System and method for measuring a resonance frequency of a tube

A method of assisting a cough based on a resonance frequency of a tube, the method comprising the steps of:

• oscillating, via an oscillator, the tube at a plurality of oscillation frequencies;
• detecting, via one or more sensors, a time delay of transmitting a pressure pulse from a first position to a second position in the tube while the tube oscillates at an individual frequency of the plurality of oscillation frequencies, wherein, when the tube is oscillated at different oscillation frequencies in a specific oscillation frequency range of the plurality of oscillation frequencies, the detecting step includes detecting a variation of the time delay at each of the different oscillation frequencies;
• determining, via a computer, a maximal variation of the time delay when the tube is oscillated at the different oscillation frequencies in the specific oscillation frequency range;
• indicating, via the computer, an oscillation frequency corresponding to the maximal variation of the time delay, the oscillation frequency corresponding to the maximal variation of the time delay being a resonance frequency of the tube;
• and
• assisting, via the computer, a cough based on the resonance frequency of the tube.