Injection/transfusion needle tube for preventing blood backflow

Abstract

The invention relates to an injection needle tube for preventing blood backflow. An elastic backflow prevention rubber tube is used as a backflow prevention device; the front end of the backflow prevention rubber tube is flat; the back end of the backflow prevention rubber tube is round; when flowing to the front end from the back end, the medicine liquid can smoothly pass; when the medicine liquid injection or transfusion is completed, the flat tube part is automatically closed; and a blood backflow passage is sealed, so that the backflow is avoided.

Description

technical field [0001] The invention belongs to medical instruments, in particular to a needle tube for injection / transfusion. Background technique [0002] The needle tube for injection is a relatively common medical device, and it is also a medical device with a relatively large amount of medical equipment. Through searching, there is a needle tube for injection that uses negative pressure to prevent blood backflow. Filling syringe, patent number: 2010206647845, the technical principle of this patent is that "the inner wall of the front end of the syringe includes a frusto-conical conical surface surrounding the outlet of the liquid medicine, and the front end surface of the rubber stopper is conical. The taper angle of the front end face of the plug is less than the taper angle of the taper face. When the prefilled syringe of the present invention is injected with the liquid medicine, the rubber plug and the inner wall of the front end of the syringe are in linear contact...

AI Technical Summary

Problems solved by technology

In the prefilled syringe of the present utility model, when the liquid medicine is injected, the rubber stopper is in linear contact with the inner wall of the front end of the syringe, and there is no obvious elastic deformation between the rubber stopper and the needle barrel, and there is no possibility of sucking back the liquid medicine. At the same time, there is a gap between the rubber plug and the front end of the inner wall of the syringe, which can avoid the phenomenon of backflow of the liquid medicine or even blood backflow into the syringe barrel due to negative pressure.” However, the inventor believes that it is doubtful whether this patent can be realized. The inventor of this patent only emphasized that there is a linear contact between the rubber plug and the inner wall of the front end of the syringe, and there is a needle tube at the front end of the syringe. According to the principle that the forces are mutual, if the push rod is pulled back, the resulting suction force It is not enough to cause blood backflow, so when the push rod advances, the thrust generated is not enough to inject the liquid medicine. What is linearity? As far as general knowledge is concerned, the push rod needs to have a sealing part. If there is no sealing part or sealing part It is not very strict, as the 2010206647845 patent describes linear contact, which may cause the liquid to flow out of the syringe during injection. This patent solves a problem and creates a more serious problem.

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