlusions.

Poorly designed septum seal integrity, large gaps or openings at the critical outer septum area (or entry point), could allow microbial contamination ingress into the patient's injection port fluid pathway. Additionally, septum surface designs could make effective disinfection of the septum surface very difficult prior to accessing the needleless injection port; which could lead to downstream contamination into the patient's bloodstream. Most conventional needleless injection ports have torturous fluid pathways within their valve system designs that exhibit dead spaces that are difficult to effectively flush blood, air bubbles, and/or critical drugs from the injection port. Entrapped blood, within <NUM> hours, could begin developing blood fibrin and biofilm colonies within the injection port itself. The blood fibrin buildup within the injection port fluid pathway dead spaces can become a food source for microorganisms. Many conventional needleless injection ports with torturous fluid pathway valve designs have multiple-moving valve components within the fluid pathway of the injection port. This leads to large priming volumes (the amount of fluid to fill the fluid pathway of the needleless injection port), which increases the possibility for dead spaces within the injection port fluid pathway. Also, the majority of conventional needleless injection ports on the market exhibit either a negative or positive fluid displacement functional feature that exhibits a reflux of the patient's blood into the catheter lumen immediately upon disconnecting a syringe or IV set from the injection port (Negative Fluid Displacement designs) or reflux of the patient's blood immediately upon connecting a syringe or IV set to the injection port (Positive-Pressure Displacement designs). Most needleless injection ports are accessed many times over the life of the product; typically the life cycle for a conventional injection port is up to <NUM> to <NUM> hours before being replaced in an acute care hospital, and up to <NUM> days in a home care setting. This is due to a concern for potential infection and/or occlusion occurring. Each time blood is refluxed into the catheter lumen, blood fibrin develops on the inner wall of the catheter. The blood fibrin buildup contributes to intraluminal thrombotic catheter occlusions and becomes the food source for microorganisms coming down from the needleless injection port. The problems mentioned above can potentially be harmful to a patient or otherwise undesirably jeopardize the safety of the patient.

Additionally, the first and second portions of the injection port body in many conventional needleless injection ports are either sonically-welded or solvent-bonded together during the assembly process in manufacturing in order to firmly connect the two portions together and create an internal seal within the body. This manufacturing process can be difficult and time consuming, as well as costly.

What is needed, then, are improvements to a new needleless, intermittent injection port that is designed to reduce catheter-related bloodstream infections (CR-BSIs) and intraluminal thrombotic catheter occlusions, thereby, improving better patient safety and care.

In one embodiment an injection port assembly includes a body having a first mating structure and a second mating structure configured to be coupled to the first mating structure. A resilient barrier is configured to be received within the body and is compressible from a less compressed first position in which fluid flow through the injection port assembly is blocked, to a more compressed second position in which fluid flow through the injection port assembly is permitted. The resilient barrier includes an internal cavity. When the resilient barrier is in a relaxed state, the internal cavity includes a cavity nose portion, a cavity sealing portion, and a cavity guide portion. The cavity nose portion has a cavity nose portion maximum inside diameter. The cavity sealing portion has a cavity sealing portion length, the cavity sealing portion having a cavity sealing portion inside diameter smaller than the cavity nose portion inside diameter along at least a majority of the cavity sealing portion length. The cavity guide portion is located on an opposite side of the cavity sealing portion from the cavity nose portion. The cavity guide portion has a cavity guide portion inside diameter greater than the cavity sealing portion inside diameter. A hollow cannula is coupled to the first mating structure and is configured to be received within the resilient barrier. The hollow cannula has a cannula distal end portion configured to extend through the resilient barrier when the resilient barrier is in the more compressed second position. The cannula distal end portion has at least one lateral outlet window having a window length less than the cavity sealing portion length. The cannula distal end portion includes a cannula nose located distally of the lateral outlet window and configured to be closely received in the cavity nose portion of the resilient barrier when the resilient barrier is in the less compressed first position. The cannula distal end portion both distally and proximally of the lateral outlet window has a cannula distal end portion outside diameter sufficiently greater than the cavity sealing portion inside diameter such that when the cannula is received in the resilient barrier with the cannula nose received in the cavity nose portion there is an interference fit between the cannula and the resilient barrier extending along the lateral outlet window and both proximally and distally of the lateral outlet window so that the cavity sealing portion of the resilient barrier seals across the lateral outlet window.

The cavity nose portion may be bulbous in shape and may have a semi-spherical distal end. The cavity nose portion may include a frusto-conical portion of increasing diameter in a proximal direction from the semi-spherical distal end to the cavity nose portion maximum inside diameter.

The cavity sealing portion may include a frusto-conical portion of increasing diameter in a proximal direction from a cavity sealing portion minimum inside diameter to a cavity sealing portion maximum inside diameter.

The cavity guide portion may include a frusto-conical portion of increasing diameter in a proximal direction from the cavity sealing portion.

The interference fit between the cannula and the resilient barrier may extend into the frusto-conical portion of the cavity guide portion.

The cavity guide portion may include a first frusto-conical portion of increasing diameter in a proximal direction adjacent the cavity sealing portion and a second frusto-conical portion adjacent the first frusto-conical portion, the second frusto-conical portion having a smaller included angle than the first frusto-conical portion.

The interference fit between the cannula and the resilient barrier may extend at least about <NUM> inch proximally and distally of the outlet window.

The cannula and the resilient barrier may be configured such that the interference fit provides at least about <NUM>,<NUM> (<NUM> inch) radial interference between the cannula and the resilient barrier. Optionally the interference fit may provide at least about <NUM>,<NUM> (<NUM> inch) radial interference. Optionally the interference fit may provide at least about <NUM>,<NUM> (<NUM> inch) radial interference. Optionally the interference fit may provide at least about <NUM>,<NUM> (<NUM> inch) radial interference.

The cannula nose may substantially fill the cavity nose portion when the resilient barrier is in the less compressed first position with the cannula nose closely received in the cavity nose portion.

When the resilient barrier is in a relaxed state the cavity sealing portion inside diameter may be smaller than the cavity nose portion maximum inside diameter along the entire cavity sealing portion length.

The at least one lateral outlet window in one embodiment includes two diametrically opposed outlet windows, and in another embodiment includes three circumferentially equally spaced outlet windows.

In another embodiment an injection port assembly includes a body having a first mating structure and a second mating structure configured to be coupled with the first mating structure. A resilient barrier may be received within the body and compressible between a less compressed first position in which fluid flow through the injection port assembly is blocked to a more compressed second position in which fluid flow through the injection port assembly is permitted. The resilient barrier includes an internal cavity. A hollow cannula is coupled to the first mating structure and configured to be received within the internal cavity of the resilient barrier. The hollow cannula may have a longitudinal central axis. The hollow cannula includes a cannula distal end portion configured to extend through the resilient barrier when the resilient barrier is in the more compressed second position. The cannula further includes at least one lateral outlet window formed in the cannula distal end portion, the at least one lateral outlet window having a window width perpendicular to the longitude central axis. An internal fluid passageway is defined in the hollow cannula and configured to communicate the at least one lateral outlet window with a fluid conduit connected to the first mating structure. The internal fluid passageway may have a non-circular cross section axially proximal from the window. The non-circular cross section may have a cross section area greater than a cross section area of a circle of diameter equal to the window width.

The at least one lateral outlet window may comprise two diametrically opposed outlet windows.

The two diametrically opposed outlet windows may be diametrically spaced apart by a window spacing.

The internal fluid passageway may extend laterally to each of the two diametrically opposed outlet windows and the non-circular cross section may have a first lateral cross section dimension at least equal to the window spacing immediately adjacent a proximal end of the windows.

The non-circular cross section immediately adjacent the proximal ends of the windows may have a second lateral cross section dimension perpendicular to the first lateral cross section dimension, which second lateral cross section dimension is at least equal to the window width.

The non-circular cross section of the internal fluid passageway may be at least partially defined between first and second generally parallel opposed interior walls of the hollow cannula.

The first and second interior walls may extend along a length of the windows.

The hollow cannula may further include first and second diametrically opposed reinforcing ribs extending radially inward from the first and second opposed interior walls, respectively, along at least the length of the windows.

The first and second reinforcing ribs may continue proximally beyond the length of the windows further into the internal fluid passageway.

The at least one lateral outlet window may comprise three circumferentially equally spaced outlet windows.

The non-circular cross section of the internal fluid passageway may be a three lobed cross section.

The three lobed cross section may taper radially outward and extend proximally from the windows for a distance at least as long as the window length.

The at least one window may have a window length, and the non-circular cross section of the internal fluid passageway may extend proximally beyond the length of the window further into the internal fluid passageway by a further distance at least as long as the window length.

In another embodiment the injection port assembly may include a snap lock feature for locking the first and second mating structures together. The snap lock feature may include a first locking portion and a second locking portion. One of the first and second locking portions may include a locking edge and the other of the first and second locking portions may include a tapered locking surface. The locking edge is configured to engage the tapered locking surface to resist disengagement of the first and second mating structures.

The locking edge may be defined by a substantially <NUM> degree corner.

The tapered locking surface may be a curved tapered locking surface.

The tapered locking surface may be defined on the second locking portion of the second mating structure, and the tapered locking surface may be a segmented surface defined on a plurality of stabilizing ring securement segments of the second mating structure.

The first and second locking portions may be configured such that a force of at least <NUM>,<NUM> N (<NUM> pounds), and more preferably at least <NUM>,<NUM> N (<NUM> pounds), is required to pull apart the first and second mating structures.

Numerous objects features and advantages of the present invention will be readily apparent to those skilled in the art upon a review of the following description when taken in conjunction with the accompanying drawings.

While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that are embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.

The general arrangement of needleless IV injection ports and the various usages thereof in combination with other medical devices is described in greater detail in pending <CIT>entitled "Needleless, Intermittent, Neutral Displacement IV Injection Port" published as <CIT>.

Referring now to the drawings, and particularly to <FIG>, a first embodiment of an injection port assembly is shown and generally designated by the numeral <NUM>. The injection port assembly <NUM> has a longitudinal axis <NUM>. The injection port assembly <NUM> includes a body <NUM> made up of a first mating structure <NUM> and a second mating structure <NUM>. The first mating structure <NUM> may also be referred to as a lower body part <NUM>, and the second mating structure <NUM> may also be referred to as an upper body part <NUM>. The first and second mating structures <NUM> and <NUM> are coupled together by a snap lock feature <NUM>.

The injection port assembly <NUM> further includes a resilient barrier <NUM> which is configured to be received within the body <NUM> and which is compressible from a less compressed first position as seen for example in <FIG>, in which fluid flow through the injection port assembly <NUM> is blocked, to a more compressed second position in which fluid flow through the injection port assembly <NUM> is permitted. It is noted that <FIG> illustrate a similar less compressed first position and more compressed second position for the alternative embodiment of <FIG>, and <FIG> are also representative of the change in shape of the resilient barrier <NUM> for the injection port assembly <NUM>.

The details of construction of the first mating structure <NUM> are best shown in <FIG>. The details of construction of the second mating structure <NUM> are best shown in <FIG>. The details of construction of the resilient barrier <NUM> are best shown in <FIG> and <FIG>.

<FIG> shows the injection port assembly <NUM> in an assembled cross section view with the first and second mating structures <NUM> and <NUM> coupled together and with the resilient barrier <NUM> received within the body <NUM> between the first and second mating structures <NUM> and <NUM>.

As best seen in <FIG> and <FIG>, the resilient barrier <NUM> includes an internal cavity <NUM>. It will be appreciated that the resilient barrier <NUM> is formed from an elastomeric material, and is shown in <FIG> and <FIG> in its relaxed state in which the elastomeric material is relatively undeformed. It will also be appreciated that in <FIG> a hollow cannula <NUM> of the first mating structure <NUM> has been received in the internal cavity <NUM>, thus deforming portions of the resilient barrier <NUM> radially outward so that the shape of the resilient barrier <NUM> as seen in <FIG>, and particularly of its internal cavity <NUM>, are different due to the resilient deformation thereof.

Referring now to <FIG> and <FIG> which show the resilient barrier <NUM> and particularly its internal cavity <NUM> in their relaxed state, the internal cavity <NUM> in this relaxed state may be described as including a cavity nose portion <NUM>, a cavity sealing portion <NUM>, and a cavity guide portion <NUM>.

As shown in <FIG>, the cavity nose portion <NUM> has a cavity nose portion maximum inside diameter <NUM>.

The cavity sealing portion <NUM> may be described as having a cavity sealing portion length <NUM>. The cavity sealing portion <NUM> has a minimum cavity sealing portion inside diameter <NUM> at its upper end and is slightly tapered to a maximum cavity sealing portion inside diameter <NUM> at its lower end. It is noted that the cavity sealing portion <NUM> overall can be described as having a cavity sealing portion inside diameter smaller than the cavity nose portion maximum inside diameter <NUM> along at least a majority of the cavity sealing portion length <NUM>. The cavity sealing portion inside diameter may be smaller than the cavity nose portion maximum inside diameter <NUM> along substantially the entire cavity sealing portion length <NUM>.

The cavity sealing portion <NUM> of internal cavity <NUM> may be described as including a frusto-conical portion of increasing diameter in a proximal direction which increases from cavity sealing portion minimum inside diameter <NUM> to cavity sealing portion maximum inside diameter <NUM>.

The cavity nose portion <NUM> may be described as being bulbous in shape as seen best in <FIG>, and having a semi-spherical distal end <NUM>. The cavity nose portion <NUM> may be further described as including a frusto-conical portion <NUM> of increasing diameter in a proximal direction from the semi-spherical distal end <NUM> to the cavity nose portion maximum inside diameter <NUM>.

The cavity guide portion <NUM> is located on an opposite side of the cavity sealing portion <NUM> from the cavity nose portion <NUM>. The cavity guide portion <NUM> tapers radially outward from the cavity sealing portion <NUM> and thus may be described as having a cavity guide portion inside diameter greater than the cavity sealing portion inside diameter <NUM>. The cavity guide portion <NUM> may be further described as including a first frusto-conical portion <NUM> of increasing diameter in a proximal direction from the cavity sealing portion <NUM>, and a second frusto-conical portion <NUM> adjacent the first frusto-conical portion <NUM>, the second frusto-conical portion <NUM> having a smaller included angle than the first frusto-conical portion <NUM>.

As previously noted, a hollow cannula <NUM> is coupled to the first mating structure <NUM>, and in the example illustrated, the hollow cannula <NUM> is integrally formed with the first mating structure <NUM>. The hollow cannula <NUM> is configured to be received within the resilient barrier <NUM> as shown for example in <FIG>.

The hollow cannula <NUM> includes a distal end portion <NUM> shown in enlarged view in <FIG>. The distal end portion <NUM> is configured to extend through the resilient barrier <NUM> when the resilient barrier <NUM> is in the more compressed second position. The cannula distal end portion <NUM> has at least one lateral outlet window <NUM> and in the example shown has a pair of lateral outlet windows <NUM> and <NUM>.

As seen in <FIG>, each of the lateral outlet windows <NUM>, <NUM> has a window length <NUM> which is less than the cavity sealing portion length <NUM>. As best seen in <FIG>, the windows <NUM> and <NUM> also have a width <NUM> perpendicular to the longitudinal central axis <NUM>, <NUM> of the injection port assembly <NUM> and the cannula <NUM>.

The cannula distal end portion <NUM> includes a cannula nose <NUM> located distally of the lateral outlet windows <NUM> and <NUM>, and configured to be closely received in the cavity nose portion <NUM> of the resilient barrier <NUM> when the resilient barrier <NUM> is in the less compressed first position as shown in <FIG>. The cannula nose may substantially fill the cavity nose portion when the resilient barrier is in the less compressed first position with the cannula nose closely received in the cavity nose portion. More particularly, the cannula nose may fill at least <NUM>%, and more preferably at least <NUM>%, of the cavity nose portion <NUM> by volume.

The cannula distal end portion <NUM> has a cannula distal end portion outside diameter both distally and proximally of the lateral outlet windows <NUM> and <NUM>, which cannula distal end portion outside diameter is sufficiently greater than the respective inside diameters of the cavity sealing portion <NUM> of internal cavity <NUM> of resilient barrier <NUM> when the cannula nose <NUM> is received in the cannula nose portion <NUM> such that there is an interference fit between the cannula <NUM> and the resilient barrier <NUM>. The interference fit extends along the lateral outlet windows <NUM> and <NUM> and both proximally and distally of the lateral outlet windows <NUM> and <NUM> so that the cavity sealing portion <NUM> of the resilient barrier <NUM> seals across the lateral outlet windows <NUM> and <NUM>.

This is visualized in <FIG>, wherein the relaxed position of the cavity sealing portion <NUM> of resilient barrier <NUM> is shown in dashed lines, and thus the extent of radially outward resilient deformation of the resilient barrier <NUM> by the cannula <NUM> received therein is readily apparent and it is apparent that this radially deformed portion of the cavity sealing portion <NUM> of resilient barrier <NUM> extends both distally and proximally from the lateral outlet windows <NUM> and <NUM>.

The area between the dashed line relaxed state representation <NUM> and the solid line position of cavity sealing portion <NUM> as seen in <FIG> may be described as an interference fit <NUM> between the hollow cannula <NUM> and the resilient barrier <NUM>. As is apparent in <FIG>, this interference fit <NUM> between the cannula <NUM> and the resilient barrier <NUM> extends proximally into the first frusto-conical portion <NUM> of the cavity guide portion <NUM> of internal cavity <NUM> of resilient barrier <NUM>. The interference fit <NUM> may also be described as a resilient interference zone spanning the length of the lateral windows <NUM> and <NUM>.

At any one cross section along the axis <NUM> of injection port assembly <NUM>, the interference fit <NUM> may be described as a radial interference which is mathematically determined by comparing the outside diameter of the cannula <NUM> to the inside diameter of the cavity sealing portion <NUM> in its relaxed state, and dividing that difference by two to provide the radial interference. Preferably the radial interference along the interference fit <NUM> is at least about <NUM>,<NUM> (<NUM> inch), optionally at least about <NUM>,<NUM> (<NUM> inch), optionally at least about <NUM>,<NUM> (<NUM> inch) and optionally at least about <NUM>,<NUM> (<NUM> inch).

Preferably the interference fit <NUM> between the cannula <NUM> and the resilient barrier <NUM> extends at least about <NUM>,<NUM> (<NUM> inch) both proximally and distally from the lateral outlet windows <NUM> and <NUM>.

The hollow cannula <NUM> has a longitudinal central axis <NUM> which is coincident with the central axis <NUM> of the injection port assembly <NUM>.

The cannula <NUM> has an internal fluid passageway <NUM> defined therein as best seen in <FIG>. The internal fluid passageway <NUM> communicates the lateral outlet windows <NUM> and <NUM> with a proximal end of the first mating structure <NUM> which is configured to communicate with a fluid conduit <NUM> schematically illustrated in <FIG>. The fluid conduit <NUM> may be representative of any structure to which the injection port assembly <NUM> is to be connected for fluid flow therewith.

<FIG> shows a downward facing cross section of the cannula <NUM> taken along line <NUM>-<NUM> of <FIG> and shows that the internal fluid passageway <NUM> has a non-circular cross section axially proximal from the windows <NUM> and <NUM>. This non-circular cross section may be described as having a cross sectional area greater than a cross section area of a circle of diameter equal to the window width <NUM>.

The two outlet windows <NUM> and <NUM> may be described as being diametrically opposed as is best seen in <FIG>, and as being diametrically spaced apart by a window spacing <NUM>. The non-circular cross section internal fluid passageway <NUM> as seen in <FIG> may be described as extending laterally to each of the two diametrically opposed outlet windows <NUM> and <NUM>, and the non-circular cross section has a first lateral cross section dimension <NUM> at least equal to the window spacing <NUM> at an axial location immediately adjacent to a proximal end <NUM> of the windows <NUM> and <NUM>.

The non-circular cross section of the internal fluid passageway <NUM> as seen in <FIG> immediately adjacent the proximal ends <NUM> of windows <NUM> and <NUM> may also be described as having a second lateral cross section dimension <NUM> which is at least equal to the window width <NUM>.

As is best visualized in <FIG>, the non-circular cross section of the internal fluid passageway <NUM> may be described as being at least partially defined between first and second generally parallel opposed interior walls <NUM> and <NUM> of the hollow cannula <NUM>.

The cannula <NUM> may further include first and second reinforcing ribs <NUM> and <NUM>. The ribs <NUM> and <NUM> may be described as first and second diametrically opposed reinforcing ribs <NUM> and <NUM> extending radially inwardly from the first and second opposed interior walls <NUM> and <NUM>, respectively.

This cross sectional shape of the internal fluid passageway <NUM> as visually depicted in <FIG> preferably extends along a non-circular cross section length <NUM> shown in <FIG>. As is apparent in <FIG>, the non-circular cross section length <NUM> extends along the window length <NUM> and continues proximally beyond the window length <NUM> into the internal passageway <NUM> of cannula <NUM> by a further distance <NUM> at least as long as the window length <NUM> and preferably longer than the window length <NUM>.

Proximally of the non-circular cross sectional length <NUM>, the internal passageway <NUM> may transition into a circular cross section extending to the proximal end <NUM> of the first mating structure <NUM>.

The internal fluid passageway of non-circular cross section as depicted for example in <FIG> provides for increased fluid flow through the cannula <NUM> while maintaining the structural integrity of the cannula <NUM>.

It will be appreciated by those skilled in the art that the typical dimensions of the cannula <NUM> are relatively small. For example, the cannula <NUM> may have an outside diameter <NUM> adjacent its distal end of approximately <NUM>,<NUM> (<NUM> inch), and the window width <NUM> may for example be approximately <NUM>,<NUM> (<NUM> inch). Thus if the internal fluid passageway <NUM> were of completely circular cross section as was typical in the prior art, a circular internal fluid passageway <NUM> leading to the lateral windows <NUM> and <NUM> would typically have a circular cross section with a diameter of about <NUM>,<NUM> (<NUM> inch). By constructing the cannula <NUM> with the non-circular cross sectional area depicted in <FIG> having a cross sectional area greater than a cross section of a circle of diameter equal to the window width <NUM>, increased fluid flow through the cannula <NUM> for any given pressure of fluid supplied thereto is provided. Furthermore, due to the very small structures involved, the presence of the reinforcing ribs <NUM> and <NUM> aids in maintaining structural integrity of the tip portion of the cannula <NUM> around the windows <NUM> and <NUM>, while still allowing this greater cross section internal passageway to be provided.

The snap lock feature <NUM> is improved over prior designs so as to provide a substantial increase in the tension force required to pull the first and second mating structures <NUM> and <NUM> apart after assembly.

Referring to <FIG>, the first mating structure <NUM> includes a first locking portion 18a defined by a snap lock ring <NUM> having an outermost surface <NUM> defined between a tapered upper guiding surface <NUM> and a locking shoulder <NUM>. The locking shoulder <NUM> is at substantially <NUM> degrees to the outer surface <NUM> thus defining a relatively sharp locking edge <NUM>. Located below the snap lock ring <NUM> is a stabilizing ring shelf <NUM>.

The second mating structure <NUM> includes a second locking portion 18b best seen in <FIG>. The second locking portion 18b includes a snap lock ring channel <NUM> in which the snap lock ring <NUM> is to be received. Located below the snap lock ring channel <NUM> is a plurality of stabilizing ring securement segments <NUM> separated by gaps <NUM>. It can be seen that the snap lock ring channel <NUM> is curved in cross-section and forms a curved tapered upper locking surface <NUM> on each of the stabilizing ring securement segments <NUM>.

When the first and second mating structures <NUM> and <NUM> are snapped together as seen in <FIG>, The sharp locking edge <NUM> of the snap lock ring <NUM> bites into the curved tapered upper locking surfaces <NUM> of the stabilizing ring securement segments <NUM> to securely prevent the first and second mating structures <NUM> and <NUM> from being pulled back apart.

When the current design is compared to a snap lock feature like that shown in <CIT> wherein the engaging surfaces of the snap lock ring and of the stabilizing ring securement segments are both tapered at complementary angles, a substantial increase in the force required to pull apart the first and second mating structures is provided. The required pull apart force was increased from about <NUM>,<NUM> N (<NUM> pounds) with the design of <CIT> to about <NUM>,<NUM> N (<NUM> pounds) with the present design. The snap lock feature <NUM> can be described as having the first and second locking portions 18a and 18b configured such that a force of at least <NUM>,<NUM> N (<NUM> pounds), and more preferably at least <NUM>,<NUM> N (<NUM> pounds), is required to pull apart the first and second mating structures <NUM> and <NUM>.

An alternative embodiment of an injection port assembly having three lateral outlet windows instead of two lateral outlet windows is shown in <FIG> and is generally designated by the number <NUM>.

The injection port assembly <NUM> has a longitudinal axis <NUM>. The injection port assembly <NUM> is shown in assembled cross section in <FIG> and includes a body <NUM> made up of a first mating structure <NUM> and a second mating structure <NUM>. The first mating structure <NUM> may also be referred to as a lower body part <NUM>, and the second mating structure <NUM> may also be referred to as an upper body part <NUM>. The first and second mating structures <NUM> and <NUM> are coupled together by a snap lock feature <NUM>.

The injection port assembly <NUM> further includes a resilient barrier <NUM> which is configured to be received within the body <NUM> and which is compressible from a less compressed first position as seen for example in <FIG>, in which fluid flow through the injection port assembly <NUM> is blocked, to a more compressed second position as seen for example in <FIG>, in which fluid flow through the injection port assembly <NUM> is permitted.

The details of construction of the first mating structure <NUM> are best shown in <FIG>. The details of construction of the second mating structure <NUM> are substantially the same as was shown for the second mating structure <NUM> in <FIG>. The details of construction of the resilient barrier <NUM> are best shown in <FIG>.

As best seen in <FIG>, the resilient barrier <NUM> includes an internal cavity <NUM>. It will be appreciated that the resilient barrier <NUM> is formed from an elastomeric material, and is shown in <FIG> in its relaxed state in which the elastomeric material is relatively undeformed. It will also be appreciated that in <FIG> a hollow cannula <NUM> of the first mating structure <NUM> has been received in the internal cavity <NUM>, thus deforming portions of the resilient barrier <NUM> radially outward so that the shape of the resilient barrier <NUM> as seen in <FIG>, and particularly of its internal cavity <NUM>, are different due to the resilient deformation thereof.

Referring now to <FIG> which show the resilient barrier <NUM> and particularly its internal cavity <NUM> in their relaxed state, the internal cavity <NUM> in this relaxed state may be described as including a cavity nose portion <NUM>, a cavity sealing portion <NUM>, and a cavity guide portion <NUM>.

The hollow cannula <NUM> includes a distal end portion <NUM> shown in enlarged view in <FIG>. The distal end portion <NUM> is configured to extend through the resilient barrier <NUM> when the resilient barrier <NUM> is in the more compressed second position of <FIG>. The cannula distal end portion <NUM> has at least one lateral outlet window <NUM> and in the example shown has three lateral outlet windows <NUM>, <NUM> and <NUM>.

As seen in <FIG>, each of the lateral outlet windows <NUM>, <NUM> and <NUM> has a window length <NUM> which is less than the cavity sealing portion length <NUM>. As best seen in <FIG>, the windows <NUM>, <NUM> and <NUM> also have a width <NUM> perpendicular to the longitudinal central axis <NUM>, <NUM> of the injection port assembly <NUM> and the cannula <NUM>.

The cannula distal end portion <NUM> includes a cannula nose <NUM> located distally of the lateral outlet windows <NUM>, <NUM> and <NUM>, and configured to be closely received in the cavity nose portion <NUM> of the resilient barrier <NUM> when the resilient barrier <NUM> is in the less compressed first position as shown in <FIG>.

The cannula distal end portion <NUM> has a cannula distal end portion outside diameter both distally and proximally of the lateral outlet windows <NUM>, <NUM> and <NUM>, which cannula distal end portion outside diameter is sufficiently greater than the respective inside diameters of the cavity sealing portion <NUM> of internal cavity <NUM> of resilient barrier <NUM> when the cannula nose <NUM> is received in the cannula nose portion <NUM> such that there is an interference fit between the cannula <NUM> and the resilient barrier <NUM>. The interference fit extends along the lateral outlet windows <NUM>, <NUM> and <NUM> and both proximally and distally of the lateral outlet windows <NUM>, <NUM> and <NUM> so that the cavity sealing portion <NUM> of the resilient barrier <NUM> seals across the lateral outlet windows <NUM>, <NUM> and <NUM>.

Preferably the radial interference along the interference fit is at least about <NUM>,<NUM> (<NUM> inch), optionally at least about <NUM>,<NUM> (<NUM> inch), optionally at least about <NUM>,<NUM> (<NUM> inch) and optionally at least about <NUM>,<NUM> (<NUM> inch). Preferably the interference fit between the cannula <NUM> and the resilient barrier <NUM> extends at least about <NUM>,<NUM> (<NUM> inch) both proximally and distally from the lateral outlet windows <NUM>, <NUM> and <NUM>.

The cannula <NUM> has an internal fluid passageway <NUM> defined therein as best seen in <FIG>. The internal fluid passageway <NUM> communicates the lateral outlet windows <NUM>, <NUM> and <NUM> with a proximal end of the first mating structure <NUM> which is configured to communicate with a fluid conduit <NUM> schematically illustrated in <FIG>. The fluid conduit <NUM> may be representative of any structure to which the injection port assembly <NUM> is to be connected for fluid flow therewith.

<FIG> shows an upward facing cross section of the cannula <NUM> taken along line D-D of <FIG> show downward facing cross sections of the cannula <NUM> taken along lines A-A, B-B and C-C, respectively. <FIG> show that the internal fluid passageway <NUM> has a non-circular cross section axially proximal from the windows <NUM>, <NUM> and and <NUM>. This non-circular cross section may be described as having a cross sectional area greater than a cross section area of a circle of diameter equal to the window width <NUM>.

The three outlet windows <NUM>, <NUM> and <NUM> may be described as being equally circumferentially spaced about the axis <NUM>. The non-circular cross section internal fluid passageway <NUM> as seen in <FIG> may be described as extending laterally to each of the outlet windows <NUM>, <NUM> and <NUM>.

The non-circular cross section of internal fluid passageway <NUM> may be described as a three lobed cross section. As can be seen in comparing <FIG>, the three lobed cross section tapers radially outward. This cross sectional shape of the internal fluid passageway <NUM> as visually depicted in <FIG> preferably extends along a non-circular cross section length <NUM> shown in <FIG>. As is apparent in <FIG>, the non-circular cross section length <NUM> extends along the window length <NUM> and continues proximally beyond the window length <NUM> into the internal passageway <NUM> of cannula <NUM> by a further distance <NUM> at least as long as the window length <NUM> and preferably longer than the window length <NUM>. Proximally of the non-circular cross sectional length <NUM>, the internal passageway <NUM> may transition into a circular cross section extending to the proximal end <NUM> of the first mating structure <NUM>.

The provision of the interference fit <NUM> between the cannula <NUM> and the resilient barrier <NUM> of <FIG>, and of the cannula <NUM> and resilient barrier <NUM> of the embodiment of <FIG>, has provided substantially increased resistance to leaking due to back pressure within the injection port assemblies <NUM> and <NUM> as compared to a similar prior design of the assignee of the present invention as depicted in <CIT>.

For example, using the embodiment of <FIG>, tests were run on back pressure resistance, flow rate and fluid displacement.

Average back pressure resistance has improved from <NUM>,<NUM> Pa (<NUM> psi) with the previous design to over <NUM>,<NUM> Pa (<NUM> psi) with the design depicted herein having the interference fit. Testing was done using standardized procedures wherein each sample was submerged in water and subjected to increased pressure until air bubbles were observed leaking from the submerged sample.

Average fluid flow rates at gravity increased from <NUM>/min for a similar design having a circular cross section internal fluid passageway, up to an average of approximately <NUM>/min for the cross sectional area generally like that shown in <FIG>. In these tests for a lot of <NUM> samples, flow rates ranged from a minimum of <NUM>/min to a max of <NUM>/min for sterilized samples, and from a minimum of <NUM>/min to a max of <NUM>/min for non-sterilized samples.

Additionally, fluid reflux was measured at <NUM> with the embodiment of <FIG>.

As depicted in <FIG> and <FIG> for the respective embodiments, the upper and lower parts <NUM>, <NUM> and <NUM>, <NUM> of the bodies <NUM>, <NUM> are assembled with the resilient barriers <NUM>, <NUM> contained therein and with the cannula <NUM>, <NUM> received with the internal cavity <NUM>, <NUM> of respective resilient barrier <NUM>, <NUM>. It will be appreciated that in the assembled arrangement as seen in <FIG> and <FIG>, there may be a slight axial compression of the resilient barrier <NUM>, <NUM> from its completely relaxed state. The position of the resilient barrier <NUM>, <NUM> as depicted in <FIG> and <FIG> may be described as a less axially compressed first position in which fluid flow through the injection port assembly <NUM>, <NUM> is blocked. It will be appreciated that the distal end of the resilient barrier <NUM>, <NUM> has a precut slit <NUM>, <NUM> formed therein through which the distal end portion <NUM>, <NUM> of cannula <NUM>, <NUM> will protrude when the resilient barrier <NUM>, <NUM> is moved to its more axially compressed second position like that shown in <FIG>.

The injection port assembly <NUM>, <NUM> may be connected to various conduits and medical devices so as to provide for intravenous injection into the patient's body and for collection of blood samples from the patient. The injection port assembly <NUM> may be incorporated into an IV pump set or IV administration set in a Y-site injection port configuration. <FIG> for example, show a Y-site injection port arrangement <NUM> utilizing the three window embodiment of <FIG>.

As depicted in <FIG>, the resilient barrier <NUM> may be moved from its closed first position to its open second position by engagement of the injection port assembly <NUM> by a male-luer slip syringe <NUM>. Beginning in the closed position of <FIG>, as is indicated by the arrow <NUM> the syringe <NUM> is pushed downward engaging the distal end of the resilient barrier <NUM> and forcing it downward relative to the cannula <NUM> so as to expose the distal end portion <NUM> of cannula <NUM> thus allowing the lateral windows such as <NUM>, <NUM> and <NUM> to communicate with the interior <NUM> of syringe <NUM>. This allows fluids to be injected into or withdrawn from the patient's blood stream.

Claim 1:
An injection port assembly (<NUM>, <NUM>), comprising:
a body (<NUM>, <NUM>) having a first mating structure (<NUM>, <NUM>) and a second mating structure (<NUM>, <NUM>) configured to be coupled to the first mating structure (<NUM>, <NUM>);
a resilient barrier (<NUM>, <NUM>) configured to be received within the body (<NUM>, <NUM>) and compressible from a less compressed first position in which fluid flow through the injection port assembly (<NUM>, <NUM>) is blocked to a more compressed second position in which fluid flow through the injection port assembly (<NUM>, <NUM>) is permitted, the resilient barrier (<NUM>, <NUM>) including an internal cavity (<NUM>, <NUM>); and
a hollow cannula (<NUM>, <NUM>) coupled to the first mating structure (<NUM>, <NUM>) and configured to be received within internal cavity (<NUM>, <NUM>) of the resilient barrier (<NUM>, <NUM>), the hollow cannula (<NUM>, <NUM>) having a longitudinal central axis (<NUM>, <NUM>), the hollow cannula (<NUM>, <NUM>) including:
a cannula distal end portion (<NUM>, <NUM>) configured to extend through the resilient barrier (<NUM>, <NUM>) when the resilient barrier (<NUM>, <NUM>) is in the more compressed second position;
at least one lateral outlet window (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) formed in the cannula distal end portion (<NUM>, <NUM>) the at least one lateral outlet window (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) having a window width (<NUM>, <NUM>) perpendicular to the longitudinal central axis (<NUM>, <NUM>); and
characterized in that, an internal fluid passageway (<NUM>, <NUM>) defined in the hollow cannula (<NUM>, <NUM>) and configured to communicate the at least one lateral outlet window (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) with a fluid conduit connected to the first mating structure (<NUM>, <NUM>),
the internal fluid passageway (<NUM>, <NUM>) having a non-circular cross section taken in a plane perpendicular to the longitudinal axis, the non-circular cross section extending axially proximal from the window (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), the non-circular cross section having a cross section area greater than a cross section area of a circle of diameter equal to the window width (<NUM>, <NUM>).