Purpose: 1. To find out whether the Eustachian tube is open and whether there is fluid in the middle ear tympanic chamber. 2.To treat the occlusion of the Eustachian tube, to drain the fluid in the middle ear drum, and to improve hearing. Preparation: 1.Self-blowing method: No material is needed. 2.Ear drum balloon blowing method: 1 ear drum balloon, 1 olive joint, 1 bowl of warm boiled water, and 1 pair of stethoscopic rubber tubes. 3.Catheter blowing method: 1 Eustachian tube catheter, 1 rubber ball, and 1 rubber tube for auscultation. Operation method 1.Self-blowing method: (1) After dropping 1% ephedrine in the nasal cavity, clear the nasal mucus. (2) pinch both sides of the nose with your fingers, inhale first, then close your mouth and whistle hard to increase the pressure in the nasopharyngeal cavity, so that the gas can enter the middle ear through the Eustachian tube, which can be repeated several times. 2.Ear drum balloon blowing method (also called Bo’s blowing method), mainly for children and those who cannot perform catheter blowing. There are two methods: (1) Drinking water method: The patient takes a sitting position, clears the nose first, and plugs the two ends of the auscultating rubber tube in the outer ear canal of the child and the operator respectively to determine the degree of Eustachian tube patency. Ask the patient to hold a mouthful of water, ask the family members to hold the child’s nostril with their fingers, the operator holds the rubber ball in his right hand and plugs the olive head into the child’s nostril on the other side with his left hand, ask the patient to swallow the water, while swallowing the water, quickly press the air into the rubber ball, then remove the olive head to inflate the rubber ball and repeat the operation several times. (2) shouting method: without swallowing water, ask the child to continuously call “open an open an open”, so that the soft palate up, close the nasopharyngeal cavity, while the gas in the rubber ball pressed into the eustachian tube. 3. Catheter blowing method: (1) The patient takes a sitting position, blows away the nasal secretions, astringes the nasal mucosa with 3% ephedrine cotton tablets, and removes the cotton tablets after 5 minutes. (2) The two ends of the auscultation tube are placed in the external auditory canal of the patient and the examiner respectively. The elbow is turned 90° outward and the catheter is pulled slightly toward the operator while doing so, allowing it to cross the rongeur and enter the pharyngeal orifice of the eustachian tube. Alternatively, turn the catheter 90° toward the nasal septum as it reaches the posterior pharyngeal wall, then pull it outward so that the elbow of the catheter hooks over the posterior edge of the nasal septum and then turn it 180° downward and outward to allow the tip to enter the pharyngopharyngeal orifice. Fix the catheter with the left hand, hold the rubber ball with the right hand, and inject air into the end of the catheter, the pressure can be adjusted according to the degree of ventilation of the eustachian tube. Relax the catheter after blowing, and it will slide out of the nasal cavity naturally. Precautions: 1. When there is acute inflammation or pus in the nasal cavity, blowing should not be performed to avoid blowing secretions into the tympanic chamber and secondary acute otitis media. 2, the affected side of the nasal cavity with bleeding, ulcers, tumors should not be blowing Zhang. 3.Before blowing, the tympanic membrane must be inspected, and depending on its thickness, the amount of force and the number of operations should be decided. 4, blowing process must be patient and meticulous, the action should be light, in the case of septal curvature, can choose the curved end of the longer catheter, while the other side of the nasal cavity can be inserted, the elbow to the affected ear side blow. 5. Blowing should be done from light to heavy, and should not be done with too much force, in order to prevent blowing the eardrum, bleeding or emphysema. 6. In case of fluid accumulation in the middle ear cavity, repeated blowing in a drooping position can be used several times to make the fluid flow outward along the catheter, which can reduce symptoms and improve hearing. 7.The operator can diagnose by auscultation through the auscultation tube: (1) Normal: soft “whistling” sound and soft “grating” sound; (2) Eustachian tube stenosis: frictional, rough and uneven sound can be heard; (3) Middle ear effusion: blistering sound or twisting sound; (4) Eustachian tube perforation: blistering sound or twisting sound (4) Tympanic membrane perforation: small perforations can be heard as a flute sound, while large perforations can be felt as air blowing into the outer ear canal of the examiner.