In terms of medical devices, one-way valves are widely used in tracheal intubation, urinary catheters, laryngeal masks, anesthesia masks and other medical devices. Cap, l spring, sealant gasket. Because the principle of its sealing is that the pressure of the spring is used to compress the rubber gasket to seal, the pressure of the spring is not enough, the sealing will not be good, and the pressure will be too high, and the ventilating syringe will be pushed open during use, which will affect the operation of the nurse. , and due to the small size and complex structure of the one-way valve, the precision of the parts is extremely high, and the manufacturing cost is high. In addition, in the process of treating patients, sometimes while assisting the patient to ventilate normally, the patient also needs to bring MRI with trachea and intubation. If the one-way valve used for tracheal intubation contains l at this time, it will inevitably affect the examination results of MRI.