APPARATUS FOR INJECTING LIQUID MEDICINE WHICH CAN REGULATE INSIDE PRESSURE DEPENDING ON MODES OF CHARGING AND INJECTING LIQUID MEDICINE

摘要

A liquid drug injection device of the present invention is related to the improvement of a precise and specific technology which enables a liquid drug injection pressure to be maintained at a high level while facilitating filling of the liquid drug, in a single device without the addition of an additional device. In other words, the present invention is related to a technology that efficiently regulates the internal pressure of the device according to a liquid drug charging or a liquid drug injection mode. According to the present invention, when filling the liquid drug, a closing valve does not operate so the inside of the device communicates with the outside atmosphere, thus leading to a decrease in the resistance of the liquid drug to a piston that may occur when filling the liquid drug in a liquid drug storage space inside the device, and thus facilitating filling of the liquid drug. When injecting the liquid drug to a patient, the closing valve operates due to the propelling force of air generated in an air generation unit inside the device, and thereby blocks the communication between the inside of the device and the external atmosphere. Hereupon, the high pressure caused by the air generated inside the device works on the piston and allows the charged liquid drug to be stably and consistently injected into the patient at a constant rate while being less influenced by external changes such as the height of the liquid drug injection device or the external temperature.