Ambulatory infusion pumps and reservoir assemblies for use with same
Ambulatory infusion pumps, medicament reservoirs, and plungers, including both dynamic and static seals, plus related components, as well as component combinations and related methods.
1. An infusion pump reservoir assembly, comprising:
a medicament reservoir including a reservoir barrel with an inner surface;
a plunger moveable within the medicament reservoir in a dispensing direction from a full position and including a dynamic seal that is in contact with the inner surface of the reservoir barrel and a rear surface that faces in a direction opposite the dispensing direction; and
a static seal that engages a sealing surface of the rear surface of the plunger that faces in the direction opposite the dispensing direction when the plunger is in the full position;
wherein the plunger, dynamic seal and static seal are respectively configured and positioned relative to one another such that the plunger defines an outer surface diameter that is greater than a static seal outer diameter of the static seal, the static seal is disengaged from the sealing surface of the rear surface of the plunger that the static seal is engaged with in response to movement of the plunger in the dispensing direction from the full position and the dynamic seal remains in contact with the inner surface of the reservoir barrel as the plunger moves in the dispensing direction, and wherein a static seal inner diameter of the static seal is smaller than an outer diameter of the sealing surface, the static seal establishes an interference fit with elastomeric deformation with respect to the sealing surface when the plunger is in the full position, and the sealing surface separates from the static seal in response to movement of the plunger in the dispensing direction from the full position.
2. The infusion pump reservoir assembly as claimed in claim 1 , wherein the static seal is a static vapor seal.
3. The infusion pump reservoir assembly as claimed in claim 1 , wherein the static seal is stationary.
4. The infusion pump reservoir assembly as claimed in claim 1 , wherein
the plunger includes a rigid core and the dynamic seal is carried by the rigid core.
5. The infusion pump reservoir assembly as claimed in claim 4 , wherein
the dynamic seal comprises at least first and second o-ring seals.
6. A method, comprising:
disengaging a static radial seal, which defines a static seal inner diameter and a static seal outer diameter, from a sealing surface in a medicament reservoir assembly in an infusion pump in response to movement in a dispensing direction of a plunger within a reservoir barrel from a full position while maintaining contact between a dynamic seal associated with the plunger and an inner surface of the reservoir barrel along which the dynamic seal travels and which, defines an inner surface diameter of the reservoir barrel that is greater than the static seal outer diameter, in response to movement in the dispensing direction of the plunger within the reservoir barrel from the full position, wherein the static seal inner diameter of the static radial seal is smaller than an outer diameter of the sealing surface, the static radial seal establishes an interference fit with elastomeric deformation with respect to the sealing surface when the plunger is in the full position, and the sealing surface separates from the static radial seal in response to movement of the plunger in the dispensing direction from the full position.
7. The method as claimed in claim 6 , wherein
the static radial seal is a vapor seal.
8. The method as claimed in claim 6 , wherein
the sealing surface comprises a plunger surface; and
the static radial seal is disengaged from the plunger surface in response to movement in the dispensing direction of the plunger from the full position.