User state selection based on the shape of the exhale stream

A method for selecting a state of a user, comprising:

• taking, using at least one inward-facing head-mounted thermal camera (CAM), thermal measurements of at least three regions below the nostrils (THS);
• wherein THS are indicative of shape of the exhale stream (SHAPE);
• generating feature values based on THS;
• whereby the feature values are indicative of the SHAPE;
• and
• utilizing a machine learning-based model for selecting the state of the user, from among potential states of the user, based on the feature values.

A system configured to detect the shape of exhale stream, comprising:

• at least one inward-facing head-mounted thermal camera (CAM) configured to take thermal measurements of at least three regions below the nostrils (THS) of a user;
• wherein THS are indicative of the shape of the exhale stream (SHAPE);
• and
• a computer configured to detect the SHAPE based on THS and a machine learning-based model;
• wherein the machine learning-based model was trained based on previous THS of the user.

A system configured to present a user's state based on shape of the exhale stream (SHAPE), comprising:

• at least one inward-facing head-mounted thermal camera (CAM) configured to take thermal measurements of at least three regions below the nostrils (THS);
• wherein THS are indicative of the SHAPE;
• and
• a user interface (UI) configured to present the user's state based on THS;
• wherein, for the same breathing rate, the UI presents different states for the user when THS are indicative of different SHAPEs that correspond to different potential states.