Drowsiness level estimation device, apparatus including drowsiness level estimation device, and air-conditioning apparatus

A drowsiness level estimation device comprising:

• a Doppler sensor configured to detect a pulse wave of a user;
• and
• an analysis unit configured to analyze the pulse wave detected by the Doppler sensor, wherein
• the analysis unit is configured to generate an index value by digitizing the pulse wave based on chaos analysis in which a source of analysis is a pulse waveform shift that is a time-series shift of a waveform of the pulse wave, estimate a drowsiness level of the user based on the index value, and output drowsiness level information related to the estimated drowsiness level,
• wherein the chaos analysis is a process of sequentially performing:
• a step of calculating vectors determined from time-series data of the pulse waveform shift and a preset delay time;
• a step of generating an attractor having the vectors arranged in time series in a multidimensional state space having three or more dimensions;
• and
• a step of calculating, as a Lyapunov exponent that is the index value, an enlargement factor obtained by giving a hypersphere as an initial state to trajectories of the attractor and repeating an operation of stretching the hypersphere at intervals of a preset slide time based on the trajectories so that the hypersphere turns into an ellipse
• the index value shows a degree of separation of the trajectories compared with the initial state, and shows that a brain activity level increases as the index value increases,
• the analysis unit is configured to output the drowsiness level information showing that the drowsiness level decreases as the index value increases, and that the drowsiness level increases as the index value decreases, and
• the drowsiness level information is information showing a current drowsiness level, time-series drowsiness levels, or both of the current drowsiness level and the time-series drowsiness levels.