INJECTION DEVICE Russian patent published in 2016 - IPC A61M5/32 A61M5/28 

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, namely to an injection device. The injection device comprises a prefilled syringe and a protective device. The syringe comprises a cylinder having an inner cavity pneumohydraulically connected to a needle for subcutaneous injections attached to a distal end of the prefilled syringe, and a piston generating a tight seal at a proximal end of the inner cavity. The protective device comprises a support body configured to hold the pre-filled syringe, an outer body functionally connected with the piston, a needle case and a detachable retainer. The needle case, support body and outer body are configured to move telescopically in relation to each other. The piston is configured to move in the distal direction to eject a medicinal agent contained in the inner cavity through the needle for subcutaneous injections by actuating the outer body manually. The telescopic motion of the outer body in relation to the support body is limited by the retainer, when the needle case moved in relation to the support body in the proximal direction from an initial position towards the retraction position. The retainer is unlocked when the needle case reaches the retraction position enabling the outer body to move telescopically in relation to the support body to eject the medicinal agent contained in the prefilled syringe through the needle for subcutaneous injections. The retainer comprises a radial projection connected to any of the support body or outer body, or making an integral part thereof, and a long slot formed in the other of the outer body or support body and configured to receive the radial projection. The long slot comprises a first section and second section separated from each other by means of a bridge. The radial projection engages with the first section of the long slot to prevent the telescopic motion of the outer body in relation to the support body until the needle case reaches the retraction position. The radial projection is expected to cross the bridge before the outer body is enabled to move telescopically in relation to the support body. Holding force required to deflect the radial projection exceeds that required to move the needle case in relation to the support body from the initial position into the retraction position.

EFFECT: invention is simple and safe to use, applicable for unassisted injections, or injections performed by a healthcare professional.

19 cl, 21 dwg