Blood pressure measuring apparatus and blood pressure measuring method

A blood pressure measuring apparatus comprising:

• a touch sensor configured to output a touch signal when a touch is detected;
• a pulse wave measurer configured to measure pulse waves from a finger of a user when the finger is in contact with the touch sensor;
• a force sensor configured to measure a contact force between the finger and the touch sensor;
• and
• a processor configured to:
• identify a contact area between the finger and the touch sensor and a shape of a contact surface, based on the touch signal when the touch sensor is in contact with the finger;
• in response to a size of the contact area being greater than a predetermined contact area size, and the shape of the contact surface matching a predetermined shape, estimate a blood pressure of the user based on the pulse waves and the contact force;
• and
• in response to the size of the contact area being less than or equal to the predetermined contact area size, or the shape of the contact surface not matching the predetermined shape, provide guide information to the user through an output device, adjust reliability of an estimation result of the blood pressure, or perform a re-measurement of the blood pressure.