Wearable device and a method of using a wearable device

A wearable device, the wearable device comprising:

• an inflatable body configured to be mounted to a torso of a user;
• an air pump configured to inflate the inflatable body and to drive chest wall oscillation therapy while the inflatable body is mounted to the user's torso;
• a first sensing device, wherein the first sensing device comprises a first sensor and a first actuator coupling the first sensor to the inflatable body;
• and
• a memory storing computer-readable instructions that, when executed, cause the wearable device to:
• inflate the inflatable body from a first state of the inflatable body to a second state of the inflatable body;
• after the inflatable body has been inflated to the second state, actuate the first actuator from a first state of the first actuator to a second state of the first actuator, wherein actuating the first actuator from the first state of the first actuator to the second state of the first actuator reduces a volume of a first air gap between the torso and the first sensor;
• and
• while the inflatable body is in the second state of the inflatable body and the first actuator is in the second state of the first actuator, receive a first signal from the first sensor.