Syringe type pump
The subcutaneous injection device contains a pump and a mechanism for inserting a cannula into the patient's skin. The cannula is fixedly positioned relative to the pump and the insertion mechanism has a flexible surface adhering to the skin. The flexible surface is positioned relative to the cannula in such a way that in a first position the tip of the cannula is concealed by the surface and in a second position the cannula is exposed beyond the surface. The insertion mechanism brings the surface from the first to the second position, thereby pulling the skin against the tip of the cannula.
1. A device for subcutaneous injection of fluid into a patient's skin, comprising:
a casing to house a pump;
a cannula having a tip for insertion into the patient's skin, the cannula being fixed in a position relative to the pump;
a flexible base plate, the base plate fixed to the casing and including (1) a pre-stressed convex position in which the tip of the cannula is concealed, and (2) a released flat position in which the tip of the cannula is exposed beyond the base plate; and
an adhesive layer fixed to a central region of the flexible base plate and extending without interruption towards an outer portion of the flexible base plate to adhere the base plate onto the patient's skin,
wherein when moving from the pre-stressed convex position to the released flat position, a portion of the base plate which is moving pulls the skin which is adhered to the base plate so that the patient's skin moves against and is pierced by the tip of the cannula,
wherein when the device is in (1) the pre-stressed convex position, a tip of the cannula is contained within the device,
wherein when the device is in (2) the released flat position, the tip of the cannula is exposed beyond the baseplate, and
wherein as the device transitions from (1) the pre-stressed convex position to (2) the released flat position, the cannula moves from being contained within the device to being exposed beyond the base plate such that a tip of the cannula is outside of the device.
2. The device according to claim 1 wherein the pump is a circular syringe pump.
3. The device according to claim 1 wherein the device includes more than one cannula for insertion into the skin simultaneously by a single cannula insertor.
4. The device according to claim 1 further comprising:
a cannula insertor, the cannula insertor actuates the piercing of a septum before insertion into the skin.
5. The device according to claim 1 wherein the device comprises more than one pump for delivery of injection fluid into the patient.
6. The device according to claim 1 wherein the adhesive layer is temporarily worn by the patient.
7. The device according to claim 6 wherein a surface of the flexible base plate is smaller than a surface of the adhesive layer.
8. The device according to claim 1 wherein the flexible base plate is elastic for rapid movement between the pre-stressed convex position and the released flat position.
9. The device according to claim 1 wherein the device is applied to the skin using a functional package with a rim pressing the adhesive layer towards the skin.