Wearable system and blood pressure measurement method which can be performed by the wearable system

A wearable system, comprising:

• a first wearable device, worn on a first body portion of a user, comprising:
• a first pressure sensor;
• a second wearable device, comprising:
• a compression device, configured to compress a second body portion of the user;
• and
• a second pressure sensor;
• and
• a processing circuit, configured to compute a time difference between a first arriving time of a first pressure signal and a second arriving time of a second pressure signal when the compression device compresses the second body portion and then releases the second body portion, wherein the first arriving time means a time that a peak region of the first pressure signal reaches the first pressure sensor and the second arriving time means a time that a peak region of the second pressure signal reaches the second pressure sensor;
• wherein the processing circuit computes the blood pressure of the user according to the time difference, signal start times of the first pressure signal and the second pressure signal, signal end times of the first pressure signal and the second pressure signal and a heart rate of the user.

A blood pressure measurement method, applied to a first wearable device with an enclosed outer ring, comprising:

• (a) emitting first light toward an internal wearing space of the first wearable device by a first light source of the first wearable device, wherein the internal wearing space is adjustable while a length of the enclosed outer ring is fixed, wherein a user puts a first body portion thereof in the internal wearing space while wearing the first wearable device;
• (b) detecting a first PPG signal generated according to the first light, by a first PPG sensor of the first wearable device;
• (c) sensing a pressure caused by the first body portion by a first pressure sensor of the first wearable device;
• and
• (d) computing a blood pressure of the user according to the pressure and a signal integrity of the first PPG signal.