Abstract: This disclosure provides gas monitoring apparatuses, methods and medical devices. A gas monitoring apparatus can include a gas concentration monitoring module, a respiratory mechanics monitoring module and a correction module. The correction module can determine a first correction value based on the gas ingredients and the gas concentration measured by the gas concentration monitoring module, so that the respiratory mechanics monitoring module can correct respiratory mechanics parameter(s) based on the first correction value. The correcting module can also determine a second correction value based on the pressure-related quantity measured by the respiratory mechanics monitoring module, so that the gas concentration monitoring module can correct gas concentration based on the second correction value.