Infusion device with pressurizable liquid medicament chamber
A disposable infusion device comprises a base arranged to adhere to a patient's skin, a cannula arranged to extend from the base to beneath the patient's skin to deliver a liquid medicament to the patient, and a source arranged to provide the cannula with a liquid medicament. The source includes a reservoir that holds the liquid medicament and a pressurizer that pressurizes the liquid medicament from within the reservoir to provide a flow of the liquid medicament to the cannula.
1 . A disposable infusion device comprising:
a base arranged to adhere to a patient's skin;
a cannula arranged to extend from the base to beneath the patient's skin to deliver a liquid medicament to the patient; and
a source arranged to provide the cannula with a liquid medicament, the source including a reservoir that holds the liquid medicament and a pressurizer that pressurizes the liquid medicament from within the reservoir to provide a flow of the liquid medicament to the cannula.
2 . The device of claim 1 , wherein the reservoir includes a chamber that holds the liquid medicament and wherein the pressurizer includes a moveable wall of the chamber that exerts a compressive force on the liquid medicament to pressurize the liquid medicament.
3 . The device of claim 2 , wherein the pressurizer further comprises a spring member that urges the moveable wall against the liquid medicament.
4 . The device of claim 3 , wherein the spring member is a coil spring.
5 . The device of claim 2 , wherein the chamber is a first chamber and wherein the reservoir further includes a second chamber and a fixed wall separating the first chamber from the second chamber, the fixed wall including a flow restrictor that permit the liquid medicament to flow into the second chamber from the first chamber, and wherein the cannula is in fluid communication with the second chamber.
6 . The device of claim 5 , wherein the flow restrictor is an orifice.
7 . The device of claim 1 , wherein the source is a first source, wherein the liquid medicament is a first liquid medicament, and wherein the device further includes a second source that provides the cannula with a second liquid medicament.
8 . The device of claim 7 , wherein the second source comprises a pump that pumps the second liquid medicament to the cannula.
9 . The device of claim 8 , wherein the pump is a fixed volume pump.
10 . The device of claim 8 , wherein the pump is a piston pump.
11 . The device of claim 8 , wherein the pump is a fixed stroke piston pump.
12 . The device of claim 11 , wherein the second source further comprises a reservoir that holds the second liquid medicament.
13 . The device of claim 1 , wherein the pressurizer is a pressurized gas.
14 . A disposable infusion device comprising:
a base arranged to adhere to a patient's skin;
a cannula arranged to extend from the base to beneath the patient's skin to deliver a liquid medicament to the patient; and
a first source arranged to provide the cannula with a first liquid medicament, the first source including a reservoir that holds the first liquid medicament under pressure to provide a flow of the first liquid medicament to the cannula; and
a second source arranged to provide a second liquid medicament to the cannula.
15 . The device of claim 14 , wherein the reservoir includes a moveable wall that exerts a compressive force on the liquid medicament to pressurize the liquid medicament.
16 . The device of claim 15 , further comprising a spring member that urges the moveable wall against the liquid medicament.
17 . The device of claim 14 , wherein the reservoir contains a pressurized gas to place the first liquid medicament under pressure.
18 . The device of claim 14 , wherein the second source comprises a pump that pumps the second liquid medicament to the cannula.
19 . The device of claim 14 , wherein the second source further comprises a second reservoir that holds the second liquid medicament.
20 . The device of claim 19 , wherein the second source further comprises a pump that pumps the second liquid medicament from the second reservoir to the cannula.