SEALING ELEMENT FOR A HOLLOW NEEDLE OF A FLUID INFUSION DEVICE
Disclosed herein is a fluid infusion device of the type that delivers medication fluid to the body of a patient. The device includes or cooperates with a fluid reservoir, and the device has a sealing assembly to receive and form a fluid seal with the fluid reservoir. A retractable sealing element surrounding a hollow fluid delivery needle may be used to seal a port of the fluid reservoir. The port may include a pressure vent that is sealed by the retractable sealing element. In one variation, the reservoir includes a moving valve sleeve that holds a septum. The septum moves to allow the reservoir to vent, and to form a seal with the port when the needle pierces the septum. In another variation, the device includes a needleless sealing assembly. In yet other variations, the device uses a needled fluid reservoir.
1 . A sealing element for a fluid infusion device comprising a hollow fluid delivery needle, the sealing element comprising:
a base section;
a tip section extending from the base section;
a retractable body section between the base section and the tip section;
a needle cavity formed in the retractable body section and continuing through the base section to define a needle opening in the base section, the needle cavity sized to receive the hollow fluid delivery needle; and
a self-sealing slit formed in the tip section to accommodate the hollow fluid delivery needle when the sealing element is in a retracted position.
2 . The sealing element of claim 1 , wherein the base section, the tip section, and the retractable body section are integrally formed and continuous with one another.
3 . The sealing element of claim 2 , wherein the base section, the tip section, and the retractable body section are formed from a silicone material.
4 . The sealing element of claim 1 , further comprising a guide channel formed in the tip section and communicating with the needle cavity and the self-sealing slit, wherein the guide channel leads a tip of the hollow fluid delivery needle into the self-sealing slit during retraction of the sealing element.
5 . The sealing element of claim 1 , wherein:
the needle cavity defines internal relief features of the retractable body section;
the internal relief features facilitate refraction of the sealing element over the hollow fluid delivery needle in response to a longitudinal force applied to the tip section; and
the internal relief features cause the sealing element to extend over and cover the hollow fluid delivery needle in response to removal of the longitudinal force.
6 . The sealing element of claim 5 , wherein the internal relief features comprise an accordion structure within the needle cavity.
7 . The sealing element of claim 5 , wherein the internal relief features comprise a plurality of internal annular channels within the needle cavity.
8 . The sealing element of claim 5 , wherein the internal relief features comprise a plurality of internal annular ridges within the needle cavity.
9 . The sealing element of claim 5 , wherein the internal relief features comprise a plurality of bottleneck structures within the needle cavity.
10 . The sealing element of claim 1 , wherein:
the fluid infusion device comprises a fluid reservoir having a fluid delivery port;
the retractable body section comprises an exterior surface;
the exterior surface moves outward when the sealing element is retracting; and
the exterior surface forms a fluid seal with an interior of the fluid delivery port when the sealing element is retracted.
11 . The sealing element of claim 1 , wherein the tip section comprises a barbed external profile.
12 . The sealing element of claim 1 , further comprising a circumferential compression element coupled around the tip section to impart an inward biasing force to the self-sealing slit.
13 . The sealing element of claim 12 , wherein the circumferential compression element comprises a rigid ring.
14 . The sealing element of claim 12 , wherein the circumferential compression element comprises a resilient band.
15 . A sealing element for a fluid infusion device comprising a hollow fluid delivery needle, the sealing element comprising:
a base section;
a tip section extending from the base section;
a retractable body section between the base section and the tip section; and
a needle cavity formed in the retractable body section and continuing through the base section to define a needle opening in the base section, the needle cavity sized to receive the hollow fluid delivery needle, and the needle cavity defining internal relief features of the retractable body section; wherein
the internal relief features cause the sealing element to deform and retract over the hollow fluid delivery needle in response to a longitudinal force applied to the tip section; and
the internal relief features cause the sealing element to regain a nominal shape, extend over the hollow fluid delivery needle, and enclose the hollow fluid delivery needle in response to removal of the longitudinal force.
16 . The sealing element of claim 15 , further comprising a self-sealing slit formed in the tip section to accommodate the hollow fluid delivery needle when the sealing element is in a retracted position.
17 . The sealing element of claim 16 , further comprising a guide channel formed in the tip section and communicating with the needle cavity and the self-sealing slit, wherein the guide channel leads a tip of the hollow fluid delivery needle into the self-sealing slit during retraction of the sealing element.
18 . The sealing element of claim 15 , wherein the base section, the tip section, and the retractable body section are integrally formed and continuous with one another.
19 . The sealing element of claim 15 , wherein the internal relief features comprise an accordion structure within the needle cavity.
20 . The sealing element of claim 15 , wherein the internal relief features comprise a plurality of internal annular channels within the needle cavity.
21 . The sealing element of claim 15 , wherein the internal relief features comprise a plurality of internal annular ridges within the needle cavity.
22 . The sealing element of claim 15 , wherein the internal relief features comprise a plurality of bottleneck structures within the needle cavity.
23 . The sealing element of claim 15 , wherein:
the fluid infusion device comprises a fluid reservoir having a fluid delivery port; and
the retractable body section expands to form a fluid seal with an interior of the fluid delivery port when the fluid reservoir engages the sealing element and the hollow fluid delivery needle.