Wearable vital signs monitoring device and method

A wearable device for blood pressure measurement comprising:

• an armband with an inner surface and an outer surface;
• a bladder within the armband configured to be inflated and deflated;
• pumping means for inflating and deflating said bladder, the pumping means comprising a pump, a pipe in fluid communication with the bladder and a valve;
• at least one optical sensor within the armband, the optical sensor being at least partially exposed at the inner surface of the armband, so as to permit acquisition of an optic signal from an arm of the subject wearing the armband;
• at least one pressure sensor configured to acquire a signal indicative of a pressure within the bladder;
• and
• a processing unit configured to:
• receive the signal from the optical sensor and the signal from the pressure sensor;
• calculate a first blood pressure value of the wearer based on the signal from the optical sensor, and a second blood pressure value based on the signal from the pressure sensor;
• and
• calibrate the first blood pressure value on the basis of the second blood pressure value.