Pivoting joint infusion system with seal

[0001] This application is a continuation-in-part application of U.S. patent application Ser. No. 09/896,149, filed Jun. 29, 2001, now U.S. Pat. No. 6,579,267, issued Jun. 17, 2003, which claims priority to U.S. Provisional Application No. 60/259,971, filed Jan. 5, 2001, all of which are incorporated herein by reference for all purposes.

[0002] The present invention relates to an improved system for subcutaneous delivery of fluid to a patient. More particularly, the present invention relates to an infusion system having an improved sealing subsystem cooperating with a rotating pivot joint member that delivers the fluid from a remote source to a delivery cannula of the main infusion assembly of the system.

[0003] Prior art infusion sets or systems provide numerous ways for engaging a fluid connector to a base to deliver a therapeutic fluid subcutaneously to a patient. Most of these prior art systems are plagued with leaking connections and inefficient ways to allow the patient to disconnect the fluid connector from the base without a backflow of fluid from the patient through the base and back into the environment.

[0004] The present invention provides an improved sealing subsystem incorporated into a pivoting or rotating “ball” joint that moves from an emplacement position to an infusion or delivery position to a disconnected, protected, closed position.

[0015] FIG. 1 is a perspective view of the infusion system 10 of the present invention. In FIG. 1, the main infusion unit 12 is shown with the fluid connector assembly 14 attached to the rotating pivot joint member 16. The joint member 16 is rotatably attached to the housing 17 of unit 12. The emplacement needle 18 (FIG. 5) has been withdrawn and the connector assembly is still in an upright or vertical position. Therapeutic fluid from a remote source (not shown but well known in the art) such as a wall or rack hung bottle or plastic fluid bag may be delivered through delivery tube 20 to the connector assembly 14 and into the patient. However, the preferred procedure is for the needle to be withdrawn and the joint member 16 slightly rotated downwardly to misalign the emplacement channel 54 (FIG. 5A) and the injection channel 40. This will prevent or significantly avoid a backflow of patient fluids as will be discussed below. The connector assembly 14 is then attached to the joint member 16 and the rotating joint member and the connector assembly 14 are to be rotated about joint member 16 to the horizontal delivery or infusion position shown in FIG. 2. In FIG. 2, the fluid connector 14 has rotated about joint 16 and has locked onto the locking tabs 22 (FIG. 1) of the main infusion unit 12 and is thereby held securely in place.

[0016] FIG. 3 shows a slightly modified main infusion unit 12a having a pivot joint member 16a with an 0-ring seal 24 on neck section 26 of the joint. Neck 26 has opposing wings 28 which serve to ensure an aligned rotation of the joint 16a about the housing 17a. The wings further function to ensure proper alignment of the connector assembly 14a to the main infusion unit 12a. FIG. 9 additionally shows how wings 28 hold the neck 26 in a third distinct position. FIG. 3 also illustrates a recess section 30 and cover 32 in housing 17a. As will be described below, the recess 30 accepts the top section of neck 26 in a third rotated position of joint 16a and cover 32 shields, protects, and seals the central fluid channel 34 in the joint member 16a when the fluid connector has been removed from the rotating pivot joint member 16a.

[0017] FIG. 4 illustrates in a perspective view the underside or bottom side of the fluid connector 14a which attaches at a near end 36 to the rotating pivot joint member. It should be noted in FIG. 4 that the fluid delivery channel 38 in connector 14a has a slight approach angle variation as will be described in more detail in the discussion of FIG. 10.

[0018] The structural arrangement or relationship of the joint member 16a to housing 17a is seen in the partial cross sectional view of FIG. 5. FIG. 5 shows the joint 16a in a first emplacement position with an emplacement needle 18 extending through the rotating joint 16a, through the injection channel 40 of cannula 42, and subcutaneously piercing the skin of the patient. A retainer plate 44 holds the cannula 18 within the housing 17a. The emplacement of the needle and how the main infusion unit may be affixed to the patient are well understood as described in U.S. Pat. No. 6,579,267. Also shown in FIG. 5 is the placement and retention of sealing assembly 50 within housing 17. FIG. 8 shows the sealing assembly in greater detail.

[0019] The rotating pivot joint member 16a is shown in a side elevational cross sectional view in FIG. 5A. Central fluid channel 34, needle emplacement channel 54, and fluid infusion channel 56 intersect in a central portion 58 of the joint 16a. Grooves 60 are provided for 0-ring seals in the neck section.

[0020] FIG. 6 shows the pivot member or joint 16a with the emplacement needle withdrawn and fluid connector assembly 14a attached. The joint 16a is rotated to an infusion or delivery position with the infusion channel 56 aligned with the injection channel 40 in cannula 42. Thus, therapeutic fluid 60 from the remote source flows through fluid delivery channel 38 in connector assembly 14a into central fluid channel 34, into infusion channel 56 through cannula injection channel 40 into the patient. As would be understood by one of skill in the art, the connector assembly 14a is secured to the main infusion unit 12a by the locking tabs 22 urging against the body 15 of the connector assembly.

[0021] In FIG. 7 an exploded perspective illustration is provided of pivot joint member 16, housing 17, sealing assembly 50, and rotating pivot joint member receiving chamber 51. The joint 16 has axial rotation journals or ears 72 which engage in slots 70 in the receiving chamber 51. The sealing assembly also fits snugly between the housing 17 and the joint 16 when the system is fully assembled. Turning to FIGS. 5 and 6 it may be seen that elastomeric seal 50 is urged beneath overhanging ledge 53 of housing 17 and is thereby further held in position. When the joint 16 is rotatably secured in the chamber 51, the seal 50 provides a sealing surface for the joint body 19 to sealingly rotate upon. In FIG. 8, the L-shaped seal assembly 50 has an orifice 61 to allow the needle or fluid to pass through. A raised rib 80 along the inner surface 81 of the seal may be used to provide an additionally tight seal. It should be understood that the use of various cooperating materials may be used in the construction of the seal 50 and the joint body 19. A hard-to-soft surface interface may be employed. The seal may be softer than the joint or vice versa. Two hard surfaces with cooperating coefficients of friction may be employed.

[0022] A protected, closed, and sealed third position of the rotating pivot joint member 16a is shown in FIG. 9. When the patient removes the connector assembly 14 or 14a from the pivot joint 16 or 16a, the alignment of the injection channel and the infusion channel in the joint would allow patient fluids to flow back through the infusion assembly and leak or flow into the environment. However, a unique feature of the present invention allows the user to rotate the pivot joint 16a downwardly to a third distinct position placing the neck 26 and central fluid channel 34 into recess 30 with cover 32 sealing off the open channel 34. Thus, no patient fluids backflow through the system. FIG. 9 also illustrates that alignment wings 28 also function to stop the downward rotation of the joint 16a; and, because they rub or slide tightly along housing shoulder 27 of the main infusion assembly 12a, the neck 26 is retained in the recess during the user's movement.

[0023] The distinct positions of the rotating “ball” pivot joint member 16 are illustrated in FIG. 10. In position A, the emplacement needle may be guided through the appropriate channels in the joint to allow the main infusion unit 12 to be attached to the patient. In position B, the needle has been removed and the fluid connector assembly 14 attached to the joint 16. The fluid channels in the connector assembly and the joint are aligned to allow for the therapeutic fluid to flow from the remote source through the delivery tube, through the joint and cannula channels to the patient. In position C, the fluid connector assembly 14 has been removed and the joint rotated further downwardly to rest in recess 30 with cover 32 sealing the fluid channel 34. Additionally, the further rotation of the joint misaligns the infusion channel 56 of the joint from the injection channel 40 of the cannula thereby further sealing off the backflow of any patient fluids through the system to the environment.

[0024] It may be seen in FIG. 10 that the sealing assembly 50 directly engages over 90° of the surface of the pivot joint 16 in any one of the distinct positions; but, because of the rotatability of the joint, over 270° of the ball joint surface is sealingly urged against the seal assembly 50. This feature provides for a more efficient sealing of the channels in the joint thereby reducing leakage problems associated with the prior art.

[0025] Although the invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. On the contrary, various modifications of the disclosed embodiments will become apparent to those skilled in the art upon reference to the description of the invention. It is therefore contemplated that the appended claims will cover such modifications, alternatives, and equivalents that fall within the true spirit and scope of the invention.