Impairment detection with environmental considerations

A device for monitoring impairment indicators, the device comprising:

• a housing configured to be attached to or carried by a person;
• an environmental sensor;
• a processing unit disposed in the housing comprising a processor and a movement sensor;
• wherein, during a first time window, the movement sensor measures a first movement signal related to movement of the person and the environmental sensor measures a first environmental signal;
• wherein the processor stores at least one numerical descriptor derived from the first movement signal and at least one numerical descriptor derived from the first environmental signal as reference data for the person;
• wherein, during a second time window, the movement sensor measures a second movement signal related to movement of the person and the environmental sensor measures a second environmental signal;
• and
• wherein the processor compares at least one numerical descriptor derived from the second movement signal and at least one numerical descriptor derived from the second environmental signal to the reference data to identify an impairment indicator.