2. For safety reasons, NMR*** vibration is not recommended in this case. If the check is very necessary, you can use simple breathing airbag, but the breathing tube can not be blindly lengthened, the need to extend the tube is recommended to give up. This is because after tracheotomy, the tube becomes part of the patient's airway, and the gas inside does not participate in gas exchange, which is called "dead space". If the tube is too long, the following situation will occur: when the patient exhales, the exhaled gas enters and stays in the tube, and the next inhalation, the exhaust gas in the tube is sucked back again, as a result, the patient is always breathing the exhaust gas in the tube instead of fresh oxygen, which may ultimately cause asphyxiation.