Fluid delivery device
A fluid delivery device comprises a housing having a fluid reservoir. A needle is in fluid communication with the fluid reservoir in an engaged position and out of fluid communication with the fluid reservoir in armed and storage positions. A proximal end of a biasing member is coupled to the housing and a distal end of the biasing member is configured to deliver a force to the fluid reservoir. A piston member extends through the biasing member and is coupled to the distal end of the biasing member. The piston member is fixed with respect to the housing in a locked position such that the biasing member does not deliver the force to the fluid reservoir and moveable with respect to the housing in a released position such that the biasing member delivers the force to the fluid reservoir. Transitioning the needle from the storage position to the armed position transitions the piston from the locked position to the released position.
1 . A fluid delivery device comprising:
an attachment surface configured to engage with a skin surface and having a first thermal conductance;
a hydraulic pump chamber;
a hydraulic basal chamber having an outer wall including a portion proximate the attachment surface and having a second thermal conductance, the second thermal conductance being greater than the first thermal conductance;
a flow restrictor fluidly coupling the hydraulic basal chamber and the hydraulic pump chamber;
a fluid reservoir coupled to the hydraulic pump chamber, the fluid reservoir configured to contain a fluid deliverable to a patient; and
an actuator coupled to the hydraulic basal chamber, the actuator configured to pressurize the hydraulic pump chamber to transfer energy through the hydraulic basal chamber and the hydraulic pump chamber to the fluid reservoir to deliver the fluid at a sustained basal rate.
2 . The fluid delivery device of claim 1 , wherein the attachment surface includes an insulating member.
3 . The fluid delivery device of claim 2 , wherein the insulating member is at least partially relieved to at least partially expose the portion of the outer wall of the hydraulic basal chamber proximate the attachment surface.
4 . The fluid delivery device of claim 1 , wherein the fluid reservoir is at least partially spaced from the housing.
5 . The fluid delivery device of claim 1 , further comprising a housing having a bottom surface, wherein the outer wall portion of the hydraulic basal chamber extends outwardly from the bottom surface of the housing.
6 . The fluid delivery device of claim 1 , wherein the portion of the outer wall of the hydraulic basal chamber has an imaginary tangent generally aligned with the attachment surface.
7 . The fluid delivery device of claim 1 , wherein the portion of the outer wall of the hydraulic basal chamber is configured to directly contact the skin surface.
8 . The fluid delivery device of claim 1 , wherein a remainder of the outer wall of the hydraulic basal chamber has a third thermal conductance, the third thermal conductance being less than the second thermal conductance.