Pulse wave detector, biological information measurement device, pulse wave detection method and storage medium

A biological information measurement device comprising:

• a pulse wave detector, wherein
• the pulse wave detector comprises:
• a flexible strain sensor having a plurality of strain detection elements arranged on a substrate;
• a flexible pressing member configured to press the strain sensor fixed thereto against a body surface of a living body;
• a drive section configured to drive the pressing member;
• and
• a controller configured to
• control a pressing force of the pressing member for pressing the strain sensor against the body surface by controlling the drive section;
• determine a deformation stop timing at which deformation of a detection face of the strain sensor has been stopped based on a strain detection signal detected by each of the plurality of strain detection elements in a pressure raising process in which the pressing force is increased by the controller;
• set a level of the strain detection signal detected by each of the plurality of strain detection elements at the deformation stop timing as a reference level,
• calibrate a first strain detection signal detected by each of the plurality of strain detection elements after the deformation stop timing based on the reference level,
• generate a pressure signal from the calibrated first strain detection signal, and
• calculate biological information based on the pressure signal.

A pulse wave detection method, comprising:

• increasing a pressing force of a pressing member configured to press a flexible strain sensor fixed thereto against a body surface, the strain sensor having a plurality of strain detection elements arranged on a substrate;
• determining a deformation stop timing at which deformation of a detection face of the strain sensor has been stopped based on the strain detection signal detected by each of the plurality of strain detection elements in a pressure raising process in which the pressing force is increased;
• setting a level of the strain detection signal detected by each of the plurality of strain detection elements at the deformation stop timing as a reference level;
• calibrating a first strain detection signal detected by each of the plurality of strain detection elements after the deformation stop timing based on the reference level;
• and
• generating a pressure signal from the calibrated first strain detection signal.

A computer-readable non-transitory storage medium that stores a program for causing a computer to execute a process, the process comprising:

• increasing a pressing force of a pressing member configured to press a flexible strain sensor fixed thereto against a body surface, the strain sensor having a plurality of strain detection elements arranged on a substrate;
• determining a deformation stop timing at which deformation of a detection face of the strain sensor has been stopped based on the strain detection signal detected by each of the plurality of strain detection elements in a pressure raising process in which the pressing force is increased;
• setting a level of the strain detection signal detected by each of the plurality of strain detection elements at the deformation stop timing as a reference level;
• calibrating a first strain detection signal detected by each of the plurality of strain detection elements after the deformation stop timing based on the reference level;
• and
• generating a pressure signal from the calibrated first strain detection signal.