4. Invasive ventilators can also be used with masks, but they have the characters of high oxygen consumption and high oxygen concentration, making them unsuitable for long-term use without humidifiers.

5. Invasive emergency ventilators can be divided into two types: electric control type with built-in turbine and pneumatic control type without turbine (the mainstream is this type).

6. High-end invasive ventilators (imported) have built-in turbines and can also be connected to high-pressure oxygen, which can achieve an integrated non-invasive and invasive approach. However, the price is relatively high and the maintenance and usage requirements are very high. Therefore, many mainstream emergency ventilators in the market still use pneumatic and electronic control (including imported ones).