Wake-up device

Wake-up device comprising:

• clock means for generating an actual time signal corresponding to an actual time of day;
• wake-up timer means for generating a wake-up time signal corresponding to an intended time of waking up;
• controllable wake-up stimulus means for generating at least one wake-up stimulus for causing a user to wake up, the wake-up stimulus having at least one variable stimulus quantity, wherein a wake-up effectiveness of the wake-up stimulus depends on a value of the stimulus quantity;
• a control device having inputs coupled to receive the actual time signal and the wake-up time signal and adapted to generate a control signal for controlling the wake-up stimulus means;
• wherein the wake-up stimulus means is responsive to said control signal to vary the value of said stimulus quantity;
• and wherein the control device is adapted to generate the control signal such that the wake-up stimulus is generated in accordance with a predefined wake-up program, the wake-up program including:
• a) an initial value for the stimulus quantity of the wake-up stimulus, the initial value having a relatively low wake-up effectiveness;
• b) an end value (IM) for the stimulus quantity of the wake-up stimulus, the end value having a relatively high wake-up effectiveness;
• c) a wake-up duration (tΔ), defining an advance time (tA) before the intended time of waking-up (tWU) according to the formula tA=tWU−tΔ;
• d) wherein, at the advance time (tA), the wake-up stimulus is started with the said stimulus quantity having said initial value;
• e) wherein, in a time interval from the advance time (tA) until the intended time of waking-up (tWU), the value of said stimulus quantity is gradually varied from said initial value to said end value;
• f) wherein, at the intended time of waking-up (tWU), said stimulus quantity has said end value;
• wherein the wake-up device further comprises sleep quality monitor means for monitoring a quality of the sleep of a user and for generating a sleep quality monitor signal (S) indicative of the momentary quality of sleep of the user;
• and wherein the control device has an input to detect a go to sleep time of the user before the advance time, and in that the control device is responsive to the sleep quality monitor signal (S) received from the sleep quality monitor means to calculate an overall sleep quality parameter (SQ) of the user on the basis of a plurality of measurements of the sleep quality monitor signal performed at a respective plurality of times between the go to sleep time and the advance time, and to amend the wake-up program as a function of the overall sleep quality parameter (SQ).