RESUMEN
Objective:To develop a new type of biopsy sampling device which is usable, easy practice and has long service life.Methods:Pneumatic alarm device is added to the traditional biopsy system. During the process of doctor draw piston stem, when the syringe tube was blocked, air can drive the sealing cover open due to the external pressure is greater than the pressure of the cylinder, it is from the holes into the cylinder body to maintain the pressure balance and trigger the air alarm device alarm; when cylinder pressure restored normally, rod drives the sealing cover is closed under the action of the spring.Results: The new system is able to control the biopsy sampling pull the speed of the piston stem, and can automatically exhaust and alarm on the needle plug.Conclusion: The utility model has the advantages of convenient use, strong practicability and long service life. It’s worthy of popularization.