Patent ID: 8444597

Claim:
A patch-like infusion device, comprising: a first reservoir having at least one movable wall containing a first substance at a first pressure; at least one patient needle in selective fluid communication with said first reservoir; a second reservoir having at least one movable wall containing a second substance at a second pressure wherein said first and second pressures form a differential pressure; a selective fluid communication conduit between said first reservoir and said second reservoir, wherein when said selective fluid communication conduit between said first reservoir and said second reservoir is enabled, said first substance and said second substance are intermingled to form a medicament, and whereby said intermingling is caused by said differential pressure; a spring having a central aperture for applying pressure to said movable wall of said first reservoir to cause fluid to flow from said first reservoir to said patient needle; a pin engageable with said central aperture and disengageable therefrom for causing said spring to begin applying a third pressure to said first reservoir when said infusion device is placed into operation; and an activation means wherein said movable wall of said second reservoir is moved by said activation means, thereby reducing a volume of said second reservoir whereby said volume reduction results in movement of said medicament from said second chamber into said first chamber.